Manipulation of pixel density and other energy saving measures for head-up displays with rotating display devices

Abstract

The invention relates to a method for operating a field-of-view display device which is designed to gradually display a virtual image by reflection on a reflective glass, in particular a window glass, arranged in the field of view of at least one user, wherein the imaged display surface comprises at least one rotary drive and consists of a plurality of circular display surface sections, which lie in one or more parallel planes and are offset from one another in a direction perpendicular to the surface normal thereof; -each circular display face section is produced by at least one radial illumination arm, which is rotated by at least one rotary drive in order to cover the circular surface; -each lighting arm carries a plurality of light sources arranged one above the other in the radial direction, which are rotationally synchronized therewith and are actuatable independently of one another; and-the actuation of the at least one rotary drive and the light source comprises one or more predetermined energy-saving measures in accordance with one or more predetermined operating parameters in the event of generating the image.

Description

TECHNICAL FIELD

[0001] The invention relates to a method for operating a field-of-view display device, which is also known by the name head-up display (HUD) and which can be used in particular in a motor vehicle or other land vehicle, aircraft or watercraft. Field-of-view display devices of this type are configured for producing a virtual image which is gradually displayed into the field of view of at least one user by reflection on a window pane or a combination pane set for this purpose. The invention also aims at a correspondingly embodied projection unit, a field-of-view display device comprising the projection unit and a vehicle equipped with the field-of-view display device. BACKGROUND

[0002] It is known in particular for motor vehicles to overlap display content, such as explanations about speed limits or other useful navigation and vehicle operation instructions, in the form of a virtual image with the real environment image observed by the driver in front of the vehicle, by means of a head-up display (HUD), whereby the driver does not have to divert his gaze from the road in order to read the display. In the classic construction, the HUD comprises for this purpose a projection unit which is arranged in the interior of the dashboard. The projection unit typically comprises a display for generating a light beam with the desired display content and imaging and projection optics, mostly with a concave mirror, in order to form the light beam and deflect it onto the windshield in such a way that the light beam is reflected by the windshield to the eyes of the driver and the driver can thus see the virtual image in the appropriate size and distance. Naturally, the size of the concave mirror scales linearly with the size of the virtual display area, which greatly limits it.

[0003] As an alternative to this, and thus for applications which require a significantly larger virtual display area, a HUD construction is known which comprises a large-area display which extends in the upper side of the dashboard directly opposite the windshield. This is in particular considered for future fully automated or self-driving vehicles, which are supposed to cope without user input for guiding the vehicle, so that the importance of the entertainment system in the passenger compartment is increasing. It is for example intended that a virtual image of this type of HUD is gradually displayed on the entire width of the windshield and can also display a continuous panorama, depending on the external environment, for the driver and / or co-driver of the vehicle and situationally and in accordance with additional information. For this purpose, the display which generates the image must extend over the entire width of the windshield.

[0004] In order to meet the high intensity requirements for the display light in the case of reflection in the transparent area of the windshield on bright days, LED displays are better suited than liquid crystal displays in which a high intensity loss in the liquid crystal layer is unavoidable. However, for such a large display surface an excessively large number of LEDs (several million) is necessary, which in turn greatly influences the energy balance of the vehicle and the associated greenhouse gas emissions. Thus, the possible display size for a panorama display is 1200 mm (length) x 300 mm (width) in a 4:1 ratio. In the case of the application of a conventional display, approximately 2 million LEDs are necessary for this. These LEDs are arranged next to one another in approximately 1920 columns over the width of the HUD display. These large numbers of LEDs would result in greenhouse gas emissions of more than 1.2 carbon dioxide equivalents.

[0005] In the prior art, rotating display devices are known, for example for the design and toy articles or greeting cards, which have a circular display surface that can be generated by rotation, as described, for example, in the documents US 9,190,028 B2 or EP 4 030 412 A1. Such rotating display devices comprise a stationary motor, on the motor shaft of which a rotating unit is fastened, so that the rotating unit is rotated by the motor. The rotating unit is designed as at least one rod-shaped, radially arranged lighting arm, on which a LED strip is fastened in the longitudinal direction. In order to synchronize the LED drive with the rotation of the lighting arm, a suitable rotation or position sensor is provided. The known circular display devices can comprise, depending on the embodiment, for example, only one radial lighting arm, two individual radial lighting arms spaced 180° apart, or four individual radial lighting arms spaced 90° apart from one another. SUMMARY

[0006] It is the task of the present application to propose an alternative and / or improved construction and operating concept for a field of view display device, with which it is also possible to generate large-area virtual images, for example for a panorama display. In particular, the field of view display device should be suitable for integration in a vehicle and for a virtual display by reflection on the windshield of the vehicle.

[0007] This task is solved by the method for operating a field of view display device according to claim 1, the corresponding projection unit according to the attached claims, and the field of view display device and the vehicle equipped with the field of view display device comprising the projection unit. Further design options are proposed in the dependent claims. All further features and effects described in the claims and the subsequent description for the method also apply to the projection unit, the field of view display device and the vehicle and vice versa.

[0008] According to a first aspect, a method for operating a field-of-view display device is provided, which can in particular be configured for use in a vehicle. The field-of-view display device is configured for gradually displaying a virtual image into the field of view of at least one user by reflection on a reflective glass, in particular a vehicle window, arranged in the field of view. The field-of-view display device can for example be configured as a head-up display (HUD).

[0009] Furthermore, the field-of-view display device comprises a projection unit which is designed to generate a light beam having a desired display content during operation of the field-of-view display device and to project it onto the reflective glass and thus to display the desired virtual image to the user. The user can in particular be a driver and / or a co-driver, but can also be another passenger of the vehicle.

[0010] Furthermore, the field-of-view display device comprises an imaged display surface which can be designed in particular for being arranged in or below the upper side or the headliner of the dashboard of the vehicle. The imaged display surface is equipped with at least one rotary drive and consists of a plurality of circular display surface segments which can be generated by rotation, here also referred to as "rotating display device", which lie in one or more parallel planes. In order to realize a respectively specifically predetermined, for example almost rectangular, display surface, all circular display surface segments are offset to each other with or without overlap in a direction perpendicular to their surface normal.

[0011] Here each circular display surface segment is generated during operation of the field-of-view display device by at least one radial illumination arm, which is in addition rotated by at least one rotary drive. For example, each circular display surface segment can be equipped with its own rotary drive, for example in the form of a small electric motor. This is however not mandatory, in particular because a plurality of circular display surface segments can in addition or even should be rotated synchronously in the case of the generation of an image.

[0012] On each illumination arm a plurality of light sources, for example LEDs, are fastened which are arranged in the radial direction from each other, are synchronized with the rotation of the illumination arm and are controllable independently of each other in order to generate a desired image in the imaged display surface. Here a single circular display surface segment can in particular be generated by a unique or a plurality of radial illumination arms, which can in particular be fastened radially symmetrically, i.e. at the same angular interval from each other, on a rotating rotary drive shaft. Such a circular display surface segment can comprise for example a unique radial illumination arm, two radial illumination arms which are spaced 180° apart, or four radial illumination arms which are spaced 90° apart from each other, or six radial illumination arms which are spaced 60° apart from each other, depending on the embodiment. Even here the LEDs are mentioned as the above-mentioned light sources below purely by way of example, but are not to be understood as limiting. Rather, instead of LEDs every other suitable type of light source can in principle be used.

[0013] The drive of at least one rotary drive and the light source in the case of the generation of an image comprises one or more predetermined energy-saving measures in accordance with one or more predetermined operating parameters.

[0014] The concept of the method is on the one hand that a large-area image-generating display surface with very high illumination intensity if required, such as the illumination intensity is required for example for a virtual display of a panorama or for the playback of a video film, is replaced by a plurality of rotary display devices of the initially mentioned type. The number of installed LEDs can thereby already be reduced so significantly that despite the increased consumption of rotary drives, a substantial reduction in the energy balance of the vehicle and in turn also a substantial reduction in the greenhouse gas emissions and, if the vehicle comprises a battery electric drive, a correspondingly greater range can be achieved. Furthermore, the display surface is easily scalable by adding further circular display surface segments and can thus be flexibly adapted to the optical and geometric requirements of different applications.

[0015] A further concept is that the pixel density and thus the resolution of the virtual image in operation is always adapted to the current requirements. In contrast to conventional display surfaces, which have a fixed number of pixels and pixel density, this construction of the imaging display surface, i.e. provides a unique flexibility in operation with regard to the pixel density. By suitable drive of at least one rotary drive and the light source in the case of the generation of an image, the pixel density can be manipulated in such a way that it can be optimized in real time and thus again greatly reduce the energy consumption of the construction.

[0016] As mentioned above, the rotary illumination arms of adjacent circular display surface segments can be arranged in one or two planes in such a way that their display areas overlap. This can be used to increase the frame rate (Frames per Second, FPS) in the overlapping area and / or in combination with a corresponding arrangement of the LED strips for increasing the pixel density.

[0017] Furthermore, for energy saving, the rotary drives and light sources of the rotary illumination arms in currently unused display areas can be deactivated. Thus, if no passenger is seated on the co-driver side, the display on the right half of a panoramic HUD is not necessary, for example. The occupancy of the respective user position can be detected, for example, by interior space cameras and / or pressure sensors on the seat / position.

[0018] If the field of view display device currently only shows static or graphically very simple symbols, such as navigation arrows or warning indications during a manually controlled driving mode, for example, the rotary illumination arms in one of the two overlapping planes can be deactivated. Furthermore, the number of revolutions of the rotary display devices involved can be reduced in accordance with the source of the display content and their light source strips can be partially deactivated. Last but not least, the energy recovery of at least one of the rotary display devices at the end of the operation can be possible.

[0019] Thus, the operating parameters used in the method for determining suitable energy-saving measures can comprise, for example, the following:

[0020] - the number of users and / or the respective position in relation to the reflective glass in the spatial area set for this purpose, in particular the seat occupancy of the seats set for this purpose; and / or

[0021] - the temporal data rate and / or the spatial resolution of the display content to be displayed; and / or

[0022] - the maximum data rate of the data source providing the display content to be displayed, in particular of the (rearview) camera; and / or

[0023] - the presence of a predetermined driving mode of the vehicle, in particular a manual control or fully automated or autonomous driving mode or the presence of a parking state, in which the field-of-view display device is integrated.

[0024] Thus, for example in the case of a recognized manual driving mode, it is possible to focus on the smallest possible distraction of the driver and to display warnings and driving instructions, such as speed instructions and navigation aids, separately for the driver and with a relatively low resolution. For this purpose, only a small part of the maximum available temporal and spatial resolution capability of the imaged display surface is required, so that energy can be saved by the corresponding measures proposed below. If, for example, entertainment content, such as a video game or a film with high image quality, is presented to one or more passengers in an autonomous driving or stopped vehicle, this is different. For this purpose, the entire imaged display surface with its maximum luminous intensity and resolution can be used for producing a large virtual screen. In particular, the intensity of the individual light sources can also be adapted individually in accordance with the same operating parameters.

[0025] The energy-saving measures can thus comprise, for example, one or more of the following measures:

[0026] - determining the currently unneeded sub-surface of the imaged display surface in accordance with the above-mentioned operating parameters and switching off the lighting arm rotation and / or the light sources in this sub-surface, so that this sub-surface remains completely unlit. Thus, for example, a circular display surface section completely contained in the currently unneeded sub-surface can be switched off completely and thus can require no energy at all. In the case of a circular display surface section that is only partially unneeded, in contrast, the lighting arm rotation can continue to run without interruption and only the light sources in the unneeded sub-area can be switched off.

[0027] - reducing the spatial and / or temporal resolution by switching off the lighting arm rotation and / or the light sources for a circular display surface section that almost completely overlaps with other still switched-on circular display surface sections in the case of the production of an image in at least one section of the imaged display surface.

[0028] - in the case of the generation of an image in at least one section of the imaged display surface, by correspondingly reducing the rotation rate of the illumination arms and / or the number of switched-on light sources in at least some of the display surface sections of the circular display surface section in the surface section in order to reduce the spatial and / or temporal resolution.

[0029] - in the case of at least one of the rotating display devices being switched off or braked, recovering the rotational energy of the illumination arms.

[0030] According to one embodiment form, the individual rotating display devices can be mechanically coupled to one another, so that for these coupled rotating display devices only one common electrical drive is necessary. Furthermore, according to an extension of this embodiment form it is possible for the individual rotating display devices to be coupled and uncoupled automatically depending on the operating parameters described above, in order to enable the adaptation of the display as described here. In other words, in this embodiment form the rotating drive shafts of all or some of the circular display surface sections are couplable and uncouplable or permanently mechanically coupled to one another, so that they are rotated by a unique common rotating drive. The coupling is for example realizable by a common drive belt, which extends over the plurality of circular display surface sections or their rotating drive shafts and drives them here synchronously.

[0031] By the mechanical coupling of the individual rotating display devices the number of necessary electrical drives for the arrangement can be reduced. Furthermore, the coupled rotating display devices are automatically synchronized in their number of revolutions, so that the number of position sensors described further below can be reduced. In this way the energy balance of the arrangement can be improved overall and - if the vehicle comprises an electrical battery drive - the range can be increased.

[0032] According to one embodiment form, the imaged display surface comprises at least one row of circular display surface sections lying in one plane, which all have the same radius and which are each staggered from one another by a radius length along the arrangement direction. Here, the illumination arms of the respective overlapping circular display surface sections of the row are rotated so synchronously that the illumination arms always interleave contactlessly with one another. In other words, in this embodiment form the overlapping display devices rotate like contactlessly interlaced gears.

[0033] According to another aspect there is provided the above-mentioned projection unit, which furthermore comprises a control unit, which is constituted and set up for automatically carrying out the method presented here. Furthermore, for example a corresponding computer program (software) can be loaded in the processor of the control unit and this computer program can be run in the case of the field of view display device being operated.

[0034] The individual circular display surface sections of the imaged display surface can, but must not, be constructed identically to one another. Rather, their design can change, for example, with the requirement for a change in the display characteristics (such as intensity, color, resolution, contrast, etc.) of the display content along the combined display surface, in order to thereby also meaningfully save resources at the construction level. The resolution for each circular display surface section can thus be influenced, for example, by the number and size of the LEDs installed therein. The displayable color space can furthermore be influenced by the construction type and the driving of the LEDs. The construction type and the driving of the LEDs furthermore influence the frame rate, which is furthermore produced by the number and the mutual arrangement of the lighting arms and the number and arrangement of the LED strips installed thereon. The number and arrangement of the LED strips furthermore influence the displayable pixel density. In the case of a unique radial lighting arm, the fixed rotary drive or motor of the circular display surface section must be rotated maximally quickly in order to achieve the desired frame rate. Furthermore, rotational uniformity can be caused by one-sided loading. The same frame rate can be achieved with two radial lighting arms (i.e. double arms) in the case of half the rotational speed of the fixed rotary drive / motor, only a quarter thereof is necessary in the case of four radial lighting arms (i.e. two double arms), and only a sixth thereof is necessary in the case of six radial lighting arms (i.e. three double arms). In contrast, a plurality of lighting arms carry a plurality of LEDs, which overall leads to a higher weight, so that a more powerful motor, which is larger and heavier and requires a higher supply voltage, is necessary if possible. These boundary conditions must be taken into account in the design of the circular display surface sections of the imaged display surface.

[0035] According to one embodiment, all of the circular display surface sections of the imaged display surface have the same radius and are arranged in two parallel planes. Here, the circular display surface sections in the respective plane directly adjoin one another and form a straight-line arrangement. The two planes are arranged directly on top of one another, i.e. overlapping one another, so that their arrangement extension directions exactly overlap. Here, the circular display surface sections in one plane are staggered by one radius length in the arrangement extension direction with respect to the display surface sections of the other plane, which results in a minimum overlap and / or a gap-free and, in terms of area, best-approximated rectangular imaged display surface. In other words, thereby an almost rectangular imaged display surface can be achieved, which has a face coverage by the rotating lighting arms of the individual circular display surface sections as uniform as possible and which has a face section with the smallest edge region that is not covered by a circular display surface section.

[0036] More generally, the circular display face segments can be arranged in two parallel planes and in each plane in one or more parallel straight-line arrangements. Here, the circular display face segments in at least one of these arrangements can also directly adjoin one another, which, however, is not mandatory. Here, the arrangements of one plane are arranged above the arrangements of the other plane with such lateral offset along the arrangement extension direction and / or in a direction perpendicular thereto, so that the resulting imaged display face is as free of gaps as possible and / or as good an approximation as possible to the predetermined face shape and / or has a minimum overlap of the circular display face segments of the two planes.

[0037] In particular, the projection unit can also comprise a plurality of position and / or revolution sensors which are configured for measuring and / or determining the rotational position and / or the number of revolutions of the respective circular display face segment and its illumination arm. Here, in particular at least some of these sensors can be arranged between each two adjacent circular display face segments of one plane and / or between two adjacent planes, so that each such sensor can be used to measure and / or determine the rotational position and / or the number of revolutions of at least two adjacent / different circular display face segments, in order to reduce the total number of sensors. Also in the above-mentioned implementation form with mechanically coupled rotating display devices some of the other necessary sensor mechanisms can be dispensed with.

[0038] In particular, the imaged display face can additionally comprise at least one edge region which is not covered by the circular display face segments and has at least one edge display device which is independently configured and controllable from the circular display face segments. This edge display device is not co-rotating, but rather stationary relative to the projection unit. This edge display device is in particular suitable for displaying safety-relevant information, such as warning indications, etc., and can be specifically set up for this purpose and, for example, additionally equipped with particularly robust and less prone to operating errors light fixtures, for example in the form of particularly pre-fabricated warning lights. The edge region and / or the edge display device configured therein can in particular supplement the face covered by the circular display face segments to the predetermined display face shape, such as a rectangle, etc.

[0039] Furthermore, the projection unit can comprise a cover plate which extends along the imaged display face in the light path of the light beam output by the projector and is configured such that the light beam passes through it substantially without loss and here at least partially closes and protects the projection unit outwardly. The cover plate can also serve to prevent vehicle occupants from entering the rotating illumination arms, and can optionally be equipped with additional mechanical and / or optical functions. The cover plate can be made of any material suitable therefor, for example from glass or transparent plastic, such as plexiglass, etc.

[0040] According to another aspect, the above-described field-of-view display device is provided, which comprises, in addition to the above-described projection unit, a further above-described reflection glass, which can be formed, for example, by a vehicle window or be configured as an additionally provided combination glass. The reflection glass is arranged in the light path of the light beam output by the projection unit. The reflection glass is reflective on the user side and can be at least partially transparent, in particular to ambient light incident from the rear side, thereby enabling the virtual image to be superimposed on the real environment observed by the user through the reflection glass. Here, the reflection glass is arranged in the field of view of the user and configured such that it reflects the light beam to a predetermined eye box for the user's eye, thereby enabling the user to be shown the display content in the form of a virtual image on the other side of the reflection glass.

[0041] In particular, the above-described arrangement extension direction of the individual arrangements of the circular display face sections can here be oriented along or substantially parallel to the glass root of the reflection glass, in particular of the vehicle window. Thereby, in particular a panoramic virtual display can be realized.

[0042] According to another aspect, a vehicle, for example a motor vehicle or any other land vehicle, an aircraft or a watercraft, is provided. The vehicle has a passenger compartment and a vehicle window which at least partially delimits the passenger compartment to the outside. The vehicle window can be, for example, a windshield with a dashboard arranged thereunder or a rear window with a headliner arranged thereunder, which delimits the passenger compartment in the longitudinal direction of the vehicle to the front or to the rear. All spatial directional terms applied here, such as "horizontal", "vertical", "above", "below", "under", "in front of", "behind", "to the left", "to the right", etc., relate here to a generally vehicle-fixed Cartesian coordinate system comprising a longitudinal, a transverse and a height direction of the vehicle, which are perpendicular to one another. Furthermore, the vehicle comprises the above-described field-of-view display device, the projection unit of which is arranged in the passenger compartment, in particular on the upper side of the dashboard or in or under the headliner, and the reflection glass of which is configured as part of the vehicle window or as an additionally provided combination glass in the passenger compartment.

[0043] In particular, the windshield can be delimited in the horizontal direction to the left and to the right each by an A-pillar of the vehicle and the projection unit and the display face imaged thereby are arranged in or under the upper side of the dashboard in such a way that the windshield serves as reflection glass of the field-of-view display device at least with a large part of its horizontal extension. Thereby, in particular a panoramic virtual display is realizable for the driver and / or the front-seat passenger. BRIEF DESCRIPTION OF DRAWINGS

[0044] The above-mentioned aspects of the application and embodiments and particular designs thereof are further explained below on the basis of examples shown in the drawings. The drawings, which can also be partly understood as being to scale, are not limiting. The drawings show:

[0045] Figure 1Part of a vehicle with a field-of-view display device according to an embodiment in vertical longitudinal section;

[0046] Figure 2 : Figure 1 Top view of an imaged display surface of a field-of-view display device according to an embodiment, comprising seven identical, rotated display devices stacked in two parallel planes;

[0047] Figure 3 : Figure 1 Top view of another example of an imaged display surface of a field-of-view display device according to an embodiment, comprising seven identical, each overlapping one radius length, rotated display devices in one plane, whose rotated illumination arms rotate past each other without contact;

[0048] Figure 4 a-4c: Figure 3 Three vertical cross-sectional views of two adjacent display devices according to an embodiment for further elucidating their mutual arrangement.

[0049] All further different embodiments, variants and specific design features of the operating method according to the above-mentioned aspects of the application, respectively the projection unit, the field-of-view display device and the vehicle set up accordingly, mentioned in the description above and in the following claims can be realized in the examples shown in Figures 1 to 4 c, in particular also alternatively or additionally to the features shown therein. Therefore not all of them will be repeated hereinafter. The same applies accordingly to the further above-mentioned term definitions and effects with respect to the individual features shown in Figures 1-4 c. DETAILED DESCRIPTION

[0050] Figure 1 A part of a vehicle 1 with a field-of-view display device 2 according to an embodiment of the application is shown in a vertical longitudinal section in a highly simplified schematic view. The field-of-view display device 2 is here purely exemplarily constituted as a head-up display (HUD). The spatial directional terms like "horizontal", "vertical", "above", "below", etc. applied in the description of this and further examples refer here to a usual vehicle-fixed Cartesian coordinate system comprising a longitudinal, a transversal and a height direction of the vehicle 1 perpendicular to each other.

[0051] The field-of-view display device 2 is constituted for generating a virtual image V in a field-of-view of at least one user, e.g. a driver of the vehicle 1, who is Figure 1in a vertical longitudinal section only by its eyes 3 and an eye box E determined for this in the passenger compartment of the vehicle 1. (As is usual, the eye box is understood here as a spatial region determined for the eyes of a user of the field-of-view display device 2 from which the user can see the virtual image V in the set display quality) The vehicle 1 is purely exemplarily a motor vehicle. The vehicle is indicated in Figure 1 in a vertical longitudinal section only by its windshield 4, a dashboard 5 extending thereunder and not further represented, and a roof 6 extending thereover.

[0052] The field-of-view display device 2 comprises a projection unit 7, which in this example is arranged in the dashboard 5 under the windshield 4. The projection unit 7 is constituted and arranged for generating and outputting a light beam L with a desired display content in the direction of the windshield 4, so that the light beam L is reflected from the windshield 4 to the respective user eye box E and thereby appears to the user as a virtual image V as if floating in front of the vehicle 1 when looking towards the windshield 4.

[0053] The projection unit 7 furthermore has an imaging display surface 8 comprising at least one rotary drive M, the imaging display surface being arranged with its face in or almost directly under the upper side of the dashboard 5 of the vehicle 1 and in Figure 2 and Figure 3 is further shown in two different examples. The light beam L is indicated solely by its central beam, which leads from the center of the imaging display surface 8 to the center of the eye box E. The projection unit 7 can optionally comprise a cover plate 11, which covers and protects the imaging display surface 8 towards the windshield 4 and so that the light beam L output thereby passes here almost loss-free.

[0054] Figure 2 A first possible design of the imaging display surface 8 of the projection unit 7 is shown in a plan view. Figure 1 In this example, the imaging display surface 8 consists of purely exemplarily seven circular display surface segments 81-84 and 91-93, which are arranged in two parallel planes (each parallel to the drawing plane), as well as these complementing edge regions 12 of rectangular shape.

[0055] Each circular display surface segment 81-84, 91-93 can in this example be equipped with its own rotary drive M (visible only once in a vertical longitudinal section of Figure 1 and is formed by four 90°-spaced radial illumination arms 10, which are rotated by the respective rotary drive M. Alternatively, the rotary drive shaft 14 of at least some of these circular display surface segments 81-84, 91-93 (visible only once in a vertical longitudinal section of Figure 4The illumination arms 10 (shown in a-c) can be permanently or couplable and detachable mechanically coupled to one another, for example by a common drive belt coupling, so that they rotate synchronously based on the coupling. In this case, the number of necessary rotary drives is correspondingly reduced. Each illumination arm 10 carries light sources, for example LEDs, which are arranged along its longitudinal direction independently of one another and synchronously with the rotation for the purpose of generating an image in the imaged display surface 8.

[0056] In Figure 2 The structure shown in is composed of four circular display surface segments 81-84 located in the rear plane and three circular display surface segments 91-93 located in the front plane, so that the rear display surface segments 81-84 and the front display surface segments 91-93 overlap. The pixel density of the arrangement is increased by this overlap. All circular display surface segments 81-84, 91-93 have the same radius in this example. The number of display surface segments and their size can be chosen according to the size of the display area desired. The circular display surface segments 81-84 / 91-93 here adjoin one another directly in the respective plane and each form an arrangement with straight lines in the arrangement extension direction R. The display surface segments 81-84 of the rear plane are here staggered by one radius length in the arrangement extension direction R with respect to the display surface segments 91-93 of the front plane. The arrangement extension direction R can extend along or almost parallel to the windshield 4 (see Figure 1 ) or parallel to its windshield root, in order to be able to achieve a panoramic display, for example. The face section of the windshield 4 that can be used as a reflection glass for the field of view display device 2 can here be extended in particular from A-pillar to A-pillar, wherein the number and / or size of the circular display surface segments 81-84 / 91-93 can also arbitrarily differ from the example outlined here.

[0057] In at least some of the display surface segments 81-84 / 91-93 are in addition located in this example Hall sensors for measuring and synchronizing the number of revolutions of the illumination arms 10 of the display surface segments (not shown). In order to apply as few Hall sensors as possible, these are in particular each located between two display surface segments 81-84 / 91-93. The number of sensors required can in addition be reduced by the above-mentioned mechanical coupling of the individual display surface segments 81-84 / 91-93 to one another. The display surface segments 81-84 / 91-93 are provided behind a cover plate 11 (see Figure 1 ) that extends over the entire face of the imaged display surface 8 in order to prevent, for example, the entry of vehicle passengers and to only allow the emitted light to pass through directionally.

[0058] For the display surface segments 81-84 / 91-93 shown in Figure 2The display area shown—generated by one LED column for each of the lighting arms 10—in this example requires only 7*4=28 LED columns. The total energy balance of the seven fixed motors along with the 28 LED columns is less than that of a relatively large conventional display with 2-3 million LEDs, which significantly reduces greenhouse gas emissions from vehicle 1 and—if vehicle 1 includes a battery-powered drive—can increase its driving range. Furthermore, the energy-saving measures presented herein allow energy consumption to be flexibly adapted to the respective current operating parameter values, thereby further greatly reducing energy consumption.

[0059] Based on the circular shape of the display face segments 81-84 / 91-93, which do not cover the rectangular imaging display surface 8, Figure 2 The edge area 12 is marked with a dark symbol. This loss of display surface is acceptable for a variety of applications. Alternatively, the edge area 12 may be equipped with, for example, μLEDs (micro light-emitting diodes) or more advantageous and / or robust luminaires, such as warning lights, whose shape and color are specifically determined for a particular warning or fault display.

[0060] Figure 3 Show Figure 1 Another example of a top view of the imaged display surface 8, which is consistent with... Figure 2 The only difference in the arrangement is that all seven circular display face segments 81-84 / 91-93 are located in a common plane. Here, the lighting arms 10 of the adjacent, overlapping display face segments 81-84 / 91-93 are arranged in a gear-like and non-contact manner, and are rotated synchronously with each other, so that the lighting arms will not collide with each other.

[0061] Figure 4 a-4c are each shown in a vertical cross-section. Figure 3 Two adjacent rotating display devices 81 and 91, which are in Figure 4 The exploded view of a shows the rotational drive shafts 14 spaced apart, for example, by double the intervals. Figure 4 b and 4c correspond to according to Figure 3 The arrangement structure of the display devices. For example... Figure 4 As shown in b, the illumination arms 10 of the overlapping rotating display devices 81 and 91 are at the same height in this example, so that the illumination arms can only extend to the rotation drive shaft 14 of the corresponding other display device. Figure 4 The non-contact interlacing of the illumination arms 10 in b is evident from the following: the illumination arm 10 of the rotating display device 91 on the right is located in the plane of the drawing and is therefore shown as a solid line, while the illumination arm 10 of the rotating display device 81 on the left rotates out of the plane of the drawing by approximately 45° at the same time (see Figure 81). Figure 3) and therefore the dashed line shows.

[0062] Figure 4 c shows an expansion, in which at least one illumination arm 10 has a raised illumination arm extension 15, which, due to its heightening, can extend into the area of an adjacent rotary drive shaft 14 and thereby enables additional light sources into this area of the imaged display surface 8, which would otherwise only be covered by the end side of the rotary drive shaft 14. Thereby, a corresponding resolution increase and redundancy with regard to pixel density and light source functionality can also be provided in this area.

[0063] List of reference signs

[0064] 1 vehicle

[0065] 2 field of view display device

[0066] 3 eye of the user

[0067] 4 windshield

[0068] 5 dashboard

[0069] 6 roof

[0070] 7 projection unit

[0071] 8 imaged display surface

[0072] 81-93 circular display surface segments, also referred to as rotating display devices

[0073] 10 illumination arm

[0074] 11 cover plate

[0075] 12 edge region

[0076] 14 rotary drive shaft

[0077] 15 raised illumination arm extension

[0078] E eyebox of the user

[0079] L bundle of light rays

[0080] R arrangement extension direction

[0081] V virtual image

[0082] M rotary drive

Claims

1. A method for operating a field-of-view display device (2), the field-of-view display device being configured to gradually display a virtual image (V) through reflection on a reflective glass, particularly a vehicle window glass (4), disposed in the field of view of at least one user, wherein - The imaging display surface (8) of the field of view display device includes at least one rotary driver (M) and is composed of a plurality of circular display surface segments (81-84, 91-93), which are located in one or more parallel planes and are offset from each other in a direction perpendicular to their surface normals. - Each circular display face segment (81-84, 91-93) is generated by at least one radial illumination arm (10), which is rotated by the at least one rotary driver (M) to cover the circular face; - Each lighting arm (10) carries multiple light sources arranged radially relative to each other, the light sources being synchronized with the rotation of the lighting arm and independently controllable; and - The driving control of the at least one rotary drive (M) and the light source includes one or more predetermined energy-saving measures based on one or more predetermined operating parameters when generating an image.

2. The method according to claim 1, wherein, The one or more predetermined operating parameters include: - The number of users and / or the corresponding positions of users in the space area designated for this purpose relative to the reflective glass, particularly the occupancy of the seats designated for this purpose; and / or - The temporal data rate and / or spatial resolution of the content to be displayed; and / or - Provide the data source for the content to be displayed, especially the camera's maximum data rate; and / or - The presence of a predetermined driving mode of the vehicle (1), particularly a manual control driving mode, a fully automated driving mode, an autonomous driving mode, or a parking state, wherein the vision display device (2) is integrated in the vehicle.

3. The method according to claim 1 or 2, wherein, The one or more predetermined energy-saving measures include: - Identify the currently unwanted sub-surfaces of the display surface (8) of the image and turn off the illumination arm rotation and / or light source for the display surface segments (81-84, 91-93) or their sub-segments contained therein, so that the sub-surfaces remain completely unilluminated; and / or - In the case of generating an image in at least one segment of the imaging display surface (8), spatial and / or temporal resolution is reduced by shutting off the rotation of the illumination arm and / or the light source for the circular display surface segments (81-84, 91-93) that almost completely overlap with the other still-connected circular display surface segments (81-84, 91-93) in that surface segment; and / or -When an image is generated in at least one segment of the display surface (8) of the imaging, the spatial and / or temporal resolution is reduced by correspondingly decreasing the rotation rate of the illumination arm and / or the number of light sources switched on in at least some of the display surface segments (81-84, 91-93) of the circular display surface segments; and / or - The rotational energy of the lighting arm (10) is recovered when at least one of the circular display face segments (81-84, 91-93) is turned off or braked.

4. The method according to any one of the preceding claims, wherein - The rotation drive shafts (14) of at least some of the circular display face segments (81-84, 91-93) are mechanically connected and separable or permanently connected to each other, so that the lighting arms (10) in all the interconnected display face segments (81-84, 91-93) are rotated synchronously by a single common rotation drive (M).

5. The method according to any one of the preceding claims, wherein - The imaging display surface (8) comprises at least one row of circular display surface segments (81-84, 91-93) located in a plane, all of which have the same radius and are staggered from each other by a radius length along their arrangement direction (R); and - The lighting arms (10) of the overlapping circular display face segments (81-84, 91-93) of the row rotate synchronously, so that the lighting arms always intersect each other without contact.

6. A projection unit (7) for a field-of-view display device (2), the field-of-view display device being configured to gradually display a virtual image (V) by reflection on a reflective glass, particularly a vehicle window glass (4), disposed in the field of view of at least one user, comprising: - An imaging display surface (8), including at least one rotary actuator (M), the display surface being configurable on the upper side or lower side of the dashboard (5) of the vehicle (1) and composed of a plurality of circular display surface segments (81-84, 91-93), the display surface segments being located in one or more parallel planes and offset from each other in a direction perpendicular to their surface normals; and - A control unit configured and set up to perform the method according to any one of the preceding claims; -In which each circular display face segment (81-84, 91-93) is generated by at least one radial illumination arm (10), which can be rotated by the at least one rotary actuator (M) to cover the circular face; and - Each lighting arm (10) carries multiple light sources arranged radially to each other, the light sources being synchronized with the rotation of the lighting arm and being independently controllable.

7. The projection unit (7) according to claim 6, wherein, - The circular display face segments (81-84, 91-93) are arranged in two parallel planes; - The circular display face segments (81-84, 91-93) in each plane are arranged in an arrangement of one or more parallel straight lines and are directly adjacent to each other in at least one arrangement; and - The arrangement of the one plane is positioned above the arrangement of the other plane with such a lateral offset along the direction of arrangement extension (R) and / or along a direction perpendicular to it that the resulting display surface (8) of the image is substantially without gaps and / or approximates as well as possible the predetermined surface shape and / or the minimum overlap of the circular display surface segments (81-84, 91-93) with two planes.

8. The projection unit (7) according to any one of the preceding claims further includes: - Multiple position and / or rotation sensors configured to measure and / or determine the rotational position and / or rotation of the rotational drive shaft (14) of each circular display face segment (81-84, 91-93) and the illumination arm (10) of the display face segment; - Preferably, at least a portion of these sensors are disposed between every two adjacent circular display face segments (81-84, 91-93) on a plane and / or between two adjacent planes, such that each such sensor is designed to measure and / or determine the rotational position and / or number of revolutions in at least two different circular display face segments (81-84, 91-93).

9. A field of view display device (2), said field of view display device being particularly used in a vehicle (1), comprising: - Projection unit (7) according to any one of claims 6 to 8; as well as - A reflective glass, particularly a car window glass (4), or an additionally set composite glass, is placed in the optical path of the light beam (L) output by the projection unit (7); - A reflective glass is set and configured in the field of view of at least one user such that the reflective glass reflects the light beam (L) to a predetermined eye box (E) for his / her eye (3), thereby enabling the user to display content in the form of a virtual image (V).

10. A vehicle (1), having mutually perpendicular longitudinal, lateral, and height directions in a fixed Cartesian coordinate system, said vehicle, particularly a motor vehicle, comprising: - Passenger compartment and window glass, the window glass at least partially restricting the passenger compartment outward, the window glass particularly having a windshield (4) with an instrument panel (5) disposed thereunder. as well as - According to claim 9, the field of view display device (2) is provided in the passenger compartment and the reflective glass of the field of view display device is part of the window glass or a combination glass additionally provided in the passenger compartment; - The projection unit (7) and its imaging display surface (8) are preferably disposed on the upper side of the instrument panel (5) or on the upper side below it, such that the windshield (4) serves at least most of its horizontally extending portion as the reflective glass of the field of view display device (2).

Images