Parallax compensation in a HUD with a stepped display arrangement for a vehicle

Abstract

Method for operating a field-of-view display device (2) designed to display a virtual image (V) by reflection on a reflective disk arranged in the field of view of a user, wherein - whose image-generating display area consists of at least two display area elements (81-83, 91-93), each of which is controlled to generate a partial display content of a total display content to be displayed; - the at least two display area elements (81-83, 91-93) are arranged in at least two rows (8, 9) which are offset from each other in a predetermined beam propagation direction (A) of the display area in a step-like or stair-like manner and, in projection onto a common beam cross-sectional plane (Q) which extends perpendicular to the said beam propagation direction (A), border each other directly or with predetermined lateral distances which are at least one pixel size or multiples thereof; - a current height position of the user's eyes (3) with respect to the field of view display device (2) is determined and, depending on this, a vertical parallax compensation is carried out by a corresponding shift of the partial display contents in at least one of the rows (8, 9) in a direction orthogonal to their row extension direction, so that the user always sees the entire display content to be shown in the virtual image (V) without overlaps or interruptions of the partial display contents from the individual rows (8, 9).

Description

[0001] The invention relates to a method for operating a field-of-view display device, also known as a head-up display (HUD), which can be used in particular in a motor vehicle or other land, air, or watercraft. Field-of-view display devices of this type are designed to generate a virtual image projected into the user's field of vision by reflection off a reflective surface located within the user's field of vision, in particular a vehicle windshield. The invention also relates to a correspondingly configured control unit, a projection unit for emitting a suitable beam of light, a field-of-view display device containing this unit, and a vehicle equipped therewith. The field-of-view display device can, in particular, be configured as a mirror replacement system for at least one side mirror of a vehicle.

[0002] Particularly in motor vehicles, it is common practice to use a head-up display (HUD) to overlay information such as speed limits or other useful navigation and vehicle operating instructions onto the driver's real-world view in front of the vehicle as a virtual image, thus allowing the driver to view the information without taking their eyes off the road. To generate the displayed content, a conventional HUD includes a projection unit located below the windshield inside the instrument panel. This unit typically contains a display for generating a beam of light with the desired content, as well as suitable imaging and projection optics to shape and direct the generated beam of light onto the windshield or combiner lens so that it is reflected back to the driver's eyes, allowing them to see the virtual image at an appropriate size and distance.In a classic HUD design, the projection optics include a concave mirror whose dimensions scale linearly with the size of the virtual display area, severely limiting it due to the limited installation space inside the instrument panel.

[0003] Alternatively, a HUD design with a display extending directly opposite the windshield on the upper surface of the instrument panel is known. One approach involves arranging multiple displays side-by-side in a single plane to increase the display area. However, the installation space for implementing such a HUD is also limited, making its integration into a vehicle complex. For example, there are restrictions regarding the orientation of the display area, as certain requirements for the optical performance of the HUD must be met, while the shape and orientation of the windshield are fixed. Such restrictions typically lead to space constraints, i.e., conflicts with other structures and elements of the vehicle, if, for example, the display area needs to be expanded.

[0004] For design reasons, to minimize the vehicle's air resistance, or to reduce vehicle dimensions (in the Y-direction), the use of camera-based mirror replacement systems instead of the two exterior mirrors is also known. The display content of such camera systems must also be brought into the driver's field of vision, so here too, a HUD projection via reflection off the windshield is effective. The lower area of ​​the windshield printed with black, which can be particularly well-suited as a dark background for this purpose, must be located below the so-called 4° line of sight. This means that the display unit must be positioned relatively close to the base of the windshield. Here, too, the available installation space in the vehicle is very limited.

[0005] Patent application US 2018 / 0188529 A1 discloses a screen device and a head-up display with two screens arranged at different focal lengths. The screens generate virtual images on different virtual image planes, i.e., at different distances from the user. A light-shielding element is located between the screens, preventing light from passing from one screen to the other.

[0006] DE 10 2014 019 122 A1 discloses a method for operating a display system with parallax compensation. The display system comprises two display areas that represent objects in two different virtual image planes. By means of eye position detection, the user's line of sight is corrected in order to display objects that extend across both virtual image planes more coherently.

[0007] DE 10 2016 214 673 A1 concerns a mirror replacement system with HUD projection onto side windows.

[0008] It is therefore an object of the present invention to provide an alternative and / or improved design and operating concept for a field-of-view display device with regard to optical performance and / or the required installation space, which can also be designed for a panoramic virtual display and / or as a mirror replacement system for the side mirrors of a vehicle. It should therefore be suitable, among other things, for integration into a vehicle and, in particular, for virtual display via reflection off its windshield.

[0009] This problem is solved by an operating method according to claim 1, as well as by a correspondingly configured control unit, a projection unit, a field-of-view display device containing the latter, 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 of the method also apply to the control unit, the projection unit, the field-of-view display device, and the vehicle, and vice versa.

[0010] According to a first aspect, a method for operating a field-of-view display device is provided, which is designed to project a virtual image via reflection off a reflective disc arranged in the user's field of vision. The field-of-view display device can, for example, be designed as a head-up display (HUD). It can be designed, in particular, for use, i.e., installation, in a vehicle.

[0011] The vehicle can be a motor vehicle, but also any other land, air, or water vehicle. The vehicle has a passenger compartment and a window that at least partially defines its external boundaries, in particular a windshield or a rear window. All spatial orientation terms used herein, such as "horizontal," "vertical," "above," "below," "underneath," "front," "rear," "left," "right," etc., can, when installed in the vehicle, refer specifically to the usual vehicle-mounted Cartesian coordinate system with mutually perpendicular longitudinal, transverse, and vertical directions of the vehicle.

[0012] The projection unit is designed to generate a beam of light containing the required display content during operation of the field-of-view display device and project it onto the aforementioned reflective disc, from which it is reflected to the user's eyes, thus making the virtual image appear to float beyond the reflective disc. The reflective disc can be, for example, a section of a vehicle windshield or a specially designed combiner disc. The user can be, in particular, the driver and / or passenger of the vehicle.

[0013] The projection unit comprises an image-generating display surface, which, when installed in a vehicle, can be designed for placement in or beneath the top of the instrument panel. The image-generating display surface consists of at least two display elements, each designed to generate a portion of the total displayed content and controlled separately during operation. In principle, any display technology suitable for use in a vehicle can be used for the display elements, such as flat panel displays or waveguide displays. LED displays, whose pixels are formed by light-emitting diodes (LEDs), can be used, particularly to avoid unusable edges.

[0014] The at least two display surface elements are arranged in at least two rows within the projection unit. The individual rows are offset from each other in a step-like or stair-like arrangement along a predetermined beam propagation direction of the display surface. When projected onto a common beam cross-sectional plane extending perpendicular to the aforementioned beam propagation direction, the rows either abut each other directly or with a predetermined lateral distance.

[0015] The system determines the user's eye position relative to the viewfinder in real time and, based on this, performs vertical parallax compensation by shifting the partial display content in at least one of the rows in a direction orthogonal to the row's extension. This ensures that the user always sees the entire displayed content in the virtual image without any overlap or interruption of the partial display content from the individual rows. Therefore, if the user's eye height changes, a corresponding vertical shift of the partial display content within the virtual image area is implemented to compensate for the resulting parallax shift.The user's eye height can be determined, for example, using a suitable camera system, whose cameras can be located in the projection unit and / or at other suitable positions in the vehicle. For instance, at least one part of the display content can be shifted by the amount of the determined change in eye height, so that no edges or separations between the offset rows remain visible in the virtual image.

[0016] One idea is to significantly reduce the installation space required for the display area by arranging the individual display rows in a stepped fashion. This approach also compensates for the strong dependence of the vertical parallax effect resulting from the stepped arrangement on the user's eye level by shifting the partial display content within each row. Furthermore, this stepped display arrangement allows for greater freedom in orienting the display area within the installation space. This enables maximum optimization of the optical performance of the view-field display device, in contrast to conventional arrangements where the freedom to orient a large HUD display area in a vehicle is severely limited by installation space constraints such as other displays or vehicle support structures.

[0017] In this context, all characteristics of the display surface elements, or of the rows composed of one or more display surface elements, always refer to that surface of the respective display surface element from which the partial light beam it generates originates. The total light beam emitted by the projection unit is composed of these partial light beams. The individual display surface elements and the rows formed from them can be rectangular and thus straight in the direction of the rows' extension. Alternatively, however, trapezoidal, parallelogram-shaped, or other polygonal or curved display surface elements are also possible, from which correspondingly angled or curved rows can be assembled.

[0018] To generate a uniform, interference-free display, particularly in the transition areas of the virtual image corresponding to the transitions between rows, a lateral row spacing of at least one pixel spacing (i.e., pixel size) or a multiple thereof has proven suitable. For example, the display area elements can have one or more predetermined linear pixel sizes, such as pixel side lengths for rectangular pixels or pixel diameters for other pixel shapes. When projected onto a common beam cross-section plane, the adjacent display area elements or rows always do not abut each other directly, but rather with predetermined lateral distances, each of which is no less than one such pixel size or a multiple thereof.

[0019] According to one embodiment, the at least two rows of display surface elements are each oriented with respect to the reflective screen and offset from one another by a step height such that the virtual partial image areas of the individual rows appear to partially overlap within the entire spatial area intended for the user's eyes (eyebox). In this embodiment, the aforementioned shift of the partial display content for vertical parallax compensation can be limited to those rows whose virtual partial image areas partially overlap the virtual partial image areas of other rows.

[0020] According to another aspect, a control unit is provided which is designed and configured to automatically execute the procedure presented herein. For this purpose, for example, a corresponding computer program (software) can be loaded into a processor of the control unit and run during operation of the field-of-view display device.

[0021] According to another aspect, the projection unit mentioned above also includes this control unit. The control unit can be, but does not have to be, integrated into the actual housing of the projection unit. Rather, for example, when used in a vehicle, it can also be implemented in the vehicle's control unit, with which the projection unit communicates wirelessly or via a wired connection to execute the procedure presented herein.

[0022] In the simplest case, successive rows can be identical with regard to the number, shape, and orientation of the display surface elements within each row. The display surface elements of the successive rows can be aligned with each other in the direction of the row's extension, or at least partially offset from one another, depending on the specific conditions of the available installation space and / or the requirements of the virtual image to be displayed by the assembled display surface.

[0023] By varying the number, shape, and / or orientation of the display surface elements from row to row, the installation space and / or manufacturing effort can be significantly reduced. In particular, the required installation space can also be saved and / or adapted to the required virtual display area by arranging identically shaped (e.g., standardized) rectangular display surface elements in different numbers and / or orientations within the respective display plane from row to row.

[0024] The aforementioned beam propagation direction can, for example, be a central beam direction of the viewing device and / or the direction of a surface normal of the display area or the respective display area element. In the case of varying orientations of individual display area elements, a mean beam propagation direction across the entire display area can be considered the aforementioned beam propagation direction. As is customary, the central beam direction of the viewing device is understood to be the direction of a light beam emanating from the center of the imaging display area or the common beam cross-sectional plane and leading to the center of the eyebox.

[0025] Depending on the circumstances and requirements of a specific application, the individual display elements can be approximately the same. However, if necessary, they can have varying sizes and / or other properties, such as pixel size, shape, or display technology, along the assembled display surface.

[0026] In particular, at least one of the rows can comprise two or more display area elements. The individual display area elements of the respective row either border each other directly on their own surface / plane or in projection onto the common beam cross-sectional plane, or each with a predetermined lateral distance. Here too, this lateral distance can, similar to the above, be at least a single pixel pitch or a multiple thereof to achieve a continuous and uniform or interference-free display.

[0027] Alternatively, at least one of the rows can consist of a single display surface element, for example with a square or rectangular shape, the longer side of which corresponds to the row extension direction.

[0028] According to one embodiment, all display surface elements within a given row or across the entire display area are oriented with their planes parallel to one another, at least to the extent technically feasible. This can, for example, contribute to ensuring a consistently high display quality across the entire coverable virtual display area. If slight scattering effects are present in the radiation pattern of the individual display surface elements, as an alternative to this embodiment, the plane of at least one of the display surface elements can also be slightly inclined relative to the other display surface elements in order to compensate for these effects.

[0029] In cases of particularly critical installation space conditions or conditions that vary along the row's extension direction, especially in the case of locally occurring installation space limitations, a specific stepped or stair-like arrangement of one or more display area elements within a row is also possible (ideally maintaining a pixel spacing or a multiple thereof between adjacent display area elements and again ideally parallel to the adjacent display area elements). In other words, this embodiment allows a space limitation that varies along the row's extension direction or is local to be overcome by arranging at least one of the display area elements in a row in a stepped or stair-like manner relative to the adjacent display area elements of the same row in the beam propagation direction of the display surface.Since in this case a horizontal parallax effect due to two user eyes at a horizontal distance from each other would be difficult to effectively compensate, for example, less relevant or coarser display content can be shown in adjacent areas of steppedly offset display surface elements of a series.

[0030] If the desired image size or height requires it, more than two rows of display elements can be arranged consecutively in the projection unit in a stepped or stair-like manner. The successive rows can, for example, be offset from each other by the same step height.

[0031] In a specific embodiment, the projection unit further comprises a light well arranged around the assembled display surface, the side walls of which extend parallel or at least obliquely along the direction of beam propagation and at least partially enclose the display surface. This light well can, for example, protect the image-forming display surface from dirt, dust, and damage, acting as a mechanical housing, and / or serve as an optical aperture to suppress unwanted light scattering and disruptive reflections of external and / or internal origin. In particular, the light well can be covered towards the reflector by a cover plate (also called a cover glass) that is transparent to the generated light beam and can likewise be designed for mechanical protection and / or to suppress disruptive reflections from sunlight and ambient light.In particular, at least one camera of the aforementioned camera system, designed to capture the user's eyes, may be located on an edge of the light shaft facing the user.

[0032] According to another aspect, the aforementioned field-of-view display device is provided, comprising at least one projection unit of the type described herein. As mentioned above, this field-of-view display device further comprises a reflective disc arranged in the field of view of at least one user, designed to reflect the beam of light emitted by the projection unit into an eyebox intended for the eyes of the respective user. The reflective surface may, in particular, be at least partially transparent to the ambient light incident from the rear in order to superimpose the virtual image of a real environment observed through the reflective disc. However, this is not mandatory.

[0033] In this system, the reflector disc is positioned in the beam path of the light beam during operation of the field-of-view display device such that the individual rows of display surface elements extend with their row extension direction in the transverse direction of the vehicle, or along the reflector disc, or at least locally approximately parallel to it. In particular, the display plane of at least one of the display surface elements can extend approximately perpendicular to a central ray of the field-of-view display device, which leads from a center of the common beam cross-sectional plane to a center of the eyebox.

[0034] In particular, several alternative projection units of the aforementioned type, which can be assembled modularly into a larger complex, may be provided, each designed for different mounting locations in the vehicle. For example, one projection unit may be provided for the driver of a vehicle designed for right-hand traffic and / or another for the driver of a vehicle designed for left-hand traffic and / or one or more passengers, etc., whereby the respective projection units can be sold individually and retrofitted modularly in a vehicle.

[0035] According to one embodiment, the reflective disc is arranged directly opposite the composite display surface, with the exception of any covers of the projection unit that do not have a beam-shaping, deflecting, or imaging optical effect on the light beams, such as the aforementioned cover plate. 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 after it leaves the display surface and before it strikes the reflective disc. Any protective or optical coatings (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.) are also excluded.However, it is possible to have elements that are arranged directly on the display surface elements or on the reflective disc and are therefore considered part of it.

[0036] According to one embodiment, the field-of-view display device is designed as a mirror replacement system for at least one side mirror of the vehicle and can, for example, include a camera system designed to capture the vehicle's lateral and rear surroundings. Alternatively or additionally, sensors already installed in the vehicle can be used for this functionality. In this embodiment, the control unit is designed and configured to control the display surface to generate a display content based on image data of the vehicle's lateral and rear surroundings, provided in particular by the aforementioned camera system, so that the user, especially the driver, is shown a virtual image corresponding to the view in a side mirror.

[0037] According to another aspect, the aforementioned vehicle is equipped with the above-mentioned field-of-view display device. Its projection unit can be arranged, in particular, in or under the upper surface of an instrument panel or parcel shelf, and its reflector can be designed as part of the vehicle windshield or as a separate combiner lens provided in the passenger compartment.

[0038] In particular, the windshield can have a black or dark-colored or coated printed area in its lower region, which, by way of example, can extend across the entire horizontal width of the windshield. The projection unit and its display surface can be arranged in or below the top of the instrument panel in such a way that the windshield, and at least part of its printed black area, serves as a reflective surface for the field-of-view display. With the stepped or stair-like display arrangement presented here, the image-generating display surface can be positioned particularly close to the base of the windshield, so that almost the entire printed black area can be used for a particularly high-contrast virtual display, largely independent of the ambient light.

[0039] In particular, the windshield can be bounded to the left and right in the transverse direction of the vehicle by an A-pillar, and the projection unit and its display surface can be arranged in or below the top of the instrument panel in such a way that the windshield, at least with a large part of its horizontal extent, serves as a reflective surface for the field-of-view display device. This makes a panoramic virtual display possible for the driver and / or front passenger.

[0040] In practice, the projection unit or its aforementioned light shaft can be installed within an opening provided for the exit of the light beam in the top of the instrument panel or the parcel shelf, for example approximately flush with an edge of this opening.

[0041] According to one embodiment, the projection unit of the field-of-view display device is arranged in and / or below the upper surface of the instrument panel such that its display surface elements form an acute angle with said upper surface of between approximately 25° and 65°, for example, between approximately 35° and 55°. This allows, for example, a particularly space-saving arrangement for a given display surface size and / or particularly high optical performance of the field-of-view display device. In particular, this acute angle can be approximately 45°.Depending on the requirements and circumstances of a specific application, such as the angle of inclination between the vehicle window (used as a reflective surface) and the underlying upper surface of the interior trim, and / or the required position for the eyebox, a different angle may be suitable for orienting the display surface and its individual display elements. For example, a shallower angle of approximately 15° to 35°, particularly approximately 20° to 30°, or even a shallower angle of approximately 10° to 20°, or even an angle approximately parallel to the aforementioned upper surface of the vehicle trim, may be appropriate. In particular, an approximately horizontal orientation of the display elements within the vehicle can also result in optimal optical performance of the field-of-view display device.

[0042] The above aspects of the invention, its embodiments, and specific configurations are explained in more detail below with reference to the examples shown in the accompanying drawings. While some of the schematic drawings may be understood as being to scale, this is by no means mandatory or limiting. They show: Fig. 1 a section of a vehicle with a field-of-view display device according to an embodiment of the invention, partly in a vertical longitudinal section and partly in perspective; Fig. 2 a perspective view of a windshield of the vehicle Fig. 1 from driver's perspective with virtual display areas that replace the left and right exterior mirrors; Fig. 3 another section of the vehicle Fig. 1, which shows the integrated field-of-view display device from a different perspective; and Fig. 4 a section of a vehicle with a field of view display device according to a further embodiment of the invention, again partly in a vertical longitudinal section and partly in perspective.

[0043] All the various embodiments, variants, and specific design features of the operating method, the projection unit, the field-of-view display device, and the vehicle mentioned above in the description and in the subsequent claims, according to the aspects of the invention above, can be found in the Fig. 1, Fig. 2, Fig. 3 to Fig. The four examples shown, in particular also as alternatives or in addition to the features shown therein, can 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 shown in the Fig. 1-4 are shown.

[0044] Fig. Figure 1 shows, in a highly simplified schematic representation, partly in a vertical longitudinal section and partly in perspective, a section of a vehicle 1 with a field-of-view display device 2 according to an embodiment of the invention. The field-of-view display device 2 is here purely by way of example configured as a head-up display (HUD). The spatial orientation terms used below, such as "horizontal," "vertical," "above," "below," "front," "rear," "side," etc., refer to the usual vehicle-fixed Cartesian coordinate system K with mutually perpendicular longitudinal, transverse, and vertical directions X, Y, Z of the vehicle 1.

[0045] The field-of-view display device 2 is designed to generate a virtual image V, which is intended, for example, to serve as a panoramic display or as a replacement for exterior mirrors, in the field of vision of at least one user, in this example a driver of the vehicle 1. This is in Fig. 1 is indicated by his eyes 3 and a predetermined eyebox E in the passenger compartment of vehicle 1. Vehicle 1 is purely an example of a motor vehicle. It is in Fig. 1 is indicated by its windshield 4, an instrument panel 5 extending below it (not shown in detail), and a headliner 6 extending above it. At least part of the virtual image V can be displayed with particularly high contrast in a dark or black tinted or coated black print area 16 in the lower area of ​​the windshield 4.

[0046] Fig. Figure 2 shows a perspective view of the windshield 4 of vehicle 1. Fig. Figure 1 shows the driver's perspective with purely exemplary suitable virtual display areas 17 and 18 for replacing the left and right exterior mirrors. Part 19 of display area 17 and part 20 of display area 18 lie within the black print area 16 of the windscreen 4. Also shown is the aforementioned 4° line of sight 21, up to which the black print area 16 can extend upwards so that display areas 17 and 18 are completely contained within it.

[0047] Fig. Figure 3 shows another section of vehicle 1. Fig. 1, which shows the field of view display device 2 from a slightly different perspective.

[0048] The field of view indicator device 2 of the Fig. 1-3 comprises a projection unit 7, which in this example is arranged below the windshield 4 in the instrument panel 5. The projection unit 7 is designed and arranged to generate and output a beam of light L with the required display content in the direction of the windshield 4, such that the beam of light L is reflected from the windshield 4 to the eyebox E, and the virtual image V appears to the user when looking at the windshield 4.

[0049] For this purpose, the projection unit 7 has an image-generating display surface, which, by way of example, is composed of six identical rectangular display surface elements 81-83 and 91-93, arranged in two rows 8 and 9. The rows 8 and 9 extend in their row extension direction, which in this example corresponds to the long sides of the rectangle (see Fig. 3) of the display surface elements 81-83 and 91-93, along or sectionally substantially parallel to the windscreen 4 or to its windscreen root or to the vehicle transverse direction Y.

[0050] Rows 8 and 9 are offset from each other in the beam propagation direction A of the field-of-view display device 2 in a stepped arrangement with a predetermined first step height 14, thus forming a kind of staircase. Each display surface element 81-83, 91-93 is designed to generate a partial display content and a partial light beam transporting this content. Together, these form a light beam L emanating from the display surface in beam propagation direction A, containing the display content required to generate the virtual image V. The light beam L is indicated solely by its central ray, which leads from a center C of the common beam cross-sectional plane Q to a center of the user's eyebox E.

[0051] In this example, the display planes of all display surface elements 81-83 and 91-93 in the projection unit 7 are oriented parallel to each other. The two rows 8 and 9, projected onto a common beam cross-sectional plane Q extending perpendicular to the beam propagation direction A, border each other with a predetermined lateral distance of at least one single pixel pitch, thus enabling a uniform and interference-free display even in the corresponding transition area of ​​the virtual image V.

[0052] If the vertical position Z of the user's eyes 3 changes, the vertical position of the virtual sub-image areas V8 and V9 of the two rows 8 and 9 relative to each other changes due to the parallax effect caused by their step-like offset. In this example, the spatial orientation and step height 14 of rows 8 and 9 are chosen such that, from the entire user eyebox E, the upper virtual sub-image area V9 is visible in such a way that it partially overlaps the lower virtual sub-image area V8, thus preventing any gaps between them. However, the overlap of the sub-image areas V8 and V9 varies depending on the vertical position Z of the user's eyes 3.

[0053] To resolve this problem, a real-time vertical position Z of the user's eyes 3 relative to the viewfinder display 2 is determined using a camera system 22 designed to capture the user's eyes 3. Based on this, a corresponding shift of the partial display content in at least one of the rows 8 and 9 is performed in a direction orthogonal to their row extension direction, so that the user always sees the entire display content in the virtual image V without any overlap of the partial display content from the individual rows 8 and 9. In this example, it is particularly sufficient to shift only the partial display content of row 9 for vertical parallax compensation, because its partial image area V9 always at least partially overlaps the partial image area V8 of row 8.

[0054] In this example, the steps mentioned are carried out by a control unit 23 set up for this purpose, which communicates accordingly with the individual display surface elements 81-83, 91-93 and the camera system 22.

[0055] According to the specific configuration mentioned above, the projection unit 7 comprises a light shaft 10 arranged around the display area, the side walls of which, in this example, extend downwards from a top surface of the instrument panel 5 (not shown) parallel to the direction of beam propagation A, completely enclosing the display area laterally. The light shaft 10 is covered towards the windshield 4 by a cover plate 11, which is transparent to the generated light beam L and which—like the light shaft 10 itself—is designed both to mechanically protect the projection unit 7 and to shield it from disruptive reflections of sunlight and ambient light.

[0056] In Fig. 1 The cover plate 11 is shown, purely as an example, to be approximately planar and aligned along the aforementioned upper surface of the instrument panel 5, so that the circumferential upper edges of the light shaft 10 (cf. Fig. 3) for example, approximately flush with the edge of an opening in the top of the instrument panel 5 provided for the light beam L. It is advantageous to position at least one camera of the above camera system 22 for capturing the user's eyes 3 in the area of ​​the upper edges of the light shaft 10.

[0057] How to Fig. As can be seen from Figure 1, the individual display surface elements 81-83, 91-93 are aligned at an acute angle of approximately 40°-50° to the cover plate 11 or to the aforementioned upper surface of the instrument panel 5 in order to achieve the best optical performance and the desired position of the eyebox E for the field-of-view display device 2 with the given windshield 4. Thanks to the overall space-saving design of the projection unit 7 presented here, this angle is achievable even with the limited installation space within the instrument panel 5. As mentioned above, however, a shallower acute angle of, for example, 15°-25° or even a nearly parallel alignment of the display surface elements 81-83, 91-93 to the upper surface of the instrument panel 5 or other vehicle trim may also be suitable and achievable, for example, with a different design of the reflective surface and / or a different desired position of the eyebox E.

[0058] How to in Fig. By recognizing the common beam cross-sectional plane Q, which corresponds to a continuous display area that would be required in a conventional field-of-view display device with the same size of the virtual image V, the stepped / stair-like display arrangement allows an otherwise unavoidable installation space restriction due to a fixed support structure 12 of the vehicle 1 to be avoided.

[0059] If required, any other number or shape of display surface elements and rows than shown is also possible. Fig. 1 and Fig. 3. A stepped / stair-like display arrangement can be implemented using the same construction principle. The display planes of the individual display surface elements can be inclined differently in the vehicle's own coordinate system K, depending on the application and available installation space, and if required, with a tilt angle that varies from display surface element to display surface element or from row to row.

[0060] The stepped / stair-like display arrangement presented herein makes it possible in particular to achieve a significant reduction of the X-dimension chain (i.e. the dimension in the longitudinal direction of the vehicle) of the display area in the vehicle 1, in order, for example, to integrate both a HUD in the aforementioned classic design and a view field display device 2 presented herein, designed as a mirror replacement or for panoramic display, simultaneously and optimally in the available installation space of a vehicle 1.

[0061] Fig. Figure 4 shows a section of a vehicle 1 with a field-of-view display device 2 according to a further embodiment of the invention, again partly in a vertical longitudinal section and partly in perspective. To avoid repetition, only the differences to the field-of-view display device 2 of the Fig. 1-3 described.

[0062] It could be, in particular, the same vehicle 1 as in Fig. 1-3. In order to meet particularly critical or varying or locally occurring installation space constraints along the row extension direction, a stepped arrangement of the display area elements 91-93 within the row 9 is additionally implemented (here too, maintaining a pixel distance or a multiple thereof between the adjacent display area elements 91-93 of this row).

[0063] In other words, a display surface element 92 affected by a local installation space restriction is offset in the beam propagation direction A by a suitable predetermined second step height 15 relative to the adjacent display surface elements 91 and 93 of the same row. For example, a significantly lower second step height 15 than the first step height 14 between rows 8 and 9 is sufficient. Reference symbol list 1 vehicle 2. Viewing field indicator device 3. User eye, especially the driver's eye 4 Windscreen 5 Instrument panel 6 Headliner 7 projection unit 8, 9 rows of the display surface offset from each other in the direction of beam propagation 81-83 Display surface elements of a first row 91-93 Display surface elements of a second row 10 light shafts 11 Cover plate 12 Supporting structure 14 First step height between two rows 15 second step height between individual display surface elements of the second row 16 Black printing area 17 virtual display area as a replacement for the left exterior mirror 18 virtual display area as a replacement for the right-hand exterior mirror 19, 20 parts of the virtual display areas in the black print area 21 4° line of sight 22 camera systems for capturing the user's eyes 23 Control unit E Occupant's eyebox, spatial area L Light beam A Beam propagation direction Q Beam cross-sectional plane C Center of the beam cross-sectional plane V virtual image V8 virtual partial image area of ​​a first row of display area elements V9 virtual partial image area of ​​a second row of display area elements K vehicle-fixed Cartesian coordinate system X, Y, Z Longitudinal, transverse and vertical directions of the vehicle

Claims

[1] Method for operating a field-of-view display device (2) designed to display a virtual image (V) by reflection on a reflective disk arranged in the field of view of a user, wherein - whose image-generating display area consists of at least two display area elements (81-83, 91-93), each of which is controlled to generate a partial display content of a total display content to be displayed; - the at least two display area elements (81-83, 91-93) are arranged in at least two rows (8, 9) which are offset from each other in a predetermined beam propagation direction (A) of the display area in a step-like or stair-like manner and, in projection onto a common beam cross-sectional plane (Q) which extends perpendicular to the said beam propagation direction (A), border each other directly or with predetermined lateral distances which are at least one pixel size or multiples thereof; - a current height position of the user's eyes (3) with respect to the field of view display device (2) is determined and, depending on this, a vertical parallax compensation is carried out by a corresponding shift of the partial display contents in at least one of the rows (8, 9) in a direction orthogonal to their row extension direction, so that the user always sees the entire display content to be shown in the virtual image (V) without overlaps or interruptions of the partial display contents from the individual rows (8, 9). [2] Method according to claim 1, wherein - the at least two rows (8, 9) of the display surface elements (81-83, 91-93) are each oriented with respect to the reflective disc and offset from each other by such a step height (14) that, from an entire spatial area (E) intended for the user's eyes (3), virtual partial image areas (V8, V9) of the individual rows (8, 9) can be seen as partially overlapping; and - the aforementioned shift of the partial display content for vertical parallax compensation is limited to those rows (9) whose virtual partial image areas (V9) partially overlap the virtual partial image areas (V8) of other rows (8). [3] Control unit (23) which is designed and configured to automatically execute the method according to claim 1 or 2. [4] Projection unit (7) for a field-of-view display device (2) designed to project a virtual image (V) into the field of view of a user, in particular for use in a vehicle (1), comprising: - an image-generating display surface to be arranged in or under the top of an instrument panel (5) of the vehicle (1) and comprising at least two display surface elements (81-83, 91-93), each designed and controllable for generating a partial display content and a partial light beam transporting this content from a total light beam (L) emitted by the projection unit (7); and - a control unit (23) according to claim 3 and preferably further a camera system (22) which is designed and configured to detect the user's eyes (3) and to provide corresponding image data to the control unit (23) for determining the current height position of the user's eyes (3); - wherein the at least two display surface elements (81-83, 91-93) in the projection unit (7) are arranged in at least two rows (8, 9) which are offset from each other in a predetermined beam propagation direction (A) of the display surface in a step-like or stair-like manner and, in projection onto a common beam cross-sectional plane (Q) which extends perpendicular to the said beam propagation direction (A), are directly adjacent to each other or with predetermined lateral distances which are at least one pixel size or multiples thereof. [5] Projection unit (7) according to claim 4, wherein - at least one of these rows (8, 9) comprises two or more display area elements (81-83; 91-93); and - the individual display area elements (81-83; 91-93) of the respective row (8, 9) also border each other directly or with predetermined lateral distances, at least in projection onto the common beam cross-sectional plane (Q), which are at least a single pixel size or a multiple thereof. [6] Projection unit (7) according to claim 4 or 5, wherein - at least one of the rows (9) comprises two or more display area elements (91-93); and - at least one of these display surface elements (92) is offset in a step-like or stair-like manner to the adjacent display surface elements (91, 93) of the same row (9) in the direction of ray propagation (A) of the display surface. [7] A field of vision display device (2), in particular for use in a vehicle (1), comprising: - a projection unit (7) according to any one of claims 4 to 6; as well as - a reflective disc arranged in the user's field of vision, designed to reflect the beam of light rays (L) emitted by the projection unit (7) to a spatial area (E) predetermined for his eyes (3), so that a virtual image (V) floating beyond the reflective disc is presented to him; - wherein the reflection disk is arranged in the beam path of the light beam (L) emitted by the projection unit (7) such that the individual rows (8, 9) of the display surface elements (81-83, 91-93) extend along the reflection disk or at least locally parallel to it with their row extension direction. [8] Viewing display device (2) according to claim 7, - which is designed as a mirror replacement system for at least one side mirror of the vehicle (1); and - preferably comprising a camera system designed to capture the lateral and rear surroundings of the vehicle (1); - wherein the control unit (23) is designed and configured to control the display surface for generating a display content based on image data of a lateral and rear environment of the vehicle (1) currently provided, in particular by the aforementioned camera system, for generating a virtual image (V) corresponding to the view in a side mirror. [9] Viewing field display device (2) according to claim 7 or 8, wherein - the reflective disc is positioned directly opposite the display surface, with the exception of any covers of the projection unit (7) which have no beam-shaping, -deflectoring or imaging optical effect on the light beam (L). [10] Vehicle (1) with mutually perpendicular longitudinal, transverse and vertical directions (X, Y, Z) of a vehicle-fixed Cartesian coordinate system (K), in particular a motor vehicle, comprising: - an occupant compartment and a vehicle window that at least partially encloses it, in particular a windshield (4); and - a field-of-view display device (2) according to one of claims 7 to 9, the projection unit (7) of which is arranged in the passenger compartment and the reflection disc of which is designed as part of the vehicle window or as a combiner disc arranged separately in the passenger compartment; - wherein the front glass (4) has in its lower area a black printed area (16) that is at least partially black or dark colored or coated; and - the projection unit (7) and its display surface are preferably arranged in or under a top surface of an instrument panel (5) such that the front window (4) and at least part of its black print area (16) serve as a reflective screen for the field of view display device (2).

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