DE102023201959A1 - Method for generating a light distribution by a headlight of a motor vehicle and headlight for carrying out the method - Google Patents

Abstract

The invention relates to a method for generating a light distribution (LV) by a headlight (1) of a motor vehicle (K), wherein the light distribution (LV) is formed from at least a first partial light distribution (LV1) and a second partial light distribution (LV2) that differs from the first partial light distribution (LV1). The first partial light distribution (LV1) is generated by a plurality of light sources (10) arranged in the headlight (1) in a matrix-like manner, the light rays (L1) of which at least partially reach an imaging optics (12) and are projected by this into an area in front of the motor vehicle (K). The second partial light distribution (LV2) is generated by at least one additional light source (16) arranged in the headlight (1), the light rays (L2) of which are only directed towards the imaging optics (12) after being deflected in one direction and are also projected by the imaging optics (12) into an area in front of the motor vehicle (K).

Description

The invention relates to a method for generating a light distribution by a headlight of a motor vehicle. The invention also relates to a headlight for carrying out the method.

Headlights on a motor vehicle are generally used to create a specific light distribution in front of the vehicle. On the one hand, the light distribution should give the driver an optimal view of the surroundings in all traffic situations, and on the other hand, other road users should not be unnecessarily impaired by the light distribution, in particular not blinded. Possible light distributions include, for example, dipped beam, high beam, city light and motorway light.

Modern headlights are increasingly using LEDs (light-emitting diodes) as light sources. LED headlights are now available in the state of the art, in which, among other things, a large number of LEDs are arranged in a matrix on a carrier element. Headlights are already known that have, among other things, an LED matrix consisting of more than 20,000 LEDs. Such headlights are particularly dense and compact, while being highly efficient. The light rays from the LEDs can be projected directly onto the area in front of the vehicle using suitable imaging optics (e.g. projection lens). The LEDs can usually be controlled individually, which means that the light distribution generated can be adapted extremely flexibly to the respective traffic conditions (e.g. oncoming traffic) even without mechanical actuators (so-called adaptive light control).

From the EN 10 2004 032 797 A1 A headlight of a motor vehicle is known with which different light distributions can be generated. Specifically, the headlight has a flat light source and an imaging optic arranged at a distance in front of it. The flat light source consists of a plurality of individually switchable LEDs that are arranged in an elongated, rectangular field. The imaging optics are designed as an aspherical lens. By controlling the LEDs accordingly, they can be switched in different groups, arrangements and distributions, so that light distributions of a low beam, a high beam and also a fog light can be generated.

Headlights are also known whose housings carry several light modules whose light is combined with one another. Each of the light modules has light sources and a downstream optics to create a specific partial light distribution. The partial light distributions formed by the individual light modules (e.g. adaptive driving lights, approach lighting) can be superimposed on one another to achieve the desired light distribution. However, there may also be applications in which the presence of as few light modules as possible or even just a single light module in a headlight is desired purely for design, installation space or cost reasons.

The term light module in the sense of the present invention is to be understood as an assembly of a headlight which consists of at least one light source and a downstream optic through which generated light rays pass and emerge from the headlight in a main radiation direction of the headlight to produce a light distribution to the outside.

Against this background, the present invention is based on the object of proposing a method for generating a light distribution by a headlight of a motor vehicle, which creates the basic prerequisite for a desired light distribution to be generated with as few light modules as possible or even with only a single light module.

A further object of the invention is to provide a suitable headlight for carrying out the method.

These objects are achieved by a method having the features of patent claim 1 and by a headlight having the features of patent claim 5. Advantageous embodiments or further developments of the invention can be found in the respective dependent claims.

The invention describes a method for generating a light distribution by a headlight of a motor vehicle. In the method according to the invention, the light distribution is formed from at least a first partial light distribution and a second partial light distribution that differs from the first partial light distribution. The first partial light distribution is generated by a large number of light sources arranged in a matrix in the headlight. The large number of light sources arranged in a matrix are preferably formed by microscopically small LEDs that are arranged in many rows and columns. The light rays from the LEDs arranged in a matrix reach at least partially, but preferably at least predominantly, an imaging optics and are projected by this into an area in front of the motor vehicle. The imaging optics can, for example, be formed by a projection lens. The light rays from the matrix-like light sources are projected directly into the environment in front of the vehicle by a projection lens. The imaging optics are therefore direct-imaging. If required, a collecting optics can be arranged in front of the imaging optics in the direction of light emission to collect the light rays from the matrix-like LEDs. Such a collecting optics can preferably be designed as a collimator. The imaging optics and the collecting optics can also be connected to one another in one piece.

In the method, the second partial light distribution is generated by at least one additional light source arranged in the headlight, which is not part of the matrix-like light sources. However, their light rays are only directed in a direction towards the imaging optics after being deflected by a deflection device and then also projected by the imaging optics into an area in front of the motor vehicle. Preferably, the light rays are additionally collected and/or bundled onto the imaging optics after or with the deflection. It is also conceivable to design the deflection device as a component of the above-mentioned, optional collecting optics.

It is conceivable, for example, that the method is intended to generate a low beam distribution as a light distribution. In this case, it is conceivable that the first partial light distribution mentioned, which is generated via the large number of light sources arranged in a matrix in the headlight, has a distribution in the horizontal direction of approximately ±15° and a distribution of up to approximately ±5° in the vertical direction on a conventional measuring screen.

The second light distribution mentioned can have a distribution in the horizontal direction of approximately ±35° and a distribution in the vertical direction of approximately -12° on the measuring screen. By superimposing the two partial light distributions, a desirable light distribution for low beam can be achieved with just a single light module.

According to a further development of the method, the light rays are redirected by reflecting the light rays of the at least one additional light source on a carrier element in the headlight, which also carries the matrix-like light sources. This method is structurally easy and inexpensive to implement. Since a carrier element for the matrix-like LEDs must be present anyway, additional components can be omitted.

According to an alternative procedure, however, it is also conceivable that the light rays are redirected by reflecting the light rays from the at least one additional light source on at least one separate component in the headlight that is not itself formed by the carrier element for the matrix-like light sources. This allows a very flexible and precise alignment of the reflection by appropriately designing the separate component.

It is conceivable to design the separate component as a reflector, for example, and to arrange it in the immediate vicinity of the matrix-like light sources. It is also conceivable to design the separate component as a semi-transparent mirror, which is arranged in such a way that it lets the light rays of the matrix-like LEDs pass through unhindered in the direction of the imaging optics, but reflects light rays of the at least one additional light source in the direction of the imaging optics. It is also conceivable to design the separate component as a prism optic, which is operated close to the angle of total internal reflection.

According to another embodiment of the method, the light beams can be redirected by redirecting light beams from the at least one additional light source by means of at least one light guide in the direction of the imaging optics. This offers the advantage of very high flexibility as far as the arrangement of the at least one second light source is concerned. By appropriately designing the light guide, the light from the second light source can be optimally aligned with the imaging optics, regardless of the positioning and alignment of the second light source.

At the same time as the light rays are deflected by the deflection device, they can also be bundled and/or collected on the imaging optics. The deflection device (e.g. reflector, prism optics or light guide) can therefore also be part of a collection device (collimation optics) or combined with one.

The present invention also proposes a headlight for carrying out the method according to the invention. The headlight has a housing in which at least one carrier element is present, on which a plurality of light sources arranged in a matrix for generating light rays of a first partial light distribution are arranged. Viewed in a main radiation direction of the headlight, at least one projection lens is arranged downstream of the carrier element.

The large number of light sources arranged in a matrix is preferably formed by microscopically small LEDs that are arranged in many rows and lines to form an LED matrix. The number of LEDs arranged in a matrix can be, for example, 20,000 or more. This offers the advantage that the first partial light distribution can be generated with an extremely high resolution.

The headlight also has at least one additional light source, not arranged on the carrier element, for generating light rays of a second partial light distribution. The additional light source is assigned at least one deflection device for deflecting the light rays of the at least one additional light source in the direction of the projection lens.

These features of the headlight create the prerequisites for the method to be easily carried out with the headlight. Furthermore, the headlight requires only a few light modules in the sense of the invention, in particular only a single light module. The headlight can therefore be kept compact and cost-effective.

According to one embodiment, it is proposed that the deflection device is formed by the carrier element itself for the plurality of light sources arranged in a matrix. The carrier element is designed to be at least partially reflective. Such a design is easy to implement, inexpensive and efficient.

For example, it is conceivable that only an area of the carrier element next to the LED matrix (e.g. above, below or to the side of the LED matrix), which is not occupied by LEDs, is designed to be reflective. However, it is also conceivable that the entire carrier element is designed to be reflective. For example, the carrier element can be provided with a reflective layer (e.g. white or metallized) in some areas or completely.

According to another development, the deflection device can be formed by a separate, reflective component in the headlight, which is arranged in the immediate area of the matrix-like light sources. For this purpose, the separate, reflective component can preferably be attached to the carrier element for the matrix-like light sources. However, it is also conceivable to attach the separate, reflective component to another component in the headlight.

With regard to the flexibility of the orientation of the reflected light rays, it can be advantageous if the separate reflective component is a reflector, a semi-transparent mirror or a prism optic.

According to another embodiment, it is proposed that the deflection device is formed by at least one light guide, with at least one light coupling surface and at least one light coupling surface. The light coupling surface of the light guide is arranged downstream of the at least one additional light source in its light emission direction and the light coupling surface of the light guide is aligned in the direction of the projection lens.

Finally, the present invention is also intended to protect a motor vehicle which is equipped with at least one headlight according to the invention.

Preferred embodiments of the invention are shown in the figures and are explained in more detail in the following description with reference to the figures. This also makes further features and advantages of the invention clear. The same reference symbols, even 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 may be exaggerated in order to be able to highlight features of an embodiment more clearly. If the term "and/or" is used in a list of two or more terms or objects, this can mean that any of the terms or objects listed can be used alone. It can also mean that any combination of two or more of the terms or objects listed can be used.

They show, each schematically

• 1 a front part of a motor vehicle with a headlight to explain the procedure,
• 2a a first partial light distribution generated by the headlight,
• 2b a second partial light distribution generated by the headlight,
• 2c a light distribution that can be generated by superimposing the partial light distributions,
• 3 a headlight for carrying out the method, in a first embodiment,
• 4 a view of the matrix-like light sources with support element according to view IV of 3 , the imaging optics are not shown
• 5 a headlight for carrying out the method, in a second embodiment,
• 6 a headlight for carrying out the method, in a third embodiment,

First, 1 , which primarily serves to explain the method. In this figure, a front area of a motor vehicle K is indicated. The motor vehicle K is equipped with two headlights 1, of which only one is visible in this illustration. The headlight 1 has a housing 14, which is covered in a main radiation direction HA by a translucent cover plate 14a. In the headlight 1, there are a large number of light sources 10 arranged in a matrix. The light sources 10 are designed as microscopically small LEDs (light-emitting diodes) which are arranged in a large number of rows and columns to form an LED matrix 11. The matrix-like light sources 10 can, for example, be arranged in more than 80 rows and more than 240 columns. The LED matrix 11 can therefore have more than 20,000 microscopically small LEDs. The light sources 10 of the LED matrix 11 can be controlled individually and/or in groups via a control device (not shown). Light rays L1 generated by the LED matrix 10 (only two are shown by way of example) reach at least partially, but preferably at least predominantly, an imaging optics 12 arranged downstream of the LED matrix 11 in the main emission direction HA. If required, the light rays L1 can be collected on the imaging optics 12 by a suitable collimation optics (not shown) upstream of the imaging optics 12 in the main emission direction HA.

The imaging optics 12 is preferably designed as a projection lens. Light rays L1 of the LED matrix 11 are projected by the imaging optics 12 outwards through the cover plate 14a into the surroundings of the motor vehicle K and generate a first partial light distribution LV1. Each light source 10 of the LED matrix 11 corresponds to a pixel in the generated light distribution LV1. Due to the large number of light sources 10 and their controllability, a high-resolution, highly flexibly adaptable light distribution LV1 is thus possible. In the exemplary embodiment, the first partial light distribution LV1 is part of a light distribution LV, whereby a low beam can be realized with the light distribution LV.

As can also be seen from the figure, at least one additional light source 16 is arranged in the headlight 1, which can preferably also be designed as an LED. The additional light source 16 is not a component of the LED matrix 11.

The light source 16 can generate light rays L2. However, at least most of these are not emitted in the direction of the imaging optics 12. Rather, the light rays L2 are first directed in a direction towards the imaging optics 12 by a deflection device 13. The light rays L2 are then also projected by the imaging optics 12 into an area in front of the motor vehicle K. There, the light rays L2 generate a second partial light distribution LV2 that differs from the first partial light distribution LV1 and forms part of the light distribution LV in the exemplary embodiment. In particular, the light distribution LV2 forms an area lighting. Otherwise, only the most important elements for explaining the method are shown in the figure.

In the 2a to 2c The light distributions generated or producible by the procedure are now shown, as they are visible on an imaginary, virtual measuring screen due to a simulation of the procedure.

It can be seen that the first partial light distribution LV1 has a width of approximately ± 20° in the horizontal direction H. In the vertical direction V, the first partial light distribution LV1 forms a height of up to approximately ± 5° (cf. 2a) .

The second partial light distribution LV2 creates a width of approximately ± 35° in the horizontal direction H. In the vertical direction V, the second partial light distribution LV2 creates a height of up to approximately + 2° and approximately -12° (cf. 2b) The partial light distribution LV2 therefore deviates from the partial light distribution LV1 and is different from it.

By superimposing the partial light distributions LV1 and LV2 as described, a light distribution LV can now be generated with a single light module, which has a width of up to approximately ± 35° in the horizontal direction H (apron lighting) and a height of up to approximately + 5° and approximately -12° in the vertical direction V (cf. 2c ).

Deviating from the embodiment example, the partial light distributions LV1, LV2 and the light distribution LV can also be other types of light distributions.

In the 3 a headlight 1a for carrying out the method is shown. In this figure it is clearly visible that an LED matrix 11 consisting of a plurality of light sources 10 (LEDs) is accommodated in a housing 14 of the headlight 1a (see also 4 and explanations of 1 ). The LED matrix 11 is mounted on a carrier element 15. The carrier element 15 itself can in turn be arranged on a circuit board 17, which has further electronic components (not shown). Around the LED matrix 11, for example above and below, there are optically unused regions 15a and 15b of the carrier element 15. In the exemplary embodiment, the upper, optically unused region 15a is preferably provided with a reflective coating 18. The reflective coating 18 can preferably be a white coating (e.g. white paint) or a metallic coating (e.g. vapor-deposited aluminum layer). Deviating from the exemplary embodiment, it is also conceivable that not only part of the carrier element 15, but the entire carrier element 15 is designed to be reflective.

Light rays L1 generated by the LED matrix 11 (only two shown as an example) in turn reach at least partially, preferably for the most part, a downstream imaging optics 12, seen in a main radiation direction HA of the headlight 1a, which is preferably designed as a projection lens. The imaging optics 12 can deflect the light rays L1 in the direction of a cover plate 14a and finally project them into the environment in front of a motor vehicle.

Furthermore, at least one second light source 16 is present in the headlight 1a, which is not arranged on the carrier element 15. This can generate light rays L2, which, however, are not emitted at least to a large extent in the direction of the imaging optics 12. Therefore, the carrier element 15 or a part of the carrier element 15, in particular its reflective coating 18, serves as a deflection device 13 for the light rays L2 in the direction of the imaging optics (see also 1 ). Optionally, an indicated primary optics 16a can also be present for "collecting" the emitted light rays L2. The imaging optics 12 can in turn project the light rays L2 onto the environment in front of a motor vehicle and superimpose them with the light rays L1 to create a desired light distribution.

From the 5 a headlight 1b is visible in which, in contrast to the previous embodiment, the deflection device 13 is designed as a separate, reflective component 19. The reflective component 19 is preferably attached to the carrier element 15. The reflective component 19 is preferably arranged above the LED matrix 11. Light rays L2 of the additional light source 16 generated in this embodiment can also be deflected in the direction of the imaging optics 12 by the reflective component 19.

Finally, in the 6 a headlight 1c is shown in which, in contrast to the previous embodiments, the deflection device 13 is designed as at least one light guide 20. The light guide 20 is arranged with a light coupling surface 20a downstream of the additional light source 16 in the direction of its light emission. The light coupling surface 20b of the light guide 20 is aligned in the direction of the imaging optics 12. The advantage of this solution lies in a very high degree of flexibility with regard to a possible positioning and arrangement of the additional light source 16.

In the 5 and 6 In the embodiments shown, it is conceivable that the deflection device 13 simultaneously bundles and/or collects the deflected light rays L2 onto the imaging optics 12. In other words, the deflection device 13 can simultaneously form a collecting device or be combined with such a collecting device.

List of reference symbols

1, 1a-1c

Headlights

10

matrix-like light sources; LEDs

11

LED matrix

12

imaging optics; projection lens

13

Deflection device

14

Housing

14a

Cover plate

15

Support element

15a

optically unused area of the support element

15b

optically unused area of the support element

16

additional light source

16a

Primary optics

17

Board

18

reflective coating

19

reflective component

20

Light guide

20a

Light coupling surface

20b

Light coupling surface

H

horizontal direction

HA

Main radiation direction

K

Motor vehicle

L1

Light rays

L2

Light rays

LV1

first partial light distribution

LV2

second partial light distribution

LV

Light distribution

V

vertical direction

QUOTES INCLUDED IN THE DESCRIPTION

This list of documents listed by the applicant was 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 accepts no liability for any errors or omissions.

Cited patent literature

• DE 102004032797 A1 [0004]

Claims (10)

Method for generating a light distribution (LV) by a headlight (1, 1a, 1b, 1c) of a motor vehicle (K), wherein the light distribution (LV) is formed from at least a first partial light distribution (LV1) and a second partial light distribution (LV2) that differs from the first partial light distribution (LV1), wherein the first partial light distribution (LV1) is generated by a plurality of light sources (10) arranged in a matrix in the headlight (1, 1a, 1b, 1c), the light rays (L1) of which at least partially reach an imaging optics (12) and are projected by the latter into an area in front of the motor vehicle (K), and wherein the second partial light distribution (LV2) is generated by at least one additional light source (16) arranged in the headlight (1, 1a, 1b, 1c), which is not part of the matrix-arranged light sources (10) and whose light rays (L2) only reach the imaging optics (12) after being deflected by a Deflection device (13) is aligned in a direction towards the imaging optics (12) and is also projected by the imaging optics (12) into an area in front of the motor vehicle (K). Procedure according to Claim 1 , characterized in that the deflection of the light rays (L2) takes place by reflection of the light rays (L2) of the at least one additional light source (16) on a carrier element (15) in the headlight (1a), which also carries the matrix-like arranged light sources (10). Procedure according to Claim 1 , characterized in that the deflection of the light rays (L2) takes place by reflection of the light rays (L2) of the at least one additional light source (16) on at least one separate component (19) in the headlight (1b) which is not formed by the carrier element (15) itself. Procedure according to Claim 1 , characterized in that the deflection of the light rays (L2) is carried out by deflecting the light rays (L2) of the at least one additional light source (16) by means of at least one light guide (20) in the direction of the imaging optics (12). Headlight (1, 1a, 1b, 1c) for a motor vehicle (K) for carrying out the method according to one of the preceding claims, with a housing (14) in which at least one carrier element (15) is present, on which a plurality of light sources (10) arranged in a matrix-like manner for generating light rays (L1) of a first partial light distribution (LV1) are arranged, wherein at least one projection lens (12) is arranged downstream of the carrier element (15) as seen in a main radiation direction (HA) of the headlight (1, 1a, 1b, 1c), and wherein at least one additional light source (16) not arranged on the carrier element (15) is present for generating light rays (L2) of a second partial light distribution (LV2), to which at least one deflection device (13) for deflecting the light rays (L2) of the at least one additional light source (16) in the direction of the projection lens (12) is assigned. Headlight (1a) after Claim 5 , characterized in that the deflection device (13) is formed by the carrier element (15) for the plurality of matrix-like arranged light sources (10) itself and is at least partially reflective. Headlight (1b) after Claim 5 , characterized in that the deflection device (13) is formed by a separate reflective component (19) in the headlight (1b), which is arranged in the immediate area of the matrix-like arranged light sources (10). Headlight (1b) after Claim 7 , characterized in that the separate reflective component (19) is a reflector, a semi-transparent mirror or a prism optic. Headlight (1c) after Claim 5 , characterized in that the deflection device (13) is formed by at least one light guide (20) with at least one light coupling surface (20a) and at least one light coupling surface (20b), wherein the light coupling surface (20a) of the light guide (20) is arranged downstream of the at least one additional light source (16) in its light emission direction and wherein the light coupling surface (20b) of the light guide (20) is aligned in the direction of the projection lens (12). Motor vehicle (K) with at least one headlight (1, 1a, 1b, 1c) according to one of the Claims 5 until 9 .

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