DE102014212186A1 - A visual field display device for displaying an image for an occupant of a vehicle - Google Patents

Abstract

The invention relates to a visual field display device (500) for displaying an image for an occupant of a vehicle. The visual field display device (500) comprises a holographic-optical element (450) as a projection surface onto which the image can be projected by means of an imaging device (510). Here, the holographic-optical element (450) is designed to produce a rendered image for imaging in a field of view (530) of the occupant. In this case, the holographic-optical element (450) has a virtual image (550) of a microlens arranged at a distance (d) and in which an optical function of at least one microlens arranged at a distance (d) from the holographic-optical element (450) (440) is stored. In this case, the distance (d) is adapted to at least one parameter (525) of an optical device (520) which is optically connected downstream of the holographic-optical element (450).

Description

State of the art

The present invention relates to a visual field display device for displaying an image for an occupant of a vehicle, to a method of displaying an image for an occupant of a vehicle, to a method of manufacturing a holographic-optical element as a projection surface for a visual field display device for displaying an image for an occupant of a vehicle, to a corresponding device and to a corresponding computer program.

A vehicle head-up display (HUD) may typically include a light source, a display, and an imaging optic. As a light source can usually z. B. LED backlight are used, so that the display can be backlit. Here a corresponding display content can be visualized. A subsequent HUD optics may then generate a desired virtual image for a driver. A superposition of the virtual image with an environment can be z. B. reach over a Combinerscheibe or with a windshield. The driver sees a virtual image at some distance, eg. B.> 2.5 m. The WO 2009/136218 A1 describes a device for displaying three-dimensional images or for three-dimensional visualization.

Disclosure of the invention

Against this background, with the approach presented here, a visual field display device for displaying an image for an occupant of a vehicle, a method for displaying an image for an occupant of a vehicle, a method for producing a holographic optical element as a projection surface for a visual field display device for displaying a Image for an occupant of a vehicle, further an apparatus that uses this method, and finally presented a corresponding computer program according to the main claims. Advantageous embodiments emerge from the respective subclaims and the following description.

According to embodiments of the present invention, in particular for realizing a speckle-free field of view display device or a speckle-free head-up display (HUD), a volume hologram of at least one microlens or, for example, a microlens grid can be used as the projection surface of a visual field display device. By adaptability of a distance of the at least one microlens from a holographic surface in the recording of the hologram, such a projection surface, in particular independently of Eyebox d. H. an area in which, for example, the driver's eyes are located, and magnification of a subsequent imaging optics are adjusted. Thus, the projection surface of the visual field display device can be realized via a recording of a volume hologram of at least one microlens.

Advantageously, according to embodiments of the present invention, in particular a speckle-free holographic projection surface for visual field displays or head-up displays, in particular for vehicles, can be provided. In particular, a projection surface in the form of at least one holographically recorded microlens or a holographically recorded microlens grid can be or can be realized. In this case, a decoupling of an optical function of the at least one microlens or of an action location to the location of the projection surface or location at which the hologram can be generated is possible. Also, a very homogeneous brightness distribution can be achieved in the image. Due to the advantageously selectable distance of a holographic material with respect to the at least one microlens, in particular an advantageous degree of freedom can be provided in order to realize an adaptation to different imaging optics for different head-up displays.

A visual field display device for displaying an image for an occupant of a vehicle is presented, wherein the visual field display device has a holographic-optical element as a projection surface onto which the image can be projected by means of an imaging device, wherein the holographic-optical element is designed to form a processed image for imaging in a field of view of the occupant, wherein the holographic-optical element has a volume hologram in which an optical function of at least one microlens arranged at a distance from the holographic-optical element is stored, the distance being adapted to at least one parameter of the holographic-optical element optically downstream optical device is adapted.

The visual field display device may be a head-up display for mounting in a vehicle, such as a road-bound vehicle, such as a passenger car or the like. The visual field display device may be configured to project the image into an area (eyebox) that lies on a line of sight of the driver when viewing a traffic situation through the windshield. The optical device which is optically connected downstream of the holographic-optical element can comprise imaging optics of the visual field display device. At least a parameter of the optical device downstream of the holographic-optical element can be at least one optical, geometric and / or other physical property with influence on a beam path, in particular a focal length. The distance can also be adapted to at least one parameter of an optical device which is optically connected upstream of the holographic-optical element. The visual field display device may also include an imaging device or a controllable light source for projecting the image onto the projection surface.

According to one embodiment, an optical function of a plurality of optically connected microlenses, a microlens grid having a plurality of microlenses and additionally or alternatively a plurality of microlens screens connected optically one behind the other can be stored in the holographic-optical element. Such an embodiment offers the advantage that a plurality of individual optical functions can be stored in the volume hologram, so that space can be saved and a field of application or field of application of the visual field display device is even more comprehensive and diverse.

Also, in the holographic-optical element, an optical function of at least one additional optical system arranged adjacent to the at least one microlens for deflection and additionally or alternatively collimation can be stored. Thus, additional optics for redirection and additionally or alternatively for collimation or collimation as optical functionality can be integrated into the hologram. Such an embodiment has the advantage that in the volume hologram a plurality of individual optical functions of different types can be deposited, so that a required installation space of the visual field display device can be minimized and a field of application or field of application of the visual field display device can be made more comprehensive and diverse.

In particular, the holographic-optical element may be a transmission hologram or a reflection hologram. Thus, reflective and transmissive designs are possible through appropriate volume holograms. Such an embodiment offers the advantage that new designs or designs of the visual field display device are made possible and the visual field display device is particularly versatile adaptable to different applications, vehicle dimensions or the like.

A method for displaying an image for an occupant of a vehicle is also presented, the method comprising the following steps:
Providing a field of view display device with a holographic-optical element as the projection surface, the holographic-optical element having a virtual image in which an optical function of at least one microlens spaced from the holographic-optical element is stored, the distance being at least one Parameter adapted to the holographic optical element optically downstream optical device; and
Projecting the image by means of an imaging device on the holographic-optical element to produce a processed image for imaging in a field of view of the occupant.

The method of displaying may be advantageously carried out using or in conjunction with an embodiment of the above-described visual field display device to display an image to an occupant of a vehicle. When mapping the rendered image into the field of view, the rendered image may undergo imaging optics of the field of view display device.

Furthermore, a method for producing a holographic-optical element as a projection surface for a visual field display device for displaying an image for an occupant of a vehicle is presented, the method comprising the following steps:
Arranging at least one microlens at a distance from a holographic material, wherein the distance is adapted to at least one parameter of an optical device which is to be optically connected downstream of the holographic-optical element in the field of vision display device; and
Exposing the holographic material to a reference light beam and an object light beam passing through the at least one microlens to produce an interference pattern resulting from an overlapping position of the reference light beam and the object light beam as a volume hologram in the holographic-optical element in the holographic material, wherein in the holographic-optical element an optical function of the at least one spaced-apart microlens is stored to produce the holographic-optical element.

By carrying out the method of manufacturing, a holographic-optical element can be advantageously produced as a projection surface for an embodiment of the above-mentioned visual field display device. The result is a very cost-effective solution by simply reproducible volume holograms.

According to one embodiment, in the step of arranging a plurality of optically cascaded microlenses, a microlens grid with a plurality of microlenses, a plurality of optically cascaded microlens grid and additionally or alternatively at least one adjacently arranged to the at least one microlens additional optics for deflection and / or collimation can be arranged, and may be traversed through the object beam in the step of exposing to store a corresponding optical function in the holographic-optical element. A corresponding optical function may be an optical function of a plurality of optically connected microlenses, an optical function of a microlens grid having a plurality of microlenses, an optical function of a plurality of optically connected microlens screens and additionally or alternatively an optical function of at least one additional optic adjacent to the at least one microlens have for deflection and / or collimation. Such an embodiment has the advantage that, for example, a plurality of microlenses connected in series and / or z. B. additional optics for deflection or collimation can be integrated in a component and thus pupil opening angles are adjustable in a very wide range. The main advantage here is in a space savings, by the substitution of several successive optics by a holographic optical element.

Also, the arranging step and the exposing step can be repeated for different arrangement positions of a microlens in the distance from the holographic material to store in the holographic-optical element an optical function representing a spaced-apart microlens grating. With holograms it is also possible to store several optical functions in a hologram. This feature makes it possible to realize the hologram of a microlens grid by repeatedly exposing a single microlens and sequentially changing the position thereof. Thus, when recording or generating the hologram, a single microlens can be used and the hologram can be exposed sequentially. Such an embodiment offers the advantage that a hologram of a microlens array with almost any angular configuration can be realized.

In a method of manufacturing a visual field display device, a holographic-optical element manufactured according to an embodiment of the above-mentioned method may be disposed in a range of a focal length of an optical device to be optically post-connected to the holographic-optical element.

The approach presented here also creates a device that is designed to perform the steps of a variant of a method presented here in appropriate facilities to drive or implement. Also by this embodiment of the invention in the form of a device, the object underlying the invention can be solved quickly and efficiently.

In the present case, a device can be understood as meaning an electrical device which processes sensor signals and outputs control and / or data signals in dependence thereon. The device may have an interface, which may be formed in hardware and / or software. In the case of a hardware-based embodiment, the interfaces can be part of a so-called system ASIC, for example, which contains a wide variety of functions of the device. However, it is also possible that the interfaces are their own integrated circuits or at least partially consist of discrete components. In a software training, the interfaces may be software modules that are present, for example, on a microcontroller in addition to other software modules.

Also of advantage is a computer program product or computer program with program code which can be stored on a machine-readable carrier or storage medium such as a semiconductor memory, a hard disk memory or an optical memory and for carrying out, implementing and / or controlling the steps of the method according to one of the embodiments described above is used, especially when the program product or program is executed on a computer or a device.

The approach presented here will be explained in more detail below with reference to the accompanying drawings. Show it:

1 a schematic representation of a visual field display device;

2A and 2 B Simulation results of an image quality of a visual field display device;

3 a schematic representation of a visual field display device;

4 a schematic representation of a holographic-optical element according to an embodiment of the present invention in the manufacture thereof;

5 a schematic representation of a visual field display device according to an embodiment of the present invention;

6 a flow chart of a method for displaying according to an embodiment of the present invention; and

7 a flowchart of a method of manufacturing according to an embodiment of the present invention.

In the following description of favorable embodiments of the present invention, the same or similar reference numerals are used for the elements shown in the various figures and similar acting, with a repeated description of these elements is omitted.

1 shows a schematic representation of a visual field display device 100 , Shown are the field of view display device 100 here a projector or a scanner 110 For example, a laser scanner, as an imaging device, a lens 120 , a first microlens grid 130 , a second microlens grid 140 , a first ray path 152 , a second beam path 154 and an eye represented symbolically and representing a so-called eyebox 160 an observer. The first beam path 152 and the second beam path 154 extend from the scanner 110 through the lens 120 , the first microlens grid 130 and the second microlens grid 140 through in the direction of the eye 160 ,

In other words, in 1 a projection screen for a visual field display device 100 or for a head-up display with micro lens grids 130 and 140 shown. At the in 1 described approach is a microlens grid as a direct projection surface for the realization of an image. By means of an expansion optics and a microlens grid adapted thereto, it is possible to allow the observer to move almost directly into the laser beam of the scanner 110 or projector and can see a constant phase front. A size of the microlenses of the microlens grid 130 and 140 and a beam diameter of the scanning laser are approximately identical and by a desired resolution of the visual field display device 100 determined, z. B. 150 microns. A focal length of the microlenses is chosen, for example, such that each microlens, in conjunction with a subsequent imaging optics, illuminates the entire eyebox. It follows that each lens or each pixel of the microlens grid illuminates the entire eyebox and the observer due to the scanner 110 or laser scanner successively each pixel and thus the entire picture sees.

2A and 2 B show simulation results using the in 1 visual field display device shown with a projection screen with microlens grid. The simulation was performed with the simulation program VirtualLab. Thus, the approach was off 1 checked with the simulation program VirtualLab and the results are in 2A and 2 B shown. In this case, an evaluation was made from the perspective of the observer or a view from the direction of the observer is shown. 2A shows a simulation result of an image quality of the visual field display device 1 in the case of an image by adapted beam diameter, microlens screen size or microlens size and focal lengths. 2 B shows a simulation result of an image quality of the visual field display device 1 in the case of an image with unmatched size of the microlens grid to the beam diameter. If components of the field of view display device are not adapted to each other, one obtains the in 2 B shown result. Here, the beam diameter of the laser scanner and the size of the microlens grid do not match. This system provides an image in which an image with brightness fluctuations is obtained by the projection onto the microlens array with subsequent magnification optics.

3 shows a schematic representation of a visual field display device 300 , Shown are the field of view display device 300 here a projector or a scanner 310 For example, a laser scanner, as an imaging device, a lens 320 , a first microlens grid 330 , a second microlens grid 340 , a subsequent optical device 350 with a focal length f or focal length 355 , an eye represented symbolically and representing a so-called eyebox 360 an observer and an image visible to the observer 370 of the microlens grid 330 , Here, the visual field display device correspond 300 and the representation in 3 the visual field display device or the presentation 1 with the exception that in 3 in addition the subsequent optical device 350 , the focal length 355 and the picture 370 are shown and beam paths and the subsequent optical device 350 run through. In other words, in 3 a visual field display device 300 with a projection surface with micro lens grids 330 and 340 with subsequent optical device 350 or head-up display optics (HUD optics). Through an illustration of the microlens grid realized here 330 the observer sees unwanted light-dark areas through apparently enlarged lenses in the image 370 ,

4 shows a schematic representation of a holographic-optical element according to an embodiment of the present invention in the manufacture thereof or in the storage of a volume program in the same. Shown are a recording structure 400 , an object light source 410 , an object beam 415 or an object wave, a reference light source 420 , one reference beam 425 or a reference wave, a collimation optics 430 , a microlens grid 440 or microlens array (MLA), a holographic-optical element 450 (HOE) and a distance d. The holographic-optical element 450 is off by performing the procedure 7 advantageous to produce. The holographic-optical element 450 For a visual field display device for displaying an image for an occupant of a vehicle, it is intended to function as a projection surface to be projected from the origin of the reference light source by means of an imaging device 420 the image is projectable. Here is the holographic-optical element 450 formed in a finished state to produce a processed image for imaging in a field of view of the occupant.

The object beam 415 extends from the object light source 410 through the collimation optics 430 and the microlens grid 440 through to the holographic-optical element 450 , The reference beam 425 extends from the reference light source 420 directly on the holographic-optical element 450 , Here the object beam hits 415 from a first angle to the holographic-optical element 450 on, with the reference beam 425 from a second angle different from the first angle to the holographic-optical element 450 incident.

The holographic-optical element 450 has a holographic material. The holographic-optical element 450 is at the distance d from the microlens grid 440 spaced apart. By exposing the holographic material to the holographic-optical element 450 with the reference light beam 425 and the object light beam 415 is an interference pattern that is at a superposition position of the reference light beam 425 and the object light beam 415 arises as a volume hologram generated in the holographic material. Thus, in the volume hologram is an optical function of the arranged at the distance d microlens grid 440 storable to the holographic-optical element 450 manufacture. The distance d is in particular at least one parameter of the holographic-optical element 450 optically downstream optical device adapted to a visual field display device.

The volume hologram of the holographic-optical element 450 is according to the in 4 illustrated embodiment of the present invention as a transmission hologram executed. Alternatively, the volume hologram of the holographic-optical element 450 be designed as a reflection hologram. According to one embodiment, in the volume hologram of the holographic-optical element 450 an optical function of a plurality of optically successively connected microlenses and additionally or alternatively a plurality of optically successively connected microlens grid storable. According to one embodiment, in the volume hologram of the holographic-optical element 450 an optical function at least one adjacent to the microlens grid 440 arranged additional optics for deflection and / or collimation storable. According to the in 4 Illustrated embodiment of the present invention is in the volume hologram of the holographic-optical element 450 also an optical function of the collimation optics 430 saved.

In other words, shows 4 a recording set-up or a recording structure for a hologram of a microlens grid 440 (MLA) with prior collimation optics 430 , The optical function or lens function of collimating lens 430 and microlens grid 440 is by a shot in the hologram of the holographic-optical element 450 saved.

When recording the hologram of the microlens grid 440 including previous collimation optics 430 stores the holographic material of the holographic-optical element 450 the by reference beam 425 and object beam 415 generated interference structure. The microlens grid 440 becomes at the distance d the holographic-optical element 450 with the object beam 415 lit, which is expanded. At the same time, the holographic-optical element becomes 450 with the reference beam 425 exposed by the superposition at the location of the holographic-optical element 450 resulting interference pattern is stored in the holographic material or a holographic layer. Stored according to the in 4 illustrated embodiment of the present invention, the optical function or lens function of the microlens grid 440 and the collimation optics 430 , The stored information can now be illuminated by illuminating the holographic-optical element 450 from the direction of the reference light source 420 be retrieved again. The function of the volume hologram is identical to the microlens grid at a distance d 440 including previous collimation optics 430 , Exposure reference beam 425 and object beam 415 the holographic material from the same side of the holographic-optical element 450 from, a transmission hologram is obtained, whereas a reflection hologram is obtained when reference beam 425 and object beam 415 the holographic material from different sides of the holographic-optical element 450 from illuminate. In the case of the microlens grid 440 Both solutions are feasible and open up new design possibilities of visual field display devices, especially for vehicles.

The illustrated recording set-up results in certain angle configurations the distance d between the microlens grid 440 and the holographic-optical element 450 , In addition to the recording described here, with holograms it is also possible to store several image contents in a hologram. This feature makes it possible to realize the hologram of a microlens grid by exposing a single microlens and sequentially changing the position thereof. It can thus be used in the recording even a microlens and the holographic-optical element 450 be exposed sequentially. Thus, a hologram of a microlens grid is possible with almost any angular configuration. A particular advantage in this case is also the possibility of holographing several microlenses connected in series and / or, for example, additional optics for deflection or collimation, in order to then combine respective optical functions together in one component, the holographic-optical element 450 , to have. So then pupil opening angles are adjustable in a very wide range.

5 shows a schematic representation of a visual field display device 500 and a head-up display (HUD) for displaying an image for an occupant of a vehicle according to an embodiment of the present invention. Shown are the holographic-optical element 450 out 4 an imaging device 510 , a holographic-optical element 450 optically downstream optical device or HUD optics 520 with a focal length f or focal length 525 , an eye represented symbolically and representing a so-called eyebox 530 an observer, here the occupant of the vehicle, an image displayed to the observer 540 , a virtual picture 550 and a distance d.

The holographic-optical element 450 functions as a projection surface of the visual field display device 500 , The holographic-optical element 450 assigns the virtual picture 550 (a microlens grid), which is the virtual image 4 is. In the holographic-optical element 450 is an optical function of the microlens raster recorded at the distance d 4 saved and at 550 a virtual picture forms. , In this case, the distance d is at least one parameter of the holographic-optical element 450 optically downstream optical device or HUD optics 520 customized. The holographic-optical element 450 is within a range of focal length 525 the HUD optics 520 arranged.

The imaging device 510 is designed to image the holographic-optical element 450 to project. In this case, the imaging device 510 formed to light rays representing the image in a reference light beam from 4 corresponding direction to the holographic-optical element 450 to project. Thus, the virtual picture is 550 at the distance d from the holographic-optical element 450 reconstructed. In the presentation of 5 Here is the holographic-optical element 450 between the virtual picture 550 and the HUD optics 520 arranged, using the HUD optics 520 between the holographic-optical element 450 and the eye 530 is arranged, the virtual image 550 between the holographic-optical element 450 and the picture 540 is arranged. The virtual picture 550 is essentially exactly in the focal length 525 the HUD optics 520 arranged. So that's in the virtual picture 550 stored optical function substantially exactly at the focal length 525 the HUD optics 520 effective. The holographic-optical element 450 is designed to be based on the projected image and the virtual image 550 to produce a rendered image for imaging in a field of view of the occupant or observer.

In other words, shows 5 a speckle-free projection surface for the field of view display device 500 that is the holographic-optical element 450 with the virtual picture 550 a microlens grid and the subsequent HUD optics 520 having. The observer now sees a homogeneous enlargement of the projected image 540 on the hologram plane. Since the optical function or lens function of the microlens grid in the holographic-optical element 450 with the distance d to the element 450 is stored, a speckle-free image is obtained.

In this case, the microlens grid during recording or during the production of the holographic-optical element 450 be arranged in the adjustable distance d to the holographic material or a film or a holographic plate. The holographic film itself serves in the field of view display device 500 as a projection surface onto which the imaging device 510 or a laser scans. A reconstruction of the object microlens in the form of the virtual image 550 thus finds in an exposure of the holographic-optical element 450 by means of the imaging device 510 again in the distance d used during manufacture. This virtual picture 550 is adapted to receive a laser beam from the imaging device 510 expand into the desired Eyebox with a relatively constant phase front. The observer looks back on a widening optics in the laser. In addition, a real image content can be written on the holographic-optical element. By an arrangement of the holographic-optical element 450 with the virtual picture 550 of the MLA at the distance d within the focal length 525 the subsequent HUD optics 520 The virtual image of the real information, which is the imaging device, is created 510 or the laser scanner on the virtual image 550 writes. The reconstructed For example, a microlens object is almost directly in the focal length 525 the subsequent HUD optics 520 arranged and is infinitely enlarged. Thus, the observer sees each pixel or the virtual image, which is apparently illuminated by a speckle-free backlighting.

The reconstructed object, the microlens grid 550 , is characterized by its location near the focal length 525 the HUD optics 520 seemingly enlarged to infinity and thus visible to the observer as a homogeneous surface.

Disturbing brightness differences, which can occur in a non-holographic approach, are thus avoidable.

6 shows a flowchart of a method 600 for displaying an image for an occupant of a vehicle according to an embodiment of the present invention. The procedure 600 for display is such as using the visual field display device using or in conjunction with a visual field display device 5 advantageously executable to display an image of an occupant of a vehicle.

The procedure 600 has a step 610 the provision of a visual field display device with a holographic-optical element as a projection surface. In this case, the holographic-optical element has a virtual image in which an optical function of at least one microlens arranged at a distance from the holographic-optical element is stored. In this case, the distance is adapted to at least one parameter of an optically downstream optical device to the holographic-optical element.

Also, the procedure assigns 600 a step 620 projecting the image by means of an imaging means onto the holographic-optical element to produce a rendered image for imaging in a field of view of the occupant. For example, when imaging the rendered image into the field of view, the rendered image undergoes imaging optics of the field of view display device.

7 shows a flowchart of a method 700 for producing a holographic-optical element as a projection surface for a visual field display device for displaying an image for an occupant of a vehicle according to an embodiment of the present invention. By performing the procedure 700 For manufacturing, a holographic-optical element such as the holographic-optical element is made 4 respectively. 5 , as a projection screen for a visual field display device, such as the visual field display device 5 , advantageous to produce.

The procedure 700 has a step 710 arranging at least one microlens at a distance from a holographic material. In this case, the distance is adapted to at least one parameter of an optical device which is to be optically connected downstream of the holographic-optical element in the field of vision display device.

Also, the procedure assigns 700 one step 720 of exposing the holographic material to a reference light beam and an object light beam passing through the at least one microlens to produce an interference pattern resulting from an overlapping position of the reference light beam and the object light beam as a virtual image in the holographic material. In this case, an optical function of the at least one microlens arranged in the distance is stored in the virtual image in order to produce the holographic-optical element.

According to one embodiment, in step 710 arranging a plurality of optically successively connected microlenses, a microlens grid with a plurality of microlenses, a plurality of optically cascaded microlens grid and additionally or alternatively at least one adjacent to the at least one microlens arranged additional optics arranged for deflection and / or collimation and are in step 720 of the exposure through the object beam to store a corresponding optical function in the virtual image. The corresponding optical function comprises an optical function of a plurality of optically successively connected microlenses, an optical function of a microlens grid with a plurality of microlenses, an optical function of a plurality of optically successively connected microlens grid and additionally or alternatively an optical function of at least one adjacent to the at least one microlens Additional optics for redirection and / or collimation.

According to one embodiment, the step 710 of arranging and the step 720 of exposing for different arrangement positions of a microlens in the distance from the holographic material to repeatedly store in the virtual image an optical function representing a spaced-apart microlens grid. By repeating the steps sequentially 710 and 720 Thus, a hologram of a microlens grid is realized by repeatedly exposing a single microlens and sequentially changing the position thereof. Thus, a single microlens is used in the recording or in the generation of the virtual image and the holographic material is exposed sequentially.

With reference to the 4 to 7 Embodiments of the present invention will be summarized below briefly and in other words.

According to embodiments of the present invention, a realization of a holographic projection surface, in the form of the holographic-optical element 450 , with a desired Eyebox, and also an elimination of Speckle possible. Using such a holographic solution, so-called speckle effects can be significantly reduced or eliminated and, moreover, it is possible to expand radiation representing the image to be displayed only into a desired eyebox and yet to subsequent HUD optics 520 the visual field display device 500 or to adapt to different magnification scales, for example, for a conventional head-up display, a contact-analogous head-up display or the like. A realization of a pupil multiplication with subsequent imaging optics is also advantageous here 520 to the Specklefreiheit. It can be significantly reduced or eliminated by a pupil multiplication a so-called speckle.

Through appropriate holographic-optical elements 450 with a virtual picture 550 at a distance d from 450 at least one microlens or a microlens grid 440 can be an efficient beam redistribution in a desired angular distribution and direction, especially when using laser light, for. B. with laser projectors can be achieved. Thus, a simple adaptability to a variety of imaging optics with different magnification scales, especially contact analog head-up displays with high magnification can be achieved.

Advantages according to embodiments of the present invention are particularly important in further growth of the market for head-up displays. Increasingly, miniaturized projectors based on laser technology, eg. B. flying spot method can be used. Unlike a projection onto a conventional diffuser, without the widening of the laser beam, no disturbing speckle is created, so that outstanding image qualities can be achieved. In contrast to a microlens grid as a projection surface, it can also advantageously be prevented that other undesired non-uniformity irregularities occur, which would likewise severely impair the image quality. Likewise, unlike a microlens grid (pupil expander) as a projection surface accounts for necessary adjustments to different designs of head-up displays, such as changes in focal lengths, field of view, front window of the vehicle or the like according to embodiments of the present invention. In contrast to an image of a microlens grid on the optics of a head-up display, for example, no elaborately precise adjustment of focal lengths is required according to embodiments of the present invention and a susceptibility to windscreen tolerances can be reduced or eliminated. Thus, it can be avoided that for different types of windscreen and different imaging optics, with different magnification scales, a size and focal length of micro lens grids are adapted to a particular design of a head-up display. It is also possible to avoid or compensate for brightness fluctuations otherwise occurring due to a magnification function of a HUD-disc or a visibility of enlarged lens-heads in the image. It is also possible to dispense with further optical elements, for example for illumination, in particular for collimated illumination, of microlenses in the direction of their optical axis.

The embodiments described and shown in the figures are chosen only by way of example. Different embodiments may be combined together or in relation to individual features. Also, an embodiment can be supplemented by features of another embodiment.

Furthermore, the method steps presented here can be repeated as well as executed in a sequence other than that described.

If an exemplary embodiment comprises a "and / or" link between a first feature and a second feature, then this is to be read so that the embodiment according to one embodiment, both the first feature and the second feature and according to another embodiment either only first feature or only the second feature.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• WO 2009/136218 A1 [0002]

Claims (11)

Visual field display device ( 500 ) for displaying an image for an occupant of a vehicle, wherein the visual field display device ( 500 ) a holographic-optical element ( 450 ) as a projection surface on which the image is processed by means of an imaging device ( 510 ) is projectable, wherein the holographic-optical element ( 450 ) is adapted to form a rendered image for imaging in a viewing area ( 530 ) of the occupant, the holographic-optical element ( 450 ) a virtual image ( 550 ), in which an optical function of at least one at a distance (d) from the holographic-optical element ( 450 ) arranged microlens ( 440 ), wherein the distance (d) to at least one parameter ( 525 ) of the holographic-optical element ( 450 ) optically downstream optical device ( 520 ) is adjusted. Visual field display device ( 500 ) according to claim 1, characterized in that in the holographic-optical element ( 450 ) an optical function of a plurality of optically successively connected microlenses, a microlens grid ( 440 ) with a plurality of microlenses and / or a plurality of optically cascaded microlens grids ( 440 ) is stored. Visual field display device ( 500 ) according to one of the preceding claims, characterized in that in the holographic optical element ( 450 ) an optical function of at least one adjacent to the at least one microlens ( 440 ) arranged additional optics ( 430 ) is stored for redirection and / or collimation. Visual field display device ( 500 ) according to one of the preceding claims, characterized in that the holographic-optical element ( 450 ) is a transmission hologram or a reflection hologram. Procedure ( 600 ) for displaying an image for an occupant of a vehicle, the method ( 600 ) comprises the following steps: providing ( 610 ) a visual field display device ( 500 ) with a holographic-optical element ( 450 ) as a projection surface, wherein the holographic-optical element ( 450 ) a virtual image of a microlens grid ( 550 ), in which an optical function of at least one at a distance (d) from the holographic-optical element ( 450 ) arranged microlens ( 440 ), wherein the distance (d) to at least one parameter ( 525 ) of the holographic-optical element ( 450 ) optically downstream optical device ( 520 ) is adjusted; and projecting ( 620 ) of the image by means of an imaging device ( 510 ) to the holographic-optical element ( 450 ) to form a rendered image for imaging in a viewing area ( 530 ) of the occupant. Procedure ( 700 ) for producing a holographic-optical element ( 450 ) as a projection surface for a visual field display device ( 500 ) for displaying an image for an occupant of a vehicle, the method ( 700 ) comprises the following steps: arranging ( 710 ) at least one microlens ( 440 ) at a distance (d) from a holographic material, wherein the distance (d) to at least one parameter ( 525 ) in the field of vision display device ( 500 ) the holographic-optical element ( 450 ) optically nachzuschaltenden optical device ( 520 ) is adjusted; and exposing ( 720 ) of the holographic material with a reference light beam ( 425 ) and one the at least one microlens ( 440 ) passing object light beam ( 415 ) at a superposed position of the reference light beam (FIG. 425 ) and the object light beam ( 415 ) resulting interference pattern as a volume hologram in the holographic-optical element ( 450 ) in the holographic material, wherein in the holographic-optical element ( 450 ) an optical function of the at least one microlens arranged in the distance (d) ( 440 ) is stored to the holographic-optical element ( 450 ). Procedure ( 700 ) according to claim 6, characterized in that in step ( 710 ) arranging a plurality of optically successively connected microlenses, a microlens grid ( 440 ) having a plurality of microlenses, a plurality of microlens rasters ( 440 ) and / or at least one adjacent to the at least one microlens ( 440 ) arranged additional optics ( 430 ) are arranged for redirection and / or collimation and in step ( 720 ) of exposure by the object beam ( 415 ) to be detected in the holographic-optical element ( 450 ) to store a corresponding optical function. Procedure ( 700 ) according to one of claims 6 to 7, characterized in that the step ( 710 ) of arranging and the step ( 720 ) of the exposure for different arrangement positions of a microlens at the distance (d) from the holographic material to be repeated in the holographic-optical element (FIG. 450 ) to store an optical function which comprises a microlens grid (10) arranged at the distance (d). 440 ). Device designed to handle all the steps of a method ( 600 ; 700 ) according to one of claims 5 to 8. Computer program adapted to perform all steps of a procedure ( 600 ; 700 ) according to one of claims 5 to 8. A machine-readable storage medium having a computer program stored thereon according to claim 10.

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