Video conferencing display device

A video conferencing display device a display panel, at least one imaging device and processing structure. The at least one imaging device has a field of view aimed at an inner surface of the display panel and captures images through the display panel such that when a user is positioned adjacent an outer surface of the display panel, the user appears in the captured images. The processing structure communicates with the at least one imaging device and processes the captured images to create a direct eye image for transmission to a remote device over a network.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No. 61/470,440 to Morrison et al. filed on Mar. 31, 2011 and entitled “Interactive Input System”, the entire content of which is incorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates generally to video conferencing and in particular, to a video conferencing display device.

BACKGROUND OF THE INVENTION

Video conferencing systems that allow two-way video communication between two or more users or conferees at different sites in real-time are known. Typically, each conferee's site is equipped with a video camera and a display. The video camera and display are coupled to a communications network. In this manner, video signals captured by the video camera can be transmitted over the communications network to one or more displays at remote sites and video signals received from the communication network that were transmitted by one or more video cameras at a remote sites can be displayed. Typically, a microphone and a speaker are also present at each site to record and playback corresponding audio signals respectively, in a generally synchronized manner.

One of the most commonly encountered problems with video conferencing systems is the “off camera” problem, also referred to as the “parallax effect”, whereby conferees appear as being unable to establish direct eye contact while looking at their respective displays. Ideally, the video camera is placed in a space directly in front of each conferee. Unfortunately however, the display also occupies space in front of each user. As a result, the video camera is placed away from its ideal location, typically just above, just below, or just to the side of the display. If the video camera is not placed directly in front of the user, the user will appear to be looking off to the side, above or below the line of sight that corresponds to direct eye contact, depending on the placement of the video camera. This “off camera” or “parallax effect” is undesirable.

An exemplary conventional video conferencing system10is shown inFIG. 1. As can be seen, at a local site an imaging device such as video camera22-1connected to a computer24-1is placed above a display26-1for use by a first conferee U1. Similarly, at a remote site, an imaging device such as video camera22-2connected to computer24-2is placed above a remote display26-2for use by a second conferee U2. The two computers24-1and24-2communicate via a communications network28such as for example a local area network (LAN) or a wide area network (WAN) such as for example the Internet.

Displays26-1and26-2are standard liquid crystal display (LCD) or cathode ray tube (CRT) monitors. Video cameras22-1and22-2can be stand-alone cameras or embedded web-cams that are formed integrally with displays26-1and26-2respectively. Each computer24-1and24-2processes captured images from its respective video camera22-1and22-2for transmission.

As noted above, video conferencing system20depicted inFIG. 1suffers from the ‘off camera’ problem or ‘the parallax effect’ problem. The conference users U1and U2would appear unable to establish direct eye contact while looking at their respective displays26-1and26-2.

Known approaches to counteract this effect have sometimes involved placing beam-splitters or partial mirrors between the display and the conferee so that the camera records a reflected image of the conferee while the conferee is simultaneously looking directly at a display. One such approach is described in International PCT Application Publication No. WO 2007/087142 to Hunter et al.

Other approaches utilize a wide-angle lens camera, a homing device placed on a conferee and corresponding sensors, and use image manipulation techniques to provide the appearance of eye contact. One such technique is described in U.S. Pat. No. 5,438,357 to McNelley.

Unfortunately, the above described approaches often entail costs associated with additional hardware such as beam splitters or mirrors, wide-angle lens cameras, homing devices, and the associated costs. Accordingly, it is the object to provide a novel video conferencing display device.

SUMMARY OF THE INVENTION

Accordingly, in one aspect there is provided a video conferencing display device comprising a display panel, at least one imaging device having a field of view aimed at an inner surface of the display panel, the at least one imaging device capturing images through the display panel such that when a user is positioned adjacent an outer surface of the display panel the user appears in the captured images, and processing structure in communication with the at least one imaging device, said processing structure processing the captured images to create a direct eye image for transmission to a remote device over a network.

In one embodiment, the processing structure is configured to receive images from the remote device over the network, the received images being displayed on the display panel. The display panel may be a transparent display panel such as a liquid crystal display panel or an organic light emitting diode panel.

In one embodiment, the video conferencing display device is operable in an image capture mode and a display mode. The video conferencing display device may further comprise at least one film having an electrically controllable transparency positioned intermediate the at least one imaging device and the display panel. The film layer may be a polymer-disbursed liquid crystal film layer that is substantially transparent during operation in the image capture mode and non-transparent during operation in the display mode.

In one embodiment, the display panel and the at least one imaging device are accommodated by a housing with the at least one imaging device being spaced from the display panel. The processing structure may be accommodated by the housing or positioned outside of the housing.

According to another aspect there is provided a video conferencing display device comprising a display panel, an illumination source providing illumination through the display panel such that when a user is positioned adjacent to an outer surface of the display panel, the user's eyes reflect illumination from the illumination source back through the display panel, at least one first imaging device having a field of view aimed at an inner surface of the display panel, each first imaging device capturing images through the display panel including illumination reflected by the user's eyes through the display panel, at least one second imaging device having a field of view aimed at an outer surface of the display panel, each second imaging device capturing images of the outer surface of the display panel such that when a user is positioned adjacent to the outer surface, an image of the user appears in the captured images, and processing structure in communication with the at least one first and at least one second imaging devices, said processing structure processing the images captured by each first imaging device to obtain eye tracking data and processing the images captured by each second imaging device using the eye tracking data to create a direct eye image for transmission to a remote device over a network.

According to yet another aspect there is provided a method comprising capturing images of a user positioned adjacent an outer surface of a display device using at least one imaging device having a field of view aimed at an inner surface of the display device, and processing the captured images to generate a direct eye image for transmission to a remote display device over a network.

According to yet another aspect there is provided a method comprising providing illumination towards an outer surface of a display device using a first illumination source, capturing images of a user positioned adjacent to the outer surface of the display device using at least one first imaging device having a field of view aimed at an inner surface of the display panel including illumination from the first illumination source reflected by the user's eyes towards the first imaging device, capturing images of the user positioned adjacent to the outer surface of the display device using at least one second imaging device having a field of view aimed at the outer surface of the display device, and processing images captured by the at least one first imaging device to obtain eye tracking data and processing the images captured by the at least one second imaging device using the eye tracking data to create a direct eye image for transmission to a remote device over a network.

According to still yet another aspect there is provided a display device comprising a display panel; and at least one imaging device having a field of view aimed at an inner surface of the display panel, the at least one imaging device capturing images through the display panel such that when a user is positioned adjacent an outer surface of the display panel the user appears in the captured images.

DETAILED DESCRIPTION OF THE EMBODIMENTS

In the following, a video conferencing system having two or more video conferencing display devices is described. At least one of the video conferencing display devices comprises a display panel and at least one imaging device having a field of view aimed at an inner surface of the display panel. The imaging device captures images through the display panel such that when a user is positioned adjacent an outer surface of the display panel, the user appears in the captured images. The imaging device communicates captured images to a general purpose computing device for processing. The general purpose computing device communicates processed images to a remote display device over a communications network. As such, images of the user can be displayed on the remote display device thus creating the appearance of the user having direct eye contact with a user of the remote display device.

FIG. 2shows a schematic diagram of a video conferencing system30. As can be seen, video conferencing system30comprises a video conferencing display device40-1communicatively connected to a video conferencing display device40-2via a communications network42. In this embodiment, video conferencing display devices40-1and40-2each comprise processing structure in the form of a general purpose computing device44-1and44-2. Video conferencing display devices40-1and40-2also comprise imaging devices46-1and46-2positioned behind transparent display panels48-1and48-2for capturing images of users or conferees U1and U2, respectively. Each general purpose computing device44-1and44-2has a network interface card (not shown) providing interconnections to the communications network42such as for example an Ethernet network interface card (NIC), a wireless network interface card (WiFi, Bluetooth, etc.), a cellular radio frequency (RF) transceiver, etc. As is well known, network interface cards communicate with a gateway device such as for example a cable modem, a digital subscriber line (DSL) modem, an integrated digital services network (ISDN), etc. to provide a two-way communications channel over communications network42.

During operation, users U1and U2enter into a video conferencing session via communications network42. For user U1, image data is captured by imaging device46-1and communicated to the general purpose computing device44-1. The general purpose computing device44-1in turn communicates the image data over communications network42to general purpose computing device44-2. The general purpose computing device44-2processes the received image data for display on display panel48-2. As such, user U2is presented with an image of user U1. As will be appreciated, image data for user U2is similarly captured by imaging device46-2and communicated over communications network42for display on display panel48-1. As such, users U1and U2are able to partake in a video conferencing session with the appearance of direct eye contact with one another.

FIG. 3further illustrates one of the video conferencing display devices40(e.g., video conferencing display device40-1or40-2). As can be seen, in this embodiment video conferencing display device40comprises a generally rectangular housing50having an opening50ain its front or forward major surface that is surrounded by a bezel50b. The housing50accommodates a layered arrangement of components positioned adjacent the opening50aincluding, in the following order starting from furthest from the opening50a, a support layer52, a diffuser54, and a display panel48.

In this embodiment, the support layer52is formed of transparent acrylic or other suitable light transmissive material. The diffuser54and display panel48are also light transmissive. Positioned interior of the support layer52is a backlight illumination source60that provides backlight illumination to the display panel48in the form of visible light. In this embodiment, the backlight illumination source60is spaced from the support layer52thereby to define an interior space62within the housing50.

An imaging device46is positioned interior of the illumination source60and is spaced from the display panel48. The imaging device46is oriented such that its field of view (FOV) is aimed at the inner surface of the display panel48. As the display panel48, diffuser54and support layer52are light transmissive, the imaging device46is able to capture images of a user positioned in front of the outer surface48aof the display panel48. As will be appreciated, the terms “interior”, “inner”, and the like are relative terms that may change depending on the orientation of the video conferencing display device40.

The imaging device46is connected to general purpose computing device44also accommodated by housing50via a data communication link such as a universal serial bus (USB) cable64. The general purpose computing device44provides display data to a circuit block66which in turn provides the display data to the display panel48via an HDMI cable or other suitable connection (not shown). The display panel48in turn displays an image thereon. The general purpose computing device44also processes image data captured by the imaging device46to provide image data to a remote device via communications network42.

The display panel48in this embodiment is a generally planar, liquid crystal display (LCD) panel comprising a layer of protection glass70, a liquid crystal panel72, and a brightness enhancing film74such as for example a dual brightness enhancing film (DBEF).

The backlight illumination source60in this embodiment comprises a light guide80and a plurality of light emitting diodes (LEDs)82positioned about the periphery of the light guide80. The LEDs82emit visible light rays into the light guide80, which in turn guides at least a portion of the visible light rays through the interior space62and support layer52, towards the diffuser54. The diffuser54, in turn diffuses the visible light rays thereby to provide the display panel48with suitable backlighting and illuminate the image displayed thereon.

Interior space62defined between illumination source60and the support layer52is dimensioned so that that at least a portion of outer surface48aof the display panel48delimited by the opening50afalls within the FOV of the imaging device46. In this manner, a user positioned in front of the outer surface48aof the display panel48will be captured in images acquired by the imaging device46.

FIG. 4shows components of the imaging device46. As can be seen, in this embodiment imaging device46comprises a two-dimensional camera image sensor90such as for example a CMOS sensor, CCD sensor, etc., and an associated lens assembly92. The image sensor90is interconnected to a first-in-first-out (FIFO) buffer94via an analog-to-digital (A/D) converter96. The imaging device46also comprises a digital signal processor (DSP)98, an input-output (I/O) interface100such as for example a USB port, as well as volatile and non-volatile memory (not shown). DSP98communicates image data acquired by image sensor90to the general purpose computing device44via the I/O interface100. The imaging device components receive power from a power-supply102.

In this embodiment, the imaging device46is a compact board level camera device manufactured by Imaging Development Systems GmbH of Oversulm, Germany under the part number UI-1226LE. The image sensor90is a CMOS image sensor configured for a 752×480 pixel sub-array that can be operated to capture image frames at high rates such as for example 30, 60, 100 frames per second (fps) or higher. The exposure time and frame rate of the imaging device46is controllable by the DSP98to permit operation in both dark rooms and well lit rooms.

General purpose computing device44in this embodiment is a personal computer or other suitable processing device or structure executing one or more applications programs. Thus, general purpose computing device44comprises, for example, a processing unit such as for example an Intel x86 based architecture, system memory (volatile and/or non-volatile), other non-removable and removable memory (e.g., a hard disk drive, RAM, ROM, EEPROM, CD-ROM, DVD, flash memory, etc.) and a system bus coupling the various components to the processing unit. The general purpose computing device44may also comprise a network connection to access shared or remote devices, one or more networked computing devices, and/or other network devices.

In this embodiment, the circuit block66comprises an interface circuit configured to receive display data and other input from the general purpose computing device44and a display driver circuit configured to output display data to the display panel48.

Image data acquired by the imaging device46is sent to the general purpose computing device44via USB cable64. In particular, the imaging device46captures image frames of the display panel48within the field of view of its image sensor90and associated lens assembly92at the frame rate established by the DSP clock signals. The general purpose computing device44polls the imaging device46at a set frequency (in this embodiment thirty (30) times per second) to obtain the image data. Each time the imaging device46is polled, image data is communicated to the general purpose computing device44for processing.

Turning now toFIGS. 5 and 6, another embodiment of a video conferencing display device is shown. In this embodiment, like reference numerals will be used to indicate like components of the first embodiment with a “100” added for clarity. As can be seen, the video conferencing display device140is similar to that of video conferencing display device40. Video conferencing display device140however, further comprises a film layer184having an electrically controllable transparency such as for example polymer dispersed liquid crystal (PDLC) used to achieve a shuttering effect, specifics of which will be described below. Housing150encloses the film layer184and imaging devices146aand146b. The general purpose computing device144is positioned outside of housing150. The video conferencing display device140is operable in two modes, namely a display mode and an image capture mode. In the event that no image capture is desired, the video conferencing display device140is conditioned to operate in the display mode in which case the imaging devices146aand146bare turned OFF, and the film layer184is operated as a diffusive element. In the event that image capture is desired, the video conferencing display device140is conditioned to operate in the image capture mode in which case the imaging devices146aand146bare turned ON, and the film layer184is conditioned to a transparent state by exciting film layer184via a power source186.

FIG. 6illustrates a simplified cross-sectional diagram of the film layer184. In this embodiment, the film layer184is a polymer-dispersed liquid crystal (PDLC) film such as that manufactured by Scientsry Inc. of Richardson, Tex., U.S.A., and comprises a layer184-1formed of liquid crystal droplets dispersed in a solid polymer matrix. The layer184-1is positioned intermediate a pair of parallel substrates184-2,184-3that are coated with a thin layer of a conducting material such as indium tin oxide (ITO). The orientation of the liquid crystal droplets in the layer184-1may be altered with controlled application of an electric field from power source186. It is thus possible to controllably vary the intensity of transmitted light through the film layer184.

In the unexcited state, the liquid crystal droplets in layer184-1are oriented in random fashion and thus the film layer184acts as a non-transparent diffusive element. An electric field applied from power source186causes the film layer184to operate in the excited state. In the excited state, the electric field applied from power source186orients the crystal droplets in a predetermined direction, such that the film layer184becomes substantially transparent. Thus, the film layer184allows light to pass through relatively unobstructed. As will be appreciated, the power source186may be selectively applied to the film layer184causing it to become transparent in the event the respective imaging devices146aand146bare required to capture image frames. When the imaging devices146aand146bare not required to capture image frames, the power source186may be turned OFF, such that the film layer184may act as a non-transparent diffusive element, diffusing visible light emitted from the LEDs182.

When video conferencing display device140is conditioned to operate in the display mode, power source186is turned OFF causing film layer184to operate as a diffusive element, diffusing visible light emitted by the LEDs182. As mentioned above, when in the display mode, the imaging devices146aand146bare powered OFF. In contrast, when the video conferencing display device140is conditioned to operate in the image capture mode, power source186applies an electric field to the film layer184, causing film layer184to become transparent. As will be appreciated, when in the capture mode, the imaging devices146aand146bare powered ON.

The operation of the film layer184is synchronized to that of the imaging devices146aand146band thus, switching of the film layer184between transparent and non-transparent states is performed at a rate that matches the frame rate of the imaging devices146aand146b.

Turning now toFIG. 7, yet another embodiment of video conferencing display device is shown. In this embodiment, like reference numerals will be used to indicate like components of the first embodiment with a “200” added for clarity. As can be seen, video conferencing display device240is similar to the video conferencing display device40shown inFIG. 3. In this embodiment however, the imaging device246is an infrared (IR) imaging device. Also, two visible light imaging devices288aand288bare positioned adjacent the top right and top left corners of the display panel248.

FIGS. 8 and 9further illustrate IR imaging device246. Similar to the imaging device46ofFIG. 4, imaging device246comprises a two-dimensional camera image sensor290, an associated lens assembly292and an IR filter306. As will be appreciated, IR filter306allows IR illumination to pass through to the image sensor290while blocking out other wavelengths of illumination such as visible light. An IR illumination source is also associated with the image sensor290. The IR illumination source comprises a plurality of IR LEDs304that are circumferentially spaced about the periphery of the lens292. The image sensor290is connected to a FIFO buffer294via an A/D converter296. The imaging device246also comprises a DSP298, and an input-output interface300as well as volatile and non-volatile memory (not shown).

In comparison to video conferencing display device40, the use of an IR imaging device246and IR LEDs304with video conferencing display device240does not require the use of a transparent display panel. In this embodiment, the general purpose computing device244and IR imaging device246are used to track the pupils of a user using known eye-tracking techniques.

Infrared light emitted from IR LEDs304is at least partially reflected from the eyes of a user U back towards the IR imaging device246. In the visible light spectrum, this effect is commonly known as the red eye effect. The IR imaging device246captures IR images and communicates these captured images to the general purpose computing device244. The general purpose computing device244processes the received IR images to track eye movement and rotation from changes in corneal reflection, the center of the pupil and/or reflections from the back of the eye lens using known eye tracking techniques.

As mentioned above, the video conferencing display device240comprises two visible light imaging devices288aand288bare positioned adjacent the top right and top left corners of the display panel248. The visible light imaging devices288aand288balso capture images of the user U and communicate the captured images to the general purpose computing device244. The general purpose computing device244processes the received visible light images using know facial recognition techniques and, with the eye tracking data obtained by processing the IR images, the general purpose computing device244forms an image of user U for transmission to a remote display such that the appearance of direct eye contact is established.

Turning now toFIG. 10, a flowchart showing a method of processing the visible light images and IR images performed by the general purpose computing device244is shown and is generally identified by reference numeral400. Method400begins in the event a video conferencing session is established and the general purpose computing device244receives visible light images from visible light imaging devices288aand288b(step402). An infrared image is also from IR imaging device246(step404). The infrared image is processed to obtain eye tracking data (step406). The visible images are then processed using the eye tracking data obtained from the infrared image (step408) to create a warped image of the user U having the appearance of direct eye contact (step410). An exemplary method used during step410is described in the publication entitled “Real-time software method for preserving eye contact in video conferencing”, authored by Tsai, Y. P., Kao, C. C., Hung, Y. P., and Shih, Z. C.Journal of information science and engineering, vol. 20 (5), Sep. 2004, pp 1001-1017, the entire content of which is incorporated herein by reference. The warped image having the appearance of direct eye contact is then sent to a remote video conferencing device over a communications network (step412). A check is then performed to determine if the video conferencing session is complete (step414). If the video conferencing session is not complete, the method returns to step402. If the video conferencing session is complete, the method ends.

Turning now toFIG. 11, yet another embodiment of a video conferencing display device is shown and is identified by reference numeral440. In this embodiment, like reference numerals will be used to indicate like components of the embodiment shown inFIG. 7, with a “200” added for clarity. As can be seen, video conferencing display device440is similar to the video conferencing display device240shown inFIG. 7with the exception that the two visible light imaging devices488aand488bare positioned at an approximate midpoint along the right and left sides of the display panel448. The video conferencing operation of video conferencing display device440is similar to that of video conferencing display device240and as such, the specifics will not be further described.

Although embodiments described above with reference toFIGS. 7 and 11utilize two visible light imaging devices, those skilled in the art will appreciate that additional visible light imaging devices may be used such as for example four imaging devices positioned adjacent corners of the video conferencing display device.

Turning now toFIG. 12, yet another embodiment of a video conferencing display device is shown. In this embodiment, like reference numerals will be used to indicate like components of the embodiment shown inFIG. 5, with a “400” added for clarify. As can be seen, video conferencing display device540is similar to that of video conferencing display device140. In this embodiment, however, the backlight illumination source560comprises a direct backlight board584having an array of LEDs586positioned about the upper surface thereof. The LEDs586emit visible light rays though the interior space562and support layer552, towards the diffuser554. The diffuser, in turn, diffuses the visible light rays thereby to provide the display panel548with suitable backlighting and illuminate the image displayed thereon. Further, the video conferencing display device540comprises three (3) IR imaging devices546a,546band546cand two (2) visible imaging devices588a,588b. The direct backlight board584is provided with openings589a,589band589ccorresponding to the locations of imaging devices546a,546band546c, to ensure that the field of view of each imaging device is not obstructed. The operation of video conferencing display device540is similar to video conferencing display device240and thus the specifics will not be described further.

In another embodiment, video conferencing display device540may be provided with film layers having electrically controllable transparency such as for example PDLC film positioned adjacent the openings589a,589band589c. In this embodiment, the film layers may be controlled during image capture in the manner described above.

Turning now toFIG. 13, yet another embodiment of a video conferencing display device is shown. In this embodiment, like reference numerals will be used to indicate like components of the embodiment shown inFIG. 3, with a “600” added for clarify. As can be seen, video conferencing display device640is similar to that of video conferencing display device40with the addition of infrared touch detection. The infrared touch detection is achieved through use of an IR imaging device720and an IR illumination source724.

The imaging device720is connected to general purpose computing device644via a data communication link such as a USB cable722. The imaging device720is positioned below the backlight illumination source660and is oriented such that its field of view (FOR) is aimed at the inner surface of the display panel648. As mentioned previously, the general purpose computing device644provides display data to circuit block666which in turn provides the display data to the display panel648via an HDMI cable or other suitable connection (not shown). The display panel648in turn displays an image thereon. The general purpose computing device644processes image data captured by the imaging device720to detect one or more characteristics and the location of each pointer brought into proximity with the outer surface648aof the display panel648and updates display data provided to the display panel648, if appropriate, so that the image presented on display panel648reflects pointer activity. In this manner, pointer activity in proximity with the outer surface648aof the display panel648can be recorded as writing or drawing or used to control execution of one or more application programs executed by the general purpose computing device644.

The IR illumination source724in this embodiment comprises a plurality of IR light emitting diodes (LEDs)724aand a holographic diffuser724bpositioned beneath the bezel650b. The LEDs724aare positioned at spaced location about the periphery of the opening650a. The holographic diffuser724balso extends about the periphery of the opening650a. The holographic diffuser724bdiffuses IR light rays emitted by the IR LEDs724asuch that at least a portion of the IR light rays exiting the diffuser724bextend generally parallel to the outer surface648aof the display panel648. In this embodiment, the holographic diffuser724bis of the type manufactured by Wavefront Technologies, Inc. of Paramount, Calif., USA, of the type manufactured by RPC Photonics, Inc., Rochester, N.Y., USA, or of the type manufactured by Fusion Optix Inc. of Woburn, Mass., USA. Of course, other suitable infrared diffusers may be employed.

In the event one or more pointers are brought into proximity with the outer surface648aof the display panel648, IR illumination emitted across the outer surface648aof the display panel116by IR illumination source724is reflected by each such proximate pointer. For each such proximate pointer, at least a portion of the reflected IR illumination is directed through the display panel648, diffuser654and support layer652towards the imaging device720. The redirected IR illumination impinging on the imaging device720is captured in acquired image frames. Image data of acquired image frames is sent to the general purpose computing device644via USB cable722, where the image data is processed to determine one or more characteristics and the location of each pointer with respect to the outer surface648aof the display panel648using known image processing routines such as for example blob detection and morphology operations (edge detection, binarization, etc.). The general purpose computing device644in turn adjusts display data output to the display panel648via the circuit block666, if appropriate, such that the image presented on the display panel648reflects pointer activity. As will be appreciated, the general purpose computing device644may provide the touch data to a remote device over a communications network such that the image presented on the remote display device reflects pointer activity.

Above-incorporated U.S. Provisional Application No. 61/470,440 to Morrison et al. discloses many equivalent variations that may also be adapted for use in a video conferencing system described herein.

Although embodiments are described above wherein the general purpose computing device polls the imaging device to obtain image data, those skilled in the art will appreciate that alternatives are available. For example, in another embodiment the imaging device sends an interrupt signal to the general purpose computing device in the event a predetermined amount of image data is available. Upon receipt of the interrupt, the general purpose computing device requests the image data and thus the image data is communicated thereto.

Although embodiments are described above wherein IR images are processed to locate track the positions of a user's eye, those skilled in the art will appreciate that visible light images may be processed to track the positions of a user's eye.

As will be appreciated, facial recognition techniques may be employed by the general purpose computing device, within the DSPs associated with the imaging devices, or as a combination of the general purpose computing device and the DSPs.

Although embodiments are described above wherein film layers having electrically controllable transparency are used to achieve a shuttering effect, those skilled in the art will appreciate that the display panel may be configured to achieve the shuttering effect.

Although embodiments are described above with reference to the accompanying drawings, those skilled in the art will appreciate that variations and modifications may be made without departing from the scope thereof as defined by the appended claims.