Patent Application
20130321686
Remote collaboration and videoconferencing systems allow remotely located users to collaborate with one another. Users at one location can see and interact with users at other locations in real-time and without noticeable delay. In many of these systems, users are confronted with the choice of directing their gaze at either a display screen or a camera. If the user primarily looks at the display screen, the user may appear to a remote user to be looking down or away from the remote user rather than making eye contact with the remote user. If the user primarily looks at the camera instead, the user may not be able to see a remote user sufficiently to interact with the remote user.
In the following detailed description, reference is made to the accompanying drawings, which form a part hereof, and in which is shown by way of illustration specific embodiments in which the disclosed subject matter may be practiced. It is to be understood that other embodiments may be utilized and structural or logical changes may be made without departing from the scope of the present disclosure. The following detailed description, therefore, is not to be taken in a limiting sense, and the scope of the present disclosure is defined by the appended claims.
As described herein, a display-camera system is configured to sequentially display content to one or more local users and capture images of the local users for transmission to a remotely located system, such as a remote display system or a remote display-camera system with one or more remote users or a remote processing system. The displayed content on the display-camera system may include images or other content from a remote display system, a remote display-camera, and/or a remote processing system. The communication between the local display-camera system and the remote system or systems may allow local and remote users to interact collaboratively or processing operations to be performed on the captured images. The display-camera system may be used in remote collaboration or videoconferencing systems or in human-machine interactions (e.g., automatic teller machine (ATM) transactions, for example.
LCD panel 20 includes a front side and a back side. The front side forms an external surface for displaying content to the users, and the back side is disposed adjacent to switchable diffuser 30. In the display mode, LCD panel 20 modulates light from light source 40 that passes through switchable diffuser 30 responsive to control unit 60. Control unit 60 provides control signals that control the amount of light that each pixel in LCD panel 20 transmits from the back side to the front side of LCD panel 20. In the capture mode, control unit 60 provides control signals that cause at least a portion of LCD panel 20 (e.g., the portion of LCD in a field of view of camera 50) to be transparent such that the pixels in the portion allow light to pass from the front side to the back side of LCD panel 20.
In one embodiment, LCD panel 20 includes a liquid crystal (LC) layer, electrode layers disposed adjacent to and on opposite sides of the LC layer, polarized panels disposed adjacent to each electrode layer, and a glass cover adjacent to the front side polarized panel. The LC layer may include twisted nematic liquid crystals such as substituted phenyl-cyclohexane liquid crystals, cyano-biphenyl liquid crystals, substituted (1,1′-bicyclohexyl)-4-ylbenzene liquid crystals, substituted tolane liquid crystals, substituted diphenyl-diacetylene liquid crystals, substituted diphenyl-hexendiyne liquid crystals, and substituted bistolane liquid crystals.
The front side electrode layer (i.e., the electrode layer positioned closer to the front side of LCD panel 20) may be a transparent substrate with transparent electrodes patterned thereon. The pattern of the transparent electrodes determines the shapes of pixels that will appear when the LCD panel 20 is turned on. The back side electrode layer (i.e., the electrode layer positioned closer to the back side of LCD panel 20) may be a transparent substrate with a transparent common electrode established thereon. An example of the transparent substrate for each of the electrode layers includes glass, and examples of suitable electrode materials include indium tin oxide (ITO) or polyethylenedioxythiophene polystyrenesulfonate (PEDOT:PSS), etc.
The back side polarized panel (i.e., the polarized panel positioned closer to the back side of LCD panel 20) has a glass filter with a microscopically grooved surface facing the liquid crystal layer and a polarizing film attached to a surface opposite the microscopically grooved surface. The polarizing film of the back side polarized panel is oriented in the same direction as the microscopically grooved surface of the glass filter. Similarly, the front side polarized panel includes has a glass filter with a microscopically grooved surface facing the liquid crystal layer and a polarizing film attached to a surface opposite to the microscopically grooved surface. The polarizing film of the front side polarized panel is oriented in the same direction as the microscopically grooved surface of the glass filter. The grooves and polarized film of the front side polarized panel are oriented at a right angle (i.e., 90°) with respect to the grooves and polarized film of the back side polarized panel.
The grooves, for example, in the glass filter of the back side polarized panel cause a first sub-layer of the nematic liquid crystals (e.g., a layer deposited on the glass filter of the back side polarized panel) to align with the orientation of the back side polarized panel. Successive sub-layers of nematic liquid crystals that are deposited will gradually twist until the outermost sub-layer is at a 90° angle with respect to the orientation of the crystals in the first sub-layer. As such, the nemetic liquid crystals in the outermost sub-layer match the orientation of the front side polarized panel. In this example, the liquid crystal layer includes multiple sub-layers of nemetic liquid crystals. The back side polarized panel polarizes light that passes through it, and the nemetic liquid crystals in each sub-layer of the liquid crystal layer guide the light to the next sub-layer. As the light passes through the liquid crystal sub-layers, the liquid crystals change the plane of vibration of the light to match their own angle. When the light reaches the outermost sub-layer of liquid crystals, the light vibrates at the same angle as the outermost sub-layer. When the orientation of the crystals in the outermost sub-layer is matched up with the orientation of the front side polarized panel, the light passes through the front side polarized panel and into the glass cover. Control unit 60 causes a voltage applied to the respective surrounding electrode layers to alter the alignment of the liquid crystals in the sub-layers of the liquid crystal layer to control the transmission of light.
In other embodiments, LCD panel 20 may include an LC layer with other suitable layers.
Switchable diffuser 30 is disposed adjacent to the back side of LCD panel 20 and between LCD panel 20 and camera 50. Switchable diffuser 30 is an electronically controllable diffuser (e.g., a polymer dispersed liquid crystal (PDLC) film) that switches between transparent and diffuse states responsive to control signals from control unit 60. In the display mode, switchable diffuser 30 is switched to diffuse to allow light from light source 40 to uniformly illuminate LCD panel 20. Switchable diffuser 30 may include any suitable light guide structures to further enhance uniform lighting across LCD panel 20. In the capture mode, switchable diffuser 30 is switched to transparent to allow light that passes through LCD panel 20 to pass through switchable diffuser 30 and on to camera 50.
Light source 40 may be any suitable visible light source that functions as a backlight of display-camera system 10 and can be rapidly switched between on and off states. Light source 40 may include one or more point lights (e.g., arranged in an array), one or more line lights, one or more surface (i.e., plate-shaped) lights, or a combination of different types of lights. As shown and described in the embodiments below, light source 40 may include one or more light emitting diodes in some embodiments. In the display mode, light source 40 is switched on to emit light and illuminate LCD panel 20 through switchable diffuser 30. In the capture mode, light source 40 is switched off and does not emit light. By being turned off during the capture mode, light from light source 40 does not transmit through LCD panel 20 while the panel is transparent and prevents any light interference with the image capture.
Camera 50 may be any suitable type and number of cameras that capture images through LCD panel 20 while LCD panel 20 and switchable diffuser 30 are transparent. Camera 50 is disposed behind LCD panel 20 and switchable diffuser 30 with a distance that is selected so that a field of view of camera 50 encompasses all or a portion of LCD panel 20 and/or with a distance that provides increased image quality. Camera 50 captures images within the field of view and with a focal range that at least partially extends beyond the front side of LCD panel 20 (e.g., the interactions of the local users with display-camera system 10). Camera 50 may include any suitable image sensor, such as a digital charge couple device (CCD) or complementary metal-oxide-semiconductor (CMOS) active pixel sensor.
Control unit 60 provides control signals that control the operation of LCD panel 20, switchable diffuser 30, light source 40, and camera 50 in both the display and capture modes. In the display mode, control unit 60 causes LCD panel 20 to display content, switches switchable diffuser 30 to diffuse, and switches light source 40 to on. Control unit 60 may receive the content to display from another system (not shown), such as another display-camera system, or may access the content to display from a memory 64 in control unit 60 or another processing system. In the capture mode, control unit 60 switches LCD panel 20 and switchable diffuser 30 to transparent, switches light source 40 to off, and causes camera 50 to capture an image through LCD panel 20 and switchable diffuser 30 while LCD panel 20 and switchable diffuser 30 are transparent and light source 40 is off.
In the embodiment of
Processors 62, memory system 64, and communications device 68 communicate using a set of interconnections 69 that includes any suitable type, number, and/or configuration of controllers, buses, interfaces, and/or other wired or wireless connections. Each processor 62 is configured to access and execute instructions 66 stored in memory system 64. Each processor 62 is also configured to access and store data, including content 66 and captured images 67, in memory system 64. Memory system 64 includes any suitable type, number, and configuration of volatile or non-volatile storage devices configured to store instructions and data. The storage devices of memory system 64 represent computer readable storage media that store computer-readable and computer-executable instructions. Communications devices 68 include any suitable type, number, and/or configuration of network and/or port devices configured to allow control unit 60 to communicate across one or more wired or wireless networks (not shown) or other communications media. Communications devices 68 may operate according to any suitable networking protocol and/or port protocol to allow information to be transmitted by control unit 60 to a network and/or another system or received by control unit 60 from a network and/or another system.
In other embodiments, control unit 60 may be implemented using other suitable types of logic circuitry that may or may not execute computer-readable instructions.
Housing 70 (shown conceptually in
Housing 70 substantially defines a three-dimensional enclosure with an interior surface that may be black and/or coated with a light absorbing material to prevent outside light from entering system 10 and bouncing around inside the enclosure behind LCD panel 20 when light source 40 is off during capture mode. The size and depth of the enclosure may be defined largely by the distance between camera 50 and LCD panel 20 as described above.
In one embodiment, control unit 60 may be fully or partially disposed on and/or in housing 70. In other embodiments, control unit 60 may be housed separately from display-camera system 10, either locally or remotely, and operatively coupled to LCD panel 20, switchable diffuser 30, light source 40, and camera 50 using any suitable set of wired and/or wireless interconnections.
In some embodiments, housing 70 may include separate and/or unconnected structural elements that dispose one or more of the components of system 10 independently of the remaining components. For example, camera 50 may be disposed on a structural element of housing 70 that is not physically connect to any other structural element of housing 70 that disposes LCD panel 20, switchable diffuser 30, and/or light source 40.
In one embodiment of display-camera system 10, LCD panel 20 includes color filters for different colors (e.g., red, green, and blue color filters to define red, green, and blue pixels), and light source 40 emits white light. In another embodiment, LCD panel 20 does not include color filters, and light source 40 sequentially emits different colors of light (e.g., red, green, and blue light). In this embodiment, the on cycle of light source 40 shown in
In some embodiments, switchable diffuser 30 may take some time to switch from diffuse to transparent and from transparent to diffuse. Control unit 60 may operate light source 40 and switchable diffuser 30 as shown in the embodiments of
In
In one embodiment of
Control unit 60 may also turn off light source 40 while switchable diffuser 30 is switching from diffuse to transparent and from transparent to diffuse as shown in
Various embodiments of display-camera system 10 will now be described with reference to
The above embodiments of display-camera system 10 may advantageously provide increased dynamic range over embodiments where a backlight remains on in both a display mode and a capture mode. By turning light source 40 off while LCD panel 20 and switchable diffuser 30 are transparent, light from light source 40 does not impact the black level of display-camera system 10 during the capture mode. In addition, during the capture mode, users will not see a contrasting region through the LCD panel 20 and switchable diffuser 30 formed by the location of camera 50 (dark) surrounded by the backlight (white) from light source 40. Further, embodiments that use LEDs as light source 40 and LCD panel 20 may operate more quietly and with sharper image features than projector-based see-through configurations.
