Lighting Device for a Motor Vehicle Headlight

Abstract

The invention relates to a lighting device (1) for a motor vehicle headlight, comprising: a light module (2), wherein the light module (2) comprises a light source (2a) and a collimator (3), which is set up in such a manner that the light generated by the light source (2a) is emitted via a light-emitting surface (3a) in a light propagation direction (4), an optical element (5) having a light-coupling surface (5a) and a light-decoupling surface (5b), wherein the light of the collimator is guided through the optical element (5), wherein the light-decoupling surface (5b) of the optical element (5) has multiple optical elements (6) through which the light is emitted as a divergent light beam, wherein
the light-emitting surface (3a) of the collimator (3) is formed from multiple lenses (7), wherein each lens (7) is set up for emitting the light of the light source (2a) to the light-coupling surface (5a) of the optical element (5) in a divergent manner, wherein all lenses (7) have essentially the same focal length, wherein the collimator (3) and the optical element (5) are spaced apart from each other, wherein the distance between them essentially corresponds to the focal length of the lenses (7).

Claims

1. A lighting device (1) for a motor vehicle headlight, comprising: at least one light module (2), wherein the light module (2) comprises a light source (2a) and a collimator (3) associated with the light source (2a), wherein the light source (2a) is configured to generate light and couple the light into the collimator (3), wherein the collimator (3) is is configured to emit the light generated by the light source (2a) via a light-emitting surface (3a) of the collimator (3) as a divergent light beam in a light propagation direction (4); and an optical element (5) which is arranged downstream of the collimator (3), as seen in the light propagation direction (4), with a light-coupling surface (5a) and a light-decoupling surface (5b), wherein the light which is emitted from the collimator (3) strikes the light-coupling surface (5a) of the optical element (5), is directed through the optical element (5) to the light-decoupling surface (5b) of the optical element (5), and is emitted from the optical element (5) at the light-decoupling surface (5b), wherein the light-coupling surface (5a) of the optical element (5) has a Fresnel optics, wherein the Fresnel optics is configured to refract the light beams as they enter the optical element (5) in such a manner that the light beams propagate parallel to each other within the optical element (5), wherein the light-decoupling surface (5b) of the optical element (5) has multiple optical elements (6), wherein each optical element (6) is configured such that the light is emitted from each optical element (6) as a light beam, wherein the light-emitting surface (3a) of the collimator (3) is formed from multiple lenses (7), which are arranged in a uniform grid on the entire light-emitting surface (3a) of the collimator (3), wherein each lens (7) is set up for emitting the light of the light source (2a) toward the light-coupling surface (5a) of the optical element (5) in a divergent manner, such that each of the multiple lenses (7) illuminates the light-coupling surface (5a) of the optical element (5), wherein all lenses (7) have essentially the same focal length, wherein the collimator (3) and the optical element (5) are spaced apart from each other, wherein the distance between them essentially corresponds to the focal length of the lenses (7).

2. The lighting device (1) according to claim 1, wherein the optical element (5) is plate-shaped, wherein the plate-shaped optical element (5) is curved or flat.

3. The lighting device (1) according to claim 1, wherein each of the multiple lenses (7) illuminates the light-coupling surface (5a) of the optical element (5) completely, which means that the illumination of the light-coupling surface (5a) is composed of an overlap of the light emitted by all lenses (7).

4. The lighting device (1) according to claim 1, wherein each lens (7) has the same dimensions and/or optical properties.

5. The lighting device (1) according to claim 1, wherein the diameter of each lens is 0.2 mm to 5 mm.

6. The lighting device (1) according to claim 1, wherein the light-emitting surface (3a) of the collimator (3) is smaller than the light-coupling surface (5a) of the optical element (5).

7. The lighting device (1) according to claim 1, wherein the light-emitting surface (3a) of the collimator (3) is spaced apart from the light-coupling surface (5a) of the optical element (5) and arranged in such a manner that the light emitted from each lens (7) exclusively illuminates the light-coupling surface (5a) of the optical element (5) completely and exactly.

8. The lighting device (1) according to claim 1, having a first (2) and a second light module (2a), wherein the first light module (2) illuminates a first partial area of the light-coupling surface (5a), and the second light module (2b) illuminates a second partial area of the light-coupling surface (5a), wherein the first and the second partial area each form one half of the light-coupling surface (5a).

9. The lighting device (1) according to claim 8, wherein the first and the second partial surface are illuminated without overlap.

10. A lighting system (8) comprising: a lighting device (1) according to claim 1; and a lighting unit (9), wherein the lighting unit (9) is configured to generate light and radiate the light along a light-emitting direction (10), wherein the light-emitting direction (10) is aligned toward the focal plane of the lenses (7) of the collimator (3) of the light module (2), wherein the lighting system (8) comprises an adjusting device (11) by means of which the optical element (5) of the lighting device (1) can be transposed between a first and a second position, wherein the optical element (5) in the first position is arranged in such a manner that the light emitted by the at least one light module (2) of the lighting device (1) strikes the light-coupling surface (5a) of the optical element (5), wherein the optical element (5) in the second position is arranged in such a manner that no light emitted by the at least one light module (2) of the lighting device (1) strikes the light-coupling surface (5a) of the optical element (5), and the optical element (5) is positioned outside the light-emitting direction (10) of the light emitted by the lighting unit (9).

11. The lighting system (8) according to claim 10, wherein the light module (2) of the lighting device (1) and the lighting unit (9) are arranged relative to each other in such a manner that the light propagation direction (4) of the collimator (3) of the light module (2) and the light-emitting direction (10) of the lighting unit (9) have an acute angle to each other.

12. The lighting system (8) according to claim 10, wherein the light propagation direction (4) of the collimator (3) of the light module (2) and the light-emitting direction (10) of the lighting unit (9) intersect, wherein the point of intersection is in the focal plane of the lenses (7) of the collimator (3).

13. The lighting system (8) according to claim 10, wherein, when the optical element (5) is in the first position, the at least one light module (2) of the lighting device (1) is in an active state in which light is emitted onto the light-coupling surface (5a) by the at least one light module (2), wherein the lighting unit (9) is in an inactive state in which it does not emit light while the lighting device (1) is in the active state.

14. The lighting system (8) according to claim 10, wherein, when the optical element (5) is in the second position, the lighting unit (9) is in an active state in which light is emitted as a light beam by the lighting unit (9), wherein the at least one light module (2) of the lighting device (1) is in an inactive state in which the at least one light module (2) does not emit light while the lighting unit (9) is in the active state.

15. The lighting system (8) according to claim 10, wherein the lighting system (8) generates a first light distribution when the optical element (5) is in the first position and the at least one light module (2) of the lighting device (1) is in an active state, and generates a second light distribution when the optical element (5) is in the second position and the lighting unit (9) is in an active state.

16. The lighting system (8) according to claim 15, wherein the first light distribution comprises a light distribution of a daytime running light or a signal light function, and the second light distribution comprises a low-beam distribution or high-beam distribution.

17. The lighting system (8) according to claim 10, wherein the lighting device (1) and/or the lighting unit (9) each have a light source which is configured to generate white and/or coloured light.

18. The lighting device (1) according to claim 1, wherein each optical element (6) is configured such that the light is emitted from each optical element (6) as a divergent light beam.

19. The lighting device (1) according to claim 5, wherein the diameter of each lens is from 0.6 mm to 3 mm.

20. The lighting device (1) according to claim 5, wherein the diameter of each lens is from 1 mm to 2 mm.

21. The lighting system (8) according to claim 15, wherein the first light distribution and the second light distribution are different from one another.

Description

[0029] The invention is further explained below on the basis of a preferred embodiment, to which it should not be limited, however. In the drawings:

[0030] FIG. 1 is a perspective view of a lighting device according to the invention having two light modules;

[0031] FIG. 2 is a top view of the lighting device according to FIG. 1;

[0032] FIG. 3 is a back view of the lighting device according to FIG. 1;

[0033] FIG. 4 is a top view of the lighting device with a light module with a schematic light beam progression;

[0034] FIG. 4a is a top view of the lighting device according to FIG. 1 with a schematic light beam progression;

[0035] FIG. 5 is a side view of the lighting device with a schematic light beam progression;

[0036] FIG. 6 is a side view of the lighting system in a first operating state; and

[0037] FIG. 7 is a side view of the lighting system in a second operating state.

[0038] The drawings are greatly simplified for a better overview and show only the essential components of the invention.

[0039] FIG. 1-3 show different views of a lighting device 1 for a motor vehicle headlight having two light modules 2, wherein the light modules 2 each have a light source 2a and a collimator 3. The light modules 2 are preferably designed identically. An embodiment with one light module 2 is shown in FIG. 4. The collimator 3 is set up in such a manner that the light generated by the light source 2a is emitted as a divergent light beam in a light propagation direction 4 via a light-emitting surface 3a of the collimator 3 (see FIG. 4-5). In the embodiment shown here, the collimator 3 is conically shaped and has an opening angle α of 25° to 30° (see FIG. 2). The lighting device further comprises an optical element 5, which is arranged downstream of the collimator 3, as seen in the light propagation direction 4. The optical element 5 has a light-coupling surface 5a and a light-decoupling surface 5b, wherein the light from the collimator 3 strikes the light-coupling surface 5a, is directed to the light-decoupling surface 5b through the optical element 5 and is emitted from the optical element 5 at the light-decoupling surface 5b. The light-coupling surface 5a has a Fresnel optics, which is designed to refract the light beams as they enter the optical element 5 in such a manner that the light beams propagate parallel to each other within the optical element 5. The light-decoupling surface 5b of the optical element 5 has multiple optical elements 6, wherein each optical element 6 is designed and set up in such a manner that the light from each optical element 6 is emitted as a divergent light beam (see FIG. 4-5).

[0040] The light-emitting surface 3a of the collimator 3 is formed from multiple lenses 7. The lenses 7 are arranged in a uniform grid on the entire light-emitting surface 3 of the collimator 3. Each lens 7 is set up for radiating the light of the light source 2a divergently onto the light-coupling surface 5a of the optical element 5, such that each of the multiple lenses 7 illuminates the light-coupling surface 5a of the optical element 5. All lenses 7 have essentially the same focal length, with the distance between the collimator 3 and the optical element 5 essentially equal to the focal length of the lenses 7.

[0041] In the embodiment shown, the optical element 5 is designed flat or planar and plate-shaped, wherein the optical element 5 can also be designed as a curved plate. Each of the multiple lenses 7 completely illuminates the light-coupling surface 5a of the optical element 5. As a result, the illumination of the light-coupling surface 5a is composed of an overlap of the light emitted by all lenses 7. Each lens 7 has the same dimensions and/or optical properties. The diameter of each lens is 0.2 mm to 5 mm, preferably 0.6 mm to 3 mm, particularly preferably 1 mm to 2 mm.

[0042] As shown in FIG. 3, the light-emitting surface 3a of the collimator 3 is smaller than the light-coupling surface 5a of the optical element 5. The light-emitting surface 3a of the collimator 3 is spaced apart from the light-coupling surface 5a of the optical element 5, wherein the light emitted from each lens 7 exclusively illuminates the light-coupling surface 5a of the optical element 5 completely or exactly. In particular, no light beams extend laterally or beyond an edge of the optical element 5. The lenses 7 of the light-emitting surface 3a are thus calculated to the size of the light-coupling surface 5a.

[0043] In the embodiment according to FIG. 4, the collimator 3 illuminates the entire light-coupling surface 5a. In the embodiment according to FIG. 4a, the first light module 2 illuminates a first partial area of the light-coupling surface 5a, and the second light module 2 illuminates a second partial area of the light-coupling surface 5a, wherein, for example, the first and the second partial area each form one half of the light-coupling surface 5a. The first and second partial areas are preferably illuminated without overlapping.

[0044] FIG. 4-5 schematically represent the beam path of the light beams between the collimator 3 and the optical element 5 and downstream of the optical element 5, wherein only the two outer and one central light beam are shown. The Fresnel optics of the light-coupling surface 5a has a structure which compensates for the angle between the collimators 3 and the light-coupling surface 5a, such that all light beams within the optical element are aligned parallel.

[0045] FIG. 6 and FIG. 7 show a lighting system 8 having a lighting device 1 and a lighting unit 9. The lighting unit 9 is set up for generating light and radiating the same along a light-emitting direction 10. The light-emitting direction 10 is aligned toward the focal plane of the lenses 7 of the collimator 3 of the light module 2 or toward the optical element 5 when the latter is arranged in a first position (see FIG. 6). The lighting system 8 comprises an adjusting device 11, by means of which the optical element 5 can be transposed between the first and a second position. The second position is shown in FIG. 7. In the first position, the light emitted by the collimator 3 of the lighting device 1 strikes the light-coupling surface 5a of the optical element 5. The lighting unit 9 is inactive at this time and does not emit any light, which is indicated by the dashed lines. In the second position, the optical element is positioned outside the light propagation direction 4 of the collimator 3 and also outside the light-emitting direction 10 of the lighting unit 9. Thus, the light of the lighting unit 9 can be emitted unhindered, for example onto a roadway.

[0046] The light module 2 of the lighting device 1 and the lighting unit 9 are arranged relative to each other in such a manner that the light propagation direction 4 of the collimator 3 of the light module 2 and the light-emitting direction 10 of the lighting unit 9 have an acute angle to each other. The light propagation direction 4 and the light-emitting direction 10 intersect at a point which is positioned in the focal plane of the lenses 7 of the collimator 3.

[0047] When the optical element 5 is in the first position, the light module 2 of the lighting device 1 is in an active state in which light is emitted from the light module 2 to the light-coupling surface 5a. The lighting unit 9 at this time is in an inactive state, in which the lighting unit 9 does not emit any light.

[0048] When the optical element 5 is in the second position (see FIG. 7), the lighting unit 9 is in an active state in which light is emitted by the lighting unit 9 as a light beam. The light module 2 of the lighting device 1 at this time is in an inactive state, in which the light module 2 does not emit any light. This is indicated by the dashed lines in FIG. 7. The first position of the optical element 5 is also indicated in FIG. 7 as a dashed line.

[0049] The lighting system 8 may generate a first light distribution when the optical element 5 is in the first position and the at least one light module 2 of the lighting device 1 is in an active state. Furthermore, a second light distribution can be generated when the optical element 5 is in the second position and the lighting unit 9 is in an active state.

[0050] The first light distribution for example is a light distribution of a daytime running light or a signal light function, and the second light distribution is a low-beam distribution or high-beam distribution. Accordingly, it is possible to switch between different light distributions, depending on the position of the optical element 5.