“APPARATUS FOR DETECTING OPTICAL PROPERTIES OF AN OBJECT”

FIELD OF THE INVENTION

The present invention concerns an apparatus for detecting optical properties of an object, in particular identifying the presence of substances or molecules present in or associated with the object by detecting and processing one or more desired ranges of wavelengths relating to said substances or molecules.

The present apparatus can be applied in the industrial, food, chemical, biochemical, medical or other fields and in a particularly advantageous way in those fields in which it is required to process a large number of objects in a short time and with high specificity.

BACKGROUND OF THE INVENTION

It is known that, by studying the interaction between any substance or molecule whatsoever and a light radiation or electromagnetic spectrum, it is possible not only to detect the substance/molecule contained in, or associated with, an object, but possibly also to discriminate it from other substances/molecules always contained therein. Typically, a spectrophotometer is used for this purpose.

One disadvantage of spectrophotometers is that they cannot be configured and optimized for specific applications since it is not possible to set their functioning to detect specific wavelengths of interest.

Another disadvantage of the spectrophotometer is that it is not applicable where it is required to analyze a large number of objects, moved, for example, on a transport conveyor at a high speed and with very short acquisition times.

To at least partly solve some of these problems, it is known to use apparatuses for detecting wavelengths, provided with optical sensor elements, such as photodiodes. If it becomes necessary to detect more than one substance or molecule in the same object, each having its own specific spectrum, it may be necessary to provide a number of photodiodes suitable to detect the different wavelengths of interest that characterize the substances or molecules to be detected.

Therefore, the photodiode apparatus is configured so that, if possible, only the wavelength or wavelength range that corresponds to the substance or molecule to be identified and for which the photodiode is provided, reaches each photodiode, limiting as much as possible any contamination from wavelengths that are not of interest.

To do this, depending on the application, it may be necessary to further isolate the wavelengths leaving the object, which must be made to reach the photodiode, through the use of optical elements such as filters, dichroic mirrors or other, able to select and/or direct the spectrum of interest that has to reach the photodiode.

One disadvantage of known apparatuses is, therefore, the loss of intensity of the light radiation which reaches the photodiode.

Another disadvantage of known apparatuses is that filtering the wavelength further reduces the light information arriving at the photodiode, limiting its capacity to discriminate the substance or molecule.

Therefore, known photodiode apparatuses are not convenient due to the undesirable low signal/noise ratio they generate and the fact that they are complex, delicate and expensive.

In addition, the complex optics formed by different optical elements cooperating with each other and with which these apparatuses are provided, do not allow them to be reconfigured to detect other substances or molecules or, if they do allow it, do so only by means of laborious operations and with the intervention of specialized technicians.

Another disadvantage is that known photodiode apparatuses cannot be configured to be used in the detection of other substances or molecules other than those for which they have already been configured.

This disadvantage can be particularly burdensome in those production processes in which the final product entails a series of intermediate transformations, each of which requires a spectrophotometric quality control, in practice making it necessary to equip the production plant with multiple known detection devices.

A typical application of known detection devices, in the food sector, is in egg selection and/or packaging plants for the detection of blood inside the eggs themselves.

The apparatuses known in the state of the art up to now cannot be used to analyze different types of eggs other than those for which they have been configured.

Since the characteristics of the eggs are very variable, known apparatuses are also prone to generate false positives or false negatives.

There is therefore a need to perfect an apparatus for detecting the optical parameters of one or more objects which can overcome at least one of the disadvantages of the state of the art.

In particular, one purpose of the present invention is to provide an apparatus for detecting parameters or optical properties which is simple, easy to apply and with a high cost/benefit ratio. Another purpose of the present invention is to provide an apparatus for detecting optical parameters able to analyze a large number of objects in a limited time.

Another purpose of the present invention is to provide an apparatus for detecting optical parameters able to produce reliable results, avoiding or reducing false positives.

It is also a purpose of the present invention to provide an apparatus for detecting optical parameters able to be easily adapted to the substance or molecule to be detected.

The Applicant has devised, tested and embodied the present invention to overcome the shortcomings of the state of the art and to obtain these and other purposes and advantages.

SUMMARY OF THE INVENTION

The present invention is set forth and characterized in the independent claims. The dependent claims describe other characteristics of the present invention or variants to the main inventive idea.

In accordance with the above purposes, some embodiments described here concern an apparatus for detecting optical properties of an object which overcomes the limits of the state of the art and eliminates the defects present therein. The apparatus for detecting optical properties is able to detect a wavelength range of a light radiation or electromagnetic spectrum, in particular the wavelength range resulting from the interaction of an incident light radiation with the substances or the molecules contained in an object suitable for a light radiation to pass through it.

Some embodiments described here concern an apparatus for detecting optical properties of one or more objects comprising:

- at least one emitter, provided with a light source, configured to emit a first light radiation, or incident radiation, able to hit and pass through an object located in a detection zone, in order to generate a second radiation, or transmitted radiation, at exit from the object;

- a collimator member, provided with an inlet able to receive the second radiation and an outlet, a reflective surface developing internally between the inlet and the outlet so as to supply, at the outlet of the collimator member, the second radiation in collimated form;

- an optical detection assembly, provided at least with an optical sensor device comprising an optical detection matrix provided with a plurality of optical sensor elements able to receive the second radiation in collimated form, and each supply corresponding electrical signals;

- a processing unit, hereafter also referred to as a processing board, able to receive and process the electrical signals in order to supply at exit, to a user interface or to other processing or actuation means, data correlated to the optical property of the object. The optical detection assembly can also comprise a diffuser, cooperating on one side with the collimator member and on the other with the optical sensor device.

The diffuser can be configured to diffuse the second light radiation over an area of the optical sensor device which comprises at least the plurality of optical sensor elements.

In this way, each optical sensor element is reached by the same light radiation at exit from the object, reducing the possibility of introducing variables due to the division of the beam into several channels which, for example, due to poor processing tolerances or other, can transmit the light radiation to the optical sensor devices in a different manner each one from the other.

According to some embodiments, the optical sensor elements preferably comprise photodiodes that allow to focus the wavelength in the desired range, optimizing the cost/benefit ratio substantially. According to some embodiments, the detection apparatus can be configured to detect emission spectra and/or absorption spectra, depending on the application.

According to some embodiments, the detection apparatus can be configured to detect ranges of the spectrum corresponding to one or more substances or molecules.

In this way, the detection apparatus provides to supply detailed data on the spectrum of the substance or molecule to be detected, allowing an analysis program to process a more detailed amount of information with the purpose of obtaining more precise and reliable results.

The embodiments described here are particularly advantageous, therefore, in cases where the application of known techniques in the analysis of particular objects, often with varying characteristics, yield unsatisfactory results in terms of sensitivity and specificity.

In accordance with some embodiments, the detection apparatus allows to modify, easily and without the aid of a specialized technician, the range of wavelengths to which the apparatus is sensitive, providing a flexible apparatus for different applications.

According to some embodiments, the optical detection assembly can be, in fact, removed and replaced with an optical detection assembly with sensitivity to a different range of wavelengths.

The optical detection assembly can be manufactured as a plug & play type device, which makes it simple in its application to the detection apparatus.

This advantageously allows to reconfigure the detection apparatus according to the required application in a fast, practical and effective manner.

For example, therefore, it can be possible to use the same detection apparatus in different applications, replacing the optical detection assembly when necessary in order to configure the apparatus to analyze, on each occasion, different objects or objects with a different composition.

Therefore, where possible, a same transport conveyor, or suchlike, on which objects, on which to perform an optical analysis, move on can also be used to analyze, on each occasion, different objects simply by replacing the optical detection assembly, thus considerably reducing its bulk and management costs.

Some embodiments also concern a method to detect the optical properties of one or more objects comprising:

- emitting a first light radiation or incident radiation, which hits and passes through an object located in a detection zone, in order to generate a second radiation, or transmitted radiation, at exit from the object; - collimating the second radiation in order to direct it toward an optical detection assembly comprising an optical detection matrix provided with a plurality of optical sensor elements which receive the second collimated radiation;

- generating, by means of the optical sensor elements, corresponding electrical signals; - processing, by means of a processing unit that receives the electrical signals, in order to supply at exit at least to a user interface, or other processing or actuation means, data correlated to the optical property of the object.

One application in which Applicant has applied the apparatus in an advantageous manner is the detection of blood, more precisely hemoglobin (Hb), inside eggs, in particular eggs moving on a transport conveyor.

BRIEF DESCRIPTION OF THE DRAWINGS These and other aspects, characteristics and advantages of the present invention will become apparent from the following description of some embodiments, given as a non-restrictive example with reference to the attached drawings wherein:

- fig. 1 is an example diagram of an apparatus for detecting optical properties in accordance with embodiments described here;

- fig. 2 is an example diagram seen from above of a detail of an apparatus for detecting optical properties in accordance with embodiments described here. To facilitate comprehension, the same reference numbers have been used, where possible, to identify identical common elements in the drawings. It is understood that elements and characteristics of one embodiment can conveniently be incorporated into other embodiments without further clarifications.

DETAILED DESCRIPTION OF SOME EMBODIMENTS We will now refer in detail to the possible embodiments of the invention, of which one or more examples are shown in the attached drawings. Each example is supplied by way of illustration of the invention and shall not be understood as a limitation thereof. For example, one or more characteristics shown or described insomuch as they are part of one embodiment can be varied or adopted on, or in association with, other embodiments to produce another embodiment. It is understood that the present invention shall include all such modifications and variants.

Before describing these embodiments, we must also clarify that the present description is not limited in its application to details of the construction and disposition of the components as described in the following description using the attached drawings. The present description can provide other embodiments and can be obtained or executed in various other ways. We must also clarify that the phraseology and terminology used here is for the purposes of description only, and cannot be considered as limitative.

Embodiments described here concern an apparatus 10 for detecting optical properties of one or more objects comprising:

- at least one emitter 12 provided with a light source 12a, configured to emit a first light radiation, or incident radiation, able to hit and pass through an object O located in a detection zone, in order to generate a second radiation, or transmitted radiation, at exit from the object O;

- a collimator member 14, provided with an inlet 19 able to receive the second radiation and an outlet 21, a reflective surface 13 developing internally between the inlet 19 and the outlet 21 so as to supply, at the outlet 21 of the collimator member 14, the second radiation in collimated form;

- an optical detection assembly 15 provided at least with an optical sensor device 16 comprising an optical detection matrix 17 provided with a plurality of optical sensor elements 18 able to receive the second radiation in collimated form and each supply corresponding electrical signals;

- a processing unit 22, hereafter also referred to as processing board, able to receive and process the electrical signals in order to supply at exit, to a user interface 23 or to other processing or actuation means, data correlated to the optical property of the object O.

The optical detection assembly 15 can also comprise a diffuser 20, cooperating on one side with the collimator member 14 and on the other with the optical sensor device 16.

The diffuser 20 can be configured to diffuse the second light radiation over an area of the optical sensor device 16 which comprises at least the plurality of optical sensor elements 18.

Some embodiments can provide that the diffuser 20 is interchangeable, independently from the optical sensor device 16, as a function of the performance sought or the application.

According to some embodiments, the optical detection assembly 15 can be configured to detect a desired range of wavelengths chosen to identify at least one substance or molecule present in the object O.

According to some embodiments, the optical detection assembly 15 can be manufactured so that it is selectively removable from the apparatus 10.

In this way, it is possible to alternate different optical detection assemblies 15 on the same apparatus 10 according to the object O to be analyzed.

In accordance with some embodiments, the optical detection assembly 15 can be connected to the processing unit 22 by means of data communication ports that allow the optical detection assembly 15 to be easily disconnected in order to provide an easy replacement thereof.

In accordance with some embodiments, the optical detection assembly 15 can be configured as a plug & play type device.

Some embodiments can provide that the data communication ports are any port whatsoever, of the serial, parallel or other type, which allow the transfer of bits.

Some embodiments can provide that the processing unit 22 comprises a processor 25 and a memory 24 in which algorithms can be stored, suitable to use the data supplied by at least the optical sensor elements 18 in order to determine the optical properties of the object O.

Some embodiments can provide that the data generated by the processing unit 22 are also stored, on each occasion, in the memory 24.

In alternative embodiments, the data generated by the processing unit 22 can be stored on other memories, possibly also transferred outside the processor.

According to further embodiments, the processing unit 22 can be connected to one or more optical sensors 26 configured to detect at least a signal correlated to one or more of: color, volume, shape, presence of the object O in the detection zone, or a combination thereof. The optical sensors 26 can be cameras, photocells or other suitable optical sensors.

The detection zone can be the zone in which the object O is hit by the first light radiation supplied by the emitter 12 and the resulting second light radiation can have a direction, or is directed, toward the optical detection assembly 15. In accordance with some embodiments, the algorithms stored in the memory 24 of the processing unit 22 can use at least a signal correlated to one or more of color, volume and presence of the object O supplied by the one or more optical sensors 26.

According to preferred embodiments, the optical sensor device 16 can comprise a plurality of optical sensor elements 18.

The optical sensor device 16 can comprise the circuitry that allows the communication between the optical sensor elements 18 and, possibly, between the optical sensor elements 18 and the processing unit, or processor, 22.

Some embodiments provide that at least one optical sensor element 18 is used to detect at least a wavelength or a wavelength range corresponding to the emission or absorption spectrum of a substance or molecule, hereafter defined, for short, as spectrum of a substance or molecule.

Advantageously, the invention provides that the optical sensor elements 18 are configured so that their sensitivity is centered on a specific and desired wavelength with a full width at half maximum (FWHM) smaller than 50 nm, preferably smaller than 20 nm.

In accordance with some embodiments, the apparatus 10 described here can provide to use at least two optical sensor elements 18, centered on different wavelengths comprised in the spectrum of a same substance or molecule. Advantageously, therefore, the apparatus 10 can be configured to detect at least one portion of the spectrum of a substance or molecule, thus detecting a larger portion than the one detected by known photodiode devices, in order to obtain more information regarding this spectrum.

In accordance with some embodiments, the plurality of optical sensor elements 18 can be organized to form a matrix 17 in which the optical sensor elements 18 are suitably disposed in order to receive the light radiation.

Preferred embodiments can provide that the optical sensor elements 18 comprise photodiodes 18a. According to some embodiments, the photodiodes 18a can also be of a different type for example, be provided with different communication interfaces, such as, for example, IIC, UART or others.

According to some embodiments, the optical sensor elements 18 can be organized in sub-matrices.

With reference to fig. 2, by way of example only, the matrix 17 can comprise the sub-matrix 17a and the sub-matrix 17b, wherein each sub-matrix can comprise photodiodes 18a which share, for example, the same communication interface.

The light source 12a can be configured to have sufficient power to emit a first light radiation of intensity suitable to advisably illuminate the object O, and to generate a second light radiation, or transmitted radiation, at exit from the object O, able to be detected by the optical sensor device 16. Advantageously, the light source 12a can be equipped with a power that allows to reach acquisition times of the spectrum of the substance or molecule of less than 100 ms.

This aspect is particularly advantageous for acquiring spectra of objects moving on a transport conveyor.

The light source 12a can emit a light radiation in a spectrum suitable to allow the detection of a substance or molecule to be detected in the object O.

According to some embodiments, the light source 12a can emit a radiation of a wavelength corresponding to the visible and/or infrared and/or ultraviolet spectrum, or portions thereof.

In accordance with some embodiments, the light source 12a can be an LED (Light Emitting Diode) or more, provided with a power and spectrum suitable for the application.

In some embodiments, it can be provided that the emitter 12 comprises and/or cooperates with elements that allow to focus the light radiation generated by the light source 12a toward a specific zone of the object O.

According to some embodiments, the collimator member 14 can be configured to capture the light radiation coming from the object O, even from zones not in axis with the longitudinal axis of the member 14, in order to lead it to the opposite side.

In accordance with some embodiments, the collimator member 14 can be of a tubular shape. In possible embodiments, the collimator member 14, for example of a tubular shape, can have a diameter which can be chosen on the basis of the size of the object O and/or the intensity of the light radiation that is to reach the optical sensor device 16.

The collimator member 14 can have a reflective internal surface 13, which extends substantially along the longitudinal development of the collimator member 14, offering the advantage of supplying a light radiation at exit that is intense and homogeneous compared to the one at entry.

Furthermore, the collimator member 14 is conformed so as to at least partly prevent unwanted extraneous environmental light radiations from being able to reach the optical sensor device 16 in an undesired manner.

The collimator member 14, for example of a tubular shape, can be sized according to requirements in terms of length and diameter, since these sizes do not limit or condition the purpose of the present invention.

In alternative embodiments, it is possible to contemplate using a collimator member 14 with a curved shape or other shapes that are necessary and are suitable to perform the intended function.

In some embodiments, the collimator member 14 can be provided with an optical element, for example a lens, to induce changes in the direction of the light radiation.

In alternative embodiments, the collimator member 14 can be replaced by other systems able to confine and/or direct a light radiation.

According to one aspect of the invention, the apparatus 10 can comprise a transport conveyor 29 for moving objects O with respect to the emitter 12 and a control unit 28 connected both to the processing unit 22 and also to the transport conveyor 29.

In accordance with some embodiments, the control unit 28 can be connected to the processing unit 22 of the apparatus 10 and to the transport conveyor 29 able to move objects O, substantially transversely to the first radiation, in order to position them in sequence in the detection zone.

The control unit 28 can be configured to control the transport conveyor 29 as a function of the data received from the processing unit 22.

Some embodiments also concern a method to detect the optical properties of one or more objects O comprising:

- emitting a first light radiation, or incident radiation, which hits and passes through an object O located in a detection zone, in order to generate a second radiation, or transmitted radiation, at exit from the object O; - collimating the second radiation in order to direct it toward an optical detection assembly 15 comprising an optical detection matrix 17 provided with a plurality of optical sensor elements 18 which receive the second collimated radiation;

- generating, by means of the optical sensor elements 18, corresponding electrical signals; - processing, by means of a processing unit 22 that receives the electrical signals, in order to supply at exit at least to a user interface 23, or to other processing or actuation means, data correlated to the optical property of the object O.

Applicant has applied and tested the apparatus 10 in detecting the presence of blood inside eggs, and in particular searching for traces of hemoglobin inside eggs, identifying settings that have allowed to obtain relevant results in terms of efficacy, reliability and productivity.

According to what has been experimented by Applicant, the apparatus 10 can use a light source 12a capable of irradiating an egg at working distances between about 1 and 20 cm, preferably between 1 and 10 cm, even more preferably between 2 and 5 cm.

According to some embodiments, the diffuser 20 can comprise a layer of diffuser material with a thickness comprised between 1 and 12 mm, advantageously between 2 and 10 mm, even more preferably between 5 and 8.5 mm. In accordance with preferred embodiments, the layer of material with which the diffuser 20 is made can be opal.

In accordance with the purposes, the apparatus 10 can be provided with an optical sensor device 16 comprising a plurality of photodiodes 18a configured to detect at least a range of wavelengths corresponding at least to the partial spectrum of hemoglobin.

According to some embodiments, the plurality of photodiodes 18a can be configured to also detect a partial range of wavelengths corresponding at least to another substance or molecule present in the egg, for example protoporphyrin. This substance or molecule is chosen so that the data obtained from the detection of its spectrum can, once processed by the processing unit 22 and combining them with the data relating to the hemoglobin, be advantageous for generating a reliable result.

In accordance with some embodiments, the data obtained from the analysis of the spectra or the analysis itself can be integrated by the physical parameters of the egg, for example size, volume, color, etc., obtained by means of the optical sensor 26.

In accordance with some embodiments, the apparatus 10 can be configured to detect a wavelength range advantageously comprised between 530 and 650 nm, preferably between 540 and 630 nm, even more preferably between 550 and 620 nm.

The ranges mentioned above allow to obtain information both on the hemoglobin spectrum and also on the protoporphyrin spectrum.

Applicant has experimentally applied the apparatus 10 on an egg selection and/or packaging line. On the basis of the experimental studies carried out, it appears that the apparatus 10 proposed by Applicant is very reliable, able, in the specific case of checking the presence of blood inside eggs, to keep the false positive rate below 0.1%, with an acquisition time of less than 100 ms.

It is clear that modifications and/or additions of parts and/or steps may be made to the apparatus 10 for detecting optical properties, and to the corresponding method, as described heretofore, without departing from the field and scope of the present invention as defined by the claims.

It is also clear that, although the present invention has been described with reference to some specific examples, a person of skill in the art shall certainly be able to achieve many other equivalent forms of apparatus for detecting optical properties and corresponding method, having the characteristics as set forth in the claims and hence all coming within the field of protection defined thereby.

In the following claims, the sole purpose of the references in brackets is to facilitate reading: they must not be considered as restrictive factors with regard to the field of protection claimed in the specific claims.