Light guide for a vehicle lighting unit

Abstract

The invention relates to a light guide for a vehicle lighting unit, having at least one light-conducting body, which conducts the light along at least one light direction; and at least one, in particular band-shaped, optically active flat material which interacts with the light guided into the body in order to produce a light effect. The light guide according to the invention is characterized in that the flat material with its longitudinal extension direction along the direction of light of the light-conducting body in the light-conducting body is completely surrounded and embedded by the same at least transversely to the direction of longitudinal extent.

Claims

1. A light guide for a vehicle lighting unit, comprising: at least one light conducting body that conducts light along at least one direction of light; and comprising at least one, particularly band-shaped, optically effective flat material which interacts with the light conducted into the body to produce a light effect, wherein the flat material is embedded with its longitudinal extension direction along the direction of light of the light conducting body in the light conducting body and completely surrounded by the same, at least transversely to its longitudinal extension direction.

2. The light guide according to claim 1, wherein the flat material comprises at least one projection, particularly multiple projections, transversely to the longitudinal extension direction, such as an imprint, particularly a three-dimensional imprint.

3. The light guide according to claim 1, wherein the flat material comprises a film and/or the light effect includes a three-dimensional depth effect.

4. The light guide according to claim 1, wherein the light effect comprises a decoupling of the light at least partially from the light conducting body (101).

5. The light guide according claim 1, wherein the flat material and the light conducting body have a different refractive index, particularly that the flat material is at least in sections transparent, semi-transparent, and/or opaque.

6. The light guide according to claim 1, wherein the flat material is centrally arranged in the light conducting body.

7. The light guide according to claim 1, wherein the light conducting body comprises an injection molded part that is injected onto the flat material, particularly by multiple flat material back molding.

8. The light guide according to claim 1, wherein the flat material comprises at least one continuous recess extending transversely to the longitudinal extension direction through which the light from one side of the light guide can get to another side of the light guide and/or to the outside.

9. The light guide according to claim 1, wherein the flat material is configured such that it homogenizes the light conducted through the body and/or the light conducting body has an oblong shape, and the direction of light extends along a main axis of the body.

10. The light guide according to claim 1, wherein the light conducting body is of a rod or disc-shaped, particularly disc-shaped and curved design.

11. The light guide according to claim 1, wherein the light conducting body has an end surface that is adjacent to a component unit of the light source, wherein the flat material is disposed at a spacing from the end surface.

12. The light guide according to claim 11, wherein the light conducting body is shielded from view at the end surface, particularly by a second flat material and/or a plastic housing attached to the end surface.

13. A rear view device of a motor vehicle, having at least one light guide according to claim 1 which comprises at least one light conducting body which conducts light along at least one direction of light; and which comprises at least one, particularly band-shaped, optically effective flat material that interacts with the light conducted in the body to produce a light effect, wherein the flat material is embedded with its longitudinal extension direction along the direction of light of the light conducting body in the light conducting body and completely surrounded by the same, at least transversely to its longitudinal extension direction.

14. A method for producing a light guide for a vehicle lighting unit, comprising the following process steps: providing a flat material, having a first surface and a second surface that faces in the opposite direction; Back injecting the first surface of the flat material with a transparent injection molding material; and Back injecting the second surface of the flat material with the transparent injection molding material, wherein the flat material together with the transparent injection molding material are molded to a light guide, which conducts light in an intended direction of light, wherein the steps of back injecting the first and second surfaces of the flat material fully embeds the flat material in the transparent injection molding material.

15. A motor vehicle having at least one rear view device according to claim 13 and/or having at least one light guide according to claim 1.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a perspective top view of a light guide for a lighting unit in an outside mirror of a vehicle according to one embodiment;

(2) FIG. 2 is a detailed side view of the light guide according to FIG. 1; and

(3) FIGS. 3a) to 3d) are schematic cross sectional views of each process step of a production method of a light guide for a vehicle lighting unit.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

(4) FIG. 1 shows a three-dimensional design drawing of a light guide half with incorporated flat material 105 of a light guide 100 for a lighting unit in an outside mirror of a vehicle according to one embodiment in top view.

(5) The light guide 100 comprises a light conducting body 101 and a flat material 105 embedded in the body 101, in which the flat material is completely surrounded by the body 101 transversely to its longitudinal extension direction. FIG. 1 shows a half of the light guide 100 onto which the flat material 105 is injected. The light conducting body 101 conducts light along a direction of light described by the arrows 103. The light conducting body 101 is injected onto the flat material along the direction of light 103. The direction of light 103 is the same as the longitudinal extension direction of the flat material 105. A second half, which is not shown in FIG. 1, can be deposited onto the first half, for example in another injection molding process as described below in FIG. 3 to produce the complete light guide 100. The flat material 105 interacts with the light conducted into the body 101 to produce a light effect. The light effect can be a three-dimensional depth effect. The light effect produced by the flat material is associated with a decoupling of the light from the light conducting body 101. The light passes through the body 101, for example from a coupling on the right side of the body 101, and is decoupled from the transparent body 101 depending on the flat material 105 and its properties while passing through the body 101. In order to produce a suitable light effect or to achieve good decoupling of the light from the body 101, the flat material 105 can be provided with an imprint, such as a three-dimensional imprint. The flat material 105 and the light conducting body 101 can have a different refractive index, for example, be made of different materials, in order to create the three-dimensional light effect shown in FIG. 1. For example, the flat material 105 can be transparent, semi-transparent, or opaque. The flat material 105 can be centrally attached in the light conducting body 101, as shown in FIG. 1. FIG. 1 shows that the flat material 105 is embedded in the light conducting body 101 along the direction of light 103.

(6) The light conducting body 101 can for example be formed as an injection molded body that is injected onto the flat material 105, for example using a multiple flat material back molding process as described below with reference to FIG. 3.

(7) The flat material 105 can comprise recesses (not shown in FIG. 1) through which the light from one side of the light guide 100 can get to another side of the light guide 100 and/or to the outside. The flat material 105 can comprise suitable windows or holes or three-dimensional structures at which the light is reflected and/or refracted for homogenizing the light conducted through the body 101.

(8) The light guide 100 can be used for a lighting unit in an outside mirror of a vehicle. Therefore, it has an oblong shape, and the direction of light 103 extends along a main axis of the body. The light conducting body 101 can particularly be disc-shaped so that it can be used for a lighting unit of a motor vehicle. FIG. 1 shows that the body 101 is disc-shaped and curved to adapt to the outside mirror of a motor vehicle.

(9) On its right side, which is shown in FIG. 1, the light conducting body 101 comprises an end surface 107 that is adjacent to a component unit (not shown) in which an insert for a light source can be provided for coupling light into the light guide. The flat material 105 is attached at a spacing from the end surface 107 which is visible in FIG. 1. The end surface 107 can be shielded from view, for example by a second flat material attached to the end surface 107 or a plastic housing. The components will then not be visible from outside and cannot interfere with the light effect that results from embedding the flat material in the light conducting body.

(10) The light conducting body 101 can for example be made of a transparent, cost-effective plastic material, such as polycarbonate or PMMA.

(11) The light guide 100 can be used in a lighting unit in an outside mirror of a vehicle, e.g. as a mirror indicator. The light guide 100 can be joined with an indicator housing to produce a mirror indicator. The joint which can be moisture-resistant, may enclose an installation space in which the light sources, e.g. one or several LEDs, as well as one or several PCBs, metalized regions for forming reflectors and light conducting structures, which can be connected to the light guide 100 or not, can be installed. The light guide 100, however, is not limited to mirror indicators or to indicators having a modular structure. The light guide 100 can advantageously be cost-effectively injection molded in a multiple (e.g. dual) back molding process.

(12) FIG. 2 shows a section of the three-dimensional design drawing of the light guide 100 from FIG. 1 in a side view.

(13) The light guide 100 comprises the light conducting body 101 and the flat material 105 embedded in the light conducting body 101. The central embedding of the flat material 105 in the body 101 is visible in this figure. The light conducting body 101 conducts light along the intended direction of light, which is described by the arrows 103. The flat material 105 is embedded along the direction of the light 103 in the light conducting body 101 and interacts with the light conducted in the body 101 to produce a light effect. The flat material 105 is at a spacing from the end surface 107. A holder for receiving light sources, e.g. one or several LEDs, can be provided in the end surface 107. The end surface 107 can be opaque to close off the components of the component unit from view.

(14) FIGS. 3a) to 3d) are schematic views of each of the process steps 301, 302, 303, 304 of a manufacturing method of a light guide 100 for a vehicle lighting unit according to one embodiment.

(15) In a first process step 301 the method comprises the provision 301 of a flat material 105, having a first surface 312 and a second surface 314 that faces in opposite direction. The flat material 105 can be a polycarbonate film, which can have the three-dimensional structure described in FIGS. 1 and 2. It can for example be printed with a colored ink and have a varying pattern to produce the light effect described.

(16) In a second process step 302, the method comprises the back injection of the first surface 312 of the flat material 105 with a transparent injection molding material 313, such as a crystal clear plastic like polycarbonate or PMMA. The flat material 105 can be placed onto an injection molding carrier 309 for manufacturing and covered with the first injection mold 311a, which can correspond to the negative shape of the first side of the formed part. A first nozzle 315a can be used to fill forming material or injection molding material 313 into the first injection mold 311a in order to form the first side of the light conducting body 101, as described, for example, in FIGS. 1 and 2.

(17) In a third process step 303, the method comprises back injection of the second surface 314 of the flat material 105 with the transparent injection molding material 313.

(18) The injection molding carrier 309 can for this purpose be detached from the molded body of flat material 105 and cooled down injection molding material 313, and a second injection mold 311b, which can correspond to the negative shape of the second side of the molded body, can cover the molded body. A second nozzle 315a can be used to fill forming material or injection molding material 313 into the second injection mold 311b in order to form the second side of the light conducting body 101, as described, for example, in FIGS. 1 and 2.

(19) After the injection molding material 313 has cooled down, a light guide 100 can be formed in a fourth process step 304, or as a result of the third process step 303, which light guide conducts light along an intended direction of light, as described in more detail in the introductory part and in the description of FIGS. 1 and 2. By this process, the flat material 105 can be completely embedded in the light conducting body 101.

(20) The first nozzle 315a and the second nozzle 315b can be realized as a single nozzle. The first injection mold 311a and the second injection mold 311b can be realized as a single injection mold, for example, if a symmetrical structure of the light conducting body 101 is to be achieved.

(21) In one embodiment of the method, the second and third process steps can be repeated multiple times to embed multiple flat materials in the light conducting body by means of multiple back injection.

(22) Both the light conducting body 101 and the flat material 105 can have different colors to create colored light or to produce various color effects. The flat material can be imprinted with a logo, for example a manufacturer's note, such as a manufacturer's or car maker's trademark.

(23) One aspect of the invention also comprises a computer program product which can be loaded directly into the internal memory of a digital computer and comprises software code sections by means of which the process steps 301, 302, 303, and 304 of the method described in FIG. 3 can be executed when the program is running on a computer. The computer program product can be stored on a computer-suitable medium and include the following: computer-readable program means, which cause a computer to provide a flat material 105 having a first surface 312 and a second surface 314 that faces in the opposite direction; to back inject the first surface 312 of the flat material 105 with a transparent injection molding material 313; to back inject the second surface 314 of the flat material 105 with a transparent injection molding material 313; and to mold the flat material 105 together with the injection molding material 313 to a light guide 100, which conducts light along an intended direction of light. The computer can be a control device that controls the injection molding processes, for example as part of a CNC machine. The computer can be configured as a chip, an ASIC, a microprocessor, or a signal processor and can be arranged in the control unit of an injection molding system.

(24) It is self-evident that the features of the various exemplary embodiments described herein can be combined with one another unless specifically stated otherwise. As shown in the description and in the figures, individual elements shown to be connected do not have to be directly connected; intermediate elements can be provided between such connected elements. It is further self-evident that embodiments of the invention can be implemented in individual circuits, partially integrated circuits, or fully integrated circuits or programming means. The term exemplary is meant to denote an example, not the best or optimum. While specific embodiments were illustrated and described herein, it is obvious to a person skilled in the art that a multitude of alternative and/or similar implementations can be realized instead of the embodiments shown and described without deviating from the scope of the present invention.

(25) The principle and mode of operation of this invention have been explained and illustrated in its preferred embodiment. However, it must be understood that this invention may be practiced otherwise than as specifically explained and illustrated without departing from its spirit or scope.