LIGHTING DEVICE FOR A MOTOR VEHICLE

Abstract

A lighting device is provided for a motor vehicle. The lighting device comprises at least one imaging component with at least one active surface, on which imaging elements for the generation of pixels of a light distribution are arranged matrix-like. The lighting device further comprises a light-guiding optics having at least one entry surface and one exit surface. During operation of the lighting device, the light emanating from the at least one active surface enters the light-guiding optics through the at least one entry surface and exits the light-guiding optics through the exit surface. The exit surface has a different shape and/or a different size than the at least one active surface, and/or a plurality of active surfaces and only one exit surface or a plurality of adjacent exit surfaces are provided.

Claims

1. A lighting device for a motor vehicle comprising: at least one imaging component with at least one active surface, on which imaging elements for the generation of pixels of a light distribution are arranged matrix-like, light-guiding optics having at least one entry surface and one exit surface, wherein during operation of the lighting device, the light emanating from the at least one active surface enters the light-guiding optics through the at least one entry surface and exits the light-guiding optics through the exit surface, wherein at least one of: the exit surface has a different shape and/or a different size than the at least one active surface, and a plurality of active surfaces and only one exit surface or a plurality of adjacent exit surfaces are provided.

2. The lighting device according to claim 1, wherein the exit surface or the adjacent exit surfaces have an aspect ratio different from the aspect ratio of the at least one active surface.

3. The lighting device according to claim 1, wherein the lighting device further comprises: a plurality of imaging components each having an active surface, wherein the light-guiding optics comprises a plurality of light-guiding optical components and wherein each of the optical components is assigned to one of the active surfaces so that the light emanating from the respective active surface enters the associated optical component through an entry surface of the associated optical component.

4. The lighting device according to claim 3, wherein during operation of the lighting device, the light emanating from a plurality of active surfaces exits through the exit surface, wherein a plurality of active surfaces being imaged next to one another on the exit surface or a plurality of adjacent exit surfaces.

5. The lighting device according to claim 1 wherein the at least one entry surface of the light-guiding optics is in contact with the at least one active surface.

6. The lighting device according to claim 1 wherein the light-guiding optics has an increasing cross-section starting from the at least one active surface, wherein the cross-section is frustoconical or frustopyramidal and the smaller diameter of the frustum of the cone or frustum of the pyramid faces the active surface.

7. The lighting device according to claim 1 wherein the light guiding within the light-guiding optics is based on the Anderson Localization, preferably the Transversal Anderson Localization.

8. The lighting device according to claim 1 wherein the light-guiding optics has at least one transparent, light-guiding material such as plastic, glass or ceramic.

9. The lighting device according to claim 1 wherein the light-guiding optics comprises a plurality of fibers having a cross-section smaller than 500 nm.

10. The lighting device according to claim 9, wherein the light-guiding optics comprises a plurality of first fibers having a first refractive index and a plurality of second fibers having a second refractive index different from the first refractive index.

11. The lighting device according to claim 10, wherein the first and second fibers are arranged randomly next to each other in transverse directions, the transverse directions being perpendicular to the direction of propagation of the light propagating from the at least one entry surface to the exit surface.

12. The lighting device according to claim 1 wherein the light-guiding optics comprises at least two different transparent light-guiding materials, wherein a second of the at least two different transparent light-guiding materials being air with a refractive index of 1.

13. The lighting device according to claim 10, wherein the light-guiding optics is produced by compressing, heating and drawing the plurality of first and second fibers or a plurality of first fibers with air inclusions in random arrangement, so that by fusing the different fibers or the fibers with air inclusions a mixed light-guiding material with at least two different refractive indices is produced.

14. The lighting device according to claim 1 wherein the imaging elements on the at least one active surface are in the form of light emitting diodes or laser diodes.

15. The lighting device according to claim 1 wherein the lighting device comprises a projection optics, from which the exit surface of the light-guiding optics is projected into the exterior space of the motor vehicle during operation of the lighting device.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Reference is now made more particularly to the drawings, which illustrate the best presently known mode of carrying out the invention and wherein similar reference characters indicate the same parts throughout the views.

[0024] FIG. 1 is a schematic plan view of a first version of a lighting device according to an embodiment of the invention.

[0025] FIG. 2 is a schematic plan view of a second version of a lighting device according to another embodiment of the invention.

DETAILED DESCRIPTION OF THE DRAWINGS

[0026] In the figures, identical and functionally identical parts are provided with the same reference signs.

[0027] The design of a lighting device 1 according to the invention shown in FIG. 1 comprises a plurality of imaging components 2 each with an active surface 3 on which matrix-like imaging elements for the targeted generation of pixels of a light distribution are arranged. The imaging component 2, for example, is a solid-state LED array, so that the imaging elements of each active surface 3 are designed as light-emitting diodes (LED).

[0028] The design also includes light-guiding optics 4 with a plurality of light-guiding optical components 7, each with an entry surface 5. The optical components 7 have a common exit surface 6 on the side opposite the entry surfaces 5. However, it can also be provided that each of the optical components 7 has a separate exit surface 6, whereby these exit surfaces 6 are connected to each other.

[0029] Each of the entry surfaces 5 is adjacent to one of the active surfaces 3 of the imaging components 2. This means that one of the optical components 7 is assigned to each of the active surfaces 3, so that the light emitted from the respective active surface 3 enters it through an entry surface 5 of the assigned optical component 7. The entry surface 5 is flat in order to be able to fully abut the likewise flat active surface 3.

[0030] The light entering the light-guiding optics 4, in particular the light entering the individual entry surfaces 5 of the optical components 7, exits the light-guiding optics 4 through the common exit surface 6 or through several adjacent exit surfaces 6.

[0031] The light-guiding optics 4, in particular each of the light-guiding optical components 7, has an enlarging cross-section starting from the entry surface 5 associated with the respective active surface 3, the cross-section being frustoconical or frustopyramidal and the smaller diameter of the frustoconical or frustopyramidal facing the active surface 3. Due to the special shape of the light guiding optical system 4 it is possible that the distances between the imaging components 2 are closed. Thus, during operation of the lighting device 1, the light emitted from several active surfaces 3 can be imaged seamlessly next to each other on the exit surface 6 by the light-guiding optics 4.

[0032] This has the advantage that the imaging components 2 can be placed locally separated from each other and nevertheless a coherent image can be generated. The separate placement offers an advantage for the cooling of the lighting device 1, as better heat dissipation is possible from imaging components 2 that are placed separately from each other than from connected imaging components 2.

[0033] The light-guiding optics 4, in particular each of the optical components 7, comprise at least two different transparent light guiding materials. The materials can be materials such as plastic, glass or ceramics. Air with a refractive index of 1 can also be selected as the second material. By using air as the second material, two different materials are used in a simple form.

[0034] The light-guiding optics 4, in particular each of the optical components 7, is manufactured in such a way that the plurality of first and second fibers or a plurality of first fibers with air inclusions are compressed, heated and drawn in random arrangement so that by fusing the different fibers or the fibers with air inclusions a mixed light-guiding material with at least two different refractive indices is produced. If air is used as the second material, the compression, heating and drawing of the air inclusions creates elongated air ducts extending between the entry surface 5 and the exit surface 6. The fibers and the air ducts are arranged stochastically or randomly.

[0035] In both cases, the resulting light guiding material shows desired material properties, so that light guidance can be based on Transversal Anderson Localization.

[0036] Here, at least two optical materials with different refractive indices are arranged stochastically/randomly along two dimensions of the light-guiding optics 4 and run homogeneously along a third dimension which corresponds to the direction between the entry surface 5 and the exit surface 6. The refractive index is therefore constant in one dimension along the respective fiber and is randomized over all fibers along the other two dimensions. Thus it is possible to limit the light guidance within the light-guiding optics 4 very precisely to a desired dimension and thus to a desired direction. In the other two dimensions there is almost no propagation of light.

[0037] Due to the special type of light-guiding optics 4, it is possible to change the size and shape of the image generated by the imaging components 2. In this way, the image created on the exit surface 6 of the light-guiding optics 4 can be changed. It is particularly possible here to adapt the size to specific requirements, in particular in such a way that the dimensions optimally match the headlamp used.

[0038] The design according to FIG. 2 differs from that according to FIG. 1 by an additional projection optics 8. The projection optics 8 project the combined image of the active surfaces 3 of the imaging components 2 at the exit surface 6 into the exterior of the vehicle. When the lighting device is used in a high-resolution headlamp, the lighting device serves to illuminate the road.

LIST OF REFERENCE SIGNS

[0039] 1 lighting device [0040] 2 imaging component [0041] 3 active area of the imaging component [0042] 4 light-guiding optics [0043] 5 entry surface of the light-guiding optics [0044] 6 exit surface of the light-guiding optics [0045] 7 light-guiding optical component of the light-guiding optics [0046] 8 projection optics