LIGHTING DEVICE WITH FIBER GUIDES FOR VEHICLES

Description

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

[0002] From EP 2 354 637 A2, a lighting device for vehicles is known, comprising a first lighting unit and a second lighting unit, each containing a light source and a planar light guide. The planar light guides of the first and second lighting units are integrally connected and intersect at a crossover point. The first and second lighting units each have planar light guides with a light coupling surface on one narrow side, where the light is coupled in and transmitted via opposite flat surfaces of the respective planar light guides. While the first planar light guide has a deflection section and a first flat section extending from the crossover point, the second planar light guide is planar and extends in a single plane.In this way, a linear light output can be achieved on one side of the second planar light guide opposite the light coupling surface to generate a light function. The second light guide has output coupling means so that light is coupled out at a front flat side of the same to generate a light function. Advantageously, this allows a linear light function and a planar light function to be arranged directly next to each other. It is desirable to arrange extended light functions in a space-saving manner.

[0003] From EP 4 166 843 A1, a lighting device for vehicles is known, comprising a first lighting unit and a second lighting unit, wherein both the first and the second lighting unit each have a light source and a planar light guide. The two planar light guides have an intersection area where opposite flat surfaces of one light guide and opposite flat surfaces of the other light guide intersect. At the intersection area, the first planar light guide and the second planar light guide are extended as a further section, and the light is then coupled out at the extension sections.

[0004] The object of the present invention is therefore to further develop a lighting device for vehicles with two intersecting planar light guides in such a way that several lighting functions can be provided in a space-saving manner.

[0005] To solve this problem, the invention has the features of claim 1.

[0006] The particular advantage of the invention lies in the fact that a multitude of lighting functions can be generated in a space-saving manner. In a front view of the lighting device, only one light-emitting surface is visible, consisting of a planar light beam generated by a first light unit on the one hand and a linear light beam generated by the second light unit on the other. The light-emitting surface of the emerging planar light beam is limited by a deflection section of the first light unit and the intersection area from which the second planar light guide projects in the main direction of emission. By providing a U-shaped light guide element, the width of the planar light emission between the intersection area and the deflection area can be defined.The emission of the linear light beam by the first light unit takes place in the direction of light guidance within the planar light guide, so that a defined luminous flux for the planar and linear light emission of the first light unit can be easily adjusted by forming coupling means of the first light unit.

[0007] According to the invention, the U-shaped light guide element has a relatively large apex formed by the second section of the first light guide. A first leg is formed by a first section of the first light guide, and a second leg by a first section of the second light guide. Advantageously, the light-emitting surface can be generated in a space-saving manner, with the first leg and the second leg running approximately parallel or at an acute opening angle in one of the extraction directions of an injection mold.

[0008] According to the invention, narrow sides of the extension sections of the first and second light guides are formed as light output surfaces on a side facing away from the intersection area. Advantageously, this allows two different linear light functions to be generated, which are preferably emitted at right angles. The extension section of the first light guide can, in particular, serve to generate a side marker light that runs perpendicular to the direction of the light beam exiting the second section of the first light guide, which runs in the direction of the vehicle's longitudinal axis.

[0009] According to the invention, linear light extraction occurs at the extension sections of the first and second optical fibers, each in the direction of a light guidance direction of the first and second optical fibers, respectively. Advantageously, this results in a relatively high light yield.

[0010] According to a further development of the invention, an axis of extension of the crossing area runs parallel to an axis of extension of the linear light outputs at the extension sections of the first and second optical fibers. The axis of extension of the crossing area, as well as the axis of extension of the light coupling surfaces, runs in a vertical direction.

[0011] According to the invention, at least the second section of the first light guide has coupling means, such that light is coupled out at a front flat side of the second section to generate a predetermined light distribution. Optionally, further second coupling means can be provided, so that, additionally or alternatively, the coupled light is generated at the second section of the first light guide according to a predetermined inscription or to generate a logo. The illuminated area can thus be used for informational purposes. According to a further development of the invention, an inclined surface is provided in the deflection section of the first light guide, by means of which the coupled light is deflected by 90°. The inclined surface is preferably flat and arranged at an angle of between 40° and 50°, preferably 45°, to a direction of extension of the first and second sections of the first light guide.Preferably, the inclined surface has reflective optical elements or a mirrored surface.

[0012] According to a further development of the invention, retaining arms for attaching the U-shaped light guide element to a housing of the lighting device extend along a light-coupled narrow side of the first section of the first light guide and the second light guide. In this way, a relatively large U-shaped light guide element can be held stably.

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

[0014] An embodiment of the invention is explained in more detail below with reference to the drawings.

[0015] They show: Fig. 1 a perspective view of a lighting device according to the invention and Fig. 2 a horizontal section through the lighting device.

[0016] A lighting device according to the invention for vehicles can, for example, serve in the rear area to generate a taillight function, outline light function and a side marker light function.

[0017] The lighting device according to the invention has a first light unit 1 and a second light unit 2, which independently generate a predetermined light distribution.

[0018] The first light unit 1 comprises a number of light sources 3 and a first planar light guide 4, which has two opposing flat sides 5, 5'. The opposing flat sides 5, 5' are connected to each other via a narrow side 6. At a first end of the first light guide 4, a narrow side 6 is configured as a linear light coupling surface. Several light sources 3 are arranged along the light coupling surface 6', such that a first light 7 is coupled at the light coupling surface 6' and transmitted along the opposing flat sides 5, 5' by total internal reflection towards a linear light output surface 6" of the first light guide 4. The linear light coupling surface 6' can be straight or curved, with the light sources 3 arranged contour-following the light coupling surface 6'.

[0019] The second light unit 2 comprises light sources 8 and a second light guide 9, which has opposite flat sides 10, 10' and connecting narrow sides 11. One narrow side 11' of the second light guide 9 is designed as a linear light coupling surface, along which several light sources 8 are arranged in a row or elongated configuration. The second light 12 emitted by the light sources 8 is coupled into the second light guide 9 through the light coupling surface 11' and totally reflected at the opposite flat sides 10, 10' of the same towards another narrow side 11, which is designed as a linear light coupling surface 11". The second light 12 is coupled out at the linear light coupling surface 11".

[0020] The first optical fiber 4 and the second optical fiber 9 are formed in one piece and are manufactured primarily as injection-molded parts. In a crossing area 13, the parallel flat sides 5, 5' of the first optical fiber 4 intersect with the flat sides 10, 10' of the second optical fiber 9. Since the crossing area 13 is located in a region of the first optical fiber 4 and the second optical fiber 9 where, downstream of the optical flow, only a comparatively short extension section 14 of the first optical fiber 4 and an extension section 15 of the second optical fiber 9 are connected, the proportion of light 7, 12 lost due to scattering in the intersecting optical fiber 9 or 4 is relatively small. In particular, with respect to the first optical fiber 4, the extension section 14 has a significantly shorter length IV1 than the length I1 of a second section 20 of the first optical fiber 4, which is located upstream of the crossing area 13.The length I V1 of the extension section 14 is less than 50%, preferably less than 30%, and in particular less than 10% of the length I 1 of the second section 20 of the first optical fiber 4.

[0021] A length I V2 of the extension section 15 of the second optical fiber 9 is smaller than a length I 2 of the first section 16 of the second optical fiber 9 running upstream of the crossing area 13.

[0022] The total length of the second optical fiber 9 is the sum of the length I2 of the first section 16, the length IV2 of the extension section 15, and the thickness d1 of the first optical fiber 4. Both the extension section 15 and the first section 16 of the second optical fiber 9 are arranged at an angle of 85° to 95° with respect to the second section 20 of the first optical fiber 4 passing through the intersection area 13 (intersection point), preferably not at a right angle, to allow for removal from an injection mold. The linear light output surface 11" arranged opposite the linear light coupling surface 11' can have scattering optical elements 17 for scattering light coupling according to a predetermined light distribution.

[0023] An upstream section of the first optical fiber 4, located towards the intersection 13, has a first planar section 18 comprising the light coupling surface 6'. A deflecting section 19 adjoins the first section 18 in the direction of the light flow. At this deflection, the coupled first light 7 is deflected by approximately 90° towards the second section 20, which is planar and extends to the intersection 13. The deflecting section 19 has an inclined surface 29 at which the light 7 is deflected. The inclined surface 29 can comprise reflective optical elements or a mirrored surface.

[0024] The first section 18, the deflection section 19, and the second section 20 of the first optical fiber 4, together with the first section 16 of the second optical fiber 9, form a U-shaped light guide element 21 in a plane extending transversely to the linear light coupling surface 6', 11' of the first optical fiber 4 and the second optical fiber 9. The intersection area 13 is located in a light output region of the first optical fiber 4 and the second optical fiber 9. The second section 20 of the first optical fiber 4 forms a vertex of the U-shaped light guide element. The first section 18 and the deflection section 19 of the first optical fiber 4 form a first leg of the U-shaped light guide element 21. The first section 16 of the second optical fiber 9 forms a second leg of the U-shaped light guide element 21.

[0025] In the intersection area 13, the flat sides 5, 5' of the first light guide 4 and the flat sides 10, 10' of the second light guide 9 continue in the same direction, with the flat sides 5, 5' and 10, 10' of the first light guide 4 and the second light guide 9 being alternately interrupted.

[0026] Preferably the first optical fiber 4 and the second optical fiber 9 have a constant thickness d 1 and d 2 respectively, so that the gap width of the respective flat sides 5, 5' of the first optical fiber 4 and flat sides 10, 10' of the second optical fiber 9 are the same in the intersection area 13.

[0027] The flat sides 5, 5' of the first optical fiber 4 and the flat sides 10, 10' of the second optical fiber 9 extend in a straight line towards the intersection area 13 in the direction of the light flow, enclosing an angle φ in the intersection area 13. Since the flat sides 5, 5' and 10, 10' of the first optical fiber 4 and the second optical fiber 9, respectively, extend in a straight line, the extension sections 14 of the first optical fiber 4 and extension sections 15 of the second optical fiber 9 also enclose the same angle φ with each other. Because, in the present embodiment, the flat sides 5, 5' and 10, 10' of the first optical fiber 4 and the second optical fiber 9 do not converge exactly perpendicularly, the opening angle φ is not 90°, but has a deviation of 90° of ± 5°.

[0028] An extension axis EK of the intersection area 13 runs parallel to an extension direction of the light coupling surfaces 6', 11' of the first and second optical fibers 4, 9 or parallel to the light coupling surface 6", 11" of the extension sections 14, 15.

[0029] Between the deflection section 19 and the intersection area 13, in which the second section 20 of the first light guide 4 is located, coupling means (not shown) are arranged such that the light coupled into the first light guide 4 is coupled out at a front flat side 5' of the same in the main emission direction H of the lighting device. The coupled-out light 30 can, for example, be used to generate a taillight function. For example, elongated prism elements or diffusing elements can be arranged as coupling means on the rear flat side 5 of the second section 20 of the first light guide 4. Alternatively, corresponding coupling means can also be arranged on the front flat side 5'.

[0030] Additionally or alternatively, in the second section 20 of the first light guide 4 coupling means can be arranged such that light 31 in the main emission direction H exits on the front flat side 5' according to a predetermined inscription or logo 22.

[0031] If the light beam emitted in the main emission direction H from the second section 20 of the first light guide 4 is to have the light function (tail light function) and the logo function, the first coupling means responsible for the light function can lead to a different luminance of the coupled light than the second coupling means responsible for the logo 22. In the present embodiment, the first coupling means are arranged over the entire surface of the second section 20, while the second coupling means for displaying the logo 22 are only arranged in a portion of the second section 20 of the first light guide where the logo 22 is to be located.

[0032] To support the U-shaped light guide element 21, retaining arms 23 are arranged on a side facing the light sources 3, 8 as extensions on a narrow side of the first section of the light guide 4 and the second light guide 9 running towards the light coupling surface. At their ends, the retaining arms 23 have mounting tabs 24 for attaching the U-shaped light guide element 21 to a housing of the lighting device (not shown).

[0033] The extension section 14 of the first light guide 4 has a linear light output surface 6" on a side facing away from the intersection area 13, which can be used to generate a side marker light 26. The side marker light 26 is thus emitted essentially perpendicular to the tail light 30 or the outline light 28 and to the logo illumination 31.

[0034] The linear light output surface 11" of the extension section 15 of the second light guide 9, located on a side facing away from the intersection area 13, can serve to generate an outline light function 28. This outline light is emitted in the same direction (main emission direction H) as the tail light 30.

[0035] Advantageously, the invention allows for the compact creation of multiple lighting functions in a space-saving manner.

[0036] The light sources 3 and 8 are preferably designed as LED light sources, each arranged on a circuit board (not shown). The light sources 3 and 8 are arranged in a row. Reference symbol list

[0037] 11. Light unit 22. Light unit 3 Light sources 41. Light guide 5.5' Flat sides 6 Narrow sides 6' Light coupling area 6" Light coupling area 71. Light 8 Light sources 92. Light guide 10.10' Flat sides 11 Narrow sides 11' Light coupling area 11" Light coupling area 122. Light 13 Crossover area 14 Extension section 15 Extension section 161. Section 17 Diffuser optic elements 181. Section 19 Deflection section 202. Section 21 U-shaped light guide element 22 Logo 23 Mounting arm 24 Mounting tabs 25 Light coupling area 26 Side marker light 27 Light coupling area 28 Outline light function 29 Slanted surface 30 Tail light 31 Logo light function H Main beam direction EK Extension axis φAngle I 1 ,I 2 Length I V1 ,I V2 Length d 1 ,d 2 Thickness

Claims

1. A lighting device for motor vehicles with a first light unit (1) containing a light source (3) and a first flat light guide (4) having a first linear light coupling surface (6') and a linear light decoupling surface (6"), and with a second light unit (2) containing a light source (8) and a second flat light guide (9) having a linear light coupling surface (11') and a linear light decoupling surface (11"), - wherein the first flat light guide (4) and the second flat light guide (9) are connected integrally to each other to form a light guide element, - wherein opposite flat sides (5, 5') of the first light guide (4) and opposite flat sides (10, 10') of the second light guide (9) intersect in an intersection area (13), and - wherein the first flat light guide (4) has a deflection section (19) between a first flat section (18) and a second flat section (20) of the first flat light guide (4), wherein the first flat light guide (4) and the second flat light guide (9) form a U-shaped light guide element (21) in a transverse plane extending in a transverse plane to the linear light-coupling surface (6', 11') of the first light guide (4) and of the second light guide (9), wherein an extension section (14) of the first light guide (4) and an extension section (15) of the second light guide (9) project from the intersection area (13) at an angle (φ), characterised in that the second flat section (20) of the first light guide (4) forms a vertex of the U-shaped light guide element (21), the first flat section (18) of the first light guide (4) forms a first leg and a first section (16) of the second light guide (9) forms a second leg of the U-shaped light guide element (21), that the first planar light guide (4) has decoupling means in the second flat section (20) thereof such that coupled-in light (7) is decoupled at a front flat side (5') of the second flat section (20) in the main radiation direction (H) in order to generate a predetermined light function, that on a side of the extension sections (14, 15) facing away from the intersection area (13) a narrow side is formed as a linear light decoupling surface (6") of the first light guide (4) and as a linear light decoupling surface (11") of the second light guide (9), whereby the light is decoupled at the linear light decoupling surface (6") of the first light guide (4) and at the linear light decoupling surface (11") of the second light guide (9), in each case in the direction of the light guidance of the first light guide (4) and of the second light guide (9) respectively.

2. A lighting device according to Claim 1, characterised in that the extension sections (14, 15) enclose an equal angle (φ) with each other as the second flat sections (20) of the first light guide (4) and the first section (16) of the second light guide (9) running in the light flux direction towards the intersection area (13).

3. A lighting device according to Claim 2, characterised in that the enclosed angle (φ) between the extension sections (14, 15) is 90°.

4. A lighting device according to one of Claims 1 to 3, characterised in that an extension axis (EK) of the intersection area (13) runs parallel to an extension direction of the linear light coupling surface (6', 11') of the first light guide (4) and of the second light guide (9).

5. A lighting device according to Claim 4, characterised in that the extension axis (EK) of the intersection area (13) runs in vertical direction.

6. A lighting device according to one of Claims 1 to 5, characterised in that the decoupling means are distributed in the second section (20) of the first light guide (4) in such a way that light is decoupled over the entire surface of the second flat section (20) of the first light guide (4) in the main radiation direction (H) to generate the light function.

7. A lighting device according to one of Claims 1 to 6, characterised in that in the second flat section (20) of the first flat light guide (4), second decoupling means are arranged only in certain areas in such a way that light (31) is decoupled at the front flat side (5') of the first light guide (4) to display lettering or a logo (22).

8. A lighting device according to one of Claims 1 to 7, characterised in that the deflection section (19) of the first light guide (4) has an inclined surface (29) at which the light coupled in (7) is deflected.

9. A lighting device according to one of Claims 1 to 8, characterised in that the inclined surface (29) is flat or has reflective optical elements and extends at an angle in a range from 40° to 50°, preferably at an angle of 45°, to a direction of extension of the first section (18) and the second section (20) of the first light guide (4).

10. A lighting device according to one of Claims 1 to 9, characterised in that a row of light sources (3, 8) is arranged on the linear light coupling surface (6') of the first light guide (4) and on the linear light coupling surface (11') of the second light guide (9).

11. A lighting device according to one of Claims 1 to 10, characterised in that a retaining arm (23) is formed in the extension of a narrow side of both the first light guide (4) and the second light guide (9) connected to the light coupling surface (6', 11') for attaching the U-shaped light guide element (21) to a housing of the lighting device.

12. A lighting device according to one of Claims 1 to 11, characterised in that the second flat section (20) of the first light guide (4) runs essentially perpendicularly to the first section (18) of the first light guide (4) and perpendicularly to the second light guide (9).