Lighting device for vehicles

Abstract

Lighting device for vehicles with a light source (15) and a light guide unit (31, 41) associated with the light source (15), which consists of a plurality of integrally connected light guides (12, 13, 14; 32, 33, 34), wherein a first light guide (12, 32, 42) is made of a transparent material without light-scattering effect and a second light guide (13, 33) and a third light guide (14, 34) are made of a transparent material with light-scattering effect, such that the second light guide (3, 4, 13, 14, 33, 34, 43, 44) emits light (9) to generate a predetermined signal light function, characterized in that the first light guide (12, 32, 34), the second light guide (13, 33) and the third light guide (14, 34) are planar and connected to The narrow sides facing each other have the same wall thickness. - that a first end face (16) of the first optical fiber (12) facing the light source (15) and a first end face (19) of the second optical fiber (13) facing the light source (15) and a first end face (20) of the third optical fiber (14) facing the light source (15) are designed as a light coupling surface and that the second optical fiber (13) and the third optical fiber (14) are connected to opposite narrow sides (18) of the first optical fiber (12) or - that a narrow end face (35) of the second light guide (33) facing the light source (5) and a narrow longitudinal side (36) of the second light guide (33) running in the direction of light guidance (10) is connected to a narrow side of the first light guide (32), so that the second light guide (33) is partially surrounded by the first light guide (32).

Description

[0001] The invention relates to a lighting device for vehicles according to the preamble of claim 1.

[0002] From DE 10 2006 016 656 A1, a lighting device for vehicles is known, comprising a light source and a light guide plate associated with the light source. The light guide plate consists of a main material and a secondary material integrated at specific points. The main material of the light guide plate, which essentially consists of a transparent material without light-scattering properties, has areas on one flat side made of a different plastic material (secondary material) that is refractive and / or reflective. The secondary material is designed as a light-extraction element for deflecting the coupled light towards a light-extraction surface.

[0003] From DE 10 2007 035 021 A1, a lighting device for vehicles is known, comprising a light source and a light guide associated with the light source, wherein the light guide is composed of several light guide segments manufactured by injection molding. These light guide segments are joined together, for example, by adhesive bonding. This allows the production of light guides with particularly complex geometries.

[0004] From DE 10 2006 034 972 A1, a lighting device for vehicles is known, comprising a light source and a light guide unit associated with the light source, consisting of a plurality of integrally connected light guides. The light guides differ in that they exhibit different temperature resistance properties. Specifically, a light guide facing the light source is intended to be more temperature-tolerant or temperature-resistant. This is intended to prevent the light guide located further away from the light source from overheating, which could lead to undesirable yellowing. This is intended to increase the service life of the light guide unit.

[0005] From DE 10 2008 044 357 A1, a lighting device for vehicles is known, comprising a light source and a light guide unit containing a first and a second light guide. One light guide is designed as a light disk. The other light guide runs in a rod-like form on the light disk, forming several layers that are either light-diffusing or non-light-diffusing. A disadvantage of the known lighting device is that the light guides must be arranged in a stacked fashion with corresponding optical interfaces. The lighting device therefore does not have a homogeneous appearance.

[0006] From DE 10 2011 016 430 A1, a lighting device for vehicles is known, comprising a light source and a light guide that incorporates nanoparticles as coupling elements, giving the light guide a light-scattering effect. Light is thus emitted uniformly across the entire flat surface of the light guide. If the lighting device is to be used for parking assistance, several light guides are layered on top of each other, with each light guide assigned a separately switchable light source. Since the light guides are separated from each other by total internal reflection boundaries, the light-scattering areas of the respective light guides can be controlled separately by individually controlling the light sources.

[0007] The object of the present invention is to further develop a lighting device for vehicles with a light source and a light guide unit associated with the light source in such a way that a predetermined illumination pattern is generated in a simple and effective manner.

[0008] To solve this problem, the invention has the features of claim 1.

[0009] The particular advantage of the invention lies in the fact that a light guide configuration can be created which, when the light source is switched off, exhibits a homogeneous appearance and, when the light source is switched on, a predetermined illumination pattern. The illumination pattern is determined by the at least second light guide, which consists of a transparent material with light-diffusing properties. When the light source is switched on, this light-diffusing property manifests itself in such a way that the entire second light guide illuminates to create a signal function. When switched off, the second light guide appears just as transparent as the first and, together with it, preferably forms a homogeneous surface.

[0010] According to the invention, the light guide unit consists of several planar light guides, the light guides being connected to each other at their narrow ends facing each other. This means that the first light guide, made of a transparent material without light-scattering properties, and the second light guide, made of a transparent material with light-scattering properties, are at least partially arranged side by side. In an unilluminated state of the light guide unit, i.e., with the light source switched off, this results in a continuous, homogeneous surface. In an illuminated state of the light guide unit, a predetermined illumination pattern is generated by means of the at least second light guide.

[0011] According to a further development of the invention, the first and second optical fibers of the optical fiber assembly are simply joined together by injection molding. This allows for a clear demarcation between a light-emitting zone and a non-light-emitting zone of the optical fiber assembly.

[0012] Since the light guide unit is manufactured using an injection molding process, no light-blocking areas are formed between the first and second light guides. The coupled light can propagate unhindered through the planar light guide unit and is only coupled out in the area of ​​the second light guide due to its light-scattering effect, and is thus visible to the observer.

[0013] Further advantages of the invention will become apparent from the further dependent claims.

[0014] Exemplary embodiments of the invention are explained in more detail below with reference to the drawings.

[0015] They show: Fig. 1 a perspective view of a lighting device according to a first embodiment, Fig. 2 a perspective view of the lighting device according to a second embodiment, Fig. 3 a perspective view of the lighting device according to a third embodiment and Fig. 4 a perspective view of the lighting device according to a fourth embodiment.

[0016] A lighting device for vehicles can be used to generate a signal light function in the front or rear area of ​​a vehicle.

[0017] According to a first embodiment of the lighting device Fig. 1 is a fiber optic unit 1 which consists of three rod-shaped fiber optic cables 2, 3, 4.

[0018] A first light guide 2 is arranged on the side of the light guide unit 1 facing a light source 5 and has a light coupling surface 6 at its end face. The light source 5 is designed as an LED light source, which is positioned on a carrier plate 7, e.g., a printed circuit board. The first light guide 2 consists of a transparent material without light-scattering properties, e.g., a transparent plastic material such as polycarbonate (PC).

[0019] A second light guide 3 is attached to the end face of the first light guide 2 facing away from the light source 5 and is connected to the first light guide 2 by injection molding. The second light guide 3 consists of a transparent material with light-scattering properties. For example, the second light guide 3 can be made of a plastic material in which aluminum particles or coated glass particles are distributed, such that light 9 coupled into the second light guide 3 is emitted from a light-emitting surface 8 of the same to generate the signal light function.

[0020] In an alternative embodiment, light scattering can also be achieved by a preferably uniform distribution of light-scattering nanoparticles, i.e., particles with a diameter in the nanometer range. In this embodiment, the light-scattering particles are not visible to the observer when unilluminated.

[0021] A third light guide 4 is attached to the second light guide 3 on the side facing away from the first light guide 2. Like the first light guide 2, this third light guide 4 is made of a transparent material without light-scattering properties. It is connected to the second light guide 3 by injection molding. In the present embodiment, the first light guide 2, the second light guide 3, and the third light guide 4 have the same cross-section, so that the first light guide 2 transitions seamlessly into the second light guide 3, and vice versa.

[0022] When the light source 5 is switched on, only the second light guide 3 illuminates, while the first light guide 2 and the third light guide 4 do not illuminate or emit light. The first light guide 2 serves as a feed light guide for the second light guide 3, by means of which the light is guided caustic-free in the direction of light guidance 10 to the second light guide 3. Since the first light guide 2 and the third light guide 4 do not emit light for the specified signal function, they can optionally be covered with a visor so that they are not visible even when the light guide unit 1 is unilluminated.

[0023] According to a second embodiment of the lighting device Fig. 2. A light guide unit 11 can be provided, consisting of planar light guides 12, 13, 14. A first planar light guide 12 consists of a transparent material without light-scattering properties and extends in an arc shape between a first end face 16 facing a light source 15 and a second end face 17 facing away from the light source 15. A second light guide 13 and a third light guide 14, each consisting of a transparent material with light-scattering properties, are attached to opposite narrow sides 18 of the first light guide 12. The second light guide 13 and the third light guide 14 each have a first end face 19 and 20, respectively, facing the light source 15, with the first end face 19, 20 serving as the light coupling surface. A second end face 21, 22 of the second light guide 13 and 20, respectively, opposite the first end face 19, 20, serves as the light coupling surface.14 together with the second end face 17 of the first light guide 12 form a common, preferably flat surface.

[0024] Since the first end face 16 of the first light guide 12 is also designed as a light coupling surface through which light emitted by the light source 15 is coupled, the first light guide 2 serves to supply light to the second light guides 13 and 14. Here, the light is transferred to the second light guide 13 and third light guide 14 at the virtually seamless narrow sides 18. When the light source 15 is switched on, however, only the second light guide 13 and the third light guide 14 illuminate, thereby generating, for example, a predefined signal light function such as a tail light, position light, and the like (see arrows 9). When the light source 15, which is mounted on a carrier plate 23, is switched off, the light guides 12, 13, and 14 form a homogeneous common surface, which characterizes the appearance of the lighting device in the switched-off state.

[0025] According to an alternative embodiment of the invention, to generate high-intensity signal light functions, such as brake lights, turn signals, or daytime running lights, coupling elements can be assigned to the light guides 3, 13, 14, which effect targeted light extraction. For example, coupling elements can be arranged on one of the rear sides of the corresponding light guides 3, 13, 14, which are located at the rear in the desired direction of light emission of the lighting device.

[0026] According to a further embodiment of the invention according Fig. 3 A light guide unit 31 is provided, comprising a planar first light guide 32, a planar second light guide 33, and a planar third light guide 34. The first light guide 32 consists of a transparent material without light-scattering properties. The second light guide 33 and the third light guide 34 consist of a transparent material with light-scattering properties. In contrast to the embodiment according to Fig. In the present embodiment, the second optical fiber 34 is integrated into the first optical fiber 32. It essentially forms a segment of the first optical fiber 32. A narrow end face 35 of the second optical fiber 34, facing the light source 15, and a narrow longitudinal side 36 of the optical fiber 34, extending in the direction of light transmission 10, are connected to a narrow side of the first optical fiber 32. The second optical fiber 34 is thus partially surrounded by the first optical fiber 32 and therefore not directly associated with the light source 15.

[0027] The first optical fiber 32 serves, firstly, to supply light to the second optical fiber 33 and, if applicable, to the third optical fiber 34. Secondly, the first optical fiber 32 acts as a frame for the second optical fiber 33, so that the entire optical fiber assembly 31 forms a homogeneous, planar structure when unilluminated. As in the other embodiments of the invention, the interfaces between the different optical fibers 32, 33, 34 are not visible when unilluminated.

[0028] According to a further embodiment of the invention according Fig.4. A planar optical fiber unit 41 can be multilayered, wherein a first optical fiber 42, consisting of a transparent material without light-scattering properties, is connected via one of its flat sides 45 to a second optical fiber 43 and to a third optical fiber 44. The second optical fiber 43 and the third optical fiber 44 each consist of a transparent material with light-scattering properties.

[0029] The first light guide 42 serves as a light guide to the second light guide 43 and the third light guide 44, whereby the light from the first light guide 42 is transferred via its flat side 45 into the second light guide 43 and the third light guide 44. Only the first light guide 42 and the second light guide 43 are arranged with one end facing the light source 15. A narrow end face 46 of the third light guide 44 is arranged at a distance from the light source 15.

[0030] The first light guide 42 thus serves as a base surface for the further light guides 43, 44. In the unilluminated state of the light guide unit 41, it has a profiled character.

[0031] Identical components or component functions of the exemplary embodiments are provided with the same reference numerals. Reference symbol list 1, 11, 31, 41 Fiber optic unit 2, 3, 4; 12, 13, 14; 32, 33, 34; 42, 43, 44 fiber optic cable 5, 15 light source 6 Light coupling area 7; 23 Carrier plate 8 Surface area 9 arrows 10 Light guidance direction 18, 35, 36, 46 narrow pages 16, 17; 19, 20; 21, 22 Front 45 flat side

Claims

[1] Lighting device for vehicles with a light source (15) and a light guide unit (31, 41) associated with the light source (15), which consists of a plurality of integrally connected light guides (12, 13, 14; 32, 33, 34), wherein a first light guide (12, 32, 42) is made of a transparent material without light-scattering effect and a second light guide (13, 33) and a third light guide (14, 34) are made of a transparent material with light-scattering effect, such that the second light guide (3, 4, 13, 14, 33, 34, 43, 44) emits light (9) to generate a predetermined signal light function, characterized by , that the first optical fiber (12, 32, 34), the second optical fiber (13, 33) and the third optical fiber (14, 34) are formed as flat surfaces and have the same wall thickness on their narrow sides facing each other, - that a first end face (16) of the first optical fiber (12) facing the light source (15) and a first end face (19) of the second optical fiber (13) facing the light source (15) and a first end face (20) of the third optical fiber (14) facing the light source (15) are designed as a light coupling surface and that the second optical fiber (13) and the third optical fiber (14) are connected to opposite narrow sides (18) of the first optical fiber (12) or - that a narrow end face (35) of the second light guide (33) facing the light source (5) and a narrow longitudinal side (36) of the second light guide (33) running in the direction of light guidance (10) is connected to a narrow side of the first light guide (32), so that the second light guide (33) is partially surrounded by the first light guide (32). [2] Lighting device according to claim 1, characterized by, that the light guide unit (1, 11, 31, 41) is manufactured by two-component injection molding. [3] Lighting device according to claim 1 or 2, characterized by , that the second optical fiber (3, 13, 33, 34) is additionally provided with a number of coupling elements for the guided deflection of light coupled into it in the direction of the light coupling surface of the same. [4] Lighting device according to any one of claims 1 to 3, characterized by , that the second optical fiber (3, 13, 14, 33, 34, 43, 44) consists of a transparent plastic material that is permeated with nanoparticles for light scattering.

Images