Front optic assembly for a light module of a motor vehicle headlight and motor vehicle headlight with such a front optic assembly

Description

[0001] The present invention relates to an add-on optics assembly for a light module of a motor vehicle headlight. The add-on optics assembly comprises a plurality of light-guiding elements arranged in a series, each of which has a light-intake surface and a light-output surface and is configured to guide light entering the light-intake surface to the light-output surface, where the light exits. The total amount of light exiting the light-output surfaces of the light-guiding elements is intended to produce a dimmed light distribution with a light-dark boundary. Edge geometries in a region of the light-output surfaces of the light-guiding elements define the profile of the light-dark boundary.

[0002] Furthermore, the invention relates to a motor vehicle headlight with such a front optics assembly.

[0003] Prior art includes light modules for automotive headlights that implement a segmented high beam (or partial high beam) together with a low beam. These light modules are also referred to as bi-function ADB (Adaptive Driving Beam) modules. Such light modules are known, for example, from US 2020 / 318 804 A1 and DE 10 2020 115 242 A1. These known technical solutions utilize two different LED arrays for the high beam and the low beam. This requires separate circuit boards on which the LEDs for the high beam and the low beam are arranged, as well as the positioning, mounting, and contacting of the different circuit boards within the light module. DE 10 2020 115 242 A1 also uses a separate reflector made of a metal sheet.

[0004] To reduce costs and assembly effort, a reduction in the number of components is desirable. This can be achieved, for example, by using only one LED layer or only one continuous circuit board for the LEDs for high beam and low beam. A corresponding technical solution is known, for example, from EP 3 872 394 A1.

[0005] To achieve a segmented high beam, it is known to arrange focusing light guides in front of the corresponding LEDs. This largely defines the LED plane. A possible technical solution for the low beam distribution is described in DE 10 2018 125 157 A1 using a hybrid approach. This involves a combination of focusing light guide optics for the high beam segments and a totally reflecting deflecting optic to generate a low beam distribution with as few LEDs as possible.

[0006] It is also known, for example from US 2019 / 234 571 A1, to achieve a further reduction in parts through a monolithic design of a front optics assembly. There, it is proposed to realize focusing optical fibers and a deflecting optic for the low beam using a monolithically integrated optical element.

[0007] Further front-mounted optical assemblies are known from DE 10 2009 053 581 B3 and from DE 10 2018 209 303 A1.

[0008] In addition to reducing the number of parts and the associated cost reduction, reducing the installation space required by the light module or the front optics assembly is becoming increasingly important, especially in the vertical direction, i.e., in terms of the installation height.

[0009] This can be achieved, for example, by replacing the deflecting optics for the low beam with a light guide optic, similar to those used for the segmented high beam. A possible technical solution is presented, for example, in WO 2021 / 244 735 A1 and WO 2021 / 244 736 A1. The homogenization of the low beam distribution necessary for the low beam can be achieved by appropriately structuring the primary and secondary optics.

[0010] The article "Silicone in Headlights," pp. 86-89, Kunststoffe 3 / 2016, Carl Hanser Verlag, Munich, describes, for example, the use of optics made from transparent liquid silicone rubber (LSR) in automotive headlights. This offers particular advantages with regard to the good thermal properties and the high UV and aging resistance of silicones. The good thermal properties refer to the rubber's ability to withstand relatively high temperatures without its chemical properties changing.

[0011] Based on the described prior art, the present invention aims to design and further develop a front optics assembly of the type mentioned at the outset in such a way that the components and materials of the front optics assembly are selected in such a way that thermomechanical tolerances (i.e., mechanical changes of the components due to temperature fluctuations), in particular due to principle and design, are minimized.

[0012] To solve this problem, a front optics assembly with the features of claim 1 is proposed. According to the invention, starting from the front optics assembly of the type mentioned at the outset, it is proposed that the light guides are made of a transparent silicone material and The optical elements are made from a transparent material that is more thermally stable than silicone.

[0013] Thermal stability refers to the ability of a material to maintain its physical properties, especially its dimensions at room temperature, under increasing temperatures over a longer period of time without changing, in particular without deforming excessively.

[0014] Thermal stability depends on various factors, such as the material's chemical composition, its crystalline structure, and its specific heat treatment. A material with high thermal stability can be used at high temperatures without losing its shape or undergoing excessive changes.

[0015] For the optically efficient use of fiber optics, it is thermally advantageous to use silicone as the material. This allows the coupling surfaces of the fiber optics to be positioned as close as possible to the respective light sources without the fiber optic material deforming. Silicone can withstand relatively high temperatures of around 250°C, and even up to 300°C for short periods. High-temperature silicones can withstand significantly higher temperatures. Preferably, the entire volume of the fiber optics consists of silicone.

[0016] However, silicone has a relatively high linear coefficient of thermal expansion (also called coefficient of heat expansion) according to ISO 11359-1, -2 (i.e., determined by thermomechanical analysis (TMA)) of greater than 150 × 10⁻⁶ < 1 / K, in particular from about 250 × 10⁻⁶ < 1 / K to 350 × 10⁻⁶ < 1 / K. This results in a relatively large expansion of the silicone material due to temperature increases during operation of the associated light sources of the light module.

[0017] Defining the path of a light-dark boundary in a dimmed light distribution using edge geometries in the area of ​​the output sides / surfaces of optical fibers, or using edges of the output sides / surfaces of optical fibers made of silicone material, would have the undesirable consequence that the silicone optical fibers would deform considerably during headlight operation, and the location and / or path of the edge geometries, and thus also of the light-dark boundary of the dimmed light distribution, would change significantly. This is particularly problematic for bi-functional light modules used to implement ADB high beam, as light segments of the high beam distribution are often directed very close to other road users (drivers of vehicles ahead or approaching).An uncontrolled change in the location and / or course of the light-dark boundary would lead to poorer illumination of the area in front of the vehicle and / or to glare for other road users.

[0018] For this reason, the present invention proposes that the edge geometries and / or edges of optical elements be formed from a thermally more stable material than silicone in order to ensure the thermal stability of the light-dark boundary required by law. Preferably, the entire volume of the optical elements consists of the thermally more stable material.

[0019] Furthermore, improved thermal stability also offers advantages regarding mechanical tolerances across a wide temperature range and can be used to further reduce costs. By manufacturing the additional optical element of a light guide from a more thermally stable material and illuminating it with light coupled out from the light guide, the edge regions of the optical element can be used to define the light-dark boundary. This allows for a simplified light module assembly, as active color fringing adjustment can be omitted with a suitable mechanical design. Consequently, faster and simpler assembly of the front optics assembly or the light module is possible, resulting in further cost reductions.

[0020] Furthermore, the additional optical surfaces resulting from the two-part design of the light guide elements (e.g., light output surfaces of the light guides and light entry surfaces of the optical elements) can be textured to improve the homogenization of the low-beam light distribution. Tilting the plane of a circuit board on which the low-beam and high-beam light sources are mounted and contacted allows for the optimal positioning of the high-beam LEDs, maintaining a performance-optimized distance between the high-beam optics and the aperture plane, while simultaneously increasing the distance between the low-beam LEDs and the aperture plane, further improving the homogenization of the low-beam light distribution. The edge geometries and / or edges of the optical elements are preferably located in the region of the aperture plane.

[0021] Advantageously, the light coupling surfaces of the optical fibers form the light entry surfaces of the light-guiding elements. Similarly, the optical elements or light exit surfaces of the optical elements can form the light exit surfaces of the light-guiding elements.

[0022] Preferably, several optical elements assigned to the various light guide elements or silicone light guides, preferably several adjacent and adjoining optical elements, are combined into a single optical component. Particularly preferably, all optical elements of the front-mounted optical assembly are combined into a single, one-piece optical component. This simplifies and speeds up the adjustment and / or assembly of the front-mounted optical assembly as well as its integration into the light module or the vehicle headlight.

[0023] The more thermally stable material from which the optical elements are formed can be any transparent material that is more thermally stable than silicone, i.e., expands less under the influence of heat than silicone. According to an advantageous embodiment of the invention, it is proposed that the optical elements be made of polycarbonate (PC). PC has a linear coefficient of thermal expansion according to ISO 11359-1, -2 of approximately 65 × 10⁻⁶ < 1 / K. This means that a 1 m long PC rod will lengthen by approximately 1.3 mm when the temperature increases by 20°C. The coefficient of thermal expansion of PC is therefore four to five times lower than that of silicone. For this reason, PC is particularly well suited for manufacturing the optical elements. Of course, the optical elements could also be made of other materials, e.g., polymethyl methacrylate (PMMA), whose coefficient of thermal expansion is approximately 75 × 10⁻⁶ < 1 / K.This means that a 1 m long PMMA rod will expand by approximately 1.5 mm when the temperature increases by 20°C. While this is a slightly greater thermal expansion than with PC, it is still significantly less than with silicone.

[0024] Therefore, thermal stabilization of the component edges or edge geometries forming the light-dark boundary is achieved by using a more thermally stable material than silicone (e.g., PC, PMMA, etc.) for the optical elements in which the edges or edge geometries are formed or arranged.

[0025] According to a preferred embodiment, it is proposed that the optical elements are arranged at a distance from the light output surfaces of the optical fibers. By additionally introducing an air gap between the silicone optical fibers and the entry surfaces of the optical elements, it can be prevented that the silicone optical fibers expand towards the LEDs during operation of the headlight due to thermal expansion, thus preventing them from colliding with the LEDs and causing color shifts in the light distribution.

[0026] Advantageously, the distance between a light-emitting surface of an optical fiber and an entrance surface of an optical element is at least 2.5% of the length of the optical fiber. The length of the optical fiber is preferably considered to be the distance between the entrance surface of the optical fiber and its exit surface along the optical axis. The optical axis is preferably defined by a surface normal of a light-emitting surface of a semiconductor light source (e.g., LED) associated with the optical fiber, passing through the center of the light-emitting surface.

[0027] The gap between the light guide and the optical element prevents the silicone light guide from colliding with the light-emitting surfaces of the associated semiconductor light sources, even during significant thermal expansion during headlight operation. Instead, thermal expansion reduces the dimensions of the gap between the light-emitting surfaces of the light guides and the light-intake surfaces of the optical elements. This controlled thermal expansion of the light guides towards the gap, rather than towards the light-emitting surfaces of the semiconductor light sources, can be achieved by appropriately mounting or supporting the light guides and optical elements relative to each other and / or to a fixed part of the vehicle headlight, such as a headlight housing.

[0028] According to a preferred embodiment of the invention, the edge geometries each comprise a side wall of the optical elements, which has an extent substantially parallel to the main direction of the light coupled out of the optical fibers. "Substantially parallel" within the scope of the present invention means that the light rays coupled out of the optical fiber strike the side wall at a very shallow angle after entering the optical element. "Very shallow" means light rays whose angle of incidence on the side wall is <45°, preferably <35°, and particularly preferably <22.5°. The side wall is preferably the lower side wall of the optical elements.

[0029] The side wall preferably has a substantially horizontal surface area to form a substantially horizontal cut-off line for a dimmed light distribution, e.g., a low beam, a fog light, or a low beam base light. The side wall can have a flat surface area or an area with a bend or step. The bend or step preferably runs parallel to an optical axis of the light-guiding elements. A flat side wall area can be used to generate a dimmed light distribution with a flat, symmetrical cut-off line, e.g., a low beam base light or a dynamic cornering light. A side wall area with a bend or step can be used to generate a dimmed light distribution with an asymmetrical cut-off line, e.g., a low beam.The surface area of ​​the side walls of the optical elements can differ from one another.

[0030] The side walls of the optical elements are preferably designed to reflect at least a portion of the light coupled out of the light guides, entering the optical elements, and striking the side walls. Thus, the side walls of the optical elements preferably form integrated mirror apertures of the light guide elements. The mirror apertures can reflect the incident light by total internal reflection and / or they are provided with a reflective coating so that incident light is reflected. The proposed two-part design of the light guide elements (silicone light guides and downstream optical elements made of a more thermally stable material) makes it possible, on the one hand, to utilize the advantages of silicone and, on the other hand, to implement an integrated mirror aperture, thereby eliminating the need for the arrangement, adjustment, and mounting of a separate mirror aperture in the light module.

[0031] Preferably, each of the side walls of the optical elements is designed to form or define a section of the light-dark boundary. All sections together then constitute the light-dark boundary of the stopped-down light distribution.

[0032] If the optical elements of the light guide elements are combined into a single, integrally formed optical component, this component has a single side wall that extends across all light guide elements. Sections of the side wall in the region of the outer light guide elements preferably have a flat surface, whereas sections of the side wall in the region of the central light guide elements preferably have a surface with a bend or a step.

[0033] Edge geometries or edges of the side walls, preferably leading edges on the sides of the side walls facing forward in the direction of light emission and adjacent to the light emission surfaces of the optical elements, define the location and course of the light-dark boundary of the stopped-down light distribution. If the optical elements are combined into a single optical component, an edge geometry or edge of a single side wall of the optical component, preferably a leading edge on the side of the side wall facing forward in the direction of light emission and adjacent to the light emission surface of the optical component, defines the location and course of the light-dark boundary of the stopped-down light distribution.

[0034] It is proposed that the sidewalls of the optical elements have a length of at least 0.5 mm in the main direction of the light coupled out of the optical guides. This offers both optical and manufacturing advantages. The length of the sidewalls corresponds approximately to the thickness of the optical elements.

[0035] Finally, it is proposed that the total amount of light emitted from the light-emitting surfaces of the light-guiding elements is intended to generate a low-beam distribution or a low-beam spot. The low-beam spot generated by the add-on optics assembly, together with a low-beam basic light distribution generated by another optics assembly of the light module or by another light module of the vehicle headlight, can produce a low beam that meets the legal requirements (according to ECE R48 §6.2, R98 and R112). The low-beam distribution generated by the add-on optics assembly, together with a high-beam distribution that illuminates a far range above the cut-off line of the low-beam distribution, can produce a high beam that meets the legal requirements (according to ECE R48 §6.1, R98 and R112).The high beam distribution can be generated by a different optical assembly of the light module or by a different light module of the vehicle headlight.

[0036] The problem underlying the present invention is also solved by a motor vehicle headlight with the features of claim 12. In particular, starting from the motor vehicle headlight of the type mentioned at the outset, it is proposed that the headlight comprises a front optics assembly according to the invention with a horizontal cut-off line. Furthermore, it is proposed that the motor vehicle headlight has a further optics assembly designed to generate a further light distribution, wherein the further optics assembly is designed to illuminate at least a part of an area above the cut-off line of the dimmed light distribution generated by the front optics assembly.

[0037] The front optics assembly can be designed, for example, to generate a low beam or a low beam spot. The additional optics assembly can be designed, for example, to illuminate a long-range area above the cut-off line of the low beam, in order to produce, together with the low beam, a high beam that meets the legal requirements for a high beam. Alternatively, the additional optics assembly can be designed, for example, to generate a basic low beam light distribution, which, together with the low beam spot, produces a low beam that meets the legal requirements for a low beam.

[0038] According to an advantageous embodiment of the invention, it is proposed that the vehicle headlight comprises a projection optic configured to project the light emitted from the front optic assembly and the further optic assembly onto a screen arranged at a distance from the vehicle headlight to generate the overall light distribution of the vehicle headlight. The projection optic is thus arranged downstream of the optic assemblies in the beam path and is configured to project the light emitted by both optic assemblies onto the road surface in front of the vehicle as the overall light distribution. The overall light distribution can, for example, be a low beam or a high beam. The projection optic can comprise a reflector and / or a lens.

[0039] According to a preferred embodiment, the light emitted from the entirety of the light-emitting surfaces of the light-guiding elements of the front optics assembly is intended to generate a low beam, and the further optics assembly is configured to generate a high beam, in particular an ADB (Adaptive Driving Beam) high beam, above the cut-off line of the low beam generated by the front optics assembly. The ADB high beam illuminates the far range above the cut-off line with several individually controllable light segments or blocks. By selectively controlling the light segments or blocks, or the corresponding high beam light sources, the far range can be illuminated with different combinations of light segments. In this way, for example, areas in the far range can be darkened or shaded from the light distribution where other road users (e.g., vehicles ahead or approaching) are located.It is conceivable that the headlight is equipped with at least one sensor that detects other road users in advance and generates corresponding sensor signals, and a processing unit that receives and processes the sensor signals and generates corresponding control signals for the ADB optical assembly or the light sources associated with it. The sensor could, for example, include a camera located at the front of the vehicle, particularly at the upper edge of the windshield.

[0040] According to an alternative embodiment, the light emerging from the entirety of the light-emitting surfaces of the light-guiding elements of the front optics assembly is intended to generate a low-beam spot, and the vehicle headlight has a deflecting optic designed to generate a basic low-beam light distribution. A portion of the deflecting optic is arranged in the main direction of the light coupled out from the light guides, downstream of the light-coupling surfaces of the light guides, and forms the optical element. Consequently, the light emerging from the light guides first passes through the slit before entering the portion of the deflecting optic that forms the optical element. In this portion of the deflecting optic, a preferably horizontal side wall, particularly preferably a lower horizontal side wall, can be designed as an integrated mirror aperture.Edge geometries or edges of the side wall, preferably a leading edge of the side wall, define the path of the light-dark boundary of the low-beam spot. The basic low-beam light distribution generated by the deflecting optics, together with the low-beam spot, forms a low-beam that meets the legal requirements. For this purpose, the light emitted by the deflecting optics is preferably projected onto the road in front of the vehicle by a projection optic.

[0041] The low beam main beam preferably has a symmetrical, flat, horizontal cut-off line without kinks or steps. The low beam main beam can be swivelled horizontally, for example, to enable a dynamic cornering light function. Swiveling the low beam main beam can be achieved mechanically by pivoting at least one component of the headlight around a vertical axis or purely electronically via appropriate control of the light sources. The low beam spot preferably has an asymmetrical horizontal cut-off line with a kink and / or a step. The asymmetrical cut-off line is preferably higher on the driver's side of the road than on the oncoming side.The low beam spot illuminates a central area of ​​the light distribution below the light-dark boundary of the low beam and in the vicinity of a vertical median plane of the light distribution (around the optical axis) particularly brightly.

[0042] In the described example, the vehicle headlight or light module can also include a further optical assembly designed to generate a high beam, in particular an ADB (Adaptive Driving Beam) high beam, above the cut-off line of the low beam produced by the front optical assembly. The low beam and the illumination of the far range together constitute a high beam that meets legal requirements.

[0043] Further features and advantages of the present invention are explained in more detail below with reference to the figures. It is emphasized that the features shown in the figures can each be essential to the invention individually, even if this is not expressly mentioned in the description. Furthermore, it is conceivable that the features shown in the various figures can be combined with one another in any way within the scope of the present invention, even if this is not shown in the figures and not expressly mentioned in the description. The figures show: Fig. 1 shows a front optics assembly according to a first embodiment in a perspective view from a rear oblique angle; Fig. 2 shows the front optics assembly made of Fig. 1 in a perspective view from a slightly oblique front view; Fig. 3 the front optics assembly made of Fig. 1 in a side view; Fig. 4 the front optics assembly made of Fig. 1in a side view with exemplary beam paths shown; Fig. 5 a section of the front optics assembly made of Fig. 4 Fig. 6 shows a front optics assembly according to a second embodiment in a perspective view from a rear oblique angle; Fig. 7 shows the front optics assembly made of Fig. 6 in a front view; Fig. 8 the front optics assembly made of Fig. 6 in a side view; Fig. 9 the front optics assembly made of Fig. 6 in a side view with exemplary beam paths shown; and Fig. 10 a motor vehicle headlight according to the invention in a preferred embodiment.

[0044] In Fig. 10The headlight 101 of a motor vehicle according to the invention is designated in its entirety by reference numeral 101. The headlight 101 comprises a housing 102, which is preferably made of plastic. In a light emission direction 103, the headlight housing 102 has a light emission opening which is closed by a transparent cover 104. The cover 104 is made of colorless plastic or glass. The cover 104 can be designed without optically effective profiles as a so-called clear cover.

[0045] Alternatively, the disk 104 can be provided at least partially with optically effective profiles (e.g. cylindrical lenses or prisms) that cause a scattering of the passing light, preferably in a horizontal direction.

[0046] Inside the headlight housing 102, two light modules 105 and 106 are arranged in the illustrated example. The light modules 105 and 106 are arranged either fixedly or movable relative to the housing 102. A dynamic cornering light function can be implemented by moving the light modules 105 and 106 relative to the housing 102 in a horizontal direction. Moving the light modules 105 and 106 about the horizontal axis of rotation 18, i.e., in a vertical direction, allows for headlight range control. With the light modules 105 and 106 fixedly arranged in the housing 102, a variable or dynamic light distribution of at least one of the light modules 105 and 106 can be achieved by controlling one or more subcomponents of the light module 105 or 106, for example, individual light sources of a matrix light source within the light module 105 or 106.

[0047] Of course, the headlight housing 102 can also contain more or fewer than the two light modules 105, 106 shown. At least one of the light modules 105, 106 is designed as a light module according to the invention and comprises an attachment optic assembly according to the invention, as will be explained further below.

[0048] A control unit 107 can be arranged on the outside of the headlight housing 102 within a control unit housing 108. Of course, the control unit 107 can also be arranged at any other location within the lighting device 101. In particular, a separate control unit can be provided for each of the light modules 105, 106, with the control units being an integral part of the light modules 105, 106. Naturally, the control unit 107 can also be arranged remotely from the lighting device 101, for example, in the engine compartment of the vehicle. The control unit 107 serves to control and / or regulate the light modules 105, 106 or subcomponents of the light modules 105, 106, such as light sources of the light modules 105, 106 or actuators for the horizontal and / or vertical adjustment of the light modules 105, 106 or aperture elements of the light modules.

[0049] The control of the light modules 105, 106 or the subcomponents by the control unit 107 is effected via connecting lines 110, which are in Fig. 10 The lines 110 are shown symbolically only. The lines 110 can also supply electrical energy to the light modules 105 and 106. The lines 110 run from inside the lighting unit 101 through an opening in the headlight housing 102 into the control unit housing 108 and are connected there to the circuit of the control unit 107. If control units are provided as an integral part of the light modules 105 and 106, the lines 110 and the opening in the headlight housing 102 can be omitted. Finally, the control unit 107 can include a connector 109 for connecting a cable to a higher-level control unit (e.g., a body controller unit) and / or a power source (e.g., the vehicle battery).

[0050] A Cartesian coordinate system is shown in the figures, which is referenced in the following explanations. An x-axis corresponds to the direction of light emission 103 from the light module 10. With the light module 10 aligned horizontally, this can correspond to the direction of travel of the motor vehicle in which the headlight 101 is installed. A y-axis runs horizontally and perpendicular to the x-axis. A z-axis runs vertically and perpendicular to both the x-axis and the y-axis.

[0051] The following section describes the light module according to the invention in more detail. Current bi-functional ADB (Adaptive Driving Beam) modules known from the prior art must meet not only customer requirements regarding optical performance but also increasingly stringent requirements regarding installation space and cost reduction. This cost pressure and the desire for installation space reduction necessitate a reduction in the number of components and a simplification of the assembly and adjustment processes. Complex adjustment and thus long cycle times can be avoided if the components and materials are selected in such a way that thermomechanical tolerances are minimized by design and principle.

[0052] The Figures 1 to 5Figure 1 shows a first embodiment of a light module 10 according to the invention, which can be used, for example, as light module 105 and / or 106 in the headlight 101, in various views. The light module 10 comprises a front optics assembly 12 (or primary optics assembly) with a plurality of light guide elements 14 arranged in a row, each of which has a light entry surface 16 and a light exit surface 18 and is designed to guide light entering the light entry surface 16 to the light exit surface 18, where the light exits. The total amount of light exiting from the light exit surfaces 18 of the light guide elements 14 is intended to produce a dimmed light distribution with a light-dark boundary. Edge geometries 28 (see Figure 1) Fig. 5In a region of the light-emitting surfaces 18 of the light-guiding elements 14, a light-dark boundary is defined. The light-dark boundary preferably has a substantially horizontal course. It can be flat or designed with bends and / or steps.

[0053] Light sources 17 are assigned to the light guiding elements 14 or their light entry surfaces 16 (see figure). Figures 3 to 5 ), which emit light that enters the light guide elements 14 via the light entry surfaces 16. Preferably, each light entry surface 16 is assigned at least one separate, independently controllable light source. The light sources 17 preferably comprise semiconductor light sources, in particular LEDs, OLEDs, or laser diodes. Preferably, all semiconductor light sources 17 assigned to the light guide elements 14 are arranged on a common circuit board (not shown) and contacted via this board.

[0054] In the first embodiment, ten light guide elements 14 are arranged side by side in a row. Of course, a different number of light guide elements 14 and / or a different arrangement can also be provided.

[0055] As shown by the Fig. 5As can be seen, each of the light-guiding elements 14 comprises a light guide 20, which has a light-input coupling surface 22 and a light-output coupling surface 24 and is configured to guide light coupled into the light-input coupling surface 22 to the light-output coupling surface 24, where the light is coupled out. Furthermore, each of the light-guiding elements 14 comprises an optical element 26 located downstream in a principal direction of light coupled out of the light guide 20, through which light coupled out of the light guide 20 passes. The light guides 20 are made of a transparent silicone material. The optical elements 26 are made of a transparent material that is more thermally stable than silicone. The edge geometries 28 of the light-guiding elements 14, which define the light-dark boundary, are formed in the optical elements 26.

[0056] The optical elements 26 each have a light entry surface 30 and a light exit surface 32. Preferably, the light entry surfaces 16 of the light guide elements 14 correspond to the light coupling surfaces 22 of the light guides 20. Equally preferably, the light exit surfaces 18 of the light guide elements 14 correspond to the light exit surfaces 32 of the optical elements 26. Several adjacent optical elements 26 can be combined to form a single optical component, which has a common, continuous light exit surface 32 and preferably also a common, continuous light entry surface 30. The continuous light entry surface 30 and / or light exit surface 32 can be flat or curved or have bends and / or steps.

[0057] Particularly preferably, all optical elements 26 of the front optics assembly 12 are combined into a single optical component 26', which has a common, flat light exit surface 32. The light exiting from the light guides 20 arranged in series or their light output surfaces 24 preferably passes through various sections of the optical component 26' arranged in series, whereby crosstalk from one section of the optical component 26' to an adjacent section is not excluded.

[0058] By using silicone as the material for the light guides 20, the light coupling surfaces 22 of the front optics assembly 12 can be positioned particularly close to the associated light sources 17. This allows the light emitted by the light sources 17 to be coupled into the light guides 20 with particular efficiency.

[0059] Thermal stabilization of the edge geometries 28 or component edges forming the light-dark boundary of the dimmed light distribution can be achieved by using a more thermally stable material than silicone for this part of the light-guiding element 14, preferably, for example, polycarbonate (PC). In this way, a thermally stable light-dark boundary of the dimmed light distribution can be created.

[0060] By additionally providing an air gap 34 between the light output surfaces 24 of the light guides 20 and the light entry surfaces 30 of the optical elements 26, it can be prevented that the silicone light guides 20 expand in the direction of the light sources 17 under the influence of heat and collide with them, which would result in color shifts in the overall light distribution.

[0061] In addition to the thermal tolerance advantages, the air gap 34 also provides an optical advantage. By placing the additional optical elements 26 only in front of the front optics assembly 12 responsible for forming the low beam distribution, a section of a side wall 36 or an entire side wall 36 of the optical elements 26 can be used as an optical interface (see Figure 1). Fig. 5 Total internal reflection of parts of the incoming light rays at this interface 36 can increase the intensity at the light-dark boundary edge, which is advantageous for the optical performance (especially for the range near the light-dark boundary) of the dimmed light distribution. In this way, the efficiency of the overall system can be increased.

[0062] The side wall 36 thus serves as an integrated mirror aperture of the front optics assembly 12. Besides total internal reflection, the reflection of the light rays entering the optical elements 26 and striking the side wall 36 could also occur specularly. For this purpose, the side wall 36 can be at least partially provided with a reflective coating. The shape of the side wall 36, or an edge geometry 28, in particular a leading edge of the side wall 36, defines the shape of the light-dark boundary of the resulting apertureed light distribution of the front optics assembly 12. Fig. 2 The diagram shows a profile of the interface 36 to generate an asymmetric light-dark boundary with a kink and step in the horizontal direction approximately in the middle of the interface 36.

[0063] The front optics assembly 12 can be combined with another optics assembly to create a light module 10 in the form of an ADB bi-functional module. Various optical arrangements are conceivable for this implementation. Examples are shown in the Figures 1 to 5 and Figures 6 to 9 Two possible arrangements are shown in different views. These do not use a separate mirror aperture to create the light-dark boundary of the blocked light distribution.

[0064] In the example of the Fig. 3The light module 10 comprises a front optics assembly 12 with light guides 20 and optical elements 26 for the corresponding light sources 17 (e.g., LEDs) for the low beam and a further optical assembly 38 with a light guide arrangement comprising several light guides 40 arranged side by side in a row for corresponding light sources 42 (e.g., LEDs) for the high beam, in particular for the ADB high beam. Silicone is used as the material for the light guides 20 and / or 40. In the area of ​​the light guides 20 responsible for the low beam, an optical element 26, e.g., made of PC (polycarbonate), is positioned, which is illuminated by light emerging from the low beam light guides 20. The resulting light distribution is projected onto the road surface in front of the vehicle by a secondary optic 44. The resulting light distribution is, for example, low beam when only the front optics assembly 12 or its LEDs 17 are active, or high beam when the front optics assembly 12 or its LEDs 17 are active.whose LEDs 17 are active together with the further optical assembly 38 or its LEDs 42. The ADB high beam exiting the further optical assembly 38 or the light guides 40 does not pass through the additional optical element 26.

[0065] In the example of the Figures 1 to 5The further optical assembly 38 comprises a total of 16 high-beam light guides 40 arranged side by side in a row. Of course, a different number and arrangement of the light guides 40 is also conceivable. Each of the light guides 40 is preferably assigned at least one separate light source 42 (e.g., LEDs). The light sources 42 can be controlled separately from one another to enable partial or segmented high beams. The control of the light sources 42 can be dependent on other road users (ahead and / or oncoming) detected in front of the vehicle, so that the high beam distribution can be dimmed or shaded in the areas where other road users are located.

[0066] In Fig. 5 is the side wall 36 of the first example (cf. Fig. 3) illuminated. The thickness or length 46 of the side wall 36 in the direction of the beam path through the optical element 26 is at least 0.5 mm. This offers photometric and manufacturing advantages. The distance 48 between the exit surface 24 of the silicone optical fiber optics or the individual silicone optical fibers 20 and the entry surface 30 in the additional component 26 is preferably at least 2.5% of the length of the silicone optical fiber 20, where the length of the silicone optical fiber 20 is defined as the distance between the coupling surface 22 of the optical fiber 20 and its output coupling surface 24 along the optical axis. The optical axis is defined by a surface normal of an exit surface of a semiconductor light source 17 (e.g., LED) through the center of the corresponding light source 17. Fig. 4shows the beam components 50 transmitted in the vicinity of the side wall 36 and beam components 52 reflected from the side wall 36, which are imaged by the secondary optics 44.

[0067] At the in Fig. 8 In the second embodiment shown, the resulting low beam is formed as an overall light distribution from the interaction of an inventive front optics assembly 12, which generates a low beam spot, and a deflecting optics assembly 54 made of polycarbonate (PC) or another suitable material, which generates a low beam base light distribution. A lower part of the deflecting optics assembly 54 is arranged in front of the light extraction surfaces 24 of the silicone light guides 20 of the front optics assembly 12, which generates the low beam spot, and is illuminated by the light extracted from the light guides 20 (see figure). Fig. 9The lower part of the deflecting optics 54 thus forms the additional optical element 26 according to the invention. Light coupled into the deflecting optics 54 from basic light sources (e.g., LEDs) passes through an upper part of the deflecting optics 54 and exits through a light-emitting surface 55 of the upper part of the deflecting optics 54.

[0068] The overall light distribution is then projected onto the road surface using a secondary optic 44. Fig. 6 , which shows a view of the light module 10 from the rear, and Fig. 7 , which shows a view from the front, this combination of a deflecting optic 54 made of polycarbonate and the light guide optic with the light guides 20 made of silicone is shown.

[0069] In addition to the light guides 20, this example also includes a further light guide arrangement 38 with several light guides 40 arranged side by side in a series, which is designed, for example, to generate an ADB high beam. The ADB high beam emerging from the further optical assembly 38 or the light guides 40 does not pass through the additional optical element 26. However, the high beam can very well pass through the secondary optics 44 and be projected by them in front of the vehicle. In the example of the Figures 6 to 9 The further optical assembly 38 comprises a total of 16 high-beam light guides 40 arranged side by side in a row. Of course, a different number and arrangement of the light guides 40 is also conceivable.

[0070] Behavior comparable to the first example is found in Fig. 9 for the in Fig. 8The example shown depicts the illuminated PC deflecting optic 54 and the lower part of the deflecting optic 54 forming the additional optical element 26, 26'. Here, too, beam components 52 are reflected by the side wall 36, and other beam components 50 are transmitted in the vicinity, which are imaged by the corresponding secondary optic 44. The width 48 of the air gap 34 should again be at least 2.5% of the length of the corresponding light guide 20, where the length refers to the distance between the coupling surface 22 of the light guide 20 and its coupling surface 24. Furthermore, this side wall 36 should also have a length 46 of at least 0.5 mm.

[0071] In summary, the invention describes a compact low-beam light module 10 which, in combination with a further optical module 38 that illuminates a high-beam area above the light-dark boundary of the low-beam light distribution, can be supplemented to form an ADB bi-functional light module. The light module 10 has a front optics assembly 12 comprising silicone light guides 20 and downstream additional optical elements 26 made of polycarbonate or another suitable material. For reasons of cost and space, the mirror aperture is integrated into the front optics assembly 12, so that an additional separate mirror aperture can be dispensed with.

[0072] Since the silicone from which the light guides 20 are made has a high coefficient of thermal expansion and is very soft, the mirror aperture cannot be directly integrated into the silicone optics with the light guides 20. Therefore, the invention proposes extending the silicone light guides 20 with one or more additional optical elements 26, 26', the lower side wall 36 of which acts as a mirror aperture, for example, by means of total internal reflection. The course of the light-dark boundary of the apertureed light distribution formed by the front optic assembly 12 is defined by an edge geometry 28 of the side walls 36. An air gap 34 is formed between the silicone light guides 20 and the optical elements 26, 26' so that thermal expansion of the silicone does not affect the mirror aperture integrated into the optical element 26, 26' (on the side walls 36) and its edge geometry 28, or the position and course of the light-dark boundary.The proposed arrangement is particularly advantageous for compact light modules 10 and improves the thermal stability of the light-dark boundary.

Claims

1. Attachment optics assembly (12) for a light module (10) of a motor vehicle headlight (101), comprising a plurality of light-guiding elements (14) arranged in a row, each of which has a light entry surface (16) and a light exit surface (18) and is designed to guide light entering the light entry surface (16) to the light exit surface (18), where the light exits, wherein the entirety of the light exiting from the light exit surfaces (18) of the light-guiding elements (14) is intended for producing a dipped beam light distribution with a light-dark boundary, wherein each of the light-guiding elements (14) comprises a light guide (20) which has a light-coupling surface (22) and a light-decoupling surface (24) and is designed to guide light coupled into the light-coupling surface (22) to the light-decoupling surface (24), where the light is coupled out, and an optical element (26) arranged downstream in a main direction of light coupled out of the light guide (20), through which light coupled out of the light guide (20) passes, wherein edge geometries (28) in a region of the light exit surfaces (18) of the light-guiding elements (14) define a course of the light-dark boundary, wherein the edge geometries (28) of the light-guiding elements (14) defining the light-dark boundary are formed in the optical elements (26), characterised in that the light guides (20) are made of a transparent silicone material and the optical elements (26) are made of a transparent material that is more thermally stable than silicone.

2. Attachment optics assembly (12) according to claim 1, characterised in that the light-coupling surfaces (22) of the light guides (20) form the light entry surfaces (16) of the light-guiding elements (14).

3. Attachment optics assembly (12) according to claim 1 or 2, characterised in that light exit surfaces (32) of the optical elements (26) form the light exit surfaces (18) of the light-guiding elements (14).

4. Attachment optics assembly (12) according to one of the preceding claims, characterised in that the optical elements (26) are made of polycarbonate.

5. Attachment optics assembly (12) according to one of the preceding claims, characterised in that the edge geometries (28) each comprise a side wall (36) of the optical elements (26), which have an extension running substantially parallel to the main direction of the light coupled out of the light guides (20).

6. Attachment optics assembly (12) according to claim 5, characterised in that the side walls (36) of the optical elements (26) are designed to reflect at least part of the light coupled out of the light guides (20) and incident on the side walls (36).

7. Attachment optics assembly (12) according to claim 5 or 6, characterised in that edges of the side walls (36) of the optical elements (26) are part of the edge geometries (28) and define the light-dark boundary.

8. Attachment optics assembly (12) according to one of claims 5 to 7, characterised in that the side walls (36) of the optical elements (26, 26') have a length of at least 0.5 mm in the main direction of the light coupled out of the light guides (20).

9. Attachment optics assembly (12) according to one of the preceding claims, characterised in that the optical elements (26) are arranged at a distance (48) from the light-decoupling surfaces (24) of the light guides (20).

10. Attachment optics assembly (12) according to one of the preceding claims, characterised in that the optical elements (26) are arranged at a distance (48) from the light-decoupling surfaces (24) of the light guides (20), wherein the distance (48) is at least 2.5% of a length of the light guides (20) between the light-coupling surface (22) and the light-decoupling surface (24).

11. Attachment optics assembly (12) according to one of the preceding claims, characterised in that the entirety of the light emerging from the light exit surfaces (18; 32) of the light-guiding elements (14) is intended for producing a low beam or a low beam spot.

12. Motor vehicle headlight (101) comprising an attachment optics assembly (12) according to one of the preceding claims, characterised in that the attachment optics assembly (12) has a horizontal light-dark boundary and in that the motor vehicle headlight (101) has a further optical assembly (38) designed to produce a further light distribution, wherein the further optical assembly (38) is designed to illuminate at least part of an area above the light-dark boundary of the dipped beam light distribution produced by the attachment optics assembly (12).

13. Motor vehicle headlight (101) according to claim 12, characterised in that the motor vehicle headlight (101) comprises a projection optic (44) which is designed to produce an overall light distribution of the motor vehicle headlight (101) on a screen arranged at a distance from the motor vehicle headlight (101) by means of the light emitted by the attachment optics assembly (12) and the further optical assembly (38).

14. Motor vehicle headlight (101) according to claim 12 or 13, characterised in that the light emitted from the entirety of the light-emitting surfaces (18; 32) of the light-guiding elements (14) of the attachment optics assembly (12) is intended to produce a low beam, and the further optical assembly (38) is designed to produce a high beam, in particular an ADB (Adaptive Driving Beam) high beam, above the light-dark boundary of the low beam produced by the attachment optics assembly (12).

15. Motor vehicle headlight (101) according to one of claims 12 to 14, characterised in that the light emitted from the entirety of the light-emitting surfaces (18; 32) of the light-guiding elements (14) of the attachment optics assembly (12) is intended to produce a low beam spot, and the motor vehicle headlight (101) has a deflection optics (54) which is designed to produce a low beam basic light distribution, wherein a part of the deflection optics (54) is arranged in the main direction of the light coupled out of the light guides (20) after the light coupling surfaces (24) of the light guides (20) and forms the optical element (26).