Illumination device for a vehicle headlight as well as vehicle headlights

Description

[0001] The invention relates to a lighting device for a motor vehicle headlight for generating a light distribution with a light-dark boundary, comprising the features of the preamble of claim 1. Such lighting devices are known from EP 4053447 A1 and DE 11 2021 004 426 T5.

[0002] Furthermore, the invention relates to a motor vehicle headlight with at least one such lighting device.

[0003] Lighting devices described above are known from the prior art, in which, by modifying the translucent body, the light coupling element or the projection device, a signlight light distribution can be generated in addition to a front or low beam light distribution with at least one light source.

[0004] These modifications are often such that the part of the light emitted by the light source which, without modification, either remains unused or contributes to the front or low beam distribution, and which is used to generate the signlight light distribution, exits the translucent body before it is projected as the signlight light distribution via the projection device – either directly or after re-entering the translucent body.

[0005] However, it has been found that the light emanating from the translucent body is difficult to control and often leads to scattered light, which can cause undesirable optical effects.

[0006] It is an object of the invention to provide a lighting device with which, in addition to a front-end or low-beam light distribution, a signlight light distribution can be generated and in which the aforementioned disadvantages do not occur.

[0007] This problem is solved with a lighting device having the characterizing features of claim 1.

[0008] In contrast to existing solutions where an optical path is generated outside the light-guiding body, the invention for generating the signlight realizes an optical path exclusively within the light-guiding body, so that the problems of the prior art described above, such as uncontrollable stray light, which for example leads to excessive light in the area of ​​the HV line, can be avoided.

[0009] The signlight light distribution can be easily controlled without negatively affecting the front or low beam light distribution.

[0010] The use of three totally reflective areas, which realize the optical path of the light rays that Signlight generates, also allows the generated Signlight light distribution to be optimally adapted to the desired requirements by coordinating these three areas with each other, for example with regard to their distance, dimensions (size), shape, inclinations, etc.

[0011] Advantageous embodiments of the invention are described in the dependent claims. It can be provided that the first deflection structure comprises a deflection surface or is designed in the form of a deflection surface, wherein, for example, the deflection surface is designed as a flat surface or as a concavely curved surface.

[0012] A concave curvature can, for example, be used to generate a parallel beam that hits the second deflection structure on the upper boundary surface in a uniformly distributed manner, thus enabling better control of the intensities.

[0013] Furthermore, it may be provided that the second deflection structure is designed as a surface, in particular as a flat surface.

[0014] This allows, for example, a simple design, since only the surface inclination needs to be designed; the light pre-shaping and quantity of light are ensured by the first deflection structure.

[0015] It may be provided that the first surface area of ​​the first lower surface forms a straight intersection curve in vertical sections.

[0016] Furthermore, it can be provided that the first surface area of ​​the first lower surface forms curved intersection curves, in particular convex intersection curves, in horizontal sections.

[0017] Preferably, these convex intersection curves follow a Petzval surface or focal surface of the projection device.

[0018] Horizontal intersection curves are obtained by intersecting the respective surface with horizontal planes, vertical intersection curves are obtained by intersecting the respective surface with vertical planes that run parallel to or contain the optical axis of the lighting device or the projection device.

[0019] Preferably, the first surface area is provided to be a boundary surface of a depression in the first lower boundary surface.

[0020] Below the first surface area, a third surface area of ​​the first boundary surface adjoins it. Due to the formation of a depression, this second surface area is positioned in such a way that no light from the second deflecting structure reaches it. By using at least one surface area that reflects light towards the projection device, it becomes easier to control the generation of the sign light distribution.

[0021] Furthermore, it can be advantageous to provide that the first area is spaced away from the second boundary surface and that a further, second area of ​​the first boundary surface is arranged between the first area and the second boundary surface, which connects the first area with the second boundary surface.

[0022] In this context, it may also be provided that the second surface area is arranged and designed in such a way that no light from the second deflecting structure reaches the second surface area.

[0023] With this second surface area, which for example forms a strip between the first surface area and the second boundary surface, a dark stripe can be realized in the light image, between the light-dark boundary of the front or low beam distribution and the lower boundary of the signlight light distribution.

[0024] Furthermore, it may be provided that the second deflection structure is formed by a depression in the upper boundary surface.

[0025] This depression is formed by the, preferably flat, surface and possibly by a further boundary surface or further boundary surfaces which are / are facing away from the light source and onto which light usually does not strike or which have / have no function in terms of lighting technology.

[0026] Furthermore, it may be provided that the aperture edge lies in or substantially in the Petzval surface or a focal surface of the projection device.

[0027] Finally, it can be advantageous to provide that at least one light coupling element, the translucent body and the projection device are formed in one piece from a translucent material and together form a single body.

[0028] The light distribution with a light-dark boundary is preferably a front-area light distribution or a low-beam light distribution.

[0029] The invention is discussed in more detail below with reference to the drawing. This drawing shows Fig. 1 A lighting device for a motor vehicle headlight according to the state of the art in a perspective view from a rear oblique angle, Fig. 1a the lighting device Figure 1 in a vertical section and an exemplary ray path of the light rays emitted by a light source, Fig. 2 a lighting device according to the invention in a side view, Fig. 2a the lighting device Figure 2 in a top view Fig. 2b the lighting device Figure 2 in a perspective view from a slightly elevated angle, Fig. 2c the lighting device Figure 2 in a perspective view from a low angle, Fig. 3 a section through the lighting device according to plane BB from Figure 2a with the schematic representation of a ray path, Fig. 3a the cut from Figure 3with the schematic representation of a further ray path, Fig. 3b a vertical section in the area of ​​the aperture device, Fig. 4 a perspective view of the lighting device Figure 2 in the area of ​​the light coupling element with a first deflection structure, Fig. 4a a perspective view of the lighting device Figure 2 in the area of ​​a second deflection structure, Fig. 4b a perspective view of the entire lighting device, Fig. 4c a perspective view of the lighting device Figure 2 with a focus on the aperture device, Fig. 5 schematically a front light distribution and relevant points of a signlight light distribution, and Fig. 6 a simulation of a low-beam light distribution and signlight light distribution generated with a lighting device according to the invention.

[0030] Figure 1 and 1aWe first show a lighting device 1 for a motor vehicle headlight according to the prior art for generating a light distribution LV with a light-dark boundary HDG. This light distribution is, for example, a front-beam or low-beam distribution.

[0031] The invention is based on such a known lighting device 1 from the prior art; therefore, corresponding technical features of the lighting device according to the prior art and the lighting device according to the invention are characterized by identical reference numerals.

[0032] The lighting device 1 comprises a translucent body 100, a light coupling element 101, and a light source 10 associated with the at least one light coupling element 101. The light emitted by the light source 10 is coupled into the translucent body 100 by the light coupling element 101 and propagates towards a projection device 200 of the lighting device 1.

[0033] For example, light source 10 consists of one or more LEDs, or light source 10 comprises one or more LEDs.

[0034] The projection device 200 is located, for example, opposite the light coupling element 101.

[0035] The light coupling element 101 is designed to couple at least a part of the light emitted by the light source 10 into the translucent body 100 in such a way that it propagates as the first light beam S1 to the projection device 200.

[0036] The translucent body 100 has a diaphragm device 103 with a diaphragm edge 104, wherein the diaphragm edge 104 is arranged between the light coupling element 101 and the projection device 200 when viewed in the direction of light propagation X1.

[0037] The first light beam S1 is modified by the aperture edge 104 into a second light beam S2, which second light beam S2 is imaged by the projection device 200 as the light distribution LV with a light-dark boundary HDG. The light-dark boundary HDG, in particular its shape, is determined by the aperture edge 104.

[0038] The light rays of the light beam S2 are modified by the projection device 200 to light beam S2'.

[0039] The aperture edge 104 is formed by a first lower boundary surface 105 and a second lower boundary surface 106 of the translucent body 100, which are opposite an upper boundary surface 107, by the lower boundary surfaces 105, 106 converging in a common edge, the aperture edge 104.

[0040] The aperture edge 104 lies in or essentially in the Petzval surface or a focal surface of the projection device 200.

[0041] It is preferably provided that the light coupling element 101 shapes the light emitted by the light source and coupled into the light coupling element into the first light beam, wherein preferably the light beam is directed into an area, in particular into an area above, preferably just above, the aperture edge.

[0042] It is possible, particularly in the case of the lighting device according to the invention, to deviate from the schematic representation of the Figure 1 It is provided that the aperture edge is curved in the horizontal direction, in particular concavely curved, and that the aperture edge preferably follows the focal line of the projection device, wherein the aperture edge preferably lies in or approximately in the Petzval surface of the projection device.

[0043] Regarding the statement that the aperture edge lies within the Petzval surface, it should be noted that, strictly speaking, the relationships are as follows: the projection device has a focal point F200, which lies on the optical axis X of the projection device 200. The Petzval surface, or focal point surface, contains this focal point F200, just as a focal line passes through this focal point and lies within the Petzval surface.

[0044] The aperture edge 104 - fundamentally independent of whether it is a straight aperture edge as in Figure 1 Whether the edge shown is curved, e.g., as described above, it is not usually located exactly on the Petzval surface or at the focal point F200, but rather at a (slight) distance above the focal point F200. Typically, the light-dark boundary (HDG) in the image is lowered slightly below the horizontal 0°-0° line or below the horizon, usually by 0.573°. To achieve this in the image, the aperture edge 104 is positioned slightly above the optical axis X of the projection device 200, or above the focal point F200, in the vertical direction – in practice, usually by a few tenths of a millimeter.

[0045] Preferably, the light coupling element 101, the light-transmitting body 100 and the projection device 200 are formed in one piece from a light-transmitting material and together form a body 1000.

[0046] Starting from such a lighting device 1, it is now possible, as described in the Figure 2, 2a- 2c , 3, 3a, 3b and 4, 4a - 4c As shown in more detail below, in a lighting device 1 according to the invention, the light coupling element 101 has a first deflecting structure 101a, which is designed such that light from the light source 10, which enters the light coupling element 101 and strikes the deflecting structure 101a, is totally reflected such that the totally reflected light S3 is directed onto a second deflecting structure 107a. The second deflecting structure 107a is arranged on the upper boundary surface 107 of the light-guiding body 100, opposite the lower boundary surfaces 105, 106.

[0047] Preferably, the light coupling element 101, the light-guiding body 100, and the projection device 200 form a continuous, one-piece body 1000. The transparent, light-transmitting material from which the individual elements, or in the case of the one-piece body 1000, this body 1000, can be formed, has a refractive index greater than that of air. The material contains, for example, PMMA (polymethyl methacrylate) or PC (polycarbonate) and is particularly preferably formed from these materials. However, the bodies can also be made of glass material, in particular inorganic glass material.

[0048] Figure 3 This again shows a ray path analogous to Figure 1a , i.e., the path of light rays that form the light distribution with a light-dark boundary (HDG). According to the invention, how this is achieved Figure 3ashows that a portion of the light rays emitted by the light source 10 and entering the light coupling element 101 is used to form a signlight light distribution SV.

[0049] The second deflecting structure 107a is designed such that the light S3 incident on it strikes a first surface area 105a of the first lower boundary surface 105. The first lower boundary surface 105 is the boundary surface which, viewed in the direction of light propagation, is located after the second boundary surface 106, or the aperture edge 104.

[0050] The second deflecting structure 107a deflects the incident light rays S3 as a fourth light beam S4 (or the incident light rays S3 are totally reflected at the deflecting structure 107a).

[0051] The surface area 105a deflects the incident light as a fifth light beam S5 into an area 200a of the projection device 200, specifically into an area 200a at the light-refracting light exit surface 201 of the projection device, which area 200a maps the light of the fifth light beam S5 as a signlight light beam S6 into an area B of the light distribution lying above the light-dark boundary HDG as an additional light distribution, namely as a signlight light distribution SV.

[0052] The first deflection structure 101a is preferably designed in the form of a deflection surface, as shown, wherein the deflection surface is, for example, a flat surface or preferably, as shown, a concave curved surface.

[0053] A concave curvature can, for example, be used to generate a parallel beam beam which strikes the second deflection structure 107a at the upper boundary surface 107 in a uniformly distributed manner, thereby enabling better control of the intensities.

[0054] Following the second deflection structure 101a, a region 101b adjoins the light-guiding body 100, which is optically ineffective. Preferably, this region 101b is inclined to the deflection structure 101a such that the light rays S3 deflected by the first deflection structure 101a, in particular totally reflected light rays, can propagate unhindered towards the second deflection structure 107a.

[0055] The second deflection structure 107a is preferably designed as a surface, in particular as a planar surface.

[0056] For example, the second deflection structure 107a is formed by a recess 117 in the upper boundary surface 107. This recess 117 is formed by the, preferably flat, surface 107a and optionally by a further boundary surface or further boundary surfaces which are / are facing away from the light source 10 and onto which light does not usually strike or which have no function in terms of lighting technology.

[0057] The first surface area 105a of the first lower surface 105 is preferably, as is particularly evident in Figure 4c It can be clearly seen that it is designed in such a way that in vertical sections through the light-guiding body 100 in the area of ​​the lower surface 105, intersection curves 105a' result which are straight.

[0058] Furthermore, it can be provided that the first surface area 105a of the first lower surface 105 forms curved intersection curves, in particular convex intersection curves, in horizontal sections. Preferably, these convex intersection curves follow a Petzval surface or focal surface of the projection device.

[0059] Horizontal intersection curves are obtained by intersecting the respective surface with horizontal planes, vertical intersection curves are obtained by intersecting the respective surface with vertical planes that run parallel to or contain the optical axis of the lighting device or the projection device.

[0060] The first surface area 105a forms a boundary surface of a recess 115 in the first lower boundary surface 105. A third surface area 105c of the first boundary surface 105 adjoins the first surface area 105a below it. Due to the formation of a recess 115, this second surface area 105c is positioned such that no light from the second deflecting structure 107a reaches it. By using only one surface area 105a, which reflects light towards the projection device, it becomes easier to control the generation of the signlight light distribution.

[0061] Furthermore, it can be advantageous to provide that the first surface area 105a is spaced apart from the second boundary surface 106, and that a further, second surface area 105b of the first boundary surface 105 is arranged between the first surface area 105a and the second boundary surface 106, connecting the first surface area 105a with the second boundary surface 106. In this context, it is advantageous if the second surface area 105b is arranged and designed in such a way that no light from the second deflecting structure 107a reaches the second surface area 105b.

[0062] With this second surface area 105b, which for example forms a strip between the first surface area 105a and the second boundary surface 106, a dark strip BAN can be realized in the light image, between the light-dark boundary of the front or low beam distribution and the lower boundary of the signlight light distribution.

[0063] Figure 5 shows a light distribution LV in the form of a schematic pre-light distribution with a light-dark boundary HDG, as can be achieved, for example, with a lighting device according to Figure 1 , but can also be generated with a lighting device 1 according to the present invention. Figure 5 further shows an area B in which a signlight light distribution SV is to be generated, as well as relevant measuring points for which - in this case according to the corresponding ECE regulation - defined illuminance values ​​must be maintained.

[0064] Figure 6 The diagram shows a light distribution SV in the form of a low beam distribution with a cut-off line HDG, and above it a signlight light distribution SV. As can be seen, there is a dark band or stripe BAN between the cut-off line HDG and the lower boundary of the signlight light distribution SV, which – as explained above, especially based on the Figure 4c described - can be realized through the existence of the second area 105b.

Claims

1. Lighting device (1) for a motor vehicle headlight for generating a light distribution (LV) with a cut-off line (HDG), wherein the lighting device comprises: □ a light-transmissive body (100), □ at least one light coupling element (101), □ a light source (10) associated with at least one light coupling element (101), wherein the at least one light coupling element (101) is designed to couple light emitted by the at least one light source (10) into the light-transmissive body (100), and □ a projection device (200), wherein the light coupling element (101) is designed to couple at least part of the light emitted by the at least one light source (10) into the light-transmissive body (100) in such a way that it propagates from the light-transmissive body (100) as a first light beam (S1) essentially in a light propagation direction toward the projection device (200), and wherein the light-transmissive body (100) has an aperture device (103) with an aperture edge (104), wherein the aperture edge (104) is arranged between the light coupling element (101) and the projection device (200) as seen in the light propagation direction, and wherein the aperture edge (104) is formed by a first lower boundary surface (105) and a second lower boundary surface (106) of the light-transmissive body (100), in that the lower boundary surfaces (105, 106) converge in a common edge, the aperture edge (104), the light coupling element (101) has a first deflection structure (101a) which is designed in such a way that light from the at least one light source (10) which enters the light coupling element (101) and strikes the deflection structure (101a) is totally reflected in such a way that the totally reflected light (S3) is directed onto a second deflection structure (107a), characterized in that the second deflection structure (107a) is arranged on an upper boundary surface (107) of the light-conducting body (100) opposite the lower boundary surfaces (105, 106), and wherein the second deflection structure (107a) is designed such that the light striking it is deflected as a fourth light beam (S4) onto a first surface area (105a) of the first lower boundary surface (105) of the aperture device (103), which first lower boundary surface (105) is located, viewed in the light propagation direction (X1), after the second boundary surface (106) of the aperture device (103) when viewed in the light propagation direction (X1), and wherein the surface area (105a) deflects the light incident upon it as a fifth light beam (S5) into an area (200a) of the projection device (200), which projects the light of the fifth light beam (S5) as a signal light beam (S6) into an area (B) of the light distribution above the light-dark boundary as an additional light distribution, as a signal light distribution (SV).

2. Lighting device according to claim 1, wherein the first deflection structure (101a) comprises a deflection surface or is designed in the form of a deflection surface, wherein, for example, the deflection surface is designed as a flat surface or as a concave curved surface.

3. Lighting device according to one of the preceding claims, wherein the second deflection structure (107a) is designed as a surface, in particular as a flat surface.

4. Lighting device according to one of the preceding claims, wherein the first surface area (105a) of the first lower surface (105) forms a straight intersection curve in vertical sections.

5. Lighting device according to one of the preceding claims, wherein the first surface area (105a) of the first lower surface (105) forms curved intersection curves, in particular convex intersection curves, in horizontal sections.

6. Lighting device according to one of the preceding claims, wherein the first surface area (105a) is a boundary surface of a recess (115) in the first lower boundary surface (105).

7. Lighting device according to one of the preceding claims, wherein the first surface area (105a) is spaced apart from the second boundary surface (106) and a further, second surface area (105b) of the first boundary surface (105) is arranged between the first surface area (105a) and the second boundary surface (106), which connects the first surface area (105a) to the second boundary surface (106).

8. Lighting device according to claim 7, wherein the second surface area (105b) is arranged and designed in such a way that no light from the second deflection structure (107a) reaches the second surface area (105b).

9. Lighting device according to one of the preceding claims, wherein the second deflection structure (107a) is formed by a recess (117) in the upper boundary surface (107).

10. Lighting device according to one of the preceding claims, wherein the glare edge (104) lies in or essentially in the Petzval surface or a focal surface of the projection device (200).

11. Lighting device according to one of the preceding claims, wherein the at least one light coupling element (101), the light-transmissive body (100) and the projection device (200) are formed integrally from a light-transmissive material and together form a body (1000).

12. Lighting device according to one of the preceding claims, wherein the light distribution (LV) with light-dark boundary (HDG) is a front field light distribution or a low beam light distribution.

13. Motor vehicle headlamp with at least one lighting device according to one of claims 1 to 12.