Hud having a cover pane for a vehicle, which cover pane can be rotated for solar ray deflection depending on the position of the sun

Abstract

The invention relates to a compact projection unit for a vehicle. Said projection unit comprises an image generator and a cover pane which is substantially transparent to the light beam of said image generator, protects the projection unit from the outside and is rotatably mounted therein and 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 the light beam is subsequently reflected by a reflection pane arranged in the field of vision of a user to the eyebox of the user, and the display content thereby appears to the user as a real or virtual image floating in the air. The cover pane is designed to rotate via the correspondingly designed control unit of the cover pane depending on the position of the sun in such a way that no solar rays coming directly from the sun can be reflected by the cover pane to the reflection pane and by the reflection pane into the eyebox of the user.

Description

[0001] 24-1761

[0002] 1

[0003] Description

[0004] HUP with a cover glass that can be rotated for sun-position-dependent beam deflection for a vehicle

[0005] The invention relates to a field-of-view 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 suspended in the air by reflection off a reflective surface, such as a vehicle windshield or a specially provided combiner screen, which is arranged in the user's field of vision. The invention also relates to a projection unit designed to emit a suitable beam of light with the desired display content, and to a vehicle equipped therewith.

[0006] Particularly in motor vehicles, it is known to use a head-up display (HUD) to overlay display content, such as speed information or other useful navigation and vehicle operating instructions, as a virtual image of the real-world surroundings observed by the driver, so that the driver does not have to take their eyes off the road to read the information. For this purpose, a HUD comprises a reflective screen positioned in the driver's field of vision, which is largely transparent to ambient light incident from behind and is designed either as a section of the windshield or as a combiner screen mounted inside the vehicle. In a classic design, a HUD also includes 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.

[0007] 2

[0008] Projection optics are used to shape the generated beam of light rays and direct them onto the reflecting screen so that they are reflected back to the driver's eyes, allowing them to see the virtual image at a suitable size, quality, and distance. Typically, the projection optics include a beam-deflectoring, image-correcting, and magnifying concave mirror, but its dimensions scale linearly with the size of the virtual display area, thus severely limiting it.

[0009] Implementing such a high-intensity display (HLID) in a vehicle is very complex, due in part to space constraints. A key component of its projection unit is a transparent cover plate (also called a cover glass) that seals the protective housing of the projection unit at the output side and transmits the generated light beam. The cover plate must be designed so that no direct or indirect reflections of ambient light, especially sunlight, can enter the HUD beam path and thus the driver's eye via its outer surface. Prior art uses, for example, a specific, concavely curved cover plate shape that deflects disruptive light reflections from the beam path and is referred to as "geometric anti-reflection." However, this requires a considerable cover plate dimension in the vertical direction of the vehicle.The concave mirror, which is usually mounted to rotate for eyebox adjustment and therefore requires even more space, represents a restriction on the cover glass design, because the cover glass must maintain predetermined minimum distances in the vertical direction of the vehicle to the concave mirror.

[0010] The object of the present invention is to provide an alternative and / or improved projection unit for a view-field display device for installation in a vehicle, with regard to installation space, image quality and / or other aspects. 24-1761

[0011] 3

[0012] This problem is solved by a compact projection unit according to claim 1, as well as by a field-of-view display device containing this unit and a vehicle equipped therewith according to the dependent 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 field-of-view display device and the vehicle, and vice versa.

[0013] According to a first aspect, a compact (i.e., optimizable or optimized with regard to the required installation space) projection unit for a field-of-view display device is provided, designed for installation in a vehicle. The field-of-view display device can, for example, be designed as a head-up display (HUD). The vehicle can be a motor vehicle, but also any other land, air, or watercraft. Unless otherwise specified, 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, lateral, and vertical directions of the vehicle.

[0014] The projection unit has an image generator (also called a picture generating unit, or PGU) designed to produce a beam of light with the desired display content. In principle, any imaging technology is suitable for the image generator, such as a light-transmitting or light-emitting flat panel display, a projector-based image generator, or a waveguide-based display.

[0015] Furthermore, the projection unit includes a cover plate (also called a cover glass) designed to protect the image sensor and any other optical and mechanical components of the projection unit from external influences such as dust, moisture, aggressive substances, and / or mechanical impact. The cover plate is for the [missing information - likely a reference to a specific product or model] from 24-1761

[0016] The light beams emitted by the projection unit (hereinafter also referred to as projection light) are largely transparent (i.e., within the limits of what is technically feasible) and are mounted in the projection unit so as to be rotatable about at least one axis. The projection unit also includes 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 image sensor or any optics of the projection unit, can be planar or concave.

[0017] At least one of the rotational axes can be fixed relative to the projection unit, but this is not mandatory. Particularly with two or more rotational axes that are interlocked or with a superimposed translational movement, at least one of the rotational 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, offer an additional space advantage, such as allowing another component to be moved out of the way, and / or contribute to achieving one of the purposes of the cover plate movement mentioned below.

[0018] The cover glass adjustment can be motorized or pneumatic, for example. Ideally, existing drives in the vehicle or projection unit can be used for this purpose. The specific, optimal position and orientation of the axis(es) of rotation for the cover glass may vary depending on the vehicle and HUD design.

[0019] The mutual arrangement and design of the image transmitter, the cover plate, and any (but not necessarily) imaging and / or projection optics in the projection unit are chosen such that the light beam leaves the projection unit in a predetermined shape and direction, in order to be subsequently reflected by a typically (but not necessarily) semi-transparent reflective disc located in the user's field of vision to their eyebox, thereby displaying the user the content in the form of a real or virtual image, as shown in 24-1761

[0020] 5. To represent the image of the object floating in the air in front of or behind this reflective disc, within the user's direct field of vision, in a predetermined shape, size, and distance. A virtual image can be generated at virtually any distance beyond the reflective disc, which can be determined by appropriately designed projection optics. Here, the image distance can be chosen, for example, to minimize the eye accommodation required to simultaneously observe the road ahead through the semi-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, and can therefore be captured at this point in space, for example, by light-sensitive material or made visible to everyone by a light-diffusing surface.A significantly shorter image distance compared to virtual image generation can be better suited for reading, for example. A real image suspended in the air can also offer several advantages over a conventional light-scattering projection surface, such as visibility from a limited area (eyebox) or the ability to freely choose the image distance and orientation in the air, which would not be possible with rigid screens or scattering surfaces in a vehicle due to the required freedom of movement for the occupants.

[0021] The reflective disc can be formed, for example, by a section of a vehicle windshield, or alternatively by a dedicated combiner disc. The reflective disc is thus 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 manner known per se (e.g., retractable). As is customary, the eyebox of the field-of-view display device is understood to be a two- or three-dimensional area within the vehicle from which the displayed floating image is visible in the intended quality. 24-1761

[0022] 6

[0023] The cover plate is designed to rotate automatically, via its rotary drive and corresponding control unit, 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 reflective plate and from there into the user's eyebox. The necessary sun position detection can be performed by suitable sensors on board the vehicle.

[0024] One idea behind the projection unit presented here is to make its cover glass rotatable / adjustable relative to the projection unit and thus also relative to the vehicle, in order to achieve a targeted deflection of directly incident sunlight from an optical path leading to the user's eyes, depending on the sun's position. For example, a cover glass, which deflects the incident sunlight into a so-called HUD mirror array (light trap), can be rotatably mounted in a vehicle-mounted HUD housing cover. This allows the cover glass to be swiveled into an optimal position depending on the sun's position, while requiring minimal installation space, because in each of its rotational positions, the cover glass only needs to be "anti-reflective" in the sense described here for a corresponding sub-area within a larger angular range that encompasses all possible angles of incidence of sunlight.The HUD housing cover, which usually consists of one part, thus 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.

[0025] According to one embodiment, an imaging and / or projection optic is provided in the beam path of the light beam between the image sensor and the cover plate, which can significantly contribute to ensuring that the light beam leaves the projection unit in the required 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 to provide the user with the 24-1761

[0026] 7

[0027] The display content is represented as a real or virtual image suspended in mid-air, in a desired shape, size, and distance. For this purpose, the imaging and / or projection optics can include, for example (but are 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.). Depending on the requirements of a specific application, the imaging and / or projection optics are designed for a predetermined optical functionality, such as image magnification and / or imaging effect and / or beam shaping and / or correction of other aberrations and / or beam deflection.

[0028] Alternatively, it could 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 image transmitter and the reflective screen. Such a setup can be particularly well-suited for AR (Augmented Reality) applications, as it provides a significantly larger virtual display area than is possible with a classic HUD using mirror optics.

[0029] 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 image sensor and is designed to essentially completely intercept and block sunlight coming directly from the sun and reflected by the cover plate within at least one predetermined solar angle range and at a corresponding 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.

[0030] Furthermore, the practical analysis of the system presented herein has shown that shallowly incident solar rays (for example, in a range of approximately 40° - 50° with respect to the horizontal) are not reflected by a conventional 24-1761

[0031] 8

[0032] Light trapping, also known in the prior art as a "HUD mirror array" in connection with the aforementioned geometric anti-reflective coating of the cover glass, can be completely or partially absorbed. This radiation range is followed by another radiation angle range (between, for example, 50° and 60°), which can also be reliably deflected into the conventional HUD mirror array by further optimization of the cover glass curvature. Sunlight in the range around 70°, and especially in the range around 80°, can only be deflected into the conventional HUD mirror array with considerable effort, which would be unacceptable in many cases, both in terms of the manufacturing of the cover glass and the additional installation space required in the vehicle.Furthermore, this deflection would mean that, in the classic HUD setup described above, its concave mirror would have to be trimmed, which would correspondingly reduce the display area of ​​the HUD (this can easily be a third of the otherwise possible display area).

[0033] The proposed rotation of the entire cover glass allows for sun-position-dependent adjustment to solve these problems, enabling, for example, the targeted deflection of direct sunlight into the conventional HUD mirror array when the sun is above 60°, above 70°, or at approximately 80°. This adjustment position can then be designed, for example, for a first angle range of direct sunlight of approximately 60°–90°, and especially approximately 70°–80°. A second, different adjustment position of the cover glass can, for example, be preset to handle a second angle of incidence range of approximately 40°–70°. More than two different adjustment positions, each with corresponding sun angle ranges, can also be provided, and continuous adjustment (for example, for a planar cover glass) is also possible.However, by limiting the adjustment to only two (or a few) positions, the new cover glass adjustment system can be used particularly economically. 24-1761.

[0034] 9

[0035] The cover plate can be designed, in particular, to rotate via a suitably configured control unit in such a way that direct sunlight is always directed into the light trap above via reflection from the cover plate (where it is essentially completely intercepted and blocked). The cover plate can be concavely curved on its side facing away from the image sensor (also called "geometric anti-reflection") in such a way that reliable guidance of all directly incident sunlight into the light trap is achieved by switching between only a few (in particular only two or three) discrete cover plate rotation positions, depending on the sun's position, and is indeed achieved during operation of the field-of-view display device.

[0036] Alternatively to this embodiment, a planar or concave curved cover plate and its sun-position-dependent predetermined rotation positions can also be designed to direct sunlight into the light trap only in a sub-range of all possible sun angles where sunlight directly hits the cover plate, while at all other angles of incidence direct sunlight is directed in other predetermined directions to the reflecting plate or other surfaces in the vehicle, ensuring that it cannot be reflected into the user's eyebox.

[0037] As already mentioned, in a specific configuration, at least one of the cover plate rotary drives can be used alternately, via a switch or clutch, to move the cover plate and at least one other element of the projection unit, in particular its concave mirror or another movable element for adjusting the eyebox position to different user eye positions. 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 used, thus eliminating the need for an additional drive. 24-1761

[0038] 10

[0039] According to one embodiment, the projection unit further comprises a protective housing that at least partially surrounds it and is sealed towards the reflecting disc by the cover plate. In particular, at least one sealing device may be provided, which is formed on the rotatable cover plate and / or on the housing fixed to the projection unit in their adjacent edge regions such that it seals the interior of the projection unit against dust and / or moisture in all of its cover plate rotation positions, which vary depending on the sun's position.For this purpose, the sealing device may, for example, include 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 thereby compensate for the change in relative positions of the cover plate and housing edges when the cover plate rotates.

[0040] According to another aspect, the above-mentioned field-of-view display device is provided. As already mentioned, the field-of-view display device comprises, in addition to the projection unit presented herein, a reflective disc arranged in the beam path of the light beam emitted by the projection unit, which is designed in particular as a partial surface section of a vehicle windshield or as a separately provided combiner disc and may, for example, be at least partially transparent.The reflecting disc is positioned and designed within the user's field of vision such that it reflects the beam of light rays into an eyebox predetermined for their eyes, thereby displaying the content as a virtual image beyond the reflecting disc (or, in an alternative optical setup, as a real image suspended in mid-air between the reflecting disc and the eyebox), and this image is indeed displayed during operation of the field-of-vision display device. 24-1761.

[0041] 11

[0042] According to an embodiment mentioned above, the reflective disk is arranged directly opposite the image sensor, with the exception of the cover plate which serves as a cover for the projection unit. In other words, in this specific embodiment, the field-of-view display device does not include any optical elements, such as deflecting or concave mirrors or lenses, etc., in the beam path of the light beam generated by the image sensor before it strikes the reflective disk. However, any protective or optical coatings on the image sensor or the reflective disk, and in particular microlens or microprism layers or area-covering lens or prism arrays with optical functionality, such as autostereoscopic or other beam splitting, etc., directly on an image-generating surface of the image sensor or on the reflective disk, are still possible.

[0043] This design, for example, with a large display extending directly opposite the windshield on the upper part of the instrument panel or a large planar waveguide, allows for a significant expansion of the virtual display area. With a HUD of this type, a driver or front passenger can be shown, among other things, a continuous panoramic virtual image with entertainment or driving-related content, which can ideally extend across the entire width of the windshield in the transverse direction of the vehicle.

[0044] According to another aspect, the above-mentioned vehicle is provided. The vehicle comprises a passenger compartment and a vehicle window that at least partially delimits it, in particular a windshield. 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 located below the windshield, and the reflector of which is designed as a section of the aforementioned vehicle window or as a combiner lens arranged in the passenger compartment. 24-1761

[0045] 12

[0046] In particular, the cover glass in the vehicle can be rotatable about a first axis of rotation, as proposed herein, which runs approximately parallel to (or along) the transverse direction of the vehicle or to the root of a vehicle window. This allows the deflection angle of the sun's rays to be adjusted vertically, for example, to adapt to a lower or higher sun angle and / or a user sitting lower or higher. Alternatively or additionally, the cover glass in the vehicle can be rotatable about another axis of rotation, as proposed herein, which runs approximately parallel to (or along) the longitudinal direction of the vehicle or transversely, in particular orthogonally, to the root of a vehicle window. This allows the deflection angle of the sun's rays to be adjusted, for example, horizontally or simply laterally.

[0047] As already mentioned, for example a light trap can be provided in or on the projection unit or at another location in the vehicle, and the cover plate can be designed to rotate via the appropriately configured control unit depending on the position of the sun in such a way that in at least one predetermined sun position angle range at a respective corresponding cover plate rotation position, sun rays coming directly from the sun and 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, within at least one predetermined sun position angle range and at a corresponding cover plate rotation position, direct sunlight coming from the sun is reflected by the cover plate not into the light trap, but to other surfaces of the vehicle interior via a specular reflection, preventing it from entering the eyebox of the user, and preferably also of any other occupant. These surfaces could be, for example, areas of the windshield located higher up, interior lining surfaces, the headliner, etc. On the other hand, depending on the sun's position relative to the vehicle, this method can also ensure that sunlight passing through a side window onto 24-1761.

[0048] 13. hit the cover glass, be deflected into the light trap or other non-critical directions and thus certainly not reach the user's eyes.

[0049] The above aspects of the invention and its embodiments and specific configurations are explained in more detail below with reference to the examples shown in the accompanying drawings. For the sake of clarity, in the various examples, not only identical but also differently designed elements of the same type or with similar functionality are designated with the same reference numerals. The drawings are to be understood as purely schematic illustrations of the basic optical principle, i.e., in particular, not to scale. They show:

[0050] Figure 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

[0051] Figure 2 shows an enlarged section of Fig. 1, which shows two different cover plate rotation positions.

[0052] All the various embodiments, variants, and specific design features of the projection unit, the field-of-view display device, and the vehicle mentioned above in the description and the subsequent claims, according to the aspects of the invention described above, can be implemented in the examples shown in Figures 1 and 2, particularly as alternatives or additions to the features shown therein. Therefore, they are not all repeated below. The same applies accordingly to the definitions and effects of terms already given above with regard to individual features shown in Figures 1 and 2.

[0053] Fig. 1 shows in a schematic perspective side view a section of a vehicle 1 with a field of view indicator device 2 according to 24-1761

[0054] Figure 14 shows an embodiment of the invention. In this example, the vehicle 1 is a motor vehicle, indicated in Fig. 1 only by its windshield 3, which serves as the aforementioned reflective screen for the field-of-view display device 2. A projection unit 5 of the field-of-view display device 2 is arranged below it in an instrument panel 4 (not shown in detail). This is, again purely by way of example, a head-up display (HUD). As already mentioned, unless otherwise stated, the spatial orientation terms such as "horizontal," "vertical," "upper," "lower," "below," etc., refer to the usual vehicle-mounted Cartesian coordinate system K with mutually perpendicular longitudinal, transverse, and vertical directions X, Y, and Z of the vehicle 1.

[0055] The projection unit 5 contains an image sensor 6, which is designed to generate a beam of light rays (not shown) with a desired display content and can, for example, be 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 sensor 6, so that it is only symbolically indicated by a functional block in Fig. 1. In the beam path of the light beam generated by the image sensor 6, the projection unit 5 in this example includes an imaging and / or projection optic 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 towards the front glass 3 by a cover glass 8 (also referred to here as the cover plate).The cover plate 8 is largely transparent to the light beam and can, for example, be arranged flush or recessed in a top surface of the instrument panel 4 (not shown in detail).

[0056] The image generator 6, the concave mirror 7, and the windscreen 3 are designed and arranged relative to each other such that the light beam leaves the projection unit 5 in a suitable shape and direction, and is then projected from the windscreen 3 to a position suitable for the eyes of a user (not shown, for example, driver) in the passenger compartment of the vehicle 1 24-1761

[0057] 15 predetermined spatial area (eyebox, not shown) to be reflected and thereby display the display content as a real or virtual floating image (not shown) with desired properties directly into the user's field of vision.

[0058] The cover plate 8 is rotatably mounted in the projection unit 5 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 may be located in the projection unit 5 and / or at another location in the vehicle 1 (for example, also as part of the central vehicle control system) and has access to all necessary sensors and drives on board.

[0059] The cover plate 8 can be designed, in particular, to rotate via the appropriately configured control unit 10 in such a way that direct sunlight S (see Fig. 2) is always directed into a light trap 11 via reflection from the cover plate 8, where it is essentially completely intercepted and blocked. In this example, the cover plate 8 is concavely curved on its side facing away from the image sensor 6, so that reliable guidance of all directly incident sunlight 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), and is also achieved during operation of the field-of-view display device 2.Alternatively, a planar or concave curved cover plate 8 and its sun-position-dependent predetermined rotation positions can also be designed to direct sunlight into the light trap 11 only in a sub-range of all possible sun angles where sunlight S directly strikes the cover plate 8, while at all other angles of incidence, direct sunlight S is directed in other predetermined directions towards the windshield 3 or other surfaces in the vehicle 1, such that it is certain they cannot enter the user's eyebox. 24-1761.

[0060] 16

[0061] For comparison, Fig. 1 also shows a conventional geometrically anti-reflective cover plate 800, whose concave outer geometry is designed to direct all incident sunlight from the entire relevant angle of incidence range of 40°–80° (with respect to the horizontal direction) into the HUD mirror bank (light trap 11). However, for this purpose, the conventional cover plate 800, which is fixed relative to the projection unit 5, requires such a strong curvature of its entire surface that it would significantly obstruct the concave mirror 7 of the desired size. In contrast, the rotatable cover plate 8 in this example is designed, in its rotation position shown in Fig. 1, to direct only rays within a vertical angle of incidence range of 40°–60° with respect to the horizontal direction into the HUD mirror bank 11 – without obstructing the concave mirror 7.For a steeper angle of incidence, the cover plate 8 is rotated to a different position when a corresponding sun position is detected, as indicated, for example, in Fig. 2. Even in this position, the cover plate 8 does not obstruct the generously dimensioned concave mirror 7 shown in Fig. 1.

[0062] As indicated in Fig. 1, the cover plate 8 in the vehicle 1 can, as proposed herein, be rotated 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. This axis runs approximately parallel to or along the vehicle's transverse direction Y or a disc root of the windshield 3. This allows the deflection angle of the sun's rays to be adjusted vertically, for example, to adapt to a lower or higher sun angle and / or to a user sitting lower or higher. Alternatively or additionally, the cover plate 8 in the vehicle 1 can also be rotated about a second axis of rotation (direction of rotation D2), which runs approximately parallel to (or along) the vehicle's longitudinal direction X or transversely, in particular orthogonally, to a disc root of the windshield 3.This allows the deflection angle of the sun's rays to be adjusted, for example, horizontally or simply to the side. Fig. 2 shows an enlarged section of Fig. 1, illustrating two different cover plate rotation positions P1 and P2 in the direction of rotation D1. Here, the cover plate 8 is in position P1 to direct shallow incident sun rays S (e.g., 40–70°) into the HUD mirror array 11 (see Fig. 1), while it is in position P2 when the sun rays S are at a steeper angle (e.g., 70–80°) to deflect them into a higher area of ​​the front lens 3, from which they cannot be reflected into the user's eyebox. Alternatively, the cover plate 8 can also be rotated in the opposite direction to direct the steeply incident sun rays S into the light trap 11.

[0063] As indicated by the dashed lines in Fig. 2, the same principle can also be applied to a field-of-view display device 2 or projection unit 5, which does not have any imaging and projection optics (and in particular no concave mirror 7) between the image sensor 6 and the cover plate 8. In this case, the image sensor 6 extends (as indicated purely symbolically) directly opposite the front plate 3 (see Fig. 1), with only the protective cover plate 8 lying between them, which, as proposed, is rotatable depending on the sun's position to reduce reflections of the sun's rays S.

[0064] 18

[0065] Reference symbol list

[0066] 1 vehicle

[0067] 2. Viewing display device, in particular HUD

[0068] 3 Windscreen

[0069] 4 Instrument panel

[0070] 5 projection units

[0071] 6 image sensors

[0072] 7 Concave mirrors

[0073] 8 Cover plate, also called cover glass

[0074] 800 conventional cover glass with geometric anti-reflective coating

[0075] 9 Rotary drive

[0076] 10 Control unit

[0077] 11 Light trap, also called HUD mirror bank

[0078] Sunbeams

[0079] D1, D2 directions of rotation

[0080] P1, P2 different rotation positions of the cover plate

[0081] K vehicle-fixed Cartesian coordinate system

[0082] X, Y, Z Longitudinal, transverse and vertical directions of the vehicle

Claims

24-1761 19 Claims 1. Compact projection unit (5) for installation in a vehicle (1), comprising: an image generator (6) designed to generate a beam of light rays with the desired display content; and a cover plate (8) that is essentially transparent to this beam of light rays, protects the projection unit (5) externally and is rotatably mounted therein 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 designed to output the beam of light rays in such a predetermined shape and direction that it is subsequently reflected by a reflective disc arranged in the user's field of vision to their 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, so 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's eyebox.; 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 configured such that the light beam leaves the projection unit (5) in the predetermined shape and direction, in order to subsequently be projected by the lens arranged in the user's field of vision 24-1761 20 to be reflected to its 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 in particular comprise 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 plate (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 each associated cover plate rotation position, solar rays (S) coming directly from the sun and reflected by the cover plate (8).

4. Projection unit (5) according to claim 3, wherein the cover plate (8) is configured 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 direct sun rays (S) coming 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) such that this is achievable 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 particular in conjunction with claim 2, wherein 24-1761 21 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 element of the projection unit (5), in particular its concave mirror (7) or another movable element to adapt the eyebox position to different user eye positions.

6. Projection unit (5) according to 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 that is formed on the rotatable cover plate (8) and / or on the housing fixed with respect to the projection unit (5) in their adjacent edge regions such that it seals the interior of the projection unit (5) against dust and / or moisture at all of its cover plate rotation positions (P1 , P2) which are predetermined differently depending on the position of the sun.

7. Field-of-view display device (2) for use in a vehicle (1), comprising: a projection unit (5) according to one of the preceding claims; and a reflective disc, in particular at least partially transparent, arranged in the beam path of the light beam emitted by the projection unit (5); wherein the reflective disc is arranged and designed in the user's field of view such that it 24-1761 22 The light beams are reflected to the eyebox predetermined for his eyes, allowing the display content to be presented to him in the form of a virtual image floating beyond the reflection disc or a real image floating between the reflection 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 delimits the passenger compartment, in particular a windshield (3); and a view indicator 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 below the windshield (3), and the reflection disc of which is designed as a section of the said vehicle window or as a combiner disc arranged in the passenger compartment.

9. Vehicle (1) according to claim 8, wherein the cover plate (8) is rotatable in the manner described above about a first axis of rotation which is approximately parallel to or along the transverse direction (Y) of the vehicle or a disc root of a vehicle disc; and / or the cover plate (8) is rotatable in the manner described above about a second axis of rotation which is approximately parallel to or along the longitudinal direction (X) of the vehicle or transverse, in particular orthogonal, to a disc root of a vehicle disc.

10. Vehicle (1) according to claim 8 or 9, wherein -1761 23 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 depend on the position of the sun, such that in at least one predetermined sun position angle range at a respective associated cover plate rotation position (P1, P2) sun rays (S) coming directly from the sun, which are 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 position angle range at a respective associated 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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