Lighting device for vehicle

Abstract

The invention relates to a lighting device for a vehicle, comprising a lighting module (1) which has at least one light-emitting diode (2), preferably a plurality of light-emitting diodes (2), and a light-emitting surface which is illuminated by the at least one light-emitting diode (2) and from which light (3) emits during operation of the lighting device, the lighting module (1) comprises an optical component (9) provided with a converter, which optical component is arranged between the at least one light-emitting diode (2) and the light-emitting surface or forms the light-emitting surface, the light (3) emitted by the at least one light-emitting diode (2) passes through the optical component (9) and impinges on the light-emitting surface, and wherein the converter changes the wavelength spectrum of the light (3) passing through the optical component (9).

Description

Technical Field

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

[0002] The lighting device of the type mentioned above is known from WO2023 / 025626A1. The lighting device described therein comprises: a lighting module having a plurality of light-emitting diodes and a lighting surface illuminated by the light-emitting diodes, from which light is emitted during operation of the lighting device; and an LC display, which is arranged at least partially in front of the lighting surface, so that at least a portion of the light emitted from the lighting surface is incident on the incident surface of the LC display during operation of the lighting device and is emitted from the exit surface of the LC display, wherein the lighting device is designed to: control the LC display so as to specifically allow part of the light incident on the incident surface to pass through the LC display and not allow other parts of the light incident on the incident surface to pass through the LC display. In this case, the lighting module has a planar light conductor, which has an incident surface for the light of the light-emitting diodes at the end side and an exit surface perpendicular to the incident surface, from which light propagates in a direction toward the light-emitting surface.

[0003] It has proven disadvantageous that the contrast ratio on the exit surface of the LC display between the region through which the light incident on the entrance surface is allowed to at least partially pass and the region through which the light incident on the entrance surface is not allowed to at least partially pass is generally considered to be too low. This is partly the result of insufficiently intense and / or insufficiently uniform illumination of the luminous surface of the lighting module. It has also been shown that red light-emitting diodes used to generate signal functions (such as tail lights or brake lights) degrade rapidly, so that the contrast ratio is further reduced. Summary of the invention

[0004] The problem underlying the present invention is therefore to provide a lighting device of the type mentioned at the outset, which is able to achieve a higher contrast on the luminous surface of the luminous module and / or in which the at least one light-emitting diode (from which light is emitted during operation of the lighting device for illuminating the luminous surface) does not degrade too quickly.

[0005] This is achieved according to the invention by a lighting device of the type mentioned at the outset having the characterizing features of claim 1. The dependent claims relate to preferred embodiments of the invention.

[0006] According to claim 1, the light-emitting module comprises an optical component provided with a converter, the optical component being arranged between the at least one light-emitting diode and the light-emitting surface or constituting the light-emitting surface, wherein the lighting device is designed to allow the light emitted from the at least one light-emitting diode to pass through the optical component and be emitted onto the light-emitting surface, wherein the converter changes the wavelength spectrum of the light passing through the optical component. The converter can contribute to homogenizing the light emitted from the light-emitting module by scattering, thereby in particular being able to omit the scattering optical sheet usually used in the light-emitting module. In addition, the converter can avoid red light-emitting diodes, so that the at least one light-emitting diode (light is emitted from the light-emitting diode during operation of the lighting device for illuminating the light-emitting surface) does not degrade too quickly.

[0007] Here, it can be provided that the lighting device comprises an LC display, which is arranged at least partially in front of the luminous surface, so that during operation of the lighting device, at least part of the light emitted from the luminous surface is incident on the incident surface of the LC display and is emitted from the exit surface of the LC display, wherein the lighting device is designed to control the LC display so as to specifically allow part of the light incident on the incident surface to pass through the LC display and not allow other parts of the light incident on the incident surface to pass through the LC display. By designing the lighting module according to the invention, a higher contrast can be achieved on the exit surface of the LC display.

[0008] It can be provided that the at least one light emitting diode is designed to emit blue or white light and the converter is designed to change the color of the light emitted by the at least one light emitting diode, for example, to convert blue or white light into red light or to convert blue light into white light.

[0009] There is the possibility that the optical component provided with the converter is designed as an optical sheet or an optical film. Both the optical sheet and the optical film can be designed to be thin, so that despite the optical component provided with the converter, the lighting device can still be designed to be compact.

[0010] It can be provided that at least one surface of the optical component provided with the converter, through which the light emitted by the light emitting diode passes, is curved. Thus, the optical component can assume other optical functions in addition to converting the color of the light.

[0011] Alternatively or additionally, it may be provided that at least one surface of the optical component provided with the converter, through which the light emitted by the light emitting diode passes, has a structuring portion. The structuring portion can contribute to homogenizing the light emitted from the light emitting module.

[0012] There is the possibility that the converter is designed as a coating with a converter material on at least one surface of the optical component through which the light emitted by the light-emitting diode passes. Alternatively or additionally, it can be provided that the converter is designed as a converter material integrated into the optical component, in particular, the optical component is an injection-molded part, the raw material of which for injection molding has the converter material. In both cases, the converter material can contribute to homogenizing the light emitted from the light module by scattering.

[0013] It is possible to arrange the optical component provided with the converter at a distance from the at least one light emitting diode, thereby ensuring that the optical component provided with the converter is illuminated over the largest possible area by the light of the at least one light emitting diode.

[0014] It can be provided that the at least one light emitting diode is arranged in the light module such that the light generated during operation of the lighting device is emitted from the at least one light emitting diode substantially directly in the direction of the light emitting surface. By means of such direct illumination, the light generated by the at least one light emitting diode can reach the light emitting surface more efficiently, so that the contrast on the exit surface of the LC display can be increased. In addition, when a plurality of light emitting diodes are used, it can be achieved by targeted control, such as targeted dimming of individual light emitting diodes, that different areas of the entrance surface of the LC display are illuminated with different intensities, so that the contrast on the exit surface can be further increased.

[0015] Here, there is the possibility that the light module includes at least one reflector, which is assigned to the at least one light emitting diode, so that part of the light emitted from the at least one light emitting diode is reflected in the direction toward the light emitting surface during operation of the lighting device. Preferably, the light module includes a plurality of reflectors, which are respectively assigned to one of the light emitting diodes, so that part of the light emitted from the corresponding light emitting diode is reflected in the direction toward the light emitting surface during operation of the lighting device. The at least one reflector can further improve the efficiency with which the light generated by the at least one light emitting diode reaches the light emitting surface.

[0016] It can be provided that the light module comprises a planar light conductor having an incident surface at the end and at least one exit surface, wherein the lighting device is designed to cause the light generated by the at least one light emitting diode to be incident into the light conductor at least partially through the incident surface and to be emitted from the at least one exit surface at least partially in a direction toward the light emitting surface. Here, the light conductor can have a structured portion, wherein the lighting device is designed to cause the light moving through the light conductor to be at least partially deflected by the structured portion so that the light is emitted from the light conductor through the exit surface. This design can also make it possible to illuminate the light emitting surface or the incident surface of the LC display relatively uniformly.

[0017] It is possible that the lighting module includes an optical sheet provided with a structured portion, which is arranged between the optical component provided with the converter and the luminous area or forms the luminous area. This additional optical sheet can further improve the uniformity of the illumination of the luminous area or the incident surface of the LC display.

[0018] It may be provided that the lighting device comprises a housing, on or in which a light-emitting module is arranged, and in particular, the LC display is mounted on the light-emitting module or on the housing.

[0019] There is the possibility that the LC display is a guest-host display or smart glass display. In such LC displays, no polarization filter is required, so that a higher transmittance is available, which is advantageous and decisive for fulfilling the optical function in the case of small light-emitting elements. In addition, due to the omission of the polarizer, the LC display is also independent of the viewing angle. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The present invention will be described in more detail below with the aid of the accompanying drawings.

[0021] Figure 1 A schematic cross-sectional view showing a first embodiment of an illumination device according to the present invention;

[0022] Figure 2 A schematic cross-sectional view shows a second embodiment of an illuminating device according to the present invention. DETAILED DESCRIPTION

[0023] In the figures, identical or functionally identical components are provided with the same reference symbols.

[0024] Lighting devices in Figure 1 The first embodiment shown in FIG. 1 comprises a lighting module 1 having a plurality of light-emitting diodes 2 which are designed, in particular, to generate blue or white light 3. The light-emitting diodes 2 are arranged on a common printed circuit board 4.

[0025] The lighting module 1 has a lighting surface, which can be formed, for example, by an outer sheet (not shown) or by another component of the lighting module 1, which is described in more detail below. An LC display 5 is connected to the lighting surface, which has an incident surface 6 facing the lighting surface and an exit surface 7 opposite the incident surface 6.

[0026] Alternatively, provision can be made for no LC display to be provided.

[0027] The light emitting diodes 2 are arranged in the light emitting module 1 so that the light 3 generated during operation of the lighting device is emitted from the light emitting diodes substantially directly in the direction toward the light emitting surface or in the direction toward the incident surface 6 of the LC display 5. The light emitting module 1 further comprises a plurality of reflectors 8, each of which surrounds one of the light emitting diodes 2 so that part of the light 3 emitted from the corresponding light emitting diode 2 is reflected in the direction toward the light emitting surface during operation of the lighting device.

[0028] The lighting module 1 further comprises an optical component 9 provided with a converter, which is arranged between the light emitting diode 2 or the reflector 8 and the luminous area. Alternatively, it can be provided that the optical component 9 forms the luminous area.

[0029] The light 3 emitted from the light emitting diode 2 can pass through the optical component 9 and be incident on the incident surface 6 of the LC display 5, wherein the converter changes the wavelength spectrum of the light 3 passing through the optical component 9. In particular, the converter is designed to change the color of the light 3 emitted from the light emitting diode, for example, converting light having a blue or white color into light having a red color or converting light having a blue color into light having a white color.

[0030] The optical component 9 provided with the converter can be configured as an optical sheet or an optical film, for example, and has an incident surface for the light 3 emitted from the light emitting diode 2 facing the light emitting diode 2 or the reflector 8 and an exit surface opposite to the incident surface.

[0031] At least one of the surfaces through which the light 3 emitted from the light emitting diode passes can be curved. Thus, the optical component 9 provided with the converter can also assume the function of a lens, for example. Alternatively or additionally, at least one of the surfaces of the optical component 9 can have a structured portion. The structured portion can help to homogenize the light 3 emitted from the light emitting module 1.

[0032] The converter may be configured as a coating having a converter material on at least one of the surfaces of the optical component 9 serving as an incident surface or an exit surface. Alternatively or additionally, the converter may be configured as a converter material integrated into the optical component 9. Here, the optical element 9 may be an injection molded part, the raw material of which for injection molding has a converter material. In both cases, the converter material may contribute to homogenizing the light 3 emitted from the light emitting module 1 by scattering.

[0033] Furthermore, the lighting module 1 comprises an optical sheet 10 provided with a structured portion, which is arranged between the optical component 9 provided with a converter and a lighting surface, which is formed, for example, by an external sheet (not shown). Alternatively, the optical sheet 10 provided with a structured portion can form the lighting surface. The homogeneity of the illumination of the lighting surface or the entrance surface 6 of the LC display 5 can be further improved by means of the additional optical sheet 10.

[0034] Furthermore, the lighting device comprises a housing 11 in which the light emitting module 1 is accommodated. Figure 1 In the embodiment shown in the figure, the LC display 5 is mounted on the housing 11 on the exit side of the light 3 generated by the light-emitting module 1, so that the incident surface 6 of the LC display is adjacent to the light-emitting surface of the light-emitting module 1, wherein the light-emitting surface is formed by an external sheet (not shown) or by an optical component 10 provided with a structured part or by an optical component 9 provided with a converter.

[0035] The LC display 5 is designed in particular as a guest-host display or smart glass display. The LC display 5 can be controlled in order to selectively allow part of the light 3 incident on the entrance surface 6 to pass through the LC display 5 and not allow another part of the light 3 incident on the entrance surface 6 to pass through the LC display 5.

[0036] exist Figure 2 The second embodiment shown in Figure 1 The difference from the first embodiment of the present invention is that the light emitting diodes 2 are arranged in the light module 1 so that the generated light 3 emerges from the light emitting diodes 2 substantially parallel to the luminous surface or the incident surface 6 of the LC display 5 during operation of the lighting device. Figure 2 A plurality of light emitting diodes 2 are provided, which are arranged side by side in a direction extending into Figure 2 in the plane of the diagram.

[0037] A second embodiment of the lighting device comprises a light guide 12 having an end-side incident surface 13, into which the light 3 emitted by the light emitting diode 2 is incident and Figure 2 The light conductor 12 comprises an exit surface 14 facing the light-emitting surface or the incident surface 6 of the LC display 5 , through which the light 3 is emitted in the direction of the light-emitting surface or the incident surface 6 of the LC display 5 .

[0038] In this case, the optical waveguide 12 can have a structure on a surface 15 opposite the exit surface 14 , which structure can at least partially deflect the light 3 moving through the optical waveguide 12 so that it exits the optical waveguide 12 through the exit surface 14 .

[0039] according to Figure 2 The lighting module 1 can optionally have a reflector 16, which is arranged outside the light conductor 12 on the side facing away from the LC display 5. In this case, the lighting module 1 is designed to make the light 3 Figure 2 The light is emitted to the right from the surface 15 opposite to the exit surface 14, and is reflected by the reflector 16 in the direction toward the optical waveguide 12, and is incident on the optical waveguide 12 through the surface 15 opposite to the exit surface 14 and is emitted through the exit surface 14. Figure 2The light emerges from the optical waveguide 12 to the left or in the direction of the optical component 9 provided with the converter.

[0040] Reference numerals list

[0041] 1 Light emitting module

[0042] 2 LEDs

[0043] 3 Light generated by light emitting diodes

[0044] 4 Circuit Board

[0045] 5 LC Display

[0046] 6 LC display incident surface

[0047] 7. LC display output surface

[0048] 8 Reflector

[0049] 9 Optical component with converter

[0050] 10 Optical sheet with structured portion

[0051] 11 Housing

[0052] 12 Photoconductor

[0053] 13 Entrance surface of the light conductor

[0054] 14. Light guide exit surface

[0055] 15 Surface of the light conductor opposite the exit surface

[0056] 16 Reflector

Claims

1. A lighting device for a vehicle, comprising a lighting module (1), the lighting module having at least one light-emitting diode (2), preferably a plurality of light-emitting diodes (2), and a lighting surface illuminated by the at least one light-emitting diode (2), light (3) being emitted from the lighting surface during operation of the lighting device, characterized in that The light-emitting module (1) comprises an optical component (9) provided with a converter, the optical component being arranged between the at least one light-emitting diode (2) and the light-emitting surface or constituting the light-emitting surface, the lighting device being designed to allow the light (3) emitted from the at least one light-emitting diode (2) to pass through the optical component (9) and irradiate onto the light-emitting surface, the converter changing the wavelength spectrum of the light (3) passing through the optical component (9).

2. The lighting device according to claim 1, characterized in that: The lighting device comprises an LC display (5), which is at least partially arranged in front of the luminous surface so that at least a portion of the light (3) emitted from the luminous surface is incident on an incident surface (6) of the LC display (5) during operation of the lighting device and is emitted from an exit surface (7) of the LC display (5), and the lighting device is designed to control the LC display (5) so as to specifically allow a portion of the light (3) incident on the incident surface (6) to pass through the LC display (5) and not allow another portion of the light (3) incident on the incident surface (6) to pass through the LC display (5).

3. The lighting device according to any one of claims 1 or 2, characterized in that: The at least one light emitting diode (2) is designed to emit light (3) having a blue or white color, and the converter is designed to change the color of the light (3) emitted by the at least one light emitting diode (2), for example, to convert the light (3) having a blue or white color into light (3) having a red color or to convert the light (3) having a blue color into light (3) having a white color.

4. The lighting device according to any one of claims 1 to 3, characterized in that: The optical component (9) provided with the converter is constructed as an optical sheet or an optical film.

5. The lighting device according to any one of claims 1 to 4, characterized in that: At least one surface of the optical component (9) provided with the converter is curved, through which the light (3) emitted from the light emitting diode (2) passes.

6. The lighting device according to any one of claims 1 to 5, characterized in that: At least one surface of the optical component (9) provided with a converter, through which the light (3) emitted by the light-emitting diode (2) passes, has a structured portion.

7. The lighting device according to any one of claims 1 to 6, characterized in that: The converter is configured as a coating having a converter material on at least one surface of the optical component (9), through which surface the light (3) emitted by the light-emitting diode (2) passes; and / or the converter is configured as a converter material integrated into the optical component (9), in particular, the optical component (9) is an injection-molded part, the raw material of which used for injection molding has the converter material.

8. The lighting device according to any one of claims 1 to 7, characterized in that: The optical component (9) provided with the converter is arranged at a distance from the at least one light emitting diode (2).

9. The lighting device according to any one of claims 1 to 8, characterized in that: The at least one light emitting diode (2) is arranged in the light module (1) such that the light (3) generated during operation of the lighting device is emitted from the at least one light emitting diode (2) substantially directly in the direction of the light emitting surface.

10. The lighting device according to claim 9, characterized in that: The light-emitting module (1) comprises at least one reflector (8), which is assigned to the at least one light-emitting diode (2), so that part of the light (3) emitted from the at least one light-emitting diode (2) is reflected in the direction toward the light-emitting surface during operation of the lighting device. Preferably, the light-emitting module (1) comprises a plurality of reflectors (8), each of which is assigned to one of the light-emitting diodes (2), so that part of the light (3) emitted from the corresponding light-emitting diode (2) is reflected in the direction toward the light-emitting surface during operation of the lighting device.

11. The lighting device according to any one of claims 1 to 8, characterized in that: The lighting module (1) comprises a planar light conductor (12), the light conductor having an end-side incident surface (13) and at least one exit surface (14), the lighting device being designed to allow light (3) generated by the at least one light-emitting diode (2) to at least partially enter the light conductor (12) through the incident surface (13) and to at least partially exit from the at least one exit surface (14) in a direction toward the light-emitting surface.

12. The lighting device according to claim 11, characterized in that: The optical waveguide (12) has a structured portion, and the lighting device is designed to deflect light (3) moving through the optical waveguide (12) at least partially by the structured portion so that the light emerges from the optical waveguide (12) through the exit surface (14).

13. The lighting device according to any one of claims 1 to 12, characterized in that: The light-emitting module (1) comprises an optical sheet (10) provided with a structured portion, the optical sheet being arranged between the optical component (9) provided with a converter and the light-emitting surface or constituting the light-emitting surface.

14. The lighting device according to any one of claims 1 to 13, characterized in that: The lighting device comprises a housing (11), on or in which a light emitting module (1) is arranged, and in particular, the LC display (5) is mounted on the light emitting module (1) or on the housing (11).

15. The lighting device according to any one of claims 1 to 14, characterized in that: The LC display (5) is a guest-host display or a smart glass display.

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