Lighting device for vehicles

Abstract

The invention relates to a lighting device for vehicles with a light guide arrangement (1, 1') comprising a first planar light guide (2, 2') arranged transversely to a main emission direction (H) of the lighting device and a second planar light guide (3, 3') arranged transversely to the main emission direction (H) of the lighting device, wherein the first flat side (6) of the first planar light guide (2, 2') forms a front side of the light guide arrangement (1, 1') and the first flat side (14) of the second planar light guide (3, 3') forms a rear side of the light guide arrangement (1, 1'), and wherein a decorative part (17) is provided with a rear surface section (18) arranged behind the light guide arrangement (1, 1) and with a side surface section (19) arranged next to the light guide arrangement (1, 1'), wherein at least the rear surface section (18) is designed as a reflective surface.wherein a narrow side of the light guide arrangement (1, 1') opposite the light coupling side is arranged at a distance (a) from the lateral surface section (19) of the decorative part (17) to form a gap (20) and wherein the reflective surface is designed such that at least a part of the light coupled out from the second planar light guide (3, 3') is deflected in the direction of the gap (20) to generate a secondary light beam (5), such that the light is emitted as a main light beam (4) in the main emission direction (H) from the first flat side (6) of the first planar light guide (2, 2').

Description

[0001] The invention relates to a lighting device for vehicles with a light guide arrangement comprising a first planar light guide arranged transversely to a main emission direction of the lighting device and a second planar light guide arranged transversely to the main emission direction of the lighting device, wherein the planar light guides each comprise a first flat side and an oppositely arranged second flat side for total reflection of light coupled into the planar light guide, a light coupling surface for coupling light onto a light coupling side of the light guide arrangement, and coupling elements for deflecting the coupled light in the direction of the first flat side designed as a light coupling surface.

[0002] From DE 10 2022 127 222 A1, a lighting device for vehicles is known, comprising a first planar light guide and a second planar light guide running parallel to it, each having opposite flat sides for total internal reflection and transmission of the coupled light. The light is coupled in at a narrow side of each planar light guide and coupled out at a flat side. The light coupled out at a flat side of a light guide located behind the main emission direction of the lighting device is emitted through the front light guide via a mask surface. The rear light guide has an extension section that curves in a finger-like shape towards the main emission direction of the lighting device and allows for additional light coupling at a front narrow side of the rear light guide.Advantageously, this allows for the creation of an additional lighting function besides the illuminating flat surface of the front light guide. However, a disadvantage of the known lighting device is that the manufacturing effort required to provide a different lighting function in addition to the light-emitting flat surface of the front light guide, from which light is emitted to generate the first lighting function, is relatively high. Parallel-arranged planar light guides are also known, for example, from DE 10 2010 006 348 A1. However, no additional lighting function is provided there through light emission beside the front light guide.

[0003] From DE 10 2022 113 052 A1, a lighting device for vehicles is known, comprising a planar light guide with a first flat side and a second flat side. A series of light sources is arranged on one narrow side of the planar light guide, such that light is coupled into the planar light guide at this narrow-sided light-entry side via a narrow-sided light-entry coupling surface. The planar light guide has output coupling elements, such that the coupled-in light is coupled out towards a front first flat side. Here, the output coupling elements are arranged as structural elements on a rear second flat side. No additional light emission extending beyond the planar light guide is provided.

[0004] The object of the present invention is to further develop a lighting device for vehicles comprising a number of planar light guides in such a way that the provision of two different lighting functions side by side is ensured in a manufacturing-technically simple manner.

[0005] To solve this problem, the invention, in conjunction with the preamble of claim 1, is characterized in that an aperture is arranged between the first planar light guide and the second planar light guide, that the output elements are arranged such that the light coupled into the first planar light guide and the second planar light guide is coupled out in opposite directions, wherein the first flat side of the first planar light guide forms a front side of the light guide arrangement and the first flat side of the second planar light guide forms a rear side of the light guide arrangement, that a decorative part is provided with a rear surface section arranged behind the light guide arrangement and with a side surface section arranged next to the light guide arrangement, wherein at least the rear surface section is designed as a reflective surface.wherein a narrow side of the light guide arrangement opposite the light coupling side is arranged at a distance from the lateral surface section of the decorative part to form a slit and wherein the reflective surface is designed such that at least a part of the light coupled out by the second planar light guide is deflected in the direction of the slit to generate a secondary light beam, such that the light is emitted as a main light beam in the main emission direction from the first flat side of the first planar light guide.

[0006] The particular advantage of the invention lies in the fact that two different light functions can be emitted simultaneously in a simple manner. A first light function is achieved by the planar emission of a first planar light guide, and a second light function by the planar emission of a second planar light guide. The basic concept of the invention is to emit light from two planar light guides in planar mode, each in different directions. By providing a decorative element with a reflective effect, the rearward-emitting light from the rear planar light guide can be deflected by approximately 180° into the main emission direction of the lighting device. The deflected light can then pass through a gap formed between the front planar light guide and the decorative element.Advantageously, this allows a relatively bright light output to be generated by the front flat light guide, while a comparatively weaker light output is generated by the rear flat light guide. According to the invention, the first flat light guide serves for direct light emission in the main emission direction, while the second flat light guide, in conjunction with the reflective decorative element, serves for indirect light emission in the main emission direction. Only through additional reflective means is the light from the second flat light guide deflected in the main emission direction and then emerges as a secondary light beam alongside the main light beam emitted by the first flat light guide.

[0007] According to a further development of the invention, the aperture is T-shaped with a longitudinal strut along a plane of extension of the planar light guides and a transverse strut extending perpendicular to it. Advantageously, the T-shaped aperture can serve to hold the two planar light guides, since their second flat sides rest against the longitudinal strut and one narrow side rests against the transverse strut.

[0008] According to a further development of the invention, the crossbar of the aperture serves as a spacer to a lateral part of the decorative element, and thus determines the gap width for the second light function.

[0009] According to a first embodiment of the invention, the first planar light guide and the second planar light guide are integrally connected to form a U-shaped light guide assembly. The first planar light guide and the second planar light guide each form one leg of this U-shaped light guide assembly. A vertex of the U-shaped light guide assembly is formed by a connecting piece between the first planar light guide and the second planar light guide. Advantageously, the vertex of the light guide assembly serves as a light coupling section from which the coupled light is distributed towards the two planar light guides. Advantageously, only a single row of light sources is provided along the vertex of the light guide assembly.

[0010] According to a second embodiment of the invention, the longitudinal strut of the aperture extends raised between a light coupling surface of the first planar light guide and the second planar light guide. The light coupling surfaces of the first planar light guide and the second planar light guide are thus arranged separately from one another, so that no mixing of the light coupled into the respective planar light guides can occur within a light coupling area. Light is coupled separately into each planar light guide. Advantageously, for example, a series of light sources emitting light of different colors can be assigned to each planar light guide.In this way, for example, a signal light function, such as a tail light or direction indicator light, can be generated using the first flat light guide, while ambient lighting is generated using the second flat light guide.

[0011] According to a further development of the invention, the longitudinal strut of the aperture extends directly to a circuit board on which the series of light sources, each assigned to a specific planar light guide, are arranged. Advantageously, this allows for light channel separation, ensuring that only light from a first series of light sources can be coupled into the first planar light guide and only light from a second series of light sources can be coupled into the second planar light guide.

[0012] Further advantages of the invention will become apparent from the further dependent claims.

[0013] Exemplary embodiments of the invention are explained in more detail below with reference to the drawings.

[0014] They show: Fig. 1 a schematic side view of a lighting device according to a first embodiment and Fig. 2 a schematic side view of the lighting device according to the invention in a second embodiment.

[0015] The lighting device for vehicles according to the invention can be used to generate different lighting functions. It comprises a light guide arrangement 1 containing at least one first planar light guide 2 and one second planar light guide 3. The first planar light guide 2 serves to emit a main light beam 4, by means of which a signal light function, such as a tail light, turn signal light, or daytime running light, can be generated. The second planar light guide 3 serves to emit a secondary light beam 5, which preferably serves to generate ambient light.

[0016] The first planar light guide 2 has a first flat side 6 and a second flat side 7 opposite it, at which coupled light is totally reflected. On a narrow-sided light coupling side, the first planar light guide 2 has a light coupling surface 8 for coupling the light into the first planar light guide 2. The first planar light guide 2 has output coupling elements so that coupled light is coupled out of the first planar light guide 2 at the first flat side 6. The first planar light guide 2 is arranged transversely to a main emission direction H of the lighting device. The first flat side 6 is arranged in the main emission direction H in front of the second flat side 7 of the first planar light guide 2. The first flat side 6 forms a front face of the light guide arrangement 1.

[0017] The second planar light guide 3 is arranged parallel to the first planar light guide 2 and spaced apart. An aperture 9, made of an opaque material, extends between the first planar light guide 2 and the second planar light guide 3.

[0018] In the present embodiment, the aperture 9 is T-shaped with a longitudinal strut 10 extending along a plane or direction of extension of the first planar light guide 2 and the second planar light guide 3, and a transverse strut 11 extending perpendicular to the same. The transverse strut 11 is arranged on a side opposite the light coupling side of the first planar light guide 2 and the second planar light guide 3. A narrow side 12 of the first planar light guide 2 and a narrow side 13 of the second planar light guide 3 abut the transverse strut 11, with these narrow sides 12, 13 being located on the side of the light guides 2, 3 opposite the light coupling side. The transverse strut 11 of the aperture 9 thus limits the light guide arrangement 1 on a side of the planar light guides 2, 3 opposite the light coupling side.

[0019] The second planar light guide 3 has a first flat side 14 and a second flat side 15 running parallel to it, at which the coupled light is totally reflected and directed towards the narrow side 13. At the light coupling side, the second planar light guide 3 has a light coupling surface 16 at which the light is coupled into the second planar light guide 3. Furthermore, the second planar light guide 3 includes output coupling elements, so that light coupled into it is coupled out at its first flat side 14. The first flat side 14 of the second planar light guide 3 forms a back side of the light guide assembly 1. The first flat side 14 is arranged behind the second flat side 15 of the second planar light guide 3 in the main emission direction H.

[0020] The second flat side 7 of the first planar light guide 2 and the second flat side 15 of the second planar light guide 3 each lie against the longitudinal strut 10 of the aperture 9.

[0021] Preferably, the second flat sides 7, 15 of the first planar light guide 2 and of the second planar light guide 3, as well as the narrow sides 12, 13 thereof, are materially bonded to the aperture 9, so that they form a single component to be installed in the housing of the lighting device.

[0022] The lighting device further comprises a decorative element 17, which has a surface section 18 located behind the light guide assembly 1 and a surface section 19 located to the side of the light guide assembly 1. In the present embodiment, the rear surface section 18 and the side surface section 19 are integrally connected and made of the same material. Thus, not only the rear surface section 18 but also the side surface section 19 has a mirrored surface that serves as a reflective surface. In this way, the secondary light beam 5 emitted to the rear by the second planar light guide 3 can be deflected so that it can be emitted in the main emission direction H through a slit 20. The slit 20 is formed by the crossbar 11 of the aperture 9 being arranged in a slit width a relative to the second side surface section 19 of the decorative element 17.The gap width a is less than the length of the longitudinal strut 10 of the aperture 9. Preferably, the gap width a is less than 50% of the length of the longitudinal strut 10, and in particular less than 30% of the length of the longitudinal strut 10. The length of the longitudinal strut 10 extends transversely to the plane of extension of the transverse strut 11 of the aperture 9 and transversely to the main emission direction H.

[0023] The optical fiber assembly 1 has a U-shaped cross-section, with opposite legs formed by the first planar optical fiber 2 and the second planar optical fiber 3. The light coupling surface 8 of the first planar optical fiber 2 and the light coupling surface 16 of the second planar optical fiber 3 are integrally connected to each other via a vertex 21 of the optical fiber assembly 1. The vertex 21 has a light coupling surface 22 of the optical fiber assembly 1 on a side opposite the light coupling surfaces 8, 16 of the first planar optical fiber 2 and the second planar optical fiber 3. Light emitted by a first row of light sources 23 is coupled into the optical fiber assembly 1 at this surface and distributed via the vertex 21 to the first planar optical fiber 2 and the second planar optical fiber 3.The coupled light is then emitted directly in the main emission direction H from the first planar light guide 2 via its first flat side 6 as the main light beam 4, while from the second planar light guide 3 it exits via its first flat side 14 into a rear space in the direction of the decorative element 17 and is then deflected by the decorative element 17 in the main emission direction H, so that it exits the housing of the lighting device as indirect light emission through the slit 20 as a secondary light beam 5 in the main emission direction H. The secondary light beam 5 has the same color temperature as the main light beam 4, but a significantly lower light intensity, so that it can serve as ambient light.

[0024] Out of Fig. Figure 1 shows that the U-shaped light guide assembly 1 and the T-shaped aperture 9 are nested inside each other, forming a rectangular contour in cross-section. The second flat sides 7 of the first planar light guide 2 and the second planar light guide 3 lie flat and directly against the flat upper surfaces of the longitudinal strut 10 of the aperture 9. A narrow side of the longitudinal strut 10 rests against the apex 21 of the light guide assembly 1. At the level of the free end of the longitudinal strut 10, the light coupling surfaces 8, 16 of the first planar light guide 2 and the second planar light guide 3, respectively, extend in the Fig. 1 are represented by a dashed line.

[0025] In the main emission direction H in front of the apex 21 of the light guide arrangement 1 and the series of light sources 23, an opaque sight 24 is provided, which is preferably attached to a circuit board 25 on which the light sources 23 are arranged.

[0026] According to a second embodiment of the lighting device Fig. 2 a light guide arrangement 1' is provided which differs from the light guide arrangement 1 according to Fig. 1 differs in that a first planar light guide 2' is not integrally connected to a second planar light guide 3', but is arranged separately on both sides of a longitudinal strut 10' of the aperture 9.

[0027] Identical components or component functions of the exemplary embodiments are provided with the same reference numerals.

[0028] The longitudinal strut 10' of the aperture 9 extends on the light coupling side of the light guide arrangement 1' raised to light coupling surfaces 8 of the first planar light guide 2' and a light coupling surface 16 of the second planar light guide 3'.

[0029] In the present embodiment, a free end of the longitudinal strut 10' of the aperture 9 abuts the circuit board 25, thus forming two separate light channels. One light channel is formed by a first row of light sources 23' and the first planar light guide 2'. A second light channel is formed by a second row of light sources 23' and the second planar light guide 3'. The light from the first row of light sources 23' is coupled into the light coupling surface 8 of the first planar light guide 2'. The light from the second row of light sources 23' is coupled into the light coupling surface 16 of the second light guide 3'. The design of the first planar light guide 2' essentially corresponds to the design of the first planar light guide 2 of the first light guide arrangement 1 according to [reference to relevant figure]. Fig. 1.

[0030] The design of the second planar light guide 3' essentially corresponds to the design of the second planar light guide 3 of the first light guide arrangement 1 according to Fig. 1. The first flat side 6 of the first planar light guide 2' thus forms the front side of the light guide assembly 1'. The first flat side 14 of the second planar light guide 3' thus forms the back side of the light guide assembly 1'. The main light beam 4 is emitted in the main emission direction H via the first flat side 6 of the first planar light guide 2'. The secondary light beam 5 is emitted in the direction of the decorative element 17 via the first flat side 14 of the second planar light guide 2', so that it exits through the gap 20 in the main emission direction H.

[0031] The flat sides 6, 7, 14, 15 of the first planar light guide 2' and second planar light guide 3' are arranged parallel and flat to each other.

[0032] The flat sides 6, 7 of the first planar light guide 2 and the flat sides 14, 15 of the second planar light guide 3 are each arranged in a plane. The second flat sides 7 of the planar light guide 2 and the second flat side 15 of the second planar light guide 3 are arranged at a slight inclination and tapering towards the apex 21. Only the first flat side 6 of the first planar light guide 2 and the first flat side 14 of the second planar light guide 3 are arranged parallel to each other.

[0033] The light sources 23, 23', 23" are designed as LED light sources. The circuit board 25 is preferably rigid.

[0034] According to an alternative embodiment of the invention (not shown), several light guide arrangements can also be arranged side by side and offset from the plane of the sheet. In this case, the light guide arrangements are arranged along the extension of a housing opening of the lighting device.

[0035] According to an embodiment of the invention not shown, the aperture 9 can also have only the longitudinal strut 10, 10', so that it is designed as an aperture plate. The gap 20 is then limited by the narrow sides 12, 13 of the planar light guides 2, 2'; 3, 3', which are arranged opposite the light coupling side. Reference symbol list 1.1' Optical fiber arrangement 2.2' 1. planar optical fiber 3.3' 2. planar optical fiber 4 main light beams 5 sidelight bundles 6 1. Flat side 7 2. Flat side 8 Light coupling area 9 aperture 10.10' longitudinal strut 11.11' Cross brace 12 Narrow side 13 Narrow side 14 1. Flat side 15 2. Flat side 16 Light coupling area 17 Decorative part 18 rear surface section 19 lateral surface section 20 gaps 21 vertices 22 Light coupling area 23,23',23" light sources 24 Viewfinder 25 circuit boards H Main radiation direction a gap width QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] DE 10 2022 127 222 A1

[0002] DE 10 2010 006 348 A1

[0002] DE 10 2022 113 052 A1

[0003]

Claims

[1] Lighting device for vehicles with a light guide arrangement (1, 1') comprising a first planar light guide (2, 2') arranged transversely to a main emission direction (H) of the lighting device and a second planar light guide (3, 3') arranged transversely to the main emission direction (H) of the lighting device, wherein the planar light guides (2, 2'; 3, 3') each contain: - a first flat side (6, 14) and a second flat side arranged opposite (7, 15) for total internal reflection of light coupled into the planar light guide (2, 2'; 3, 3'), - a light coupling surface (8, 16) for coupling light to a light coupling side of the optical fiber arrangement (1, 1'), - Coupling elements for deflecting the coupled light towards the first flat side designed as a light coupling surface (6, 14), characterized by , - that an aperture (9) is arranged between the first planar light guide (2, 2') and the second planar light guide (3, 3'), - that the coupling elements are arranged such that the light coupled into the first planar light guide (2, 2') and the second planar light guide (3, 3') is coupled out in opposite directions, wherein the first flat side (6) of the first planar light guide (2, 2') forms a front side of the light guide arrangement (1, 1') and the first flat side (14) of the second planar light guide (3, 3') forms a back side of the light guide arrangement (1, 1'), - that a decorative part (17) is provided with a rear surface section (18) arranged behind the light guide arrangement (1, 1) and with a side surface section (19) arranged next to the light guide arrangement (1, 1'), wherein at least the rear surface section (18) is designed as a reflective surface, wherein a narrow side of the light guide arrangement (1, 1') opposite the light coupling side is arranged at a distance (a) from the side surface section (19) of the decorative part (17) to form a gap (20) and wherein the reflective surface is designed such that at least a part of the light coupled out by the second planar light guide (3, 3') is deflected in the direction of the gap (20) to generate a secondary light beam (5), - that on the first flat side (6) of the first planar light guide (2, 2') the light is emitted as the main light beam (4) in the main emission direction (H). [2] Lighting device according to claim 1, characterized by , that the aperture (9) is T-shaped with a longitudinal strut (10, 10') and a transverse strut (11, 11'), wherein the second flat side (7) of the first planar light guide (2, 2') and the second flat side (15) of the second planar light guide (3, 3') are located on opposite sides of the longitudinal strut (10, 10') of the aperture (9) and wherein a narrow side opposite the light coupling surface (8, 16) of the first planar light guide (2, 2') and of the second planar light guide (3, 3') is located on one side of the transverse strut (11, 11') of the aperture (9). [3] Lighting device according to claim 2, characterized by, that the crossbar (11, 11') of the aperture (9) limits the light guide arrangement (1, 1') in a transverse direction to the main emission direction (H) of the lighting device, wherein the gap (20) is formed by the clear distance (a) between the crossbar (11, 11') of the aperture (9) and the lateral surface section (19) of the decorative part (17). [4] Lighting device according to any one of claims 1 to 3, characterized by, that the first planar light guide (2) and the second planar light guide (3) are integrally connected to form a U-shaped light guide arrangement (1), wherein opposite legs of the U-shaped light guide arrangement (1) are formed by the first planar light guide (2) and the second planar light guide (3), and wherein a vertex (21) of the U-shaped light guide arrangement (1) connects the first planar light guide (2) and the second planar light guide (3) and has a light coupling surface (22) into which the light is coupled into the light guide arrangement (1). [5] Lighting device according to claim 4, characterized by , that the U-shaped light guide arrangement (1) and the T-shaped aperture (9) are arranged nested inside each other, forming a rectangular contour in the cross-section of the same. [6] Lighting device according to claim 4 or 5, characterized by, that a single row of light sources (23) is arranged on the light coupling side of the light guide arrangement (1). [7] Lighting device according to any one of claims 4 to 6, characterized by , that in the main emission direction (H) in front of the apex (21) of the light guide arrangement (1) a sight glass (24) is arranged, which is attached to a circuit board (25) on which the series of light sources (23) is arranged. [8] Lighting device according to any one of claims 1 to 3, characterized by , that the aperture (9) is arranged raised above the light coupling surface (8) of the first planar light guide (2') and the light coupling surface (16) of the second planar light guide (3') on the light coupling side of the light guide arrangement (1'), so that the light coupling surfaces (8, 16) of the first planar light guide (2') and of the second planar light guide (3') are arranged separately by the aperture (9). [9] Lighting device according to any one of claims 1 to 8, characterized by , that the light coupling surface (8) of the first planar light guide (2') is assigned a first row of light sources (23') and the light coupling surface (16) of the second planar light guide (3') is assigned a second row of light sources (23"). [10] Lighting device according to claim 8 or 9, characterized by , that the aperture (9) rests on the narrow side of the circuit board (25) on which the rows of light sources (23', 23") are arranged. [11] Lighting device according to any one of claims 1 to 10, characterized by , that the first flat sides (6, 14) of the first planar light guide (2, 2') and of the second planar light guide (3, 3') as well as the second flat sides (7, 15) of the first planar light guide (2, 2') and of the second planar light guide (3, 3') are planar. [12] Lighting device according to any one of claims 1 to 11, characterized by, that the aperture (9) is made of an opaque material. [13] Lighting device according to any one of claims 1 to 12, characterized by , that the first planar light guide (2, 2') and the second planar light guide (3, 3') are materially bonded to the longitudinal strut (10, 10') and the transverse strut (11, 11') of the aperture (9). [14] Lighting device according to any one of claims 1 to 13, characterized by , that the width (a) of the gap (20) is smaller than the extent of the first planar light guide (2, 2') and the second planar light guide (3, 3') perpendicular to the circuit board (25).

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