Lighting device for the exterior of a motor vehicle

Abstract

The invention relates to a lighting device for the exterior of a motor vehicle, comprising a microlens array (4) with a plurality of microlenses in the form of projection lenses (401) and a first light source (1), wherein the first light source (1) is provided for illuminating an imaging structure (5) comprising a translucent substructure and an opaque substructure, and the microlens array (4) is configured such that it generates a first light distribution in the exterior by projection of the illuminated imaging structure (3).The lighting device includes a second light source (6) which directs light onto a reflective structure (5, 5') which overlaps the microlens array (4) when viewed from above, wherein the reflective structure (5, 5') is designed such that it reflects at least part of the light from the second light source (6) and thereby produces a second light distribution in the form of a signal light with a luminous surface which covers at least part of the microlens array (4) when viewed from above.

Description

[0001] The invention relates to a lighting device for the exterior of a motor vehicle and to a corresponding motor vehicle.

[0002] It is known from the prior art to use microlens arrays in automotive lighting devices. For example, publication WO 2017 / 15764 A1 discloses a headlight for a motor vehicle which includes a multi-aperture display with an array of projection lenses to project segments of a planar image source, illuminated by a light source, in front of the headlight. This multi-aperture projection display can generate a low beam distribution and / or a high beam distribution and / or a glare-free high beam.

[0003] German patent application DE 10 2009 041 189 A1 discloses a vehicle headlight with a plurality of semiconductor emitters that uses the same illuminating surface to generate both daytime running light and low beam distributions. The vehicle headlight does not use a microlens array for light generation.

[0004] The object of the invention is to integrate a further lighting function in a lighting device for the exterior of a motor vehicle, in addition to a lighting function based on a microlens array.

[0005] This problem is solved by the lighting device according to claim 1. Further developments of the invention are defined in the dependent claims.

[0006] The lighting device according to the invention is intended for the exterior of a motor vehicle; that is, it is an exterior light of the motor vehicle. The motor vehicle is preferably a passenger car, but can optionally also be a truck or a motorcycle. Where interactions between the lighting device and the motor vehicle are described below, and in particular in the claims, this is always to be understood as meaning that the interaction occurs when the lighting device is arranged or installed in the motor vehicle. The components of the lighting device that have a corresponding interaction with the motor vehicle or components of the motor vehicle are therefore designed such that the interaction is caused when the lighting device is arranged or installed in the motor vehicle.

[0007] The illumination device according to the invention comprises a microlens array with a plurality of microlenses in the form of projection lenses. Preferably, the microlens array contains between 50 and 2000 microlenses. Here and in the following, a microlens is understood to be, in particular, an optical lens which, in top view, has an extent of at most 5000 µm, preferably at most 2000 µm, and most preferably at most 1000 µm, along the directions in which the lens is curved. If the microlens is dome-shaped with a circular outline in top view, the radius of the lens is preferably at the maximum extents mentioned above. If the lens is designed as a cylindrical lens (i.e., as a lens in the form of a cylinder or a segment of a cylinder), the radius of the cylinder preferably has a maximum extent according to the values ​​mentioned above.

[0008] The lighting device according to the invention comprises a first light source for illuminating an imaging structure comprising a translucent substructure and an opaque substructure. The microlens array is configured to generate a first light distribution in the exterior of the motor vehicle by projecting the imaging structure illuminated by the first light source.

[0009] In addition to the first light source, the lighting device according to the invention provides a second light source which directs light onto a reflective structure that overlaps the microlens array when viewed from above. Preferably, the reflective structure lies completely within the outline of the microlens array when viewed from above. The reflective structure is designed such that it reflects at least a portion of the light from the second light source, thereby generating a second light distribution in the form of a signal light with a luminous area that covers at least a portion of the microlens array when viewed from above. For example, the luminous area can coincide with the microlens array when viewed from above. Likewise, the luminous area can be smaller than the microlens array and lie completely within its outline. Other overlapping configurations are also conceivable.

[0010] The lighting device according to the invention has the advantage that, by means of a reflective structure, the surface of a microlens array is used not only for projecting a light distribution but also for a signal light function. This allows several lighting functions to be compactly integrated into a motor vehicle exterior light that uses a microlens array for light generation.

[0011] In the lighting device according to the invention, depending on the design, the first light distribution and the second light distribution can be generated simultaneously or, if necessary, separately at different times or in different time periods by activating the first or second light source.

[0012] The first and / or second light source can have different designs. Preferably, these light sources each contain one or more light sources, which are, for example, LEDs and / or laser diodes. Furthermore, these light sources may optionally include additional optical elements for light generation, with the light from the respective light sources of the light sources falling onto these additional optical elements. For example, the optical elements may comprise one or more lenses and / or one or more reflectors.

[0013] In a preferred embodiment, the imaging structure is a component or layer with a metallic, opaque substructure. For example, it can be a metallic layer applied to a transparent substrate, wherein the metallic layer is removed, and in particular etched away, in areas where the translucent structure is provided.

[0014] In a particularly preferred embodiment, the lighting device according to the invention is a front headlight, wherein the first light distribution comprises a low beam distribution and / or a high beam distribution.

[0015] In another preferred embodiment, the first light distribution comprises a projection of symbols in the outdoor space, preferably onto a ground area outdoors. Symbols are understood to be one or more signs and / or graphics that have semantic meaning for the human observer. For example, the symbols can include warning messages for other road users, such as the insufficient following distance between two vehicles.

[0016] In a further preferred embodiment, the second light distribution generated by means of the reflective structure is a daytime running light and / or a position light and / or a direction indicator light (i.e. a flashing light).

[0017] The lighting device according to the invention can also be designed as a rear light, in which case the second light distribution includes a tail light and / or a reversing light.

[0018] In a particularly preferred embodiment of the lighting device according to the invention, the opaque substructure of the imaging structure is reflective on its surface facing the outside and thereby forms at least part of the reflective structure provided for generating the second light distribution. Preferably, the reflective structure can also be formed exclusively by this opaque substructure. This variant of the invention achieves a particularly compact design of the lighting device, since a component used to generate the first light distribution is also used to generate the second light distribution.

[0019] In a further embodiment, the lighting device according to the invention comprises, in addition to the imaging structure, one or more reflective elements, which form at least a part of the reflective structure provided for generating the second light distribution. Optionally, the reflective structure can also be formed exclusively by the reflective element(s).

[0020] In a preferred embodiment of the above-described design, the reflecting element(s) comprise one or more prisms. The prism(s) can be made of a transparent material, in which case light reflection is effected by total internal reflection at the boundary surfaces of the respective prism. The prism(s) are preferably formed on an externally facing front face of the microlens array.

[0021] In a further embodiment of the lighting device according to the invention, the second light source directs the light at least partially and optionally completely towards the reflective structure via a front face of the microlens array facing the outside. This allows the space in front of the microlens array to be used efficiently for installing the second light source. Alternatively or additionally, it is also possible for the second light source to direct the light at least partially and optionally completely towards the reflective structure without passing through the microlens array.

[0022] In a further embodiment of the invention, the imaging structure is arranged on the rear side of a translucent substrate facing away from the outside, while the plurality of projection lenses is provided on the front side of the translucent substrate facing the outside. This results in a compact design of the microlens array in combination with the imaging structure.

[0023] In a further preferred embodiment, the illumination device comprises, in addition to the microlens array of projection lenses, a further microlens array with a plurality of microlenses in the form of condenser lenses, wherein each projection lens of the plurality of projection lenses is assigned to a different condenser lens through which light from the first illuminant passes before entering the assigned projection lens. This embodiment is preferably combined with the previously described embodiment of the invention such that a further substrate is provided on the back side of the translucent substrate with the imaging structure arranged thereon, the further microlens array of condenser lenses being provided on the back side of this substrate facing away from the outside space.

[0024] In a further preferred embodiment of the invention, the imaging structure comprises a plurality of segments, each segment being separately assigned to a single projection lens, i.e., each projection lens corresponds to a different segment. Each projection lens projects its assigned segment as an individual image onto the exterior of the motor vehicle, the first light distribution being a superposition of the individual images. Preferably, each individual image covers substantially the entire first light distribution. Such a setup is known from the prior art and is described, for example, in EP 3 013 642 B1.

[0025] The illumination device according to the invention can optionally also be configured such that the areas of the imaging structure which are projected into the outside space by the respective projection lenses of the microlens array have overlaps. In other words, each area of ​​the imaging structure that is projected by a respective projection lens has an overlap with at least one area of ​​the imaging structure that is projected by another projection lens.

[0026] In addition to the lighting device described above, the invention relates to a motor vehicle comprising one or more lighting devices according to the invention or one or more preferred variants of the lighting device according to the invention.

[0027] Exemplary embodiments of the invention are described in detail below with reference to the accompanying figures.

[0028] They show: Fig. 1 a schematic sectional view of a first embodiment of a lighting device according to the invention; Fig. 2 a schematic sectional view of a second embodiment of a lighting device according to the invention; Fig. 3 a schematic sectional view of a third embodiment of a lighting device according to the invention; and Fig. 4 a schematic sectional view of a fourth embodiment of a lighting device according to the invention.

[0029] The embodiments of the invention described below are based on a lighting device in the form of a headlight, which projects a low-beam light distribution onto the road in front of the corresponding motor vehicle. In all figures, the light exits the lighting device towards the outside on the right-hand side.

[0030] The lighting device according to Fig. The first light source 1 comprises a light source 101 and a collimator lens 102. The light from the light source 101 falls onto the collimator lens 102, which generates a parallel beam of light. The light source 101 is preferably an LED or laser diode. In the embodiment described here, the light source 101 generates white light. Optionally, the light source 1 can also comprise several light sources and several collimator lenses for generating the parallel beam of light.

[0031] The light beam exiting the collimator lens 102 first falls onto a microlens array 2 consisting of a plurality of condenser lenses 201. Adjacent to this microlens array 2 is a microlens array 4 consisting of a plurality of projection lenses 401. Each condenser lens 201 of the microlens array 2 is separately assigned a single projection lens 401 of the microlens array 4. The light exiting each condenser lens 201 is directed via an imaging structure 5 towards the assigned projection lens 401. In the embodiment of the Fig. 1 as well as in the embodiments of the Fig. 2 and Fig. 3. The condenser lenses 201 and the projection lenses 401 are designed as round lenses with a dome-shaped surface on one side.

[0032] Between microlens array 2 and microlens array 4 are the transparent substrates 301 and 302, with substrate 301 being adjacent to microlens array 4 and substrate 302 adjacent to microlens array 2. Optionally, microlens array 4 can be integrally formed within substrate 301 and microlens array 2 integrally formed within substrate 302. At the interfaces between the two substrates 301 and 302, the imaging structure 5 is formed as a metallic layer with etched areas. The etched areas form a translucent substructure, and the non-etched areas form an opaque substructure. The opaque substructure is preferably a layer of chromium, but this layer can also consist of aluminum or another material. Crucially, the layer is reflective on the side facing the outside.

[0033] In the embodiment of the Fig. Each projection lens 401 is separately assigned a segment of the imaging structure 5. The segment is projected as a single image onto the road in front of the vehicle by the associated projection lens. The individual segments are identical in structure and represent a diaphragm with a light-dark boundary corresponding to the low-beam distribution. The individual images projected by the respective projection lenses 401 superimpose to form the low-beam distribution, with each individual image covering the entire area of ​​the low-beam distribution. This projection principle is known, for example, from the aforementioned publication EP 3 013 642 B1.

[0034] A key aspect of the embodiment of the invention described here is that the light-emitting surface or front face of the microlens array 4 is used not only to generate a low-beam light distribution but also to generate a second light distribution in the form of a signal light, such as a daytime running light or a position light. To achieve this, a second light source 6 is used in addition to the first light source 1, which in the embodiment of Fig. 1. A light source 601 and a reflector 602 are included. This configuration is merely exemplary, and the light source 6 can, for example, also contain several light sources and, instead of or in addition to a reflector 602, also use a lens, as in the embodiments of the Fig. 2 and Fig. 4 is shown.

[0035] The light from light source 601 falls via reflector 602 onto the front face of microlens array 4. The light paths of light from light source 601 are indicated by dotted lines, some of which are labeled with the reference symbol L for clarity. Corresponding light paths based on dotted lines are also described below. Fig. Figures 2 to 4 show the following. The light from the light source 601 enters the substrate 301 via the microlens array 4. The light is reflected towards the exterior of the vehicle via the opaque substructure of the imaging structure 5. The reflected light exits the lighting device via the microlens array 4 and generates a further light distribution in the form of a signal light. Thus, the area of ​​the lighting device used to generate the low beam distribution can also be used for a signal light function.

[0036] Fig. Figure 2 shows a second embodiment of a lighting device according to the invention, which is a modification of the embodiment of the Fig. 1 represents. In Fig. 2 and also in the further Fig. 3 and Fig. 4 are components that correspond to the components of the Fig. 1 corresponds to the components designated with the same reference symbols. These components will not be explained in detail again.

[0037] The construction of the lighting device of the Fig. 2 largely corresponds to the structure of Fig. 1. In other words, the embodiment of the Fig. 2 in turn generates a low beam distribution using the first light source 1, the microlens arrays 2, 4 and the imaging structure 5. Furthermore, a second light source 6 is also present, which serves to generate a signal light. In contrast to the embodiment of Fig. 1. The light from the second light source 6 no longer shines onto the imaging structure 5 via the front of the microlens array 4, but is directed laterally across the substrate 301 towards the imaging structure 5. Furthermore, the second light source 6 contains a collimator lens 603 instead of a reflector 602, which directs the light towards the imaging structure 5.

[0038] Fig. Figure 3 shows a third embodiment of a lighting device according to the invention, which is a further modification of the embodiment of Fig. 1 is. The structure of the embodiment of the Fig. 3 differs from Fig. 1 The only difference is that, for the reflection of the light from the second light source 6, not only the imaging structure 5 but also reflective elements 5' are used. These reflective elements 5' are designed as individual prisms arranged between the projection lenses 401 of the microlens array 4. The additional reflective elements 5' enable higher brightness for the signal light function in the headlight.

[0039] Fig. Figure 4 shows a schematic sectional view of a fourth embodiment of the lighting device according to the invention. In contrast to the preceding embodiments, the projection lenses 401 of the microlens array 4 are no longer separately assigned to segments of an imaging structure. Rather, the imaging structure 5 is projected onto the road as a whole by the projection lenses 401. The imaging structure is designed as an aperture with a light-dark boundary to generate the corresponding low-beam distribution. Furthermore, the imaging structure is no longer arranged on the substrate 301, but is located as a separate element between the light source 101 and the collimator lens 102. In addition, in this embodiment, Fig. 4 no second substrate 302 nor a microlens array 2 made of condenser lenses 201 is required.

[0040] The embodiment of the Fig. 4 further differs from the other embodiments in that the projection lenses 401 of the microlens array 4 are no longer designed as dome-shaped lenses, but as cylindrical lenses in the form of cylindrical segments. The longitudinal direction of the respective cylindrical segments of the lenses extends perpendicular to the plane of the sheet. Fig. 4.

[0041] In analogy to the preceding embodiments, the embodiment of Fig.4 A second light source 6 is used, the light of which is directed towards the imaging structure 5. This second light source comprises the light source 601 and the collimator lens 603. As in the preceding embodiments, the imaging structure 5 is reflective, and the reflected light passes through the microlens array 4 into the exterior of the vehicle. The reflected light is then used to create a signal function in the form of daytime running lights or position lights.

[0042] The embodiments of the invention described above offer a number of advantages. In particular, a microlens array of projection lenses, through which a first light distribution is generated, also serves as a luminous surface for a second light distribution in the form of a signal light. For this purpose, a reflective structure is used, which is preferably the imaging structure projected by the microlens array. In this way, several lighting functions can be realized via the same luminous surface, while simultaneously ensuring a compact design of the lighting device. Reference sign 1 first light source 101 Light source 102 Collimator lens 2 microlens arrays made of condenser lenses 201 condenser lenses 301, 302 Substrates 4 microlens array made of projection lenses 401 projection lenses 5 imaging structure 5' reflective elements 6 second light source 601 Light source 602 Reflector 603 Collimator lens L lines QUOTES INCLUDED IN THE DESCRIPTION

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

[0000] WO 2017 / 15764 A1

[0002] DE 10 2009 041 189 A1

[0003] EP 3 013 642 B1 [0024, 0033]

Claims

[1] Lighting device for the exterior of a motor vehicle, comprising a microlens array (4) with a plurality of microlenses in the form of projection lenses (401) and a first illuminating means (1), wherein the first illuminating means (1) is provided for illuminating an imaging structure (5) which comprises a translucent partial structure and an opaque partial structure, and the microlens array (4) is designed such that it generates a first light distribution in the exterior by projecting the illuminated imaging structure (3), characterized byin that the lighting device contains a second illuminant (6) which directs light onto a reflective structure (5, 5') which, in a plan view of the microlens array (4), overlaps therewith, wherein the reflective structure (5, 5') is designed such that it reflects at least part of the light of the second illuminant (6) and thereby generates a second light distribution in the form of a signal light with a luminous surface which covers at least part of the microlens array (4) in a plan view. [2] Lighting device according to claim 1, characterized by that the lighting device is a headlight and the first light distribution comprises a low beam distribution and / or a high beam distribution. [3] Lighting device according to claim 1 or 2, characterized by that the first light distribution comprises a projection of a symbol in the outdoor space, preferably onto a floor area in the outdoor space. [4] Lighting device according to claim 2 or 3, characterized by that the second light distribution comprises a daytime running light and / or a position light and / or a direction indicator light. [5] Lighting device according to claim 3 or 4, characterized by that the lighting device is a rear light and the second light distribution comprises a tail light and / or a reversing light. [6] Lighting device according to one of the preceding claims, characterized by that the opaque partial structure of the imaging structure (5) is reflective on its surface directed towards the outside and thereby forms at least part of the reflective structure (5, 5') which is provided for generating the second light distribution. [7] Lighting device according to one of the preceding claims, characterized byin that the illumination device comprises, in addition to the imaging structure (5), one or more reflective elements (5') which form at least part of the reflective structure (5, 5') provided for generating the second light distribution. [8] Lighting device according to claim 7, characterized by that the reflecting element(s) (5') comprise one or more prisms. [9] Lighting device according to one of the preceding claims, characterized by that the second illuminant (6) directs light at least partially via a front side of the microlens array (4) directed towards the outside towards the reflective structure (5, 5'). [10] Lighting device according to one of the preceding claims, characterized by that the second illuminant (6) directs light at least partially towards the reflective structure (5, 5') without passing through the microlens array (4). [11] Lighting device according to one of the preceding claims, characterized by in that the imaging structure (5) is arranged on a rear side of a light-transmissive substrate (301) directed away from the outside, wherein the plurality of projection lenses (401) is provided on a front side of the light-transmissive substrate (301) directed towards the outside. [12] Lighting device according to one of the preceding claims, characterized by that the illumination device comprises a further microlens array (2) with a plurality of microlenses in the form of condenser lenses (201), wherein each projection lens (401) of the plurality of projection lenses (401) is associated with a different condenser lens (201) through which light from the first illuminant (1) passes before entering the associated projection lens (401). [13] Lighting device according to one of the preceding claims, characterized byin that the imaging structure (5) comprises a plurality of segments, each segment being separately assigned to an individual projection lens (401) which projects the assigned segment as an individual image into the external space, the first light distribution being a superposition of the individual images. [14] Lighting device according to one of claims 1 to 12, characterized by that the illumination device is designed such that the regions of the imaging structure (5) which the respective projection lenses (401) of the microlens array (4) project into the external space have overlaps. [15] Motor vehicle, characterized by that the motor vehicle comprises one or more lighting devices according to one of the preceding claims.

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