Device and method for determining information in a motor vehicle by means of a 3D sensor with a holographic mirror

Abstract

The invention relates to a device for determining information in at least one partial area of ​​the interior of a motor vehicle, wherein the motor vehicle has a light source for illuminating the interior and the illumination is performed by means of a light beam emitted by the light source, wherein the light beam follows a transmission path from the light source to the partial area of ​​the interior to be illuminated, characterized in that the motor vehicle has a sensor for detecting information and the information detection is performed by means of light containing data about the partial area of ​​the interior, wherein the light beam follows a reception path from the illuminated partial area of ​​the interior to the sensor, and wherein a hologram is present for diffracting the light beam and the hologram is positioned such that the hologram enables diffraction of the light beam both along the transmission path and along the reception path. A method for determining the information is also provided.

Description

Technical Field

[0001] The invention relates to a device for determining information in at least one partial area of ​​the interior of a motor vehicle, wherein the motor vehicle has a light source for illuminating the interior and the illumination is performed by means of a light beam emitted by the light source, wherein the light beam follows a transmission path from the light source to the partial area of ​​the interior to be illuminated, characterized in that the motor vehicle has a sensor for detecting information and the information detection is performed by means of a light beam containing data relating to the partial area of ​​the interior, wherein the light beam follows a reception path from the illuminated partial area of ​​the interior to the sensor, and wherein a hologram is present for diffracting the light beam and the hologram is positioned such that the hologram enables diffraction of the light beam both along the transmission path and along the reception path. A method for determining the information is also provided. Background Art

[0002] Motor vehicles are increasingly equipped with assistance systems, safety systems or even autonomous driving systems. In the context of this partially or highly automated driving, the observation of the vehicle interior space is becoming increasingly important. Ideally, 3D data of all occupants should be detected here. The detection of these data is particularly related to passive safety. For example, the way the airbag is deployed should be adapted to the occupant to be protected. The seat belt reminder can only be activated when someone is actually sitting in the corresponding seat. This function of the seat belt should be adapted to extreme body postures (feet on the dashboard, knees clamped to the backrest of the front seat, lying down...). In addition, if the corresponding occupants are identified and known, the comfort and infotainment functions can be automatically adapted to these occupants. In addition, gesture control is increasingly used within the scope of new HMI concepts, for which it is advantageous to detect high-resolution 3D data. One possibility for detecting such data is to use a ToF camera (Time-of-Flight camera) which operates with light in the near-infrared range, for example with a wavelength of 850 nm or 940 nm.

[0003] The car manufacturers refused to install an optical sensor with a fisheye lens in the middle of the roof lining, because such a concept is not suitable for vehicles with panoramic roofs or convertibles. On the contrary, an optical sensor installed at the position of the rearview mirror cannot detect the entire rear seat for geometric reasons, not to mention possible other rows of seats, because the front seats block a large area of ​​space. However, for example, the recognition of children on the rear seats, possibly in rear-facing child seats, is an important and difficult application.

[0004] Holographic elements are known from optical devices. In contrast to conventional optical devices, in the case of holographic optical elements realized as volume holograms, the beam deflection is not predetermined by refraction, but by diffraction at a volume grating. The holographic optical elements can be produced in transmission and reflection and, by freely selecting the angles of incidence and of emission or diffraction, they allow new construction forms. In this case, a holographic diffraction grating is exposed into a film (holographic material 6 μm-200 μm + carrier substrate>60 μm), where a Bragg grating is formed and theoretically an efficiency of 100% is achieved. By means of volume diffraction, the holographic optical element can additionally also be assigned a characteristic wavelength and angle selectivity or a filter function. Depending on the recording conditions (wavelength, angle), only light from a defined direction and with a defined wavelength is diffracted at the structure. Summary of the invention

[0005] Advantageously, the device according to the invention makes it possible to extend the recording range of the sensor to a plurality of additional sub-areas of the interior.

[0006] According to the invention, this is made possible by the features specified in the independent patent claim. Further embodiments of the invention are the subject matter of the dependent claims.

[0007] According to the invention, a device for determining information in at least one partial area of ​​the interior space of a motor vehicle, wherein the motor vehicle has a light source for illuminating the interior space and the illumination is performed by means of a light beam emitted by the light source, wherein the light beam follows a transmission path from the light source to the partial area of ​​the interior space to be illuminated, is characterized in that the motor vehicle has a sensor for information detection and the information detection is performed by means of a light beam containing data related to the partial area of ​​the interior space, wherein the light beam follows a reception path from the illuminated partial area of ​​the interior space to the sensor, and wherein a hologram is present for diffracting the light beam and the hologram is positioned so that the hologram enables diffraction of the light beam both along the transmission path and along the reception path.

[0008] This is understood as the detection of data from a partial area of ​​the interior. In this case, this can be, for example, general information about the interior (e.g., seat occupancy) or the determination of the occupants (e.g., recognition) and / or the observation (monitoring) of the body posture, gestures, head orientation, facial expressions, etc. of the occupants. Here, the determined data can also be three-dimensional data. For determining these data, a 3D camera is used, for example, a time-of-flight camera. In addition, any type of holographic optical element can be used as a hologram, in particular a reflection hologram. A hologram is also understood as an entire system of multiple holograms (e.g., a layer complex of multiple holograms) and / or integration into a vehicle component (e.g., applying a hologram to a glass plate in the roof lining). In addition, the positioning of the hologram is coordinated with the position of the camera and the lighting device. The partial area to be observed, the wave and angle selectivity, and the planned light wavelength are also taken into account. Positioning is understood to refer to both the local position and the possible installation at a specific angle. Taking into account the known geometric relationships of the interior and the positions of the elements, the desired information, for example about the position of the occupants in the subarea, can be determined from the light waves, for example with the aid of a computer unit. In addition to the terms "transmitting path" and "receiving path", "transmitting direction" or "transmitting channel" are often mentioned, as are reception direction or reception channel. In this case, the transmitting path extends from the light source to the object to be determined, and the receiving path extends from the object to be determined to the sensor. The emitted light beam can be either a light beam for pure illumination of the interior or a light beam for recording the interior. Of course, in a physically correct manner, instead of light beam, only the term "light" would be mentioned, and the term "light beam" would be used for the graphical representation to support this idea.

[0009] Thus, a system for observing a special sub-area of ​​the interior can be advantageously created. In particular, it is thereby possible to observe the interior, which cannot be directly detected due to the position of the camera, using simple means. In addition, a flexible use of the system is possible, since the hologram can be adapted to vehicles with different geometric dimensions. Due to the action of the hologram in two directions, the hologram can be used both to illuminate a sub-area along the transmission path and to guide the light beam back along the reception path. The system makes it possible to reduce costs, since all sub-areas or occupants can be detected using only one (or a small number of) sensors. Furthermore, no additional light sources are required in the sub-areas to be analyzed. The reduced number of components also results in a reduced installation space. Since not only the front passengers can be identified by the system, the comfort of the passengers in the rear seats is improved, for example by automatically adapting the infotainment and comfort functions. Furthermore, the proposed solution is characterized by a low cost structure, since in addition to the reduced number of components, the hologram used is also relatively inexpensive. Furthermore, the angle and wave selectivity of the hologram reduces the interfering light caused by ambient light, so that the determined data has a high quality.

[0010] In an advantageous embodiment, the device is characterized in that the sensor for information detection comprises a 3D camera.

[0011] This is understood as determining three-dimensional data about the sub-area. For this purpose, so-called 3D cameras are used. For example, a time-of-flight camera can be used. The time-of-flight camera has a special imager with special pixels and determines the time required for a light beam between emission and return, from which the distance can be determined. By completely three-dimensionally detecting all sub-areas and occupants, safety can be further increased, for example by special adaptations in terms of passive safety.

[0012] In one possible embodiment, the device is characterized in that the hologram is positioned on the roof of the vehicle.

[0013] As already mentioned, the term "positioning" should be understood in a broad sense, for example how the hologram is introduced, applied, mounted, integrated, etc. Advantageously, by means of such positioning - for example by means of a camera mounted at the location of the rearview mirror, the rear seats can be detected geometrically completely. The light path is not obstructed by the front seats. Advantageously, the hologram can also be positioned at the panoramic roof in vehicles with a panoramic roof, since the panoramic roof remains transparent to visible light.

[0014] In a preferred embodiment, the device is characterized in that the light beam emitted by the light source is deflected at the optical element in the direction of the hologram.

[0015] Optical elements should be understood as objective lenses or other optical devices with special shapes or special material combinations, and thus can achieve limited angles of incidence and angles of emission. The optical elements are positioned and / or mounted at or near the lighting device and / or sensor. The optical elements also work in multiple directions, that is, they enable light waves to be conducted and deflected along the emission path and the receiving path. In this case, the light beam is deflected in the direction of the hologram in the emission direction. In addition, the light beam is deflected substantially in the direction of the sensor in the receiving direction. Alternatively, it is also possible to deflect in the direction of a spatially known receiver away from the sender by means of an optical element. This can advantageously improve the function of the system. This also results in an expanded design margin and installation space advantage regarding the positioning and orientation of the sensor and the light source.

[0016] In an alternative embodiment, the device is characterized in that a plurality of holograms are present and in particular in that different holograms diffract different light wavelengths.

[0017] This is understood to mean that different partial areas of the interior space can be illuminated or observed with the aid of different holograms. For example, polychromatic light can be used for illumination for this purpose. At each hologram, only light waves of a special light wavelength or a special light wavelength range are diffracted. Corresponding to the angular selectivity of the corresponding diffraction hologram, the corresponding light beam of the special light wavelength range is forwarded to a specific partial area of ​​the interior space at a corresponding exit angle. Advantageously, by using a plurality of holograms, other rows of seats in a bus, such as the third or other rows of seats, can be detected. The positioning of the hologram can be carried out, for example, at the same position in the vehicle. Of course, it is also advantageously conceivable to position at least one or more holograms at a second position and / or other positions.

[0018] In an advantageous embodiment, the device is characterized in that the hologram is designed as a multiple hologram or as a layer stack individual hologram or as a combination of a multiple hologram and a layer stack individual hologram.

[0019] This is understood to mean that there are multiple holograms for diffracting the light beam. Each hologram has its own characteristics. These holograms can be located at the same position in space. This embodiment is carried out, for example, as a layer stack of individual holograms. The use of multiple holograms with different characteristics, such as wave selectivity, is particularly suitable in combination with the use of polychromatic light from light sources emitting different light wavelengths or different light wavelength ranges. The efficiency of the individual holograms can thus be advantageously adapted to the system. In the case of multiple holograms, the efficiency decreases as the number of holograms increases. In the case of a layer stack, scattering effects at the layer stack may be problematic, or there may be an impractical layer stack. In addition, a color filter can advantageously be used in front of the sensor.

[0020] In one possible embodiment, the device is characterized in that the light beams emitted for illumination have different light wavelengths.

[0021] This is understood as the use of light beams with different light wavelengths. Through the corresponding characteristics of the hologram, a specific light wavelength is then diffracted at a specific angle at the hologram. For example, multiple holograms can be positioned at the same position as a stacked hologram. In this case, the incident light beam (emission path) has the same angle of incidence. The defined light wavelength is diffracted at the associated hologram and output at a specific exit angle. Here, different light waves have different exit angles. The diffraction or deflection of the reflected light beam (receiving path) is carried out in a similar manner. The information at the sensor can be separated by using color filters and in combination with color filters. Advantageously, the information determination in different areas of the interior space can be carried out by the high angle and wave selectivity of the hologram. Thereby, for example, different partial areas of the interior space can be observed.

[0022] In a preferred extension, the device is characterized in that the light beam is constructed as polychromatic light, in particular, the polychromatic light is generated using a light source with a wide spectrum, or a light source with multiple defined light wavelengths is used to generate the polychromatic light, or a light source emitting in a narrowband spectrum is used to generate the polychromatic light, and the light wavelength of the light source can be tuned.

[0023] Advantageously, by combining polychromatic light with a plurality of holograms with different light wavelengths and angular selectivities, different partial areas of the interior space can be recorded and observed using only one light source and only one camera.

[0024] In an alternative embodiment, the device is characterized in that a plurality of light sources are present, and in particular a plurality of light sources emitting light having different light wavelengths are present.

[0025] Advantageously, by using a plurality of light sources, for example with different light wavelengths, each sub-region of the interior to be recorded can be illuminated individually, thereby achieving advantages in terms of installation space and installation volume.

[0026] In one possible embodiment, the device is characterized by the presence of a color filter, in particular a switchable color filter for selecting a defined wavelength of light.

[0027] This is understood to mean the presence and use of color filters in order to selectively extract information from light beams with different light wavelengths in front of the sensor. The color filter is in particular positioned and / or mounted at or in the immediate vicinity of the sensor. For example, a plurality of color filters may also be present and used. Furthermore, the color filters are advantageously assigned to defined pixels of the sensor. Alternatively, the light sources may also be controlled sequentially with a synchronous evaluation of the light beams received in the sensor.

[0028] In a preferred embodiment, the device is characterized in that a plurality of sensors are present, and in particular a plurality of sensors for detecting different light wavelengths are present.

[0029] This is understood to mean the presence and use of one or more further sensors, at least further imagers, to observe different partial areas of the interior space. These additional sensors are positioned slightly displaced from the original sensors (imagers). Furthermore, advantageously, not only one or more further sensors can be used, but also a corresponding light source can be used for each camera.

[0030] Furthermore, according to the invention, a method for determining information in at least one partial area of ​​the interior of a motor vehicle is provided, wherein the motor vehicle has a light source for illuminating the interior and the light source emits light for illuminating the partial area of ​​the interior along a transmission path, in which partial area the information is to be determined. According to the invention, the method is characterized in that the motor vehicle has a sensor for information detection, and the sensor receives light for transmitting data related to the partial area of ​​the interior along a reception path, and wherein the light is diffracted at a hologram to determine the information of the partial area, wherein the hologram is designed such that the light is diffracted at the hologram both along the transmission path and along the reception path.

[0031] For further explanation and advantages of the method, reference is made to the preceding description.

[0032] In a preferred embodiment, the method is characterized in that three-dimensional data of the partial area of ​​the interior space are determined with the aid of a 3D camera, wherein the optical path of the 3D camera in the emission direction and in the reception direction is deflected at the hologram, wherein the hologram is in particular positioned at the vehicle roof.

[0033] This is understood to be the use of at least one (or more) 3D camera, for example, to observe the partial area of ​​the interior or to recognize a person or a person's body posture or gesture. For example, a time-of-flight camera is used for this purpose. The hologram is positioned on the vehicle roof, for example, between the pillars AB and / or between BC and / or between CD and / or between AC. Of course, it is also conceivable to install the hologram in different areas and / or also across multiple areas.

[0034] In a possible embodiment, the method is characterized in that information from a partial region of the interior is determined by means of light diffracted at the hologram and in addition, information from a further partial region of the interior is determined by means of light taking a direct path.

[0035] This is understood to mean that partial areas are observed with the aid of the hologram, which partial areas can only be observed with the aid of the diffraction of the light beam, but not with the aid of the direct light beam. The method thus makes it possible to determine information from partial areas of the interior space with the aid of the light beam diffracted at the hologram, wherein the partial areas cannot be detected with the aid of the direct light beam. However, other partial areas are also observed directly. As a result, the recording area of ​​the sensor can advantageously be significantly enlarged and other components can be saved.

[0036] In a preferred embodiment, the method is characterized in that information is determined from different partial areas of the interior, a plurality of holograms are used and different holograms diffract light of different wavelengths, and the information is determined for each partial area by light having a respectively defined wavelength.

[0037] This is understood to mean that each hologram diffracts light of a specific wavelength (actually a small wavelength range) (wavelength selectivity). In addition, the light of the specific wavelength is diffracted in a characteristic manner by the hologram (angle selectivity). That is, for example, the hologram deflects light of a special wavelength at an incident angle of 10° to an exit angle of 30°. Other light wavelengths are not diffracted or are not diffracted to this exit direction. In contrast, the second hologram diffracts light of a different wavelength at an incident angle of 10° to an exit angle of 40°. However, again, the second hologram does not diffract the first light wavelength. This feature is of course defined and known. This feature can be adapted to the respective system / requirements via material parameters (thickness and refractive index modulation of the holographic layer). In combination with the known hologram positioning, it can be determined very precisely which wavelengths of light can be used to observe which partial area of ​​the interior space. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] It should be pointed out that the features listed individually in the description can be combined with one another in any technically meaningful manner and represent other configurations of the invention. Other features and suitability of the invention are obtained from the description of the embodiments based on the drawings.

[0039] In the attached picture:

[0040] Figure 1 A schematic diagram showing information determination by means of a hologram; and

[0041] Figure 2 shows the diffraction behavior of a monochromatic light beam at a hologram; and

[0042] Figure 3 shows the diffraction behavior of a polychromatic light beam at a holographic complex; and

[0043] Figure 4 shows the receive path of a ToF camera with the light beam deflected by the HOE; and

[0044] Figure 5 shows a receive path of a ToF camera with multiple light beams, each appropriately deflected by a HOE complex, and exemplary optical elements and color filters; and

[0045] Figure 6 An exemplary representation of the method steps is shown. DETAILED DESCRIPTION

[0046] Figure 1A schematic diagram of information determination by means of a hologram is shown. A motor vehicle 1 is shown here, in the interior 3 of which there is an occupant 2. In the front sub-region 5 of the interior 3 there is, for example, a driver, and in the rear sub-region 4 of the interior 3 there is a child. There is also a driver observation system. The driver observation system comprises a sensor 8, for example a time-of-flight (ToF) camera, for three-dimensional detection of the interior 3 and the occupant 2. In addition, a lighting device 9, for example a light source in the near-infrared range, is provided. The sensor 8 and the lighting device 9 are installed here approximately at the position of the rearview mirror. From this position of the camera, the driver in the front sub-region 5 can be directly observed. However, in order to observe the child in the rear sub-region 4, the beam path must be deflected. This is done by means of a hologram 7, which is positioned on the roof lining 6 of the motor vehicle. The light beam 10 is diffracted and forwarded at the hologram 7 in accordance with its wavelength and its angle of incidence. By means of this deflection at the vehicle roof, spatial regions that are otherwise obscured can also be detected by the camera. The deflection is carried out both in the direction of the emission path of the light beam 10 for illuminating the rear partial area 4 and in the direction of the reception path of the light beam directed back to the sensor. Since the path from the lighting device 9 to the hologram 7 (and back) is known, the relationship between the angle of incidence and the angle of exit at the hologram 7 is also known, so that the depth information as well as the direction and position information remain unchanged when deflecting at the hologram 7.

[0047] Figure 2 An exemplary diffraction behavior of a monochromatic light beam at a hologram is shown. The mode of operation of the hologram 7 is illustrated here using the example of an 80°-60° deflector. Here, a light beam 11 incident at 80° (measured relative to the normal to the hologram) is diffracted at the hologram 7 to an angle of 60° (measured relative to the normal to the hologram). The diffraction angle is predetermined by the holographic grating and can be adapted to the respective vehicle geometry. The exit angle 14 of the diffracted light beam 12 therefore depends on the angle of incidence 13 of the incident light beam 11 and, of course, generally also on the wavelength of the light beam 10. Due to the characteristic wavelength and angle selectivity, the film of the hologram 7 is transparent to all other directions and wavelengths outside the selectivity curve.

[0048] Figure 3The diffraction behavior of a polychromatic light beam at a holographic complex is also shown. In this case, a plurality of diffraction angles are fanned out by a plurality of holograms for a plurality of wavelengths (for example for detecting different sitting positions). In this case, each wavelength range corresponds to a diffraction angle range. In this case, the resolution of the system is defined in particular by the number of holograms. In the example shown, incident light beams 11a, 11b, 11c, 11d are found, which each have a different light wavelength. These incident light beams all have the same angle of incidence 13. These light beams fall on the hologram complex consisting of four holograms 7a, 7b, 7c, 7d. The light beams of the defined light wavelength are diffracted at (and only at) the corresponding hologram and forwarded as diffracted light beams 12 at an exit angle 14. Thus, for example, light beam 11a is diffracted at hologram 7a and forwarded as light beam 12a at an angle 14a. In a similar manner, this also applies to other light beams and holograms.

[0049] The different individual holograms can be stored (i.e. converted) either as a so-called multiple hologram in one layer, as a layer stack consisting of individual holograms, or a combination of both (adapted to the respective system configuration). By careful selection of the material parameters, the selectivity of the individual holograms can be adapted so that they only diffract light of the relevant wavelength. The hologram or the layer stack can also be used simultaneously for the return channel. The beam path is reversible and the hologram bundles the reflected light beam and sends it directionally in the direction of the light source or sensor.

[0050] Figure 4 The receiving path of a ToF camera with light beams via a hologram and optical elements is shown. Here, an exemplary receiving path of two light beams 10a and 10b is shown, which are incident on the hologram 7 at angles 14a and 14b, respectively. These light beams are diffracted accordingly at the hologram 7 and forwarded at angles 13a and 13b, respectively, in the direction of the sensor 8. In the further process, the light captured by the sensor 8 must be appropriately deflected, so that part of the pixels 17 of the ToF imager 16 of the sensor 8 can be used for this path. This is done by an objective lens 15. The light beams 10a and 10b are refracted at this objective lens 15 and deflected in the direction of the sensor 8. The pixels 17 must be calibrated individually, or the information detected by the pixels 17 must be recalculated accordingly within the scope of postprocessing to take into account the deflection by the hologram 7. If the inspection area (Field of View, FoV) of the sensor is large enough, additional optical elements can be omitted. In the case of a TOF camera, the emitted and received light are advantageously coordinated with each other. Otherwise, the light travel time etc. and therefore also the associated distance (depth information) cannot be determined.

[0051] Figure 5The receiving path along the hologram and optical elements and color filters of a ToF camera with multiple light beams is shown. This embodiment involves the use of polychromatic light. In this case, it is possible to work with spectrally broad light sources as well as with multiple defined wavelengths or light sources that emit in a spectrally narrow band but whose wavelength can be tuned. A hologram is required for each wavelength to be used. Accordingly, in the embodiment shown, multiple holograms 7a, 7b, 7c, 7d are superimposed. In this case, multiple diffraction angles can be monitored by multiple holograms for multiple wavelengths (for example, for detecting different sitting postures). In this case, each wavelength corresponds to a diffraction angle. The resolution of the system is defined in this case, in particular, by the number of holograms. In addition, for the technical description, reference is also made to the description of the system. Figure 3 On the detector side, wavelength separation can be achieved with the aid of a color filter 18. The color filter 18 is advantageously implemented as a diffractive element. In this case, a color filter can be assigned to each of the different pixels. In this case, the superimposed light beams are fanned out in the spectrum and a defined wavelength is "assigned" to each pixel or pixel region.

[0052] Figure 6 The method steps of the exemplary expression of the method are shown. Here, the method starts, for example, when the vehicle is started or when the auxiliary function or monitoring function is activated. In the first method step S1, for example, a polychromatic light source is manipulated so that polychromatic light is emitted from the light source. The light is deflected in the direction of the hologram at the objective lens between the light source and the hologram. In the second step S2, the light is diffracted at the hologram corresponding to the angle and wave selectivity of the hologram. The corresponding light beam of a specific wavelength is forwarded to a limited partial area of ​​the interior space at a specific angle for illumination. In step S3, information recording of the partial area or the occupant and its position, body posture, gesture, facial expression, etc. is performed. The light beam is reflected at the object and guided back in the direction of the hologram. In step S4, it is diffracted again at the hologram corresponding to the angle and wave selectivity of the hologram. The returned guided light beam is deflected again at the objective lens, this time in the direction of the image sensor. The image sensor can be, for example, a time-of-flight camera with a corresponding imager. In the next step S5, data recording of the light is performed by means of the image sensor. The method is then continued with step S1. Furthermore, after step S5, the data material is analyzed in step S6, for example by means of a control device. Corresponding information can be derived from the data material, which information is used, for example, as input for other method steps. For example, in step S7, a passive safety system (such as an airbag or a seat belt system) can be adapted to the body posture of the occupant. In this case, it is even conceivable to switch off the passive safety system if this increases the safety of the occupant. Of course, it is also possible to automatically control and adapt the comfort and infotainment functions.

Claims

1. A device for determining information in at least one sub-region (4) of an interior (3) of a motor vehicle (1), wherein the motor vehicle (1) has a light source (9) for illuminating the interior (3) and the illumination is performed by means of a light beam (10) emitted by the light source (9), wherein the light beam (10) follows a transmission path from the light source (9) to the sub-region (4) of the interior (3) to be illuminated, characterized in that The motor vehicle (1) has a sensor (8) for detecting information, and the information detection is performed by means of a light beam (10) containing data about the sub-area (4) of the interior (3), wherein the light beam (10) follows a reception path from the illuminated sub-area (4) of the interior (3) to the sensor (8), and wherein a hologram (7) is present for diffracting the light beam (10) and the hologram (7) is positioned such that the hologram (7) enables diffraction of the light beam (10) both along the transmission path and along the reception path, wherein the hologram (7) is constructed as a reflection hologram, and The hologram (7) is positioned on the vehicle roof (6).

2. The device according to claim 1, characterized in that The sensor (8) for information detection includes a 3D camera.

3. The device according to any one of the preceding claims 1 to 2, characterized in that The light beam (10) emitted by the light source (9) is deflected at the optical element (15) in the direction of the hologram (7).

4. The device according to any one of the preceding claims 1 to 2, characterized in that There are multiple holograms (7).

5. The device according to claim 4, characterized in that Different holograms (7) diffract different wavelengths of light.

6. The device according to claim 4, characterized in that The hologram (7) is designed as a multiple hologram or as a layer stack individual hologram or as a combination of a multiple hologram and a layer stack individual hologram.

7. The device according to any one of the preceding claims 1 to 2, characterized in that The light beams (10) emitted for illumination have different light wavelengths.

8. The device according to any one of the preceding claims 1 to 2, characterized in that The light beam (10) is designed as polychromatic light.

9. The device according to claim 8, characterized in that At least one of the following types of light sources (9) is used: - a spectrally broad light source (9) for generating said polychromatic light, - a light source (9) having a plurality of defined light wavelengths for generating said polychromatic light, A light source (9) emitting in a narrow spectral band to generate the polychromatic light, the wavelength of light of the light source (9) being tunable.

10. The device according to any one of the preceding claims 1 to 2, characterized in that There are multiple light sources (9).

11. The device according to claim 10, characterized in that The plurality of light sources emit light beams (10) having different light wavelengths.

12. The device according to any one of the preceding claims 1 to 2, characterized in that A color filter (18) is present.

13. The device according to claim 12, characterized in that There is a switchable color filter (18) for selecting a defined wavelength of light.

14. The device according to any one of the preceding claims 1 to 2, characterized in that There are multiple sensors (8).

15. The device according to claim 14, characterized in that There are multiple sensors (8) for detecting different wavelengths of light.

16. A method for determining information in at least one partial region (4) of an interior (3) of a motor vehicle (1), wherein the motor vehicle (1) has a light source (9) for illuminating the interior (3) and the light source (9) emits a light beam (10) which illuminates a partial region (4) of the interior (3) along a beam path in which the information is to be determined, characterized in that The motor vehicle (1) has a sensor (8) for detecting information, and the sensor (8) receives a light beam (10) which transmits data relating to the sub-region (4) of the interior space (3) along a receiving path, and wherein the light beam (10) is diffracted at the hologram (7) to determine the information of the partial area (4), wherein the hologram (7) is positioned such that the light beam (10) is diffracted at the hologram (7) both along the transmission path and along the reception path, wherein the hologram (7) is positioned on the vehicle roof (6), and The hologram (7) is designed as a reflection hologram.

17. The method according to claim 16, characterized in that Three-dimensional data of the partial region (4) of the interior (3) are determined by means of a 3D camera, wherein the beam path of the 3D camera in both the transmission direction and the reception direction is deflected at the hologram (7).

18. The method according to claim 17, characterized in that The hologram (7) is positioned on the vehicle roof (6).

19. The method according to any one of claims 16 to 18, characterized in that Information from the partial region (4) of the interior is determined by means of the light beam (10) diffracted at the hologram (7), and additionally information from a further partial region (5) of the interior (3) is determined by means of the direct light beam (10).

20. The method according to any one of claims 16 to 18, characterized in that Information is determined from different sub-regions (4) of the interior (3), wherein a plurality of holograms (7) are used and different holograms (7) diffract different light wavelengths, and information is determined for each sub-region (4) by means of a light beam (10) having a respectively defined light wavelength.

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