DE102017114476B4 - Lighting device of a motor vehicle - Google Patents

Abstract

Lighting device (2) of a motor vehicle, the lighting device (2) comprising at least one light source (18; 18a, 18b) for emitting light (22), at least one optical system (24) for collimating or parallelizing the emitted light (22), at least a transparent body (32) into which the collimated or parallelized light (22) enters via a light entry surface (34) and from which the light (36) that has entered exits again via a light exit surface (38), the light entry surface (34) and the light exit surface (38) represent light passage surfaces of the at least one transparent body (32), and at least one optical element (42) into which the light (36) from the at least one transparent body (32) enters and exits via a light entry surface (44). which the light (46) which has entered exits again via a light exit surface (48), the light which has exited via the light exit surface (48) of the optical element (42). Light (50) is used to generate a signal light function of the lighting device (2), matting with a random surface structure being applied to at least one of the light passage surfaces (34, 38) of the transparent body (32), which is used for random scattering of the light from the transparent body (32) and ensures the most homogeneous possible appearance of the illuminated light exit surface (48) of the optical element (42), characterized in that the at least one optical system (24) comprises at least one light guide plate (56) which a longitudinal extent of the at least one light source (18; 18a, 18b) to the at least one transparent body (32), wherein the light guide plate (56) has a greater extent transversely to the longitudinal extent in a horizontal section than in a vertical section, and one of the at least one light sources (18; 18a, 18b ) facing light entry surface (58) and a light exit surface (60) opposite this, facing the light entry surface (34) of the at least one transparent body (32), and lateral boundary surfaces (62) which connect the light entry surface (58) to the light exit surface (60). and which reflect light beams (22) hitting the boundary surfaces (62) below a critical angle by means of total reflection and that the at least one light guide plate (56) has a stepped light exit surface (60) when viewed in horizontal section.

Description

The present invention relates to a lighting device of a motor vehicle. The lighting device comprises at least one light source for emitting light, at least one optical system for collimating or parallelizing the emitted light, at least one transparent body into which the collimated or parallelized light enters via a light entry surface and from which the light that has entered emerges again via a light exit surface exits, wherein the light entry surface and the light exit surface represent light passage surfaces of the at least one transparent body, and at least one optical element into which the light from the at least one transparent body enters via a light entry surface and from which the light that has entered exits again via a light exit surface. The light exiting via the light exit surface of the optical element is used to generate a signal light function of the lighting device. Furthermore, a frosting with a random surface structure is applied to at least one of the light passage surfaces of the transparent body, which ensures random scattering of the light emerging from the transparent body and the most homogeneous possible appearance of the illuminated light exit surface of the optical element.

Such a lighting device is, for example, from DE 10 2014 110 347 A1 previously known.

A similar lighting device is, for example, from EP 2 372 234 A2 famous. It is proposed there to provide discrete scattering optics, for example in the form of cushion optics, on a light exit surface of the at least one optical element, in order to generate vertical scattering of the exiting light for a signal light function to be fulfilled. The signal light function can be, for example, a position light, a parking light or boundary light, a daytime running light, a turn signal light, a rear light, a brake light, a reversing light, or the like. However, when the lighting device is switched on, the use of scattering optics leads to relatively large local differences in brightness in the area of the light exit surface. This is not illuminated particularly homogeneously and has a characteristic light-dark structure depending on the type, design and arrangement of the scattering optics. For example, a pincushion structure typically has point structures over a certain range of viewing angles, with each pincushion optic producing an illuminated point. The areas between the diffusing optics are significantly darker if no special measures are taken to brighten these areas.

Another similar lighting device in the form of a motor vehicle signal light is, for example, from DE 10 2011 076 621 A1 famous. The light can be used to implement any signal light function. In the known lamp, design surfaces that do not contribute to the generation of the signal light function of the lighting device, but only serve to influence the external appearance of the switched-on lamp, are provided with a frosted pane, so that there is a particularly homogeneously illuminated surface on the outside of the frosted slice results.

A difference between scattering optics and a frosting is seen in the context of the present invention in particular that scattering optics have precisely defined shapes (e.g. prismatic, cylindrical, etc.) and dimensions (e.g. base area, height, distance to adjacent scattering optics, etc.) and are arranged in precisely defined positions on a light entry or light exit surface in order to realize a previously precisely calculated, controlled scattering of the light passing through. This applies even to very small structures with dimensions of the base area in the millimeter range and a height of the scattering optics in the millimeter or even micrometer range (so-called microstructures). In contrast, matting is a scattering structure that is applied to a light entry or light exit surface in a more random pattern, which leads to a random scattering of the light passing through.

Furthermore, it is from the DE 10 2013 227 195 A1 known to arrange a lens in front of a light guide with prism decoupling. From the DE 10 2015 218 134 it is known to use a light guide in a reflector shaft.

Furthermore, from the DE 102 31 326 A1 a lighting unit for vehicles is already known in which, in order to increase the lighting efficiency with a compact design, adjacent light guide elements converge in the direction of the lens at least in a connecting line running transversely to the optical axis, the connecting line running in the light exit direction in or behind the center plane of the lens.

Also revealed the EP 2 530 372 A1 Light guide components for motor vehicle lights, with which both a high optical quality of the motor vehicle light is to be achieved and the manufacturing costs of the same are to be reduced. This is achieved here by a light guide element that at least one provided in the beam path of the light between at least one light coupling part and at least one light decoupling part and in and against at least one direction of light propagation by at least one first optical boundary surface and at least one second optical boundary surface for light guidance, with light incident on at least one light coupling part being refracted in its beam path to at least one light coupling-out part at least on at least one first optical boundary surface and on at least one second optical boundary surface will.

Furthermore, from the EP 2 317 214 A1 a lighting and/or signaling device for a motor vehicle with a light guide is already known.

Ultimately reveals the DE 10 2014 206 593 A1 a motor vehicle light with a wiping effect, which on the one hand wants to achieve a homogeneous appearance and on the other hand a wiping light effect with little effort and, in particular, with lower costs. The motor vehicle light with wiping effect described here achieves this in that the light guide has a deflection surface opposite the light exit surface, which has a first sector and a second sector, and wherein the light guide is set up to direct light coupled in via the first light entry surface preferably towards the first sector and wherein the first sector is arranged to direct the light that is preferentially directed at it towards the first zone, and wherein the second sector is arranged to preferentially direct the light that is preferentially directed towards it towards the second zone, and wherein the first sector is not identical to the second sector.

Proceeding from the prior art described, the object of the present invention is to achieve uniformly luminous light exit surfaces of the at least one optical element of the lighting device.

Starting with the lighting device of the type mentioned at the outset, this object is achieved in that it comprises at least one light guide plate which has a longitudinal extent from the at least one light source to the at least one transparent body, the light guide plate having a greater extent transversely to the longitudinal extent in a horizontal section has than in a vertical section. In addition, the light guide plate has a light entry surface facing the at least one light source and a light exit surface opposite this, facing the light entry surface of the at least one transparent body, and lateral boundary surfaces which connect the light entry surface to the light exit surface and which reflect light rays impinging on the boundary surfaces below a critical angle by means of total reflection . The at least one light source is arranged in front of an end face of the light guide plate, with the main emission direction of the light source being directed in the direction of the end face, so that the emitted light enters the light guide plate via the end face. There, the light propagates through the light guide plate along its length by means of total reflection at the lateral boundary surfaces. Opposite boundary surfaces of the transparent body can run parallel to one another or at an angle to one another. The light then exits the light guide plate again on an end face opposite the end face through which the light entered. In addition, the at least one light guide plate has a stepped light exit surface when viewed in the horizontal section. The lateral boundary surfaces of the at least one light guide plate, viewed in the horizontal section, preferably run towards the at least one light source assigned to the respective light guide plate in a rear section of the respective light guide plate. Starting from the light entry surface of each light guide plate, this becomes wider in the horizontal section, ie in the direction of light propagation.

The fluctuations in brightness on the at least one light exit surface of the at least one optical element are significantly lower than when using diffusing optics due to the frosting of at least one of the light exit surfaces. In this respect, the present invention already means a significant improvement over the prior art, even if—in particular if only one of the two light passage surfaces is provided with a frosting—small fluctuations in brightness can still be discernible with the human eye. A slow, continuous brightness progression with brightness changes of less than 50% is hardly perceived as such by the human eye. If a frosting is arranged on both light passage surfaces of the transparent body, changes in brightness of less than 50% can be achieved. In principle, the fluctuations in brightness are washed out in such a way that the changes in brightness are no longer visible to the human eye.

In order to achieve further homogenization of the light exit surface of the at least one optical element, it is proposed that a frosting with a random surface structure is additionally applied to the light entrance surface and/or the light exit surface of the optical element, which ensures random scattering of the light emitted by the optical element Element passing light provides.

According to an advantageous development of the invention, it is proposed that at least an optical system comprises at least one reflector shaft, each of which has a longitudinal extension starting from at least one of a plurality of light sources to the at least one transparent body, and which each has lateral reflection surfaces which, viewed in a horizontal section, starting from the at least one light source, widen along the longitudinal extension . In a vertical section, starting from the at least one light source, they can narrow or widen along the longitudinal extension or run parallel to one another. In the vertical section, the light beams are bundled in particular by the light exit surface of the transparent body, which is curved in the vertical section. In this respect, an additional bundling of the light beams in the vertical section by the reflection surfaces of the reflector shaft can actually be dispensed with. A bundling of the light beams through the reflector shaft is achieved by reflecting surfaces that diverge in the longitudinal extension. The light is not bundled as a result of reflection surfaces running parallel to one another along the longitudinal extent of the reflector shaft. A (slight) scattering of the light in the vertical section is even achieved by convergent reflection surfaces in the vertical section, but this can be compensated for again by the curvature of the light exit surface of the transparent body or even converted into a bundling of the light rays in the vertical section.

The light emitted by the at least one light source is coupled into the reflector shaft, where it is bundled in a horizontal plane, but rather scattered in a vertical plane. The bundling in the vertical plane can then take place later in the beam path, in particular in the downstream transparent body and/or in the optical element. The reflective surfaces are preferably mirrored and either glossy or slightly frosted. Several of these reflector shafts in horizontal section can be lined up along a desired luminaire contour. In this way, curved, curved or even round or oval luminaire contours can be realized.

The light emerging from the reflector shaft or the light guide plate preferably enters the transparent body completely via the light entry surface of the latter. This can be realized, for example, in that the light guide plate is also arranged in a reflector shaft and a light exit opening of the reflector shaft is connected to the light entry surface of the transparent body in a light-tight manner.

According to a preferred embodiment, it is proposed that the at least one transparent body comprises an intermediate pane made of a transparent glass or plastic material, which has a longitudinal extent transverse to a longitudinal extent of the at least one optical system. In particular, it is proposed that the intermediate pane, viewed in a horizontal section, extends along the light exit opening(s) of the at least one reflector shaft.

The light entry surface and the light exit surface of the at least one transparent body are advantageously formed on opposite sides of the intermediate pane. In particular, it is proposed that the light entry surface of the intermediate pane, viewed in a horizontal section, extends along the light exit opening(s) of the at least one reflector shaft.

According to another preferred embodiment, it is proposed that the at least one optical element is designed as a cylindrical lens, which has a longitudinal extent transverse to a longitudinal extent of the at least one optical system. The longitudinal extent of the cylindrical lens preferably runs parallel to the longitudinal extent of the transparent body or the intermediate pane. The light entry surface and the light exit surface of the at least one optical element are advantageously formed on opposite sides of the cylindrical lens. In particular, it is proposed that the light entry surface of the cylindrical lens, viewed in a horizontal section, extends along the light exit surface(s) of the at least one transparent body. Viewed in a vertical section, the light exit surface of the cylindrical lens has a convex, round or elliptical profile. Viewed in a vertical section, the light entry surface of the cylindrical lens can be flat or slightly convex. It is particularly preferred if a radius of the convexly curved light exit surface is smaller (ie the surface is more strongly curved) than a radius of a convexly curved light entry surface.

According to another advantageous development of the invention, it is proposed that a frosting with a random surface structure is applied to the light entry surface and/or the light exit surface of the cylindrical lens, which ensures random scattering of the light passing through the cylindrical lens in order to ensure the most homogeneously illuminated appearance possible the light exit surface of the cylindrical lens.

According to a further preferred embodiment of the invention, it is proposed that the at least one transparent body or the Intermediate disc and the at least one optical element or the cylindrical lens are formed in one piece as a single integral component. In this case, therefore, there is no air gap between the light exit surface of the transparent body and the light entry surface of the optical element. Rather, the transparent body and the optical element merge into one another in the area of these surfaces. Only the light entry surface of the transparent body and the light exit surface of the optical element remain for a possible matting.

Furthermore, it is proposed that at least one light passage surface of the at least one transparent body is provided with scattering optics, which implement a precisely defined surface structure and ensure a defined scattering of the light passing through. The matting can also be applied to the surface of the scattering optics or the corresponding light passage surface provided with scattering optics. The scattering optics can be designed as cushion or cylinder structures, preferably each with dimensions of a base area in the millimeter range and a height of the scattering optics in the micrometer range.

It is particularly preferred if the scattering optics are applied to a thin film. The foil can consist of a transparent material and form the transparent body itself. Or the film is attached to the at least one light passage surface of a separate transparent body.

According to a further preferred development of the invention, it is proposed that the at least one optical system for collimating or parallelizing the light emitted by the at least one light source comprises at least one reflector which has a parabolic shape at least in a horizontal section, the at least one light source being in the region of a Focal point of the at least one reflector is arranged. The at least one reflector can also have a parabolic shape in a vertical section, so that the reflector as a whole has the shape of a paraboloid. Viewed in a horizontal section, it is conceivable to arrange a plurality of reflectors next to one another along the length of the at least one transparent body and along the light entry surface of the at least one transparent body, so that the entire light entry surface can be exposed to collimated light from the reflectors.

According to yet another development of the present invention, it is proposed that the at least one optical element has a complex three-dimensional shape, the at least one optical element having a plurality of discrete sections viewed in a horizontal section and/or in a vertical section, which together form the complex three-dimensional optical Form the element, and opaque screen elements are provided between these sections on a light exit surface of the at least one transparent body in order to prevent light from escaping from the at least one transparent body in a region between the sections. The screen elements are preferably produced together with the at least one transparent body in a so-called 2K (two-component) injection molding process. Finally, it is proposed that the panel elements include a dark, preferably black, coating.

• 1 eine erfindungsgemäße Beleuchtungseinrichtung gemäß einer bevorzugten Ausführungsform;
• 2 einen Vertikalschnitt durch eine Leuchteneinheit einer erfindungsgemäßen Beleuchtungseinrichtung gemäß einer weiteren bevorzugten Ausführungsform;
• 3 einen Horizontalschnitt durch die Leuchteneinheit aus 2;
• 4 einen Vertikalschnitt durch eine Leuchteneinheit einer erfindungsgemäßen Beleuchtungseinrichtung gemäß einer weiteren bevorzugten Ausführungsform;
• 5 einen Vertikalschnitt durch eine Leuchteneinheit einer erfindungsgemäßen Beleuchtungseinrichtung gemäß einer weiteren bevorzugten Ausführungsform;
• 6 eine Leuchteneinheit einer erfindungsgemäßen Beleuchtungseinrichtung gemäß einer weiteren bevorzugten Ausführungsform, umfassend einen Reflektorschacht, einen schmalen Lichtleiter und eine Linse;
• 7 eine Leuchteneinheit einer erfindungsgemäßen Beleuchtungseinrichtung gemäß einer weiteren bevorzugten Ausführungsform, umfassend einen Reflektorschacht und eine Linse;
• 8 eine Leuchteneinheit einer erfindungsgemäßen Beleuchtungseinrichtung gemäß einer weiteren bevorzugten Ausführungsform, umfassend einen Reflektorschacht, eine gestufte Lichtleiterplatte und eine Linse;
• 9 eine Leuchteneinheit einer erfindungsgemäßen Beleuchtungseinrichtung gemäß einer weiteren bevorzugten Ausführungsform, umfassend eine gestufte Lichtleiterplatte, einen schmalen Lichtleiter und eine Linse;
• 10 einen Vertikalschnitt durch eine Leuchteneinheit einer erfindungsgemäßen Beleuchtungseinrichtung gemäß einer weiteren bevorzugten Ausführungsform;
• 11 einen Horizontalschnitt durch eine Leuchteneinheit einer erfindungsgemäßen Beleuchtungseinrichtung gemäß einer weiteren bevorzugten Ausführungsform;
• 12 einen Horizontalschnitt durch eine Leuchteneinheit einer erfindungsgemäßen Beleuchtungseinrichtung gemäß einer weiteren bevorzugten Ausführungsform;
• 13 eine perspektivische Ansicht einer Leuchteneinheit einer erfindungsgemäßen Beleuchtungseinrichtung gemäß einer weiteren bevorzugten Ausführungsform;
• 14 eine Visualisierung eines beleuchteten optischen Elements der Leuchteneinheit aus 13;
• 15 einen Horizontalschnitt durch eine Leuchteneinheit einer erfindungsgemäßen Beleuchtungseinrichtung gemäß einer weiteren bevorzugten Ausführungsform;
• 16 einen Horizontalschnitt durch eine Leuchteneinheit einer erfindungsgemäßen Beleuchtungseinrichtung gemäß einer weiteren bevorzugten Ausführungsform;
• 17 einen Ausschnitt der Leuchteneinheit aus 13;
• 18 eine perspektivische Ansicht der Leuchteneinheit aus 13;
• 19 eine perspektivische Ansicht von vorne einer Leuchteneinheit einer erfindungsgemäßen Beleuchtungseinrichtung gemäß einer weiteren bevorzugten Ausführungsform;
• 20 eine perspektivische Ansicht von hinten der Leuchteneinheit aus 19;
• 21 einen Vertikalschnitt durch die Leuchteneinheit aus 19;
• 22 eine Lichtverteilung der Leuchteneinheit aus 19 auf einem Messschirm; und
• 23 eine Visualisierung eines beleuchteten optischen Elements der Leuchteneinheit aus 19.

Further features and advantages of the present invention are explained in more detail below with reference to the figures. The features shown in the various exemplary embodiments of the figures can also be individually significant for the present invention or can be present in combinations other than those shown in the exemplary embodiments. Show it:

• 1 a lighting device according to the invention according to a preferred embodiment;
• 2 a vertical section through a lighting unit of a lighting device according to the invention according to a further preferred embodiment;
• 3 a horizontal section through the lighting unit 2 ;
• 4 a vertical section through a lighting unit of a lighting device according to the invention according to a further preferred embodiment;
• 5 a vertical section through a lighting unit of a lighting device according to the invention according to a further preferred embodiment;
• 6 a lighting unit of a lighting device according to the invention according to a further preferred embodiment, comprising a reflector shaft, a narrow light guide and a lens;
• 7 a lighting unit of a lighting device according to the invention according to a further preferred embodiment, comprising a reflector shaft and a lens;
• 8th a lighting unit of a lighting device according to the invention according to a further preferred embodiment, comprehend send a reflector shaft, a stepped light guide plate and a lens;
• 9 a lamp unit of a lighting device according to the invention according to a further preferred embodiment, comprising a stepped light guide plate, a narrow light guide and a lens;
• 10 a vertical section through a lighting unit of a lighting device according to the invention according to a further preferred embodiment;
• 11 a horizontal section through a lighting unit of a lighting device according to the invention according to a further preferred embodiment;
• 12 a horizontal section through a lighting unit of a lighting device according to the invention according to a further preferred embodiment;
• 13 a perspective view of a lighting unit of a lighting device according to the invention according to a further preferred embodiment;
• 14 a visualization of an illuminated optical element of the lighting unit 13 ;
• 15 a horizontal section through a lighting unit of a lighting device according to the invention according to a further preferred embodiment;
• 16 a horizontal section through a lighting unit of a lighting device according to the invention according to a further preferred embodiment;
• 17 a section of the lighting unit 13 ;
• 18 a perspective view of the lamp unit 13 ;
• 19 a perspective view from the front of a lighting unit of a lighting device according to the invention according to a further preferred embodiment;
• 20 12 is a rear perspective view of the lamp unit 19 ;
• 21 a vertical section through the lighting unit 19 ;
• 22 a light distribution of the lighting unit 19 on a measuring screen; and
• 23 a visualization of an illuminated optical element of the lighting unit 19 .

In 1 a lighting device according to the invention according to a preferred exemplary embodiment is denoted in its entirety by the reference numeral 2 . In this example, the lighting device 2 is designed as a motor vehicle lamp, which is arranged at a suitable point in the motor vehicle body. However, the lighting device 2 could also be part of a motor vehicle headlight. It comprises a housing 4, which is preferably made of an opaque plastic material. In a light exit direction 6 the housing 4 has a light exit opening 8 which is closed by means of a transparent cover plate 10 . The cover plate 10 is made of plastic or glass, for example. It can be designed with or without optically effective elements for scattering the light passing through. A lighting unit can be seen inside the lighting device 2, which is denoted in its entirety by the reference numeral 12 and which has an annular shape in this example. In this example, the shape of the lighting unit 12 is adapted to the contour of the housing 4 in the area of the light exit opening 8 . Of course, the lighting unit 12 can also only extend along part of the exit opening 8, e.g. along a lower or upper edge and/or along one or both side edges of the exit opening 8. The lighting device 2 according to the invention allows the shape of the lighting unit 12 to be almost arbitrary to vary.

The lighting unit 12 is designed to implement a signal light function and accordingly emits light in the light exit direction 6 to meet the legal requirements for this signal light function. The signal light function can be, for example, a position light, a parking light or boundary light, a daytime running light, a turn signal light, a rear light, a brake light, a reversing light, or the like. In the interior of the housing 4, in particular in the interior of the ring-shaped lighting unit 12, further light modules of the lighting device 2 can be arranged, which are shown only symbolically by a circle 16. The other light modules can also be designed to implement a signal light function. Alternatively, however, it would also be conceivable, for example if the lighting device 2 according to the invention is part of a motor vehicle headlight, for the further light modules to be designed to implement one or more headlight functions. The headlight function can be, for example, a low beam, a high beam, a cornering light, any dynamic headlight function (town light, country road light, freeway light, etc.), a fog light or the like.

The aim of the invention is in particular to propose measures so that a light exit surface surface 14 of the lighting unit 12 lights up as evenly as possible. This goal can be achieved by various measures, which are explained in detail below with reference to the other figures.

In 2 a vertical section through a first exemplary embodiment of the lighting unit 12 as part of the lighting device 2 is shown. The lighting unit 12 comprises at least one light source 18 for emitting light. The light source 18 is preferably designed as a semiconductor light source, in particular as an LED. This emits light 22 in a main emission direction 20 in a 180° hemisphere.

Furthermore, the lamp unit 12 comprises at least one optical system 24 for collimating or parallelizing the emitted light 22 at least in a horizontal plane (cf. 3 ). In the example shown, the optical system 24 includes a reflector shaft 26 ( 2 ) or two reflector shafts 26 arranged next to one another in the horizontal plane ( 3 ). Starting from the at least one light source 18 , each reflector shaft 26 has a longitudinal extension essentially in the direction of the main emission direction 20 of the light source 18 . Each reflector shaft 26 has in the vertical section 2 two sloping boundary surfaces 28 which, starting from the end of the reflector shaft 26 facing the light source 18, run towards one another along the longitudinal extent. This leads to a scattering of the light 22 propagated therein in the vertical section. The greater the scattering of the light 22, the more homogeneously the light exit surface of the lighting unit 12 can be illuminated. The light 22 can be bundled in the vertical section by means of optical components arranged downstream in the beam path. Furthermore, each reflector shaft 26 in a horizontal section (cf. 3 ) has two oblique boundary surfaces 30 which, starting from the end of the reflector shaft 26 facing the light source 18, diverge along the longitudinal extent. This leads to a bundling of the light 22 propagated therein in the horizontal section. The boundary surfaces 28, 30 are preferably mirrored (provided with a reflective coating or made from a material with reflective properties) and are either glossy or slightly frosted.

If several LEDs 18 are provided per reflector shaft 26 (cf. the LEDs 18a, 18b in 3 ), these can emit light 22 of the same or different colors. If several LEDs 18a, 18b are used, they can be controlled and activated separately from one another, for example to control the brightness of the resulting signal light function. When using LEDs 18a, 18b of different colors, these can be activated alternately or one LED 18b is dimmed while the other LED 18a is activated in order to be able to implement different signal light functions with the lighting unit 12 (e.g. white daytime running lights and yellow flashing lights, the white daytime running light LED 18b being inactive or dimmed, while the flashing light function is implemented using the yellow flashing light LED 18a).

Furthermore, the lighting unit 12 comprises at least one transparent body 32 into which the collimated or parallelized light 22 enters via a light entry surface 34 and from which the light 36 that has entered exits again via a light exit surface 38 . The light entry surface 34 and the light exit surface 38 represent light passage surfaces of the at least one transparent body 32. The transparent body 32 is light-tightly connected to the boundary surfaces 28, 30 of the optical system 24, so that if possible all of the light 22 from the optical system 24 in the transparent body 32 passes. In the exemplary embodiment shown, the at least one transparent body 32 comprises an intermediate pane 40 made of a transparent glass or plastic material. The intermediate disk 40 has a longitudinal extent essentially transverse to a longitudinal extent of the at least one optical system 24 . According to 3 the intermediate pane 40 thus extends with its longitudinal extent along the opposite ends of the LEDs 18 (light exit openings) of the reflector shafts 26 of the two lighting units 12 arranged next to one another. Preferably, the light entry surface 34 and the light exit surface 38 of the at least one transparent body 32 are on opposite sides of the intermediate pane 40 educated.

Finally, the lighting unit 12 comprises at least one optical element 42 into which the light 36 from the at least one transparent body 32 enters via a light entry surface 44 and from which the light 46 that has entered exits again via a light exit surface 48 . The light 50 exiting via the light exit surface 48 of the optical element 42 is used to generate the signal light function of the lighting device 2. The light exit surface 48 of the transparent body 32 thus corresponds to the light exit surface 14 of the entire lighting unit 12, which according to the invention is to be illuminated particularly homogeneously. The at least one optical element 42 is preferably embodied as a cylindrical lens 52, which has a longitudinal extent transverse to the longitudinal extent of the at least one optical system 24. According to 3 the cylindrical lens 52 thus extends with its longitudinal extent along the longitudinal extent of the at least one trans parent body 32 or the intermediate disk 40. The light entry surface 44 and the light exit surface 48 of the at least one optical element 42 are preferably formed on opposite sides of the cylindrical lens 52. The light entry surface 44 of the cylindrical lens 52 can be viewed in a vertical section (cf. 2 ) can be flat or slightly convex with a large radius. The light exit surface 48 of the cylindrical lens 52 can be viewed in a vertical section (cf. 2 ) be formed as a lateral surface of a cylinder section with a small radius more convex. In particular, the light exit surface 48 can be curved in a circular (round) or elliptical manner. The small radius of the convex light exit surface 48 is smaller than the large radius of the convex light entry surface 44. The cylindrical lens 52 ensures that the light 46 is focused in a vertical section. Preferably, viewed in a vertical section, the height of the light entry surface 44 is less than the diameter of the cylindrical lens 52. In this case, the cylindrical lens 52 has sloping connecting surfaces 54 in the vertical section, which connect the upper and lower edge of the light entry surface 44 with the upper and lower edge of the light exit surface 48 connect.

In order to improve the homogeneous illumination of the light exit surface 14 of the lighting unit 12, it is proposed that a frosting with a random surface structure be applied to at least one of the light exit surfaces 34, 38 of the transparent body 32, which ensures random scattering of the light 36 and ensures that the illuminated light exit surface 48 of the optical element 42 appears as homogeneous as possible. In the figures, the matting is illustrated by a particularly thick line on the corresponding areas. In the example shown 2 and 3 Both the light entry surface 34 and the light exit surface 38 of the transparent body 32 are provided with a frosting. In addition, the light entry surface 44 and/or the light exit surface 48 of the optical element 42 can also be provided with a frosting with a random surface structure, which ensures random scattering of the light 46 passing through the optical element. In the example of 2 only the light entry surface 44 of the optical element 42 is provided with a frosting. In the example of 3 Both the light entry surface 44 and the light exit surface 48 of the optical element 42 are provided with a frosting. The matting of one or more of the surfaces 34, 38, 44, 48 results in a particularly homogeneous illumination of the light exit surface 14 of the lighting unit 12, which could not be achieved, for example, with discrete scattering optics. The matting can be applied to the desired surface 34, 38, 44, 48, for example, by means of sandblasting. If the transparent body 32 or the optical element 42 is produced in an injection molding process, then the corresponding surfaces in the tool are structured accordingly to produce the frosting, for example by etching.

In 4 is a vertical section of another embodiment of a lighting unit 12 of the lighting device 2 according to the invention. The main difference from the previous embodiments is the configuration of the optical system 24 for collimating or parallelizing the light emitted by the light source 18 at least in a horizontal plane. The optical system 24 comprises at least one light guide plate 56, which has a longitudinal extension from the at least one light source 18 to the at least one transparent body 32 (or the intermediate pane 40), which essentially runs along the longitudinal extension of the reflector shaft 26. For each reflector shaft 26 (cf. e.g 3 ) a separate light guide plate 56 can be provided (in 3 Not shown). The light guide plate 56 has a greater extent, viewed transversely to the longitudinal extent, in a horizontal section than in a vertical section. It also has a light entry surface 58 facing the at least one light source 18 and a light exit surface 60 opposite this, facing the light entry surface 34 of the at least one transparent body 32, and lateral boundary surfaces 62, which connect the light entry surface 58 to the light exit surface 60 and which are below a critical angle the boundary surfaces 62 reflect incident light rays 22 by means of total internal reflection.

In the example shown, the light exit surface 60 of the light guide plate 56 is arranged at a distance from the light entry surface 34 of the transparent body 32, so that there is an air gap between them. The longitudinal extension of the light guide plate 56 runs approximately perpendicularly to the light entry surface 34 of the transparent body 32. The air gap has a constant width in the vertical section.

The light guide plate 56 is preferably arranged in the reflector shaft 26, but could also be provided without such a reflector shaft 26. In practice, however, a reflector shaft 26 will usually be present, and the light guide plate 56 practically fills the entire reflector shaft 26. In this case, at least one outer surface (boundary surface 62, cf. 4 and 5 ) of the light guide plate 56, preferably all outer surfaces, with a reflective coating (cf. 8th and 9 ). In the example of 4 are the surfaces 34, 38, 44 and 48 with a matting verse hen. Of course, only one of the surfaces 34, 38, 44, 48 or fewer than four surfaces could be provided with the frosting.

In 5 a vertical section of a further exemplary embodiment of a lighting unit 12 of the lighting device 2 according to the invention is shown. The longitudinal extent of the light guide plate 56 runs obliquely to the light entry surface 34 of the transparent body 32. In the vertical section, the air gap has a direction from below, ie from the lower edge of light exit surface 60 and light entry surface 34, to the top, ie to the upper edge of light exit surface 60 and light entry surface 34, an increasing width. In the example of 5 the surfaces 34, 38 and 44 are provided with a matt finish. Of course, only one of the surfaces 34, 38, 44, 48 or other surfaces 34, 38, 44, 48 could be provided with the frosting.

A vertical section of another exemplary embodiment of a lighting unit 12 of the lighting device 2 according to the invention is shown in FIG 10 shown. The at least one transparent body 32 or the intermediate pane 40 on the one hand and the at least one optical element 42 or the cylindrical lens 52 on the other hand are designed in one piece as a single integral component. The transparent body 32 and the optical element 42 are thus connected to one another along the surfaces 38, 44 or these surfaces 38, 44 are no longer present since the two parts 32, 42 were produced in one piece as a single component, for example by means of a injection molding process. In this example, only surfaces 34 and 48 are matted. However, it would also be conceivable that only one of the surfaces 34, 48 is provided with the frosting.

the 6 until 9 show new geometry variants for a homogeneous illumination of the light exit surface 48 of the optical element 42 or the lighting unit 12. In 6 until 9 each show in part a) a vertical section, in part b) a side view and in FIG c ) a horizontal section. 6 shows a geometric variant with a reflector shaft 26, a narrow light guide in the form of the intermediate disk 40 and a cylindrical lens 52. In 7 is a geometric variant with a reflector shaft 26, without a narrow light guide in the form of the intermediate pane 40, but again with a cylindrical lens 52. 8th shows a geometric variant with a stepped light guide plate 56, without a narrow light guide in the form of the intermediate disk 40, but again with a cylindrical lens 52, the entry surface 44 extends along the stepped exit surface 60 of the light guide plate 56. In 9 Finally, a geometric variant with a stepped light guide plate 56, a narrow light guide in the form of the intermediate disk 40, and with a cylindrical lens 52 is shown. The entry surface 34 of the intermediate disk 42 extends along the stepped exit surface 60 of the light guide plate 56.

It is also proposed that at least one light passage surface 34, 38 of the at least one transparent body 32 be equipped with diffusing optics 64 (cf. 11 , 12 , 15 , 16 ) is provided, which realize a precisely defined surface structure and which ensure a defined scattering of the light passing through. The figures mentioned each show a horizontal section through various other exemplary embodiments of the lighting unit 12. The scattering optics 64 can be designed, for example, as cushion or cylinder structures, preferably with dimensions of a base area in the millimeter range and a height of the scattering optics in the micrometer range. Of course, in the embodiments of 2 until 5 and 10 Scattering optics can be formed or applied on one of the light passage surfaces 34, 38. In the examples of the figures mentioned, the scattering optics 64 are only arranged on the light entry surface 34 of the transparent body 32 .

A frosting can also be applied to the surface of the diffusing optics 64 or to the areas 34 and/or 38 surrounding them, with the dimensions of the structural elements of the frosting, which cause the uncoordinated (random) scattering of the light passing through, both with regard to the base area as well as in height in the micrometer range. Fluctuations in brightness on the light exit surface 14 of the lighting element 12 due to the diffusing optics 64 can already be significantly reduced by a frosting applied on one side. If the matting is then applied to at least two of the surfaces 34, 38, 44, 48, the differences in brightness can be washed out and reduced to less than 50% so that they can usually no longer be perceived by the human eye.

It is particularly preferred if the scattering optics 64 on a thin film, such as the film 70 from the 13 and 14 , are applied, which in turn is attached to the at least one light passage surface 34, 38 of the at least one transparent body 32. If a transparent film 70 is used, an additional separate transparent body 32 can also be dispensed with, in which case the film 70 itself then forms the transparent body 32 with the diffusing optics 64 and the frosting on one or both sides of the film. The scattering optics 64 can also be designed as extra parts or on the surfaces 34, 38 of the at least one transparent body 32 can be integrated.

In the examples of 11 , 12 , 15 , 16 the at least one optical element 42 preferably has a complex three-dimensional shape, as is the case, for example, in 13 is shown. Viewed in a horizontal section and/or in a vertical section, the at least one optical element 42 has a plurality of discrete sections 66 which together form the complex three-dimensional optical element 42 . Opaque screen elements 68 are provided between these sections 66 on a light exit surface 38 or on a light entry surface 34 of the at least one transparent body 32 in order to prevent light from escaping from the at least one transparent body 32 into an area between the sections 66. The panel elements 68 can, for example, be produced together with the transparent body 32 as part of a 2K injection molding process. It would be conceivable, for example, to inject the transparent body 32 and then in a second step to inject a black component for the screen elements 68 over the transparent material. It would also be conceivable to place the complex three-dimensional optical element 42 on one side 72 of a thin transparent film 70 (cf. 13 and 14 ) to be designed, on the other side 74, which faces the optical system 24 for collimating or parallelizing the emitted light 22, scattering optics 64 (in Figs 13 and 14 not shown) and the frosting can be formed. In this case, the foil 70 forms the transparent body 32 itself. The screen elements 68 can be provided as an opaque, e.g. black coating 76 (cf. 14 ) can be executed on one of the sides 72, 74 of the film 70.

Another special feature of the exemplary embodiments mentioned 11 , 12 , 15 , 16 is that the optical system 24 for collimating or parallelizing the light emitted by the light source 18 comprises at least one reflector 78, which has a parabolic shape at least in a horizontal section, the at least one light source 18 being in the region of a focal point F of the at least one reflector 66 is arranged. Overall, the reflector 78 preferably has the shape of a paraboloid.

The light 22 emitted by the light source 18 is parallelized by the reflector 78 and strikes the light entry surface 34 of the transparent body 32 almost perpendicularly. After the scattering optics 64, the light 36 passes through the transparent body 32 and leaves it via the exit surface 38, and then enters the optical element 42 to be illuminated via the entry surface 44. The light 46 is passed on there by total reflection and then exits again on the front side 48 of the lamp unit 12 or the light exit surface 48 of the optical element 42 . The front side 48 is frosted in order to scatter the light and to create a homogeneous appearance of the illuminated light exit surface 48 of the optical element 42 . However, the entry surface 44 can also be matted in addition to this in order to produce an even more homogeneous appearance. The front surface 48 can also be somewhat curved or not flat.

In the example of 11 the transparent body 32 and the optical element 42 are formed as separate parts, and there is an air gap between them (between the light exit surface 38 and the light entry surface 44). The frosting is provided on surfaces 44 and 48. The screen elements 68 are formed between the sections 66 on the exit surface 38 of the transparent body 32 . In the example of 12 the transparent body 32 and the optical element 42 are designed as a single integral component and are connected to one another in the area of the light exit surface 38 and the light entry surface 44 . The frosting is only formed on the exit surface 48 . The screen elements 68 are formed between the sections 66 on the exit surface 38 of the transparent body 32 . In the example of 15 the transparent body 32 and the optical element 42 are also designed as a single integral component and are connected to one another in the area of the light exit surface 38 and the light entry surface 44 . The frosting is only formed on the exit surface 48 . The screen elements 68 are formed between the sections 66 on the entry surface 34 of the transparent body 32 . In the example of 16 the transparent body 32 and the optical element 42 are also designed as a single integral component and are connected to one another in the area of the light exit surface 38 and the light entry surface 44 . The frosting is only formed on the exit surface 48 of the optical element 42 . The screen elements 68 are formed between the sections 66 on the exit surface 38 of the transparent body 32 . In order to facilitate the application of the screen elements 68 to the exit surface 38 between the sections 66, e.g. by spraying on an opaque coating 76, in 16 the transparent body 32 viewed in the light exit direction 6 has a greater thickness and the sections 66 viewed in the light exit direction 6 are shorter than in the previously described examples of FIG 11 , 12 , 15 educated.

In 17 one possibility is shown of how a film 70 with the complex three-dimensional optical element 42 formed thereon can be aligned with respect to the separately formed screen elements 68 . The screen elements 68 are, for example, integrated in the transparent body 32, as is the case, for example, in FIGS 11 , 12 , 15 , 16 is shown. The screen elements 68 should namely be positioned as precisely as possible between the sections 66 into which light is to be coupled so that the exit surfaces 48 illuminate, in order to be able to effectively prevent light from escaping between the sections 66 and the exit surfaces 48 . For this purpose, positioning pins 80 can be formed on a component connected to the screen elements 68, e.g. the transparent body 32, which engage in corresponding holes in the film 70, so that the complex three-dimensional optical element 42 on the film 70 is formed, with respect to the screen elements 68 is precisely positioned.

18 shows the lighting element 12 again 13 in a slightly different perspective.

the 19 and 20 relate to a further preferred exemplary embodiment in which the optical element 42, whose light exit surface 48 is intended to illuminate as homogeneously as possible, has the shape of a spiral 82. The scroll 82 has scroll wraps 84 with a spacing and air gap 86 formed between adjacent scroll wraps 84 . The light 50 exiting via the spiral-shaped light exit surface 48 in the area of the spiral windings 84 produces the signal lamp function of the lighting element 12. A transparent film 70 is arranged on the back of the spiral 82, which has a spiral-shaped screen element 68 in the area of the spiral-shaped air gaps 86 between the spiral windings 84 , such that collimated light 22 from reflectors 78 can only enter spiral wraps 84 . The film 70 can also have a matt finish at least in areas between the spiral-shaped screen elements 68 . The light exit surface 48 of the spiral windings 84 can also have a frosting. In addition, the foil 70 can be provided with diffusing optics. In the embodiment of 19 and 20 the transparent body 32 of the lighting element 12 is thus formed by the film 70 which is arranged and fastened on the back (light entry side) of the spiral-shaped optical element 42 .

In the example off 21 the transparent body 32 and the optical element 42 are integrally formed as a common component. The component 32, 42 has a stepped light exit surface 48 which forms the light exit surface 14 of the lighting element 12. A spiral-shaped diaphragm element 68 is introduced into the exit surface 48, so that when viewed against the direction of light exit 6, spiral windings 84 with spiral-shaped distances 86 in between result. The light exit surface 48, via which the light 50 can exit, thus also has a spiral shape. In this example, a frosting can be formed on the light entry surface 34 of the component 32, 42. The spiral-shaped light exit surface 48 can also have a frosting. Furthermore, scattering optics can be formed on the entry surface 34 .

In the examples of 19 and 20 For example, the circular geometry of the spiral optical element 42 could rotate while it is lit to create a special effect. It is conceivable that the optics, which only scatter the light in certain directions and are not rotationally symmetrical, are arranged in a separate part and are arranged in front of the optical element 42, e.g. on the film 70, and only the optical element 42 is rotates. For this purpose, the optical element 42 can be provided with an edge that has a toothed profile. A gear wheel driven by a motor can engage in it.

In 22 a light distribution is shown which results on a measuring screen 88 arranged at a defined distance from the lighting element 12 . In the center of the light distribution, the greatest light intensity is in area A of around 600 to 800 Cd. The maximum light intensity is about 930 Cd and is marked with an X on the measuring screen 88 . Area A extends over approximately +/-8° horizontally and -4° to +5° vertically. Area A is followed by an annular area B, in which light intensities of about 500 to 600 Cd prevail. Area B extends outside of area A to about +/-12° horizontally and -5° to +6° vertically. Area B is followed by an annular area C, in which light intensities of about 400 to 500 Cd prevail. Area C extends outside of area B to about +/-14° horizontally and -6° to +7° vertically. Area C is followed by an annular area D in which light intensities of about 300 to 400 Cd prevail. Area D extends outside of area C to approximately +/-16° horizontally and -7° to +8° vertically. The light intensity gradually decreases towards the outside until an area E is reached at the edge, where the light intensity is between 25 and 40 Cd.

23 12 shows a visualization of the illuminated spiral optical element 42 of the light assembly 12 of FIGS 19 or 20 . It is very easy to see that the light exit surface 48 of the optical element 42 is illuminated very homogeneously.

Claims (18)

Lighting device (2) of a motor vehicle, the lighting device (2) comprising at least one light source (18; 18a, 18b) for emitting light (22), at least one optical system (24) for collimating or parallelizing the emitted light (22), at least a transparent body (32) into which the collimated or parallelized light (22) enters via a light entry surface (34) and from which the light (36) that has entered exits again via a light exit surface (38), the light entry surface (34) and the light exit surface (38) represent light passage surfaces of the at least one transparent body (32), and at least one optical element (42) into which the light (36) from the at least one transparent body (32) enters and exits via a light entry surface (44). which the light (46) which has entered exits again via a light exit surface (48), the light which has exited via the light exit surface (48) of the optical element (42). Light (50) is used to generate a signal light function of the lighting device (2), matting with a random surface structure being applied to at least one of the light passage surfaces (34, 38) of the transparent body (32), which is used for random scattering of the light from the transparent body (32) and ensures the most homogeneous possible appearance of the illuminated light exit surface (48) of the optical element (42), characterized in that the at least one optical system (24) comprises at least one light guide plate (56) which a longitudinal extent of the at least one light source (18; 18a, 18b) to the at least one transparent body (32), wherein the light guide plate (56) has a greater extent transversely to the longitudinal extent in a horizontal section than in a vertical section, and one of the at least one light sources (18; 18a, 18b ) facing light entry surface (58) and a light exit surface (60) opposite this, facing the light entry surface (34) of the at least one transparent body (32), and lateral boundary surfaces (62) which connect the light entry surface (58) to the light exit surface (60). and which reflect light beams (22) hitting the boundary surfaces (62) below a critical angle by means of total reflection and that the at least one light guide plate (56) has a stepped light exit surface (60) when viewed in horizontal section. Lighting device (2) after claim 1 , characterized in that a frosting with a random surface structure is applied to the light entry surface (44) and/or to the light exit surface (48) of the optical element (42), which is used for random scattering of the light passing through the optical element (42). (46) cares. Lighting device (2) after claim 1 or 2 , characterized in that the at least one optical system (24) comprises at least one reflector shaft (26), which in each case has a longitudinal extent from at least one of a plurality of light sources (18; 18a, 18b) to the at least one transparent body (32), and each of which has lateral reflection surfaces (28, 30) which, viewed in a horizontal section, widen along the longitudinal extension starting from the at least one light source (18; 18a, 18b). Lighting device (2) after claim 1 , characterized in that the lateral boundary surfaces (62) of the at least one light guide plate (56), viewed in the horizontal section, in a rear section of the respective light guide plate (56) onto the at least one light source (18; 18a, 18b ) run up. Lighting device (2) according to one of Claims 1 until 4 , characterized in that the at least one transparent body (32) comprises an intermediate pane (40) made of a transparent glass or plastic material, which has a longitudinal extent transverse to a longitudinal extent of the at least one optical system (24). Lighting device (2) after claim 5 , characterized in that the light entry surface (34) and the light exit surface (38) of the at least one transparent body (32) are formed on opposite sides of the intermediate pane (40). Lighting device (2) according to one of Claims 1 until 6 , characterized in that the at least one optical element (42) is designed as a cylindrical lens (52) having a longitudinal extent transverse to a longitudinal extent of the at least one optical system (24). Lighting device (2) after claim 7 , characterized in that the light entry surface (44) and the light exit surface (48) of the at least one optical element are formed on opposite sides of the cylindrical lens (52). Lighting device (2) after claim 7 or 8th , characterized in that the light entry surface (44) of the cylindrical lens (52) is flat or slightly convex with a large radius and the light exit surface (48) of the cylindrical lens (52) is more convexly curved as a lateral surface of a cylinder section with a small radius, the small radius of the convex light exit surface (48) being smaller than the large radius of the convex light entry surface (44). Lighting device (2) according to one of Claims 1 until 9 , characterized in that the at least one transparent body (32) and the at least one optical element (42) are formed in one piece as a single integral component. Lighting device (2) according to one of Claims 1 until 10 , characterized in that at least one light passage surface (34, 38) of the at least one transparent body (32) is provided with scattering optics (64) which implement a precisely defined surface structure and which ensure a defined scattering of the light passing through. Lighting device (2) after claim 11 , characterized in that the scattering optics (64) are designed as cushion or cylinder structures, preferably each with dimensions of a base area in the millimeter range and a height of the scattering optics (64) in the micrometer range. Lighting device (2) after claim 11 or 12 , characterized in that the scattering optics (64) are applied to a thin film (70) which is attached to the at least one light passage surface (34, 38) of the at least one transparent body (32). Lighting device (2) according to one of Claims 1 until 13 , characterized in that the at least one optical system (24) for collimating or parallelizing the light emitted by the at least one light source (18; 18a, 18b) comprises at least one reflector (78) which has a parabolic shape at least in a horizontal section, wherein the at least one light source (18; 18a, 18b) is arranged in the area of a focal point (F) of the at least one reflector (78). Lighting device (2) according to one of Claims 1 until 14 , characterized in that the at least one optical element (42) has a complex three-dimensional shape, the at least one optical element (42) viewed in a horizontal section and/or in a vertical section having a plurality of discrete sections (66) which together form the complex form a three-dimensional optical element (42), and between these sections (66) opaque screen elements (68) are provided on a light exit surface (38) of the at least one transparent body (32), in order to prevent light from exiting from the at least one transparent body (32) in to prevent an area between the sections (66). Lighting device (2) after claim 15 , characterized in that the screen elements (68) are produced together with the at least one transparent body (32) in what is known as a 2K injection molding process. Lighting device (2) after claim 15 or 16 , characterized in that the screen elements (68) comprise a dark, preferably black, coating. Lighting device (2) according to one of Claims 1 until 17 , characterized in that the at least one transparent body (32) is rotatably mounted relative to a housing (4) of the lighting device (2) about at least one axis of rotation relative to the housing (4) and diffusing optics (64), which can be used, for example, as cushions - Are formed or cylindrical structures, are arranged in a fixed manner in the housing (4), so that when the at least one transparent body (32) rotates, it rotates relative to the fixed scattering structures (64).

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