Lighting device for a vehicle

Abstract

A lighting device for a vehicle comprises: a plurality of light sources (1), which are arranged in an array, in particular in rows and columns, and are capable of operating at least partially independently of one another, wherein the light sources (1) emit light (13) during operation; an exit surface (4) through which the light (13) emitted from the light sources (1) passes; and a plurality of planar delimiting elements (3), which extend at least partially in the region between the light sources (1) and the exit surface (4) and are used to separate the light (13) emitted from different light sources (1), wherein at least some, preferably all, of the planar delimiting elements (3) have reflectors (14) that reflect at least part of the light (13) emitted from one of the light sources (1) in the direction of the exit surface (4).

Description

Field of the Invention

[0001] The present invention relates to a lighting device for a vehicle. Background Art

[0002] A lighting device of the above type is known from DE 10 2016 119 326 A1. The lighting device described therein includes a plurality of light-emitting diodes serving as light sources and an exit surface, the light-emitting diodes being arranged in an array in rows and columns and being operable at least partially independently of one another, and the light emitted from the light sources passes through the exit surface. By independently controlling the light-emitting diodes, different sections of the exit surface can be illuminated differently, so that for example a logo can be produced on the exit surface. In addition, the lighting device includes a plurality of planar delimiting elements, which extend in the region between the light sources and the exit surface and are used to separate the light emitted from different light sources. Here, for large and curved lighting devices, such as taillights integrated into the vehicle contour, a plurality of circuit boards offset relative to one another and inclined relative to one another are provided, and a set of light-emitting diodes is respectively arranged on the circuit boards.

[0003] The structure known from DE 10 2016 119 326 A1 can be well applied to lighting devices with a slightly swept horizontal profile, i.e., for flatter light-emitting device profiles. However, many lighting devices on vehicles have a greater sweep angle and a more strongly curved contour, such as a horizontal angle of 30° or more. Here, the above structure reaches its limit, because in a structure with a circuit board, the orientation of the planar circuit board and thus the orientation of the light-emitting diodes become more and more strongly outwardly oriented with the increase of the horizontal angle after the curved and swept optical sheet. As a result, the light is not emitted against the driving direction, where in order to approve the lamp, the legislator stipulates and the highest light intensity must be met. In a segmented lamp, with the increase of the horizontal angle for the circuit board, a strong grading from column to column occurs, and an unfavorable distribution and different grading in the rear view occur considering the demolding angle of the component. Summary of the Invention

[0004] The problem underlying the present invention is to implement a lighting device of the type described at the beginning, which is suitable for strongly swept vehicle headlights and is particularly simply constructed and can be manufactured inexpensively or resource-conservingly.

[0005] According to the present invention, this is achieved by a lighting device of the type described at the beginning and according to the present invention.

[0006] According to the provisions of the present invention, at least some, preferably all, of the planar boundary elements of the planar boundary element have reflectors that reflect at least part of the light emitted from one of the light sources in the direction of the exit surface. Through the reflector, the light can also be deflected, for example, into the desired main direction in a highly swept-back vehicle headlight. In particular, the deflection of the light can be achieved both in the horizontal direction and in the vertical direction. Here, the arrangement structure of the boundary elements can form a planar pixel matrix for variably representing signal light functions and information.

[0007] It can be provided that the reflector is arranged such that the light emitted from the light source is reflected in a direction forming an angle greater than 0° with the normal on the exit surface, especially an angle greater than 25°, preferably greater than 30°. Thereby, even in the case of a large sweep angle and a strongly curved contour, the light of each light source can be deflected appropriately. In particular, it can be provided that in the state where the lighting device is installed in a vehicle, the direction in which the light emitted from the light source is reflected is oriented substantially parallel to the driving direction or parallel to the longitudinal direction of the vehicle.

[0008] There is a possibility that one reflector of the reflectors is assigned to each light source of the light sources. At least some, preferably all, of the reflectors can be designed as parabolic reflectors or free-form reflectors. In particular, through the reflectors designed in this way, the light of at least some, preferably all, of the light sources can be deflected and concentrated appropriately to ensure the high efficiency of the lighting device. This results in the desired light concentration in the axial central region of the statutory light distribution and the high performance of the overall system, thereby enabling the use of low-cost and low-power light sources.

[0009] It can be provided that at least some, preferably all, of the light sources include at least one light-emitting diode, especially an RGB light-emitting diode or a two-color light-emitting diode or two light-emitting diodes of different colors. Here, each light source of the light sources can be individually controlled, especially each light-emitting diode of each light-emitting diode of a single light source can also be individually controlled. In this way, different colors can be arbitrarily selected for each section or each pixel of the exit surface, and in particular, the individual implementation and positioning of the adaptability of the light function can also be achieved within the matrix formed by the sections. For example, a two-color variant with red and yellow signal colors provides the possibility of implementing all three main signal functions of a taillight with different lighting signs and animations in the entire pixel function surface: taillight, brake light, and turn signal light.

[0010] There is a possibility that the lighting device includes at least one circuit board, on which light-emitting diodes are arranged, in particular all the light-emitting diodes are arranged on at most three, in particular two, preferably only one circuit board. In particular, when using only one circuit board, the structure of the lighting device is significantly simplified and can be realized at low cost. In addition, a common orientation or inclination of the respective reflectors can be achieved by the corresponding orientation of the single circuit board without forming horizontal and / or vertical strip-shaped areas.

[0011] It can be provided that the at least one circuit board is substantially parallel to the exit surface, in particular so that the circuit board has rotation and tilting angles. Thereby, a very compact structure of the lighting device can be achieved, because ultimately a flat and elongated housing can be used to accommodate the individual components.

[0012] There is a possibility that the planar delimiting element is arranged in a grating-like manner, wherein in particular at least one delimiting element is arranged between two adjacent light sources in the array and / or between the light emitted from adjacent light sources. The planar delimiting element thus forms a segmented light shield, through which a clear demarcation of the light of the individual adjacent light sources can be achieved with a simple device. Here, the grating-like arrangement structure of the delimiting element can be implemented differently and can have, for example, rectangular, rhombic, trapezoidal, hexagonal, octagonal or other shapes.

[0013] It can be provided that a plurality of the delimiting elements form a one-piece structural unit, or all of the delimiting elements form a one-piece structural unit. In this way, components can be saved, because the structural unit formed by the delimiting elements simultaneously includes reflectors.

[0014] There is a possibility that the lighting device includes an optical sheet, which is arranged between the light source and the exit surface, in particular between the reflector and the exit surface, and the light emitted from the light source passes through the optical sheet. Here, the optical sheet can be structured, in particular the optical sheet is provided with scattering optical devices, preferably with pillow-shaped optical devices or diffractive optical devices. Thereby, uniform illumination of the exit surface can be achieved, so that the exit surface can also be used, for example, as a display and a display device.

[0015] It can be provided that the optical sheet is configured and / or arranged such that the light source and / or the reflector is invisible or not directly visible when observing the lighting device through the exit surface. In particular, for the observer, the line of sight through the optical sheet to the optical system arranged behind the optical sheet is blocked. In addition, the corresponding sectional surfaces or pixel surfaces on the exit surface thus appear to be uniformly and evenly illuminated.

[0016] There is a possibility that the lighting device includes a grating, which is arranged in the region of the optical sheet, in particular on the side of the optical sheet facing away from the light source, wherein the grating preferably continues the grating-like arrangement structure of the reflector. For example, a grating configured as a grating baffle or a designed grating can more significantly highlight the division of the optical sheet into sections. In this way, a design element can also be provided, which can be used, for example, in different color combinations for design variants of the lighting device. Description of the Drawings

[0017] The present invention will be described in more detail below with reference to the drawings. In the figures:

[0018] Figure 1 shows a cross-sectional view of a first embodiment of a lighting device according to the present invention;

[0019] Figure 2 shows a cross-sectional view of a second embodiment of a lighting device according to the present invention;

[0020] Figure 3 shows Figure 2 details of

[0021] Figure 4 shows Figure 3 details of, wherein the paths of some light rays are exemplarily shown;

[0022] Figure 5 shows a front view of the individual sections of a third embodiment of a lighting device according to the present invention;

[0023] Figure 6 shows a front view of the individual sections of a fourth embodiment of a lighting device according to the present invention;

[0024] Figure 7 shows Figure 6 details of

[0025] Figure 8 shows a rear view of the individual sections of a fifth embodiment of a lighting device according to the present invention;

[0026] Figure 9 shows details of the optical sheet of a sixth embodiment of a lighting device according to the present invention;

[0027] Figure 10 shows details of the optical sheet of a seventh embodiment of a lighting device according to the present invention;

[0028] Figure 11 shows a front view of an eighth embodiment of a lighting device according to the present invention;

[0029] Figure 12Front view showing a ninth embodiment of the lighting device according to the invention. Detailed Description

[0030] In the drawings, identical or functionally identical components are provided with the same reference numerals.

[0031] In Figures 1 to 10 each embodiment of the lighting device according to the invention shown, includes a plurality of light sources 1, which are arranged in a two-dimensional array in rows and columns (see, for example, Figures 1 to 4 and Figure 8 ). These embodiments also include an optical sheet 2 and a planar boundary element 3, which extends between the light source 1 and the optical sheet 2. These embodiments also include an exit surface 4, which is, for example, part of a transparent closing sheet 5, which closes the housing 6 included by the lighting device.

[0032] The light source 1 may include at least one light emitting diode 7, in particular an RGB light emitting diode or two light emitting diodes 8 of different colors (see, for example, Figures 5 to 7 ). For example, a two-color variant with red and yellow signal colors provides the possibility of implementing all three main signal functions of a tail light with different lighting signs and animations over the entire pixel functional surface: tail light, brake light, and turn signal light. Here, for example, one red light emitting diode and one yellow light emitting diode or a plurality of RGB light emitting diodes can be used, which are configured as multi-chip LEDs or dual-chip LEDs with red and yellow chips.

[0033] Each light source 1 in the light sources, in particular each light emitting diode 7, 8 in the light source 1, can also be individually controlled. In this way, different colors can be arbitrarily selected for each section or each pixel of the exit surface, and in particular, the individual implementation and positioning of the adaptability of the light function can also be achieved within the matrix formed by the individual sections.

[0034] The light emitting diodes 7, 8 of all the light sources 1 are preferably mounted on a common circuit board 9. The optical sheet 2 and the exit surface 4 are arranged parallel to the circuit board 9 respectively, where the optical sheet 2 is spaced apart from both the circuit board 9 and the exit surface 4. Here, Figure 1 an embodiment is shown, in which there is a large box-shaped housing 6. Figure 2 an embodiment is shown, in which the housing back 18 is also oriented parallel to the circuit board 9 and the exit surface 4, resulting in a very flat lighting device.

[0035] The lighting device is installed in the vehicle such that the normal 10 on the exit surface 4 forms an angle α greater than 25°, preferably greater than 30°, with the longitudinal direction 11 of the vehicle. Correspondingly, the exit surface 4 forms the same angle α with the transverse direction 12 of the vehicle (see Figure 1 and Figure 2 ).

[0036] The planar boundary element 3 extends between the light source 1 and the optical sheet 2 such that the planar boundary elements are arranged respectively similar to a grating. Here, at least one boundary element 3 is arranged respectively between two adjacent light sources 1 in the array or between the light 10 emitted from adjacent light sources 1 (for example see Figure 3 , Figure 4 and Figure 8 ).

[0037] The boundary elements 3 each have a reflector 14, wherein one reflector of the reflectors 14 is assigned to each light source of the light sources 1. The reflectors 14 can each be designed as a parabolic reflector or a free-form reflector. The reflectors 14 are shaped and oriented such that the horizontal and, if necessary, also the vertical inclination of the circuit board 9 with respect to the transverse direction 12 of the vehicle is compensated and the light 13 reflected by the reflectors 14 extends as parallel as possible to the longitudinal direction of the vehicle after reflection (see Figure 4 ). For example, when the lighting device is used as a tail light, the light 13 is emitted backward against the driving direction by the reflector 14.

[0038] Thereby, the reflectors 14 are arranged such that the light 13 emitted from the light sources 1 is reflected in a direction forming an angle α with the normal 10 on the exit surface 4. Thereby, even in the case of a large rake angle and a strongly curved contour course of the lighting device, the light 13 of each light source 1 can be appropriately deflected.

[0039] When using two light-emitting diodes 8 for each light source 1, it is advantageous that the two light-emitting diodes 8 are positioned next to each other or one above the other in the corresponding section (see Figure 7 ). Then, the reflector 14 designed as a parabolic reflector or a free-form reflector is designed to be aligned with the focus 15, and the focus is arranged centrally between the two light-emitting diodes 8 positioned closely to each other (see Figure 7 ). Due to the small focal length of the reflector 14, scattering of the light 13 is already generated by the closely positioned light-emitting diodes 8, and this scattering can also be supported by the structure or optics or white implementation of the reflector 14, which is responsible for evenly illuminating the optical sheet 2 or the section of the optical sheet 2 assigned to the light source 1. Thus, high-quality and balanced lighting can be achieved. Here, due to the small defocusing of the two light-emitting diodes 8 with respect to the reflector 14, no large additional errors or scattering are introduced into the system.

[0040] Furthermore, it is stipulated that the light-emitting diode 7 or the plurality of light-emitting diodes 8 are respectively positioned tightly at the vehicle interior boundary of the section (see Figures 5 to 7 ). Thereby, in the case of a given horizontal torsion of the system, the surface of the reflector 14 for compensating the horizontal rotation angle to correctly deflect and orient the light 13 can occupy the largest area in a section and thus provides high efficiency. The efficiency is further optimized because in this arrangement of the at least one light-emitting diode 7, 8, its light 13 is not only emitted directly forward in the direction of the optical sheet 2 but also emitted onto the reflecting surface of the reflector 14 for effective steering, so that the light 13 of the light-emitting diodes 7, 8 is optimally utilized (see Figure 4 ). Here, the reflecting surface of the reflector 14 is effectively illuminated because the at least one light-emitting diode 7, 8 has been oriented more strongly relative to the surface of the reflector 14 to be reflected than forward relative to the optical sheet 2 by the circuit board 9 and the horizontal rotation of the light-emitting diodes 7, 8 arranged thereon.

[0041] The optical sheet 2 through which the light 13 passes is provided with scattering optics 16 (for example, see Figure 3 and Figure 4 ). The scattering optics 16 can be a conventional pillow-shaped optics, but its dimensions a, b (see Figure 9 ) should be selected to be less than 1 mm, ideally about 0.5 mm or less, in order to generate a uniform illumination of the exit surface. For special adaptation, for example, in a system arranged extremely obliquely, the pillow-shaped optics can also be implemented on a (not shown) prism surface.

[0042] Alternatively, diffractive optics, in particular diffractive holographic diffuser optics, can also be used, which have optical structures in the range of a few micrometers or in the nanometer range or higher, and the optical structures are no longer resolvable for an observer and are perceived as a diffusive scattering surface.

[0043] In Figure 10 the illustrated embodiment, a grating 17 is provided, and the grating is arranged on the side of the optical sheet 2 facing away from the light source 1. The grating 17, for example configured as a grating baffle or a design grating, can more prominently highlight the division of the optical sheet 2 into sections. In this way, a design element can also be provided, which can be used, for example, in different color schemes for design variants of the lighting device.

[0044] The grating 17 can be implemented as a plastic injection molded part, for example as a black component, a gray component or a colored component, or it can be mirrorized or painted afterwards. Alternatively, the grating 17 can also be configured as a flat component, for example as a metallic grating element, which can also be directly joined as an insert in a die casting mold to the optical sheet 2 in a die casting process. As another alternative, it is also conceivable to simply print the black or colored grating 17 onto the optical sheet 2, for example by means of screen printing or pad printing. This is particularly suitable in the case of flat optical sheets 2.

[0045] Figure 11 Shows an embodiment of the lighting device without the optical sheet 2, which constitutes an alternative in the case of sufficient scattering by the reflector 14 in order to save the optical sheet 2 as a component. Figure 12 Shows an embodiment of the lighting device with the optical sheet 2. In this embodiment, the reflector 14 and the light source 1 are not visible when viewed through the exit surface 4.

[0046] List of reference signs

[0047] 1 Light source

[0048] 2 Optical sheet

[0049] 3 Planar bounding element

[0050] 4 Exit surface

[0051] 5 Transparent cover sheet

[0052] 6 Housing

[0053] 7, 8 Light emitting diodes

[0054] 9 Circuit board

[0055] 10 Normal to the exit surface 4

[0056] 11 Longitudinal direction of the vehicle

[0057] 12 Vehicle transverse direction

[0058] 13 Light emitted from the light source 1

[0059] 14 Reflector

[0060] 15 Focus of the reflector 14

[0061] 16 Scattering optics of the optical sheet 2

[0062] 17 Grating

[0063] 18 Back of the housing

[0064] Dimensions of the a, b scattering optical device

[0065] The angle between the normal to the exit surface 4 and the direction in which the light 13 is reflected

Claims

1. A lighting device for a vehicle, the lighting device comprising: - a plurality of light sources (1), which are arranged in an array and are capable of operating at least partly independently of one another, wherein the light sources (1) emit light (13) during operation, - an exit surface (4) through which the light (13) emitted from the light sources (1) passes, - a plurality of planar delimiting elements (3), which extend at least partly in the region between the light sources (1) and the exit surface (4) and are used for separating the light (13) emitted from different light sources (1), characterized in that at least some of the planar delimiting elements (3) have reflectors (14), each of which reflects at least partly the light (13) emitted from one of the plurality of light sources (1) in the direction of the exit surface (4), and the reflectors (14) are arranged such that the light (13) emitted from the light sources (1) is reflected in a direction forming an angle (α) greater than 0° with the normal (10) on the exit surface (4), and in the state where the lighting device is mounted in the vehicle, the direction in which the light (13) emitted from the light sources (1) is reflected by the reflectors (14) is oriented substantially parallel to the driving direction or parallel to the longitudinal direction (11) of the vehicle.

2. The lighting device according to claim 1, characterized in that, The light sources are arranged in an array in rows and columns.

3. The lighting device according to claim 1, characterized in that, All of the planar delimiting elements (3) have reflectors (14).

4. The lighting device according to claim 1, characterized in that The angle (α) is greater than 25°.

5. The lighting device according to claim 1, characterized in that, The angle (α) is greater than 30°.

6. The lighting device according to any one of claims 1 to 5, characterized in that, One reflector in the reflectors (14) is assigned to each of the light sources (1).

7. The lighting device according to any one of claims 1 to 5, characterized in that, At least some of the reflectors (14) are designed as parabolic reflectors or free-form reflectors.

8. The lighting device according to claim 7, characterized in that, All of the reflectors (14) are designed as parabolic reflectors or free-form reflectors.

9. The lighting device according to any one of claims 1 to 5, characterized in that, At least some of the light sources (1) include at least one light-emitting diode (7, 8).

10. The lighting device according to claim 9, characterized in that, All of the light sources (1) include at least one light-emitting diode (7, 8).

11. The lighting device according to claim 9, characterized in that, The light-emitting diodes include RGB light-emitting diodes or dual-color light-emitting diodes or two light-emitting diodes of different colors.

12. The lighting device according to claim 9, characterized in that, Each of the light sources (1) can be individually controlled.

13. The lighting device according to claim 12, characterized in that, Each of the light-emitting diodes (7, 8) in a single light source (1) can also be individually controlled.

14. The lighting device according to claim 9, characterized in that, The lighting device includes at least one circuit board (9) on which the light-emitting diodes (7, 8) are arranged.

15. The lighting device according to claim 14, characterized in that, All of the light-emitting diodes (7, 8) are arranged on at most three circuit boards (9).

16. The lighting device according to claim 14, characterized in that, All of the light-emitting diodes (7, 8) are arranged on two circuit boards (9).

17. The lighting device according to claim 14, characterized in that, All of the light-emitting diodes (7, 8) are arranged on only one circuit board (9).

18. The lighting device according to claim 14, characterized in that, The at least one circuit board (9) is substantially parallel to the exit surface (4).

19. The lighting device according to any one of claims 1 to 5, characterized in that, The planar delimiting elements (3) are arranged similar to a grating.

20. The lighting device according to claim 19, characterized in that, At least one delimiting element (3) is arranged respectively between two adjacent light sources (1) in the array and / or between the light (13) emitted from adjacent light sources (1).

21. The lighting device according to any one of claims 1 to 5, characterized in that, A plurality of the boundary elements in the boundary element (3) form an integral structural unit, or all of the boundary elements in the boundary element (3) form an integral structural unit.

22. The lighting device according to any one of claims 1 to 5, characterized in that, The lighting device includes an optical sheet (2) arranged between a light source (1) and an exit surface (4), wherein light (13) emitted from the light source (1) passes through the optical sheet (2).

23. The lighting device according to claim 22, wherein The optical sheet is arranged between a reflector (14) and the exit surface (4).

24. The lighting device according to claim 22, characterized in that, The optical sheet (2) is structured.

25. The lighting device according to claim 24, characterized in that, The optical sheet (2) is provided with scattering optics (16).

26. The lighting device according to claim 24, wherein The optical sheet (2) is provided with barrel optics or diffractive optics.

27. The lighting device according to claim 22, characterized in that, The optical sheet (2) is configured and / or arranged such that the light source (1) and / or the reflector (14) is invisible or not directly visible when observing the lighting device through the exit surface (4).

28. The lighting device according to claim 22, characterized in that, The lighting device includes a grating (17) arranged in the region of the optical sheet (2).

29. The lighting device according to claim 28, characterized in that, The grating is arranged on the side of the optical sheet (2) facing away from the light source (1).

30. The lighting device according to claim 28, characterized in that, The grating (17) continues the grating-like arrangement structure of the reflector (14).

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