Head-up display with rotating display devices, sometimes used as a blower for an air conditioning system, especially for a vehicle

Abstract

Viewing display device (2) for use in a vehicle (1), comprising: - a projection unit (7); and - a reflecting disc arranged in the beam path of a light beam (L) emitted by the projection unit (7), which is reflective towards the user and at least partially transparent to the ambient light incident from the rear, such as a vehicle window (4) or a specially provided combiner disc;- wherein the reflective disc is arranged and designed in the user's field of vision such that it reflects the light beam (L) to an eyebox (E) predetermined for the user's eyes (3), thereby making the display content present to the user in the form of a virtual image (V) behind the reflective disc, wherein the projection unit (7) comprises: - an image-forming display surface (8) with at least one rotary drive (M), which is to be arranged in or under a top surface of an instrument panel (5) of the vehicle (1) and is composed of several circular display surface sections (81-84, 91-93) which are arranged in one or more parallel planes and are all offset from one another in a direction orthogonal to their surface normals; wherein - each circular display surface section (81-84, 91-93) is generated by at least one radial light arm (10) which is rotatable by the at least one rotary drive (M) to cover a circular area;and- each luminaire arm (10) carries several light sources arranged in a radial direction, which can be controlled synchronously with its rotation and independently of each other.;

Description

The invention relates to a projection unit for a head-up 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. Head-up display devices of this type are designed to generate a virtual image projected into the user's field of vision by reflection off a vehicle window, in particular a windshield, or off a specially provided combiner lens located in the user's field of vision. The invention also relates to such a head-up display device and to a vehicle equipped with it. It is common practice, particularly in motor vehicles, 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 them to keep their eyes on the road. A conventional HUD typically uses a projection unit located below the windshield inside the instrument panel to generate the displayed content.This system typically includes a display to generate a beam of light with the desired display content, as well as imaging and projection optics, typically in the form of a concave mirror, to shape the beam of light and direct it onto the windshield so that it is reflected back to the driver's eyes, allowing them to see the virtual image at a suitable size and distance behind the reflecting glass. However, the dimensions of the concave mirror scale linearly with the size of the virtual display area, thus severely limiting its usable size. Alternatively, for applications requiring a significantly larger virtual display area, a HUD design with a large display extending across the top of the instrument panel directly opposite the windshield is known. This is particularly relevant for future fully automated or autonomous vehicles that are intended to operate without driver input, making the associated in-car entertainment systems increasingly important. Such entertainment systems are expected to include large head-up displays. For example, with this type of HUD, the driver and / or front passenger could be shown additional information across the entire width of the windshield, depending on the external environment, and, if necessary, a continuous panoramic virtual image.For this to work, the image-generating display would have to extend across the entire width of the windshield. To meet the high intensity requirements for display light when reflected off the transparent area of ​​the windshield in bright daylight, an LED display would be more suitable than a liquid crystal display, because significant intensity losses in the liquid crystal layer are unavoidable. However, such a large display area would require an excessive number of LEDs (several million), which in turn would have a considerable impact on the vehicle's energy balance and the associated greenhouse gas emissions. For example, a possible display size for a panoramic view is 1200 mm (length) by 300 mm (width) with a 4:1 aspect ratio. Using a conventional screen, this would require approximately 2,000,000 LEDs. These would be arranged in approximately 1920 columns across the width of the HUD display. This large number of LEDs would generate greenhouse gas emissions of more than 1.2 CO2 equivalents. In the prior art, rotating display devices with a circular display area generated by rotation are known, for example, for design and toy articles or greeting cards, as described, for instance, in US 9,190,028 B2 or EP 4 030 412 A1. Such a rotating display device comprises a fixed motor to whose motor shaft a rotating unit is attached, so that the rotating unit is rotated by the motor. The rotating unit is designed as at least one rod-shaped arm arranged radially, with an LED strip attached longitudinally to the arm. Suitable rotation or position sensors are provided for synchronizing the LED control with the rotation of the arm. Depending on the embodiment, this known circular display device can, for example, comprise a single radial arm, two individual radial arms spaced 180° apart, or four individual radial arms spaced 90° apart. Furthermore, WO 2019 / 023489 A1 discloses a device and a method for displaying an image produced by emitting or reflecting light through rotating elements such as fan blades. Modern vehicles typically include an air conditioning system, which uses a blower located in the instrument panel to distribute air into the passenger compartment. The air conditioning blower requires considerable space in the instrument panel, necessitating compromises in terms of installation space with other instruments and features that also need to be accommodated there. Patent US 11,222,559 B2 discloses a display unit with a display surface having at least one rotary drive, which is composed of several circular display surface sections lying in one or more parallel planes, wherein each circular display surface section is generated by radial light arms which are rotatable by the at least one rotary drive to cover a circular area; and each light arm carries several light sources arranged in a radial direction which are synchronous with its rotation and can be controlled independently of each other. German patent application DE 10 2009 010 614 A1 discloses a display device in a motor vehicle, comprising: a display unit arranged on the top of the vehicle's dashboard opposite the vehicle's windshield and configured to selectively display a plurality of information points in a row or in a rectangular array on the windshield such that the plurality of information points superimpose an actual image in the direction of travel of the vehicle; a target information acquisition unit configured to obtain the target information for a driver of the vehicle; and a display control unit which controls the display unit such that the display unit displays the information point that corresponds to the target information acquired by the target information acquisition unit. The object of the present invention is to provide an alternative and / or improved design concept for a field-of-view display device with regard to energy efficiency and / or the required installation space, which also enables the generation of a large-area virtual image, for example for a panoramic display. In particular, this field-of-view display device should be suitable for integration into a vehicle and for virtual display via reflection on its windshield. This problem is solved by a field-of-view display device according to claim 1 and a vehicle equipped therewith according to the dependent claim. Further embodiments are specified in the dependent claims. All further features and effects mentioned in the claims and the following description for the projection unit also apply to the field-of-view display device and the vehicle, and vice versa. According to a first aspect, a field-of-view display device is provided, which can be designed, in particular, for use in a vehicle. The field-of-view display device is designed to project a virtual image into the user's field of vision by reflection off a reflective disc arranged in their field of vision, in particular a vehicle window. It can, for example, be designed as a head-up display (HUD). The field-of-view display device comprises a projection unit and a reflective disc arranged in the beam path of a light beam emitted by the projection unit, which is reflective towards the user and at least partially transparent to the ambient light incident from the rear, wherein the reflective disc is arranged and designed in the user's field of view in such a way that it reflects the light beam to an eyebox predetermined for the user's eyes, whereby the display content can be presented to him in the form of a virtual image behind the reflective disc.The projection unit comprises an image-generating display surface with at least one rotary drive, which is to be arranged in or under the top of an instrument panel of the vehicle and is composed of several circular display surface sections arranged in one or more parallel planes and offset from one another in a direction orthogonal to their surface normals; wherein each circular display surface section is generated by at least one radial light arm, which is rotatable by the at least one rotary drive to cover a circular area; and each light arm carries several light sources arranged in a radial direction, which are synchronous with its rotation and can be controlled independently of one another. The projection unit is designed to generate a beam of light with the desired display content during operation of the field-of-view display device and project it onto the aforementioned reflective screen, from which it is reflected to the user's eyes, thus making the desired virtual image appear to float behind the reflective screen. The user may be, in particular, a driver and / or front passenger, but also other occupants of the vehicle. The projection unit comprises an image-generating display surface, which is designed for installation in or beneath the top of the instrument panel or the parcel shelf of the vehicle. The image-generating display surface is equipped with at least one rotary drive and consists of several circular display surface sections that can be generated by rotation and are arranged in one or more parallel planes. To fill a specifically defined, for example, nearly rectangular, display area, all circular display surface sections are offset from each other in a direction orthogonal to their surface normals, with or without overlap. In this system, each circular display area section is generated during operation of the field-of-view display device by at least one radial light arm, which is rotated by at least one rotary drive. In particular, each circular display area section can be equipped with its own rotary drive, for example, in the form of a small electric motor. However, this is not mandatory, especially since the multiple circular display area sections can or even should be rotated synchronously during image generation. Each light arm is equipped with several light sources, such as LEDs, arranged radially in a row. These light sources can be controlled synchronously with the arm's rotation and independently of one another to generate the desired image on the display surface. A single circular section of the display surface can be created by one or more radial light arms, which can be attached to the rotating drive shaft in a radially symmetrical manner, i.e., at equal angular intervals from one another. Thus, depending on the embodiment, a circular section of the display surface can, for example, comprise a single radial light arm, or two radial light arms spaced 180° apart, or four radial light arms spaced 90° apart, or six radial light arms spaced 60° apart. Although the following descriptions primarily refer to LEDs as the light sources mentioned above, this is not intended to be a limiting factor.Rather, any other suitable type of light source can always be used instead of LEDs. One idea behind this field-of-view display device is to replace a large, high-intensity image-generating display surface, such as those required for panoramic virtual displays or AR (Augmented Reality) applications in a vehicle's windshield, with a multitude of rotating displays of the type mentioned above. This significantly reduces the number of LEDs required, resulting in a substantial reduction in the vehicle's energy consumption and, consequently, its greenhouse gas emissions, despite the added energy consumption of the rotating drive. If the vehicle is battery-electric, this also leads to a correspondingly greater driving range. Furthermore, this display surface is easily scalable by adding further circular display sections, allowing it to be flexibly adapted to the geometric requirements of various applications. The individual circular display area sections of the image-generating display surface can be, but do not have to be, identical to each other. Rather, their design can vary along the composite display surface, for example, to accommodate varying requirements for display properties (such as intensity, color, resolution, contrast, etc.) of the displayed content, in order to save resources effectively. For example, the resolution for each circular display area section can be influenced by the number and size of the LEDs used. The displayable color gamut can be influenced, among other things, by the design and control of the LEDs. The design and control of the LEDs also affect the frames per second (FPS), which is further determined by the number of light arms and the number and arrangement of the LED strips mounted on them. The number and arrangement of the LED strips also influence the displayable pixel density. When using a single radial light arm, the fixed rotary drive or motor of the circular display area section must rotate at maximum speed to achieve the desired frame rate. Furthermore, the uneven load can lead to rotational irregularities. The same frame rate can be achieved with two radial light arms (i.e., two or more).With a double arm, the required power output can be achieved at half the rotational speed of the fixed rotary drive / motor; with four radial light arms (i.e., two double arms), only a quarter of this is needed; and with six radial light arms (i.e., three double arms), only a sixth. However, more light arms support more LEDs, resulting in a higher overall weight. Therefore, a more powerful motor, which is larger, heavier, and requires a higher supply voltage, may be necessary. These constraints must be considered when designing the circular display sections of the imaging display area. According to one embodiment, all circular display area sections of the imaging display surface have the same radius and are arranged in two parallel planes. The circular display area sections in each plane are directly adjacent to one another and form a straight row. The rows of the two planes are arranged directly above one another, i.e., overlapping each other, so that their row extension directions exactly overlap. The circular display area sections in one plane are offset by a radius length relative to the display area sections of the other plane in the row extension direction, resulting in minimal overlap and / or a gapless and area-wise best approximation of a rectangular imaging display surface.In other words, this makes it possible to achieve an almost rectangular image-forming display area with the most uniform possible area coverage through rotating light arms of the individual circular display area sections and with a minimal area of ​​edge areas that are not covered by the circular display area sections. More generally, the circular display area sections can be arranged in two parallel planes, and in each plane in one or more parallel, straight rows. The circular display area sections in at least one of these rows can also be directly adjacent to each other, although this is not mandatory. Ideally, the rows of one plane are arranged above the rows of the other plane with a lateral offset in the direction of the row extension and / or in a direction orthogonal to it, such that the resulting image-forming display area is as seamless as possible and / or approximates a predefined surface shape as closely as possible and / or exhibits a minimal overlap of the circular display area sections of the two planes. In particular, the projection unit can further comprise several position and / or speed sensors designed to measure and / or determine the rotational positions and / or speeds of the individual circular display area sections and their illuminating arms. In particular, at least some of these sensors can be arranged between any two adjacent circular display area sections of a plane and / or between two adjacent planes, so that each such sensor can be used to measure and / or determine the rotational positions and / or speeds of at least two adjacent / different circular display area sections, thereby reducing the total number of sensors. In particular, the image-generating display area can additionally include at least one edge area that is not covered by the circular display area sections and has at least one edge display device that is independently designed and controllable from the circular display area sections. These edge display devices do not rotate with the projection unit but are stationary relative to it. Therefore, they are particularly suitable for displaying safety-relevant information such as warning indicators, etc., and can be specifically designed for this purpose and, for example, additionally equipped with particularly robust light sources that are less susceptible to operational errors, such as specifically pre-shaped warning lights. The aforementioned edge areas and / or the edge display devices formed therein can transform the area covered by the circular display area sections into a predefined display area shape, such as a rectangle, etc.add to. Furthermore, the projection unit can include a cover plate that extends along the image-forming display surface in the beam path of a light beam emanating from it and is designed to transmit the light beam with essentially no loss while at least partially sealing and protecting the projection unit from the outside. The cover plate can also serve to prevent a vehicle occupant from interfering with the rotating light arms and may optionally be equipped with further mechanical and / or optical functions. It can be made of any suitable material, for example, glass or transparent plastic such as acrylic glass, etc. According to one embodiment, the light arms of at least some of the circular display surface sections are designed as fan blades of a fan wheel and thus for simultaneous use as a blower for an air conditioning system during operation of the projection unit. For this purpose, the light arms can, for example, be equipped with aerodynamically suitable three-dimensional profiles designed to convey air from the interior of the projection unit to the outside, for example, towards the passenger compartment and / or the vehicle windshield when installed in a vehicle. In a further development of this embodiment, at least one outlet opening, which, when installed in the vehicle, faces the passenger compartment, and / or at least one windshield defrosting opening, which, when installed in the vehicle, faces the relevant vehicle windshield and can extend along its length, can be provided for air to escape from the above cover plate. Alternatively, a projection unit without a cover plate is also possible, in which case the aforementioned openings are omitted. Alternatively or additionally, an outer housing can be provided that at least partially surrounds the projection unit and whose outlet-side section can optionally form the aforementioned cover plate, wherein at least one fresh air duct is formed in the outer housing for drawing in fresh air from the outside. When the projection unit is installed in the vehicle, the at least one fresh air duct can, for example, be located at a suitable position in the windshield base area and / or in the front of the vehicle, suitable for supplying or drawing in clean fresh air for the passenger compartment. In particular, the fresh air ducts, but also the windshield defrost openings and / or exhaust openings, can be equipped with electrically and / or manually controlled opening valves, depending on the situation, in order to adapt the airflow conveyed by the light arms to, for example, a current need and / or a current driving situation. The design and mutual arrangement of the at least one fresh air duct and the at least one window defrosting opening and / or the at least one outlet opening can be designed in such a way that the fresh air drawn in from outside is guided past the at least one rotary drive and thereby heated before flowing out through the at least one window defrosting opening and / or through the at least one outlet opening. The aforementioned field-of-view display device comprises, in addition to the projection unit, a reflective disc, which can be formed, for example, by a vehicle window or designed as a separate combiner disc. The reflective disc is positioned in the beam path of a light beam emitted by the projection unit. It is reflective on the user side and can be at least partially transparent to the ambient light incident from behind, so that the virtual image is superimposed on the real environment observed by the user through the reflective disc. The reflective disc is positioned and designed within the user's field of view such that it reflects the light beam into an eyebox predetermined for the user's eyes, thus making the display content appear as a virtual image behind the reflective disc.In particular, the above row extension direction of the individual rows of the circular display area sections can be aligned along or substantially parallel to a disk root of the reflective disk, especially the vehicle windshield. This makes a panoramic virtual display possible. According to another aspect, a vehicle, for example a motor vehicle or any other land, air, or watercraft, is defined. It has a passenger compartment and a vehicle window that at least partially delimits it externally. The vehicle window can be, for example, a windshield with an instrument panel located below it, or a rear window with a parcel shelf located below it, which delimits the passenger compartment longitudinally to the front or rear of the vehicle. All spatial orientation terms used herein, such as "horizontal," "vertical," "above," "below," "underneath," "front," "rear," "left," "right," etc., refer to the usual vehicle-fixed Cartesian coordinate system with mutually perpendicular longitudinal, transverse, and vertical directions of the vehicle.Furthermore, the vehicle includes the above-mentioned field-of-view display device, the projection unit of which is arranged in the passenger compartment, in particular in or under an upper part of the instrument panel or parcel shelf, and the reflection disc of which is designed as part of the vehicle window or as a separate combiner disc arranged in the passenger compartment. 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 image-generating 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 transverse extent, serves as a reflective surface for the field-of-view display device. This makes a panoramic virtual display for the driver and / or front passenger possible. The above aspects of the invention and its embodiments and specific configurations are explained in more detail below with reference to examples shown in the accompanying drawings. While some of the schematic drawings can be understood as being to scale, this is not a limitation. They show: Fig. 1 a section of a vehicle with a field-of-view display device according to an embodiment of the invention in a vertical longitudinal section; Fig. 2 a top view of an imaging display surface of the field-of-view display device of Fig. 1, which comprises seven circular display surface sections arranged one above the other in two parallel planes; and Fig. 3 a top view of another example of the imaging display surface of the field-of-view display device of Fig. 1, which comprises four circular display surface sections in one plane, the rotating light arms of which also serve as fans for an air conditioning system. All the various embodiments, variants, and specific features of 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 described above, can be implemented in the examples shown in Figures 1, 2 to 3, 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 1-3. Fig. 1 shows a highly simplified schematic representation in a vertical longitudinal section of 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, designed as a head-up display (HUD). The spatial orientation terms used in the description of this and the other examples, such as "horizontal," "vertical," "above," "below," etc., refer to the usual vehicle-fixed Cartesian coordinate system with mutually perpendicular longitudinal, transverse, and vertical directions of the vehicle 1. The field-of-view display device 2 is designed to generate a virtual image V in the field of vision of a user, for example, the driver of the vehicle 1, who is indicated in the vertical longitudinal section view of Fig. 1 only by his eyes 3 and a designated eyebox E in the passenger compartment of the vehicle 1. (As is customary, the eyebox here refers to a spatial area designated for the eyes of a user of the field-of-view display device 2, from which he can see the virtual image V in the intended display quality.) The vehicle 1 is purely an example of a motor vehicle. In Fig. 1, it is indicated solely by its windshield 4, an instrument panel 5 extending below it (not shown in detail), and a headliner 6 extending above it. The field-of-view display device 2 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 desired display content in the direction of the windshield 4, such that the beam of light L is reflected from the windshield 4 to the user's eyebox E, and the virtual image V appears to the user as if floating behind the windshield 4 when looking at it. For this purpose, the projection unit 7 has an image-forming display surface 8 with at least one rotary drive M, the surface of which is arranged in or almost directly below the upper surface of an instrument panel 5 of the vehicle 1 and is shown in more detail in two different examples in Fig. 2 and Fig. 3. The light beam L is indicated solely by its central ray, which leads from the center of the image-forming display surface 8 to the center of the eyebox E. The projection unit 7 can optionally include a cover plate 11, which covers and protects the image-forming display surface 8 from the windshield 4 and allows the light beam L emanating from it to pass through without loss. Fig. 2 shows a top view of a first possible embodiment of the image-forming display surface 8 of the projection unit 7 of Fig. 1. In this example, the image-forming display surface 8 consists of seven purely exemplary circular display surface sections 81-84 and 91-93, which are arranged in two parallel planes (each parallel to the drawing plane), as well as edge areas 12 that complete these to form a rectangular shape. Each circular display area section 81-84, 91-93 is equipped in this example with its own rotary drive M (visible only once in the vertical longitudinal section of Fig. 1) and is formed by four radial light arms 10 spaced 90° apart, which are rotated by the rotary drive M. Each light arm 10 carries light sources, for example LEDs, arranged in a row along its longitudinal direction, which can be controlled independently of one another and synchronously with this rotation to generate the image in the display area 8. The arrangement shown in Fig. 2 comprises four circular display area sections 81-84 positioned in a rear plane and three circular display area sections 91-93 positioned in a front plane, such that the rear display area sections 81-84 and the front display area sections 91-93 overlap. This overlap increases the pixel density of the arrangement. In this example, all circular display area sections 81-84 and 91-93 have the same radius. Their number and size can be selected depending on the size of the desired display area. The circular display area sections 81-84 / 91-93 are directly adjacent to each other in their respective planes and each form a straight row with the row extension direction R. The display area sections 81-84 of the rear plane are offset by a radius length relative to the display area sections 91-93 of the front plane in the row extension direction R.The row extension direction R can run along or nearly parallel to the windscreen 4 (see Fig. 1) or to its windscreen root, for example to enable a panoramic display. The area of ​​the windscreen 4 that can be used as a reflective surface for the field-of-view display device 2 can extend, in particular, from A-pillar to A-pillar, whereby the number and / or size of the circular display area sections 81-84 / 91-93 can also deviate arbitrarily from the example sketched here. In this example, at least some of the display area sections 81-84 / 91-93 are also equipped with Hall sensors for measuring and synchronizing the rotational speed of their light arms 10 (not shown). To minimize the number of Hall sensors required, these are located, in particular, between two display area sections 81-84 / 91-93. The display area sections 81-84 / 91-93 are arranged behind a cover plate 11 (see Fig. 1), which extends over the entire surface of the imaging display area 8, for example, to prevent interference by a vehicle occupant and to allow only the emitted light to pass through in a directed manner. For the display area shown in Fig. 2, which is generated by one LED column per light arm 10, only 7*4=28 LED columns are required in this example. The combined energy consumption of the seven fixed motors together with that of the 28 LED columns is lower than the energy consumption of a conventional display of comparable size with 2-3 million LEDs, which can significantly reduce the greenhouse gas emissions of the vehicle 1 and – if the vehicle 1 has a battery-electric drive – increase its range. Due to the circular shape of the display area sections 81-84 / 91-93, they do not cover the edge areas 12 of the rectangular image-forming display area 8, which are marked in dark in Fig. 2. This loss of display area is acceptable for many applications. Alternatively, the edge areas 12 can be equipped, for example, with microLEDs or with more cost-effective and / or robust light sources, such as warning lights whose shape and color are specifically defined for particular warning or fault indications. Fig. 3 shows a top view of another example of the imaging display surface 8 of the field-of-view display device 2 of Fig. 1, which, purely by way of example, is composed of four circular display surface sections 81-84 in one plane, whereby here too the entire basic arrangement according to Fig. 2 can alternatively be used as a basis. To avoid repetition, only additional features that are added in Fig. 3 compared to Fig. 2 are described below: For an air conditioning concept of the vehicle 1 of Fig. 1, the [missing information] with reference to Fig.The basic arrangement of its projection unit 7 described in Figure 2 is modified as follows so that the rotating circular display surface sections 81-84 simultaneously perform the function of a blower, thus eliminating a corresponding part of the air conditioning system: - the light arms 10 of the circular display surface sections 81-84 are designed like fan blades of a fan wheel, the three-dimensional geometry of which is not shown separately in the top view of Figure 3. In this example, each circular display surface section 81-84 contains six radial light arms 10 spaced 60° apart; - the cover plate 11 facing the passenger compartment has outlet openings 14 for the outflow of air, the position, number, size, and shape of which are only symbolically indicated in Figure 3; - on one side facing the front of the vehicle of a section shown in Figure 3, a light arm 10 is mounted on a circular display surface section 81-84.In the housing of the projection unit 7 (not shown separately), fresh air channels 15 are provided for the supply of fresh air, the position, number, size and shape of which are only symbolically indicated in Fig. 3; on one side of the cover plate 11 facing the windshield 4, a windshield defrosting opening 16 is provided in the form of a channel extending over the entire width of the imaging display surface 8 in the transverse direction of the vehicle 1 for defrosting the windshield 4. Since the rotating circular display sections 81-84 in Fig. 3 also function as a blower, the additional space, material, and energy required for the air conditioning blower of vehicle 1 can be minimized. This results in a saving of installation space, allowing for a smaller instrument panel and / or the creation of additional space for other devices on board vehicle 1. Furthermore, the simultaneous use of the rotating light arms 10 as both blowers and display elements significantly improves the energy efficiency of vehicle 1. Reference symbol list 1 Vehicle 2 Viewfinder 3 User's eye 4 Windscreen 5 Instrument panel 6 Headliner 7 Projection unit 8 Image-forming display surface 81-84 Circular display surface sections of a first level 91-93 Circular display surface sections of a second level 10 Light arm 11 Cover plate 12 Edge area 14 Air outlet openings 15 Fresh air ducts 16 Windscreen defrost openings E User's eyebox L Light beam beam R Row extension direction V Virtual image M Rotary drive

Claims

Viewing display device (2) for use in a vehicle (1), comprising: - a projection unit (7); and - a reflecting disc arranged in the beam path of a light beam (L) emitted by the projection unit (7), which is reflective towards the user and at least partially transparent to the ambient light incident from the rear, such as a vehicle window (4) or a specially provided combiner disc;- wherein the reflective disc is arranged and designed in the user's field of vision such that it reflects the light beam (L) to an eyebox (E) predetermined for the user's eyes (3), thereby making the display content present to the user in the form of a virtual image (V) behind the reflective disc, wherein the projection unit (7) comprises: - an image-forming display surface (8) with at least one rotary drive (M), which is to be arranged in or under a top surface of an instrument panel (5) of the vehicle (1) and is composed of several circular display surface sections (81-84, 91-93) which are arranged in one or more parallel planes and are all offset from one another in a direction orthogonal to their surface normals; wherein - each circular display surface section (81-84, 91-93) is generated by at least one radial light arm (10) which is rotatable by the at least one rotary drive (M) to cover a circular area;and- each luminaire arm (10) carries several light sources arranged in a radial direction, which can be controlled synchronously with its rotation and independently of each other.; Viewing display device (2) according to claim 1, wherein: - all circular display surface sections (81-84, 91-93) have the same radius and are arranged in two parallel planes; - the circular display surface sections (81-84; 91-93) are directly adjacent to each other in the respective plane and form a straight row; and - the rows of the two planes are arranged overlapping each other, wherein the circular display surface sections (81-84) in one plane are offset by a radius length with respect to the display surface sections (91-93) of the other plane in the row extension direction (R). Viewing display device (2) according to claim 1, wherein: - the circular display area sections are arranged in two parallel planes; - the circular display area sections in each plane are arranged in one or more parallel straight rows and are directly adjacent to each other in at least one row; and - the rows of one plane are arranged above the rows of the other plane with such a lateral offset in the row extension direction and / or in a direction orthogonal thereto that the resulting imaging display area (8) is substantially gapless and / or approximates a predetermined surface shape as closely as possible and / or has a minimal overlap of the circular display area sections of the two planes. Viewing display device (2) according to one of the preceding claims, further comprising: - several position and / or rotational speed sensors designed for measuring and / or determining rotational positions and / or rotational speeds of the individual circular display surface sections (81-84, 91-93) and of their illuminating arms (10); - wherein preferably at least one part of these sensors is arranged between each two adjacent circular display surface sections (81-84, 91-93) of a plane and / or between two adjacent planes, such that each such sensor is designed for measuring and / or determining rotational positions and / or rotational speeds of at least two different circular display surface sections (81-84, 91-93). Viewing display device (2) according to one of the preceding claims, wherein the imaging display area (8) additionally comprises at least one edge area (12) which is not covered by the circular display area sections (81-84, 91-93) and has at least one edge display device which is designed and controllable independently of the circular display area sections (81-84, 91-93); and preferably at least one of these edge display devices is equipped with robust warning lights and / or is configured to display safety-relevant information. Viewing display device (2) according to one of the preceding claims, further comprising: - a cover plate (11) which extends along the imaging display surface (8) in the beam path of a light beam (L) emanating from it and is designed to allow the light beam (L) to pass through essentially without loss and to at least partially close off and protect the projection unit (7) to the outside. Viewing field display device (2) according to one of the preceding claims, wherein the luminous arms (10) of at least some of the circular display surface sections (81-84, 91-93) are designed as fan blades of a fan wheel and thus for simultaneous use as a blower of an air conditioning system during operation of the projection unit (7). Viewing display device (2) according to claims 6 and 7, further comprising: - at least one outlet opening (14) and / or at least one windscreen defrosting opening (16) in the cover glass (11), each designed to allow air to flow out; and / or - an outer housing that at least partially surrounds the projection unit (7) and whose outlet-side section is formed by the cover glass (11), wherein at least one fresh air channel (15) is formed in the outer housing for drawing in fresh air from the outside;- wherein the design and mutual arrangement of the at least one fresh air duct (15) and the at least one windscreen defrosting opening (16) and / or the at least one outlet opening (14) are preferably such that fresh air drawn in from the outside is guided past the at least one rotary drive (M) and thereby heated before flowing out through the at least one windscreen defrosting opening (16) and / or through the at least one outlet opening (14). Vehicle (1) with mutually perpendicular longitudinal, transverse and vertical directions of a vehicle-fixed Cartesian coordinate system, in particular a motor vehicle, comprising: - a passenger compartment and a vehicle window that at least partially delimits it externally, in particular a windshield (4) with an instrument panel (5) arranged below it; and - a view indicator device (2) according to one of claims 1 to 8, 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 projection unit (7) and its imaging display surface (8) are preferably arranged in or below an upper surface of the instrument panel (5) such that the windshield (4) serves as a reflection disc of the view indicator device (2) at least with a large part of its extent in the transverse direction of the vehicle.

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