Lighting device for a motor vehicle and motor vehicle headlights with such a lighting device

Description

[0001] The invention relates to a lighting device for a motor vehicle for generating at least one lighting function and / or signaling function, wherein the lighting unit has a housing with a housing opening, wherein the housing opening is closed, for example, by a cover plate, wherein in the housing at least one elongated optical fiber and at least one light source associated with the at least one optical fiber are arranged, wherein light from the at least one light source can be coupled into the optical fiber via an input area of ​​the at least one optical fiber, wherein the at least one optical fiber has a light output surface on its front side and a light deflection surface on a rear side opposite the front side, such that light coupled into the at least one optical fiber from the at least one light source is deflected at the light deflection surface and emitted from the optical fiber via the light output surface. where the at least one light guide has a termination surface limiting the light guide in an end section, and wherein the lighting device further comprises optics, such as a diffuser or thick-walled optics, which is arranged in the direction of light emission after the light coupling surface of the light guide.

[0002] Furthermore, the invention relates to a lighting device mentioned above, which is designed as a motor vehicle headlight.

[0003] Finally, the invention relates to a motor vehicle headlight which has one or more of the aforementioned lighting devices.

[0004] Elongated light guides are frequently used in automotive headlight construction, for example, to generate parking light distributions or daytime running light distributions, or to generate signaling functions, such as a turn signal function. The term "elongated" or "oblong" means that the longitudinal extent of the light guide (i.e., the extent in the direction of light propagation within the light guide) is significantly greater, e.g., at least 5 or at least 10 times greater than the transverse extent (the transverse extent being, for example, the largest, smallest, or an average diameter of the light guide). In the present invention, the light guide used has two open ends; light from a light source is coupled into one end, while no light coupling occurs at the other open end. The invention also encompasses cases where, for example,Two (or more) optical fibers converge into a common coupling region, and light from a light source, coupled into this common coupling region, is directed in a known manner, e.g., by means of suitable deflecting devices such as deflecting prisms, into the two or more optical fibers. In this case, the coupling region represents one open end for each optical fiber, and the open end of each optical fiber facing away from the coupling region represents its second open end.

[0005] For example, US 2008 / 225548 A1, EP 3 190 332 A1 and US 2006 / 050282 A1 show lighting devices for motor vehicle headlights in which elongated light guides are used.

[0006] Light coupled into the optical fiber propagates longitudinally along the fiber due to total internal reflection. To selectively couple light out of the optical fiber, a light deflection surface is provided on its rear side. This surface is designed such that, in a known manner, light is deflected to the light output surface and strikes it at an angle that allows the light to exit the optical fiber.

[0007] The light deflection surface typically comprises a prismatic structure. Generally, the light deflection surface can be designed such that the light is deflected towards the light output surface in a way that results in a largely continuous or homogeneous warm light appearance of the optical fiber. This means that, to an observer from the outside, the optical fiber appears uniformly luminous when the light source is switched on. Usually, it is desirable for the optical fiber to appear as uniformly bright as possible along its entire length; however, it may also be desirable for the brightness to decrease towards the end. The important thing, however, is a warm light appearance that is as continuous as possible.

[0008] However, a certain amount of light always "remains" at the end of an optical fiber. This essentially consists of light rays whose angle of incidence has not exceeded the angle of total internal reflection along the entire length of the optical fiber. This is unavoidable, because otherwise, if all the light were deflected and coupled out via the light deflection surface, the optical fiber would appear dark towards the end, which is neither permissible nor desirable. For example, vehicle manufacturers specify requirements for homogeneity, such as limits on the maximum luminance difference of the illuminated area of ​​the optical fiber.

[0009] At the termination surface, which closes off the optical fiber at the end or end region facing away from the light source, reflections of this "remaining" light occur. These reflections at the termination surface typically result in a significant increase in light intensity in the end section of the optical fiber, and this reflected light exits, at least partially, through the light-emitting surface of the optical fiber in that end section. This typically results in one, and occasionally several, hotspots visible in the luminous area of ​​the optical fiber, which can negatively affect the warm appearance of the optical fiber. A hotspot is typically understood to be a narrowly defined area of ​​high luminance within a darker area (i.e., an area of ​​lower luminance) compared to this area of ​​high luminance.

[0010] Such a hotspot is highly noticeable, visually disruptive, and adversely affects the appearance of the light guide when the light source is switched on for an observer outside the vehicle, as the homogeneity of the appearance is disturbed by such a hotspot (or by several).

[0011] To solve the problem described above, prior art includes, for example, apertures by means of which the problematic end section of the light guide can be covered so that the hotspot(s) are not visible, or the light guide ends with its end section in a headlight housing in such a way that the end section is not visible to a viewer.

[0012] However, this reduces the effective length of the light guide, the light guide is optically shortened, and consequently the installation space, which is usually limited in a motor vehicle anyway, cannot be optimally utilized.

[0013] Furthermore, this results in the optical fiber having a smaller effective light emission area and therefore emitting less light at the same power of the light source than an identical optical fiber that is not covered by an aperture.

[0014] Furthermore, it is a disadvantage that such a lens requires installation space, which is already severely limited in modern motor vehicles, or that there is no installation space in the headlight housing to conceal the end of the light guide.

[0015] It is an object of the invention to provide a solution to the problems mentioned above.

[0016] This problem is solved with a lighting device for a motor vehicle mentioned above in that the shape of the end surface follows the shape of a virtual base surface, wherein the shape of the virtual base surface follows the contour of an end surface of the optic, in particular lying in a common plane with it, and wherein the virtual base surface, for example a plane, is inclined obliquely to a central longitudinal axis of the light guide, and wherein at least in areas of the virtual base surface, targeted deviations from the shape of the virtual base surface are provided by providing several optical surface segments, wherein the end surface in the areas where a targeted deviation is present is formed by the optical surface segments and corresponds to the virtual base surface in the areas without deviation, and wherein the optical surface segments are arranged inclined to the virtual base surface, such that more light can exit the optical fiber from one, several, or preferably each optical surface segment than from a virtual base shape surface segment corresponding to the respective optical surface segment, and / or one, several, or preferably each optical surface segment reflects light propagating in the optical fiber to the termination surface in such a way that the amount of light exiting the light coupling surface per unit area in an end section of the optical fiber is less than would be the case with reflection at the virtual base surface. and wherein the end surface in a boundary area, in particular in a circumferential, self-contained boundary area which encloses the optical surface segments, corresponds to the virtual base area, wherein a texture, e.g. a regular or irregular geometric texture, is provided in the boundary area.

[0017] The term "terminal surface" refers to a real, optically effective surface ("effective surface") that delimits the optical fiber to the outside and at which light is reflected and / or can escape from the optical fiber.

[0018] The length of the end section, measured from the termination surface, can be approximately 2 to 6 times, and in particular approximately 4 times, the diameter of the optical fiber. This diameter can be a minimum diameter, a maximum diameter, an average diameter, or a diameter at a specific point along the optical fiber.

[0019] The invention allows the "behavior" of the light at the termination surface to be controlled in a targeted manner, so that hotspots can be avoided or at least the luminance in the hotspot(s) can be significantly reduced, so that they are no longer noticeably disruptive in the illuminated area of ​​the light guide.

[0020] At the same time, it may be possible to adapt the virtual base area, for example, to an optic downstream of the light guide, which is illuminated by the light guide, and / or the shape of the headlight housing.

[0021] The invention thus makes it possible to significantly reduce or avoid hotspots, even with a predetermined shape of the end of the light guide and / or a predetermined shape of the termination surface.

[0022] It may be provided that the optical surface segments deviate from the virtual base surface in such a way that, in an end region of the light guide, viewed in the direction of the longitudinal extension of the light guide, the reflected light is reflected into a larger area than would be the case with the virtual base surface.

[0023] In this way, the reflected light can be distributed over a larger area, thus reducing the luminance and avoiding or mitigating hotspots.

[0024] In particular, it may be provided that the optical surface segments are arranged at an angle to the virtual base surface.

[0025] In particular, it may be provided that each optical surface segment is individually arranged with regard to its inclination and / or with regard to its shape and / or with regard to its size, in particular the size of its area.

[0026] The optical surface segments can be identical with respect to one, several, or all of the parameters listed above (inclination, shape, size); this simplifies calculation and / or manufacturing. Individual design of the optical surface segments with respect to one, several, or all of the parameters listed above can allow for an even more targeted reduction or avoidance of hotspots.

[0027] According to the invention, the optical surface segments are inclined in such a way that more light can exit the respective optical surface segment than would exit the respective virtual basic shape or a virtual basic shape surface segment corresponding to the respective optical surface segment, and / or optical surface segments are inclined in such a way that, in an end region of the optical fiber, viewed in the direction of the longitudinal extent of the optical fiber, the reflected light is reflected into a larger area than would be the case with the virtual basic surface or a virtual basic shape surface segment corresponding to the respective optical surface segment.

[0028] In particular, it may be provided that the optical surface segments are each inclined at an angle, the magnitude of which is greater than 0° and less than 90°, relative to a central longitudinal axis of the light guide.

[0029] The "central axis" of the optical fiber is, for example, an axis in the longitudinal extent of the optical fiber that connects the geometric centers of the cross-sectional areas along the longitudinal extent of the optical fiber that are normal to this axis.

[0030] Depending on the situation, it may be advantageous to reflect the light at the surfaces in a specific direction (in this case, surfaces are preferably inclined at an angle of 0° to 45° to the center line, i.e., to a central longitudinal axis of the light guide) or to direct the light out through them in a specific direction (preferably at an angle of 45° to 90°).

[0031] It can be provided that all optical surface segments are inclined in the same direction, or that one or more optical surface segments of the optical surface segments are inclined in one direction and the other optical surface segments in the opposite direction.

[0032] This allows the light to be "divided" over a wider angular range, thereby reducing the intensity of a hotspot in a specific viewing direction from which an external observer is looking at the lighting device.

[0033] Furthermore, it may be provided that connecting surfaces are arranged between the optical surface segments due to an offset of the surface segments to each other in the direction of a central longitudinal axis of the light guide, which arises, for example, from an inclination of the optical surface segments to the virtual base surface.

[0034] The angle of the connecting surfaces or offset surfaces with respect to the longitudinal axis of the optical fiber can preferably be up to 45°. Larger angles can also be provided, so that at such inclined connecting surfaces, instead of reflection, the light rays pass through the optical fiber with corresponding refraction in a desired direction.

[0035] For example, the virtual base surface may be curved, e.g. parabolic, hyperbolic, or following the shape of an ellipsoid, or be planar.

[0036] It can be provided that the virtual basic shape is formed from one or more surface areas, wherein preferably each surface area is continuous in itself, and wherein different surface areas connect to each other discontinuously, e.g. step-like, or transition into each other.

[0037] The virtual base can be formed, for example, as a single continuous surface; it can also be formed from two or more individual surfaces. Adjacent individual surfaces of the virtual interface can be stepped or merge seamlessly into one another. Preferably, the steps extend from the rear face of the at least one optical fiber to its front face. One, more, or all of these individual surfaces can then contain optical surface segments, as described above.

[0038] The continuous surface or the individual surfaces can be flat. For example, the individual surfaces can be arranged parallel to each other. The continuous surface or the individual surfaces can be inclined at a defined angle to the longitudinal axis. In this way, for example, the virtual base surface and thus the end surface can be adapted to the shape of the headlight housing and / or other optical elements, e.g., to the shape of a thick-walled optic mounted in front of the light guide.

[0039] It may be provided that the individual optical surface segments are flat or planar, or curved, e.g. parabolic, hyperbolic, or following the shape of an ellipsoid.

[0040] It may be provided that the optical surface segments are inclined with respect to a light guide vertical plane and / or with respect to a light guide horizontal plane.

[0041] In this context, it may be provided that some or all of the optical surface segments are inclined at a different angle to the optical fiber vertical plane than to the optical fiber horizontal plane.

[0042] The optical fiber vertical plane is a plane which contains the tangent to the central longitudinal axis of the optical fiber at the point of intersection with the virtual base surface, whereby this plane is oriented approximately normal to the direction of light emission of the optical fiber.

[0043] The optical fiber horizontal plane H is a plane which contains the tangent to the longitudinal axis of the optical fiber at the point of penetration through the virtual base, wherein this plane is oriented normal to the optical fiber vertical plane.

[0044] It should be noted here that the terms "vertical" and "horizontal" are correct when the light guide, in its installed position in a motor vehicle, is approximately horizontal and, for example, positioned perpendicular to the direction of travel. If, however, the light guide is mounted vertically, so that its longitudinal extent runs more or less vertically, the plane referred to here as the light guide "horizontal" plane is actually a second vertical plane. If the light guide is in any arbitrarily "rotated" position, neither the light guide's vertical plane nor its horizontal plane is horizontal.

[0045] For example, it is planned that the optical surface segments are arranged in a grid-like pattern in rows and columns.

[0046] Furthermore, according to the invention, the finishing surface in an edge area, in particular in a circumferential, self-contained edge area which encloses the optical surface segments, corresponds to the virtual base area, wherein a texture, e.g. a regular or irregular geometric texture, is provided in the edge area.

[0047] At this edge, which may be useful or necessary for manufacturing and / or lighting purposes, light is still reflected back into the optical fiber. This can be used to precisely control the amount of light at the end of the optical fiber. If too much light is reflected, a textured surface can remedy this by scattering the reflected light more strongly, thus mitigating or preventing adverse effects caused by concentrating light rays in a specific area, which in turn can prevent or reduce hotspots.

[0048] The term "graining" generally refers to a surface or surface structure that is designed, particularly irregularly, in such a way that light is diffusely reflected and / or diffusely refracted (upon passing through). For example, the "roughness depth" of the graining can be adjusted to determine how "coarse" the graining or surface structure is.

[0049] Furthermore, according to the invention, an optic, such as a diffuser or a thick-walled optic, is arranged in the direction of light emission after the light coupling surface of the light guide, wherein preferably the shape of the virtual base surface of the termination surface of a contour of an end surface of the optic lies in a common plane with it.

[0050] This optical system has at least one optical light entry surface, which is designed to refract incident light rays into the optical system. Light or light rays exiting the optical output surface of the optical element strike the optical surface of the optical system, pass through the optical system, and exit again at an optical output surface of the optical system to form a signaling function and / or a light distribution.

[0051] For example, the optical light entry surface is designed in the form of a plane, and / or it runs parallel to the light output coupling surface of the optical fiber.

[0052] The optics may include several optical elements, e.g., on the optical light entry surface and / or on an optical light exit surface facing away from the optical light entry surface, e.g., micro-optics and / or cushion optics and / or facet optics, wherein preferably the optical elements on the active surface are configured to scatter incident light, and / or wherein the optical elements of the optical light exit surface are configured to align the light exiting via the optical light exit surface so that it is emitted in the required direction and / or is further fanned out or scattered.

[0053] At its lateral end, in the region of the optical fiber end or termination surface, the optic has an end surface. Preferably, the shape of the virtual base of the termination surface and this end surface merge seamlessly; that is, if the virtual base were conceptually extended, it would connect directly, and in particular continuously, to the end surface of the optic. In this way, the entire optic can be illuminated.

[0054] In other words, preferably the end of the light guide is beveled so that the trimming follows the contour of the optics.

[0055] At least one light source is designed as an LED, for example, or includes at least one LED.

[0056] The "central axis" of an optical fiber is an axis in the longitudinal extent of the optical fiber that connects the geometric centers of the cross-sectional areas along the longitudinal extent of the optical fiber that are normal to this axis.

[0057] The above-mentioned task is further solved with a lighting unit described above, which is designed as a motor vehicle headlight.

[0058] Furthermore, the above-mentioned task is solved with a motor vehicle headlight which has one or more of the lighting devices described above.

[0059] The invention is discussed in more detail below with reference to the drawing. This drawing shows Fig. 1 a front view of a lighting device according to the invention with two light guides in an exploded view, Fig. 2 a light guide for use in a lighting device Figure 1 , Fig. 3a perspective view of the end region of an optical fiber according to the invention from a rear oblique angle, Fig. 4 the end area from Figure 3 in an enlarged view, Fig. 5 the representation from Figure 3 in a side view, Fig. 6 a schematic top view of a light guide with upstream optics, and Fig. 7 the representation from Figure 6 in a front view in a partially cutaway representation.

[0060] The directional terms used below refer to the installed state of the lighting unit in a motor vehicle or in a motor vehicle headlight, which in turn is installed in a motor vehicle.

[0061] Figure 1Figure 1 shows a lighting device 100 for a motor vehicle for generating at least one lighting function and / or signaling function, wherein the lighting unit 100 has a housing 101 with a housing opening 102 and a cover plate 103 closing the housing opening 102.

[0062] The housing 101 contains two elongated light guides 1, each light guide 1 being assigned a light source 2, as can be seen from one of the light guides 1 in Figure 2 The light source 2 is typically an LED light source, where such an LED light source has one or more light-emitting diodes (LEDs). In principle, other light sources can also be used.

[0063] Generally speaking, it should be noted that Figure 1This is merely one example, in this case with two light guides. The invention also encompasses lighting devices with only one or with multiple light guides.

[0064] The two light guides 1 are held in the housing 101 by a holder 15 as an example. The holder 15 can be clipped to the housing 101 or otherwise attached to it.

[0065] Each of the light guides 1 is followed in the light emission direction X by an optic 300, as shown in Figure 1The optics can, of course, also be manufactured as a single unit. These optics are, for example, so-called thick-walled optics, into which the light guides 1 feed the light they emit. In the optical bodies 300, this light propagates, for example by means of total internal reflection, and exits at a front face of the respective optical body 300 and is emitted through the cover plate 103 into an area in front of the illumination unit 100, where it creates a desired light distribution or part of a light distribution or a signaling function.

[0066] The light distribution produced by a light guide 1, 2 is rather broadly scattered; the thick-walled optics collect the light by total internal reflection and thus form a sharply defined luminous surface on its front side, where the light exits.

[0067] Instead of the thick-walled optics, a diffuser lens can also be used, for example.

[0068] The cover plate can be completely clear, but it can also have an optical structure to influence the light passing through it.

[0069] The lighting unit shown in the present example is designed to implement daytime running lights, which typically should have a homogeneous lighting effect characterized by its shape. However, other lighting functions, such as a turn signal, brake light, tail light, position light, rear fog light, etc., can also be implemented with a lighting unit according to the invention.

[0070] Figure 2 ,As already mentioned, Figure 1 shows a light guide 1 of the lighting unit 100, with a light source 2, which is, for example, arranged on a heat sink 17. The light guide 1 consists of an optically transparent material in which light from the light source 2 can be coupled into the light guide 1 via an coupling area 10.

[0071] On its front side, the light guide 1 has a light output surface 11 and on a rear side opposite the front side a light deflection surface 12, so that light coupled into the light guide 1 from the light source 2, which propagates in the light guide 1 by means of total internal reflection, is deflected at the light deflection surface 12 and can exit the light guide 1 via the light output surface 11.

[0072] For example, the light deflection surface 12 – generally, i.e., not limited to the embodiment shown – comprises in a known manner a plurality of prismatic, preferably adjacent, elements which deflect light incident on the light deflection surface 12, which propagates along the light guide 1 in it, to the front side, where it can exit via the light coupling surface / light exit surface 11 as already described above.

[0073] Furthermore, the optical fiber 1 has a termination surface 21 in an end section 20, which limits the optical fiber 1. The termination surface 21 is formed from a light-transmitting material of the optical fiber 1.

[0074] To avoid hotspots in the heat appearance pattern of the light guide 1, which are also visible in the upstream optics 300, as described at the beginning, it is provided that – as is particularly evident in Figure 3 and Figure 4 as well as the Figure 5 - 7It is clearly visible that the shape of the end surface 21 follows the shape of a virtual base surface 30, whereby at least in areas of the virtual base surface 30, targeted deviations from the shape of the virtual base surface 30 are provided. These targeted deviations result from several optical surface segments 40, such that the end surface 21 is formed by the optical surface segments 40 in the areas where a targeted deviation exists and corresponds to the virtual base surface 30 in the areas without deviation.

[0075] The optical surface segments 40, i.e., their shape and arrangement, or the termination surface segment formed by each individual surface segment 40, deviates from the virtual base surface 30 in such a way that more light can exit the optical guide 1 from each optical surface segment 40 than via a corresponding virtual base shape surface segment 30a, and / or each optical surface segment 40 reflects light propagating in the optical guide 1 up to the termination surface 21 in such a way that the amount of light exiting the light coupling surface 11 per unit area in an end section 20 of the optical guide 1 is less than would be the case with reflection at the virtual base surface 30.

[0076] The virtual basic shape surface segment 30a corresponding to a respective optical surface segment 40 is obtained, for example, by projecting this optical surface segment 40 onto the virtual base surface 30.

[0077] Figure 5 and in particular Figure 6 The figures show exemplary light rays in the light guide 1. An exemplary light ray S1 can be seen, which has propagated in the light guide 1 up to the termination surface 21 and strikes it.

[0078] If the termination surface were formed entirely from the virtual base surface 30, for example a plane inclined obliquely to the central longitudinal axis Y of the optical fiber 1, the light ray S1 would be reflected and, as shown, emerge from the optical fiber 1 as light ray S2 and pass through the optics 300.

[0079] Without optical elements, most light rays that are reflected at a similar angle to light ray S1 onto the end surface would be reflected like light ray S2, which can result in an intense hotspot.

[0080] The optical surface elements 40, as shown, can split the light incident on the end surface. A portion of the light is still reflected as light ray S2, for example, the light incident on the edge region 22, which follows the shape of the virtual base 30. Other light rays incident on the optical elements 40, however, are reflected, for example, as light ray S3. In this way, light rays reflected at the end surface 21 can be "distributed" over the end region 20 or beyond by suitable arrangement and / or design of the optical surface elements 40, thus avoiding hotspots or significantly reducing their intensity.

[0081] Alternatively or additionally, it is also possible that light rays S4 exit the light guide 1 via optical surface elements 40 and the termination surface 21 and do not contribute to a hotspot.

[0082] Alternatively or additionally, it is also possible that light rays S5 are reflected back into the light guide 1 via optical surface elements 40 and thus cannot contribute to a hotspot.

[0083] Ideally, the optical surface elements 40 are designed in such a way that all these effects occur together.

[0084] It should be noted that the radiation pattern shown is purely schematic and is only intended to illustrate the basic functionality of the invention.

[0085] Specifically, as shown, it can be provided that the optical surface segments 40 are arranged inclined to the virtual base surface 30.

[0086] In particular, it may be provided that each optical surface segment 40 is individually arranged with regard to its inclination and / or with regard to its shape and / or with regard to its size, in particular the size of its area.

[0087] The optical surface segments can be identical with respect to one, several, or all of the parameters listed above (inclination, shape, size); this simplifies calculation and / or manufacturing. Individual design of the optical surface segments with respect to one, several, or all of the parameters listed above can allow for an even more targeted reduction or avoidance of hotspots.

[0088] The optical surface segments 40 are inclined such that more light can exit the respective optical surface segment 40 and thus the light guide 1 than light would exit the respective virtual basic shape 30 or a virtual basic shape surface segment 30a corresponding to the respective optical surface segment 40, and / or optical surface segments 40 are inclined such that in an end region 20 of the light guide 1, viewed in the direction of the longitudinal extent of the light guide 1, the reflected light is reflected into a larger area than would be the case with the virtual basic surface 30 or with a virtual basic shape surface segment 30a corresponding to the respective optical surface segment 40.

[0089] In particular, it can be provided that the optical surface segments 40 are each inclined at an angle, the magnitude of which is greater than 0° and less than 90°, relative to the central longitudinal axis Y of the optical fiber 1.

[0090] Depending on the situation, it may be advantageous to reflect the light at the surfaces in a specific direction (in this case, surfaces are preferably inclined at an angle of 0° to 45° to the center line, i.e., to a central longitudinal axis of the light guide) or to direct the light out through them in a specific direction (preferably at an angle of 45° to 90°).

[0091] It can be provided that all optical surface segments 40 are inclined in the same direction as shown, or that one or more optical surface segments of the optical surface segments are inclined in one direction and the other optical surface segments in the opposite direction.

[0092] Furthermore, it can be provided that connecting surfaces 41 are arranged between the optical surface segments 40 due to an offset of the surface segments 40 to each other in the direction of a central longitudinal axis Y of the light guide 1, which arises, for example, from an inclination of the optical surface segments 40 to the virtual base surface 30, as is particularly the case in Figure 4 It is clearly visible.

[0093] The angle of the connecting surfaces 41 or offset surfaces with respect to the longitudinal axis Y of the optical fiber can preferably be up to 45°. Larger angles can also be provided so that, at such inclined connecting surfaces, no reflection occurs, but rather the light rays pass through the optical fiber with corresponding refraction in a desired direction.

[0094] For example, it may be provided that the virtual base 30 is curved, e.g. parabolic, hyperbolic, or following the shape of an ellipsoid, or is planar.

[0095] In the example shown, the virtual base area 30 and therefore also the boundary area 22 is a plane.

[0096] The individual optical surface segments 40 can be flat or planar, as shown. Alternatively, they can be curved, e.g., parabolic, hyperbolic, or following the shape of an ellipsoid.

[0097] It can be provided that the optical surface segments 40 are inclined with respect to a light guide vertical plane V and / or with respect to a light guide horizontal plane H, wherein the planes V, H in Figure 5 are shown.

[0098] The optical fiber vertical plane V is a plane which contains the tangent to the central longitudinal axis Y of the optical fiber 1 at the point of intersection P through the virtual base 30, wherein this plane is oriented approximately normal to the direction of light emission of the optical fiber 1.

[0099] The optical fiber horizontal plane H is a plane which contains the tangent to the longitudinal axis Y of the optical fiber 1 at the point of intersection P through the virtual base 30, wherein this plane is oriented normal to the optical fiber vertical plane V.

[0100] It should be noted here that the terms "vertical" and "horizontal" are correct when the light guide, in its installed position in a motor vehicle, is approximately horizontal and, for example, arranged perpendicular to the direction of travel of the vehicle. If, however, the light guide is arranged vertically, so that its longitudinal extent runs more from top to bottom, the plane referred to here as the light guide "horizontal" plane is actually a second vertical plane. In any "rotated" position of the light guide, neither the light guide vertical plane V nor the light guide horizontal plane H is vertical.

[0101] For example, it is planned that the optical surface segments 40 are arranged in a grid-like pattern in rows and columns.

[0102] In the example shown, the end surface 21 has, as already described, a continuous, self-contained edge region 22 which encloses the optical surface segments 40. A texture, e.g., a regular or irregular geometric texture, is provided in the edge region 22.

[0103] At this edge, which may be useful or necessary for manufacturing and / or lighting purposes, light is still reflected back into the optical fiber. This can be used to precisely control the amount of light at the end of the optical fiber. If too much light is reflected, a textured surface can remedy this by scattering the reflected light more strongly, thus mitigating or preventing adverse effects caused by concentrating light rays in a specific area.

[0104] As explained above, an optic 300, such as a diffuser or, as shown, a thick-walled optic, can be arranged in the light emission direction X (for example, the "light emission direction" of the optical fiber 1 denotes the resulting component of all light rays exiting the optical fiber via the light coupling surface 11) after the light coupling surface 11 of the optical fiber 1. Preferably, the optic is spaced apart in the direction of the optical fiber 1. Preferably, the shape of the virtual base 30 of the end surface 21 follows the contour of an end surface 330 of the optic 300, and in particular lies in a common plane with it.

[0105] In other words, the shape of the virtual base 30 of the end surface 21 and the end surface 330 merge seamlessly; that is, if the virtual base 30 were conceptually extended, it would connect directly, and in particular continuously, to the end surface 330 of the optic 300. In this way, the entire optic 300 can be illuminated by the light guide 1.

[0106] Finally, it should be noted that the optics 300, as shown, has an optical light entry surface 310, which is designed to refract incident light rays into the optics 300. Light or light rays exiting the light output surface 11 of the optical fiber 1 strike the light entry surface 310 of the optics 300, pass through the optics 300, i.e., through the optically transparent material that forms the optics 300, and exit at a light exit surface 320 of the optics 300 to form a signaling function and / or a light distribution.

[0107] For example, the optical light entry surface 310 is designed in the form of a plane or is planar, and / or it runs parallel to the light output coupling surface 11 of the light guide 1.

[0108] The optics 300 may be provided to have several optical elements 311, 321, e.g. optical elements 311 on the optical light entry surface 310 and / or optical elements 321 on the optical light exit surface 320 facing away from the light entry surface 310, e.g. micro-optics and / or cushion optics and / or facet optics, wherein preferably the optical elements 311 on the light entry surface 310 are configured to scatter incident light, and / or wherein the optical elements of the optical light exit surface are configured to emit the light exiting via the optical light exit surface in a required direction and / or to further fan out or scatter it.

[0109] The "central axis" Y of an optical fiber is, for example, an axis in the longitudinal extent of the optical fiber that connects the geometric centers of the cross-sectional areas along the longitudinal extent of the optical fiber that are normal to this axis.

Claims

1. Lighting device (100) for a motor vehicle for generating at least one lighting function and / or signaling function, wherein the lighting unit (100) has a housing (101) with a housing opening (102), wherein the housing opening (102) is closed, for example, by a cover plate (103), wherein at least one elongated light guide (1) and at least one light source (2) associated with the at least one light guide (1) are arranged in the housing (101), wherein light from the at least one light source (2) is guided through the light guide (1) and emitted through the cover plate (103) - at least one elongated light guide (1) and at least one light source (2) associated with the at least one light guide (1) are arranged, wherein light from the at least one light source (2) can be coupled into the light guide (1) via a coupling area (10) of the at least one light guide (1), - wherein the at least one light guide (1) has a light coupling surface (11) on its front side and a light deflection surface (12) on a rear side opposite the front side, so that light coupled into the at least one light guide (1) from the at least one light source (2) (1) is deflected at the light deflection surface (12) and emitted from the light guide (1) via the light coupling surface (11), wherein the at least one light guide (1) has a terminating surface (21) in an end section (20) which delimits the light guide (1), and wherein the illumination device (100) further comprises an optical system (300), such as a diffuser or a thick-walled optical element, which is arranged in the light exit direction (X) after the light coupling surface (11) of the light guide (1), and the shape of the end surface (21) follows the shape of a virtual base surface (30), wherein the shape of the virtual base surface (30) of the end surface (21) follows a contour of an end surface (330) of the optics (300), in particular lies in a common plane with the latter, and wherein the virtual base surface (30), for example a plane, is inclined at an angle to a central longitudinal axis (Y) of the light guide (1), and wherein, at least in areas of the virtual base surface (30), specific deviations from the shape of the virtual base surface (30) are provided by providing a plurality of optical surface segments (40), wherein the end surface (21) is formed by the optical surface segments (40) in the areas where there is a specific deviation and corresponds to the virtual base surface (30) in the areas without deviation, and wherein the optical surface segments (40) are arranged at an angle to the virtual base surface (30) so that - more light can exit the light guide (1) from one, several, or preferably each optical surface segment (40) than via a virtual basic shape surface segment (30a) corresponding to the respective optical surface segment (40), and / or - one, several or preferably each optical surface segment (40) reflects light propagating in the light guide (1) up to the end surface (21) in such a way that in an end section (20) of the light guide (1) the amount of light emerging from the light coupling surface (11) per surface unit is less than would be the case with reflection at the virtual base surface (30), and wherein the end surface (21) corresponds to the virtual base surface (30) in an edge region (22), in particular in a circumferential, self-enclosed edge region (22) which surrounds the optical surface segments (40), corresponds to the virtual base surface (30), wherein a grain, e.g. a regular or irregular geometric grain, is provided in the edge region (22).

2. Lighting device according to claim 1, wherein the optical surface segments (40) deviate from the virtual base surface (30) in such a way that in an end region of the light guide (1), viewed in the direction of the longitudinal extension of the light guide (1), the reflected light is reflected into a larger area than would be the case with the virtual base area (30).

3. Lighting device according to claim 1 or 2, wherein each optical surface segment (40) is individually arranged with regard to its inclination and / or individually designed with regard to its shape and / or size, in particular the size of its surface area.

4. Lighting device according to claim 3, wherein optical surface segments (40) are inclined in such a way that more light can emerge from the respective optical surface segment (40) than light would emerge from the respective virtual basic shape (30) or from a virtual basic shape surface segment (30a) corresponding to the respective optical surface segment (40), and / or surface segments are inclined such that, in an end region of the light guide, viewed in the direction of the longitudinal extension of the light guide, the reflected light is reflected into a larger area than would be the case with the virtual base surface or with a virtual base shape surface segment corresponding to the respective optical surface segment.

5. Lighting device according to claim 3 or 4, wherein the optical surface segments (40) are each inclined at an angle whose magnitude is greater than 0° and less than 90° relative to a central longitudinal axis (Y) of the light guide.

6. Lighting device according to one of claims 3 to 5, wherein all optical surface segments are inclined in the same direction, or one or more optical surface segments of the optical surface segments are inclined in one direction and the other optical surface segments are inclined in the opposite direction.

7. Lighting device according to one of claims 1 to 6, wherein connecting surfaces (41) are arranged between the optical surface segments (40) due to an offset of the surface segments (40) relative to each other in the direction of a central longitudinal axis (Y) of the light guide (1), which is created, for example, by an inclination of the optical surface segments (40) to the virtual base surface (30).

8. Lighting device according to one of claims 1 to 7, wherein the virtual base surface (30) is curved, e.g., parabolic, hyperbolic, or in the shape of an ellipsoid, or is flat.

9. Lighting device according to one of claims 1 to 8, wherein the virtual base shape (30) is formed from one or more surface areas, wherein preferably each surface area is continuous in itself, and wherein different surface areas are connected to each other or merge into each other in a discontinuous manner, e.g., in a stepped manner.

10. Lighting device according to one of claims 1 to 9, wherein the individual optical surface segments (40) are formed to be flat or curved, e.g., parabolic, hyperbolic, or in the shape of an ellipsoid.

11. Lighting device according to one of claims 1 to 10, wherein the optical surface segments (40) are inclined with respect to a light guide vertical plane (V) and / or with respect to a light guide horizontal plane (H), wherein, for example, some or all of the optical surface segments (40) are inclined at a different angle with respect to the light guide vertical plane (V) than with respect to the light guide horizontal plane (H).

12. Lighting device according to one of claims 1 to 11, wherein the optical surface segments (40) are arranged in rows and columns in a grid-like pattern.

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