Exterior lighting system for a motor vehicle

Abstract

Exterior lighting device (30) for a motor vehicle (40), wherein the exterior lighting device (30) comprises a design cover (31) and at least one detection device (10) with an image detection device (35) and a carrier medium (12), wherein the carrier medium (12) is designed as a light guide on which an input area (16) and an output area (18) are provided, wherein - the carrier medium (12) with the coupling area (16) and the coupling area (18) is designed as a planar detection element (11) adapted to a surface shape (33) of the design aperture (31) for the design aperture (31); - the coupling area (16) is designed as a holographic element (14) with a first deflection structure (20) designed to couple light (100) falling from an environment onto the first deflection structure (20) into the carrier medium (12); - the carrier medium (12) is designed to transfer the coupled light (100) from the coupling area (16) to the coupling area (18) by means of internal reflection; - the coupling area (18) is designed as a holographic element (14) with a second deflection structure (22) designed to couple the transmitted light (100) falling on the second deflection structure (22) out of the carrier medium (12); - the image acquisition device (35) is designed to capture the light (100) coupled out from the acquisition element (11) at the coupling area (18) and to provide it as image data that correlates with the captured light (100); and - the external lighting device (30) comprises two detection devices (10) which are spatially separated from each other and arranged on two opposing edge areas of the design panel (31).

Description

[0001] The invention relates to an exterior lighting device for a motor vehicle, wherein the exterior lighting device comprises a design lens and at least one detection device with an image capture device and a carrier medium. The invention further 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 a near-complete view of its surroundings, providing a 360-degree view. For this purpose, camera sensors are typically installed in the center of the front and at the rear of the vehicle. However, not all exterior components of the vehicle are suitable for positioning such camera sensors. Various limitations arise regarding positioning, such as limited available space, a high probability of contamination (e.g., from splashing water), or optical limitations affecting the surroundings that can be captured from that location.Therefore, camera sensors are often positioned in predetermined locations, such as in the center of the front, at the rear, and / or on the side mirrors of the vehicle. With regard to positioning on the vehicle, conventional camera systems are thus only of limited use.

[0003] Optical diffraction gratings that are holographically fabricated and therefore referred to as holographic gratings are known from the prior art. 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 striking such a holographic grating at an angle significantly outside the range of angles satisfying the Bragg condition passes through the grating undiffracted. However, if light strikes the holographic grating at an angle such that the Bragg condition is at least approximately satisfied, the light is diffracted at that angle. A similar behavior is observed with respect to the wavelength dependence of the holographic grating's influence on light.Light with a wavelength significantly outside the range defined by the Bragg condition (the so-called Bragg wavelength) passes through the holographic grating without diffracting. Only light with a wavelength that at least approximately meets the Bragg condition is diffracted by the holographic grating. Using complex holographic grating structures, it is therefore possible, for example, to diffract light with two different wavelength ranges at the same angle. Furthermore, a holographic grating can split light with different wavelengths into separate light paths, thus enabling the implementation of a dispersive beam splitter.

[0004] US Patent 5,268,985 A discloses a light-guiding device having an input area and an output area for light, wherein the light is guided from the input area to the output area through the light-guiding device. The light-guiding device includes a holographic layer for this purpose.

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

[0006] The problem is solved by the subject matter of the independent patent claims. Advantageous embodiments 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 to provide image data that correlates with the detected light. The exterior lighting device thus ultimately enables photographic and / or video-based capture of the vehicle's surroundings. The exterior lighting device according to the invention is, for example, configured as a headlight, taillight, turn signal, or brake light. The exterior lighting device comprises a design cover and at least one detection device. The design cover is, for example, made of plastic and serves to shield a lighting unit of the exterior lighting device, i.e., a lamp, which is, for example, a light-emitting diode (LED), from the vehicle's surroundings. The design cover can, for example, be colored, for example, red in the case of the brake light.

[0008] The detection unit of the outdoor lighting system is designed to provide image data of the surroundings. For this purpose, it comprises an image detection unit and a carrier medium. The carrier medium is designed as a light guide with an input area and an output area. The carrier medium thus acts as a light guide. The carrier medium can, for example, be planar, meaning its width and length are greater than its thickness. This planar carrier medium is mounted perpendicular to its thickness, for example, on the design panel. The carrier medium can be made of transparent plastic or glass, for instance, as a plate or film. The carrier medium, with its input and output areas, is designed as a planar detection element adapted to the surface shape of the design panel.This detection element can, for example, be adhered 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, as a fastening element, with which the detection element is adhered to the design panel. The detection element itself is not designed as a rigid plate, but is bendable without damage by at least a radius of typically 2 cm, so that it can, for example, be positioned on a curved design panel, which is designed, for instance, to cover a vehicle's headlight.

[0009] The coupling region itself is designed as a holographic element with a first deflection structure. A description of the operation of such a holographic element, often referred to as an optical grating and which can be fabricated using holographic methods, can be found, for example, in the scientific publication cited above. The coupling region can, for instance, be implemented as a diffraction grating. The first deflection structure is designed to couple light incident on it from an environment into the support medium, deflecting it sufficiently to satisfy the critical angle condition. The support medium is designed to transfer the coupled light from the coupling region to the output region via internal reflection, preferably total internal reflection.The light that falls from the environment onto the first deflection structure and is coupled into the carrier medium can thus be guided, for example, within the carrier medium in zigzag-like movements along a direction parallel to a plane of the surface of the detection element.

[0010] The decoupling area is designed as a holographic element with a second deflection structure. Both the first deflection structure of the coupling area and the second deflection structure of the decoupling area can each be implemented, for example, as a diffraction grating. The second deflection structure is designed to decouple the coupled light, which falls onto the second deflection structure, from the carrier medium. The coupling area and the decoupling area can be located, for example, on different sides of the detection element. For instance, the coupling area can encompass the entire surface of the detection element that faces the design aperture towards the surroundings and is thus oriented towards the vehicle's environment. The decoupling area can be located on the opposite side and is therefore oriented towards the surface of the design aperture.Alternatively or additionally, the coupling area can be arranged on one side of the carrier medium, so that the coupling area is oriented perpendicular to the described coupling area.

[0011] The image acquisition unit of the image acquisition device is designed to capture the light coupled out from the capture element (i.e., the carrier medium with the coupling and decoupling areas) at the decoupling area and to provide image data that correlates with the captured light. The image acquisition unit is thus designed to generate image data from the light coupled into it. To capture the light coupled out from the carrier medium, the image acquisition unit rests against the decoupling area. For attachment to the carrier medium, the image acquisition unit can, for example, be glued to the carrier medium. Alternatively, the carrier medium can be clamped in a holding device of the image acquisition unit.Preferably, the image acquisition device can be implemented as an image sensor or camera, with or without imaging optics, such as a lens or lens system. The image acquisition device can, for example, be designed as a CCD sensor (Charged Coupled Device) or as a CMOS sensor (Complementary Metal Oxide Semiconductor). In this configuration of the image acquisition device as an image sensor, the substrate on which the coupling and output regions are located can function as a lens, i.e., an imaging optic. Alternatively, the image acquisition device can also be implemented as a camera or photographic apparatus, in particular as a microcamera, such as those found in modern devices like smartphones, with its own imaging optics.The image capture device is designed to create a photographic and / or video-based image of the area surrounding the exterior lighting unit. Typically, a vehicle's exterior lighting unit is positioned high enough relative to the road surface that it is less prone to dirt accumulation than, for example, a camera sensor located lower down, such as one in the shock absorber. The capture element is thus positioned relatively exposed on the vehicle, providing a favorable overview of the vehicle's surroundings. Furthermore, due to its positioning relative to the road surface, the capture element is generally less likely to become dirty and is easily visible.

[0012] Integrating the image capture device into the exterior lighting system of a vehicle allows for the discreet implementation of an image capture device, such as a camera system. With appropriate positioning, for example, below the trim panel or in an edge area such as a frame adjacent to the trim panel, the image capture device can be invisible to an observer of the vehicle and thus seamlessly integrated into the vehicle. Furthermore, the exposed position of the exterior lighting system on the vehicle, when individual image capture devices are positioned appropriately within each of the vehicle's exterior lighting systems, offers the possibility of capturing a complete 360-degree view of the vehicle's surroundings.In this case, an angular range of 360 degrees around the vehicle can be provided entirely in the form of image data.

[0013] According to the invention, the external lighting device comprises two detection devices arranged spatially separated from each other on two opposing edge regions of the design panel. For example, in the case of an external lighting device serving as a front headlight of the vehicle, the design panel can be curved such that a front part of the design panel is oriented in the longitudinal direction of the vehicle, while a rear, opposing 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 and side regions of the vehicle can be monitored by the two detection devices.This contributes to the fact that, for example, in both headlights and both taillights of the vehicle, the all-around detection of the vehicle's surroundings is ultimately enabled by the detection device. Alternatively, instead of the described arrangement on or in the design panel, flat detection elements can be arranged in the upper and lower sections of the design panel in the vertical direction of the vehicle. Ultimately, all-around detection of the vehicle's surroundings is thus enabled by means of appropriately positioned detection devices.

[0014] The invention also includes embodiments that offer additional advantages.

[0015] One embodiment provides that the coupling area and the coupling area have at least one optical grating as a deflection structure, in particular a holographic surface grating or a holographic volume grating. In this context, the detection device can also be referred to as a HoloCam, short for holographic camera.

[0016] An optical grating, also called a diffraction grating, as well as its operating principle and manufacturing process, is, as already mentioned, generally known, as can be seen, for example, in the scientific publication cited above. In principle, an optical grating can be based on at least partially periodic structures, a so-called grating structure, embedded in a substrate. Using such a grating structure, an optical grating can achieve light deflection through the physical effect of diffraction, similar to that achieved by mirrors, lenses, or prisms. When light falls on the optical grating, that is, when light rays fall on the optical grating, and these incident light rays, in particular, satisfy the Bragg equation, the light rays are diffracted or deflected by the optical grating. Light deflection can thus occur, in particular, through interference phenomena of the light rays diffracted by the optical grating.The deflection structure of the coupling area or coupling area can therefore also be referred to as a diffraction structure.

[0017] Preferably, an optical grating can be configured to be directionally or angle-selective with respect to the incident light. Thus, only light, and in particular a portion of the light, that falls onto the optical grating from a predetermined direction of incidence, for example at a predetermined angle, can be deflected. Light, and in particular a portion of the light, that falls onto the optical grating from a different direction is preferably not deflected, or the deflection decreases the greater the difference from the predetermined direction of incidence. The portion of light that deviates from the predetermined or optimal direction of incidence can therefore preferably propagate unhindered through the substrate containing the optical grating.

[0018] Additionally or alternatively, an optical grating can be wavelength-selective or frequency-selective. Thus, only light, in particular a first component 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 component of the light with a wavelength other than the predetermined one, is preferably not deflected, or the deflection decreases the greater the difference from the predetermined wavelength. The second component of light, which deviates from the predetermined wavelength or optimal wavelength, can therefore preferably propagate unhindered through the substrate containing the optical grating. This allows, for example, at least a monochromatic component of light to be separated from polychromatic light striking the optical grating.Advantageously, the deflection effect is maximal for the optimal wavelength and decreases or weakens towards longer and shorter wavelengths, for example according to a Gaussian curve. In particular, the deflection effect only acts on a fraction of the visible light spectrum and / or in an angular range of less than 90 degrees.

[0019] Optical gratings can be fabricated, in particular, by exposing a substrate, for example, photolithography or holography. In this context, the optical grating can also be referred to as a holographic or holographic-optical grating. Two types of holographic-optical gratings are known: surface holographic gratings (SHGs) and volume holographic gratings (VHGs). In a surface holographic grating, the grating structure can be created by optically deforming the surface structure of the substrate. The altered surface structure allows incident light to be deflected, for example, reflected. Examples of holographic surface gratings are sawtooth and blaze gratings.In contrast, the grating structure of holographic volume gratings can be incorporated into the entire volume or a portion of the substrate's volume. 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 multiple-volume holographic gratings (MVHGs) and can be produced, for example, by modifying the periodicity of an optical grating's structure or by arranging several holographic volume gratings in series.

[0020] Suitable materials for the substrate used to incorporate an optical grating include a polymer, especially a photopolymer, or a film, especially a photosensitive film, for example made of plastic or organic materials. Substrates that have a deflection structure for diffracting light, for example in the form of an optical grating, can also be called holographic optical elements (HOEs).

[0021] The described design of the coupling area and the coupling area therefore makes it possible to diffract the light falling on the coupling area to the image capture device, which is arranged, for example, laterally on the cover plate, so that the capture element can be designed in such a way 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 cover.

[0022] In a further advantageous embodiment of the invention, the detection element is attached to the design panel by means of a fastening unit or integrated into the design panel. The fastening unit can, for example, be designed as an adhesive or an adhesive film. This allows the detection element to adhere directly to a surface of the design panel by molecular forces, i.e., without adhesive, if the fastening unit is designed as an adhesive film. The detection element can thus be manufactured in various ways and in a particularly cost-effective manner, since it can, for example, simply be designed as a thin holographic film that is glued to the design panel.

[0023] Alternatively, the detection element can be integrated into the design panel itself. For example, a predefined section of the design panel, which may be made of plastic, can be provided with a holographic plate, thus firmly integrating the detection element into the design panel. This has the advantage of making such an arrangement of the detection element particularly robust, for example, with regard to external forces acting on the design panel. Even during daily driving and the associated external forces, such as frequent and intense weather changes, the detection element remains firmly integrated into the design panel and therefore cannot detach from it without a correspondingly strong external force.Because if the sensor is attached using, for example, adhesive, it is quite conceivable that under certain weather conditions the sensor element could detach from the design panel.

[0024] Another particularly advantageous embodiment of the invention provides that the detection element is designed as a transparent plate, film, or lacquer. Preferably, the support medium of the detection element is planar. The planar support medium can be, for example, between half a millimeter and five millimeters thick. If the planar support medium is designed as a transparent film, it is also flexible, meaning it can be deformed non-destructively, whereby non-destructive deformation is understood to mean bending the film around a bending radius of less than two centimeters. If the planar support medium is designed as a transparent lacquer, it can have a thickness in the micrometer range and consequently less than one millimeter.This allows the flat carrier medium, with its coupling and decoupling areas—that is, the detection element—to be positioned arbitrarily on the design panel without obscuring, for example, the design panel itself or the lighting unit. This makes it possible to integrate the detection element into or onto the design panel at any desired location.

[0025] Another advantageous embodiment of the invention provides that the external lighting device includes an evaluation unit designed to detect at least one object in the vicinity of the 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 unit can, for example, perform object recognition based on a machine learning method, such as an artificial neural network. With the aid of the evaluation unit, it can thus be determined whether a coherent object, such as a person, an object, or a symbol, such as a traffic sign, located in the vicinity of the vehicle, can be identified in the image data correlated with the detected light.

[0026] Furthermore, the evaluation unit is designed to recognize the detected object based on the object recognition criteria. These criteria comprise, for example, characteristics of various objects stored in a database. This includes, for instance, typical size, color, and / or shape, typical light reflection behavior, and / or typical location-dependent and / or time-dependent arrangement of the object. The object could, for example, be another vehicle approaching the vehicle in the opposite lane. The evaluation unit provides object data describing the detected object, which can then be transmitted, for example, to a control unit of the vehicle or the vehicle's exterior lighting system.In this example, the object data includes the information that a vehicle has been detected moving towards the motor vehicle.

[0027] The evaluation unit includes, for example, a processor configured to perform the described object recognition. This processor can include at least one microprocessor or at least one microcontroller. Furthermore, the processor can contain program code configured to perform the described object recognition when executed by the processor. This program code can be stored in a data memory within the processor.

[0028] The detection device can therefore not only capture and provide an image of the vehicle's surroundings, but also, using suitable evaluation methods, actually analyze the vehicle's environment and provide object data describing the detected objects. Such an evaluation of the data captured by the detection device is useful, for example, to support a vehicle's parking assistant during a parking maneuver. This is because, for instance, the detection device, positioned in and / or on the design panel of the vehicle's exterior lighting system, captures relevant environmental data that provides information about one or more objects in the surroundings, thus enabling their identification.

[0029] In a further particularly advantageous embodiment of the invention, the exterior lighting device includes a control unit for controlling a lighting unit of the exterior lighting device. The control unit allows, for example, the adjustment of the luminous intensity of the respective lighting unit, i.e., the headlight or taillight of the motor vehicle. The evaluation unit is configured, by applying the object recognition criterion, to detect a light-emitting vehicle moving towards the detection element. Based on the object recognition described above, it is thus possible to determine whether an object in the vicinity of the motor vehicle is another vehicle. Furthermore, it is possible to determine 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.

[0030] If a vehicle approaching the detection element and emitting light is detected, the evaluation unit is designed to provide a dimming signal for the headlight unit based on a driving situation criterion. This driving situation criterion includes information such as whether the vehicle and the detected vehicle are moving towards each other head-on or not. The system therefore considers the direction of movement of the detection device and the detected vehicle relative to each other. For example, only when the vehicles are moving towards each other should the intensity of the currently activated high beams of the vehicle's headlights be reduced and consequently dimmed.That a vehicle is moving towards another vehicle can be recognized, for example, by the color of the respective lights emitted by the other vehicle. A vehicle traveling in the same direction in front of another vehicle emits red light from its taillights towards the other vehicle, whereas a vehicle moving towards the other vehicle from behind or in front of it in the longitudinal direction emits white light from its headlights. Alternatively or additionally, data from corresponding sensors on the other vehicle can be provided to and transmitted to the evaluation unit to determine the direction of movement of the other vehicle. This allows the direction of movement of the other vehicle and the vehicle relative to each other to be determined particularly reliably and accurately using this sensor data and 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 darkness, since, especially when driving in darkness, it is useful to dim the high beam in good time in order not to dazzle and possibly irritate the driver of the approaching light-emitting vehicle.

[0031] The control unit for 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 unit. Thus, if the control unit detects, for example, that a vehicle with its headlights activated is approaching in the oncoming lane, it is informed of this vehicle via the dimming signal and will then reduce the intensity of the currently activated high beams, i.e., dim them.

[0032] The exterior lighting system thus enables the early detection of any potential glare from oncoming vehicles and provides the control unit with the necessary information to adjust the brightness of the vehicle's exterior lights, such as the headlights. This allows for reliable and rapid automatic dimming of the high beams.

[0033] According to a particularly advantageous embodiment of the invention, the external lighting device comprises a light source, a sensor device, and an evaluation device, and a sensor coupling area is provided on the carrier medium. The light source is, for example, a laser that emits light in the infrared wavelength range. This light source is also configured to emit pulsed light. The light emitted by the light source is, for example, emitted directly into the vicinity of the vehicle, where, for example, an object is located. The evaluation device mentioned here can be an additional evaluation device of the external lighting device.However, this can alternatively correspond to the evaluation unit already mentioned above for determining the dimming signal, meaning that the external lighting unit can only include one evaluation unit that can perform various evaluation processes.

[0034] The first deflection structure of the coupling area is designed to couple light emitted by the light source and reflected by an object in the vicinity into the carrier medium. The light source is positioned such that it emits pulsed light, for example, towards a wall in the vicinity of the vehicle. This light is then reflected by the wall and coupled into the carrier medium via the coupling area. The carrier medium is designed to transfer the coupled-in reflected light from the coupling area to the sensor output area via internal reflection. The sensor output area is configured as a holographic element on a third deflection structure. This third deflection structure can be, for example, a diffraction grating, just like the corresponding deflection structures at the output and coupling areas.The third deflection structure is designed to extract the reflected light coupled into the carrier medium. The sensor device is oriented relative to the detection element and ultimately to the sensor extraction area in such a way that it is configured to detect the light extracted at the sensor extraction area and provide it in the form of sensor data. The sensor data describes the travel 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 then configured to provide distance data, describing the distance of the object from the detection device, by evaluating the sensor data.

[0035] With a suitable choice of light source and sensor device, a laser distance measurement can be performed, for example, to determine the distance between the vehicle and the object—more precisely, between the vehicle's exterior lighting and the object, where in this example the wall in the vicinity of the vehicle. This distance data can then be provided to a driver assistance system or other control unit of the vehicle, enabling, for instance, a parking assistant to plan and execute an automatic or at least semi-automatic parking maneuver in a parking space next to the aforementioned wall.Alternatively or additionally, the distance data can be used to monitor and optimize exiting a driveway, detect an approaching object and / or one already in the vehicle's blind spot, identify an object visible only when the driver looks over their shoulder, and / or initiate an emergency stop if an object is moving towards the vehicle from the front or side. The advantage of the external lighting system over conventional environmental sensing systems is that it covers a large area at an optimal height relative to the vehicle's height, capturing relevant sections of the vehicle's surroundings.This is because the individual detection areas of the exterior lighting devices are not point-like, as is the case with conventional camera sensors, but rather large-area, extending across the entire surface of the detection element, which, for example, completely or at least partially covers the design panel. This means that even if, for example, the vehicle is partially soiled and this soiling extends at least partially across the design panel of the exterior lighting device, the vehicle's surroundings are still captured, as it is unlikely that the large-area detection element will be completely affected by the soiling.

[0036] An additional embodiment of the invention provides that, in addition to the sensor coupling area on the carrier medium, a light coupling area and a light coupling area are provided. The light coupling area is designed as a holographic element with a fourth deflection structure, which is, for example, configured as a diffraction grating. The fourth deflection structure is designed to couple light falling from the light source onto the fourth deflection structure into the carrier medium. This light coupling area is, for example, positioned 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 area. The carrier medium is designed to transfer the coupled light from the light coupling area to the light coupling area by means of internal reflection.The light output area is designed as a holographic element with a fifth deflection structure, which is, for example, configured as a diffraction grating. This fifth deflection structure is designed to extract the transmitted light falling upon it from the carrier medium and emit it into the surroundings. In addition to the simple coupling, transport, and extraction of light emitted from the surroundings towards the detection element, the light from the light source itself can be transported via the carrier medium, and consequently via the detection element, to a desired output area, the so-called light output area, and from there emitted into the surroundings. The carrier medium containing the light input and output areas can be spatially separated from the carrier medium containing the input area in the output area.The four coupling areas mentioned can also be provided on one and the same carrier medium, so that the detection device of the outdoor lighting system only has a planar carrier medium into which light is emitted from different directions and with different coupling areas as target positions. This makes it possible, for example, for the light source, the image capture device, and the sensor device to be located at respective edge areas of the outdoor lighting system, such as at the edge of the design panel or behind the design panel, and yet light from the light source is emitted or ambient light is coupled in from a predefined area on the design panel and transmitted to the corresponding sensor device or image capture device.This makes the detection element of the external lighting device visually inconspicuous and allows it to be installed, for example in a headlight or taillight of the motor vehicle, invisibly to an observer.

[0037] The light coupling area can, for example, coincide at least partially with the output coupling area, and the light output coupling area can coincide at least partially with the coupling area.

[0038] The motor vehicle according to the invention has an external lighting device as described above. The preferred embodiments and their advantages presented in connection with the external lighting device according to the invention apply accordingly, insofar as applicable, to the motor vehicle according to the invention. For this reason, the corresponding further developments of the motor vehicle according to the invention are not described again here.

[0039] 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.

[0040] The invention also includes combinations of the features of the described embodiments.

[0041] The following are exemplary embodiments of the invention described. This is illustrated by: Fig. 1 a schematic representation of a motor vehicle with an external lighting device; Fig. 2 a schematic representation of an external lighting device for a motor vehicle with a detection element attached to a design panel; Fig. 3 an external lighting device for a motor vehicle with a detection element integrated into a design panel; Fig. 4 a schematic representation of a detection element for a design panel of a motor vehicle; and Fig. 5 a schematic representation of distance determination using an external lighting device of a motor vehicle.

[0042] The exemplary embodiments described below are preferred embodiments of the invention. In these exemplary embodiments, the described components each represent individual features of the invention, which can be considered independently of one another and each further develops the invention independently. Therefore, the disclosure is intended to include combinations of features of the embodiments other than those shown. Furthermore, the described embodiments can also be supplemented by further features of the invention already described.

[0043] In the figures, identical reference symbols denote functionally equivalent elements.

[0044] In Fig. Figure 1 shows a motor vehicle 40, which has an exterior lighting device 30 as a front left headlight in the longitudinal direction of the vehicle. The exterior lighting device 30 comprises a design panel 31, a lighting unit 34 arranged behind it, which is configured to emit white light through the design panel 31, and a detection device 10. The detection device 10 comprises a detection element 11 and an image capture device 35, which is arranged here behind the design panel 31. The exterior lighting device 30 comprises two detection elements 11, one in a forward region of the design panel 31 in the longitudinal direction of the vehicle and one in a rear region of the design panel 31 in the longitudinal direction of the vehicle. Alternatively, the exterior lighting device 30 can have only one detection element 11 or more than two detection elements 11.The external lighting device 30 is designed to provide image data that is generated by light 100 from the environment striking the two detection elements 11 (represented by the reference numeral 100 in . Fig. 4) are correlated. The external lighting device 30 thus enables the detection of the vehicle's surroundings 40. A respective detection area 46, 46' of the two detection elements 11 is defined as the front detection area 46 in the longitudinal direction of the vehicle and as the rear detection area 46' in the longitudinal direction of the vehicle, each in the form of conically sketched areas in Fig. Figure 1 is sketched. The front detection element 11 is designed to "see" at least partially in the longitudinal direction in front of and alongside the vehicle 40 in the transverse direction, that is, to detect the surroundings there. In contrast, the rear detection element 11 with the detection area 46' is designed to detect only a lateral area surrounding the vehicle 40, that is, the area to the left of the vehicle 40 in the longitudinal direction.

[0045] Preferably, a further external lighting device 30, namely a front right headlight (not shown here), and two further external lighting devices 30, namely rear lights (not shown), are integrated into the motor vehicle 40. If the motor vehicle 40 has at least these four external lighting devices 30, complete all-round illumination of the area surrounding the motor vehicle 40 is possible.

[0046] In Fig. Figure 2 shows the external lighting device 30, wherein the detection element 11 is positioned on the design panel 31 by means of a mounting unit 32. The detection element 11 may 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. Fig. Figure 2 also outlines that the detection device 10, as components of the external lighting device 30, can include, in addition to the image detection device 35, an evaluation device 36 and a control device 37 for controlling the lighting unit 34.

[0047] In Fig. Figure 3 shows the external lighting device 30, in which three detection elements 11 are directly integrated into the design panel 31. For this purpose, for example, transparent plates shaped to match the local surface contour of the design panel 31 are integrated into the design panel 31. Furthermore, in Fig. Figure 3 shows the respective image acquisition devices 35 for the two upper detection elements 11, which are positioned behind the design panel 31 and thus not directly visible to an observer. It also becomes clear that the respective detection elements 11 are spatially separated from one another, for example, on 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 direction of travel.

[0048] In Fig. Figure 4 outlines the operation of the external lighting device 30. It clearly shows that the detection device 10 comprises a carrier medium 12, which is designed as a light guide and on which an input area 16 and an output area 18 are provided. The carrier medium 12 with the input area 16 and the output area 18 is the planar detection element 11 for the design cover 31, which is adapted to the surface shape 33 of the design cover 31.

[0049] The coupling area 16 is configured as a holographic element 14 with a first deflection structure 20. The first deflection structure 20 is designed to couple light 100, which falls onto the first deflection structure 20 from the surroundings of the vehicle 40, into the carrier medium 12. The carrier medium 12 is configured to transfer the coupled light 100 from the coupling area 16 to the decoupling area 18 by means of internal reflections. The decoupling area 18 is configured as a holographic element 14 with a second deflection structure 22. The second deflection structure 22 is designed to decouple the transferred light 100, which falls onto the second deflection structure 22, from the carrier medium 12. The image acquisition device 35, for example, is arranged directly behind it.The image acquisition device 35 is configured to capture the light 100 coupled out from the detection element 11 at the output area 18 and to provide it as image data that correlates with the captured light 100. The image acquisition device 35 can therefore be configured, for example, as a camera sensor. The input area 16 and the output area 18 each have at least one optical grating, in particular a holographic volume grating or a holographic surface grating, as a deflection structure 20, 22. The detection element 11 itself can be configured as a transparent plate, film, or lacquer.

[0050] The evaluation unit 36 ​​can be designed to detect at least one object 42 in the environment by evaluating the image data provided by the image acquisition unit 35, to recognize the detected object 42 using an object recognition criterion, and to provide object data describing the detected object 42.

[0051] In Fig. Figure 5 depicts such an object 42 as a wall in the vicinity of the motor vehicle 40. The object 42, i.e., the wall, is located at a distance 44 from the motor vehicle 40. The external lighting device 30 also includes a light source 38 and a sensor device 39. Furthermore, a sensor coupling area 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 vicinity of the motor vehicle 40. The pulsed light 100' can, for example, be infrared laser light. As shown in Fig. As outlined in Figure 5, the pulsed light 100' emitted by the light source 38 can also be emitted indirectly to the object 42 through the planar carrier medium 12, i.e., through the detection element 11. For this purpose, a light coupling area 17 and a light coupling area 19 are provided on the planar carrier medium 12. The light coupling area 17 is designed as a holographic element 14 with a fourth deflection structure 26, which is designed 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 transfer the coupled pulsed light 100' from the light coupling area 17 to the light coupling area 19 by means of internal reflection.The light output coupling area 19 is designed as a holographic element 14 with a fifth deflection structure 28, which is designed to couple the transmitted light 100' emitted by the light source 38, which falls on the fifth deflection structure 28, out of the carrier medium 12 and emit it into the environment, i.e. in the direction of the object 42. The light 100" reflected at 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 coupling area 16 if this reflected light 100" falls on the first deflection structure 20.

[0052] The carrier medium 12 is configured to transfer this coupled reflected light 100" from the coupling area 16 to the sensor coupling area 15 by means of internal reflection. The sensor coupling area 15, with its third deflection structure 24, serves to couple the reflected light 100" striking the third deflection structure 24 out of the carrier medium 12. The sensor device 39 is configured to detect the light 100" coupled out at the sensor coupling area 15 and to provide it in the form of sensor data. This sensor data describes the transit 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.

[0053] The evaluation unit 36 ​​is also designed to detect a light-emitting vehicle moving towards the detection element 11 by applying the object recognition criterion. If the light-emitting vehicle moving towards the detection element 11 is detected, a dimming signal for the lighting unit 34 is provided by applying a driving situation criterion. The control unit 37 of the external lighting unit 30, which is located in Fig.As outlined in Figure 2, the control unit 37 is designed to adjust the light intensity of the lighting unit 34 in accordance with the dimming signal provided by the evaluation unit 36. For example, if it is detected that a vehicle is approaching the motor vehicle 40, it can be determined that the motor vehicle 40 is currently driving with its high beams activated, but that the high beams should be dimmed due to the approaching vehicle. In this case, the control unit 37 can reduce the light intensity of the lighting unit 34 after receiving the dimming signal. The oncoming vehicle can be identified, for example, by the color of the headlight beam emitted by the vehicle, which is detected as light 100 by one of the image acquisition devices 35 of the motor vehicle 40.Based on the movement data of the vehicle 40 itself provided by the evaluation unit 36, as well as the information stored in the object recognition criterion, for example, regarding the object recognition of vehicles, it can also be clearly determined that an object 42 is located in the vicinity of the vehicle 40, which is recognized as an illuminated vehicle, and that the recognized vehicle is approaching the vehicle 40 from the front, so that the high beam of the vehicle 40 should consequently be deactivated. Such evaluation steps and control commands for the luminous intensity of the lighting unit 34 can therefore be determined and carried out by means of the external lighting unit 30.

[0054] Overall, the invention describes the integration of a holographic element (HOE) into vehicle lighting, specifically 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 captured via detection elements 11 arranged in or on the design panel 31 of the motor vehicle 40. This results in the following advantages: Due to the planar design of the detection element 11, it is less susceptible to dirt accumulation, can be made transparent and thus not directly visible, and can be equipped with various optical functions, such as providing image data and / or emitting pulsed light 100° by means of the light source 38.The position of the design panel 31 is also chosen for an exposed location on the vehicle 40, providing an optimal view of the surroundings and thus enabling the provision of particularly reliable environmental data. The information provided by the exterior lighting system 30 can contribute, for example, to at least semi-autonomous parking, the detection of approaching objects or objects already in the blind spot 42, the ability to exit driveways that obstruct the view to the left and right, or fully automated parking and the associated detection of available space. Furthermore, the exterior lighting system 30 can register any glare from oncoming vehicles and provide the associated information for adjusting the lighting unit 34, i.e., determine the corresponding dimming signal and make it available to the control unit 37 of the lighting unit 34.

[0055] The respective detection elements 11 can also determine the distance 44 between the motor vehicle 40 and the object 42 in the vicinity of the motor vehicle 40 by means of a laser distance measurement, thus increasing, for example, the measurement accuracy of the sensors of the motor vehicle 40 when parking. The laser distance measurement is carried out by detecting and evaluating the light 100 emitted by the light source 38 and reflected from the object 42.

[0056] The external lighting device 30 can be equipped with a separate mounting unit 32 to which the detection element 11 is attached. Alternatively, the design cover 31 itself can encompass the detection element 11. The detection element 11, i.e., the planar carrier medium 12, can be relatively small and thus measure approximately at a single point, or it can be designed to cover an entire area, for example, to enable wide-angle recordings of the surroundings.

[0057] It is also possible to use multiple detection elements 11 with multiple image capture devices 35 to counteract any loss of light or image quality. The image capture devices 35 can each be installed behind the design panel 31, either behind the body itself or in a concealed position inside the exterior lighting unit 30, and thus be hidden. It is also possible to emit light 100° from the light source 38 directly or through the detection element 11 into the surroundings to illuminate the environment or, as described above, to measure the distance to the object 42, that is, to determine the distance 44.

Claims

[1] Exterior lighting device (30) for a motor vehicle (40), wherein the exterior lighting device (30) comprises a design cover (31) and at least one detection device (10) with an image detection device (35) and a carrier medium (12), wherein the carrier medium (12) is designed as a light guide on which an input area (16) and an output area (18) are provided, wherein - the carrier medium (12) with the coupling area (16) and the coupling area (18) is designed as a planar detection element (11) adapted to a surface shape (33) of the design aperture (31) for the design aperture (31); - the coupling area (16) is designed as a holographic element (14) with a first deflection structure (20) designed to couple light (100) falling from an environment onto the first deflection structure (20) into the carrier medium (12); - the carrier medium (12) is designed to transfer the coupled light (100) from the coupling area (16) to the coupling area (18) by means of internal reflection; - the coupling area (18) is designed as a holographic element (14) with a second deflection structure (22) designed to couple the transmitted light (100) falling on the second deflection structure (22) out of the carrier medium (12); - the image acquisition device (35) is designed to capture the light (100) coupled out from the acquisition element (11) at the coupling area (18) and to provide it as image data that correlates with the captured light (100); and - the external lighting device (30) comprises two detection devices (10) which are spatially separated from each other and arranged on two opposing edge areas of the design panel (31). [2] External lighting device (30) according to the preceding claim, wherein the coupling area (16) and the coupling area (18) comprise at least one optical grating, in particular a holographic volume grating or a holographic surface grating, as a deflection structure (20, 22). [3] Outdoor lighting device (30) according to one of the preceding claims, wherein the detection element (11) is attached to the design panel (31) by means of a fastening unit (32) or is integrated into the design panel (31). [4] Outdoor lighting device (30) according to one of the preceding claims, wherein the detection element (11) is designed as a transparent plate, film or paint. [5] Outdoor lighting device (30) according to one of the preceding claims, wherein the outdoor lighting device (30) comprises an evaluation device (36) which is configured to detect at least one object (42) in the environment by evaluating the image data, to recognize the detected object (42) using an object recognition criterion and to provide object data describing the detected object (42). [6] Exterior lighting device (30) according to the preceding claim, wherein the exterior lighting device (30) comprises a control device (37) for controlling a lighting unit (34) of the exterior lighting device (30), the evaluation device (36) is configured by applying the object recognition criterion to detect a light-emitting vehicle moving towards the detection element (11) and, if the light-emitting vehicle moving towards the detection element (11) has been detected, to provide a dimming signal for the lighting unit (34) by applying a driving situation criterion, and the control device (37) is configured to adjust a light intensity of the lighting unit (34) in accordance with the dimming signal provided by the evaluation device (36). [7] Outdoor lighting device (30) according to one of the preceding claims, wherein the outdoor lighting device (30) comprises a light source (38), a sensor device (39) and an evaluation device (36) and a sensor coupling area (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 coupling area (16) is designed to couple light (100") emitted by the light source (38) and reflected by the object in the environment into the carrier medium; - the carrier medium (12) is designed to transfer the coupled reflected light (100') from the coupling area (16) to the sensor coupling area (15) by means of internal reflection; - the sensor coupling area (15) is designed as a holographic element (14) with a third deflection structure (24) designed to couple the reflected light (100") coupled into the carrier medium (12) out of the carrier medium (12); and - the sensor device (39) is configured to detect the light (100") coupled out at the sensor coupling area (15) and to provide it in the form of sensor data describing a transit time of the light (100") emitted by the light source (38) and reflected at the object (42) that was detected by the sensor device (39); and - the evaluation unit (36) is designed to provide distance data describing the distance of the object (42) from the detection unit (10) by evaluating the sensor data. [8] External lighting device (30) according to the preceding claim, wherein a light coupling area (17) and a light coupling area (19) are provided on the carrier medium (12), wherein - the light coupling area (17) is designed as a holographic element (14) with a fourth deflection structure (26) designed to couple light (100') falling from the light source (38) onto the fourth deflection structure (26) into the carrier medium (12); - the carrier medium (12) is designed to transfer the coupled light (100') from the light coupling area (17) to the light coupling area (19) by means of internal reflection; and - the light coupling area (19) is designed as a holographic element (14) with a fifth deflection structure (28) which is designed to couple the transmitted light (100') falling on the fifth deflection structure (28) out of the carrier medium (12) and emit it into the environment. [9] Motor vehicle (40) with an external lighting device (30) according to one of the preceding claims.

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