WO2014009186A1

WO2014009186A1 - Image-generating unit

Info

Publication number: WO2014009186A1
Application number: PCT/EP2013/063765
Authority: WO
Inventors: Michael Graef
Original assignee: Bayerische Motoren Werke Aktiengesellschaft
Priority date: 2012-07-11
Filing date: 2013-07-01
Publication date: 2014-01-16
Also published as: DE102012212088A1

Abstract

Disclosed is an image-generating unit (1) which comprises a micro-concave mirror arrangement (2 ) having a plurality of micro-concave mirrors (3) and a projector (11), the micro-concave mirror arrangement (2) being designed as a front projection surface (5) for an image emitted by the projector (11).

Description

description

Image-forming unit

It becomes an image-forming unit with a

Mikrohohlspiegelanordnung and a Proj ector described. Furthermore, a head U display with an image-forming unit and a mirror system will be described.

With the help of a head-up display, information can be displayed directly in the field of vision of a driver on a windshield of a vehicle. As a result, information content can be detected while the road conditions remain in the driver's field of view.

Modern head-up displays create a virtual image that, for the driver, is some distance in front of the windscreen,

For example, at the end of the hood, seems to lie. The virtual image can generally only be seen from a defined viewing window, the so-called eyebox. The

The viewing window is usually designed so that the entire virtual image can be seen from the entire desired viewing window.

Various projection and rear projection screens can generate a picture for direct viewing or further optical imaging, for example in a head-up display, with the aid of a projector, for example a bearaer. In a head-üp display can be spanned on the Abstahlwinkel of individual pixels, the viewing window.

From the document US 2010/0079861 AI a combination of micro lens arrays with microprism reflectors for

Known on roj ektion with tilting of the beam angle. However, such arrangements have a multicolored projection disturbing color dispersion by the included refractive optics. Moreover, they are by a necessary custom-fit

Machining of front and back to produce expensive.

It is a task to be solved, an improved one

to provide imaging unit.

The object is solved by the features of the independent claims. Advantageous developments of the invention are characterized in the subclaims.

According to one embodiment, an image-forming unit is provided, which has a micro-hollow mirror arrangement with a multiplicity of hollow micro-mirrors and a projector, wherein the micro-hollow-mirror arrangement is designed as a surface for projecting an image emitted by the projector. A concave mirror refers to a concave mirror, also called concave mirror1. The projector can be designed, for example, as a projector. In particular, the projector can be designed as a micro-laser beamer.

In addition, that of the projector on the

Micro hollow mirror arrangement radiated image of the

Mikrohohlspiegelanordnung radiated and irradiated in a subsequent head-up display optics. In particular, the image emitted by the micro-cavity mirror arrangement can be irradiated into a mirror system of a head-up display optical system.

According to a further embodiment, at least one

Subset of microvoid one of others

Micro hollow mirrors have different focal lengths.

For example, a number of micro-cavities may have the same focal length. Alternatively, all

Micro hollow mirror be provided with a different focal length. Alternatively, all micro-cavities with the be provided with the same focal length. The preferred focal length of an icrohohlspiegel is in particular of his

Diameter and a desired emission cone dependent. The radiating cone can be designed using the following formula, where α is the angle of the radiating cone, D is the diameter of the micro-hollow mirror and f is the focal length of the mirror:

a = 2 * arctane (D / f). The focal length and the emission cone of a micro-hollow mirror can influence the representation of a virtual image generated by a subsequent head-up display optics. For example, the focal length and the emission cone can have an influence on the illumination of a viewing window, from which a driver can perceive a virtual image.

According to a further embodiment, at least a subset of microcavity mirrors may be one of others

Micro hollow mirrors have differently oriented mirror axis. For example, a number of

Micro hollow mirrors have an aligned mirror axis. According to an alternative embodiment, all mirror axes may be aligned in parallel. By suitable alignment of the mirror axes, optical axes of irradiated and emitted light can deviate from a symmetry at the perpendicular of the projection surface,

in particular the micro hollow mirror arrangement, be set. For example, the mirror axes may be aligned such that light radiated from a projector onto the micro-cavity mirror assembly is at an angle from the

Micro hollow mirror assembly is radiated, which is not symmetrical relative to the Lot of Aufproj ektionsfläche to the angle of the incident light.

According to one embodiment, the micro-cavities are arranged on a planar surface. The area can

for example, a rectangular or a hexagonal shape exhibit. Alternatively, the micro-cavities may be arranged on a free-formed surface. For example, the surface may be curved. By suitable shaping of the surface, for example, distortions in the representation of a virtual image or other optical defects can be compensated.

According to a further embodiment, the

Micro hollow mirror be arranged differently spaced at least in a predetermined range than in at least one other predetermined range. For example, the

Micro hollow mirror have at least in a predetermined range equal distances from each other. By a suitable arrangement of the micro-hollow mirrors, in particular by a suitable spacing of the micro-hollow mirrors, any superimposing effects which may occur can be compensated. Such an overlay effect is, for example, the moire effect, which is manifested by the superimposition of regular fine grids by additional apparent coarse grids. The micro-hollow mirrors can, for example, at least in a predetermined range in the form of a

Rectangles or a hexagon may be arranged.

The tuning of a virtual image generated by means of a micro-mirror arrangement can be done in a simulation,

especially in a calculation of the virtual image. By means of such a simulation, at least some influencing variables which influence the virtual image can be interpreted op imal. Such influencing variables include, among other things, the focal length of the micromirrors, the orientation of their mirror axes, the shape of the surface on which the micromirrors are arranged, and the spacings of the micromirrors, as already described above. Each of these factors can be independent of the others

Influencing variables are adjusted. The use of a micro-concave mirror arrangement can reduce the occurrence of a disturbing granular interference pattern, so-called speckle, in a virtual image. Such a granular interference pattern occurs, for example, in diffuser screens and holographic up and down

Rear projection screens, especially when using

coherent light, up. Furthermore, it is an optimal one

Utilization of the light output of a projector possible. This advantage results from the bendability of the optical axis of the micromirror arrangement, in particular by the individual alignment of the mirror axes of the individual

Micro hollow mirror. Through this property, the

Streucharakteristik vary over an area. In particular, a scattering angle can be selected such that the viewing window is optimally illuminated. This is particularly advantageous in the use of micro laser beamers, since they have a low light output. By a suitable geometry of the optics can be a reduced space requirement. This advantage results primarily from the fact that the orientation of the micro-cavity mirror assembly can be adapted to the position and orientation of the projector.

There is further provided a head-up display for a vehicle having an image forming unit and a

Mirror system, wherein the image forming unit comprises a micro hollow mirror assembly having a plurality of

Micro hollow mirrors and a projector, wherein the micro hollow mirror assembly is formed as Aufproj ektionsflache for a radiated image from the projector, and wherein the Mikrohohlspiege1anordnung is adapted to irradiate an image in the mirror system.

The mirror system can be a deflection mirror and a

have imaging mirror. In addition, that can Mirror system additionally or alternatively have one or more lenses. The micro-cavity mirror assembly may be formed as previously described.

Embodiments of the invention are explained in more detail below with reference to the drawings. It shows:

Figure 1A is a schematic representation of a vehicle with

a head-up display,

FIG. 1B shows a detailed schematic illustration of the head-up display according to FIG. 1A

Figure 2 is a schematic representation of an image-forming

Unit,

Figure 3 is a schematic representation of an image-forming

Unit with a micro-hollow mirror arrangement,

Figure 4 is a further schematic representation of a

image-forming unit with a

Mikrohohlspiege1anordnung,

FIG. 5 shows a micro-cavity mirror,

FIG. 6 shows a further schematic representation of a head-up display,

FIG. 7A shows a schematic arrangement of a head-up display in a vehicle,

FIG. 7B shows a further schematic arrangement of a head-up display in a vehicle. FIG. 1A schematically shows a vehicle 30 with a head-up display 23.

FIG. 1B shows a more detailed illustration of the head-up display 23 according to FIG. 1A. The head U display has an image forming unit 1 and a mirror system 25. The mirror system 25 has a deflection mirror 27 and an imaging mirror 29. One of the image-forming

Unit 1 radiated image 21 is irradiated in the mirror system 25.

FIG. 2 schematically shows an image-forming unit 1, as can be used, for example, in a head-up display 23 according to FIGS. 1A and 1B. The image-forming unit 1 has a Aufproj ektionsfläche 5 and a Pro ector 11. The Aufpro shown in Figure 2 ektionsfläche 5 has no Mikrohohlspiegelanordnung. Further, an optical axis 13 of a radiated from a projector 11 and on the Aufproj ektionsfläche 5 irradiated light beam and an optical axis 15 of the surface of the Aufproj ection. 5

radiated light beam shown. The optical axes 13, 15 are symmetrical to a Lot 9 of

Aufproj ektionsfläche 5. In particular, a Ausfallswinkel to Lot 9 of Aufproj ektionsfläche 5 is equal to

Angle of incidence. Such a radiation characteristic occurs, for example, in conventional diffuser screens. These do not permit bending of an emergent beam axis deviating from the law of reflection.

Figure 3 shows schematically an image-forming unit 1 with a micro-hollow mirror assembly 2 as Aufproj ektionsfläche 5 and a projector 11. The optical axis 13 of the projector 11 on the Aufproj ektionsfläche 5 irradiated light beam and the optical axis 15 of a

Aufpro ektionsfläche 5 radiated light beam are not In particular, the angle of reflection of the optical axis 15 to the solder 9 of the Aufproj ektionsflache 5 differs from the angle of incidence of the optical axis 13 to the Lot 9th

A suitable emission characteristic, in particular a

suitable direction of the optical axis 15 of a radiated light beam, by a suitable orientation of

Mirror axes of individual micro hollow mirror can be achieved.

A schematic representation of a Mikrohohlspiegelanordnung 2 as Aufproj ektionsflache 5 with a variety of

Micro hollow mirrors 3 is shown in FIG. The mirror axes 17 of the individual micro-hollow mirror 3 are tilted relative to the Lot 9 of the Aufpro ektionsflache 5, so that the optical axes 13, 15 of irradiated and radiated light are not symmetrical to the Lot 9 of the micro-cavity mirror assembly 2. In the illustrated figure, the mirror axes 17 of

single mirror 3 parallel to each other. In an alternative embodiment, at least some mirrors 3 may be so

be aligned so that their mirror axes 17 are not parallel to each other. By a suitable alignment of

Micro hollow mirror 3 is achieved a suitable radiation characteristic. As a result, for example, an optimal

Illumination of a generated by a head-up display

Viewing window can be achieved.

Another influencing factor on the emission characteristic is the focal length of the individual micromill mirrors 3. In particular, the angle of an emission cone of a micromobular mirror 3 has an effect on the emission characteristic.

The relationship between focal length f, mirror geometry and

Radiating cone a is shown in FIG. The focal length f depends in particular on the diameter D of a mirror and from its curvature. An emanating from a projector 11 quasi-parallel beam 19 is bundled after hitting a micro-concave mirror 3 corresponding to the focal length f and opens at an angle. The angle α corresponds to the angle of the emission cone.

Figure 6 shows schematically a head-up display 23 with an image forming unit 1 and a mirror system 25. The image forming unit 1 is formed as previously described. One of the micro hollow mirror assembly 2

radiated image 21 is in the mirror system 25th

irradiated. The mirror system 25 is not shown for the sake of simplicity. For example, the mirror system 25 has a deflection mirror 27 and an imaging mirror 29. The micro hollow mirror arrangement 2 is in particular for

Illumination of a viewing window 31 is formed. The

Micro hollow mirror 3 of the micro hollow mirror assembly 2 are in particular arranged so that the viewing window 31 is optimally illuminated. For example, the mirror axes 17 of the micro-cavity mirror 3 are aligned so that a

suitable radiation characteristic for optimal illumination of the viewing window 31 results. In particular, at least a subset of micro-cavity mirrors 3 is one of others

Micro hollow mirrors differently oriented mirror axis 17. In FIG. 6, three micro-cavity mirrors are shown by way of example for a plurality of micro-hollow mirrors 3.

Figure 7A shows schematically an arrangement of a head-up display 23 in a vehicle with an image-forming

Unit 1, which has a projector 11 and a

Rear projection 7 and a mirror system 25. The mirror system 25 may, for example, a deflection mirror and an imaging mirror. For the sake of simplicity, to illustrate the position of the head-up display 23 instead of the entire vehicle only one windscreen 33rd represented of the vehicle. When using a

Imaging unit 1 with a rear projection 7, the projector 11, the Rückproj ektionsflache 7 and the mirror system 25 must be arranged substantially in a line. This can result in disadvantages for the space requirement of the head-up display 23, since the position of Pro ector 11, rear projection 7 and mirror system 25 to each other largely determined.

Figure 7B shows schematically an arrangement of a head-up display 23 in a vehicle with an image-forming

Unit 1, which has a Proj ektor 11 and a

Aufproj ektionsflache 5, and a mirror system 25. The mirror system 25 may for example have a deflection mirror and an imaging mirror. For simplicity, only one windscreen 33 of the vehicle is shown to illustrate the location of the head-up display 23 instead of the entire vehicle. The Aufproj ektionsflache 5 is for example a Mikrohohlspiegelanordnung 2. Bei

Use of a micro hollow mirror arrangement 2 as

Aufproj ektionsflache 5, the location of projector 11,

Aufpro ektionsflache 5 and mirror system 25 to each other are designed so that there is a space requirement, which is advantageous for the entire vehicle. In particular, a smaller space requirement may result. The location of projector 11, Aufproj ektionsfläche 5 and mirror system 25 to each other in particular by a suitable orientation of

Mirror axes of the individual micro hollow mirror can be influenced. By a suitable alignment of the mirror axes, in particular the optical axes of the

Au project surface 5 irradiated and from this

emitted light can be aligned so that a

advantageous arrangement of projector 11, Aufproj ektionsflache 5 and mirror system 25 is possible. reference numeral

1 image-forming unit

2 micro hollow mirror arrangement

3 micro hollow mirror

5 front projection area

7 rear projection area

9 lots

11 Pro ector

13 optical axis of irradiated light

15 optical axis of emitted light

17 mirror axis

19 quasiparallel beam

21 radiated image

23 Head-Up Display

25 mirror system

27 deflection mirror

29 imaging mirror

30 vehicle

31 viewing window

33 windscreen

D Diameter of a micro hollow mirror f focal length

α angle radiating cone

Claims

claims

An image-forming unit (1) comprising a

Micro hollow mirror assembly (2) having a plurality of hollow micro mirrors (3) and a projector (11), wherein the Mikrohohlspiege1anordnung (2) as Aufproj ektionsflache (5) for a of the Proj ector (11) radiated image is formed.

2. The image forming unit (1) according to claim 1, wherein

at least a subset of hollow micro-mirrors (3) one of other micro-hollow mirrors (3) different

Focal length (f) has.

3. Image-forming unit (1) according to one of the preceding

Claims, wherein at least a subset of

Micro hollow mirrors (3) has a mirror axis (17) differently oriented from other micro hollow mirrors (3).

4. Image-forming unit (1) according to one of the preceding

Claims, wherein the micro-concave mirror (3) are arranged differently spaced at least in a predetermined area than in at least one other predetermined area.

5. A head-up display (23) for a vehicle (30), comprising an image-forming unit (1) and a mirror system (25), wherein the image-forming unit (1) has a

Micro hollow mirror assembly (2) having a plurality of micro hollow mirrors (3) and a projector (11), wherein the micro hollow mirror assembly (2) as

On roj ektionsflache (5) is formed for a radiated by the projector (11) image, and wherein the Micro hollow mirror assembly (2) is adapted to irradiate an image (21) in the mirror system (25).