Head-up display in which a concave mirror is optimized and / or lowered into the park position by way of an eccentric with a separate drive

Abstract

The invention relates to a projection unit for a field-of-view display device for use in a vehicle, comprising: - an imaging unit for creating a light beam with display content; - a concave mirror arranged and formed in the beam path such that the light beam leaves the projection unit with a predetermined shape and direction in order to subsequently be reflected to the eye box of a user by a partly transparent reflection pane arranged in the field of view of said user and in order to display the display content in the form of a virtual image behind the reflection pane to the user; - wherein, for the purpose of adapting the eye box position and by way of a mirror shaft drive, the concave mirror is rotatable about a mirror shaft fixedly connected thereto, the mirror shaft being rotatably mounted in a primary bearing to this end; and - the primary bearing is mounted off-center in a secondary bearing at at least one end of the mirror shaft, the secondary bearing being drivable to a rotation about its eccentric axis fixed in relation to the projection unit by way of an independently controllable eccentric drive, in order to bring about a translational movement of the mirror shaft and hence of the concave mirror in a direction transverse thereto.

Description

[0001] Description

[0002] Head-up display with concave mirror optimization and / or lowering into the parking position by a self-propelled eccentric

[0003] The invention relates to a projection unit for a head-up display (HUD) device, which is also known as a head-up display (HUD) and can be used in particular in a motor vehicle or other land, air, or water vehicle. Head-up display devices of this type are designed to generate a virtual image superimposed into the user's field of vision via reflection from a vehicle window, in particular a windshield, or from a combiner window provided specifically for this purpose and arranged in the user's field of vision. The invention also relates to such a head-up display device and to a vehicle equipped therewith.

[0004] Particularly in motor vehicles, it is known to use a head-up display to superimpose display content such as information on speed limits or other useful navigation and vehicle operating instructions in the form of a virtual image on the real surroundings in front of the vehicle as observed by the driver, so that the driver does not have to take their eyes off the road to read the display. For this purpose, a HUD comprises a reflective screen arranged in the driver's field of vision, which is largely transparent to the ambient light falling from behind and is designed either as a section of the windshield or as a combiner screen provided inside the vehicle in front of the windshield. To generate the display content, a classic HUD comprises a projection unit located below the windshield inside the instrument panel.This typically includes a display for generating a light beam with the desired display content, as well as suitable imaging and projection optics for shaping the generated light beam and directing it onto the reflection disc so that it is reflected back to the driver's eyes, allowing the driver to see the virtual display image at a suitable size and distance behind the reflection disc. In a classic HUD design, the projection optics include a concave mirror whose dimensions scale linearly with the size of the virtual display area, thus constraining it.

[0005] Implementing such a head-up display in a vehicle is very complex, partly due to space restrictions. A key component of its projection unit is a transparent cover plate (also called cover glass), which closes the protective housing of the projection unit on the output side and transmits the generated light beam. The cover plate should be designed in such a way that no direct or indirect light reflections caused by reflection of outside light, and in particular sunlight, from the cover plate enter the HUD beam path and thus the driver's eye. This results, among other things, in a specific curved cover plate shape for directing disruptive light reflections out of the beam path. This is also referred to as geometric anti-reflection coating and requires a considerable dimension of the cover plate in the vertical direction of the vehicle.When designing the cover screen, influences of the vehicle's installation space, such as its design and package allowance, must be taken into account. Of the internal HUD components, the concave mirror in particular represents a restriction in the cover screen design, as the cover screen must maintain predetermined minimum clearances to the concave mirror in the vehicle's vertical direction.

[0006] When the HUD is not in use, the concave mirror is typically in its parked position, where the vertical distance between the cover plate and the concave mirror is usually at its smallest. The parked position is typically achieved by rotating the concave mirror around its axis of rotation, which moves its focus out of the HUD's beam path to prevent unwanted focusing of external light entering the projection unit onto the light- and heat-sensitive HUD optics and electronics.

[0007] The size of the concave mirror is also influenced by opto-mechanical restrictions. Different drivers sit in different positions in the vehicle depending on their height. To ensure that each driver receives the optimal HUD display and eyebox position, adjustment options are provided, which can also be achieved by rotating the concave mirror around the aforementioned mirror rotation axis. The effectively used concave mirror surface usually differs for different drivers due to different beam paths and the individual eyebox position. To cover all possible seating positions, the concave mirror is therefore usually designed with a larger surface area than would be necessary for a single fixed seating position in the vehicle. The optical performance is optimized by taking into account the various adjustment options of the concave mirror.This usually leads to compromises, since a fixed axis of rotation limits the degrees of freedom for optimization.

[0008] It is an object of the present invention to provide an alternative projection unit for a field of view display device and an associated operating method, which projection unit is improved with regard to installation space, optical performance and / or other aspects and is particularly suitable for use in a vehicle.

[0009] This object is achieved by a projection unit according to claim 1, as well as by a field-of-view display device containing the same, an associated operating method, a correspondingly configured control unit, and a vehicle equipped therewith according to the independent claims. Further embodiments are specified in the dependent claims. All further features and effects mentioned in the claims and the following description for the projection unit also apply to the field-of-view display device, the operating method, the control unit, and the vehicle, and vice versa.

[0010] According to a first aspect, a projection unit for a field of view display device is provided, which can be used in particular in a vehicle. The field of view display device can be designed, for example, as a head-up display (HUD). The vehicle can be a motor vehicle, but also any other land, air, or water vehicle.

[0011] The projection unit has an imaging unit (also called a picture generating unit, PGU) designed to generate a light beam with the desired display content. In principle, any image generation technology suitable for a vehicle can be used for this. This can be a display, such as a flat screen or a waveguide display, but also a projector system, such as a DLP projector or a diffuser illuminated or scanned with a light beam, and many more.

[0012] In the beam path of the light beam generated by the imaging unit, the projection unit (apart from optional additional optical elements for beam shaping and deflection) comprises a concave mirror arranged and configured such that the light beam exits the projection unit in a predetermined required shape and direction. It is then reflected by an at least partially transparent reflection disc arranged in the user's field of vision to their eyebox, thereby presenting the display content to the user in the form of a virtual image behind the reflection disc. The reflection disc can be formed, for example, by a section of a vehicle window or by a specially provided combiner disc.It is therefore a component of the field-of-view display device specified below, but not necessarily a component of the projection unit, which can also be manufactured and sold without the vehicle windshield, for example, when using the windshield. However, in the case of a specially provided combiner screen, this can also be integrated into the projection unit (e.g., even movable) in a known manner. The eyebox of the field-of-view display device is understood here, as usual, to be a two- or three-dimensional spatial area from which the virtual image is fully visible to the associated user.

[0013] To adapt the eyebox to different user sizes and seating positions, the concave mirror can be rotated about a mirror rotation axis by means of a suitable mirror rotation axis drive. The mirror rotation axis is either an integral part of the concave mirror or firmly connected to it in some other way. The mirror rotation axis drive can, for example, be designed in the form of an electric motor or another type of actuator that is connected to the mirror rotation axis for torque transmission, either directly or via a gear. The mirror rotation axis can, for example, be rotatably mounted at each of its two ends in an associated primary bearing. If one of the two ends of the mirror rotation axis is mounted in a primary bearing that is stationary with respect to the projection unit, this end in particular can be suitable for the mirror rotation axis drive. Otherwise, it can, for example, also be integrated into a movably mounted primary bearing.

[0014] At least at one end of the mirror rotation axis, the associated primary bearing is eccentrically mounted in an independently rotatable secondary bearing. In other words, this secondary bearing (also called an eccentric) can be driven for rotation about an eccentric axis that is fixed / stationary with respect to the projection unit by an eccentric drive that can be controlled independently of the mirror rotation axis drive. To transmit torque to the secondary bearing, the eccentric drive can, for example, comprise a driver that is rotated about the eccentric axis by a motor that is decoupled from the mirror axis drive and engages positively with the secondary bearing. Because the drives of the mirror rotation axis and the eccentric are decoupled from one another, the magnitude and / or direction of the applied torque can, for example, be varied independently of one another over time.

[0015] If the secondary bearing is driven to rotate around the eccentric axis, the eccentrically mounted primary bearing also rotates around the eccentric axis. This creates an approximately translational movement of the mirror's rotation axis and thus of the concave mirror in a direction transverse to the mirror's rotation axis. The resulting additional degrees of freedom for adjusting the concave mirror can be used to optimize various aspects of its optical performance, size, and / or fit within the available installation space. Some examples of this optimization are described below. In particular, it can solve problems mentioned at the beginning:

[0016] The movement of the mirror rotation axis, and thus of the concave mirror, caused by the eccentric drive in a direction transverse to the mirror rotation axis can be implemented, for example, by lowering the concave mirror in the vertical direction of the vehicle. This allows the concave mirror to be lowered significantly further to reach the parking position compared to the conventional stationary mounting of the mirror rotation axis, and overcomes the aforementioned space conflict with the cover plate of the projection unit in the parking position. Alternatively or additionally, this transverse movement of the mirror rotation axis can also be used to optimize the optical performance and / or size of the concave mirror during operation of the projection unit, particularly during eyebox adjustment.

[0017] A concrete relationship between the rotation of the secondary bearing and the resulting translational movement of the concave mirror in the direction transverse to its mirror rotation axis can be influenced by specifically selectable design details, such as the radial distance and the angular position of the primary bearing mounted in the secondary bearing.

[0018] The respective primary bearing at one or both ends of the mirror rotation axis can be designed, for example, as a spherical head to enable the greatest possible mobility of the mirror rotation axis. The primary bearing mounted in the secondary bearing can be mounted, in particular also fastened, in a fixed position therein, in particular at a point fixed relative to the secondary bearing at a predetermined radial distance from the eccentric axis. To enable the greatest possible mobility of the mirror rotation axis, the primary bearing in the secondary bearing can, in particular, be mounted with a plain or roller bearing.

[0019] One idea behind the above projection unit is to adjust the concave mirror by eccentrically mounting its mirror rotation axis, which is firmly connected to it and rotatable by a mirror rotation axis drive, in a secondary bearing that is independently rotatable about another axis (eccentric axis) and rotatable by an independently controllable eccentric drive. This can be designed for adjustment of the concave mirror to the aforementioned parking position and / or for user-specific adjustment or eyebox adaptation during operation of the field of view display device, for example, during vehicle operation. This can, in particular, optimize the optical performance of the overall system and / or reduce the installation space required for the field of view display device by minimizing the concave mirror surface and / or by additional lowering or raising or other transverse movement of the rotatable concave mirror.

[0020] Two independently controllable drives allow the adjustment movements (rotations) of the concave mirror around its own mirror rotation axis and around the stationary eccentric axis to be carried out either simultaneously or decoupled in time, particularly sequentially. This makes it possible, for example, to keep the distance between the concave mirror and the cover plate as large as possible during the lowering sequence into its parked position. Furthermore, the adjustment or lowering of the concave mirror into its parked position can be initiated from any operating position of the concave mirror that occurs during operation of the projection unit. Alternatively or additionally, this can also be used to achieve the greatest possible flexibility and precision in adjusting the position and orientation of the concave mirror during eyebox adjustment to the individual position and, if necessary, to the movement of the user during operation.The eyebox adjustment can, for example, be based on eye tracking of the user and thus be completely automated.

[0021] Although the invention is primarily described herein using the example of a one-sided eccentric bearing of the mirror rotation axis (i.e., only at one of its two ends) and thus also a one-sided lowering / raising of the concave mirror, an eccentric adjustment at both ends / bearing points of the mirror rotation axis is also possible according to the same design and functional principle. This can, for example, enable an even greater reduction in the required concave mirror surface and / or even greater optimization freedom in eyebox adjustment and / or an even greater distance of the entire concave mirror from the cover plate in its parked position.

[0022] For example, both the mirror rotation axis drive and the eccentric drive can each comprise their own motor for independent control. Alternatively or additionally, the mirror rotation axis drive and the eccentric drive can comprise a common motor with a coupling that is designed and controlled for alternating, independent control of the mirror rotation axis drive and the eccentric drive using the common motor.

[0023] According to one embodiment, the projection unit further comprises a protective housing that protects the above-mentioned elements of the projection unit from the outside, with a transparent cover plate that closes the housing on the output side and transmits the light beam emitted by the projection unit during operation. A predetermined angular position of the mirror rotation axis allows a parking position of the concave mirror to be set, in which a focus or a main optical axis of the concave mirror lies outside a beam path intended for the operation of the projection unit. In this embodiment, the mirror rotation axis is mounted in the secondary bearing in such a way that when the concave mirror is adjusted from an operating position to its parking position, a rotation of the secondary bearing, which can be generated by the eccentric drive, results in a translational movement of the mirror rotation axis and thus of the concave mirror in a direction away from the cover plate.For a projection unit installed in the instrument panel of a vehicle, this corresponds to a lowering of the mirror's rotation axis in the vertical direction of the vehicle (at least on one side, i.e., occurring at one of its ends). Purely as an example, suitable positions of the primary bearing and a driver of the eccentric drive in the secondary bearing are illustrated in Figure 2.

[0024] The mirror rotation axis and the eccentric axis can, for example, be arranged approximately parallel to one another with a predetermined axial distance from one another. Alternatively, the mirror rotation axis and the eccentric axis can also be arranged offset from one another, in particular with a predetermined minimum distance from one another, so that the two axes do not intersect. In particular, the eccentric axis and an orthogonal projection of the mirror rotation axis onto a plane in which the eccentric axis lies can form an acute angle to one another (which varies during rotation) that is significantly less than 90° and, for example, is always less than 80°, 70°, 60°, 50°, 40°, 30°, or 20°.

[0025] In a specific embodiment, the mirror rotation axis and / or its primary bearing and / or secondary bearing is / are designed with automatic axis length adjustment, so that the length of the mirror rotation axis automatically adapts to a possibly varying distance between the primary bearings at its two ends upon rotation of the secondary bearing. For example, a length-compensating spring mechanism can be provided at one or both ends of the mirror rotation axis, or the mirror rotation axis can be constructed as a telescopic rod consisting of at least two coaxially slidable rod sections, which in turn are pushed apart by a suitable spring mechanism to the available axis length.

[0026] According to a further aspect, a method for operating a projection unit presented herein is provided. As already mentioned above, in this operating method, the mirror rotation axis can be driven by the mirror rotation axis drive, and the secondary bearing can be driven by the eccentric drive, sequentially and / or simultaneously to adjust the concave mirror during operation of the projection unit, in particular to adjust the eyebox position. Alternatively or additionally, as also mentioned above, they can be driven sequentially and / or simultaneously to adjust the concave mirror to its parked position.

[0027] According to a further aspect, a control unit is provided which is designed and configured to automatically execute this method.

[0028] According to a further aspect, a field of view display device, in particular for use in a vehicle, is provided. In addition to the projection unit presented herein, the field of view display device also comprises a reflection plate, in particular a partially transparent one, arranged in the beam path of the light beam emitted by the projection unit. This reflection plate can be designed in particular as a partial surface section of a windshield or another vehicle window of the vehicle, or as a specially provided combiner plate. The reflection plate is arranged and designed in the field of view of a user, for example a driver or another occupant of the vehicle, in such a way that it reflects the light beam to an eyebox predetermined for the user, whereby the display content can be presented to the user in the form of a virtual image behind the reflection plate and is also presented during operation of the field of view display device.In particular, the field of view display device may also comprise the above control unit.

[0029] According to a further aspect, a vehicle, in particular a motor vehicle or any other land, air, or water vehicle, is provided. The spatial orientation terms used herein, such as "above," "below," "in front," "side," "horizontal," "vertical," etc., refer to the usual vehicle-fixed Cartesian coordinate system with mutually perpendicular longitudinal, transverse, and vertical directions of the vehicle.

[0030] The vehicle has a vehicle window that at least partially defines a passenger compartment, in particular a windshield, and is equipped with the above-mentioned field of view display device, the projection unit of which is arranged in the passenger compartment and the reflection disc of which is designed as a section of the vehicle window or as a combiner disc arranged in the passenger compartment. For example, the projection unit can be installed directly below the upper side of an instrument panel of the vehicle, such that the light beam from the projection unit is projected onto a windshield arranged above the instrument panel or onto a combiner disc positioned in front of it in the field of vision of the driver or another passenger.

[0031] The translational movement of the mirror rotation axis resulting from the rotation of the secondary bearing includes its one- or two-sided lowering or raising in the height direction of the vehicle-fixed Cartesian coordinate system.

[0032] According to one embodiment, the aforementioned parking position of the concave mirror can be adjusted in the projection unit by a predetermined angular position of the mirror rotation axis. For a predetermined operating angular range of the mirror rotation axis, which is required for eyebox adjustments during operation of the projection unit, an electromechanical or mechanical fixation of the bearing of the mirror rotation axis in the primary bearing is provided, which is designed to suppress vibrations of the concave mirror caused by vehicle movements during vehicle operation. The projection unit is designed to automatically open, i.e., cancel, this fixation for adjusting the concave mirror to the parking position.

[0033] The above aspects of the invention and their embodiments and specific configurations are explained in more detail below with reference to examples shown in the accompanying drawings. The drawings are schematic illustrations and are therefore not to scale. They show:

[0034] Figure 1 shows a vertical longitudinal section of a section of a motor vehicle with a field of view display device according to an embodiment of the invention;

[0035] Figure 2 is a cross-sectional view of an example of an eccentric mounting of the mirror rotation axis of the concave mirror of the field of view display device of Figure 1 in a secondary bearing rotatable independently of the mirror rotation axis, looking in the direction of the mirror rotation axis;

[0036] Figure 3a shows a longitudinal section of the concave mirror of Figure 2 and its eccentric mounting in the rotatable secondary bearing, viewed along the mirror rotation axis, in an operating position of the concave mirror; and

[0037] Figure 3b shows the same longitudinal sectional view as in Fig. 3a, but this time with a parking position of the concave mirror, into which it has been vertically lowered from the operating position of Fig. 3a by an independent rotation of the secondary bearing in addition to a rotation about its mirror rotation axis.

[0038] All of the various embodiments, variants, and specific design features of the projection unit, the associated operating method and control unit, as well as the field of view display device and the vehicle according to the above aspects of the invention mentioned above in the description and in the subsequent claims can be implemented in the examples shown in Figures 1 to 3b, in particular also alternatively or in addition to the features shown therein. Therefore, they will not all be repeated below. The same applies accordingly to the definitions of terms and effects already given above with regard to individual features shown in Figures 1-3b.

[0039] Fig. 1 shows a vertical longitudinal section of a section of a vehicle 1 with a field of view display device 2 according to an exemplary embodiment of the invention. The field of view display device 2 is embodied here purely as an example as a head-up display (HUD). Spatial orientation terms used in the description of this and the other examples, such as "horizontal," "vertical," "above," "below," "from," "rear," etc., refer to the usual vehicle-fixed Cartesian coordinate system K with mutually perpendicular longitudinal, transverse, and vertical directions X, Y, and Z of the vehicle 1.

[0040] The field of vision display device 2 is designed to generate a virtual image V in the field of vision of a user, for example a driver of the vehicle 1, who is indicated in Fig. 1 only by an eyebox E intended for his eyes in the passenger compartment of the vehicle 1. In this example, the eyebox E is defined as a two-dimensional spatial region perpendicular to a central ray of the field of vision display device 2, from which spatial region the virtual image V is visible in the intended display quality. The vehicle 1 here is purely an example of a motor vehicle. It is indicated in Fig. 1 only by its windshield 3, an instrument panel 4 extending below it and not shown in more detail, and a roof liner 9 extending above it.

[0041] The field of view display device 2 comprises a projection unit 5, which in this example is arranged below the windscreen 3 inside the instrument panel 4 and is protected from any external interference such as dust and moisture, etc. by a housing 10. The projection unit 5 contains an imaging unit 6 designed to generate a light beam L with the desired display content. The light beam L emanating from the imaging unit 6 is indicated in simplified form by the above-mentioned central beam of the field of view display device 2, which, as usual, leads approximately from a center of the imaging unit 6 to a center of the eyebox E.

[0042] In this example, an optional folding mirror 7 (which can also be omitted in the present invention) is arranged in the beam path of the generated light beam L for additional folding of the beam path, and a concave mirror 8 is arranged opposite it. The concavely curved front side of the concave mirror 8, which faces the folding mirror 7 (and, without it, the imaging unit 6), is designed as a freeform surface so that the light beam L leaves the projection unit 5 in a suitable shape and direction by reflection thereon, to then be reflected by the front panel 3 to the eyebox E. The front panel 3 thus serves as the reflection panel, referred to herein, of the field of view display device 2.

[0043] The housing 10 of the projection unit 5 is closed off from the windscreen 3 by a cover plate 11 that is transparent to the emitted light beam L and, in this example, is designed both to mechanically protect the projection unit 5 and to protect it from disruptive sunlight and ambient light reflections. In this example, the cover plate 11 is located somewhat lower than an adjacent upper side 0 of the instrument panel 4 and, in this example, has a concavely curved outer surface for the geometric anti-reflection coating mentioned above. The latter requires a considerable overall dimension of the cover plate 11 in the vertical direction Z of the vehicle 1, as can be seen in Fig. 1.

[0044] In order to adapt the position of the eyebox E to different user sizes and seating positions, the concave mirror 8 can be rotated about a mirror rotation axis A1 firmly connected to it by an associated mirror rotation axis drive M1 (see Fig. 2-3b) in the form of a first electric motor. A predetermined angular position of the mirror rotation axis A1 also allows a parking position P of the concave mirror 8 to be set, in which a focus or a main optical axis of the concave mirror 8 lies outside the beam path provided for the operation of the projection unit 5. A rotation 12 of the mirror rotation axis A1 when adjusting the concave mirror 8 from its operating position, shown as an example in Fig. 1 and 3a, to its parking position P, schematically indicated in Fig. 1 and 3b, is indicated in Fig. 1 by a rotation arrow.

[0045] As can be seen in Fig. 1, the concave mirror 8, in its parking position P, has its largest overall dimension in the vertical direction Z of the vehicle 1 and thus influences the design of the cover plate 11 located above it, for which a predetermined minimum distance from the concave mirror 8 must be maintained. This, in turn, has a direct limiting influence on the design of the instrument panel 4 and other technical components of the vehicle 1 in the vicinity of the field of view display device 2. To solve this problem, the concave mirror 8 in this exemplary embodiment is not only rotated about its mirror rotation axis A1, as in the prior art, but is additionally lowered into the parking position P by means of a lowering kinematics in the form of an eccentric that can be rotated independently of the mirror rotation axis A1 and has an eccentric drive M2 that is independent of the mirror rotation axis drive M1, as schematically illustrated in Fig. 2-3b.

[0046] Fig. 2 shows an example of an eccentric mounting of the mirror rotation axis A1 of a concave mirror 8 of a field of view display device according to an embodiment of the invention in a rotatable secondary bearing 14 (eccentric). This can in particular, but not necessarily, be the field of view display device 2 of Fig. 1.

[0047] Fig. 2 shows a cross-sectional view looking in the direction of the mirror rotation axis A1, which here extends purely by way of example parallel to an eccentric axis A2 at a predetermined radial distance. The secondary bearing 14 is driven for its rotation 19 about its eccentric axis A2 by an associated eccentric drive M2. In this example, the eccentric drive M2 is designed with a second motor provided specifically for this purpose, the motor housing of which is indicated by a dashed circular line and is concealed in Fig. 2 by a bearing block 17 in which the secondary bearing 14 is rotatably mounted. The bearing block 17, like the eccentric axis A2, is fixed / immovable with respect to the projection unit 5 and the housing 10 and is indicated purely schematically by a rectangle in Figs. 2-3b.In this example, the eccentric drive M2 further comprises a driver 18 which, for transmitting torque from the second motor to the secondary bearing 14, engages almost positively in an opening 20 formed in the secondary bearing 14, the position of which is shown in Fig. 2 purely as an example and whose inner dimensions are, for example, only slightly larger than the outer dimensions of the driver 18 in order to allow the driver 18 the mobility in the opening 20 required during operation.

[0048] Fig. 3a shows a longitudinal sectional view of the concave mirror 8 of Fig. 2 and its eccentric mounting in the rotatable secondary bearing 14 with a view of the mirror rotation axis A1 in an operating position of the concave mirror 8. In other words, Fig. 3a shows the concave mirror 8 from a driver's perspective, i.e. from a viewing direction in the longitudinal direction X of the vehicle 1. Fig. 3b shows the same longitudinal sectional view as in Fig. 3a, after the concave mirror 8 has been adjusted to its parking position P. As can be seen in Fig. 1, the clearance between the cover plate 11 and the concave mirror 8 is greatest in that operating angular range of the mirror rotation axis A1 which is used for eyebox adjustment during operation of the projection unit 5.In the angular range beyond this, which is used to adjust the concave mirror 8 into the parking position P, the asymmetrical windshield and vehicle geometry from the driver's perspective would mean that (without additional lowering kinematics) the right-hand end of the mirror rotation axis A1 in Fig. 3a-3b would come too close to the cover plate 11 shown in Fig. 1 with a desired anti-reflection geometry. To solve this problem, the concept presented in Fig. 2 and 3a-3b therefore provides, purely by way of example, for the concave mirror 8 to be lowered on one side only when adjusting the concave mirror 8 into the parking position P, i.e. at the aforementioned right-hand end of the mirror rotation axis A1 (also possible on both sides) using the eccentric kinematics presented here in the region of the constriction to the cover plate 11.

[0049] As shown in Fig. 3a, in this example a primary bearing 15, in which the left end of the mirror rotation axis A1 is rotatably mounted, is designed as a fixed bearing, the fixation of which with respect to the projection unit 5 or in the housing 10 is indicated by a triangular fastening device. This bearing point is therefore particularly suitable for connecting the mechanical mirror rotation axis drive M1; however, this is by no means mandatory. The primary bearing 15 is designed, for example, as a spherical head in order to give the opposite bearing point at the second end of the mirror rotation axis A1 the necessary degrees of freedom of movement. At the opposite bearing point, which is designed as a loose bearing, a primary bearing 16, in which the right end of the mirror rotation axis A1 is rotatably mounted, can also be designed with a spherical head.In this example, the two primary bearings 15 and 16 are used, in particular, to adjust the concave mirror 8 for normal operation of the field of view display device 2, i.e., to adjust the eyebox position, which can be performed, for example, during driving operation of the vehicle 1. The primary bearing 16 is eccentrically implemented in the secondary bearing 14 by being mounted or supported, for example, by sliding or rolling bearings, at a fixed position at a predetermined distance from the eccentric axis A2 (see Fig. 2).

[0050] The concave mirror 8 can be moved from any operating position into its parking position P along an optimally selectable adjustment path by a combination of a rotation 12 of the mirror rotation axis A1 and an independent rotation 19 of the secondary bearing 14. The latter lowers the concave mirror 8 in the height direction Z of the vehicle 1, and the distance between the concave mirror 8 and the cover plate 11 increases in this example by a height amount AZ, which depends on the specific position of the primary bearing 16 in the secondary bearing 14 and its distance from the eccentric axis A2. This lowering AZ is also shown in Fig. 3a-3b. A two-sided lowering, i.e. also for the primary bearing 15 at the other end of the mirror rotation axis A1, can be implemented in a similar way.

[0051] Alternatively or in addition to the described adjustment of the concave mirror 8 into its parking position P, an eccentrically driven lowering or raising of the concave mirror 8 can also be used in a similar way for its adjustment during operation, in particular for the eyebox adjustment. The independently driven rotation 19 of the secondary bearing 14 can be used as additional translational degrees of freedom for the concave mirror adjustment. This can be achieved by a suitable selection of the geometric parameters of the eccentric bearing of the mirror rotation axis A1 in the secondary bearing 14 and the time functions of both drives M1 and M2 for additional optimization of the optical performance of the field of view display device 2 during operation and / or for better utilization of the effective concave mirror surface during the eyebox adjustment, i.e.to reduce the required concave mirror size, and much more, alternatively or in addition to the lowering into the parking position P described above. Depending on the diameter of the bearing of the mirror rotation axis A1 in the secondary bearing 14 and the respective timing sequences of the independent drives M1 and M2, the eccentrically driven translational movement of the mirror rotation axis A1 can be specifically adapted to desired design parameters (such as the optical performance of the field of view display device 2, installation space restrictions, etc.). In particular, the concave mirror 8 can be lowered significantly further in the Z direction to reach its parking position P compared to conventional bearing and adjustment. The independent control of the two drives M1 and M2 can take place simultaneously or at different times, depending on the situation.This makes it possible to keep the distance to the cover plate 11 as large as possible during the lowering sequence.

[0052] List of reference symbols

[0053] 1 vehicle

[0054] 2 Field of view display device

[0055] 3 Windscreen

[0056] 4 Instrument panel

[0057] 5 Projection unit

[0058] 6 imaging unit

[0059] 7 folding mirrors

[0060] 8 concave mirrors

[0061] 9 Headliner

[0062] 10 housings

[0063] 11 Cover plate

[0064] 12 Rotation of the mirror rotation axis

[0065] 14 secondary bearings

[0066] 15, 16 Primary bearings for opposite ends of the mirror rotation axis

[0067] 17 Bearing block

[0068] 18 carriers

[0069] 19 Rotation of the secondary bearing

[0070] 20 Driver opening

[0071] L bundle of light rays

[0072] 0 Top of the instrument panel

[0073] A1 Mirror rotation axis

[0074] A2 eccentric axis

[0075] E Eyebox

[0076] M1 Drive of the mirror rotation axis, ie mirror rotation axis drive

[0077] M2 Drive of the secondary bearing, ie eccentric drive

[0078] P Parking position of the concave mirror

[0079] K vehicle-fixed coordinate system X, Y, Z longitudinal, transverse and vertical directions of the vehicle

[0080] V virtual image

Claims

Claims 1. A projection unit (5) for a field of view display device (2), in particular for use in a vehicle (1), comprising: an imaging unit (6) configured to generate a light beam (L) with the desired display content; a concave mirror (8) arranged and configured in the beam path of the generated light beam (L) such that the light beam (L) leaves the projection unit (5) in a predetermined shape and direction, to then be reflected by a partially transparent reflection plate arranged in the user's field of vision to their eyebox (E), thereby presenting the display content to the user in the form of a virtual image (V) behind the reflection plate; wherein, to adjust the eyebox position, the concave mirror (8) is rotatable about a mirror rotation axis (A1) rigidly connected to it by a mirror rotation axis drive (M1), which is rotatably mounted for this purpose in a primary bearing (15, 16);and the primary bearing (16) is mounted eccentrically at least at one end of the mirror rotation axis (A1) in a secondary bearing (14) which can be driven to rotate (19) about its eccentric axis (A2) fixed with respect to the projection unit (5) by an independently controllable eccentric drive (M2) in order to effect a translational movement of the mirror rotation axis (A1) and thus of the concave mirror (8) in a direction transverse to it.; 2. Projection unit (5) according to claim 1, wherein both the mirror rotation axis drive (M1) and the eccentric drive (M2) each comprise their own motor for independent control; and / or the mirror rotation axis drive (M1) and the eccentric drive (M2) comprise a common motor with a coupling which is designed for alternating, independent control of the mirror rotation axis drive (M1) and the eccentric drive (M2) using the common motor.

3. Projection unit (5) according to claim 1 or 2, wherein the primary bearing (15, 16) is designed as a spherical head at one or both ends of the mirror rotation axis (A1); and / or the primary bearing (16) is mounted in the secondary bearing (14) in a stationary manner, in particular at a point fixed to the secondary bearing (14) at a predetermined radial distance from the eccentric axis (A2), in particular by sliding or rolling bearings.

4. Projection unit (5) according to one of the preceding claims, further comprising: a housing (10) protecting the projection unit (5) from the outside; and a transparent cover plate (11) which closes the housing (10) on the output side and transmits the light beam bundle (L) emitted by the projection unit (5); wherein a parking position (P) of the concave mirror (8) can be set by a predetermined angular position of the mirror rotation axis (A1), in which a focus or a main optical axis of the concave mirror (8) is outside a for the operation of the projection unit (5); and when the concave mirror (8) is adjusted from an operating position to its parking position (P), a rotation (19) of the secondary bearing (14) which can be generated by the eccentric drive (M2) results in a translational movement of the mirror rotation axis (A1) and thus of the concave mirror (8) in a direction away from the cover plate (11).

5. Projection unit (5) according to one of the preceding claims, wherein the mirror rotation axis (A1) and the eccentric axis (A2) are arranged parallel to one another with a predetermined axial distance from one another; or the mirror rotation axis (A1) and the eccentric axis (A2) are arranged interlaced with one another.

6. Projection unit (5) according to one of the preceding claims, wherein the mirror rotation axis (A1) and / or its primary bearing (15, 16) and / or secondary bearing (14) is / are designed with an automatic axis length adjustment, so that a length of the mirror rotation axis (A1) automatically adapts to a possibly varying distance between the primary bearings (15, 16) of its two ends during the rotation (19) of the secondary bearing (14).

7. Method for operating a projection unit (5) according to one of the preceding claims, wherein the mirror rotation axis (A1) is moved by the mirror rotation axis drive (M1) and the secondary bearing (14) is moved by the eccentric drive (M2) successively and / or simultaneously to adjust the concave mirror (8) during operation of the projection unit (5), in particular for adjusting the eyebox position; and / or the mirror rotation axis (A1) is driven by the mirror rotation axis drive (M1) and the secondary bearing (14) is driven by the eccentric drive (M2) successively and / or simultaneously for adjusting the concave mirror (8) into its parking position (P).

8. Control unit designed and configured to automatically execute the method according to claim 7.

9. A field of view display device (2), in particular for use in a vehicle (1), comprising: a projection unit (5) according to one of claims 1 to 6; a reflection plate, in particular an at least partially transparent one, arranged in the beam path of the light beam (L) emitted by the projection unit (5), which is arranged and configured in the field of view of a user such that it reflects the light beam (L) to an eyebox (E) predetermined for the user, whereby the display content can be presented to the user in the form of a virtual image (V) behind the reflection plate; and preferably further comprising a control unit according to claim 8.

10. Vehicle (1), in particular a motor vehicle, with mutually perpendicular longitudinal, transverse and height directions (X, Y, Z) of a vehicle-fixed Cartesian coordinate system (K), comprising: a vehicle window which at least partially delimits a passenger compartment, in particular a windscreen (3); and a field of view display device (2) according to claim 9, the projection unit (5) of which is arranged in the passenger compartment, in particular in the interior of a Instrument panel (4) or directly below its upper side (0), and whose reflection disc is designed as a section of the vehicle window or as a combiner disc arranged in the passenger compartment; wherein the translational movement of the mirror rotation axis (A1) resulting from the rotation (19) of the secondary bearing (14) comprises its one- or two-sided lowering (AZ) or raising in the height direction (Z) of the vehicle-fixed Cartesian coordinate system (K).

Images