DE102018204269A1 - ARRANGEMENT, METHOD FOR ARRANGEMENT, HEADLAMP AND SENSOR SYSTEM - Google Patents

Abstract

Disclosed is an arrangement with a radiation source for a sensor system for environmental detection. The radiation of the radiation source can be guided for radiation guidance through a structure having at least one liquid crystal element, it being possible to set a molecular orientation of the at least one liquid crystal element by means of an electric field.

Description

The invention relates to an arrangement according to the preamble of claim 1. Furthermore, the invention relates to a method and a headlight and a sensor system with such an arrangement.

From the prior art, sensor systems for environment detection or for distance and speed measurement of objects, e.g. a Light Detection and Ranging (LiDAR) system known. The LiDAR distance measurement is based on a transit time measurement of emitted electromagnetic pulses. If these impinge on an object, the pulse is proportionately reflected back to a distance measuring unit on its surface and can be recorded as an echo pulse with a suitable receiver unit or a suitable sensor.

For aligning or steering the electromagnetic pulses, it is known in the art to either source a plurality of pulse sources or radiation sources, e.g. a plurality of infrared emitting (IR) radiation emitting laser diodes, for example in the range between 850 nm and 1600 nm, which are arranged in different directions, or to use only one pulse or radiation source, which is either aligned itself for the radiation orientation or deflection or in the the radiation is directed by means of a system having one or more rotating mirrors or micromirrors. In the first case, several radiation sources and in the second case motors or actuators are necessary to align the radiation accordingly. In both cases, the overall system becomes complex and / or expensive. Furthermore, moving parts can render the overall system unwieldy and more susceptible to wear or less durable. In the first case (multiple radiation sources) there are no moving parts, but the total system is limited in its resolution due to the number of radiation sources.

The object of the present invention is to provide an arrangement for a sensor system for environmental detection, with which compared to the prior art energy, space, weight and cost can be reduced. It is another object of the invention to provide a method of using a sensor system having such an arrangement. In addition, it is an object of the invention to provide a headlight or a lighting device or an irradiation arrangement with such an arrangement. It is another object of the invention to provide a sensor system with such an arrangement.

The object with regard to the arrangement is achieved according to the features of claim 1, with respect to the method according to the features of claim 10, with regard to the headlamp according to the features of claim 11 and with respect to the sensor system according to the features of claim 12.

Particularly advantageous embodiments can be found in the dependent claims.

According to the invention, an arrangement with a radiation source for a sensor system for environmental detection is provided. The arrangement according to the invention is characterized in that the radiation of the radiation source for radiation guidance can be conducted through a structure having at least one liquid crystal element, wherein an, in particular molecular, orientation of the at least one liquid crystal element can be adjusted by means of an electric field.

In comparison with the prior art, with the arrangement according to the invention, the radiation of the radiation source can be targeted to a detection area or scan it without having to use multiple radiation sources or rotating mirrors / micromirrors. Therefore, neither multiple radiation sources are necessary, which have a large footprint, nor does the inventive arrangement has moving parts that can make the entire system vulnerable to wear.

The arrangement according to the invention can be equipped with a receiver unit or a sensor or sensor system for measuring the radiation of the radiation source and used in a LiDAR system. The receiver unit or the sensor can be designed such that it can measure the incident radiation without spatial resolution. However, the receiver unit can also be configured with spatial-angle resolution. The receiver unit or sensor may comprise a photodiode, e.g. an avalanche photo diode (APD) or a single photon avalanche diode (SPAD), a PIN diode or a photomultiplier.

The structure through which the radiation to be aligned is guided may comprise at least two layers coated with electrically conductive and transparent coating material, in particular in sections Plate elements (a first and second plate member), eg glass plates have. The radiation of the radiation source to be aligned is preferably perpendicular to one of the plate elements. The plate elements are preferably transparent and spaced apart in parallel. The transparency of the plate elements and the electrically conductive coating material allows transmission of the radiation. The electrically conductive and transparent coating material may be at least partially or entirely made of a material with a high electrical conductivity or a small electrical resistance such as indium tin oxide (ITO) and / or a material with a low electrical conductivity or a large electrical Resistance such as poly-3,4-ethylenedioxythiophene (PEDOT) exist.

Preferably, at least one of the plate elements, e.g. the first plate element, on at least one side, in particular on its side facing away from the radiation source, coated over the entire surface with the coating material, in particular indium tin oxide. The other of the two plate elements, the second plate element, is preferably on at least one side, in particular on its side facing the radiation source, in the width direction of the plate element in sections next to each other with the coating material, in particular indium tin oxide (first coating), poly-3,4-ethylenedioxythiophene ( second coating) and indium tin oxide (third coating). In other words, the second plate element is coated in a strip-like manner, the second coating being arranged in the width direction of the plate element between the first and third coating. The coating materials or coatings of the plate elements can serve as electrodes. By applying different electrical voltages to the electrically conductive coating materials or coatings, an electric field or an electric field strength gradient can be formed between the coated plate elements.

The electric field generated in this way can be adjustable in its strength. The electric field can be adjustable in particular by applying an electrical voltage to the coating material or the coatings of the plate elements in its strength. Depending on the size or height of the applied electrical voltages on the coating materials or coatings of the plate elements formed as described above, differently sized potential differences and thus a different electric field form between the coating materials or coatings.

The electric field formed between the coated plate members may be homogeneous or inhomogeneous. A homogeneous electric field is formed when the potential difference across the entire width of the at least two coated plate elements is constant. In other words, an electric field strength gradient formed across the width or in the width direction of the plate elements has the value zero. An inhomogeneous electric field is formed when the potential difference across the width of the at least two coated plate members is variable. In other words, the electric field strength gradient formed over the width of the plate elements has a value greater than zero. The electric field can be brought from a homogeneous to an inhomogeneous state for radiation steering. For example, when a voltage applied to the coating of the first plate member is 0V, by applying a relatively large electric voltage in the range of 3V-100V, preferably in the range of 5V-20V, e.g. 5V, on a coating of the second plate member at a first widthwise end of the second plate member, e.g. on the first coating, and applying no voltage to a coating of the second plate member at a second widthwise end of the second plate member, e.g. on the third coating, an inhomogeneous electric field with an electric field strength gradient are formed. When, in the widthwise direction of the second plate member, between the first and third coatings, a coating having a large electrical resistance, e.g. the second coating is formed, a stress compensation between the first and third coating can be prevented. The electric field strength between the first coating of the second plate element and the coating of the first plate element is therefore relatively large and decreases from the first coating of the second plate element in the width direction of the plate elements to the third coating of the second plate element.

Depending on the strength of the electric field, ie, depending on the strength of the voltages applied to the coatings, the molecules of the liquid crystal elements can align in accordance with the field lines of the electric field. Due to the differently oriented liquid crystal elements within the structure, different refractive indices can be achieved. As a result, the radiation passing through the structure, depending on the molecular orientation, moves at different speeds through the liquid crystal elements located between the plate elements. Overall, the liquid crystal elements located between the plate elements have the function of a prism that can deflect or direct incident radiation. As a result, with appropriately applied voltage to the electrically conductive coatings of the plate elements the radiation passing through the structure can be oriented or deflected, whereby the deflection angle can be controlled and changed by the level of the applied voltage.

The at least one liquid crystal element may be arranged on a reflective substrate. The reflective substrate may be provided on the side of the liquid crystal element, e.g. a silver surface, a metal surface, titanium oxide or the like. In this case, a respective liquid crystal element can be arranged on a respective substrate. The radiation conducted by the liquid crystal element can be reflected by the reflective substrate. In other words, the radiation can thus be passed through the liquid crystal element twice ("double-pass"). As a result, in comparison to the case in which the radiation is conducted only once through the liquid crystal element ("single-pass"), the most diverse detection ranges of the sensor system can be realized.

The radiation of the radiation source may be capable of being guided for radiation guidance by a plurality of the structures described above. If only one radiation source is used, a plurality of structures, for example, in particular in parallel, can be arranged next to each other in order to deflect the radiation emitted by the radiation source into an emission angle range in each case. However, it is also possible to use a plurality of radiation sources, it being possible for each radiation source to be assigned at least one separate structure which can deflect the radiation into an emission angle range, wherein the emission angle ranges of the plurality of structures can differ from one another. In other words, each of the multiple structures captures only a portion of the total area to be detected, thereby increasing the resolution of the overall system.

Within the structure, a radiation-redirecting element, e.g. a triangular in cross-section prism or glass prism be arranged. The radiation passing through the structure is deflected by the radiation-deflecting element in accordance with its refractive index. If an electrical voltage is applied to the coated plate elements and if the liquid crystal elements arranged between the plate elements are aligned in accordance with the field lines of the electric field, then the radiation deflected by the radiation-deflecting element can be deflected again by the liquid crystal elements. The electrical voltage or the electric field strength can be adjusted so that the resulting refractive index of the liquid crystal elements corresponds to the refractive index of the radiation-deflecting element. This means that the radiation passing through the structure as a whole is not deflected, since the radiation deflection by the radiation-deflecting element and the radiation deflection of the liquid-crystal elements cancel each other out. It should be noted that an element arranged in an electric field may be a dielectric that can change the electric field. The electric field is therefore preferably inhomogeneous in order to be able to compensate for influences by the introduced into the electric field dielectric. If no voltage is applied to the coated plate elements and thus no electric field is formed, the radiation passing through the structure is deflected by the radiation-deflecting element according to its refractive index and passes the then randomly oriented liquid crystal elements without further deflection.

The radiation of the radiation source can be polarized light, e.g. Light of a laser diode, or unpolarized light, e.g. Light of a light-emitting diode (LED), be. However, the liquid crystal element deflects only the light of a polarization plane. If the radiation of the radiation source is unpolarized light, radiation components which oscillate perpendicular to this plane of polarization can pass through the structure without deflection. In order to align or divert these radiation components, the following possibilities exist. The (unpolarized) radiation can be successively passed through two structures. In this case, the orientation directions of the liquid crystal elements aligned in an electric field of both structures are preferably rotated at 90 ° to one another transversely to the direction of radiation. This means that the first of the two structures can rotate one polarization plane of the passing radiation and the second of the two structures can deflect those radiation components which oscillate perpendicular to the one polarization plane. Alternatively, the (unpolarized) radiation may be detected by means of, e.g. are arranged directly behind the radiation source, polarizing beam splitter divided into two mutually orthogonal radiation components, which are each passed through a structure of the inventive arrangement whose orientation direction of the liquid crystal elements can deflect the corresponding vibration component. The polarizing beam splitter may e.g. be arranged directly behind the radiation source, wherein the two radiation components oscillating orthogonal to each other in each case via at least one optical element, e.g. a mirror into which appropriate structures can be directed.

A light emitting diode (LED) or light emitting diode may be in the form of at least one individually packaged LED or in the form of at least one LED chip having one or more light emitting diodes or in the form of a micro LED. Multiple LED chips on a common substrate ("submount") be mounted and form an LED or individually or together, for example, on a circuit board (eg FR4, metal core board, etc.) be attached ("CoB" = chip on board). The at least one LED can be equipped with at least one own and / or common optics for beam guidance, for example with at least one Fresnel lens or a collimator. Instead of or in addition to inorganic LEDs, for example based on AlInGaN or InGaN or AlInGaP, it is generally also possible to use organic LEDs (OLEDs, eg polymer OLEDs). The LED chips can be directly emitting or have an upstream phosphor. Alternatively, the light emitting component may be a laser diode or a laser diode array. It is also conceivable to provide an OLED luminescent layer or a plurality of OLED luminescent layers or an OLED luminescent region. The emission wavelengths of the light emitting components may be in the ultraviolet, visible or infrared spectral range. The light-emitting components may additionally be equipped with their own converter. Preferably, the LED chips emit white light in the standardized ECE white field of the automotive industry, for example realized by a blue emitter and a yellow / green converter.

In a method according to the invention for an arrangement according to one or more of the preceding aspects, the electric field can be changed such that the radiation of the radiation source is directed over a predetermined angular range. The voltages applied to the coated plate elements can be repeatedly varied such that the electric field gradient is changed between zero and a maximum value and the radiation is thus deflected between a minimum and a maximum emission angle. When the radiation is reflected on an object, the back-reflected radiation of the radiation source can be detected via the sensor system.

According to the invention a headlight, e.g. for a vehicle, provided with an arrangement according to one or more of the preceding aspects.

The vehicle may be an aircraft, e.g. a drone, or a waterborne vehicle or land-based vehicle. The land-based vehicle may be a motor vehicle, e.g. an autonomously driving electric car, or a rail vehicle or a bicycle. Particularly preferred is the use of the headlight in a truck or passenger car or motorcycle.

Further areas of application may be, for example, floodlights for effect lighting, entertainment lighting, architainment lighting, general lighting, medical and therapeutic lighting, horticulture lighting, etc.

According to the invention, a sensor system with an arrangement according to one or more of the preceding aspects is provided

• 1a in einer schematischen Ansicht eine erfindungsgemäße Anordnung gemäß einem ersten Ausführungsbeispiel,
• 1b in einer weiteren schematischen Ansicht die erfindungsgemäße Anordnung gemäß dem ersten Ausführungsbeispiel,
• 2 in einer schematischen Ansicht eine erfindungsgemäße Anordnung gemäß einem zweiten Ausführungsbeispiel,
• 3 in einer schematischen Ansicht eine erfindungsgemäße Anordnung gemäß einem dritten Ausführungsbeispiel,
• 4a in einer schematischen Ansicht eine erfindungsgemäße Anordnung gemäß einem vierten Ausführungsbeispiel,
• 4b in einer weiteren schematischen Ansicht die erfindungsgemäße Anordnung gemäß dem vierten Ausführungsbeispiel, und
• 5 in einer schematischen Ansicht die erfindungsgemäße Anordnung gemäß einem fünften Ausführungsbeispiel.

In the following, the invention will be explained in more detail with reference to exemplary embodiments. The figures show:

• 1a 1 shows a schematic view of an arrangement according to the invention according to a first exemplary embodiment,
• 1b in a further schematic view of the arrangement according to the invention according to the first embodiment,
• 2 1 shows a schematic view of an arrangement according to the invention in accordance with a second exemplary embodiment,
• 3 in a schematic view of an inventive arrangement according to a third embodiment,
• 4a 1 shows a schematic view of an arrangement according to the invention in accordance with a fourth exemplary embodiment,
• 4b in a further schematic view of the arrangement according to the invention according to the fourth embodiment, and
• 5 in a schematic view of the arrangement according to the invention according to a fifth embodiment.

The 1a shows an inventive arrangement with a radiation source SQ for a sensor system for environmental detection. The radiation source SQ in the form of a laser diode emits polarized radiation 1 ,

The specified in the figures y -Axis points opposite to the direction of radiation of the polarized radiation 1 , where the x - and z -Axis each perpendicular to each other and perpendicular to y -Axis are aligned. The (here in x Direction) polarized radiation 1 becomes the radiation excursion through a structure 20 directed. The structure 20 has two in y Direction spaced and coated with a coating material plate elements 2 . 4 on. The first plate element 2 has a coating on its side facing away from the radiation source SQ 6 formed entirely of indium-tin-oxide having a high electrical conductivity and a small electrical resistance, respectively. The second plate element 4 is on its side facing the radiation source SQ in the width direction ( x- Direction) of the plate member 4 in sections next to each other with indium tin oxide (first coating 8th ), Poly-3,4-ethylenedioxythiophene (second coating 10 ), which has a low electrical conductivity or a high electrical resistance, and indium tin oxide (third coating 12 ) coated. To the coatings 6 . 8th . 12 the two plate elements 2 . 4 In each case, an electrical voltage can be applied, so that the coatings 6 . 8th . 12 serve as electrodes and between the plate elements 2 . 4 , in particular in the y-direction, an electric field is built up. The electric field generated in this way is adjustable in its strength. Depending on the size or height of the applied electrical voltages on the coatings 6 . 8th . 12 the plate elements formed as described above 2 . 4 form between the coatings 6 . 8th . 12 different large potential differences and thus a different strong electric field.

Furthermore, the structure has 20 in 1a between the coated plate elements 2 . 4 several liquid crystal elements 14 on. A molecular orientation of the multiple liquid crystal elements 14 is adjustable by means of the electric field described above.

In 1a amount to the coatings 6 . 8th . 12 applied voltages each 0 V. Between the plate elements 2 . 4 no electric field is formed.

An in x Direction or transverse to the radiation direction showing electric field strength gradient 18 has the value zero. The molecular orientation of the between the plate elements 2 . 4 located liquid crystal elements 14 is therefore not affected by any electric field. In general, the liquid crystal elements are 14 disordered when on the coatings 6 . 8th . 12 no voltage is applied. In the 1a shown ordered alignment of the liquid crystal elements 14 results from a special surface treatment of the plate elements 2 . 4 , eg by polishing, so that the liquid crystal elements 14 maintain their aligned parallel to the plate surfaces even without an electric field. The polarized radiation 1 passing through the structure 20 in 1a is passed through the liquid crystal elements 14 not distracted. The out of the structure 20 emerging radiation 16 has the same direction of radiation as the one in the structure 20 incoming polarized radiation 1 ,

In 1b is also the structure 20 shown, wherein on the first coating 8th an electrical voltage of for example 5 V is applied. The tension on the layers 6 and 12 is in each case 0 V. Between the plate elements 2 . 4 forms due to the coating 10 with their high electrical resistance an inhomogeneous electric field or an electric field strength gradient 18 with a value greater than zero. The electric field strength between the first coating 8th of the second plate member 4 and the coating 6 of the first plate element 2 is relatively large and increases from the first coating 8th of the second plate member 4 in the x direction to the third coating 12 of the second plate member 4 from.

Depending on the strength of the electric field, the molecules of the liquid crystal elements are directed 14 according to the field lines of the electric field. The the structure 20 passing polarized radiation 1 Depending on the molecular orientation undergoes a different refractive index and therefore runs at different speeds through the between the plate elements 2 . 4 formed liquid crystal elements 14 , In other words, can be adjusted by the liquid crystal elements adjustable in their orientation 14 within the structure 20 reach different refractive indices. In 1b the refractive index increases along the plate elements 2 . 4 in the x direction. The between the plate elements 2 . 4 arranged liquid crystal elements 14 Overall, they have the function of a prism that can deflect or direct incident radiation. As a result, the structure becomes 20 passing polarized radiation 1 deflected, ie the radiation directions of the exiting radiation 16 and the polarized radiation 1 are different.

The inventive arrangement is used in a LiDAR system for environmental detection. In 1a and 1b is a receiver unit 21 or a sensor that reflects the radiation reflected back from an object 16 measures, shown schematically.

2 shows a schematic view of an inventive arrangement according to a second embodiment. The radiation 1 The radiation source SQ is used for radiation guidance in parallel by a plurality (six in 2 ) the in 1a and 1b shown structures 20 directed. The electric fields of each of the structures 20 are adjusted to that of the radiation source SQ emitted radiation 1 each deflected in a same Abstrahlwinkelbereich. The radiation angle of the emerging radiation 16 each of the structures 20 are equal. In the 2 shown structures 20 are in one xz Level arranged and in x Direction each not spaced or close each directly to each other. Furthermore, the structures have 20 common plate elements 2 . 4 , which allows a total of space-saving design.

At the in 3 shown third embodiment, several, in x Direction spaced radiation sources SQ used, with each radiation source SQ a separate structure 20 is assigned, which can deflect the radiation in a respective Abstrahlwinkelbereich, wherein the Abstrahlwinkelbereiche or radiation directions of the exiting radiation 16 of several structures 20 differ from each other. In other words, each of the multiple structures captures 20 only a part of the total area to be detected, whereby the resolution of the entire system can be increased.

The 4a and 4b show in schematic views an inventive arrangement according to a fourth embodiment. The plate element 2 is on his the radiation source SQ opposite side over the entire surface coated with indium tin oxide (coating 6 ). The plate element 4 is on its side facing the radiation source SQ also coated over the entire surface with indium tin oxide (coating 8th ). Within the structure 20 is additionally a radiation-redirecting element 22 arranged in the form of a cross-sectionally triangular glass prism. An entrance area 23 of the radiation-redirecting element 22 lies parallel and without clearance on the coating 6 of the plate element 2 so that the the structure 20 passing radiation 1 perpendicular to the entrance surface 23 meets. The the structure 20 passing radiation 1 becomes from the radiation redirecting element 22 according to its refractive index at one to the entrance surface 23 angled exit surface 24 distracted. If on the coatings 6 . 8th the plate elements 2 . 4 there is a potential difference and that between the plate elements 2 . 4 located liquid crystal elements 14 are aligned according to the field lines of the self-adjusting electric field, as in 4a shown, then the radiation-deflecting element 22 deflected radiation 1 from the liquid crystal elements 14 distracted again. In 4a the electric field is homogeneous (the potential difference between the coatings 6 . 8th the plate elements 2 . 4 is constant along the x direction) and set so that the resulting refractive index of the liquid crystal elements 14 the refractive index of the radiation-redirecting element 22 equivalent. That means that the structure 20 passing radiation 1 is not distracted as the radiation deflection by the radiation-deflecting element 22 and the radiation redirection of the liquid crystal elements 14 cancel each other out. It should be noted that the arranged in the electric field radiation-deflecting element 22 is a dielectric that changes the electric field. The electric field must therefore be inhomogeneous in order to be able to compensate for influences by the introduced into the electric field dielectric. If on the coatings 6 . 8th the plate elements 2 . 4 no voltage is applied and thus no electric field is formed, as in 4b shown, that will be the structure 20 passing radiation 1 from the radiation-redirecting element 22 according to its refractive index at the exit surface 24 deflected and passes the then randomly aligned liquid crystal elements 14 without another distraction.

The 5 shows a schematic view of an inventive arrangement according to a fifth embodiment. The radiation source SQ, eg an LED, emits unpolarized radiation 1 by means of a polarizing beam splitter arranged directly behind the radiation source SQ 26 in two orthogonal oscillating radiation components 1a . 1b is split. The radiation component 1a is 5 in x Direction and the radiation component 1b polarized in z-direction. The radiation component 1b will be over a mirror 28 so deflected that its radiation direction of the radiation component 1a corresponds (in the example opposite to the y direction). The radiation components 1a . 1b are each by a structure 20 passed the inventive arrangement, their liquid crystal elements 14 are oriented so that they have the vibration component 1a respectively. 1b can deflect. As the radiation component 1a in x Direction and the radiation component in z Direction is polarized (orthogonal to each other), the structure is 20 that the radiation component 1b diverts, compared to the structure 20 that the radiation component 1a deflects, rotated by 90 degrees (see the corresponding axis systems of the structures 20 ).

In the arrangement according to the embodiments, the electric field is changed in each case such that the radiation 1 the radiation source SQ is directed over a predetermined angular range. The to the coatings 6 . 8th . 12 the plate elements 2 . 4 applied voltages are repeatedly changed so that the electric field gradient is changed between zero and a maximum value and the radiation 1 Thus, between a minimum and a maximum radiation angle is deflected. If the out of the structure 20 emerging radiation 16 is reflected on an object, the reflected back radiation of the radiation source SQ is detected by the sensor system.

Disclosed is an arrangement with a radiation source for a sensor system for environmental detection. The radiation of the radiation source can be guided for radiation guidance through a structure having at least one liquid crystal element, it being possible to set a molecular orientation of the at least one liquid crystal element by means of an electric field.

LIST OF REFERENCE NUMBERS

radiation 1 radiation component 1a, 1b first plate element 2 second plate element 4 coating 6 first coating 8th second coating 10 third coating 12 liquid crystal element 14 emerging radiation 16 electric field strength gradient 18 structure 20 receiver unit 21 radiation-redirecting element 22 entry surface 23 exit area 24 polarizing beam splitter 26 mirror 28

Claims (12)

Arrangement with a radiation source (SQ) for a sensor system for environmental detection, characterized in that the radiation (1) of the radiation source (SQ) for radiation guidance through a structure (20) with at least one liquid crystal element (14) is conductive, wherein a molecular orientation of the at least one liquid crystal element (14) is adjustable by means of an electric field. Arrangement according to Claim 1 in addition to a receiver unit (21) for measuring the radiation (1) of the radiation source (SQ). Arrangement according to Claim 1 or 2 wherein the structure (20) comprises at least two plate elements (2, 4) coated with electrically conductive and transparent coating material (6, 8, 10, 12). Arrangement according to one of Claims 1 to 3 , wherein the electric field is adjustable in its thickness by applying an electrical voltage to the coating material (6, 8, 10, 12) of the plate elements (2, 4). Arrangement according to one of Claims 1 to 4 wherein the at least one liquid crystal element (14) is arranged on a reflective substrate. Arrangement according to one of Claims 1 to 5 , wherein a plurality of structures (20) are provided and the radiation (1) of the radiation source (SQ) for radiation guidance through the plurality of structures (20) is conductive. Arrangement according to one of Claims 1 to 6 wherein within the structure (20) a radiation-deflecting element (22) is arranged. Arrangement according to one of Claims 1 to 7 additionally with a polarizing beam splitter (26). Arrangement according to one of Claims 3 to 8th wherein the electrically conductive and transparent coating material (6, 8, 10, 12) is indium tin oxide and / or poly-3,4-ethylenedioxythiophene. Method for an arrangement according to one of Claims 1 to 9 , comprising the steps of - changing the electric field such that the radiation (1) of the radiation source is directed over a predetermined angular range, - detecting the back-reflected radiation (1) of the radiation source (SQ) via the sensor system. Headlamp with an arrangement according to one of Claims 1 to 9 , Sensor system with an arrangement according to one of Claims 1 to 9 ,

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