EXTERIOR LIGHTING SYSTEM FOR A MOTOR VEHICLE

Description

[0001] The invention relates to an exterior lighting device for a motor vehicle, wherein the exterior lighting device comprises a design panel and at least one detection device with an image capture device and a carrier medium. Furthermore, the invention relates to a motor vehicle with such an exterior lighting device.

[0002] A motor vehicle often has a camera system designed to capture at least almost all of the vehicle's surroundings, i.e. to provide a panoramic view around the vehicle. For this purpose, corresponding camera sensors are installed, for example, in the center of the front and rear of the vehicle. However, not all exterior components of the vehicle are suitable for positioning such camera sensors. For example, various restrictions arise with regard to positioning due to locally limited installation space, a high probability of contamination, for example from splashing puddle water, or an optical restriction associated with positioning with regard to the surroundings that can be captured from there.Therefore, the camera sensors are often arranged in predetermined positions, such as in the center of the front, in the rear, and / or on the side mirrors of the vehicle. Conventional camera systems therefore have limited application in terms of positioning on the vehicle.

[0003] Optical diffraction gratings that are manufactured holographically are known from the prior art and are therefore referred to as holographic gratings. In this regard, it is known from the scientific publication "Volume-phase holographic gratings and their potential for astronomical applications" (SC Barden, JA Arns, and WS Colburn, Proceedings SPIE 3355, Optical Astronomical Instrumentation, 1998) that light incident on such a holographic grating at an angle significantly outside the angular range that satisfies the Bragg condition passes through the holographic grating undiffracted. However, if light strikes the holographic grating from an angle such that the Bragg condition is at least approximately satisfied, the light is diffracted at an angle. A similar behavior is observed with regard to the wavelength dependence of the influence of the holographic grating on light.This is because light with a wavelength that lies significantly outside the wavelength range specified by the Bragg condition, the so-called Bragg wavelength, also passes through the holographic grating without being diffracted, and only light with a wavelength that at least approximately satisfies the Bragg condition is diffracted by the holographic grating. Using complex holographic grating structures, it is thus possible, for example, for light with two different wavelength ranges to be diffracted at the same angle. Furthermore, a holographic grating can be used to split light with different wavelengths into different light paths, so that a dispersive beam splitter can be realized using a holographic grating.

[0004] DE 10 2017 109 905 A1 shows a motor vehicle lighting device with a headlight which has a light source for visible light, an infrared radiation source and a light exit optic which has a light entry surface illuminated by the light source and the infrared radiation source and a light exit surface, and with an optical output deflection element which directs infrared radiation emanating from the infrared radiation source onto the light entry surface.

[0005] It is the object of the invention to provide a camera system for a motor vehicle that can be inconspicuously integrated into the motor vehicle.

[0006] This object is achieved by the subject matter of the independent patent claim. Advantageous developments of the invention are disclosed by the dependent patent claims, the following description, and the figures.

[0007] The exterior lighting device according to the invention for a motor vehicle is designed overall to provide image data that correlates with the detected light. The exterior lighting device for a motor vehicle thus ultimately enables photographic and / or video-based recording of the surroundings of the motor vehicle. The exterior lighting device according to the invention is designed, for example, as a headlight, tail light, vehicle turn signal, or brake light. The exterior lighting device comprises a design cover and at least one detection device. The design cover is made, for example, from plastic and serves to conceal a lighting unit of the exterior lighting device, i.e. a lamp that is designed, for example, as a light-emitting diode (LED), from the surroundings of the motor vehicle. The design cover can, for example, be colored, for example, red in the case of the brake light.

[0008] The detection device of the outdoor lighting device is designed to provide image data of the surroundings. For this purpose, it comprises, on the one hand, an image detection device and, on the other hand, a carrier medium. The carrier medium is designed as a light guide on which an input coupling region and an output coupling region are provided. The carrier medium therefore represents a light-guiding medium. The carrier medium can, for example, be flat, i.e. a width and a length of the carrier medium are greater than a thickness of the carrier medium. This flat carrier medium is attached perpendicular to the thickness of the carrier medium, for example, to the design panel. The carrier medium can, for example, be manufactured as a plate or film made of transparent plastic or glass. The carrier medium with the input coupling region and the output coupling region is designed as a flat detection element for the design panel, adapted to a surface shape of the design panel.This detection element can, for example, be glued to a surface of the design panel. For this purpose, an adhesive can be arranged on one side of the detection element, i.e., the carrier medium, for example as a fastening element, with which the detection element is glued to the design panel. The detection element itself is not designed as a rigid plate, but rather can be bent non-destructively by at least a radius of typically 2 cm, so that it can be arranged, for example, on a curved design panel, which is designed, for example, to conceal a motor vehicle's headlight.

[0009] The coupling region itself is designed as a holographic element with a first deflection structure. A description of the functionality of such a holographic element, which is often referred to as an optical grating and can be manufactured using holographic methods, can be found, for example, in the scientific publication cited above. The coupling region can accordingly be implemented, for example, as a diffraction grating. The first deflection structure is designed to couple light incident on the first deflection structure from an environment into the carrier medium and, in doing so, to deflect it to such a great or great extent that the coupled-in light fulfills the critical angle condition. The carrier medium is accordingly designed to transmit the coupled-in light from the coupling region to the coupling-out region by means of internal reflection, preferably total internal reflection.The light which falls from the environment onto the first deflection structure and is coupled into the carrier medium can thus, for example, be guided within the carrier medium in zigzag-like movements along a direction parallel to a plane of the surface of the detection element.

[0010] The coupling-out region is designed as a holographic element with a second deflection structure. Both the first deflection structure of the coupling-in region and the second deflection structure of the coupling-out region can each be implemented, for example, as a diffraction grating. The second deflection structure is designed to couple the coupled-in light, which falls on the second deflection structure, out of the carrier medium. The coupling-in region and the coupling-out region can, for example, be located on different sides of the detection element. For example, the coupling-in region can comprise the entire surface of the detection element, which is directed from the design panel towards the surroundings and is thus oriented towards the surroundings of the motor vehicle. The coupling-out region can be located on the opposite side and thus be oriented towards the surface of the design panel.Alternatively or additionally, the decoupling region can be arranged on one side of the carrier medium so that the decoupling region is oriented perpendicular to the described coupling region.

[0011] The image capture device of the capture device is designed to capture the light coupled out of the capture element, i.e., the carrier medium with the input coupling region and the output coupling region, at the output coupling region and to provide image data that correlates with the captured light. The image capture device is thus designed to produce or generate image data from the light coupled into the image capture device. To capture the light coupled out of the carrier medium, the image capture device rests against the output coupling region. To attach the image capture device to the carrier medium, the image capture device can, for example, be glued to the carrier medium. Alternatively, the carrier medium can be clamped in a holding device of the image capture device.The image capture device can preferably be implemented as an image sensor or camera, each with or without imaging optics, such as a lens or a lens system. The image capture device can be designed, for example, as a CCD sensor (charged coupled device) or as a CMOS sensor (complementary metal oxide semiconductor). In this embodiment of the image capture device as an image sensor, the carrier medium on which the coupling-in region and the coupling-out region are arranged can perform the function of a lens, i.e., an imaging optics. Alternatively, the image capture device can also be implemented as a camera or still camera, in particular as a microcamera, as is designed, for example, in a modern terminal device such as a smartphone, with its own imaging optics.

[0012] The image capture device is thus designed to generate a photographic and / or video-based image of the surroundings of the exterior lighting device. As a rule, an exterior lighting device of a motor vehicle is positioned so high relative to the road surface that it becomes dirty less quickly than, for example, a camera sensor located lower down, such as one in the shock absorber. The capture element is thus arranged relatively exposed on the motor vehicle, providing an advantageous overview of the surroundings of the motor vehicle. Due to its positioning relative to the road surface, the capture element also rarely becomes dirty and is clearly visible.

[0013] The integration of the detection device into the exterior lighting system for a motor vehicle enables the inconspicuous implementation of an image capture device, such as a camera system for a motor vehicle. With appropriate positioning of the image capture device, for example below the design panel or in an edge area, such as a frame of the exterior lighting system adjacent to the design panel, the image capture device can be invisible to an observer of the vehicle and thus inconspicuously integrated into the motor vehicle. Due to the exposed position of the exterior lighting system on the motor vehicle, with appropriate positioning of individual detection devices in all respective exterior lighting systems of the motor vehicle, it is also possible to capture the surroundings of the motor vehicle as a complete all-round view.In this case, an angular range of 360 degrees around the vehicle can be provided entirely in the form of image data.

[0014] According to the invention, the exterior lighting device comprises a light source, a sensor device, and an evaluation device, and a sensor output region is provided on the carrier medium. The light source is, for example, a laser that emits light in the infrared wavelength range, for example. This light source is also designed to emit pulsed light. The light emitted by the light source is, for example, emitted directly into the surroundings of the motor vehicle, wherein, for example, an object is located in the surroundings. The evaluation device mentioned here can be an additional evaluation device of the exterior lighting device.However, this may alternatively correspond to the evaluation device for determining the dimming signal already mentioned above, i.e. the exterior lighting device may comprise only one evaluation device which can carry out various evaluation processes.

[0015] The first deflection structure of the coupling region is designed to couple light emitted by the light source and reflected by the object in the surroundings into the carrier medium. The light source is therefore positioned such that it emits the pulsed light, for example, towards a wall in the surroundings of the motor vehicle. The light is then reflected by this wall and coupled into the carrier medium via the coupling region. The carrier medium is designed to transmit the coupled-in reflected light from the coupling region to the sensor decoupling region by means of internal reflection. The sensor decoupling region is designed as a holographic element on a third deflection structure. The third deflection structure can be designed, for example, as a diffraction grating, just like the corresponding deflection structure at the decoupling region and at the coupling region.The third deflection structure is designed to decouple the reflected light coupled into the carrier medium from the carrier medium. The sensor device is now oriented relative to the detection element and ultimately to the sensor decoupling region in such a way that it is configured to detect the light decoupled at the sensor decoupling region and provide it in the form of sensor data. The sensor data describe a propagation time of the light emitted by the light source and reflected by the object, which was detected by the sensor device. The evaluation device is now configured to provide distance data describing a distance of the object from the detection device by evaluating the sensor data.

[0016] With a suitable choice of light source and sensor device, a laser distance measurement can be performed, for example, which determines a distance between the motor vehicle and the object—more precisely, between the exterior lighting device of the motor vehicle and the object, where the object in this example is the wall in the vicinity of the motor vehicle. Corresponding distance data can be made available, for example, to a driver assistance system or another control device of the motor vehicle, so that, for example, a parking assistant can use this data to plan and execute an automatic or at least semi-automatic parking maneuver of the motor vehicle in a parking space next to said wall.Alternatively or additionally, the distance data can be used to monitor and optimize exit from a driveway, detect an approaching object and / or an object already in the vehicle's blind spot, detect an object that is only visible when the driver looks back over their shoulder, and / or initiate an emergency stop if an object is approaching the vehicle from the front or side. The advantage of the exterior lighting system over conventional environment detection systems is that it covers specific areas of the vehicle's surroundings over a large area at an optimal height in the vertical direction of the vehicle.This is because the individual detection areas of the exterior lighting devices are not designed as point-like sensors, as is the case with conventional camera sensors, but rather as a large area, extending over the entire surface of the detection element, which, for example, completely or at least partially covers the design panel. This allows the vehicle's surroundings to be detected even if, for example, the vehicle's interior is soiled, extending at least partially over the design panel of the exterior lighting device, since it is unlikely that the large-area detection element will be completely affected by the soiling.

[0017] The invention also includes embodiments which provide additional advantages.

[0018] One embodiment of the invention provides that, in addition to the sensor coupling-out region, a light coupling-in region and a light coupling-out region are provided on the carrier medium. The light coupling-in region is designed as a holographic element with a fourth deflection structure, which is designed, for example, as a diffraction grating. The fourth deflection structure is configured to couple light, which falls from the light source onto the fourth deflection structure, into the carrier medium. This light coupling-in region can be positioned, for example, next to the light source that emits pulsed light, so that the pulsed light emitted by it is coupled into the carrier medium via the light coupling-in region. The carrier medium is configured to transmit the coupled light from the light coupling-in region to the light coupling-out region by means of internal reflection.The light output region is designed as a holographic element with a fifth deflection structure, which is configured, for example, as a diffraction grating. The fifth deflection structure is designed to output the transmitted light incident on the fifth deflection structure from the carrier medium and emit it into the environment. In addition to the pure input, transport, and output of the light emitted from the environment in the direction of the detection element, the light from the light source can be transported by means of the carrier medium and consequently by means of the detection element to a desired output region, the so-called light output region, and from there emitted into the environment. The carrier medium with the light input region and the light output region can be spatially separated from the carrier medium with the input region in the output region.However, the four coupling regions mentioned can also be provided on one and the same carrier medium, so that the detection device of the exterior lighting device has only a flat carrier medium into which light is emitted from different directions and with different output regions as target positions. This makes it possible, for example, for both the light source and, for example, the image detection device and the sensor device to be arranged at respective edge regions of the exterior lighting device, for example, at the edge of the design panel or behind the design panel, and yet still emit light from the light source or couple ambient light from a predetermined area on the design panel and transmit it to the corresponding sensor device or image detection device.This makes the detection element of the exterior lighting device visually inconspicuous and can be installed invisibly for an observer, for example in a headlight or rear light of the vehicle.

[0019] For example, the light coupling area may at least partially coincide with the coupling-out area, wherein the light coupling-out area may at least partially coincide with the coupling area.

[0020] One embodiment provides that the coupling-in region and the coupling-out region have at least one optical grating, in particular a holographic surface grating or a holographic volume grating, as a deflection structure. In this context, the detection device can also be referred to as a HoloCam, short for holographic camera.

[0021] An optical grating, also called a diffraction grating, as well as its mode of operation and manufacturing process are, as already mentioned, generally known, as can be seen, for example, from the scientific publication cited above. In principle, an optical grating can be based on at least partially periodic structures, a so-called grating structure, in a substrate. Using such a grating structure, an optical grating can bring about light guidance through the physical effect of diffraction, as is known, for example, from mirrors, lenses, or prisms. When light, i.e., light rays, fall on the optical grating, whereby the incident light rays in particular satisfy the Bragg equation, the light rays are diffracted or deflected by the optical grating. The light guidance can thus occur in particular through interference phenomena of the light rays diffracted by the optical grating.The deflection structure of the coupling region or coupling-out region can accordingly also be referred to as a diffraction structure.

[0022] An optical grating can preferably be designed to be directionally or angle-selective with respect to the incident light. Thus, only light, in particular a portion of the light, that falls onto an optical grating from a predetermined direction of incidence, for example, at a predetermined angle, can be deflected. Light, in particular a portion of the light that falls onto the optical grating from a different direction, is preferably not deflected, or the greater the difference from the predetermined direction of incidence, the less deflected it is. The portion of light that deviates from the predetermined direction of incidence or optimal direction of incidence can therefore preferably propagate unhindered through the substrate with the optical grating.

[0023] Additionally or alternatively, an optical grating can also be wavelength-selective or frequency-selective. Thus, only light, in particular a first portion of the light with a predetermined wavelength, can be deflected or diffracted by the optical grating at a specific diffraction angle. Light, in particular a second portion of the light with a wavelength other than the predetermined wavelength, is preferably not deflected, or the greater the difference from the predetermined wavelength, the less deflected. The second portion of light, which deviates from the predetermined wavelength or optimal wavelength, can therefore preferably propagate unhindered through the substrate with the optical grating. As a result, at least a monochromatic portion of light can be split off from polychromatic light that strikes the optical grating, for example.Advantageously, the deflection effect is maximum for the optimal wavelength and decreases or becomes weaker towards longer and shorter wavelengths, for example, according to a Gaussian bell curve. In particular, the deflection effect only affects a fraction of the visible light spectrum and / or in an angular range smaller than 90 degrees.

[0024] An optical grating can be produced in particular by exposing a substrate, for example photolithographically or holographically. In this context, the optical grating can then also be referred to as a holographic or holographic-optical grating. Two types of holographic-optical gratings are known: holographic surface gratings (SHGs for short) and holographic volume gratings (VHGs for short). With a holographic surface grating, the grating structure can be created by optically deforming a surface structure of the substrate. The changed surface structure can deflect incident light, for example, by reflecting it. Examples of holographic surface gratings are so-called sawtooth or blaze gratings.In contrast, the grating structure of holographic volume gratings can be incorporated into the entire volume or a portion of the volume of the substrate. Holographic surface gratings and holographic volume gratings are generally frequency-selective. However, optical gratings capable of diffracting polychromatic light are also known. These are called multiplexed volume holographic gratings (MVHGs) and can be produced, for example, by changing the periodicity of the grating structure of an optical grating or by arranging multiple holographic volume gratings in series.

[0025] A polymer, especially a photopolymer, or a film, especially a photosensitive film, for example made of plastic or organic materials, is particularly suitable as a material for the substrate for incorporating an optical grating. Substrates that have a deflection structure for diffracting light, for example in the form of an optical grating, can also be referred to as holographic optical elements (HOEs).

[0026] The described design of the coupling-in area and the coupling-out area therefore makes it possible to diffract the light falling on the coupling-in area to the image capture device arranged, for example, laterally on the cover plate, whereby the capture element can be designed such that the image capture device does not cover the lighting unit in the preferred installation position of the capture device on or in the design panel.

[0027] In In a further advantageous embodiment of the invention, the detection element is attached to the design panel by means of a fastening unit or is integrated into the design panel. The fastening unit can be designed, for example, as an adhesive or adhesive film. This enables the detection element, if the fastening unit is designed as an adhesive film, to adhere directly to a surface of the design panel through molecular forces, i.e., without adhesive. The detection element can thus be manufactured in various ways and particularly cost-effectively, since it can, for example, be designed merely as a thin holographic film that is glued to the design panel.

[0028] Alternatively, the detection element can be built into the design panel itself. For example, a predefined section of the design panel, made of plastic, for example, can be provided for this purpose, in which a holographic plate is arranged, so that the detection element is firmly integrated into the design panel. This has the advantage that this type of arrangement of the detection element is particularly robust, for example with regard to external forces acting on the design panel. This is because, even during daily driving and the associated external forces, such as frequent and intense weather changes, the detection element is always firmly integrated into the design panel and therefore cannot detach from the design panel without correspondingly strong external influences.If it is attached using adhesive, for example, it is quite conceivable that the detection element could be detached from the design panel under certain weather conditions.

[0029] A further particularly advantageous embodiment of the invention provides that the detection element is designed as a transparent plate, film, or lacquer. The carrier medium of the detection element is preferably flat. The flat carrier medium can, for example, be between half a millimeter and five millimeters thick. If the flat carrier medium is designed as a transparent film, it is also designed to be bendable, i.e. it can be deformed non-destructively, whereby non-destructive deformation is understood to mean non-destructive bending of the film by a bending radius of less than two centimeters. If the flat carrier medium is designed as a transparent lacquer, it can have a thickness in the micrometer range and thus less than one millimeter.This allows the flat carrier medium with the input and output areas, i.e., the detection element, to be positioned anywhere on the design panel without, for example, obscuring the design panel itself or the lighting unit. This allows the detection element to be integrated into or onto the design panel as desired.

[0030] According to a further embodiment, the exterior lighting device comprises two detection devices that are spatially separated from one another and arranged on two opposite edge regions of the design panel. For example, in the case of an exterior lighting device as a headlight of a motor vehicle, the design panel can be curved so that a front part of the design panel is directed in the longitudinal direction of the vehicle, whereas a rear, opposite, lateral part of the design panel points in the transverse direction of the vehicle. If respective detection devices are positioned in both the front and rear regions, i.e. if respective detection elements with associated image capture devices are arranged, both the front region of the motor vehicle and the side region of the motor vehicle can be monitored with the two detection devices.This ultimately contributes to enabling, for example, the detection device for the respective exterior lighting devices in both headlights and both taillights of the vehicle to provide all-round detection of the vehicle's surroundings. As an alternative to the described arrangement on or in the design panel, flat detection elements can be arranged, for example, in an upper and lower area of ​​the design panel in the vertical direction of the vehicle. Ultimately, therefore, all-round detection of the vehicle's surroundings is enabled by appropriately positioned detection devices.

[0031] A further advantageous embodiment of the invention provides that the exterior lighting device comprises an evaluation device which is designed to detect at least one object in the surroundings of the motor vehicle by evaluating the image data, to recognize the detected object using an object recognition criterion, and to provide object data describing the recognized object. The evaluation device can therefore perform object recognition, for example, based on a machine learning method, for example by means of an artificial neural network. With the aid of the evaluation device, it can thus be detected whether a coherent object can be recognized in the image data correlated with the detected light, such as a person, an object, or a symbol, such as a traffic sign, which is arranged in the surroundings of the motor vehicle.

[0032] In addition, the evaluation device is designed to recognize the detected object taking into account the object recognition criterion, i.e. the object recognition criterion comprises, for example, characteristics of various objects stored in a database. For example, a typical size, color and / or shape, a typical reflection behavior of light on the object and / or a typical location-dependent and / or time-dependent arrangement of the object is stored here. For example, another vehicle approaching the motor vehicle in the opposite lane can be detected and recognized as an object. Object data describing the detected object is provided by the evaluation device so that it can be transmitted, for example, to a control device of the motor vehicle or the exterior lighting device itself.In this example, the object data includes the information that a vehicle has been detected that is moving towards the motor vehicle.

[0033] For this purpose, the evaluation device comprises, for example, a processor device configured to perform the described object recognition. The processor device may comprise at least one microprocessor or at least one microcontroller for this purpose. Furthermore, the processor device may comprise program code configured to perform the described object recognition when executed by the processor device. The program code may be stored in a data memory of the processor device.

[0034] The detection device can therefore not only capture and provide an image of the vehicle's surroundings, but also, with the aid of suitable evaluation methods, actually examine the vehicle's surroundings and provide the object data describing the detected objects. Such an evaluation of the data captured by the detection device is useful, for example, to assist a vehicle's parking assistant during a parking maneuver. For example, the detection device positioned in and / or on the design panel of the respective exterior lighting device of the vehicle captures corresponding environmental data that provides information about one or more objects in the surroundings and thus enables their respective identification.

[0035] In a further particularly advantageous embodiment of the invention, it is provided that the exterior lighting device comprises a control device for controlling a lighting unit of the exterior lighting device. By means of the control device, for example, a luminous intensity of the respective lighting unit, i.e., for example, the headlight or the rear light of the motor vehicle, can be adjusted. The evaluation device is designed to detect a light-emitting vehicle moving towards the detection element by applying the object detection criterion. Based on the object detection described above, it can therefore be detected whether an object in the vicinity of the motor vehicle is another vehicle. Furthermore, it can be detected whether this other vehicle is emitting light, i.e., whether it has at least one activated exterior light.The emission of light, i.e. an activated exterior light of the approaching vehicle, can be detected, for example, by means of corresponding light intensity signals emitted by the approaching vehicle and detected by the exterior lighting device.

[0036] If a light-emitting vehicle moving toward the detection element is detected, the evaluation device is configured to provide a dimming signal for the lighting unit based on a driving situation criterion. This driving situation criterion includes information such as whether the motor vehicle and the detected vehicle are moving toward each other head-on. Thus, the direction of movement of the detection device and the detected vehicle relative to each other is considered. For example, only when moving toward each other should the currently activated high beams of the vehicle's headlights be reduced in intensity and consequently dimmed.The fact that the vehicle is moving towards the motor vehicle can be detected, for example, by the color of the respective light emitted by the vehicle. This is because a vehicle traveling in front of the motor vehicle and moving in the same direction of travel emits red light from its taillights in the direction of the motor vehicle, whereas a vehicle moving towards the motor vehicle from behind or in front in the longitudinal direction of the vehicle emits white light from its headlights. To determine the direction of movement of the motor vehicle, data from corresponding sensors of the motor vehicle can be provided to the evaluation device and transmitted to it, alternatively or additionally, so that the direction of movement of the motor vehicle and the vehicle relative to each other can be determined particularly reliably and precisely using this sensor data by applying the driving situation criterion.The driving situation criterion can also be used to take into account whether the motor vehicle and the vehicle are driving in daylight or in the dark, since it is particularly useful when driving in the dark to dim the high beam in good time in order not to dazzle or possibly irritate the driver of the approaching light-emitting vehicle.

[0037] The control device of the exterior lighting system is designed to adjust the light intensity of the lighting unit in accordance with the dimming signal provided by the evaluation device. Thus, if it detects, for example, that a vehicle is traveling in the opposite lane with its headlights activated and moving toward the vehicle, the control device is informed of this vehicle via the dimming signal and will then reduce the intensity of the high beams, i.e., dim them, if they are currently activated.

[0038] The exterior lighting system can therefore ensure that any glare from oncoming vehicles is detected early on, and the corresponding information for adjusting the brightness of the vehicle's exterior lights, such as the headlights, is provided to the control unit via the evaluation unit. The exterior lighting system thus enables reliable and rapid automatic dimming of the high beam.

[0039] The motor vehicle according to the invention has an exterior lighting device as described above. The preferred embodiments and their advantages presented in connection with the exterior lighting device according to the invention apply accordingly, to the extent applicable, to the motor vehicle according to the invention. For this reason, the corresponding developments of the motor vehicle according to the invention are not described again here.

[0040] The motor vehicle according to the invention is preferably designed as a motor vehicle, in particular as a passenger car or truck, or as a passenger bus or motorcycle.

[0041] The invention also includes combinations of the features of the described embodiments.

[0042] Exemplary embodiments of the invention are described below. Shown are: Fig. 1 shows a schematic representation of a motor vehicle with an exterior lighting device; Fig. 2 shows a schematic representation of an exterior lighting device for a motor vehicle with a detection element attached to a design panel; Fig. 3 shows an exterior lighting device for a motor vehicle with a detection element integrated into a design panel; Fig. 4 shows a schematic representation of a detection element for a design panel of a motor vehicle; and Fig. 5 shows a schematic representation of a distance determination using an exterior lighting device of a motor vehicle.

[0043] The exemplary embodiments explained below are preferred embodiments of the invention. In the exemplary embodiments, the described components of the embodiments each represent individual features of the invention that can be considered independently of one another, each of which also develops the invention independently of one another. Therefore, the disclosure is intended to encompass combinations of the features of the embodiments other than those shown. Furthermore, the described embodiments can also be supplemented by further features of the invention already described.

[0044] In the figures, the same reference symbols denote elements with the same function.

[0045] In Fig. 1 A motor vehicle 40 is sketched, which has an exterior lighting device 30 as a front left headlight in the vehicle's longitudinal direction. The exterior lighting device 30 comprises a design panel 31, a lighting unit 34 arranged behind it, which is designed to emit white lighting unit light through the design panel 31, and a detection device 10. The detection device 10 comprises a detection element 11 and an image detection device 35, which is arranged here behind the design panel 31. The exterior lighting device 30 comprises two detection elements 11, namely one in a front region of the design panel 31 in the vehicle's longitudinal direction and one in a rear region of the design panel 31 in the vehicle's longitudinal direction. Alternatively, the exterior lighting device 30 can have only one detection element 11 or more than two detection elements 11.The exterior lighting device 30 is designed to provide image data which is generated by light 100 (shown with reference number 100 in ) striking the two detection elements 11 from the surroundings. Fig. 4 ) are correlated. The exterior lighting device 30 thus enables the detection of the surroundings of the motor vehicle 40. A respective detection area 46, 46' of the two detection elements 11 is shown as a front detection area 46 in the vehicle longitudinal direction and as a rear detection area 46' in the vehicle longitudinal direction, each in the form of conically sketched areas in Fig. 1 outlined. The front detection element 11 is designed to "look" at least partially in front of the motor vehicle 40 in the vehicle's longitudinal direction and to the side of the motor vehicle 40 in the vehicle's transverse direction, i.e., to detect the surroundings there. The rear detection element 11 with the detection area 46', in contrast, is designed to detect only a lateral surrounding area of ​​the motor vehicle 40, i.e., the area to the left of the motor vehicle 40 in the vehicle's longitudinal direction.

[0046] Preferably, a further exterior lighting device 30 is integrated into the motor vehicle 40 as a front right headlight (not shown here) and two further exterior lighting devices 30 as respective rear lights (not shown). If the motor vehicle 40 has at least these four exterior lighting devices 30, complete all-round detection of the surroundings of the motor vehicle 40 is possible.

[0047] In Fig. 2 The exterior lighting device 30 is outlined, wherein the detection element 11 is positioned on the design panel 31 by means of a fastening unit 32. The detection element 11 can have a slight curvature and thus be positioned parallel to a surface shape 33 of the design panel 31, but at a predetermined distance from the surface of the design panel 31. In Fig. 2 It is also outlined that the detection device 10 can have, as components of the external lighting device 30, in addition to the image detection device 35, an evaluation device 36 and a control device 37 for controlling the lighting unit 34.

[0048] In Fig. 3 The exterior lighting device 30 is outlined, with three detection elements 11 being directly integrated into the design panel 31. For this purpose, for example, transparent plates shaped to fit the local surface contour of the design panel 31 are integrated into the design panel 31. In addition, Fig. 3 For the two upper detection elements 11, the respective image capture devices 35 are outlined, which are positioned here behind the design panel 31 and thus not directly visible to an observer. It is also clear that the respective detection elements 11 can be spatially separated from one another, for example, at opposite edge regions of the design panel 31, or can extend, for example, over an entire longitudinal side of the design panel 31 running in the longitudinal direction of travel.

[0049] In Fig. 4 The operation of the exterior lighting device 30 is outlined here. It is clear that the detection device 10 comprises a carrier medium 12, which is designed as a light guide and on which a coupling region 16 and a coupling region 18 are provided. The carrier medium 12 with the coupling region 16 and the coupling region 18 is the flat detection element 11 for the design panel 31, which is adapted to the surface shape 33 of the design panel 31.

[0050] The coupling region 16 is designed as a holographic element 14 with a first deflection structure 20. The first deflection structure 20 is configured to couple light 100, which falls onto the first deflection structure 20 from the surroundings of the motor vehicle 40, into the carrier medium 12. The carrier medium 12 is configured to transmit the coupled light 100 from the coupling region 16 to the coupling-out region 18 by means of internal reflections. The coupling-out region 18 is designed as a holographic element 14 with a second deflection structure 22. The second deflection structure 22 is configured to couple the transmitted light 100, which falls onto the second deflection structure 22, out of the carrier medium 12. The image capture device 35, for example, is arranged directly behind it.The image capture device 35 is designed to capture the light 100 coupled out of the capture element 11 at the coupling-out region 18 and to provide it as image data that correlates with the captured light 100. The image capture device 35 can thus be designed, for example, as a camera sensor. The coupling-in region 16 and the coupling-out region 18 have at least one optical grating, in particular a holographic volume grating or a holographic surface grating, as a deflection structure 20, 22. The capture element 11 itself can be designed as a transparent plate, film, or lacquer.

[0051] The evaluation device 36 can be designed to detect at least one object 42 in the environment by evaluating the image data provided by the image capture device 35, to detect the detected object 42 using an object detection criterion and to provide object data describing the detected object 42.

[0052] In Fig. 5 A wall in the surroundings of the motor vehicle 40 is sketched as such an object 42. The object 42, i.e. the wall, is located at a distance 44 from the motor vehicle 40. The exterior lighting device 30 also comprises a light source 38 and a sensor device 39. Furthermore, a sensor coupling-out region 15 is provided on the carrier medium 12, which is designed as a holographic element 14 with a third deflection structure 24. The light source 38 is designed to emit pulsed light 100' directly into the surroundings of the motor vehicle 40. The pulsed light 100' can be, for example, infrared laser light. As shown in Fig. 5 As outlined, the pulsed light 100' emitted by the light source 38 can also be emitted indirectly to the object 42, namely through the planar carrier medium 12, i.e., through the detection element 11. For this purpose, a light coupling region 17 and a light coupling region 19 are provided on the planar carrier medium 12. The light coupling region 17 is designed as a holographic element 14 with a fourth deflection structure 26, which is configured to couple the pulsed light 100' emitted by the light source 38, which falls on the fourth deflection structure 26, into the carrier medium 12. The carrier medium 12 is designed to transmit the coupled-in pulsed light 100' from the light coupling region 17 to the light coupling region 19 by means of internal reflection.The light output region 19 is designed as a holographic element 14 with a fifth deflection structure 28, which is designed to output the transmitted light 100' emitted by the light source 38, which falls on the fifth deflection structure 28, from the carrier medium 12 and emit it into the environment, i.e., in the direction of the object 42. The light 100" reflected on the wall, which was first emitted by the light source 38 and then reflected by the object 42 in the environment, can be coupled back into the carrier medium 12 by means of the input region 16 when this reflected light 100" falls on the first deflection structure 20.

[0053] The carrier medium 12 is configured to transmit this coupled-in reflected light 100" from the coupling-in region 16 to the sensor decoupling region 15 by means of internal reflection. The sensor decoupling region 15 with the third deflection structure 24 serves to decouple the reflected light 100" impinging on the third deflection structure 24 from the carrier medium 12. The sensor device 39 is configured to detect the light 100" decoupled at the sensor decoupling region 15 and to provide it in the form of sensor data. This sensor data describes a propagation time of the light 100" emitted by the light source 38 and reflected by the object 42, which was detected by the sensor device 39. The evaluation device 36 is then configured to provide distance data by evaluating the sensor data. The distance data describes the distance 44 of the object 42 from the detection device 10, that is, ultimately from the motor vehicle 40.

[0054] The evaluation device 36 is also designed to detect a light-emitting vehicle moving toward the detection element 11 by applying the object detection criterion. If the light-emitting vehicle moving toward the detection element 11 has been detected, a dimming signal is provided for the lighting unit 34 using a driving situation criterion. The control device 37 of the exterior lighting device 30, which is Fig. 2is outlined, is designed to adjust a light intensity of the lighting unit 34 in accordance with the dimming signal provided by the evaluation device 36. If, for example, it is detected that a vehicle is moving towards the motor vehicle 40, it can be detected that the motor vehicle 40 is currently driving with its high beam activated, for example, but that the high beam should be dimmed due to another vehicle approaching from the front. In this case, the control device 37 can reduce the light intensity of the lighting unit 34 after receiving the dimming signal. The oncoming vehicle can be detected, for example, based on a color of the headlight light emitted by the vehicle, wherein the headlight light was detected as light 100 by one of the image capture devices 35 of the motor vehicle 40.Based on the movement data of the motor vehicle 40 itself provided by the evaluation device 36, as well as the information stored in the object recognition criterion, for example, relating to the object recognition of vehicles, it can also be clearly recognized that an object 42 is located in the vicinity of the motor vehicle 40, which is recognized as an illuminated vehicle, and that the recognized vehicle is approaching the motor vehicle 40 from the front, so that the high beam of the motor vehicle 40 should consequently be deactivated. Such evaluation steps as well as control commands for the luminous intensity of the lighting unit 34 can thus be determined and executed using the exterior lighting device 30.

[0055] Overall, the invention describes the integration of a holographic element (HOE) into vehicle lighting, i.e., it describes the exterior lighting device 30 for the motor vehicle 40. By means of the exterior lighting device 30, image content relating to the surroundings of the motor vehicle 40 can be recorded via detection elements 11 arranged in the design panel 31 or on the design panel 31 of the motor vehicle 40. This results in the following advantages: Due to the flat design of the detection element 11, it can become dirty less quickly, can be kept transparent and thus not directly visible, and can be equipped with various optical functions, such as the provision of image data and / or the emission of pulsed light 100' by means of the light source 38.The position of the design panel 31 also selects an exposed location on the motor vehicle 40, allowing an optimal overview of the surroundings, ultimately enabling particularly reliable environmental data to be provided. The information provided by the exterior lighting device 30 can, for example, contribute to at least partially autonomous parking, to detecting objects 42 approaching or already in the blind spot, to exiting driveways that block the view to the left and right, or to fully automated parking and the associated detection of open spaces. In addition, the exterior lighting device 30 can register any glare from oncoming vehicles and provide the associated information for adjusting the lighting unit 34, i.e., determine the appropriate dimming signal and provide it to the control device 37 of the lighting unit 34.

[0056] The respective detection elements 11 can also determine the distance 44 between the motor vehicle 40 and the object 42 in the surroundings of the motor vehicle 40 by means of a laser distance measurement and thus increase the measurement accuracy of sensors of the motor vehicle 40, for example, when parking. The laser distance measurement is carried out by detecting and evaluating the light 100 emitted by the light source 38 and reflected by the object 42.

[0057] For this purpose, the outdoor lighting device 30 can either be equipped with a separate fastening unit 32 to which the detection element 11 is attached. Alternatively, the design panel 31 itself can comprise the detection element 11. The detection element 11, i.e., the flat carrier medium 12, can be relatively small and thus measure approximately at a point, but can also be designed to be flat, for example, to enable wide-angle recordings of the surroundings.

[0058] It is also possible to use multiple detection elements 11 with multiple image capture devices 35 to counteract any loss of light or loss of image quality. The image capture devices 35 can each be installed behind the design panel 31, either behind the body itself or in a hidden position inside the exterior lighting device 30, and thus hidden. It is also possible to emit light 100' from the light source 38 directly or through the detection element 11 into the surroundings in order to illuminate the surroundings or, as described above, to measure the distance to the object 42, i.e., to determine the distance 44.

Claims

1. An external lighting device (30) for a motor vehicle (40), wherein the external lighting device (30) comprises a design screen (31) and at least one capturing device (10) comprising an image-capturing device (35) and a carrier medium (12), wherein the carrier medium (12) is designed as an optical waveguide, on which an in-coupling region (16) and an out-coupling region (18) are provided, wherein the carrier medium (12) comprising the in-coupling region (16) and the out-coupling region (18) is designed as a capturing element (11), adapted to a surface shape (33) of the design screen (31), for the design screen (31); the in-coupling region (16) is designed as a holographic element (14) comprising a first deflection structure (20), which is configured to couple light (100) incident on the first deflection structure (20) from the surroundings into the carrier medium (12); the carrier medium (12) is designed to transmit the coupled-in light (100) from the in-coupling region (16) to the out-coupling region (18) by means of internal reflection; the out-coupling region (18) is designed as a holographic element (14) comprising a second deflection structure (22), which is configured to couple the transmitted light (100) incident on the second deflection structure (22) out of the carrier medium (12); and the image-capturing device (35) is designed to capture the light (100) coupled out of the capturing element (11) at the out-coupling region (18) and to provide it as image data that correlates with the captured light (100), wherein the external lighting device (30) comprises a light source (38), a sensor device (39) and an evaluation device (36), and a sensor out-coupling region (15) is provided on the carrier medium (12), wherein the light source (38) is designed to emit pulsed light (100') into the surroundings; the first deflection structure (20) of the in-coupling region (16) is configured to couple light (100") emitted by the light source (38) and reflected by an object in the surroundings into the carrier medium; the carrier medium (12) is designed to transmit the coupled-in reflected light (100') from the in-coupling region (16) to the sensor out-coupling region (15) by means of internal reflection; the sensor out-coupling region (15) is designed as a holographic element (14) comprising a third deflection structure (24), which is configured to couple the reflected light (100") coupled into the carrier medium (12) out of the carrier medium (12); and the sensor device (39) is designed to capture the light (100") coupled out at the sensor out-coupling region (15) and to provide it in the form of sensor data describing a time of flight of the light (100") that is emitted by the light source (38), reflected by the object (42), and has been captured by the sensor device (39); and the evaluation device (36) is designed to provide distance data describing a distance between the object (42) and the capturing device (10) by evaluating the sensor data.

2. The external lighting device (30) according to the preceding claim, wherein a light in-coupling region (17) and a light out-coupling region (19) are provided on the carrier medium (12), wherein the light in-coupling region (17) is designed as a holographic element (14) comprising a fourth deflection structure (26), which is configured to couple light (100') incident on the fourth deflection structure (26) from the light source (38) into the carrier medium (12); the carrier medium (12) is designed to transmit the coupled-in light (100') from the light in-coupling region (17) to the light out-coupling region (19) by means of internal reflection; and the light out-coupling region (19) is designed as a holographic element (14) comprising a fifth deflection structure (28), which is configured to couple the transmitted light (100') incident on the fifth deflection structure (28) out of the carrier medium (12) and to emit it into the surroundings.

3. The external lighting device (30) according to the preceding claim, wherein the in-coupling region (16) and the out-coupling region (18) comprise at least one optical grating, in particular a holographic volume grating or a holographic surface grating, as a deflection structure (20, 22).

4. The external lighting device (30) according to any of the preceding claims, wherein the capturing element (11) is fastened to the design screen (31) by means of a fastening unit (32) or is integrated in the design screen (31).

5. The external lighting device (30) according to any of the preceding claims, wherein the capturing element (11) is designed as a transparent plate, film, or coating.

6. The external lighting device (30) according to any of the preceding claims, wherein the external lighting device (30) comprises two capturing devices (10), which are arranged to be spatially separated from one another on two opposing edge regions of the design screen (31).

7. The external lighting device (30) according to any of the preceding claims, wherein the external lighting device (30) comprises an evaluation device (36), which is designed to, by evaluating the image data, capture at least one object (42) in the surroundings, recognize the captured object (42) by applying an object recognition criterion, and provide object data describing the captured object (42).

8. The external lighting device (30) according to the preceding claim, wherein the external lighting device (30) comprises a control device (37) for actuating a lighting unit (34) of the external lighting device (30), wherein, by applying the object recognition criterion, the evaluation device (36) is designed to recognize a vehicle emitting light moving toward the capturing element (11), and if the vehicle emitting light moving toward the capturing element (11) is recognized, to provide a low-beam signal for the lighting unit (34) by applying a driving situation criterion, and wherein the control device (37) is designed to set a light intensity of the lighting unit (34) in accordance with the low-beam signal provided by the evaluation device (36).

9. A motor vehicle (40) comprising an external lighting device (30) according to any of the preceding claims.