Device for measuring time of flight of measurement beam, user terminal, detection and illumination device, method for measuring time of flight of measurement beam, computer program and / or computer-readable medium, and data processing device

Abstract

The invention relates to a device (10) for measuring the time of flight (92) of a measurement light beam (80), comprising a measurement light source (20) for emitting the measurement light beam (80), a light sensor (30) for detecting the measurement light beam (80), a waveguide (50), and a data processing device (90), the waveguide (50) is designed such that a measurement light beam (80) emitted by the measurement light source (20) to an object (15) located in an object region (16) of the device (10) and a measurement light beam (85) reflected from the object (15) to the light sensor (30) are guided at least partially through the waveguide (50), the waveguide (50) having a measurement diffraction structure (51, 52) for wavelength-dependent deflection of the measurement light beams (81, 86), and the measurement beam (86) passes through a wavelength dependent path length (91) in the waveguide (50), and wherein the data processing device (90) is configured to determine an optical path length contribution (93) and / or a time-of-flight contribution (94) of the measurement beam (80) detected by the light sensor (30) during measurement of the time-of-flight (92) taking into account the wavelength dependent path length (91) of the measurement beam (86) within the waveguide (50).

Description

[0001] The present disclosure relates to a device for measuring the flight time of a measuring beam, the device comprising a measuring light source for emitting the measuring beam, a light sensor for detecting the measuring beam, a waveguide, and a data processing device, wherein the waveguide is designed so that the measuring beam emitted by the measuring light source to an object located in an object region of the device and the measuring beam reflected from the object to the light sensor are at least partially guided through the waveguide, the waveguide comprising a measuring diffraction structure for wavelength-dependent deflection of the measuring beam, and the measuring beam travels a wavelength-dependent path length in the waveguide. The present disclosure also relates to a user terminal, a detection and illumination device, a method for measuring the flight time of a measuring beam, a computer program and / or a computer-readable medium, and a data processing device.

[0002] Waveguides are known from the prior art. For example, WO 2020 / 157306 A1 discloses a functionalized waveguide for a detector system, wherein the waveguide comprises a transparent waveguide having a front side and a rear side, wherein the waveguide comprises a partially transparent input coupling region and an output coupling region spaced apart from the input coupling region in a first direction, wherein the input coupling region comprises a diffraction structure which deflects only a portion of the radiation coming from the object to be detected and incident on the front side, such that the deflected portion propagates as input coupled radiation in the waveguide by means of reflection as far as the output coupling region and is incident on the output coupling region, wherein the output coupling region deflects at least a portion of the input coupled radiation incident thereon, such that the deflected portion exits the waveguide via the front side or the rear side in order to be incident on the detector system, wherein the dimension of the input coupling region in a second direction transverse to the first direction is larger than the dimension of the output coupling region in the second direction.

[0003] Devices for measuring the flight time of a measuring light beam are known from the prior art.

[0004] The flight time of the measuring beam and therefore the measurement result of the flight time and / or the measurement of the distance between the object and the device may be influenced by a wavelength-dependent deflection of the measuring beam and, associated therewith, a wavelength-dependent optical path length of the measuring beam, since the measuring beam is coupled into and out of the waveguide differently due to different wavelengths and may therefore travel different optical path lengths.

[0005] The problem solved is to enhance the prior art and enable improved measurement of the time of flight of a measuring beam.The configuration of the present disclosure enables solving the problem of obtaining a wavelength-dependent improvement in the measurement of the distance between an object and a device.

[0006] This problem is solved by the subject-matter of the independent claims. The dependent claims, the following description and the figures disclose optional developments of the disclosure.

[0007] According to one aspect of the present disclosure, a device for measuring the flight time of a measuring beam is provided. The device comprises a measuring light source for emitting the measuring beam, a light sensor for detecting the measuring beam, a waveguide, and a data processing device, wherein the waveguide is designed so that the measuring beam emitted by the measuring light source to an object located in an object region of the device and the measuring beam reflected from the object to the light sensor are at least partially guided through the waveguide, the waveguide comprises a measuring diffraction structure for wavelength-dependent deflection of the measuring beam, and the measuring beam travels a wavelength-dependent path length in the waveguide, wherein the data processing device is configured to determine the optical path length contribution and / or flight time contribution of the measuring beam detected by the light sensor during the measurement of the flight time, taking into account the wavelength-dependent path length of the measuring beam in the waveguide.

[0008] According to one aspect of the present disclosure, a user terminal is provided, which includes the above-mentioned device for measuring the flight time of a measurement light beam.

[0009] According to one aspect of the present disclosure, a detection and illumination device is provided, which includes the above-mentioned device for measuring the flight time of a measurement light beam.

[0010] According to an aspect of the disclosure, a method for measuring the flight time of a measuring beam is provided. In this case, the method comprises: guiding the measuring beam at least partially through a waveguide to an object located in an object region and guiding the measuring beam reflected from the object to a light sensor, the waveguide having a measuring diffraction structure for wavelength-dependent deflection of the measuring beam, the measuring beam traversing a wavelength-dependent path length in the waveguide; and determining an optical path length contribution and / or a flight time contribution of the measuring beam detected by the light sensor taking into account the wavelength-dependent path length of the measuring beam in the waveguide.

[0011] According to one aspect of the present disclosure, a computer program and / or a computer-readable medium is provided, comprising commands, which, when executed by a computer, cause the computer to perform the above method and / or the steps of the method.

[0012] According to one aspect of the present disclosure, a data processing device is provided. In this context, the data processing device is configured to perform the above-mentioned method for measuring the flight time of a measurement beam.

[0013] The device for measuring the flight time of a measuring beam according to one aspect of the present disclosure may be configured to determine the flight time of the measuring beam. In this case, the flight time may be the difference between the first time when the measuring beam is emitted by the light source and the second time when the measuring beam reflected from the object is detected by the light sensor. The path traversed by the measuring beam can be derived from the flight time, and the path allows the distance between the device and the object to be inferred. In some aspects, in view of possible application areas, the device for measuring the flight time of the measuring beam may be similar to the application area of ​​the laser radar sensor, wherein the difference between the device and the laser radar sensor is at least that the device according to the present disclosure does not necessarily require the laser beam to move or scan within the angle range to be observed. Instead, the device according to the present disclosure may allow the emitted measuring beam to capture the entire measurement area to be captured without the need for the measuring beam to move or scan. In addition, the device according to the present disclosure may be particularly different from the laser radar sensor in that the possible range of the measurement area is different from the range of the laser radar sensor. Therefore, the measurement area of ​​the device according to the present disclosure may optionally have a range of about 3 m.

[0014] In this context, the device is optionally configured such that the measuring beam is at least partially guided through the waveguide along an optical path between an object located in the object area and the light sensor. In the process, the measuring beam can enter the waveguide, i.e. input coupled into the waveguide, can pass through an optical path within the waveguide and can be emitted from the waveguide, i.e. output coupled from the waveguide. In this case, the object area can be defined as a capture area or field of view of the device, within which an object can be arranged to measure the time of flight. Because the waveguide includes a measuring diffraction structure configured to deflect the measuring beam in a wavelength-dependent manner, the measuring beam can pass through a wavelength-dependent path length within the waveguide. The wavelength-dependent deflection of the measuring beam can mean that the measuring beam passes through different paths within the waveguide depending on the wavelength, because the measuring beam can be input coupled into the waveguide differently depending on the wavelength, i.e. in particular deflected by different angles.

[0015] In order to be able to determine the path length of the measuring beam as accurately as possible, the data processing device may determine an optical path length contribution of the measuring beam. In this case, the optical path length contribution optionally specifies a wavelength-dependent optical path length of the measuring beam in the waveguide for a specific wavelength of the measuring beam, which is due to the propagation of the measuring beam through the waveguide at this wavelength. It has been recognized that measuring beams at mutually different wavelengths may pass through different optical path lengths in the waveguide. The optical path that the measuring beam passes through in the waveguide may be different from the wavelength-independent optical path in the absence of the waveguide. Thus, due to the wavelength-dependent deflection, a first part of the measuring beam at a first wavelength and / or a first measuring beam may pass through a first optical path in the waveguide, while a second part of the measuring beam at a second wavelength different from the first wavelength and / or a second measuring beam may pass through a second optical path. Thus, the optical path length contribution may depend on the wavelength. In the case where the propagation speed of the measuring beam in the waveguide is known, a flight time contribution may be defined similarly. In this case, the flight time contribution may specify a wavelength-dependent flight time of the measuring beam in the waveguide for a specific wavelength of the measuring beam. In other words, due to the wavelength-dependent deflection, a first portion of the measuring beam at a first wavelength and / or the first measuring beam may pass through a first optical path within the waveguide within a first flight time, while a second portion of the measuring beam at a second wavelength different from the first wavelength and / or the second measuring beam may pass through a second optical path within a second flight time. Thus, the flight time contribution may depend on the wavelength.

[0016] The present disclosure provides the advantage that, by determining the path length contribution and / or the flight time contribution, it allows the use of a polychromatic measuring beam and / or a measuring beam at a plurality of wavelengths to accurately determine the distance between an object and a device, while allowing to avoid differences in the measurement results of the flight time due to different wavelengths of the measuring beams due to wavelength-dependent deflections of the measuring beams in the waveguide. Furthermore, the polychromatic measuring beam can be used in a targeted manner, so that the measuring beams can be coupled into the waveguide and / or coupled out of the waveguide, for example, at different angles, in order to increase the capture area of ​​the device for measuring the flight time. Furthermore, due to the wavelength-dependent deflection in the waveguide, a waveguide can be provided that can be at least partially transparent to the human eye, while the measuring beam can be deflected. Thus, the measuring beam can be deflected in such a way that the components for measuring the optical path length, i.e. in particular the measuring light source and the light sensor, can be arranged at a position that is not visible to the user.

[0017] The measuring diffraction structure can be configured to cause a wavelength-dependent deflection of the measuring light beam in the near infrared spectral range, i.e., the NIR range. In this case, if the measuring light beam satisfies the Bragg condition due to its wavelength and / or its angle of incidence relative to the measuring diffraction structure, the wavelength-dependent deflection is implemented due to the diffraction at the measuring diffraction structure. Outside this spectral range, the measuring light beam does not satisfy the Bragg condition. Therefore, outside this spectral range, there is no such deflection of the measuring diffraction structure. Therefore, the measuring diffraction structure can be transparent outside this spectral range and transmit the light outside this spectral range to a large extent without diffraction and / or deflection. In this spectral range, the measuring light beam is invisible to the human eye, thereby improving the user-friendliness of the device, because it can be managed without the need for visible "illumination" of the object by the measuring light beam. Further, in one embodiment of the present disclosure, the device is capable of using visible light to reconstruct the display and / or image the object, while avoiding crosstalk (i.e., mutual interference) between the visible light and the measuring light beam. In particular, the measuring diffraction structure can be configured to deflect the measuring beam in a wavelength-dependent manner in a spectral range of 700 nm to 940 nm and / or to 1100 nm. Thus, cost-effective light sensors can be used. Alternatively, the measuring diffraction structure can also be configured for wavelength-dependent deflection in different spectral ranges, wherein, for this purpose, different light sources, different light sensors and / or waveguides made of different materials need to be provided.

[0018] The light sensor may comprise a plurality of pixels or picture elements, and the data processing device may be configured to retrieve and / or calculate the optical path length contribution and / or the flight time contribution of the respective detected portion of the measuring beam for a plurality of these picture elements. The light sensor comprises a plurality of picture elements or pixels, wherein each picture element is configured to detect the measuring beam and / or a portion of the measuring beam. In this case, the light sensor comprises a plurality of picture elements in order to improve the capture area of ​​the device for measuring the flight time of the measuring beam. In this case, it has been recognized that as a result of the wavelength-dependent deflection of the measuring beam, spectrally different components of the measuring beam (i.e., a plurality of portions of the measuring beam and / or the measuring beam at different wavelengths) are output differently from the waveguide in the direction of the light sensor. In this case, there is a correlation between the wavelength of the measuring beam and one of the picture elements, since the portion of the measuring beam at a specific wavelength is detected by a specific picture element. Therefore, for a given picture element, the wavelength of the measuring beam is known, from which the optical path length of the measuring beam can be inferred. Therefore, for different picture elements, there are respective path length contributions caused by the different wavelengths of the portions of the measuring beam incident on the picture element.

[0019] The optical path length contribution and / or the time-of-flight contribution can correspond to the vertical pixel position and the horizontal pixel position. In this context, the light sensor includes a plurality of picture elements, and each of the picture elements can be assigned a vertical pixel position and / or a horizontal pixel position. For example, the picture elements are arranged in a matrix. The wavelength of the measurement beam can be inferred based on the position of the pixels. Thus, the optical path length contribution can be determined based on the pixel position. The capture region or the field of view can be resolved based on the pixels in the matrix, and the optical path length can be assigned to the corresponding pixels in the matrix.

[0020] The measurement diffraction structure can be configured to input-couple a measurement beam reflected from an object and incident on the surface of the waveguide at a first angle of incidence of + / - 20° into the waveguide and / or to input-couple a measurement beam reflected from an object and incident on the surface of the waveguide at a second angle of incidence of + / - 20° defined perpendicular to the first angle of incidence into the waveguide. In this case, the first angle of incidence can define the capture region of the device in the vertical direction. The second angle of incidence can define the capture region of the device in the horizontal direction. In this context, it has been recognized that a waveguide, in particular a measurement diffraction structure for deflecting the measurement beam, can be used to particularly effectively set a specified range of angles of incidence in the near-infrared spectral range. By utilizing this spectral range, i.e., by emitting measurement beams having a plurality of wavelengths within this spectral range, more light within a larger range of angles of incidence can be input-coupled into the waveguide compared to known optical units, and this can increase the capture region relative to an optical unit having, for example, lens elements. The waveguide can also be configured to output-couple the measurement beam from the waveguide at a first angle of emergence of + / - 20° arranged in a manner similar to the first angle of incidence and / or at a second angle of emergence of + / - 20° arranged in a manner similar to the second angle of incidence.

[0021] The data processing device can be configured to capture distance data related to an object via an input device and to calibrate the determination of the optical path length and / or the time-of-flight based on the distance data. In this process, it has been recognized that the device can be calibrated so that, for example, even when the type of waveguide and / or measurement diffraction structure is unknown, the time-of-flight measurement can still be performed. In this context, the optical path length through the waveguide can be calibrated by means of measuring the time-of-flight of the measurement optical signal at a known wavelength and a known object distance.

[0022] The device may include an image light source for emitting a visible image beam, and the waveguide may include an image diffraction structure for wavelength-dependent deflection of the image beam. The image light source is optionally configured to couple the image beam input into the waveguide so that the image beam is deflected by the image diffraction structure. Optionally, the image beam may be coupled into the waveguide by the optical structure input. The deflected image beam is coupled out of the waveguide output so as to reconstruct a virtual image or a real image, i.e. a visually perceptible representation, in the visible light range outside the waveguide.

[0023] The apparatus may be configured to control the image light source based on the optical path length and / or flight time of the measurement light beam. Thus, the image light source may emit image information that matches the object. For example, the object may be a body part of a user, whose position relative to the waveguide is captured, and the image may be reconstructed or displayed in the surroundings of the waveguide in a manner that matches the position.

[0024] The device can be configured to image a user interface spaced apart from the waveguide in a second direction, and to capture user input through the user interface based on the flight time of the measurement beam. In this case, it has been recognized that the user interface can be imaged by an image light source and an image diffraction structure. In this context, the user interface is reconstructed in such a way that the user interface appears to float in the surroundings of the waveguide at a distance from the waveguide. The user can interact with the user interface, for example, by means of the user locating a body part according to the user interface. The position of the user's body part can be captured based on the flight time of the measurement beam, and can be interpreted as the user's input.

[0025] The device can be configured to image an imaging object spaced apart from the waveguide in a second direction relative to the object. In this context, it has been recognized that, in this example, the device can provide advantageous applications in the field of augmented reality (AR). For example, the object can be a surrounding scenery or surrounding environment of the waveguide, into which the imaging object is imaged. For example, in an application where a user looks through the waveguide, the imaging object can be imaged as a virtual object. For example, in an application where a user looks through the waveguide at an image light source, the imaging object can be imaged as a real object. In order to be able to advantageously image the imaging object, the device captures the geometry of the object by measuring the flight time of the measuring beam. Therefore, the imaging object can be imaged at a depth corresponding to the object.

[0026] The device may be configured to control the image light source dynamically and / or based on captured movements of the object. In this way, in particular dynamic (ie time-dependent) applications may be provided in the field of augmented reality.

[0027] The device may comprise a reflector and / or a prism for deflecting a measuring beam emerging from a waveguide and / or for deflecting a measuring beam reflected from an object. Deflecting a measuring beam emerging from a waveguide and / or a measuring beam reflected from an object may be particularly advantageous for application in a user terminal, since the possible deflection allows the device or its components to be arranged in many different ways. Thus, in addition to the waveguide, components of the device may advantageously be arranged in a housing of the user terminal in a manner that is not visible to a user of the user terminal.

[0028] According to one aspect of the present disclosure, a user terminal is provided. The user terminal includes the above-mentioned device for measuring the flight time of the measurement beam. In this case, the device of the user terminal may have one or more of the above-mentioned optional technical features to obtain the technical effects related thereto.

[0029] According to one aspect of the present disclosure, a detection and illumination device is provided. The detection and illumination device includes the above-mentioned device for measuring the flight time of the measurement beam. In this case, the device of the detection and illumination device may have one or more of the above-mentioned optional technical features to obtain the technical effects related thereto.

[0030] According to an aspect of the disclosure, a method for measuring the flight time of a measuring beam is provided. In this case, the method comprises: guiding the measuring beam at least partially through a waveguide to an object and guiding the measuring beam reflected from the object to a light sensor, the waveguide having a measurement diffraction structure for wavelength-dependent deflection of the measuring beam, the measuring beam traversing a wavelength-dependent path length in the waveguide; and determining an optical path length contribution and / or a flight time contribution of the measuring beam detected by the light sensor taking into account the wavelength-dependent path length of the measuring beam in the waveguide.

[0031] In particular, the method can be performed using the above-described device for measuring the flight time of a measuring beam. Therefore, the description about the device applies analogously to the method and vice versa.

[0032] The optical path length contribution and / or the time of flight contribution may be determined based on the wavelength-dependent number of total internal reflections within the waveguide and / or the wavelength-dependent deflection angle within the waveguide. In this context, it has been recognized that the number of total internal reflections and the deflection angle have an influence on the optical path of the measurement beam within the waveguide. Taking into account the number of total internal reflections and / or the deflection angle within the waveguide allows the optical path length contribution and / or the time of flight contribution to be calculated given a known geometry of the waveguide.

[0033] Optionally, the measuring light source and / or the image light source may include one or more of the following types of light sources: a light emitting diode (LED), a laser diode, a semiconductor laser, and a solid-state laser.

[0034] In this case, the emission spectrum of the measuring light source can optionally be located in the infrared spectral range. This can provide the following advantages: the light emitted by the measuring light source is invisible to the human eye, and accordingly the light emitted by the measuring light source is not perceived by the person as being disturbing. Optionally, the emission spectrum can be located in a spectral range in which the waveguide is optically transparent. Optionally, the emission spectrum of the measuring light source can be located in a range from about 780 nm to about 2 μm. Optionally, the emission spectrum of the measuring light source can be located in a range from about 780 nm to about 1100 nm. This can provide the following advantages: silicon-based detectors (such as CMOS sensors and / or CCD arrays) can be used to detect the measuring light. In particular, for wavelengths greater than 1100 nm, it can be advantageous to select a detector suitable for this purpose, such as an AlGaAs-based detector and / or an InGaAs-based detector. The choice of the detector can be matched to the measuring light source and the emission spectrum of the measuring light source. In this context, the specified spectral range does not mean that the emission spectrum must cover the entire specified spectral range in each case. Instead, the emission spectrum can cover a smaller spectral range within a given spectral range. Optionally, the full width at half maximum (FWHM) of the emission spectrum of the measurement light source may be 100 nm or less, optionally 50 nm or less, optionally 10 nm or less.

[0035] Alternatively or additionally, the measuring light source can be designed to provide an emission spectrum at 1.55 µm and / or in a spectral range around 1.55 µm. This spectral range, which is widely used in telecommunications, can offer the following advantages: the absorption by water (and also by moisture in the air) can be particularly low, and accordingly the losses associated therewith can be kept low, whereby the range can be increased and / or the transmission power to be provided can be reduced.

[0036] Optionally, the one or more diffractive structures or holographic structures used may be matched to the emission spectrum of the measurement light source and / or the emission spectrum of the image light source. Optionally, the one or more diffractive structures or holographic structures used may be designed to have a particularly high efficiency in the spectral range of the measurement light. Optionally, the one or more diffractive structures or holographic structures used may be designed in an expected angular range for coupling light input into the corresponding diffractive structure or holographic structure and / or coupling light out of the corresponding diffractive structure or holographic structure.

[0037] The emission spectrum of the image light source may optionally lie in the visible light range, ie, for example, in the spectral range between 400 nm and 780 nm. This may provide the advantage that the image information represented by means of the light emitted by the image light source may be visible to the human eye.

[0038] Using a light emitting diode as a measuring light source or as part of a measuring light source can provide the following advantages: the measuring light is emitted in a predetermined emission angle range greater than zero, instead of a collimated laser beam with an emission angle of almost zero. Therefore, a larger emission angle range can be achieved, and this can result in a larger field of view (FOV), i.e. a larger measurement area. Optionally, the measurement area or FOV can correspond to an angular range of 15° or more and optionally 50°.

[0039] According to one aspect of the present disclosure, a computer program and / or a computer-readable medium is provided, comprising commands, which, when executed by a computer, cause the computer to perform the above method and / or the steps of the method.

[0040] According to one aspect of the present disclosure, a data processing device is provided. In this context, the data processing device is configured to perform the above-mentioned method for measuring the flight time of a measurement beam.

[0041] The following describes exemplary embodiments of the present disclosure. In the accompanying drawings:

[0042] Figure 1 shows a schematic illustration of an apparatus for measuring time of flight according to an aspect of the present disclosure;

[0043] Figure 2 shows a schematic illustration of an apparatus for measuring time of flight according to an aspect of the present disclosure;

[0044] Figure 3 shows a schematic illustration of a waveguide of an apparatus for time of flight measurement according to an aspect of the present disclosure in order to illustrate the wavelength dependent optical path length contribution;

[0045] Figure 4 shows a schematic illustration of a waveguide of an apparatus for time of flight measurement according to an aspect of the present disclosure in order to illustrate the wavelength dependent optical path length contribution;

[0046] Figure 5 shows a schematic illustration of a waveguide of an apparatus for time of flight measurement according to an aspect of the present disclosure in order to illustrate the wavelength dependent optical path length contribution;

[0047] Figure 6A schematic illustration of a deflection curve of a measured diffraction structure of a waveguide of an apparatus for measuring time of flight according to an aspect of the present disclosure is shown;

[0048] Figure 7 shows a schematic illustration of a waveguide of an apparatus for time of flight measurement according to an aspect of the present disclosure in order to illustrate the wavelength dependent optical path length contribution;

[0049] Figure 8 A schematic illustration showing the dependence of wavelength on a first angle of incidence and a second angle of incidence for a measurement diffraction structure of a waveguide of an apparatus for measuring time of flight according to an aspect of the present disclosure;

[0050] Fig. 9 A schematic illustration showing the dependence of an optical path length contribution on a first incident angle and a second incident angle of a waveguide of an apparatus for measuring time of flight according to an aspect of the present disclosure;

[0051] Fig.10 shows a schematic illustration of the deflection efficiency of a light beam deflected by measuring a diffractive structure;

[0052] Fig.11 shows a schematic illustration of an apparatus for measuring time of flight according to an aspect of the present disclosure;

[0053] Fig.12 A schematic illustration of an apparatus for measuring time of flight according to an aspect of the present disclosure is shown; and

[0054] Fig.13 A flow chart of a method for measuring time of flight according to an aspect of the present disclosure is shown.

[0055] Figure 1 A schematic illustration of an apparatus 10 for measuring a time of flight 92 is shown in accordance with an optional aspect of the present disclosure.

[0056] The device 10 is configured to measure a flight time 92 of a measuring beam 80. To this end, the device 10 comprises a measuring light source 20 for emitting the measuring beam 80, a light sensor 30 for detecting the measuring beam 80, a waveguide 50, and a data processing device 90.

[0057] The measuring light source 20 is configured to emit a measuring light beam 80. The measuring light beam 80 emitted by the measuring light source 20 in the process comprises light in the near infrared spectral range, i.e., the NIR range S, whose wavelength L is in the range of 700 nm to 940 nm. For example, the measuring light source 20 comprises a light emitting diode (LED) and emits the measuring light beam 80 as polychromatic light of multiple wavelengths in the NIR range S.

[0058] The measuring light source 20 is connected to the data processing device 90 in a communication-permitting manner so as to be controllable by the data processing device 90. Thus, the data processing device 90 is able to coordinate, in particular temporally coordinate, the transmission or emission of the measuring light beam 80 and / or is able to capture the first time that the measuring light beam 80 is emitted by the measuring light source 20.

[0059] The device 10 comprises an imaging device 21 which is configured to steer the measuring beam 80 in the direction of the waveguide 50. For example, the imaging device 21 comprises a prism, a mirror and / or a lens element.

[0060] The measuring beam 80 is input coupled into the waveguide 50 in the transmission input coupling region 55 of the waveguide 50 and propagates through the waveguide 50 as a measuring beam 81 input coupled into the waveguide 50. In the process, the input coupled measuring beam 81 is reflected within the waveguide 50. In particular, there is a total internal reflection 57 of the input coupled measuring beam 81.

[0061] In the following exemplary embodiment, the waveguide 50 has the following geometry 56: height 266 mm (dimension in the first direction R1), thickness 1.2 mm (dimension in the second direction R2 perpendicular to the first direction R1), width 150 mm (dimension in the third direction R3 perpendicular to the first direction R1 and perpendicular to the second direction R2, the third direction being schematically illustrated by a cross). The waveguide 50 can be made of, for example, glass, in particular borosilicate glass, and can have a refractive index N1 in the range of 1.45 to 1.5, which depends only slightly on the wavelength L in the spectral range S.

[0062] In this case, the measuring light beam 81 input coupled into the waveguide 50 specifically propagates through the waveguide 50 in the first direction R1 and is incident on the measuring diffraction structure 51 in the transmission output coupling region 60. The measuring diffraction structure 51 in the transmission output coupling region 60 is configured to deflect the input coupled measuring light beam 81 at a deflection angle 58 determined by the wavelength L in a manner that depends on the wavelength L of the measuring light beam 81. Therefore, further total internal reflection 57 of the measuring light beam 81 can be avoided at the interface between the waveguide 50 and the surrounding environment 59 of the waveguide 50, and the measuring light beam 81 can be output coupled from the waveguide 50 and propagate in the surrounding environment 59 of the waveguide 50 as a measuring light beam 82 output coupled from the waveguide 50.

[0063] Object 15 (in Figure 1The object 15 is schematically illustrated as a circle in the figure and is arranged in the surroundings 59 of the waveguide 50. The geometry of the object 15 is such that the object 15 has sections at different distances from the waveguide 50. The object 15 is arranged in an object region 16. In this case, the object region may be arranged in a capture region (field of view) of the device 10. The object region 16 is a section of the surroundings of the waveguide 50 that is arranged outside the waveguide 50. The device 10 is configured to emit a measurement beam 82 into the object region 16. Thus, the out-coupled measurement beam 82 may reach the object 15 and may be reflected from the object 15 for measuring a flight time 92 from the object 15 in a direction toward the waveguide 50. The out-coupled measurement beam 82 is reflected from the object and propagates in the direction of the waveguide 50 as a measurement beam 85 reflected from the object 15. Here, the propagation of the out-coupled measurement beam 82 and the reflected measurement beam 85 is very different from each other to help better illustration.

[0064] In the sensor input coupling region 65 of the waveguide 50, a measuring beam 85 in the form of a measuring beam 86 input coupled into the sensor input coupling region 65 and reflected from the object 15 is incident on the measuring diffraction structure 52 in the sensor input coupling region 65. The measuring diffraction structure 52 in the sensor input coupling region 65 is configured to deflect the input coupled measuring beam 86 in a manner that depends on the wavelength L of the measuring beam 86. This may ensure that the measuring beam 86 is deflected in the waveguide 50 in such a manner that the measuring beam 86 propagates through the waveguide 50 in a first direction R1 and in the process propagates via multiple total internal reflections 57 to the sensor output coupling region 70.

[0065] The measuring diffraction structures 51, 52 are configured to perform a wavelength-dependent deflection of a measuring beam 81, 86 of a wavelength L in the NIR range S. The wavelength L of the measuring beam 80, 81, 82, 85, 86 in this case denotes a wavelength L determinable in a vacuum or in air and / or a wavelength L of the measuring beam 80 as emitted by the measuring light source 20. Within the waveguide 50, the measuring beam 81, 86 has a wavelength L which is influenced by the refractive index N1 of the waveguide 50.

[0066] In the sensor outcoupling region 70, the measuring beam 86 is coupled out of the waveguide 50 in such a way that the measuring beam 86 is deflected in the direction of the light sensor 30. For this purpose, the device 10 comprises an imaging device 31, which is arranged between the waveguide 50 and the light sensor 30. For example, the imaging device 31 comprises a prism, a mirror and / or a lens element.

[0067] In this case, the measuring light beams 80, 81, 85 propagating from the measuring light source 20 to the object 15 are Figure 11 and 1 , while the measuring light beams 80, 85, 86 reflected from the object 15 and propagating to the light sensor 30 are depicted by dashed lines. Overall, the measuring light beams 80, 81, 82, 85, 86 travel an optical path length 91 during a flight time 92. The optical path length 91 and the flight time 92 depend on the geometry 56 of the waveguide 50, the refractive index N1 of the waveguide 50 and the wavelength-dependent deflection of the measuring light beams 80, 81, 82, 85, 86 by the measuring diffractive structures 51, 52 included in the waveguide 50. The deflection of the measuring diffractive structures 51, 52 at a different deflection angle 58 for each wavelength L makes the optical path through the waveguide 50 different, and therefore makes the number of total internal reflections 57 in the waveguide 50 potentially different for each wavelength L. Thus, for the measuring beam 80 detected by the optical sensor 30, an optical wavelength contribution 93 and / or a flight time contribution 94 is generated within the waveguide 50 for the measuring beam 80, 81, 82, 85, 86. In this case, the path length contribution 93 is the contribution caused by the waveguide 50 to the total optical path length 91 traversed by the measuring beam 80, 81, 82, 85, 86. The flight time contribution 94 is the contribution caused by the waveguide 50 to the total flight time 92 of the measuring beam 80, 81, 82, 85, 86 required for said measuring beam 80, 81, 82, 85, 86 and measured by the device 10.

[0068] Therefore, the waveguide 50 is arranged so that the measuring light beam 80 emitted by the measuring light source 20 to the object 15 and the measuring light beam 85 reflected from the object 15 to the light sensor 30 are at least partially guided through the waveguide 50, the waveguide 50 includes measurement diffraction structures 51, 52 for causing a wavelength-dependent deflection of the measuring light beams 81, 86, and the reflected measuring light beam 86 passes a wavelength-dependent path length 91 in the waveguide 50.

[0069] The optical sensor 30 is connected to the data processing device 90 in a communication-allowing manner in order to transmit information related to the detection of the measuring beam 80 to the data processing device 90. Thus, the data processing device 90 is able to capture the second time when the measuring beam 80 is detected by the optical sensor 30.

[0070] Thus, the flight time 92 of the measuring beam 80 may be determined by the data processing device 60 as the difference between a first time when the measuring beam 80 is emitted by the measuring light source 20 and a second time when the measuring beam 80 is detected by the light sensor 30 .

[0071] The data processing device 90 is configured to determine an optical path length contribution 93 and / or a flight time contribution 94 of the measurement beam 80 detected by the light sensor 30 taking into account the wavelength-dependent path length 91 of the emitted and reflected measurement beam 86 in the waveguide 50 during the measurement of the flight time 92. The distance between the object 15 and the device 10 can be accurately determined based on the path length contribution 93 and / or the flight time contribution 94.

[0072] The light sensor 30 comprises a pixel matrix having a plurality of picture elements 32. Figure 1 Schematically depicts a row of picture elements 32, i.e. a one-dimensional arrangement. The picture elements 32 of the light sensor 30 are also arranged perpendicular to the Figure 1 The image plane of the image elements 30 is thus formed in a two-dimensional arrangement of the picture elements 32. The picture elements 32 are arranged at specific positions relative to the waveguide 50. The positions of the picture elements 32 are defined in each case by a vertical pixel position vp, which is schematically indicated by an arrow, and a horizontal pixel position hp, which is schematically indicated by a cross and reaches into the image plane.

[0073] The picture elements 32 are each configured to detect a measuring beam 80. Figures 3 to 9 As described, the wavelength L of the measuring beam 80 can be assigned to each of the picture elements 32. In other words, different picture elements 32 detect different parts of the measuring beam 80 at different wavelengths L, which different parts pass through different optical paths 91 in the waveguide 50 and have different flight times 92. Therefore, the picture elements 32 or pixel positions vp, hp can each be assigned an optical path length contribution 93 and / or a flight time contribution 94. In this case, it is also possible that the picture element 32 or its vertical pixel position vp can be assigned an optical path length contribution 93 and / or a flight time contribution 94, while each horizontal angle of the capture area is propagated at a different horizontal angle due to the refraction of the waveguide 50. In this case, the optical path length is different for different horizontal angles and therefore different horizontal pixel positions hp, whereby each picture element 32 can be assigned a horizontal angle of incidence and therefore a horizontal angle of propagation in the waveguide 50.

[0074] The data processing device 90 is configured to retrieve an optical path length contribution 93 and / or a flight time contribution 94 for the respective detected portion of the measuring beam 80 for the picture element 32. To this end, the data processing device 90 comprises a memory 95 in which the optical wavelength contribution 93 and / or the flight time contribution 94 for each wavelength L (i.e. for the portion of the measuring beam 80) is stored. The pixel position vp, hp of the detected measuring beam 80 may be captured by the light sensor 30 and transmitted to the data processing device 90. Based on the pixel position vp, hp, the data processing device 90 retrieves the path length contribution 93 and / or the flight time contribution 94 corresponding to the pixel position vp, hp from a memory 96 or a look-up table, such as Fig. 9 Shown by way of example.

[0075] Alternatively or additionally, the data processing device 90 is configured to calculate an optical path length contribution 93 and / or a flight time contribution 94 for the picture element 32 of the corresponding detected portion of the measuring beam 80. To this end, the data processing device 90 comprises a processor 96. In this case, the geometry 56 of the waveguide 50 and the refractive index N1 of the waveguide 50 are known. The optical path length contribution 93 and / or the flight time contribution 94 can be calculated based on the number of total internal reflections 57 within the waveguide 50 and / or the wavelength-dependent deflection angle 58.

[0076] When the optical path length contribution 93 and / or the time of flight contribution 94 are retrieved and / or calculated, the optical path length contribution 93 and / or the time of flight contribution 94 correspond to the vertical pixel position vp and the horizontal pixel position hp.

[0077] The measurement diffraction structure 52 of the sensor input coupling region 60 is configured to couple into the waveguide 50 a measurement beam 86 reflected from the object 15 and incident on the surface 66 of the waveguide 50 at a first angle of incidence A1 of + / - 20° and to couple into the waveguide 50 a measurement beam 86 reflected from the object 15 and incident on the surface 66 of the waveguide 50 at a second angle of incidence A2 of + / - 20°. In this case, the first angle of incidence A1 is defined in a plane formed by the first direction R1 and the second direction R2, between the direction of the measurement beam 86 and a normal vector (not drawn) to the surface 66. In this case, the second angle of incidence A2 is defined in a plane formed by the second direction R2 and the third direction R3, between the direction of the measurement beam 86 and a normal vector (not drawn) to the surface 66.

[0078] The device 10 comprises an input device 97. The input device 97 and the data processing device 90 are connected to each other in a communication-permitting manner, so that distance data 98 ​​relating to the object 15 can be acquired or input via the input device 97. The data processing device 90 is configured to calibrate the determination of the optical path length 91 and / or the flight time 92 based on the distance data 98. In the case where the distance between the object 15 and the device 10 is known, the path length contribution 93 and / or the flight time contribution 94 can be determined relatively, in particular by using a polychromatic measuring beam 80 and / or by a plurality of measuring beams 80 at different wavelengths L. Thus, the distance measurement between the object 15 and the device 10 can be calibrated. In another embodiment (not shown), the device 10 can be connected to such an input device 97.

[0079] In an embodiment not shown here, the device 10 comprises mirrors and / or prisms for deflecting the measuring light beam 82 emerging from the waveguide 50 and / or for deflecting the measuring light beam 85 reflected from the object 15 .

[0080] exist Figure 1 In the embodiment of the device 10 shown, the measurement diffraction structure 51 of the transmission outcoupling region 60 and the measurement diffraction structure 52 of the sensor input coupling region 65 are arranged to overlap in the first direction R1. In embodiments not shown here, the measurement diffraction structure 51 of the transmission outcoupling region 60 and the measurement diffraction structure 52 of the sensor input coupling region 65 may be arranged to partially overlap or not overlap (i.e. not intersect) in the first direction R1.

[0081] The measurement diffraction structures 51, 52 contained by the waveguide 50 are, for example, reflective volume holograms, transmissive volume holograms, surface holograms and / or relief gratings, as described in WO 2020 / 157306 A1. In this case, the arrangement of the measurement diffraction structures 51, 52 may depend on the type of measurement diffraction structures 51, 52. For example, the reflective measurement diffraction structures 51, 52 may be arranged in a section of the waveguide 50 facing away from the object 15, and / or the transmissive measurement diffraction structures 51, 52 may be arranged in a section of the waveguide 50 facing the object 15.

[0082] The measurement diffraction structures 51, 52 or the sensor input coupling region 65 and / or the transmission output coupling region 60 of the transmission output coupling region 60 and / or the sensor input coupling region 65 can be designed so that no optical imaging function is generated except for the deflection. However, it is also possible that the measurement diffraction structures 51, 52 or the sensor input coupling region 65 and / or the transmission output coupling region 60 provide an optical imaging function in addition to the deflection, thus generating optical imaging. Therefore, the optical imaging function can realize, for example, the function of a converging lens or a diverging lens, a concave mirror or a convex mirror, wherein the curved surface can be a (centered or eccentric) spherical curved or aspherical curved surface. Therefore, the characteristics of the waveguide 50 can be adapted so that, for example, the image plane or the focal plane can be arranged in the object region 16.

[0083] In another embodiment (not shown), the waveguide 50 comprises only one of the measuring diffractive structures 51, 52 in order to make the construction of the device 10 more cost-effective and / or simpler. A beam splitter may be provided in the process.

[0084] Figure 2 A schematic illustration of an apparatus 10 for measuring a time of flight 92 according to an optional aspect of the present disclosure is shown. Figure 1 The device 10 described in Figure 2 In doing so, the device 10 is described according to Figure 1 and Figure 2 The differences between the devices 10.

[0085] according to Figure 2 The waveguide 50 of the device 10 comprises a measurement diffraction structure 53 in a transmission input coupling region 55. The waveguide 50 further comprises a measurement diffraction structure 54 in a sensor output coupling region 70. In another embodiment not shown here, the device 10 may comprise one of the two measurement diffraction structures 53, 54, i.e. the measurement diffraction structure 53 of the transmission input coupling region 55 or the measurement diffraction structure 54 of the sensor output coupling region 70.

[0086] In a manner similar to the measurement diffraction structure 51 of the transmission output coupling region 60 or the measurement diffraction structure 52 of the sensor input coupling region 65, the measurement diffraction structure 53 of the transmission input coupling region 55 and the sensor output coupling region 70 are configured to cause a wavelength-dependent deflection of the measurement light beam 81, 86 of the wavelength L in the NIR range S. In this case, the measurement diffraction structure 53 of the transmission input coupling region 55 and the measurement diffraction structure 51 of the transmission output coupling region 70 can be configured to produce similar wavelength-dependent deflections. Similarly, the measurement diffraction structure 54 of the sensor output coupling region 70 and the measurement diffraction structure 52 of the sensor input coupling region 65 can be configured to produce similar wavelength-dependent deflections. Therefore, the measurement light beams 80, 85 to be input coupled and the measurement light beams 80, 82 to be output coupled can undergo mutually similar deflections by the measurement diffraction structures 51, 52, 53, 54. In this case, Figure 2 The deflection by the measuring diffraction structures 51, 52, 53, 54 is shown purely schematically. In particular, the deflection angle 58 is not illustrated to scale. In particular, the deflection angle of the measuring diffraction structure 53 of the transmission incoupling region 55 is not drawn to scale and can be larger than that drawn in order to obtain a total internal reflection of the incoupled measuring beam 81.

[0087] exist Figure 2 In the embodiment of the device 10 shown, the measurement diffraction structure 53 of the transmission input coupling region 55 and the measurement diffraction structure 54 of the sensor output coupling region 70 are arranged to overlap in the first direction R1. In embodiments not shown here, the measurement diffraction structure 53 of the transmission input coupling region 55 and the measurement diffraction structure 54 of the sensor output coupling region 70 may be arranged to partially overlap or not overlap (i.e. not intersect) in the first direction R1.

[0088] The measurement diffraction structures 53, 54 or the transmission input coupling region 55 and / or the sensor output coupling region 70 of the transmission input coupling region 55 and / or the sensor output coupling region 70 can be designed so that no optical imaging function is generated except for the deflection. However, it is also possible that the measurement diffraction structures 53, 54 or the transmission input coupling region 55 and / or the sensor output coupling region 70 provide an optical imaging function in addition to the deflection, thus generating optical imaging. Therefore, the optical imaging function can realize the function of, for example, a converging lens or a diverging lens, a concave mirror or a convex mirror, wherein the curved surface can be a (centered or eccentric) spherical curved or aspherical curved surface.

[0089] Figure 3 A schematic illustration of a waveguide 50 of an apparatus 10 for measuring a time of flight 92 is shown in order to illustrate a wavelength-dependent optical path length contribution 93 in accordance with an optional aspect of the present disclosure. Figure 3 Shows Figure 2 A simplified representation of the waveguide 50. In this case, Figure 3 The waveguide 50 is shown with a measurement diffractive structure 52 of a sensor input coupling region 65 and a measurement diffractive structure 54 of a sensor output coupling region 70 . Figure 3 The measurement diffraction structure 53 of the transmission incoupling region 55 and the measurement diffraction structure 51 of the transmission outcoupling region 60 are not depicted in FIG. Figure 3 The schematically illustrated section of measuring beams 80 , 85 , 86 shows measuring beam 85 reflected from object 15 (not shown), measuring beam 86 input coupled into waveguide 50 in sensor input coupling region 65 and measuring beam 80 output coupled from waveguide 50 in sensor output coupling region 70 .

[0090] Figure 3 The diagram shows three different parts of the measuring beams 80, 85, 86, which in each case have mutually different wavelengths L in the NIR range S. In this case, the parts of the measuring beams 80, 85, 86 with mutually different wavelengths L are represented by different types of lines. A part of the measuring beams 80, 85, 86 is depicted using a solid arrow, a dash-dotted arrow and a dashed arrow, respectively. Figure 1 As described, the measuring light beam 85 is incident on the surface 66 of the waveguide 50 at a first angle of incidence A1 and is coupled into the waveguide 50 as a function of the wavelength L.

[0091] according to Figure 3 When the measuring beam 85 is input coupled into the waveguide 50 in the sensor input coupling region 65, parts of the measuring beam 85 are deflected by the measuring diffraction structure 52 of the sensor input coupling region 65. In this case, the deflection is implemented such that the individual parts of the measuring beams 85, 86 have different deflection angles 58 and travel through different optical paths within the waveguide 50, and accordingly, have different optical path lengths 91 and different flight times 92, i.e., different optical path length contributions 93 and / or flight time contributions 94 are generated.

[0092] The measuring light beam 86 propagates through the waveguide 50 and is incident on the measuring diffraction structure 54 of the sensor outcoupling region 70, where it is deflected according to the respective wavelength L of the respective portion of the measuring light beam 86 and outcoupled from the waveguide 50. In the process, the outcoupled measuring light beam 80 is directed towards the optical sensor 30 ( Figure 3 Due to the deflection of the measuring beams 80, 86 by the measuring diffraction structure 54 of the sensor outcoupling region 70, individual parts of the measuring beam 80 are steered to picture elements 32 (not shown) having mutually different vertical pixel positions vp. Figure 3), such as Figure 3 Thus, depending on the wavelength L, individual parts of the measuring beam 80, 85, 86 are detected by different picture elements 32 of the light sensor 30. Different picture elements 32 of the light sensor 30 can be assigned an optical path of the measuring beam 80, 85, 86 and thus an optical path length 91 and a flight time 92.

[0093] The arrangement of the measuring diffractive structures 51, 52, 53, 54 and optionally an additional deflection functionality of the measuring diffractive structures 51, 52, 53, 54 allow light to be directed to areas not visible to a user of the device 10. Thus, the measuring light source 20 and the light sensor 30 may be arranged in a manner hidden from the user.

[0094] Figure 4 A schematic illustration of a waveguide 50 of an apparatus 10 for measuring a time of flight 92 according to an optional aspect of the present disclosure is shown to illustrate a wavelength-dependent optical path length contribution 93. Here, Figure 4 Shown as Figure 2 and Figure 3 The waveguide 50 of the described device 10. In doing so, Figure 4 Different views of the waveguide 50 are shown. Figure 1 As described, the measuring beam 85 is incident on the surface 66 of the waveguide 50 at a second angle of incidence A2 and is coupled into the waveguide 50 as a function of the wavelength L.

[0095] according to Figure 4 , such as about Figure 3 As described, the measuring light beams 80, 85, 86 are deflected by the measuring diffraction structures 52, 54 as a function of the wavelength L. However, the horizontal component of the deflection preferably has no wavelength dependency, or only a small wavelength dependency, and is substantially determined by the entry angle due to the refraction of the light beams when entering the waveguide 50. Advantageously, this is due to the design of the measuring diffraction structures 52, 54, in particular due to their grating vectors. Thus, each portion of the measuring light beams 80, 85, 86 is coupled out of the waveguide 50 in the sensor outcoupling region 70 by the measuring diffraction structure 54 and, depending on the entry angle, is incident on a picture element 32 which can be assigned to the entry angle and which has a horizontal pixel position hp assigned to the entry angle.

[0096] The measuring diffractive structure 52 of the sensor input coupling region 65 has a height of 16 mm, a width of 150 mm and a thickness of 100 μm. The measuring diffractive structure 54 of the sensor output coupling region 70 has a height of 16 mm, a width of 16 mm and a thickness of 100 μm.

[0097] Figure 5A schematic illustration of a waveguide 50 of an apparatus 10 for measuring a time of flight 92 according to an optional aspect of the present disclosure is shown to illustrate a wavelength-dependent optical path length contribution 93. Here, Figure 5 Shown as Figures 2 to 4 The waveguide 50 of the device 10 is described. In this case, Figure 5 Another perspective of the waveguide 50 is shown, the illustration showing only the measurement beam 86 within the waveguide 50. In this case, the waveform of the measurement beam 86 shows that the measurement beam 86 propagates through the waveguide 50 from the measurement diffraction structure 52 of the sensor input coupling region 65 to the measurement diffraction structure 54 of the sensor output coupling region 70 with multiple total internal reflections 57.

[0098] Figure 6 A schematic illustration of a deflection curve 200 of a measured diffractive structure 51, 52, 53, 54 of a waveguide 50 of an apparatus 10 for measuring a time of flight 92 according to an optional aspect of the present disclosure is shown. In this case, Figure 6 Shows about Figures 1 to 5 The relationship between the deflection angle 58 of the measured diffraction structures 51, 52, 53, 54 and the wavelength L is shown. In this context, it is obvious that the deflection angle 58 during the input coupling decreases monotonically with increasing wavelength L in the spectral range S, wherein the deflection angle 58 is, for example, +20° at a wavelength L of 720 nm and, for example, -20° at a wavelength L of 950 nm.

[0099] Figure 7 A schematic illustration of a waveguide 50 of an apparatus 10 for measuring a time of flight 92 is shown in order to illustrate a wavelength-dependent optical path length contribution 93 in accordance with an optional aspect of the present disclosure. Figure 7 It is a reference Figure 3 and its description. In this case, the input coupling structure and the output coupling structure (i.e. the measurement diffraction structures 52, 54 of the sensor input coupling region 65 and the sensor output coupling region 70) are designed such that the incident angles A1, A2 remain unchanged when being output from the waveguide 50, i.e., the measurement beams 80, 85, 86 undergo a deflection of the same deflection angle 58 during the input coupling and output coupling process, depending on the wavelength L. The two measurement diffraction structures 52, 54 have the same optical function and can be produced in a similar manner to each other. Due to the different incident angles and the dispersion of the waveguide material, different propagation angles and optical path lengths are generated in the waveguide 50.

[0100] according to Figure 7 , such as about Figure 6As described, the measurement beams 80, 85, 86 are deflected by the measurement diffraction structures 52, 54. The measurement beams 80, 85, 86 with a wavelength L of 951 nm are input-coupled at an incident angle A1 of -20°, and according to the reference Figure 1 and Figure 5 the geometry 56 of the waveguide 50 and the measurement diffraction structures 52, 54 in the waveguide 50, have an optical path length contribution 93 of 477.4 mm due to propagation through the waveguide 50. The measurement beams 80, 85, 86 with a wavelength L of 861 nm are input-coupled at an incident angle A1 of 0° and have an optical path length contribution 93 of 411.6 mm. The measurement beams 80, 85, 86 with a wavelength L of 725 nm are input-coupled at an incident angle A1 of +20° and have an optical path length contribution 93 of 365.9 mm.

[0101] Figure 8 FIG. shows a schematic illustration of an optional correlation between the wavelength L and the first incident angle A1 and the second incident angle A2 of the measurement diffraction structures 51, 52, 53, 54 of the waveguide 50 of the device 10 for measuring the time-of-flight 92 according to an aspect of the present disclosure. In this case, Figure 8 represents a generalization related to two incident angles A1, A2 of the deflection curve 200 according to Figure 6 . Figure 8 illustrates those incident angles A1, A2 at which the wavelength L can be input-coupled into the waveguide 50 and / or output-coupled from the waveguide using one of the measurement diffraction structures 51, 52, 53, 54. In this case, the first incident angle A1 is the angle between the normal to the surface 66 of the waveguide 50 and the direction of the measurement beams 80, 81, 86 in or projected onto the plane formed by the first direction R1 and the second direction R2. The second incident angle A2 is the angle between the normal to the surface 66 of the waveguide 50 and the direction of the measurement beams 80, 81, 86 in or projected onto the plane formed by the second direction R2 and the third direction R3 (see Figures 1 to 7 ).

[0102] Fig. 9 FIG. shows a schematic illustration of an optional correlation between the optical path length contribution 93 and the first incident angle A1 and the second incident angle A2 of the waveguide 50 of the device 10 for measuring the time-of-flight 92 according to an aspect of the present disclosure.

[0103] In this process, it is obvious that the optical path length contribution 93 can be inferred from the incident angles A1, A2. Again according to Figure 8 , the wavelength L can also be inferred from the incident angles A1, A2. Therefore, a corresponding path length contribution 93 is generated for each wavelength L, and since Figure 8 and Fig. 9 The path length contribution is unique relative to the second angle of incidence A2 due to the symmetry of the incident angles A1, A2. Therefore, the incident angles A1, A2, the optical path length contribution 93 and the wavelength L are related to each other in a manner predetermined by the geometry of the waveguide 50 and the properties of the measuring diffractive structures 51, 52, 53, 54. Fig. 9 The information can be retrievably stored in Figures 1 to 7 Therefore, Fig. 9 can be used as a lookup table, where the wavelength L of the measuring beam 80 can be determined from the horizontal pixel position hp and the vertical pixel position vp, as described with respect to Figure 1 , Figure 3 and Figure 4 The path length distribution caused by the waveguide 50 (ie the distribution of the path length contribution 93) is subtracted from the distance distribution of the distance between the object 15 and the device 10 as determined by the time-of-flight measurement in order to obtain a corrected measurement of the distance distribution.

[0104] Fig.10 1 shows a schematic illustration of a deflection efficiency I of a measuring beam 80, 81, 82, 85, 86 deflected by a measuring diffractive structure 51, 52, 53, 54. In this case, such a measuring diffractive structure 51, 52, 53, 54 is one of the measuring diffractive structures 51, 52, 53, 54 described with reference to the preceding figures. In this context, Fig.10 The upper graph of shows the relationship between the deflection efficiency I and the deflection angle 58 and the wavelength L in the spectral range S. In doing so, it is obvious that when the wavelength L is relatively short, the deflection efficiency I is relatively precisely concentrated around a certain deflection angle 58, and as the wavelength L increases, the concentration around the deflection angle 58 corresponding to the wavelength L decreases. This is also Fig.10 58. It shows curves for different wavelengths L, where shorter wavelengths L result in a substantially unimodal and concentrated angular distribution around the deflection angle 58, while at longer wavelengths L the angular distribution around the corresponding deflection angle 58 is less concentrated. The measuring diffraction structures 51, 52, 53, 54 can be produced by suitable exposure of the waveguide 50. During the exposure of the waveguide 50, the deflection efficiency I and therefore the object area 16 or the field of view (FOV) can be set by one or more suitable exposure angles. By increasing the thickness of the volume hologram (increasing the number of Bragg planes), the angular selectivity can be increased as required, so that a narrower spectrum is output coupled at the corresponding angle, and thus the flight time uncertainty.

[0105] Fig.11 A schematic illustration of an apparatus 10 for measuring a time of flight 92 according to an optional aspect of the present disclosure is shown. Fig.11In the description of the foregoing drawings, reference is made to the description of the foregoing drawings.

[0106] The device 10 includes an image light source 22 for emitting a visible image light beam 23. For example, the image light source 22 includes a light emitting diode matrix and / or an LC display. The waveguide 50 includes an image diffraction structure 77 for wavelength-dependent deflection of the image light beam 23. Thus, a user interface 87 spaced apart from the waveguide 50 in the second direction R2 is imaged or reconstructed, as described in WO2020 / 157306 A1 regarding an illumination and projection system. In this case, the image light source 22 can be arranged in such a way that the image light source 22 and the image diffraction structure 77 are spaced apart from each other in the first direction R1. Thus, a wavelength-dependent transparency of the device 10 in the region of the image diffraction structure 77 and / or a more diverse arrangement of components of the device 10 can be obtained.

[0107] The data processing device 90 is configured to capture the user input 24 through the user interface 87 based on the flight time 92 of the measuring light beam 80. In this case, for example, the object 15 whose distance from the device 10 should be determined is a body part of the user. The user moves the object 15 in order to interact with the user interface 87. In order to image the response to the user input 24, the device 10 is configured to control the image light source 22 based on the optical path length 91 and / or the flight time 92 of the measuring light beam 80, i.e. based on the distance between the object 15 and the device 10.

[0108] Fig.11 The embodiment of the device 10 shown is particularly suitable for use in a user terminal 210 and is here comprised by the user terminal 210. For example, the user terminal 210 is a device on a smart phone, a computer (particularly a portable computer), and / or a motor vehicle. In particular, this makes it possible to implement gesture monitoring and / or motion detectors. The arrangement of the image diffraction structure 77 and optionally the additional deflection function of the image diffraction structure 77 allow light to be directed to an area that is not visible to the user of the user terminal 210.

[0109] Fig.12 A schematic illustration of an apparatus 10 for measuring a time of flight 91 according to an optional aspect of the present disclosure is shown. Fig.12 In the description of the foregoing drawings, reference is made to the description of the foregoing drawings.

[0110] The apparatus 10 is configured to virtually image an imaging object 88 spaced apart from the waveguide 50 in the second direction R2 relative to the object 15. Therefore, the user can look through the waveguide 50 and see the imaging object 88 arranged relative to the object 15. To this end, the image light source 22 and the image diffraction structure 77 are arranged in a manner spaced apart from each other in the first direction R1.

[0111] The apparatus 10 is configured to control the image light source 22 dynamically and / or based on captured movement of the object 15 .

[0112] Fig.12 The illustrated embodiment is particularly suitable for use with the detection and illumination device 220 and is encompassed herein by the detection and illumination device.

[0113] Fig.13 A flow chart of an alternative method 100 for measuring the time of flight 92 according to an aspect of the present disclosure is shown. The method 100 may be performed using one of the apparatuses 10 for measuring the time of flight 92 as described in the previous figures.

[0114] The method 100 is a method 100 for measuring a flight time 92 of a measuring light beam 80. The method 100 comprises guiding 110 the measuring light beam 80 at least partially through a waveguide 50 having a measuring diffraction structure 51, 52 for a wavelength-dependent deflection of the measuring light beam 81, 86, the measuring light beam 86 traversing a wavelength-dependent path length 91 in the waveguide 50, to an object 15 located in an object region 16 of the device 10, and guiding the measuring light beam 85 reflected from the object 15 to a light sensor 30.

[0115] Taking into account the wavelength-dependent path length 91 of the measurement beam 86 in the waveguide 50 , an optical path length contribution 93 and / or a time-of-flight contribution 94 of the measurement beam 80 detected by the light sensor 30 is determined 120 .

[0116] List of Reference Numerals

[0117] 10. Device for measuring time of flight

[0118] 15 Objects

[0119] 16 Object Area

[0120] 20 Measurement light source

[0121] 21 Imaging device

[0122] 22 Image Light Source

[0123] 23 Image beam

[0124] 24 User Input

[0125] 30 light sensors

[0126] 31 Imaging device

[0127] 50 waveguide

[0128] 51 Measured diffraction structure of the transmission output coupling region

[0129] 52Measured diffraction structure of the sensor input coupling area

[0130] 53 Measured diffraction structure of the transmission input coupling area

[0131] 54Measured diffraction structure of the sensor output coupling area

[0132] 55 Transmission Input Coupling Area

[0133] 56 Geometric shapes

[0134] 57 Total Internal Reflection

[0135] 58 deflection angle

[0136] 59 Surroundings

[0137] 60 Transmission Output Coupling Area

[0138] 65 Sensor input coupling area

[0139] 70 Sensor output coupling area

[0140] 75 Image input coupling area

[0141] 76 Image output coupling area

[0142] 77 Image Diffraction Structure

[0143] 80 measuring beams

[0144] 81 Input coupled measurement beam

[0145] 82The measuring beam is emitted from the waveguide in the direction of the object

[0146] 85Reflected measuring beam

[0147] 86 Input coupled to the measuring beam in the sensor input coupling area

[0148] 87 User Interface

[0149] 88 Imaging Objects

[0150] 90 Data processing device

[0151] 91 Optical path length

[0152] 92 flight hours

[0153] 93 Optical path length contribution

[0154] 94 flight time contribution

[0155] 95 Memory

[0156] 96 processors

[0157] 97 Input Device

[0158] 98 distance data

[0159] 100 Methods

[0160] 110 Guide the measuring beam

[0161] 120 OK

[0162] 200 Deflection Curve

[0163] 210 User Terminal

[0164] 220 Detection and lighting equipment

[0165] A1 Angle of incidence

[0166] A2 Angle of incidence

[0167] IDeflection efficiency

[0168] L wavelength

[0169] N1 refractive index

[0170] R1 first direction

[0171] R2 Second direction

[0172] R3 Third Party

[0173] SNIR range

[0174] hp horizontal pixel position

[0175] vp vertical pixel position

Claims

1. A device (10) for measuring the flight time (92) of a measuring light beam (80), the device comprising a measuring light source (20) for emitting the measuring light beam (80), a light sensor (30) for detecting the measuring light beam (80), a waveguide (50), and a data processing device (90), in, - the waveguide (50) is designed such that a measuring light beam (80) emitted by the measuring light source (20) to an object (15) located in an object region (16) of the device (10) and a measuring light beam (85) reflected from the object (15) to the light sensor (30) are at least partially guided through the waveguide (50), the waveguide (50) comprising a measuring diffraction structure (51, 52) for wavelength-dependent deflection of the measuring light beam (81, 86), and the measuring light beam (86) travels a wavelength-dependent path length (91) in the waveguide (50), characterised in that - the data processing device (90) is configured to determine, during the measurement of the flight time (92), an optical path length contribution (93) and / or a flight time contribution (94) of the measurement light beam (80) detected by the light sensor (30) taking into account the wavelength-dependent path length (91) of the measurement light beam (86) within the waveguide (50).

2. The device (10) as claimed in claim 1, in, The measuring diffraction structure (51, 52) is configured to effect a wavelength-dependent deflection of a measuring light beam (81, 86) in the near infrared spectral range, ie the NIR range (S).

3. The device (10) as claimed in claim 1 or 2, in, The light sensor (30) comprises a plurality of picture elements (32), the data processing device (90) being configured to retrieve and / or calculate an optical path length contribution (93) and / or a flight time contribution (94) of a respective detected portion of the measurement beam (80) for a plurality of the picture elements (32).

4. The device (10) as claimed in any one of the preceding claims, in, The optical path length contribution (93) and / or the time of flight contribution (94) corresponds to a vertical pixel position (vp) and a horizontal pixel position (hp).

5. The device (10) as claimed in claim 4, in, The measuring diffraction structure (52) is configured to couple into the waveguide (50) a measuring light beam (86) reflected from the object (15) and incident on the surface (66) of the waveguide (50) at a first incident angle (A1) of + / - 20° and / or couple into the waveguide (50) a measuring light beam (86) reflected from the object (15) and incident on the surface (66) of the waveguide (50) at a second incident angle (A2) of + / - 20° defined perpendicularly to the first incident angle (A1).

6. The device (10) as claimed in any one of the preceding claims, in, The data processing device (90) is configured to capture distance data (98) related to the object (15) via an input device (97) and to calibrate the determination of the optical path length (91) and / or the time of flight (92) based on the distance data (98).

7. The device (10) as claimed in any one of the preceding claims, in, The device (10) comprises an image light source (22) for emitting a visible image light beam (23), and the waveguide (50) comprises an image diffraction structure (77) for wavelength-dependent deflection of the image light beam (23).

8. The device (10) as claimed in claim 7, in, The device (10) is configured to control the image light source (22) based on the optical path length (91) and / or the flight time (92) of the measurement beam (80).

9. The device (10) as claimed in claim 8, in, The apparatus (10) is configured to image a user interface (87) spaced apart from the waveguide (50) in a second direction (R2) and to capture a user input (24) through the user interface (87) based on a time of flight (92) of the measurement beam (80).

10. The device (10) as claimed in any one of claims 7 to 9, in, The apparatus is configured to image an imaging object (88) spaced apart from the waveguide (50) in a second direction (R2) relative to the object (15).

11. The device (10) according to any one of claims 7 to 10, in, The apparatus (10) is configured to control the image light source (22) dynamically and / or based on captured movement of the object (15).

12. The device (10) as claimed in any one of the preceding claims, in, The device (10) comprises a mirror and / or a prism for deflecting a measuring light beam (82) emerging from the waveguide (50) and / or for deflecting a measuring light beam (85) reflected from the object (15).

13. A user terminal (210), comprising the device (10) according to any one of claims 1 to 12.

14. A detection and illumination device (220), comprising the apparatus (10) according to any one of claims 1 to 12.

15. A method (100) for measuring the flight time (92) of a measuring beam (80), the method (100) include: - guiding (110) the measuring light beam (80) at least partially through a waveguide (50) to an object (15) located in the object region (16), and guiding the measuring light beam (85) reflected from the object (15) to a light sensor (30), the waveguide having a measuring diffraction structure (51, 52) for wavelength-dependent deflection of the measuring light beam (81, 86), the measuring light beam (86) traversing a wavelength-dependent path length (91) in the waveguide (50); and - determining (120) an optical path length contribution (93) and / or a time-of-flight contribution (94) of the measurement light beam (80) detected by the light sensor (30) taking into account the wavelength-dependent path length (91) of the measurement light beam (86) within the waveguide (50).

16. The method (100) as claimed in claim 15, in, The optical path length contribution (93) and / or the flight time contribution (94) are determined based on a wavelength-dependent number of total internal reflections (57) within the waveguide (50) and / or a wavelength-dependent deflection angle (58) within the waveguide (50).

17. A computer program and / or a computer readable medium comprising commands which, when the program or the commands are executed by a computer, cause the computer to perform the method (100) and / or the steps of the method (100) as claimed in claim 15 or 16.

18. A data processing device (90), in, The data processing device (90) is configured to perform the method (100) according to claim 15 or 16.

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