Optical system with a front camera hidden behind a display

Abstract

The invention relates to an optical display and detection system. It comprises a display with a display surface and a rear surface facing away from it, on which an optical detection device, in particular a camera, is arranged. It further comprises a mirror system with a first pair of mirrors on the display surface, configured to deflect the incident light to two opposite edges of the display, a second pair of mirrors on said edges, configured to direct this light around the respective edge, and a third pair of mirrors on the rear of the display, configured to direct this light into the detection device, so that the detection device detects a spatial area in front of the display surface from the perspective of the first pair of mirrors.

Description

[0001] The invention relates to an optical display and detection system. It comprises a display and an optical detection device arranged on its rear side, in particular an image and / or video recording camera, which serves to detect a spatial area lying in front of the display surface. The invention also relates to a vehicle equipped with it.

[0002] Displays with integrated front cameras are particularly common in smartphones. These cameras are located in a cutout in the display surface to capture the area in front of the screen while taking up as little screen space as possible. They are used for various functions, such as taking selfies or unlocking the device via facial recognition. Similar solutions exist in other electronic devices, such as tablets and laptops, to include a front camera without significantly reducing the screen area. To minimize space requirements, these devices typically use very small cameras with correspondingly limited image quality. Furthermore, the limited space leaves little room for additional features, such as an infrared sensor.

[0003] Furthermore, DE 93 00 765 U1 discloses a subscriber device for videophone systems with an image capture and image reproduction device and with mirrors in the beam path between a viewer and the image capture device. Specifically, an image capture device, for example in the form of a video camera, is mounted behind an image reproduction device, which is formed, for example, by a screen or a display. To the left and right of the screen, a mirror is arranged in the same plane, approximately at the user's eye level. These two mirrors redirect the light rays coming from objects or persons located in front of the screen to two further mirrors. The latter are arranged behind the screen directly in front of the video camera in such a way that they reflect the light rays into its lens. In particular, this makes stereoscopic image recordings possible.

[0004] Furthermore, a videophone system is known from US patent 2008 / 0106592 A1. In this system, lenses and a semi-mirror are arranged between a display and its cover, with sufficiently small surface areas compared to the display area. The semi-mirror allows the display light to reach the cover and reflects the incoming light in such a way that it is directed to a camera. The camera is positioned so that the light reflected by the semi-mirror can be imaged. In particular, another deflecting mirror can be provided in the path of this light so that the camera's orientation corresponds to the display orientation (i.e., a frontal orientation). In this way, cameras that are used as front cameras in conventional videophone systems can be used.Here too, stereoscopic imaging is possible by arranging two sets of lenses and half-mirrors at a predetermined horizontal distance from each other, directing light to two different halves of an image recording area of ​​the camera.

[0005] The object of the present invention is to provide an alternative and / or improved display and acquisition system that enables frontal recordings of a spatial area lying in front of a display.

[0006] This problem is solved by an optical display and detection system according to claim 1 and by a vehicle equipped therewith according to the dependent claim. Further embodiments are specified in the dependent claims. All further features and effects mentioned in the claims and the following description for the display and detection system also apply to the vehicle, and vice versa.

[0007] According to a first aspect, an optical display and acquisition system is provided, comprising a display with a display surface designed to show desired content and a rear surface facing away from this surface. In principle, any imaging technology is suitable for the display, in particular a light-transmitting or light-emitting flat panel display or a waveguide-based display. Furthermore, the display and acquisition system includes an optical acquisition device (hereinafter also referred to as a camera) that is arranged on or opposite the rear of the display (in other words, hidden behind the display from the user's perspective) and can, in particular, be designed as an image and / or video recording camera.

[0008] The display and detection system further comprises a mirror system mounted on or integrated into the display. This system includes a first pair of mirrors arranged on the display surface and designed to deflect the light incident on the display surface to two opposite edges of the display. To direct this light around each edge, a correspondingly angled mirror of a second pair of mirrors is arranged on each of these edges. Finally, the mirror system includes a third pair of mirrors arranged on the back of the display and designed to direct the light deflected by the second pair of mirrors into the detection device, so that the detection device captures a spatial area in front of the display surface from the perspective of the first pair of mirrors.

[0009] One idea behind this display and capture system is that the mirror system, with its three pairs of mirrors, is designed so that the capture device's perspective is almost identical to that of a display. This allows the capture device behind the display to achieve a perspective similar to that of traditional cameras, capturing precisely the area where a user's face, and especially their eyes, are typically located. This mirror arrangement therefore enables optimal results for applications such as video conferencing, as the user is looking almost directly into the camera while viewing the display. Because the camera is hidden behind the display, larger cameras can be used in addition to the fully usable display area.These can have better quality compared to smaller cameras (for example, through more and / or larger pixels), which means that you can still get a good camera image even in poor lighting conditions.

[0010] The detection device and mirror system in the presented display and detection system can, for example, be primarily designed for visible light. However, they can also be configured to detect infrared light, either alternatively or additionally (since sufficient space is available behind the display). Because a target object is captured from two slightly different viewing angles (corresponding to the design of the first pair of mirrors), this information can optionally be used for a 3D reconstruction of the target object, for example, to create an avatar of a person.

[0011] The display can be, in particular, a direct-view display. Alternatively, the display can, for example, serve as an image source in a projection display device, in which the image generated by the display is projected into the user's field of vision via reflection off a semi-transparent combiner lens. Such projection display devices are known, among other things, as head-up displays (HUDs). In this case, optical detection also occurs via reflection off the same combiner lens, which, when used in a vehicle, can also be formed by its windshield, for example.

[0012] According to one embodiment, the display and detection system further comprises a transparent cover plate (also called a cover or cover glass) that covers the display surface and the first pair of mirrors from the outside, thereby providing them with mechanical protection. For example, the first pair of mirrors can be arranged in a space between the display surface and the cover plate. Alternatively, it can be embedded in or formed within a cover plate that rests directly on the display surface. Ideally, the cover plate is largely transparent to both the display light and the ambient light incident from the outside and can be made of any suitable material, such as plastic or glass.

[0013] In a specific configuration, the first pair of mirrors is positioned approximately in the center of the display area. This mirror arrangement ensures, for example, that the user always looks almost directly at the first pair of mirrors and thus into the camera, and / or that their face and eyes are always captured frontally. Alternatively or additionally, the third pair of mirrors can also be positioned approximately in the center of the back of the display to achieve the aforementioned, most natural camera perspective possible. For these purposes, the mirror system can be designed to be mirror-symmetrical with respect to a central axis located within the display area. This central axis can be, for example, vertical or, alternatively, horizontal.

[0014] The first pair of mirrors can be essentially transmitting on the back side, meaning with respect to the display light incident from the display surface, in order to minimize any interference with the displayed image. "Essentially transmitting with respect to the display light" can, for example, mean a transmission coefficient of more than 50%, especially more than 60 or 70%, and ideally more than 80 or 90% for this light.

[0015] According to one embodiment, at least one of the mirror pairs and / or the detection device is adjustable, thereby enabling different detection perspectives. In particular, varying the mirror and / or camera positions in this embodiment allows for different perspectives, which, for example, enable the detection of varying virtual perspectives in front of the display "as if at a table".

[0016] In one specific configuration, the optical axis of the detection device is essentially perpendicular to the display surface and / or the back of the display (which may or may not be parallel to each other), corresponding to the aforementioned natural frontal orientation of the camera. Alternatively, the optical axis of the detection device can also be oriented differently, for example, approximately parallel to the back of the display, which can offer additional space-saving advantages. In any case, the three pairs of mirrors are designed and arranged to direct light beams striking the display surface in the area of ​​the first pair of mirrors into the detection device with minimal loss.

[0017] In particular, the display may also have a permanently attached holder designed for setting up or placing the display and in which the mirror system and / or the detection device is / are at least partially integrated.

[0018] According to a further aspect, a vehicle is provided with an integrated display and acquisition system as described in the first aspect. The vehicle can be a motor vehicle, but also any other land, air, or watercraft. For example, the display and acquisition system can be located in a passenger compartment of the vehicle or externally.

[0019] The above aspects of the invention and its embodiments and specific configurations are explained in more detail below with reference to an example shown in the accompanying drawing. The drawing is to be understood in particular as a schematic illustration of the basic optical design principle, i.e., not to scale. It shows: Fig. 1 a horizontal cross-section taken at the level of user eyes through a display and detection system according to an embodiment of the invention.

[0020] All the various embodiments, alternatives, and specific design features of the display and detection system mentioned above in the description and in the subsequent claims, according to the first aspect of the invention above, can be implemented in the Fig. The features shown in the example above, in particular alternatively or additionally to those shown therein, may be implemented in other ways. Therefore, they are not all repeated below. The same applies accordingly to the definitions and effects of individual features already given above, which are described in the example above. Fig. 1 are shown.

[0021] Fig. Figure 1 shows a highly simplified schematic representation of a horizontal cross-section of an optical display and detection system 1 according to an embodiment of the invention. This system comprises a display 2 with a display surface 4 facing the user 3 and a rear surface 5 facing away from the user 3. In this cross-sectional view, which corresponds to a view directly from above onto the system 1, the user 3 is indicated solely by his head and his two eyes 6.

[0022] System 1 further comprises an optical detection device 7, in this example a camera, which is mounted / hidden behind the display 2 from the user's perspective. For illustrative purposes, the camera 7 is positioned approximately centrally opposite the back of the display 5, with its optical axis 8 oriented perpendicular to it. To ensure that the camera 7 still provides the desired image of a spatial area 9 in front of the display surface 4, which in this example also contains the user's face 3, the necessary light rays L are directed around the display 2 by the following mirror system: To ensure that the perspective of camera 7 corresponds as directly as possible to that of a camera pointed at the user's face, two plane mirrors 10 and 11 (forming the first pair of mirrors mentioned above) are mounted approximately in the center of the display surface 4 at an angle to each other. These mirrors deflect the light rays L, which originate from the spatial area 9 (and are only symbolically indicated by their exemplary marginal rays), to the left and right, respectively, to opposite edge sides 12 and 14 of the display 2. The light rays L thus divided are then further divided by two additional mirrors, each of which forms a corner mirror 15 or 16 at the respective edge side 12 or 14.14 form (the second pair of mirrors above), are guided around the display 2 to the left and right of the display 2 and directed to the center of the back of the display 5, where two further plane mirrors 17 and 18 angled to each other (the third pair of mirrors above) are attached, which bring the split light rays back together and direct them into the camera 7 in such a way that the perspective of the captured area 9 is approximately as if the display 2 were not there.

[0023] This achieves the familiar perspective of camera 7 precisely from the area where the face and eyes of the user's conversation partner are typically displayed on the screen 4 during video calls. By mounting the camera behind the screen 2, significantly larger / better cameras can be used compared to conventional front-facing cameras, and the mirrors 10 to 18 can, for example, be integrated into a support structure for the screen 2. Further design options include arranging camera 7 vertically instead of horizontally and / or integrating it as part of a hinge. Other camera positions are also possible, with the mirror system being adjusted accordingly.

[0024] In this example, the mirror system is designed to be mirror-symmetrical with respect to a vertical center axis located in the display area 4 (which is not visible in the cross-sectional view). The display area 4, together with the first pair of mirrors 10 / 11, is covered on the user side by a transparent cover plate 19 and thus protected from external light. The first pair of mirrors 10 / 11 is largely transparent on its back side, allowing the display light to pass through.

[0025] The optical arrangement presented here, compared to known solutions that also use cameras for frontal images of an area positioned in front of the display, allows for the use of significantly larger cameras for larger imagers (i.e., with larger pixels for, for example, low-light performance) and / or achieves the aforementioned advantages through a direct and natural perspective of optical capture. Furthermore, the presented system enables significantly better integration with regard to design-technology convergence, which can be a decisive advantage, particularly in vehicle applications. Reference symbol list 1 optical display and detection system 2 Display 3 users 4 Display area 5 Display back 6 user eyes 7. Optical detection device, in particular camera 8 optical axis of the camera 9. Area of ​​space in front of the display surface 10 / 11 first pair of mirrors 12 / 14 two opposite edges of the display 15 / 16 second pair of mirrors 17 / 18 third pair of mirrors 19 transparent cover plate L Light rays QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] DE 93 00 765 U1

[0003] US 2008 / 0106592 A1

[0004]

Claims

[1] Optical display and detection system (1), comprising: - a display (2) with a display surface (4) and a rear side (5) facing away from the latter; - an optical detection device (7), in particular an image and / or video recording camera, arranged on or opposite the back of the display (5); and - a mirror system with a first pair of mirrors (10 / 11) on the display surface (4), which is designed to deflect the light incident on the display surface (4) to two opposite edge sides (12 / 14) of the display (2), a second pair of mirrors (15 / 16) on the said edge sides (12 / 14), which is designed to direct this light around the respective edge side (12 / 14), and a third pair of mirrors (17 / 18) on the back of the display (5), which is designed to direct this light into the detection device (7); - so that a spatial area (9) lying in front of the display surface (4) can be detected by the detection device (7) from the perspective of the first pair of mirrors (10 / 11). [2] Display and detection system (1) according to claim 1, wherein - the display (2) is a direct view display. [3] Display and detection system (1) according to claim 1 or 2, further comprising: - a transparent cover plate (19) which covers the display surface (4) and the first pair of mirrors (10 / 11) to the outside. [4] Display and detection system (1) according to one of the preceding claims, wherein - the first pair of mirrors (10 / 11) is arranged approximately centrally in the display surface (4); and / or - the third pair of mirrors (17 / 18) is arranged approximately centrally on the back of the display (5). [5] Display and detection system (1) according to one of the preceding claims, wherein - the first pair of mirrors (10 / 11) is essentially transmissive for the display light incident thereon from the display surface (4). [6] Display and detection system (1) according to one of the preceding claims, wherein - at least one of the mirror pairs (10 / 11, 15 / 16, 17 / 18) and / or the detection device (7) are adjustable, whereby different detection perspectives can be achieved. [7] Display and detection system (1) according to one of the preceding claims, wherein - an optical axis (8) of the detection device (7) is substantially perpendicular to the display surface (4) and / or the display back (5). [8] Display and detection system (1) according to one of the preceding claims, wherein - the mirror system is mirror-symmetrical with respect to a central axis lying in the display surface (4). [9] Display and detection system (1) according to one of the preceding claims, wherein - the display (2) further comprises a holder which is firmly connected to it and which is designed for setting up or placing the display (2) and in which the mirror system and / or the detection device (7) is / are at least partially integrated. [10] Vehicle with an integrated display and detection system (1) according to one of the preceding claims.

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