阅读说明：本技术 用于与颜色相关的图像内容检测的装置以及具有这种装置的计算设备和机动车 (Device for detecting color-related image content, and computing device and motor vehicle having such a device ) 是由 M·克鲁格 T·莫尔 J·朔伊切恩普夫鲁格 于 2020-04-30 设计创作，主要内容包括：本发明涉及一种用于与颜色相关的图像内容检测的装置(10),所述装置具有：载体介质(12)以及布置在载体介质的不同部段中的光耦入装置(24)、测量区域(18)、耦出区域(16),其中,光耦入装置(24)将具有第一波长的光耦入到载体介质(12)中。测量区域(18)被设计为具有第一衍射结构(20)的全息元件(14),该第一衍射结构将耦入的光从载体介质(12)中耦出以及将第一波长的光和从载体介质外部射到第一衍射结构(20)上的、第二波长范围的光返回耦入到载体介质(12)中。耦出区域(16)被设计为具有第二衍射结构(22)的全息元件(14),该第二衍射结构将返回耦入的光从载体介质(12)中耦出到摄像机装置(32)上；其中,摄像机装置(32)检测与检测到的光相关的图像数据。(The invention relates to a device (10) for color-dependent image content detection, having: a carrier medium (12) and light incoupling means (24), a measurement region (18), an outcoupling region (16) arranged in different sections of the carrier medium, wherein the light incoupling means (24) incouples light having a first wavelength into the carrier medium (12). The measuring region (18) is designed as a holographic element (14) having a first diffractive structure (20) which couples in light out of the carrier medium (12) and couples in light of a first wavelength and light of a second wavelength range which impinges on the first diffractive structure (20) from outside the carrier medium back into the carrier medium (12). The coupling-out region (16) is designed as a holographic element (14) having a second diffractive structure (22) which couples out the light coupled in back from the carrier medium (12) onto the camera device (32); wherein the camera device (32) detects image data related to the detected light.)

1. An apparatus (10) for color dependent image content detection, the apparatus having: a carrier medium (12) which is designed as an optical waveguide for transmitting the light that is coupled in, and light coupling-in means (24), a measuring region (18), a coupling-out region (16) which are arranged in different sections of the carrier medium, wherein

-the light incoupling means (24) comprises a light source (26), wherein the light source (26) is designed for emitting light having a first wavelength, wherein the light incoupling means (24) is arranged and designed for incoupling light having the first wavelength into the carrier medium (12);

-the carrier medium (12) is designed for transmitting the incoupled light from the light incoupling means to the measurement region (18) by means of internal reflection;

-the measurement region (18) is designed as a holographic element (14) having a first diffractive structure (20) which is designed for coupling out of the carrier medium (12) light of a first wavelength which is coupled in onto the first diffractive structure (20) and for coupling in into the carrier medium (12) light of the first wavelength which is coupled in from outside the carrier medium onto the first diffractive structure (20) in the direction of the coupling-out region (16), wherein the first diffractive structure (20) is also designed as a multiplexing diffractive structure which is designed for additionally coupling in light in a second wavelength range which is coupled in from outside the carrier medium onto the first diffractive structure (20) in the direction of the coupling-out region;

-the coupling-out region (16) is designed as a holographic element (14) having a second diffractive structure (22) which is designed as a multiplexing diffractive structure and is designed for coupling out light of the first wavelength and light of the second wavelength range, which is incident on the second diffractive structure (22) from the direction of the measurement region, from the carrier medium (12) onto the camera device (32); wherein

The camera device (32) is designed to detect light coupled out onto the camera device (32) and to provide it in the form of image data which is dependent on the detected light.

2. Device (10) according to claim 1, wherein the carrier medium is designed as a rectangle, the light incoupling means (24) being arranged on a narrow side of the carrier medium and the camera means being arranged on a flat side of the carrier medium.

3. The device (10) according to any one of the preceding claims, wherein the first wavelength is in the infrared wavelength range, in particular in the wavelength range of 800 nm to 1000 nm.

4. The device (10) according to any one of the preceding claims, wherein the second wavelength range is in the visible wavelength range, in particular in the wavelength range of 380 nm to 780 nm.

5. The device (10) as claimed in any of the preceding claims, wherein the measurement region (18) and the coupling-out region (16) are formed directly in the carrier medium (12), in particular in a surface structure of the carrier medium, or the carrier medium (12) is designed as a separate element from the measurement region (18) and the coupling-out region (16).

6. The device (10) according to any one of the preceding claims, wherein the first diffractive structure (20) and the second diffractive structure (22) are designed as volume holographic gratings or as surface holographic gratings.

7. The apparatus (10) according to any one of the preceding claims, wherein the provided image data is a combination of individual images of the respective detected wavelengths.

8. The device (10) according to any one of the preceding claims, wherein the light incoupling means (24) comprises a further light source (28) designed for emitting light having a third wavelength, wherein the light incoupling means (24) is arranged and designed for incoupling light having the third wavelength into the carrier medium (12);

the first diffraction structure (20) is also designed to couple out light of a third wavelength that impinges on the first diffraction structure (20) from the carrier medium (12) and to couple in light of the third wavelength that impinges on the first diffraction structure (20) from outside the carrier medium into the carrier medium in the direction of the coupling-out region, wherein the first diffraction structure (20) is also designed as a multiplexing diffraction structure that is designed to additionally couple in light of the third wavelength that impinges on the diffraction structure from outside the carrier medium in the direction of the coupling-out region;

the second diffraction structure (22) designed as a multiplexing diffraction structure is also designed to couple out light having a third wavelength, which impinges on the second diffraction structure from the direction of the measurement region, from the carrier medium (12) onto the camera device (32).

9. The device (10) according to claim 8, wherein the third wavelength is in the ultraviolet wavelength range, in particular in a wavelength range between 180 nm and 380 nm.

10. The apparatus (10) as claimed in one of the preceding claims, wherein the apparatus (10) further has an identification device (34) which is designed to receive image data of the camera apparatus and to check the image data in view of a predetermined biometric feature and to generate a control signal when a predetermined comparison condition occurs.

11. A motor vehicle (36) having a device according to claim 10, wherein the device (10) is integrated in a window pane (38) of the motor vehicle and the control signal actuates an opening mechanism (40) of the motor vehicle.

12. A motor vehicle (36) having a device (10) according to claim 10, wherein the device (10) is integrated in a screen and/or an armrest of the motor vehicle, the control signal operating a starting device of the motor vehicle.

13. A computing device (42) having an apparatus (10) as claimed in claim 10, wherein the apparatus (10) is integrated in a screen of the computing device, the control signal triggering access to the computing device (42).

Technical Field

The invention relates to a device for color-dependent image content detection, and to a motor vehicle and a computing device having such a device.

Background

Today there are a variety of camera systems which are capable of colour-dependent capturing of image content by means of light sources having different wavelengths and by means of colour filters. This may be used, for example, to extend the visible spectrum in order to identify, for example, surface details, disease, or biometric features, such as palm vein patterns.

A disadvantage of previous camera systems is that the light source cannot be superimposed with the optical axis of the camera, thereby resulting in oblique illumination and thus the position of the image content may shift, which corresponds to a shift of the optical axis. This may occur as the number of light sources increases. One way of compensating for this offset is to use optical elements, such as prisms, which however require more construction space.

DE 102016206290 a1 discloses a camera system having at least one camera module and at least one scattered-light trap, wherein the at least one scattered-light trap, in particular on the inside thereof, comprises a scattered-light reducing structure, wherein the scattered-light reducing structure comprises at least one holographic element, in particular a volume hologram.

Disclosure of Invention

It is an object of the present invention to provide an apparatus for color dependent image content detection.

This object is achieved by the subject matter of the independent claims. Advantageous developments of the invention are disclosed by the dependent claims, the following description and the drawings.

The invention provides an apparatus for color dependent image content detection. The device is equipped with a carrier medium which is designed as an optical waveguide for transmitting the light coupled in, and with light coupling-in means, a measuring region and a coupling-out region which are arranged in different sections of the carrier medium. The light incoupling means comprise a light source, wherein the light source is designed for emitting light having a first wavelength, wherein the light incoupling means are arranged and designed for incoupling light of the first wavelength into the carrier medium. The carrier medium is designed for transmitting the coupled-in light from the light coupling-in device to the measurement region by means of internal reflection, wherein the measurement region is designed as a holographic element having a first diffractive structure, which is designed for coupling out the coupled-in light having a first wavelength, which impinges on the first diffractive structure, from the carrier medium, and for coupling in light having the first wavelength, which impinges on the first diffractive structure from outside the carrier medium, into the carrier medium in the direction of the coupling-out region.

The first diffractive structure is also designed as a multiplexing diffractive structure, which is designed to additionally couple in light in the second wavelength range, which light impinges on the diffractive structure from outside the carrier medium, in the direction of the coupling-out region.

The coupling-out region is designed as a holographic element having a second diffractive structure which is designed as a multiplexing diffractive structure and is designed for coupling out light of the first wavelength and light of the second wavelength range which impinges on the second diffractive structure from the direction of the measurement region from the carrier medium onto the camera device. The camera device is designed to detect the light coupled out to the camera device and to provide it in the form of image data which is correlated with the detected light.

In other words, the device for color-dependent detection or image recording is designed with a carrier medium for guiding the light coupled in, a light coupling-in device and two regions, namely a measurement region and a coupling-out region, which can be located in different sections of the carrier medium. That is, the regions are arranged spaced apart from each other. The carrier medium can be made of glass and/or plastic, for example, wherein light can be transmitted within the carrier medium by means of internal reflection, i.e. total reflection. Color here refers to the two mentioned types of light, i.e. a first wavelength and a second wavelength range different from the first wavelength.

The light incoupling means of the device comprise a light source which can emit light having a first wavelength, wherein the light source can in particular have a photodiode or a laser diode. The light incoupling means may couple light of the first wavelength into the carrier medium, for example via one or more lenses, however the light incoupling means can also comprise a holographic element having a diffractive structure designed for coupling light of the first wavelength from the light source into the carrier medium. For example, the light incoupling means may also be arranged on the outcoupling region in such a way that a holographic element having the second diffractive structure can incouple light of the first wavelength into the carrier medium. The light coupled in this way from the light incoupling means can be transmitted within the carrier medium to the measurement region, wherein the measurement region has a holographic element with a first diffractive structure which can diffract the light coupled in to the carrier medium with the first wavelength, so that the light is coupled out of the carrier medium.

The light of the first wavelength coupled out of the measuring region can then be used to illuminate an object of the first wavelength, wherein the light of the first wavelength, which is reflected back into the measuring region by the object again, can be coupled out of the first diffractive structure into the carrier medium in the direction of the coupling-out region. In the direction of the coupling-out region, this means a macroscopic direction from the measuring region along the carrier medium to the coupling-out region, or a directional vector in the propagation direction of the light by means of internal reflection. Here, the light path can of course have a zigzag course due to internal reflection.

A holographic element, which is also referred to as a Holographic Optical Element (HOE), is an optical element whose functional principle is based on holography and which can be produced by means of a holographic method, i.e. holographic exposure. The holographic element can be designed in particular as a grating or a diffraction grating, wherein the grating essentially has an at least partially periodic structure, a so-called grid structure, which can cause a diversion of the light by means of a physical effect of diffraction, as is known, for example, from mirrors, lenses or prisms. If light or an optical beam impinges on the grating, wherein the incident optical beam in particular satisfies the bragg equation, the optical beam is diffracted or deflected by the grating. Thus, light turning can be achieved, in particular, by the interference phenomenon of the light beam diffracted due to the grating.

The grating can preferably be designed to be angle-or direction-selective and/or wavelength-or frequency-selective with respect to the incident light. Thus, only light impinging on the grating from one direction, e.g. in an angular range of about 180 degrees, can be deflected. Light impinging on the grating from another direction is preferably not deflected. Additionally or alternatively, light of only one wavelength, in particular light of a narrow wavelength range, may also be deflected by the grating at a specific diffraction angle. Thus, for example, only one component of the light in a specific wavelength or frequency range is deflected by the grating, while the remaining components of the light can propagate through the grid without being deflected. At least one monochromatic light component can thus be separated from the polychromatic light impinging on the grating.

The first diffractive structure is also designed as a multiplexing diffractive structure, i.e. the holographic grating can diffract polychromatic light, in particular light of the first and second wavelengths. These gratings are also referred to as Multiplexed Volume Holographic Gratings (MVHG) and can be produced, for example, by varying the periodicity of the grating structure of the grating or by arranging a plurality of volume holographic gratings one after the other.

This additionally achieves that the first diffractive structure couples in light in the second wavelength range, which light impinges on the diffractive structure from outside the carrier medium, in the direction of the coupling-out region. The light in the second wavelength range may comprise, for example, external light, i.e. ambient light which may impinge on the object to be photographed. The second wavelength range may also comprise only certain sections of the spectrum, for example only the red, green or blue components of the external light. The light of the first wavelength and of the second wavelength range can be guided inside the carrier medium to a coupling-out region which can be designed with a second diffractive structure which in turn is designed as a multiplexing diffractive structure and can couple out the light coupled into the carrier medium from outside the carrier medium onto the camera device.

The camera device, which may comprise, for example, a CMOS or CCD sensor, may detect the light coupled out in this way, in particular as a sensor array, and record it in the form of image data which is dependent on the detected light. To this end, the sensor of the camera device may be sensitive to light of different wavelengths, for example by means of a beam splitter, such as a prism or a grid, or by means of a color filter or a color filter assembly.

This embodiment has the advantage that the light source having the first wavelength can be switched on in addition to the ambient light in the second wavelength range, wherein the light having the first wavelength can be emitted from the measurement region of the device without the need to shift the position of the light source, whereby no displacement of the optical axis occurs. Furthermore, the space required for the prism or the grid can be saved by the holographic element.

The invention also includes embodiments that yield additional advantages.

One embodiment provides that the carrier medium is designed as a rectangle/cuboid, the light coupling-in means are arranged on the narrow side of the carrier medium, and the camera means are arranged on the flat side of the carrier medium. In other words, the carrier medium can have, for example, edges in the longitudinal direction a, edges in the width direction b and edges in the height direction c, the longitudinal direction a preferably being greater than b and c. The light coupling-in means can be arranged on the narrow side or end side of the carrier medium, i.e. on the sides or surfaces spanned by b and c. The camera device can be arranged on a flat side of the carrier medium, wherein the flat side is a surface spanned by a and b. Preferably, it can be provided that the measuring region and the coupling-out region are arranged offset from one another in the longitudinal direction a, wherein in particular the direction of the measuring region, in which the light is coupled out, and the camera device are arranged on the opposing surface at a distance from one another.

However, preferably only the planar sides lying opposite one another, i.e. the top surface of the carrier medium, can be plane-parallel or have the same radius of curvature, and light can be coupled in either via the planar sides or via the narrow sides. This means that, for example, any geometric shape, for example a cylindrical shape, with planar sides parallel to the plane can be provided.

An advantage of this embodiment is that the light incoupling means and the camera means can be designed to be spaced apart from each other, whereby installation space can be saved and a more planar structure can be achieved.

Preferably, the first wavelength is in the infrared wavelength range, in particular in the wavelength range from 800 nm to 1000 nm. The following advantages are thereby obtained: the object may be illuminated by switching on a light source having a first wavelength in the infrared wavelength range.

Preferably, the second wavelength range is in the visible wavelength range, in particular in the wavelength range from 380 nm to 780 nm. Thus, the device may absorb ambient light and, for example, additionally superimpose the ambient light with infrared light.

One embodiment provides that the measuring region and the coupling-out region are formed directly in the carrier medium, in particular in a surface structure of the carrier medium, or that the carrier medium is designed as a separate element from the measuring region and the coupling-out region. In the first case, for example, the measuring region and the outcoupling region can thus be formed directly in the surface structure of the carrier medium. Thus, the carrier medium itself may be designed as a HOE. In the second case, the measuring region, the outcoupling region and the carrier medium can be designed separately. The measuring region and the coupling-out region can form at least one first element, for example, and the carrier medium can form a second element which lies against the first element. A measurement region and a coupling-out region can thus be formed in the at least one HOE. For example, the measurement region and the outcoupling region may be formed in different sections of the holographic film or plate. In order to fix the membrane or plate on the carrier medium, the membrane or plate can be glued to the carrier medium. Alternatively, the holographic film can also be designed as an adhesive film and be attached by molecular force directly, that is to say without adhesive, to the surface of the support medium.

Another embodiment provides that the first and second diffractive structures are designed as volume or surface holographic gratings. The grating can be produced particularly preferably by means of exposure of the substrate, i.e. for example in a photolithographic manner or in a holographic manner. In this case, the grating may also be referred to as a holographic grating or holographic grating. Two types of holographic gratings are known: surface Hologram Gratings (SHG) and Volume Hologram Gratings (VHG). In a surface holographic grating, the grating structure may be produced by optically deforming the surface structure of the substrate. By means of the changed surface structure, the incident light can be deflected, for example reflected. Examples of surface holographic gratings are so-called sawtooth or blazed gratings. In contrast, in the case of volume holographic gratings, the grating structure can be machined into the entire volume or into partial regions of the volume of the substrate. The area-holographic and volume-holographic gratings are usually frequency-selective, but can also be designed selectively as multiplexed or multiple volume gratings for a plurality of wavelengths.

Another embodiment provides that the image data provided is a combination/merger of individual images of the respective detected wavelengths. The combination of the individual images of the respective detected wavelengths may for example comprise mathematical operations of the respective images with each other, such as additive superposition, subtraction, complementing the color regions of the images with image information of the respective wavelengths, convolution and filtering. In particular, it can be provided that, by means of the transparency effect which can be produced by adjusting the alpha channel of a single image, a plurality of planes can be represented, which can be recorded, for example, by increasing the penetration depth of the first wavelength. An advantage of this embodiment is that the data of a single image can be provided globally within the provided image data.

A further embodiment provides that the light incoupling means comprise a further light source designed for emitting light having a third wavelength, wherein the light incoupling means are arranged and designed for incoupling light having the third wavelength into the carrier medium. The first diffractive structure is also designed for coupling out light of a third wavelength that impinges on the first diffractive structure from the carrier medium and for coupling in light of the third wavelength that impinges on the first diffractive structure from outside the carrier medium into the carrier medium in the direction of the coupling-out region, wherein the first diffractive structure is also designed as a multiplexing diffractive structure that is designed for additionally coupling in light of the third wavelength that impinges on the diffractive structure from outside the carrier medium in the direction of the coupling-out region. The second diffractive structure, which is designed as a multiplexing diffractive structure, is also designed for coupling out light having a third wavelength, which impinges on the second diffractive structure from the direction of the measurement region, from the carrier medium onto the camera device. In other words, the light incoupling means may comprise a further light source which emits light of a third wavelength and can incouple it into the carrier medium, wherein the first diffractive structure of the measurement region can outcoupling light of the third wavelength from the carrier medium and incoupling it again, and the second diffractive structure of the outcoupling region can outcoupling light of the third wavelength, so that the camera means can detect the outcoupled light. An advantage of this embodiment is that a light source with another wavelength can be switched on in order to make another feature of the illuminated object visible.

Preferably, the third wavelength is in the ultraviolet wavelength range, in particular in the wavelength range between 180 nm and 380 nm. In this case, it can be provided in particular that the carrier medium is transparent to ultraviolet light and can conduct it, for example the carrier medium can comprise predominantly quartz glass.

One embodiment provides that the device also has an identification device which is designed to receive image data of the camera device and to check the image data in view of a predetermined biometric feature and to generate a control signal when a predetermined comparison condition occurs. In other words, an identification device can be provided which receives image data of the camera arrangement and compares the image data with a predetermined biometric feature, wherein the control signal can be generated under predetermined comparison conditions. The identification device may for example be a processor which is able to compare image data with each other, in particular predetermined biometric features which may be stored in a database of the identification device. The control signal can be generated when a predetermined comparison condition occurs, by means of which, for example, a similarity between the image data and the predetermined biometric feature can be determined. The predetermined biometric feature may be, for example, a surface structure or a pigment structure of the skin of a person, e.g. a finger, a line structure or a biological structure, e.g. a vein structure in the skin, below the surface of a hand of the user, or below the surface of an iris of an eye of the user. The predetermined comparison conditions may include, for example: pattern recognition showed agreement of over 90%. This embodiment has the advantage that the image data can be checked for predetermined biometric features and, if consistent, control signals can then be generated to operate further devices.

Another aspect of the invention relates to a motor vehicle having a device according to one of the preceding embodiments, wherein the device is integrated in a window pane of the motor vehicle and the control signal actuates an opening mechanism of the motor vehicle. The actuation of the opening mechanism may preferably comprise the opening of a lock of a door of the motor vehicle. This embodiment has the advantage that the vehicle can be opened without a key. The motor vehicle according to the invention is preferably designed as a motor vehicle, in particular as a passenger or truck vehicle, or as a passenger vehicle.

One embodiment of the motor vehicle provides that the device is integrated in a screen and/or an armrest of the motor vehicle, and the control signal actuates a starting device of the motor vehicle. This embodiment has the advantage that an authorized user can start the vehicle without a key.

According to the invention, a computing device is also provided with a device according to one of the preceding embodiments, wherein the device is integrated in a screen of the computing device, and the control signal triggers an access to the computing device. Computing devices may include computers, tablet PCs, and smart phones, among others. This embodiment has the advantage that the computing device may be enabled by a predetermined biometric feature of the authorized user.

The invention also comprises a development of the device according to the invention, which has the features already described in connection with the development of the motor vehicle according to the invention. Accordingly, corresponding modifications of the device according to the invention are not described here.

The invention also comprises a combination of features of the described embodiments.

Drawings

Embodiments of the present invention are described below. The figures show:

fig. 1 shows a schematic side view of an apparatus according to an exemplary embodiment;

FIG. 2 illustrates an interior side of a motor vehicle door according to an exemplary embodiment;

FIG. 3 illustrates an outboard side of a motor vehicle door according to an exemplary embodiment;

FIG. 4 illustrates a computing device in a motor vehicle according to an exemplary embodiment.

The examples described below are preferred embodiments of the present invention. In the examples, the components of the embodiments are individual features of the invention which can be regarded as independent of one another and which further improve the invention independently of one another. Therefore, the present disclosure is intended to include other combinations of features in addition to those of the illustrated embodiments. Furthermore, the described embodiments can also be supplemented by other features of the invention which have been described.

In the drawings, like reference numbers indicate functionally similar elements, respectively.

Detailed Description

Fig. 1 shows a schematic diagram of an apparatus 10 for color dependent image content detection. The device 10 comprises a carrier medium 12, which is designed as an optical waveguide for transmitting the light coupled in by internal reflection.

The carrier medium 12 can be designed rectangular, for example with separate rectangular elements, i.e. plates, which are constructed in a sandwich structure to form the carrier medium. For example, the carrier medium 12 may comprise two glass plates which serve as light conductors and form a coating of the carrier medium. The core of the carrier medium, which is surrounded by the two glass plates, can have a holographic element 14, which can be designed, for example, as a transparent photopolymer film. The glass plate is in direct contact with the respective opposite surfaces of the hologram element with the respective surfaces. In other words, the hologram 14 and the glass plate lie flat against one another with their respective surfaces bounded by the longitudinal and the wide side. In addition to the light guide, the glass plate may also protect the holographic element 14 from external environmental factors. Fig. 1 shows in particular a cross-sectional view of an apparatus for color-dependent image content detection, wherein an apparatus 10 having a cross-section along a longitudinal axis is shown.

The carrier medium 12 may comprise a coupling-out region 16 and a measuring region 18, which are arranged in different sections of the carrier medium and are arranged, for example, offset in the longitudinal extension direction of the carrier medium. The hologram element 14 can be exposed to the respective regions in the coupling-out region 16 and the measuring region 18 by means of a holographic method in such a way that a first diffractive structure 20 can be formed in the measuring region and a second diffractive structure 22 can be formed in the coupling-out region, which can be designed in particular as a volume holographic grating or as a surface holographic grating. This means that the first and second diffractive structures 20 and 22 have grating structures that can diffract light having a predetermined wavelength at a predetermined angle. The measuring region and the outcoupling region may be formed directly in the carrier medium, or these regions may be designed as elements separate from the carrier medium.

The device 10 further comprises light incoupling means 24, which may be arranged at the narrow side or end side of the carrier medium. The light incoupling means 24 may preferably comprise an infrared light source 26 and a UV light source 28, which may be switched on for the device 10 depending on the application.

The infrared light source 26 may emit light having a first wavelength in the infrared wavelength range, i.e., for example, in the wavelength range of 800 to 1000 nanometers. The infrared light source 26 may preferably have a photodiode that emits light having a wavelength of 850 nanometers. The UV light source 28 may emit light having a third wavelength, wherein the third wavelength is in the ultraviolet wavelength range, for example between 180 and 380 nanometers. The UV light source 28 can preferably also be designed as a light emitting diode emitting light with a wavelength of 340 nm. The wavelength specified for the photodiode here is the peak wavelength ("peak wavelength"), which represents the range where the spectrum of the light emitting diode reaches the highest intensity. Those skilled in the art will appreciate that the peak wavelength may have a deviation of several nanometers, e.g., +/-30 nanometers.

The light incoupling means 24 on the front side of the carrier medium 12 are also designed to incouple light from the light source into the carrier medium 12. For this purpose, for example, a lens system (not shown) can be provided which satisfies the coupling-in condition or resonance condition of the carrier medium 12 and can couple light into the carrier medium 12 such that it can be transmitted within the carrier medium by means of total reflection.

In this embodiment, the infrared light source 26 emits light having a first wavelength into the carrier medium 12, as shown by the solid lines in FIG. 1. The light having the first wavelength is conducted further by means of internal reflection within the carrier medium to the measurement region, where it then impinges on the first diffractive structure and is diffracted. Thus, light of the first wavelength can be coupled out of the carrier medium to expose the object 30.

In this embodiment, the object 30 to be measured may be a hand of a user and may, for example, specify that a palm vein pattern is determined. For this purpose, light in the infrared wavelength range is particularly suitable, since the palm vein pattern recognition is carried out by means of infrared light according to known methods. In this case, the infrared light emitted from the carrier medium 12 onto the hand 30 can be reflected and again reflected onto the first diffractive structure 20 in the measurement region.

In addition to infrared light, ambient light scattered by the hand 30 may also enter the measurement region 18 and impinge on the first diffractive structure 20, as indicated by the dashed line. The ambient light may be in a second wavelength range, wherein the second wavelength range may be in the visible wavelength range of preferably 380 nm to 780 nm.

Furthermore, the first diffractive structure 20 can be designed as a multiplexing diffractive structure which can diffract light of a predetermined wavelength at a predetermined angle and can thus couple it back into the carrier medium 12. The multiplexed diffractive structure may comprise an interleaved diffractive structure, wherein a plurality of gratings, for example in the form of volume gratings, are generated interleaved by multiple exposure of the holographic element during generation of the multiplexed diffractive structure in such a way that a plurality of grating structures are generated, wherein the respective grating structures may diffract light having different wavelengths at a predetermined angle. Alternatively or additionally, it can also be provided that a plurality of holographic elements are arranged in a layered or sandwich structure, which are connected to one another by means of a transfer adhesive, wherein each layer is formed by means of a suitable exposure method for the respective wavelength. For example, three holographic elements can be provided which are bonded to one another, wherein, for example, one holographic element is sensitive to the infrared wavelength range, the ultraviolet wavelength range and the visible wavelength range.

The light coupled into the carrier medium 12 in this way can then be guided in the direction of the coupling-out region, where it impinges on the second diffractive structure 22, which in turn can be designed as a multiplexing diffractive structure and can be designed for coupling out light from the carrier medium in the direction of the measurement region onto the camera device 32.

The camera device 32 may have in particular a photodetector, for example a CCD detector or a CMOS detector, which may be designed in particular as a detector array for recording image data. Here, image data related to the detected light may be provided. The camera device 32 can preferably be arranged on a flat side of the carrier medium.

The image data provided by the camera device 32 may preferably have a combination of individual images of the respective detected wavelengths, so that in this embodiment, on the one hand, for example, an image of the hand 30 is obtained which may be superimposed with the palm vein pattern from the individual images of the infrared wavelengths. The image data thus detected can then be received by a recognition device 34, which may be, for example, a computer processor.

The identification device 34 may then examine the image data for predetermined biometric features and generate a control signal upon the occurrence of a predetermined comparison condition. In this embodiment, the predetermined biometric feature may comprise a palm vein pattern, wherein the recognition device 34 for example compares the photographed palm vein pattern with a predetermined pattern, i.e. stored in the recognition means, and may generate a control signal when the correspondence exceeds for example 90%, with which other devices may be controlled.

Fig. 2 shows an inside of a motor vehicle 36, in particular an inside of a motor vehicle door, according to an exemplary embodiment. In this embodiment, the device 10 for color-dependent image content detection can be provided, for example, in a coating of a motor vehicle door. For example, the user can place his hand 30 on the measuring region 18 of the device 10 in order to verify his identity, wherein the reflected light can be guided from the hand 30 into the coupling-out region 16, which can be arranged, for example, in a door trim, by means of the method described above. Furthermore, the camera device 32 and the identification device 34 can also be provided in the door trim, wherein the identification device 34 can, for example, send a control signal to a starter device (not shown) of the motor vehicle, which starter device can start the engine of the motor vehicle, after an inspection has been carried out.

Another exemplary embodiment of the device 10 is shown in fig. 3. In this embodiment, the device 10 may be integrated into a window pane 38 of a motor vehicle. For example, when the user's hand 30 is placed on the measurement region 18, an image of the palm vein pattern may be detected and examined by the recognition device 34. When the predetermined comparison condition occurs, a control signal can be sent, for example, to an opening mechanism 40 of the motor vehicle door, which can open a lock of the door, for example.

FIG. 4 illustrates a computing device 42, according to an example embodiment. In this embodiment, the computing device 42 is integrated into a dashboard 44 of the motor vehicle. The computing device 42 may be, in particular, an infotainment system of a motor vehicle. The computing device 42 may preferably have a screen, wherein, for example, in this embodiment the glass of the screen, in particular the cover glass, may be the measurement region 18 of the apparatus 10 for color-dependent image content detection. For example, when the hand 30 is placed or approached, the palm vein pattern recognition described previously herein may begin, and, for example, when the recognition is successful, access to the computing device 42 may be triggered.

In another exemplary embodiment, it is an aspect that it is sufficient for the hand, for example for palm vein recognition, to approach the measurement region for recording. This means that no hand has to be placed on the measuring region 18, whereby contamination of the measuring region or contamination of the hand can be avoided.

Another possibility of use consists in integrating the device into the gear lever, steering wheel, rear view mirror, center console surface and/or roof hatch of the motor vehicle in order to be able to identify the user.

In summary, these examples demonstrate how the present invention provides color-related image content detection as well as biometric identification through palm vein recognition via holographic elements.