Lighting device for a motor vehicle lamp

Abstract

The invention relates to a lighting device for a motor vehicle headlight, comprising a plate-shaped transparent light guide. The light sources are arranged on the narrow edges, light enters the light guide body through the narrow edges and is transmitted to the opposite narrow edges in the first light main transmission direction, and at least part of light beams entering the front main face is completely reflected on the front main face and enters the rear main face. And the rear main surface is provided with a decoupling structure, so that at least part of the light beam irradiated to the rear main surface is emitted from the light guide body through the decoupling structure. The rear main face is provided with opposite reflecting faces, the reflecting faces enable the light beams to reverse towards the second light ray propagation direction in the direction of the light guide body, and the reversed light beams penetrate through the rear main face and the front main face and irradiate the area in front of the lighting device. The decoupling structure of the rear main face is of a structure with a concave section or a convex section extending out of the rear main face, the reflecting face is composed of sub-reflecting faces, each concave section and each convex section are opposite to one sub-reflecting face, and the sub-reflecting faces form concave structures in the normal direction of the cross section surface in the longitudinal direction of the sub-reflecting faces.

Description

Technical Field

[0001] The present invention relates to a lighting device for a motor vehicle lamp, wherein the lighting device comprises:

[0002] In particular, a plate-shaped transparent light guide, wherein the light guide is limited to two main surfaces, a front main surface and a rear main surface, which are opposite to each other, and side surfaces; one or more light sources, wherein the light sources are arranged on at least one narrow edge, wherein the light emitted by the light source enters the light guide through the narrow edge on which the light source is arranged, and propagates in the light guide essentially along the main propagation direction of the first light to the narrow edge opposite to the narrow edge through which the light from the light source enters. Background Art

[0003] Such a plate-shaped light guide can be used to construct a thin light-emitting module with high surface uniformity, which is currently used as a replacement for OLEDs (organic light-emitting diodes). Most of the known solutions are based on a thin plate equipped with LEDs (light-emitting diodes), whose light is coupled to the edge of the plate and decoupled from the plate in the required direction, usually perpendicular to the plate surface / front main face. However, in the known devices, the light decoupled from the plate is not very uniform and an additional diffusion layer is required to achieve the required OLED-like uniformity. The not very effective light decoupling method using an additional diffusion layer means that strong signal functions such as stop, turn, DRL (daytime running lights), etc. can only be realized under very difficult circumstances or only when the area of ​​the front main face or light radiation surface of the plate is large. Summary of the invention

[0004] One of the objects of the present invention is to provide a lighting device equipped with a plate-shaped light guide which is designed to be as thin as possible and has a high surface uniformity.

[0005] This object is achieved by the lighting device mentioned in the opening paragraph, wherein the front main surface is constructed so that at least a part, preferably all, of the light beams of the light rays propagating basically along the main propagation direction of the first light rays and impinging on the front main surface are completely reflected at the front main surface, so that these light beams can impinge on the rear main surface; the rear main surface has a decoupling structure, and wherein at least a part of the light beams impinging on the rear main surface and completely reflected at the front main surface are emitted from the light guide through the decoupling structure; the rear main surface is arranged opposite to the reflecting surface, and the reflecting surface is constructed so that the light beams emitted from the rear main surface and impinging on the reflecting surface are reversed by the reflecting surface in the direction of the light guide, especially basically in the propagation direction of the second light rays, and the reversed light beams pass through the rear main surface and the front main surface of the light guide and impinge on the area in front of the lighting device to form a light distribution; the decoupling structure in the rear main surface is constructed in the form of a profile depression (Profilvertiefungen) or a profile bulge extending from the rear main surface. In the form of; wherein the reflecting surface is composed of sub-reflecting surfaces, wherein each section is concave and each section is

[0006] The surface protrusions are all arranged opposite to a sub-reflecting surface; wherein the sub-reflecting surface is normally concave in its longitudinal direction in the cross-sectional surface, and in particular forms a concave structure in the reflective element.

[0007] The expression "substantially along the propagation direction of the light beam" is intended to express that the direction vectors generated by the corresponding light beams all point in this direction, but each light beam may deviate from this direction.

[0008] The first light propagation direction and the second light propagation direction are preferably orthogonal to each other.

[0009] In an advantageous embodiment of the invention, a device which is very thin in the light propagation direction can be realized, while ensuring that the front main surface emits light as uniformly as possible, through which the light coupled from the light source is emitted in the desired light propagation direction.

[0010] The rear main surface is preferably configured to consist of a plane.

[0011] In addition, it can also be arranged that one or more light sources couple light to a narrow side opposite to the narrow side through which the light passes in the light guide and is constructed as a retroreflector or has retroreflectivity, so that at least a portion of the light propagating in the light guide and irradiating the retroreflective narrow side is reflected back, especially completely reflected back into the light guide.

[0012] In this way, the light coupled into the light guide can be utilized as efficiently as possible.

[0013] All light sources can be arranged so that they are exactly on one narrow edge.

[0014] If a plurality of light sources are located on one narrow side, the light sources are preferably arranged side by side along the longitudinal extension of the narrow side, and the light sources are preferably arranged so that the main light ray emission directions of the light rays emitted from the light sources are parallel to each other.

[0015] The decoupling structure can be configured to include a first surface, in particular a first plane, which is arranged orthogonally to the second light propagation direction, and a second surface, in particular a second plane, which is not arranged orthogonally to the second light propagation direction, for example, arranged parallel to the second light propagation direction.

[0016] The cross-sectional depression or cross-sectional elevation may be arranged to extend transversely to the first light propagation direction, in particular, to extend orthogonally to the first light propagation direction.

[0017] The cross-sectional depression or cross-sectional elevation is also preferably transverse to the second light propagation direction, in particular substantially orthogonal to the second light propagation direction.

[0018] The cross-sectional depression or cross-sectional bulge preferably extends over the entire first width in its longitudinal extension, i.e., from one narrow side to the narrow side opposite to this narrow side, and / or over the entire second width extending from one narrow side to the narrow side opposite to this narrow side, and the cross-sectional depression or cross-sectional bulge is arranged in or at the plane.

[0019] The light irradiated to the cross-sectional depression and cross-sectional protrusion can be emitted from the light guide body backward through them. If the light guide body on the rear main surface is continuously configured as a plane, for example, most of the light will be completely reflected and will not be emitted from the light guide body.

[0020] In particular, it can be set to

[0021] - all the profile depressions and all the profile elevations are designed identically with respect to their height and / or their width, and / or

[0022] - all profile depressions and profile elevations have the same spacing from each other as their adjacent profile depressions and profile elevations, and / or

[0023] All profile depressions and all profile elevations run parallel to one another.

[0024] Page 3 / 9

[0025] Furthermore, each sub-reflecting surface is preferably arranged with respect to its longitudinal extension to extend within the entire longitudinal extension of the associated profile depression and profile elevation, wherein the sub-reflecting surface preferably extends in a longitudinal direction parallel to the longitudinal direction of the associated profile depression and profile elevation.

[0026] Furthermore, in a cross-sectional surface normal to the longitudinal direction of the sub-reflecting surface, the cross-sectional depression and the cross-sectional elevation are each configured in a mirror-symmetrical manner with respect to a symmetry line of the sub-reflecting surface associated therewith.

[0027] The cross-sectional depressions and cross-sectional elevations may be configured to have a rectangular, square or trapezoidal cross section.

[0028] Furthermore, the sub-reflective surface may be configured to have a parabolic shape in a cross-sectional surface.

[0029] In this way, the reflected light beams can be aligned in parallel.

[0030] Furthermore, all the partial reflection surfaces can advantageously also be provided to be designed identically in terms of their shape and / or adjacent partial reflection surfaces can be directly adjacent to one another and, for example, converge in a common edge, for example.

[0031] In addition, it can be arranged that, viewed from the main propagation direction of the second light, a transparent plate-shaped light shaping element is arranged behind the light guide, the light shaping element has a light shaping structure, the light shaping structure has a large number of facets, each of which is inclined toward the main propagation direction of the second light.

[0032] On the one hand, the light uniformity can be further improved by the light shaping element, and on the other hand, the light can be directed to a desired direction or a desired area in a targeted manner by the light shaping structure.

[0033] For example, in such a relationship, the surface vector of a facet is set to include a first horizontal inclination, for example, relative to the second main propagation direction of the second light, and a second vertical inclination, for example, wherein the inclination angles of all facets are distributed so that the horizontal inclination angle and the vertical inclination angle are each distributed around an expected value, wherein the expected value corresponds to the maximum luminous intensity of the light distribution, so that the light beam is coupled into the light forming element and / or decoupled from the light guide through the facets having the horizontal inclination angle and the vertical inclination angle corresponding to the expected value, forming the maximum luminous intensity of the light distribution, wherein the light forming structure constitutes a light entry side and / or a light exit side of the light forming element.

[0034] The facets may be arranged such that the facets are distributed substantially evenly with respect to their respective slopes on the light entry side and / or the light exit side of the light shaping element.

[0035] Furthermore, the front main surface of the light guide may be arranged as a plane which is preferably parallel to the plane of the second main surface.

[0036] For example, it can be arranged that, viewed from the main propagation direction of the second light, a transparent plate-shaped second light guide is arranged behind the light shaping element, wherein the second light guide is preferably configured so that the light beam from the reflective surface is scattered when passing through the second light guide.

[0037] In this case, it can be provided in particular that one or more further light sources, so-called second light sources, couple light into the second light guide via one or more narrow sides of the second light guide, and wherein the second light guide is constructed such that the light coupled from the one or more second light sources is scattered by the light guide and emitted from the light guide in a direction away from the reflecting surface.

[0038] A further, second light function can be implemented by means of this arrangement, for example as a design element or as a light function with less stringent requirements with regard to intensity or homogeneity, for example as a side light or tail light.

[0039] Page 4 / 9

[0040] In this case, the second light source and the (first) light source can preferably be actuated independently of each other.

[0041] The light from the first light source will also be scattered and generate diffuse light, but the target maximum value of the intensity distribution can still be achieved through the facets.

[0042] In this alternative embodiment, the invention combines a new approach to an efficient optical system for light decoupling, a crystal optical modulator and a volume scattering material. Each function can be distinguished by the lighting appearance, for example the rear of the vehicle provides a uniform lighting surface, for example when switched to stop, the same lighting device has a crystalline appearance, meeting the legal requirements for a stop signal.

[0043] An optical coupling element is preferably arranged between each light source and the light guide, wherein light emitted from a light source enters the optical coupling element associated with the light source and is thereby sent into the light guide, so that the light propagates in the light guide essentially along the main propagation direction of the first light.

[0044] Finally, the invention also relates to a motor vehicle lamp having at least one lighting device as described above.

[0045] The motor vehicle light can be designed, for example, as a motor vehicle headlight or taillight, or can be arranged in a motor vehicle headlight or a taillight. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] The present invention will be described in more detail below with reference to the accompanying drawings.

[0047] Figure 1 An oblique front perspective view of a lighting device for a motor vehicle headlight is shown;

[0048] Figure 2 Shows Figure 1 A view of a light guide used in the lighting device;

[0049] Figure 3 Shows Figure 1 A view of a reflective surface used in the lighting device;

[0050] Figure 4 A cross-sectional view of the lighting device along an ER plane in the region of the light guide and the reflective surface is shown;

[0051] Figure 5 A plan view of the entire lighting device along the ER plane is shown;

[0052] Figure 6 shows a light distribution diagram generated by a light beam from a first light source reflected by the reflector;

[0053] Figure 7 shows a light distribution diagram generated by a second light source and by light scattering on another second light guide;

[0054] Figure 8 The light distribution diagram generated by the light beam reflected by the reflector and passing through a light shaping element is shown. DETAILED DESCRIPTION

[0055] Figure 1 A lighting device 100 for a motor vehicle lamp is shown, wherein the lighting device 100 comprises a light guide 1 made of an optically transparent material, in particular a plate-shaped light guide 1, also as shown in FIG. Figure 2 As shown, the light guide 1 is limited to two opposite main surfaces, a front main surface 10 and a rear main surface 11, and side surfaces 12, 13, 14, 15. The front main surface 10 of the light guide 1 is preferably a plane, parallel to a plane 11' of the second main surface 11 (see the following description for details).

[0056] The lighting device 100 includes a plurality of light sources 2, and the light sources 2 are arranged on a narrow side 12 of the light guide 1. The light emitted by the light source 2 enters the light guide 1 through the narrow side 12, and propagates in the light guide substantially along a direction X1 to a narrow side 13 opposite to the narrow side 12 through which the light from the light source 2 enters, which is the so-called first main propagation direction X1 of the light.

[0057] As shown in the figure, an optical coupling element 3 in the form of a roughly collimated light tube is preferably arranged between each light source 2 and the light guide 1, wherein light emitted from a light source 2 enters the optical coupling element 3 corresponding to the light source 2, and enters the light guide 1 from the optical coupling element, so that the light propagates in the light guide 1 basically along the main propagation direction X1 of the first light.

[0058] On the one hand, the optical coupling element 3 captures the light emitted from the corresponding light source 2 as completely as possible, but on the other hand, the light is arranged along the first light propagation direction X1, so that the light beam may be irradiated onto the front main surface and the rear main surface 10, 11 when propagating in the light guide 1, wherein at least part, preferably most or all of the incoming light beam is completely reflected on the front main surface 10.

[0059] The light sources 2 are preferably arranged adjacent to each other along a longitudinal extension of the narrow side 12 , wherein the light sources 2 are arranged in such a manner that the main light propagation directions of the light emitted from the light sources 2 are parallel to each other.

[0060] As described above, the construction or arrangement or geometric relationship of the front main surface 10 is such that, among the light beam S1 that enters the front main surface 10 and propagates basically along the main propagation direction X1 of the first light ray (or preferably also along the direction opposite to the main propagation direction of the first light ray, as described below for details), at least a part, preferably all, of the light beam S1 is completely reflected on the front main surface 10 and can enter the rear main surface 11 (light beam S1'), wherein the rear main surface 11 has a decoupling structure 111, so that at least a part of the light beam S1' that is completely reflected on the front main surface 10 and irradiated on the rear main surface 11 is emitted from the light guide 1 through the decoupling structure 111.

[0061] The lighting device 100 also includes a reflecting surface 40 opposite to the rear main surface 11. The reflecting surface 40 is constructed in such a way that a light beam S1″ emitted from the rear main surface 11 through the decoupling structure 111 and irradiated on the reflecting surface 40 is reversed by the reflecting surface 40 along the direction of the light guide 1, especially basically toward the second light propagation direction X2. The reversed light beam S1″ passes through the rear main surface 11 and the front main surface 10 of the light guide 1, and irradiates an area in front of the lighting device 100 to form a light distribution LV.

[0062] In addition, a light beam that propagates along the main propagation direction X1 of the first light ray (or preferably also in the direction opposite to this direction, as described below) and is not completely reflected on the front main surface 10 in advance and is directly irradiated onto the rear main surface 11 can also be emitted from the light guide 1 and reflected on the reflecting surface 40 along the main propagation direction X2 of the second light ray when necessary, thereby helping to form a light distribution LV.

[0063] like Figure 1 and 2 As shown, the narrow edge 13 opposite to the narrow edge 12 through which the light from the light source 2 is coupled to the light guide 1 is advantageously constructed as a retroreflector 13' or has retroreflectivity, so that at least a portion of the light propagating in the light guide 1 and irradiating the retroreflective narrow edge 13 is reflected back into the light guide 1, so that it can be utilized when it is emitted from the light guide 1 through the rear main surface 10 and reflected by the reflecting surface 40 along the second light propagation direction X2.

[0064] Figure 6 The light distribution diagram generated by the light reflected only by the reflecting surface 40 is shown.

[0065] Page 6 / 9

[0066] As especially Figure 4 As shown, the decoupling structure 111 of the rear main surface 11 has a profile elevation 11 ″ protruding from the rear main surface 11 . In the example shown, as described above, the rear main surface 11 is designed as a plane 11 ′, from which the profile elevation 11 ″ protrudes.

[0067] like Figure 3 As shown, the reflecting surface 40 is preferably constructed on a reflecting element or reflector 4. The reflecting surface 40 is composed of sub-reflecting surfaces 41, and each cross-sectional protrusion 11" has an opposite sub-reflecting surface 41.

[0068] The reflective surface 40 is preferably a specular reflector, such as a metallized reflector.

[0069] like Figure 4 As shown, the sub-reflection surface 41 is, for example, on a cross-sectional surface E extending in a particularly vertical direction. R In its longitudinal direction R R The upper normal forms a concave structure, especially a concave structure in the reflective element 4 .

[0070] The reflective surface 40, especially the sub-reflective surface 41, is constructed in such a way that the light irradiated thereon is reflected along the second main light propagation direction X2. The second main light propagation direction X2 is, for example, orthogonal to the plane 11' of the rear main surface 11 and / or orthogonal to the first main light propagation direction X1.

[0071] The light reflected from the sub-reflection surface 41 may accordingly enter the light guide 1 through the plane 11 ′ of the rear main surface 11 , and propagate through the light guide to the front main surface 10 without deflection in the propagation direction, where it is emitted from the light guide 1 again.

[0072] The decoupling structure 111 can be configured to have a first plane 111″ and a second surface, wherein the first plane is arranged orthogonally to the second light propagation direction X2, and the second surface, especially the second plane 111″ (side), is not arranged orthogonally to the second light propagation direction X2, for example, is arranged parallel to the second light propagation direction X2.

[0073] In the example shown, the profile ridge 11″ is specifically configured to have a rectangular or square cross section.

[0074] The preferred design is that the light is irradiated only onto the side surfaces of each reflector 41, and not onto a reflector surface opposite to the first plane 111" of the cross-sectional ridge 11". This is achieved by designing the light to be mainly or preferably only decoupled at the side surfaces (second surface 111"') of the cross-sectional ridge 11", so that it is guided in parallel by the reflector 41, which is particularly parabolic.

[0075] like( Figure 2 ), the cross-sectional ridge 11" is, for example, transverse to the first light propagation direction X1, and in particular is orthogonal to the first light propagation direction X1. In addition, the cross-sectional depression or cross-sectional ridge is also preferably transverse to the second light propagation direction X2, and in particular is substantially orthogonal to the second light propagation direction.

[0076] The longitudinal extension of the cross-sectional ridge 11″ preferably extends over the entire first width b1 of the light guide 1, that is, extends from one narrow side 14 to another narrow side 15 opposite to the narrow side 14. In addition, it is also preferably arranged over the entire second width (or height) b2 extending from a narrow side 12 with the light source 2 to another narrow side 13 opposite to the narrow side 12.

[0077] As described above, the light irradiated onto the cross-sectional protrusions 11″ can be emitted from the light guide body backward through them. If the light guide body 1 on the rear main surface is continuously configured as, for example, a plane, most of the light will be completely reflected and will not be emitted from the light guide body 1.

[0078] Page 7 / 9

[0079] Furthermore, all the cross-sectional ridges 11" are preferably arranged to have the same structure in terms of height hP and / or width bP. The cross-sectional ridges preferably have the same spacing AP with respect to adjacent cross-sectional ridges. In particular, all cross-sectional ridges are parallel to each other. (See Figure 4 )

[0080] from Figure 3It can be seen from the above that the sub-reflecting surfaces 41 are advantageously arranged such that each sub-reflecting surface 41 extends in the entire longitudinal extension range of the corresponding cross-sectional protrusion 11″ in terms of longitudinal extension, and each sub-reflecting surface 41 is preferably arranged along the longitudinal direction R R Parallel to the longitudinal direction R of the corresponding cross-sectional ridge 41 P .

[0081] Furthermore, the profile ridge 11" is preferably configured to be formed on the cross-sectional surface E R In the longitudinal direction R of the sub-reflection surface 41 R The symmetry line G of the corresponding sub-reflection surface 41 is PR ( Figure 4 )Normal mirror symmetry.

[0082] The sub-reflecting surface 41 itself is located on the cross-sectional surface E R (i.e., the sub-reflection surface 41 and the cross-sectional surface E R The intersection curve produced by the intersection) is relative to a line on the cross-sectional surface E R At point P R A symmetry line G intersecting the sub-reflection surface 41 and intersecting the normal of the intersection curve PR Mirror symmetry.

[0083] The sub-reflecting surface 41 is preferably arranged on the cross-sectional surface E R It has a parabolic shape. This allows the reflected light beams to be aligned in parallel.

[0084] Similar to the profile bulge 11 ″, all sub-reflection surfaces 41 are advantageously provided in the same shape, and adjacent sub-reflection surfaces 41 are preferably directly adjacent to each other or respectively converge in, for example, a common edge.

[0085] like Figure 1 and especially Figure 5 As shown, it can also be arranged that, viewed from the main propagation direction X2 of the second light, another transparent plate-shaped light shaping element 5 ("additional first light shaping element") is arranged behind the light guide 1, and the shaping element has a light shaping structure, which has a large number of facets 50, each of which is inclined toward the main propagation direction X2 of the second light.

[0086] On the one hand, the light uniformity can be further improved by the light shaping element, and on the other hand, the light can be directed to a desired direction or a desired area in a targeted manner by the light shaping structure. Figure 8 The light distribution diagram is shown after the light from the reflective surface 40 passes through the additional first light shaping element 5. It can be seen that a maximum value is maintained in the light distribution, but the angle range of the light emission is larger.

[0087] Each facet 50 refers to, for example, a (transparent) plane, and the surface vector of the facet includes a first horizontal inclination angle, for example relative to the second main propagation direction X2 of the second light, and a second vertical inclination angle, for example, wherein the distribution of the inclination angles of all facets achieves the following effect: the horizontal inclination angle and the vertical inclination angle or the values ​​of the inclination angles can be set to be distributed around an expected value, and the expected value corresponds to the maximum luminous intensity of the light distribution LV, so that the light beam is coupled to the light forming element 5 and / or decoupled from the light guide through the facet having a horizontal inclination angle and a vertical inclination angle consistent with the expected value, forming the maximum luminous intensity of the light distribution, and the light forming structure constitutes a light entry side and / or a light exit side of the light forming element 5.

[0088] The facets may be arranged to be substantially uniformly distributed on the light entry side and / or the light exit side of the light shaping element 5 with respect to respective inclination angles.

[0089] Page 8 / 9

[0090] The light shaping element 5 can be used to modulate the incident collimated light from the reflective surface into a desired light distribution, for example, for a stop light function or a turn light function.

[0091] In addition, it can also be arranged that, viewed from the main propagation direction X2 of the second light ray, a transparent plate-shaped second light guide 6 ("additional second light guide") is arranged behind the light forming element 5, wherein the second light guide 6 is preferably constructed in such a way that the light beam from the reflecting surface 40 (and the light beam passing through the light guide 5) is scattered when passing through the second light guide 6.

[0092] In this case, it can be provided in particular that one or more other light sources, so-called second light sources 62, couple light into the second light guide 6 via one or more narrow sides of the second light guide 6, and the second light guide 6 is constructed in such a way that the light coupled from the one or more second light sources 62 is scattered by the light guide 6, in particular strongly scattered, and is emitted from the light guide 6 in a direction away from the reflecting surface 40. In this case, the second light guide 6 has an optical system with a scattering element, in particular a volume element, or a scattering, for example rough surface.

[0093] The light from the reflecting surface 40 will also be (slightly) scattered by the second light guide 6, while the light from the light source 62 of the second light guide 62 will be strongly scattered, thereby causing the light source 62 to produce a luminous surface.

[0094] The lighting device can thus be used, for example, as a design element or for generating (additional) light functions that do not make high demands on intensity or homogeneity, such as side lights or tail lights.

[0095] The light from the reflecting surface 40 will also be scattered, but the target maximum value of the intensity distribution can be achieved through the previous shaping of the light shaping element 5 .

[0096] A further, second light function can be implemented by means of this arrangement, for example as a design element or as a light function with less stringent requirements with regard to intensity or homogeneity, for example as a side light or tail light.

[0097] In this case, the second light source and the (first) light source can preferably be actuated independently of each other.

[0098] The light from the first light source will also be scattered and generate diffuse light, but the target maximum value of the intensity distribution can still be achieved through the facets and the reflector that guides the light beam in parallel.

[0099] In this alternative embodiment, the invention combines a new approach to an efficient optical system for light decoupling, a crystal optical modulator and a volume scattering material. Each function can be distinguished by the lighting appearance, for example the rear of the vehicle provides a uniform lighting surface, for example when switched to stop, the same lighting device has a crystalline appearance, meeting the legal requirements for a stop signal.

[0100] The light guide 1 and the two additional light guides 5, 6 are approximately or exactly the same in terms of their first width (width b1 of the light guide 1) and their second width or height (second width b2 of the light guide 1), and are arranged in such a way that the light radiating surfaces are parallel to each other. In addition, the light guides 1, 5, 6 are arranged in such a way that they overlap each other. The distance between adjacent light guides 1, 5, 6 can be greater than zero, or they can be directly adjacent to each other.

[0101] In an advantageous embodiment of the invention, a device which is very thin in the light propagation direction can be realized, while ensuring that the front main surface emits light as uniformly as possible, through which the light coupled from the light source is emitted in the desired light propagation direction.

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[0103] As shown in the figure, in a specific design, at least two lighting functions can be generated, such as a tail light or stop light function and a turn signal. The amount of light can be increased by using light sources on multiple narrow sides of a light guide 1, 6, or by using light sources of different colors on different narrow sides, so that different lighting functions can be achieved through a light guide.

[0104] An ultra-thin lighting device can be realized by the present invention.

Claims

1. A lighting device (100) for a motor vehicle lamp, wherein the lighting device (100) comprises: In particular, the transparent light guide (1) is in the form of a plate, the light guide (1) being limited to two main surfaces, a front main surface (10) and a rear main surface (11), which are opposite to each other, and side surfaces (12, 13, 14, 15). One or more light sources (2), the light sources (2) being arranged on at least one narrow side (12), wherein the light emitted by the light source (2) enters the light guide (1) through the narrow side (12) on which the light source (2) is arranged, and propagates in the light guide (1) substantially along a first light main propagation direction (X1) to a narrow side (13) opposite to the narrow side (12) through which the light from the light source (2) enters, The front main surface (10) is configured so that at least part, preferably all, of the light beams (S1) of the light rays propagating substantially along the main propagation direction (X1) of the first light rays and impinging on the front main surface (10) are completely reflected at the front main surface (10), so that these light beams can impinge on the rear main surface (11), and The rear main surface (11) has a decoupling structure (111), and at least a portion of the light beam (S1') that is completely reflected at the front main surface (10) and irradiated on the rear main surface (11) is emitted from the light guide (1) through the decoupling structure (111). And wherein the rear main surface (11) and the reflecting surface (40) are arranged opposite to each other, The reflecting surface (40) is configured such that a light beam (S1") emitted from the rear main surface (11) and irradiated on the reflecting surface (40) is reversed by the reflecting surface (40) along the direction of the light guide (1), in particular substantially along the second light propagation direction (X2), and the reversed light beam (S1"') passes through the rear main surface (11) and the front main surface (10) of the light guide (1) and irradiates the area in front of the lighting device (100) to form a light distribution (LV), wherein The decoupling structure (111) in the rear main surface (11) is configured in the form of a cross-sectional depression, or in the form of a cross-sectional protrusion (11") extending from the rear main surface (11), wherein The reflecting surface (40) is composed of sub-reflecting surfaces (41), wherein each cross-sectional depression and each cross-sectional protrusion (11") is opposite to a sub-reflecting surface (41), and Wherein, the sub-reflecting surface (41) has a cross-sectional surface (E R ) in its longitudinal direction (R R ) is normally concavely constructed, in particular a concave structure is formed in the reflective element (4).

2. The lighting device (100) according to claim 1, wherein: The rear main surface (11) is formed by a plane (11'), and / or the front main surface (10) of the light guide (1) is a plane, which preferably runs parallel to the plane or a plane (11') of the second main surface (11).

3. The lighting device according to claim 1 or 2, wherein: One or more light sources (2) couple light into a narrow side of the light guide (1) opposite to the narrow side (12) passing through the light guide (1) (13) is constructed as a retroreflector (13') or has retroreflectivity, so that at least a portion of the light propagating in the light guide (1) and irradiating the retroreflective narrow edge (13) is reflected back, in particular completely, into the light guide (1).

4. A lighting device according to any one of the preceding claims, wherein: All light sources (2) are arranged exactly on one narrow side (12), wherein, for example, when a plurality of light sources (2) are arranged side by side along the longitudinal extension of one narrow side (12), the light sources (2) are preferably arranged such that the main light ray emission directions of the light rays emitted from the light sources (2) are parallel to each other.

5. A lighting device according to any one of the preceding claims, wherein: The decoupling structure (111) comprises a first surface, in particular a first plane (111"), which is arranged orthogonally to the second light propagation direction (X2), and comprises a second surface, in particular a second plane (111"), which is not arranged orthogonally to the second light propagation direction (X2), for example, is arranged parallel to the second light propagation direction (X2).

6. A lighting device according to any one of the preceding claims, wherein: The cross-sectional depression or cross-sectional elevation (11") runs transversely to the first light propagation direction (X1), in particular, runs orthogonally to the first light propagation direction (X1).

7. A lighting device according to any one of the preceding claims, wherein: The profile depression or profile bulge (11") extends in its longitudinal extension over the entire first width (b1), i.e., from a narrow side (14) to a narrow side (15) opposite to the narrow side (14), and / or over the entire second width (b2) from a narrow side (12) to a narrow side (13) opposite to the narrow side (12), and the profile depression or profile bulge (11') is arranged in the plane (11') or at the plane (11').

8. A lighting device according to any one of the preceding claims, wherein: - all the profile depressions and all the profile elevations are designed identically with respect to their height and / or their width, and / or - all profile depressions and profile elevations have the same spacing from each other as their adjacent profile depressions and profile elevations, and / or All profile depressions and all profile elevations run parallel to one another.

9. A lighting device according to any one of the preceding claims, wherein: Each sub-reflection surface (41) extends in its longitudinal extension over the entire longitudinal extension of the associated profile depression and profile elevation, and wherein the sub-reflection surface (41) is preferably arranged along the longitudinal direction (R R ) is parallel to the longitudinal direction of the associated profile depression and profile protrusion (R P ) direction.

10. A lighting device according to any one of the preceding claims, wherein: In the longitudinal direction (R R ) of the cross-sectional surface (E R ), the cross-sectional depression and the cross-sectional protrusion are each symmetrically aligned with the sub-reflection surface (41) associated therewith. PR ) is constructed in a mirror-symmetrical manner.

11. A lighting device according to any one of the preceding claims, wherein: The profile depression and profile elevation (11") have a rectangular, square or trapezoidal cross section.

12. A lighting device according to any one of the preceding claims, wherein: The sub-reflecting surface (41) is disposed on the cross-sectional surface (E R ) has a parabolic shape.

13. A lighting device according to any one of the preceding claims, wherein: All partial reflection surfaces (41) are designed identically in terms of their shape and / or adjacent partial reflection surfaces (41) are directly adjacent to one another and converge in a common edge, for example.

14. A lighting device according to any one of the preceding claims, wherein: Viewed from the main propagation direction (X2) of the second light, a transparent plate-shaped light shaping element (5) is arranged behind the light guide (1), the light shaping element having a light shaping structure, the light shaping structure having a large number of facets (50), each of the facets being inclined toward the main propagation direction (X2) of the second light, wherein - the surface vector of a facet preferably comprises a first horizontal inclination, for example relative to the second main propagation direction of light (X2), and a second vertical inclination, for example, wherein the inclinations of all facets are distributed in such a way that the horizontal inclination and the vertical inclination are each distributed around an expected value, wherein the expected value corresponds to the maximum luminous intensity of the light distribution (LV), so that the light beam is coupled into the light shaping element (5) and / or decoupled from the light guide through the facets having the horizontal inclination and the vertical inclination corresponding to the expected value, forming the maximum luminous intensity of the light distribution, wherein the light shaping structure constitutes a light entry side and / or a light exit side of the light shaping element (5), and / or The facets are preferably arranged in such a way that they are distributed substantially evenly with respect to their respective inclinations on the light entry side and / or light exit side of the light shaping element (5).

15. A lighting device according to any one of the preceding claims, wherein: When viewed from the main propagation direction (X2) of the second light beam, a transparent plate-shaped second light guide (6) is arranged behind the light shaping element (5), wherein the second light guide (6) is preferably configured such that the light beam from the reflecting surface (40) is scattered when passing through the second light guide (6), wherein, for example, one or more additional light sources, so-called second light sources (62), can be provided, which couple light into the second light guide (6) through one or more narrow sides of the second light guide (6), and wherein the second light guide (6) is configured such that the light beam coupled from the one or more second light sources (62) is scattered. The combined light is scattered by the light guide (6) and emitted from the light guide (6) in a direction away from the reflecting surface (40).

16. A lighting device according to any one of the preceding claims, wherein: An optical coupling element (3) is arranged between each light source (2) and the light guide (1), wherein light emitted from a light source (2) enters the optical coupling element (3) associated with the light source (2) and is thereby sent into the light guide (1), so that the light propagates in the light guide (1) substantially along the main propagation direction (X1) of the first light.

17. A motor vehicle light having at least one lighting device (100) according to any one of the preceding claims, wherein: The motor vehicle light is designed, for example, as a motor vehicle headlight or taillight, or is arranged in a motor vehicle headlight or a taillight.

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