Motor vehicle lighting device with at least one micro-projector light module and method for manufacturing same

Abstract

The invention proposes a motor vehicle lighting device having at least one micro-projector light module with a light source, auxiliary optics and a micro-projector optical element having a plurality of micro-projectors arranged in rows and columns, each of the plurality of micro-projectors having a light entry face, an aperture layer and an exit lens face. The motor vehicle lighting device is characterized in that the aperture layer is arranged directly on the light entry face and attached to the exit lens face. One independent claim relates to a method for manufacturing such a motor vehicle lighting device.

Description

Technical Field

[0001] This invention relates to a vehicle lighting device having at least one micro-projection light module, the micro-projection light module having a light source, auxiliary optics, and a micro-projection optical element, the micro-projection optical element having a plurality of micro-projectors arranged in rows and columns, each of the plurality of micro-projectors having a light incident surface, an aperture layer, and an exit lens surface. The invention also relates to a method for manufacturing such a vehicle lighting device. Background Technology

[0002] To project an image of the light distribution inside a projector as an external light distribution onto, for example, a road surface, within limited structural space, a structure consisting of multiple microprojectors has proven suitable. Such projectors, as components of motor vehicle headlights, are known from DE102017112971A1 and WO2019 / 120900A1. These projectors operate with a very short focal length, thus requiring minimal structural space.

[0003] In conjunction with this invention, miniature projection light modules that operate based on the so-called fly-eye principle are of particular interest. These projectors can homogenize non-uniform light distributions, which is desirable for many image projections (see DE102017217345B4, DE102006047941A1).

[0004] In conventional methods for manufacturing micro-projection optical modules, an aperture structure, along with incident and exit lenses, are sequentially applied to a glass wafer. This necessitates a process requiring extremely high precision to position the lenses relative to each other, resulting in high costs (e.g., processes from the semiconductor industry) (see EP3282181A1).

[0005] The goal is to reduce these costs without having to endure undesirable changes to the projector's functionality. Summary of the Invention

[0006] Against this backdrop, an object of the present invention is to provide a motor vehicle lighting device of the type described at the beginning, which can achieve tolerance-insensitive image projection using a miniature projection light module with a small structural depth, without expensive processes or complex lens readjustment. Another object is to provide a method for manufacturing such a motor vehicle lighting device.

[0007] This objective is achieved, in terms of the apparatus, by the sum of the features of claim 1, and in terms of the method, by the sum of the features of the independent method claims.

[0008] Here, the motor vehicle lighting device according to the present invention is characterized in that the aperture layer is directly arranged on the light incident surface and attached to the incident lens surface.

[0009] These features allow for the separate design of the aperture layer after the fabrication of the micro-projection optics. Applying the aperture layer only after the fabrication of the micro-projection optics eliminates the need for the high-precision and therefore expensive process required in existing technologies to position the aperture between the light incident surface and the lens exit surface. For example, during the injection molding of the micro-projection optics, positioning can be performed directly after the injection molding step. Furthermore, the same micro-projection optics can be configured with different apertures, making them particularly suitable for use in various motor vehicle lighting systems, whether headlights or signal lights, and especially suitable for a wide range of applications. This increases the number of identical components that can be used in various motor vehicle lighting systems, which advantageously reduces costs.

[0010] The aperture can be applied, for example, by metallization or painting. This has the advantage that, due to the thinness of the layer, the entire aperture can be clearly imaged, and the light component is not blocked by the expanded metal aperture implemented as an insert (see DE102016112617B3 or WO2015 / 058227A1).

[0011] Another advantage is that, after the manufacturing process of the micro-projection optics, it is possible to make simpler changes to the outline and position of the light-transmitting area of ​​the aperture layer, since the aperture is not fixedly built into the micro-projection optics.

[0012] A preferred design is characterized by an aperture layer having translucent sub-regions and almost opaque sub-regions. Here, the opaque sub-regions are understood to be sub-regions with a transmittance of less than 1%.

[0013] Preferably, the light incident surface is the incident lens surface, and the focal lengths of the incident lens surface and the exit lens surface are almost the same.

[0014] Preferably, the distance between the exit lens surface and the light incident surface of the microprojector almost corresponds to the focal length of either the incident or exit lens surface. Due to these characteristics, thin aperture layers produce clear images, which is particularly beneficial for generating sharp light and dark boundaries.

[0015] Another preferred design feature is that the micro-projection optical element is a component connected in a one-piece, material-fitted manner. This, in particular, allows the light incident surface with the aperture layer to be automatically and precisely positioned relative to the lens exit surface to a certain extent without the need for further positioning measures.

[0016] Preferably, the total light incident surface of the micro-projection optical element, formed by the sum of the light incident surfaces of the micro-projector, forms the central internal region of the micro-projection optical element, which is surrounded by an outer edge region that is transparent. Due to the opacity of the outer edge region, light from the light source emitted from the auxiliary optics is blocked from passing through the side edges of the micro-projection optical element and impairs the desired light distribution as undesirable scattered light.

[0017] Preferably, multiple micro-projection light modules (micro-projection optics plus associated auxiliary optics and light sources) are arranged side-by-side transversely to their optical axis. The micro-projection light modules can be arranged in a manner that closely follows the shaping of lighting devices inserted into the vehicle body. Another advantage of this arrangement is that animation effects (e.g., running light effects) can be generated by controlling the light sources in a time-staggered manner.

[0018] Another preferred design is characterized by the side-by-side arrangement of micro-projection light modules differing in their focal length, the number of their micro-projectors, and the aperture shape and / or aperture size of their micro-projection optics. This allows the light distribution to be generated by the vehicle lighting device to be determined during the design phase by appropriately selecting the aforementioned parameters.

[0019] Preferably, the side-by-side micro-projection optical elements are part of an arrangement where the micro-projection optical elements are connected in a single, integrated material configuration. Also preferably, the side-by-side auxiliary optical devices are part of an arrangement where the auxiliary optical devices are connected in a single, integrated material configuration. Both of these design schemes also offer the advantage of eliminating the need for positioning measures.

[0020] Another preferred design is characterized in that each of the microprojectors has an optical axis, wherein at least most of the microprojectors are arranged such that their optical axes extend parallel to each other, and at least two of the microprojectors have incident lens surfaces and / or exit lens surfaces arranged staggered from each other along their optical axes. Through these features, the shape of the light exit surface generated by the collective of the multiple microprojectors, determined by the sum of the lens exit surfaces, can be variably determined within a wide range.

[0021] Preferably, the height and width of the light incident surface and the exit lens surface of the microprojector are not the same. Therefore, even if the shape and size of the light-transmitting area of ​​the aperture layer are the same, the light intensity in the projected image can be changed.

[0022] Preferably, the light incident surface is a plane and therefore not used as the beam incident lens surface. This reduces the tolerance between the light incident surface and the exit lens surface.

[0023] A preferred design of the method is characterized in that, firstly, in a first step, a miniature projection optical element having a light incident surface and an exit lens surface is manufactured; secondly, in a second step, a metal layer or a paint layer is coated on the light incident surface of the miniature projector; and thirdly, the light-transmitting area is exposed by ablation using a laser.

[0024] By using lasers to expose the light-transmitting area, and then, for example, by injection molding to generate micro-projection optical elements, high precision in aperture contours and aperture positions, as well as the customizable design of aperture layers, can be achieved.

[0025] Since the aperture layer is applied only after injection molding, the high-precision and therefore expensive process required for positioning the aperture component between the light incident surface and the lens exit surface is unnecessary.

[0026] Furthermore, advantages corresponding to the advantages of the apparatus of the present invention also arise in its method.

[0027] A particular advantage is that the aperture layer can be applied and the light-transmitting area positioned directly after the injection molding step. Another advantage is that the same micro-projection optics can be configured with different apertures, making it particularly suitable for use in various headlights and for a wide range of applications. This increases the number of identical components that can be used in various headlights, which advantageously reduces costs. Furthermore, it is possible to more easily modify the contour and position of the light-transmitting area of ​​the aperture layer after the micro-projection optics are manufactured, because the aperture is not fixedly built into the micro-projection optics.

[0028] It goes without saying that, without departing from the scope of the invention, the features mentioned above and described below can be used not only in their respective specified combinations, but also in other combinations or individually. Attached Figure Description

[0029] Embodiments of the present invention are shown in the accompanying drawings and described in more detail in the following description. Here, the same reference numerals in the different figures denote the same or at least functionally comparable elements. The drawings are shown in schematic form:

[0030] Figure 1 A cross-sectional view of a motor vehicle lighting device with a housing and a miniature projection light module is shown;

[0031] Figure 2 It shows Figure 1 A 3D view of the miniature projection optical module;

[0032] Figure 3 A longitudinal section of a single micro-projector of a micro-projection optical module is shown;

[0033] Figure 4 A top view of the entire light incident surface of the micro-projection optics element is shown;

[0034] Figure 5 A top view of a miniature projection optics element with an edge region is shown;

[0035] Figure 6 The arrangement of multiple micro-projection light modules arranged side by side without spacing is shown;

[0036] Figure 7 Shown from the front Figure 6 The arrangement;

[0037] Figure 8 It shows the relationship with Figure 6 and Figure 7 A side view of an arrangement comparable to the previous one;

[0038] Figure 9 A flowchart illustrating an embodiment of the manufacturing method according to the present invention is shown;

[0039] Figure 10 A miniature projection optics element with an uncoated light incident surface is shown after the injection molding step; and

[0040] Figure 11 The image shows a miniature projection optics after the desired light-transmitting area is coated in a second step and exposed in a third step. Detailed Implementation

[0041] In detail, Figure 1 A cross-sectional view of a motor vehicle lighting device 10 with a housing is shown, the light emission opening of which is covered by a transparent cover plate 14. A miniature projection light module 16 is arranged within the interior space of the housing 12. This miniature projection light module 16 has a light source 18, auxiliary optics 20, and miniature projection optical elements 22. The light source 18 is preferably a semiconductor light source, which can emit light 19 towards the auxiliary optics 10.

[0042] Figure 2 It shows Figure 1 A perspective view of the micro-projection light module 16. The micro-projection light module 16 has multiple micro-projectors 28 arranged in rows 24 and columns 26.

[0043] Figure 3 A longitudinal section of a single microprojector 28 of a microprojection light module is shown. Each individual microprojector 28 has a light incident surface 30, an aperture layer 32, and an exit lens surface 34.

[0044] According to the present invention, the aperture layer 32 is directly disposed on and attached to the light incident surface 30.

[0045] The aperture layer 32 has a light-transmitting sub-region 36 and a nearly opaque sub-region 38.

[0046] exist Figure 3 In the case of the microprojector 28 shown, the light incident surface 30 is an incident lens surface, which is convex. Similarly, the exit lens surface 34 is also a convex lens surface. The focal lengths of the incident lens surface and the exit lens surface 34 on the microprojector side are almost the same, which here should mean that the smaller of the two focal lengths is greater than 90% of the larger of the two focal lengths, and in particular greater than 95% of the larger of the two focal lengths.

[0047] As Figure 3 As an alternative to the illustration, the light incident surface 30 of the microprojector 28 can also be implemented as a plane in a simplified design.

[0048] The distance between the exit lens surface 34 and the light incident surface 30 of the micro-projector 28 almost corresponds to the focal length of the exit lens surface 34. This also means that the smaller of the two lengths (distance and focal length) is greater than 90% of the larger of the two lengths, and especially greater than 95% of the larger of the two lengths. Due to this constellation, the exit lens surface enables clear imaging of the patterns in the opaque sub-region 38 and the translucent sub-region 36.

[0049] Light from the light source is almost collimated by auxiliary optics (such as TIR optics or converging lenses) and illuminates a miniature projection optics that projects light onto the road.

[0050] The nearly collimated light illuminating the micro-projection optics is reflected, scattered, and / or completely or partially absorbed by the opaque sub-regions of the aperture. The light passing through the transparent sub-regions of the aperture is focused by the incident lens surface onto the exit lens surface and projected onto the road.

[0051] Here, the patterns from all the microprojectors are projected at the same solid angle or onto the same spatial region and superimposed there to form the desired light distribution. The intensity at a point in the light distribution is the sum of the intensities generated by each microprojector at that point.

[0052] Figure 4 A top view of the entire light incident surface 40 of the micro-projection optics 22 is shown, wherein the light incident surface 40 is not yet covered by the aperture layer. Figure 4In particular, a micro-projection optical element 22 is shown as an element connected in a monolithic, material-fit manner, having light-incident lenses that are directly and therefore adjacent to each other in a contact manner to a certain extent without spacing. This applies to all embodiments.

[0053] The sum of the light incident surfaces of the microprojector forms the total light incident surface of the microprojection optical element 22. Similarly, in... Figure 4 The light-emitting lenses hidden by the micro-projection optics 22 are also directly and therefore adjacent to each other in a contact manner. This also applies to all embodiments. The sum of the emission lens surfaces of the micro-projector 22 forms the interconnected total light-emitting lens surface of the micro-projection optics 22.

[0054] Figure 5 A top view of a micro-projection optical element is shown, wherein the total light incident surface 40 formed by the sum of the light incident surfaces 30 of the micro-projector 28 forms the central region of the micro-projection optical element 22, which is surrounded by an outer edge region 42 that is light-transmitting. For example, opacity would occur if the edge region 42 were covered with an opaque layer.

[0055] Figure 6 An arrangement of multiple micro-projection light modules 16 is shown, each having an optical axis 44, and the multiple micro-projection light modules 16 are arranged side by side without spacing. The optical axes 44 of each micro-projection light module 16 are parallel to the optical axis of its respective micro-projector 28. At least a majority of the micro-projectors 28 in the entire arrangement are arranged such that their optical axes extend parallel to each other, and at least two of the majority of the micro-projectors 28 have incident lens surfaces and / or exit lens surfaces that are staggered from each other along their optical axes.

[0056] The micro-projection light modules 16 arranged side by side may differ from each other in the number of their micro-projectors, their focal length, and the aperture shape and / or aperture size of their micro-projection optics.

[0057] In a preferred design, the side-by-side micro-projection optical elements 22 are part of an arrangement 46 in which the micro-projection optical elements 22 are connected in a monolithic, material-fitted manner. Similarly, the auxiliary optical elements 20, which are associated with the micro-projection optical elements 22 and arranged side-by-side, are part of an arrangement 48 in which the auxiliary optical elements 20 are connected in a monolithic, material-fitted manner.

[0058] The arrangement of microprojectors does not necessarily have to be in a cuboid shape. Arranging microprojectors on a curved surface can be advantageous. Here, it is beneficial to use multiple auxiliary optics and light sources. The number of microprojectors in each row, the height of the lenses, or the focal length can also be varied three-dimensionally in this design.

[0059] Figure 7 Shown from the front Figure 6 The arrangement. Figure 8 It shows the relationship with Figure 6 and Figure 7 The arrangement is comparable to the side view of the arrangement. In one aspect... Figure 6 and Figure 7 The theme and the other party Figure 8 The difference between the themes lies in the height and width of the light incident surface and the exit lens surface of the microprojector. Figure 8 The themes are not all the same, but... Figure 6 and Figure 7 The themes are all the same.

[0060] Figure 9 A method for manufacturing a motor vehicle lighting device according to the invention is shown. The method is characterized in particular by forming an aperture layer 32 directly attached to the light incident surface 30 and the incident lens surface. For this purpose, in a first step 50, a micro-projection optical element 22 having a light incident surface 40 and an exit lens surface 34 is manufactured, for example by injection molding. Then, in a second step 52, the aperture layer 32 is coated onto the entire light incident surface 40 of the micro-projector, i.e., the micro-projection optical element 22. Thus, the aperture layer 32 is initially a continuous layer covering the entire light incident surface 40. Here, the material thickness of the aperture layer is so large that the aperture layer is almost opaque (transmittance less than 1%). The aperture layer is preferably a metal layer or a paint layer. When the micro-projection optical element 22 has an edge region 42 surrounding the central region in addition to the central region, this edge region 42 is preferably also covered with an opaque layer and thus is opaque. Then, in a third step 54, the light-transmitting sub-region 36 is exposed by ablation using a laser. Alternatively, photolithography and etching techniques can be used to generate the patterns needed to create the desired light distribution in the light-transmitting sub-regions of the aperture layer. However, ablation by laser beam is more precise and much more flexible than etching in terms of pattern modification, as such changes only require reprogramming the laser beam control.

[0061] Figure 10 A miniature projection optics element with an uncoated light incident surface is shown after the injection molding step. Figure 11 The image shows a miniature projection optics after the desired light-transmitting sub-region 36 is coated in a second step and exposed in a third step.

[0062] Alternatively, transparent sub-regions can be generated by selectively applying opaque sub-regions (e.g., using a mask, pad printing).

Claims

1. A motor vehicle lighting device (10) having at least one micro-projection light module (16), the micro-projection light module (16) having a light source (18), auxiliary optics (20) and a micro-projection optical element (22), the micro-projection optical element (22) having a plurality of micro-projectors (28) arranged in rows (24) and columns (26), each of the plurality of micro-projectors (28) having a light incident surface (30), an aperture layer (32) and an exit lens surface (34), wherein, The light incident surface (30) is a convex incident lens surface, the exit lens surface (34) is a convex lens surface, and wherein the light from the light source is almost collimated by the auxiliary optical device (20) and illuminates the micro-projection optical element, the micro-projection optical element being configured to project light onto a road, characterized in that the micro-projection optical element (22) is a component connected in an integral material-fit manner, the aperture layer (32) is directly arranged on and attached to the light incident surface (30), wherein the exit lens surface (34) of the micro-projector (28) is convex with the light incident surface (30). The distance between the light incident surfaces (30) of the micro projector (28) is almost corresponding to the focal length of the exit lens surface (34), such that the smaller of the distance and the focal length is greater than 90% of the larger of the two. The light incident surface (30) is an incident lens surface, and the focal length of the incident lens surface is almost the same as the focal length of the exit lens surface (34), such that the smaller of the focal length of the incident lens surface and the focal length of the exit lens surface (34) is greater than 90% of the larger of the two. The aperture layer (32) has a light-transmitting sub-region (36) and a nearly opaque sub-region (38).

2. The motor vehicle lighting device (10) according to claim 1, characterized in that, The smaller of the two focal lengths is greater than 95% of the larger of the two focal lengths.

3. The motor vehicle lighting device (10) according to claim 1 or 2, characterized in that, The total light incident surface (40) formed by the sum of the light incident surfaces (30) of the micro projector (28) forms the central region of the micro projection optical element (22), which is surrounded by an outer edge region (42) that is transparent.

4. The motor vehicle lighting device (10) according to claim 1, characterized in that, Multiple micro-projection light modules (16) are arranged side by side transversely to their optical axis (44).

5. The motor vehicle lighting device (10) according to claim 4, characterized in that, The side-by-side micro-projection optical modules (16) differ in their focal length, the number of their micro-projectors (28), and the shape and / or size of their apertures in their micro-projection optical elements (22).

6. The motor vehicle lighting device (10) according to claim 5, characterized in that, The side-by-side micro-projection optical elements (22) are part of the arrangement (46) of the micro-projection optical elements (22) connected in an integral material-fitting manner.

7. The motor vehicle lighting device (10) according to claim 5 or 6, characterized in that, The side-by-side auxiliary optical devices (20) are part of the arrangement (48) of the auxiliary optical devices (20) connected in an integral material-fitting manner.

8. The motor vehicle lighting device (10) according to claim 1, characterized in that, Each of the micro-projectors (28) has an optical axis, wherein at least most of the micro-projectors (28) are arranged such that their optical axes extend parallel to each other, and at least two of the micro-projectors (28) have incident lens surfaces and / or exit lens surfaces (34) arranged offset from each other along their optical axes.

9. The motor vehicle lighting device (10) according to claim 1, characterized in that, The height and width of the light incident surface (30) and the exit lens surface (34) of the micro projector (28) are not the same.

10. The motor vehicle lighting device (10) according to claim 1, characterized in that, The smaller of the distance and the focal length of the exit lens surface (34) is greater than 95% of the larger of the two.

11. A method for manufacturing a motor vehicle lighting device (10) according to claim 1, the motor vehicle lighting device (10) having at least one micro-projection light module (16), the micro-projection light module (16) having a light source (18), auxiliary optics (20) and a micro-projection optical element (22), the micro-projection optical element (22) having a plurality of micro-projectors (28) arranged in rows (24) and columns (26), each of the plurality of micro-projectors (28) having a light incident surface (30), an aperture layer (32) and an exit lens surface (34), characterized in that, The micro-projection optical element (22) is formed into an integral material-fitted element by injection molding, and the aperture layer (32) is formed as an aperture layer (32) directly attached to the light incident surface (30).

12. The method according to claim 11, characterized in that, First, in the first step (50), the micro-projection optical element (22) having a light incident surface (30) and an exit lens surface (34) is manufactured; in the second step (52), a metal layer or a paint layer is coated on the light incident surface (30) of the micro-projector (28); and in the third step (54), the light-transmitting sub-region (36) is exposed by ablation using a laser.

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