Patent Publication Number: US-7714923-B2

Title: Integrated display and capture apparatus

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
   Reference is made to commonly assigned U.S. patent application Ser. No. 11/341,945 filed Jan. 27, 2006, entitled “EL Device Having Improved Power Distribution” by Ronald S. Cok et al; U.S. patent application Ser. No. 11/555,822 filed Nov. 2, 2006, entitled “An Integrated Display Having Multiple Capture Devices” by Ronald S. Cok et al and U.S. patent application Ser. No. 11/555,834 filed Nov. 2, 2006, entitled “Two Way Communication System” by Ronald S. Cok et al, the disclosures of which are incorporated herein. 
   FIELD OF THE INVENTION 
   The present invention relates to apparatus for two-way communication of images and in particular relates to an integrated capture and display apparatus that provides both image display and image capture functions. 
   BACKGROUND OF THE INVENTION 
   Two-way video systems are available that include a display and camera in each of two locations connected by a communication channel that allows communication of video images and audio between two different sites. Originally, such systems relied on setup at each site of a video monitor to display a remote scene and a separate video camera, located on or near the edge of the video monitor, to capture a local scene, along with microphones to capture the audio and speakers to present the audio thereby providing a two-way video and audio telecommunication system between two locations. 
   Referring to  FIG. 1 , a typical prior art two-way telecommunication system is shown wherein a first viewer  71  views a first display  73 . A first image capture device  75 , which can be a digital camera, captures an image of the first viewer  71 . If the image is a still digital image, it can be stored in a first still image memory  77  for retrieval. A still image retrieved from first still image memory  77  or video images captured directly from the first image capture device  75  will then be converted from digital signals to analog signals using a first D/A converter  79 . A first modulator/demodulator  81  then transmits the analog signals using a first communication channel  83  to a second display  87  where a second viewer  85  can view the captured image(s). 
   Similarly, second image capture device  89 , which can be a digital camera, captures an image of second viewer  85 . The captured image data is sent to a second D/A converter  93  to be converted to analog signals but can be first stored in a second still image memory  91  for retrieval. The analog signals of the captured image(s) are sent to a second modulator/demodulator  95  and transmitted through a second communication channel  97  to the first display  73  for viewing by first viewer  71 . 
   Although such systems have been produced and used for teleconferencing and other two-way communications applications, there are some significant practical drawbacks that have limited their effectiveness and widespread acceptance. Expanding the usability and quality of such systems has been the focus of much recent research, with a number of proposed solutions directed to more closely mimicking real-life interaction and thereby creating a form of interactive virtual reality. A number of these improvements have focused on communication bandwidth, user interface control, and the intelligence of the image capture and display components of such a system. Other improvements seek to integrate the capture device and display to improve the virtual reality environment. 
   There have been a number of solutions proposed for addressing the problem of poor eye contact that is characteristic of many existing solutions. With conventional systems that follow the pattern of  FIG. 1 , poor eye contact results from locating the video camera on a different optical axis than the video monitor and causes the eyes of an observed participant to appear averted, which is undesirable for a video communication system. Traditional solutions for addressing this problem, employing a display, camera, beam splitter, and screen, are described in a number of patents, including U.S. Pat. No. 4,928,301 entitled “Teleconferencing terminal with camera behind display screen” to Smoot; U.S. Pat. No. 5,639,151 entitled “Pass-through reflective projection display” and U.S. Pat. No. 5,777,665 entitled “Image blocking teleconferencing eye contact terminal” to McNelley, et al.; and U.S. Pat. No. 5,194,955 entitled “Video telephone” to Yoneta et al., for example. Alternately, commonly assigned U.S. Patent Application Publication No. 2005/0024489 entitled, “Image capture and display device” by Fredlund et al. describes a display device for capturing and displaying images along a common optical axis. The device includes a display panel, having a front side and a back side, capable of being placed in a display state and a transmissive state. An image capture device is provided for capturing an image through the display panel when it is in the transmissive state. An image supply source provides an image to the display panel when it is in the display state. A mechanism is also provided for alternating placing the display panel between the display state and the transmissive state, allowing a first image to be viewed and a second image to be captured of the scene in front of the display at high rates such that alternating between the display state and the transmissive state is substantially imperceptible to a user. 
   Commonly assigned U.S. Pat. No. 7,042,486 entitled, “Image capture and display device” to Manico et al. describes an image capture and display device that includes an electronic motion image camera for capturing the image of a subject located in front of the image display device and a digital projector for projecting the captured image. An optical element provides a common optical axis electronic camera and a light valve projection screen electronically switchable between a transparent state and a frosted state located with respect to the common optical axis for allowing the electronic camera to capture the image of the subject through the projection screen when in the transparent state and for displaying the captured image on the projection screen when in the frosted state. A controller, connected to the electronic camera, the digital projector, and the light valve projection screen, alternately places the projection screen in the transparent state allowing the electronic camera to capture an image and in the frosted state allowing the digital projector to display the captured image on the projection screen. This system relies on switching the entire display device rapidly between a transparent and a frosted state. However, with many types of conventional imaging components, this can induce image flicker and result in reduced display brightness. Furthermore, the single camera used cannot adjust capture conditions such as field of view or zoom in response to changes in scene. 
   Although such solutions using partially silvered mirrors and beam splitters have been implemented, their utility is constrained for a number of reasons. Solutions without a common optical axis provide an averted gaze of the participant that detracts from the conversational experience. Partially silvered mirrors and beam splitters are bulky particularly in the depth direction. Alternately transparent or semi-transparent projection display screens can be difficult to construct and with rapid alternation between states, ambient contrast can suffer and flicker can be perceptible. As a number of these solutions show, this general approach can result in a relatively bulky apparatus that has a limited field of view and is, therefore, difficult for the viewer to use comfortably. 
   As an alternative approach, closer integration of image display and sensing components has been proposed. For example, U.S. Patent Application Publication No. 2005/0128332, entitled “Display apparatus with camera and communication apparatus” by Tsuboi describes a portable display with a built-in array of imaging pixels for obtaining an almost full-face image of a person viewing a display. The apparatus described in the Tsuboi &#39;8332 disclosure includes a display element in which display pixels are arranged, along with a number of aperture areas that do not contain display pixels. In its compound imaging arrangement, multiple sensors disposed behind the display panel obtain a plurality of images of the scene through a plurality of clustered lenses that are disposed over aperture areas formed among the display pixels. Each sensor then converts the sensed light photo-electrically to obtain a plurality of tiny images of portions of the scene that are then pieced together to obtain a composite image of the scene. To do this, the display apparatus must include an image-combining section that combines image information from the plurality of images obtained by using the camera. 
   As another variation of this type of compound imaging approach, U.S. Patent Application Publication No. 2006/0007222, entitled “Integrated sensing display” by Uy discloses a display that includes display elements integrated with image sensing elements distributed along the display surface. Each sensing pixel may have an associated microlens. As with the solution proposed in the Tsuboi &#39;8332 disclosure, compound imaging would presumably then be used to form an image from the individual pixels of light that are obtained. As a result, similar to the device in the Tsuboi &#39;8332 disclosure, the integrated sensing device described in the Uy &#39;7222 application can both output images (e.g., as a display) and input light from multiple sources that can then be pieced together to form image data, thereby forming a low-resolution camera device. 
   Similarly, U.S. Patent Application Publication No. 2004/0140973, entitled “System and method of a video capture monitor concurrently displaying and capturing video images” by Zanaty describes an apparatus and method for compound imaging in a video capture monitor that uses a four-part pixel structure having both emissive and sensing components. Three individual emissive pixel elements display the various Red, Green, and Blue (RGB) color components of an image for display of information on the video-capture monitor. Additionally, as part of the same pixel architecture, a fourth pixel element, a sensing element, captures a portion of an image as part of a photo-electronic array on the video capture monitor. Although this application describes pixel combinations for providing both image capture and display, however, the difficulty in obtaining image quality with this type of a solution is significant and is not addressed in the Zanaty &#39;0973 disclosure. As an example of just one problem with this arrangement, the image capture pixels in the array are not provided with optics capable of responding to changes in the scene such as movement. 
   The compound imaging type of solution, such as proposed in the examples of the Tsuboi &#39;8332, Uy &#39;7222, and Zanaty &#39;0973 disclosures, is highly constrained for imaging and generally falls short of what is needed for image quality for the captured image. Field of view and overall imaging performance (particularly resolution) are considerably compromised in these approaches. The optical and computational task of piecing together a continuous image from numerous tiny images, each of which may exhibit considerable distortion, is daunting, requiring highly complex and costly control circuitry. In addition, imaging techniques using an array of imaging devices pointed in essentially the same direction tend to produce a series of images that are very similar in content so that it is not possible to significantly improve the overall image quality over that of one of the tiny images. Fabrication challenges, for forming multi-function pixels or intermingling image capture devices with display elements, are also considerable, indicating a likelihood of low yields, reduced resolution, reduced component lifetimes, and high manufacturing costs. 
   A number of other attempts to provide suitable optics for two-way display and image capture communication have employed pinhole camera components. For example, U.S. Pat. No. 6,888,562 entitled, “Integral eye-path alignment on telephony and computer video devices using a pinhole image sensing device” to Rambo et al., describes a two-way visual communication device and methods for operating such a device. The device includes a visual display device and one or more pinhole imaging devices positioned within the active display area of the visual display. An image processor can be used to analyze the displayed image and to select the output signal from one of the pinhole imaging devices. The image processor can also modify the displayed image in order to optimize the degree of eye contact as perceived by the far-end party. 
   In a similar type of pinhole camera imaging arrangement, U.S. Pat. No. 6,454,414 entitled “Device for image output and input” to Ting describes an input/output device including a semi-transparent display and an image capture device. To be semi-transparent, the display device includes a plurality of transparent holes. As yet another example, U.S. Pat. No. 7,034,866 entitled “Image-sensing display device with particular lens and sensor arrangement” to Colmenarez et al. describes an in-plane array of display elements alternating with pin-hole apertures for providing light to a camera. 
   The pinhole camera type of solution, as exemplified in the Rambo et al. &#39;562, Ting &#39;414, and Colmenarez et al. &#39;866 disclosures suffer from other deficiencies. Images captured through a pinhole reflect low brightness levels and high noise levels due to low light transmission through the pinhole. Undesirable “screen door” imaging anomalies can also occur with these approaches. Display performance and brightness are also degraded due to the pinhole areas producing dark spots on the display. Overall, pinhole camera solutions inherently compromise both display image quality and capture image quality. 
   As just indicated, a structure of integrated capture pixels intermingled in a display may cause artifacts for either the image capture system or the image display performance. To some extent, the capture pixel structures can be thought of as defective pixels, which might be corrected or compensated for by appropriate methods or structure. As an example, European Patent Application EP1536399, entitled “Method and device for visual masking of defects in matrix displays by using characteristics of the human vision system” to Kimpe, describes a method for reducing the visual impact of defects present in a matrix display using a plurality of display elements and by providing a representation of a human vision system. The Kimpe EP1536399 disclosure describes at least one defect present in the display deriving drive signals for at least some of the plurality of non-defective display elements in accordance with the representation of the human vision system, characterizing the at least one defect, to reduce an expected response of the human vision system to the defect, and then driving at least some of the plurality of non-defective display elements with the derived drive signals. However, a display having an occasional isolated defective pixel is a different entity than a display having a deliberate sub-structure of intermingled capture aperture or pixels. Thus the corrective measures to enhance display image quality can be significantly different. 
   One difficulty with a number of conventional solutions relates to an inability to compensate for observer motion and changes in the field of view. Among approaches to this problem have been relatively complex systems for generating composite simulated images, such as that described in U.S. Patent Application Publication No. 2004/0196360 entitled “Method and apparatus maintaining eye contact in video delivery systems using view morphing” by Hillis et al. Another approach to this problem is proposed in U.S. Pat. No. 6,771,303 entitled “Video-teleconferencing system with eye-gaze correction” to Zhang et al. that performs image synthesis using head tracking and multiple cameras for each teleconference participant. However, such approaches side-step the imaging problem for integrated display and image capture devices by attempting to substitute synthesized image content for true real-time imaging and thus do not meet the need for providing real-life interaction needed for more effective video-conferencing and communication. 
   The proliferation of solutions proposed for improved teleconferencing and other two-way video communication shows how complex the problem is and indicates that significant problems remain. Thus, it is apparent that there is a need for a combined image capture and display apparatus that would allow natural two-way communication, provide good viewer eye contact, adapt to different fields of view and changes in scene content, provide good quality capture images with reduced artifacts, and provide a sufficiently bright display without noticeable defects in the displayed image. 
   SUMMARY OF THE INVENTION 
   In accordance with this invention, there is provided an integrated imaging apparatus for displaying images while capturing images of a scene, comprising: 
   a) an electronic display having an array of display pixels which are used to display image content; 
   b) at least one image capture device which captures an image, wherein the image capture device includes at least an imaging lens and an image sensor array; and 
   c) wherein the image capture device looks through an aperture in the display, the aperture having at least one partially transparent pixel; and wherein the partially transparent pixels also provide light to display image content. 
   The present invention provides an apparatus comprising an integrated image display and image capture device that provide improved capture capability and improved display image quality. In addition, using the solution of the present invention, image capture conditions can be changed in response to changes in the scene. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     In the detailed description of the preferred embodiments of the invention presented below, reference is made to the accompanying drawings in which: 
       FIG. 1  is a block diagram of a typical prior art telecommunication system; 
       FIGS. 2A and 2B  are perspective views showing an apparatus in accordance with the present invention, operating in a display mode and in an image capture mode, respectively.; 
       FIG. 3  shows a timing diagram for image display and image capture for the present invention; 
       FIG. 4  is a perspective of an image capture device as used in the present invention; 
       FIG. 5  is a cross section of one embodiment of the present invention; 
       FIG. 6  is a more detailed cross section of the embodiment of  FIG. 5 ; 
       FIG. 7  is a cross section of an alternative embodiment of the present invention having transparent thin-film electronic components; 
       FIG. 8  is a cross section of a further embodiment of the present invention having a plurality of transparent display pixels; 
       FIG. 9  is a cross section of another embodiment of the present invention having a plurality of transparent display pixels of a common color; 
       FIG. 10  is a cross section of yet another embodiment of the present invention having adjacent transparent portions; 
       FIG. 11  is a top view of the embodiment of  FIG. 10 ; 
       FIG. 12  is a cross section of an alternative embodiment of the present invention having common light-emitting materials and color filters; 
       FIG. 13  is a cross section of an additional embodiment of the present invention having an electrode with reflective and transparent portions; 
       FIG. 14A  is a top view of a further embodiment of the present invention having multiple transparent portions and image capture devices; 
       FIG. 14B  is a top view of a display of the present invention depicting various exemplary groupings of the semi-transparent pixels; 
       FIG. 15  is a cross section of an alternative embodiment of the present invention having Fourier plane spatial filtering; 
       FIG. 16  is a block diagram showing system components of the present invention in one embodiment; 
       FIG. 17  is a top view showing system components of the present invention in one embodiment; and 
       FIG. 18  is a block diagram showing system components of the present invention in a networked embodiment. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   The apparatus and method of the present invention address the need for an integrated display and image capture device by taking advantage of a combination of factors including the following: 
   (i) fabrication of display device components of various types having substantially transparent electrode materials; 
   (ii) use of light modulation components that can be alternately emissive (or absorptive or reflective) and transparent; 
   (iii) timing to synchronize alternating image capture and image display functions for various apparatus components; 
   (iv) structural device layout and design to enhance image capture and image display; and 
   (v) corrective methods to enhance image quality for image capture and image display. 
   Significantly, the apparatus and method of the present invention avoid the pitfalls of compound imaging, as was described earlier with reference to the examples of the Tsuboi &#39;8332, Uy &#39;7222, and Zanaty &#39;0973 disclosures by using imaging optics and sensor components, rather than merely using sensors that detect light and attempting to assemble an image by tiling or other image synthesis methods. In addition, the apparatus and method of the present invention avoid problems typically associated with pinhole imaging, as was described earlier with reference to the Rambo et al. &#39;562, Ting &#39;414, and Colmenarez et al. &#39;866 disclosures. This is because the apparatus and method of the present invention utilize transparency properties of various types of display components to provide a suitable aperture for imaging, without significant detriment to display image quality. 
   It should be noted that drawings used to show embodiments of the present invention are not drawn to scale, but are illustrative of key components and principles used in these embodiments. Moreover, it must be emphasized that the apparatus of the present invention can be embodied in a number of different types of systems, using a wide variety of types of supporting hardware and software. 
     FIGS. 2A and 2B  show an important feature of operation that is utilized by the apparatus and method of the present invention. An integrated display and capture apparatus  100  of the present invention generally includes a display  5  and one or more capture devices  40 . Display  5  has an arrangement of pixel elements or pixels  8  and  9  that form a display screen that is observed by one or more viewers (not shown). Display pixels  8 , shown shaded in  FIGS. 2A and 2B , are conventional display pixels, such as emissive OLED pixels or transmissive LCD pixels. Pixels  9 , shown white or clear in  FIGS. 2A and 2B , also act as display pixels, but are fabricated and controlled to be at least partially transparent, and are thus termed as at least partially transparent (or semi-transparent) display pixels  9  in the present application. Capture device  40  is nominally a digital or video camera having a lens  42  for directing light toward an image sensor  41  for capturing a plurality of image pixels. In the depiction of  FIG. 2A , at least partially transparent pixels  9  are in a display mode, contributing a portion of display image light  62 . Pixels  9  either emit light (for an OLED display) or transmit (or reflect) light (for an LCD display). In the depiction of  FIG. 2B , at least partially transparent pixels  9  are in a transparent mode or clear mode, and receiving incident light  60  from a distant scene. The timing chart of  FIG. 3  shows a display timing pattern  102  for at least partially transparent pixels  9  and a capture timing pattern  104  for capturing an image from the image sensor  41 . A frame time (Δt) is spanned by one full cycle through ON and OFF states (an exemplary 50% duty cycle is shown). When the at least partially (in time) transparent pixels  9  are in a clear or transparent state, an image capture cycle can be executed, as is shown in  FIG. 2B . When the at least partially transparent pixels  9  are in a display state, nominally no image capture takes place. The timing patterns ( 106   a,b,c ) for the operation of the display pixels  8  will be discussed subsequently. 
   As is shown in  FIG. 4 , the capture device  40  includes imaging optics with an optical axis  43 . The basic components of capture device  40  are the lens  42  and an image sensor  41 , optionally encased in a housing  44  (shown in dotted lines in  FIG. 4 ). Image sensor  41  has an array of sensor pixels  45 , arranged in rows  46  and columns  47 , as is well known in the imaging arts. Incident light  60 , represented by dotted lines, is directed toward image sensor  41  by lens  42  to form an image thereon. Baffles (not shown) internal to lens  42  can be provided to minimize any stray light or ghost images from degrading the image capture. Lens  42  can employ folded optics the thickness of the housing. Image sensor  41  can capture an image having a large number of pixels. Image sensor  41  is likely a CCD or CMOS sensor array, having a resolution of ˜1-8 megapixels. The image that is captured can be a full scene image or a portion or tile of a larger, composite image. Unlike many of the display/capture device solutions of earlier approaches that attempt to capture a single pixel using a sensor optically coupled to a lenslet, the use of an image sensor  41  in the present invention acts as a camera and provides a two-dimensional image from each capture device  40 . 
   As noted earlier, transparency of display components at least during image capture is an important attribute for their implementation in the integrated display and capture device  100  of the present invention. Subsequent figures and description outline a number of embodiments using this principle with image sensor  41  and employing the timing and synchronization described with reference to  FIGS. 2A ,  2 B, and  3 . 
   Referring to  FIG. 5 , one embodiment of an integrated display and the capture apparatus  100  according to the present invention includes display  5  having a plurality of display pixels  8  wherein one or more of the display pixels  8  is at least partially transparent (as shown by at least partially transparent display pixel  9  in  FIG. 5 ) and partially opaque (as shown by display pixels  8  in  FIG. 5 ). Capture device  40  has an image sensor  41  for capturing a plurality of image pixels, as described earlier with reference to  FIG. 4 . 
   Display  5  has a first side  6  from which it is viewed. Capture device  40  is located on a second side  7  opposite the first side  6 , in a position corresponding to the location of the at least partially transparent display pixel  9 . Capture device  40  receives light  60  from the scene on first side  6  through at least partially transparent pixel  9  to form an image of the scene. In one embodiment of the present invention, display  5  is formed on a substrate  10  and includes a cover  20  adhered to the substrate  10  for protecting the display  5 . The first side  6  from which the display is viewed can be the cover  20  side; second side  7  can be the substrate  10  side and the capture device  40  located adjacent to substrate  10 , with light emitted through cover  20 . Alternately, capture device  40  can be located on cover  20  side with light emitted from the substrate  10  side. In one embodiment of the present invention, display pixels  8  include a reflective electrode  12  and a common transparent electrode  16 . Display pixels  8 , which can be either monochrome or color pixel, emit light in a forward direction (towards a display viewer), with the back-emitted light re-directed forwards by the reflective electrode  12 . The semi-transparent pixel  9  that is at least partially transparent can include two transparent electrodes  16  and  13 . As shown, there is a particular type of display pixel  8 , which is a white light emitter  14 W, which includes a semi-transparent pixel  9  and a portion with a thin film electronic component  30 . Thin film electronic components  30  can be electrodes, transistors, resistors, or other basic circuitry components. 
   As the term is employed herein, a partially transparent pixel is one that transmits sufficient light to form an effective image when viewed or recorded by a capture device  40 . For apparatus of the present invention, at least 50% transparency is needed and better than 80% transparency is preferred. Transparency is possible by virtue of device design and composition. For example, OLED devices, because they use thin-film components, can be fabricated to be substantially transparent, as has been described in the article “ Towards see - through displays: fully transparent thin - film transistors driving transparent organic light - emitting diodes ,” by Gorrn et al., in Advanced Materials, 2006, 18(6), 738-741. Typically, the patterned materials are deposited in thin films (e.g. 100 nm thick) that are effectively transparent. In the case of an OLED display, display pixels  8  can include a layer  14  of patterned organic materials  14 R,  14 G,  14 B that emit red, green, or blue light respectively. In the case of a monochrome display, display pixels  8  and semi-transparent pixels  9  can both emit white light. OLED devices are well known in the display imaging arts. 
   Another alternative for providing transparency is using LCD display technology. Where display  5  is an LCD display, layer  14  includes switchable liquid crystals that switch between a transparent and a light-absorbing state. Reflective and transparent electrodes are known in the art and can include, for example, metals and metal oxides such as reflective aluminum or silver layers and transparent indium tin oxide conductors. Transparent electrodes can also be somewhat reflective, formed, for example, from thin layers of silver. LCD devices are similarly well known in the display imaging arts. In particular, the general architecture of a trans-reflective LCD, in which the pixels have both reflective and transmissive portions could be extended to create an integrated display and capture device. 
   As shown in  FIG. 5 , transparent display pixel  9  forms an aperture A in the display screen through which image sensor  41  obtains light  60 . The size of aperture A, or window, through which one or more capture devices look, is an important factor for the performance of the system. Optically, it is desirable that the size of the aperture A be as large as possible. An aperture A should be large enough (for example, &gt;25 μm) that significant diffraction effects are not imparted to the light  60  in such a way that the image formed by the capture device  40  would be degraded. Increasing the size of aperture A increases the optical throughput of the light  60  available to a capture device  40 , enabling a brighter image with less noise. Larger effective apertures A with less intervening structure will also help lens focusing, as there will be less “screen door effect” to confuse the lens. Also, as it is difficult to make small cameras having optical components such as lens  42  and image sensor  41 , it is preferred to make the aperture A as large as possible. 
   For the apparatus and method of the present invention, the relationship of aperture A to pixel size is important. As is well known, pixel size can vary significantly between devices. In some large-format display devices, the pixel size can be on the order of 0.05 to 1 mm 2  in area. In particular, current cell phone displays typically have pixels that are ˜0.1-0.2 mm wide, while computer monitors use ˜0.3 mm wide pixel structures, and large panel entertainment systems have 0.5-0.8 mm wide pixel structures. Embodiments described subsequently outline approaches for arranging pixels in such a way as to maximize aperture A as well as to compensate for inherent problems in obtaining a sufficiently sized or sufficiently transparent aperture A. For example, for the displays  5  of  FIGS. 7 ,  8 , and  10 , the effective aperture size A is increased with pixel structures in which regions of transparency are expanded by greater use of semi-transparent materials (such as ITO electrodes) or pixel patterning to enhance aperture adjacency. In other cases ( FIGS. 9 and 15 ), the effective aperture A is increased by having image capture devices  40  look through multiple offset transparent pixels ( 9 ). However, it should be noted that the design of these apertures A of semi-transparent pixels (or ensembles thereof), including their size and patterning, needs to be designed with consideration for their visibility as potential display artifacts for a display user. Nominally the capture device  40  is aligned to be centered and normal (optical axis perpendicular to) an aperture A, unless it is deliberately askew, including being tilted or panned to track motion. 
   According to another embodiment of the present invention for an integrated display and capture apparatus  100 , display pixels  8  are active-matrix pixels that include thin-film electronic components  30  to control the light emission or reflection of the display pixels. Referring to  FIG. 6 , display  5  has thin-film electronic components  30  are formed on substrate  10 . Planarization layers  32  and  34  are employed to smooth layer surfaces and provide insulation between layers and between electrodes  12  and  13  formed in a common layer. In one embodiment, the thin-film electronic components are formed on relatively opaque silicon. Electrode  13 , within aperture A, is transparent. Emitted light  62  can be provided from both transparent and opaque pixels. 
   Referring to the embodiment of  FIG. 7 , display  5  has thin-film electronic components are formed of one or more transparent materials, for example zinc oxide or doped zinc oxide, and indium tin oxide (ITO). As an example, light  60  can pass through any thin-film electronic components  30  which are “relatively transparent”, such as partially transparent electrodes  30   a , to be incident upon image sensor  41 . Thus, the size of semi-transparent pixels can effectively be expanded, thereby increasing the aperture A size and improving the performance of the capture device  40 . 
   In  FIG. 8 , the capture device  40  receives light  60  through multiple display pixels  8  and  9  of display  5 , thereby increasing aperture A. In the example shown, some amount of light is obtained from the imaged scene through the portion of light emitting pixel  14 W, including semi-transparent pixel  9 , and further light from the portion with a partially transparent electrode  30   a . Image light is also collected through at least a portion of green color pixel  14 G, which is partially transparent layer of green patterned organic  14 G material in an OLED device. The aperture A can be expanded further by providing other color-emitting pixels with a partially transparent electrode  30   a  instead of a nominally opaque electrode ( 30 ). Likewise, the partially transparent electrode  30   a  of pixel  14 W can be of the light blocking variety ( 30 ). Even so, the effective aperture A is still increased, as incident light  60  passes through both the semi-transparent pixel portions of the white pixels ( 9 ) and the color pixels. Of course, any semi-transmissive color pixels that are also functioning as windows for image capture should be off (not light emitting) during the capture time. Various other spatial arrangements of partially transparent display pixels  9  can be employed, with filtered or non-filtered light directed toward image sensor  41 , as is described subsequently. 
     FIG. 9  shows another embodiment for apparatus  100  in which light is obtained through an aperture A that comprises a plurality of offset or spaced apart window pixels that are interspersed among the display pixels. In  FIG. 9 , the depicted light transmitting or window pixels are only at least partially transparent display pixels  9 . In this embodiment, all of at least partially transparent display pixels  9  emit the same color light, white in this case. However, the spaced apart light transmitting pixels could be both white and color pixels, distributed individually or in clusters, to form aperture A. Since, with either OLED or LCD devices, different colors can have different light emission efficiencies, it can be useful to group commonly-colored transparent pixels to reduce differences between the differently colored pixel groups. In particular, white emitters can be more efficient than other colors. Using this improved efficiency can help to mitigate the visual impact of employing a non-reflective electrode. 
   As another alternative embodiment for integrated display and image capture apparatus  100 , shown in  FIG. 10 , the effective aperture A can be increased beyond that available through a single partially transparent display pixel  9  by fabricating the display  5  with the partially transparent display pixels  9  clustered or adjacent. In these cases, the capture device  40  can be larger and can thus receive more light, possibly increasing the signal of image sensor  41 . Reflected pixel layouts can be arranged to accomplish this as taught in commonly assigned, above cited U.S. Ser. No. 11/341,945. Referring to  FIG. 11 , a top view of a portion of display  5  having such an arrangement is shown. Here, the component layout employs a bus connector  31 , thin-film transistors  30   b , and at least partially transparent pixels  9  located adjacent to each other to form an increased aperture A generally indicated by the dashed oval. 
   In an OLED embodiment of the present invention employing patterned organic materials to form light emitters, the organic materials do not significantly absorb light that passes through the at least partially transparent display pixels  9 . In an LCD embodiment, the liquid crystals are likewise substantially transparent. In these embodiments, the capture device  40  can employ additional color filters to form a color image of the scene on the first side  6  of the display  5 . 
   Referring to  FIG. 12 , there is shown an OLED embodiment of the present invention employing unpatterned organic materials  14  to form broadband light emitters together with color filters  24 R,  24 G, and  24 B to form a color display. In this embodiment, the color filters  24 R,  24 G, and  24 B can significantly absorb light that passes through them, providing a colored image to capture device  40 . If an RGBW configuration is employed, the white emitter does not have any color filter. If capture device  40  is located in alignment with such a white pixel with no color filters, then the capture device  40  will not receive colored light. Hence, the capture device  40  can form a monochrome or a color image record without the need for separate color filters on image sensor  41 . An optional black matrix  22  can be employed to reduce ambient reflection. The color filters  24 R,  24 G, and  24 B can be located on the electrode as shown in  FIG. 12  or on the inside of the protective cover  20  as shown in  FIG. 7 . 
   Referring to  FIG. 13 , reflective electrode  12  of display  5  can have a reflective area  12   a  and a transparent area  13   a  through which light passes to capture device  40 . In particular, for top-emitter structures such as is shown in  FIGS. 5 ,  7 ,  8 , and  10 , a portion of the bottom electrode is formed over areas corresponding to thin film electronic components  30  such as thin-film transistors, and another portion is formed for the areas between these thin-film components (transistors ( 30 )). In such instances, it can be useful to provide the reflective area  12   a  above the areas corresponding to thin-film transistors ( 30 ) and the transparent area  13   a  for the areas between the thin-film transistors ( 30 ). In this way, the use of emitted light is maximized. Such an electrode structure can be formed by providing a reflective, possibly conductive layer in the reflective areas  12   a  only and a transparent layer over both the reflective areas  12   a  and the transparent areas  13   a  as shown in  FIG. 13 . 
   In operation, the display  5  is controlled to emit or control light that forms a display image on the first side  6  of the display  5 , as was shown in  FIG. 5 . Ambient light  60  that illuminates a scene on the first side  6  is incident on the display  5 , passes through the one or more semi-transparent display pixels  9 , and is sensed by image sensor  41  of capture device  40  to form an image of the scene on the first side  9 . As shown in  FIG. 14   a , integrated display and capture apparatus  100  can be equipped with one or more capture devices  40  that look through the display  5 . This plurality of capture devices (cameras)  40  can have different imaging attributes, either individually or in combination. Most likely, these devices use lenses that have different focal lengths, and image with different fields of view (such as wide angle and telephoto) or magnifications. A lens for one camera  40  can have zoom capability, while the other lenses do not. These cameras  40  can have different numbers of pixels (different sensor resolutions), different spectral sensitivities of the light-sensing elements, different color filters, and other varying attributes. Some of these cameras  40  can be mounted with means (not shown) to facilitate pan and tilt functionality, to enable motion tracking in the user/viewer scene environment. Thus, the plurality of capture devices  40  can be directed to look at different parts of a scene, in an overlapping or a non-overlapping manner. An image processor  120  can output either multiple images or multiple image data (video) streams, or composite images or composite image streams. A controller  122  could facilitate both automatic and manual control of the variable features (zoom, pan, tilt, changing field of view, changing scene brightness, etc. . . . ) of the capture devices  40  to respond to changing scene conditions. 
   As shown in  FIG. 15 , the capture device  40  can include a spectral filter  66  somewhere prior to image sensor  41 . Depending on the application, spectral filter  66  could be a band pass or band rejection filter. For example, spectral filter  66  could be a filter that transmits red and infrared light (600-1200 nm, for example) while rejecting ultraviolet, blue, green, and out of band infrared light. As another option, spectral filter  66  could be a filter that preferentially transmits ultraviolet light. In such cases, the associated image sensor  41  will also need sufficient sensitivity in the chosen spectral range. Those skilled in the art will recognize that in the case wherein the capture device  40  is designed to operate in extreme low light conditions, it is beneficial to eliminate the spectral filter  66  to allow as much light as possible to reach the image sensor  41 . 
   In addition, it should be noted that in certain cases where it is desirable to produce images with light from outside the visible spectrum (350-700 nm), it is within the scope of the invention to add one or more capture devices  40  that operate outside the visible spectrum such as in the ultraviolet or the infrared. In these cases, it is important to select a lens  42  that will operate in the ultraviolet (below 350 nm) or infrared (above 700 nm) regions. A spectral filter  66  can be used to eliminate light outside the region that is to be imaged. The invention also anticipates the need for capture devices  40  operating inside the visible spectrum to be combined with capture devices  40  operating outside the visible spectrum to enable sequential or simultaneous multi-spectral imaging. 
   It is recognized that the integrated display and capture apparatus  100  of the present invention, including a display  5  with display pixels  8  and at least partially transparent pixels  9 , as well as one or more capture devices  40 , can be subject to image artifacts in either the image display or image capture spaces. These potential artifacts include spatial frequency effects, “screen door” effects, pin hole “defect” effects, stray and ghost light issues, color or spectral effects, flicker effects, and non-uniform shading issues. These artifacts (and others), which can occur individually or in combination, can generally be reduced with appropriate hardware designs or image processing corrections, which can likewise be applied individually or in combination. In general, the goal would be to reduce the presence of any image display or image capture artifacts to at least just below the appropriate threshold for human perception thereof, thereby enhancing the image quality. As will be seen, the hardware design and the image processing can both be tailored to meet these needs. 
   As one example,  FIG. 15  illustrates an integrated display and capture apparatus  100  that has baffles  64  to reduce image artifacts for both image display and image capture. Incident light  60  passes through semi-transparent pixels  9  or display pixels  8 , and miss a given image capture device  40 . That light could enter the capture device  40  after various reflections and scattering events, and create ghost images or flare light, reducing image quality for either the displayed or captured images. Capture device  40  can have an external housing  44  and internal baffles (not shown) that reduces this risk. Additionally, some incident light could re-emerge from behind the display  5 , through transparent pixels and display pixels  8 , and provide ghosts or flare light into the images seen by a viewer of the display. To counter this, integrated display and capture apparatus  100  is equipped with one or more light absorbing baffles  64 , which can include coated plates and surfaces, sheet polymer materials, or light trapping structures. Baffles  64  can be formed on either side of substrate  10  of display  5 . It is noted that baffles  64 , which are similar to a backing for display  5 , are generally distinct from any thin film light absorbing layers that might be provided within the display micro-structure to reduce unintended stray reflections from incoming ambient light. With respect to  FIG. 14   a , these baffles would be located behind display  5 , in the regions at least between the various image capture devices  40 . Of course, if semi-transparent pixels  9  are provided only in camera locations (see  FIG. 14   a ), then baffles  64  may not be needed, or may only be need in proximity to apertures A. 
   The integrated structure of integrated display and capture apparatus  100  can cause various capture image artifacts, including shadowing. For example, some portion of the light incident on image sensor  41  may have been occluded by thin-film electronic components  30  in the optical path. In this case, the capture device  40  records a scene with shadows imaged on image sensor  41 . Such shadows can have a regular, periodic structure. Since these shadow areas are out of focus and are caused by a known part of the fixed optical structure of the digital capture device-display system, the effects of the shadows on the image can be modeled, tested, and compensated. Compensation techniques for ambient lighting conditions and for artifacts in the optics such as occlusions of the optical path are known and can be implemented in an image post-processing step. This step can be performed, for example, at image processor  120 , as shown in  FIG. 18 . 
   The structure of display  5  can also cause other capture image defects, as image content is transmitted differently, removed, or obscured by the device structure. For example, in the case of the  FIG. 8  embodiment, a light-transmitting aperture A can span portions of semi-transparent pixels  14 W both with and without partially transparent electrodes  30   a , as well as portions color emitting pixels (such as  14 G) that can also be partially transparent, again either with or without partially transparent electrodes  30   a . As these different partially transparent pixels or pixel portions can have different transmittances in at least the blanking state, then the transmittance across an aperture A will vary spatially across the display  5 . As long as the objects in the captured scene are sufficiently distant from the display, these transmission variations should be averaged out for all field points. But as the objects become closer, these spatial variations in an aperture A of display  5  could lead to image non-uniformities. These differences can be most readily corrected or compensated for by the image processor  120 . Likewise, if the incident light  60  passes through a color filter ( 24 R,  24 G, or  24 B—see  FIG. 7 ), the image that is obtained at image sensor  41  can be adjusted to compensate for the filtering to correct spatial color variations in the image. 
   As another example, periodic spatial structures in display  5  can cause capture image artifacts, where image content is removed, or obscured or altered by the effective frequencies of the structure. In some cases, optical compensation or correction techniques could be used. In particular, Fourier plane spatial filtering can be used to reduce the visibility of artifacts caused by regular periodic structures. As an example, an integrated display and capture apparatus  100  is depicted in  FIG. 15 , where display  5  has a repeating structure of red, green, blue and white pixels. Capture device  40 , which includes a lens  42  with multiple lens elements  42   a ,  42   b  and  42   c  and an image sensor  41 , looks through a multitude of semi-transparent pixels  9 . Depending on the size of the lens  42  and the size and pitch of the semi-transparent pixels  9 , the capture device  40  can be looking through several, or several hundreds or more, of semi-transparent pixels  9  that are separated by color (or monochrome) pixels. Relative to the capture device  40 , imaging through this array of apertures formed by the semi-transparent pixels  9  can be much like imaging through a screen door, with a consequent loss of light intensity and the distraction of the structure itself, which can make focusing difficult, as well as impacting the image quality of scenes with similar spatial frequencies. Aliasing could also occur. These semi-transparent pixels  9  can include white pixels (as in  FIGS. 9 ,  10 , and  11 ), as well as semi-transparent structures where light is transmitted through nominally transparent electronic components (aperture A of  FIG. 7 ) and/or through semi-transparent patterned color pixel structures (aperture A of  FIG. 8 ). 
   When the multitude of pixel semi-transparent pixels ( 9 ) are spatially repeated in a periodic manner, or even a quasi-periodic manner, a static structure can occur in frequency space. In the case of an optical system, this frequency structure is evidenced in the Fourier plane of a lens system. For example, as shown in  FIG. 15 , capture device  40  includes image sensor  41  and lens  42  with multiple lens elements ( 42   a ,  42   b , and  42   c ). Within this optical system, a Fourier plane  68  exists, at, or in proximity to, an aperture stop  69 . Incident light  60 , which is incident from multiple locations in the field of view, is collected through semi-transparent pixels  9  and focused or converged towards the Fourier plane  68  (shown by a dashed line) and an aperture stop  69 , where after multiple lens elements  42   b  and  42   c  create images on image sensor  41 . Most easily, spatial filtering with a fixed pattern Fourier plane filter  70  can reduce the fixed or static spatial frequency patterns created by a display structure. For example, this filter can include a (two-dimensional) spatial pattern of highly absorbing regions formed on a transparent substrate, which is mounted between the multiple lens elements  42   a ,  42   b  and  42   c.    
   The distribution or pattern of semi-transparent pixels  9  and apertures A can also create display image artifacts that could affect the display viewer. In designing display  5 , there is a choice whether pixels  9  and apertures A occur only where the plurality of capture devices  40  reside (per  FIG. 14   a ) or are across larger areas, and even the entire display  5 . As these at least partially transparent pixel  9  structures can be fairly large (˜0.1-1.0 mm for a linear dimension) and patterned, they can create visible artifact that irritate the display user. For example, within an area with a pattern with different display intensities, the user can perceive a “banding effect”, where the structures appear as an artifact with a several mm pitch that aligns with regions of maximal human spatial pattern sensitivity. The pattern of semi-transparent pixel structures can also create a speckled appearance to the display that could annoy the viewer. For example, in extremum, the pattern of window or transparent pixels could seem like a grid of dark spots (in either a clear/transparent or dark state). This is illustrated in  FIG. 14   b , in which different pixel groupings ( 26   a ,  26   b ,  26   c ) of semi-transparent pixels  9  are shown, and pixel groupings  26   a  and  26   b  represent regular grids. If the pixels  9  are small enough, they might exist generally un-noticed. However, as an example, the traverse of a displayed motion image across the display could increase their perceptibility for a viewer. 
   There are various approaches that can be used to reduce the visibility of the semi-transparent pixels  9  (or apertures A) for the display viewer. To begin with, the semi-transparent pixels  9  can only be fabricated where cameras will be located, and not across an entire display. The semi-transparent pixels  9  (white) can also be smaller than the RGB pixels. However, as it is desirable to locate a camera behind the display, at or near the screen center, for the purpose of “eye contact” image capture for teleconferencing applications, further mitigating design features may be needed. The semi-transparent pixels  9  might be kept patterned in the same pitch within a row, but be staggered across rows, to appear less like a regular grid (less like pixel grouping  26   a ). As another approach, display  5  could have the intermingled semi-transparent pixels  9  (or apertures A) distributed quasi-periodically (pseudo-periodically) or randomly within a capture aperture of the capture device  40 , or more broadly, across different regions of the display  5 , to reduce this effect. These concepts are exemplified by the illustrated pixel grouping  26   c  of  FIG. 12   b . However, as electronic devices, and array electronic devices in particular, are conventionally fabricated with predefined repeating structures, random pixelization would be quite difficult. A quasi-periodic structure is more likely, which could be either identical or non-identical in the XY directions (horizontal and vertical of  FIG. 14   b ) of a display  5 . In optical frequency space (Fourier plane  68 ) for image capture, a quasi-periodic pattern of pixels  9  could create a frequency pattern with gaussian profiles. Fourier plane filter  70  could then have a spatial patterned absorbance that followed a functional dependence (such as a gaussian) in one or more locations, rather than the more traditional pattern of constant high absorbance (or reflectance) regions. Alternately, or in addition, frequency filtering to remove structural display artifacts from the image capture could be done in the capture image processing electronics. The virtue of optical filtering, as compared to electrical/software filtering, is that it occurs without requiring any computing power for data processing. 
   It can also be desirable to reduce the visibility of the semi-transparent pixels  9  for image capture by modulating these pixels temporally. In a sense, the timing diagram ( FIG. 3 ) would be more complex, as the modulation within a frame time (Δt) would could be staggered (out of phase) or segmented from one pixel  9  to another. This modulation could change the apparent spatial pattern or frequency of these pixels as perceived by a viewer, whether the display  5  includes groupings ( 26 ) of semi-transparent pixels  9  that were periodically or quasi-periodically arrayed. In turn, that could affect the spatial frequency pattern seen at the Fourier plane  68 . Conceivably, Fourier plane filter  70  could be a dynamic device, such as a spatial light modulator (such as an LCD or DMD) that was temporally modulated in synchronization with the modulation of pixels  9 . However, such synchronized frequency space corrections are likely best handled directly in the image processor  120  that handle the captured images. 
   The existence of semi-transparent pixels  9  or apertures A can cause non-uniformity artifacts (in addition to flare) that will impact the displayed image, depending on whether these pixels appear dark or bright. The spatial distribution and size of semi-transparent pixels  9  across display  5  very much affects these artifacts. Some of these issues are resolved if the dark state of semi-transparent pixels is a condition of both no light emission and no light transmission. However, there are still cases where display pixels  8  surrounding or adjacent to each of the semi-transparent pixels  9  (or apertures A) can be modulated in a calibrated compensating way to reduce the visibility of the semi-transparent pixels  9  to a viewer of the display. The display scene calibration can be undertaken in a scene dependent way, using the fact that the display electronics has information on the (static) structure of display  5 , has control of the pixel modulation timing and intensity, and can pre-process the image to be displayed. For example, when a semi-transparent pixel  9  is in a white state in an area where a generally bright whitish image is being displayed by the color pixels, the proximate display pixels  8  could be darkened to compensate. Likewise, when a semi-transparent pixel  9  (which can only be clear, dark, or white) resides in a displayed screen area of constant color content (say red), the adjacent display pixels  8  could be brightened to compensate for this pixel (as compared to red display pixels  8  further away from a semi-transparent pixel  9 ). In another sense, the semi-transparent pixels  9  might be used for display image contrast enhancement, given that they can be driven to either clear (dark) or white states. 
   The application of local or adjacent display pixels  8  to compensate or correct for the operation of a semi-transparent pixel  9 , depends on how the display pixels are operated. For example, if non-transparent light emitting display pixels are on or emitting light during most of a frame time Δt, then they are in operation for some portion (see display timing pattern  106   b  of  FIG. 3 ) of the clear state for image capture for a semi-transparent pixel  9 . The timing of display and capture is then at least somewhat de-coupled, although the defined frame time Δt is presumed constant. Local changes in display pixel brightness can be attained by providing an average constant intensity or by actively changing the intensity within a frame time (display timing patterns  106   c  of  FIG. 3 ). Thus, adjacent or proximate display pixels neighboring a semi-transparent pixel  9  could be driven higher when that pixel switches clear (for example, if the ensemble of proximate color pixels give a white image) or lower or left constant depending on the scene content. If the ON or light emission state timing for the non-transparent light emitting display pixels is comparable to that of the semi-transparent pixels  9  (display timing pattern  106   a ˜semi transparent pixel timing pattern  102 ), then pixel brightness differences probably can likely only be compensated via differences in display pixel intensity without temporal manipulation. This is particularly true for devices of the  FIG. 8  variety, where at least some display pixels  8  have transparent electrode structures rather than reflective electrode structures. In that case, those pixels should follow the same nominal timing diagram (pattern  106   a =pattern  102 , per  FIG. 3 ) as the semi-transparent pixels  9 , so that they do not back emit light towards a capture device  40 . 
   Likewise, on a larger scale, and considering again  FIG. 14   a , display  5  can be fabricated with semi-transparent pixels  9  or apertures A in places where capture devices  40  are present, or across the entire display  5 . In either case, whether these window pixels are across the entire display (suggesting the use of the baffles  64 ) or only in regions localized for cameras  40 , the displayed images could look different in the capture regions versus the non-capture regions. In particular, there can be large areas with a different display appearance than other large areas (that is, large spatial non-uniformities). By and large, these macro-non-uniformities should be anticipated and correctable (perhaps with the help of a calibration step) in the image processing electronics  120 , and compensated for in advance of image display. 
   However, the primary purpose of semi-transparent pixels  9  is to act as windows or apertures for image capture by one or more cameras  40 . For an OLED type device, these pixels can be driven to an “ON”, light emitting state, to reduce their visibility to a display viewer. But all the pixels within a cameras field of capture nominally need to be “OFF” or transparent for a sufficient time period that a nominally uniform image capture can occur over the capture field of view. Relative to the semi-transparent pixel timing pattern  102  ( FIG. 3 ), the display state definition of a dark pixel can be key. Generally, it is intended that a dark semi-transparent pixel  9  is still ON or in a display state, and does not transmit light to a capture device  40 . However, with some designs or device technologies for display  5 , a dark state can equate to an OFF/clear state, in which case incident light  60  can be transmitted to the capture device  40 . For example, that could mean that a semi-transparent pixel might be left in its clear or transparent state (dark state for the display viewer) for a prolonged period of time (relative to the capture frame time), if it resides in an image region that is dark for a prolonged time period. Light would then be incident to the capture device (camera)  40  during the previously defined blank state. Capture device  40  could have a shutter (not shown) to eliminate this concern. Alternately, a spatially and/or temporally variant correction or gain adjustment might be made for the captured image as the prolonged dark semi-transparent pixels  9  within a cameras field of capture will have much more light transmission in time than the pixels that are reaching ON states. 
   As was described with reference to  FIG. 3 , the simplest form of periodic control can be to switch the semi-transparent pixels  9  off (clear) for some portion of time to allow the capture device to capture the scene. Since, nominally, only the at least partially transparent display pixels  9  are switched rather than all of the pixels, the switching can be unobtrusive in the display. Moreover, the image capture can be made in a short portion of a period of time (e.g. 1/100 th  of a second or a portion of a single frame at 30 Hz) reducing both the duty cycle for image capture and the visibility of temporal artifacts. The operation of non-transparent light emitting display pixels is at least somewhat linked to the operation of the semi-transparent pixels  9 . For example, if they follow the same timing (pattern  106   a =pattern  102 ), then reducing the off state time means that the same pixel intensity can be attained with less drive loading. Then, if a display pixel ( 8  or  9 ) is switched off for 50% of the time while image capture occurs, the display pixel can emit twice the light during the remaining 50% of the time during which the display pixel is switched on. As the time required for image capture lengthens, it becomes more desirable (relative to flicker and instantaneous loading) to decouple the operation of the non-transparent light emitting display pixels from the operation of the pixels comprising a semi-transparent aperture A. 
   Another image artifact, flicker, can affect both image display and image capture devices. In this case, by employing at least partially transparent display pixels  9  that switch between a non-active (transparent for image capture) and an active (ON) state, while the display pixels are active (emitting or reflecting) during most of the frame time, flicker is reduced relative to the image display. Since only the display pixels having at least partially transparent areas are switched between active and non-active states, the visual effect of the switching on the display quality is reduced and the user experience is improved. Admittedly, having display pixels on during image capture means that some display light can encounter objects in the capture field of view and reflect or scatter back towards the capture devices  40 . This light could raise the noise floor, change the spectrum, or temporally alter the captured images. However, the effects of this return light are likely minimal compared to the ambient lighting. Moreover, electrical techniques like supplying clocking or carrier frequency signals could be used to reduce such effects. In the case that the display and semi-transparent pixels (white or color) follow the same timing diagram, it can be desirable to reduce the capture time (smaller duty cycle) or increase the frame rate, to reduce flicker perceptibility. 
   As previously mentioned, back-emitted light (white or color) from the display  5 , for example in an OLED embodiment, with the reflective electrodes replaced by transmissive electrodes, can be incident on image sensor  41 . This issue can largely be addressed by only emitting light from these window pixels with matched timing patterns  102  and  106   a  of  FIG. 3 . Additionally, capture device  40  can be equipped with a synchronized light blocking shutter or sensor drains. Alternately, it can be desirable to extend image capture (timing pattern  104 ″) to occur while image display is occurring. That is, the window pixels (semi-transparent pixels  9  and semi-transparent color pixels (per  FIG. 8 )) of an aperture A would emit light (both forwards and backwards) during at least a portion of image capture. As the display controller  122  knows the light  60  emitted by the display  5 , the light emission from the display  5  can be subtracted from the light signal received by image sensor  41  to improve the quality of image capture of the scene. As another option, the light emitted by the at least partially transparent display pixel  9  can be periodically reduced during simultaneous image capture by image sensor  41  to improve the image capture of the scene. In embodiments relying upon controllable light absorption to form an image (e.g. in an LCD), the amount of light absorbed by the partially transparent display pixel  9  is likewise known to a display controller and a correction can be made to the corresponding image sensors to correct for the absorption of ambient light by the partially transparent display pixel  9 . 
   The prior discussions concerning the impact the structure of the integrated display and capture apparatus  100  on the quality of image capture and image display has principally focused on the embodiments integrated display and capture apparatus  100  is an OLED type device and where at least partially transparent pixel  9  is then a light emitting pixel. However, as was previously discussed, integrated display and capture apparatus  100  can also be a LCD type device. Even so, many of the previously discussed image artifacts, such as shadowing, flare light, spatial pattern frequency effects, spectral transmission differences, can affect the quality of the image capture. Likewise, many of the previously discussed image display artifacts, such as pixel pattern perception and local and macro brightness differences, can affect the quality of the image display. Thus, many of the various hardware remedies (quasi-periodic pixel patterning, baffles, Fourier plane filtering, etc. . . . ) and image processing remedies (pixel brightness changes, shadow removal, gain and offset adjustments, etc. . . . ) can be applied to the LCD case to reduce the presence of such image artifacts. 
   It is also worth considering how the integrated display and capture apparatus  100  of the present invention interacts with a network, particularly given its potential use for telecommunications. Again, for context,  FIG. 1 , presents a typical prior art two-way telecommunication system is shown wherein the first viewer  71  views the first display  73 . A first image capture device  75 , which can be a digital camera, captures an image of the first viewer  71 . In the present invention, the display and capture apparatus will be much more highly integrated than is implied by  FIG. 1 . Thus,  FIG. 16  shows, in block diagram form, an integrated display and capture apparatus  100  within part of a communications network. A viewer  80  looks at display  5  that includes an integrated digital capture device  40 . Capture device  40  obtains an image signal, as described subsequently, and provides the image signal to an image processor  86  that provides the image data for transmission to another site through a modulator  82 . A demodulator  84  provides the controlling signals from the other site for operating display  5 . The block diagram of  FIG. 17  shows a top view of integrated display and capture apparatus  100  in an alternate embodiment having a control logic processor  90  and a communications module  92  for providing the image along a network  94  or  96 . 
   The block diagram of  FIG. 18  shows a two-way communication system  110  that utilizes an integrated capture device and a display, for communication between a viewer  80   a  at a first site  112  and a viewer  80   b  at a second site  114 . Each viewer  80   a ,  80   b  has an integrated image capture and display apparatus ( 100 ) comprising a display  5  with one or more integrated capture devices  40 . A central processing unit (CPU)  116  coordinates control of the image processor  120  and the controller  122  that provides display driver and image capture control functions. A communication control apparatus  124  acts as interface to a communication channel, such as a wireless or wired network channel, for transferring image and other data from one site to the other. In the arrangement of  FIG. 17 , two-way communication system  110  is optimized to support video conferencing. Each viewer  80   a ,  80   b  is able to see the other viewer displayed on display  5  at that site, enhancing human interaction for teleconferencing. Image processing electronics  120  potentially serve multiple purposes, including improving the quality of image capture at the local display  5 , improving the quality of images displayed at the local display  5 , and handling the data for remote communication (by improving the image quality, data compression, encryption, etc.). It must be noted that  FIG. 18  shows a general arrangement of components that serve one embodiment. Capture devices  40  and display  5  are assembled into a frame or housing (not shown) as part of the device integration. This system housing can also encompass the image processor  120 , controller  122 , CPU  116 , and communication control  124 . Also not shown are audio communications and other support components that would also be used, as is well known in the video communications arts. 
   In summary, the present invention provides an effective user experience as the capture device and display are naturally integrated in a mechanically thin package. In particular, the use of at least partially transparent display pixels  9  as opposed to pinholes formed in the display improves the fill factor or aperture ratio of the display, enabling more of the display area to emit or reflect light, thereby improving life times and display image quality. Display resolution can also be improved. Moreover, the use of at least partially transparent display pixels  9  with the capture device  40  located behind the at least partially transparent display pixels  9  allows the remainder of the display area to be reflective or light absorbing, thereby improving the amount of light output or reflected or improving the ambient contrast of the display, improving display image quality as a result. Forming multiple transparent areas improves the image capture capability by increasing the light available to capture devices  40  located behind the transparent areas or enabling a plurality of capture devices  40  to be employed. 
   The integrated display and capture apparatus  100  of the present invention certainly has potential application for teleconferencing or video telephony. Additionally, this device might be used as an interpretive display for advertising or as an interactive display for video games and other entertainment formats. The displayed image content can include photographic images, animation, text, charts and graphs, diagrams, still and video materials, and other content, either individually or in combination. In particular, the integrated capture and display apparatus  100  could be used to capture an image of one or more display users and then insert their images, in part or in total, into the displayed image content. Other applications for integrated display and capture apparatus  100 , in areas such as medical imaging, can be considered. Integrated display and capture apparatus  100  can be sized for cell phone or handheld applications, or for use in a laptop or desktop computer, or for use in an entertainment display. Integrated display and capture apparatus  100  can also be equipped with integrated light emitting devices for the purpose of illuminating a scene, which can be useful if the ambient lighting is low, or an unusual capture spectrum is desired. For example, the illuminating devices might be places around the outer edges of display  5 . Likewise, other optical sensing or detection devices could be substituted for image sensor  41  in one or more capture devices  40  used with an integrated display and capture apparatus  100 . For example, a low resolution wide angle lens and a quad cell, with simple sum and differencing electronics, could be used to track motion, such as recognizing that someone has entered the capture field of view. A specialized device, such as an optical fingerprint imager could be provided, as a security feature. Alternately, single cell sensors could be used to detect ambient light levels or function as a photovoltaic cell for solar energy conversion. Most basically, an optical sensor needs to generate a useful electrical signal in response to incident light. 
   The present invention can be employed in display devices. Such display devices can also include additional layers or optical devices, for example protective or encapsulating layers, filters, and polarizers e.g. circular polarizers. In a preferred embodiment, the present invention is employed in a flat-panel OLED device composed of small molecule or polymeric OLEDs as disclosed in but not limited to U.S. Pat. No. 4,769,292, issued Sep. 6, 1988 to Tang et al., and U.S. Pat. No. 5,061,569, issued Oct. 29, 1991 to VanSlyke et al. Many combinations and variations of organic light-emitting displays can be used to fabricate such a device, including both active-matrix and passive-matrix OLED displays having either a top-emitter or bottom-emitter architecture. Other display device technologies can also be used in the present invention, including devices based on inorganic phosphorescent materials, such as quantum dots. 
   The invention has been described in detail with particular reference to certain preferred embodiments thereof, but it will be understood that variations and modifications can be effected within the spirit and scope of the invention. It should be understood that the various drawing and figures provided within this invention disclosure are intended to be illustrative of the inventive concepts and are not to scale engineering drawings. 
   PARTS LIST 
   
       
       A aperture 
         5  display 
         6  first side 
         7  second side 
         8  display pixels 
         9  at least partially transparent display pixel (or semi-transparent pixel) 
         10  substrate 
         12  reflective electrode 
         12   a  reflective area 
         13  transparent electrode 
         13   a  transparent area 
         14  organic layer 
         14 R red patterned organic material 
         14 G green patterned organic material 
         14 B blue patterned organic material 
         14 W white patterned organic material 
         16  transparent electrode 
         20  cover 
         22  black matrix 
         24 R red color filter 
         24 G green color filter 
         24 B blue color filter 
         26  pixel groupings 
         26   a  pixel grouping 
         26   b  pixel grouping 
         26   c  pixel grouping 
         30  thin-film electronic components 
         30   a  partially transparent electrodes 
         30   b  thin film transistors 
         31  bus connector 
         32  insulating planarization layer 
         34  insulating planarization layer 
         40  capture device (or camera) 
         41  image sensor 
         42  lens 
         42   a  lens element 
         42   b  lens element 
         24   c  lens element 
         43  optical axis 
         44  housing 
         45  pixel 
         46  row 
         47  column 
         60  light 
         62  light 
         64  baffle 
         66  spectral filter 
         68  Fourier plane 
         69  Aperture stop 
         70  Fourier plane filter 
         71  first viewer 
         73  first Display 
         75  first image capture device 
         77  first still image memory 
         79  first D/A converter 
         80  viewer 
         80   a  viewer 
         80   b  viewer 
         81  first modulator/demodulator 
         82  modulator 
         83  first communication channel 
         84  demodulator 
         85  second viewer 
         86  image processor 
         87  second display 
         89  second image capture device 
         90  control logic processor 
         91  second still image memory 
         92  communications module 
         93  second D/A converter 
         94  network 
         95  second modulator/demodulator 
         96  network 
         97  second communication channel 
         100  integrated display and capture apparatus 
         102  semi-transparent pixel timing pattern 
         104  capture timing pattern 
         106   a  display timing pattern 
         106   b  display timing pattern 
         106   c  display timing pattern 
         110  two-way communication system 
         112  site 
         114  site 
         116  central processing unit (CPU) 
         120  image processor 
         122  controller 
         124  communication control apparatus