Lighting device for a vehicle

Abstract

The invention relates to a lighting device for a vehicle, having a housing (9, 9') which contains a number of light sources (3, 3') for emitting light (14), an optical system for deflecting the light (14) according to a predefined light distribution, a closure cap (10, 10') which closes an opening of the housing, wherein the optical system is configured as an optical film (4, 15, 16) which has optical structures arranged on at least one side of the optical film.

Description

Technical Field

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

[0002] A lighting device for a vehicle is known from DE102020102226A1. The lighting device includes a light source and multiple optical systems for pre-shaping light emitted from the light source and subsequently deflecting the pre-shaped light according to a predetermined light distribution. To pre-shape the light, a collimating optical system is provided, configured as a lens that parallelizes the light emitted from the light source. The collimating optical system has a light-shielding plate on the light-incident side, forming a light-transmitting window through which light from the light source can be transmitted. The edge of the light-shielding plate is then imaged as a light-dark boundary by a subsequent optical system. The subsequent optical system is configured as a lens array having multiple lens elements distributed on a surface. This lens array optical system has a first lens array on the light-incident side and a second lens array on the light-outcident side, wherein the lens array on the light-incident side produces multiple intermediate images of the light-shielding plate located in an intermediate space between the two lens arrays. These intermediate images are then imaged as light spots by means of the lens array on the light-outcident side, forming a light distribution. A known drawback of lighting devices is that the optical system comprises injection-molded plastic lenses or pressed glass lenses, which are manufactured through costly molding processes. Due to manufacturing constraints, not all desired shapes and structures are feasible. Further reduction in the weight of the optical system is desired.

[0003] A lighting device for a vehicle is known from DE102019124555A1. This device has a light source and optics, wherein a holographic element is particularly provided as the optics, storing diffraction information to generate a three-dimensional holographic image in the front area. Therefore, a three-dimensional light marker for generating a signal light function can be produced. Advantageously, the signal light function is generated using a film. However, a disadvantage of this is that the manufacturing cost for introducing the diffraction structure is relatively high, and the optical function is limited.

[0004] A lighting device for a vehicle is known from DE102017114476A1, the lighting device having multiple light sources and an optical system for deflecting light. The optical system includes a transparent body having a matte layer with a random surface structure. This achieves random scattering of light emitted from the transparent body. The transparent body is made of glass or plastic. The matte layer is applied to the surface of the transparent body by sandblasting or etching.

[0005] A lighting device for a vehicle is known from DE102022127235A1, the lighting device having multiple light sources and an optical system for deflecting light. The optical system includes a flat light conductor made of a flexible silicone material and an optical sheet placed on the front side of the flat light conductor, the optical sheet being configured as an optical film. The optical film locally has micro-optical elements arranged coaxially with the light sources disposed on the back side of the flat light conductor and scattering light, thereby preventing bright spots from appearing on the light-emitting surface of the lighting device. Summary of the Invention

[0006] Therefore, the object of the present invention is to improve lighting equipment for vehicles so as to provide a predetermined light distribution, especially headlight distribution, in a space-saving manner and with a small weight.

[0007] To solve the aforementioned task, the present invention has the features of claim 1.

[0008] A particular advantage of this invention is that, by providing an optical film (which has an optical structure on at least one side), light can be deflected, enabling the generation of a predetermined light distribution or partial light distribution. The optical structure contained within the film partially replaces the function of a conventional refractive solid (especially a lens). Unlike solids, the optical film according to the invention can be manufactured as a mass-produced product using simple methods, such as roll-to-roll. The optical structure comprises a plurality of optical elements distributed on a surface. These optical elements each have refractive properties. The optical elements, and therefore the optical structure, can be calculated such that the optical film is constructed, for example, in an arc shape and extends parallel to and offset from the enclosure of the lighting device. If the optical film is arranged with a relatively small distance from the enclosure and has an area size within the enclosure, the internal space of the lighting device can be covered by the optical film. Therefore, the lighting device has a regular and consistent appearance.

[0009] According to the invention, a first optical film having a plurality of optical elements and a second optical film having a plurality of optical elements are provided. The optical elements of the first optical film are configured or arranged such that light is scattered along a first direction. The optical elements of the second optical film are arranged or configured such that light is scattered in a direction perpendicular to the first direction. Advantageously, light can thus be deflected or scattered horizontally by means of the first optical film and can be deflected or scattered vertically by means of the second optical film. Advantageously, a predetermined light distribution for a headlight, such as a low beam distribution, can thus be produced. Preferably, the edge of the light source, configured as an LED light source, can be used here as the edge of a light shield, which is imaged as the light-dark boundary of the light distribution.

[0010] According to an improved embodiment of the invention, the optical film has a wall thickness ranging from 100 μm to 800 μm. Therefore, the optical film is relatively thin. Due to the flexibility of the optical film, it can be clamped while bent about one and / or two different bending axes, giving it a three-dimensional appearance. Even in the bent state, the optical film maintains a constant wall thickness across its entire surface. Preferably, the optical film is clamped without stretching, such that the optical structure or optical element has a predetermined relative position to the bottom surface of the substrate in the mounting position.

[0011] According to an improved embodiment of the invention, a collimator is disposed between a first optical film and a second optical film on one side and a light source on the other side, by means of said collimator to parallelize the light emitted by the light source. In this way, the light is incident parallel to the first optical film, and at the first optical film, the light is deflected along a first direction.

[0012] According to an improved embodiment of the invention, the first optical film has a cylindrical protrusion as an optical structure on only one side, such that light is deflected or scattered along a first direction. When the first direction corresponds to a horizontal direction, the light is scattered according to a predetermined illumination width of the light distribution.

[0013] According to an improved embodiment of the invention, the second optical film has freely shaped protrusions on both sides, through which incident light is deflected along a second direction at different angular ranges, such that the light is deflected into illumination strips of different lengths. The freely shaped protrusions are formed such that the boundary rays of the corresponding light beams emitted by the protrusions are emitted at an angle, thereby forming the light and dark boundaries of the light distribution. The superposition of the light beams deflected by the corresponding protrusions forms a predetermined light distribution. Therefore, the light distribution is formed by a plurality of illumination strips extending vertically at different angles, wherein the illumination strips are formed by light beams with different or the same angular range. Advantageously, this allows for the production of a headlight function in a space-saving and weight-saving manner.

[0014] According to an improvement of the invention, the optical protrusions of the optical film have a preferred direction. Therefore, these protrusions are configured to extend elongatedly along the preferred direction. These protrusions are arranged parallel to each other and staggered, wherein adjacent protrusions preferably have different shapes.

[0015] Other advantages of the invention are derived from the other dependent claims. Attached Figure Description

[0016] The embodiments of the present invention will now be described in more detail with the aid of the accompanying drawings.

[0017] In the attached diagram:

[0018] Figure 1A schematic side view of a lighting device according to a first embodiment is shown;

[0019] Figure 2 Showing according to Figure 1 Front view of the lighting equipment;

[0020] Figure 3 A side view of a lighting device according to a second embodiment is shown;

[0021] Figure 4 Show along Figure 3 The cross section of line IV-IV in the middle; and

[0022] Figure 5 Show Figure 3 An enlarged side view of a single unit X in the image. Detailed Implementation

[0023] according to Figure 1 and Figure 2 The lighting device 1 is used to generate signal light functions, such as brake light / taillight functions, turn signal functions, and daytime running light functions. The lighting device 1 can be arranged in the front or rear area of ​​the vehicle.

[0024] The lighting device 1 has a circuit board 2 on which multiple light sources 3 are arranged. The light sources 3 are configured as LED light sources or LED chips. The light sources 3 emit light L along the main emission direction H of the lighting device 1. An optical film 4 is arranged in front of the light sources 3 (preferably arranged in a matrix on the rectangular circuit board 2) along the main emission direction H as an optical system. The optical film is clamped in the support receiving portion 5 of the support device 6 at opposite sides. For this purpose, the opposite edges 7 of the optical film 4 are respectively engaged into the support receiving portion 5 and held by the support receiving portion in a force-locking and / or form-locking manner. For example, the opposite edges 7 can be connected to the support receiving portion 5 by clips.

[0025] In this embodiment, the optical film 4 does not extend flatly, but rather extends curvedly around a curved axis 8 extending between the edges 7. In this way, the optical film 4 is arranged in a slightly arched manner along the main emission direction H. The spacing a between the opposing carrier receiving portions 5 is... T The extension dimension I between the opposite fixed edges 7 of the optical film 4 is smaller than that of the optical film 4. F The rigidity of the optical film 4 contributes to its arched mounting position.

[0026] For example, the optical film 4 can be constructed to be arched in the same direction as the closure 10 that covers the opening of the housing 9 of the lighting device 1. Therefore, the optical film 4 can have the same curvature on its surface as the closure 10. The optical film 4 can, for example, extend at a constant parallel distance s from the closure 10. Therefore, it has a shape adapted to the closure 10. The optical film 4 can have an area equal to or smaller than the area of ​​the closure 10. The closure 10 preferably extends flush with the surface of the vehicle body K.

[0027] The optical film 4 has the following optical structure, which includes a plurality of protrusions 11. According to... Figure 1 and Figure 2 In some embodiments, the protrusions 11 are configured as prismatic protrusions that protrude from the plane of the substrate 12 of the optical film 4. The prismatic protrusions 11 extend, for example, continuously in strips from the first edge of the optical film 4 to the opposite edge of the optical film. In cross-section, they may be configured, for example, as triangular.

[0028] In this embodiment, on the light incident side, the prismatic protrusion 11' extends horizontally, while on the light emitting side, the prismatic protrusion 11" extends vertically, that is, it extends perpendicular to the protrusion 11' on the light incident side. In this way, scattering is generated in two directions arranged perpendicular to each other to produce a signal light function, such as a taillight function.

[0029] Multiple light sources 3 can be distributed, preferably evenly distributed, or regularly arranged on a rectangular circuit board 2.

[0030] In this embodiment, the optical film 4 has a wall thickness d in the range of 100 μm to 800 μm. The protrusions 11, 11', 11" can be configured as microlenses that protrude from the substrate 12 in the range of 10 μm to 50 μm.

[0031] In this embodiment, the optical film 4 has a bending radius r in the range of 10 mm. Preferably, the bending radius r is in the range of greater than 10 mm. Alternatively, the optical film 4 can also be clamped flat on the support device 6, thereby simplifying the calculation of the shape of the protrusions 11, 11', 11"

[0032] According to an alternative embodiment of the invention (not shown), the protrusion 11 may also be configured such that the optical film 4 has the shape and / or function of a Fresnel lens on one side.

[0033] Alternatively, the protrusions 11 of the optical film 4 may also be cylindrical, partially cylindrical, or other shapes.

[0034] The optical structure, i.e. the optical protrusion 11, is preferably manufactured by imprinting resin applied to the substrate 12 or by a combination of imprinting resin applied to the substrate and crosslinking it simultaneously.

[0035] The substrate can be made of, for example, polycarbonate (PC), polyethylene terephthalate (PET), or other polymers.

[0036] According to the present invention Figures 3 to 5 In another embodiment, a lighting device 1' is provided, which is used as a headlight.

[0037] The lighting device 1' has a circuit board 2' on which multiple light sources 3' are arranged. The light sources 3' are constructed as LED light sources or LED chips. They are evenly distributed on one side of the circuit board 2'.

[0038] A number of collimators 13 are arranged in front of the light source 3' along the main emission direction H. These collimators are respectively configured as lenses made of plastic and / or glass materials and are shaped in a lens shape, so that the light 14 emitted by the light source 3' is parallelized.

[0039] A first optical film 15 and a second optical film 16 are arranged in front of the collimators 13 arranged side by side along the main emission direction H.

[0040] The first optical film 15 has a plurality of optical elements 17 on the light incident side, which are configured such that the light 14 is deflected along a first direction (horizontally in the mounting position of the lighting device 1') within a predetermined angular range. The optical elements 17 may, for example, be configured as prismatic protrusions. On the light emitting side, the first optical film 15 has no optical elements.

[0041] Alternatively, the first optical film 15 may also have cylindrical protrusions as optical elements 17.

[0042] The second optical film 16 has free-form optical elements 18 and 19 on both sides. The optical element 18 on the light-incident side and the optical element 19 on the light-outceasing side can be configured to coordinate with each other in pairs. The optical element 18 on the light-incident side can be configured as a facet in the light-incident side facet array, and the optical element 19 on the light-outceasing side can be configured as a facet in the light-outceasing side facet array. The light-incident side facet 18 and the light-outceasing side facet 19 extend linearly in the horizontal direction in the mounting position of the lighting device 1', such that light diffuses or scatters in a direction perpendicular to the first direction, i.e., in the vertical direction.

[0043] In this embodiment, the light-incident side facet 18 and / or the light-exit side facet 19 are constructed in a triangular or wedge shape in cross-section and have a protrusion of 0.03 mm to 0.6 mm relative to the base surface of the substrate 12. The light-incident side facet 18 is formed such that incident light is focused in the region between the corresponding light-incident side facet 18 facing that facet and the light-exit side facet 19 arranged subsequently thereafter along the main emission direction H, preferably focused at the center between the first light-incident side facet 18 and the light-exit side facet 19 facing those facets. Therefore, the focal point of the light-incident side facet 18 is located in the region between the light-incident side facet 18 and the light-exit side facet 19 facing the same facet. The facets are arranged side by side and extend in different horizontal planes.

[0044] The light-emitting side facet 19 of the corresponding facet is configured such that an imaginary parallel beam of light incident on the light-emitting side facet 19 opposite to the main emission direction H is focused into a plane in which the light-incident side facet 18 of the same facet lies. Therefore, the focal point of the light-emitting side facet 19 lies in the vertical plane of the light-incident side facet 18 of the same facet.

[0045] The light incident side facets 18 are arranged in a regular pattern on the surface and / or plane. They preferably have the same shape and / or size.

[0046] The light-emitting side facets 19 are arranged in a regular pattern on the surface and / or plane, parallel to the surface and / or plane of the light-incident side facets 18. They are preferably not of the same size, but have a shape and / or size such that they deflect the light from the light-incident side facets 18 into light spots to form a symmetrical light distribution.

[0047] Each light-emitting side facet 19 preferably has the same length in its extending direction. They differ in cross-section. Different profiles in the cross-section cause different vertical light emission angles.

[0048] Each light-emitting side facet 19 deflects the light 14 into a beam within a pre-defined angular range. The angular ranges of the different light-emitting side facets 19 can be different or the same. What all the light emitted from each light-emitting side facet 19 has in common is that the upper boundary rays of the corresponding beams form a common light-dark boundary in the light distribution. A light distribution with increased illumination intensity in the central region and decreased illumination intensity in the edge regions is produced by overlapping light bands. In this way, for example, a symmetrical light distribution (low beam) can be produced.

[0049] The light-incident side facet 18 and the light-exit side facet 19 (optical elements) extend along a preferred direction, which in this embodiment extends horizontally. They are constructed to be elongated.

[0050] Preferably, the optical elements 17, 18, and 19 extend in width and / or height within the range of mm or μm.

[0051] The components of the lighting device 1', namely the light source 3', collimator 13, first optical film 15 and second optical film 16, are arranged in the housing 9' of the lighting device 1', the opening of which is closed by a cover 10'. The cover 10' is constructed to be transparent and / or glass-like transparent.

[0052] The first optical film 15 and the second optical film 16 are clamped and / or fixed in a support device 6 (not shown), as in the optical film 4 according to the first embodiment. In this embodiment, the first optical film 15 and the second optical film 16 are spaced apart from each other and extend flatly or perpendicularly to the main emission direction H of the lighting device 1', respectively. The first optical film 15 and the second optical film 16 extend parallel to each other.

[0053] The first optical film 15 can be arranged before or after the second optical film 16 along the main emission direction H.

[0054] List of reference numerals

[0055] 1.1' Lighting equipment

[0056] 2.2' circuit board

[0057] 3. 3' light source

[0058] 4 Optical films

[0059] 5. Bearing and receiving section

[0060] 6 bearing devices

[0061] 7 edges

[0062] 8. Bending axis

[0063] 9, 9' shell

[0064] 10, 10' Enclosed Cover

[0065] 11, 11', 11” protrusions

[0066] 12 base

[0067] 13 Collimators

[0068] 14 light

[0069] 15 First Optical Film

[0070] 16 Second optical film

[0071] 17 optical elements

[0072] 18 optical elements / prisms

[0073] 19 Optical Elements / Prisms

[0074] L-light

[0075] H Main Launch Direction

[0076] a T spacing

[0077] I F Extended dimensions

[0078] s spacing

[0079] d wall thickness

[0080] bending radius

Claims

1. A lighting device for a vehicle, the lighting device having a housing (9') comprising: —A certain number of light sources (3') used to emit light (14). —An optical system for deflecting the light (14) according to a pre-given light distribution. —A cover (10) that closes the opening of the housing. The optical system has an optical film (15, 16), the optical film having an optical structure disposed on at least one side of the optical film, characterized in that, A first optical film (15) having multiple optical elements is provided, and light is scattered along a first direction by means of the optical elements of the first optical film. A second optical film (16) having multiple optical elements (18, 19) positioned in front along the main emission direction (H) is provided, and light is scattered along a second direction perpendicular to the first direction by means of the optical elements of the second optical film.

2. The lighting device according to claim 1, characterized in that, The optical films (15, 16) have a wall thickness (d) in the range of 100 μm to 800 μm.

3. The lighting device according to claim 1 or 2, characterized in that, A collimator (13) is provided between the first optical film (15) and the light source (3'), and the light (14) of the light source (3') is parallelized by means of the collimator.

4. The lighting device according to any one of claims 1 to 3, characterized in that, The first optical film (15) has an optical element (17) on only one side. The first optical film includes a cylindrical protrusion as the optical element (17) so that the incident light is scattered along a first direction.

5. The lighting device according to any one of claims 1 to 4, characterized in that, The second optical film (16) has free-form optical elements (18, 19) on both sides. Incident light is deflected along the second direction at different angle ranges by means of the optical elements, so that beams with different emission angles are formed into illumination strips of different lengths. The illumination strips form the light distribution, and the upper boundary ray of the beam extends so that the upper boundary ray of the beam is emitted at an angle, thus forming the light and dark boundary of the light distribution.

6. The lighting device according to any one of claims 1 to 5, characterized in that, The optical films (15, 16) and the circuit board (2) carrying the light source (3') are constructed in an elongated shape.

7. The lighting device according to any one of claims 1 to 6, characterized in that, The optical elements of the optical films (15, 16) have a preferred orientation, and the optical elements extend along the preferred orientation from one edge of the optical films (15, 16) to the opposite edge of the optical films.

8. The lighting device according to any one of claims 1 to 7, characterized in that, The optical element has a width and / or height in the range of mm or μm.

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