System for video conference and cooperative communication

Abstract

The utility model discloses a system for video conference and cooperative communication, which comprises a transparent projection screen, a projector, a camera and an optical device, and the optical device is arranged in a light path between a light-emitting lens of the projector and a light-receiving lens of the camera. The optical device has the functions of changing the light path so that the camera can clearly capture and demonstrate the portrait of a user and present the projected digital content, the optical device can adopt linear polarization filters which are perpendicular to each other or micron shutter films, and meanwhile, reflecting films are arranged in orthographic projection arrangements respectively. A scattering layer is arranged in rear projection arrangement, and the technical problems that in an existing video conference, gesture and eye contact communication of a demonstrator is not transmitted to participants in real time, so that the conference participation sense is poor, and the conference effect is affected due to non-target image exudation existing in a holographic-like system combining a projector and a transparent display screen are solved.

Description

Technical Field

[0001] The utility model relates to the technical field of video conferencing display and collaboration, and particularly relates to a system for video conferencing and collaborative communication. Background Art

[0002] Video conferencing refers to a meeting in which people located at two or more locations have a face-to-face conversation through communication devices and networks. Usually, a webcam is located at the top center of the display screen border. This configuration allows individuals to conduct video conferencing, where the computer of each participant captures video, which is sent to other participants. In traditional video conferencing, since each participant has to look at the digital content displayed on the screen, their eyes focus below the webcam, and they rarely look at the webcam. Therefore, in video conferencing or remote presentations, there is a lack of natural eye contact or eye-to-eye communication between participants, resulting in a significant experience gap compared to in-person face-to-face meetings.

[0003] Holographic-like systems use projectors and transparent display screens to display projected digital content to a large audience. However, currently, holographic-like systems often have non-target image leakage, that is, the transmission or display of secondary images on the side opposite to the projector on the screen, resulting in poor display effects. The secondary images will distract the audience and cannot be directly applied to video conferencing. For transparent display screens, the person facing the display screen, i.e., the presenter, is easily interfered by reflected light, especially when high-lumen light is used for better projection effects. And the webcam behind the display screen can only receive about 10% of the light from the front, resulting in poor effects of the webcam capturing the human figure and the presenter using the transparent display screen. At the same time, in today's video conferencing systems, when the presenter demonstrates digital content, the screen sharing function must be used. At this time, the view of the person by the webcam is reduced to a thumbnail in the sidebar or corner, and the presenter's eye contact or gestures are easily ignored, or the presenter's figure deviates from the webcam's field of view. Such separate display of the presenter's figure and digital content results in a poor immersive experience for participants at the remote end. Therefore, it is necessary to embed the presenter's webcam view into the digital content on the screen so that the audience can see the content the presenter is viewing, the position the presenter is pointing at, as well as the presenter's facial expressions and body postures. Existing video conferencing and online collaborative communication systems are not sufficient to meet such requirements. Summary of the Utility Model

[0004] The purpose of the utility model is to solve the technical problems that in existing video conferencing, the presenter's gestures and eye contact cannot be transmitted to remote participants in real time, resulting in a poor immersive experience for the participants, and that the holographic-like system combining a projector and a transparent display screen has non-target image leakage, which affects the meeting effect.

[0005] The present utility model provides a system for video conferencing and collaborative communication, comprising:

[0006] A transparent projection screen having a front surface facing the presenter and a rear surface opposite to the front surface;

[0007] A projector, which includes a light-emitting lens, and is arranged on one side of the front surface with the light-emitting lens facing the front surface;

[0008] A camera, which includes a light-receiving lens, and is arranged on one side of the rear surface with the camera lens facing the rear surface;

[0009] An optical device, which is arranged in the optical path between the light-emitting lens of the projector and the light-receiving lens of the camera, and has the function of changing the light path so that the camera can clearly capture the portrait of the presenter and present the projected digital content.

[0010] Preferably, the optical device includes a first polarization filter and a second polarization filter. The first polarization filter is arranged between the transparent projection screen and the projector; the second polarization filter is arranged between the camera and the transparent projection screen, and the transmission axis of the first polarization filter is perpendicular to the transmission axis of the second polarization filter.

[0011] Preferably, the optical device includes a microshutter film, which is arranged on the rear surface of the transparent projection screen.

[0012] Preferably, it further includes a controller and a processor. The controller controls the projector to insert one or more black pixel lines when projecting digital content. The camera synchronously captures images through the black pixel lines. The processor performs Fourier transform on the images from the spatial domain to the frequency domain, then processes them through a frequency-domain filter and inversely transforms them back to the spatial domain, and applies Y-channel correction to the images in the spatial domain.

[0013] Preferably, the optical device includes a reflective film, which is arranged on the front surface. The reflective film is used to reflect the projected image of the projector into the eyes of the presenter, and has the function of transmitting the light from the presenter side for the receiving lens of the camera to capture the portrait of the presenter and present the projected digital content.

[0014] Preferably, the reflective film is a multi-layer dielectric coating or a single layer or a metal coating or an alloy coating made of optical materials with significantly different refractive indices.

[0015] The present utility model also provides a system for video conferencing and collaborative communication, comprising:

[0016] A transparent projection screen having a front surface facing the presenter and a rear surface opposite to the front surface;

[0017] A projector and a camera, the projector including a light-emitting lens, the camera including a light-receiving lens, the projector and the camera both being disposed on one side of the rear surface and the light-emitting lens and the light-receiving lens facing the rear surface;

[0018] An optical device disposed in the optical path between the light-emitting lens of the projector and the light-receiving lens of the camera, the optical device having the function of changing the optical path so that the camera can clearly capture the portrait of the presenter and present the projected digital content.

[0019] Preferably, the optical device includes a scattering layer disposed on the front surface or the rear surface, the scattering layer containing metal or crystal particles to scatter light.

[0020] Preferably, the transparency of the transparent display screen having the scattering layer is at least 35%, preferably more than 60%.

[0021] Preferably, the optical device includes a first polarization filter and a second polarization filter, the first polarization filter being disposed between the transparent projection screen and the projector; the second polarization filter being disposed between the camera and the transparent projection screen, the transmission axis of the first polarization filter being perpendicular to the transmission axis of the second polarization filter.

[0022] Preferably, the optical device includes a micro-louver film disposed on the rear surface of the transparent projection screen.

[0023] Preferably, the scattering layer contains metal particles sputtered onto the film, the density of the metal particles increasing linearly, geometrically or cosine-inversely with respect to the distance from the center of the transparent projection screen, the density of the metal particles being lowest at the center and highest at the outermost periphery.

[0024] Preferably, the projector is a short-throw projector or an ultra-short-throw projector, the projector projects a video image of digital media content onto the transparent projection screen, and the projection angle between the projection light of the projector and the horizontal plane is less than 45 degrees.

[0025] Preferably, the angle between the incident light rays emitted by the light-emitting lens of the projector and the horizontal plane is less than or equal to 70 degrees.

[0026] Preferably, it further includes a controller and a processor. The controller controls the projector to insert one or more black pixel lines when projecting digital content. The camera synchronously captures images through the black pixel lines. The processor performs Fourier transform on the images from the spatial domain to the frequency domain, then processes them through a frequency domain filter and inversely transforms them back to the spatial domain, and applies Y-channel correction to the images in the spatial domain.

[0027] The utility model has the following beneficial effects compared with the prior art:

[0028] A system for video conferencing and collaborative communication disclosed by the utility model includes a transparent projection screen, which has a front surface facing the presenter and a rear surface opposite to the front surface; a projector, which includes a light-emitting lens, and the projector is arranged on one side of the front surface with the light-emitting lens facing the front surface (front projection arrangement) or on one side of the rear surface with the light-emitting lens facing the rear surface (rear projection arrangement); a camera, which includes a light-receiving lens, and the camera is arranged on one side of the rear surface with the camera lens facing the rear surface; an optical device, which is arranged in the optical path between the light-emitting lens of the projector and the light-receiving lens of the camera, and the optical device has the function of changing the light path so that the camera can clearly capture the portrait of the presenter and present the projected digital content. The optical device can adopt mutually perpendicular linear polarization filters or a micron shutter film, and at the same time, a reflective film is respectively arranged in the front projection arrangement and a scattering layer is arranged in the rear projection arrangement. Further, a controller and a processor are provided. The controller controls the projector to insert one or more black pixel lines when projecting digital content. The camera synchronously captures images through the black pixel lines. The processor performs Fourier transform on the images from the spatial domain to the frequency domain, then processes them through a frequency domain filter and inversely transforms them back to the spatial domain, and applies Y-channel correction to the images in the spatial domain; in the above-mentioned front projection arrangement and rear projection arrangement, the leakage of non-target secondary images is eliminated, and the technical problems that the gestures and eye contact of the presenter during existing video conferencing cannot be transmitted to the participants in real time, resulting in a poor sense of participation in the meeting, and the non-target image leakage in the holographic-like system combining the projector and the transparent display screen affects the meeting effect are solved; it has a strong sense of face-to-face collaboration in video conferencing. The passive transparent display screen with a scattering layer can achieve 95%-99% clear camera images relative to glass when the transparency is only 60%; the camera only captures the images of the presenter and the environmental images, does not image any projected digital content from the projector, and combines the video of the presenter in real time, that is, embeds the portrait of the presenter and the digital content projected by the projector in real time into a separate software application, thereby forming an embedded image of the presenter, and achieving the beneficial effect of immersive video conferencing. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] To fully understand the present utility model and its advantages, reference is now made to the following description taken in conjunction with the accompanying drawings briefly described as follows:

[0030] Figure 1 FIG. shows a schematic diagram of the front projection arrangement system of Embodiment 1 of the present utility model.

[0031] Figure 2 FIG. shows a schematic diagram of the rear projection arrangement system of Embodiment 1 of the present utility model.

[0032] Figure 3 FIG. shows a schematic diagram of the setting of the polarization filter of Embodiment 1 of the present utility model.

[0033] Figure 4 FIG. shows a schematic diagram of the setting of the polarization filter and the application of the scattering layer of Embodiment 1 of the present utility model.

[0034] Figure 5 FIG. shows an inverse relationship diagram between the scattering luminance and the transparency of the scattering layer of Embodiment 2 of the present utility model.

[0035] Figure 6 FIG. shows a schematic diagram of the optical device of Embodiment 1 of the present utility model using a micron louver film.

[0036] Figure 7 FIG. shows a schematic diagram of the type of the micron louver film of the present utility model. DETAILED DESCRIPTION OF THE INVENTION

[0037] Please refer to Figures 1 to 7 , and the preferred embodiments and advantages of the present utility model can be understood. The features, structures or characteristics of the present utility model can be combined in any suitable manner in one or more embodiments. It will be apparent to those skilled in the art that various modifications can be made to the present utility model without departing from the spirit and scope of the present utility model. Therefore, the present utility model is intended to cover modifications and variations that are consistent with the scope of the appended claims and their equivalents.

[0038] Although the present utility model is discussed in the context of capturing video of a person in front of a transparent projection screen, the present utility model can be used in the absence of a person in front of the transparent projection screen. As used herein, the term "transparent" includes translucent.

[0039] Embodiment 1

[0040] Please refer to the related drawings. A system for video conferencing and collaborative communication is arranged in a front projection manner and includes a transparent projection screen. The transparent projection screen has a front surface facing the presenter and a rear surface opposite to the front surface. The transparent material used for the transparent projection screen is, for example but not limited to, glass or acrylic with higher transparency, that is, at least 25% transparency, but preferably greater than 40% and up to 90% to 92%. Compared with T-OLED and transparent micro-LED display screens, the transparent projection screen can only reflect or scatter light but cannot emit light actively.

[0041] A projector, the projector includes a light-emitting lens, the projector is arranged on one side of the front surface and the light-emitting lens faces the front surface; a camera, the camera includes a light-receiving lens, the camera is arranged on one side of the rear surface and the camera lens faces the rear surface;

[0042] An optical device, the optical device is arranged in the optical path between the light-emitting lens of the projector and the light-receiving lens of the camera. The optical device has the function of changing the light path so that the camera can clearly capture the portrait of the presenter and present the projected digital content. The optical device includes a first linear polarization filter and a second linear polarization filter. The first linear polarization filter and the second linear polarization filter are orthogonal to each other, that is, their axes are oriented 90 degrees to each other to prevent the projected image from being received by the camera; alternatively, the two orthogonal polarization filters can be replaced by a micrometer louver film;

[0043] The optical device further includes a reflective film. The reflective film is arranged on the front surface. The reflective film is used to reflect the projected image of the projector into the eyes of the presenter. The reflective film has the function of transmitting the light on the presenter side for the receiving lens of the camera to capture the portrait of the presenter and present the projected digital content. The reflective film is used to reflect a bright projected image to the presenter while allowing the ambient light on the presenter side to transmit to the camera. The reflective film can be a multi-layer dielectric coating, a single layer made of optical materials with significantly different refractive indices, or a metal or alloy coating.

[0044] Please refer to the attached Figure 1, which illustrates the front projection arrangement 2300 of Embodiment 1 of the present utility model. In this arrangement, the projector 2310 is disposed in front of or on the same side as the presenter ("person"). The transparent projection screen 2320 is located between the projector 2310 and the rear camera 2330 of the display. As described above, a reflective film is provided on the front surface of the transparent projection screen facing the projector 2310 and the presenter. In this core configuration, a part of the video image projected by the projector 2310 onto the screen 2320 will transmit through the screen 2320 (if untreated) and reach the lens of the rear camera 2330 of the display. For the purpose of video conferencing or video recording, it is desired that the camera 2330 only captures the image of the presenter and the presenter's environment. Therefore, a cross-polarized filter or a micron blind film is provided. At the same time, the video stream captured by the camera 2330 in real time is combined with the video of the digital content displayed by the projector 2310, and the image of the person is embedded with the projected digital content, thereby forming an embedded image of the presenter. Such a front projection arrangement provides the presenter with the brightest image because the nature of the transparent screen is brighter on the front side of the screen 2320 where the projector 2310 projects light.

[0045] Please refer to the attached Figure 3 , which illustrates a schematic diagram of the setting of the polarization filter of the embodiment of the present utility model. The first polarization filter 2510 is placed in front of or coated on the lens of the projector 2310, and the second polarization filter 2530 is directly placed behind the transparent projection screen 2320, and the polarization of the second polarization filter is orthogonal to the polarization of the first polarization filter 2510.

[0046] As an alternative embodiment, the controller 2340 is an optional processor. The controller 2340 controls the projector 2310 to insert one or more black pixel lines when projecting digital content. The camera synchronously captures images through the black pixel lines. The processor performs a Fourier transform on the images from the spatial domain to the frequency domain, and then performs an inverse transform back to the spatial domain after being processed by a frequency domain filter, and applies Y-channel correction to the images in the spatial domain. The controller 2340 performs black pixel line insertion as described above, replacing the cross-polarized filter setting or the micron blind film setting. The controller 2340 inserts black pixel lines at a time interval of 6 ms to 14 ms or at 70 Hz to 120 Hz to eliminate the leakage light captured by the camera and prevent non-target images from being captured by the camera.

[0047] Please refer to the attached Figure 6, which illustrates a schematic diagram of an optical device according to an embodiment of the present invention using a micron louver film. The polarization filter in the optical device can be replaced by a micron louver, and is not limited to the micron louver film of 3M's Advanced Light Control Film (ALCF-PABR0). The transparent projection screen includes a glass substrate and a reflective film, and the micron louver film is disposed between the reflective film and the glass substrate of the transparent projection screen. For an observer on the side of the presenter, the micron louver film provides light transmission blocking at an angle greater than 30°. In other words, the micron louver film effectively shields the viewing outside a 60-degree viewing angle relative to the central axis of the display screen. The camera 2330 is aimed along the central axis of the display screen and can directly view through the display screen. Applying the micron louver film can prevent the transmission of the projected image emitted by the projector 2310, and the central optical axis of the projector 2310 is oriented outside the 60-degree viewing angle. The projected image is reflected by the reflective film for the presenter to view. However, the micron louver film prevents the projected image from transmitting through the display screen, thereby preventing the camera 2330 from capturing the projected image. The images of the presenter and the surrounding environment of the presenter (such as those appearing within the 60-degree viewing angle) can pass through the micron louver film and be seen by the camera 2330. Such a system provides a novel technique for eliminating the projected image of the projector in the images captured by the camera. Please refer to the attached Figure 7 , which illustrates different types of louvers that can be used in the micron louver film.

[0048] Embodiment 2

[0049] Please refer to the related drawings. A system for video conferencing and collaborative communication is a rear projection arrangement, including a transparent projection screen having a front surface facing the presentation user and a rear surface opposite to the front surface; the transparent material used for the transparent projection screen is, for example but not limited to, glass or acrylic with higher transparency, that is, at least 25% transparency, but preferably greater than 40% and up to 90% to 92%. Compared with T-OLED and transparent micro-LED display screens, the transparent projection screen can only reflect or scatter light but cannot emit light actively by itself.

[0050] A projector and a camera, the projector includes a light-emitting lens, the camera includes a light-receiving lens, the projector and the camera are both disposed on the side of the rear surface and the light-emitting lens and the light-receiving lens face the rear surface;

[0051] To optimize the brightness of the projected video image while preventing the rear camera of the display from capturing the same projected video image through the screen, an optical device is provided in the optical path between the light-emitting lens of the projector and the light-receiving lens of the camera. The optical device has the function of changing the light path so that the camera can clearly capture the portrait of the presenter and present the projected digital content. The optical device includes a scattering layer, which is disposed on the front surface or the rear surface. The scattering layer contains metal or crystal particles to scatter light. The transparency of the transparent display screen having the scattering layer is at least 35%, preferably more than 60%.

[0052] The scattering layer contains metal particles sputtered onto the film, and the density of the metal particles increases in a linear, geometric, or inverse cosine relationship with respect to the distance from the center of the transparent projection screen. The density of the metal particles is the lowest at the center and the highest at the outermost periphery. The scattering layer is designed to transmit the bright projected image to the presenter while allowing the ambient light on the presenter's side to transmit to the camera.

[0053] The projector is a short-throw projector or an ultra-short-throw projector that projects a video image of digital media content onto a transparent projection screen. The projection angle between the projection light of the projector and the horizontal plane is less than 45 degrees. The identification and implementation of short-throw projectors or ultra-short-throw (UST) projectors are obvious to those of ordinary skill in the art. The camera captures video images through the transparent projection screen. Such a passive transparent projection screen configuration improves presenter image capture and significantly reduces the distortion associated with active light-emitting display screens. UST projectors can project light at an angle greater than 70 degrees and are suitable for rear-projection arrangements.

[0054] The scattering layer can include metal particles such as silver or crystals to scatter light. When the transparent projection screen having the scattering layer has only 60% transparency, the present utility model achieves 95%-99% (compared to capturing images through a piece of transparent glass) clear camera images.

[0055] Please refer to the appendix Figure 2, which illustrates the rear projection arrangement 2400 of Embodiment 1 of the present utility model. In this arrangement, the projector 2310 is disposed on the rear side or the back of the transparent screen 2420 and on the same side as the display rear camera 2330. The "rear" surface of the transparent screen 2320 may include a scattering layer facing the projector 2310 and the camera 2330. In this configuration, the projection light showing digital media content, if not further processed, "leaks out" through the screen 2320 and generally illuminates and projects the same digital content onto the viewer's body in a larger size, and then is captured by the camera 2330 through the screen. The present utility model believes that the camera 2330 can be prevented from "seeing" the projected digital content. Therefore, the camera 2330 is called a "perspective" camera, which only captures the image of the presenter and the visible objects in the surrounding environment within the line of sight of the presenter. At the same time, the video stream captured by the camera 2330 is combined with the video of the digital content displayed by the projector 2310 in real time, and the image of the person is embedded with the projected digital content, thereby forming a presenter-embedded image. Since the projector 2310 projects light on the same side of the screen 2320, such a rear projection arrangement provides the brightest image for the camera.

[0056] Please refer to the attached Figure 3, which shows a schematic diagram of the arrangement of the polarization filter of the embodiment of the present invention. The first polarization filter 2510 is placed in front of or coated on the lens of the projector 2310, and the second polarization filter 2530 is placed directly behind the transparent projection screen 2320, and the polarization of the second polarization filter is orthogonal to that of the first polarization filter 2510. The light projected from the lens of the projector 2310 is filtered by the first polarization filter 2510 with horizontal polarization, which eliminates the vertical polarization component. When this filtered light reaches the surface of the projection screen 2320, the digital image is visible to the viewer at approximately half of the original image brightness. However, once the remaining 50% of the light passes through the second polarization filter 2530 with vertical polarization, it will be eliminated. However, since the first polarization filter 2510 is not in the optical path of the presenter and the ambient light around the presenter, it is transmitted through the second polarization filter 2530 to the camera 2330. Because polarization is never 100% horizontal or vertical, or the two polarization filters 2510 and 2530 can be precisely vertically oriented, a small amount of projected light always leaks to the camera 2330. A leakage of 1% or 2% is a normal effect, but since it is not perceptible to the human eye in the captured image, it is still acceptable. When placed adjacent to the rear surface of the second polarization filter 2530 (if it is a film, or if the second polarization filter 2530 is coated on its lens), the camera 2330 can "see through" the rear of the transparent projection screen 2320 to the front area of the presenter. Similarly, the camera 2330 only captures the image of the presenter and the surrounding environment as if there were no projection screen 2320 showing the projected digital content in between, which is beneficial for video conferencing and capturing the presentation of the presenter facing the camera 2330. The use of polarization filters reduces the need for black pixel line insertion and rolling shutter processes in the system combination of the camera and the display screen. This process only requires lightweight calculations for simple digital filtering because there is no active LED matrix in the transparent projection screen. The brightness of the projector 2310 must be at least 1500 lumens, preferably higher than 3000 lumens.

[0057] Please refer to the attached Figure 4, which illustrates the schematic diagram of the setting of the polarization filter in Embodiment 2 of the present utility model and the application of the scattering layer. Here, the first polarization filter 2510 is placed in front of the lens of the projector 2310 or coated thereon, and the second polarization filter 2530 is placed in front of the lens of the camera 2330 or coated thereon. However, the first polarization filter 2510 and the second polarization filter 2530 are located on the rear side of the transparent projection screen 2420. The presenter can see the projected image on the transparent projection screen 2420, but the camera 2330 cannot. The camera 2330 only sees the presenter. The transparent projection screen 2420 includes a scattering layer in the form of a film or coating on its rear surface. The scattering layer scatters the light from the projector 2530. The scattered light is transmitted through the transparent projection screen 2420 to the presenter.

[0058] Since when the light reaches these outer regions, the incident angle increases, resulting in brightness degradation caused by the acute angle of the light incident from the projector 2310, especially more significant near the outer frame or periphery away from the center of the display screen 2420. For example, at an incident angle of 70 degrees, the light reaches the outer frame of the top edge region of a 16:9 display at an angle of 86 degrees. In this case, the light scattering caused by the metal or crystal particles in the scattering layer is away from the front viewing angle of the presenter and deflects in various tangential directions. Therefore, the projected image looks brighter near the center of the display screen 2420 and significantly darker towards the outer periphery. Such uneven display brightness is unacceptable for practical applications. When the particle density is high enough, the scattering layer including the metal particles sputtered on the film scatters enough light to the presenter. The smaller the light incident angle, the higher the required particle density. However, the higher density comes at the cost of losing transparency. Transparency is only possible when the particles occupy a relatively small percentage of the surface area but are evenly distributed. Intuitively, a higher particle deposition density causes a higher percentage of light scattering, but is less transparent for ambient light to pass through. In the extreme case where the metal particles cover the entire surface 100%, the display is at maximum brightness while the transparency approaches 0%.

[0059] The inverse relationship between the scattering brightness and transparency is applied in the present utility model as the density of the particles in the scattering layer is variable. Please refer to the attached Figure 5, as shown by the scattering layer 2720, when the camera 2330 is pointed at the center of the display screen 2420, the density of the metal particles (shown by solid circles) increases linearly or geometrically with respect to the distance from the center of the display screen. In such a configuration, the brightness drop caused by the higher incident angle sharpness is compensated by the higher density of light-scattering particles deposited in the outer region. This makes the displayed image appear uniformly bright in both the outer region and the central region. In this construction, the transparency is highest at the center and lowest at the outermost periphery. The particle density is lowest at the center and highest at the outermost periphery. This inverse relationship between the density of the display material and the transparency ensures uniform brightness across the entire surface, where the center is highly transparent and the edge region has a significantly lower transparency but high display brightness.

[0060] Please refer to the appendix Figure 4 , the camera 2330 is behind the display screen 2420 on the rear side. Its function is to capture a regular portrait video stream for the presenter in the front. Similarly, it is desired that the camera 2330 does not "see" any content displayed on the screen 2420 by the projector 2310, which means the presenter sees the projected content with maximum brightness and clarity, while the camera 2330 clearly sees the viewer as if it were looking through a completely clear glass. Since the camera 2330 is set in the central region on the rear side, almost next to the display screen 2420 itself, it enjoys the highest level of transparency without suffering from the low transparency near the outer region. Such a rear configuration allows the UST projector to achieve a compact and aesthetic industrial design, with uniformly bright projected content on the passive display screen, while enabling clear camera image capture, just like looking through a completely transparent glass.

[0061] Furthermore, the camera and the display controller implement machine vision processing to identify people, and then move the camera 2330 with x-axis and y-axis movements to always directly face the people, even when the people move around within the field of view.

[0062] Please refer to the appendix Figure 6 , which shows a schematic diagram of an optical device of an embodiment of the present utility model using a micron louver film. The polarization filter in the optical device can be replaced by a micron louver, not limited to the micron louver film of 3M's Advanced Light Control Film (ALCF-PABR0). Please refer to the appendix Figure 7 , which shows different types of louvers that can be used in the micron louver film.

[0063] The above are only the preferred embodiments of the present utility model, and do not impose any form of limitation on the present utility model. Although the present utility model is disclosed above with the preferred embodiments, it is not intended to limit the present utility model. Any person skilled in the art, without departing from the scope of the technical solution of the present utility model, when making some changes or modifications using the above-disclosed technical content to equivalent embodiments of equivalent changes, as long as it does not depart from the content of the technical solution of the present utility model, any simple modification, equivalent change and modification made to the above embodiments according to the technology of the present utility model shall fall within the scope of the technical solution of the present utility model.

Claims

1. A system for video conferencing and collaborative communication, characterized in that: include: A transparent projection screen having a front surface facing a presentation user and a rear surface facing away from the front surface; A projector, the projector comprising a light-emitting lens, the projector being arranged on one side of the front surface and the light-emitting lens facing the front surface; A camera, the camera comprising a light receiving lens, the camera being arranged at one side of the rear surface and the camera lens facing the rear surface; An optical device, wherein the optical device is arranged in the light path between the light-emitting lens of the projector and the light-receiving lens of the camera, and the optical device has the function of changing the light path so that the camera can clearly capture the portrait of the demonstration user and present the projected digital content. The optical device includes a micron louver film, and the micron louver film is arranged on the rear surface of the transparent projection screen.

2. The system for video conferencing and collaborative communication according to claim 1, characterized in that: The optical device includes a reflective film, which is arranged on the front surface. The reflective film is used to reflect the projection image of the projector into the eyes of the demonstration user. The reflective film has the function of transmitting light from the side of the demonstration user, and is used for the receiving lens of the camera to capture the portrait of the demonstration user and present the projected digital content.

3. The system for video conferencing and collaborative communication according to claim 2, characterized in that: The reflective film is a multi-layer dielectric coating or a single layer made of optical materials with significantly different refractive indices or a metal coating or alloy coating.

4. A system for video conferencing and collaborative communication, characterized in that: include: A transparent projection screen having a front surface facing a presentation user and a rear surface facing away from the front surface; A projector and a camera, wherein the projector includes a light-emitting lens, and the camera includes a light-receiving lens, and the projector and the camera are both arranged on one side of the rear surface, and the light-emitting lens and the light-receiving lens face the rear surface; An optical device is arranged in the light path between the light-emitting lens of the projector and the light-receiving lens of the camera, the optical device includes a micron louver film, and the micron louver film is arranged on the rear surface of the transparent projection screen. The optical device has the function of changing the light path so that the camera can clearly capture the portrait of the demonstration user and present the projected digital content.

5. The system for video conferencing and collaborative communication according to claim 4, characterized in that: The projector is a common projector or a short-throw projector or an ultra-short-throw projector, and the projector projects the video image of the digital media content onto the transparent projection screen, and the projection angle between the projection light of the projector and the horizontal plane is less than 45 degrees.

6. The system for video conferencing and collaborative communication according to claim 4, characterized in that: The angle between the incident light emitted by the light-emitting lens of the projector and the horizontal plane is less than or equal to 70 degrees.

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