EP3203140B1 - Lighting device for a vehicle and associated operating method - Google Patents

Description

The invention relates to a lighting device for a vehicle according to the preamble of patent claims 1 and 2 and a method for operating such a lighting device for a vehicle according to the preamble of patent claims 7 and 8.

By means of an anamorphic element, a light distribution striking it can generally be distorted, for example stretched or compressed. After interaction with the anamorphic element, a distorted image of the irradiated light distribution results. For the purposes of the present invention, the term “light” is not necessarily limited to the spectral range perceivable by humans, but can also refer to other and/or additional frequencies of electromagnetic radiation.

The US 2014 / 0 092 619 A1 describes a fog lamp with an LED and a refractive/TIR lens, the central area of which is purely refractive, while total internal reflection (TIR) is provided in a peripheral area. Converging light emanating from the lens passes through a light guide plate and then through an anamorphic lens. The latter forms an emergent light beam that has a wider divergence in a lateral direction than in a vertical direction. The anamorphic lens can have a flat side and a ridged side, whereby the corresponding ridges can have a repeating pattern.

From the DE 10 2012 008 833 A1 a lighting arrangement for a headlight with several optical imaging elements is known, in which a number of light-emitting diodes are combined in groups to form light-emitting diode fields. Using the imaging elements, a height or Width of a light beam generated by a light-emitting diode field can be stretched or compressed. The light-emitting diode fields can be arranged offset from an optical axis of a respective associated imaging element. Due to the arrangement, a boundary of a light beam of a light-emitting diode field lies directly on a boundary of a light beam of a light-emitting diode field arranged immediately adjacent. An undistorted image is made possible in a central region of a light distribution, with an increase in the light distribution resulting from a distortion of the outer light bundles.

The US 2015 / 0 377 442 A1 discloses a vehicle headlight with a DMD, a light source and each with lighting and projection optics. At least one of these elements shapes a light beam in such a way that pixelated light reflected by the DMD has a non-uniform beam profile, which is suitable for projecting a portion of the headlight's overall light beam. The total light beam has a low beam part, a high beam part and a middle part. It is intended that the non-uniform distribution of white light on the DMD has a higher intensity centrally, which decreases starting from the center. The projection optics may include an anamorphic lens to stretch the DMD light to a field of view (FOV).

From the EP 1 983 253 A2 a headlight for vehicles is known with an optical unit arranged in front of a light source unit to generate a predetermined light distribution. The optical unit has, on a side facing away from the light source unit, a bulbous light decoupling surface which, at least in a horizontal central section, has a conical shape with a conical constant in a range between -1 and 0. The light decoupling surface can be anamorphic and have several different curvature line areas that merge into one another.

From the EP 2 752 615 A1 For example, a motor vehicle headlight device is known in which a light source composed of a plurality of light-emitting elements and a projection lens are arranged at a distance from each other which is smaller than the focal length of the projection lens. This allows more uniform illumination to be achieved by minimizing the effects of the distances between the individual light-emitting elements on the light image. Optionally you can do this on one of On the side of the projection lens facing away from the light source, a convex and a concave lens can also be provided, which together can form an anamorphic lens system, so that a corresponding shaping of the light distribution is possible.

The US 2014/0092619 A1 discloses a fog light for a vehicle in which light emitted by an LED is directed through a special lens, which has usual light-refractive properties in a central section and enables total reflection on internal surfaces in external areas. An anamorphic lens is provided in the further beam path, by means of which the angular extent of the light beam is to be reduced in a vertical direction and increased in a horizontal direction. A surface of the anamorphic lens can have a uniformly repeating pattern such as a vertical groove structure.

The US 2008/0285293 A1 describes a vehicle exterior mirror, the housing of which houses a light source and a lens arranged in the beam path of the light source. The lens can be a cylindrical lens or an anamorphic lens, by means of which an elongated light distribution is to be generated on a floor surface next to the vehicle, which extends essentially in the longitudinal direction of the vehicle. In particular, the lens is rotatably coupled to a mechanism for folding the exterior mirror, so that the elongated shape of the illuminated surface can be achieved regardless of the position of the exterior mirror.

The object of the present invention is to provide a lighting device for a vehicle and a method for operating such a lighting device, by means of which a light distribution can be individually designed with as little effort as possible.

This object is achieved according to the invention by a lighting device with the features of patent claims 1 and 2 and by a method with the features of patent claims 7 and 8. Advantageous embodiments of the invention with useful further developments are the subject of the dependent claims.

In order to provide a lighting device for a vehicle by means of which a light distribution can be individually designed with as little effort as possible, it is provided according to the invention that the light distribution can be distorted non-linearly in at least one direction by the anamorphic element, i.e. is distorted. In other words, not all subregions of the light distribution are distorted uniformly in at least one direction, but subregions of the light distribution arranged successively in this direction are distorted to different degrees. The degree or the extent of the distortion therefore increases from a first sub-region of the distorted light distribution to a second second sub-region starting from this first sub-region in the said at least one direction, this increase along a sequence of sub-regions extending in the at least one direction follows a non-linear relationship or progression. Such a non-linear distortion of the light distribution irradiated by the pixel light source onto the anamorphic element makes it possible to project the light distribution - in particular in the form of patterns or images - onto a surface in the area surrounding the vehicle in a particularly advantageous manner in such a way that a Particularly good visibility can be achieved, especially for observers in the area surrounding the vehicle, and/or more uniform illumination of the illuminated surface can be achieved.

In the present case, such a lighting device is provided in particular as or in conjunction with a headlight of the vehicle, but it is also conceivable to use it in almost any other location on the vehicle, for example as a rear headlight or taillight or on the sides of the vehicle. In any case, the lighting device mounted on a vehicle will, in normal operation, be located above a surface traveled by the vehicle, which for the sake of simplicity will be referred to below as the roadway, regardless of its specific nature. This inevitably results in the fact that with a constant uniform pixel size of the pixel light source or the undistorted light distribution emitted by the pixel light source without a specially adapted distortion, that is here without the anamorphic element, when illuminating the road in the area around the Vehicle through the lighting device the size of the areas of the illuminated area on the road assigned to a pixel increases with increasing distance from the vehicle. In this case, the surface brightness as well as the pixel density and thus the resolution would be one The pattern or image radiated from the lighting device onto the road varies in an unfavorable manner. This effect of pixel enlargement or the decrease in pixel density increases non-linearly as the distance from the vehicle increases.

This undesirable, negative effect is compensated for by the anamorphic element provided in the beam path of the lighting device, in that the undistorted light distribution emitted by the pixel light source is distorted non-linearly by the anamorphic element. The anamorphic element is designed in such a way that those pixels or partial areas of the light distribution that contribute to the illumination of parts of the road that are further away from the vehicle are more strongly distorted, i.e. those pixels or partial areas of the light distribution that contribute to the illumination of parts of the road that are closer to the vehicle Contribute to areas of the roadway lying on the vehicle. This means that the pixel density on the illuminated surface can be specifically increased using a single anamorphic element, especially in those areas where the greatest positive effect can be achieved due to the given geometry. This represents a significantly less complex and therefore simpler option compared to, for example, the alternative of increasing the pixel density of the pixel light source.

In principle, the anamorphic element can be implemented in various ways, preferably as a transmissive element - such as a lens - or, for example, as a reflective element - such as a mirror element.

In one embodiment of the invention, the anamorphic element is designed as a free-form lens. Such a free-form lens can have a flat side facing the pixel light source and an aspherical side opposite it. The latter can also have very complex, non-rotationally symmetrical shapes, which enables particularly precise adaptation to the respective circumstances and requirements, such as the exact installation position or position and the desired size and shape of the area that can be illuminated or illuminated. In principle, however, such a free-form lens can also have any practical shape on both opposite sides or on all sides.

According to one embodiment, the anamorphic element is designed as a gradient lens. Such a gradient lens can be independent of its Shape due to inherent material properties have continuously or regionally varying optical properties, in particular refractive properties, and can be realized, for example, by targeted doping of the lens material. A gradient lens can, for example, be designed cylindrical, which may simplify assembly or integration into the lighting device and/or improve the utilization of installation space. In principle, however, almost any other shape for a gradient lens is also conceivable. It is also conceivable to implement a multi-layer structure of the gradient lens, for example made of different plastics.

In a further embodiment of the invention, the anamorphic element is designed as an arrangement of a plurality of lenses or individual lenses, which differ in at least one optical property, in particular a refractive property. Such an arrangement can be referred to as a lens array. The individual lenses can each be regularly shaped, for example as a half cylinder, which may make it possible to achieve more cost-effective production. The individual lenses can then differ from one another, for example in terms of their size, shape, the material used or other properties, provided that the desired effect is achieved overall.

In the invention it is provided that within a sequence of partial areas of the distorted light distribution extending in one direction, respective extensions of the partial areas extending in this direction are distorted by the anamorphic element in accordance with a monotonous square relationship compared to the corresponding partial areas of the undistorted light distribution, for which a curvature of the anamorphic element decreases asymmetrically in this direction. The distorted light distribution is the light distribution that occurs immediately after the interaction with the anamorphic element.

In other words, it is provided that, for example, a partial area of the light distribution is assigned or corresponds to a pixel of the pixel light source, all pixels of the pixel light source have the same size or extent in at least one direction and these emitted by the pixel light source, Light distribution composed of pixels of the same size is distorted by the anamorphic element in such a way that the extent of the light illuminated by one pixel at a time is distorted Areas of the roadway are just constant regardless of the distance from the lighting device or from the vehicle in the lighting direction - that is, for example, when the lighting device is used as a headlight, i.e. in the longitudinal direction of the vehicle.

A square course of the distortion is particularly advantageous, since the extent in the illumination direction of the illuminated areas on the road, each assigned to a pixel, increases quadratically as the distance from the vehicle increases. An anamorphic element, which causes a square distortion, can therefore precisely compensate for the effect of pixel enlargement caused by the angle between the light rays emanating from the lighting device and the road or the illuminated surface - that is, by the projection of the light distribution onto the road by compressing parts of the light distribution hitting the vehicle at a flatter angle and thus at a greater distance from the vehicle to a greater extent in accordance with the square of the distance.

The size of the partial area of the distorted light distribution corresponding to a pixel immediately after interaction with the anamorphic element or at other points in the beam path is therefore not necessarily uniform and only the partial areas or pixels shown as an image on the road have a uniform size again.

In a further embodiment of the invention, the pixel light source comprises a surface light modulator, in particular a digital micromirror device (DMD). Such a DMD has a large number of micromirrors, which can be tilted between at least two positions, so that any light distributions, patterns or images composed of pixels can be generated by targeted control. For this purpose, the micromirrors can be tilted accordingly so that the light hitting them is directed to an absorber and does not reach the surroundings of the lighting device or the vehicle.

It is intended that the DMD is illuminated directly or indirectly by an active light source and in turn serves as a passive pixel light source that illuminates the anamorphic element. In other words, this is DMD is therefore arranged in the beam path emanating from the primary, active light source between this active light source and the anamorphic element.

By using a DMD, any high-resolution light distribution can be generated particularly advantageously, with fluid animations or moving images or patterns being able to be generated or displayed without any problems due to the high switching frequency of the micromirror actuators. Any areas can also be specifically hidden or darkened so that, for example, vehicles in front or oncoming vehicles or other road users are not illuminated and therefore not blinded.

In another embodiment of the lighting device, the pixel light source is composed of a plurality of active light sources. For example, a matrix of individual lasers or LEDs can be provided which directly or indirectly illuminate the anamorphic element, in which case the desired light distribution can be generated by specifically switching the individual light sources on and off. Such an arrangement makes it possible to reduce the number of optical elements in the beam path and thus to construct the lighting device in a more compact design.

In a further embodiment of the invention, the lighting device comprises at least one laser and an optical converter element, in particular a phosphor element, arranged in a beam path of the laser. In other words, in this case it is provided that the laser represents the primary, active light source of the lighting device and in the further course of the beam the optical converter element is illuminated, which converts the incident laser radiation into light, which differs in at least one property from that through the light produced by the laser differs. For example, at least approximately monochromatic laser light can typically be converted into white light, which is particularly suitable for ambient lighting purposes in the automotive sector. The optical converter element can also have a less pronounced point source characteristic or emit light at a larger angle or with greater divergence than the laser. According to a further embodiment of the invention, the lighting device comprises a sensor system for detecting a surface that can be illuminated by means of the lighting device, wherein a pattern composed of pixels of at least approximately the same size can be generated on the detected surface by means of the lighting device. In other words, the light distribution emitted from the pixel light source to the anamorphic element can, depending on the data supplied by the sensor system, possibly already be adjusted in such a way that in interaction with the distortion caused by the anamorphic element and the projection geometry on the detected surface a particularly well-recognizable representation or an image of the light distribution results. Here, in particular, the visibility should be improved from outside the vehicle equipped with the lighting device according to the invention, whereby, depending on the situation, the respective vehicle occupants can of course also benefit from an improved or specially adapted representation. A corresponding sensor system can include a large number of different sensors. These include, for example, radar, ultrasonic and laser sensors as well as cameras and generally optical sensors, with respective corresponding transmitting devices also being provided if necessary.

The light distribution can be adjusted by specifically controlling the pixel light source, for which, for example, an electronic control unit (ECU) can be provided. It is therefore conceivable to adapt or control the light distribution using appropriately designed software and/or electronics, so that different light distributions or representations can be realized with a single lighting device.

Specifically, for example, several pixels of the pixel light source can be combined or assigned to a larger pixel or partial area of the light distribution. The angle between the light rays emanating from the lighting device and the detected illuminated surface can have a particular influence here. Although typical road bumps and inclines typically have only a negligibly small influence, for example a wall rising in front of the vehicle in the direction of illumination approximately perpendicular to the road traveled by the vehicle, a significant modification of the light distribution emitted by the pixel light source may be required in order to achieve this to obtain a representation on the wall - or generally on an inclined surface - composed of pixels of at least approximately the same size.

Through this combination of the sensory detection of the surface to be illuminated and the corresponding specifically coordinated control of the pixel light source or the modification of the light distribution, an optimally recognizable representation can be achieved particularly advantageously in a wide variety of situations.

For all embodiments of the invention, geometries other than those described are also conceivable, so that, for example, the pixel light source does not necessarily have to emit light distributions, patterns or images that are composed of pixels of the same size. In this case too, however, the anamorphic element would cause a distortion which follows a quadratic relationship along at least one direction.

It is also conceivable that the illuminated surface corresponds to the at least essentially flat roadway traveled by the vehicle, but is formed, for example, by any other surface. Such other surfaces can be surfaces of other vehicles or surfaces - for example walls - of buildings.

In order to provide a method for operating a lighting device for a vehicle, by means of which a light distribution can be individually designed with as little effort as possible, it is provided according to the invention that the anamorphic element is at least partially illuminated with a light distribution by means of a pixel light source and this light distribution in at least one direction is distorted non-linearly by the anamorphic element, wherein within a sequence of partial areas of the distorted light distribution extending in this direction, respective extensions of the partial areas extending in this direction according to a monotonous square relationship compared to the corresponding partial areas of the undistorted light distribution by the anamorphic element be distorted, for which purpose a curvature of the anamorphic element (10) decreases asymmetrically in this direction.

The functional designs of the lighting device according to the invention described so far and below as well as in the patent claims can also be transferred accordingly to the method according to the invention or to the devices and components used to carry out the method according to the invention and vice versa.

Overall, the lighting device according to the invention or the method according to the invention can be used particularly advantageously in each embodiment to transmit information to the environment through targeted representations, that is, for example, to other road users, but also to the respective occupants of the vehicle equipped with the lighting device according to the invention, whereby one For communication purposes, a display or projection with a uniform resolution, i.e. with a uniform pixel size, is particularly desirable.

Fig. 1

eine schematische und perspektivische Prinzipdarstellung einer Beleuchtungseinrichtung;

Fig. 2

eine schematische Darstellung eines Verzerrungsmusters;

Fig. 3a

eine schematische und perspektivische Darstellung einer anamorphotischen Freiformlinse; und

Fig. 3b

eine schematische und perspektivische Darstellung eines aus einer Anordnung mehrerer Einzellinsen gebildeten anamorphotischen Elements.

Further advantages, features and details of the invention emerge from the following description of a preferred exemplary embodiment and from the drawings. Show:

Fig. 1

a schematic and perspective representation of the principle of a lighting device;

Fig. 2

a schematic representation of a distortion pattern;

Fig. 3a

a schematic and perspective view of an anamorphic free-form lens; and

Fig. 3b

a schematic and perspective representation of an anamorphic element formed from an arrangement of several individual lenses.

Fig. 1 shows a schematic and perspective representation of the principle of a lighting device 1 with a laser 2 as the primary active light source, which emits a laser beam 3. In the present case, several optical elements are arranged in a beam path of the laser 2 or the laser beam 3, with the lighting device 1 as a whole being designed as a headlight. Below are according to your Sequence in the beam path starting from the laser 2 describes the optical elements arranged in the beam path.

The laser beam 3 first hits an optical converter element, which in the present case is designed as a phosphor element 4 and stimulates it to glow or to convert the irradiated, for example blue, laser light into white light. While the laser 2 represents a very bright point light source that emits an intense light beam with little divergence, the phosphor element 4 can emit a less strongly directed cone of white light. The phosphor element 4 can also be shaped accordingly, in that the desired beam expansion is supported, for example, by convex surfaces or generally a lens shape.

In order to be able to optimally use the light that may be emitted over a large area by the phosphor element 4, a refractive element in the form of a lens 5 is provided in the beam path, which is to be understood here as an example and can also be representative of several optical elements. Overall, the light emitted by the phosphor element 4 is bundled, expanded or generally shaped by the lens or lenses 5, depending on the specific requirements, in order to achieve optimal illumination of subsequent optical elements.

Following the lens 5, an optical deflection element in the form of a digital micromirror device (DMD) 6 is arranged in the further path of the beam, which in the present case has an illuminated area or mirror area 7 arranged on a support. The individual micromirrors of the DMD 6 can each be viewed as individual pixels, so that a desired light distribution can be generated by specifically adjusting the tilting of the micromirrors. However, several micromirrors can also be combined to form a single pixel of light distribution. In this way, the DMD 6 illuminated at an angle serves as a passive pixel light source, which emits a predeterminable light distribution 9. In the present case, a hidden area 8 is created by deliberately tilting a subset of micromirrors of the DMD 6, which therefore represents or creates a dark area in the light distribution 9.

The light distribution 9 emitted by the DMD 6 impinges on an anamorphic element, which in the present case is a single anamorphic lens 10 is realized. When passing through this anamorphic lens 10, the light distribution 9 is distorted and projected as an image 11 of the light distribution 9 onto a surface in the vicinity of the lighting device 1 - in the present case onto a roadway 12. In the image 11 of the light distribution 9, an image 13 of the hidden area 8 can be clearly seen, with a foreign vehicle 14 being shown in this unilluminated area. By hiding or not illuminating the area in which the foreign vehicle 14 is located, glare or irritation of the respective vehicle occupants can advantageously be avoided, which can increase safety in road traffic.

In known lighting devices for vehicles which use no or only a conventional, simple anamorphic lens with a uniform distortion, the effect that is inevitably given by the geometry of the projection can be observed that in an image of a light distribution 9 that is actually displayed or recognizable on the road 12 Even with a constant pixel size of the pixel light source, the size of the partial areas or partial images corresponding to the individual pixels varies with increasing distance from the vehicle. In order to compensate for this undesirable effect, it is provided here that the anamorphic lens 10 causes a different degree of distortion of partial areas of the light distribution 9 corresponding to different pixels. Specifically, it is intended that those pixels in the light distribution 9 whose images are displayed at a greater distance from the lighting device 1 in the image 11 of the light distribution 9 on the road 12 are more distorted than those pixels in the light distribution 9 whose images are represented as parts of the Image 11 of the light distribution 9 on the road 12 can be shown closer to the lighting device 1 on the road 12.

In particular, the degree or strength of the distortion increases quadratically from the less distorted to the more strongly distorted pixels of the light distribution 9. This quadratic increase in distortion is caused when the thus distorted light distribution is projected onto the roadway 12 by the projection onto the roadway 12, that is to say due to the effect of pixel enlargement that arises due to the angle between the light rays emanating from the lighting device 1 and the roadway 12 increasing distance from the vehicle. In the end, the light distribution 9 on the road 12 in Figure 11 is independent Depending on the distance from the vehicle or from the lighting device 1, the areas assigned to the individual pixels of the light distribution 9 are of the same size or extend over equally large areas of the road 12.

Thus, in this typical case, without additional calculation or control effort solely due to the inherent optical properties of the anamorphic lens 10, even with a particularly easy-to-implement constant pixel size of the pixel light source used, that is here the DMD 6, other people in the environment Road users or people are presented with an optimal, undistorted representation of information and/or more uniform illumination and/or more precise cut-out of areas that should not be illuminated can be achieved.

A light distribution 9 or an image 11 of a light distribution 9, which is useful for communication and/or information purposes and can be projected onto the roadway 12, can, for example, represent a zebra crossing - possibly also animated or possibly provided with animated arrows - by means of which pedestrians can be signaled that they have been recognized by the vehicle and safe crossing of the road is possible.

Fig. 2 shows a schematic representation of a distortion pattern 15, which can be understood as a distorted light distribution, which results when a light distribution 9 composed of pixels of the same size passes through the anamorphic lens 10 immediately after it. For orientation, a two-dimensional coordinate system with x and y directions is shown. It can be clearly seen that, for example, pixel 16 is the largest pixel and as the distortion pattern 15 passes through in the y direction, the subsequent pixels become smaller, so that, for example, pixel 17 only has a fraction of the height or extent in the y direction of pixel 16 . The same applies to every other pixel, so that starting from any pixel, the sequence of pixels adjoining it in the y-direction extends in the y-direction according to a quadratic relationship, that is to say a mathematical relationship that is determined by a quadratic function can be described, decrease.

In addition to this increasing compression or distortion in the positive y-direction, an increasing distortion in the x-direction - albeit less pronounced - can also be seen here, which leads to the fact that, starting from any pixel, the sequence of the negative x-direction The direction of these adjoining pixels decreases in their extent in the x direction. This increasing distortion in the negative x-direction is to be viewed as optional, since, for example, with an illumination direction in the longitudinal direction of the vehicle, the x-direction of the distortion pattern 15 describes the extent of the illuminated area on the road 12 in the road and vehicle transverse directions and here the extent of the illuminated area is typically significantly smaller than the extent of the illuminated area on the roadway 12 in the roadway and vehicle longitudinal direction, corresponding to that in the y-direction of the distortion pattern 15. This also means the effect of the pixel enlargement caused by the projection in the image 11 of the light distribution 9 on the roadway 12 in the x direction is significantly less pronounced or less noticeable for observers.

In Fig. 3a and in Fig. 3b A possible embodiment of the anamorphic lens 10 is shown in each case. Fig. 3a shows a free-form lens 19, which has a half-lens shape with a flat side 20 and a curved side 21. The curvature of the curved side 21 decreases in the negative y-direction, so that a deviation from a spherical shape is present and also clearly recognizable.

In the Fig. 3b The variant shown shows a lens arrangement 22, which also has a flat side 23. However, the side opposite this flat side 23 is here composed of a plurality of individual lenses 24, 25, 26, 27, each of which has a half-lens or half-cylindrical shape with the same or regular curvature. The individual lenses 24 to 27 differ both in their curvature and in their thickness or material thickness, with the corresponding values decreasing in the negative y-direction from one of the individual lenses 24 to 27 to the next. This means that the individual lens 24 has both the greatest thickness or material thickness and the greatest curvature of all individual lenses 24 to 27 and the individual lens 27 correspondingly has the smallest thickness or material thickness and the smallest curvature.

Due to their respective regular shape, each of the individual lenses 24 to 27 causes a uniform distortion of the parts of the light distribution 9 passing through them and the described, overall non-linear distortion of the light distribution 9 only arises over the entire area when comparing the respective partial areas. For an anamorphic lens arrangement 22 composed of individual lenses 24 to 27 in this way, a large number of other variants are conceivable in addition to the one shown schematically here, whereby in principle the individual lenses 24 to 27 do not have to be regularly shaped in themselves, but also as a free-form lens and / or can be designed as a gradient lens. The semi-cylindrical shape of the individual lenses 24 to 27 shown here is only to be understood as an example and a hemispherical or other shape would also be conceivable. This means that each individual lens 24 to 27 can be assigned a single or several rows of pixels or a single or several pixels.

The same is of course also true for those in Fig. 3a Free-form lens 19 shown, a variety of shapes are conceivable. This variety offers the advantage that optimal adaptation to the respective circumstances and requirements is possible, while the lens arrangement 22 composed of several individual lenses 24 to 27 can possibly be produced more cost-effectively.

Regardless of the specific shape of the anamorphic lens 10, it can be made of glass or a plastic material, for example. In order to improve the optical properties of the lighting device 1, a reflection-reducing coating can be provided in order to minimize losses.

Overall, regardless of the specific embodiment, a particularly non-linear distortion of a light distribution 9 can be caused by an anamorphic lens 10 in the beam path of the lighting device 1, whereby a particularly advantageous adjustment of the pixel size or pixel density in the image 11 of the light distribution 9 that is ultimately visible on an illuminated surface can be achieved is. This means that the recognizability and perceived quality of an image or a pattern can be significantly improved, and in particular the number of pixels or pixel density of the pixel light source used does not have to be increased, so that this provides a particularly efficient and resource-saving solution and the pixel density or resolution can be targeted in a targeted manner can be increased or improved in those areas in which the greatest positive effect can be achieved.

Claims (8)

1. A lighting device (1) for a vehicle, comprising a pixel light source (6) and an anamorphic element (10) capable of being at least partially lighted with a light distribution (9) by the pixel light source (6),
   characterized in that
   the light distribution (9) is non-linearly distorted in at least one direction by the anamorphic element (10), wherein, within a sequence of partial areas of the distorted light distribution extending in one direction, respective extents of the partial areas extending in this direction are distorted by the anamorphic element (10) according to a monotonous quadratic relation with respect to the corresponding partial areas of the undistorted light distribution (9), whereto a curvature of the anamorphic element (10) asymmetrically decreases in this direction, wherein

   - the anamorphic element (10) is configured as a freeform lens (10, 19),
   or

   - the anamorphic element (10) is formed as an arrangement (22) of a plurality of individual lenses (24, 25, 26, 27), which differ by at least one optical characteristic.
2. A lighting device (1) for a vehicle, comprising a pixel light source (6) and an anamorphic element (10) capable of being at least partially lighted with a light distribution (9) by the pixel light source (6),
   characterized in that
   the light distribution (9) is non-linearly distorted in at least one direction by the anamorphic element (10), wherein, within a sequence of partial areas of the distorted light distribution extending in one direction, respective extents of the partial areas extending in this direction are distorted by the anamorphic element (10) according to a monotonous quadratic relation with respect to the corresponding partial areas of the undistorted light distribution (9), wherein the anamorphic element (10) is formed as a gradient lens.
3. The lighting device (1) according to any one of the preceding claims, characterized in that
   the pixel light source (6) includes an area light modulator (6), in particular a digital micromirror device (6).
4. The lighting device (1) according to claim 1 or 2,
   characterized in that
   the pixel light source (6) is composed of a plurality of active light sources.
5. The lighting device (1) according to any one of the preceding claims, characterized in that
   the lighting device (1) includes at least one laser (2) and an optical converter element (4), in particular a phosphor element (4), arranged in a beam path of the laser (2), which converts a wavelength of incident laser light of the laser (2) into light of another wavelength.
6. The lighting device (1) according to any one of the preceding claims, characterized in that
   the lighting device (1) includes a sensor technology for capturing a surface (12) capable of being lighted by means of the lighting device (1) and an electronic control unit for adapting the light distribution radiated from the pixel light source (6) to the anamorphic element (10) depending on data provided by the sensor technology about an angle between light beams originating from the lighting device and the lighted surface (12) by controlling the pixel light source (6), such that a pattern (11) composed of at least approximately equally sized pixels is generated on the captured surface (12) by means of the lighting device (1).
7. A method for operating a lighting device (1) for a vehicle, in which an anamorphic element (10) is at least partially lighted with a light distribution (9) by means of a pixel light source (6), characterized in that the light distribution (9) is non-linearly distorted in at least one direction by the anamorphic element (10), wherein, within a sequence of partial areas of the distorted light distribution extending in this direction, respective extents of the partial areas extending in this direction are distorted by the anamorphic element (10) according to a monotonous quadratic relation with respect to the corresponding partial areas of the undistorted light distribution (9), whereto a curvature of the anamorphic element (10), which is configured as a freeform lens (10, 19) or is formed as an arrangement (22) of a plurality of individual lenses (24, 25, 26, 27), which differ by at least one optical characteristic, asymmetrically decreases in this direction.
8. A method for operating a lighting device (1) for a vehicle, in which an anamorphic element (10) is at least partially lighted with a light distribution (9) by means of a pixel light source (6), characterized in that the light distribution (9) is non-linearly distorted in at least one direction by the anamorphic element (10), wherein, within a sequence of partial areas of the distorted light distribution extending in this direction; respective extents of the partial areas extending in this direction are distorted by the anamorphic element (10), which is formed as a gradient lens, according to a monotonous quadratic relation with respect to the corresponding partial areas of the undistorted light distribution (9).

Images