Device and method for detecting the condition of a motor vehicle part

Abstract

Device for detecting the state of a motor vehicle part (102, 103, 104, 106, 122) which can be brought selectively into at least a first state or a second state, wherein the device has a display element by means of which the state of the motor vehicle part (102, 103, 104, 106, 122) can be determined, characterized in that the display element has a reflector (1) and in that a detection device (2) spaced apart from the reflector (1) is assigned to the reflector (1), which detection device contains a transmitter for generating a bundled electromagnetic radiation (Si) which can be reflected by the reflector (1) when it impinges on the reflector (1), and which further contains a receiver for receiving the radiation (Ri) reflected by the reflector (1), wherein the reflector (1) is designed and arranged in such a way that the electromagnetic radiation (Si) is only in one of the two states of the motor vehicle part (102, 103, 104, 106,122) is reflected to the receiver, and wherein in the other of the two states of the motor vehicle part (102, 103, 104, 106, 122) the reflector (1) is not reached at all by the bundled radiation (Ri) or the reflector (1) is arranged such that it does not reflect incident radiation (Ri) to the receiver in the other of the two states.

Description

[0001] The invention relates to a device for detecting the condition of a motor vehicle part according to the preamble of claim 1 and a corresponding method according to patent claim 22.

[0002] Such a device is used in particular for detecting the state of a motor vehicle part that can be selectively brought into at least a first state or a second state, wherein the device has a display element by means of which the state of the motor vehicle part can be determined. The states to be detected can be, for example, different locking states of the motor vehicle part ("locked", "unlocked") and / or different positions of the motor vehicle part. Microswitches or visually detectable displays, for example, are used as display elements, but also the motor vehicle part itself, if the position of the motor vehicle part makes it possible to determine whether it is in the first or second state.

[0003] EP 1 606 147 B1 discloses a system and a method for detecting seat occupancy in a motor vehicle, wherein high-frequency radiation is emitted in the form of a wave field in the direction of a plurality of seats to be monitored and wherein the radiation transmitted to a receiver as a function of the occupancy of a respective seat is evaluated with regard to its intensity.

[0004] DE 699 32 045 T2 discloses a system for measuring the position of a backrest. The system determines the position of the backrest by measuring the propagation time between a fixed position in the vehicle interior and the backrest itself. The system uses the time it takes for a signal to propagate between a transmitter and a receiver to determine the distance between the transmitter and the receiver, and thus the position of the backrest.

[0005] DE 10 2006 055 343 B3 describes a device for distinguishing between rear-facing child seats and adult passengers in a motor vehicle, in which a fan-shaped or conical light beam is emitted by means of a light source over a seat back and a seat surface of a seat, wherein light reflected by an object, such as a seat back and / or an adult passenger, is scattered back to a receiver.

[0006] US 2014 / 0 319 895 A1 describes a device for adjusting a seat position for a vehicle seat with the aid of various sensor units.

[0007] DE 196 37 108 A1 describes a distance measuring device for the interior of a motor vehicle. A transmitting and receiving device and several additional receiving devices are used to determine the varying distances between the transmitting and receiving device or the additional receiving devices and an illuminated, radiation-reflecting area of ​​a seat belt. When one or more receiving devices are temporarily covered, the distance is calculated using the uncovered receiving device. The radiation incident on the seat belt is always reflected to at least one of the receiving devices.

[0008] DE 10 2013 019 143 A1 describes a method for detecting the orientation and position of a display device in a vehicle interior. A radiation source, a portable display device having at least one reflector, a detection device for detecting radiation reflected by the at least one reflector, and a processing device are arranged in the vehicle interior. The processing device determines the orientation and position of the portable display device from the radiation detected by the detection device.

[0009] The invention is based on the problem of further improving a device and a method of the type mentioned at the outset with little effort, in particular with a view to efficient and reliable detection of the condition of a motor vehicle part to be monitored.

[0010] This problem is solved with regard to the device by the features of patent claim 1.

[0011] According to this, in a generic device, the display element is designed as a reflector to which a detection device (e.g. arranged outside the motor vehicle part) is assigned, which detection device contains a transmitter for generating a bundled electromagnetic radiation which can be reflected by the reflector (e.g. along its direction of incidence) when it strikes the reflector, and also has a receiver for receiving the radiation reflected by the reflector, wherein the reflector is designed and arranged (and optionally also movable) in such a way that the electromagnetic radiation is reflected back to the receiver by the reflector only in one of the two states of the motor vehicle part.

[0012] For this purpose, in one of the two states of the motor vehicle part, the reflector is either not reached at all by the bundled radiation (i.e., the electromagnetic radiation only hits the reflector in one state) or the reflector is arranged in such a way in the first-mentioned state that it does not reflect any incident radiation to the receiver.

[0013] The solution according to the invention has the advantage that the detection device can emit the bundled electromagnetic radiation in a targeted manner in the direction of a respective reflector serving as a display element, so that the state of a respective motor vehicle part can be reliably detected with little energy expenditure; for example, by the motor vehicle part changing its position during the transition from the first state to the second state in such a way that the electromagnetic radiation only impinges on the receiver in one of the two states of the motor vehicle part.

[0014] This can be achieved, on the one hand, by connecting the reflector to the motor vehicle part, e.g. in such a way that the reflector is displaced together with the motor vehicle part when the motor vehicle part is displaced from the first state to the second state.

[0015] According to a further embodiment, it is provided that the reflector is arranged in such a way that in one of the two states of the motor vehicle part it is covered by the motor vehicle part or by a cover element which can be displaced together with the motor vehicle part and the electromagnetic radiation cannot impinge on the reflector, while in the other of the two states the reflector is not covered by the cover element and the electromagnetic radiation can impinge on the reflector.

[0016] The solution according to the invention can be implemented with particular advantages when a detection device of the above-mentioned type is already provided on the motor vehicle for other purposes, such as occupant detection.

[0017] By using a reflector as a retroreflector that reflects the incident light in a direction opposite to the direction of incidence, the transmitter and receiver of the detection device can be spatially combined into one assembly, which further simplifies the design of the arrangement.

[0018] According to one embodiment of the invention, the electromagnetic radiation emitted by the detection device strikes the reflector precisely when the motor vehicle part is in the first (e.g., locked) state. According to another embodiment, the electromagnetic radiation emitted by the detection device strikes the reflector precisely when the motor vehicle part is in the second (e.g., unlocked) state.

[0019] According to one variant of the invention, the motor vehicle part can be brought into a locking state as a first state or into an unlocking state as a second state. In this case, the motor vehicle part can be part of a locking mechanism with which an associated motor vehicle assembly, such as a seat assembly, can be locked and unlocked. On the other hand, the motor vehicle part can be part of a motor vehicle assembly (e.g. a seat assembly or another interior assembly, such as a console) that can be locked and unlocked by means of an associated locking mechanism. For example, the motor vehicle part can be a seat part of a motor vehicle seat, such as a seat back or a headrest, which is designed to support a seat occupant. For example, the reflector could be used to detect the locking of a seat back or the presence of a headrest.The invention is primarily intended for the binary detection of safety-relevant states (locked or unlocked; present or not present, etc.).

[0020] According to a further variant of the invention, the motor vehicle part can be transferred into a plurality of different positions, wherein in at least one of the positions of the motor vehicle part, the electromagnetic radiation emitted by the detection device strikes the reflector, and in at least one other position of the motor vehicle part, the electromagnetic radiation emitted by the detection device does not strike the reflector. This can be used, in particular, to detect whether the motor vehicle part is located outside a certain (predetermined) position range.

[0021] According to a further development of the invention, the detection device is configured to emit bundled electromagnetic radiation along different spatial directions in the direction of different (spaced apart) reflectors and to receive the electromagnetic radiation reflected by the reflectors in question (from the opposite spatial directions), so that the condition of a plurality of mutually defective motor vehicle parts can be detected by means of a detection device by scanning the respectively assigned reflector.

[0022] The detection device can in particular be arranged inside a motor vehicle, e.g. on the roof of a motor vehicle or on another component of the vehicle interior.

[0023] The detection device can be designed, for example, as a radar device (“radio detection and ranging”) or as a LIDAR device (“light detection and ranging”) and can be intended not exclusively for the purpose according to the invention, but also for other aspects of the interior monitoring of a motor vehicle.

[0024] A method for detecting the condition of a motor vehicle part is characterized by the features of claim 22. Advantageous developments of the method are specified in the dependent claims.

[0025] Further details and advantages of the invention will become clear from the following description of embodiments with reference to the figures.

[0026] They show: Fig. 1A shows a device for detecting the locking state of a locking mechanism on a motor vehicle seat, using the example of the locked state; Fig. 1B the device from Fig. 1B using the example of the unlocked state; Fig. 2 a device for detecting the position state of a seat back on a motor vehicle seat, using the example of a front seat and a rear seat; Fig. 3A shows a device for detecting the locking state of a motor vehicle assembly, using the example of a first state; Fig. 3B the device from Fig. 3A using the example of a second state; Fig. 4A a device for detecting the position state of a seat longitudinal guide for a motor vehicle seat; Fig. 4B a detail of the device from Fig. 4A; Fig. 5 a modification of the device from the Fig. 1A and Fig. 1B; Fig. 6 a further development of the device from the Fig. 1A and Fig. 1B.

[0027] The characters Fig. 1A and Fig. 1B show a device arranged within a motor vehicle, i.e., in the vehicle interior, for detecting the state of a motor vehicle part, which can assume at least two different states. These can, for example, be two different locking states of the motor vehicle part, such as "locked" and "unlocked," or two different position states of the motor vehicle part, such as: "the vehicle part is located within a certain (predetermined) spatial area" or "the vehicle part is located outside a certain (predetermined) spatial area."

[0028] In the exemplary embodiment, the motor vehicle part whose state is to be detected is a locking element 103 of a locking mechanism with which a motor vehicle seat 100 can be locked in a (previously set) seating position. In particular, this can be a locking lever 103, which can be selectively pivoted into a first pivot position P1, as in Fig. 1A, and a second pivot position P2, as shown in Fig. 1B, wherein the first pivot position P1 of the motor vehicle part in the form of a locking lever 103 corresponds, for example, to the locked state of an associated seat assembly 102, 104, 106 (for example a seat back 104 or a seat longitudinal guide) and the second pivot position P2 corresponds, for example, to the unlocked state.

[0029] The motor vehicle part in the form of the locking lever 103 is in the embodiment of the Fig. 1A and Fig. 1B, on the one hand, a display element in the form of a reflector 1 and, on the other hand, a cover element 3. As a summary of the Fig. 1A and Fig. 1B shows, here, for example, both the display element and the cover element 3 are each connected to the locking lever 103 in such a way that they are moved along when the locking lever 103 is pivoted from the locked state to the unlocked state (or vice versa, from the unlocked state to the locked state). Alternatively, for example, only one of these two elements (1, 3) can be connected to the relocation lever 103, and the respective other element (3, 1) can be arranged in such a fixed position that it is not moved along when the locking lever 103 is actuated.

[0030] The motor vehicle part in the form of the locking lever 103 is further assigned a detection device 2, which can be, for example, a radar device or a LIDAR device. This comprises a transmitter for emitting a (focused) electromagnetic radiation S1, for example in the form of radio waves in the case of a radar system or in the form of laser radiation in the case of a LIDAR system. The (focused) electromagnetic radiation S1 emitted by the detection device 2 is oriented such that it can generally impinge on the reflector 1 assigned to the locking lever 103 as a display element. In the locked state of the locking lever, as shown in Fig. 1A, however, the locking lever 103 is covered by the cover element 3 in such a way that the emitted radiation cannot reach the reflector 1. After the transition of the locking lever 103 into the position shown in Fig. 1B, wherein the display element in the form of the reflector 1 and the cover element 3 are taken along, the cover element 3 is no longer in the radiation path between the detection device 2 and the reflector, so that the bundled electromagnetic radiation S1 emitted by the detection device 2 can impinge on the reflector 1. In the unlocked state of the locking lever 103, the reflector is oriented such that it acts as a retroreflector and reflects the reflected radiation R1 back to the detection device 2 in the opposite direction of its incidence, where it is received by a receiver of the detection device 2, which, depending on certain characteristics of the received radiation, such as the amplitude or intensity, outputs a corresponding signal to an evaluation unit.

[0031] By evaluating the electromagnetic radiation received (reflected) at the detection device 2, e.g. with regard to its amplitude or intensity, it is possible to distinguish between the Fig. 1A and the locking state shown in Fig. 1B, the latter being defined by a maximum of the electromagnetic radiation reflected back onto the detection device 2.

[0032] In general, taking into account the position of the motor vehicle part whose condition is to be detected, a cover element can be attached in such a way that, depending on the direction (spatial orientation) of the beam emitted by the detection device 2, a logical minimum angular position, approximately related to the angle a between the emitted electromagnetic radiation S1 and the vehicle roof D, can be detected, at which the radiation R1 reflected back to the detection device 2 has a maximum.

[0033] According to a further embodiment, it can be provided that in one of the two states of a motor vehicle part to be monitored, the bundled radiation emitted by the detection device 2 or its transmitter strikes the reflector 1, wherein the reflector is arranged in the respective state in such a way that it does not reflect or throw back the radiation to the receiver of the detection device 2.

[0034] In the exemplary embodiment, the detection device 2 is mounted on the vehicle roof D; however, other areas of the vehicle interior I are also suitable for this purpose, from which focused electromagnetic radiation can be emitted in the direction of a vehicle part to be monitored. Furthermore, it can perform other functions in the interior monitoring of a motor vehicle.

[0035] In Fig. 2 shows an embodiment in which the detection or recording of position states of a motor vehicle part (instead of locking states, as in the case of Fig. 1A and Fig. 1B). Specifically, in the example, the Fig. 2, it can be detected whether a motor vehicle part is outside a certain position or adjustment range. In this case, the motor vehicle part in question is the seat back 104 of a motor vehicle seat, whereby in the case of Fig. 2 shows, by way of example, both a front motor vehicle seat 100 and a rear motor vehicle seat 100' with a tilt-adjustable seat back 104 (backrest).

[0036] In this case, the respective vehicle seat 100, 100' in Fig. 2, on the one hand, is shown in dashed lines with an adjustment of the seat back 104 in which a vehicle occupant can sit as intended on the respective vehicle seat 100, 100' and their back is supported in a substantially upright position by the seat back 104. On the other hand, the front vehicle seat 100 is also shown (with solid lines) in a state in which the seat back 104 has been folded forward from the first-mentioned adjustment range, for example, to facilitate entry of a vehicle occupant to a rear vehicle seat. The rear vehicle seat 100', in turn, is shown in an additional position (with solid lines) in which the seat back 104 has been folded far back, for example, to create additional loading space.The last two states of the motor vehicle seats 100, 100', shown by solid lines, are also referred to as oop states (“out of position” states), since they are not suitable for the intended accommodation of an upright seated vehicle occupant.

[0037] As shown by Fig. 2, a reflector 1 is arranged on each of the two vehicle seats 100, 100' in such a way that bundled electromagnetic rays emitted by the associated detection device 2 are reflected by the respective reflector 1 and can be reflected back to the detection device 2 if the seat back 104 of the respective vehicle seat 100, 100' has an inclination that lies outside the normal pivoting or adjustment range of the seat back 104 (in which the vehicle seat 100, 100' is designed to accommodate an upright seated vehicle occupant). Specifically, in the front vehicle seat 100, a reflector 1 assigned to the seat back 104 is accessible to the electromagnetic radiation S1 emitted by the detection device 2 precisely when its seat back, as shown in Fig. 2 shown with solid lines, is folded forward. In the Fig. In contrast, in the upright position (a so-called "normal position") of the seat back of the front vehicle seat 100, shown in dashed lines in Figure 2, the reflector 1 is covered by an upper section of the seat back 104 itself. This means that an upper section of the seat back 104 serves as a covering element that covers the reflector 1 as long as the seat back 104 is within the normal adjustment range with regard to its pivoting position, so that the radiation S1' emitted by the detection device 2 cannot impinge on the reflector 1. However, if the seat back 104 is folded forward out of the normal adjustment range, the reflector 1 is no longer covered by the upper section of the seat back 104 and is exposed to receive the electromagnetic radiation S1 emitted by the detection device 2, which can accordingly be reflected (or bounced back) to generate reflected radiation R1.

[0038] In a similar way, the rear in Fig. 2, a reflector 1 provided on the seat back 104 is covered by an associated cover element 3 when the pivoting position of the seat back 104 is within the normal adjustment range, thus allowing the support of the back of a substantially upright seated vehicle occupant, as in Fig. 2 is shown in dashed lines. In this case, the electromagnetic radiation emitted by the detection device 2 in the direction of the reflector 1 cannot reach the latter and thus cannot be reflected or bounced back by it. If, on the other hand, the seat back 104 is folded back so far that it is outside the normal adjustment range, the cover element 3 is no longer in the beam path between the detection device 2 and the reflector, so that the radiation S2 emitted by the detection device 2 in the direction of the reflector 1 now strikes the latter and is bounced back to the detection device 2 as reflected radiation R2.

[0039] In the Fig. 2, the arrangement comprising a reflector 1, a cover element 3 (or a section of the seat back 104) and a detection device 2 each serves to detect a positional state of a motor vehicle part, namely, for example, a seat back 104, as to whether the motor vehicle part is outside a predetermined position or adjustment range. In the exemplary embodiment, this adjustment range is the normal range in which the seat back 104 of a motor vehicle seat 100 is adjustable (with regard to its inclination) in order to be able to support the rear of a substantially upright seated vehicle occupant, specifically with regard to the selected angle of inclination (within the normal range) adapted to the needs of a respective user. If the seat back 104 is moved far forwards or backwards out of such a normal range.folded backwards, this can be detected by means of a reflector 1 assigned to the respective seat back 104 in the manner described in more detail above.

[0040] In the Fig. 3A and Fig. 3B shows a further embodiment of a display element 10 in the form of a locking display, wherein the display element 10 provided with a reflector 1 is covered, depending on the locking state of an associated locking mechanism, either by a surrounding vehicle assembly 30, which accordingly functions as a cover element ( Fig. 3A) or protrudes from that vehicle assembly 30 ( Fig. 3B), so that the reflector 1 provided on the display element 10 can reflect the electromagnetic radiation emitted by an associated detection device.

[0041] The Fig. 4A and Fig. 4B again refer to an embodiment which involves the detection of a positional state of a motor vehicle part 102, 122, in this case, for example, the longitudinal position of a motor vehicle seat 100, which is detected by means of a Fig. 4A - formed by two pairs of interlocking guide rails 121, 122 extending in the seat longitudinal direction L and displaceable relative to one another. In the exemplary embodiment, the seat longitudinal adjustment comprises, in a known manner, two pairs of rails, each with a body-mounted guide rail 121 and a guide rail 122 assigned to the vehicle seat 100 to be adjusted (attached to the seat base 102), which is displaceable along the body-mounted guide rail 121, whereby the associated vehicle seat 100 is carried along (via the seat base 102) and thus changes its seat longitudinal position.

[0042] As shown by Fig. 4B, a reflector 1 can be arranged on one of the two longitudinally adjustable guide rails 121, 122, in this case on the body-mounted guide rail 121, which, depending on the relative position of the two guide rails 121, 122, is either covered by the seat-side guide rail 122 or not. This means that the seat-side guide rail 122 acts here as a covering element. By scanning using electromagnetic radiation emitted by an associated detection device, it can be determined whether the seat-side guide rail 122, and thus the vehicle seat itself, is in a position or adjustment range in which the seat-side guide rail 122 covers the reflector 1 or not.

[0043] Corresponding arrangements can in principle be used for any motor vehicle parts, in particular the vehicle interior, in order to distinguish between the position and / or locking states of a respective motor vehicle part, for example also for detecting the position and / or locking state of a headrest or a vehicle mirror.

[0044] Fig. Figure 5 shows a situation in which a (focused) electromagnetic radiation S1 emitted by the detection device 2 arranged on the roof impinges on a reflective element 11 and is reflected back by the latter, although no reflection is expected in the associated evaluation unit for the said direction of the electromagnetic radiation S1, for example because no suitable reflector 1 is stored for the said spatial direction. In this case, the evaluation unit can output a corresponding signal upon detection of the reflected radiation R1, for example to prompt the vehicle user to visit a workshop. Furthermore, the evaluation unit can store the relevant spatial direction of the signal and, if applicable, the calculated coordinates of the reflective element 11, so that these can be used for further investigations.

[0045] A single detection device 2 can furthermore be assigned a plurality of reflectors 1, so that the condition of a plurality of motor vehicle parts can be monitored and detected by means of a single detection device 2, in that a respective motor vehicle part is assigned a reflector 1 which lies in the detection range of that detection device 2, cf. Fig. 6. This means that a respective motor vehicle part to be monitored or the associated reflector 1 is spaced from the detection device 2 along a spatial direction along which the (focused) electromagnetic radiation S1, S2, S3, S4, S5, S6, S7 emitted by the detection device 2 can impinge on the reflector 1; unless the reflector is covered by an associated cover element. A central arrangement of the detection device 2 in the vehicle interior, such as the arrangement already described on the vehicle roof D, is particularly suitable for this purpose.

[0046] Fig. 6 shows, by way of example, a plurality of reflectors 1 which are arranged (spaced apart from one another) at different locations in the vehicle interior I of a motor vehicle and which are each assigned to a motor vehicle part in order to be able to detect its state. For example, a first reflector 1 can be used to detect the locking state of a headrest 106 on the front seat 100, another reflector 1 can be used to detect the unlocking of a seat longitudinal adjustment (e.g., in order to be able to move a motor vehicle seat into a far forward position to provide an entry aid), and yet another reflector 1 can be used to detect the locking state of a seat back 104 on the front seat.

[0047] In addition, for example, with additional reflectors 1, the locking state of a child seat 200 on the rear seat 100', the locking state of a locking mechanism for the seat back 104 on the rear seat, the state of an upper backrest lock and / or the state of a headrest lock on the rear seat 100 can be detected.

[0048] Depending on how a respective reflector 1 and any associated cover element are arranged, and depending on how the reflector 1 and any additional cover element move (or do not move) when the associated motor vehicle or seat part is displaced, a reflection of the radiation S1 emitted by the detection device 2 in the direction of a respective reflector 1 can occur either precisely when the corresponding motor vehicle part is in the locked state, or alternatively precisely when the corresponding motor vehicle part is in the unlocked state. In this case, a respective reflected radiation R1, R2, R3, R4, R5, R6, R7 is generated.

[0049] The possibility of detecting the state of a motor vehicle part, and in particular a locking state or a positional state thereof, has been described above using several exemplary embodiments. In addition to the applications shown, the present solution can also be used for a variety of other applications, for example, for detecting the locking state of motor vehicle doors or tailgates, i.e., in particular, for detecting the locking state of motor vehicle locks, as well as for detecting the positional state of a window pane or other motor vehicle parts in the interior of a motor vehicle, and furthermore, for detecting the state of electrical or electronic assemblies in a motor vehicle, for example, in electric drives, the associated controls, or associated sensors.

Claims

[1] Device for detecting the state of a motor vehicle part (102, 103, 104, 106, 122) which can be brought selectively into at least a first state or a second state, wherein the device has a display element by means of which the state of the motor vehicle part (102, 103, 104, 106, 122) can be determined, characterized bythat the display element has a reflector (1) and that a detection device (2) spaced apart from the reflector (1) is assigned to the reflector (1), which detection device contains a transmitter for generating a focused electromagnetic radiation (Si) which can be reflected by the reflector (1) when it impinges on the reflector (1), and which further contains a receiver for receiving the radiation (Ri) reflected by the reflector (1), wherein the reflector (1) is designed and arranged such that the electromagnetic radiation (Si) is reflected to the receiver only in one of the two states of the motor vehicle part (102, 103, 104, 106, 122), and wherein in the other of the two states of the motor vehicle part (102, 103, 104, 106, 122) the reflector (1) is not reached at all by the focused radiation (Ri) or the reflector (1) is arranged such that that it does not reflect incident radiation (Ri) to the receiver in the other of the two states. [2] Device according to claim 1, characterized by that the motor vehicle part (102, 103, 104, 106, 122) changes its position during the transition from the first to the second state in such a way that the electromagnetic radiation (Si) is reflected to the receiver only in one of the two states of the motor vehicle part (102, 103, 104, 106, 122). [3] Device according to claim 1 or 2, characterized by that the electromagnetic radiation (Si) only strikes the reflector (1) in one of the two states of the motor vehicle part (102, 103, 104, 106, 122) in such a way that it is reflected by the reflector to the receiver. [4] Device according to one of the preceding claims, characterized by that the electromagnetic radiation (Si) only strikes the reflector (1) in one of the two states of the motor vehicle part (102, 103, 104, 106, 122). [5] Device according to one of the preceding claims, characterized bythat the reflector (1) is connected to the motor vehicle part (102, 103, 104, 106, 122). [6] Device according to claim 5, characterized by that the reflector (1) is connected to the motor vehicle part (102, 103, 104, 106, 122) in such a way that the reflector (1) is displaced together with the motor vehicle part (102, 103, 104, 106, 122) when the motor vehicle part (102, 103, 104, 106, 122) is displaced from the first state to the second state. [7] Device according to one of the preceding claims, characterized by that the reflector (1) is arranged in such a way that in one of the two states of the motor vehicle part (102, 103, 104, 106, 122) it is covered by the motor vehicle part (102, 103, 104, 106, 122) or by a cover element (3) which can be displaced together with the latter and the electromagnetic radiation (Si) cannot impinge on the reflector (1). [8] Device claim 7, characterized bythat the reflector (1) is arranged in such a way that it is not covered in the other of the two states and the electromagnetic radiation (Si) can impinge on the reflector (1). [9] Device according to one of the preceding claims, characterized by that the electromagnetic radiation (Si) emitted by the detection device (2) strikes the receiver precisely when the motor vehicle part (102, 103, 104, 106, 122) is in the first state, and the electromagnetic radiation (Si) does not strike the receiver when the motor vehicle part (102, 103, 104, 106, 122) is in the second state. [10] Device according to one of the preceding claims, characterized by that the reflector (1) is designed as a retroreflector which reflects the incident electromagnetic radiation (Si) opposite to the direction of incidence. [11] Device according to one of the preceding claims, characterized bythat the motor vehicle part can be brought into a locking state as the first state or an unlocking state as the second state. [12] Device according to claim 11, characterized by that the motor vehicle part (103) is a component of a locking mechanism with which an associated motor vehicle assembly can be locked and unlocked. [13] Device according to claim 11, characterized by that the motor vehicle part (102, 104, 106, 122) is a component of a motor vehicle assembly (100) which can be locked and unlocked by means of an associated locking mechanism. [14] Device according to one of claims 1 to 11, characterized bythat the motor vehicle part (102, 104, 106, 122) can be transferred into a plurality of different positions, wherein in at least one of the positions of the motor vehicle part (102, 104, 106, 122) the electromagnetic radiation emitted by the detection device (2) strikes the reflector (1) and in at least one other position of the motor vehicle part (102, 104, 106, 122) the electromagnetic radiation (Si) emitted by the detection device (2) does not strike the reflector (1). [15] Device according to one of the preceding claims, characterized by that the motor vehicle part (102, 104, 106, 122) is a part of the interior equipment of the motor vehicle, in particular a seat part of a motor vehicle seat (100). [16] Device according to claims 12 and 15, characterized bythat the motor vehicle part (103) is a component of a locking mechanism with which an associated seat assembly can be locked and unlocked, which is designed to support a seat occupant. [17] Device according to claims 12 and 15, characterized by that the motor vehicle part (102, 104, 106) is a component of a seat assembly designed to support a seat occupant. [18] Device according to one of the preceding claims, characterized by that the detection device (2) is designed to emit bundled electromagnetic radiation (Si) along different spatial directions and to receive reflected electromagnetic radiation (Ri) from the opposite spatial directions, so that by means of a detection device (2) the state of a plurality of mutually defective motor vehicle parts (102, 103, 104, 106, 122) can be detected by scanning the respectively assigned reflector (1). [19] Device according to one of the preceding claims, characterized by that the detection device (2) is intended to be arranged in the interior (I) of a motor vehicle. [20] Device according to claim 19, characterized by that the detection device (2) is intended to be arranged on the roof (D) of a motor vehicle. [21] Device according to one of the preceding claims, characterized by that the detection device (2) is designed as a radar device or as a LIDAR device. [22] Method for detecting the state of a motor vehicle part (102, 103, 104, 106, 122) which can be selectively brought into a first state or a second state, wherein the device has a display element by means of which the state of the motor vehicle part (102, 103, 104, 106, 122) is determined, characterized bythat the display element has a reflector (1) and that a detection device (2) is assigned to the reflector (1) which is spaced apart from the latter and which generates a focused electromagnetic radiation (Si) which is reflected by the reflector (1) when it strikes the reflector (1) and which can receive the reflected radiation (Ri), wherein the reflector (1) is designed and arranged such that the electromagnetic radiation (Si) is reflected to the receiver only in one of the two states of the motor vehicle part (102, 103, 104, 106, 122), and wherein in the other of the two states of the motor vehicle part (102, 103, 104, 106, 122) the reflector (1) is not reached at all by the focused radiation (Ri) or the reflector (1) is arranged such that it does not direct incident radiation (Ri) to the receiver in the other of the two states reflected. [23] Method according to claim 22, characterized bythat the motor vehicle part (102, 103, 104, 106, 122) is displaced during the transition from the first to the second state in such a way that the electromagnetic radiation (Si) is reflected from the reflector (1) to the receiver only in one of the two states of the motor vehicle part (102, 103, 104, 106, 122). [24] A method according to claim 22 or 23, carried out using an apparatus according to any one of claims 1 to 21.

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