Patent Publication Number: US-2012038738-A1

Title: Gaze correcting apparatus, a method of videoconferencing and a videoconferencing system

Description:
TECHNICAL FIELD 
     This application is directed, in general, to interactive video displays, such as, a videoconferencing terminal. 
     BACKGROUND 
     This section introduces aspects that may be helpful in facilitating a better understanding of the disclosure. Accordingly, the statements of this section are to be read in this light and are not to be understood as admissions about what is in the prior art or what is not in the prior art. 
     Communication via computer networks frequently involves far more than transmitting text. Computer networks, such as the Internet, can also be used for audio communication and visual communication. Still images and video are examples of visual data that may be transmitted over such networks. 
     One or more cameras may be coupled to a computing device, such as a personal computer (PC), to provide visual communication. The camera or cameras can then be used to transmit real-time visual information, such as video, over a computer network. Dual transmission can be used to allow audio transmission with the video information. Whether in one-to-one communication sessions or through videoconferencing with multiple participants, participants can communicate via audio and video in real time over a computer network (i.e., voice-video communication). 
     During video conferences, the cameras and images of remote users are physically separate. This leads to participants appearing not to look at the camera but to an off-axis location, which many video conferencing participants find uncomfortable and annoying. This gaze misdirection is often cited as one of the major subjective issues in conferencing, especially during one-on-one meetings. This problem requires that, relative to the user, the direction of the image of the remote user and the direction of the camera should be coincident, which is generally impractical. 
     SUMMARY 
     One aspect provides an apparatus. In one embodiment, the apparatus includes: (1) a monitor configured to provide a remote image for viewing, (2) a camera located in front of the monitor and positioned to face the monitor and capture a local image reflected therefrom and (3) a light filter positioned between the camera and the monitor to reduce light originating from the monitor on the camera. 
     In another aspect, a method of videoconferencing is provided. In one embodiment, the method includes: (1) providing a remote image from a first location on a monitor at a second location, (2) simultaneously with the providing, capturing a local image reflected from the monitor on a camera, the camera located in front of the monitor and positioned to face the monitor, the local image for display at the first location and (3) filtering the local image reflected from the monitor employing a light filter positioned between the camera and the monitor to reduce light originating from the monitor onto the camera. 
     In yet another aspect, a videoconferencing system is disclosed. In one embodiment, the videoconferencing system includes a first videoconferencing terminal connectable to support a videoconferencing session video with a second videoconferencing terminal via a telecommunications network, wherein the first terminal has: (1) a microphone configured to generate an audio signal based on acoustic energy received thereby, (2) a speaker configured to generate acoustic energy based on an audio signal received thereby, (3) a monitor associated with the speaker and configured to provide a remote image from the second videoconferencing terminal, (4) a camera associated with the microphone and located in front of the monitor, the camera positioned to face the monitor and capture a local image reflected therefrom, the local image for display at the second videoconferencing terminal and (5) a light filter positioned between the camera and the monitor to reduce light originating from the monitor on the camera. 
    
    
     
       BRIEF DESCRIPTION 
       Reference is now made to the following descriptions of embodiments, provided as examples only, taken in conjunction with the accompanying drawings, in which: 
         FIG. 1  is a schematic block diagram of an embodiment of a videoconferencing infrastructure within which a videoconferencing terminal constructed according to the principles of the disclosure may operate; 
         FIG. 2  is a side elevation view of an embodiment of a videoconferencing terminal, e.g., of the videoconferencing infrastructure of  FIG. 1 , constructed according to the principles of the disclosure; and 
         FIG. 3  is a flow diagram of one embodiment of a method of videoconferencing carried out according to the principles of the disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     Even with voice-video communication, videoconferencing sessions can seem rigid with strained interaction between participants. To improve interaction and provide an immersive feel for users, various devices have been used. For example, a camera is often positioned as close as possible to the image of the remote user. Other conventional devices may add a secondary semi-reflective surface to a monitor at an angle of 45 degrees to reflect the image of a user to a camera positioned to the side of the monitor (i.e., a reversed teleprompter). Some conventional devices have attempted to place a camera behind a monitor and obtain an image of the user by either using a hole in the monitor or by modulating the transparency of the monitor. These conventional devices, however, provide approximate solutions that can be distracting to the users, cause poor image quality or increase the size of the display to uncomfortable proportions. 
     Disclosed herein is an apparatus, such as a computer terminal, that employs the front surface or screen of a monitor (e.g., a liquid crystal display (LCD) monitor) as a low efficiency mirror and a camera (e.g., a video camera) either located above, below or to the side of the monitor to capture an image of the user. The computer terminal may be used for videoconferencing (i.e., a videoconferencing terminal). The addition of a light filter, such as a polarizing filter, in front of the camera removes the component of light coming from or originating from the monitor, leaving just the reflected image. The component of light originating from the monitor may be a remote image being displayed on the monitor. 
     The light filter is located between the camera and the monitor. As such, the light filter is positioned in front of the camera (i.e., located in front of the lens of the camera) to filter out unwanted light generated by the monitor. As disclosed below, the light filter may be attached to the camera, attached to another device such as a keyboard or may be an independent device that can support itself. 
       FIG. 1  is a schematic block diagram of one embodiment of a videoconferencing infrastructure  100  within which a videoconferencing terminal constructed according to the principles of the disclosure may operate. This embodiment of the videoconferencing infrastructure  100  is centered about a telecommunications network  110  that is employed to interconnect two or more videoconferencing terminals  120 ,  130 ,  140 ,  150  for communication of video signals or information, and perhaps also audio signals or information, therebetween. An alternative embodiment of the videoconferencing infrastructure  100  is centered about a computer network, such as the Internet. Still another embodiment of the videoconferencing infrastructure  100  involves a direct connection between two videoconferencing terminals, e.g., connection of the videoconferencing terminals  120 ,  130  via a plain old telephone (POTS) network. As represented in the videoconferencing terminal  120 , the videoconferencing terminals  120 ,  130 ,  140 ,  150 , may include components typically included in a conventional videoconferencing terminal, such as, a microphone, a speaker, a monitor and controller. Additionally, the videoconferencing terminals  120 ,  130 ,  140 ,  150 , may include a camera located in front of the monitor and positioned to face the monitor and capture an image reflected therefrom. The front or viewing side of the monitor is the screen-side of the monitor where displayed images are viewed. A light filter is also located between the camera and the monitor. The light filter may be coupled to camera. In some embodiments, the light filter may be a self-supporting device with a base that allows the light filter to be positioned independently between the monitor and the camera. These embodiments provide a configuration that allows the light filter to be fixed to maintain a set-up for operation and also allow different cameras to be used. The light filter may also be coupled to a keyboard associated with videoconferencing terminal  120 . In the various embodiments, the light filter may be fastened or positioned employing conventional means. 
     The microphone can be configured to generate an audio signal based on acoustic energy received thereby, and the speaker can be configured to generate acoustic energy based on an audio signal received thereby. The monitor can include a display screen that provides a visual output and the controller can be configured to direct the operation of the terminal. The videoconferencing terminals  120 ,  130 ,  140 ,  150 , may be computer terminals, including but not limited to, a personal computer, a laptop, a computing pad, a personal digital assistant (PDQ) or a mobile telephone. 
       FIG. 2  is a side elevation view of an embodiment of a videoconferencing terminal  200 , e.g., of the videoconferencing infrastructure of  FIG. 1 , constructed according to the principles of the disclosure. The videoconferencing terminal  200  includes a monitor  210 , a camera  220  and a light filter  230 . 
     The monitor  210  includes a screen  215  and is configured to provide an image for viewing, such as, a remote image communicated over the telecommunications network  110  of  FIG. 1  from a remote videoconferencing terminal. The monitor  210  may be a flat panel display (FPD) monitor. In one embodiment, the monitor  210  is a liquid crystal display (LCD) monitor. In an alternative embodiment, the monitor  210  is a liquid-crystal-on-silicon (LCoS) monitor. In further alternative embodiments, the monitor  210  is another conventional or later-developed FPD technology that allows filtered images, such as, a monitor that provides polarized images. Those skilled in the pertinent art understand the structure and operation of conventional FPDs. 
     The camera  220  is located in front of the monitor  210  and positioned to face the monitor  210  and capture an image reflected therefrom. The camera  220  may be a conventional webcam. The local image may be the face of a local user in front of the monitor  210 . The local user may be, for example, employing the monitor  210  for a videoconferencing session or recording a video blog. The camera  220  may be coupled to the monitor  210  via conventional audio-video cable to transmit the captured image to the monitor  210  for, for example, transmission to another terminal for video conferencing. Wireless connections may also be employed. 
     The camera  220  includes a base  225  that is designed to support the camera  220  and allow the camera  220  to be tilted to adjust the field of view. One skilled in the pertinent art will understand the structure and operation of a base that allows the field of view of the camera  220  to be adjusted. The field of view may be adjusted to align with the angle that the local image is reflected (i.e., the angle of reflection) from the monitor  210 . 
     As illustrated in  FIG. 2 , the camera  220  may be coupled to a keyboard associated with the monitor  210 . The camera  220  may be coupled to the keyboard via a conventional means. The camera  220  may also be fastened to the monitor  210  via an arm  227  as indicated by the dashed line in  FIG. 2 . The distance the camera  220  is extended from the monitor  210  or positioned in front of the monitor  210  may be based on the type of monitor  210  (e.g., the size of the monitor  210 ). The distance may be known based on experimentation. In some embodiments, a particular distance for various types of displays may be marked on the arm  227  to position the camera  220 . The arm  227  may be mechanically coupled to the monitor  210  through conventional means and may be attached at various locations on the monitor  210  that allow the camera  220  to be positioned in front of the monitor  210 . For example with respect to the monitor  210 , the arm  227  may support the camera  220  from the bottom of the monitor  210 . In other embodiments, the arm  227  may support the camera  210  from sides of the monitor  210  of from the top of the monitor  210 . Additionally, the camera  220  may be attached to the top side of the keyboard, to the left side or, as illustrated, to the right side of the keyboard. 
     The light filter  230  is positioned between the camera  220  and the monitor  210  to reduce light originating from the monitor  210  onto the camera  220 . The light filter  230  is detached from the monitor  210  (i.e., not attached to the screen of the monitor) and, in  FIG. 2 , is coupled to the front of the camera  220 . In other embodiments, the light filter  230  may be a self-supporting device with a base that allows the light filter  230  to be positioned independently between the monitor  210  and the camera  220 . Alternatively, the light filter  230  may be coupled to the keyboard or the arm  227 . These embodiments provide a configuration that allows the light filter  230  to be fixed to maintain a set-up for operation and also allow different cameras to be used. The light filter  230  may be fastened or positioned employing conventional means. 
     In one embodiment, the light filter  230  is a polarizing filter. The polarizing filter may be a linearly polarizing filter or a circularly polarizing filter. For example, the light filter  230  may be a linearly polarizing filter that transmits one of two states of linearly polarized light. Light originating from the monitor  210  is polarized in a known state (e.g., red, blue and green light may be produced with the same linear polarization), as such, a linear polarizing filter can be configured with its transmission axis orthogonal to the known state to prevent light originating from the monitor  210  passing through the light filter  230  to the camera  220 . For circularly polarizing, a circular polarization filter may be configured with a clockwise or anticlockwise transmission filter to prevent light originating from the monitor  210  passing through the light filter  230  to the camera  220 . Employing a circular polarization filter may reduce misalignment effects of the light filter  230 . One skilled in the art will understand how to make and attach such a linear polarizing filter to a surface. 
       FIG. 3  is a flow diagram of one embodiment of a method of videoconferencing carried out according to the principles of the disclosure. In one embodiment a videoconferencing terminal as disclosed herein with respect to  FIG. 1  or  FIG. 2 , (e.g., including a monitor, a camera and a light filter) may be employed for the videoconferencing. The method begins in a step  305 . 
     In a step  310 , a remote image from a first location is provided on a monitor at a second location. The first location may be a remote location from the monitor. In one embodiment, the remote image may be communicated over a telecommunications network to the monitor. In some embodiments, the first location and the second location may be located proximate each other. For example, the first location and the second location may be located in the same building or may be separated by a wall. The remote image may originate from a videoconferencing terminal coupled to the telecommunications network. 
     While providing the remote image, a local image reflected from the monitor (or a screen of the monitor) is captured on the camera in a step  320 . The camera is located in front of the monitor and positioned to face the monitor. The local image is reflected from the display at an angle of reflection and the camera captures the local image at the angle of reflection. The camera may be mechanically coupled to the monitor. The local image is captured to be displayed at the first location. As such, users at the first location and the second location may participate in a video conference. For example, the local image may be of a local user of the monitor and the camera is positioned between the local user and the monitor. 
     While capturing the local image and providing the remote image, the local image reflected from the monitor is filtered in a step  330 . The local image may be filtered employing a polarizing filter positioned between the camera and the monitor. The polarizing filter may be a linear or a circular polarization filter. The filtering reduces the amount of light originating from the monitor. The method  300  then ends in a step  340 . 
     Those skilled in the art to which the application relates will appreciate that other and further additions, deletions, substitutions and modifications may be made to the described embodiments. Additional embodiments may include other specific apparatus and/or methods. The described embodiments are to be considered in all respects as only illustrative and not restrictive. In particular, the scope of the invention is indicated by the appended claims rather than by the description and figures herein. All changes that come within the meaning and range of equivalency of the claims are to be embraced within their scope.