HUD with a cover glass that can be rotated to deflect the sun's beam depending on the position of the sun for a vehicle

Abstract

The invention relates to a compact projection unit for a vehicle. This comprises an imager and a cover plate that is essentially transparent to the light beams, protects the projection unit from the outside, and is rotatably mounted therein. The cover plate has at least one associated rotary drive and associated control unit. The projection unit is designed to output the light beam in a predetermined shape and direction such that it is subsequently reflected by a reflection plate arranged in the user's field of vision to their eyebox, and the display content thus appears to the user as a real or virtual image floating in the air.The cover plate is designed to rotate via its appropriately configured control unit depending on the position of the sun in such a way that no sun rays coming directly from the sun can be reflected from the cover plate to the reflection plate and from there into the user eyebox.

Description

[0001] The invention relates to a head-up display device for a motor vehicle or other land, air, or water vehicle, also known as a head-up display (HUD). Such devices serve to generate an image floating in the air via reflection from a reflective disc, such as a vehicle window or a specially provided combiner disc arranged in the user's field of vision. The invention also relates to a projection unit designed to output a suitable light beam with the desired display content, as well as to a vehicle equipped with such a projection unit.

[0002] It is known, particularly in motor vehicles, to use a head-up display to superimpose display content such as speed information or other useful navigation and vehicle operating instructions in the form of a virtual image onto the real surroundings in front of the vehicle as observed by the driver, so that they do not have to take their eyes off the road when reading. For this purpose, a HUD comprises a reflective screen arranged in the driver's field of vision, which is largely transparent to the ambient light falling from behind and is designed either as a section of the windshield or as a combiner screen provided inside the vehicle. In the classic design, a HUD also comprises a projection unit located below the windshield inside the instrument panel. This typically contains a display for generating the desired display content as well as a suitable imaging or projection system.Projection optics shape the generated light beam and direct it onto the reflection screen so that it is reflected back to the driver's eyes, allowing them to view the virtual image at a suitable size, display quality, and distance. The projection optics typically include a beam-deflecting, image-correcting, and magnifying concave mirror, whose dimensions, however, scale linearly with the size of the virtual display area, thus severely limiting it.

[0003] Implementing such a HUD in a vehicle is very complex, partly due to space constraints. A key component of its projection unit is a transparent cover plate (also called a cover glass), which closes the protective housing of the projection unit on the output side and transmits the generated light beam. The cover plate must be designed in such a way that no direct or indirect light reflections from outside light, especially sunlight, can enter the HUD beam path and thus the driver's eye on its outer surface. For this purpose, the state of the art, for example, uses a specific, concavely curved cover plate shape on the outside. This deflects disruptive light reflections from the beam path and is referred to as "geometric anti-reflection coating," but requires the cover plate to be considerably larger in the vertical direction of the vehicle.In particular, the concave mirror, which is usually mounted so that it can rotate for eyebox adjustment and thus requires even more space, represents a restriction on the cover plate design, because the cover plate must maintain predetermined minimum distances to the concave mirror in the height direction of the vehicle.

[0004] In this context, DE 10 2015 221 970 A1 discloses a projection device for projecting an image onto a viewing window of an operator, in particular onto a windshield of a motor vehicle. The projection device comprises a housing in which a projection device for projecting the image onto a combining surface of the viewing window is arranged, and a transparent cover plate that closes the housing and through which the projected image is transmitted. The cover plate is mounted so as to be tiltable about a tilt axis, and a tilt actuator is provided to tilt the cover plate. The cover plate can be connected to the housing, in particular via a bellows, to prevent foreign matter from penetrating the housing. Within the framework of a glare prevention system, a control unit is provided to control the tilt actuator depending on whether the operator is dazzled.The cover plate can also be curved, in particular concavely curved, in order to focus a glare beam when reflected on the cover plate.

[0005] It is an object of the present invention to provide an alternative and / or improved projection unit with regard to installation space, image quality and / or other aspects for a field of view display device for installation in a vehicle.

[0006] This object is achieved by a compact projection unit according to claim 1, as well as by a visual field display device containing the same, and a vehicle equipped therewith according to the independent claims. Further embodiments are specified in the dependent claims. All further features and effects mentioned in the claims and the following description for the projection unit also apply to the visual field display device and the vehicle, and vice versa.

[0007] According to a first aspect, a compact (i.e., one that can be optimized or has been optimized with regard to the required installation space) projection unit is provided for a field of view display device, which is designed for installation in a vehicle. The field of view display device can be designed, for example, as a head-up display (HUD). The vehicle can be a motor vehicle, but also any other land, air, or water vehicle. Unless otherwise stated, all spatial orientation terms mentioned herein, such as "vertical," "horizontal," "below," "above," etc., refer to the usual vehicle-fixed Cartesian coordinate system with mutually perpendicular longitudinal, transverse, and vertical directions of the vehicle.

[0008] The projection unit has an imager (also called a picture generating unit, PGU) designed to generate a light beam with the desired display content. In principle, any imaging technology is suitable for the imager, such as a light-transmitting or light-emitting flat panel display, a projector-based imager, or a waveguide-based display.

[0009] The projection unit further comprises a cover plate (also called cover glass) which is designed to protect the imager and any other optical and mechanical components of the projection unit from external influences such as dust, moisture, aggressive substances and / or mechanical forces. The cover plate is largely (i.e. within the scope of what is technically feasible) transparent to the light beam bundle emitted by the projection unit (also called projection light herein) and is mounted in the projection unit so that it can rotate about at least one axis of rotation. The projection unit also comprises at least one associated rotary drive with an associated control unit. The outer surface of the cover plate, i.e. the surface facing away from the imager or any optics of the projection unit, can be planar or concavely curved.

[0010] At least one of the rotation axes can be fixed relative to the projection unit, but this is not mandatory. Particularly in the case of two or more interlaced rotation axes or a superimposed translational movement, at least one of the rotation axes can also be movable relative to the projection unit. An optional translational movement of the cover plate superimposed on the aforementioned rotational movement can, for example, provide an additional space advantage, such as allowing the movement of another component to evade, and / or contribute to achieving one of the purposes of the cover plate movement mentioned further below.

[0011] The cover glass can be adjusted, for example, by motor or pneumatic means. As described in more detail below, existing drives in the vehicle or in the projection unit can be utilized. The specific, optimal position and orientation of the rotation axis(es) for cover glass rotation can vary depending on the vehicle and HUD design.

[0012] The mutual arrangement and design of the image generator, the cover plate, and any (but not necessarily) provided imaging and / or projection optics in the projection unit are selected such that the light beam leaves the projection unit in a predetermined shape and direction, is then reflected by a typically (but not necessarily) partially transparent reflection plate arranged in the user's field of vision to their eyebox, thereby presenting the display content to the user in the form of a real or virtual image that floats in the air in their direct field of vision in front of or behind this reflection plate, in a predetermined shape, size, and distance. A virtual image can be created at essentially any distance beyond the reflection plate, which can be determined by appropriately designed projection optics.Here, for example, the image distance can be selected so that as little accommodation of the eyes as possible is required to simultaneously observe the road ahead through the partially transparent reflective disc. In contrast to a virtual image, a floating real image is actually generated by suitable imaging optics at the position in the beam path (between the reflective disc and the eyebox) where it is seen. It can therefore be recorded at that point in the room, for example, using light-sensitive material or made visible to everyone using a light-diffusing surface. A significantly shorter image distance compared to virtual image generation can, for example, be more suitable for reading.A real image floating in the air can also have a number of advantages over a conventional light-diffusing projection surface, such as visibility from a restricted spatial area (eyebox) or a constructively freely selectable image distance and image orientation in the air, which would not be possible with hard screens or diffusing surfaces in a vehicle due to the required freedom of movement for the occupants.

[0013] The reflection disc can, for example, be formed by a section of a vehicle window, but can also be formed by a combiner disc specifically designed for this purpose. The reflection disc is therefore a component of the overall field-of-view display device, but not necessarily also a component of the projection unit, which can generally be manufactured and sold without it. A combiner disc can also be integrated into the projection unit in a conventional manner (e.g., retractable and extendable). The eyebox of the field-of-view display device is, as usual, understood to be a two- or three-dimensional spatial area in the vehicle from which the displayed floating image is visible in the intended quality.

[0014] The cover plate is designed to rotate automatically, via its rotary drive and its correspondingly configured control unit, depending on the position of the sun, in such a way that no direct sunlight (which can enter the vehicle directly from the sun through a vehicle window and is not already reflected or scattered by any surfaces) can be reflected from the cover plate to the reflection plate and from there into the user eyebox. The sun position detection required for this can be achieved by suitable sensors on board the vehicle.

[0015] At least one of the cover plate rotary drives serves, via a switch or a clutch, to alternately move the cover plate and at least one other element of the projection unit, which can be moved to adapt the eyebox position to different user eye positions. Such a movable element can, in particular, be a concave mirror, as described further below in the context of imaging and / or projection optics. Since the angle of the sun changes only slowly during operation and the cover plate therefore usually only needs to be adjusted occasionally, existing drives of the projection unit can be utilized, thus eliminating the need for an additional drive.

[0016] One idea behind the projection unit presented here is to make its cover plate rotatable / adjustable relative to the projection unit and thus also relative to the vehicle, in order to specifically deflect the directly incident sunrays from an optical path leading to the user's eyes, depending on the position of the sun. For example, a cover glass, through which the incoming sunrays are deflected into a so-called HUD mirror bank (light trap), can be rotatably mounted in a vehicle-mounted HUD housing cover. This allows the cover glass to be pivoted into an optimal position depending on the position of the sun, while requiring minimal installation space, because the cover glass, in each of its rotational positions, only needs to be "anti-reflective" in the sense described here for a corresponding sub-range of an overall larger angular range that encompasses all possible angles of sunlight incidence.The HUD housing cover, which usually consists of one part, therefore consists of two parts, one of which (the cover glass, i.e. the cover plate) is rotatably mounted, and the other (bezel, frame or housing edge) is not.

[0017] According to one embodiment, an imaging and / or projection optics system is provided in the beam path of the light beam between the imager and the cover plate. This system can significantly contribute to ensuring that the light beam leaves the projection unit in the required shape and direction. It is then reflected by the reflection plate arranged in the user's field of vision to their eyebox, presenting the display content to the user as a real or virtual image floating in the air in a desired shape, size, and distance. For this purpose, the imaging and / or projection optics system can comprise, for example (but not limited to), a concave mirror designed as a freeform mirror and / or other optical elements (such as lenses, prisms, concave mirrors, convex mirrors, or plane mirrors, etc.).The imaging and / or projection optics are designed - depending on the requirements of a specific application - for a predetermined optical functionality, such as image magnification and / or imaging effect and / or beam shaping and / or correction of other imaging errors and / or beam deflection.

[0018] Alternatively, it can also be a projection unit (or field-of-view display device, which is described in more detail below) without imaging and / or projection optics between the imager and the reflection screen. This type of setup may be particularly suitable for AR (augmented reality) applications, providing a significantly larger virtual display area than is possible with a classic HUD with mirror optics.

[0019] According to one embodiment, the projection unit further comprises a light trap as mentioned above, which is arranged on or opposite a side of the cover plate facing away from the imager and is designed to essentially completely intercept and block sun rays coming directly from the sun, which are reflected by the cover plate, in at least one predetermined angular range of the sun's position and at a respective associated cover plate rotation position. Alternatively, such a light trap can also be arranged separately from the projection unit in the vehicle and can therefore be manufactured and sold independently of it or as a component of the vehicle.

[0020] During the practical analysis of the system presented here, it has also been shown that shallowly incident solar rays (e.g., in a range of approximately 40° - 50° relative to the horizontal) can be completely or partially absorbed by a conventional light trap, which is also known in the art as a "HUD mirror bank" in connection with the geometric anti-reflection coating of the cover glass mentioned above. This beam range is followed by a further beam angle range (e.g., between 50° and 60°), which can also be reliably redirected into the conventional HUD mirror bank by further optimizing the cover glass curvature.Sun rays in the range of 70°, and especially in the range of 80°, can only be redirected into the conventional HUD mirror bank with considerable effort, which in many cases would be prohibitive both in terms of the manufacturing of the cover screen and the additional space required in the vehicle. Furthermore, in the classic HUD setup described above, this redirection would require the concave mirror to be trimmed, which would accordingly reduce the HUD's display area (this can easily be a third of the otherwise possible display area).

[0021] To solve these problems, the rotation of the entire cover glass proposed here enables its adjustment depending on the position of the sun, for example, to specifically deflect the directly incident sun rays into the conventional HUD mirror bank when the sun is above 60°, above 70°, or by approximately 80°. This adjustment position can then be designed, for example, for a first angular range of directly incident sun rays of approximately 60°-90°, in particular approximately 70°-80°. A second adjustment position of the cover glass that deviates from this can, for example, be pre-adjusted to assume a second angle of incidence range of, for example, approximately 40°-70°. More than two different adjustment positions, each with associated sun angle ranges, can also be provided, whereby continuous adjustment (for example, for a planar cover glass) is also possible.However, by limiting the number of adjustment positions to just two (or a few), the new cover glass adjustment system can be used particularly economically.

[0022] Thus, the cover plate can in particular be designed to rotate via the appropriately configured control unit depending on the position of the sun in such a way that sunlight coming directly from the sun is always directed into the above light trap via the reflection from the cover plate (where it is essentially completely intercepted and blocked). In this case, the cover plate can in particular be concavely curved on its side facing away from the imager (also called "geometric anti-reflection coating") in such a way that reliable steering of all directly incident sunlight into the light trap can be achieved by a sun-position-dependent change between only a few (in particular only two or three) discrete cover plate rotation positions and is also achieved during operation of the field of view display device.

[0023] As an alternative to this embodiment, a planar or concavely curved cover plate and its predetermined rotational positions depending on the position of the sun can also be designed to direct the sun's rays into the light trap only in a partial range of all possible angles of the sun's position at which they directly hit the cover plate, while at all other angles of incidence direct sun rays are directed in other predetermined directions to the reflection plate or other surfaces in the vehicle in such a way that they cannot be reflected into the user's eyebox in this way.

[0024] According to one embodiment, the projection unit further comprises a protective housing that at least partially surrounds it and is closed off from the reflection plate by the cover plate. In particular, at least one sealing device can be provided, which is formed on the rotatable cover plate and / or on the housing fixed with respect to the projection unit in their adjacent edge regions in such a way that it seals the interior of the projection unit against dust and / or moisture at all of its cover plate rotation positions, which are predetermined differently depending on the position of the sun.For this purpose, the sealing device can comprise, for example, brushes, felt and / or a labyrinth in a folding area, in particular also using materials that are elastically deformable in the relevant movement area and can thus compensate for the change in relative positions of the cover plate and housing edges when the cover plate rotates.

[0025] According to a further aspect, the above field of view display device is provided. As already mentioned, in addition to the projection unit presented here, the field of view display device also comprises a reflection plate arranged in the beam path of the light beam emitted by the projection unit. This reflection plate can be designed, in particular, as a partial surface section of a vehicle window or as a specially provided combiner plate and can be, for example, at least partially transparent.The reflection disc is arranged and designed in the field of vision of a user in such a way that it reflects the light beam to an eyebox predetermined for his eyes, whereby the display content can be presented to him in the form of a virtual image beyond the reflection disc (or, in an alternative optical design, in the form of a real image floating in the air between the reflection disc and the eyebox) and is also presented during operation of the field of vision display device.

[0026] According to an embodiment already mentioned above, the reflection disk is arranged directly opposite the imager, with the exception of the cover disk serving as a cover for the projection unit. In other words, in this specific embodiment, the field-of-view display device does not comprise any optical elements, such as deflecting or concave mirrors or lenses, etc., in the beam path of the light beam generated by the imager before it strikes the reflection disk. However, any protective or optical coatings on the imager or the reflection disk, and in particular also microlens or microprism layers or surface-covering lens or prism arrays with optical functionality, such as autostereoscopic or other beam splitting, etc., directly on an image-generating surface of the imager or on the reflection disk are still possible.

[0027] This design, for example, with a large-area display extending directly opposite the windshield on the upper surface of the instrument panel or a large-area planar waveguide, allows the virtual display area to be significantly expanded. A HUD of this type can, among other things, display a continuous, panoramic virtual image with entertainment or driving-related image content to the driver or passenger, ideally extending across the entire width of the windshield in the transverse direction of the vehicle.

[0028] According to a further aspect, the above-mentioned vehicle is provided. The vehicle comprises a passenger compartment and a vehicle window, in particular a windshield, which at least partially defines the passenger compartment. Furthermore, the above-mentioned field of view display device is provided in the vehicle, the projection unit of which is arranged in the passenger compartment, in particular inside an instrument panel arranged beneath the windshield, and the reflection pane of which is configured as a portion of said vehicle window or as a combiner pane arranged in the passenger compartment.

[0029] In particular, the cover panel in the vehicle can be rotatable in the manner proposed herein about a first axis of rotation, which runs approximately parallel to (or along) the transverse direction of the vehicle or a root of a vehicle window. This allows the angle of deflection of the sun's rays to be adjusted in the vertical direction, for example to adapt to a lower or higher sun and / or to a user sitting lower or higher. Alternatively or additionally, the cover panel in the vehicle can be rotatable in the manner proposed herein about another axis of rotation, which runs approximately parallel to (or along) the longitudinal direction of the vehicle or transversely, in particular orthogonally, to a root of a vehicle window. This allows the angle of deflection of the sun's rays to be adjusted, for example, in the horizontal direction or simply to the side.

[0030] As already mentioned, a light trap can be provided, for example, in or on the projection unit or at another location in the vehicle, and the cover plate can be designed to rotate via the correspondingly configured control unit depending on the position of the sun in such a way that in at least one predetermined angular range of the position of the sun, at a respective associated cover plate rotation position, sun rays coming directly from the sun, which are reflected by the cover plate, are essentially completely intercepted and blocked by the light trap.Alternatively or additionally, the sun position-dependent cover plate rotation can be designed such that, in at least one predetermined sun position angular range and for a respective cover plate rotation position, sun rays coming directly from the sun are not reflected by the cover plate into the light trap, but rather to other surfaces of the vehicle interior via a mirror reflection, where they cannot reach the eyebox of the user, and preferably also not of another occupant. These can be, for example, higher up windshield areas, interior trim surfaces, roof liner, etc. On the other hand, depending on the sun position relative to the vehicle, this can also ensure that sun rays hitting the cover glass through a side window are deflected into the light trap or other non-critical directions and thus definitely do not reach the user's eyes.

[0031] The above aspects of the invention and their embodiments and specific configurations are explained in more detail below with reference to examples illustrated in the accompanying drawings. For the sake of clarity, in the various examples, not only identical but also differently configured elements of the same type or with similar functionality are designated by the same reference numerals. The drawings are to be understood as purely schematic illustrations of the basic optical principle, i.e., in particular, they are not to scale. They show: Fig. 1 shows a section of a vehicle with a field of view display device according to an embodiment of the invention, in a perspective side view; and Fig. 2 an enlarged section of the Fig. 1, which shows two different cover disk rotation positions.

[0032] All the various embodiments, variants and specific design features of the projection unit, the field of view display device and the vehicle according to the above aspects of the invention mentioned above in the description and the following claims can be implemented in the Fig. 1 and Fig. 2, in particular alternatively or in addition to the features shown therein. They will therefore not be repeated again below. The same applies accordingly to the definitions and effects already given above with regard to individual features that are described in Fig. 1-2 are shown.

[0033] Fig. Figure 1 shows a schematic perspective side view of a section of a vehicle 1 with a field of view display device 2 according to an embodiment of the invention. In this example, the vehicle 1 is a motor vehicle, which is Fig. 1 is only indicated by its windshield 3, which serves as the aforementioned reflection disc of the field of vision display device 2. Below it, in an instrument panel 4 (not shown in detail), a projection unit 5 of the field of vision display device 2 is arranged. This is, again purely by way of example, a head-up display (HUD). As already mentioned, the spatial orientation terms such as "horizontal," "vertical," "upper," "lower," "below," etc., unless otherwise stated, refer to the usual vehicle-fixed Cartesian coordinate system K with mutually perpendicular longitudinal, transverse, and vertical directions X, Y, and Z of the vehicle 1.

[0034] The projection unit 5 contains an image generator 6, which is designed to generate a light beam (not shown) with a desired display content and can be designed, for example, as an LCD (liquid crystal display). As already mentioned, any other image-generating technology (such as a projector, a waveguide, another type of display, etc.) can also be used for the image generator 6, so that it can be used in Fig. 1 is only symbolically indicated by a functional block. In the beam path of the light beam generated by the imager 6, the projection unit 5 in this example comprises an imaging and / or projection optics in the form of a concave mirror 7. The projection unit 5 can, for example, be surrounded by a mechanically protective housing (not shown) which is closed off from the windscreen 3 by a cover plate 8 (also called cover glass herein). The cover plate 8 is largely transparent to the light beam and can, for example, be arranged flush or recessed in a top side of the instrument panel 4 (not shown in detail).

[0035] The image generator 6, the concave mirror 7 and the windscreen 3 are designed and arranged relative to one another in such a way that the light beam leaves the projection unit 5 in a suitable shape and direction in order to then be reflected by the windscreen 3 to a spatial area (eyebox, not shown) predetermined for the eyes of a user (not shown, for example driver) in the passenger compartment of the vehicle 1 and thus to display the display content as a real or virtual floating image (not shown) with desired properties directly in the user's field of vision.

[0036] The cover plate 8 is mounted in the projection unit 5 so that it can rotate about at least one axis of rotation. The projection unit 5 also includes at least one associated rotary drive 9 with an associated control unit 10, which can be housed in the projection unit 5 and / or at another location in the vehicle 1 (for example, as part of the central vehicle control system) and has access to all required sensors and drives on board.

[0037] Thus, the cover plate 8 can be designed in particular to rotate via the correspondingly configured control unit 10 depending on the position of the sun in such a way that solar rays S coming directly from the sun (cf. Fig. 2) are always directed into a light trap 11 via reflection from the cover plate 8, where they are essentially completely intercepted and blocked. In this example, the cover plate 8 is concavely curved on its side facing away from the imager 6, so that reliable guidance of all directly incident solar rays S into the light trap 11 is achieved by a sun-position-dependent change between only a few (in particular only two or three) discrete cover plate rotation positions P1, P2 ( Fig. 2) is achievable and is also achieved during operation of the field of view display device 2. Alternatively, a planar or concavely curved cover plate 8 and its predetermined rotational positions depending on the position of the sun can also be designed to direct sun rays S into the light trap 11 only in a subrange of all possible angles of the sun's position at which they directly hit the cover plate 8, while at all other angles of incidence, direct sun rays S are directed in other predetermined directions towards the windshield 3 or other surfaces in the vehicle 1 in such a way that they cannot reach the user's eyebox in this way.

[0038] This shows Fig. 1 also shows, for comparison, a conventional geometrically anti-reflective cover plate 800, whose concave outer geometry is designed to direct all incident solar rays from the entire relevant angle of incidence range of 40°-80° (relative to the horizontal direction) into the HUD mirror bank (light trap 11). However, for this purpose, the conventional cover plate 800, which is immobile with respect to the projection unit 5, requires such a strong curvature of its total surface that it would significantly cut off the concave mirror 7 of the desired size. The rotatable cover plate 8, on the other hand, is designed in this example to Fig. 1, only rays in a vertical angle of incidence range of 40°-60° with respect to the horizontal direction are directed into the HUD mirror bank 11 - without trimming the concave mirror 7. For a steeper angle of incidence, the cover plate 8 is rotated to a different rotational position upon detection of a corresponding position of the sun, for example, in Fig. 2. In this position, the cover plate 8 also cuts off the Fig. 1 generously dimensioned concave mirror 7 not.

[0039] As in Fig. 1, the cover plate 8 in the vehicle 1, as proposed herein, can be rotatable about a first axis of rotation (direction of rotation D1) via suitable rotary drives 9 and a correspondingly configured control unit 10, depending on the position of the sun, about a first axis of rotation which runs approximately parallel to or along the vehicle transverse direction Y or a pane root of the windscreen 3. This allows the deflection angle of the sun's rays to be adjusted in the vertical direction, for example to adapt to a lower or higher sun and / or to a user sitting lower or higher. Alternatively or additionally, the cover plate 8 in the vehicle 1 can also be rotatable about a second axis of rotation (direction of rotation D2) which runs approximately parallel to (or along) the vehicle longitudinal direction X or transversely, in particular orthogonally, to a pane root of the windscreen 3. This allows the deflection angle of the sun's rays to be adjusted, for example, in the horizontal direction or simply to the side.

[0040] Fig. 2 shows an enlarged section of the Fig. 1, which shows two different cover plate rotation positions P1 and P2 in the direction of rotation D1. Here, the cover plate 8 is in position P1 for directing flat incident solar rays S (e.g., 40-70°) into the HUD mirror bank 11 (see Fig. 1), while it is in position P2 when the sun's rays S are incident at a steeper angle (e.g., 70-80°), in order to deflect them into a higher area of ​​the front panel 3 from which they cannot be reflected into the user's eyebox. Alternatively, the cover panel 8 can also be rotated in the opposite direction to also direct the steeply incident sun's rays S into the light trap 11.

[0041] As in Fig. 2, the same principle can also be applied to a field of view display device 2 or projection unit 5, which has no imaging and projection optics (and in particular no concave mirror 7) between the image generator 6 and the cover plate 8. In this case, the image generator 6 extends (as indicated purely symbolically) directly opposite the front plate 3 (cf. Fig. 1), whereby only the protective cover plate 8 is located in between, which is rotatable depending on the position of the sun to prevent reflection of the sun's rays S, as suggested. List of reference symbols 1 vehicle 2 Field of view display device, in particular HUD 3 Windscreen 4 Instrument panel 5 Projection unit 6 imagers 7 concave mirrors 8 Cover plate, also called cover glass 800 conventional cover glass with geometric anti-reflective coating 9 Rotary drive 10 Control unit 11 Light trap, also called HUD mirror bank S Sunbeams D1, D2 directions of rotation P1, P2 different rotation positions of the cover disc K vehicle-fixed Cartesian coordinate system X, Y, Z longitudinal, transverse and height directions of the vehicle

Claims

[1] Compact projection unit (5) for installation in a vehicle (1), comprising: - an image generator (6) designed to produce a beam of light with the desired display content; and - a cover plate (8) which is essentially transparent to this beam of light, protects the projection unit (5) to the outside and is mounted therein so as to be rotatable about at least one axis of rotation, with at least one associated rotary drive (9) and associated control unit (10); - wherein the projection unit (5) is configured to output the light beam in such a predetermined shape and direction that it is subsequently reflected by a reflective disk arranged in the user's field of vision to his eyebox, and the display content thereby appears to the user as a real or virtual image floating in the air in a predetermined shape, size and distance; and - the cover plate (8) is designed to rotate via the appropriately configured control unit (10) in such a way as to be dependent on the position of the sun that no direct sun rays (S) coming from the sun can be reflected from the cover plate (8) to the reflection plate and from there into the user eyebox; - characterized by , that at least one of the cover plate rotary drives (9) is designed and configured via a switch or coupling for alternating use to move the cover plate (8) and at least one other movable element of the projection unit (5) to adapt the eyebox position to different user eye positions. [2] Projection unit (5) according to claim 1, further comprising: - an imaging and / or projection optic arranged in the beam path of the light beam between the image transmitter (6) and the cover plate (8), which is designed so that the light beam leaves the projection unit (5) in the predetermined shape and direction, in order to be subsequently reflected by the reflection plate arranged in the user's field of vision to his eyebox and thereby present the display content to the user as a real or virtual image floating in the air in a predetermined shape, size and distance; - wherein the imaging and / or projection optics comprise in particular a deflecting, magnifying and / or image-correcting concave mirror (7). [3] Projection unit (5) according to claim 1 or 2, further comprising: - a light trap (11) arranged on or opposite a side of the cover disk (8) facing away from the image transmitter (6) and designed to substantially intercept and block, in at least one predetermined solar angle range and at a corresponding cover disk rotation position, solar rays (S) coming directly from the sun and reflected by the cover disk (8). [4] Projection unit (5) according to claim 3, wherein - the cover plate (8) is designed to rotate via the appropriately configured control unit (10) in such a way as to be dependent on the position of the sun, so that sun rays (S) coming directly from the sun are always directed into the light trap (11) via reflection from the cover plate (8); - wherein preferably the cover plate (8) is curved concavely on its side facing away from the image sensor (6) in such a way that this can be achieved by a sun-position-dependent change between only a few discrete cover plate rotation positions (P1, P2) or is also achieved in operation. [5] Projection unit (5) according to one of the preceding claims, in conjunction with claim 2, wherein - the other element of the projection unit (5) mentioned above, for whose movement in alternating use the aforementioned cover disk rotary drive (9) is designed, whose concave mirror (7) is. [6] Projection unit (5) according to any one of the preceding claims, further comprising: - a protective housing that at least partially surrounds the projection unit (5) and is closed towards the reflection disc by the cover plate (8); and - at least one sealing device which is designed on the rotatable cover plate (8) and / or on the housing fixed to the projection unit (5) in their adjacent edge areas such that it seals the interior of the projection unit (5) against dust and / or moisture at all of its differently predetermined cover plate rotation positions (P1, P2) depending on the position of the sun. [7] Eye-view display device (2) for use in a vehicle (1), comprising: - a projection unit (5) according to any one of the preceding claims; and - a reflecting disk arranged in the beam path of the light beam emitted by the projection unit (5), in particular at least partially transparent; - wherein the reflective disc is arranged and designed in the user's field of vision in such a way that it reflects the beam of light rays to the eyebox predetermined for his eyes, thereby making it possible to present the display content to him in the form of a virtual image floating beyond the reflective disc or a real image floating between the reflective disc and the eyebox. [8] Vehicle (1), in particular a motor vehicle, with mutually perpendicular longitudinal, transverse and vertical directions (X, Y, Z) of a vehicle-fixed Cartesian coordinate system (K), comprising: - a passenger compartment with a vehicle window that at least partially encloses the passenger compartment, in particular a windshield (3); and - a view display device (2) according to claim 7, the projection unit (5) of which is arranged in the passenger compartment, in particular inside an instrument panel (4) arranged under the windscreen (3) and the reflection screen of which is designed as a section of the said vehicle windscreen or as a combiner screen arranged in the passenger compartment. [9] Vehicle (1) according to claim 8, wherein - the cover plate (8) is rotatable about a first axis of rotation in the manner described above, which runs approximately parallel to or along the transverse direction (Y) of the vehicle or a plate root of a vehicle plate; and / or - the cover plate (8) is rotatable about a second axis of rotation in the manner mentioned above, which runs approximately parallel to or along the longitudinal direction (X) of the vehicle or transversely, in particular orthogonally, to a disk root of a vehicle disk. [10] Vehicle (1) according to claim 8 or 9, wherein - a light trap (11) is provided in or on the projection unit (5) or at another location in the vehicle (1), and the cover plate (8) is designed to rotate via the appropriately configured control unit (10) in such a way as to be dependent on the position of the sun, such that in at least one predetermined sun position angle range at a respective corresponding cover plate rotation position (P1, P2), direct sunlight rays (S) coming from the sun and reflected by the cover plate (8) are substantially completely intercepted and blocked by the light trap (11), and / or - in at least one predetermined sun angle range at a respective cover plate rotation position (P1, P2), sun rays (S) coming directly from the sun are reflected from the cover plate (8) to such surfaces of the vehicle interior via a mirror reflection on which they cannot enter the eyebox of the user, and preferably also not of any other occupant.

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