LIGHTING DEVICE FOR VEHICLES AND PRODUCTION METHOD

Abstract

A lighting device for vehicles, comprising a housing containing a light source and an optical unit. The optical unit has a microstructured surface having a plurality of microstructure elements. The microstructure elements are formed from a limited selection of microstructure elements formed differently in at least two extension directions of the surface.

Claims

1. A lighting device for a vehicle, the lighting device comprising: a housing; a light source arranged in the housing; and an optical unit having a microstructured surface having a plurality of microstructure elements, the microstructure elements being formed from a limited selection of microstructure elements that are differently designed in at least two extension directions of the surface.

2. The lighting device according to claim 1, wherein the selection of different microstructure elements includes microstructure elements that have elevations that extend at least partially in a straight line and/or in an arc in at least one extension direction.

3. The lighting device according to claim 1, wherein the selection of microstructure elements has Y-shaped microstructure elements and/or U-shaped microstructure elements and/or V-shaped microstructure elements and/or linear microstructure elements and/or punctiform microstructure elements.

4. The lighting device according to claim 1, wherein a subsection of the microstructured surface has a specified number of different microstructure elements and a specified arrangement of identical and/or different microstructure elements, and wherein the microstructured surface comprises a plurality of identically designed subsections.

5. The lighting device according to claim 4, wherein the subsection has a rectangular or square size in the range between 50 m50 m and 300 m300 m.

6. The lighting device according to claim 1, wherein the optical unit includes a light guide and/or a lamp lens and/or a reflector that has the microstructured surface.

7. The lighting device according to claim 1, wherein a distance of adjacent elevations from one another and/or a length of the microstructure elements and/or a depth of the same is formed in such a manner that a light emitted by the optical component has a specified scattering pattern.

8. A method for producing an optical component of a lamp or headlamp for a vehicle having a microstructured surface via injection molding, the method comprising: providing an injection mold that has a tool surface having a microstructure; introducing into the mold surface, via laser machining, selected microstructure elements that are differently designed in an extension plane of the mold surface; and injection molding the optical components with a formation of the microstructure elements in a surface of the optical component.

9. The method according to claim 8, wherein a plurality of identically differently designed microstructure elements is introduced sequentially into the mold surface so that the mold surface is formed of a number of identical subsections that each have the same number and/or arrangement of different microstructure elements.

10. The method according to claim 8, wherein a laser device for laser machining the mold surface is controlled such that a dimension of one and/or multiple microstructure elements and/or a dimension of the subsections is varied such that the optical component produced, in cooperation with a light source, emits light with a specified scattering pattern.

11. A tool insert for an injection mold for injection molding an optical component according to claim 1, wherein a laser device and the tool insert are mounted on multiple axes such that the different microstructure elements are introduced onto a curved mold surface by laser machining.

12. A method for producing a tool insert for injection molding an optical component containing a microstructured surface, wherein a number of microstructure elements that are differently dimensioned in an extension plane of the tool insert are introduced into a surface of the same via laser machining.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus, are not limitive of the present invention, and wherein:

[0020] FIG. 1 is a schematic representation of a lighting device,

[0021] FIG. 2 is a schematic representation of an injection mold for producing an optical component containing a microstructured surface,

[0022] FIG. 3 is a top view of a microstructured surface of the optical component formed of multiple subsections containing the same microstructure elements,

[0023] FIG. 4 is an enlarged representation of a subsection according to FIG. 3,

[0024] FIG. 5a is a cross-sectional profile through at least one subsection of the microstructured surface of the optical component,

[0025] FIG. 5b is a cross-sectional profile through at least one subsection of the microstructured surface of the optical component, wherein a depth of the microstructure elements has been enlarged in comparison with FIG. 5a,

[0026] FIG. 5c is a cross-sectional profile through at least one subsection of the microstructured surface of the optical component, wherein a depth of the microstructure elements has been reduced in comparison with FIG. 5a, and

[0027] FIG. 5d is a cross-sectional profile through at least one subsection of the microstructured surface of the optical component, wherein the distance between the microstructure elements has been reduced in a preferred direction x.

DETAILED DESCRIPTION

[0028] In FIG. 1, a lighting device for vehicles that includes a light source 1 and an optical unit 2 for creating a specified light distribution 3 is shown schematically.

[0029] The optical unit 2 includes, firstly, a lens arrangement 4, which is designed as, e.g., the primary optics of the light source 1. In addition, the optical unit 2 includes a lamp lens 5 whose surface has a microstructure 6. The microstructure 6 is formed by a multiplicity of microstructure elements, which are described in detail below.

[0030] The lens arrangement 4 and the light source 1 are arranged inside a housing 7 of the lighting device, which can be designed as a rear lamp, for example. The lamp lens 5 serves as a cover plate that simultaneously seals or covers an opening of the housing 7 in the direction of light emission.

[0031] In the present example, the light distribution 3 serves to create a taillight function. Alternatively, the lighting device can also serve to create other signaling functions, as for example position light, brake light, directional indicator light, and daytime running light.

[0032] The microstructure elements scatter the light from the light source 1 in such a manner that the desired rectangular or elliptical light distribution 3 is generated. The light scattering takes place in the horizontal and vertical directions.

[0033] In the present example, the lamp lens 5 is plate-like and flat in design. Alternatively, the lamp lens 5 can also be arched in design, which is to say provided with a certain curvature.

[0034] The lamp lens 5 is produced as an optical component by injection molding. For this purpose, a tool insert 8 of an injection mold 9 is processed by a laser beam 10 of a laser device 11 in such a manner that a microstructure 6 containing a multiplicity of microstructure elements is formed on a surface 12 of the tool insert 8. The mold surface 12 constitutes a negative form of the microstructure 6 of the lamp lens 5 to be injection molded.

[0035] Once the tool insert 8 is placed in a first mold half 13 of the injection mold 9, wherein the structured surface 12 is arranged on a side facing a second mold half 14, the lamp lens 5 can be injection molded by bringing together the first mold half 13 and the second mold half 14 to close a mold space. The plastic mass injected into the mold space is deposited on the tool insert surface 12. After cooling of the plastic mass, the injection-molded lamp lens 5 can be ejected in a known manner. After assembly into the lighting device, the thus completed lamp lens 5 has the microstructure 6, which constitutes a positive form of the microstructure 6 of the tool insert 8, on an outer surface 15.

[0036] A top view of the microstructure 6 is shown in FIG. 3. It is evident that the surface of the lamp lens 5 is composed of a multiplicity of identical subsections 16 (shown dashed) that each have the same number and arrangement and design of different microstructure elements 17, 18, 19, 20, 21. The subsections 16 extend in an xy-plane (extension plane), which is perpendicular to the direction of light emission z. Shown enlarged in FIG. 4 is a subsection 16. It contains different types of microstructure elements, namely Y-shaped microstructure elements 17, U-shaped microstructure elements 18, V-shaped microstructure elements 19, linear microstructure elements 20, and punctiform microstructure elements 21. The subsection 16 has a total of three of the Y-shaped microstructure elements 17. The subsection 16 has a single one of the U-shaped microstructure elements 18. The subsection 16 has a single one of the V-shaped microstructure elements 19. The subsection 16 has a total of twelve of the linear microstructure elements 20, which are distributed throughout the subsection 16 and have identical and/or different lengths. Furthermore, the subsection 16 has punctiform microstructure elements 21.

[0037] The subsection has a dimension in the range between 50 m50 m and 300 m300 m.

[0038] The subsections 16 contain the multiplicity of microstructure elements 17, 18, 19, 20, 21, and are equal in size. They are arranged side by side in the manner of a grid. A cross-sectional profile through the subsection 16 in the X-direction is shown in FIG. 5a. The black markings shown in FIG. 3 and FIG. 4 represent elevations 22 of the microstructure elements 17, 18, 19, 20, 21 and the white markings or spaces between the elevations 22 represent depressions 23 in the microstructure 6 thus formed. Shown in FIG. 5a is a profile image of the subsection 16. It is evident that the microstructure elements 17, 18, 19, 20, 21 or the distances (widths b1) of the elevations 22 from the Y-shaped microstructure elements 17 or widths b2 of the elevations 22 of the U-shaped microstructure elements 18, V-shaped microstructure elements 19 are in a range of less than 20 m. The linear microstructure elements 20 form elevations 22 with a width less than 5 m. A depth t.sub.1 is in the range from 5 m to 12 m.

[0039] The elevations 22 of the microstructure elements 17, 18, 19, 20, 21 form upright walls that are raised compared with a base surface 24 of the lamp lens 5. In the present example, these elevations 22 or walls extend essentially in a straight line, wherein the U-shaped microstructure element 18, for example, is composed of three straight-line elevations 20.

[0040] According to an example, the elevations 22 can additionally or alternatively extend in an arc. What is essential is that the microstructure elements 17, 18, 19, 20, 21 are put together in the subsection 16 in such a manner that the lamp lens 5 in the assembled state has a specified scattering behavior or scattering pattern so that the desired light distribution 3 is projected in cooperation with, for example, the lens arrangement 4.

[0041] According to an example, the optical unit 2 can also be composed solely of the lamp lens 5, which provides for the desired scattering behavior and thus the desired light distribution 3.

[0042] According to the invention, the desired scattering behavior can be created by the selection of a specific number of different microstructure elements 17, 18, 19, 20, 21.

[0043] According to an example of the lamp lens 6, the same microstructure 6 as shown in FIGS. 3 and 4 can be introduced into the tool insert 8 by controlling the laser device 11, with the difference that the microstructure 6 has an increased depth t, which is to say a depth t increased by t in comparison with the microstructure 6 from FIG. 5a. The lamp lenses 5 injection molded with such a modified tool insert 8 then have a cross section according to FIG. 5b, in which the depth t.sub.1 or t.sub.2 is greater than the depth t.sub.1 or t.sub.2 according to the microstructures 6 from FIG. 5a. The arrangement of the microstructure elements 17, 18, 19, 20, 21 in the respective subsection 16 has remained the same in this case. Advantageously, a different scattering behavior can be created by the change in depth, which can result in a different lighting function.

[0044] Alternatively, the depth t of the microstructure 6 can also be reduced by t in comparison with the microstructure 6 from FIG. 5a, as is shown in FIG. 5c; see the reduced depths t.sub.1, t.sub.2 by way of example. Another modified scattering behavior occurs as a result.

[0045] In FIG. 3, the subsections 16 are arranged in mutually perpendicular extension directions x and y in the manner of a grid.

[0046] According to an example of the invention from FIG. 5d, the microstructure 6 can be compressed, wherein a width b of the microstructure elements 17, 18, 19, 20, 21 is reduced. A width b1 and b2 of the microstructure elements 17, 18 is smaller in comparison with the width b1 or b2 in FIG. 5a. As a result, a changed scattering behavior is created, which can serve to project a further lighting function.

[0047] The different microstructures can be created in a simple manner by appropriate controlling of the laser device 11. For different lighting functions, therefore, different tool inserts 8 can be generated that can be placed in the injection mold 9 as a function of light distributions 3 to be created.

[0048] If the tool insert 8 and the laser device 11 are mounted on multiple axes, then curved or arched lamp lenses 5 can also be created with an arched or curved microstructure 6.

[0049] According to an example of the invention that is not shown, instead of the lamp lens 5, the optical component can be designed as a light guide or as a reflector that has the microstructure 6 on a lateral surface or flat face.

[0050] The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are to be included within the scope of the following claims.