Detector for optically detecting at least one object

Description

Field of the invention

The invention relates to a detector, a detector system and a method for determining a position of at least one object. The invention further relates to a human-machine interface for exchang- ing at least one item of information between a user and a machine, an entertainment device, a tracking system, a camera, a scanning system and various uses of the detector device. The devices, systems, methods and uses according to the present invention specifically may be employed for example in various areas of daily life, gaming, traffic technology, production tech- nology, security technology, photography such as digital photography or video photography for arts, documentation or technical purposes, medical technology or in the sciences. Further, the invention specifically may be used for scanning one or more objects and/or for scanning a scenery, such as for generating a depth profile of an object or of a scenery, e.g. in the field of architecture, metrology, archaeology, arts, medicine, engineering or manufacturing. However, other applications are also possible.

Prior art

A large number of optical sensors and photovoltaic devices are known from the prior art. While photovoltaic devices are generally used to convert electromagnetic radiation, for example, ultra- violet, visible or infrared light, into electrical signals or electrical energy, optical detectors are generally used for picking up image information and/or for detecting at least one optical parame- ter, for example, a brightness.

A large number of optical sensors are known for determining a distance between an object and the optical sensor such as Time-of-Flight detectors, triangulation systems and sensors which use a depth-from-defocus technique. A further concept for determining a distance from the ob- ject is called Distance by Photon Ratio (DPR) and is proposed for example in

PCT/EP2017/079564, PCT/EP2017/079558 and PCT/EP2017/079577 filed on November 17, 2017 the full content of which is herewith included by reference. For example, in

PCT/EP2017/079577, a detector for determining a position of at least one object is disclosed which comprises:

- at least one sensor element having a matrix of optical sensors, the optical sensors each hav- ing a light-sensitive area, wherein each optical sensor is configured to generate at least one sensor signal in response to an illumination of the light sensitive area by at least one light beam propagating from the object to the detector;

- at least one evaluation device configured for evaluating the sensor signals, by

a) determining at least one optical sensor having the highest sensor signal and forming at least one center signal; b) evaluating the sensor signals of the optical sensors of the matrix and forming at least one sum signal;

c) determining at least one combined signal by combining the center signal and the sum signal; and

d) determining at least one longitudinal coordinate z of the object by evaluating the combined signal.

Determination of distance to an object of using these devices may be influenced by brightness of the object. For example, in case of using large exposure times white objects may result in overexposed sensor signals, whereas dark objects in combination with short exposure times may lead to low or weak sensor signals. For both, analysis of the sensor signals may be prob- lematic.

Problem addressed by the invention

It is therefore an object of the present invention to provide devices and methods facing the above-mentioned technical challenges of known devices and methods. Specifically, it is an ob- ject of the present invention to provide devices and methods which allow determination of a po- sition of an object in space independent from object brightness.

Summary of the invention

This problem is solved by the invention with the features of the independent patent claims. Ad- vantageous developments of the invention, which can be realized individually or in combination, are presented in the dependent claims and/or in the following specification and detailed embod- iments.

As used in the following, the terms“have”,“comprise” or“include” or any arbitrary grammatical variations thereof are used in a non-exclusive way. Thus, these terms may both refer to a situa- tion in which, besides the feature introduced by these terms, no further features are present in the entity described in this context and to a situation in which one or more further features are present. As an example, the expressions“A has B”,“A comprises B” and“A includes B” may both refer to a situation in which, besides B, no other element is present in A (i.e. a situation in which A solely and exclusively consists of B) and to a situation in which, besides B, one or more further elements are present in entity A, such as element C, elements C and D or even further elements.

Further, it shall be noted that the terms“at least one”,“one or more” or similar expressions indi cating that a feature or element may be present once or more than once typically will be used only once when introducing the respective feature or element. In the following, in most cases, when referring to the respective feature or element, the expressions“at least one” or“one or more” will not be repeated, non-withstanding the fact that the respective feature or element may be present once or more than once. Further, as used in the following, the terms "preferably", "more preferably", "particularly", "more particularly", "specifically", "more specifically" or similar terms are used in conjunction with op- tional features, without restricting alternative possibilities. Thus, features introduced by these terms are optional features and are not intended to restrict the scope of the claims in any way. The invention may, as the skilled person will recognize, be performed by using alternative fea- tures. Similarly, features introduced by "in an embodiment of the invention" or similar expres- sions are intended to be optional features, without any restriction regarding alternative embodi- ments of the invention, without any restrictions regarding the scope of the invention and without any restriction regarding the possibility of combining the features introduced in such a way with other optional or non-optional features of the invention.

In a first aspect of the present invention a detector for determining a position of at least one ob- ject is disclosed. As used herein, the term“object” refers to a point or region emitting at least one light beam. The light beam may originate from the object, such as by the object and/or at least one illumination source integrated or attached to the object emitting the light beam, or may originate from a different illumination source, such as from an illumination source directly or indi rectly illuminating the object, wherein the light beam is reflected or scattered by the object. As used herein, the term“position” refers to at least one item of information regarding a location and/or orientation of the object and/or at least one part of the object in space. Thus, the at least one item of information may imply at least one distance between at least one point of the object and the at least one detector. As will be outlined in further detail below, the distance may be a longitudinal coordinate or may contribute to determining a longitudinal coordinate of the point of the object. Additionally or alternatively, one or more other items of information regarding the location and/or orientation of the object and/or at least one part of the object may be deter- mined. As an example, additionally, at least one transversal coordinate of the object and/or at least one part of the object may be determined. Thus, the position of the object may imply at least one longitudinal coordinate of the object and/or at least one part of the object. Additionally or alternatively, the position of the object may imply at least one transversal coordinate of the object and/or at least one part of the object. Additionally or alternatively, the position of the ob- ject may imply at least one orientation information of the object, indicating an orientation of the object in space.

The detector comprises:

at least one sensor element having a matrix of optical sensors, the optical sensors each having a light-sensitive area, wherein each optical sensor is configured to gen- erate at least one sensor signal in response to an illumination of the light-sensitive ar- ea by at least one incident light beam propagating from the object to the detector, at least one transfer device, wherein the transfer device has at least one focal length in response to the incident light beam;

at least one filter element configured for generating at least two filter regions, wherein the filter element is configured such that in at least one first filter region and in at least one second filter region at least one property of the incident light beam is modified dif ferently; at least one evaluation device, wherein the at least one evaluation device is configured for evaluating at least one first sensor signal and at least one second sensor signal, wherein the first sensor signal is generated in response to illumination having passed through one of the first filter region and the second filter region and the second sensor signal is generated in response to illumination having passed through the same or the other one of the first filter region and the second filter region, and wherein the evaluation comprises determining at least one longitudinal coordinate z of the object by evaluating a combined signal Q from the first sensor signal and the second sensor signal.

As used herein, the term“sensor element” generally refers to a device or a combination of a plurality of devices configured for sensing at least one parameter. In the present case, the pa- rameter specifically may be an optical parameter, and the sensor element specifically may be an optical sensor element. The sensor element may be formed as a unitary, single device or as a combination of several devices. As further used herein, the term“matrix” generally refers to an arrangement of a plurality of elements in a predetermined geometrical order. The matrix, as will be outlined in further detail below, specifically may be or may comprise a rectangular matrix having one or more rows and one or more columns. The rows and columns specifically may be arranged in a rectangular fashion. It shall be outlined, however, that other arrangements are feasible, such as nonrectangular arrangements. As an example, circular arrangements are also feasible, wherein the elements are arranged in concentric circles or ellipses about a center point. For example, the matrix may be a single row of pixels. Other arrangements are feasible.

The optical sensors of the matrix specifically may be equal in one or more of size, sensitivity and other optical, electrical and mechanical properties. The light-sensitive areas of all optical sensors of the matrix specifically may be located in a common plane, the common plane prefer- ably facing the object, such that a light beam propagating from the object to the detector may generate a light spot on the common plane.

As used herein, an“optical sensor” generally refers to a light-sensitive device for detecting a light beam, such as for detecting an illumination and/or a light spot generated by at least one light beam. As further used herein, a“light-sensitive area” generally refers to an area of the op- tical sensor which may be illuminated externally, by the at least one light beam, in response to which illumination the at least one sensor signal is generated. The light-sensitive area may spe- cifically be located on a surface of the respective optical sensor. Other embodiments, however, are feasible.

As used herein, the term“the optical sensors each having a light-sensitive area” refers to con- figurations with single optical sensors each having one light sensitive area and to configurations with combined optical sensors. Thus, the term“optical sensor” furthermore refers to a light- sensitive device configured to generate one output signal, whereas, herein, a light-sensitive device configured to generate two or more output signals, for example at least one CCD and/or CMOS device, is referred to as two or more optical sensors. As will further be outlined in detail below, each optical sensor may be embodied such that precisely one light-sensitive area is pre- sent in the respective optical sensor, such as by providing precisely one light-sensitive area which may be illuminated, in response to which illumination precisely one uniform sensor signal is created for the whole optical sensor. Thus, each optical sensor may be a single area optical sensor. The use of the single area optical sensors, however, renders the setup of the detector specifically simple and efficient. Thus, as an example, commercially available photo-sensors, such as commercially available silicon photodiodes, each having precisely one sensitive area, may be used in the set-up. Other embodiments, however, are feasible. Thus, as an example, an optical device comprising two, three, four or more than four light-sensitive areas may be used which is regarded as two, three, four or more than four optical sensors in the context of the pre- sent invention. As an example, the optical device may comprise a matrix of light-sensitive areas. Thus, as an example, the optical sensors may be part of or constitute a pixelated optical device. The sensor element may comprise one or more of at least one bi-cell diode, at least one quad- rant diode; at least one CCD chip, at least one CMOS chip. As an example, the optical sensors may be part of or constitute a bi-cell diode and/or at least one CCD and/or CMOS device having a matrix of pixels, each pixel forming a light-sensitive area.

As further used herein, a“sensor signal” generally refers to a signal generated by an optical sensor in response to the illumination by the light beam. Specifically, the sensor signal may be or may comprise at least one electrical signal, such as at least one analogue electrical signal and/or at least one digital electrical signal. More specifically, the sensor signal may be or may comprise at least one voltage signal and/or at least one current signal. More specifically, the sensor signal may comprise at least one photocurrent. Further, either raw sensor signals may be used, or the detector, the optical sensor or any other element may be adapted to process or preprocess the sensor signal, thereby generating secondary sensor signals, which may also be used as sensor signals, such as preprocessing by filtering or the like.

The light-sensitive areas specifically may be oriented towards the object. As used herein, the term“is oriented towards the object” generally refers to the situation that the respective surfaces of the light-sensitive areas are fully or partially visible from the object. Specifically, at least one interconnecting line between at least one point of the object and at least one point of the re- spective light-sensitive area may form an angle with a surface element of the light-sensitive ar- ea which is different from 0°, such as an angle in the range of 20° to 90°, preferably 80 to 90° such as 90°. Thus, when the object is located on the optical axis or close to the optical axis, the light beam propagating from the object towards the detector may be essentially parallel to an optical axis. As used herein, the term“essentially perpendicular” refers to the condition of a per- pendicular orientation, with a tolerance of e.g. ±20° or less, preferably a tolerance of ±10° or less, more preferably a tolerance of ±5° or less. Similarly, the term“essentially parallel” refers to the condition of a parallel orientation, with a tolerance of e.g. ±20° or less, preferably a tolerance of ±10° or less, more preferably a tolerance of ±5° or less.

The incident light beam may propagate from the object towards the detector. The light beam may originate from the object, such as by the object and/or at least one illumination source inte- grated or attached to the object emitting the light beam, or may originate from a different illumi- nation source, such as from an illumination source directly or indirectly illuminating the object, wherein the light beam is reflected or scattered by the object and, thereby, is at least partially directed towards the detector. The detector may further comprise the at least one illumination source for illuminating the object, wherein the illumination source comprises at least one light source. The illumination source, as an example, may be or may comprise one or more of an external illumination source, an illumination source integrated into the detector or an illumination source integrated into a beacon device being one or more of attached to the object, integrated into the object or held by the object. Thus, the detector may be used in active and/or passive illumination scenarios. For example, the illumination source may be adapted to illuminate the object, for example, by directing a light beam towards the object, which reflects the light beam. Additionally or alternatively, the object may be adapted to generate and/or to emit the at least one light beam. The light source may be or may comprise at least one multiple beam light source. For example, the illumination source may comprise at least one laser source. For ex- ample, the light source may comprise at least one laser source and one or more diffractive opti- cal elements (DOEs).

As used herein, the term“ray” generally refers to a line that is perpendicular to wavefronts of light which points in a direction of energy flow. As used herein, the term“beam” generally refers to a collection of rays. In the following, the terms“ray” and“beam” will be used as synonyms. As further used herein, the term“light beam” generally refers to an amount of light, specifically an amount of light traveling essentially in the same direction, including the possibility of the light beam having a spreading angle or widening angle. The light beam may have a spatial exten- sion. Specifically, the light beam may have a non-Gaussian beam profile. The beam profile may be selected from the group consisting of a trapezoid beam profile; a triangle beam profile; a conical beam profile. The trapezoid beam profile may have a plateau region and at least one edge region. As used herein, the term“beam profile” generally refers to a transverse intensity profile of the light beam. The light beam specifically may be a Gaussian light beam or a linear combination of Gaussian light beams, as will be outlined in further detail below. Other embodi- ments are feasible, however. The transfer device may be configured for one or more of adjust- ing, defining and determining the beam profile, in particular a shape of the beam profile.

The light beam may be a monochromatic light beam. The light beam may comprise a narrow band of wavelengths, preferably the light beam may comprise a single wavelength. The at least one light source may be adapted to generate at least one monochromatic light beam and/or the detector may comprise at least one filter element adapted to filter a narrow band of wavelength, such as a monochromator.

The illumination source may comprise one or more of at least one light projector; at least one digital light processing (DLP) projector, at least one LCoS projector, at least one spatial light modulator; at least one diffractive optical element; at least one array of light emitting diodes; at least one array of laser light sources. The illumination source may be adapted to generate at least one pattern for illuminating the object. For example, the illumination source may comprise at least one line laser and/or at least one light projector adapted to generate a cloud of points. The illumination source may comprise at least one mask adapted to generate the pattern. The detector, in particular the illumination source, may be one of attached to or integrated into a mobile device such as a smartphone. The illumination source may be used for further functions that may be used in determining an image such as for an autofocus function. The illumination source may be attached to a mobile device such as by using a connector such as a USB- or phone-connector such as the headphone jack.

The illumination source may be adapted to generate a continuous illumination or a pulsed illu mination. The illumination source may be adapted to generate at least one light pulse. As used herein, the term“light pulse” or“pulsed illumination” refers to a light beam limited in time. The light pulse may have a pre-defined length or time duration, for example in the nanoseconds range. For example, the illumination source may be adapted to generate pulses with a pulse length of less than a nanosecond, such as a tenth of a nanosecond, up to a tenth of a second. The illumination source may be adapted to periodically generate the light pulse. For example, the illumination source may be adapted to generate the light pulse with a frequency of 10 Hz to 10 GHz. The illumination source may be adapted to generate a pulsed light beam. For example, the illumination source may be adapted to generate a continuous illumination light beam and the detector may comprise at least one interruption device adapted to interrupt the illumination, in particular periodically. The interruption device may comprise at least one shutter and/or a beam chopper or some other type of mechanical or electronical periodic beam interrupting device, for example comprising at least one interrupter blade or interrupter wheel, which preferably rotates at constant speed and which can thus periodically interrupt the illumination. By way of example, the at least one interruption device can also be wholly or partly integrated into the illumination source. Various possibilities are conceivable.

The optical sensors may be sensitive in one or more of the ultraviolet, the visible or the infrared spectral range. Specifically, the optical sensors may be sensitive in the visible spectral range from 500 nm to 780 nm, most preferably at 650 nm to 750 nm or at 690 nm to 700 nm. Specifi- cally, the optical sensors may be sensitive in the near infrared region. Specifically, the optical sensors may be sensitive in the part of the near infrared region where silicon photodiodes are applicable specifically in the range of 700 nm to 1000 nm. The optical sensors, specifically, may be sensitive in the infrared spectral range, specifically in the range of 780 nm to 3.0 microme- ters. For example, the optical sensors each, independently, may be or may comprise at least one element selected from the group consisting of a photodiode, a photocell, a photoconductor, a phototransistor or any combination thereof. For example, the optical sensors may be or may comprise at least one element selected from the group consisting of a CCD sensor element, a CMOS sensor element, a photodiode, a photocell, a photoconductor, a phototransistor or any combination thereof. Infrared optical sensors such as photoconductive sensors such as a PbS or PbSe sensor which may be used for optical sensors may be commercially available infrared optical sensors, such as infrared optical sensors commercially available under the brand name Hertzstueck™ from trinamiX GmbH, D-67056 Ludwigshafen am Rhein, Germany. Any other type of photosensitive element may be used. As will be outlined in further detail below, the pho- tosensitive element generally may fully or partially be made of inorganic materials and/or may fully or partially be made of organic materials. Most commonly, as will be outlined in further de- tail below, one or more photodiodes may be used, such as commercially available photodiodes, e.g. inorganic semiconductor photodiodes. As further used herein, the term“photosensitive el- ement” generally refers to an element which is sensitive against illumination in one or more of the ultraviolet, the visible or the infrared spectral range. Specifically, the photosensitive element may be or may comprise at least one element selected from the group consisting of a photodi- ode, a photocell, a photoconductor, a phototransistor or any combination thereof. Any other type of photosensitive element may be used.

The detector may be configured such that the light beam generated by the illumination source propagates from the detector towards the object along an optical axis of the detector. For this purpose, the detector may comprise at least one reflective element, preferably at least one prism, for deflecting the illuminating light beam onto the optical axis.

The illumination source, specifically, may be configured for emitting light in the infrared spectral range. It shall be noted, however, that other spectral ranges are feasible, additionally or alterna- tively. Further, the illumination source, as outlined above, specifically may be configured for emitting modulated or non-modulated light. In case a plurality of illumination sources is used, the different illumination sources may have different modulation frequencies which, as outlined in further detail below, later on may be used for distinguishing the light beams. The illumination source may be adapted to generate and/or to project a cloud of points, for example the illumina- tion source may comprise one or more of at least one digital light processing (DLP) projector, at least one LCoS projector, at least one spatial light modulator; at least one diffractive optical el- ement; at least one array of light emitting diodes; at least one array of laser light sources.

Specifically, the illumination source may comprise at least one laser and/or laser source. Vari- ous types of lasers may be employed, such as semiconductor lasers, double heterostructure lasers, external cavity lasers, separate confinement heterostructure lasers, quantum cascade lasers, distributed bragg reflector lasers, polariton lasers, hybrid silicon lasers, extended cavity diode lasers, quantum dot lasers, volume Bragg grating lasers, Indium Arsenide lasers, transis- tor lasers, diode pumped lasers, distributed feedback lasers, quantum well lasers, interband cascade lasers, Gallium Arsenide lasers, semiconductor ring laser, extended cavity diode la- sers, or vertical cavity surface-emitting lasers.. Additionally or alternatively, non-laser light sources may be used, such as LEDs, super luminescent devices, and/or light bulbs. The illumi nation device may comprise one or more diffractive optical elements (DOEs) adapted to gener- ate the illumination pattern. For example, the illumination source may be adapted to generate and/or to project a cloud of points, for example the illumination source may comprise one or more of at least one digital light processing (DLP) projector, at least one LCoS projector, at least one spatial light modulator; at least one diffractive optical element; at least one array of light emitting diodes; at least one array of laser light sources. The illumination source and the optical sensors may be arranged in a common plane or in different planes. The illumination source and the optical sensors may have different spatial orientation. In particular, the illumination source and the optical sensors may be arranged in a twisted arrangement. The illuminating light beam generally may be parallel to the optical axis or tilted with respect to the optical axis, e.g. including an angle with the optical axis. As an example, the illuminating light beam, such as the laser light beam, and the optical axis may include an angle of less than 10°, preferably less than 5° or even less than 2°. Other embodiments, however, are feasible. Further, the illuminating light beam may be on the optical axis or off the optical axis. As an ex- ample, the illuminating light beam may be parallel to the optical axis having a distance of less than 10 mm to the optical axis, preferably less than 5 mm to the optical axis or even less than 1 mm to the optical axis or may even coincide with the optical axis.

Preferably, the illumination source may be a movable and/or mobile illumination source. For example, the illumination source may be moved during the measurement such as to illuminate the object from different positions and/or angles. However, embodiments are feasible in which the illumination source may be positioned in at least one fixed position, for example during a complete measurement time. The evaluation device may be adapted to illumination sources with unclear position such as due to high manufacturing tolerances and/or user interaction and/or user assembly or the like. The illumination source may illuminate the object with a con- vergent and/or divergent and/or collimated light beam.

As used herein, the term“transfer device”, also denoted as“transfer system”, may generally refer to one or more optical elements which are adapted to modify the incident light beam, such as by modifying one or more of a beam parameter of the light beam, a width of the light beam or a direction of the light beam. The transfer device may be adapted to guide the light beam onto the optical sensors. The transfer device specifically may comprise one or more of: at least one lens, for example at least one lens selected from the group consisting of at least one focus- tunable lens, at least one aspheric lens, at least one spheric lens, at least one Fresnel lens; at least one aspheric lens; at least one diffractive optical element; at least one concave mirror; at least one beam deflection element, preferably at least one mirror; at least one beam splitting element, preferably at least one of a beam splitting cube or a beam splitting mirror; at least one multi-lens system.

As used herein, the term“focal length” of the transfer device refers to a distance over which incident collimated rays which may impinge the transfer device are brought into a“focus” which may also be denoted as“focal point”. Thus, the focal length constitutes a measure of an ability of the transfer device to converge an impinging light beam. Thus, the transfer device may corn- prise one or more imaging elements which can have the effect of a converging lens. By way of example, the transfer device can have one or more lenses, in particular one or more refractive lenses, and/or one or more convex mirrors. In this example, the focal length may be defined as a distance from the center of the thin refractive lens to the principal focal points of the thin lens. For a converging thin refractive lens, such as a convex or biconvex thin lens, the focal length may be considered as being positive and may provide the distance at which a beam of collimat- ed light impinging the thin lens as the transfer device may be focused into a single spot. Addi- tionally, the transfer device can comprise at least one wavelength-selective element, for exam- pie at least one optical filter. Additionally, the transfer device can be designed to impress a pre- defined beam profile on the electromagnetic radiation, for example, at the location of the sensor region and in particular the sensor area. The abovementioned optional embodiments of the transfer device can, in principle, be realized individually or in any desired combination.

The transfer device may have an optical axis. In particular, the detector and the transfer device have a common optical axis. As used herein, the term“optical axis of the transfer device” gen- erally refers to an axis of mirror symmetry or rotational symmetry of the lens or lens system. The optical axis of the detector may be a line of symmetry of the optical setup of the detector. The detector comprises at least one transfer device, preferably at least one transfer system having at least one lens. The transfer system, as an example, may comprise at least one beam path, with the elements of the transfer system in the beam path being located in a rotationally sym- metrical fashion with respect to the optical axis. Still, as will also be outlined in further detail be- low, one or more optical elements located within the beam path may also be off-centered or tilted with respect to the optical axis. In this case, however, the optical axis may be defined se- quentially, such as by interconnecting the centers of the optical elements in the beam path, e.g. by interconnecting the centers of the lenses, wherein, in this context, the optical sensors are not counted as optical elements. The optical axis generally may denote the beam path. Therein, the detector may have a single beam path along which a light beam may travel from the object to the optical sensors, or may have a plurality of beam paths. As an example, a single beam path may be given or the beam path may be split into two or more partial beam paths. In the latter case, each partial beam path may have its own optical axis and the condition noted above gen- erally may refer to each beam path independently. The optical sensors may be located in one and the same beam path or partial beam path. Alternatively, however, the optical sensors may also be located in different partial beam paths. In case the optical sensors are distributed over different partial beam paths, the above-mentioned condition may be described such that at least one first optical sensor is located in at least one first partial beam path, being offset from the optical axis of the first partial beam path by a first spatial offset, and at least one second optical sensor is located in at least one second partial beam path, being offset from the optical axis of the second partial beam path by at least one second spatial offset, wherein the first spatial off- set and the second spatial offset are different.

The transfer device may constitute a coordinate system, wherein a longitudinal coordinate I is a coordinate along the optical axis and wherein d is a spatial offset from the optical axis. The co- ordinate system may be a polar coordinate system in which the optical axis of the transfer de- vice forms a z-axis and in which a distance from the z-axis and a polar angle may be used as additional coordinates. A direction parallel or antiparallel to the z-axis may be considered a lon- gitudinal direction, and a coordinate along the z-axis may be considered a longitudinal coordi- nate I. Any direction perpendicular to the z-axis may be considered a transversal direction, and the polar coordinate and/or the polar angle may be considered a transversal coordinate.

The optical sensors may be positioned off focus. As used herein, the term“focus” generally re- fers to one or both of a minimum extend of a circle of confusion of the light beam, in particular of at least one light beam emitted from one point of the object, caused by the transfer device or a focal length of the transfer device. As used herein, the term“circle of confusion” refers to a light spot caused by a cone of light rays of the light beam focused by the transfer device. The circle of confusion may depend on a focal length f of the transfer device, a longitudinal distance from the object to the transfer device, a diameter of an exit pupil of the transfer device, a longitudinal distance from the transfer device to the light sensitive area, a distance from the transfer device to an image of the object. For example, for Gaussian beams, a diameter of the circle of confu- sion may be a width of the Gaussian beam. In particular, for a point like object situated or placed at infinite distance from the detector the transfer device may be adapted to focus the light beam from the object into a focus point at the focal length of the transfer device. For non- point like objects situated or placed at infinite distance from the detector the transfer device may be adapted to focus the light beam from at least one point of the object into a focus plane at the focal length of the transfer device. For point like objects not situated or placed at infinite dis tance from the detector, the circle of confusion may have a minimum extend at least at one lon- gitudinal coordinate. For non-point like objects not situated or placed at infinite distance from the detector, the circle of confusion of the light beam from at least one point of the object may have a minimum extend at least at one longitudinal coordinate. As used herein, the term“positioned off focus” generally refers to a position other than the minimum extent of a circle of confusion of the light beam caused by the transfer device or a focal length of the transfer device. In particu- lar, the focal point or minimum extend of the circle of confusion may be at a longitudinal coordi- nate lf _0C us, whereas the position of each of the optical sensors may have a longitudinal coordi- nate _nsor different from lf _0C us. For example, the longitudinal coordinate _ensor may be, in a longi- tudinal direction, arranged closer to the position of the transfer device than the longitudinal co- ordinate I _focus or may be arranged further away from the position of the transfer device than the longitudinal coordinate lf _0C us. Thus, the longitudinal coordinate _ensor and the longitudinal coordi- nate l _f0Cus may be situated at different distances from the transfer device. For example, the opti- cal sensors may be spaced apart from the minimum extend of the circle of confusion in longitu dinal direction by ± 2% of focal length, preferably by ± 10% of focal length, most preferably ± 20% of focal length. For example, at a focal length of the transfer device may be 20mm and the longitudinal coordinate _nsor may be 19,5 mm, i.e. the sensors may be positioned at 97,5% focal length, such that _nsor is spaced apart from the focus by 2,5% of focal length.

The optical sensors may be arranged such that the light-sensitive areas of the optical sensors differ in at least one of: their longitudinal coordinate, their spatial offset, or their surface areas.

As used herein, the term“filter element” refers to at least one optical element adapted to modify the at least one property of the incident light beam. The at least one property of the incident light beam may be a property selected from the group consisting of: intensity of the incident light beam; intensity of one or more wavelength of incident light beam; a number of photons; bright ness; a value of a sensor signal; a digitized value of a sensor signal such as a sensor signal processed by an analog digital converter; an amplified sensor signal; a pre-amplified sensor signal; a sensor signal filtered by analog or digital electronics; a noise level; a sensor signal rel- ative to a noise level. Overdriven signals or overload of the signal may refer raw sensor signals and/or may result from subsequent analog- or digital electronics such as ADC, amplifiers and the like.

As used herein, the term“modify at least one property” refers to one or more of adjusting, changing, reducing the at least one property. The term“modify”, in addition, refers to maintain- ing and/or conserving the property of the incident light beam. In particular, the filter element may be adapted to modify and/or reduce the intensity of the incident light beam passing through the filter element. The filter element may comprise at least one neutral-density filter. The neutral- density filter may be selected from the group consisting of: a circular neutral-density filter, in particular at least one semi-circle neutral-density filter; at least one square shaped neutral- density filter; at least one split neutral-density filter; at least one graduated neutral-density filter; a neutral-density filter wheel; a variable neutral density filter; a Lee Big Stopper. The filter ele- ment and the transfer device may be arranged such that the incident light beam propagating from the object passes through the filter element and subsequently through the transfer device before impinging on the sensor element. Additionally or alternatively, the filter element may be arranged between the transfer device and the sensor element.

As used herein, the term“filter region” refers to at least one spatial region generated by the filter element adapted to modify the at least one property of the incident light beam. As used herein, the term“generating a filter region” refers to providing and/or constituting at least one filter re- gion. The terms“first” and“second” filter region are used as names only and do not refer to an amount of filter regions or if more filter regions are present, i.e. a third, a fourth, etc. filter region. The filter element may be adapted to generate a plurality of different filter regions such as three filter regions, four filter regions or more filter regions. For example, the filter element may be designed as described in US 2016/154152 A1. Additionally or alternatively, the detector may comprise a plurality of filter elements each adapted to generate at least one filter region. As used herein, the expression“the at least one property of the incident light beam is modified dif ferently” refers to that each of the filter regions may have different influence on the property of the incident light beam. The filter element may comprise at least two sections having different optical depths. For example, the first filter region may comprise at least one neutral-density filter and the second filter region may be configured that the property of the incident light beam is maintained, e.g. by using a clear element such as glass or leaving a section of an aperture of the transfer device uncovered. For example, the filter element may comprise at least two neu- tral-density filters, wherein a first one of the neutral-density filters may modify a first wavelength of the incident light beam and/or has a first optical depth, wherein a second one of the neutral- density filters may modify a second wavelength, different from the first wavelength of the inci- dent light beam and/or has a second optical depth, different from the first optical depth.

The sensor element may be arranged such that the incident light beam impinging on the sensor element generates at least one light spot. The filter element may be arranged such that a first part of the light spot of the incident light beam is generated by a part of the incident light beam having passed through the first filter region and that a second part of the light spot is generated by another part of the incident light beam having passed through the second filter region. For example, the filter element may comprise at least one half-circle neutral-density filter. The half- circle neutral-density filter may be arranged such that it covers one part of the aperture of the transfer device, for example a half side, or a section. Thus, the at least one property of a part of the incident light beam passing through the half-circle neutral-density filter may be modified by the half-circle neutral-density filter, whereas the at least one property of other parts of the inci- dent light beam not passing through the half-circle neutral-density filter may be unchanged. For example, the filter element may comprise at least one graduated neutral-density filter, such as a hard edge or soft edge graduated neutral-density filter. Preferably the filter element comprises a hard edge graduated neutral-density to ensure separation of filter regions.

The light spot generated on the sensor element may have a round or non-round shape. As used herein, a“light spot” generally refers to a visible or detectable round or non-round illumination of an article, an area or object by a light beam. A blurring or confusion of the light spot may de- pend on a shape of the filter element. For example, in case of the embodiment using a half- circle neutral-density filter, half of the light spot is generated by the incident light beam having passed through the half-circle neutral-density filter and may be darker compared to the other half of the light spot not being influenced by the half-circle neutral-density filter. Thus, the filter element may be adapted to adjust an amount of light impinging on the sensor element. Light originating from a dark object can be observed via the non-filtered side of the light spot and light originating from a bright object can be observed via the filtered side of the light spot. This allows to adjust exposure times. The detector may comprise at least one control device. The control device may be adapted to adjust exposure times depending on at least one property of the ob- ject, such as brightness of the object, and/or of the sensor signals.

As further used herein, the term“evaluation device” generally refers to an arbitrary device adapted to perform the named operations, preferably by using at least one data processing de- vice and, more preferably, by using at least one processor and/or at least one application- specific integrated circuit. Thus, as an example, the at least one evaluation device may corn- prise at least one data processing device having a software code stored thereon comprising a number of computer commands. The evaluation device may provide one or more hardware el- ements for performing one or more of the named operations and/or may provide one or more processors with software running thereon for performing one or more of the named operations.

The above-mentioned operations, including determining the at least one longitudinal coordinate of the object, are performed by the at least one evaluation device. Thus, as an example, one or more of the above-mentioned relationships may be implemented in software and/or hardware, such as by implementing one or more lookup tables. Thus, as an example, the evaluation de- vice may comprise one or more programmable devices such as one or more computers, appli- cation-specific integrated circuits (ASICs), Field Programmable Gate Arrays (FPGAs), or digital signal processors (DSPs) which are configured to perform the above-mentioned evaluation, in order to determine the at least one longitudinal coordinate of the object. Additionally or alterna- tively, however, the evaluation device may also fully or partially be embodied by hardware. The evaluation device is configured for evaluating the at least one first sensor signal and the at least one second sensor signal, wherein the first sensor signal is generated in response to illu mination having passed through one of the first filter region and the second filter region and the second sensor signal is generated in response to illumination having passed through the same or the other one of the first filter region and the second filter region. For example, the first sen- sor signal is generated in response to illumination having passed through the first filter region and the second sensor signal may be generated in response to illumination having passed through first filter region, too. For example, the first sensor signal is generated in response to illumination having passed through the second filter region and the second sensor signal may be generated in response to illumination having passed through second filter region, too. For example, the first sensor signal is generated in response to illumination having passed through the first filter region and the second sensor signal may be generated in response to illumination having passed through the second filter region. For example, the first sensor signal is generated in response to illumination having passed through the second filter region and the second sen- sor signal may be generated in response to illumination having passed through first filter region. The evaluation device is configured for determining at least one longitudinal coordinate z of the object by evaluating a combined signal Q from the first sensor signal and the second sensor signal.

The evaluation device may be adapted to perform at least one image analysis and/or image processing in order to identify at least one light spot. The image analysis and/or image pro- cessing may use at least one feature detection algorithm. The image analysis and/or image processing may comprise one or more of the following: a filtering; a selection of at least one region of interest; a formation of a difference image between an image created by the sensor signals and at least one offset; an inversion of sensor signals by inverting an image created by the sensor signals; a formation of a difference image between an image created by the sensor signals at different times; a background correction; a decomposition into color channels; a de- composition into hue; saturation; and brightness channels; a frequency decomposition; a singu- lar value decomposition; applying a blob detector; applying a corner detector; applying a Deter- minant of Hessian filter; applying a principle curvature-based region detector; applying a maxi- mally stable extremal regions detector; applying a generalized Hough-transformation; applying a ridge detector; applying an affine invariant feature detector; applying an affine-adapted interest point operator; applying a Harris affine region detector; applying a Hessian affine region detec- tor; applying a scale-invariant feature transform; applying a scale-space extrema detector; ap- plying a local feature detector; applying speeded up robust features algorithm; applying a gradi- ent location and orientation histogram algorithm; applying a histogram of oriented gradients de- scriptor; applying a Deriche edge detector; applying a differential edge detector; applying a spa- tio-temporal interest point detector; applying a Moravec corner detector; applying a Canny edge detector; applying a Laplacian of Gaussian filter; applying a Difference of Gaussian filter; apply- ing a Sobel operator; applying a Laplace operator; applying a Scharr operator; applying a Prewitt operator; applying a Roberts operator; applying a Kirsch operator; applying a high-pass filter; applying a low-pass filter; applying a Fourier transformation; applying a Radon- transformation; applying a Hough-transformation; applying a wavelet-transformation; a thresh- olding; creating a binary image. The evaluation device may be adapted to determine a region of interest. The region of interest may be determined manually by a user or may be determined automatically, such as by recognizing an object within an image generated by the optical sen- sors. The evaluation device may filter the reflection beam profile by removing high spatial fre- quencies such as by spatial frequency analysis and/or median filtering or the like. The evalua- tion device may be adapted to perform a summarization by center of intensity of the light spot and averaging all intensities at the same distance to the center. The evaluation device may be adapted to identify the at least one light spot generated by the incident light beam on the sensor element using overexposed pixels of the matrix. As used herein, the term“overexposed” refers to pixels which generate a high intensity value which is independent on the intensity of the inci- dent light beam. For example, the evaluation device may be adapted to search for overexposed pixels and to determine a surrounding pixel area of the matrix as region of interest. The evalua- tion device may be adapted to determine a change in intensity due to the light beam passing through the first filter region and the second filter region within the region of interest. For exam- pie, the evaluation device may be adapted to select those optical sensors of the region of inter- est having an intensity value below or above a pre-defined or pre-determined threshold as opti- cal sensors being illuminated by the incident light beam having passed through the first filter region. For example, the evaluation device may be adapted to select those optical sensors of the region of interest having an intensity value above or equal to the pre-defined or pre- determined threshold as optical sensors being illuminated by the incident light beam having passed through the second filter region.

The first sensor signal may comprise at least one information of at least one first area of a beam profile of the incident light beam. The second sensor signal may comprise at least one infor- mation of at least one second area of the beam profile of the incident light beam. As used here- in, the term“beam profile” relates to a spatial distribution, in particular in at least one plane per- pendicular to the propagation of the light beam, of an intensity of the light beam. The beam pro- file may be a cross section of the light beam. The beam profile may be selected from the group consisting of a trapezoid beam profile; a triangle beam profile; a conical beam profile and a line ar combination of Gaussian beam profiles. As used herein, the term“area of the beam profile” generally refers to an arbitrary region of the beam profile at the position of the sensor element. The light-sensitive areas may be arranged such that the first sensor signal comprises infor- mation of the first area of the beam profile and the second sensor signal comprises information of the second area of the beam profile. The first area of the beam profile and the second area of the beam profile may be one or both of adjacent or overlapping regions. The first area of the beam profile and the second area of the beam profile may be not congruent in area.

The evaluation device may be configured to determine and/or to select the first area of the beam profile and the second area of the beam profile. The first area of the beam profile may comprise essentially edge information of the beam profile and the second area of the beam pro- file may comprise essentially center information of the beam profile. The beam profile may have a center, i.e. a maximum value of the beam profile and/or a center point of a plateau of the beam profile and/or a geometrical center of the light spot, and falling edges extending from the center. The second area may comprise inner regions of the cross section and the first area may comprise outer regions of the cross section. As used herein, the term“essentially center infor- mation” generally refers to a low proportion of edge information, i.e. proportion of the intensity distribution corresponding to edges, compared to a proportion of the center information, i.e. proportion of the intensity distribution corresponding to the center. Preferably the center infor- mation has a proportion of edge information of less than 10 %, more preferably of less than 5%, most preferably the center information comprises no edge content. As used herein, the term “essentially edge information” generally refers to a low proportion of center information corn- pared to a proportion of the edge information. The edge information may comprise information of the whole beam profile, in particular from center and edge regions. The edge information may have a proportion of center information of less than 10 %, preferably of less than 5%, more preferably the edge information comprises no center content. At least one area of the beam profile may be determined and/or selected as second area of the beam profile if it is close or around the center and comprises essentially center information. At least one area of the beam profile may be determined and/or selected as first area of the beam profile if it comprises at least parts of the falling edges of the cross section. For example, the whole area of the cross section may be determined as first area. The first area of the beam profile may be an area de- noted as A2 and the second area of the beam profile may be area denoted as A1.

Other selections of the first area A1 and second area A2 may be feasible. For example, the first area may comprise essentially outer regions of the beam profile and the second area may corn- prise essentially inner regions of the beam profile. In particular, in case of a two-dimensional beam profile, the beam profile may be divided in a left part and a right part, wherein the first area may comprise essentially areas of the left part of the beam profile and the second area may comprise essentially areas of the right part of the beam profile. The first and the second area, as an example, may be adjacent, with a minimum separation from one another. However, the separation between adjacent areas may also be varied such as enlarged to improve the dynamic range of the combined signal. As an example, the separation between two adjacent areas may be increased by not evaluating the area between the first and the second area. This may reduce the light on one of the areas relative and/or absolute as compared to the adjacent area which will may increase a quotient of the signal of the two areas. Further, one or both of the areas may consist of separated subareas which may be adjacent to each other and/or which may be separated by areas that are not evaluated and/or which may be evaluated as part of a different quotient. Further, the first and the second area may consist of a linear combination of subareas, whereas the signal contributed by each subarea may be weighted differently, in par- ticular when forming the center signal and/or the sum signal as outlined below. This may further be beneficial for increasing the dynamic range of the combined signal.

The extent of the circle of confusion may be larger than the extent of the optical sensor. For example, the optical sensor may be positioned as such that the circle of confusion extends be- yond the optical sensor. The optical sensor may thus only partially evaluate the beam profile of the light beam. The evaluation device may be adapted to extrapolate a beam profile such as due to symmetry considerations or due to comparing the partial beam profile to prerecorded beam profiles or the like. Further, the evaluation device may be adapted to evaluate a partial sum signal and a partial center signal of a partial beam profile and convert it into a sum signal and a center signal of an extrapolated and/or fitted and/or prerecorded beam profile or the like.

The edge information may comprise information relating to a number of photons in the first area of the beam profile and the center information may comprise information relating to a number of photons in the second area of the beam profile. The evaluation device may be adapted for de- termining an area integral of the beam profile. The evaluation device may be adapted to deter- mine the edge information by integrating and/or summing of the first area. The evaluation de- vice may be adapted to determine the center information by integrating and/or summing of the second area. For example, the beam profile may be a trapezoid beam profile and the evaluation device may be adapted to determine an integral of the trapezoid. Further, when trapezoid beam profiles may be assumed, the determination of edge and center signals may be replaced by equivalent evaluations making use of properties of the trapezoid beam profile such as determi- nation of the slope and position of the edges and of the height of the central plateau and deriv- ing edge and center signals by geometric considerations.

Additionally or alternatively, the evaluation device may be adapted to determine one or both of center information or edge information from at least one slice or cut of the light spot. This may be realized, for example, by replacing the area integrals in the combined signal Q, as described below, by a line integrals along the slice or cut. For improved accuracy, several slices or cuts through the light spot may be used and averaged. In case of an elliptical spot profile, averaging over several slices or cuts may result in an improved distance information.

The evaluation device may be configured to derive the combined signal Q by one or more of dividing the respective edge information and the respective center information, dividing multi- pies of the respective edge information and the respective center information, dividing linear combinations of the respective edge information and the respective center information. Thus, essentially, photon ratios may be used as the physical basis of the measurement principle. As generally used herein, the term“combine” generally may refer to an arbitrary operation in which two or more components such as signals are one or more of mathematically merged in order to form at least one merged combined signal and/or compared in order to form at least one com- parison signal or comparison result. As used herein, the term“combined signal Q” refers to a signal which is generated by combining the sensor signals, in particular by one or more of divid- ing the sensor signals, dividing multiples of the sensor signals or dividing linear combinations of the sensor signals. In the following, the combined signal is also denoted as quotient signal or combined sensor signal.

The detector may be adapted to determine depth information, in particular absolute depth in- formation, from a radiance ratio of at least two asymmetric regions of a light beam profile on the at least two optical sensors, i.e. the first optical sensor and the second optical sensor and/or the third optical senor and the fourth optical sensor. For example, the detector may comprise a plu- rality of optical sensors arranged in a matrix. The detector may be adapted to determine depth information from a radiance ratio of at least two asymmetric regions within an enclosed, in par- ticular, a defocused beam profile captured by a single matrix of optical sensors such as a CMOS detector. In particular, the detector may be adapted to determine the depth information using the radiance ratio independent of a certain object size range. This principle is called Dis- tance by Photon Ratio (DPR). The DPR principle can be applied, for example, to many sub- regions within a segmented image profile, such as a segmented image of at least one feature generated by the at least one light beam on the matrix of optical sensors, which is demonstrated hereafter. The quotient Q _A (z) , i.e. the combined signal, in the two-dimensional case can be written as

rr ^r out p( _x y z)dxdy

0 fzl = ^out — -

^ ff-j P(x,y,z)dxdy ’

' in

where P(x, y, z ) is a two-dimensional beam profile and r _in and r _out are inner and outer circle radii, respectively. For line-segmented quotients Q _y (z ) along the y-dimension, this can be rewrit- ten as

Without wishing to be bound by this theory, the overall defocused beam profile P{x, z) can be regarded as a superposition of defocused image point profiles p(x, z) along the image width b(x, z). This relationship can be modelled as a convolution given by

P(x, z) = b(x, z ) * p(x, z) , wherein p(x, z) represents the Point-Spread-Function (PSF) of a lens in defocus, which in the field of paraxial optics is also known as Circle of Confusion (CoC). By inserting P(x, z) into Q _y {z ) the above described quotient Q _y (z) can be rewritten as

The CoC radius may be r _c and r ₀ may be an image spot radius of the feature on the matrix of optical sensors, then r _out = r _c + r ₀ => r _out ³ r _c and r _out ³ r ₀ , which yields to

In case of r ₀ £ r _in < r _c , which indicates that the quotient is independent of the object size on condition that r ₀ < r _c . The Object Size Independence (OSI) in DPR applies as long as the image width i remains be- low the Circle of Confusion (CoC) width denoted as c. In the one-dimensional case, this is rep- resented by diameters d ₀ ^ d _c . Using paraxial optics, these diameters can be substituted, such that

i D _{x i} ,

- aO ^ύ <— i \d— i with a as the object distance, i as the image distance, o _s as the object size, D _x as the lens exit pupil diameter and d as the sensor position with respect to image-side principal plane. After re- arranging, this can be written as

a D,

o, < | d— i|

When focusing a single lens to infinity, this simplifies to where / is the focal length and F# the F-number of the lens.

Furthermore, with a matrix of optical sensors a defocused beam profile may be subdivided into cross-sections along lines of a certain angle Q and with a distance w from the origin of ordi nates. Accordingly, the parameterization of a single line may be given by w = x cos(0 ) + y sin(9 ) .

The integration of the intensity along parallel lines can be mathematically described by an inte- gral projection ¾{·) of the well-known Radon transform which reads where d denotes the Dirac delta function and f(x, y) is the intensity of an enclosed defocused beam profile. The photon ratio R for a given angle Q and projection width w is given by with f x, y) as the inner region. The variation of Q may yield different ratios R for skewed object surfaces at a certain distance. It is sufficient to let Q vary in the following interval {Q -e ₊ , q < p}.

The object size may be a priori unknown. An object image size, i.e. the size of the object in the image plane, may be distance dependent. However, different materials may have different scat- tering properties such that deviations from Lambertian distribution may occur. In particular, a luminance dependence may deviate significantly from a 1/z ² . In addition, due type of scattering and/or due to reflective properties and/or scattering properties of the object, for example de- pending on a material of the object, the object image size, in particular diameter of the spot, may vary. Thus, methods and devices using the spot size, for example by counting pixels, or absolute photon numbers for distance determination may be not suitable and may require cali brations depending on the material of the object. Methods and devices adapted for determina- tion of the distance independently from the object size are necessary in order to allow robust distance determination for any materials with one calibration, only. Further, the object size may be altered by the light source itself. For example, the properties of the optics may be altered by one or more of dirt, raindrops, scratches or manufacturing precision of the light source and/or its optics. Thus, the light beam emitted by the light source may be changed in one or more of its properties such as diameter, beam profile, divergence or the like. Thus, methods and devices adapted for determination of the distance independently from the object size are necessary in order to allow robust distance determination for higher manufacturing tolerances or harsher en- vironmental conditions or the like with one calibration, only. Further, object size may be altered depending on temperature as the optical properties of the detector and or the light source may change such as due to a temperature dependent change of the distance between emitter and optics of the light source or due to a temperature dependent change of the distance between sensor and optics of the detector or due to a temperature dependent change of the refracting properties of the lens or the like. Object size independence is, thus, important for measure- ments with little or no a priori knowledge on one or more of the measured object, the measure- ment environment, the temperature of the detector and its environment, the manufacturing qual- ity of the sensor and/or the light source. Further, object size independence is, thus, important for measurements that require high flexibility concerning one or more of the measured object, the measurement environment, the temperature of the detector and its environment, the manufac- turing quality of the sensor and/or the light source. Further, object size independence is im- portant, when diverging or converging illumination light beams shall be used, such as when di- verging or converging laser light beams are used where the size of the illuminated spot changes with distance. Further, object size independence is, thus, important for measurements that re- quire a high robustness in one or more of measurement quality independent of the measured object, the measurement environment, the temperature of the detector and its environment, the manufacturing quality of the sensor and/or the light source.

Known 3D sensing methods are dependent on the object size. For example US 4,675,517 and US 5,323,222 describe devices and methods exhibiting dependence on object size. Specifically, US 4,675,517 describes with respect to Figures 3A to 3C, column 2, line 16 that the distance information changes with spot size. In particular, it is described that in actual practice, with the use of such a system, as the diameter of the image of the reflection of the projected image spot P changes at random, or the optical position deviates, the defined object distance boundaries are caused to shift largely. In particular, problems due to too large spot sizes are addressed. In case the spot size is too large, the sensor is outshined and the resulting ratio is wrong. US 4,675,517 describes to correct this spot size dependence by enlarging the sensor area. Howev- er, the spot size dependence is not eliminated. In particular, problems due to too small spot siz- es are not addressed. Furthermore, specifically, US 5,323,222 describes that the ratio used for determining the distance depends on a chip size of the light source. In particular, in column 2, line 1 1 it is outlined that solid lines 11 and I2 in Fig 14A show the relationship between the recip- rocal of the distance a and the calculation output 11/(11 +12) for the light-projecting chip sizes t1 and t2 (t1 <t2), respectively. Furthermore, it is described that if the distance between the projec- tion lens and light emitting element is IT, the base length L, and the chip size of the light emit- ting element t, then the distance measuring range S will be: S= through 1T ^* L/t. However, US 5,323,222 does not further address eliminating impact of object size dependence.

As used herein, the term“object size”, generally refers to a size of the object in an object plane, in particular to the size of a spot and/or region and/or the entire object emitting the at least one light beam. As further used herein, the terms“independent from the object size” and“object size independence” refer to the fact that variations of the object size do not influence the determina- tion of the longitudinal coordinate z. As will be outlined in detail below, the quotient signal Q may be used for determining the longitudinal coordinate. Thus, object size independence fur- thermore refers to the fact that the quotient signal is essentially independent from the object size such that, in case of identical object distance, a first quotient signal determined at a first object size and a second quotient signal determined at a different object size are identical, with a tolerance of ±20% or less, preferably a tolerance of ±10% or less, more preferably a tolerance of ±5% or less. Requirement or condition of object size independence can be stated as follows: the circle of confusion of at least one light beam emitted from at least one point of the object is greater than an image size of the object, i.e. a size of the object in an image plane. The detector may be adapted to determine the longitudinal coordinate z of the object independent from the object size if the circle of confusion of the at least one light beam emitted from the at least one point of the object is greater than an image size of the object. This condition may be calculated by O _size < \z _{s åi} I, wherein z _o is a longitudinal distance from the object to the transfer de- zi

vice; E _x is a diameter of an exit pupil of the transfer device; z _s is a longitudinal distance from the transfer device to the light sensitive area, z, is a distance from the transfer device to an image of the object; O _size is an object size of the object in the object plane. As used herein, the term“di- ameter of an exit pupil” refers to an aperture of the transfer device. Given a measurement range the condition can be fulfilled by for example varying the sensor position, the diameter of the exit pupil or the image of the object, for example by varying the focal length. The detector may be adapted to determine the longitudinal coordinate z of the object independent from the object size if O _size < \z _s - z _t | holds true for at least one distance z _o . For example, the detector may zi

be adapted to determine the longitudinal coordinate z at the at least one distance z _o if the object size varies and/or changes within a large range, e.g. by more than 100% of the object size. The detector may be adapted to determine the longitudinal coordinate z at distances, at which the above-mentioned condition O _size - z _t is fulfilled only weakly, if the object size varies

and/or changes within a smaller range, in particular if the object size varies and/or changes by ±20 % or less, preferably by ±10% or less, more preferably by ±5% or less. The detector may be adapted to determine the longitudinal coordinate z over the whole measurement range if Osize < \ ^z s ^z i I holds true for the at least one distance z _o and if the object size and if the zi

object size varies and/or changes by ±20% or less, preferably by ±10% or less, more preferably by ±5% or less. As used herein, the term“holds true for at least one distance” refers to that at the at least one distance the longitudinal coordinate z may be determined independent from the object size and that the detector is adapted to determine the longitudinal coordinate z at other distances, in particular within the whole or entire measurement range, if the object size varies and/or changes by ±20% or less, preferably by ±10% or less, more preferably by ±5% or less.

As used herein, the term“measurement range” generally refers to an arbitrary range in which the determination of the longitudinal coordinate z is performed. The measurement range may be adjustable by adjusting one or more parameters selected from the group consisting of: the longi- tudinal distance from the object to the transfer device z _o ; the focal length of the transfer device f; the diameter of the exit pupil of the transfer device E _x ; the longitudinal distance from the transfer device to the light sensitive area z _s , the distance from the transfer device to an image of the object z,; the object size 0 _SiZe of the object in the object plane. For example, if the object size does not exceed an object-size limit, a unique relation of the quotient signal Q to the longitudinal distance from the object to the transfer device exists. The object-size limit may depend on the longitudinal distance from the transfer device to the light sensitive area, the longitudinal distance from the object to the transfer device, and an F-number of the transfer device F#, i.e. a ratio of the focal length of the transfer device and the diameter of an exit pupil of the transfer device.

For example, the measurement range may be adapted by selecting and/or choosing one or more of the longitudinal distance from the transfer device to the light sensitive area z _s , the dis tance from the transfer device to an image of the object z the longitudinal distance from the transfer device to the light sensitive area, the focal length and the F-number of the transfer de- vice. For example, the focal length and/or F-number may be adjusted by using a zoom objec- tive. In particular, the focal length may be between 10 and 200 mm, preferably between 20 and 150 mm. The F-number may be between 1 and 10, preferably between 1 ,5 and 6. The longitu- dinal distance from the transfer device may be as short as possible. The longitudinal distance from the transfer device to the light sensitive area may be between 0 and 200 mm, preferably between 20 and 50 mm. For a given system setup (f, F#, z _s ) a unique value of the object-size limit can be calculated. For example, in case the focal length is 3,5 mm and the F-number is 2,0, the object size may be smaller than 1 ,75 mm. Preferably a lower object size limit may be 0.5 pm or more, more preferably 1 pm or more and most preferably 10 pm or more. The lower object size limit refers to a minimum object size using an active measurement system, in par- ticular to a laser spot size.

For example, the evaluation device may be configured for deriving the combined signal Q by t _A1 E(x, y, ] )dxdy

Q (z ₀ ) = - ff _A2 E(x, y; z ₀ )dxdy wherein x and y are transversal coordinates, Ai and A ₂ are areas of the beam profile at the sen- sor position of at least one first optical sensor having generated the first sensor signal and of at least one second optical sensor having generated the second sensor signal, and E(x,y,z ₀ ) de- notes the beam profile given at the object distance z ₀ . In particular, A1 and A2 are not congru- ent. A1 and A2 may differ in one or more of the shape or content. Generally the beam profile is dependent on luminance L(z ₀ ) and beam shape S(x,y;z ₀ ), E(x, y, zo) = L - S. Thus, by deriving the quotient signal it may allow determining the longitudinal coordinate independent from lumi- nance.

In one embodiment, the light beam propagating from the object to the detector may illuminate the sensor element with at least one pattern comprising at least one feature point. As used herein, the term“feature point” refers to at least one at least partially extended feature of the pattern. The feature point may be selected from the group consisting of: at least one point, at least one line, at least one edge. The pattern may be generated by the object, for example, in response to an illumination by the at least one light source with an illumination pattern compris- ing the at least one pattern. A1 may correspond to a full or complete area of a feature point on the optical sensors. A2 may be a central area of the feature point on the optical sensors. The central area may be a constant value. The central area may be smaller compared to the full area of the feature point. For example, in case of a circular feature point, the central area may have a radius from 0.1 to 0.9 of a full radius of the feature point, preferably from 0.4 to 0.6 of the full radius.

For example, the light beam propagating from the object to the detector may illuminate the opti- cal sensors with at least one line pattern. The line pattern may be generated by the object, for example in response to an illumination by the at least one illumination source with an illumina- tion pattern comprising the at least one line pattern. A1 may correspond to an area with a full line width of the line pattern on the optical sensors, in particular on the light sensitive area of the optical sensors. The line pattern on the optical sensors may be widened and/or displaced corn- pared to the line pattern of the illumination pattern such that the line width on the optical sensors is increased. In particular, in case of a matrix of optical sensors, the line width of the line pattern on the optical sensors may change from one column to another column. A2 may be a central area of the line pattern on the optical sensors. The line width of the central area may be a con- stant value, and may in particular correspond to the line width in the illumination pattern. The central area may have a smaller line width compared to the full line width. For example, the cen- tral area may have a line width from 0.1 to 0.9 of the full line width, preferably from 0.4 to 0.6 of the full line width. The line pattern may be segmented on the optical sensors. Each column of the matrix of optical sensors may comprise center information of intensity in the central area of the line pattern and edge information of intensity from regions extending further outwards from the central area to edge regions of the line pattern.

For example, the light beam propagating from the object to the detector may illuminate the sen- sor element with at least one point pattern. The point pattern may be generated by the object, for example in response to an illumination by the at least one light source with an illumination pattern comprising the at least one point pattern. A1 may correspond to an area with a full radi- us of a point of the point pattern on the optical sensors. A2 may be a central area of the point in the point pattern on the optical sensors. The central area may be a constant value. The central area may have a radius compared to the full radius. For example, the central area may have a radius from 0.1 to 0.9 of the full radius, preferably from 0.4 to 0.6 of the full radius. The light beam propagating from the object to the detector may illuminate the sensor element with a reflection pattern comprising both point patterns and line patterns. Other embodiments in addition or alternatively to line pattern and point pattern are feasible.

The first optical sensor may be the optical sensor having the highest sensor signal of the at least two optical sensors being illuminated by the incident light beam having passed through the first filter region and/or the second filter region. The first sensor signal may be at least one cen- ter signal. The second sensor signal may be a sum signal of the at least two optical sensors being illuminated by the incident light beam having passed through the first filter region and/or the second filter region.

A predetermined or determinable relationship exists between a size of a light spot, such as a diameter of the light spot, a beam waist or an equivalent diameter, and the longitudinal coordi- nate of the object from which the light beam propagates towards the detector. Without wishing to be bound by this theory, the light spot, may be characterized by two measurement variables: a measurement signal measured in a small measurement patch in the center or close to the center of the light spot, also referred to as the center signal, and an integral or sum signal inte- grated over the light spot, with or without the center signal. For a light beam having a certain total power which does not change when the beam is widened or focused, the sum signal should be independent from the spot size of the light spot, and, thus, should, at least when line- ar optical sensors within their respective measurement range are used, be independent from the distance between the object and the detector. The center signal, however, is dependent on the spot size. Thus, the center signal typically increases when the light beam is focused, and decreases when the light beam is defocused. By comparing the center signal and the sum sig- nal, thus, an item of information on the size of the light spot generated by the light beam and, thus, on the longitudinal coordinate of the object may be generated. The comparing of the cen- ter signal and the sum signal, as an example, may be done by forming the combined signal Q out of the center signals and the sum signals and by using a predetermined or determinable relationship between the longitudinal coordinate and the combined signal for deriving the longi- tudinal coordinate.

For example, the evaluation device may be configured for evaluating the sensor signals, by a) determining at least two optical sensors being illuminated by the incident light beam having passed through the first filter region, determining therefrom at least one first optical sensor and at least one second optical sensor, wherein the first optical sensor has the sensor signal comprising at least one information of at least one first area of a beam profile of the incident light beam and the second optical sensor has the sensor signal comprising at least one information of at least one second area of the beam profile of the incident light beam, wherein at least one first sensor signal and at least one second sensor signal are formed from the sensor signal of the first optical sensor and the sensor signal of the sec- ond optical sensor, respectively; b) determining at least two optical sensors being illuminated by the incident light beam having passed through the second filter region, determining therefrom at least one third optical sensor and at least one fourth optical sensor, wherein the third optical sensor has the sensor signal comprising at least one information of the first area of the beam profile of the incident light beam and the fourth optical sensor has the sensor signal comprising at least one information of the second area of the beam profile of the incident light beam, wherein at least one third sensor signal and at least one fourth sensor signal are formed from the sensor signal of the third optical sensor and the sensor signal of the fourth optical sen- sor, respectively;

c) determining, in case both of the first sensor signal and the second sensor signal fulfill at least one pre-defined criterion, at least one first combined signal Q1 by combining the first sensor signal and the second sensor signal and/or determin- ing, in case both of the third sensor signal and the fourth sensor signal fulfill the at least one pre-defined criterion, at least one second combined sensor signal Q2 by combining the third sensor signal and the fourth sensor signal; and

d) determining at least one first longitudinal coordinate z1 of the object by evaluat- ing the first combined signal Q1 and/or at least one second longitudinal coordi- nate z2 of the object by evaluating the second combined signal Q2.

The evaluation device may be configured to determine, in case both of the first sensor signal and the second sensor signal fulfill at least one pre-defined criterion, at least one first combined signal Q1 by combining the first sensor signal and the second sensor signal and/or determining, in case both of the third sensor signal and the fourth sensor signal fulfill the at least one pre- defined criterion, at least one second combined sensor signal Q2 by combining the third sensor signal and the fourth sensor signal. As used herein, the term“pre-defined criterion” refers to at least one pre-defined or pre-determined threshold and/or limit such as at least one upper threshold of the intensity of the sensor signal and/or at least one lower threshold of the intensity of the sensor signal and/or at least one upper threshold of a signal to noise ration and/or at least one lower threshold of the signal to noise ratio. The evaluation device may be adapted to com- pare the first sensor signal and the second sensor signal to the pre-defined criterion. In case both of the first sensor signal and the second sensor signal fulfill the at least one pre-defined criterion, for example, in case intensity of the first sensor signal and the second sensor signal are below or equal the at least one upper intensity threshold and/or are above the at least one lower intensity threshold, the evaluation device determines the first combined signal Q1 by combining the first sensor signal and the second sensor signal. The evaluation device may be adapted to compare the third sensor signal and the fourth sensor signal to the pre-defined crite- rion. In case both of the third sensor signal and the fourth sensor signal fulfill the at least one pre-defined criterion, for example, in case intensity of the third sensor signal and the fourth sen- sor signal are below or equal the at least one upper intensity threshold and/or are above the at least one lower intensity threshold, the evaluation device determines the second combined sig nal Q2 by combining the third sensor signal and the fourth sensor signal. An upper limit may be chosen as follows. The pixel is oversaturated if the maximum value of the ADC is reached. Thus, in case of an 8 bit ADC, the pixel is oversaturated, when the ADC returns an intensity of 255. Thus, the upper limit would be 254. Generally, the upper limit may be the highest possible ADC output minus 5, preferably minus 2, more preferably minus 1. A lower limit may be chosen as follows. The pixel intensity is too low, if the value returned by the ADC is below the dark noise level. The dark noise level may be determined as the maximum value returned by the ADC, when the pixel is not illuminated. The dark noise level may be determined by pixel, by column, by line, or for the complete imaging device. The dark noise level may be determined as a time averaged value. The threshold for the lowest pixel intensity may be the dark noise level plus two times the standard deviation of the dark noise level, preferably plus the standard devia- tion of the dark noise level, more preferably plus 1.

The evaluation device may be adapted to reject the respective sensor signal in case the sensor signal does not fulfill the pre-defined criterion. The evaluation device may be adapted to gener- ate and/or issue information about the rejection, such as an acoustical, electrical, or optical sig- nal. In case one or more of the first or second sensor signals is rejected but both of the third and fourth sensor signals fulfill the pre-defined criterion, only the second combined signal Q2 is de- termined. In case one or more of the third or fourth sensor signals is rejected but both of the first and second sensor signals fulfill the pre-defined criterion, only the first combined signal Q1 is determined. In case all sensor signals fulfill the pre-defined criterion, both of the first combined signal Q1 and the second combined signal Q2 are determined. In case one or more of the first and second sensor signals and one or more of the third and the fourth sensor signals are re- jected, the evaluation device may be adapted to repeat determining of the incident light beam, forming the first and second sensor signals and/or forming the third and fourth sensor signals, for example with adjusted exposure time.

For example, the evaluation device may be configured for deriving the signals Qi with i = 1 , 2 by

wherein x and y are transversal coordinates, An and A21 are areas of the beam profile at the sensor position of the first optical sensor and of the second optical sensor, respectively, A12 and A22 are areas of the beam profile at the sensor position of the third optical sensor and of the fourth optical sensor, respectively, and E(x,y,z ₀ ) denotes the beam profile given at the object distance z ₀ . In particular, A11 and A21 are not congruent. A11 and A21 may differ in one or more of the shape or content. In particular, A12 and A22 are not congruent. A12 and A22 may differ in one or more of the shape or content. Generally the beam profile is dependent on lumi- nance L(z ₀ ) and beam shape S(x,y;z ₀ ), E(x, y zo ) = L S. Thus, by deriving the quotient signal it may allow determining the longitudinal coordinate independent from luminance.

In one embodiment, the light beam propagating from the object to the detector may illuminate the sensor element with at least one pattern comprising at least one feature point. As used herein, the term“feature point” refers to at least one at least partially extended feature of the pattern. The feature point may be selected from the group consisting of: at least one point, at least one line, at least one edge. The pattern may be generated by the object, for example, in response to an illumination by the at least one light source with an illumination pattern compris- ing the at least one pattern. A1 i may correspond to a full or complete area of a feature point on the optical sensors. A2i may be a central area of the feature point on the optical sensors. The central area may be a constant value. The central area may be smaller compared to the full area of the feature point. For example, in case of a circular feature point, the central area may have a radius from 0.1 to 0.9 of a full radius of the feature point, preferably from 0.4 to 0.6 of the full radius.

For example, the light beam propagating from the object to the detector may illuminate the opti- cal sensors with at least one line pattern. The line pattern may be generated by the object, for example in response to an illumination by the at least one illumination source with an illumina- tion pattern comprising the at least one line pattern. A1 i may correspond to an area with a full line width of the line pattern on the optical sensors, in particular on the light sensitive area of the optical sensors. The line pattern on the optical sensors may be widened and/or displaced corn- pared to the line pattern of the illumination pattern such that the line width on the optical sensors is increased. In particular, in case of a matrix of optical sensors, the line width of the line pattern on the optical sensors may change from one column to another column. A2i may be a central area of the line pattern on the optical sensors. The line width of the central area may be a con- stant value, and may in particular correspond to the line width in the illumination pattern. The central area may have a smaller line width compared to the full line width. For example, the cen- tral area may have a line width from 0.1 to 0.9 of the full line width, preferably from 0.4 to 0.6 of the full line width. The line pattern may be segmented on the optical sensors. Each column of the matrix of optical sensors may comprise center information of intensity in the central area of the line pattern and edge information of intensity from regions extending further outwards from the central area to edge regions of the line pattern.

For example, the light beam propagating from the object to the detector may illuminate the sen- sor element with at least one point pattern. The point pattern may be generated by the object, for example in response to an illumination by the at least one light source with an illumination pattern comprising the at least one point pattern. A1 i may correspond to an area with a full radi- us of a point of the point pattern on the optical sensors. A2i may be a central area of the point in the point pattern on the optical sensors. The central area may be a constant value. The central area may have a radius compared to the full radius. For example, the central area may have a radius from 0.1 to 0.9 of the full radius, preferably from 0.4 to 0.6 of the full radius.

The light beam propagating from the object to the detector may illuminate the sensor element with a reflection pattern comprising both point patterns and line patterns. Other embodiments in addition or alternatively to line pattern and point pattern are feasible. The first optical sensor may be the optical sensor having the highest sensor signal of the at least two optical sensors being illuminated by the incident light beam having passed through the first filter region. The first sensor signal may be at least one first center signal. The third optical sensor may be the optical sensor having the highest sensor signal of the at least two optical sensors being illuminated by the incident light beam having passed through the second filter region. The third sensor signal may be at least one second center signal. The second sensor signal may be a first sum signal of the at least two optical sensors being illuminated by the inci- dent light beam having passed through the first filter region. The fourth sensor signal may be a second sum signal of the at least two optical sensors being illuminated by the incident light beam having passed through the second filter region. The comparing of the center signal and the sum signal, as an example, may be done by forming the combined signal Q and/or the combined signals Q1 and Q2 out of the center signals and the sum signals and by using a pre- determined or determinable relationship between the longitudinal coordinate and the combined signal for deriving the longitudinal coordinate.

The use of a matrix of optical sensors provides a plurality of advantages and benefits. Thus, the center of the light spot generated by the light beam on the sensor element, such as on the common plane of the light-sensitive areas of the optical sensors of the matrix of the sensor ele- ment, may vary with a transversal position of the object. By using a matrix of optical sensors, the detector according to the present invention may adapt to these changes in conditions and, thus, may determine the center of the light spot simply by comparing the sensor signals. Con- sequently, the detector according to the present invention may, by itself, choose the center sig nal and determine the sum signal and, from these two signals, derive a combined signal which contains information on the longitudinal coordinate of the object. By evaluating the combined signal, the longitudinal coordinate of the object may, thus, be determined. The use of the matrix of optical sensors, thus, provides a significant flexibility in terms of the position of the object, specifically in terms of a transversal position of the object.

The transversal position of the light spot on the matrix of optical sensors, such as the transver- sal position of the at least one optical sensor generating the sensor signal, may even be used as an additional item of information, from which at least one item of information on a transversal position of the object may be derived, as e.g. disclosed in WO 2014/198629 A1. Additionally or alternatively, as will be outlined in further detail below, the detector according to the present invention may contain at least one additional transversal detector for, in addition to the at least one longitudinal coordinate, detecting at least one transversal coordinate of the object.

Consequently, in accordance with the present invention, the term“center signal” generally re- fers to the at least one sensor signal comprising essentially center information of the beam pro- file. As used herein, the term“highest sensor signal” refers to one or both of a local maximum or a maximum in a region of interest. For example, the center signal may be the signal of the at least one optical sensor having the highest sensor signal out of the plurality of sensor signals generated by the optical sensors of the entire matrix or of a region of interest within the matrix, wherein the region of interest may be predetermined or determinable within an image generated by the optical sensors of the matrix. The center signal may arise from a single optical sensor or, as will be outlined in further detail below, from a group of optical sensors, wherein, in the latter case, as an example, the sensor signals of the group of optical sensors may be added up, inte- grated or averaged, in order to determine the center signal. The group of optical sensors from which the center signal arises may be a group of neighboring optical sensors, such as optical sensors having less than a predetermined distance from the actual optical sensor having the highest sensor signal, or may be a group of optical sensors generating sensor signals being within a predetermined range from the highest sensor signal. The group of optical sensors from which the center signal arises may be chosen as large as possible in order to allow maximum dynamic range. The evaluation device may be adapted to determine the center signal by inte- gration of the plurality of sensor signals, for example the plurality of optical sensors around the optical sensor having the highest sensor signal. For example, the beam profile may be a trape- zoid beam profile and the evaluation device may be adapted to determine an integral of the trapezoid, in particular of a plateau of the trapezoid.

Similarly, the term“sum signal” generally refers to a signal comprising essentially edge infor- mation of the beam profile. For example, the sum signal may be derived by adding up the sen- sor signals, integrating over the sensor signals or averaging over the sensor signals of the en- tire matrix or of a region of interest within the matrix, wherein the region of interest may be pre- determined or determinable within an image generated by the optical sensors of the matrix. When adding up, integrating over or averaging over the sensor signals, the actual optical sen- sors from which the sensor signal is generated may be left out of the adding, integration or av- eraging or, alternatively, may be included into the adding, integration or averaging. The evalua- tion device may be adapted to determine the sum signal by integrating signals of the entire ma- trix, or of the region of interest within the matrix. For example, the beam profile may be a trape- zoid beam profile and the evaluation device may be adapted to determine an integral of the en- tire trapezoid. Further, when trapezoid beam profiles may be assumed, the determination of edge and center signals may be replaced by equivalent evaluations making use of properties of the trapezoid beam profile such as determination of the slope and position of the edges and of the height of the central plateau and deriving edge and center signals by geometric considera- tions.

Similarly, the term“combined signal”, as further used herein, generally refers to a signal which is generated by combining the center signal and the sum signal, too. Specifically, the combina- tion may include one or more of: forming a quotient of the center signal and the sum signal or vice versa; forming a quotient of a multiple of the center signal and a multiple of the sum signal or vice versa; forming a quotient of a linear combination of the center signal and a linear combi- nation of the sum signal or vice versa; forming a quotient of a first linear combination of the cen- ter signal and the sum signal and a second linear combination of the center signal and the sum signal. Additionally or alternatively, the combined signal may comprise an arbitrary signal or signal combination which contains at least one item of information on a comparison between the center signal and the sum signal. The light beam propagating from the object to the detector specifically may fully illuminate the at least one optical sensor from which the center signal is generated, such that the at least one optical sensor from which the center signal arises is fully located within the light beam, with a width of the light beam being larger than the light-sensitive area of the at least one optical sen- sor from which the sensor signal arises. Contrarily, preferably, the light beam propagating from the object to the detector specifically may create a light spot on the entire matrix which is small- er than the matrix, such that the light spot is fully located within the matrix. This situation may easily be adjusted by a person skilled in the art of optics by choosing one or more appropriate lenses or elements having a focusing or defocusing effect on the light beam, such as by using an appropriate transfer device.

As outlined above, the center signal generally may be a single sensor signal, such as a sensor signal from the optical sensor in the center of the light spot, or may be a combination of a plural ity of sensor signals, such as a combination of sensor signals arising from optical sensors in the center of the light spot, or a secondary sensor signal derived by processing a sensor signal de- rived by one or more of the aforementioned possibilities. The determination of the center signal may be performed electronically, since a comparison of sensor signals is fairly simply imple- mented by conventional electronics, or may be performed fully or partially by software. Specifi- cally, the center signal may be selected from the group consisting of: the highest sensor signal; an average of a group of sensor signals being within a predetermined range of tolerance from the highest sensor signal; an average of sensor signals from a group of optical sensors contain- ing the optical sensor having the highest sensor signal and a predetermined group of neighbor- ing optical sensors; a sum of sensor signals from a group of optical sensors containing the opti- cal sensor having the highest sensor signal and a predetermined group of neighboring optical sensors; a sum of a group of sensor signals being within a predetermined range of tolerance from the highest sensor signal; an average of a group of sensor signals being above a prede- termined threshold; a sum of a group of sensor signals being above a predetermined threshold; an integral of sensor signals from a group of optical sensors containing the optical sensor hav- ing the highest sensor signal and a predetermined group of neighboring optical sensors; an in- tegral of a group of sensor signals being within a predetermined range of tolerance from the highest sensor signal; an integral of a group of sensor signals being above a predetermined threshold.

Raw sensor signals of the optical sensors may be used for evaluation or secondary sensor sig- nals derived thereof. As used herein, the term“secondary sensor signal” generally refers to a signal, such as an electronic signal, more preferably an analogue and/or a digital signal, which is obtained by processing one or more raw signals, such as by filtering, averaging, demodulat- ing or the like. Thus, image processing algorithms may be used for generating secondary sen- sor signals from the totality of sensor signals of the matrix or from a region of interest within the matrix. Specifically, the detector, such as the evaluation device, may be configured for trans- forming the sensor signals of the optical sensor, thereby generating secondary optical sensor signals, wherein the evaluation device is configured for performing forming of the center and sum signals and deriving the combined signal Q and/or the combined signals Qi by using the secondary optical sensor signals. The transformation of the sensor signals specifically may comprise at least one transformation selected from the group consisting of: a filtering; a selec- tion of at least one region of interest; a formation of a difference image between an image cre- ated by the sensor signals and at least one offset; an inversion of sensor signals by inverting an image created by the sensor signals; a formation of a difference image between an image cre- ated by the sensor signals at different times; a background correction; a decomposition into col- or channels; a decomposition into hue; saturation; and brightness channels; a frequency de- composition.; a singular value decomposition; applying a Canny edge detector; applying a La- placian of Gaussian filter; applying a Difference of Gaussian filter; applying a Sobel operator; applying a Laplace operator; applying a Scharr operator; applying a Prewitt operator; applying a Roberts operator; applying a Kirsch operator; applying a high-pass filter; applying a low-pass filter; applying a Fourier transformation; applying a Radon-transformation; applying a Hough- transformation; applying a wavelet-transformation; a thresholding; creating a binary image.

As outlined above, the detection of the center of the light spot, i.e. the detection of the center signal and/or of the at least one optical sensor from which the center signal arises, may be per- formed fully or partially electronically or fully or partially by using one or more software algo- rithms. Specifically, the evaluation device may comprise at least one center detector for detect- ing the at least one highest sensor signal and/or for forming the center signal. The center detec- tor specifically may fully or partially be embodied in software and/or may fully or partially be em- bodied in hardware. The center detector may fully or partially be integrated into the at least one sensor element and/or may fully or partially be embodied independently from the sensor ele- ment.

As outlined above, the sum signal may be derived from all sensor signals of the matrix, from the sensor signals within a region of interest or from one of these possibilities with the sensor sig nals arising from the optical sensors contributing to the center signal excluded. In every case, a reliable sum signal may be generated which may be compared with the center signal reliably, in order to determine the longitudinal coordinate. Generally, the sum signal may be selected from the group consisting of: an average over all sensor signals of the matrix; a sum of all sensor signals of the matrix; an integral of all sensor signals of the matrix; an average over all sensor signals of the matrix except for sensor signals from those optical sensors contributing to the center signal; a sum of all sensor signals of the matrix except for sensor signals from those op- tical sensors contributing to the center signal; an integral of all sensor signals of the matrix ex- cept for sensor signals from those optical sensors contributing to the center signal; a sum of sensor signals of optical sensors within a predetermined range from the optical sensor having the highest sensor signal; an integral of sensor signals of optical sensors within a predeter- mined range from the optical sensor having the highest sensor signal; a sum of sensor signals above a certain threshold of optical sensors being located within a predetermined range from the optical sensor having the highest sensor signal; an integral of sensor signals above a cer- tain threshold of optical sensors being located within a predetermined range from the optical sensor having the highest sensor signal. Other options, however, exist. The summing may be performed fully or partially in software and/or may be performed fully or partially in hardware. A summing is generally possible by purely electronic means which, typi- cally, may easily be implemented into the detector. Thus, in the art of electronics, summing de- vices are generally known for summing two or more electrical signals, both analogue signals and digital signals. Thus, the evaluation device may comprise at least one summing device for forming the sum signal. The summing device may fully or partially be integrated into the sensor element or may fully or partially be embodied independently from the sensor element. The summing device may fully or partially be embodied in one or both of hardware or software.

The comparison between the center signals and the sum signals specifically may be performed by forming quotient signals. Thus, generally, the combined signal Q and/or the combined sig- nals may be a quotient signal, derived by one or more of: forming a quotient of the center signal and the sum signal or vice versa; forming a quotient of a multiple of the center signal and a mul- tiple of the sum signal or vice versa; forming a quotient of a linear combination of the center signal and a linear combination of the sum signal or vice versa; forming a quotient of the center signal and a linear combination of the sum signal and the center signal or vice versa; forming a quotient of the sum signal and a linear combination of the sum signal and the center signal or vice versa; forming a quotient of an exponentiation of the center signal and an exponentiation of the sum signal or vice versa; forming a quotient of a first linear combination of the center signal and the sum signal and a second linear combination of the center signal and the sum signal. Other options, however, exist. The evaluation device may be configured for forming the one or more quotient signals.

Thus, generally, the evaluation device may be configured for determining the longitudinal coor- dinate z by evaluating the combined signal Q. The evaluation device may be configured for de- termining the longitudinal coordinates z1 and z2 by evaluating the respective quotient signal Q1 or Q2. This determining may be a one-step process, such as by directly combining the center signal and the sum signal and deriving the longitudinal coordinate thereof, or may be a multiple step process, such as by firstly deriving the combined signal from the center signal and the sum signal and, secondly, by deriving the longitudinal coordinate from the combined signal. Both options, being fully or partially combined, shall be comprised by the present invention.

The optical sensors specifically may be or may comprise photodetectors, preferably inorganic photodetectors, more preferably inorganic semiconductor photodetectors, most preferably sili con photodetectors. Specifically, the optical sensors may be sensitive in the infrared spectral range. All of the optical sensors of the matrix or at least a group of the optical sensors of the matrix specifically may be identical. Groups of identical optical sensors of the matrix specifically may be provided for different spectral ranges, or all optical sensors may be identical in terms of spectral sensitivity. Further, the optical sensors may be identical in size and/or with regard to their electronic or optoelectronic properties.

The matrix may be composed of independent optical sensors. Thus, a matrix of inorganic pho- todiodes may be composed. Alternatively, however, a commercially available matrix may be used, such as one or more of a CCD detector, such as a CCD detector chip, and/or a CMOS detector, such as a CMOS detector chip.

Thus, generally, the optical sensors of the detector may form a sensor array or may be part of a sensor array, such as the above-mentioned matrix. Thus, as an example, the detector may comprise an array of optical sensors, such as a rectangular array, having m rows and n col- umns, with m, n, independently, being positive integers. Preferably, more than one column and more than one row is given, i.e. n>1 , m>1. Thus, as an example, n may be 2 to 16 or higher and m may be 2 to 16 or higher. Preferably, the ratio of the number of rows and the number of col- umns is close to 1. As an example, n and m may be selected such that 0.3 < m/n < 3, such as by choosing m/n = 1 :1 , 4:3, 16:9 or similar. As an example, the array may be a square array, having an equal number of rows and columns, such as by choosing m=2, n=2 or m=3, n=3 or the like.

As further outlined above, the matrix specifically may be a rectangular matrix having at least one row, preferably a plurality of rows, and a plurality of columns. As an example, the rows and columns may be oriented essentially perpendicular, wherein, with respect to the term“ essentially perpendicular”, reference may be made to the definition given above. Thus, as an example, tolerances of less than 20°, specifically less than 10° or even less than 5°, may be acceptable. In order to provide a wide range of view, the matrix specifically may have at least 10 rows, preferably at least 500 rows, more preferably at least 1000 rows. Similarly, the matrix may have at least 10 columns, preferably at least 500 columns, more preferably at least 1000 col- umns. The matrix may comprise at least 50 optical sensors, preferably at least 100000 optical sensors, more preferably at least 5000000 optical sensors. The matrix may comprise a number of pixels in a multi-mega pixel range. Other embodiments, however, are feasible. Thus, as out- lined above, in setups in which an axial rotational symmetry is to be expected, circular arrange- ments or concentric arrangements of the optical sensors of the matrix, which may also be re- ferred to as pixels, may be preferred.

The evaluation device specifically may be configured for deriving the combined signal Q, or ex- emplary the combined signal Q1 , by dividing the first and second sensor signals, by dividing multiples of the first and second sensor signals or by dividing linear combinations of the first and second sensor signals. The evaluation device specifically may be configured for deriving the combined signal Q2 by dividing the first and second sensor signals, by dividing multiples of the third and fourth sensor signals or by dividing linear combinations of the third and fourth sensor signals. As an example, Q1 may simply be determined as

Q1 = S1/S2 or

Q1 = S2/S1 , with si denoting the first sensor signal and S2 denoting the second sensor signal. Additionally or alternatively, Q1 may be determined as

Q1 = a-si/b-S2 or

Q1 = b-S2/ a-si, with a and b being real numbers which, as an example, may be predetermined or determinable. Additionally or alternatively, Q1 may be determined as

Q1 = (a-si + b-S2) / (c-si + d-S2), with a, b, c and d being real numbers which, as an example, may be predetermined or determi- nable. As a simple example for the latter, Q1 may be determined as

Q1 = Si / (si + S2).

Other quotient signals are feasible. The above-mentioned mathematical formulae used for de- riving the first combined signal Q1 can be used for determining the second combined signal Q2 by replacing si by S3, and S2 by s ₄ with s ₃ denoting the third sensor signal and s ₄ denoting the fourth sensor signal.

Typically, in the setup described above, the combined signal Q such as Q1 and Q2 are monot- onous functions of the longitudinal coordinate of the object and/or of the size of the light spot such as the diameter or equivalent diameter of the light spot. Thus, as an example, specifically in case linear optical sensors are used, the quotients Q1 =S _I S ₂ and Q2=S ₃ /s ₄ are monotonously decreasing function of the size of the light spot. Without wishing to be bound by this theory, it is believed that this is due to the fact that, in the preferred setup described above, both the first sensor signal si and the second sensor signal S2, and analogous the third sensor signal and the fourth sensor signal, decrease as a square function with increasing distance to the light source, since the amount of light reaching the detector decreases. Therein, however, the first sensor signal si decreases more rapidly than the second sensor signal S2, since, in the optical setup as used in the experiments, the light spot in the image plane grows and, thus, is spread over a larger area. Analogously the third sensor signal decreases more rapidly than the fourth sensor signal, since, in the optical setup as used in the experiments, the light spot in the image plane grows and, thus, is spread over a larger area. The quotient, thus, continuously decreases with increasing diameter of the light beam or diameter of the light spot on the light-sensitive areas. The quotient, further, is mainly independent from the total power of the light beam, since the total power of the light beam forms a factor both in the first sensor signal (in the third sensor signal respectively) and in the second sensor signal (in the fourth sensor signal respectively). Consequently, the quotient Q1 may form a secondary signal which provides a unique and un- ambiguous relationship between the first and second sensor signals and the size or diameter of the light beam and the quotient Q2 may form a secondary signal which provides a unique and unambiguous relationship between the third and fourth sensor signals and the size or diameter of the light beam. Since, on the other hand, the size or diameter of the light beam is dependent on a distance between the object, from which the light beam propagates towards the detector, and the detector itself, i.e. dependent on the longitudinal coordinate of the object, a unique and unambiguous relationship between the first and second sensor signals and the longitudinal co- ordinate z1 between the third and fourth sensor signals and the longitudinal coordinate z2 may exist. Reference e.g. may be made to WO 2014/097181 A1. The predetermined relationship may be determined by analytical considerations, such as by assuming a linear combination of Gaussian light beams, by empirical measurements, such as measurements measuring the first and second sensor signals or a secondary signal derived thereof as a function of the longitudi- nal coordinate of the object, or both.

The combined signal Q and/or the combined signals Q1 and Q2 may be determined by using various means. As an example, a software means for deriving the quotient signal, a hardware means for deriving the quotient signal, or both, may be used and may be implemented in the evaluation device. Thus, the evaluation device, as an example, may comprise at least one di- vider, wherein the divider is configured for deriving the quotient signal. The divider may fully or partially be embodied as one or both of a software divider or a hardware divider.

The evaluation device is adapted to determine the at least one first longitudinal coordinate z1 of the object by evaluating the first combined signal Q1 and/or at least one second longitudinal coordinate z2 of the object by evaluating the second combined signal Q2. As outlined above, in case one or more of the first or second sensor signals is rejected but both of the third and fourth sensor signals fulfill the pre-defined criterion, only the second combined signal Q2 is deter- mined. Thus, in this case the evaluation device may only determine the second longitudinal co- ordinate z2 of the object by evaluating the second combined signal Q2, but the evaluation de- vice may not determine the first longitudinal coordinate z1. Further, as outlined above, in case one or more of the third or fourth sensor signals is rejected but both of the first and second sen- sor signals fulfill the pre-defined criterion, only the first combined signal Q1 is determined. Thus, in this case the evaluation device may only determine the first longitudinal coordinate z1 of the object by evaluating the first combined signal Q1 , but the evaluation device may not determine the second longitudinal coordinate z2. In case all sensor signals of the first, second, third and fourth sensor signals fulfill the pre-defined criterion, both of the first combined signal Q1 and the second combined signal Q2 are determined and the evaluation device may determine both, the first longitudinal coordinate z1 and the second longitudinal coordinate z2. The evaluation device may be adapted to determine a combined longitudinal coordinate, for example, by determining a mean value or by selecting the longitudinal coordinate having lower noise or error.

The evaluation device may be configured to determine the longitudinal coordinate z1 and the longitudinal coordinate z2 by using at least one known, determinable or predetermined relation- ship between the sensor signals and the longitudinal coordinate. In particular, the evaluation device may be configured to determine the longitudinal coordinate z1 of the object by using at least one known, determinable or predetermined relationship between the combined signal de- rived from the first and second sensor signals and the longitudinal coordinate z1. In particular, the evaluation device may be configured to determine the longitudinal coordinate z2 of the ob- ject by using at least one known, determinable or predetermined relationship between the re- spective combined signal derived from the third and fourth sensor signals respectively and the longitudinal coordinate. The known, determinable or predetermined relationship for the determi- nation of the longitudinal coordinate z1 and the longitudinal coordinate z2 may be identical. The predetermined relationship may be one or more of an empiric relationship, a semi-empiric rela- tionship and an analytically derived relationship. The evaluation device may comprise at least one data storage device for storing the predetermined relationship, such as a lookup list or a lookup table.

As outlined above, by evaluating the first and second sensor signals and/or the third and fourth sensor signals, the detector may be enabled to determine the at least one longitudinal coordi- nate of the object, including the option of determining the longitudinal coordinate of the whole object or of one or more parts thereof. In addition, however, other coordinates of the object, in- cluding one or more transversal coordinates and/or rotational coordinates, may be determined by the detector, specifically by the evaluation device. The position of the center of the light spot may be extrapolated and/or estimated from one of the filtered areas. The center of the light spot may not be identical to the center of intensity. In particular, the evaluation device may be adapted to determine from the transversal position of the light spot on the matrix of the CCD and/or the CMOS pixelated sensors a transversal coordinate of the object and/or of parts there- of. The transversal coordinate may be used to verify and/or enhance the quality of the distance information. Additionally or alternatively, as an example, one or more additional transversal sensors may be used for determining at least one transversal coordinate of the object. Various transversal sensors are generally known in the art, such as the transversal sensors disclosed in WO 2014/097181 A1 and/or other position-sensitive devices (PSDs), such as quadrant diodes, CCD or CMOS chips or the like. These devices may generally also be implemented into the detector according to the present invention. As an example, a part of the light beam may be split off within the detector, by at least one beam splitting element. The split-off portion, as an exam- pie, may be guided towards a transversal sensor, such as a CCD or CMOS chip or a camera sensor, and a transversal position of a light spot generated by the split-off portion on the trans- versal sensor may be determined, thereby determining at least one transversal coordinate of the object. Consequently, the detector according to the present invention may either be a one- dimensional detector, such as a simple distance measurement device, or may be embodied as a two-dimensional detector or even as a three-dimensional detector. Further, as outlined above or as outlined in further detail below, by scanning a scenery or an environment in a one- dimensional fashion, a three-dimensional image may also be created. Consequently, the detec- tor according to the present invention specifically may be one of a one-dimensional detector, a two-dimensional detector or a three-dimensional detector. The evaluation device may further be configured to determine at least one transversal coordinate x, y of the object. The detector may be configured for evaluating a single light beam or a plurality of light beams.

In case a plurality of light beams propagates from the object to the detector, means for distin- guishing the light beams may be provided. Thus, the light beams may have different spectral properties, and the detector may comprise one or more wavelength selective elements for dis tinguishing the different light beams. Each of the light beams may then be evaluated inde- pendently. The wavelength selective elements, as an example, may be or may comprise one or more filters, one or more prisms, one or more gratings, one or more dichroitic mirrors or arbi trary combinations thereof. Further, additionally or alternatively, for distinguishing two or more light beams, the light beams may be modulated in a specific fashion. Thus, as an example, the light beams may be frequency modulated, and the sensor signals may be demodulated in order to distinguish partially the sensor signals originating from the different light beams, in accord- ance with their demodulation frequencies. These techniques generally are known to the skilled person in the field of high-frequency electronics. Generally, the evaluation device may be con- figured for distinguishing different light beams having different modulations.

The evaluating of the sensor signals may comprise at least one background correction, wherein the sensor signals are corrected for background brightness. In case the object is surrounded by a homogenous background, e.g. the object is located in front of or on a white wall, the neutral- density filter may reduce brightness of the background homogeneously. In particular, the reduc- tion may not differ or vary locally. Thus, the evaluation device may be adapter to determine background brightness as follows. A total measured intensity of the part of the light spot includ- ing the background having passed through the first filter region may be

4 = 4 + c,

wherein c is the intensity of the background and h is the intensity of the light spot originating from the part of the incident light beam having passed through the first filter region without background. A total measured intensity of the part of the light spot including the background having passed through the second filter region may be

4 ⁼ / ₂ + c,

wherein l ₂ is the intensity of the light spot originating from the part of the incident light beam having passed through the second filter region without background. Furthermore, the first filter region may reduce the intensity of the incident light beam by g1 and the second filter region may reduce the intensity of the incident light beam by y2, such that 4T ₂ = I ₂ Yi- For example, the second filter region may maintain the intensity such that g2 may be 1 and 4 = Ti· By in- serting this relation in the formulae for and T ₂ above h , l ₂ and c may be calculated. The evalu- ation device may be adapted to subtract the determined background value c from the sensor signals before determining the combined signal Q and/or the combined signals Q1 and/or Q2. Thus allows enhancing a contrast and determining of the longitudinal coordinate with enhanced accuracy.

The background correction may allow using overamplified signals for determining of the com- bined signal Q and/or the combined signals Q1 and/or Q2. In case of overamplified signals a non-reliable intensity value may be determined and the relation 4T ₂ = hYi may not hold true. The filter element may be configured to generate three or more filter regions having different gray values. For example, the detector may comprise two or more neutral-density filters having different optical density. For example, the light spot may comprise two sections originating from the parts of the incident light beam having passed the first and the second filter region and gen- erating non-overamplified signals. As described above, by using two of the filter regions the background value c and a value for the spot intensity may be determined. In case in a third sec- tion of the light spot originating from the part of the incident light beam having passed a third filter region overamplified signals are generated it is possible to determine from the known spot intensity by using the known scaling of the unknown third intensity value such as by using the known attenuation properties of the neutral density filters. Thus, it may be possible to use the whole spot for determining the combined signal Q and/or the combined signals or to adjust the exposure times.

As outlined above, the detector may further comprise one or more additional elements such as one or more additional optical elements. Further, the detector may fully or partially be integrated into at least one housing.

The distance measurement by using the detector according to the present invention may be enhanced by implementing one or more additional distance measurement means into the detec- tor and/or by combining the detector with other types of distance measurement means. Thus, as an example, the detector may comprise or may be combined with at least one triangulation dis- tance measurement device. Thus, the distance measurement can be enhanced by making use of a combination of the measurement principle discussed above and a triangulation type dis tance measurement. Further, means for measuring one or more other coordinates, such as x- and/or y-coordinates, may be provided.

In a further aspect of the present invention, a detector system for determining a position of at least one object is disclosed. The detector system comprises at least one detector according to the present invention, such as according to one or more of the embodiments disclosed above or according to one or more of the embodiments disclosed in further detail below. The detector system further comprises at least one beacon device adapted to direct at least one light beam towards the detector, wherein the beacon device is at least one of attachable to the object, holdable by the object and integratable into the object. Further details regarding the beacon device will be given below, including potential embodiments thereof. Thus, the at least one bea- con device may be or may comprise at least one active beacon device, comprising one or more illumination sources such as one or more light sources like lasers, LEDs, light bulbs or the like. As an example, the light emitted by the illumination source may have a wavelength of 300-500 nm. Alternatively, as outlined above, the infrared spectral range may be used, such as in the range of 780 nm to 3.0 pm. Specifically, the near infrared region where silicon photodiodes are applicable specifically in the range of 700 nm to 1000 nm may be used. The light emitted by the one or more beacon devices may be non-modulated or may be modulated, as outlined above, in order to distinguish two or more light beams. Additionally or alternatively, the at least one beacon device may be adapted to reflect one or more light beams towards the detector, such as by comprising one or more reflective elements. Further, the at least one beacon device may be or may comprise one or more scattering elements adapted for scattering a light beam. Therein, elastic or inelastic scattering may be used. In case the at least one beacon device is adapted to reflect and/or scatter a primary light beam towards the detector, the beacon device may be adapted to leave the spectral properties of the light beam unaffected or, alternatively, may be adapted to change the spectral properties of the light beam, such as by modifying a wavelength of the light beam.

In a further aspect of the present invention, a human-machine interface for exchanging at least one item of information between a user and a machine is disclosed. The human-machine inter- face comprises at least one detector system according to the embodiments disclosed above and/or according to one or more of the embodiments disclosed in further detail below. Therein, the at least one beacon device is adapted to be at least one of directly or indirectly attached to the user or held by the user. The human-machine interface is designed to determine at least one position of the user by means of the detector system, wherein the human-machine interface is designed to assign to the position at least one item of information.

In a further aspect of the present invention, an entertainment device for carrying out at least one entertainment function is disclosed. The entertainment device comprises at least one human- machine interface according to the embodiment disclosed above and/or according to one or more of the embodiments disclosed in further detail below. The entertainment device is config- ured to enable at least one item of information to be input by a player by means of the human- machine interface. The entertainment device is further configured to vary the entertainment function in accordance with the information.

In a further aspect of the present invention, a tracking system for tracking a position of at least one movable object is disclosed. The tracking system comprises at least one detector system according to one or more of the embodiments referring to a detector system as disclosed above and/or as disclosed in further detail below. The tracking system further comprises at least one track controller. The track controller is adapted to track a series of positions of the object at spe- cific points in time.

In a further aspect of the present invention, a camera for imaging at least one object is dis- closed. The camera comprises at least one detector according to any one of the embodiments referring to a detector as disclosed above or as disclosed in further detail below.

In a further aspect of the present invention, a readout device for optical storage media is pro- posed. The readout device comprises at least one detector according to any one of the preced- ing embodiments referring to a detector. As used therein, a readout device for optical storage media generally refers to a device which is capable of optically retrieving information stored in optical storage media such as optical storage discs, e.g. CCD, DVD or Blu-ray discs. Thus, the above-described measurement principle of the detector according to the present invention may be used for detecting data modules within an optical storage medium such as in optical storage discs. As an example, in case a reflective data module is present and reflects the illuminating light beam, the detector will not only detect the reflected light beam according to the above- mentioned measurement principle but will also detect a distance between the detector and the reflective data module, i.e. a depth of the reflective data module within the optical storage medi- um. Thus, as an example, the detector may be used for detecting different layers of information modules or data modules within the optical storage medium. Thereby, as an example, two layer discs or three layer discs or even discs having more than three layers may be generated and read out.

In a further aspect of the present invention, a scanning system for determining a depth profile of a scenery, which may also imply determining at least one position of at least one object, is pro- vided. The scanning system comprises at least one detector according to the present invention, such as at least one detector as disclosed in one or more of the embodiments listed above and/or as disclosed in one or more of the embodiments below. The scanning system further comprises at least one illumination source adapted to scan the scenery with at least one light beam, which may also be referred to as an illumination light beam or scanning light beam. As used herein, the term“scenery” generally refers to a two-dimensional or three-dimensional range which is visible by the detector, such that at least one geometric or spatial property of the two-dimensional or three-dimensional range may be evaluated with the detector. As further used herein, the term“scan” generally refers to a consecutive measurement in different regions. Thus, the scanning specifically may imply at least one first measurement with the illumination light beam being oriented or directed in a first fashion, and at least one second measurement with the illumination light beam being oriented or directed in a second fashion which is different from the first fashion. The scanning may be a continuous scanning or a stepwise scanning. Thus, in a continuous or stepwise fashion, the illumination light beam may be directed into dif- ferent regions of the scenery, and the detector may be detected to generate at least one item of information, such as at least one longitudinal coordinate, for each region. As an example, for scanning an object, one or more illumination light beams may, continuously or in a stepwise fashion, create light spots on the surface of the object, wherein longitudinal coordinates are generated for the light spots. Alternatively, however, a light pattern may be used for scanning. The scanning may be a point scanning or a line scanning or even a scanning with more com- plex light patterns. The illumination source of the scanning system may be distinct from the op- tional illumination source of the detector. Alternatively, however, the illumination source of the scanning system may also be fully or partially identical with or integrated into the at least one optional illumination source of the detector.

Thus, the scanning system may comprise at least one illumination source which is adapted to emit the at least one light beam being configured for the illumination of the at least one dot lo- cated at the at least one surface of the at least one object. As used herein, the term“dot” refers to an area, specifically a small area, on a part of the surface of the object which may be select- ed, for example by a user of the scanning system, to be illuminated by the illumination source. Preferably, the dot may exhibit a size which may, on one hand, be as small as possible in order to allow the scanning system to determine a value for the distance between the illumination source comprised by the scanning system and the part of the surface of the object on which the dot may be located as exactly as possible and which, on the other hand, may be as large as possible in order to allow the user of the scanning system or the scanning system itself, in par- ticular by an automatic procedure, to detect a presence of the dot on the related part of the sur- face of the object.

For this purpose, the illumination source may comprise an artificial illumination source, in partic- ular at least one laser source and/or at least one incandescent lamp and/or at least one semi- conductor light source, for example, at least one light-emitting diode, in particular an organic and/or inorganic light-emitting diode. As an example, the light emitted by the illumination source may have a wavelength of 300-500 nm. Additionally or alternatively, light in the infrared spectral range may be used, such as in the range of 780 nm to 3.0 pm. Specifically, the light in the part of the near infrared region where silicon photodiodes are applicable specifically in the range of 700 nm to 1000 nm may be used. On account of their generally defined beam profiles and other properties of handleability, the use of at least one laser source as the illumination source is par- ticularly preferred. Herein, the use of a single laser source may be preferred, in particular in a case in which it may be important to provide a compact scanning system that might be easily storable and transportable by the user. The illumination source may thus, preferably be a con- stituent part of the detector and may, therefore, in particular be integrated into the detector, such as into the housing of the detector. In a preferred embodiment, particularly the housing of the scanning system may comprise at least one display configured for providing distance- related information to the user, such as in an easy-to-read manner. In a further preferred em- bodiment, particularly the housing of the scanning system may, in addition, comprise at least one button which may be configured for operating at least one function related to the scanning system, such as for setting one or more operation modes. In a further preferred embodiment, particularly the housing of the scanning system may, in addition, comprise at least one fastening unit which may be configured for fastening the scanning system to a further surface, such as a rubber foot, a base plate or a wall holder, such as a base plate or holder comprising a magnetic material, in particular for increasing the accuracy of the distance measurement and/or the han- dleability of the scanning system by the user.

Particularly, the illumination source of the scanning system may, thus, emit a single laser beam which may be configured for the illumination of a single dot located at the surface of the object. By using at least one of the detectors according to the present invention at least one item of information about the distance between the at least one dot and the scanning system may, thus, be generated. Hereby, preferably, the distance between the illumination system as comprised by the scanning system and the single dot as generated by the illumination source may be de- termined, such as by employing the evaluation device as comprised by the at least one detec- tor. However, the scanning system may, further, comprise an additional evaluation system which may, particularly, be adapted for this purpose. Alternatively or in addition, a size of the scanning system, in particular of the housing of the scanning system, may be taken into account and, thus, the distance between a specific point on the housing of the scanning system, such as a front edge or a back edge of the housing, and the single dot may, alternatively, be deter- mined. The illumination source may be adapted to generate and/or to project a cloud of points, for example the illumination source may comprise one or more of at least one digital light pro- cessing (DLP) projector, at least one LCoS projector, at least one spatial light modulator; at least one diffractive optical element; at least one array of light emitting diodes; at least one array of laser light sources.

Alternatively, the illumination source of the scanning system may emit two individual laser beams which may be configured for providing a respective angle, such as a right angle, be- tween the directions of an emission of the beams, whereby two respective dots located at the surface of the same object or at two different surfaces at two separate objects may be illuminat- ed. However, other values for the respective angle between the two individual laser beams may also be feasible. This feature may, in particular, be employed for indirect measuring functions, such as for deriving an indirect distance which may not be directly accessible, such as due to a presence of one or more obstacles between the scanning system and the dot or which may otherwise be hard to reach. By way of example, it may, thus, be feasible to determine a value for a height of an object by measuring two individual distances and deriving the height by using the Pythagoras formula. In particular for being able to keep a predefined level with respect to the object, the scanning system may, further, comprise at least one leveling unit, in particular an integrated bubble vial, which may be used for keeping the predefined level by the user.

As a further alternative, the illumination source of the scanning system may emit a plurality of individual laser beams, such as an array of laser beams which may exhibit a respective pitch, in particular a regular pitch, with respect to each other and which may be arranged in a manner in order to generate an array of dots located on the at least one surface of the at least one object. For this purpose, specially adapted optical elements, such as beam-splitting devices and mir- rors, may be provided which may allow a generation of the described array of the laser beams. In particular, the illumination source may be directed to scan an area or a volume by using one or more movable mirrors to redirect the light beam in a periodic or non-periodic fashion.

Thus, the scanning system may provide a static arrangement of the one or more dots placed on the one or more surfaces of the one or more objects. Alternatively, the illumination source of the scanning system, in particular the one or more laser beams, such as the above described array of the laser beams, may be configured for providing one or more light beams which may exhibit a varying intensity over time and/or which may be subject to an alternating direction of emission in a passage of time, in particular by moving one or more mirrors, such as the micro-mirrors comprised within the mentioned array of micro-mirrors. As a result, the illumination source may be configured for scanning a part of the at least one surface of the at least one object as an im- age by using one or more light beams with alternating features as generated by the at least one illumination source of the scanning device. In particular, the scanning system may, thus, use at least one row scan and/or line scan, such as to scan the one or more surfaces of the one or more objects sequentially or simultaneously. Thus, the scanning system may be adapted to measure angles by measuring three or more dots, or the scanning system may be adapted to measure corners or narrow regions such as a gable of a roof, which may be hardly accessible using a conventional measuring stick. As non-limiting examples, the scanning system may be used in safety laser scanners, e.g. in production environments, and/or in 3D-scanning devices as used for determining the shape of an object, such as in connection to 3D-printing, body scanning, quality control, in construction applications, e.g. as range meters, in logistics applica- tions, e.g. for determining the size or volume of a parcel, in household applications, e.g. in ro- botic vacuum cleaners or lawn mowers, or in other kinds of applications which may include a scanning step. As non-limiting examples, the scanning system may be used in industrial safety curtain applications. As non-limiting examples, the scanning system may be used to perform sweeping, vacuuming, mopping, or waxing functions, or yard or garden care functions such as mowing or raking. As non-limiting examples, the scanning system may employ an LED illumina- tion source with collimated optics and may be adapted to shift the frequency of the illumination source to a different frequency to obtain more accurate results and/or employ a filter to attenu- ate certain frequencies while transmitting others. As non-limiting examples, the scanning sys- tem and/or the illumination source may be rotated as a whole or rotating only a particular optics package such as a mirror, beam splitter or the like, using a dedicated motor as such that in op- eration, the scanning system may have a full 360 degree view or even be moved and or rotated out of plane to further increase the scanned area. Further, the illumination source may be ac- tively aimed in a predetermined direction. Further, to allow the rotation of wired electrical sys- tems, slip rings, optical data transmission, or inductive couplings may be employed.

As a non-limiting example, the scanning system may be attached to a tripod and point towards an object or region with a several corners and surfaces. One or more flexibly movable laser sources are attached to the scanning system. The one or more laser sources are moved as such that they illuminate points of interest. The position of the illuminated points with respect to the scanning system is measured when pressing a designated button on the scanning system and the position information is transmitted via a wireless interface to a mobile phone. The posi- tion information is stored in a mobile phone application. The laser sources are moved to illumi nate further points of interest the position of which are measured and transmitted to the mobile phone application. The mobile phone application may transform the set of points into a 3d mod- el by connecting adjacent points with planar surfaces. The 3d model may be stored and pro- cessed further. The distances and or angles between the measured points or surfaces may be displayed directly on a display attached to a scanning system or on the mobile phone to which the position information is transmitted.

As a non-limiting example, a scanning system may comprise two or more flexible movable laser sources to project points and further one movable laser source projecting a line. The line may be used to arrange the two or more laser spots along a line and the display of the scanning de- vice may display the distance between the two or more laser spots that may be arranged along the line, such as at equal distance. In the case of two laser spots, a single laser source may be used whereas the distance of the projected points is modified using one or more beam-splitters or prisms, where a beam-splitter or prism can be moved as such that the projected laser spots move apart or closer together. Further, the scanning system may be adapted to project further patterns such as a right angle, a circle, a square, a triangle, or the like, along which a meas- urement can be done by projecting laser spots and measuring their position. As a non-limiting example, the scanning system may be adapted as a line scanning device. In particular, the scanning device may comprise at least one sensor line or row. Triangulation sys- tems require a sufficient baseline such that in the near filed no detection may be possible. Near field detection may be possible if the laser spot is tilted in direction of the transfer device. How- ever, the tilting leads to that the light spot will move out of the field of view which limits detection in far field regions. These near field and far field problems can be overcome by using the detec- tor according to the present invention. In particular, the detector may comprise a CMOS line of optical sensors. The scanning system may be adapted to detect a plurality of light beams prop- agating from the object to the detector on the CMOS line. The light beams may be generated at different positions on the object or by movement of the illumination source. The scanning sys- tem may be adapted to determine at least one longitudinal coordinate for each of the light points by determining the quotient signal Q as described above and in more detail below.

As a non-limiting example, the scanning system may be adapted to support the work with tools, such as wood or metal processing tools, such as a saw, a driller, or the like. Thus, the scanning system may be adapted to measure the distance in two opposite directions and display the two measured distances or the sum of the distances in a display. Further, the scanning system may be adapted to measure the distance to the edge of a surface as such that when the scanning system is placed on the surface, a laser point is moved automatically away from the scanning system along the surface, until the distance measurement shows a sudden change due to a corner or the edge of a surface. This makes it possible to measure the distance of the end of a wood plank while the scanning device is placed on the plank but remote from its end. Further, the scanning system may measure the distance of the end of a plank in one direction and pro- ject a line or circle or point in a designated distance in the opposite direction. The scanning sys- tem may be adapted to project the line or circle or point in a distance depending on the distance measured in the opposite direction such as depending on a predetermined sum distance. This allows working with a tool such as a saw or driller at the projected position while placing the scanning system in a safe distance from the tool and simultaneously perform a process using the tool in a predetermined distance to the edge of the plank. Further, the scanning system may be adapted to project points or lines or the like in two opposite directions in a predetermined distance. When the sum of the distances is changed, only one of the projected distances changes.

As a non-limiting example, the scanning system may be adapted to be placed onto a surface, such as a surface on which a task is performed, such as cutting, sawing, drilling, or the like, and to project a line onto the surface in a predetermined distance that can be adjusted such as with buttons on the scanning device.

As non-limiting examples, the scanning system may be used in safety laser scanners, e.g. in production environments, and/or in 3D-scanning devices as used for determining the shape of an object, such as in connection to 3D-printing, body scanning, quality control, in construction applications, e.g. as range meters, in logistics applications, e.g. for determining the size or vol- ume of a parcel, in household applications, e.g. in robotic vacuum cleaners or lawn mowers, or in other kinds of applications which may include a scanning step.

The transfer device can, as explained above, be designed to feed light propagating from the object to the detector to the optical sensor, preferably successively. As explained above, this feeding can optionally be effected by means of imaging or else by means of non-imaging prop- erties of the transfer device. In particular the transfer device can also be designed to collect the electromagnetic radiation before the latter is fed to the optical sensor. The transfer device can also be wholly or partly a constituent part of at least one optional illumination source, for exam- pie by the illumination source being designed to provide a light beam having defined optical properties, for example having a defined or precisely known beam profile, for example at least one linear combination of Gaussian beams, in particular at least one laser beam having a known beam profile.

The beacon devices and/or the at least one optional illumination source generally may emit light in at least one of: the ultraviolet spectral range, preferably in the range of 200 nm to 380 nm; the visible spectral range (380 nm to 780 nm); the infrared spectral range, preferably in the range of 780 nm to 3.0 micrometers, more preferably in the part of the near infrared region where silicon photodiodes are applicable specifically in the range of 700 nm to 1000 nm. For thermal imaging applications the target may emit light in the far infrared spectral range, preferably in the range of 3.0 micrometers to 20 micrometers. For example, the at least one illumination source is adapted to emit light in the visible spectral range, preferably in the range of 500 nm to 780 nm, most preferably at 650 nm to 750 nm or at 690 nm to 700 nm. For example, the at least one illumina- tion source is adapted to emit light in the infrared spectral range. Other options, however, are feasible.

The feeding of the light beam to the optical sensor can be effected in particular in such a way that a light spot, for example having a round, oval or differently configured cross section, is pro- duced on the optional sensor area of the optical sensor. By way of example, the detector can have a visual range, in particular a solid angle range and/or spatial range, within which objects can be detected. Preferably, the transfer device may be designed in such a way that the light spot, for example in the case of an object arranged within a visual range of the detector, is ar- ranged completely on a sensor region and/or on a sensor area of the optical sensor. By way of example, a sensor area can be chosen to have a corresponding size in order to ensure this condition.

In a further aspect, the present invention discloses a method for determining a position of at least one object by using a detector, such as a detector according to the present invention, such as according to one or more of the embodiments referring to a detector as disclosed above or as disclosed in further detail below. Still, other types of detectors may be used. The method comprises the following method steps, wherein the method steps may be performed in the given order or may be performed in a different order. Further, one or more additional method steps may be present which are not listed. Further, one, more than one or even all of the method steps may be performed repeatedly.

The method comprises the following method steps:

illuminating at least one sensor element of the detector with the at least one incident light beam propagating from the object to the detector, the sensor element having a matrix of optical sensors, the optical sensors each having a light-sensitive area, wherein each optical sensor generates at least one sensor signal in response to the illumination,

wherein the incident light beam passes through at least one filter element and at least one transfer device before impinging on the sensor element, wherein the filter ele- ment is configured such that in at least one first filter region and in at least one sec- ond filter region at least one property of the incident light beam is modified differently; evaluating the sensor signals, by evaluating at least one first sensor signal and at least one second sensor signal, wherein the first sensor signal is generated in re- sponse to illumination having passed through the first filter region and the second sensor signal is generated in response to illumination having passed through the first and/or second filter region, and wherein the evaluation comprises determining at least one longitudinal coordinate z of the object by evaluating a combined signal Q from the first sensor signal and the second sensor signal.

The evaluating may comprise

i) determining at least two optical sensors being illuminated by the incident light beam having passed through the first filter region, determining therefrom at least one first op- tical sensor and at least one second optical sensor, wherein the first optical sensor has the sensor signal comprising at least one information of at least one first area of a beam profile of the incident light beam and the second optical sensor has the sensor signal comprising at least one information of at least one second area of the beam profile of the incident light beam, wherein at least one first sensor signal and at least one second sensor signal are formed from the sensor signal of the first optical sensor and the sen- sor signal of the second optical sensor, respectively;

ii) determining at least two optical sensors being illuminated by the incident light beam having passed through the second filter region, determining therefrom at least one third optical sensor and at least one fourth optical sensor, wherein the third optical sensor has the sensor signal comprising at least one information of the first area of the beam profile of the incident light beam and the fourth optical sensor has the sensor signal comprising at least one information of the second area of the beam profile of the inci dent light beam, wherein at least one third sensor signal and at least one fourth sensor signal are formed from the sensor signal of the third optical sensor and the sensor sig- nal of the fourth optical sensor, respectively;

iii) determining, in case both of the first sensor signal and the second sensor signal fulfill at least one pre-defined criterion, at least one first combined signal Q1 by combining the first sensor signal and the second sensor signal and/or determining, in case both of the third sensor signal and the fourth sensor signal fulfill the at least one pre-defined criteri- on, at least one second combined sensor signal Q2 by combining the third sensor sig nal and the fourth sensor signal; and

iv) determining at least one first longitudinal coordinate z1 of the object by evaluating the first combined signal Q1 and/or at least one second longitudinal coordinate z2 of the ob- ject by evaluating the second combined signal Q2.

For details, options and definitions, reference may be made to the detector as discussed above. Thus, specifically, as outlined above, the method may comprise using the detector according to the present invention, such as according to one or more of the embodiments given above or given in further detail below.

In a further aspect of the present invention, use of the detector according to the present inven- tion, such as according to one or more of the embodiments given above or given in further detail below, is proposed, for a purpose of use, selected from the group consisting of: a position measurement in traffic technology; an entertainment application; an optical data storage appli cation; a security application; a surveillance application; a safety application; a human-machine interface application; a tracking application; a photography application; an imaging application or camera application; a mapping application for generating maps of at least one space; a hom- ing or tracking beacon detector for vehicles; a machine vision application; a robotics application; a quality control application; a manufacturing application.

The object generally may be a living or non-living object. The detector or the detector system even may comprise the at least one object, the object thereby forming part of the detector sys- tem. Preferably, however, the object may move independently from the detector, in at least one spatial dimension. The object generally may be an arbitrary object. In one embodiment, the ob- ject may be a rigid object. Other embodiments are feasible, such as embodiments in which the object is a non-rigid object or an object which may change its shape.

As will be outlined in further detail below, the present invention may specifically be used for tracking positions and/or motions of a person, such as for the purpose of controlling machines, gaming or simulation of sports. In this or other embodiments, specifically, the object may be selected from the group consisting of: an article of sports equipment, preferably an article se- lected from the group consisting of a racket, a club, a bat; an article of clothing; a hat; a shoe.

Thus, generally, the devices according to the present invention, such as the detector, may be applied in various fields of uses. Specifically, the detector may be applied for a purpose of use, selected from the group consisting of: a position measurement in traffic technology; an enter- tainment application; a security application; a human-machine interface application; a tracking application; a photography application; a mapping application for generating maps of at least one space, such as at least one space selected from the group of a room, a building and a street; a mobile application; a webcam; an audio device; a dolby surround audio system; a computer peripheral device; a gaming application; a camera or video application; a security ap- plication; a surveillance application; an automotive application; a transport application; a medi- cal application; a sports’ application; a machine vision application; a vehicle application; an air- plane application; a ship application; a spacecraft application; a building application; a construc- tion application; a cartography application; a manufacturing application. Additionally or alterna- tively, applications in local and/or global positioning systems may be named, especially land- mark-based positioning and/or navigation, specifically for use in cars or other vehicles (such as trains, motorcycles, bicycles, trucks for cargo transportation), robots or for use by pedestrians. Further, indoor positioning systems may be named as potential applications, such as for house- hold applications and/or for robots used in manufacturing, logistics, surveillance, or mainte- nance technology.

The devices according to the present invention may be used in mobile phones, tablet comput- ers, laptops, smart panels or other stationary or mobile or wearable computer or communication applications. Thus, the devices according to the present invention may be combined with at least one active light source, such as a light source emitting light in the visible range or infrared spectral range, in order to enhance performance. Thus, as an example, the devices according to the present invention may be used as cameras and/or sensors, such as in combination with mobile software for scanning and/or detecting environment, objects and living beings. The de- vices according to the present invention may even be combined with 2D cameras, such as con- ventional cameras, in order to increase imaging effects. The devices according to the present invention may further be used for surveillance and/or for recording purposes or as input devices to control mobile devices, especially in combination with voice and/or gesture recognition. Thus, specifically, the devices according to the present invention acting as human-machine interfaces, also referred to as input devices, may be used in mobile applications, such as for controlling other electronic devices or components via the mobile device, such as the mobile phone. As an example, the mobile application including at least one device according to the present invention may be used for controlling a television set, a game console, a music player or music device or other entertainment devices.

Further, the devices according to the present invention may be used in webcams or other pe- ripheral devices for computing applications. Thus, as an example, the devices according to the present invention may be used in combination with software for imaging, recording, surveil- lance, scanning or motion detection. As outlined in the context of the human-machine interface and/or the entertainment device, the devices according to the present invention are particularly useful for giving commands by facial expressions and/or body expressions. The devices accord- ing to the present invention can be combined with other input generating devices like e.g.

mouse, keyboard, touchpad, microphone etc. Further, the devices according to the present in- vention may be used in applications for gaming, such as by using a webcam. Further, the de- vices according to the present invention may be used in virtual training applications and/or video conferences. Further, devices according to the present invention may be used to recognize or track hands, arms, or objects used in a virtual or augmented reality application, especially when wearing head-mounted displays. Further, the devices according to the present invention may be used in mobile audio devices, television devices and gaming devices, as partially explained above. Specifically, the devices according to the present invention may be used as controls or control devices for electronic de- vices, entertainment devices or the like. Further, the devices according to the present invention may be used for eye detection or eye tracking, such as in 2D- and 3D-display techniques, espe- cially with transparent displays for augmented reality applications and/or for recognizing wheth- er a display is being looked at and/or from which perspective a display is being looked at. Fur- ther, devices according to the present invention may be used to explore a room, boundaries, obstacles, in connection with a virtual or augmented reality application, especially when wearing a head-mounted display.

Further, the devices according to the present invention may be used in or as digital cameras such as DSC cameras and/or in or as reflex cameras such as SLR cameras. For these applica- tions, reference may be made to the use of the devices according to the present invention in mobile applications such as mobile phones, as disclosed above.

Further, the devices according to the present invention may be used for security or surveillance applications. Thus, as an example, at least one device according to the present invention can be combined with one or more digital and/or analogue electronics that will give a signal if an object is within or outside a predetermined area (e.g. for surveillance applications in banks or museums). Specifically, the devices according to the present invention may be used for optical encryption. Detection by using at least one device according to the present invention can be combined with other detection devices to complement wavelengths, such as with IR, x-ray, UV- VIS, radar or ultrasound detectors. The devices according to the present invention may further be combined with an active infrared light source to allow detection in low light surroundings. The devices according to the present invention are generally advantageous as compared to active detector systems, specifically since the devices according to the present invention avoid actively sending signals which may be detected by third parties, as is the case e.g. in radar applications, ultrasound applications, LIDAR or similar active detector devices. Thus, generally, the devices according to the present invention may be used for an unrecognized and undetectable tracking of moving objects. Additionally, the devices according to the present invention generally are less prone to manipulations and irritations as compared to conventional devices.

Further, given the ease and accuracy of 3D detection by using the devices according to the pre- sent invention, the devices according to the present invention generally may be used for facial, body and person recognition and identification. Therein, the devices according to the present invention may be combined with other detection means for identification or personalization pur- poses such as passwords, finger prints, iris detection, voice recognition or other means. Thus, generally, the devices according to the present invention may be used in security devices and other personalized applications.

Further, the devices according to the present invention may be used as 3D barcode readers for product identification. In addition to the security and surveillance applications mentioned above, the devices according to the present invention generally can be used for surveillance and monitoring of spaces and areas. Thus, the devices according to the present invention may be used for surveying and monitoring spaces and areas and, as an example, for triggering or executing alarms in case prohibited areas are violated. Thus, generally, the devices according to the present invention may be used for surveillance purposes in building surveillance or museums, optionally in com- bination with other types of sensors, such as in combination with motion or heat sensors, in combination with image intensifiers or image enhancement devices and/or photomultipliers. Further, the devices according to the present invention may be used in public spaces or crowd- ed spaces to detect potentially hazardous activities such as commitment of crimes such as theft in a parking lot or unattended objects such as unattended baggage in an airport.

Further, the devices according to the present invention may advantageously be applied in cam- era applications such as video and camcorder applications. Thus, the devices according to the present invention may be used for motion capture and 3D-movie recording. Therein, the devices according to the present invention generally provide a large number of advantages over con- ventional optical devices. Thus, the devices according to the present invention generally require a lower complexity with regard to optical components. Thus, as an example, the number of lenses may be reduced as compared to conventional optical devices, such as by providing the devices according to the present invention having one lens only. Due to the reduced complexity, very compact devices are possible, such as for mobile use. Conventional optical systems hav- ing two or more lenses with high quality generally are voluminous, such as due to the general need for voluminous beam-splitters. Further, the devices according to the present invention generally may be used for focus/autofocus devices, such as autofocus cameras. Further, the devices according to the present invention may also be used in optical microscopy, especially in confocal microscopy.

Further, the devices according to the present invention generally are applicable in the technical field of automotive technology and transport technology. Thus, as an example, the devices ac- cording to the present invention may be used as distance and surveillance sensors, such as for adaptive cruise control, emergency brake assist, lane departure warning, surround view, blind spot detection, traffic sign detection, traffic sign recognition, lane recognition, rear cross traffic alert, light source recognition for adapting the head light intensity and range depending on ap- proaching traffic or vehicles driving ahead, adaptive frontlighting systems, automatic control of high beam head lights, adaptive cut-off lights in front light systems, glare-free high beam front lighting systems, marking animals, obstacles, or the like by headlight illumination, rear cross traffic alert, and other driver assistance systems such as advanced driver assistance systems, or other automotive and traffic applications. Further, devices according to the present invention may be used in driver assistance systems anticipating maneuvers of the driver beforehand for collision avoidance or the like. Further, the devices according to the present invention can also be used for velocity and/or acceleration measurements, such as by analyzing a first and second time-derivative of position information gained by using the detector according to the present invention. This feature generally may be applicable in automotive technology, transportation technology or general traffic technology. Applications in other fields of technology are feasible.

A specific application in an indoor positioning system may be the detection of positioning of passengers in transportation, more specifically to electronically control the use of safety sys- tems such as airbags. The use of an airbag may be prevented in case the passenger is located as such, that the use of an airbag will cause a severe injury. Further, in vehicles such as cars, trains, planes or the like, especially in autonomous vehicles, devices according to the present invention may be used to determine whether a driver pays attention to the traffic or is distracted, or asleep, or tired, or incapable of driving such as due to the consumption of alcohol or the like.

In these or other applications, generally, the devices according to the present invention may be used as standalone devices or in combination with other sensor devices, such as in combina- tion with radar and/or ultrasonic devices. Specifically, the devices according to the present in- vention may be used for autonomous driving and safety issues. Further, in these applications, the devices according to the present invention may be used in combination with infrared sen- sors, radar sensors, which are sonic sensors, two-dimensional cameras or other types of sen- sors. In these applications, the generally passive nature of the devices according to the present invention is advantageous. Thus, since the devices according to the present invention generally do not require emitting signals, the risk of interference of active sensor signals with other signal sources may be avoided. The devices according to the present invention specifically may be used in combination with recognition software, such as standard image recognition software. Thus, signals and data as provided by the devices according to the present invention typically are readily processable and, therefore, generally require lower calculation power than estab- lished 3D measurement systems. Given the low space demand, the devices according to the present invention such as cameras may be placed at virtually any place in a vehicle, such as on or behind a window screen, on a front hood, on bumpers, on lights, on mirrors or other places and the like. Various detectors according to the present invention such as one or more detec- tors based on the effect disclosed within the present invention can be combined, such as in or- der to allow autonomously driving vehicles or in order to increase the performance of active safety concepts. Thus, various devices according to the present invention may be combined with one or more other devices according to the present invention and/or conventional sensors, such as in the windows like rear window, side window or front window, on the bumpers or on the lights.

A combination of at least one device according to the present invention such as at least one detector according to the present invention with one or more rain detection sensors is also pos- sible. This is due to the fact that the devices according to the present invention generally are advantageous over conventional sensor techniques such as radar, specifically during heavy rain. A combination of at least one device according to the present invention with at least one conventional sensing technique such as radar may allow for a software to pick the right combi- nation of signals according to the weather conditions.

Further, the devices according to the present invention generally may be used as break assist and/or parking assist and/or for speed measurements. Speed measurements can be integrated in the vehicle or may be used outside the vehicle, such as in order to measure the speed of other cars in traffic control. Further, the devices according to the present invention may be used for detecting free parking spaces in parking lots.

Further, the devices according to the present invention may be used in the fields of medical sys- tems and sports. Thus, in the field of medical technology, surgery robotics, e.g. for use in endo- scopes, may be named, since, as outlined above, the devices according to the present inven- tion may require a low volume only and may be integrated into other devices. Specifically, the devices according to the present invention having one lens, at most, may be used for capturing 3D information in medical devices such as in endoscopes. Further, the devices according to the present invention may be combined with an appropriate monitoring software, in order to enable tracking and analysis of movements. This may allow an instant overlay of the position of a med- ical device, such as an endoscope or a scalpel, with results from medical imaging, such as ob- tained from magnetic resonance imaging, x-ray imaging, or ultrasound imaging. These applica- tions are specifically valuable e.g. in medical treatments where precise location information is important such as in brain surgery and long-distance diagnosis and tele-medicine. Further, the devices according to the present invention may be used in 3D-body scanning. Body scanning may be applied in a medical context, such as in dental surgery, plastic surgery, bariatric sur- gery, or cosmetic plastic surgery, or it may be applied in the context of medical diagnosis such as in the diagnosis of myofascial pain syndrome, cancer, body dysmorphic disorder, or further diseases. Body scanning may further be applied in the field of sports to assess ergonomic use or fit of sports equipment. Further, the devices according to the present invention may be used in wearable robots such as in exoskeletons or prosthesis or the like.

Body scanning may further be used in the context of clothing, such as to determine a suitable size and fitting of clothes. This technology may be used in the context of tailor-made clothes or in the context of ordering clothes or shoes from the internet or at a self-service shopping device such as a micro kiosk device or customer concierge device. Body scanning in the context of clothing is especially important for scanning fully dressed customers.

Further, the devices according to the present invention may be used in the context of people counting systems, such as to count the number of people in an elevator, a train, a bus, a car, or a plane, or to count the number of people passing a hallway, a door, an aisle, a retail store, a stadium, an entertainment venue, a museum, a library, a public location, a cinema, a theater, or the like. Further, the 3D-function in the people counting system may be used to obtain or esti mate further information about the people that are counted such as height, weight, age, physical fitness, or the like. This information may be used for business intelligence metrics, and/or for further optimizing the locality where people may be counted to make it more attractive or safe.

In a retail environment, the devices according to the present invention in the context of people counting may be used to recognize returning customers or cross shoppers, to assess shopping behavior, to assess the percentage of visitors that make purchases, to optimize staff shifts, or to monitor the costs of a shopping mall per visitor. Further, people counting systems may be used for anthropometric surveys. Further, the devices according to the present invention may be used in public transportation systems for automatically charging passengers depending on the length of transport. Further, the devices according to the present invention may be used in play- grounds for children, to recognize injured children or children engaged in dangerous activities, to allow additional interaction with playground toys, to ensure safe use of playground toys or the like.

Further the devices according to the present invention may be used in construction tools, such as a range meter that determines the distance to an object or to a wall, to assess whether a surface is planar, to align objects or place objects in an ordered manner, or in inspection cam- eras for use in construction environments or the like.

Further, the devices according to the present invention may be applied in the field of sports and exercising, such as for training, remote instructions or competition purposes. Specifically, the devices according to the present invention may be applied in the fields of dancing, aerobic, football, soccer, basketball, baseball, cricket, hockey, track and field, swimming, polo, handball, volleyball, rugby, sumo, judo, fencing, boxing, golf, car racing, laser tag, battlefield simulation etc. The devices according to the present invention can be used to detect the position of a ball, a bat, a sword, motions, etc., both in sports and in games, such as to monitor the game, support the referee or for judgment, specifically automatic judgment, of specific situations in sports, such as for judging whether a point or a goal actually was made.

Further, the devices according to the present invention may be used in the field of auto racing or car driver training or car safety training or the like to determine the position of a car or the track of a car, or the deviation from a previous track or an ideal track or the like.

The devices according to the present invention may further be used to support a practice of mu- sical instruments, in particular remote lessons, for example lessons of string instruments, such as fiddles, violins, violas, celli, basses, harps, guitars, banjos, or ukuleles, keyboard instru- ments, such as pianos, organs, keyboards, harpsichords, harmoniums, or accordions, and/or percussion instruments, such as drums, timpani, marimbas, xylophones, vibraphones, bongos, congas, timbales, djembes or tablas.

The devices according to the present invention further may be used in rehabilitation and physio- therapy, in order to encourage training and/or in order to survey and correct movements. There- in, the devices according to the present invention may also be applied for distance diagnostics.

Further, the devices according to the present invention may be applied in the field of machine vision. Thus, one or more of the devices according to the present invention may be used e.g. as a passive controlling unit for autonomous driving and or working of robots. In combination with moving robots, the devices according to the present invention may allow for autonomous movement and/or autonomous detection of failures in parts. The devices according to the pre- sent invention may also be used for manufacturing and safety surveillance, such as in order to avoid accidents including but not limited to collisions between robots, production parts and living beings. In robotics, the safe and direct interaction of humans and robots is often an issue, as robots may severely injure humans when they are not recognized. Devices according to the present invention may help robots to position objects and humans better and faster and allow a safe interaction. Given the passive nature of the devices according to the present invention, the devices according to the present invention may be advantageous over active devices and/or may be used complementary to existing solutions like radar, ultrasound, 2D cameras, IR detec- tion etc. One particular advantage of the devices according to the present invention is the low likelihood of signal interference. Therefore multiple sensors can work at the same time in the same environment, without the risk of signal interference. Thus, the devices according to the present invention generally may be useful in highly automated production environments like e.g. but not limited to automotive, mining, steel, etc. The devices according to the present invention can also be used for quality control in production, e.g. in combination with other sensors like 2-D imaging, radar, ultrasound, IR etc., such as for quality control or other purposes. Further, the devices according to the present invention may be used for assessment of surface quality, such as for surveying the surface evenness of a product or the adherence to specified dimensions, from the range of micrometers to the range of meters. Other quality control applications are fea- sible. In a manufacturing environment, the devices according to the present invention are espe- cially useful for processing natural products such as food or wood, with a complex 3- dimensional structure to avoid large amounts of waste material. Further, devices according to the present invention may be used to monitor the filling level of tanks, silos etc. Further, devices according to the present invention may be used to inspect complex products for missing parts, incomplete parts, loose parts, low quality parts, or the like, such as in automatic optical inspec- tion, such as of printed circuit boards, inspection of assemblies or sub-assemblies, verification of engineered components, engine part inspections, wood quality inspection, label inspections, inspection of medical devices, inspection of product orientations, packaging inspections, food pack inspections, or the like.

Further, the devices according to the present invention may be used in vehicles, trains, air- planes, ships, spacecraft and other traffic applications. Thus, besides the applications men- tioned above in the context of traffic applications, passive tracking systems for aircraft, vehicles and the like may be named. The use of at least one device according to the present invention, such as at least one detector according to the present invention, for monitoring the speed and/or the direction of moving objects is feasible. Specifically, the tracking of fast moving ob- jects on land, sea and in the air including space may be named. The at least one device accord- ing to the present invention, such as the at least one detector according to the present inven- tion, specifically may be mounted on a still-standing and/or on a moving device. An output sig nal of the at least one device according to the present invention can be combined e.g. with a guiding mechanism for autonomous or guided movement of another object. Thus, applications for avoiding collisions or for enabling collisions between the tracked and the steered object are feasible. The devices according to the present invention generally are useful and advantageous due to the low calculation power required, the instant response and due to the passive nature of the detection system which generally is more difficult to detect and to disturb as compared to active systems, like e.g. radar. The devices according to the present invention are particularly useful but not limited to e.g. speed control and air traffic control devices. Further, the devices according to the present invention may be used in automated tolling systems for road charges.

The devices according to the present invention generally may be used in passive applications. Passive applications include guidance for ships in harbors or in dangerous areas, and for air- craft when landing or starting. Wherein, fixed, known active targets may be used for precise guidance. The same can be used for vehicles driving on dangerous but well defined routes, such as mining vehicles. Further, the devices according to the present invention may be used to detect rapidly approaching objects, such as cars, trains, flying objects, animals, or the like. Fur- ther, the devices according to the present invention can be used for detecting velocities or ac- celerations of objects, or to predict the movement of an object by tracking one or more of its position, speed, and/or acceleration depending on time.

Further, as outlined above, the devices according to the present invention may be used in the field of gaming. Thus, the devices according to the present invention can be passive for use with multiple objects of the same or of different size, color, shape, etc., such as for movement detection in combination with software that incorporates the movement into its content. In par- ticular, applications are feasible in implementing movements into graphical output. Further, ap- plications of the devices according to the present invention for giving commands are feasible, such as by using one or more of the devices according to the present invention for gesture or facial recognition. The devices according to the present invention may be combined with an active system in order to work under e.g. low light conditions or in other situations in which en- hancement of the surrounding conditions is required. Additionally or alternatively, a combination of one or more devices according to the present invention with one or more IR or VIS light sources is possible. A combination of a detector according to the present invention with special devices is also possible, which can be distinguished easily by the system and its software, e.g. and not limited to, a special color, shape, relative position to other devices, speed of movement, light, frequency used to modulate light sources on the device, surface properties, material used, reflection properties, transparency degree, absorption characteristics, etc. The device can, amongst other possibilities, resemble a stick, a racket, a club, a gun, a knife, a wheel, a ring, a steering wheel, a bottle, a ball, a glass, a vase, a spoon, a fork, a cube, a dice, a figure, a pup- pet, a teddy, a beaker, a pedal, a switch, a glove, jewelry, a musical instrument or an auxiliary device for playing a musical instrument, such as a plectrum, a drumstick or the like. Other op- tions are feasible.

Further, the devices according to the present invention may be used to detect and or track ob- jects that emit light by themselves, such as due to high temperature or further light emission processes. The light emitting part may be an exhaust stream or the like. Further, the devices according to the present invention may be used to track reflecting objects and analyze the rota- tion or orientation of these objects.

Further, the devices according to the present invention generally may be used in the field of building, construction and cartography. Thus, generally, one or more devices according to the present invention may be used in order to measure and/or monitor environmental areas, e.g. countryside or buildings. Therein, one or more devices according to the present invention may be combined with other methods and devices or can be used solely in order to monitor progress and accuracy of building projects, changing objects, houses, etc. The devices according to the present invention can be used for generating three-dimensional models of scanned environ- ments, in order to construct maps of rooms, streets, houses, communities or landscapes, both from ground or from air. Potential fields of application may be construction, cartography, real estate management, land surveying or the like. As an example, the devices according to the present invention may be used in drones or multicopters to monitor buildings, production sites, chimneys, agricultural production environments such as fields, production plants, or landscapes, to support rescue operations, to support work in dangerous environments, to support fire bri- gades in a burning location indoors or outdoors, or to find or monitor one or more persons or animals, or the like, or for entertainment purposes, such as a drone following and recording one or more persons doing sports such as skiing or cycling or the like, which could be realized by following a helmet, a mark, a beacon device, or the like. Devices according to the present inven- tion could be used recognize obstacles, follow a predefined route, follow an edge, a pipe, a building, or the like, or to record a global or local map of the environment. Further, devices ac- cording to the present invention could be used for indoor or outdoor localization and positioning of drones, for stabilizing the height of a drone indoors where barometric pressure sensors are not accurate enough, or for the interaction of multiple drones such as concertized movements of several drones or recharging or refueling in the air or the like.

Further, the devices according to the present invention may be used within an interconnecting network of home appliances such as CHAIN (Cedec Home Appliances Interoperating Network) to interconnect, automate, and control basic appliance-related services in a home, e.g. energy or load management, remote diagnostics, pet related appliances, child related appliances, child surveillance, appliances related surveillance, support or service to elderly or ill persons, home security and/or surveillance, remote control of appliance operation, and automatic maintenance support. Further, the devices according to the present invention may be used in heating or cool- ing systems such as an air-conditioning system, to locate which part of the room should be brought to a certain temperature or humidity, especially depending on the location of one or more persons. Further, the devices according to the present invention may be used in domestic robots, such as service or autonomous robots which may be used for household chores. The devices according to the present invention may be used for a number of different purposes, such as to avoid collisions or to map the environment, but also to identify a user, to personalize the robot’s performance for a given user, for security purposes, or for gesture or facial recogni- tion. As an example, the devices according to the present invention may be used in robotic vac- uum cleaners, floor-washing robots, dry-sweeping robots, ironing robots for ironing clothes, an- imal litter robots, such as dog or cat litter robots, charging robot for electrical vehicles, security robots that detect intruders, robotic lawn mowers, automated pool cleaners, rain gutter cleaning robots, robotic shopping carts, luggage carrying robots, line following robots, laundry robots, ironing robots, window washing robots, toy robots, , patient monitoring robots, baby monitoring robots, elderly monitoring robots, children monitoring robots, transport robots, telepresence ro- bots, professional service robots, programmable toy robots, pathfinder robots, social robots providing company to less mobile people, following robots, smart card following robots, psycho- therapy robots, or robots translating and speech to sign language or sign language to speech.

In the context of less mobile people, such as elderly persons, household robots with the devices according to the present invention may be used for picking up objects, transporting objects, and interacting with the objects and the user in a safe way. Further, the devices according to the present invention may be used in humanoid robots, especially in the context of using humanoid hands to pick up or hold or place objects. Further, the devices according to the present inven- tion may be used in combination with audio interfaces especially in combination with household robots which may serve as a digital assistant with interfaces to online or offline computer appli- cations. Further, the devices according to the present invention may be used in robots that can control switches and buttons in industrial and household purposes. Further, the devices accord- ing to the present invention may be used in smart home robots such as Mayfield’s Kuri. Further the devices according to the present invention may be used in robots operating with hazardous materials or objects or in dangerous environments. As a non-limiting example, the devices ac- cording to the present invention may be used in robots or unmanned remote-controlled vehicles to operate with hazardous materials such as chemicals or radioactive materials especially after disasters, or with other hazardous or potentially hazardous objects such as mines, unexploded arms, or the like, or to operate in or to investigate insecure environments such as near burning objects or post disaster areas or for manned or unmanned rescue operations in the air, in the sea, underground, or the like.

Further, devices according to the present invention may be used for the inspection of adhesive beads, sealing beads, or the like, such as to recognize disruptions, slubs, contractions, asym- metries, local defects, or the like. Further, devices according to the present invention may be used to count objects such as dry fruits on a conveyer belt, such as in difficult situations, such as when fruit of similar color and shape may be in direct contact with each other. Further, devic- es according to the present invention may be used in quality control of die cast or injection molded parts such as to ensure flawless casting or molding, recognize surface damages, worn out toolings or the like. Further, devices according to the present invention may be used for la- serscribing such as for quality control and positioning of the laser. Further, devices according to the present invention may be used for sorting systems, such as to detect position, rotation, and shape of an object, compare it to a database of objects, and classify the object. Further, devices according to the present invention may be used for stamping part inspection, packaging inspec- tion, such as food and pharma packaging inspection, filament inspection, or the like.

Further, devices according to the present invention may be used for navigation purposes, where Global Positioning Systems (GPS) are not sufficiently reliable. GPS signals commonly use radio waves that are can be blocked or difficult to receive indoors or outdoors in valleys or in forests below the treeline. Further, especially in unmanned autonomous vehicles, the weight of the sys- tem may be critical. Especially unmanned autonomous vehicles need high-speed position data for reliable feedback and stability of their control systems. Using devices according to the pre- sent invention may allow short time response and positioning without adding weight due to a heavy device.

Further, the devices according to the present invention may be used in household, mobile or entertainment devices, such as a refrigerator, a microwave, a washing machine, a window blind or shutter, a household alarm, an air condition devices, a heating device, a television, an audio device, a smart watch, a mobile phone, a phone, a dishwasher, a stove or the like, to detect the presence of a person, to monitor the contents or function of the device, or to interact with the person and/or share information about the person with further household, mobile or entertain- ment devices.

Further, the devices according to the present invention may be used to support elderly or disa- bled persons or persons with limited or no vision, such as in household chores or at work such as in devices for holding, carrying, or picking objects, or in a safety system with optical, electri- cal, or acoustical signals signaling obstacles in the environment.

The devices according to the present invention may further be used in agriculture, for example to detect and sort out vermin, weeds, and/or infected crop plants, fully or in parts, wherein crop plants may be infected by fungus or insects. Further, for harvesting crops, the devices accord- ing to the present invention may be used to detect animals, such as deer, which may otherwise be harmed by harvesting devices. Further, the devices according to the present invention may be used to monitor the growth of plants in a field or greenhouse, in particular to adjust the amount of water or fertilizer or crop protection products for a given region in the field or green- house or even for a given plant. Further, in agricultural biotechnology, the devices according to the present invention may be used to monitor the size and shape of plants.

Further, devices according to the present invention may be used to automatically remove weeds such as with mechanical means, such as to avoid the use of herbicides. Further, devices ac- cording to the present invention may be used in the field of agriculture, in particular to detect and/or locate specific insects such as to decide whether or not to apply a crop protection or ferti lization substance, such as to reduce the amount of applied substance or to protect specific groups of animals such as bees.

Further, devices according to the present invention may be used to guide users during a shav- ing, hair cutting, or cosmetics procedure, or the like. Further, devices according to the present invention may be used to record or monitor what is played on an instrument, such as a violin. Further, devices according to the present invention may be used in smart household appliances such as a smart refrigerator, such as to monitor the contents of the refrigerator and transmit notifications depending on the contents. Further, devices according to the present invention may be used for monitoring or tracking populations of humans, animals, or plants, such as dear or tree populations in forests. Further, devices according to the present invention may be used in harvesting machines, such as for harvesting crops, flowers or fruits, such as grapes, corn, hops, apples, grains, rice, strawberries, asparagus, tulips, roses, soy beans, or the like. Further, devices according to the present invention may be used to monitor the growth of plants, ani- mals, algae, fish, or the like, such as in breeding, food production, agriculture or research appli cations, to control irrigation, fertilization, humidity, temperature, use of herbicides, insecticides, fungicides, rodenticides, or the like. Further, devices according to the present invention may be used in feeding machines for animals or pets, such as for cows, pigs, cats, dogs, birds, fish, or the like. Further, devices according to the present invention may be used in animal product pro- duction processes, such as for collecting milk, eggs, fur, meat, or the like, such as in automated milking or butchering processes. Further, devices according to the present invention may be used for automated seeding machines, or sowing machines, or planting machines such as for planting corn, garlic, trees, salad or the like. Further, devices according to the present invention may be used to assess or monitor weather phenomena, such as clouds, fog, or the like, or to warn from danger of avalanches, tsunamis, gales, earthquakes, thunder storms, or the like. Fur- ther, devices according to the present invention may be used to measure motions, shocks, con- cussions, or the like such as to monitor earthquake risk. Further, devices according to the pre- sent invention may be used in traffic technology to monitor dangerous crossings, to control traf- fic lights depending on traffic, to monitor public spaces, to monitor roads, gyms, stadiums, ski resorts, public events, or the like. Further, devices according to the present invention may be used in medical applications such as to monitor or analyze tissues, medical or biological as- says, changes in tissues such as in moles or melanoma or the like, to count bacteria, blood cells, cells, algae, or the like, for retina scans, breath or pulse measurements, gastroscopy, pa- tient surveillance, or the like. Further, devices according to the present invention may be used to monitor the shape, size, or circumference of drops, streams, jets, or the like or to analyze, as- sess, or monitor profiles or gas or liquid currents such as in a wind channel, or the like. Further, devices according to the present invention may be used to warn drivers such as car or train drivers when they are getting sick or tired or the like. Further, devices according to the present invention may be used in material testing to recognize strains or tensions or fissures, or the like. Further, devices according to the present invention may be used in sailing to monitor and opti- mize sail positions such as automatically. Further, devices according to the present invention may be used for fuel level gauges.

Further, the devices according to the present invention may be combined with sensors to detect chemicals or pollutants, electronic nose chips, microbe sensor chips to detect bacteria or virus- es or the like, Geiger counters, tactile sensors, heat sensors, or the like. This may for example be used in constructing smart robots which are configured for handling dangerous or difficult tasks, such as in treating highly infectious patients, handling or removing highly dangerous sub- stances, cleaning highly polluted areas, such as highly radioactive areas or chemical spills, or for pest control in agriculture.

One or more devices according to the present invention can further be used for scanning of ob- jects, such as in combination with CAD or similar software, such as for additive manufacturing and/or 3D printing. Therein, use may be made of the high dimensional accuracy of the devices according to the present invention, e.g. in x-, y- or z- direction or in any arbitrary combination of these directions, such as simultaneously. Further, the devices according to the present inven- tion may be used in inspections and maintenance, such as pipeline inspection gauges. Further, in a production environment, the devices according to the present invention may be used to work with objects of a badly defined shape such as naturally grown objects, such as sorting vegetables or other natural products by shape or size or cutting products such as meat or ob- jects that are manufactured with a precision that is lower than the precision needed for a pro- cessing step.

Further the devices according to the present invention may be used in local navigation systems to allow autonomously or partially autonomously moving vehicles or multicopters or the like through an indoor or outdoor space. A non-limiting example may comprise vehicles moving through an automated storage for picking up objects and placing them at a different location. Indoor navigation may further be used in shopping malls, retail stores, museums, airports, or train stations, to track the location of mobile goods, mobile devices, baggage, customers or em- ployees, or to supply users with a location specific information, such as the current position on a map, or information on goods sold, or the like.

Further, the devices according to the present invention may be used to ensure safe driving of motorcycles such as driving assistance for motorcycles by monitoring speed, inclination, upcom- ing obstacles, unevenness of the road, or curves or the like. Further, the devices according to the present invention may be used in trains or trams to avoid collisions.

Further, the devices according to the present invention may be used in handheld devices, such as for scanning packaging or parcels to optimize a logistics process. Further, the devices ac- cording to the present invention may be used in further handheld devices such as personal shopping devices, RFID-readers, handheld devices for use in hospitals or health environments such as for medical use or to obtain, exchange or record patient or patient health related infor- mation, smart badges for retail or health environments, or the like.

As outlined above, the devices according to the present invention may further be used in manu- facturing, quality control or identification applications, such as in product identification or size identification (such as for finding an optimal place or package, for reducing waste etc.). Further, the devices according to the present invention may be used in logistics applications. Thus, the devices according to the present invention may be used for optimized loading or packing con- tainers or vehicles. Further, the devices according to the present invention may be used for monitoring or controlling of surface damages in the field of manufacturing, for monitoring or con- trolling rental objects such as rental vehicles, and/or for insurance applications, such as for as- sessment of damages. Further, the devices according to the present invention may be used for identifying a size of material, object or tools, such as for optimal material handling, especially in combination with robots. Further, the devices according to the present invention may be used for process control in production, e.g. for observing filling level of tanks. Further, the devices according to the present invention may be used for maintenance of production assets like, but not limited to, tanks, pipes, reactors, tools etc. Further, the devices according to the present invention may be used for analyzing 3D-quality marks. Further, the devices according to the present invention may be used in manufacturing tailor-made goods such as tooth inlays, dental braces, prosthesis, clothes or the like. The devices according to the present invention may also be combined with one or more 3D-printers for rapid prototyping, 3D-copying or the like. Further, the devices according to the present invention may be used for detecting the shape of one or more articles, such as for anti-product piracy and for anti-counterfeiting purposes.

Thus, specifically, the present application may be applied in the field of photography. Thus, the detector may be part of a photographic device, specifically of a digital camera. Specifically, the detector may be used for 3D photography, specifically for digital 3D photography. Thus, the de- tector may form a digital 3D camera or may be part of a digital 3D camera. As used herein, the term photography generally refers to the technology of acquiring image information of at least one object. As further used herein, a camera generally is a device adapted for performing pho- tography. As further used herein, the term digital photography generally refers to the technology of acquiring image information of at least one object by using a plurality of light-sensitive ele- ments adapted to generate electrical signals indicating an intensity and/or color of illumination, preferably digital electrical signals. As further used herein, the term 3D photography generally refers to the technology of acquiring image information of at least one object in three spatial dimensions. Accordingly, a 3D camera is a device adapted for performing 3D photography. The camera generally may be adapted for acquiring a single image, such as a single 3D image, or may be adapted for acquiring a plurality of images, such as a sequence of images. Thus, the camera may also be a video camera adapted for video applications, such as for acquiring digital video sequences.

Thus, generally, the present invention further refers to a camera, specifically a digital camera, more specifically a 3D camera or digital 3D camera, for imaging at least one object. As outlined above, the term imaging, as used herein, generally refers to acquiring image information of at least one object. The camera comprises at least one detector according to the present inven- tion. The camera, as outlined above, may be adapted for acquiring a single image or for acquir- ing a plurality of images, such as image sequence, preferably for acquiring digital video se- quences. Thus, as an example, the camera may be or may comprise a video camera. In the latter case, the camera preferably comprises a data memory for storing the image sequence.

As used within the present invention, the expression“position” generally refers to at least one item of information regarding one or more of an absolute position and an orientation of one or more points of the object. Thus, specifically, the position may be determined in a coordinate system of the detector, such as in a Cartesian coordinate system. Additionally or alternatively, however, other types of coordinate systems may be used, such as polar coordinate systems and/or spherical coordinate systems.

As outlined above and as will be outlined in further detail below, the present invention preferably may be applied in the field of human-machine interfaces, in the field of sports and/or in the field of computer games. Thus, preferably, the object may be selected from the group consisting of: an article of sports equipment, preferably an article selected from the group consisting of a racket, a club, a bat, an article of clothing, a hat, a shoe. Other embodiments are feasible.

As used herein, the object generally may be an arbitrary object, chosen from a living object and a non-living object. Thus, as an example, the at least one object may comprise one or more articles and/or one or more parts of an article. Additionally or alternatively, the object may be or may comprise one or more living beings and/or one or more parts thereof, such as one or more body parts of a human being, e.g. a user, and/or an animal.

With regard to the coordinate system for determining the position of the object, which may be a coordinate system of the detector, the detector may constitute a coordinate system in which an optical axis of the detector forms the z-axis and in which, additionally, an x-axis and a y-axis may be provided which are perpendicular to the z-axis and which are perpendicular to each other. As an example, the detector and/or a part of the detector may rest at a specific point in this coordinate system, such as at the origin of this coordinate system. In this coordinate sys- tem, a direction parallel or antiparallel to the z-axis may be regarded as a longitudinal direction, and a coordinate along the z-axis may be considered a longitudinal coordinate. An arbitrary di- rection perpendicular to the longitudinal direction may be considered a transversal direction, and an x- and/or y-coordinate may be considered a transversal coordinate.

Alternatively, other types of coordinate systems may be used. Thus, as an example, a polar coordinate system may be used in which the optical axis forms a z-axis and in which a distance from the z-axis and a polar angle may be used as additional coordinates. Again, a direction par- allel or antiparallel to the z-axis may be considered a longitudinal direction, and a coordinate along the z-axis may be considered a longitudinal coordinate. Any direction perpendicular to the z-axis may be considered a transversal direction, and the polar coordinate and/or the polar an- gle may be considered a transversal coordinate.

The detector may be a device configured for providing at least one item of information on the position of the at least one object and/or a part thereof. Thus, the position may refer to an item of information fully describing the position of the object or a part thereof, preferably in the coor- dinate system of the detector, or may refer to a partial information, which only partially describes the position. The detector generally may be a device adapted for detecting light beams, such as the light beams propagating from the beacon devices towards the detector.

The evaluation device and the detector may fully or partially be integrated into a single device. Thus, generally, the evaluation device also may form part of the detector. Alternatively, the evaluation device and the detector may fully or partially be embodied as separate devices. The detector may comprise further components.

The detector may be a stationary device or a mobile device. Further, the detector may be a stand-alone device or may form part of another device, such as a computer, a vehicle or any other device. Further, the detector may be a hand-held device. Other embodiments of the de- tector are feasible.

The detector specifically may be used to record a light-field behind a lens or lens system of the detector, comparable to a plenoptic or light-field camera. Thus, specifically, the detector may be embodied as a light-field camera adapted for acquiring images in multiple focal planes, such as simultaneously. The term light-field, as used herein, generally refers to the spatial light propaga- tion of light inside the detector such as inside camera. The detector according to the present invention, specifically having a stack of optical sensors, may have the capability of directly re- cording a light-field within the detector or camera, such as behind a lens. The plurality of sen- sors may record images at different distances from the lens. Using, e.g., convolution-based al- gorithms such as“depth from focus” or“depth from defocus”, the propagation direction, focus points, and spread of the light behind the lens can be modeled. From the modeled propagation of light behind the lens, images at various distances to the lens can be extracted, the depth of field can be optimized, pictures that are in focus at various distances can be extracted, or dis- tances of objects can be calculated. Further information may be extracted.

The use of several optical sensors further allows for correcting lens errors in an image pro- cessing step after recording the images. Optical instruments often become expensive and chal- lenging in construction, when lens errors need to be corrected. These are especially problemat- ic in microscopes and telescopes. In microscopes, a typical lens error is that rays of varying distance to the optical axis are distorted differently (spherical aberration). In telescopes, varying the focus may occur from differing temperatures in the atmosphere. Static errors such as spher- ical aberration or further errors from production may be corrected by determining the errors in a calibration step and then using a fixed image processing such as fixed set of pixels and sensor, or more involved processing techniques using light propagation information. In cases in which lens errors are strongly time-dependent, i.e. dependent on weather conditions in telescopes, the lens errors may be corrected by using the light propagation behind the lens, calculating extend- ed depth of field images, using depth from focus techniques, and others.

The detector according to the present invention may further allow for color detection. For color detection, a plurality of optical sensors having different spectral properties may be used, and sensor signals of these optical sensors may be compared. Further, the devices according to the present invention may be used in the context of gesture recognition. In this context, gesture recognition in combination with devices according to the present invention may, in particular, be used as a human-machine interface for transmitting information via motion of a body, of body parts or of objects to a machine. Herein, the information may, preferably, be transmitted via a motion of hands or hand parts, such as fingers, in particular, by pointing at objects, applying sign language, such as for deaf people, making signs for numbers, approval, disapproval, or the like, by waving the hand, such as when asking someone to approach, to leave, or to greet a person, to press an object, to take an object, or, in the field of sports or music, in a hand or fin ger exercise, such as a warm-up exercise. Further, the information may be transmitted by mo- tion of arms or legs, such as rotating, kicking, grabbing, twisting, rotating, scrolling, browsing, pushing, bending, punching, shaking, arms, legs, both arms, or both legs, or a combination of arms and legs, such as for a purpose of sports or music, such as for entertainment, exercise, or training function of a machine. Further, the information may be transmitted by motion of the whole body or major parts thereof, such as jumping, rotating, or making complex signs, such as sign language used at airports or by traffic police in order to transmit information, such as“turn right”,“turn left”,“proceed”,“slow down”,“stop”, or“stop engines”, or by pretending to swim, to dive, to run, to shoot, or the like, or by making complex motions or body positions such as in yoga, pilates, judo, karate, dancing, or ballet. Further, the information may be transmitted by using a real or mock-up device for controlling a virtual device corresponding to the mock-up device, such as using a mock-up guitar for controlling a virtual guitar function in a computer program, using a real guitar for controlling a virtual guitar function in a computer program, using a real or a mock-up book for reading an e-book or moving pages or browsing through in a virtual document, using a real or mock-up pen for drawing in a computer program, or the like. Further, the transmission of the information may be coupled to a feedback to the user, such as a sound, a vibration, or a motion.

In the context of music and/or instruments, devices according to the present invention in combi- nation with gesture recognition may be used for exercising purposes, control of instruments, recording of instruments, playing or recording of music via use of a mock-up instrument or by only pretending to have a instrument present such as playing air guitar, such as to avoid noise or make recordings, or, for conducting of a virtual orchestra, ensemble, band, big band, choir, or the like, for practicing, exercising, recording or entertainment purposes or the like.

Further, in the context of safety and surveillance, devices according to the present invention in combination with gesture recognition may be used to recognize motion profiles of persons, such as recognizing a person by the way of walking or moving the body, or to use hand signs or movements or signs or movements of body parts or the whole body as access or identification control such as a personal identification sign or a personal identification movement.

Further, in the context of smart home applications or internet of things, devices according to the present invention in combination with gesture recognition may be used for central or non-central control of household devices which may be part of an interconnecting network of home appli ances and/or household devices, such as refrigerators, central heating, air condition, microwave ovens, ice cube makers, or water boilers, or entertainment devices, such as television sets, smart phones, game consoles, video recorders, DVD players, personal computers, laptops, tablets, or combinations thereof, or a combination of household devices and entertainment de- vices.

Further, in the context of virtual reality or of augmented reality, devices according to the present invention in combination with gesture recognition may be used to control movements or function of the virtual reality application or of the augmented reality application, such as playing or con- trolling a game using signs, gestures, body movements or body part movements or the like, moving through a virtual world, manipulating virtual objects, practicing, exercising or playing sports, arts, crafts, music or games using virtual objects such as a ball, chess figures, go stones, instruments, tools, brushes.

Further, in the context of medicine, devices according to the present invention in combination with gesture recognition may be used to support rehabilitation training, remote diagnostics, or to monitor or survey surgery or treatment, to overlay and display medical images with positions of medical devices, or to overlay display prerecorded medical images such as from magnetic res- onance tomography or x-ray or the like with images from endoscopes or ultra sound or the like that are recorded during an surgery or treatment.

Further, in the context of manufacturing and process automation, devices according to the pre- sent invention in combination with gesture recognition may be used to control, teach, or pro- gram robots, drones, unmanned autonomous vehicles, service robots, movable objects, or the like, such as for programming, controlling, manufacturing, manipulating, repairing, or teaching purposes, or for remote manipulating of objects or areas, such as for safety reasons, or for maintenance purposes.

Further, in the context of business intelligence metrics, devices according to the present inven- tion in combination with gesture recognition may be used for people counting, surveying cus- tomer movements, areas where customers spend time, objects, customers test, take, probe, or the like.

Further, devices according to the present invention may be used in the context of do-it-yourself or professional tools, especially electric or motor driven tools or power tools, such as drilling machines, saws, chisels, hammers, wrenches, staple guns, disc cutters, metals shears and nib- biers, angle grinders, die grinders, drills, hammer drills, heat guns, wrenches, sanders, engrav- ers, nailers, jig saws, biscuit joiners, wood routers, planers, polishers, tile cutters, washers, roll- ers, wall chasers, lathes, impact drivers, jointers, paint rollers, spray guns, morticers, or welders, in particular, to support precision in manufacturing, keeping a minimum or maximum distance, or for safety measures.

Further, the devices according to the present invention may be used to aid visually impaired persons. Further, devices according to the present invention may be used in touch screen such as to avoid direct context such as for hygienic reasons, which may be used in retail environ- ments, in medical applications, in production environments, or the like. Further, devices accord- ing to the present invention may be used in agricultural production environments such as in sta- ble cleaning robots, egg collecting machines, milking machines, harvesting machines, farm ma- chinery, harvesters, forwarders, combine harvesters, tractors, cultivators, ploughs, destoners, harrows, strip tills, broadcast seeders, planters such as potato planters, manure spreaders, sprayers, sprinkler systems, swathers, balers, loaders, forklifts, mowers, or the like.

Further, devices according to the present invention may be used for selection and/or adaption of clothing, shoes, glasses, hats, prosthesis, dental braces, for persons or animals with limited communication skills or possibilities, such as children or impaired persons, or the like. Further, devices according to the present invention may be used in the context of warehouses, logistics, distribution, shipping, loading, unloading, smart manufacturing, industry 4.0, or the like. Further, in a manufacturing context, devices according to the present invention may be used in the con- text of processing, dispensing, bending, material handling, or the like.

The evaluation device may be or may comprise one or more integrated circuits, such as one or more application-specific integrated circuits (ASICs), and/or one or more data processing devic- es, such as one or more computers, preferably one or more microcomputers and/or microcon- trollers, Field Programmable Arrays, or Digital Signal Processors. Additional components may be comprised, such as one or more preprocessing devices and/or data acquisition devices, such as one or more devices for receiving and/or preprocessing of the sensor signals, such as one or more AD-converters and/or one or more filters. Further, the evaluation device may corn- prise one or more measurement devices, such as one or more measurement devices for meas- uring electrical currents and/or electrical voltages. Further, the evaluation device may comprise one or more data storage devices. Further, the evaluation device may comprise one or more interfaces, such as one or more wireless interfaces and/or one or more wire-bound interfaces.

The at least one evaluation device may be adapted to perform at least one computer program, such as at least one computer program adapted for performing or supporting one or more or even all of the method steps of the method according to the present invention. As an example, one or more algorithms may be implemented which, by using the sensor signals as input varia- bles, may determine the position of the object.

The evaluation device can be connected to or may comprise at least one further data pro- cessing device that may be used for one or more of displaying, visualizing, analyzing, distrib uting, communicating or further processing of information, such as information obtained by the optical sensor and/or by the evaluation device. The data processing device, as an example, may be connected or incorporate at least one of a display, a projector, a monitor, an LCD, a TFT, a loudspeaker, a multichannel sound system, an LED pattern, or a further visualization device. It may further be connected or incorporate at least one of a communication device or communication interface, a connector or a port, capable of sending encrypted or unencrypted information using one or more of email, text messages, telephone, Bluetooth, Wi-Fi, infrared or internet interfaces, ports or connections. It may further be connected or incorporate at least one of a processor, a graphics processor, a CPU, an Open Multimedia Applications Platform

(OMAP™), an integrated circuit, a system on a chip such as products from the Apple A series or the Samsung S3C2 series, a microcontroller or microprocessor, one or more memory blocks such as ROM, RAM, EEPROM, or flash memory, timing sources such as oscillators or phase- locked loops, counter-timers, real-time timers, or power-on reset generators, voltage regulators, power management circuits, or DMA controllers. Individual units may further be connected by buses such as AMBA buses or be integrated in an Internet of Things or Industry 4.0 type net- work. The evaluation device and/or the data processing device may be connected by or have further external interfaces or ports such as one or more of serial or parallel interfaces or ports, USB, Centronics Port, FireWire, HDMI, Ethernet, Bluetooth, RFID, Wi-Fi, USART, or SPI, or analogue interfaces or ports such as one or more of ADCs or DACs, or standardized interfaces or ports to further devices such as a 2D-camera device using an RGB-interface such as CameraLink. The evaluation device and/or the data processing device may further be connected by one or more of interprocessor interfaces or ports, FPGA-FPGA-interfaces, or serial or parallel interfaces ports. The evaluation device and the data processing device may further be connected to one or more of an optical disc drive, a CD-RW drive, a DVD+RW drive, a flash drive, a memory card, a disk drive, a hard disk drive, a solid state disk or a solid state hard disk.

The evaluation device and/or the data processing device may be connected by or have one or more further external connectors such as one or more of phone connectors, RCA connectors, VGA connectors, hermaphrodite connectors, USB connectors, HDMI connectors, 8P8C con- nectors, BCN connectors, I EC 60320 C14 connectors, optical fiber connectors, D-subminiature connectors, RF connectors, coaxial connectors, SCART connectors, XLR connectors, and/or may incorporate at least one suitable socket for one or more of these connectors.

Possible embodiments of a single device incorporating one or more of the detectors according to the present invention, the evaluation device or the data processing device, such as incorpo- rating one or more of the optical sensor, optical systems, evaluation device, communication device, data processing device, interfaces, system on a chip, display devices, or further elec- tronic devices, are: mobile phones, personal computers, tablet PCs, televisions, game consoles or further entertainment devices. In a further embodiment, the 3D-camera functionality which will be outlined in further detail below may be integrated in devices that are available with con- ventional 2D-digital cameras, without a noticeable difference in the housing or appearance of the device, where the noticeable difference for the user may only be the functionality of obtain- ing and or processing 3D information. Further, devices according to the present invention may be used in 360° digital cameras or surround view cameras.

Specifically, an embodiment incorporating the detector and/or a part thereof such as the evalua- tion device and/or the data processing device may be: a mobile phone incorporating a display device, a data processing device, the optical sensor, optionally the sensor optics, and the eval- uation device, for the functionality of a 3D camera. The detector according to the present inven- tion specifically may be suitable for integration in entertainment devices and/or communication devices such as a mobile phone.

A further embodiment of the present invention may be an incorporation of the detector or a part thereof such as the evaluation device and/or the data processing device in a device for use in automotive, for use in autonomous driving or for use in car safety systems such as Daimler’s Intelligent Drive system, wherein, as an example, a device incorporating one or more of the op- tical sensors, optionally one or more optical systems, the evaluation device, optionally a com- munication device, optionally a data processing device, optionally one or more interfaces, op- tionally a system on a chip, optionally one or more display devices, or optionally further elec- tronic devices may be part of a vehicle, a car, a truck, a train, a bicycle, an airplane, a ship, a motorcycle. In automotive applications, the integration of the device into the automotive design may necessitate the integration of the optical sensor, optionally optics, or device at minimal visi bility from the exterior or interior. The detector or a part thereof such as the evaluation device and/or the data processing device may be especially suitable for such integration into automo- tive design.

As used herein, the term light generally refers to electromagnetic radiation in one or more of the visible spectral range, the ultraviolet spectral range and the infrared spectral range. Therein, the term visible spectral range generally refers to a spectral range of 380 nm to 780 nm. The term infrared spectral range generally refers to electromagnetic radiation in the range of 780 nm to 1 mm, preferably in the range of 780 nm to 3.0 micrometers. The term ultraviolet spectral range generally refers to electromagnetic radiation in the range of 1 nm to 380 nm, preferably in the range of 100 nm to 380 nm. Preferably, light as used within the present invention is visible light, i.e. light in the visible spectral range.

The term light beam generally may refer to an amount of light emitted and/or reflected into a specific direction. Thus, the light beam may be a bundle of the light rays having a predeter- mined extension in a direction perpendicular to a direction of propagation of the light beam. Preferably, the light beams may be or may comprise one or more Gaussian light beams such as a linear combination of Gaussian light beams, which may be characterized by one or more Gaussian beam parameters, such as one or more of a beam waist, a Rayleigh-length or any other beam parameter or combination of beam parameters suited to characterize a develop- ment of a beam diameter and/or a beam propagation in space.

The detector according to the present invention may further be combined with one or more oth- er types of sensors or detectors. Thus, the detector may further comprise at least one additional detector. The at least one additional detector may be adapted for detecting at least one parame- ter, such as at least one of: a parameter of a surrounding environment, such as a temperature and/or a brightness of a surrounding environment; a parameter regarding a position and/or ori- entation of the detector; a parameter specifying a state of the object to be detected, such as a position of the object, e.g. an absolute position of the object and/or an orientation of the object in space. Thus, generally, the principles of the present invention may be combined with other measurement principles in order to gain additional information and/or in order to verify meas- urement results or reduce measurement errors or noise.

As outlined above, the human-machine interface may comprise a plurality of beacon devices which are adapted to be at least one of directly or indirectly attached to the user and held by the user. Thus, the beacon devices each may independently be attached to the user by any suitable means, such as by an appropriate fixing device. Additionally or alternatively, the user may hold and/or carry the at least one beacon device or one or more of the beacon devices in his or her hands and/or by wearing the at least one beacon device and/or a garment containing the bea- con device on a body part.

The beacon device generally may be an arbitrary device which may be detected by the at least one detector and/or which facilitates detection by the at least one detector. Thus, as outlined above or as will be outlined in further detail below, the beacon device may be an active beacon device adapted for generating the at least one light beam to be detected by the detector, such as by having one or more illumination sources for generating the at least one light beam. Addi- tionally or alternatively, the beacon device may fully or partially be designed as a passive bea- con device, such as by providing one or more reflective elements adapted to reflect a light beam generated by a separate illumination source. The at least one beacon device may permanently or temporarily be attached to the user in a direct or indirect way and/or may be carried or held by the user. The attachment may take place by using one or more attachment means and/or by the user himself or herself, such as by the user holding the at least one beacon device by hand and/or by the user wearing the beacon device.

Additionally or alternatively, the beacon devices may be at least one of attached to an object and integrated into an object held by the user, which, in the sense of the present invention, shall be included into the meaning of the option of the user holding the beacon devices. Thus, as will be outlined in further detail below, the beacon devices may be attached to or integrated into a control element which may be part of the human-machine interface and which may be held or carried by the user, and of which the orientation may be recognized by the detector device. Thus, generally, the present invention also refers to a detector system comprising at least one detector device according to the present invention and which, further, may comprise at least one object, wherein the beacon devices are one of attached to the object, held by the object and integrated into the object. As an example, the object preferably may form a control element, the orientation of which may be recognized by a user. Thus, the detector system may be part of the human-machine interface as outlined above or as outlined in further detail below. As an ex- ample, the user may handle the control element in a specific way in order to transmit one or more items of information to a machine, such as in order to transmit one or more commands to the machine.

Alternatively, the detector system may be used in other ways. Thus, as an example, the object of the detector system may be different from a user or a body part of the user and, as an exam- pie, may be an object which moves independently from the user. As an example, the detector system may be used for controlling apparatuses and/or industrial processes, such as manufac- turing processes and/or robotics processes. Thus, as an example, the object may be a machine and/or a machine part, such as a robot arm, the orientation of which may be detected by using the detector system.

The human-machine interface may be adapted in such a way that the detector device generates at least one item of information on the position of the user or of at least one body part of the user. Specifically in case a manner of attachment of the at least one beacon device to the user is known, by evaluating the position of the at least one beacon device, at least one item of in- formation on a position and/or an orientation of the user or of a body part of the user may be gained.

The beacon device preferably is one of a beacon device attachable to a body or a body part of the user and a beacon device which may be held by the user. As outlined above, the beacon device may fully or partially be designed as an active beacon device. Thus, the beacon device may comprise at least one illumination source adapted to generate at least one light beam to be transmitted to the detector, preferably at least one light beam having known beam properties. Additionally or alternatively, the beacon device may comprise at least one reflector adapted to reflect light generated by an illumination source, thereby generating a reflected light beam to be transmitted to the detector.

The object, which may form part of the detector system, may generally have an arbitrary shape. Preferably, the object being part of the detector system, as outlined above, may be a control element which may be handled by a user, such as manually. As an example, the control ele- ment may be or may comprise at least one element selected from the group consisting of: a glove, a jacket, a hat, shoes, trousers and a suit, a stick that may be held by hand, a bat, a club, a racket, a cane, a toy, such as a toy gun. Thus, as an example, the detector system may be part of the human-machine interface and/or of the entertainment device.

As used herein, an entertainment device is a device which may serve the purpose of leisure and/or entertainment of one or more users, in the following also referred to as one or more players. As an example, the entertainment device may serve the purpose of gaming, preferably computer gaming. Thus, the entertainment device may be implemented into a computer, a computer network or a computer system or may comprise a computer, a computer network or a computer system which runs one or more gaming software programs.

The entertainment device comprises at least one human-machine interface according to the present invention, such as according to one or more of the embodiments disclosed above and/or according to one or more of the embodiments disclosed below. The entertainment device is designed to enable at least one item of information to be input by a player by means of the human-machine interface. The at least one item of information may be transmitted to and/or may be used by a controller and/or a computer of the entertainment device. The at least one item of information preferably may comprise at least one command adapted for influencing the course of a game. Thus, as an example, the at least one item of information may include at least one item of information on at least one orientation of the player and/or of one or more body parts of the player, thereby allowing for the player to simulate a specific position and/or orienta- tion and/or action required for gaming. As an example, one or more of the following movements may be simulated and communicated to a controller and/or a computer of the entertainment device: dancing; running; jumping; swinging of a racket; swinging of a bat; swinging of a club; pointing of an object towards another object, such as pointing of a toy gun towards a target. The entertainment device as a part or as a whole, preferably a controller and/or a computer of the entertainment device, is designed to vary the entertainment function in accordance with the information. Thus, as outlined above, a course of a game might be influenced in accordance with the at least one item of information. Thus, the entertainment device might include one or more controllers which might be separate from the evaluation device of the at least one detector and/or which might be fully or partially identical to the at least one evaluation device or which might even include the at least one evaluation device. Preferably, the at least one controller might include one or more data processing devices, such as one or more computers and/or mi- crocontrollers.

As further used herein, a tracking system is a device which is adapted to gather information on a series of past positions of the at least one object and/or at least one part of the object. Addi- tionally, the tracking system may be adapted to provide information on at least one predicted future position and/or orientation of the at least one object or the at least one part of the object. The tracking system may have at least one track controller, which may fully or partially be em- bodied as an electronic device, preferably as at least one data processing device, more prefer- ably as at least one computer or microcontroller. Again, the at least one track controller may fully or partially comprise the at least one evaluation device and/or may be part of the at least one evaluation device and/or may fully or partially be identical to the at least one evaluation de- vice.

The tracking system comprises at least one detector according to the present invention, such as at least one detector as disclosed in one or more of the embodiments listed above and/or as disclosed in one or more of the embodiments below. The tracking system further comprises at least one track controller. The track controller is adapted to track a series of positions of the object at specific points in time, such as by recording groups of data or data pairs, each group of data or data pair comprising at least one position information and at least one time infor- mation.

The tracking system may further comprise the at least one detector system according to the present invention. Thus, besides the at least one detector and the at least one evaluation device and the optional at least one beacon device, the tracking system may further comprise the ob- ject itself or a part of the object, such as at least one control element comprising the beacon devices or at least one beacon device, wherein the control element is directly or indirectly at- tachable to or integratable into the object to be tracked.

The tracking system may be adapted to initiate one or more actions of the tracking system itself and/or of one or more separate devices. For the latter purpose, the tracking system, preferably the track controller, may have one or more wireless and/or wire-bound interfaces and/or other types of control connections for initiating at least one action. Preferably, the at least one track controller may be adapted to initiate at least one action in accordance with at least one actual position of the object. As an example, the action may be selected from the group consisting of: a prediction of a future position of the object; pointing at least one device towards the object; pointing at least one device towards the detector; illuminating the object; illuminating the detec- tor.

As an example of application of a tracking system, the tracking system may be used for contin- uously pointing at least one first object to at least one second object even though the first object and/or the second object might move. Potential examples, again, may be found in industrial applications, such as in robotics and/or for continuously working on an article even though the article is moving, such as during manufacturing in a manufacturing line or assembly line. Addi- tionally or alternatively, the tracking system might be used for illumination purposes, such as for continuously illuminating the object by continuously pointing an illumination source to the object even though the object might be moving. Further applications might be found in communication systems, such as in order to continuously transmit information to a moving object by pointing a transmitter towards the moving object.

The detector according to the present invention may be realized as a simple device combining the functionality of distance measurement or measurement of z-coordinates, with the additional option of measuring one or more transversal coordinates, thereby integrating the functionality of a PSD.

When mentioning a range of measurement, the range of measurement may both refer to a range of brightness which may be used with the detector according to the present invention, such as a range of total powers of the light beam, or may refer to a range of distances between the detector and the object which may be measured. Conventional detectors, such as according to one or more of the documents listed above, are typically limited in both ranges of measure- ment. The use of the quotient signal, as mentioned above, contrarily, provides a wide range of a continuously and monotonously decreasing or increasing functions which may be used to de- termine the longitudinal coordinate from the quotient signal. Consequently, a very wide range of measurement in terms of distance between the object and the detector is given. Similarly, due to the general independence of the quotient signal from the total power of the light beam, at least as long as no saturation of one or both of the optical sensors is reached, also provides a very wide range of measurement in terms of brightness, i.e. in terms of total power of the light beam.

The light beam, within the detector, generally may propagate along an optical axis of the detec- tor. The first and second optical sensors may be placed on the optical axis. The light beam, however, may also propagate in other ways than along the optical axis. As an example, an illu mination light beam may be generated which propagates along the optical axis or which propa- gates parallel to the optical axis or at an angle to the optical axis which is different from 0°, such as an angle of 1 ° to 20°. Other embodiments are feasible.

Overall, in the context of the present invention, the following embodiments are regarded as pre- ferred: Embodiment 1 : A detector for determining a position of at least one object, the detector corn- prising:

at least one sensor element having a matrix of optical sensors, the optical sensors each having a light-sensitive area, wherein each optical sensor is configured to gen- erate at least one sensor signal in response to an illumination of the light-sensitive ar- ea by at least one incident light beam propagating from the object to the detector, at least one transfer device, wherein the transfer device has at least one focal length in response to the incident light beam;

at least one filter element configured for generating at least two filter regions, wherein the filter element is configured such that in at least one first filter region and in at least one second filter region at least one property of the incident light beam is modified dif- ferently;

at least one evaluation device, wherein the at least one evaluation device is configured for evaluating at least one first sensor signal and at least one second sensor signal, wherein the first sensor signal is generated in response to illumination having passed through one of the first filter region and the second filter region and the second sensor signal is generated in response to illumination having passed through the same or the other one of the first filter region and the second filter region, and wherein the evaluation comprises determining at least one longitudinal coordinate z of the object by evaluating a combined signal Q from the first sensor signal and the second sensor signal.

Embodiment 2: The detector according to the preceding embodiment, wherein the filter element comprises at least one neutral-density filter.

Embodiment 3: The detector according to the preceding embodiment, wherein the neutral- density filter is selected from the group consisting of: a circular neutral-density filter, in particular at least one semi-circle neutral-density filter; at least one square shaped neutral-density filter; at least one split neutral-density filter; at least one graduated neutral-density filter; a neutral- density filter wheel; a variable neutral density filter; a Lee Big Stopper.

Embodiment 4: The detector according to any one of the preceding embodiments, wherein the evaluation device is configured for deriving the combined signal Q by one or more of dividing the first sensor signal and the second sensor signal, dividing multiples of the first sensor signal and the second sensor signal, dividing linear combinations of the first sensor signal and the second sensor signal.

Embodiment 5: The detector according to any one of the preceding embodiments, wherein the evaluation device is configured for using at least one predetermined relationship between the combined signal Q and the longitudinal coordinate z for determining the longitudinal coordinate z.

Embodiment 6: The detector according to any one of the preceding embodiments, wherein the first sensor signal comprises at least one information of at least one first area of a beam profile of the incident light beam and the second sensor signal comprises at least one information of at least one second area of the beam profile of the incident light beam, wherein the first area of the beam profile comprises essentially edge information of the beam profile and the second area of the beam profile comprises essentially center information of the beam profile.

Embodiment 7: The detector according to any one of the preceding embodiments, wherein the evaluation device is adapted to determine at least one optical sensor having the highest sensor signal and forming at least one center signal, wherein the center signal is selected from the group consisting of: the highest sensor signal; an average of a group of sensor signals being within a predetermined range of tolerance from the highest sensor signal; an average of sensor signals from a group of optical sensors containing the optical sensor having the highest sensor signal and a predetermined group of neighboring optical sensors; a sum of sensor signals from a group of optical sensors containing the optical sensor having the highest sensor signal and a predetermined group of neighboring optical sensors; a sum of a group of sensor signals being within a predetermined range of tolerance from the highest sensor signal; an average of a group of sensor signals being above a predetermined threshold; a sum of a group of sensor signals being above a predetermined threshold; an integral of sensor signals from a group of optical sensors containing the optical sensor having the highest sensor signal and a predetermined group of neighboring optical sensors; an integral of a group of sensor signals being within a predetermined range of tolerance from the highest sensor signal; an integral of a group of sen- sor signals being above a predetermined threshold.

Embodiment 8: The detector according to any one of the preceding embodiments, wherein the evaluation device is adapted for evaluating the sensor signals of the optical sensors of the ma- trix and forming at least one sum signal; wherein the sum signal is selected from the group con- sisting of: an average over all sensor signals of the matrix; a sum of all sensor signals of the matrix; an integral of all sensor signals of the matrix; an average over all sensor signals of the matrix except for sensor signals from those optical sensors contributing to the center signal; a sum of all sensor signals of the matrix except for sensor signals from those optical sensors con- tributing to the center signal; an integral of all sensor signals of the matrix except for sensor sig nals from those optical sensors contributing to the center signal; a sum of sensor signals of op- tical sensors within a predetermined range from the optical sensor having the highest sensor signal; an integral of sensor signals of optical sensors within a predetermined range from the optical sensor having the highest sensor signal; a sum of sensor signals above a certain threshold of optical sensors being located within a predetermined range from the optical sensor having the highest sensor signal; an integral of sensor signals above a certain threshold of opti- cal sensors being located within a predetermined range from the optical sensor having the highest sensor signal.

Embodiment 9: The detector according to any one of the preceding embodiments, wherein the evaluation device is configured for deriving the combined signal Q by , ίί _A1 E(x, y, ,- )dxdy

Q (z ₀ ) = — - ff _A2 E(x, y; z ₀ )dxdy wherein x and y are transversal coordinates, Ai and A ₂ are areas of the beam profile at the sen- sor position of at least one first optical sensor having generated the first sensor signal and of at least one second optical sensor having generated the second sensor signal, and E(x,y,z ₀ ) de- notes the beam profile given at the object distance zo.

Embodiment 10: The detector according to any one of the preceding embodiments, wherein the evaluation device is configured for determining at least two optical sensors being illuminated by the incident light beam having passed through the first filter region, determining therefrom at least one first optical sensor and at least one second optical sensor, wherein the first optical sensor has the sensor signal comprising at least one information of at least one first area of a beam profile of the incident light beam and the second optical sensor has the sensor signal comprising at least one information of at least one second area of the beam profile of the inci- dent light beam, wherein at least one first sensor signal and at least one second sensor signal are formed from the sensor signal of the first optical sensor and the sensor signal of the second optical sensor, respectively.

Embodiment 1 1 : The detector according to the preceding embodiment, wherein the evaluation device is configured for determining at least two optical sensors being illuminated by the inci- dent light beam having passed through the second filter region, determining therefrom at least one third optical sensor and at least one fourth optical sensor, wherein the third optical sensor has the sensor signal comprising at least one information of the first area of the beam profile of the incident light beam and the fourth optical sensor has the sensor signal comprising at least one information of the second area of the beam profile of the incident light beam, wherein at least one third sensor signal and at least one fourth sensor signal are formed from the sensor signal of the third optical sensor and the sensor signal of the fourth optical sensor, respectively.

Embodiment 12: The detector according to the preceding embodiment, wherein the evaluation device is configured for determining, in case both of the first sensor signal and the second sen- sor signal fulfill at least one pre-defined criterion, at least one first combined signal Q1 by com- bining the first sensor signal and the second sensor signal and/or determining, in case both of the third sensor signal and the fourth sensor signal fulfill the at least one pre-defined criterion, at least one second combined sensor signal Q2 by combining the third sensor signal and the fourth sensor signal; and wherein the evaluation device is configured to determine at least one first longitudinal coordinate z1 of the object by evaluating the first combined signal Q1 and/or at least one second longitudinal coordinate z2 of the object by evaluating the second combined signal Q2.

Embodiment 13: The detector according to any one of the three preceding embodiments, wherein the evaluation device is configured for deriving the first combined signal Q1 by one or more of dividing the first sensor signal and the second sensor signal, dividing multiples of the first sensor signal and the second sensor signal, dividing linear combinations of the first sensor signal and the second sensor signal, and wherein the evaluation device is configured for deriv- ing the second combined signal Q2 by one or more of dividing the third sensor signal and the fourth sensor signal, dividing multiples of the third sensor signal and the fourth sensor signal, dividing linear combinations of the third sensor signal and the fourth sensor signal.

Embodiment 14: The detector according to any one of the four preceding embodiments, where- in the evaluation device is configured for using at least one predetermined relationship between the combined signal Q1 and the longitudinal coordinate z1 for determining the longitudinal coor- dinate z1 , wherein the evaluation device is configured for using the at least one predetermined relationship between the combined signal Q2 and the longitudinal coordinate z2 for determining the longitudinal coordinate z2.

Embodiment 15: The detector according to any one of the five preceding embodiments, wherein the first area of the beam profile comprises essentially edge information of the beam profile and the second area of the beam profile comprises essentially center information of the beam pro- file.

Embodiment 16: The detector according to any one of the six preceding embodiments, wherein the first optical sensor is the optical sensor having the highest sensor signal of the at least two optical sensors being illuminated by the incident light beam having passed through the first filter region, wherein the first sensor signal is at least one first center signal, wherein the third optical sensor is the optical sensor having the highest sensor signal of the at least two optical sensors being illuminated by the incident light beam having passed through the second filter region, wherein the third sensor signal is at least one second center signal, wherein the second sensor signal is a first sum signal of the at least two optical sensors being illuminated by the incident light beam having passed through the first filter region, wherein the fourth sensor signal is a second sum signal of the at least two optical sensors being illuminated by the incident light beam having passed through the second filter region.

Embodiment 17: The detector according to the seven preceding embodiment, wherein one or both of the first center signal and the second center signal are selected from the group consist- ing of: the highest sensor signal; an average of a group of sensor signals being within a prede- termined range of tolerance from the highest sensor signal; an average of sensor signals from a group of optical sensors containing the optical sensor having the highest sensor signal and a predetermined group of neighboring optical sensors; a sum of sensor signals from a group of optical sensors containing the optical sensor having the highest sensor signal and a predeter- mined group of neighboring optical sensors; a sum of a group of sensor signals being within a predetermined range of tolerance from the highest sensor signal; an average of a group of sen- sor signals being above a predetermined threshold; a sum of a group of sensor signals being above a predetermined threshold; an integral of sensor signals from a group of optical sensors containing the optical sensor having the highest sensor signal and a predetermined group of neighboring optical sensors; an integral of a group of sensor signals being within a predeter- mined range of tolerance from the highest sensor signal; an integral of a group of sensor signals being above a predetermined threshold.

Embodiment 18: The detector according to any one of the two preceding embodiments, wherein one or both of the first sum signal and the second sum signal are selected from the group con- sisting of: an average over all sensor signals of the matrix; a sum of all sensor signals of the matrix; an integral of all sensor signals of the matrix; an average over all sensor signals of the matrix except for sensor signals from those optical sensors contributing to the center signal; a sum of all sensor signals of the matrix except for sensor signals from those optical sensors con- tributing to the center signal; an integral of all sensor signals of the matrix except for sensor sig nals from those optical sensors contributing to the center signal; a sum of sensor signals of op- tical sensors within a predetermined range from the optical sensor having the highest sensor signal; an integral of sensor signals of optical sensors within a predetermined range from the optical sensor having the highest sensor signal; a sum of sensor signals above a certain threshold of optical sensors being located within a predetermined range from the optical sensor having the highest sensor signal; an integral of sensor signals above a certain threshold of opti- cal sensors being located within a predetermined range from the optical sensor having the highest sensor signal.

Embodiment 19: The detector according to any one of the nine preceding embodiments, where- in the evaluation device is configured for deriving the combined signals Qi with i = 1 , 2 by

wherein x and y are transversal coordinates, An and A21 are areas of the beam profile at the sensor position of the first optical sensor and of the second optical sensor, respectively, A12 and A22 are areas of the beam profile at the sensor position of the third optical sensor and of the fourth optical sensor, respectively, and E(x,y,z ₀ ) denotes the beam profile given at the object distance z ₀ .

Embodiment 20: The detector according to any one of the preceding embodiments, wherein the sensor element is arranged such that the incident light beam impinging on the sensor element generates at least one light spot, wherein the filter element is arranged such that a first part of the light spot is generated by a part of the incident light beam having passed through the sec- ond filter region and that a second part of the light spot is generated by another part of the inci- dent light beam having passed through the second filter region.

Embodiment 21 : The detector according to any one of the preceding embodiments, wherein the filter element is adapted to generate a plurality of different filter regions such as three filter re- gions, four filter regions or more filter regions. Embodiment 22: The detector according to any one of the preceding embodiments, wherein the filter element and the transfer device are arranged such that the incident light beam propagating from the object passes through the filter element and subsequently through the transfer device before impinging on the sensor element.

Embodiment 23: The detector according to any one of the preceding embodiments, wherein the detector comprises at least one control device, wherein the control device is adapted to adjust exposure times depending on at least one property of the object and/or of the sensor signals.

Embodiment 24: The detector according to any one of the preceding embodiments, wherein the evaluating of the sensor signals comprises at least one background correction, wherein the sensor signals are corrected for background brightness.

Embodiment 25: The detector according to any one of the preceding embodiments, wherein the evaluation device is adapted to identify at least one light spot generated by the incident light beam on the sensor element using overexposed signals.

Embodiment 26: The detector according to any one of the preceding embodiments, wherein the beam profile is selected from the group consisting of a trapezoid beam profile; a triangle beam profile; a conical beam profile and a linear combination of Gaussian beam profiles.

Embodiment 27: The detector according to any one of the preceding embodiments, wherein the first area of the beam profile and the second area of the beam profile are one or both of adja- cent or overlapping regions.

Embodiment 28: The detector according to any one of the preceding embodiments, wherein the detector further comprises at least one illumination source for illuminating the object, wherein the illumination source comprises at least one light source.

Embodiment 29: The detector according to the preceding embodiment, wherein the illumination source comprises at least one laser source, wherein the illumination source comprises at least one diffractive optical element (DOE).

Embodiment 30: The detector according to any one of the preceding embodiments, wherein the evaluation device comprises at least one divider, wherein the divider is configured for deriving the combined signal Q and/or the combined signals.

Embodiment 31 : The detector according to any one of the preceding embodiments, wherein the optical sensors are or comprise at least one element selected from the group consisting of: a CCD sensor element, a CMOS sensor element, a photodiode, a photocell, a photoconductor, a phototransistor or any combination thereof. Embodiment 32: The detector according to any one of the preceding embodiments, wherein the evaluation device is further configured for determining at least one transversal coordinate of the object by evaluating a transversal position of at least one optical sensor having the highest sen- sor signal.

Embodiment 33: A detector system for determining a position of at least one object, the detector system comprising at least one detector according to any one of the preceding embodiments, the detector system further comprising at least one beacon device adapted to direct at least one light beam towards the detector, wherein the beacon device is at least one of attachable to the object, holdable by the object and integratable into the object.

Embodiment 34: A human-machine interface for exchanging at least one item of information between a user and a machine, wherein the human-machine interface comprises at least one detector system according to the preceding embodiment, wherein the at least one beacon de- vice is adapted to be at least one of directly or indirectly attached to the user and held by the user, wherein the human-machine interface is designed to determine at least one position of the user by means of the detector system, wherein the human-machine interface is designed to assign to the position at least one item of information.

Embodiment 35: An entertainment device for carrying out at least one entertainment function, wherein the entertainment device comprises at least one human-machine interface according to the preceding embodiment, wherein the entertainment device is designed to enable at least one item of information to be input by a player by means of the human-machine interface, wherein the entertainment device is designed to vary the entertainment function in accordance with the information.

Embodiment 36: A tracking system for tracking a position of at least one movable object, the tracking system comprising at least one detector system according to any one of the preceding embodiments referring to a detector system, the tracking system further comprising at least one track controller, wherein the track controller is adapted to track a series of positions of the object at specific points in time.

Embodiment 37: A scanning system for determining a depth profile of a scenery, the scanning system comprising at least one detector according to any of the preceding embodiments refer- ring to a detector, the scanning system further comprising at least one illumination source adapted to scan the scenery with at least one light beam.

Embodiment 38: A camera for imaging at least one object, the camera comprising at least one detector according to any one of the preceding embodiments referring to a detector.

Embodiment 39: A readout device for optical storage media, the readout device comprising at least one detector according to any one of the preceding embodiments referring to a detector. Embodiment 40: A method for determining a position of at least one object by using at least one detector, the method comprising the following steps:

illuminating at least one sensor element of the detector with the at least one incident light beam propagating from the object to the detector, the sensor element having a matrix of optical sensors, the optical sensors each having a light-sensitive area, wherein each optical sensor generates at least one sensor signal in response to the illumination,

wherein the incident light beam passes through at least one filter element and at least one transfer device before impinging on the sensor element, wherein the filter ele- ment is configured such that in at least one first filter region and in at least one sec- ond filter region at least one property of the incident light beam is modified differently; evaluating the sensor signals, by evaluating at least one first sensor signal and at least one second sensor signal, wherein the first sensor signal is generated in re- sponse to illumination having passed through the first filter region and the second sensor signal is generated in response to illumination having passed through the first and/or second filter region, and wherein the evaluation comprises determining at least one longitudinal coordinate z of the object by evaluating a combined signal Q from the first sensor signal and the second sensor signal.

Embodiment 40: The method according to the preceding embodiment, wherein the evaluat- ing comprises

i) determining at least two optical sensors being illuminated by the incident light beam having passed through the first filter region, determining therefrom at least one first op- tical sensor and at least one second optical sensor, wherein the first optical sensor has the sensor signal comprising at least one information of at least one first area of a beam profile of the incident light beam and the second optical sensor has the sensor signal comprising at least one information of at least one second area of the beam profile of the incident light beam, wherein at least one first sensor signal and at least one second sensor signal are formed from the sensor signal of the first optical sensor and the sen- sor signal of the second optical sensor, respectively;

ii) determining at least two optical sensors being illuminated by the incident light beam having passed through the second filter region, determining therefrom at least one third optical sensor and at least one fourth optical sensor, wherein the third optical sensor has the sensor signal comprising at least one information of the first area of the beam profile of the incident light beam and the fourth optical sensor has the sensor signal comprising at least one information of the second area of the beam profile of the inci- dent light beam, wherein at least one third sensor signal and at least one fourth sensor signal are formed from the sensor signal of the third optical sensor and the sensor sig- nal of the fourth optical sensor, respectively;

iii) determining, in case both of the first sensor signal and the second sensor signal fulfill at least one pre-defined criterion, at least one first combined signal Q1 by combining the first sensor signal and the second sensor signal and/or determining, in case both of the third sensor signal and the fourth sensor signal fulfill the at least one pre-defined criteri- on, at least one second combined sensor signal Q2 by combining the third sensor sig nal and the fourth sensor signal; and

iv) determining at least one first longitudinal coordinate z1 of the object by evaluating the first combined signal Q1 and/or at least one second longitudinal coordinate z2 of the ob- ject by evaluating the second combined signal Q2.

Embodiment 41 : A use of the detector according to any one of the preceding embodiments re- lating to a detector, for a purpose of use, selected from the group consisting of: a position measurement in traffic technology; an entertainment application; an optical data storage appli cation; a security application; a surveillance application; a safety application; a human-machine interface application; a logistics application; a tracking application; a photography application; a machine vision application; a robotics application; a quality control application; a manufacturing application; a use in combination with optical data storage and readout; a mobile application; an information technology application; an agriculture application; a crop protection application; a medical application; a maintenance application; a cosmetics application.

Brief description of the figures

Further optional details and features of the invention are evident from the description of pre- ferred exemplary embodiments which follows in conjunction with the dependent claims. In this context, the particular features may be implemented in an isolated fashion or in combination with other features. The invention is not restricted to the exemplary embodiments. The exempla- ry embodiments are shown schematically in the figures. Identical reference numerals in the in- dividual figures refer to identical elements or elements with identical function, or elements which correspond to one another with regard to their functions.

Specifically, in the figures:

Figure 1 shows an embodiment of a detector according to the present invention;

Figure 2 shows schematically an image of a light spot on a sensor element ac- cording to the present invention;

Figure 3 shows a measured image of the light spot; and

Figure 4 shows an exemplary embodiment of a detector according to the present invention, a detector system, a human-machine interface, an entertain- ment device, a tracking system, a scanning system and a camera.

Detailed description of the embodiments

In Fig. 1 , a schematic view of a first embodiment of a detector 1 10 for determining a position of at least one object 112 is depicted. The detector 110 comprises at least one sensor element 1 14 having a matrix 1 16 of optical sensors 118. Each of the optical sensors 118 has a light- sensitive area 120. Each optical sensor 118 is configured to generate at least one sensor signal in response to an illumination of the light-sensitive area 120 by at least one incident light beam 122 propagating from the object 1 12 to the detector 110. The optical sensors 1 18 of the matrix 1 16 specifically may be equal in one or more of size, sensitivity and other optical, electrical and mechanical properties. The light-sensitive areas 120 of all optical sensors of the matrix 1 16 specifically may be located in a common plane, the common plane preferably facing the object 112, such that the incident light beam 122 propagating from the object 1 12 to the detector 1 10 may generate a light spot on the common plane. The incident light beam 122, as an example, may propagate along an optical axis 124 of the detector 110. Other embodiments, however, are feasible. The sensor element 116 may comprise one or more of at least one bi-cell diode, at least one quadrant diode; at least one CCD chip, at least one CMOS chip. As an example, the optical sensors 1 18 may be part of or constitute a bi-cell diode and/or at least one CCD and/or CMOS device having a matrix of pixels, each pixel forming a light-sensitive area.

The optical detector 1 10, further, comprises at least one transfer device 126, such as at least one lens or a lens system, specifically for beam shaping. The transfer device 126 has at least one focal length in response to the incident light beam 122 propagating from the object 1 12 to the detector 1 10. The transfer device 128 has an optical axis, wherein the transfer device 126 and the detector 1 10 preferably may have a common optical axis. The transfer device 126 con- stitutes a coordinate system. A direction parallel or anti-parallel to the optical axis 124 may be defined as a longitudinal direction, whereas directions perpendicular to the optical axis 124 may be defined as transversal directions. Consequently, the light beam 122 may be focused, such as in one or more focal points, and a beam width of the light beam 122 may depend on a longi- tudinal coordinate z of the object 1 12, such as on a distance between the detector 110 and the object 1 12. The optical sensors 118 may be positioned off focus.

The incident light beam 122 may propagate from the object 1 12 towards the detector 110. The incident light beam 122 may originate from the object 112, such as by the object 112 and/or at least one illumination source integrated or attached to the object 1 12 emitting the light beam, or may originate from a different illumination source 128, such as from an illumination source di- rectly or indirectly illuminating the object 112 with at least one illumination light beam 130. The illumination light beam 130 may be reflected or scattered by the object 1 12 and is, thereby, at least partially directed towards the detector 110. Thus, as shown in Figure 1 , the detector may further comprise the at least one illumination source 128 for illuminating the object 112, wherein the illumination source 128 comprises at least one light source. The illumination source 128, as an example, may be or may comprise one or more of an external illumination source, an illumi nation source 128 integrated into the detector 110 or an illumination source 128 integrated into a beacon device being one or more of attached to the object 112, integrated into the object 1 12 or held by the object 112. Thus, the detector 110 may be used in active and/or passive illumina- tion scenarios. For example, the illumination source 128 may be adapted to illuminate the object 112, for example, by directing a light beam towards the object 112, which reflects the light beam. Additionally or alternatively, the object 112 may be adapted to generate and/or to emit the at least one light beam 122. The light source may be or may comprise at least one multiple beam light source. For example, the illumination source 128 may comprise at least one laser source. For example, the light source may comprise at least one laser source and one or more diffractive optical elements (DOEs).

The detector 1 10 comprises at least one filter element 132 configured for generating at least two filter regions 134. The filter element 132 is configured such that in at least one first filter re- gion 136 and in at least one second filter region 138 at least one property of the incident light beam 122 is modified differently. The at least one property of the incident light beam 122 may be a property selected from the group consisting of: intensity of the incident light beam; intensity of one or more wavelength of incident light beam; a number of photons; brightness a value of a sensor signal; a digitized value of a sensor signal such as a sensor signal processed by an ana- log digital converter; an amplified sensor signal; a pre-amplified sensor signal; a sensor signal filtered by analog or digital electronics; a noise level; a sensor signal relative to a noise level. Overdriven signals or overload of the signal may refer raw sensor signals and/or may result from subsequent analog- or digital electronics such as ADC, amplifiers and the like.

In particular, the filter element 132 may be adapted to modify and/or reduce the intensity of the incident light beam 122 passing through the filter element 132. The filter element 132 may corn- prise at least one neutral-density filter 140. The neutral-density filter 140 may be selected from the group consisting of: a circular neutral-density filter, in particular at least one semi-circle neu- tral-density filter; at least one square shaped neutral-density filter; at least one split neutral- density filter; at least one graduated neutral-density filter; a neutral-density filter wheel; a varia- ble neutral density filter; a Lee Big Stopper. The filter element 132 and the transfer device 126 may be arranged such that the incident light beam 122 propagating from the object 1 12 passes through the filter element 132 and subsequently through the transfer device 126 before imping- ing on the sensor element 114. Additionally or alternatively, the filter element 132 may be ar- ranged between the transfer device 126 and the sensor element 114. The filter element 132 may be adapted to generate a plurality of different filter regions 134 such as three filter regions, four filter regions or more filter regions. In case the filter is between transfer device and sensor, the distance between filter and sensor may be larger than the distance between transfer device and filter. Additionally or alternatively, the detector 1 10 may comprise a plurality of filter ele- ments 132 each adapted to generate at least one filter region 134. Each of the filter regions 134 may have different influence on the property of the incident light beam 122. The filter element 132 may comprise at least two sections having different optical depths. For example, the first filter region 134 may comprise the at least one neutral-density filter 140 and the second filter region 138 may be configured that the property of the incident light beam 122 is maintained, e.g. by using a clear element such as glass or leaving a section of an aperture of the transfer device 126 uncovered. For example, the filter element 132 may comprise at least two neutral- density filters 140, , wherein a first one of the neutral-density filters may modify a first wave- length of the incident light beam and/or has a first optical depth, wherein a second one of the neutral-density filters may modify a second wavelength, different from the first wavelength of the incident light beam and/or has a second optical depth, different from the first optical depth. For example, the filter element 132 may comprise at least one graduated neutral-density filter, such as a hard edge or soft edge graduated neutral-density filter. Preferably the filter element corn- prises a hard edge graduated neutral-density to ensure separation of filter regions.

The sensor element 1 14 may be arranged such that the incident light beam 122 impinging on the sensor element 1 14 generates at least one light spot 144. The filter element 132 may be arranged such that a first part 142 of the light spot 144 is generated by a part of the incident light beam 122 having passed through the first filter region 134 and that a second part 146 of the light spot 144 is generated by another part of the incident light beam 122 having passed through the second filter region 138. For example, as shown in Figure 1 , the filter element 132 may comprise at least one half-circle neutral-density filter 140. The half-circle neutral-density filter 140 may be arranged such that it covers one part of the aperture of the transfer device 126, for example a half side, or a section. Thus, the at least one property of a part of the inci- dent light beam passing 122 through the half-circle neutral-density filter 140 may be modified by the half-circle neutral-density filter 140, whereas the at least one property of other parts of the incident light beam 122 not passing through the half-circle neutral-density filter 140 may be un- changed. Figure 2 shows schematically, the resulting light spot 144 on the sensor element 114 and Figure 3 shows exemplarily a measured light spot 144. The light spot 144 generated on the sensor element 144 may have a round or non-round shape. A blurring or confusion of the light spot 144 may depend on a shape of the filter element 132. For example, in case of the embod- iment using a half-circle neutral-density filter 140, half, i.e. the first part 142, of the light spot 144 may be generated by the incident light beam 122 having passed through the half-circle neutral- density filter 140 and may be darker compared to the other half of the light spot 144 not being influenced by the half-circle neutral-density filter 140. Thus, the filter element 114 may be adapted to adjust an amount of light impinging on the sensor element 116. Light originating from a dark object 112 can be observed via the non-filtered side of the light spot 144 and light origi nating from a bright object 1 12 can be observed via the filtered side of the light spot 144. This allows to adjust exposure times. The detector 110 may comprise at least one control device 148. The control device 148 may be adapted to adjust exposure times depending on at least one property of the object 112, such as brightness of the object 112, and/or of the sensor sig nals.

Each of the optical sensors 1 18, in response to the illumination by the light beam 122, may generate a sensor signal. Preferably, the optical sensors 1 18 are linear optical sensors, i.e. the sensor signals each are solely dependent on the total power of the light beam 122 or of the por- tion of the light beam 122 illuminating their respective light-sensitive areas 120, whereas these sensor signals are independent from the actual size of the light spot of illumination. In other words, preferably, the optical sensors 1 18 do not exhibit the above-described FiP effect.

The detector 1 10 furthermore comprises at least one evaluation device 150. The evaluation device 150 is configured for evaluating at least one first sensor signal and at least one second sensor signal, wherein the first sensor signal is generated in response to illumination having passed through one of the first filter region 136 and the second filter region 138 and the second sensor signal is generated in response to illumination having passed through the same or the other one of the first filter region 136 and the second filter region 138, and wherein the evalua- tion comprises determining at least one longitudinal coordinate z of the object 112 by evaluating a combined signal Q from the first sensor signal and the second sensor signal.

Specifically, the evaluation device 150 may be configured for evaluating the sensor signals, by a) determining at least two optical sensors 118 being illuminated by the incident light beam 122 having passed through the first filter region 136, determining therefrom at least one first optical sensor 152 and at least one second optical sensor 154, wherein the first optical sen- sor 152 has the sensor signal comprising at least one information of at least one first area 156 of a beam profile of the incident light beam 122 and the second optical sensor 154 has the sensor signal comprising at least one information of at least one second area 158 of the beam profile of the incident light beam 122, wherein at least one first sensor signal and at least one second sensor signal are formed from the sensor signal of the first optical sensor 152 and the sensor signal of the second optical sensor 154, respectively;

b) determining at least two optical sensors 118 being illuminated by the incident light beam 122 having passed through the second filter region 138, determining therefrom at least one third optical sensor 160 and at least one fourth optical sensor 162, wherein the third optical sensor 160 has the sensor signal comprising at least one information of the first area 156 of the beam profile of the incident light beam 122 and the fourth optical sensor 162 has the sensor signal comprising at least one information of the second area 158 of the beam pro- file of the incident light beam 122, wherein at least one third sensor signal and at least one fourth sensor signal are formed from the sensor signal of the third optical sensor 160 and the sensor signal of the fourth optical sensor 162, respectively;

c) determining, in case both of the first sensor signal and the second sensor signal fulfill at least one pre-defined criterion, at least one first combined signal Q1 by combining the first sensor signal and the second sensor signal and/or determining, in case both of the third sensor signal and the fourth sensor signal fulfill the at least one pre-defined criterion, at least one second combined sensor signal Q2 by combining the third sensor signal and the fourth sensor signal; and

d) determining at least one first longitudinal coordinate z1 of the object 1 12 by evaluating the first combined signal Q1 and/or at least one second longitudinal coordinate z2 of the object 112 by evaluating the second combined signal Q2.

The evaluation device 150 may comprise at least one divider 164 for forming the first combined signal Q1 and/or the second combined signal Q2, and, as an example, at least one position evaluation device 166, for deriving the first longitudinal coordinate z1 and/or the second longitu- dinal coordinate z2 from the respective combined signal. It shall be noted that the evaluation device 150 may fully or partially be embodied in hardware and/or software. Thus, as an exam- pie, one or more of components 164, 166 may be embodied by appropriate software compo- nents. As outlined above, the evaluation device 150 is configured to evaluate the sensor signals, by determining at least two optical sensors 118 being illuminated by the incident light beam having passed through the first filter region 136. The evaluation device 150 is configured to evaluate the sensor signals, by determining at least two optical sensors 1 18 being illuminated by the in- cident light beam having passed through the second filter region 138. The evaluation device 150 may be adapted to perform at least one image analysis and/or image processing in order to identify the light spot 144. The image analysis and/or image processing may use at least one feature detection algorithm. The image analysis and/or image processing may comprise one or more of the following: a filtering; a selection of at least one region of interest; a formation of a difference image between an image created by the sensor signals and at least one offset; an inversion of sensor signals by inverting an image created by the sensor signals; a formation of a difference image between an image created by the sensor signals at different times; a back- ground correction; a decomposition into color channels; a de-composition into hue; saturation; and brightness channels; a frequency decomposition; a singular value decomposition; applying a blob detector; applying a corner detector; applying a Determinant of Hessian filter; applying a principle curvature-based region detector; applying a maximally stable extremal regions detec- tor; applying a generalized Hough-transformation; applying a ridge detector; applying an affine invariant feature detector; applying an affine-adapted interest point operator; applying a Harris affine region detector; applying a Hessian affine region detector; applying a scale-invariant fea- ture transform; applying a scale-space extrema detector; applying a local feature detector; ap- plying speeded up robust features algorithm; applying a gradient location and orientation histo- gram algorithm; applying a histogram of oriented gradients descriptor; applying a Deriche edge detector; applying a differential edge detector; applying a spatio-temporal interest point detector; applying a Moravec corner detector; applying a Canny edge detector; applying a Laplacian of Gaussian filter; applying a Difference of Gaussian filter; applying a Sobel operator; applying a Laplace operator; applying a Scharr operator; applying a Prewitt operator; applying a Roberts operator; applying a Kirsch operator; applying a high-pass filter; applying a low-pass filter; ap- plying a Fourier transformation; applying a Radon-transformation; applying a Hough- transformation; applying a wavelet-transformation; a thresholding; creating a binary image. The evaluation device 150 may be adapted to determine a region of interest. The region of interest may be determined manually by a user or may be determined automatically, such as by recog- nizing an object within an image generated by the optical sensors. The evaluation device 150 may filter the reflection beam profile by removing high spatial frequencies such as by spatial frequency analysis and/or median filtering or the like. The evaluation device 150 may be adapted to perform a summarization by center of intensity of the light spot and averaging all intensities at the same distance to the center. The evaluation device 150 may be adapted to identify the at least one light spot 144 generated by the incident light beam 122 on the sensor element 1 18 using overexposed pixels of the matrix 1 16. For example, the evaluation device 150 may be adapted to search for overexposed pixels and to determine a surrounding pixel ar- ea of the matrix 116 as region of interest. The evaluation device 150 may be adapted to deter- mine a change in intensity due to the light beam 122 passing through the first filter region 136 and the second filter region 138 within the region of interest. For example, the evaluation device 150 may be adapted to select those optical sensors 1 18 of the region of interest having an in- tensity value below or above a pre-defined or pre-determined threshold as optical sensors 1 18 being illuminated by the incident light beam 122 having passed through the first filter region 136. For example, the evaluation device 150 may be adapted to select those optical sensors 118 of the region of interest having an intensity value above or equal to the pre-defined or pre- determined threshold as optical sensors 1 18 being illuminated by the incident light beam 122 having passed through the second filter region 138.

The evaluation device 150 is configured for determining from the at least two optical sensors 118 being illuminated by the incident light beam 122 having passed through the first filter region 136 the at least one first optical sensor 152 and the at least one second optical sensor 154. The first optical sensor 152 has the sensor signal comprising at least one information of the first area 156 of the beam profile of the incident light beam 122. The second optical sensor 154 has the sensor signal comprising at least one information of the second area 158 of the beam profile of the incident light beam 122. The evaluation device 150 is configured for determining from the at least two optical sensors 1 18 being illuminated by the incident light beam 122 having passed through the second filter region 138 the at least one third optical sensor 160 and the at least one fourth optical sensor 162. The third optical sensor 160 has the sensor signal comprising at least one information of the first area 156 of the beam profile of the incident light beam 122 and the fourth optical sensor 162 has the sensor signal comprising at least one information of the second area 158 of the beam profile of the incident light beam 122. The beam profile may be a cross section of the light beam 122. The beam profile may be selected from the group consist- ing of a trapezoid beam profile; a triangle beam profile; a conical beam profile and a linear com- bination of Gaussian beam profiles. The light-sensitive areas 120 may be arranged such that the first sensor signal comprises information of the first area 156 of the beam profile and the second sensor signal comprises information of the second area 158 of the beam profile. The first area 156 of the beam profile and second area 158 of the beam profile may be one or both of adjacent or overlapping regions. The first area 156 of the beam profile and the second area 158 of the beam profile may be not congruent in area. The evaluation device 150 may be con- figured to determine and/or to select the first area 156 of the beam profile and the second area 158 of the beam profile. The first area 156 of the beam profile may comprise essentially edge information of the beam profile and the second area 158 of the beam profile may comprise es- sentially center information of the beam profile. The beam profile may have a center, i.e. a max- imum value of the beam profile and/or a center point of a plateau of the beam profile and/or a geometrical center of the light spot 144, and falling edges extending from the center. The sec- ond are 158 may comprise inner regions of the cross section and the first area 156 may corn- prise outer regions of the cross section. Preferably the center information has a proportion of edge information of less than 10 %, more preferably of less than 5%, most preferably the center information comprises no edge content. The edge information may comprise information of the whole beam profile, in particular from center and edge regions. The edge information may have a proportion of center information of less than 10 %, preferably of less than 5%, more preferably the edge information comprises no center content. At least one area of the beam profile may be determined and/or selected as second area 158 of the beam profile if it is close or around the center and comprises essentially center information. At least one area of the beam profile may be determined and/or selected as first area 156 of the beam profile if it comprises at least parts of the falling edges of the cross section. For example, the whole area of the cross section may be determined as first area. The first area 156 of the beam profile may be an area denoted as A2 and the second area 158 of the beam profile may be an area denoted as A1.

The first optical sensor 152 may be the optical sensor 1 18 having the highest sensor signal of the at least two optical sensors 1 18 being illuminated by the incident light beam 122 having passed through the first filter region 136. The first sensor signal may be at least one first center signal. The third optical sensor 160 may be the optical sensor 1 18 having the highest sensor signal of the at least two optical sensors 1 18 being illuminated by the incident light beam 122 having passed through the second filter region 138. The third sensor signal may be at least one second center signal. The second sensor signal may be a first sum signal of the at least two optical sensors 1 18 being illuminated by the incident light beam having passed through the first filter region 136. The fourth sensor signal may be a second sum signal of the at least two optical sensors 118 being illuminated by the incident light beam 122 having passed through the second filter region 138.

The evaluation device 150 may be configured to derive the combined signals Q1 and Q2 by one or more of dividing the respective edge information and the respective center information, divid ing multiples of the respective edge information and the respective center information, dividing linear combinations of the respective edge information and the respective center information. Thus, essentially, photon ratios may be used as the physical basis of the measurement princi- ple. For example, the evaluation device 150 may be configured for deriving the signals Qi with i = 1 , 2 by

wherein x and y are transversal coordinates, An and A21 are areas of the beam profile at the sensor position of the first optical sensor 152 and of the second optical sensor 154, respective- ly, A12 and A22 are areas of the beam profile at the sensor position of the third optical sensor 160 and of the fourth optical sensor 162, respectively, and E(x,y,z ₀ ) denotes the beam profile given at the object distance z ₀ . In particular, A1 1 and A21 are not congruent. A1 1 and A21 may differ in one or more of the shape or content. In particular, A12 and A22 are not congruent. A12 and A22 may differ in one or more of the shape or content.

The evaluation device 150 is configured to determine, in case both of the first sensor signal and the second sensor signal fulfill at least one pre-defined criterion, at least one first combined sig nal Q1 by combining the first sensor signal and the second sensor signal and/or determining, in case both of the third sensor signal and the fourth sensor signal fulfill the at least one pre- defined criterion, at least one second combined sensor signal Q2 by combining the third sensor signal and the fourth sensor signal. The evaluation device 150 may be adapted to compare the first sensor signal and the second sensor signal to the pre-defined criterion. In case both of the first sensor signal and the second sensor signal fulfill the at least one pre-defined criterion, for example, in case intensity of the first sensor signal and the second sensor signal are below or equal the at least one upper intensity threshold and/or are above the at least one lower intensity threshold, the evaluation device 150 determines the first combined signal Q1 by combining the first sensor signal and the second sensor signal. The evaluation device 150 may be adapted to compare the third sensor signal and the fourth sensor signal to the pre-defined criterion. In case both of the third sensor signal and the fourth sensor signal fulfill the at least one pre-defined criterion, for example, in case intensity of the third sensor signal and the fourth sensor signal are below or equal the at least one upper intensity threshold and/or are above the at least one lower intensity threshold, the evaluation device determines 150 the second combined signal Q2 by combining the third sensor signal and the fourth sensor signal. An upper limit may be chosen as follows. The pixel is oversaturated if the maximum value of the ADC is reached. Thus, in case of an 8 bit ADC, the pixel is oversaturated, when the ADC returns an intensity of 255.

Thus, the upper limit would be 254. Generally, the upper limit may be the highest possible ADC output minus 5, preferably minus 2, more preferably minus 1. A lower limit may be chosen as follows. The pixel intensity is too low, if the value returned by the ADC is below the dark noise level. The dark noise level may be determined as the maximum value returned by the ADC, when the pixel is not illuminated. The dark noise level may be determined by pixel, by column, by line, or for the complete imaging device. The dark noise level may be determined as a time averaged value. The threshold for the lowest pixel intensity may be the dark noise level plus two times the standard deviation of the dark noise level, preferably plus the standard deviation of the dark noise level, more preferably plus 1.

The evaluation device 150 may be adapted to reject the respective sensor signal in case the sensor signal does not fulfill the pre-defined criterion. The evaluation device 150 may be adapted to generate and/or issue information about the rejection, such as an acoustical, electri cal, or optical signal. In case one or more of the first or second sensor signals is rejected but both of the third and fourth sensor signals fulfill the pre-defined criterion, only the second com- bined signal Q2 is determined. In case one or more of the third or fourth sensor signals is re- jected but both of the first and second sensor signals fulfill the pre-defined criterion, only the first combined signal Q1 is determined. In case all sensor signals fulfill the pre-defined criterion, both of the first combined signal Q1 and the second combined signal Q2 are determined. In case one or more of the first and second sensor signals and one or more of the third and the fourth sen- sor signals are rejected, the evaluation device 150 may be adapted to repeat determining of the incident light beam, forming the first and second sensor signals and/or forming the third and fourth sensor signals, for example with adjusted exposure time.

The evaluation device 150 is adapted to determine the at least one first longitudinal coordinate z1 of the object 112 by evaluating the first combined signal Q1 and/or at least one second longi- tudinal coordinate z2 of the object 112 by evaluating the second combined signal Q2. As out- lined above, in case one or more of the first or second sensor signals is rejected but both of the third and fourth sensor signals fulfill the pre-defined criterion, only the second combined signal Q2 is determined. Thus, in this case the evaluation device 150 may only determine the second longitudinal coordinate z2 of the object 112 by evaluating the second combined signal Q2, but the evaluation device 150 may not determine the first longitudinal coordinate z1. Further, as outlined above, in case one or more of the third or fourth sensor signals is rejected but both of the first and second sensor signals fulfill the pre-defined criterion, only the first combined signal Q1 is determined. Thus, in this case the evaluation device 150 may only determine the first lon- gitudinal coordinate z1 of the object 1 12 by evaluating the first combined signal Q1 , but the evaluation device 150 may not determine the second longitudinal coordinate z2. In case all sen- sor signals of the first, second, third and fourth sensor signals fulfill the pre-defined criterion, both of the first combined signal Q1 and the second combined signal Q2 are determined and the evaluation device 150 may determine both, the first longitudinal coordinate z1 and the sec- ond longitudinal coordinate z2. The evaluation device 150 may be adapted to determine a com- bined longitudinal coordinate, for example, by determining a mean value or by selecting the lon- gitudinal coordinate having lower noise or error.

As outlined above, a predetermined or determinable relationship exists between a size of the light spot 144, such as a diameter of the light spot 144, a beam waist or an equivalent diameter, and the longitudinal coordinate of the object 112 from which the light beam 122 propagates to- wards the detector 110. Without wishing to be bound by this theory, the light spot 144, may be characterized by two measurement variables: a measurement signal measured in a small measurement patch in the center or close to the center of the light spot 144, also referred to as the center signal, and an integral or sum signal integrated over the light spot 144, with or with- out the center signal. For a light beam having a certain total power which does not change when the beam is widened or focused, the sum signal should be independent from the spot size of the light spot 144, and, thus, should, at least when linear optical sensors within their respective measurement range are used, be independent from the distance between the object 112 and the detector 110. The center signal, however, is dependent on the spot size. Thus, the center signal typically increases when the light beam is focused, and decreases when the light beam is defocused. By comparing the center signal and the sum signal, thus, an item of information on the size of the light spot 144 generated by the light beam 122 and, thus, on the longitudinal co- ordinate of the object 1 12 may be generated. The comparing of the respective center signal and the respective sum signal, as an example, may be done by forming the combined signals Q1 and/or Q2 out of the center signals and the sum signals and by using a predetermined or de- terminable relationship between the respective longitudinal coordinate and the respective com- bined signal for deriving the longitudinal coordinate.

The evaluation device 150 may be configured to determine the longitudinal coordinate z1 and the longitudinal coordinate z2 by using at least one known, determinable or predetermined rela- tionship between the sensor signals and the longitudinal coordinate. In particular, the evaluation device 150 may be configured to determine the longitudinal coordinate z1 of the object 112 by using at least one known, determinable or predetermined relationship between the combined signal derived from the first and second sensor signals and the longitudinal coordinate z1. In particular, the evaluation device 150 may be configured to determine the longitudinal coordinate z2 of the object by using at least one known, determinable or predetermined relationship be- tween the respective combined signal derived from the third and fourth sensor signals respec- tively and the longitudinal coordinate. The known, determinable or predetermined relationship for the determination of the longitudinal coordinate z1 and the longitudinal coordinate z2 may be identical. The predetermined relationship may be one or more of an empiric relationship, a semi-empiric relationship and an analytically derived relationship. The evaluation device 150 may comprise at least one data storage device for storing the predetermined relationship, such as a lookup list or a lookup table.

The detector 1 10 may be adapted to provide additional information on a transversal coordinate of the object 112 and/or of parts thereof. In particular, the evaluation device 150 may be adapted to determine from the transversal position of the light spot 144 on the matrix 116 of the CCD and/or the CMOS pixelated sensors a transversal coordinate of the object 112 and/or of parts thereof. The transversal coordinate may be used to verify and/or enhance the quality of the distance information.

Figure 4 shows, in a highly schematic illustration, an exemplary embodiment of a detector 110, e.g. according to the embodiment shown in Figure 1. The detector 1 10 specifically may be em- bodied as a camera 168 and/or may be part of a camera 168. The camera 68 may be made for imaging, specifically for 3D imaging, and may be made for acquiring standstill images and/or image sequences such as digital video clips. Other embodiments are feasible.

Figure 4 further shows an embodiment of a detector system 170, which, besides the at least one detector 110, comprises one or more beacon devices 172, which, in this example, may be attached and/or integrated into an object 1 12, the position of which shall be detected by using the detector 1 10. Figure 4 further shows an exemplary embodiment of a human-machine inter- face 174, which comprises the at least one detector system 170 and, further, an entertainment device 176, which comprises the human-machine interface 174. The figure further shows an embodiment of a tracking system 178 for tracking a position of the object 1 12, which comprises the detector system 170. The components of the devices and systems shall be explained in further detail below.

Figure 4 further shows an exemplary embodiment of a scanning system 180 for scanning a scenery comprising the object 1 12, such as for scanning the object 1 12 and/or for determining at least one position of the at least one object 112. The scanning system 180 comprises the at least one detector 1 10, and, further, optionally, the at least one illumination source 128 as well as, optionally, at least one further illumination source. The illumination source 128, generally, may be configured to emit the at least one illumination light beam 130, such as for illumination of at least one dot, e.g. a dot located on one or more of the positions of the beacon devices 172 and/or on a surface of the object 112. The scanning system 180 may be designed to generate a profile of the scenery including the object 112 and/or a profile of the object 1 12, and/or may be designed to generate at least one item of information about the distance between the at least one dot and the scanning system 180, specifically the detector 110, by using the at least one detector 1 10.

As outlined above, an exemplary embodiment of the detector 110 which may be used in the setup of Fig. 4 is shown in Figure 1. Thus, the detector 110, besides the optical sensors 118 comprises the at least one evaluation device 150, which may have e.g. the at least one divider 164 and/or the at least one position evaluation device 166, as symbolically depicted in Figure 4. The components of the evaluation device 150 may fully or partially be integrated into a distinct device and/or may fully or partially be integrated into other components of the detector 1 10. Be- sides the possibility of fully or partially combining two or more components, the sensor element 114 and one or more of the components of the evaluation device 150 may be interconnected by one or more connectors 182 and/or by one or more interfaces, as symbolically depicted in Fig ure 4. Further, the one or more connectors 182 may comprise one or more drivers and/or one or more devices for modifying or preprocessing sensor signals. Further, instead of using the at least one optional connector 182, the evaluation device 150 may fully or partially be integrated into the optical sensors 118 and/or into a housing 184 of the detector 110. Additionally or alter- natively, the evaluation device 150 may fully or partially be designed as a separate device.

In this exemplary embodiment, the object 1 12, the position of which may be detected, may be designed as an article of sports equipment and/or may form a control element or a further con- trol device 186, the position of which may be manipulated by a user 188. As an example, the object 1 12 may be or may comprise a bat, a racket, a club or any other article of sports equip- ment and/or fake sports equipment. Other types of objects 1 12 are possible. Further, the user 188 himself or herself may be considered as the object 112, the position of which shall be de- tected.

As outlined above, the detector 110 comprises the sensor element 1 14. The sensor element 114 may be located inside the housing 184 of the detector 1 10. Further, the at least one transfer device 126 is comprised, such as one or more optical systems, preferably comprising one or more lenses. Furthermore, as outlined above, the detector 110 comprises the at least one filter element 132.

An opening 190 inside the housing 184, which, preferably, is located concentrically with regard to the optical axis 124 of the detector 1 10, preferably defines a direction of view 192 of the de- tector 1 10. A coordinate system 194 may be defined, in which a direction parallel or anti-parallel to the optical axis 124 may be defined as a longitudinal direction, whereas directions perpendic- ular to the optical axis 124 may be defined as transversal directions. In the coordinate system 194, symbolically depicted in Figure 4, a longitudinal direction is denoted by z, and transversal directions are denoted by x and y, respectively. Other types of coordinate systems are feasible, such as non-Cartesian coordinate systems.

One or more light beams 122 are propagating from the object 112 and/or from one or more of the beacon devices 172, towards the detector 1 10. The detector 1 10 is configured for determin- ing a position of the at least one object 1 12. For this purpose, as explained above in the context of Figure 1 , the evaluation device 150 is configured to evaluate sensor signals provided by the optical sensors 1 18. The detector 110 is adapted to determine a position of the object 112, and the optical sensors 118 are adapted to detect the light beam 122 propagating from the object 1 12 towards the detector 110, specifically from one or more of the beacon devices 172. In case no illumination source 128 is used, the beacon devices 172 and/or at least one of these beacon devices 172 may be or may comprise active beacon devices with an integrated illumination source such as a light-emitting diode. In case the illumination source 128 is used, the beacon devices 172 do not necessarily have to be active beacon devices. Contrarily, a reflective sur- face of the object 112 may be used, such as integrated reflected beacon devices 172 having at least one reflective surface such as a mirror, retro reflector, reflective film, or the like. The light beam 122 after having passed through the filter element 132 and the transfer device 126 illumi nates the light-sensitive areas 120of the optical sensors 118. For details of the evaluation, ref- erence may be made to Figure 1 above.

As outlined above, the determination of the position of the object 1 12 and/or a part thereof by using the detector 1 10 may be used for providing a human-machine interface 174, in order to provide at least one item of information to a machine 196. In the embodiments schematically depicted in Figure 4, the machine 196 may be a computer and/or may comprise a computer. Other embodiments are feasible. The evaluation device 150 may even be fully or partially inte- grated into the machine 196, such as into the computer.

As outlined above, Figure 4 also depicts an example of a tracking system 178, configured for tracking the position of the at least one object 1 12 and/or of parts thereof. The tracking system 178 comprises the detector 110 and at least one track controller 198. The track controller 198 may be adapted to track a series of positions of the object 1 12 at specific points in time. The track controller 198 may be an independent device and/or may be fully or partially integrated into the machine 196, specifically the computer, as indicated in Fig. 4 and/or into the evaluation device 150.

Similarly, as outlined above, the human-machine interface 174 may form part of an entertain- ment device 176. The machine 196, specifically the computer, may also form part of the enter- tainment device 176. Thus, by means of the user 188 functioning as the object 112 and/or by means of the user 188 handling the further control device 186 functioning as the object 1 12, the user 188 may input at least one item of information, such as at least one control command, into the computer, thereby varying the entertainment functions, such as controlling the course of a computer game. List of reference numbers

110 detector

112 object

114 sensor element

116 matrix

118 optical sensor

120 light-sensitive area 122 incident light beam 124 optical axis

126 transfer device

128 illumination source

130 Illumination light beam

132 filter element

134 filter region

136 first filter region

138 second filter region 140 neutral-density filter 142 first part

144 light spot

146 second part

148 control device

150 evaluation device

152 first optical sensor

154 second optical sensor 156 first area

158 second area

160 third optical sensor 162 fourth optical sensor 164 divider

166 position evaluation device

168 camera

170 detector system

172 beacon device

174 human-machine interface

176 entertainment device

178 tracking system

180 scanning system

182 connector

184 housing

186 further control device

188 user

190 opening direction of view coordinate system machine track controller

Cited documents

PCT/EP2017/079564, PCT/EP2017/079558, PCT/EP2017/079577 US 2016/154152 A1 US 4,675,517

US 5,323,222

WO 2014/198629 A1 WO 2014/097181 A1