Motor vehicle lamp

Abstract

The invention relates to a motor vehicle lamp (10) for producing a 3D effect, comprising a support plate (12) made of translucent material, into which plate (12) light (16) can be coupled via its rear side (14) and from which plate (12) light (20) can be decoupled via its opposite front side (18). In order to couple light (16) into the plate (20), prisms (26) having an entry surface (28) and a deflection surface (30) are formed and distributed in a special manner on the rear side (14) of the plate (12). According to the invention, in a viewing direction (b) transverse to the surface normal (n) of the plate (12) from one side of the prism (26), the angle (gamma) between the incident surface (28) of the prism (26) and the corresponding deflection surface (30) is equal in magnitude, or the incident surface (28) of the prism (26) is planar and in each case has a constant angle (delta) with respect to the surface normal (n) of the plate (12), or-the deflection surface (30) of the prism (26) is planar and in each case has a constant angle with respect to the surface normal (n) of the plate (12).

Description

[0001] The invention relates to a motor vehicle lamp. The motor vehicle lamp comprises

[0002] - a support plate made of a translucent material, the support plate having a rear side and an opposite front side, light being coupleable into the support plate through the rear side, light being decoupleable from the support plate through the front side,

[0003] and

[0004] - at least one light source, the at least one light source being arranged and oriented for emitting light in the direction of the rear side of the support plate, such that at least a portion of the emitted light is coupled into the support plate via the rear side and is decoupled again via the front side.

[0005] The at least one light source is constructed and arranged relative to the support plate in such a way that the light emitted from the at least one light source illuminates the rear side of the support plate over a large area and with an angle of incidence of the main emission direction of the light relative to the surface normal of the support plate being greater than 45°.

[0006] A plurality of prisms or prism-like structures (hereinafter only referred to as "prisms") is formed on the rear side of the support plate, the prisms or prism-like structures protrude outwardly from the rear side and have an incidence surface facing the at least one light source and a deflection surface facing away from the at least one light source. The prisms are arranged and constructed in such a way that light emitted from the at least one light source via the incidence surface can be coupled into the prisms and the coupled light can be deflected via the deflection surface into the support plate. The light deflected into the support plate can be decoupled from the support plate via the front side of the support plate. In general, the term "single prism" or "plurality of prisms" comprises two optically effective surfaces in relation to each other. The optical efficiency in the sense of the invention can include refraction, diffraction and / or reflection.

[0007] The prisms are grouped according to the angular relationship of the incidence surface and / or the deflection surface of the prisms relative to each other and / or relative to the surface normal of the support plate. When an observer observes the front side of the support plate with the at least one light source switched on, each group of identical focal points or focal lines produces a profile of virtual light points, virtual light rays or virtual objects.

[0008] Such a motor vehicle lamp is known, for example, from the subsequently published DE 10 2023 122 627 from the same applicant as the present application. The transparent support plate generates a three-dimensional image for the observer. To this end, the support plate is obliquely illuminated from below or from the side with light from one or more light sources. Prisms are located on the underside or on the rear side of the plate, which deflect the light into the desired direction. The outer dimensions of the individual prisms or of the individual structural elements of the prismatic structure can be in the order of magnitude of 0.001 mm to 1 mm. These dimensions can be both the height of the prisms or structural elements, measured from the rear side of the support plate, and the dimensions of the base surface or of the side edges of the base surface of the prisms or structural elements. These structures are therefore also referred to as microstructures or microprisms. One subject of these lamps is the placement, arrangement and / or grouping of the prisms on the rear side of the support plate. Another subject is the design, calculation and configuration of the individual prisms.

[0009] The relatively small prisms projecting from the rear side of the support plate couple the light emitted from the one or more light sources via the rear side of the support plate to the latter. The light exits from the front side of the plate and is focused into virtual points in three-dimensional space. These focal points are virtual light points for the observer. Several such adjacent focal points are a virtual light line for the observer.

[0010] The individual prisms of the microstructure can be rotated by a specific rotation angle about a rotation axis. In this case, the rotation axis of the prisms is preferably parallel to the surface normal of the support plate or, in the respective position of the prisms arranged on the support plate, perpendicular to the rear side of the support plate. Alternatively or additionally, the individual prisms of the microstructure can be tilted by a specific tilt angle about a tilt axis in each case. In this case, the tilt axis of the prisms is preferably at right angles to the surface normal of the support plate or, in the respective position of the prisms arranged on the support plate, parallel to the rear side of the support plate.

[0011] The rotation or tilting of the individual prisms is for the purpose of deflecting the light beams emitted from the light source such that they intersect in at least one virtual point or along a virtual line in three-dimensional space and thereby generate a three-dimensional illumination effect when the observer observes the front side of the support plate. Alternatively or additionally, the rotation or tilting of the individual prisms takes place for the purpose of illuminating the virtual point or line with the desired intensity, i.e. to allow the desired number of light beams to intersect in the virtual point or along the virtual line such that the observer obtains the desired intensity distribution in the three-dimensional illumination effect.

[0012] Since these prism structures have in each case a light-coupling entry surface and a reflective deflection surface, both surfaces individually influence the direction of the light beams coupled out via the front side of the support plate by their individual construction and alignment and by their arrangement and alignment relative to each other, the design, calculation and configuration of the individual prisms and their distribution on the rear side of the support plate can be very complex in the prior art. In this case, the present application is intended to provide a remedy by proposing a particularly easy-to-implement design, calculation and configuration of the individual prisms and their distribution on the rear side of the support plate, which, however, is able to produce the desired three-dimensional illumination effect and / or has the desired intensity distribution for the observer when the observer observes the front side of the support plate.

[0013] With regard to the prior art on the design, calculation and configuration of the individual prisms known to the inventors, reference is made to the following publications:

[0014] (1) DE 10 2011 114 636 A1, "Arrangement and dimensioning of an elevated element on a projection lens of a motor vehicle headlamp";

[0015] (2) DE 11 2018 000 058 T5, "Surface illumination module of an LED light source, vehicle lamp using the surface illumination module and assembly method thereof";

[0016] (3) DE 10 2020 131 517 A1, "Illumination device with light guide and light guide for an illumination device";

[0017] (4) DE 10 2008 034 052 B4, "Light guide for use as a motor vehicle clearance lamp or daytime running lamp";

[0018] (5) DE 198 04 440 A1, "Rod-shaped light guide";

[0019] (6) DE 11 2017 000 008 B4, "Stereoscopic display device";

[0020] (7) DE 10 2011 078 610 B3, "Illumination device of a motor vehicle with a windshield extending at an angle to the direction of travel";

[0021] (8) EP 2 500 754 B1, "Illumination device of a motor vehicle"; and

[0022] (9) DE 10 2012 220 472 A, "Illumination device of a motor vehicle".

[0023] In many publications, e.g. in (1), microprisms and their orientation are likewise discussed, however, the microprisms are intended to produce overhead illumination and not a three-dimensional illumination effect. Thus, the individual prisms are not specifically directed at a single point or line. Furthermore, prisms with a TIR-reflecting deflection surface are not considered in (1). The same applies to publication (2). Here, also a constant shape of the prisms is proposed, e.g. a hemisphere or a slit.

[0024] In publications (3), (4) and (5), structures within a light guide in a constant direction relative to the light guide are described. In publications of the company Omron, e.g. (6) or the following publications (10) - (21) listed below, microstructures with prisms having a TIR-reflecting deflection surface are used, however, only the first surface irradiated by light has an optical effect therein: the light propagating in the plate is irradiated onto the microstructure, directly deflected upwards and then decoupled from the front side.

[0025] The development of the prismatic structure is varied in (7). However, no light is sent to any one point. Here, also no rotation of the structure is considered. Furthermore, the structure there has only one optically effective surface.

[0026] In (8), the structure for decoupling light from the light guide is likewise used only along the direction of the light guide and only varies in size. In (9), only a single prism with a TIR-reflecting deflection surface is used, which is added to the lens as in (1). However, the TIR-deflection surface is not simultaneously rotated or tilted to the incident surface to be coupled.

[0027] With regard to prior art known to the inventors regarding the distribution of prisms on the rear side of a support plate, reference is made to the following publications:

[0028] (10) Yasuhiro Takaki: “High-density directional display for generating Natura three-dimensional images”, IEEE Transactions on Consumer Electronics, Vol. 54, No. 2, May 2008;

[0029] IEEE Conference Proceedings, Vol. 94, No. 3, March 2006;

[0030] (11) Yasuhiro Takaki: “Super multi-view display with lower resolution flat panel display”, Optics Express, Vol. 19, No. 5, February 28, 2011;

[0031] (12) DE 10 2017 200 112 A1, Volkswagen AG, “Method and device for generating a dynamic light field”;

[0032] (13) DE 10 2021 108 339 A1, Anhalt University of Applied Sciences (FH), “Light field display...”;

[0033] (14) DE 11 2017 003 640 T5, Omron Corporation, "Optical device and optical system";

[0034] (15) US2019 / 0235263A1, Omron Corporation, "Optical apparatus";

[0035] (16) US 11,067,826 B2, Omron Corporation, "Optical apparatus for presenting a stereoscopic image";

[0036] (17) DE 11 2020 006 212 T5, Omron Corporation, "Light guide plate, display device, input device, and electrical device";

[0037] (18) DE 11 2015 004 586 B4, Omron Corporation, "Optical device";

[0038] (19) US2014 / 0268327A1, Opsec Security Group, "Optically variable devices exhibiting non-diffractive three-dimensional optical effects";

[0039] (20) = (1); and

[0040] (21) DE 20 2018 106 219 U1, "Optical element arrangement, optical instrument comprising such an optical element arrangement, and vehicle headlight equipped with a corresponding optical instrument".

[0041] Publications (10) - (13) consider light field displays. In this case, the images of various high-resolution displays are directed to specific viewing directions by optical means, such as lenses or the like. Thus, different images can be seen from different directions. This brings a three-dimensional illumination effect for the viewer. However, since the publications relate to small LC displays, only a small and large number of optical means are used compared to the number of light deflecting prisms used within the scope of the present invention.

[0042] Publications (14) - (18) relate to a light guide plate. In this case, light propagates by total internal reflection (TIR) in the plate until it is deflected by light deflecting structures inside the plate to the appropriate direction and finally decouples.

[0043] Publication (14) relates to a light guide plate comprising light deflecting structures or structural elements. In order to place the structures in the plate, a virtual light beam is constructed which places the structures on the plate starting from an observer through a focal point. The disadvantage here is that the structural elements are initially positioned arbitrarily on the plate. Compliance with conditions on the plate, such as a minimum spacing between the structural elements, can lead to problems. Furthermore, the arrangement of the structural elements in a matrix structure is mentioned. The disadvantage here is that, due to the regularity of the arrangement of the structural elements, undesired visible structures appear in the image. Thus, for example, visible stripes can appear in the image. Furthermore, in (14) the image to be generated is constructed as a line, which likewise leads to undesired visible structures.

[0044] In (16) the structures are arranged linearly in a matrix structure. In addition to the undesired visible structures in the resulting image, this also leads to a pattern appearing to the observer of the unlit plate.

[0045] In (17) the structures are arranged in a matrix, at the centroid of a triangle or randomly. Here, the distance of the points varies depending on the density of the structure to be distributed, since the division of the triangle is refined depending on the density. This can lead to visible patterns on the unlit plate.

[0046] In (18) the structures located within a certain matrix field are merged. This leads to various different structures with corners and edges, thus becoming a problem of producibility and manufacture.

[0047] In (19) the same effects, such as color effects or 3D effects, are produced by placing the structures on banknotes or other surfaces when the observer moves. In this case, the structures are not arranged according to any specific, predetermined pattern, or, as mentioned above, linearly side by side, which can lead to the problems already mentioned above.

[0048] In (20) the arrangement of microstructures is proposed in principle. However, the structures used there pursue a different goal (realization of overhead lighting), so the prisms proposed here are completely different in terms of configuration and arrangement.

[0049] In (21) microstructures are arranged periodically in several layers in order to produce a three-dimensional lighting effect at the observer.

[0050] Starting from the described prior art, it is the object of the present invention to be able to design, calculate and configure individual prisms and their distribution on the rear side of a support plate in a particularly simple manner, wherein, at the same time, when an observer observes the front side of the support plate, the desired three-dimensional lighting effect and / or a lighting effect with the desired intensity distribution is produced for the observer.

[0051] To achieve this object, a motor vehicle lamp is proposed having the features of claim 1. In particular, starting from the motor vehicle lamp of the type mentioned at the outset, it is proposed that, in the viewing direction, the incidence surface and the deflection surface of the prisms or prism-like structures of each group of prisms or prism-like structures are oriented transversely to the surface normal of the support plate and transversely to the surface normal of the incidence surface and the deflection surface,

[0052] the angle (γ) between the incidence surface and the respective deflection surface of the prisms or prism-like structures of each group of prisms or prism-like structures is equal, or

[0053] the incidence surface of the prisms or prism-like structures of each group of prisms or prism-like structures is planar and has a constant angle (δ) with respect to the surface normal of the support plate at the respective position of the prism or prism-like structure on the support plate in each case, or

[0054] the deflection surface of the prisms or prism-like structures of each group of prisms or prism-like structures is planar and has a constant angle with respect to the surface normal of the support plate at the respective position of the prism or prism-like structure on the support plate in each case.

[0055] First of all, it is important that the prisms or prism-like structures protrude from the support plate, rather than protruding into the plate as in the above-mentioned publication of the company Omron, which would lead to major disadvantages in the manufacture of the tool for manufacturing the support plate with structures. The prisms are mounted underneath the plate, from which the light is coupled in. The prisms protruding from the plate now have two optically effective surfaces instead of one. This necessitates a new calculation of the prisms or of their optically effective surfaces.

[0056] In order to reduce the complexity of the design, calculation and configuration of the individual prisms, or first of all to reduce it to a practicable extent, it is proposed that the angle between the incidence surface and the respective deflection surface of the prisms or prism-like structures of each group of prisms or prism-like structures is equal. Thus, all prisms belonging to a common group of prisms have the same angle between the incidence surface and the respective deflection surface. The prisms belonging to another group of prisms can have a different angle between the incidence surface and the respective deflection surface. However, it is also conceivable that the prisms of another group have the same angle between the incidence surface and the respective deflection surface. The angle of the incidence surface and / or the deflection surface of the prisms of the common group of prisms can vary at the respective position of the prism on the support plate with respect to the surface normal of the support plate by a rotation and / or an inclination of the prisms. However, it is of paramount importance that the angle between the incidence surface and the respective deflection surface of the prisms belonging to a common group of prisms always remains constant. This means that for each prism, the incidence surface and the respective deflection surface of all prisms of the common group of prisms are always rotated or inclined congruently together.

[0057] To reduce the complexity of the design, calculation and configuration of the individual prisms, or to first reduce it to a feasible extent, it is proposed instead that the entry surfaces of the prisms or prism-like structures of each group of prisms or prism-like structures are planar and all have the same angle relative to the surface normal of the support plate at the respective position of the prism on the support plate. The rotation of the prisms of the common group of prisms is preferably effected by a common congruent rotation of the entry surface and the deflection surface for each prism in the group. To achieve the tilting of the prisms in the common group of prisms, preferably only the deflection surface of the prisms is tilted, while the angle of the entry surfaces of all prisms in the group relative to the surface normal of the prisms on the support plate always has the same size at the respective position of the prism on the support plate, independent of the angle / extent of the tilting. This means that for each prism, the entry surfaces and the respective deflection surfaces of all prisms of the common group of prisms always rotate congruently together, but only the deflection surfaces of the common group of prisms are tilted.

[0058] It is emphasized that the calculation method presented here is not limited to application in motor vehicle lights. Rather, it is generally used to simultaneously calculate the refractive normals of two optical surfaces aligned relative to each other. In particular, the calculation of the rotation and tilting of the prisms can be used in many other applications. For example, the prisms can be arranged on a non-planar surface.

[0059] Furthermore, the following features can be relevant to the invention, either individually or in any combination with each other:

[0060] - Each prism couples light incident from the entry direction via the rear side of the support plate to a given exit direction of the light incident through the front side of the support plate.

[0061] - To this end, the prism comprises two opposing optically effective surfaces (for example, an entry surface that refracts light and a deflection surface that reflects light, which are, for example, configured as TIR surfaces).

[0062] - The rotation of each prism always affects both optically effective surfaces. It rotates by the same angle about a common rotation axis. In the current case of a motor vehicle light with a 3D effect, the rotation axis corresponds to the surface normal of the support plate below which the prism lies.

[0063] - The described method for designing, calculating and configuring the individual prisms encompasses two cases, which are preferred depending on the manufacturing method:

[0064] o Both optically effective surfaces have a constant angle relative to each other. The rotation and tilting of the prism thus affect both optically effective surfaces.

[0065] o Only one of the two optically effective surfaces is tilted. The rotation preferably takes place together for both optically effective surfaces. It is also conceivable that the prism is only rotated once and not tilted.

[0066] It is conceivable that all prisms of the support plate are designed, calculated and configured according to one of the above cases. Alternatively, it is also conceivable that at least one first group of prisms of the support plate is designed, calculated and configured according to the first case and at least one further group of prisms of the support plate is designed, calculated and configured according to the second case.

[0067] Therefore, it is proposed that the entrance surfaces and the deflection surfaces of the prisms or prism-like structures of the group of prisms or prism-like structures are fitted, aligned and / or configured in such a way that the light beams of the light coupled through the entrance surfaces and deflected at the deflection surfaces intersect at a common focal point or along a common focal line. Preferably, the focal point or the focal line is located in front of, on and / or behind the front side of the support plate and the virtual light point, the virtual light line or the contour of the virtual object appears to the observer to be located on the focal point or the focal line.

[0068] It is further proposed that the prisms or prism-like structures of the group of prisms or prism-like structures each rotate around a rotation axis by a rotation angle, wherein the rotation axes of the prisms or prism-like structures of the group of prisms or prism-like structures are preferably parallel to or formed by the surface normal of the support plate at the respective position of the prism or prism-like structure on the support plate. Alternatively or additionally, it is proposed that the prisms or prism-like structures of the group of prisms or prism-like structures are tilted between the entrance surface and the respective deflection surface around a tilt axis by a tilt angle at a constant angle, wherein the tilt axis preferably extends transversely, particularly preferably at a right angle, with respect to the surface normal of the support plate at the respective position of the prism or prism-like structure on the support plate.

[0069] Furthermore, it is proposed that the entrance surfaces and / or the deflection surfaces of the prisms or prism-like structures are planar or arcuate. The curvature of one or both surfaces of the prisms is such that the incident light beam is fanned and passes not only through one focal point but also through several points on the focal line. The fanned light beams from the plurality of prisms of the group of prisms then intersect at the points on the focal line. Preferred embodiments of the curvature are spherical, cylindrical or toric.

[0070] The entrance surfaces and / or the deflection surfaces of the prisms or prism-like structures are preferably curved around at least one axis, which extends transversely, particularly preferably perpendicularly, to the surface normal of the support plate and parallel to the viewing direction. It is conceivable that the curvature of the entrance surfaces of several prisms of the common group of prisms is equal in size. However, the curvature of the entrance surfaces of the plurality of prisms of the common group of prisms is preferably equal in size. In this way, it can be ensured that the fanned light beams from the plurality of prisms of the group of prisms intersect at the points on the focal line.

[0071] A set of prisms or prism-like structures of the same focal point or focal line can be distributed on the rear side of the support plate in almost any desired manner. Depending on the 3D effect to be achieved, a set of prisms or prism-like structures of the same focal point or focal line can be arranged, for example, on a line, preferably on a straight line. For example, if the 3D effect should be purely horizontal, it makes sense to design this line accordingly. However, if a horizontal and vertical 3D effect is to be created, each focal point should illuminate from a surface (and not a line).

[0072] In order to avoid unwanted scattering and virtual ghosting, it is proposed to design the prisms in such a way that as little light as possible is refracted or reflected by the side walls of the prisms. For this purpose, it is proposed that the prisms taper downwards. In this sense, it is in particular proposed that the width of the prisms or prism-like structures decreases downwards with increasing distance from the rear side of the support plate, when viewed transversely to the transverse viewing direction and transversely to the surface normal of the support plate and transversely to the surface normals of the entry surface and the deflection surface. This can also be used to set the intensity of the deflected light of the fan-shaped light beam along the virtual focal line to a desired value in a simple manner.

[0073] It is particularly preferred that the width of the side faces of the prisms or prism-like structures is configured to be planar or arched, when viewed transversely to the viewing direction from the side faces of the prisms or prism-like structures and transversely to the surface normal of the support plate and transversely to the surface normals of the entry surface and the deflection surface. Thus, unwanted scattering and virtual ghosting can be particularly well avoided.

[0074] Furthermore, it is proposed that the prisms or prism-like structures adjacent to one another are arranged on the rear side of the support plate at a substantially equal distance from one another. In order to avoid the formation of visible patterns, stripes, etc. in the image, a slight deviation from the same distance between adjacent prisms can be useful. Preferably, the deviation is in the range of a maximum of 10% of the average distance of the adjacent prisms from one another. However, the deviation can also be greater.

[0075] According to an advantageous refinement of the application, it is proposed that the prisms or prism-like structures are arranged in a regular grid structure having a plurality of overlapping and / or side-by-side arranged cells, wherein the areas of the cells of the grid structure are preferably of equal size. Preferably, the areas of the cells deviate from one another in the range of a maximum of 10% of the average area of the cells. However, the deviation can also be greater.

[0076] According to another advantageous refinement of the application, it is proposed that the prisms or prism-like structures are arranged in a regular grid structure with a plurality of overlapping and / or side-by-side arranged cells, wherein at most one prism, preferably exactly one prism, is arranged in one cell, a plurality of cells being combined into one pixel. Preferably, within each pixel, each of the prisms or prism-like structures is constructed and / or arranged to illuminate a common focal point and / or a common focal line. However, it is also conceivable that the prisms or prism-like structures in a pixel can also illuminate different focal points.

[0077] According to the intensity with which a focal point is illuminated from a pixel, the number of prisms of the pixel is determined, which will deflect light in the direction of the focal point. If the resulting number of prisms is too large for one pixel, the determined number of prisms should be offset with the prisms of an adjacent pixel, so that no focal point remains unilluminated.

[0078] In other words, this means in the context of the algorithm per pixel:

[0079] - determining which focal points should be illuminated from this pixel (e.g. focal points B1, B2 and B3 should be illuminated, but in some cases represent more than three focal points);

[0080] - determining the intensity with which these focal points should be illuminated (e.g. focal point B2 should be illuminated twice as much as focal points B1 and B3), and

[0081] - determining from this the number of prisms to be directed at the respective focal point. (i.e.: 1 prism should be directed at focal points B2 and B3, 2 prisms should be directed at focal point B2).

[0082] - if the total number of prisms required (4 prisms in the above example) is higher than the number of cells in the pixel (1 prism per cell), the prisms are removed onto adjacent pixels.

[0083] According to a preferred embodiment of the application, the prisms or prism-like structures are constructed and / or arranged to always illuminate focal points and / or focal lines from the support plate with the same angular resolution. Thus, if focal points to be illuminated are arranged closer to the support plate, more prisms have to be placed than are required for illuminating focal points further away from the plate. The same problem can arise if one focal point or one focal line should be illuminated more intensely than another focal point or another focal line. To remedy this, it is proposed to place multiple prisms within one pixel for the focal points to be illuminated. The number thereof depends on the distance from the plate and the intensity of the focal points to be illuminated or the focal lines to be illuminated.

[0084] In this case, it is conceivable that some prisms or prism-like structures of a pixel are constructed and / or arranged to illuminate one of the focal points and / or focal lines to be illuminated, respectively, and at least one other prism or at least one other prism-like structure of the pixel is constructed and / or arranged to likewise illuminate at least one of the focal points to be illuminated and / or at least one of the focal lines to be illuminated. It is particularly preferred for the focal points to be illuminated and / or the focal lines to be illuminated that a plurality of prisms or prism-like structures is arranged in the pixels within the pixel.

[0085] The prisms are therefore preferably placed in a regular grid. The cells thereof preferably have a constant size. A prism is preferably arranged in each cell. The individual prisms therefore have a constant distance from one another. This leads to a uniform appearance of the light-emitting 3D image, prevents overlapping of individual prisms and allows direct influence on the appearance and transparency of the unilluminated plate.

[0086] In each case, a certain number of cells of the grid are combined into a pixel. Within these pixels, the focal points to be illuminated in the 3D space are determined. Each prism preferably illuminates one focal point. To this end, the prisms must be rotated and tilted, or just rotated. This allows the use of the same prism everywhere, or at least several basic prisms, leading to good producibility.

[0087] If the number of focal points to be illuminated is greater than the possible number of prisms within a pixel, the prisms of a pixel are used to illuminate some focal points, and preferably the remaining focal points of the prisms are illuminated by one or more neighboring pixels. All focal points to be illuminated are therefore always operated, ensuring uniform illumination of the 3D image.

[0088] The focal points to be illuminated are always illuminated from the plate with the same angular resolution. If the focal points to be illuminated are closer to the plate, more prisms are preferably placed closer to one another than for focal points that are further away. The same problem arises when one focal point is illuminated with a higher intensity than another. To achieve a higher intensity, a plurality of prisms is placed within one pixel for a focal point to be illuminated. The number thereof depends on the distance of the focal point to the plate and the intensity of the focal point to be illuminated.

[0089] By distributing the individual prisms randomly over the cells within a pixel, undesirable effects such as 3D image stripes are prevented. The prisms in the individual cells are therefore slightly offset with respect to one another, i.e. are slightly offset from one another in their respective cells.

[0090] The choice of the underlying grid, which can be constructed as a hexagon, triangle or other geometric shape, as well as the slight displacement of each prism within its cell, likewise prevents unaesthetic effects, such as stripes of the 3D image or recognizable structures of the unilluminated plate.

[0091] Other features and advantages of the invention will now be explained in more detail with reference to the accompanying drawings. Features shown in the drawings may themselves be essential to the invention, even if not explicitly mentioned in the following description. Similarly, it is conceivable to combine the features shown in the drawings with each other in any desired manner, even if such combinations are not explicitly mentioned in the following description. In the drawings:

[0092] Figure 1 A side view of a support plate for a motor vehicle lamp according to the present invention is shown in the schematic diagram. The support plate has a plurality of prisms or prism-like structures on the rear side of the support plate.

[0093] Figure 2 A prism or prism-shaped structure according to the first embodiment is shown. Figure 1 A side view of the rear side of the support plate;

[0094] Figure 3 A prism or prism-shaped structure according to the second embodiment is shown. Figure 1 A side view of the rear side of the support plate;

[0095] Figure 4 A prism or prism-shaped structure according to another embodiment is shown. Figure 1 The rear side view of the support plate, which has an arched deflection surface;

[0096] Figure 5 It shows according to Figure 4 A perspective view of a support plate with multiple prisms or prism-like structures;

[0097] Figure 6 It shows a prism or prism-like structure. Figure 1 Details of the support plate are shown, along with the vector and refractive index of the material used as an example;

[0098] Figure 7 A front view of a prism or prism-like structure on the rear side of a support plate according to another embodiment is shown.

[0099] Figure 8 A front view of a prism or prism-like structure on the rear side of a support plate according to yet another embodiment is shown.

[0100] Figure 9 The diagram shows dividing the rear side of a support plate into units having at least one prism or at least one prism-like structure, and combining 2×2 units into a pixel in each case;

[0101] Figure 10A light beam that can be decoupled via the front side of the support plate is shown according to one embodiment, wherein a prism or prism-like structure deflects the light to the illuminated point 1 and / or the illuminated point 2 and produces a 3D effect in two directions;

[0102] Figure 11 A light beam that can be decoupled via the front side of the support plate is shown according to an embodiment of the application, wherein a pixel comprising a plurality of prisms or prism-like structures deflects the light to the illuminated point 1 and / or the illuminated point 2; and Figure 10

[0103] Figure 12 A light beam that can be decoupled via the front side of the support plate is shown according to an embodiment of the application, wherein a pixel comprising a plurality of prisms or prism-like structures deflects the light to the illuminated point 1 and / or the illuminated point 2; and Figure 10

[0104] The application relates to a motor vehicle lamp 10. It is configured for use in a motor vehicle. The lamp 10 can be fitted on the front side, the side or the rear side of the motor vehicle. It is configured to produce a light function according to the relevant legal requirements. The light function can be, for example, a daytime running light, a flash light, a position or parking light, a side marker function, a rear light, a brake light, a rear fog light, a reversing light, etc. It is also conceivable to use the lamp as a purely decorative or design lamp in the outdoor area, for example for illuminating the radiator grille or the front panel. It is also conceivable to use the lamp 10 in the interior space of the motor vehicle. In this case, the lamp 10 can perform the function of ambient lighting, decorative lighting, a reading light or interior lighting. In particular, the motor vehicle lamp 10 should be able to produce a 3D effect in the case of an observer looking at the lamp 10 from the front, opposite the light emission direction.

[0105] The motor vehicle lamp 10 comprises:

[0106] - a support plate 12 made of a translucent material, which has a rear side 14 through which light 16 can be coupled into the support plate 12 and an opposite front side 18 through which light 20 can be decoupled from the support plate 12; and

[0107] - at least one light source 22 which is arranged and oriented for emitting light 16 in the direction of the rear side 14 of the support plate 12, such that at least a portion 24 of the emitted light 16 is coupled into the support plate 12 via the rear side 14 and is decoupled again via the front side 18.

[0108] The at least one light source 22 is configured and arranged relative to the support plate 12 in such a way that the light 16 emitted from the at least one light source 22 illuminates the rear side 14 of the support plate 12 over a large area and at an angle of incidence a of more than 45° of the main emission direction of the light 16 relative to the surface normal n of the support plate 12. The angle of incidence a is preferably > 70°, very particularly preferably > 80°.

[0109] ​​The light source 22 can comprise optical elements (not shown) configured to generate a parallel (or diverging or converging collimated) light beam 16 from the light emitted by the light source 22. The light beam 16 impinges obliquely from below on the support plate 12 with an angle b. The angle b is preferably < 20°, very particularly preferably < 10°. The illumination of the entire plate 12 should be as uniform as possible. The light 16 should impinge very flat on the bottom of the plate 12, since due to the high Fresnel reflection, most of the light 16 will be reflected downwards again. Only the light 16 impinging on the prisms or prism-like structures (hereinafter referred to simply as "prisms") 26 is deflected and used to generate the illumination function and the associated 3D effect of the lamp 10.

[0110] A plurality of prisms 26 is formed on the rear side 14 of the support plate 12, which prisms 26 project outwards from the rear side 14 and have an incidence surface 28 facing towards the at least one light source 22 and a deflection surface 30 facing away from the at least one light source 22. The prisms 26 are arranged and configured in such a way that light 16 emitted from the at least one light source 22 via the incidence surface 28 can be coupled into the prisms 26 and the coupled light 24 can be deflected via the deflection surface 30 into the support plate 12. The light 24 deflected into the support plate 12 can be decoupled from the support plate 12 via the front side 18 of the support plate 12. In general, the term "single prism" or "plurality of prisms" 26 comprises two optically effective surfaces in relation to each other. According to the application, the optical effect of the surfaces 28, 30 can comprise refraction, diffraction and / or reflection. Thus, each prism 26 refracts / reflects the light 16 from the incidence direction to a given direction of the incident light 20. The incident light 16 is refracted on passing through the incidence surface 28. The reflection at the deflection surface 30 is preferably total internal reflection (TIR).

[0111] The prisms 26 are grouped into groups (= pixels) depending on the angular relationship of the incidence surface 28 and / or the deflection surface 30 of the prisms 26 relative to each other and / or relative to the surface normal n of the support plate 12. A group of prisms 26 preferably illuminates several / different focal points (see, for example, Fig. 2). Figure 12 : 4 cells in each pixel, some pixels with cells illuminating P1 and cells illuminating P2). However, it is also conceivable that some or all prisms of a group of prisms 26 illuminate the same focal point or focal line. In this case, each group of identical focal points or focal lines produces a virtual light point P_1, P_2, a virtual light line or the contour of a virtual object for the observer 32 when the observer 32 looks at the front side 18 of the support plate 12 with the at least one light source 22 switched on.

[0112] Such a motor vehicle lamp is known, for example, from the subsequently published DE 10 2023 122 627 from the same applicant as the present application. A three-dimensional image is produced for an observer by means of a translucent, preferably transparent, support plate 12. For this purpose, the support plate is obliquely illuminated from below or from the side with light 16 from one or more light sources 22. Prisms 26 are located on the underside or rear side 14 of the plate 12, which deflect the light 16 into the desired direction. The outer dimensions of the individual prisms 26 or of the individual structural elements of the prismatic structure can be in the order of magnitude of 0.001 mm to 1 mm. These dimensions can be both the height of the prisms 26 or structural elements, measured from the rear side 14 of the support plate 12, and the dimensions of the base surface or the side edges of the base surface of the prisms 26 or structural elements. These structures are therefore also referred to as microstructures or microprisms. One subject of these lamps 10 is the placement, arrangement and / or grouping of the prisms 26 on the rear side of the support plate. Another subject is the design, calculation and configuration of the individual prisms 26.

[0113] In order to simplify the design, calculation and configuration of the individual prisms 26, these prisms 26 are first designed to protrude outward beyond the rear side 14 of the support plate 12 and the light 16 is decoupled from below via the rear side 14 of the plate 12. Thus, for each prism 26, there are two optically effective surfaces 28, 30, the alignment and arrangement of which can be varied in order to direct the incident light 16 onto the illuminated points P_1, P_2. In order to have to calculate as few different types of prisms 26 as possible, it is proposed to limit the configuration of the prisms 26 to one or two different types.

[0114] Figure 2 A first type of prism 26 is shown, in which all prisms 26 have a constant (identical size) angle γ between the two optically effective surfaces 28, 30. Despite this restriction, in order to be able to direct the incident light 16 as flexibly as possible onto the desired points P_1, P_2 to be illuminated, the individual prisms 26 can be rotated and / or tilted individually.

[0115] Figure 3 A second type of prism 26 is shown, in which the angle δ between one of the two optically effective surfaces 28, 30 and the adjacent rear side 14 of the support plate 12 or the angle (not shown) of one of the two optically effective surfaces 28, 30 with respect to the surface normal n of the support plate 12 is constant (identical size). Figure 3An example is shown in which the angle δ between the incidence surface 28 and the adjacent rear side 14 of the support plate 12 is constant. Alternatively, however, it is also conceivable that the angle δ between the deflection surface 30 and the adjacent rear side 14 of the plate 12 is constant. The angle δ shown is approximately 90°. Of course, other values of the angle δ shown are also conceivable. Despite this restriction, in order to be able to direct the incident light 16 as flexibly as possible onto the desired points P_1, P_2 to be illuminated, the angle γ between the optically effective surfaces 28, 30 or the inclination of the other one of the two optically effective surfaces 28, 30 relative to one of the two optically effective surfaces 28, 30 can be adjusted individually. This adjustment of the inclination is referred to as the tilt angle λ of the other one of the two optically effective surfaces 28, 30. In Figure 3 In the example shown, the inclination of the deflection surface 30 relative to the incidence surface 28 varies individually. If the angle δ between the deflection surface 30 and the adjacent rear side 14 of the support plate 12 is constant, the inclination of the incidence surface 28 relative to the deflection surface 30 can also vary individually. Furthermore, the individual prisms 26 can be rotated individually.

[0116] The lamp 10 according to the application can have only prisms 26 of the first type, only prisms 26 of the second type or different types of prisms 26 of the first type and the second type. The same or different types of prisms 26 can be distributed in the above-described groups of prisms 26 having the same focal point and / or the same focal line and in the units and / or pixels to be explained in further detail below.

[0117] As mentioned above, the prisms 26 can be rotated and / or tilted. The calculation of the rotation and the tilt of the prisms 26 can be used for many other applications, for example when the prisms 26 are located on a non-planar surface. The rotation of the prisms 26 always affects both optically effective surfaces 28, 30. Both are rotated by the same rotation angle ε about a common rotation axis. In the current case of the motor vehicle lamp 10 with 3D effect shown, the rotation axis corresponds to the surface normal n of the plate 12 below which the prisms 26 are located.

[0118] In the first type of prisms 26, the tilt affects both optically effective surfaces 28, 30, as Figure 2 shown. The tilt occurs on a tilt axis, which extends parallel to the surface of the rear side 14 of the plate 12 and extends perpendicularly to the drawing plane by a tilt angle λ. In the second type of prisms 26, the tilt affects only one of the two optically effective surfaces 28, 30, for example only the deflection surface 30, as Figure 3 shown, while the tilt of the incidence surface 28 relative to the adjacent rear side 14 of the plate 12 remains constant. It is conceivable to rotate the prisms 26 only and not to tilt the prisms 26 at all.

[0119] The rotation or tilting of the individual prisms 26 is such that the light beams 16 emitted from the light source 22 are deflected so that they intersect in at least one virtual point P_1, P_2 or along a virtual line in three-dimensional space and thereby create a three-dimensional lighting effect when the observer 32 observes the front side 18 of the support plate 12. Alternatively or additionally, the rotation or tilting of the individual prisms 26 takes place with the aim of illuminating the virtual point P_1, P_2 or line, respectively, with a desired intensity, i.e. allowing a desired number of light beams 20 to intersect in the virtual point P_1, P_2 or along the virtual line, thereby obtaining a desired intensity distribution in the three-dimensional lighting effect for the observer 32.

[0120] For all types of prisms 26, a vector b is first determined which describes the direction in which the light beam 16 is deflected by the prism 26 in the direction of the normal n of the plate 12. Figures 1-4 and 6, which is perpendicular to the plane of the drawing. This is thus a vector which describes the direction in the plate 12 and in each of the two optically effective surfaces 28, 30 of the prism 26. This vector b is thus, by definition, orthogonal to the normal vector n of the plate 12 and also to the normal vectors n1, n2 of the two optically effective surfaces 28, 30 of the prism 26. Figure 6 The normal vectors n, n1, n2 are shown. If r1, r2, r3 are the refractive indices of the materials successively passed through, l1, l2, l3 are the relevant vectors representing the path of the light beam, n1, n2 are the two normals of the optically effective surfaces 28, 30 of the prism 26, and n is the normal of the plate 12, the Snellius refraction law applies:

[0121]

[0122] In the example shown, the following applies: the material in front of the entry surface 28 is air (r1 = 1), the material between the entry surface 28 and the deflection surface 30 is the same material as the material between the deflection surface 30 and the front side 18 of the support plate 12 (r2 = r3).

[0123] Thus, The same applies If the vector b is described as b(ε), i.e. as any normalized vector which is orthogonal to the surface normal n of the plate 2, and in Figure 2 and Figure 3 corresponds to different observation directions into the plane of the drawing, the equation which depends on the target direction of the incident light l1 and the light l3 has the variable and can be solved analytically without any problems.

[0124] In the case of the second type of prism 26, the first surface normal n1 is obtained through a constant angle δ between the first optically effective surface 28 and the surface normal n of the plate 12. The vector n1 is uniquely defined by the two properties that it is orthogonal to the vector b calculated above and that it has the angle δ with the normal n of the plate 12. The light 24 is uniquely defined, independent of b or n1. The direction of the light 24 can be simply calculated from the target direction of the light beam 20 after it has left the plate 12 and the normal n of the exit surface 18 of the plate 12 by Snellius' law.

[0125] Since the surface normal n1 of the entrance surface 28 is now known (see the calculation above), the incident light 16 can also be refracted at this surface 28 according to Snellius' law and the light is obtained between the two optically effective surfaces 28 and 30.

[0126] Since the direction of the light immediately in front of the second optically effective surface 30 and the direction of the light immediately behind the second optical surface 30 are now known, the normal n2 of the second optically effective surface 30 can again be determined with Snellius' law. The second surface normal n2 is also obtained through Snellius' law.

[0127] In the first type of prism 26, the observation direction b is calculated such that the two surface normals n1, n2 can be represented as rotations of the normal vector n around the normal rotation axis. Since the surface normals n1 and n2 have a constant angle γ with respect to each other, for the angle ε of the observation direction b that has been calculated, the vector n1 is obtained by rotating the normal vector n around the vector b as the normal rotation axis through the angle μ. Likewise, the vector n2 is obtained by rotating the normal vector n around the vector b as the normal rotation axis through the angle λ + μ.

[0128] Likewise, with Snellius' law, the direction l3 of the emitted light 20 can be described in terms of the angle μ from the description of the two surface normals n1, n2 (the angle μ can still vary and represents an unknown in the equation). This equals the desired direction l3 and the equation is solved numerically or analytically again.

[0129] In the shown embodiment of the motor vehicle lamp 10 with 3D effect, thus both different types of prisms 26 can be calculated directly:

[0130] - a prism 26 whose optically effective surfaces 28, 30 have a constant angle γ with respect to each other (see Figure 2 ),

[0131] - a prism 26 whose entrance, refractive entrance surface 28 is planar and has a constant angle δ with respect to the plate 12 (see Figure 3 ).

[0132] As described above, the vector l3 is first calculated backwards by refraction at the front or top side 18 of the plate 12. In certain cases, it can be useful that the curved or arched optically effective surfaces 28, 30, which are described here as planes and which are also set as planes for the calculation, as shown in the following example.

[0133] If the 3D effect is only required in the direction x or y, for example in the horizontal direction x, it is possible to use the described method to only implement the rotation of the prisms 26 around the angle ε and to reject the tilt around the angle λ.

[0134] In order to still hit the points P_1, P_2 aimed at by each prism 26, while allowing the observer 32 to view from different directions orthogonal to the 3D direction x, at least one of the optically effective surfaces 28, 30 can not be planar, but rather a curved or arched surface, which scatters the light 24 in the direction z, in which no 3D effect is required (see Figure 4 ). A preferred embodiment of the surfaces 28, 30 is a spherical, cylindrical or toric surface.

[0135] Figure 5 A case with vertical scattering in the z direction and horizontal 3D effect in the x-y plane is shown. In the example shown, at least one of the optically effective surfaces 28, 30 of the prisms 26 is curved or arched. Here, the rotation of the individual prisms 26 around the angle ε of the rotation axis is first calculated using the method described above. The tilt around the angle λ is rejected. Then, one of the optically effective surfaces 28, 30 of each prism 26 is curved or arched. The light fan generated on the decoupled light beam 20 hits the points P_1 to be illuminated, among others. From different viewing angles of the observer 32, different positions of the point P_1 on the perpendicular line 36 are perceived vertically, i.e. in the z direction. Thus, a 3D effect is achieved in the horizontal direction, but not in the vertical direction. Therefore, for each illuminated point P_1, the prisms 26 must also only be arranged on a line on the plate 12. It is also conceivable that the prisms 26 are arranged in a manner deviating from a straight line.

[0136] In order to avoid unwanted scattering and ghosting, it can be advantageous to design the prisms 26 in such a way that as little light as possible is refracted / reflected from the side walls 34 of the prisms 26. For this purpose, the width B of the prisms 26 becomes smaller and smaller downwards, that is to say, with increasing distance A from the rear side 14 of the plate 12. Figure 7 and Figure 8 Examples of two design possibilities of the side walls 34 are shown. The surfaces 35 laterally delimiting the side faces 34 of the prisms 26 are preferably planar or arched.

[0137] The examples shown in the drawings are only partially simplified examples. In reality, the lamp 10 or the support plate 12 can have many more prisms 26 than shown and / or the 3D image can be formed by many more virtual light points P_1, P_2 than shown.

[0138] In summary, it can be said that the present invention relates to a method for configuring and / or aligning prisms 26 on a translucent base or support plate 12 which forms a lamp 10 with a 3D effect. The support plate 12 is illuminated obliquely. The prisms 26 protruding from the light-transmitting support plate 12 couple light 16 into the plate 12. Light 20 exits the plate 12 at the front side 18 and is focused at virtual points P_1, P_2 in 3D space. These focal points P_1, P_2 appear to the observer 32 as virtual light points. Within the scope of the present invention, the prisms 26 protrude from the light-transmitting support plate 12 and are rotated and / or tilted in such a way that the desired 3D effect can be achieved with a few basic prisms 26. In this case, the refractive effect of the light entry surface 28 and the reflection on the deflection surface 30 of the prisms 26 are taken into account. By means of the described mathematical equations, the prisms 26 can be formed and aligned in one step.

[0139] A further aspect of the motor vehicle lamp 10 described according to the present invention is that the prisms 26 are arranged on the rear side 14 of the support plate 12. In contrast to the optics in publications (10) - (13), in the present case more and smaller light-deflecting prisms 26 are placed on the underside or rear side 14 of the plate 12. These should pass through each of the focal points P_1, P_2 and into any desired viewing angle of the observer 32. It is proposed to arrange the prisms 26 on the plate 12 such that no overlap occurs between the individual prisms 26 and still each point P_1, P_2 to be illuminated in the 3D image is provided with each viewing angle.

[0140] The arrangement of the prisms should meet the following conditions:

[0141] - The pattern, the stripes, etc. of the image should not be visible when looking at the unilluminated plate 12. Therefore,

[0142] A regular arrangement or linear sequence in the arrangement of the prisms 26 should be avoided.

[0143] - The prisms 26 should remain simple in order to obtain good producibility or manufacturability and not have too much variety. It makes sense to define a few basic prisms 26 which are then only rotated and possibly tilted.

[0144] - The generated 3D photo should not have stripes or similar. Therefore, a regular or linear arrangement of the prisms 26, for example, in stripes, etc. should be avoided.

[0145] - In order to make the plate 12 transparent, the prisms 26 should have a regular distance from each other and not be too small.

[0146] - for each focal point P_1, P_2 to be illuminated, each necessary viewing angle of the observer 32 should be used.

[0147] - the arrangement should be such that the number of prisms 26 used for the perspective of the point P_1, P_2 to be illuminated and the observer 32 is proportional to the required intensity. The intensity results, inter alia, from the distance of the point P_1, P_2 to the plate 12, the desired or required intensity of the point P_1, P_2 and the angular resolution.

[0148] In addition to the selection of the arrangement of prisms 26, each individual prism 26 should be rotated and, if necessary, tilted appropriately in order to illuminate the selected focal point P_1, P_2. In calculating the rotation and / or tilt of the prisms 26, the refraction of the coupled light 16 on the light coupling surface 28 of the prisms 26, the reflection by the deflection surface 30 and the refraction on the light decoupling front side 18 of the plate 12 should also be taken into account, the prisms 26 also being rotated and sometimes also tilted. The calculation of the respective normals n1, n2 of the above-mentioned optically effective surfaces 28, 30 has already been described above.

[0149] In order to arrange the prisms 26 on the lower side 14 of the support plate 12, a basic pattern in the form of a grid 38 composed of cells 40 is first selected for the prisms 26 on the plate 12. Each cell 40 is essentially configured to accommodate at most one prism 26. However, deviations from this are conceivable in several cells 40. A polygon, for example a hexagon, is suitable as the shape of the cell 40. Alternatively, it is possible to select a subdivision of the support plate 12 into triangles or another topological subdivision, for example a rectangle (cf. Fig. 2). For a simpler representation, a grid 38 with rectangular cells 40 is selected in Figs. Figure 9 , Figure 9 , 11 and 12, however, this is not preferred for the above-mentioned reasons (for example, due to the possibility of forming stripes in the on and off state of the lamp 10).

[0150] The resulting cells 40 are then divided into pixels 42 (cf. Fig. Figure 9 ). The number of cells 40 in a pixel 42

[0151] - should not be too small, because light should be sent from each pixel 42 towards each focal point P_1, P_2 to be illuminated from this viewing angle.

[0152] - should not be too large, otherwise the discretization of the 3D image will be too coarse and the image will appear discontinuous to the viewer.

[0153] In the example shown, in each case, 2x2 cells 40 are combined into one pixel 42. In the drawing, the subdivision between the individual pixels 42 is indicated by stronger lines 44 than the grid lines 38 used to subdivide the individual cells 40.

[0154] From each pixel 42, it is checked which focus point P_1, P_2 of the 3D image should be illuminated, i.e. which point P_1, P_2 lies within a predetermined range of the perspective of the observer 32 (see Figure 10 and 11 ). As shown in Figure 12 , the prisms 26 of the first pixel 42.1 direct the light 20 in the direction of the first point P_1, and the prisms 26 of the second pixel 42.2 direct the light 20 in the direction of the second point P_2. At least one prism 26 of the pixel 42.3 in the overlap region directs the light 20 to the first point P_1, and at least one other prism 26 of the pixel 42.3 directs the light 20 to the second point P_2.

[0155] In this case, the angle can be observed only in one (e.g. horizontal) direction x, wherein the direction x extends parallel to the plate 12, or in two directions x, y, wherein the direction z extends orthogonal to the plate 12. Observing a single direction results in a 3D effect only in this direction (e.g. horizontal direction) x. However, in order to be able to perceive the light 20 and thus the 3D image from the extended spectrum of the other direction (e.g. vertical direction) y, the base prisms 26 can be selected which scatter the light in this direction y (see Figure 5 ). In this case, unlike Figure 10 and Figure 11 , it is sufficient that the prisms 26 which illuminate a particular point P_1, P_2 are arranged only in the pixels 42 which lie on a line. This line should extend along the direction x of the desired effect (e.g. horizontally).

[0156] On the other hand, observing in both directions x, y parallel and orthogonal to the plate 12 results in a 3D effect in both directions x, y, as shown in Figure 10 and Figure 11 . The individual prisms 26 are preferably calculated as described above. In particular, several types of base prisms 26 are defined, which are then rotated and / or tilted.

[0157] The intensity of the light 20 which should illuminate the focus point P_1, P_2 from the pixel 42 is now determined. The intensity depends on the desired intensity or brightness of the light emitting point P_1, P_2, the distance of the focus point P_1, P_2 to the pixel 42 and the intensity of the light 16 which reaches the pixel 42 or its prisms 26 from the light source 22. From the determined intensity, a plurality of prisms 26 are produced which should deflect the light 20 in the direction of the focus point P_1, P_2 (see Figure 12 ).

[0158] If the resulting number of prisms 26 is too large for a pixel 42, the calculated number of prisms 26 can be offset by prisms 26 of adjacent pixels 42 so that no focal points P_1, P_2 remain unilluminated. This means that prisms 26 of adjacent pixels 42 are provided and configured to deflect light 20 to focal points P_1, P_2 as well.

[0159] In order to avoid or reduce the striping and visible structure of the unilluminated plate 12 in the three-dimensional appearance of the 3D image, one or more of the following measures are proposed:

[0160] - a random arrangement of prisms 26 in the individual cells 40 of a pixel 42, and

[0161] - a targeted slight offset (for example in different directions and / or different amounts) of prisms 26 arranged in a specific position in a cell 40 of a pixel 42, in order to achieve a more unstructured placement of prisms 26.

[0162] In summary, it is also proposed here to place prisms 26 particularly advantageously on a light-transmissive support plate 12 of a vehicle light 10 with a 3D effect. The 3D effect is produced by the prisms 26 being arranged on the rear side 14 of the plate 12 and protruding outward from the plate 12. By illuminating the prisms 26 from the rear side 14, light 16 is deflected in such a way that focal points P_1, P_2 are produced above the plate 12 after leaving the plate 12, which appear to be arranged three-dimensionally when viewed by an observer 32 from a specific perspective area.

[0163] Due to the described placement of prisms 26 on the plate 12, the plate 12 appears almost structureless. In this case, the side 14 on which the prisms 26 are arranged is divided into cells 40, which each contain one prism 26. The cells 40 are then combined into pixels 42 depending on the position and intensity of the focal points P_1, P_2 to be illuminated.

Claims

1. Motor vehicle lamp (10), comprising - a support plate (12) made of a translucent material, having a rear side (14) through which light (16) can be coupled into the support plate (12), and an opposite front side (18) through which light (20) can be decoupled from the support plate (12), and - at least one light source (22) arranged and oriented for emitting light (16) in the direction of the rear side (14) of the support plate (12) such that at least a portion of the emitted light (16) is coupled into the support plate (12) via the rear side (14) and decoupled again via the front side (18), wherein - the at least one light source (22) is constructed and arranged relative to the support plate (12) in such a way that the light (16) emitted from the at least one light source (22) illuminates the rear side (14) of the support plate (12) over a large area and with an angle of incidence (a) of the main emission direction of the light (16) relative to a surface normal (n) of the support plate (12) of more than 45°, - a plurality of prisms or prism-like structures (26) is formed on the rear side (14) of the support plate (12), which prisms or prism-like structures (26) protrude outwardly from the rear side (14) and have an entrance surface (28) facing the at least one light source (22) and a deflection surface (30) facing away from the at least one light source (22), wherein the prisms or prism-like structures (26) are arranged and constructed in such a way that light (16) emitted from the at least one light source (22) via the entrance surface (28) can be coupled into the prisms or prism-like structures (26) and the coupled light (16) can be deflected into the support plate (12) via the deflection surface (30), - the light (24) deflected into the support plate (12) can be decoupled from the support plate (12) via the front side (18) of the support plate (12), and - the prisms or prism-like structures (26) are grouped according to an angular relationship of the entrance surface (28) and / or the deflection surface (30) of the prisms or prism-like structures (26) relative to each other and / or relative to the surface normal (n) of the support plate (12), wherein, when an observer (32) observes the front side (18) of the support plate (12) with at least one light source (22) switched on, each group of identical focal points (P_1, P_2) or focal lines produces a virtual light point (P_1, P_2), a virtual light line or a contour of a virtual object, characterized in that, in the direction of observation (b), from the side of the prisms or prism-like structures (26) transversely to the surface normal (n) of the support plate (12) and transversely to the surface normal (n1, n2) of the entrance surface (28) and the deflection surface (30), ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ The angle (γ) between the incidence surface (28) and the respective deflection surface (30) of the prisms or prism-like structures (26) of each group of prisms or prism-like structures (26) is equal in size, or The incidence surface (28) of the prisms or prism-like structures (26) of each group of prisms or prism-like structures (26) is planar and has a constant angle (δ) in each case with respect to the surface normal (n) of the support plate (12) at the respective position of the prism or prism-like structure (26) on the support plate (12), or The deflection surface (30) of the prisms or prism-like structures (26) of each group of prisms or prism-like structures (26) is planar and has a constant angle in each case with respect to the surface normal (n) of the support plate (12) at the respective position of the prism or prism-like structure (26) on the support plate (12).

2. Motor vehicle lamp (10) according to claim 1, wherein The incidence surface (28) and the deflection surface (30) of the prisms or prism-like structures (26) of a group of prisms or prism-like structures (26) are matched, aligned and / or configured in such a way that the light beams of the light (24) coupled by the incidence surface (28) and deflected at the deflection surface (30) intersect at a common focal point (P_1; P_2) or along a common focal line.

3. Motor vehicle lamp (10) according to claim 1 or 2, wherein The incidence surface (28) and the deflection surface (30) of the prisms or prism-like structures (26) are matched, aligned and / or configured in such a way that the focal point (P_1, P_2) or the focal line is located in front of, on and / or behind the front side (18) of the support plate (12) and a virtual light point (P_1, P_2), a virtual light ray or the contour of a virtual object appears to the observer (32) to be located on the focal point (P_1; P_2) or the focal line.

4. Motor vehicle lamp (10) according to any one of the preceding claims, wherein The prisms or prism-like structures (26) of a group of prisms or prism-like structures (26) each rotate about a rotation axis by a rotation angle (ε), wherein the rotation axis preferably extends parallel to the surface normal (n) of the support plate (12) at the respective position of the prism or prism-like structure (26) on the support plate (12).

5. Motor vehicle lamp (10) according to any one of the preceding claims, wherein The prisms or prism-like structures (26) of a group of prisms or prism-like structures (26) are tilted between the incidence surface (28) and the respective deflection surface (30) by a tilt angle (λ) about a tilt axis at the constant angle (γ), wherein the tilt axis preferably extends at right angles with respect to the surface normal (n) of the support plate (12) at the respective position of the prism or prism-like structure (26) on the support plate (12).

6. Motor vehicle lamp (10) according to any one of the preceding claims, wherein The incidence surface (28) and / or the deflection surface (30) of the prisms or prism-like structures (26) are planar or arched.

7. Motor vehicle lamp (10) according to claim 6, wherein The incidence surface (28) and / or the deflection surface (30) of the prism or prism-like structure (26) is curved about at least one axis which extends transversely to the surface normal (n) of the support plate (12) and parallel to the viewing direction (b).

8. Motor vehicle lamp (10) according to claim 6 or 7, wherein The prisms or prism-like structures (26) of one group of identical focal points (P_1, P_2) or focal lines are arranged on a line, preferably on a straight line.

9. Motor vehicle lamp (10) according to any one of the preceding claims, wherein The width (B) of the side face (34) of the prism or prism-like structure (26) decreases with increasing distance (A) from the rear side (14) of the support plate (12) when viewed transversely to the viewing direction (b) and transversely to the surface normal (n) of the support plate (12) and transversely to the surface normals (n1, n2) of the incidence surface (28) and the deflection surface (30).

10. Motor vehicle lamp (10) according to claim 9, wherein The surface (35) which laterally delimits the side face (34) of the prism or prism-like structure (26) is planar or arched when viewed transversely to the viewing direction (b) and transversely to the surface normal (n) of the support plate (12) and transversely to the surface normals (n1, n2) of the incidence surface (28) and the deflection surface (30).

11. Motor vehicle lamp (10) according to any one of the preceding claims, wherein The prisms or prism-like structures (26) which are adjacent to one another are arranged at a constant distance from one another on the rear side (14) of the support plate (12).

12. Motor vehicle lamp (10) according to any one of claims 1 to 10, wherein The prisms or prism-like structures (26) which are adjacent to one another are arranged on the rear side (14) of the support plate (12) with a slight deviation from the identical distance between adjacent prisms or prism-like structures (26), wherein the deviation is in the range of a maximum of 10% of the average distance of the adjacent prisms or prism-like structures (26) relative to one another.

13. Motor vehicle lamp (10) according to any one of the preceding claims, wherein The prisms or prism-like structures (26) are arranged in a regular grid structure (38) having a plurality of overlapping and / or side-by-side arranged cells (40), wherein the areas of the cells (40) of the grid structure (38) are preferably of equal size.

14. Motor vehicle lamp (10) according to any one of the preceding claims, wherein The prisms or prism-like structures (26) are arranged in a regular grid structure (38) having a plurality of overlapping and / or side-by-side arranged cells (40), wherein in one cell (40) at most one prism or prism-like structure (26), preferably exactly one prism or prism-like structure (26), is arranged, wherein in each case a plurality of cells (40) are combined to form one pixel (42), and wherein within the pixel (42) each of the prisms or prism-like structures (26) is constructed and / or arranged to illuminate a common focal point (P_1; P_2) and / or a common focal line.

15. Motor vehicle lamp (10) according to claim 14, wherein If the number of prisms or prism-like structures (26) determined from the intensity with which the focal point (P_1; P_2) is illuminated by a pixel (42) is greater than the number of the cells (40) of the pixel (42), all prisms or prism-like structures (26) of the pixel (42) are constructed and arranged for illuminating the focal point (P_1; P_2), and prisms or prism-like structures (26) of adjacent pixels (42) are used as prisms or prism-like structures (26) that cannot illuminate the focal point (P_1, P_2) with the desired intensity.

16. Motor vehicle lamp (10) according to any one of the preceding claims, wherein The prisms or prism-like structures (26) are constructed and / or arranged to always illuminate a focal point (P_1, P_2) and / or a focal line from the support plate (12) with the same angular resolution.

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