DE102018217651A1 - Light module for a lighting device of a motor vehicle - Google Patents

Abstract

The invention relates to a light module (1) for a lighting device of a motor vehicle. The light module (1) has a light source (10) and an optic (O) arranged downstream in the beam path of the light source (10) The light output pixels are part of the one light source (10). This allows the light module (1) to be set up in a very space-saving and energy-efficient manner.

Description

The invention relates to a light module for a lighting device of a motor vehicle with the features of the preamble of claim 1. The invention also relates to a lighting device for a motor vehicle.

Such a light module is from the DE 10 2016 103 649 A1 known. Specifically, a light module for pixel-wise and pixel-individually controllable light radiation into the surroundings of the lighting device is proposed. This is intended to produce an image formed from light pixels. The lighting device has a light source and a light emitting device connected downstream of the light source. The light emitting device can be designed as a light manipulator, such as. B. as DMD (DMD = Digital Micromirror Device) or as LCD (LCD = Liquid Crystal Display). In the case of a DMD, the light emitting device is irradiated by a light source, which can be designed as an LED or other light source. The DMD then continues to reflect the light emitted by the light source thereon to produce the desired image. Due to the multitude of individually controllable micromirrors of the DMD, the pixelated structure of the image can be influenced as desired. The optical pixels of the generated image are distorted in a horizontal and / or vertical spatial direction with respect to a light image of the light output device (original light image) by means of a registering optics downstream of the light output device. In this way it is possible to increase the light intensity of the generated image in the center of the image and also to generate and individually control more individual pixels per unit area in the center of the image compared to the edge of the image. The light emitting device can also be designed with its own light source and can thus be designed, for example, as an LED matrix, ie as a matrix of many LEDs as light sources.

In the US2015 / 0377442 A1 describes a pixel-by-pixel projection using a motor vehicle headlight. Light from an LED light source is emitted into the environment via a DMD and a downstream optic. The optics are intended to generate a wide illumination area with a low illumination height.

The present invention is based on the object of providing a light module for a lighting device of a motor vehicle which can be constructed very compactly and has good efficiency. The invention is also based on the object of providing a lighting device for a motor vehicle which is of compact design and can efficiently provide light energy.

The aforementioned objects are achieved by a light module with the features of claim 1 and a lighting device with the features of claim 7. Advantageous embodiments or further developments of the invention can be found in the respective dependent claims.

The invention starts out from a light module for a lighting device of a motor vehicle. The light module has a light source and optics arranged downstream of the light source in the beam path. A large number of pixel-by-pixel and pixel-individually controllable light emitting pixels can be used to generate an image formed from light pixels or imaging pixels in the environment.

The invention now proposes that the light emission pixels are part of the one light source.

This provides the basic requirement for a very compact construction of the light module. A light manipulator or light modulator known from the prior art, for example in the form of a DMD and the then upstream lighting optics together with the light source, can be dispensed with. The number of components is reduced. By also dispensing with a conventional LED matrix with a large number of LEDs arranged in a matrix, a space-saving, compact solution can also be created.

The light source is in particular a monolithic LED chip which has at least several hundred light emission pixels. Each light emitting pixel is preferably less than 200 microns.

The light source can, for example, be square in outline and thus have an aspect ratio (width: height) of 1: 1 in the image that can be generated directly by it due to the shape of the building. However, another outline of the light source is also conceivable, in which an image that can be generated directly by it has an aspect ratio of 2: 1 or even 3: 1.

According to a first development of the invention, it is proposed that the optics downstream of the light source have at least a first lens, a second lens and a third lens. Light rays emerging from the light source can be bundled or are bundled by the first lens and the second lens. This is done without preventing an original aspect ratio due to the outline of the light source. The second lens also contributes to the sharpness of the image produced. The third lens, on the other hand, allows the light beams to be deflected in such a way that the original aspect ratio is changeable or changed in the generated image.

In this way, the basic requirement is established for the light module to be able to contribute effectively to a desired light distribution of an illumination device.

It is therefore conceivable that the original aspect ratio is enlarged or also reduced by the third lens.

With such a design of the light module, it is very expedient if the original aspect ratio is enlarged or can be enlarged by the third lens. So is the aspect ratio due to the outline of the light source 1 , the aspect ratio can, for example, be adjusted to the value through the third lens 2nd be doubled. In this way, an image generated by the light module can be significantly broadened on an imaginary measurement projection surface. In this way, in particular, good conditions are created in order to be able to achieve the required widths for low beam distributions of a low beam and / or high beam.

In order to be able to realize an enlargement of the original aspect ratio effectively and in a space-saving manner, it is further proposed that the first lens and the second lens are rotationally symmetrical aspheres and the third lens is a non-rotationally symmetrical biconical-zernike lens.

The third lens is therefore an anamorphic lens, which changes the original aspect ratio, in particular enlarges it. An image is referred to as anamorphic, which shows different image scales in both orthogonal coordinate directions of the image and thus, for example, images a square object in a rectangular manner.

In order to be able to keep the installation space of the light module small, the first lens is arranged at a distance from the light source that is less than 3 millimeters, preferably less than 2 millimeters.

In order to achieve high efficiency and high contrasts over the entire surface area of the image produced, it is proposed that the first lens and the second lens each be effective with an anti-reflection coating in the visible wave range of the light, that is to say for a wavelength of approximately 380 to 780 nanometers , to provide. In this way, Fresnel reflections can be reduced to a minimum.

However, it is also conceivable and can be expedient for certain applications if the optics connected downstream of the light source have only said first and second lenses, so that said third lens is dispensed with. This can be useful, for example, if the light module is installed together with other, not structurally identical light modules and is not intended to change the aspect ratio.

As mentioned at the beginning, the invention is also intended to provide an effective lighting device. In order to provide a lighting device which enables the flexible generation of an overall light distribution in a space-saving and energy-efficient manner, it is proposed that such a lighting device has at least two light modules according to the invention. The light modules in the lighting device are arranged and aligned in such a way that the images that can be generated or generated overlap at least in regions.
In addition, the images generated should be almost sharp in the traffic area. A defined, possibly slight blur can be provided in order to reduce the visibility between any gaps between the individual light modules in the overall images generated.

In order to keep the development effort low and to be able to realize the highest possible proportion of identical parts, it is proposed that the light modules used in the lighting device be of identical construction.

A region-wise covering or overlaying of the generated or producible images of the at least two light modules can be realized in a simple manner by translating the light modules in the lighting device. Alternatively or additionally, it is conceivable that the light modules are tilted at an angle to one another with an axis of their main light emission direction. The translational offset or the tilting takes place in particular in the horizontal direction in order to be able to easily implement a desired width of the total light distribution.

It has been shown that a desired total light distribution can be implemented particularly efficiently if three light modules according to the invention are present in the lighting device.

A total light distribution that fulfills the light functions of a high beam and a low beam can be implemented particularly well if each of the light modules provides an image on an imaginary measurement projection surface is or can be generated which has a surface extension of approximately 20 degrees in the horizontal direction and approximately 10 degrees in the vertical direction.

With such a design, it has been shown that, while maintaining the same parts concept, an optimal total light distribution can be generated if the light modules are tilted at an angle of 5 degrees to one another. In this way, an image with a total light distribution can be realized on an imaginary measurement projection surface by the three light modules, which extends with its surface extension in an angular range of approximately 30 degrees horizontally and approximately 10 degrees vertically. A common angular range to be illuminated can thus be covered well.

Also of great importance is the resolution of the pixel-based image in the central area, which can be generated by superimposing the images of the individual light modules. Here, the resolution can be noticeably increased by the fact that each image that can be generated or generated has imaging pixels and the light modules are at least in one direction (i.e. horizontally and / or vertically) offset from one another in such a way that the imaging pixels of the superimposed images are not tilted lie directly on top of each other. Rather, the overlaid images are displayed offset from one another in terms of their pixel width and / or pixel height. The offset of the images can be, for example, half the pixel width and / or pixel height. After all, this leads to a doubling of the resolution in said area.

Finally, the invention is also intended to provide protection for a motor vehicle which is equipped with at least one light module according to the invention or with at least one lighting device according to the invention.

Preferred exemplary embodiments of the invention are shown in the figures and are explained in more detail with reference to the figures in the following description. This also makes further advantages of the invention clear. The same reference numerals, also in different figures, refer to the same, comparable or functionally identical components. Corresponding or comparable properties and advantages are achieved, even if there is no repeated description or reference to them. The figures are not, or at least not always, to scale. In some figures, proportions or distances can be exaggerated in order to be able to emphasize features of an exemplary embodiment more clearly.

• 1 die Darstellung eines erfindungsgemäßen Lichtmoduls von oben,
• 2 die Darstellung des Lichtmoduls von der Seite, gemäß Ansicht II aus 1,
• 3 die Darstellung der Lichtquelle des Lichtmoduls gemäß Ansicht III aus 1,
• 4 die Darstellung einer erzeugbaren Abbildung durch ein erfindungsgemäßes Lichtmodul auf einer gedachten Mess-Projektionsfläche gemäß Ansicht IV aus 1,
• 5 die Darstellung einer Beleuchtungsvorrichtung, welche mehrere erfindungsgemäße und darüber hinaus baugleiche Lichtmodule aufweist,
• 6 die Darstellungen unterschiedlich erzeugbarer Lichtverteilungen bei Verwendung von drei erfindungsgemäßen Lichtmodulen in einer Beleuchtungsvorrichtung,
• 7 die Darstellung unterschiedlicher Ausprägungen der Beleuchtungsvorrichtung, mit denen die Lichtverteilungen gemäß 6 realisiert werden können,
• 8 die Darstellung von Teilbereichen der überlagerten Abbildungen auf Pixelebene, ohne Versatz,
• 9 die Darstellung der überlagerten Abbildungen auf Pixelebene, mit Versatz und
• 10 die Darstellung eines Kraftfahrzeugs mit erfindungsgemäßen Lichtmodulen beziehungsweise erfindungsgemäßen Beleuchtungsvorrichtungen.

It shows, each schematically

• 1 the representation of a light module according to the invention from above,
• 2nd the view of the light module from the side, according to the view II out 1 ,
• 3rd the representation of the light source of the light module according to the view III out 1 ,
• 4th the representation of a producible image by a light module according to the invention on an imaginary measurement projection surface according to the view IV out 1 ,
• 5 the representation of a lighting device which has a plurality of light modules according to the invention and moreover of identical construction,
• 6 the representations of differently generated light distributions when using three light modules according to the invention in an illumination device,
• 7 the representation of different forms of the lighting device with which the light distributions according 6 can be realized
• 8th the representation of partial areas of the superimposed images on pixel level, without offset,
• 9 the representation of the superimposed images on pixel level, with offset and
• 10th the representation of a motor vehicle with light modules according to the invention or lighting devices according to the invention.

First, the 1 to 3rd Referred. In these figures there is a light module 1 apparent which is a light source 10th having. The light source 10th is in the indicated ray path of light rays L an optic O downstream.

The light source 10th is designed in particular as a monolithic LED chip, in a variety of light-emitting pixels in a manner not shown 11 is introduced. The number of light output pixels 11 is at least several hundred, for example 1000 or more (not shown realistically). Each light emitting pixel 11 is square and has an edge length that is preferably less than 200 microns. Each of the light emitting pixels 11 can also be individually controlled by a separate control device, not shown, also with regard to the light intensity and the light color of the emittable light.

The light source 10th , ie the monolithic LED chip is also square in shape with an edge length k . That through the outline of the light source 10th conditional (original) Aspect ratio of an undistorted image would therefore be 1.

As can also be seen, there is that of the light source 10th subordinate optics O from a first lens 20th , a second lens 30th and a third lens 40 . Both the first lens 20th as well as the second lens 30th are designed as plano-convex converging lenses. In particular, the lenses 20th , 30th designed as rotationally symmetrical aspheres.

From the light source 10th emitted light rays L are from the first lens 20th caught and bundled to a smaller angle. In order to keep the space for the light module small, there is a very small distance e between the light source 10th and the first lens 20th adhered to. The distance e is about 2 millimeters or less in the exemplary embodiment. As a material for the lens 20th glass (e.g. N-BK7) is suggested due to the high thermal load.

The second lens 30th bundles the light rays L without changing the original aspect ratio. It also serves to create sharpness in the image that can be generated. Glass, for example crown glass, can also be used as the material. However, the use of transparent, thermoplastic materials (for example PMMA) is also conceivable.

The third lens 40 is an anamorphic lens. It changes the aspect ratio of an imaginary measurement projection surface P projected, through imaging pixels AP formed image A. In particular, the lens 40 a non-rotationally symmetrical, biconical-zernike lens. This is from the comparison of the 1 and 2nd clear. For the lens 40 come from the same materials as the lens 30th questionable.

Finally, it should be noted that the lenses 20th and 30th on their light exit side with a coating S are provided, which has an anti-reflective effect. The coating acts in particular S antireflective in the visible wave range of light (approximately between 380 nanometers to 780 nanometers).

From the 4th is the view of the on the measurement projection surface P Generatable or generated image A in a plan view of the measurement projection surface P shown.

This shows that the image A consists of image pixels AP consists. Each picture pixel AP is represented by a light emission pixel 11 the light source 10th generated or can be generated by such. Thus, the image A also has a large number of image pixels AP on, the maximum of the number of light emitting pixels 11 can correspond (not represented realistically). Figure A shows an area extension c in a horizontal direction H and an area extension d in the vertical direction V on. In particular, the area extension c twice the area d . This should make it clear that due to the anamorphic lens 40 the original aspect ratio has also been doubled at the pixel level. The overall aspect ratio of Figure A is 2. Using the light module 1 in particular an image A can be generated, which is in the horizontal direction H a total surface area of approximately 20 degrees and in the vertical direction V has a total area extension of approximately 10 degrees. Due to this configuration, the light module offers 1 an excellent basis for realizing the desired light distribution in automotive technology.

This is possible in a particularly easy and inexpensive way if in a lighting device 100 for a motor vehicle several, in particular three, light modules according to the invention 1 are installed (compare 5 ).

The one in the lighting fixture 100 built-in light modules 1 are preferably identical. Each of the light modules 1 can thus generate an image A which has an aspect ratio which is doubled compared to the original aspect ratio (cf. 4th ).

As from the figure showing the lighting device 100 in an imaginary installation position from above, the individual light modules are clear 1 offset translationally from each other in the horizontal direction and at the same time at an angle in the horizontal direction α tilted against each other. In particular, the light modules 1 with one axis 12th their main light emission by the named angle α tilted against each other.

In the aforementioned embodiment with three built-in, structurally identical light modules 1 has an angle α of about 5 degrees proved to be particularly useful.

Based on 6 It is now to be shown which different light distributions can be realized with an illumination device in which three light modules according to the invention 1 are installed.

So it shows 6a a light distribution LV1 as with a lighting fixture 100 according to 5 is feasible. Specifically, the light module arranged in the middle 1 a middle figure A1 and through the two outer light modules 1 the two figures A2 and A3 on the imaginary measurement projection surface P generated. Here Figures A1 to A3 are partially overlaid or overlapped. Specifically, the mutual tilting of the light modules leads 1 at an angle α (about 5 °) to a horizontal angular offset of the figures A1 to A3 to each other on the measurement projection surface P at an angle β , which is approximately 5 degrees each.

Because of the angle β and the only partial overlay of Figures A1 to A3 shows the light distribution LV1 different light intensity ranges B1 to B3 on.

This is in the middle of the light distribution LV1 a light intensity range B1 created with maximum light intensity. In the light intensity range B1 all figures A1 to A3 are superimposed. In addition to the light intensity range B1 there are areas in which two figures (A1 with A2 respectively A1 With A3 ) are superimposed on one another. This leads to light intensity ranges B2 with medium light intensity. Finally, there are areas on the very outside of the images in which there is no longer any superimposition and which are formed by the illustration A2 or by the illustration A3. Here light intensity areas arise B3 with the lowest light intensity.

By designing the lighting device 100 according to 5 and the associated overlap and further horizontal expansion of the total light distribution that can be generated LV1 can in the horizontal direction H an angular range of approximately 30 degrees on the measurement projection surface P be covered. In the vertical direction V the area extension remains almost unchanged at about 10 degrees. A total aspect ratio of 3 to 1 is therefore realized. An angular offset of the individual figures A1 to A3 is at an angle β of about 5 degrees.

With the concept of using several, especially three, light modules 1 A wide variety of light distributions can be realized in a lighting device. To do this, however, you may have to turn away from a desired common parts concept.

So is in 6b shown that the light distribution LV1 also with three differently constructed light modules 1 can be realized. Figures A1 to A3 are based on the 6b on three light modules 1 that are not offset or tilted against each other. Rather, each light module points 1 a differently designed third lens 40 on, which leads to different opening angles or to a different width of the generated image. So with a first light module 1 an illustration A1 with a surface extension in the horizontal direction H approximately 30 degrees by 10 degrees (aspect ratio 3rd to 1 ), with a second light module 1 an image A2 with an area extension of approximately 20 degrees by 10 degrees (aspect ratio 2nd to 1 ) and with a third light module 1 an illustration A3 with an area extension of 10 degrees by 10 degrees (aspect ratio 1 ) achievable.

Although the light distributions LV1 and the associated achievable light intensity ranges B1 to B3 in the 6a and 6b same, is the development and manufacturing effort for the embodiment according to 6a significantly lower, since here only identical light modules 1 be used.

In the embodiment according to 6b shows the light module generating Figure A3 1 no anamorphic, so distorting lens 40 on. It's just the lenses 20th and 30th available as a downstream optic

In the 6c to 6f further exemplary embodiments are shown in which light distributions LV2 to LV5 through the use of three light modules 1 can be achieved in a lighting device.

To be mentioned separately 6c , which also has three identical light modules 1 are installed in a lighting device. In contrast to 6a is a mutual tilting of the light modules 1 at an angle α of approximately 6 degrees, which results in a mutual offset of the images on the measurement projection surface P at an angle β of about 6 degrees.

As can be seen, with all light distributions LV1 to LV5 a division or subdivision into the different light intensity ranges B1 to B3 possible.

Based on 7 is once again for each of the light distributions LV1 to LV5 shown that each light distribution by at least two different forms a or b can be realized. While the expression a in the light distributions LV1 and LV2 through a strict common parts concept with tilted and / or offset light modules 1 is realized, the same light distribution can be realized after a second version b without tilting or mutual displacement, simply by using different light sources 10th downstream optics can be achieved.

Based on 8th and 9 explains how to overlap the images at the pixel level.

It is conceivable that two images A1 and A2 are on the plane of their image pixels AP (compare A1 ' and A2 ') can be superimposed in such a way that the pixels AP of the superimposed figures A1, A2 also exactly overlay. With h1 is a pixel height and with b1 numbered a pixel width.

In the 9 it becomes clear what effect can be achieved if several images (e.g. A1 and A2 ) are superimposed on the pixel level in such a way that there is an offset VS towards the pixel width b1 which is, for example, half the pixel width b1 can correspond. This leads to the fact that at the level of the imaging pixels AP the resolution in the overlapped area doubled.

Finally in 10th a motor vehicle K visible, which with headlights 2nd Is provided. In the headlights 2nd is a lighting device 100 installed, in the embodiment with three structurally identical light modules 1 . The lighting fixtures 100 are via a bus system C. (CAN bus) with a higher-level evaluation and control device 5 connected. The evaluation and control device 5 controls the lighting devices 100 depending on signals from sensors 3rd (for example light sensors, environment cameras) or also from operating switches 4th receives.

For example, it is conceivable that the sensors 3rd an oncoming motor vehicle (not shown) is detected and the lighting devices as a function thereof 100 can be controlled pixel by pixel in such a way that the oncoming motor vehicle is not dazzled.

Reference list

1

Light module

2nd

Headlights

3rd

Sensors

4th

counter

5

Evaluation and control device

10th

Light source

11

Light emission pixels

12th

Axis of the main direction of light emission

20th

first lens

30th

second lens

40

third lens

100

Lighting device

a

first expression

b

second expression

A

Illustration

A1-A3

Illustrations

A1 ', A2'

Parts of pixel-level images

AP

Imaging pixels

b1

Pixel width

B1-B3

Light intensity ranges

c

Horizontal surface extension

C.

Bus system, CAN bus

d

Area extension in the vertical direction

e

distance

H

Horizontal direction

h1

Pixel height

k

Edge length

K

Motor vehicle

L

Rays of light

LV1-LV5

Light distributions

O

Optics

P

Measuring projection surface

S

Coating

V

Vertical direction

VS

Offset

α

angle

β

angle

QUOTES INCLUDE IN THE DESCRIPTION

This list of documents listed by the applicant has been generated automatically and is only included 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.

Patent literature cited

• DE 102016103649 A1 [0002]
• US 2015/0377442 A1 [0003]

Claims (14)

Light module (1) for a lighting device (100) of a motor vehicle (K), with a light source (10) and an optic (O) arranged downstream of the light source (10) in the beam path, with a plurality of pixel-by-pixel and pixel-individually controllable light-emitting pixels (11) an image (A, A1-A3) formed from imaging pixels (AP) can be generated in the environment, characterized in that the light-emitting pixels (11) are part of the one light source (10). Light module (1) after Claim 1 , characterized in that the optics (O) connected downstream of the light source (10) has at least a first lens (20), a second lens (30) and a third lens (40), with the first lens (20) and the second Lens (30) from the light source (10) light rays (L) can be bundled without changing an original aspect ratio due to the outline of the light source (10) and the third lens (40) can deflect the light rays (L) in this way is that the original aspect ratio in the generated image (A, A1-A3) has changed. Light module (1) after Claim 2 , characterized in that the original aspect ratio can be enlarged by the third lens (40). Light module (1) after Claim 3 , characterized in that the first lens (20) and the second lens (30) are rotationally symmetrical aspheres and the third lens (40) is a non-rotationally symmetrical biconical-zernike lens. Light module (1) according to one of the preceding Claims 2 to 4th , characterized in that the first lens (20) has a distance (e) from the light source (10) which is less than 3 mm, preferably less than 2 mm. Light module (1) according to one of the preceding Claims 2 to 5 , characterized in that the first lens (20) and the second lens (30) are each provided with an anti-reflection coating (S) in the visible waveband of the light. Lighting device (100) for a motor vehicle (K), characterized by at least two light modules (1) according to at least one of the preceding claims, the light modules (1) being arranged and aligned in the lighting device (100) in such a way that they can be generated cover or generated images (A1-A3) at least in certain areas. Lighting device (100) after Claim 7 , characterized in that the light modules (1) are identical. Lighting device (100) after Claim 7 or 8th , characterized in that the light modules (1) in the lighting device (100) are offset from one another in translation and / or are tilted relative to one another at an angle (a) with an axis (12) of their main light emission direction. Lighting device (100) according to one of the Claims 7 to 9 , characterized in that three light modules (1) are present. Lighting device (100) after Claim 10 , characterized in that an image (A1, A2, A3) can be generated or is generated by each of the light modules (1) on an imaginary measurement projection surface (P), which has a surface extension of 20 degrees in the horizontal direction (H) and at a height of 10 degrees in the vertical direction (V). Lighting device (100) after Claim 11 , characterized in that the light modules (1) are tilted at an angle (a) of 5 degrees to each other. Lighting device (100) according to one of the Claims 7 to 12th characterized in that each image (A, A1-A3) that can be generated or generated has imaging pixels (AP) and the light modules (1) are at least in one direction translationally offset from one another or tilted at an angle (a) that the imaging pixels ( AP) of the superimposed images (A1 'and A2') do not lie directly one above the other, but are mapped to one another in their offset (VS) in their pixel width (b1) and / or pixel height (h1). Motor vehicle (K) with at least one light module (1) according to at least one of the Claims 1 to 6 or with at least one lighting device (100) according to at least one of the preceding Claims 7 to 13 .

Images