Viewing device

The invention to which this application relates is a viewing device with a display.

Conventionally, digital still cameras are provided with an external display panel on the rear side thereof with respect to the lens assembly, for showing the user the view to be taken on activation of the camera, and/or for displaying to the user pictures already captured.

Digital video cameras are typically provided with two viewing systems each with their own display means. Usually, one viewing system is an external display panel similar to that of digital still cameras, and suitable, under most ambient light conditions, for image viewing and reviewing. The other viewing system is a micro display used in the electronic viewfinder to provide a user with a view when the device is held close to the eye, and thus can be described as a close-to-eye system. The micro display is small so as to ensure the smallest possible form factor for the unit, and is magnified via the lens assembly to provide a suitable view to the user. However, it is expensive to produce a video camera with two viewing systems.

An aim of the present invention is to provide a viewing device with a display which is cheaper to manufacture.

In addition, cameras with sensors for detecting infrared radiation are known. Near-infrared (NIR) sensors can be provided for detecting electromagnetic radiation with wavelengths in the range 0.75-1.4 microns. NIR radiation is not significantly absorbed or scattered by moisture laden air, but is significantly absorbed or scattered by smoke from fires.

Alternatively, far-infrared (FIR) sensors can be provided for detecting electromagnetic radiation with wavelengths in the range 15- 1000 microns. FIR radiation is not significantly absorbed or scattered by smoke, and firemen often use FIR sensors for locating missing persons under smoky conditions. However FIR sensors are not as effective under humid or cloudy conditions when the air has high moisture content.

It is expensive to buy two devices depending on the conditions, because components such as lenses and digital signal processors (DSPs) are expensive.

In addition it is not normally possible to mount NIR and FIR sensors in the same lens system of a device as the refractive lenses used in such devices are typically opaque to one or other of the infrared ranges (and/or visible light) to filter out unwanted wavelengths which would otherwise increase the noise level relative to the signal level. Lenses made of Germanium for example are expensive and opaque to visible and NIR radiation.

A further aim of the present invention is to provide an inexpensive device for viewing both NIR and FIR radiation.

In a first aspect of the invention, there is provided a viewing device comprising: viewing means; sensing means for sensing electromagnetic radiation; a display for displaying data from the sensing means; characterised in that the display is moveable between a first position such that the display is visible remotely from the device, and a second position such that the display is visible via the viewing means.

Thus only one display (and digital signal processor) is required to provide a view to the user either as an external system or as a close to eye system.

In one embodiment the display is pivotally and/or hingedly mounted so as to be moveable between an open position in which the display is external of the device for direct viewing, and a covert position in which light from the display is directed via directing means to the viewing means.

Typically the directing means is any or any combination or mirrors, prisms, and/or the like.

In a further embodiment the display is internally mounted in the device and is moveable by pivoting or rotating.

Typically in this embodiment the display is a micro display, although the display could also be of a more regular size as long as it fits within the housing.

Typically one or more lenses are provided to magnify the view of the micro display to provide a suitable viewing thereof to the user.

In one embodiment movement means are provided to move the display between first and second positions.

In one embodiment there is provided cover means moveable between a first position in which the remotely visible display is visible, and a second position in which the remotely visible display is covered. Typically movement of the cover means between first and second positions moves the display means between first and second positions.

In one embodiment the viewing means includes at least one optical unit such as an eyepiece assembly.

In one embodiment, the sensing means are CMOS or CCD sensors.

In one embodiment the sensing means is connected to the display via processing means, typically in the form of a digital signal processor. In one embodiment the processing means allows data from two or more sources to be combined into one image on the display.

In one embodiment the sensing means includes two or more sensors and switching means to switch between the sensors.

The provision of different sensors using the same optical systems and processing means ensures that separate devices for performing the equivalent functions are not required.

Typically one or more reflective or refractive lenses are provided to focus electromagnetic radiation on a sensor.

Typically the switching means switches the focal point of the lens between the first and second sensing means.

Typically the sensing means includes a first sensor for sensing electromagnetic radiation of a first wavelength range, and a second sensor for sensing electromagnetic radiation of a second wavelength range different to the first wavelength range;

In one embodiment the wavelength ranges correspond to any or any combination of visible, near-infrared and far-infrared radiation.

The device can thus be used to view both near-infrared and far- infrared electromagnetic wavelengths by switching between the two sensing means as required. The provision of a reflective lens allows the same optical systems to be used by both infrared sensors and therefore save cost.

In one embodiment the sensor means may have different resolution or performance characteristics. For example a low resolution sensor with high light sensitivity may be slideably or otherwise interchanged with a high resolution sensor.

In one embodiment the lens is protected from external damage by a cover transparent to both NIR and FIR electromagnetic radiation.

In one embodiment illumination means are provided for generating visible/NIR/FIR electromagnetic radiation.

In one embodiment filter means are provided to filter out wavelengths that may interfere with image quality.

In one embodiment capture means are provided for capturing data and/or images from the display. Typically memory means are provided to store captured data and/or images.

In one embodiment a microphone is provided to allow capture of audio simultaneously or independently of the capture of data and/or images.

In one embodiment the microphone is parabolic to allow capture of distant or quiet audio.

In one embodiment the microphone is provided with a mechanism to allow directional adjustment such as pan and/or

tilt. This allows the effects of wind or other factors to be countered, or the selection of audio from a different direction to that viewed.

In one embodiment two or more audio tracks can be captured to allow separate recording from different sources.

In one embodiment communication means (such as a USB socket) are provided for outputting data and/or images to a PC or other suitable device.

In a second aspect of the invention, there is provided a viewing device comprising: sensing means for sensing electromagnetic radiation of a first wavelength range; sensing means for sensing electromagnetic radiation of a second wavelength range different to the first wavelength range; at least one reflective lens to focus electromagnetic radiation on a sensing means; a display for displaying data from the sensing means; characterised in that switching means are provided to switch the focal point of the lens between the first and second sensing means.

In one embodiment the switching means moves the selected sensing means to the focal point of the lens.

In one embodiment the wavelength ranges correspond to any or any combination of visible, near-infrared and far-infrared radiation.

In one embodiment the lens is protected from external damage by a cover transparent to the selected wavelength ranges.

In one embodiment illumination means are provided for visible/NIR/FIR radiation.

In one embodiment the display can include one or more display panels for direct viewing, as for example found on the backs of digital cameras, or for viewing via one or more eyepieces and/or lenses, as for example used in video cameras or mobile phones.

In one embodiment, there is provided a first optical unit directed to the display of data from one of the sensing means or DSP. Typically there is provided a second optical unit directed to the display of data from a different source or content to that of the first optical unit.

In one embodiment capture means are provided for capturing data and/or images from the sensor and/or display. Typically memory means are provided to store captured data and/or images.

In a third aspect of the invention, there is provided a viewing device comprising: two or- more sensors with different sensitivities and/or resolutions; focusing means for focusing electromagnetic radiation at a focal point; a display for displaying data from the sensor; characterised in that switching means are provided to switch the focal point of the focusing means between sensors.

In one embodiment the focusing means is any or any combination of refractive lenses, reflective lenses, and/or the like.

Specific embodiments of the invention are now described wherein:-

Figure 1 illustrates a perspective view of a conventional digital video camera.

Figure 2 illustrates a schematic view of an embodiment of a viewing device according to the present invention; (a) with the display in a first position; (b) with the display in a second position.

Figure 3 illustrates a schematic view of a further embodiment of a viewing device according to the present invention with the display in a first position.

Figure 4 illustrates a schematic view of a yet further embodiment of a viewing device according to the present invention (a) with the display in a first position; (b) with the display in a second position.

Figure 5 illustrates a schematic view of a still further embodiment of a viewing device according to the present invention (a) with the sensing means in a first position; (b) with the sensing means in a second position.

With reference to Figure I ₅ there is illustrated a conventional digital video camera 2 provided with a main lens assembly 4 for focusing light onto at least one internal sensor to allow capture of images and video.

Data is output from the sensor to a micro display which is viewed by the user via eyepiece assembly 6, which contains lenses to magnify and focus the display to be suitable for viewing when the user places their eye adjacent the eyepiece 8.

The camera 2 is also provided with an external display 10 which can be viewed at a remote distance by the user. The display is usually hingedly mounted such that it can flip shut for protection against the main body of the camera, and may also be rotateable to suit the angle of viewing by the user.

The external display is useful in situations where for example the camera has to be held at arms length to capture a particular view, as the user can still see the view being captured.

Figure 2a illustrates a schematic view of a viewing device 3 according to the present invention. The viewing device includes a main lens assembly 4 with an internal sensor 12 onto which electromagnetic radiation is focused. The sensor 12 transfers data via a digital signal processor (not shown) to the display 10, which is hingedly connected to the housing 14 of the device.

In this overt position, the display 12 is visible remotely by the user's eye 18 as indicated by arrow 20, as it is large enough to be viewed directly from a distance.

The display can be pivoted down to lie flat against the housing 14 as shown in Figure 2b. In this position, light from the display is directed by directing means in the form of a mirror 16 towards viewing means in the form of an eyepiece assembly 8, as indicated by arrow 22. The user puts their eye 18 near or against the eyepiece assembly 8 to view the display.

Thus, in this covert position, light from the display is not visible remotely from the device.

Advantageously only one display and processor is required for both overt and covert viewing, which means the device is cheaper and easier to manufacture.

With reference to Figure 3a, there is shown a further embodiment of a viewing device according to the present invention.

In this embodiment the device with a main lens assembly 4 to focus light on the sensor 12, as indicated by arrow 26, as hereinbefore described. A micro display 24 receives data from the sensor 12. The micro display 24 is pivotally mounted to either provide light to the eyepiece assembly 8 as hereinabove described or to viewing means in the form of a lens 30 which magnifies the display 24 so as to be suitable for remote viewing by the user.

Referring to Figure 4a, cover means 32 are provided to cover the lens 30 when the micro display transmits light to the eyepiece assembly 8, so as to block out ambient light and prevent light exiting the device through the lens 30.

The cover can be mechanically connected to the display 24 such that when it is moved to the position shown in Figure 4b, the micro display 24 is rotated to a position in which light is transmitted to the lens 30, as indicated by arrow 28. When the user closes the cover, as shown in Figure 4a, the micro display is rotated back to the position in which light is transmitted to the eyepiece assembly 8.

Thus under normal daylight conditions a user moves the display so that it is visible externally. In low light conditions, or at the choice of the user, the user moves the display so that is it visible via the eyepiece assembly, which enables the user to block out

ambient light, and also allows the user to covertly view an object by limiting the visibility of light emitted from the display.

With reference to Figure 5a, there is illustrated a viewing device in which two sensors are provided.

One of the sensors is a high resolution sensor 12, the other is a low resolution sensor 12'. The user can thus configure the device such that electromagnetic radiation 26 is focused on the high resolution sensor 12, as indicated in Figure 5a, or use switching means to move the sensors such that electromagnetic radiation 26 is focused on the low resolution sensor 12' instead, as indicated in Figure 5b.

Alternatively, the high and low resolution sensors can be replaced with NIR and FIR sensors (not shown) . In this case, a reflective lens is required to focus light on the sensors as refractive lenses are typically opaque to at least part of one or other of the wavelength ranges.

The display 10 provides a view of the relevant sensor on which electromagnetic radiation is focused accordingly. As such the device can be used under smoky conditions and also when the air has a high moisture content.

Thus, as only one display, processor and set of lenses is required, this device is relatively inexpensive compared to having to purchase several individual devices to perform the same functions.

It will be appreciated that although the parts of the description relating to the detection of infrared radiation refers almost exclusively to certain wavelengths, different sensing means can

be provided to adapt the device to be used with other wavelengths of electromagnetic radiation.

It will be appreciated by persons skilled in the art that the present invention may also include further additional modifications made to the device which does not affect the overall functioning of the device.