Detector for the optical detection of at least one object

Abstract

A portable device with an optical detector comprising: a. an illumination source for generating an illumination pattern for illuminating an object, the illumination pattern comprising a regular and / or constant and / or periodic pattern; b. an array of optical sensors, each optical sensor being designed to generate at least one sensor signal in response to illumination of the object of its respective light-sensitive surface by the light beam, and c. an evaluation device for determining a region of interest.

Description

Field of the invention

[0001] The invention relates to a detector, a detector system, and a method for determining a position of at least one object. The invention further relates to a human-machine interface for exchanging at least one piece of information between a user and a machine, an entertainment device, a tracking system, a camera, a scanning system, and various uses of the detector device. The devices, systems, methods, and applications according to the present invention can be used, for example, in various areas of daily life, in gaming, traffic, production, and security technology, in photography such as digital photography or video photography for artistic, documentary, or technical purposes, in medical technology, or in science.Furthermore, the invention can be used in particular for scanning one or more objects and / or for scanning a scene, for example, for generating a depth profile of an object or a scene, e.g., in the field of architecture, metrology, archaeology, art, medicine, engineering, or manufacturing. However, other applications are also possible. State of the art

[0002] A variety of optical sensors and photovoltaic devices are known from the prior art. While photovoltaic devices generally serve to convert electromagnetic radiation, such as ultraviolet, visible, or infrared light, into electrical signals or electrical energy, optical detectors are generally used to capture image information and / or detect at least one optical parameter, such as brightness.

[0003] A variety of optical sensors are known from the state of the art, which can basically be based on the use of inorganic and / or organic sensor materials. Examples of such sensors are disclosed in US 2007 / 0176165 A1, US 6,995,445 B2, DE 2501124 A1, DE 3225372 A1, US 2007 / 0176165 A1, WO 2009 / 013282 A1, WO 2012 / 110924 A1, WO 2014 / 097181 A1, WO 2015 / 024871 A1, US 4,767,211, WO 2014 / 198629 A1, WO 2014 / 198626 A1, WO 2014 / 198629 A1 and WO 2014 / 198625 A1, the complete contents of which are hereby incorporated by reference. With regard to possible materials and optical sensors that can also be used in the context of the present invention, reference is made to European patent applications EP 15 153 215.7, filed on 30 January 2015, EP 15 157 363.1, filed on 3 March 2015, EP 15 164 653.6, filed on 22 April 2015, EP 15177275.3, filed on 17 July 2015, EP 15180354.1 and EP 15180353.3, both filed on 10August 2015, and EP 15 185 005.4, filed on 14 September 2015, EP 15 196 238.8 and EP 15 196 239.6, both filed on 25 November 2015, and EP 15 197 744.4, filed on 3 December 2015, the complete contents of which are also hereby incorporated by reference.

[0004] Furthermore, reference may be made to detector concepts that compare signals from at least two different sources to determine a position of an object. For example, reference may be made to EP 16155834.1, EP 16155835.8 or EP 16155845.7, all filed on February 16, 2016, the complete disclosure of which is hereby incorporated by reference. Furthermore, P. Bartu, R. Koeppe, N. Arnold, A. Neulinger, L. Fallon and S. Bauer describe "Conformable large-area position-sensitive photodetectors based on luminescence collecting silicone waveguides", J. Appl. Phys. 107, 123101 (2010), a type of position-sensitive detector (PSD) that could be suitable for large areas and on curved surfaces.

[0005] For example, US 5,323,222 A describes a distance measuring device that includes a light projection section for projecting a luminous flux onto an object. A light receiving section is spaced apart from the light projection section by the base length, receives the light rays reflected from the object, and generates a photoelectric current depending on the amount of light received. The light receiving section is divided into at least four light receiving elements by a first dividing line that intersects the base length at right angles and by a second dividing line that intersects the first dividing line at an angle. A first ratio calculating section calculates the ratio of the sum of the photoelectric currents generated by the light receiving elements on one side of the first dividing line to the sum of the photoelectric currents generated by the light receiving elements on the other side.A second ratio calculation section calculates the ratio of the sum of the photoelectric currents generated by the light-receiving elements on one side of the second dividing line to the sum of the photoelectric currents generated by the light-receiving elements on the other side. A distance determination section calculates the sum of the outputs of the first and second ratio calculation sections and determines the distance between the device and the object based on the resulting value.

[0006] US 4,675,517 A describes a photosensitive element having a first and a second sensitive region arranged to receive a light spot such that, when the light spot lies astride the intermediate boundary, the ratio of the areas of the two parts of the light spot received by the first and second sensitive regions, respectively, issecond sensitive region, depending on the received position of the light spot, wherein the received position of the light spot is detected from the variation in the ratio of the outputs of the first and second sensitive regions, wherein an error of the variation in the ratio of the outputs of the first and second sensitive regions for the received position of the light spot, which occurs when the diameter of the received light spot is so large as to exceed the first and second sensitive regions, is corrected by providing an additional sensitive region surrounding the first and second sensitive regions.

[0007] WO 2015 / 024871 A1 describes an optical detector. The optical detector comprises: - at least one spatial light modulator configured to modify at least one property of a light beam in a spatially resolved manner, having a matrix of pixels, wherein each pixel is individually controllable to modify the at least one optical property of a portion of the light beam passing through the pixel; - at least one optical sensor configured to detect the light beam after passing through the matrix of pixels of the spatial light modulator and to generate at least one sensor signal; - at least one modulator device configured to periodically control at least two of the pixels with different modulation frequencies; and - at least one evaluation device configured to perform a frequency analysis to determine signal components of the sensor signal for the modulation frequencies.

[0008] However, determining the distance to an object using these known methods and devices depends on the object's size. In particular, the optical sensors may exhibit a luminance dependence, which complicates the evaluation of the measurement result, and may also depend on the target spot size. This dependence on the object size can result in the distance determination being dependent on manufacturing tolerances and environmental conditions. Furthermore, these methods and devices require a large baseline and thus large dimensions to achieve a reliable distance value. Problem to be solved by the invention

[0009] It is therefore an object of the present invention to provide devices and methods that address the aforementioned technical challenges of known devices and methods. In particular, one object of the present invention is to provide devices and methods that can reliably determine the position of an object in space, preferably with minimal technical effort and with low requirements for technical resources and costs. Brief description of the invention

[0010] This problem is solved by the invention with the features of the independent patent claims. Advantageous developments of the invention, which can be implemented individually or in combination, are presented in the dependent claims and / or in the following description and the exemplary embodiments.

[0011] In the following, the terms "have / have", "comprise" or "include" or any grammatical variations thereof are used in a non-exclusive manner. These terms can therefore refer both to a situation in which, apart from the feature introduced by these terms, no other features are present in the entity described in this context, and to a situation in which one or more other features are present. For example, the expressions "A has B", "A comprises B" and "A includes B" can refer both to a situation in which, apart from B, no other element is present in A (i.e., a situation in which A consists solely of B), and to a situation in which, in addition to B, one or more other elements are present in the entity A, such as element C, elements C and D, or even other elements.

[0012] It should also be noted that the terms "at least one," "one or more," or similar expressions indicating that a feature or element may be present one or more times are generally used only once when the feature or element in question is introduced. In the following, when mentioning the feature or element in question, the terms "at least one" or "one or more" are generally not repeated, regardless of the fact that the feature or element in question may be present one or more times.

[0013] Furthermore, the terms "preferred", "particularly preferred", "particularly", "in particular" or similar terms are used below in connection with optional features, without limiting alternative possibilities. Features introduced by these terms are therefore optional features and are not intended to limit the scope of the claims in any way. As those skilled in the art will recognize, the invention can be carried out using alternative features. Likewise, features introduced with "in one embodiment of the invention" or similar expressions are to be understood as optional features, without limitation with regard to alternative embodiments of the invention, without limitation with regard to the scope of the invention, and without limitation with regard to the possibility of combining the features introduced in this way with other optional or non-optional features of the invention.

[0014] In a first aspect of the present invention, a detector for determining a position of at least one object is disclosed. The term "object" herein refers to a point or region emitting at least one light beam. The light beam may emanate from the object, for example through the object and / or at least one illumination source integrated into or attached to the object that emits the light beam, or it may emanate from another illumination source, for example from an illumination source that directly or indirectly illuminates the object, wherein the light beam is reflected or scattered by the object. In the present case, the term "position" refers to at least one piece of information about a location and / or an orientation of the object and / or at least part of the object in space.Thus, the at least one piece of information may imply at least a distance between at least one point of the object and the at least one detector. As explained in more detail below, the distance may be a longitudinal coordinate or contribute to determining a longitudinal coordinate of the point of the object. Additionally or alternatively, one or more other pieces of information about the location and / or orientation of the object and / or at least a part of the object may be determined. For example, at least one transverse coordinate of the object and / or at least a part of the object may additionally be determined. Thus, the position of the object may imply at least a longitudinal coordinate of the object and / or at least a part of the object. Additionally or alternatively, the position of the object may imply at least a transverse coordinate of the object and / or at least a part of the object.Additionally or alternatively, the position of the object may include at least one orientation information of the object that indicates an orientation of the object in space.

[0015] The detector includes: - at least one transmission device, the transmission device having at least one focal length in response to at least one incident light beam propagating from the object to the detector; - at least two optical sensors, each optical sensor having at least one light-sensitive surface, each optical sensor being designed to generate at least one sensor signal in response to illumination of its respective light-sensitive surface by the light beam, - at least one evaluation device configured to determine at least one longitudinal coordinate z of the object by evaluating a quotient signal Q of the sensor signals.

[0016] The detector can be configured to determine the longitudinal coordinate z of the object in at least one measuring range independent of the object size in an object plane.

[0017] In the present case, an "optical sensor" generally refers to a light-sensitive device for detecting a light beam, e.g., for detecting illumination and / or a light spot generated by at least one light beam. Furthermore, a "light-sensitive area" generally refers to a region of the optical sensor that can be illuminated externally by the at least one light beam, wherein the at least one sensor signal is generated in response to the illumination. The light-sensitive area can, in particular, be located on a surface of the respective optical sensor. However, other embodiments are also possible.Herein, the term "at least two optical sensors, each with at least one light-sensitive surface" refers to configurations with two individual optical sensors, each with one light-sensitive surface, and to configurations with a combined optical sensor with at least two light-sensitive surfaces. The term "optical sensor" thus refers to a light-sensitive device configured to generate one output signal, while here, a light-sensitive device configured to generate two or more output signals, for example, at least one CCD and / or CMOS device, is referred to as two or more optical sensors.As will be explained in more detail below, each optical sensor can be designed such that exactly one light-sensitive area is present in the respective optical sensor, for example by providing exactly one light-sensitive area that can be illuminated, wherein the illumination generates exactly one uniform sensor signal for the entire optical sensor. Thus, each optical sensor can be an optical sensor with a single area. However, the use of single-area optical sensors makes the construction of the detector particularly simple and efficient. For example, commercially available photosensors, such as commercially available silicon photodiodes, which each have exactly one sensitive area, can be used in the arrangement. However, other embodiments are also possible.Thus, for example, an optical device with two, three, four, or more than four light-sensitive surfaces can be used, which is considered within the scope of the present invention as two, three, four, or more than four optical sensors. The optical device can, for example, comprise a matrix of light-sensitive surfaces. For example, the optical sensors can be part of or form an optical device with pixels. The optical sensors can, for example, be part of or form at least one CCD and / or CMOS device with a pixel matrix, wherein each pixel forms a light-sensitive surface.

[0018] Furthermore, as used herein, a “sensor signal” generally refers to a signal generated by an optical sensor in response to the illumination by the light beam. In particular, the sensor signal may be or comprise at least one electrical signal, such as at least one analog electrical signal and / or at least one digital electrical signal. In particular, the sensor signal may be or comprise at least one voltage signal and / or at least one current signal. In particular, the sensor signal may comprise at least one photocurrent. Furthermore, either raw sensor signals may be used, or the detector, the optical sensor, or another element may be configured to process or pre-process the sensor signal, thereby generating secondary sensor signals that may also be used as sensor signals, e.g., pre-processing by filtering or the like.

[0019] The light-sensitive surfaces can be specifically aligned with the object. In the present case, the term "aligned with the object" generally refers to the situation where the respective surfaces of the light-sensitive surfaces are fully or partially visible from the object. In particular, at least one connecting line between at least one point of the object and at least one point of the respective light-sensitive surface can form an angle with a surface element of the light-sensitive surface that is different from 0°, for example an angle in the range of 20° to 90°, preferably 80 to 90°, for example 90°. If the object is located on the optical axis or near the optical axis, the light beam propagating from the object to the detector can thus run substantially parallel to an optical axis.The term "substantially perpendicular / right-angled" refers here to the state of a right-angled alignment with a tolerance of, for example, ±20° or less, preferably a tolerance of ±10° or less, particularly preferably a tolerance of ±5° or less. Likewise, the term "substantially parallel" refers to the state of a parallel alignment with a tolerance of, for example, ±20° or less, preferably a tolerance of ±10° or less, particularly preferably a tolerance of ±5° or less.

[0020] The light beam may propagate from the object to the detector. As explained in more detail below, the light beam may emanate from the object, for example through the object and / or at least one illumination source integrated into or attached to the object which emits the light beam, or it may emanate from another illumination source, for example from an illumination source which directly or indirectly illuminates the object, wherein the light beam is reflected or scattered by the object and is thereby at least partially directed towards the detector. The illumination source may, for example, be or comprise an external illumination source and / or an illumination source integrated into the detector and / or an illumination source integrated into a beacon device which is attached to the object and / or integrated into the object and / or held by the object.Thus, the detector can be used in active and / or passive illumination scenarios. The illumination source can, for example, be configured to illuminate the object by directing a light beam toward the object, which reflects the light beam. Additionally or alternatively, the object can be configured to generate and / or emit the at least one light beam. The light source can be or comprise at least one multi-beam light source. The light source can, for example, comprise at least one laser source and one or more diffractive optical elements (DOEs).

[0021] As used herein, the term "ray" generally refers to a line perpendicular to light wavefronts and pointing in a direction of energy flow. As used herein, the term "beam" generally refers to a collection of rays. Hereinafter, the terms "ray" and "beam" are used synonymously. As further explained herein, the term "light beam" generally refers to an amount of light, in particular an amount of light traveling in substantially the same direction, including the possibility that the light beam has a scattering angle or an expanding angle. The light beam may have a spatial extent. In particular, the light beam may have a non-Gaussian beam profile. The beam profile may be selected from the group consisting of a trapezoidal beam profile, a triangular beam profile, and a conical beam profile.The trapezoidal beam profile may have a plateau region and at least one edge region. The term "beam profile" refers generally to a transverse intensity profile of the light beam. The light beam may, in particular, be a Gaussian light beam or a linear combination of Gaussian light beams, as explained in more detail below. However, other embodiments are also possible. The transmission device may be configured to adjust and / or define and / or determine the beam profile, in particular a shape of the beam profile.

[0022] The light beam may be a monochromatic light beam. The light beam may comprise a narrow band of wavelengths; preferably, the light beam may comprise a single wavelength. The at least one light source may be configured to generate at least one monochromatic light beam, and / or the detector may comprise at least one filter element configured to filter a narrow band of wavelengths, for example, a monochromator.

[0023] The illumination source can be configured to generate at least one illumination pattern for illuminating the object. Additionally or alternatively, the illumination pattern can be generated by at least one ambient light source. The detector can be configured such that the illumination pattern propagates from the detector, in particular from at least one opening of the housing, towards the object along and / or parallel to an optical axis of the detector. For this purpose, the detector can comprise at least one reflective element, preferably at least one prism, to deflect the illumination pattern such that it propagates along or parallel to the optical axis. In particular, the illumination source can comprise at least one laser and / or a laser source. Various types of lasers can be used, for example semiconductor lasers.Additionally or alternatively, non-laser light sources may also be used, for example LEDs and / or light bulbs. As used herein, the term “pattern” refers to an arbitrary, known or predetermined arrangement comprising at least one arbitrarily shaped feature. The pattern may comprise at least one feature, e.g., a dot or a symbol. The pattern may comprise a plurality of features. The pattern may comprise an arrangement of periodic or non-periodic features. As used herein, the term “illumination pattern” refers to a pattern that illuminates the object. The illumination pattern may be generated by ambient light, for example, by at least one ambient light source, or by the at least one illumination source.The illumination pattern may comprise at least one pattern selected from the group consisting of: at least one point pattern, in particular a pseudorandom point pattern, a random point pattern, or a quasi-random pattern; at least one Sobol pattern; at least one quasi-periodic pattern; at least one pattern comprising at least one previously known feature; at least one regular pattern; at least one triangular pattern; at least one hexagonal pattern; at least one pattern comprising convex uniform tiling; at least one line pattern comprising at least one line; at least one line pattern comprising at least two lines, for example parallel or intersecting lines; at least one stripe pattern. The illumination source may, for example, be configured to generate and / or project a point cloud.The illumination pattern may comprise a regular and / or constant and / or periodic pattern, such as a triangular pattern, a rectangular pattern, a hexagonal pattern, or a pattern with further convex tiles. The illumination pattern may comprise as many features per area as possible, so a hexagonal pattern may be preferred. A distance between two features of the illumination pattern and / or an area of the at least one illumination feature may depend on the circle of confusion in the image.

[0024] The illumination source may comprise at least one light projector and / or at least one DLP (digital light processing) projector and / or at least one LCoS projector and / or at least one spatial light modulator and / or at least one diffractive optical element and / or at least one array of light-emitting diodes and / or at least one array of laser light sources. The illumination source may comprise at least one light source configured to directly generate the illumination pattern. For example, the illumination source may comprise at least one laser source. The illumination source may, for example, comprise at least one line laser. The line laser may be configured to emit a laser line to the object, for example, a horizontal or vertical laser line. The illumination source may comprise a plurality of line lasers.The illumination source may, for example, comprise at least two line lasers, which may be arranged such that the illumination pattern comprises at least two parallel or intersecting lines. The illumination source may comprise at least one light projector, which is configured to generate a point cloud such that the illumination pattern may comprise a pattern of a plurality of points. The illumination source may comprise at least one mask, which is configured to generate the illumination pattern from at least one light beam generated by the illumination source. The illumination source may either be attached to a mobile device, such as a smartphone, or integrated into it. The illumination source may be used for other functions that may be used in determining an image, for example for an autofocus function.The lighting source can be connected to a mobile device, e.g. using a USB or telephone connection element, such as the headphone jack.

[0025] The illumination source can be configured to generate pulsed illumination. The illumination source can be configured to generate at least one light pulse. As used herein, the term "light pulse" or "pulsed illumination" refers to a time-limited light beam. The light pulse can have a predefined length or duration, for example in the nanosecond range. For example, the illumination source can be configured to generate pulses with a pulse length of less than one nanosecond, for example one-tenth of a nanosecond, down to one-tenth of a second. The illumination source can be configured to generate the light pulse periodically. For example, the illumination source can be configured to generate the light pulse at a frequency of 10 Hz to 10 GHz.

[0026] The illumination source may be configured to generate a pulsed light beam. For example, the illumination source may be configured to generate a continuous illumination light beam, and the detector may comprise at least one interruption device configured to interrupt the illumination, in particular periodically. The interruption device may comprise at least one shutter and / or a beam chopper or another type of mechanical or electronic periodic beam interruption device, for example with at least one interrupter blade or interrupter wheel that preferably rotates at a constant speed and can thus interrupt the illumination periodically. For example, the at least one interruption device may also be fully or partially integrated into the illumination source. Various possibilities are conceivable.

[0027] The optical sensors can be sensitive to the ultraviolet and / or the visible and / or the infrared spectral range. In particular, the optical sensors can be sensitive to the visible spectral range from 500 nm to 780 nm, preferably from 650 nm to 750 nm or from 690 nm to 700 nm. The optical sensors can be particularly sensitive to the near infrared range. In particular, the optical sensors can be sensitive to that part of the near infrared range in which silicon photodiodes can be used, in particular in the range from 700 nm to 1000 nm. The optical sensors can be particularly sensitive in the infrared spectral range, in particular in the range from 780 nm to 3.0 micrometers.The optical sensors may, for example, independently be or comprise at least one element selected from the group consisting of a photodiode, a photocell, a photoconductor, a phototransistor, or any combination thereof. The optical sensors may, for example, be or comprise at least one element selected from the group consisting of a CCD sensor element, a CMOS sensor element, a photodiode, a photocell, a photoconductor, a phototransistor, or any combination thereof. Any other type of photosensitive element may also be used. As will be explained in more detail below, the photosensitive element may generally be made wholly or partially from inorganic materials and / or wholly or partially from organic materials.As explained in more detail below, one or more photodiodes can typically be used, such as commercially available photodiodes, e.g., inorganic semiconductor photodiodes. As used herein, the term "photosensitive element" generally refers to an element that is sensitive to illumination in the ultraviolet and / or visible or infrared spectral range. In particular, the photosensitive element can be or comprise at least one element selected from the group consisting of a photodiode, a photocell, a photoconductor, a phototransistor, or any combination thereof. Any other type of photosensitive element can also be used.

[0028] In view of the technical challenges associated with the prior art literature described above, in particular in view of the technical effort required to generate the so-called FiP effect, as described in WO 2015 / 024871, it should be noted that the present invention can be realized in particular by using optical sensors without the FiP effect. Since optical sensors with the FiP characteristic typically have a strong peak in the respective sensor signals at a focal point, the measuring range of a detector according to the present invention that uses FiP sensors as optical sensors can be limited to a range between the two positions in which the first and second optical sensors are located in the focus of the light beam. When using linear optical sensors, i.e.However, with optical sensors that do not exhibit the FiP effect, this problem can generally be avoided with the structure of the present invention. Consequently, the first and second optical sensors can have a linear signal characteristic at least within a measurement range, so that the first and second sensor signals, respectively, depend on the total illumination power of the respective optical sensor and can be independent of the diameter of a light spot of the illumination. However, it should be noted that other embodiments are also possible.

[0029] The first and second optical sensors can each be, in particular, semiconductor sensors, preferably inorganic semiconductor sensors, particularly preferably photodiodes, and most preferably silicon photodiodes. In contrast to complex and expensive FiP sensors, the present invention can thus be easily implemented using commercially available inorganic photodiodes, i.e., with a small photodiode and a large-area photodiode. Thus, the structure of the present invention can be implemented cost-effectively.

[0030] However, embodiments are also possible in which the detector may comprise at least one FiP sensor configured to generate the so-called FiP effect as described in WO 2015 / 024871, as will be explained in more detail below.

[0031] The detector may further comprise at least one illumination source for illuminating the object. The illumination source may, for example, be configured to generate an illuminating light beam that illuminates the object. The detector may be configured such that the illuminating light beam propagates from the detector to the object along an optical axis of the detector. For this purpose, the detector may comprise at least one reflective element, preferably at least one prism, to deflect the illuminating light beam onto the optical axis.

[0032] The illumination source may, in particular, be configured to emit light in the infrared spectral range. However, it should be noted that, in addition or alternatively, other spectral ranges are also possible. Furthermore, as described above, the illumination source may, in particular, be configured to emit modulated or unmodulated light. If a plurality of illumination sources is used, the different illumination sources may have different modulation frequencies, which, as explained in more detail below, can later be used to distinguish the light beams.The illumination source may be configured to generate and / or project a point cloud, for example, the illumination source may comprise at least one digital light processing (DLP) projector and / or at least one LCoS projector and / or at least one spatial light modulator and / or at least one diffractive optical element and / or at least one array of light-emitting diodes and / or at least one array of laser light sources.

[0033] In particular, the illumination source may comprise at least one laser and / or a laser source. Various types of lasers may be used, for example semiconductor lasers. Additionally or alternatively, non-laser light sources may also be used, for example LEDs and / or light bulbs. The illumination source may be configured to generate and / or project a point cloud. For example, the illumination source may comprise at least one digital light processing (DLP) projector and / or at least one LCoS projector and / or at least one spatial light modulator and / or at least one diffractive optical element and / or at least one array of light-emitting diodes and / or at least one array of laser light sources. The illumination source and the optical sensors may be arranged in a common plane or in different planes.The illumination source and the optical sensors may have different spatial orientations. In particular, the illumination source and the optical sensors may be arranged in a skewed configuration.

[0034] The illumination light beam can generally run parallel to the optical axis or be inclined with respect to the optical axis, e.g., form an angle with the optical axis. For example, the illumination light beam, e.g., the laser light beam, and the optical axis can form an angle of less than 10°, preferably less than 5° or even less than 2°. However, other embodiments are also possible. Furthermore, the illumination light beam can lie on the optical axis or outside the optical axis. For example, the illumination light beam can run parallel to the optical axis and be at a distance of less than 10 mm from the optical axis, preferably less than 5 mm from the optical axis, or even less than 1 mm from the optical axis, or can even coincide with the optical axis.

[0035] The detector comprises at least one transmission device. The term "transmission device," also called "transmission system," can generally refer to one or more optical elements configured to modify the light beam, for example, by modifying one or more beam parameters of the light beam, a width of the light beam, or a direction of the light beam. The transmission device can be configured to direct the light beam to the optical sensors.The transmission device may in particular comprise one or more of the following: at least one lens, for example at least one lens selected from the group consisting of at least one focusable lens, at least one aspheric lens, at least one spherical lens, at least one Fresnel lens; at least one aspheric lens; at least one diffractive optical element; at least one concave mirror; at least one beam deflection element, preferably at least one mirror; at least one beam splitting element, preferably a beam splitting cube and / or a beam splitting mirror; at least one multi-lens system.

[0036] In the present case, the term "focal length" of the transmission device refers to a distance over which incident collimated rays that can strike the transmission device are brought into a "focus," which can also be referred to as a "focal point." The focal length thus represents a measure of the transmission device's ability to converge an incident light beam. Thus, the transmission device can contain one or more imaging elements that can have the effect of a converging lens. The transmission device can, for example, have one or more lenses, in particular one or more refractive lenses, and / or one or more convex mirrors. In this example, the focal length can be defined as the distance between the center of the thin refractive lens and the principal focal points of the thin lens. In a converging thin refractive lens, e.g.a convex or biconvex thin lens, the focal length can be considered positive and indicates the distance at which a collimated light beam incident on the thin lens as a transmission device can be focused to a single spot. In addition, the transmission device can comprise at least one wavelength-selective element, for example at least one optical filter. In addition, the transmission device can be designed to impart a predefined beam profile to the electromagnetic radiation, e.g. at the location of the sensor region and in particular the sensor surface. The above-mentioned optional embodiments of the transmission device can in principle be implemented individually or in any desired combination.

[0037] The transmission device can have an optical axis. In particular, the detector and the transmission device have a common optical axis. In the present case, the term "optical axis of the transmission device" generally refers to a mirror-symmetric or rotationally symmetric axis of the lens or lens system. The optical axis of the detector can be a line of symmetry of the optical structure of the detector. The detector comprises at least one transmission device, preferably at least one transmission system with at least one lens. The transmission system can, for example, comprise at least one beam path, wherein the elements of the transmission system in the beam path are arranged rotationally symmetrically to the optical axis. As explained in more detail below, one or more optical elements within the beam path can also be eccentric or inclined with respect to the optical axis.In this case, however, the optical axis can also be defined sequentially, for example by connecting the centers of the optical elements in the beam path, e.g. by connecting the centers of the lenses, whereby in this context the optical sensors are not counted as optical elements. The optical axis can generally refer to the beam path. The detector can have a single beam path along which a light beam can move from the object to the optical sensors, or it can have a plurality of beam paths. For example, there can be a single beam path or the beam path can be divided into two or more sub-beam paths. In the latter case, each sub-beam path can have its own optical axis and the above condition can generally refer to each beam path independently. The optical sensors can be located in one and the same beam path or sub-beam path.Alternatively, the optical sensors can also be located in different sub-beams. In the event that the optical sensors are distributed across different sub-beams, the above-mentioned condition can be described such that at least one first optical sensor is located in at least one first sub-beam, which is offset by a first spatial offset from the optical axis of the first sub-beam, and at least one second optical sensor is located in at least one second sub-beam, which is offset by at least a second spatial offset from the optical axis of the second sub-beam, wherein the first spatial offset and the second spatial offset differ from one another.

[0038] The transmission device may represent a coordinate system where a longitudinal coordinate I is a coordinate along the optical axis and where d is a spatial offset from the optical axis. The coordinate system may be a polar coordinate system in which the optical axis of the transmission device forms a z-axis and in which a distance from the z-axis and a polar angle may be used as additional coordinates. A direction parallel or antiparallel to the z-axis may be considered a longitudinal direction and a coordinate along the z-axis may be considered a longitudinal coordinate I. Any direction perpendicular to the z-axis may be considered a transverse direction, and the polar coordinate and / or polar angle may be considered a transverse coordinate.

[0039] The optical sensors can be positioned outside the focus. In this case, the term "focus" generally refers to a minimum extent of the circle of confusion of the light beam, in particular of at least one light beam emitted from a point on the object, caused by the transmission device, and / or to a focal length of the transmission device. In this case, the term "circle of confusion" refers to a light spot caused by a cone of light rays of the light beam focused by the transmission device.The circle of confusion may depend on a focal length f of the transmission device, a longitudinal distance between the object and the transmission device, a diameter of an exit pupil of the transmission device, a longitudinal distance between the transmission device and the light-sensitive surface, and a distance between the transmission device and an image of the object. For Gaussian beams, for example, a diameter of the circle of confusion may correspond to a width of the Gaussian beam. In particular, for a point-like object located at an infinite distance from the detector, the transmission device may be configured to focus the light beam from the object into a focal point with the focal length of the transmission device.For non-point objects that are at an infinite distance from the detector, the transmission device can be configured to focus the light beam from at least one point of the object into a focal plane with the focal length of the transmission device. For point objects that are not at an infinite distance from the detector, the circle of confusion can have a minimal extent at least at one longitudinal coordinate. For non-point objects that are not at an infinite distance from the detector, the circle of confusion of the light beam from at least one point of the object can have a minimal extent at at least one longitudinal coordinate.As used herein, the term "positioned off-focus" generally refers to a position that differs from the minimum extent of a circle of confusion of the light beam caused by the transmission device or from a focal length of the transmission device. In particular, the focal point or the minimum extent of the circle of confusion may be located at a longitudinal coordinate I. Fokus lie, while the position of each of the optical sensors is one of I Fokus deviating longitudinal coordinate I Sensor For example, the longitudinal coordinate I Sensor be arranged longitudinally closer to the position of the transmission device than the longitudinal coordinate I Fokus or be further away from the position of the transmission device than the longitudinal coordinate I Fokus . Thus, the longitudinal coordinate I Sensor and the longitudinal coordinate I Fokusbe arranged at different distances from the transmission device. For example, the optical sensors can be spaced from the minimum extent of the circle of confusion in the longitudinal direction by ± 2% of the focal length, preferably by ± 10% of the focal length, and particularly preferably by ± 20% of the focal length. For example, a focal length of the transmission device can be 20 mm and the longitudinal coordinate I Sensor 19.5 mm, ie the sensors can be positioned at 97.5% focal length, so that I Sensor is 2.5% of the focal length from the focus. The optical sensors can be arranged such that the light-sensitive surfaces of the optical sensors differ in their longitudinal coordinates and / or their spatial offset and / or their surface areas.

[0040] Every light-sensitive surface can have a geometric center. In this context, the term "geometric center" of a surface can generally refer to the centroid of the surface. For example, if an arbitrary point inside or outside the surface is chosen and an integral is formed over the vectors connecting that arbitrary point to every single point on the surface, the integral is a function of the position of the arbitrary point. If the arbitrary point lies at the geometric center of the surface, the integral of the absolute value of the integral is minimized. In other words, the geometric center can be a point inside or outside the surface that has a minimum total or summed distance to all points on the surface.

[0041] For example, each geometric center of each light-sensitive surface can be located at a longitudinal coordinate I Mittelpunkt,ibe arranged, where i denotes the number of the respective optical sensor. In the case of the detector with exactly two optical sensors and in the case of the detector with more than two optical sensors, the optical sensors can comprise at least a first optical sensor, wherein the first optical sensor, in particular the geometric center, is located at a first longitudinal coordinate I Mittelpunkt,1 is arranged, and comprise at least one second optical sensor, wherein the second optical sensor, in particular the geometric center, is located at a second longitudinal coordinate I Mittelpunkt,2is arranged, wherein the first longitudinal coordinate and the second longitudinal coordinate differ from one another. For example, the first optical sensor and the second optical sensor can lie in different planes that are offset in the direction of the optical axis. The first optical sensor can be arranged in front of the second optical sensor. Thus, for example, the first optical sensor can simply be placed on the surface of the second optical sensor. Additionally or alternatively, the first optical sensor can be spaced from the second optical sensor, for example by no more than five times the square root of an area of the first light-sensitive surface. Additionally or alternatively, the first optical sensor can be arranged in front of the second optical sensor and spaced from the second optical sensor by no more than 50 mm, preferably no more than 15 mm.The relative distance between the first optical sensor and the second optical sensor may depend, for example, on a focal length or an object distance.

[0042] The longitudinal coordinates of the optical sensors can also be identical, provided one of the above conditions is met. For example, the longitudinal coordinates of the optical sensors can be identical, but the light-sensitive surfaces can be spaced apart from the optical axis and / or the surface areas can be different.

[0043] Each geometric center of each light-sensitive surface can be spaced from the optical axis of the transmission device, for example the optical axis of the bundle path or the respective bundle path in which the respective optical sensor is located. The distance, in particular in the transverse direction, between the geometric center and the optical axis is referred to as the "spatial offset." If the detector comprises exactly two optical sensors and if the detector comprises more than two optical sensors, the optical sensors can comprise at least a first optical sensor spaced from the optical axis by a first spatial offset and at least one second optical sensor spaced from the optical axis by a second spatial offset, wherein the first spatial offset and the second spatial offset differ from one another.The first and second spatial offsets may differ, for example, by at least a factor of 1.2, preferably by at least a factor of 1.5, particularly preferably by at least a factor of 2. The spatial offsets may also be zero or assume negative values, provided that one of the above-mentioned conditions is met.

[0044] In the present case, the term “area” generally refers to both a shape and a content of at least one light-sensitive area. If the detector comprises exactly two optical sensors and if the detector comprises more than two optical sensors, the optical sensors can comprise at least a first optical sensor with a first area and at least one second optical sensor with a second area. In a detector with more than two optical sensors, e.g. a sensor element with a matrix of optical sensors, a first group of optical sensors or at least one of the optical sensors of the matrix can form a first area, wherein a second group of optical sensors or at least one further optical sensor of the matrix can form a second area. The first area and the second area can be different.In particular, the first surface area and the second surface area are not congruent. The surface area of the first optical sensor and that of the second optical sensor can therefore differ in shape or area. For example, the first surface area can be smaller than the second surface area. For example, both the first and the second surface area can have the shape of a square or a rectangle, wherein the side lengths of the square or rectangle of the first surface area are smaller than the corresponding side lengths of the square or rectangle of the second surface area. Alternatively, both the first and the second surface area can have the shape of a circle, wherein a diameter of the first surface area is smaller than a diameter of the second surface area.Alternatively, for example, the first surface area may have a first equivalent diameter and the second surface area may have a second equivalent diameter, wherein the first equivalent diameter is smaller than the second equivalent diameter. The surfaces may be congruent if one of the above conditions is met.

[0045] The optical sensors, in particular the light-sensitive surfaces, may overlap or be arranged so that there is no overlap between the optical sensors.

[0046] As used herein, the term "evaluation device" refers to any device configured to perform the operations mentioned, preferably using at least one data processing device and particularly preferably using at least one processor and / or at least one application-specific integrated circuit. Thus, the at least one evaluation device may, for example, comprise at least one data processing device on which software code comprising a number of computer instructions is stored. The evaluation device may provide one or more hardware elements for performing one or more of the operations mentioned and / or one or more processors with software running thereon for performing one or more of the operations mentioned.

[0047] The aforementioned operations, including the determination of the at least one longitudinal coordinate of the object, are performed by the at least one evaluation device. Thus, for example, one or more of the aforementioned relationships can be implemented in software and / or hardware, for example by implementing one or more check tables. Thus, the evaluation device can, for example, comprise one or more programmable devices such as one or more computers, application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or digital signal processors (DSPs) configured to perform the aforementioned evaluation to determine the at least one longitudinal coordinate of the object. Additionally or alternatively, the evaluation device can also be embodied wholly or partially by hardware.

[0048] The evaluation device is configured to determine at least one longitudinal coordinate z of the object by evaluating a quotient signal Q of the sensor signals. The term "quotient signal Q" is understood here to mean a signal generated by combining the sensor signals, in particular by dividing the sensor signals and / or dividing multiples of the sensor signals or dividing linear combinations of the sensor signals. Hereinafter, the quotient signal is also referred to as a combined signal or combined sensor signal.

[0049] The object size may be unknown a priori. An object image size, i.e., the size of the object in the image plane, may be distance-dependent. However, different materials may have different scattering properties, so that deviations from the Lambertian distribution may occur. In particular, a luminance dependence may differ significantly from 1 / z 2vary. In addition, the object image size, in particular the diameter of the spot, can vary due to the type of scattering and / or due to the reflection properties and / or scattering properties of the object, e.g. depending on the material of the object. Therefore, methods and devices that use the spot size, e.g. by counting pixels, or an absolute number of photons to determine the distance may not be suitable and require calibrations that depend on the material of the object. In order to enable robust distance determination for arbitrary materials with only one calibration, methods and devices are necessary that can determine the distance independently of the object size. Furthermore, the object size can be changed by the light source itself. The properties of the optics can be changed, for example, by dirt, raindrops, scratches or the manufacturing accuracy of the light source and / or its optics.Thus, the light beam emitted by the light source can be changed in one or more of its properties, such as diameter, beam profile, divergence, or the like. Therefore, methods and devices are required that are configured for distance determination independent of object size in order to enable robust distance determination with only one calibration, even under higher manufacturing tolerances or harsher environmental conditions. Furthermore, the object size can change depending on temperature, since the optical properties of the detector and / or the light source can change, for example, due to a temperature-dependent change in the distance between the emitter and the optics of the light source, or due to a temperature-dependent change in the distance between the sensor and the optics of the detector, or due to a temperature-dependent change in the refractive properties of the lens, or the like.Independence from object size is therefore important for measurements where little or nothing is known a priori about the measured object and / or the measurement environment and / or the temperature of the detector and its environment and / or the manufacturing quality of the sensor and / or the light source. Furthermore, independence from object size is important for measurements that require high flexibility with regard to the measured object and / or the measurement environment and / or the temperature of the detector and its environment and / or the manufacturing quality of the sensor and / or the light source. Furthermore, independence from object size is important when diverging or converging illumination light beams are to be used, such as when using diverging or converging laser light beams where the size of the illuminated spot changes with distance.Independence from object size is also important for measurements that require high robustness of measurement quality independent of the measured object and / or the measurement environment and / or the temperature of the detector and its environment and / or the manufacturing quality of the sensor and / or the light source.

[0050] Known 3D acquisition methods are dependent on the object size. For example, US 4,675,517 and US 5,323,222 describe devices and methods that are dependent on the object size. In particular, US 4,675,517 describes Fig. 3A to 3C, column 2, line 16, it is described that the distance information changes with the spot size. In particular, it is described that in practice, when using such a system, the defined object distance limits shift significantly if the diameter of the image of the reflection of the projected image spot P changes randomly or the optical position deviates. In particular, problems caused by excessively large spot sizes are addressed. If the spot size is too large, the sensor is overexposed and the resulting ratio is incorrect. US 4,675,517 describes how this dependence on spot size can be corrected by enlarging the sensor area. However, the dependence on spot size is not eliminated. In particular, problems caused by excessively small spot sizes are not addressed.Furthermore, US 5,323,222 specifically describes that the ratio used to determine the distance depends on the chip size of the light source. In particular, column 2, line 11 states that the solid lines I1 and I2 in . Fig. 14A shows the relationship between the inverse of the distance a and the calculation output I1 / (I1+I2) for the light-projecting chip sizes t1 and t2, respectively (t1 <t2) zeigen. Ferner wird beschrieben, dass, wenn die Entfernung zwischen Projektionslinse und lichtemittierendem Element fT, die Basislänge L ist und die Chipgröße des lichtemittierenden Elements t beträgt, sich folgender Entfernungsmessbereich S ergibt: S = ∞ bis fT*L / t. US 5,323,222 befasst sich jedoch nicht weiter mit der Beseitigung der Auswirkungen der Abhängigkeit von der Objektgröße.

[0051] Here, the term "object size" generally refers to the size of the object in an object plane, in particular to the size of a spot and / or a region and / or the entire object that emits the at least one light beam. The terms "independent of the object size" and "independence of the object size" or "object size independence" refer to the fact that variations in the object size have no influence on the determination of the longitudinal coordinate z. As explained in more detail below, the quotient signal Q can be used to determine the longitudinal coordinate.Object size independence also refers to the fact that the quotient signal is essentially independent of the object size, so that, for the same object distance, a first quotient signal determined at a first object size and a second quotient signal determined at a different object size are identical, with a tolerance of ± 20% or less, preferably a tolerance of ± 10% or less, particularly preferably a tolerance of ± 5% or less. The requirement or condition of independence from object size can be formulated as follows: The circle of confusion of at least one light beam emitted from at least one point of the object is larger than an image size of the object, i.e. a size of the object in an image plane.The detector can be configured to determine the longitudinal coordinate z of the object independently of the object size if the circle of confusion of the at least one light beam emitted by the at least one point of the object is larger than an image size of the object. This condition can be satisfied by OSize <z0Exzi2|Zs−Zi| where z0 is a longitudinal distance from the object to the transmission device; E x is a diameter of an exit pupil of the transmission device; z s is a longitudinal distance from the transfer device to the photosensitive surface; z i is a distance from the transmission device to an image of the object; and O Größeis an object size of the object in the object plane. Here, the term "diameter of an exit pupil" refers to an aperture of the transmission device. For a given measuring range, the condition can be met, for example, by varying the sensor position, the diameter of the exit pupil, or the image of the object, e.g., by varying the focal length. The detector can be configured to determine the longitudinal coordinate z of the object independently of the object size if OSize <z0Exzi2|Zs−Zi| applies to at least one distance z0. For example, the detector can be set up to determine the longitudinal coordinate z at the at least one distance z0 when the object size varies and / or changes over a large range, e.g., by more than 100% of the object size. The detector can be set up to determine the longitudinal coordinate z at distances where the above-mentioned condition OSize <z0Exzi2|Zs−Zi| is only weakly fulfilled if the object size varies and / or changes within a smaller range, in particular if the object size varies and / or changes by ± 20% or less, preferably by ± 10% or less, particularly preferably by ± 5% or less. The detector can be set up to determine the longitudinal coordinate z over the entire measuring range if OSize <z0Exzi2|Zs−Zi| applies to the at least one distance z0 and if the object size varies and / or changes by ± 20% or less, preferably by ± 10% or less, particularly preferably by ± 5% or less. In the present case, the term “applies to at least one distance” refers to the fact that the longitudinal coordinate z can be determined at the at least one distance independently of the object size and that the detector is set up such that it determines the longitudinal coordinate z at other distances, in particular within the entire measuring range, if the object size varies and / or changes by ± 20% or less, preferably by ± 10% or less, particularly preferably by ± 5% or less.

[0052] In this context, the term "measurement range" generally refers to any range in which the determination of the longitudinal coordinate z is performed. The measurement range can be adjusted by setting one or more parameters selected from the group consisting of: the longitudinal distance between the object and the transmission device z0; the focal length of the transmission device f; the diameter of the exit pupil of the transmission device E x ; the longitudinal distance between the transfer device and the photosensitive surface z s ; the distance between the transmission device and an image of the object z i ; and the object size O Größeof the object in the object plane. If, for example, the object size does not exceed an object size limit, there is a clear relationship between the quotient signal Q and the longitudinal distance from the object to the transmission device. The object size limit can depend on the longitudinal distance between the transmission device and the light-sensitive surface, the longitudinal distance between the object and the transmission device, and an F-number of the transmission device F#, i.e. a ratio between the focal length of the transmission device and the diameter of an exit pupil of the transmission device. The measuring range can be adjusted, for example, by adjusting the longitudinal distance between the transmission device and the light-sensitive surface z s and / or the distance between the transmission device and an image of the object z iand / or the longitudinal distance between the transmission device and the light-sensitive surface and / or the focal length and the F-number of the transmission device can be selected and / or chosen. For example, the focal length and / or the F-number can be adjusted with a zoom lens. In particular, the focal length can be between 10 and 200 mm, preferably between 20 and 150 mm. The F-number can be between 1 and 10, preferably between 1.5 and 6. The longitudinal distance to the transmission device can be as short as possible. The longitudinal distance between the transmission device and the light-sensitive surface can be between 0 and 200 mm, preferably between 20 and 50 mm. For a given system configuration (f, F#, z s) a unique value for the object size limit can be calculated. For example, if the focal length is 3.5 mm and the F-number is 2.0, and the object size can be smaller than 1.75 mm, a lower object size limit is preferably 0.5 µm or more, more preferably 1 µm or more, and most preferably 10 µm or more. The lower object size limit refers to a minimum object size when using an active measuring system, in particular to a laser spot size.

[0053] The evaluation device may be configured to derive the quotient signal Q by dividing the sensor signals and / or dividing multiples of the sensor signals and / or dividing linear combinations of the sensor signals. The evaluation device may be configured to use at least one predetermined relationship between the quotient signal Q and the longitudinal coordinate to determine the longitudinal coordinate. For example, the evaluation device is configured to derive the quotient signal Q by Q(zO)=∬A1E(x,y;zO)dxdy∬A2E(x,y;zO)dxdy where x and y are transverse coordinates, A1 and A2 are areas of the beam profile at the sensor position and E(x,y,z o ) the beam profile at the object distance z oThe area A1 and the area A2 can differ from each other. In particular, A1 and A2 are not congruent. A1 and A2 can therefore differ in shape and / or content. In the present case, the term "beam profile" refers to a spatial distribution of an intensity of the light beam, in particular in at least one plane that is perpendicular to the propagation of the light beam. The beam profile can be a cross-section of the light beam. The beam profile can be selected from the group consisting of a trapezoidal beam profile, a triangular beam profile, a conical beam profile, and a linear combination of Gaussian beam profiles. In principle, the beam profile depends on the luminance L(z o ) and the bundle form S(x,y;z o), E(x, y; zo) = L · S. By deriving the quotient signal, the longitudinal coordinate can be determined independently of the luminance. Furthermore, the use of the quotient signal enables the determination of the distance z0 regardless of the object size. The quotient signal thus enables the determination of the distance z0 regardless of the material properties and / or reflection properties and / or scattering properties of the object and regardless of changes in the light source, such as those caused by manufacturing accuracy, heat, water, dirt, damage to the lens, or the like. Furthermore, a reliable determination of the longitudinal coordinate of the object is possible even with very large spot sizes, e.g. in the case of overexposure.

[0054] Each of the sensor signals can comprise at least one piece of information about at least one region of the beam profile of the light beam. As used herein, the term "region of the beam profile" generally refers to any region of the beam profile at the sensor position that is used to determine the quotient signal Q. The light-sensitive regions can be arranged such that a first sensor signal comprises information about a first region of the beam profile and a second sensor signal comprises information about a second region of the beam profile. The first region of the beam profile and the second region of the beam profile can be adjacent and / or overlapping regions. The first region of the beam profile and the second region of the beam profile may not be congruent in area.

[0055] The evaluation device can be configured to determine and / or select the first region of the beam profile and the second region of the beam profile. The first region of the beam profile can essentially comprise edge information of the beam profile and the second region of the beam profile can essentially comprise center information of the beam profile. The beam profile can have a center, i.e., a maximum value of the beam profile and / or a center point of a plateau of the beam profile and / or a geometric center of the light spot, and sloping flanks emanating from the center. The second region can comprise inner regions of the cross-section and the first region can comprise outer regions of the cross-section. Here, the term "essentially center information" generally refers to a small proportion of edge information, i.e.a proportion of the intensity distribution that corresponds to edges, compared to a proportion of the center information, i.e. a proportion of the intensity distribution that corresponds to the center. The center information preferably has a proportion of edge information of less than 10%, more preferably less than 5%, and most preferably the center information does not include any edge content. In the present case, the term “essentially edge information” generally refers to a small proportion of center information compared to a proportion of edge information. The edge information can include information about the entire beam profile, in particular from center and edge regions. The edge information can have a proportion of center information of less than 10%, preferably less than 5%, and most preferably the edge information does not include any center content.At least one region of the beam profile can be determined and / or selected as the second region of the beam profile if it is close to or around the center and substantially contains center information. At least one region of the beam profile can be determined and / or selected as the first region of the beam profile if it includes at least portions of the descending flanks of the cross-section. For example, the entire area of the cross-section can be determined as the first region. The first region of the beam profile can be region A2, and the second region of the beam profile can be region A1.

[0056] A different selection of the first region A1 and the second region A2 is also possible. The first region may, for example, comprise substantially outer regions of the beam profile, and the second region may comprise substantially inner regions of the beam profile. The center signal may, for example, be a signal corresponding to a rectangular strip encompassing the center of the light spot. The evaluation device may be configured to form a quotient of a first linear combination of the center signal and the sum signal and a second linear combination of the center signal and the sum signal. In particular, in the case of a two-dimensional beam profile, the beam profile may be divided into a left part and a right part, wherein the first region may comprise substantially regions of the left part of the beam profile, and the second region may comprise substantially regions of the right part of the beam profile.The first and second regions may, for example, be adjacent to one another, with a minimal separation. However, the separation between adjacent regions may also be varied and, for example, increased to improve the dynamic range of the quotient signal. For example, the separation between two adjacent regions may be increased by not evaluating the region between the first and second regions. This may reduce the light to one of the regions relatively and / or absolutely compared to the adjacent region, which may increase a quotient of the signal of the two regions. Furthermore, one or both regions may consist of separate sub-regions, which may be adjacent to one another and / or separated by regions that are not evaluated and / or that may be evaluated as part of another quotient.Furthermore, the first and second regions may consist of a linear combination of subregions, wherein the signal contributed by each subregion may be weighted differently when forming the center signal and / or the sum signal. This may further contribute to increasing the dynamic range of the quotient system.

[0057] The extent of the circle of confusion may be larger than the extent of the optical sensor. For example, the optical sensor may be positioned such that the circle of confusion extends beyond the optical sensor. The optical sensor may therefore only partially evaluate the beam profile of the light beam. The evaluation device may be configured to extrapolate a beam profile, for example, based on symmetry considerations or based on a comparison of the partial beam profile with previously recorded beam profiles or the like. Furthermore, the evaluation device may be configured to evaluate a partial sum signal and a partial center signal of a partial beam profile and convert them into a sum signal and a center signal of an extrapolated and / or adjusted and / or previously recorded beam profile or the like.

[0058] The edge information may comprise information about a number of photons in the first region of the beam profile, and the center information may comprise information about a number of photons in the second region of the beam profile. The evaluation device may be configured to determine a surface integral of the beam profile. The evaluation device may be configured to determine the edge information by integrating and / or summing the first region. The evaluation device may be configured to determine the center information by integrating and / or summing the second region. The beam profile may, for example, be a trapezoidal beam profile, and the evaluation device may be configured to determine an integral of the trapezoid.Furthermore, if trapezoidal beam profiles can be assumed, the determination of edge and center signals can be replaced by equivalent evaluations that utilize properties of the trapezoidal beam profile, such as determining the slope and position of the edges and the height of the central plateau and deriving edge and center signals by geometric considerations.

[0059] Additionally or alternatively, the evaluation device can be configured to determine center information and / or edge information from at least one section or cut of the light spot. This can be achieved, for example, by replacing the area integrals in the quotient signal Q with a line integral along the section or cut. To improve accuracy, multiple sections or cuts through the light spot can be used and averaged. In the case of an elliptical spot profile, averaging over multiple sections or cuts can lead to improved distance information.

[0060] The evaluation device can be configured to derive the quotient signal Q by dividing the edge information and the center information and / or dividing multiples of the edge information and the center information and / or dividing linear combinations of the edge information and the center information. Thus, photon ratios can essentially be used as the physical basis of the method.

[0061] The detector can be configured to determine depth information, in particular absolute depth information, from a radiation ratio of at least two asymmetric regions of a light beam profile on the at least two optical sensors. The detector can, for example, comprise a plurality of optical sensors arranged in a matrix. The detector can be configured to determine depth information from the radiation ratio of at least two asymmetric regions within an enclosed, in particular defocused, beam profile detected by a single matrix of optical sensors such as a CMOS detector. In particular, the detector can be configured to determine the depth information using the radiation ratio independently of a specific object size range. This principle is referred to as DPR (Distance by Photon Ratio).

[0062] The DPR principle can, for example, be applied to many subregions within a segmented image profile, such as a segmented image of at least one feature generated by the at least one light beam on the array of optical sensors, as shown below. The quotient Q A (z) can be written in the two-dimensional case as QA(z)=∬−rinnrinnP(x,z,y)dxdy∬−rinnrinnP(x,y,z)dxdy, where P(x, y, z) is a two-dimensional bundle profile and r in and r out inner and outer circle radii, respectively. For line-segmented quotients Q y (z) along the y-dimension this can be rewritten as Qy(z)=∬−rinnrinnP(x,z)dx∬−rinnrinnP(x,z)dx.

[0063] Without wishing to be bound by this theory, the defocused total beam profile P(x,z) can be considered as a superposition of defocused pixel profiles p(x,z) along the image width b(x,z). This relationship can be modeled as a convolution given by P(x,z)=b(x,z)∗p(x,z), where p(x,z) represents the point spread function (PSF) of a lens in defocus, which in the field of paraxial optics is also known as the circle of confusion (CoC). By substituting P(x,z) into Q y (z) the quotient Q described above can y (z) can be rewritten as Qy(z)=∬−rußrußb(x,z)⋅p(x,z)dx∬−rinnrinnb(x,z)∗p(x,z)dx=∬−rußräus ßb(x,z)dx⋅∫−rinnrinnp(x,z)dx∬−rinnrinnb(x,z)dx⋅∫−rinnrinnp(x,z)dx.

[0064] The CoC radius can be r c be and r o can be a pixel radius of the feature on the matrix of optical sensors, then r out = rc + r o ⇒ r out ≥ r c and r out ≥ r o , which results in Qy(z)=∫−rorob(x,z)dx⋅∫−rcrcp(x,z)dx∫−rinrinb(x,z)dx⋅∫−rinrinp(x,z)dx. In the case of r o ≤ r in < r c , Qy(z)=∫−rorob(x,z)dx⋅∫−rcrcp(x,z)dx∫−rorob(x,z)dx⋅∫−rinrinp(x,z)dx=∫−rcrcp(x,z)dx∫−rinrinp(x,z)dx, which means that the quotient is independent of the object size, provided that r o < r c ,

[0065] Object size independence (OSI) in DPR holds as long as the image width i remains below the width of the angle of scatter (CoC), denoted as c. In the one-dimensional case, this is represented by the diameters d o < d c Using paraxial optics, these diameters can be replaced, so that iaOs <Dxi|d−i|, with a as object distance, i as image distance, o s as object size, Dx as the diameter of the exit pupil of the lens and d as the sensor position with respect to the image-side principal plane.

[0066] After transformation, this can be written as Os <aDxi2|d−i|.

[0067] When focusing a single lens to infinity, this simplifies to 0s <fF#|1−fa|, where f is the focal length and F# is the F-number of the lens.

[0068] Furthermore, using an array of optical sensors, a defocused beam profile can be divided into cross sections along lines with a certain angle θ and a distance ω from the ordinate origin. Accordingly, the parameterization of a single line can be given by ω=x cos(θ)+y sin(θ).

[0069] The integration of the intensity along parallel lines can be described mathematically by an integral projection ℜ{·} of the well-known Radon transform, which is ℜ(ω,θ){f(x,y)}=∬−∞∞f(x,y)δ(x cos(θ)+y sin(θ)−ω)dx dy, where δ denotes the Dirac delta function and f (x, y) is the intensity of an enclosed defocused beam profile. The photon ratio R for a given angle θ and a given projection width ω is given by R=ℜ(ω,θ){f,(x,y)}ℜ(ω,θ){f(x,y)}, with f'(x, y) as the inner region. The variation of θ can yield different ratios R for inclined object surfaces at a certain distance. It is sufficient to let θ vary in the following interval {θ ∈ ℝ + , θ < π}.

[0070] In one embodiment, the light beam propagating from the object to the detector may illuminate the sensor element with at least one pattern comprising at least one feature point. As used herein, the term "feature point" refers to at least one at least partially extended feature of the pattern. The feature point may be selected from the group consisting of: at least one point, at least one line, at least one edge. The pattern may be generated by the object, for example, in response to illumination by the at least one light source with an illumination pattern comprising the at least one pattern. A1 may correspond to an entire or complete area of a feature point on the optical sensors. A2 may be a central area of the feature point on the optical sensors. The central area may be a constant value. The central area may be smaller compared to the entire area of the feature point.In the case of a circular feature point, the central region may, for example, have a radius of 0.1 to 0.9 of the full radius of the feature point, preferably of 0.4 to 0.6 of the full radius.

[0071] For example, the light beam propagating from the object to the detector can illuminate the optical sensors with at least one line pattern. The line pattern can be generated by the object, for example, in response to illumination by the at least one illumination source with an illumination pattern comprising the at least one line pattern. A1 can correspond to a full line width region of the line pattern on the optical sensors, in particular on the light-sensitive surface of the optical sensors. The line pattern on the optical sensors can be widened and / or shifted compared to the line pattern of the illumination pattern, so that the line width on the optical sensors is increased. In particular, in the case of an array of optical sensors, the line width of the line pattern on the optical sensors can change from one column to the next. A2 can be a central region of the line pattern on the optical sensors.The line width of the central region can be a constant value and, in particular, correspond to the line width in the illumination pattern. The central region can have a smaller line width compared to the full line width. For example, the central region can have a line width of 0.1 to 0.9 of the full line width, preferably of 0.4 to 0.6 of the full line width. The line pattern can be segmented on the optical sensors. Each column of the matrix of optical sensors can include center information about an intensity in the center region of the line pattern and edge information about an intensity from edge regions that extend further outward from the central region to edge regions of the line pattern.

[0072] For example, the light beam propagating from the object to the detector can illuminate the sensor element with at least one dot pattern. The dot pattern can be generated by the object, for example in response to illumination by the at least one light source with an illumination pattern comprising the at least one line pattern. A1 can correspond to an area with a full radius of a point of the dot pattern on the optical sensors. A2 can be a center area of the point in the dot pattern on the optical sensors. The center area can be a constant value. The center area can have a radius that is compared to the full radius. For example, the center area can have a radius of 0.1 to 0.9 of the full radius, preferably of 0.4 to 0.6 of the full radius.

[0073] The light beam propagating from the object to the detector can illuminate the sensor element with a reflection pattern that includes both dot and line patterns. In addition to or as an alternative to line and dot patterns, other embodiments are also possible.

[0074] The optical sensors may, for example, comprise a first optical sensor having a first light-sensitive surface and a second optical sensor having a second light-sensitive surface, wherein the first and second light-sensitive surfaces are arranged such that a condition ac≠bd is satisfied, where "a" is a ratio of photons incident on both an inner region of a plane perpendicular to the optical axis, which intersects the optical axis at a distance equal to half a focal length of the transmission device, and the first photosensitive surface, "b" is a ratio of photons incident on both the inner region of the plane and the second photosensitive surface, "c" is a ratio of photons incident on both an outer region of the plane and the first photosensitive surface, and "d" is a ratio of photons incident on both the outer region of the plane and the second photosensitive surface.The first light-sensitive surface and the second light-sensitive surface can be arranged such that the inner region has an area with a geometric center on the optical axis and an extent such that half of the photons impinge on the plane inside the inner region and the other half impinge on the plane outside the inner region. The first light-sensitive surface and the second light-sensitive surface can be arranged such that the inner region can be designed as a circle with a center on the optical axis and a radius r chosen such that half of the photons impinge on the plane inside the circle and the other half impinge on the plane outside the circle.

[0075] As described above, the detector can comprise at least one illumination source. A distance perpendicular to an optical axis of the detector between the illumination source and the optical sensors can be small. The distance perpendicular to the optical axis of the detector between the illumination source and the optical sensors can be less than 0.1 m, preferably less than 0.05 m and particularly preferably less than 0.025 m. The illumination source and the optical axis can be separated by a small baseline. In the present case, the term “baseline”, also called baseline, refers to a distance, e.g. in an xy plane, between the optical axis and the illumination source, in particular to a distance between the optical axis and a z-component of the illumination light beam. The illumination source can be spaced from the optical axis by a minimum distance.The minimum distance from the optical axis can be determined by further detector elements such as the size and position of the optical sensors and the at least one optional transmission device, which is described in more detail below. The baseline can be less than 0.1 m, preferably less than 0.05 m, more preferably less than 0.025 m. The baseline can be, for example, 21 mm. Preferably, the illumination source can be arranged directly next to the transmission device. For example, the transmission device can be flattened so that the illumination source can be positioned even closer to the optical axis. The illumination source can be arranged behind the transmission device.

[0076] At least one of the optical sensors can be configured to generate at least one sensor signal that depends on a time-of-flight (TOF) traveled by the illumination light beam from the illumination source to the object and the reflected light beam from the object to the light-sensitive surface of the optical sensor. The evaluation device can be configured to determine at least one TOF longitudinal coordinate z TOFof the object is determined by evaluating the TOF sensor signal. The optical sensor for generating the TOF sensor signal can be designed as a time-of-flight detector. The time-of-flight detector can be selected from the group consisting of: at least one pulsed time-of-flight detector; at least one phase-modulated time-of-flight detector; at least one direct time-of-flight detector; and at least one indirect time-of-flight detector. The pulsed time-of-flight detector can, for example, be at least one range-gated imager and / or at least one direct time-of-flight imager. The phase-modulated time-of-flight detector can, for example, be at least one RF-modulated light source with at least one phase detector. The optical sensor can be configured to determine a time delay between the emission of the illumination light beam by the illumination source and the reception of the reflected light beam.

[0077] For example, the optical sensor for generating the TOF sensor signal can be designed as a pulsed time-of-flight detector. The detector can comprise at least one interruption device, such as at least one shutter element, which is configured to generate a pulsed light beam. The optical sensor can be configured to store the TOF sensor signal in a plurality of time windows, in particular successive time windows, depending on the reception time of the reflected light beam. The optical sensor can be configured to store the generated TOF sensor signal in at least one first time window and / or in at least one second time window, depending on the reception time of the reflected light beam. The first and second time windows can be correlated with the opening and closing of the interruption device. The duration of the first and second time windows can be predefined.For example, the TOF sensor signal can be stored in the first time window during the opening of the interrupting device, while the TOF sensor signal can be stored in the second time window during the closing of the interrupting device. Other time window durations are possible. The first and second time windows can include information about background, signal height, and signal displacement.

[0078] For example, the optical sensor for generating the TOF sensor signal can be designed as a direct time-of-flight imager. The direct time-of-flight imager can comprise at least one illumination source configured to generate at least one single laser pulse. The single laser pulse can be reflected back from the object onto the optical sensor. The optical sensor can comprise at least one photodiode, e.g. at least one avalanche photodiode (APD), such as at least one Si APD, or such as at least one InGaAs APD, or at least one PIN photodetector array, or at least one single-photon avalanche photodiode (SPAD), which is suitable for imaging the reflected light beam. The direct time-of-flight imager can be configured to image at least one image with spatial and temporal data.

[0079] For example, the optical sensor for generating the TOF sensor signal can be designed as a phase-modulated time-of-flight modulator. The phase-modulated time-of-flight modulator can be configured to measure a phase difference, in particular a phase shift, by determining a correlated signal, for example by multiplying a received signal, i.e., the reflected light beam, by the emitted signal, i.e., the illumination light beam. A DC component of the correlated signal can include information about the phase difference. The evaluation device can be configured to determine the second longitudinal coordinate of the object from the phase difference. For example, the illumination source and the optical sensor for generating the TOF sensor signal can be configured as an RF-modulated light source with at least one phase detector.The illumination source may, for example, comprise at least one LED and / or at least one laser. The illumination source may comprise at least one modulation device configured to modulate the light beam with a predefined phase shift. The modulation device may, for example, comprise at least one radio-frequency module. The radio-frequency module may be configured to modulate the illumination beam with an RF carrier. The optical sensor may be configured to determine a phase shift of the reflected light beam incident on the optical sensor.

[0080] The optical sensor can be configured as and / or comprise at least one time-of-flight pixel. Preferably, the detector can comprise at least two optical sensors, each optical sensor being configured as and / or comprising at least one TOF pixel. The detector, in particular the optical sensor, can comprise, for example, a quadrant diode configured to generate the TOF sensor signal. The detector, in particular the optical sensor, can comprise, for example, at least one pixelated TOF imager.

[0081] The evaluation device may be configured to determine the at least one TOF longitudinal coordinate z TOFof the object is determined by evaluating the TOF sensor signal. Here, the term "TOF longitudinal coordinate" refers to a longitudinal coordinate derived from the TOF sensor signal. As described above, the illumination light source can be configured to periodically generate at least one light pulse. The detector can be configured to generate the first longitudinal sensor signal for each period. The evaluation device can be configured to determine, based on the second longitudinal coordinate, in which pulse period the TOF sensor signal was generated. The detector can be configured to unambiguously assign, using the combined sensor signal, to which period the TOF signal refers. Both the TOF sensor signal and the combined sensor signal can be non-monotonic functions of the longitudinal coordinate z realTherefore, the longitudinal coordinate cannot be uniquely determined from the TOF sensor signal or the combined sensor signal alone, and a measurement range does not have to be limited to a longitudinal range in which the signals are unique functions of z realare. The term "measurement range" generally refers to a range between the object and the detector in which the determination of the longitudinal coordinate is possible. The term "longitudinal range" generally refers to a range from the object to the detector in which an unambiguous determination of the longitudinal coordinate is possible. Below and / or above certain distances from the object to the detector, a determination of the longitudinal coordinate may not be possible. For example, time-of-flight measurements are not possible below a certain distance between the object and detector, which may be due to the minimum measurement time of the internal clock. Furthermore, for time-of-flight measurements, the sensor signal may be unambiguous within a longitudinal period, but the sensor signal may be the same when integer multiples of the longitudinal period are added, so the determined longitudinal coordinate may not be unambiguous.Thus, the same TOF sensor signal is used for a distance z1 and a distance z1+n z. 1p where n is an integer denoting the longitudinal period, and z 1p is the longitudinal period of the TOF sensor signal, where the distances z1 and z1+n z 1p within the measurement range. In this context, the term "longitudinal period" refers to subdivisions of a period, particularly a distance range, in which the longitudinal coordinate can be unambiguously determined from the TOF sensor signal. Non-unique longitudinal coordinates can be referred to as relative longitudinal coordinates, and the unambiguous longitudinal coordinates as absolute longitudinal coordinates.

[0082] If both the TOF sensor signal F1 and the combined sensor signals F2 are available, it may be possible to uniquely determine the longitudinal coordinate and extend the longitudinal range, provided that each signal pair (F1, F2) corresponds to a unique distance and vice versa. In particular, if a unique signal pair (F1, F2) exists for each longitudinal coordinate and vice versa, the evaluation device may be configured to determine the unique combined longitudinal coordinate by (1) selecting at least one first selected signal such as the TOF sensor signal and / or the combined sensor signal and determining non-unique first longitudinal coordinates; (2) selecting a second selected signal such as the combined signal Q and / or the TOF sensor signal not selected in step (1) and determining non-unique second longitudinal coordinates; (3) determining whether one of the non-unique first longitudinal coordinates and the non-unique second longitudinal coordinates agree up to a predetermined tolerance threshold; (4) Setting a combined unique longitudinal coordinate as the matching longitudinal coordinate.

[0083] In steps (1) and (2), signals can be selected in the specified order or in a different order. For example, in step (1), the TOF sensor signal can be selected, and in step (2), the combined signal Q can be selected. In another example, in step (1), the combined sensor signal can be selected, and the non-unique first longitudinal sensor signal can be determined from it. In step (2), the TOF sensor signal can be selected.

[0084] Additionally or alternatively to step (4), the evaluation device may be configured to output an error signal if no matching coordinates are found and / or to output an error signal if more than one matching coordinate is found. Additionally or alternatively, the signal pairs and their corresponding longitudinal coordinates may be stored in a check table. Additionally or alternatively, the signal pairs and their corresponding longitudinal coordinates may be approximated or described by an analytical function that is evaluated to find the longitudinal coordinate corresponding to a given signal pair.

[0085] The evaluation device may comprise at least two memory elements. As used herein, the term "memory element" refers to a device configured to store information. The evaluation device may be configured to receive and store information provided by the optical sensors, e.g., the at least one first sensor signal. This information may comprise raw sensor data and / or processed sensor data. The memory element may, for example, be configured to store information for further evaluation by the evaluation device. The memory element may be a volatile or non-volatile memory element.

[0086] As described above, the optical sensor can be designed as and / or comprise at least one TOF pixel. The detector can comprise at least two switches. Each of the switches can be connected to the optical sensor configured to generate the first sensor signal, e.g., by at least one connecting element. In particular, each of the switches can be connected to the ToF pixel. The switches are configured to provide the TOF sensor signal to one of the storage elements. In particular, the switches can be configured to pass the generated TOF sensor signal through one of the switches depending on a reception time of the reflected light beam. For example, the TOF sensor signal can pass through one of the switches when the interruption device is opened, while the TOF sensor signal can pass through the other switch when the interruption device is closed.Each of the switches can be controlled by a control signal whose pulse length is identical to a pulse length of a light pulse generated by the illumination source. The control signal for one of the switches can be delayed. The delay can, for example, correspond to the pulse length of the light pulse. The evaluation device can be configured to sample a first part or fraction of the TOF sensor signal and / or store it in a first memory element by a first switch, depending on the delay, and to sample the other, second part or fraction of the TOF sensor signal and / or store it in a second memory element by a second switch. The evaluation device can be configured to determine the first longitudinal coordinate by evaluating the first part and the second part of the TOF sensor signal.The evaluation device may be arranged to determine the first longitudinal coordinate z1 by. z1=12⋅c⋅t0⋅s12s11+s12+z0; where c is the speed of light, t0 is the pulse length of the illumination light beam, z0 is a distance offset often determined by the resolution of the time measurement, and S11 and S12 are the first part and the second part of the TOF sensor signal, respectively.

[0087] As described above, the detector may further comprise one or more additional elements, such as one or more additional optical elements. Furthermore, the detector may be fully or partially integrated into at least one housing.

[0088] In a first preferred embodiment of the present invention, the detector may comprise: - at least one first optical sensor having a first light-sensitive surface, wherein the first optical sensor may be configured to generate at least one first sensor signal in response to illumination of the first light-sensitive surface by a light beam propagating from the object to the detector; - at least one second optical sensor having a second light-sensitive area, wherein the second optical sensor can be configured to generate at least one second sensor signal in response to illumination of the second light-sensitive area by the light beam, wherein the first light-sensitive area can be smaller than the second light-sensitive area; and - at least one evaluation device configured to determine at least one longitudinal coordinate z of the object by evaluating the first and second sensor signals.

[0089] In this first preferred embodiment, the optical sensors can be arranged such that the light-sensitive surfaces of the optical sensors differ in their longitudinal coordinates and / or their surface areas.

[0090] As will be explained in more detail below, each optical sensor can preferably be designed such that exactly one light-sensitive surface is present in the respective optical sensor, for example by providing exactly one light-sensitive surface that can be illuminated, wherein the illumination generates exactly one uniform sensor signal for the entire optical sensor. Therefore, each optical sensor is preferably an optical single-surface sensor and not a pixelated optical sensor such as a sensor matrix. However, other embodiments are also possible. The use of optical single-surface sensors, however, makes the construction of the detector particularly simple and efficient.Thus, for example, commercially available photosensors, such as commercially available silicon photodiodes, each having exactly one photosensitive area, can be used in the structure, one with a small photosensitive area and one with a larger photosensitive area, as explained in more detail below.

[0091] The first and second light-sensitive surfaces can in particular be aligned with the object.

[0092] In particular, the light beam propagating from the object to the detector can completely illuminate the first light-sensitive surface, such that the first light-sensitive surface is located entirely within the light beam, wherein a width of the light beam is greater than the light-sensitive surface of the first optical sensor. In contrast, the light beam propagating from the object to the detector can preferably create a light spot on the second light-sensitive surface that is smaller than the second light-sensitive surface, such that the light spot is located entirely within the second light-sensitive surface. A shadow generated by the first optical sensor can be located within the light spot on the second light-sensitive surface.Thus, in general, the first optical sensor with the smaller first light-sensitive surface can be located in front of the second optical sensor as seen from the object, wherein the first light-sensitive surface is completely located within the light beam and the light beam creates a light spot on the second light-sensitive surface that is smaller than the second light-sensitive surface, and wherein a shadow is further created by the first optical sensor within the light spot. The situation can be easily adapted by a person skilled in the art by selecting one or more suitable lenses or elements that have a focusing or defocusing effect on the light beam, e.g. by using a suitable transmission device, as explained in more detail below. A light spot is generally a visible or recognizable round or non-round illumination of an article, surface, or object by a light beam.

[0093] As explained above, the first photosensitive area is smaller than the second photosensitive area. In the present case, the term "is smaller than" refers to the area of the first photosensitive area being smaller than the area of the second photosensitive area, for example by at least a factor of 0.9, e.g. by at least a factor of 0.7 or even by at least a factor of 0.5. For example, both the first and the second photosensitive area can have the shape of a square or a rectangle, wherein side lengths of the square or rectangle of the first photosensitive area are smaller than corresponding side lengths of the square or rectangle of the second photosensitive area.Alternatively, both the first and second photosensitive surfaces may be circular, with a diameter of the first photosensitive surface being smaller than a diameter of the second photosensitive surface. Alternatively, for example, the first photosensitive surface may have a first equivalent diameter and the second photosensitive surface may have a second equivalent diameter, with the first equivalent diameter being smaller than the second equivalent diameter.

[0094] The first light-sensitive surface can overlap with the second light-sensitive surface in a propagation direction of the light beam. The light beam can fully or partially illuminate both the first light-sensitive surface and the second light-sensitive surface. Thus, for example, the first light-sensitive surface can be located in front of the second light-sensitive surface when viewed from an object located on an optical axis of the detector, so that the first light-sensitive surface is located entirely within the second light-sensitive surface when viewed from the object.When the light beam propagates from this object toward the first and second photosensitive surfaces, the light beam can completely illuminate the first photosensitive surface and create a light spot on the second photosensitive surface, with a shadow generated by the first optical sensor located within the light spot. However, it should be noted that other embodiments are also possible.

[0095] In particular, as explained in more detail below, the evaluation device can be configured to determine the at least one longitudinal coordinate z of the object using at least one known, determinable, or predetermined relationship between the first and second sensor signals. In particular, the evaluation device is configured to determine the at least one coordinate z of the object using at least one known, determinable, or predetermined relationship between the quotient signal derived from the first and second sensor signals and the longitudinal coordinate.

[0096] Thus, the evaluation device may in particular be configured to derive the quotient signal Q by dividing the first and second sensor signals, by dividing multiples of the first and second sensor signals, or by dividing linear combinations of the first and second sensor signals. As an example, Q can be simply determined as Q=s1 / s2 or Q=s2 / s1, where s1 denotes the first sensor signal and s2 the second sensor signal. Additionally or alternatively, Q can be determined as Q=a⋅s1 / b⋅s2 or Q=b⋅s2 / a⋅s1, where a and b are real numbers, which may be predetermined or determinable, for example. Additionally or alternatively, Q can be determined as Q=(a⋅s1+b⋅s2) / (c⋅s1+d⋅s2), where a, b, c and d are real numbers, which can be predetermined or determinable, for example. As a simple example of the latter, Q can be determined as Q=s1 / (s1+s2).

[0097] Other quotient signals are also possible.

[0098] In the setup described above, Q is generally a monotonic function of the longitudinal coordinate of the object and / or the size of the light spot, e.g., the diameter or equivalent diameter of the light spot. For example, when using linear optical sensors, the quotient Q=s1 / s2 is a monotonically decreasing function of the size of the light spot. Without wishing to be bound by this theory, it is assumed that this is due to the fact that, in the preferred setup described above, both the first signal s1 and the second signal s2 decrease quadratically with increasing distance from the light source, since the amount of light reaching the detector decreases. However, the first signal s1 decreases more quickly than the second signal s2, since, in the optical setup used in the experiments, the light spot grows in the image plane and is thus distributed over a larger area.The quotient of the first and second sensor signals therefore decreases continuously with increasing diameter of the light beam or the light spot on the first and second light-sensitive surfaces. Furthermore, the quotient is largely independent of the total power of the light beam, since the total power of the light beam is included in both the first sensor signal and the second sensor signal. Consequently, the quotient Q can form a secondary signal that provides a clear relationship between the first and second sensor signals and the size or diameter of the light beam. On the other hand, since the size or diameter of the light beam depends on the distance between the object from which the light beam propagates towards the detector and the detector itself, i.e., on the longitudinal coordinate of the object, a clear relationship can exist between the first and second sensor signals and the longitudinal coordinate. For the latter, for example,Reference is made to WO 2014 / 097181 A1. The predetermined relationship can be determined by analytical considerations, e.g., by assuming a linear combination of Gaussian light beams, by empirical measurements, e.g., by measuring the first and second sensor signals or a secondary signal derived therefrom as a function of the longitudinal coordinate of the object, or by both.

[0099] The evaluation device is configured to determine the longitudinal coordinate by evaluating the quotient signal Q. The evaluation device may be configured to use at least one predetermined relationship between the quotient signal Q and the longitudinal coordinate. The predetermined relationship may be an empirical relationship, a semi-empirical relationship, and / or an analytically derived relationship. The evaluation device may include at least one data storage device for storing the predetermined relationship, such as a checklist or a check table.

[0100] The quotient signal Q can be determined by various means. For example, a software means for deriving the quotient signal, a hardware means for deriving the quotient signal, or both can be used and implemented in the evaluation device. Thus, the evaluation device can, for example, comprise at least one divider, wherein the divider is configured to derive the quotient signal. The divider can be implemented entirely or partially as a software divider or a hardware divider.

[0101] The first and second optical sensors can, in particular, be arranged linearly in one and the same beam path of the detector. In this context, the term "linear" generally refers to the fact that the sensors are arranged along an axis. Thus, for example, the first and second optical sensors can both be located on an optical axis of the detector. In particular, the first and second optical sensors can be arranged concentrically to an optical axis of the detector.

[0102] The first optical sensor can be arranged in front of the second optical sensor. Thus, for example, the first optical sensor can simply be placed on the surface of the second optical sensor. Additionally or alternatively, the first optical sensor can be spaced from the second optical sensor by no more than five times the square root of an area of the first light-sensitive surface. Additionally or alternatively, the first optical sensor can be arranged in front of the second optical sensor and spaced from the second optical sensor by no more than 50 mm, preferably no more than 15 mm.

[0103] As explained above, the second photosensitive area is larger than the first photosensitive area. Thus, for example, the second photosensitive area can be larger than the first photosensitive area by at least a factor of two, preferably by at least a factor of three, and particularly preferably by at least a factor of five.

[0104] The first photosensitive surface may in particular be a small photosensitive surface, so that the light beam preferably completely illuminates this photosensitive surface. As an example applicable to typical optical configurations, the first photosensitive surface may have a surface area of 1 mm 2 up to 150 mm 2 , preferably a surface area of 10 mm 2 up to 100 mm 2 have.

[0105] The second light-sensitive surface can, in particular, be a large surface. Thus, preferably within a measuring range of the detector, light spots generated by a light beam propagating from the object to the detector can lie entirely within the second light-sensitive surface, so that the light spot is located entirely within the boundaries of the second light-sensitive surface. As an example, applicable to a typical optical setup, the second light-sensitive surface can have a surface area of 160 mm 2 up to 1000 mm 2 , preferably an area of 200 mm 2 up to 600 mm 2 have.

[0106] Optical infrared sensors that can be used for the first optical sensor, for the second optical sensor, or for both the first and second optical sensors can be commercially available optical infrared sensors, such as optical infrared sensors available from Hamamatsu Photonics Deutschland GmbH, D-82211 Herrsching am Ammersee, Germany. Thus, for example, the first optical sensor, the second optical sensor, or both the first and second optical sensors can comprise at least one intrinsic photovoltaic type optical sensor, preferably at least one semiconductor photodiode selected from the group consisting of: a Ge photodiode, an InGaAs photodiode, an extended InGaAs photodiode, an InAs photodiode, an InSb photodiode, and a HgCdTe photodiode.Additionally or alternatively, the first optical sensor, the second optical sensor, or both the first and second optical sensors may comprise at least one optical sensor of an extrinsic photovoltaic type, preferably at least one semiconductor photodiode selected from the group consisting of: a Ge:Au photodiode, a Ge:Hg photodiode, a Ge:Cu photodiode, a Ge:Zn photodiode, a Si:Ga photodiode, a Si:As photodiode. Additionally or alternatively, the first optical sensor, the second optical sensor, or both the first and second optical sensors may comprise at least one bolometer, preferably a bolometer selected from the group consisting of a VO bolometer and an amorphous Si bolometer.

[0107] The first and second optical sensors can each be independently opaque, transparent, or semi-transparent. However, for simplicity, opaque sensors that do not transmit the light beam may be used, as these opaque sensors are generally readily available commercially.

[0108] The first and second optical sensors can each be, in particular, uniform sensors, each having a single light-sensitive surface. The first and second optical sensors can therefore, in particular, be non-pixelated optical sensors.

[0109] As explained above, by evaluating the first and second sensor signals, the detector can be enabled to determine at least one longitudinal coordinate of the object, including the possibility of determining the longitudinal coordinate of the entire object or one or more parts thereof. In addition, other coordinates of the object, including one or more transverse coordinates and / or rotational coordinates, can also be determined by the detector, in particular by the evaluation device. Thus, for example, one or more additional transverse sensors can be used to determine at least one transverse coordinate of the object. Various transverse sensors are generally known in the art, such as the transverse sensors disclosed in WO 2014 / 097181 A1 and / or other position-sensitive devices (PSDs), such as quadrant diodes, CCD or CMOS chips, or the like.These devices can, in principle, also be implemented in the detector according to the invention. For example, a portion of the light beam can be split within the detector by at least one beam splitter element. The split portion can, for example, be directed to a transverse sensor, such as a CCD or CMOS chip or a camera sensor, and a transverse position of a light spot generated by the split portion on the transverse sensor can be determined, thereby determining at least one transverse coordinate of the object. Consequently, the detector according to the present invention can be either a one-dimensional detector, such as a simple distance measuring device, or it can be embodied as a two-dimensional detector or even as a three-dimensional detector.Furthermore, as explained above or explained in more detail below, a three-dimensional image can also be created by one-dimensional scanning of a landscape or environment. Consequently, the detector according to the invention can, in particular, be a one-dimensional, a two-dimensional, or a three-dimensional detector. The evaluation device can further be configured to determine at least one transverse coordinate x, y of the object.

[0110] In a further embodiment, the detector may comprise: - at least one first optical sensor having a first light-sensitive surface, wherein the first optical sensor may be configured to generate at least one first sensor signal in response to illumination of the first light-sensitive surface by a light beam propagating from the object to the detector; - at least one second optical sensor having a second light-sensitive surface, wherein the second optical sensor can be configured to generate at least one second sensor signal in response to illumination of the second light-sensitive surface by the light beam, wherein the first light-sensitive surface and the second light-sensitive surface can be arranged such that the light-sensitive surfaces differ in their longitudinal coordinate; and - at least one evaluation device configured to determine at least one longitudinal coordinate z of the object by evaluating the first and second sensor signals.

[0111] For definitions and embodiments, reference can be made to the description of the first preferred embodiment. In particular, the first photosensitive area may be smaller than the second photosensitive area.

[0112] In a further preferred embodiment of the present invention, the detector may comprise: - at least one sensor element comprising a matrix of optical sensors, the optical sensors each having a light-sensitive surface, each optical sensor being configured to generate at least one sensor signal in response to illumination of the light-sensitive surface by at least one light beam propagating from the object to the detector; - at least one evaluation device can be configured to evaluate the sensor signals by a) determining at least one optical sensor with the highest sensor signal and forming at least one center signal; b) evaluating the sensor signals of the optical sensors of the matrix and forming at least one sum signal; c) determining at least one combined signal by combining the center signal and the sum signal; and d) Determining at least one longitudinal coordinate z of the object by evaluating the combined signal.

[0113] In this further preferred embodiment, the optical sensors can be arranged such that the light-sensitive surfaces of the optical sensors differ in terms of spatial offset and / or surface areas.

[0114] In the present case, the term "sensor element" generally refers to a device or a combination of a plurality of devices configured to detect at least one parameter. In the present case, the parameter can be, in particular, an optical parameter and the sensor element can be, in particular, an optical sensor element. The sensor element can be designed as a uniform, single device or as a combination of several devices. In the present case, the term "matrix" generally refers to an arrangement of a plurality of elements in a predetermined geometric order. The matrix can, as will be explained in more detail below, in particular be a rectangular matrix with one or more rows and one or more columns or can comprise these. The rows and columns can, in particular, be arranged rectangularly. However, it should be noted that other arrangements are also possible, e.g.Non-rectangular arrangements. Circular arrangements, for example, are also conceivable, in which the elements are arranged in concentric circles or ellipses around a center point. The matrix can, for example, be a single row of pixels. Other arrangements are also possible.

[0115] The optical sensors of the matrix can be similar, in particular with regard to size and / or sensitivity and / or other optical, electrical, and mechanical properties. The light-sensitive surfaces of all optical sensors of the matrix can, in particular, lie in a common plane, preferably facing the object, so that a light beam propagating from the object to the detector can generate a light spot on the common plane.

[0116] As explained in more detail in WO 2012 / 110924 A1 or WO 2014 / 097181 A1, for example, there is typically a predetermined or determinable relationship between a size of a light spot, such as a diameter of the light spot, a beam waist, or an equivalent diameter, and the longitudinal coordinate of the object from which the light beam propagates to the detector. Without wishing to be bound by this theory, the light spot can be characterized by two measurement quantities: a measurement signal measured in a small measurement spot at or near the center of the light spot, also referred to as the center signal, and an integral or sum signal integrated over the light spot, with or without a center signal.For a light beam with a certain total power that does not change when the beam is expanded or focused, the sum signal should be independent of the spot size of the light spot and thus, at least when using linear optical sensors within their respective measuring ranges, independent of the distance between the object and the detector. However, the center signal is dependent on the spot size. Thus, the center signal typically increases when the light beam is focused and decreases when the light beam is defocused. By comparing the center signal and the sum signal, information about the size of the light spot created by the light beam and thus about the longitudinal coordinate of the object can be generated.The comparison of the center signal and the sum signal can be carried out, for example, by forming the quotient signal Q from the center signal and the sum signal and by using a predetermined or determinable relationship between the longitudinal coordinate and the quotient signal to derive the longitudinal coordinate.

[0117] The use of an array of optical sensors offers a variety of advantages and benefits. Thus, the center of the light spot generated by the light beam on the sensor element, e.g., on the common plane of the light-sensitive surfaces of the optical sensors of the array of the sensor element, can vary with the transverse position of the object. By using an array of optical sensors, the detector according to the invention can adapt to these changes in conditions and thus determine the center of the light spot simply by comparing the sensor signals. Consequently, the detector according to the invention can itself select the center signal and determine the sum signal, and from these two signals, derive a combined signal containing information about the longitudinal coordinate of the object. By evaluating the combined signal, the longitudinal coordinate of the object can thus be determined.The use of the matrix of optical sensors thus offers considerable flexibility with regard to the position of the object, in particular with regard to a transverse position of the object.

[0118] The transverse position of the light spot on the matrix of optical sensors, such as the transverse position of the at least one optical sensor generating the sensor signal, can even be used as additional information from which at least one piece of information about a transverse position of the object can be derived, as disclosed, for example, in WO 2014 / 198629 A1. Additionally or alternatively, as explained in more detail below, the detector according to the invention can contain at least one additional transverse detector in order to detect at least one transverse coordinate of the object in addition to the at least one longitudinal coordinate.

[0119] Consequently, the term "center signal" in the sense of the present invention generally refers to the at least one sensor signal that essentially comprises center information of the beam profile. Here, the term "highest sensor signal" refers to a local maximum and / or a maximum in a region of interest. For example, the center signal can be the signal of the at least one optical sensor that has the highest sensor signal from the multitude of sensor signals generated by the optical sensors of the entire matrix or a region of interest within the matrix, wherein the region of interest can be predetermined or determinable in an image generated by the optical sensors of the matrix.The center signal may originate from a single optical sensor or, as explained in more detail below, from a group of optical sensors, in which case, for example, the sensor signals of the group of optical sensors may be added, integrated, or averaged to determine the center signal. The group of optical sensors from which the center signal originates may be a group of adjacent optical sensors, such as optical sensors that are less than a predetermined distance from the actual optical sensor with the highest sensor signal, or a group of optical sensors that generate sensor signals that are within a predetermined range of the highest sensor signal. The group of optical sensors from which the center signal originates may be chosen to be as large as possible to allow for maximum dynamic range.The evaluation device can be configured to determine the center signal by integrating the plurality of sensor signals, e.g., the plurality of optical sensors around the optical sensor with the highest sensor signal. The beam profile can be, for example, a trapezoidal beam profile, and the evaluation device can be configured to determine an integral of the trapezoid, in particular a plateau of the trapezoid.

[0120] Similarly, the term "sum signal" generally refers to a signal that essentially comprises edge information of the beam profile. The sum signal can be derived, for example, by summing the sensor signals, integrating over the sensor signals, or averaging over the sensor signals of the entire matrix or a region of interest within the matrix, where the region of interest can be predetermined or determinable within an image generated by the optical sensors of the matrix. When adding, integrating, or averaging the sensor signals, the actual optical sensors from which the sensor signal is generated can be excluded from the adding, integrating, or averaging, or alternatively, can be included in the adding, integrating, or averaging.The evaluation device may be configured to determine the sum signal by integrating signals from the entire matrix or the region of interest within the matrix. The beam profile may, for example, be a trapezoidal beam profile, and the evaluation device may be configured to determine an integral of the entire trapezoid. Furthermore, if trapezoidal beam profiles can be assumed, the determination of edge and center signals may be replaced by equivalent evaluations that utilize properties of the trapezoidal beam profile, such as determining the slope and position of the edges and the height of the central plateau, and deriving edge and center signals through geometric considerations.

[0121] Additionally or alternatively, the evaluation device can be configured to determine center information and / or edge information from at least one section or cut of the light spot. This can be achieved, for example, by replacing the area integrals in the quotient signal Q with a line integral along the section or cut. To improve accuracy, multiple sections or cuts through the light spot can be used and averaged. In the case of an elliptical spot profile, averaging over multiple sections or cuts can lead to improved distance information.

[0122] Similarly, the term "combined signal" generally refers to a signal generated by combining the center signal and the sum signal. In particular, the combination may comprise one or more of the following: forming a quotient of the center signal and the sum signal, or vice versa; forming a quotient of a multiple of the center signal and a multiple of the sum signal, or vice versa; forming a quotient of a linear combination of the center signal and a linear combination of the sum signal, or vice versa; forming a quotient of a first linear combination of the center signal and the sum signal and a second linear combination of the center signal and the sum signal.Additionally or alternatively, the combined signal may comprise any signal or signal combination containing at least one piece of information about a comparison between the center signal and the sum signal.

[0123] The light beam propagating from the object to the detector can, in particular, completely illuminate the at least one optical sensor from which the center signal is generated, so that the at least one optical sensor from which the center signal emanates lies completely within the light beam, wherein a width of the light beam is greater than the light-sensitive area of the at least one optical sensor from which the sensor signal emanates. In contrast, the light beam propagating from the object to the detector can, in particular, preferably generate a light spot on the entire matrix that is smaller than the matrix, so that the light spot is completely within the matrix. This situation can be easily adapted by a person skilled in the art by selecting one or more suitable lenses or elements that have a focusing or defocusing effect on the light beam, e.g.by using a suitable transmission device, as explained in more detail below. A "light spot" is generally defined herein as a visible or recognizable circular or non-circular illumination of an object, surface, or object by a light beam.

[0124] In particular, as explained in more detail below, the evaluation device can be configured to determine the at least one longitudinal coordinate z of the object using at least one known, determinable, or predetermined relationship between the sensor signals. In particular, the evaluation device is configured to determine the at least one coordinate z of the object using at least one known, determinable, or predetermined relationship between a quotient signal derived from the sensor signals and the longitudinal coordinate.

[0125] As described above, the center signal can generally be a single sensor signal, such as a sensor signal from the optical sensor in the center of the light spot, or it can be a combination of a plurality of sensor signals, such as a combination of sensor signals emanating from optical sensors in the center of the light spot, or a secondary sensor signal derived by processing a sensor signal derived by one or more of the above-mentioned possibilities. The determination of the center signal can be done electronically, since a comparison of sensor signals is relatively easy to implement using conventional electronics, or it can be done entirely or partially by software. In particular, the center signal can be selected from the group consisting of: the highest sensor signal; an average value of a group of sensor signals that lie within a predetermined tolerance range of the highest sensor signal;an average value of sensor signals from a group of optical sensors that includes the optical sensor with the highest sensor signal and a predetermined group of neighboring optical sensors; a sum of sensor signals from a group of optical sensors that includes the optical sensor with the highest sensor signal and a predetermined group of neighboring optical sensors; a sum of a group of sensor signals that are within a predetermined tolerance range of the highest sensor signal; an average value of a group of sensor signals that are above a predetermined threshold value; a sum of a group of sensor signals that are above a predetermined threshold value; an integral of sensor signals from a group of optical sensors that includes the optical sensor with the highest sensor signal and a predetermined group of neighboring optical sensors;an integral of a group of sensor signals that lie within a predetermined tolerance range of the highest sensor signal; an integral of a group of sensor signals that lie above a predetermined threshold value;

[0126] As described above, raw sensor signals from the optical sensors or secondary sensor signals derived therefrom can be used for evaluation. Here, the term "secondary sensor signal" generally refers to a signal, e.g., an electronic signal, particularly preferably an analog and / or digital signal, which is obtained by processing one or more raw signals, e.g., by filtering, averaging, demodulating, or the like. Thus, image processing algorithms can be used to generate secondary sensor signals from the entirety of the sensor signals of the matrix or from a region of interest within the matrix. In particular, the detector, such as the evaluation device, can be configured to transform the sensor signals of the optical sensor, thereby generating secondary optical sensor signals.wherein the evaluation device is configured to perform steps a)-d) using the secondary signals of the optical sensors. The transformation of the sensor signals can in particular comprise at least one transformation selected from the group consisting of: filtering; selecting at least one region of interest; forming a difference image between an image generated by the sensor signals and at least one offset; inverting sensor signals by reversing an image generated by the sensor signals; forming a difference image between an image generated by the sensor signals at different times; background correction; decomposition into color channels; decomposition into hue,Saturation and brightness channels; a frequency decomposition; a singular value decomposition; an application of a Canny edge detector; an application of a Laplace-Gaussian filter; an application of a Gaussian difference filter; an application of a Sobel operator; an application of a Laplace operator; an application of a Scharr operator; an application of a Prewitt operator; an application of a Roberts operator; an application of a Kirsch operator; an application of a high-pass filter; an application of a low-pass filter; an application of a Fourier transform; an application of a Radon transform; an application of a Hough transform; an application of a wavelet transform; thresholding; and the creation of a binary image. The region of interest can be determined manually by a user or automatically.e.g., by detecting an object in an image generated by the optical sensors. For example, a vehicle, a person, or another type of predetermined object can be identified by automatic image recognition within an image, i.e., within the totality of the sensor signals generated by the optical sensors, and the region of interest can be selected such that the object is located within the region of interest. In this case, the evaluation, e.g., the determination of the longitudinal coordinate, can be performed only for the region of interest. However, other implementations are also possible.

[0127] As explained above, the detection of the center of the light spot, i.e. the detection of the center signal and / or the at least one optical sensor from which the center signal emanates, can be carried out entirely or partially electronically or entirely or partially using one or more software algorithms. In particular, the evaluation device can comprise at least one center detector for detecting the at least one highest sensor signal and / or for forming the center signal. The center detector can be designed entirely or partially in software and / or entirely or partially in hardware. The center detector can be integrated entirely or partially into the at least one sensor element and / or designed entirely or partially independently of the sensor element.

[0128] As described above, the sum signal can be derived from all sensor signals in the matrix, from the sensor signals within a region of interest, or from one of these possibilities, excluding the sensor signals from the optical sensors that contribute to the center signal. In any case, a reliable sum signal can be generated that can be reliably compared with the center signal to determine the longitudinal coordinate. In general, the sum signal can be selected from the group consisting of: an average over all sensor signals in the matrix; a sum of all sensor signals in the matrix; an integral of all sensor signals in the matrix; an average over all sensor signals in the matrix excluding sensor signals from those optical sensors that contribute to the center signal; a sum of all sensor signals in the matrix excluding sensor signals from those optical sensors that contribute to the center signal;an integral of all sensor signals in the matrix, with the exception of sensor signals from those optical sensors that contribute to the center signal; a sum of sensor signals from optical sensors within a predetermined range of the optical sensor with the highest sensor signal; an integral of sensor signals from optical sensors within a predetermined range of the optical sensor with the highest sensor signal; a sum of sensor signals above a certain threshold from optical sensors that are within a predetermined range of the optical sensor with the highest sensor signal; an integral of sensor signals above a certain threshold from optical sensors that are within a predetermined range of the optical sensor with the highest sensor signal. However, there are also other possibilities.

[0129] Summation can be performed entirely or partially in software and / or entirely or partially in hardware. Summation is generally possible using purely electronic means, which can usually be easily implemented in the detector. In electronics, summing devices for summing two or more electrical signals, both analog and digital, are well known. Thus, the evaluation device can comprise at least one summing device for forming the summed signal. The summing device can be entirely or partially integrated into the sensor element or designed entirely or partially independently of the sensor element. The summing device can be designed entirely or partially in hardware and / or software.

[0130] As described above, the comparison between the center signal and the sum signal can be carried out in particular by forming one or more quotient signals. Thus, the combined signal can generally be a quotient signal Q derived by one or more of the following: forming a quotient of the center signal and the sum signal, or vice versa; forming a quotient of a multiple of the center signal and a multiple of the sum signal, or vice versa; forming a quotient of a linear combination of the center signal and a linear combination of the sum signal and the center signal, or vice versa; forming a quotient of the sum signal and a linear combination of the sum signal and the center signal, or vice versa.Forming a quotient from a power of the center signal and a power of the sum signal, or vice versa; Forming a quotient from a first linear combination of the center signal and the sum signal and a second linear combination of the center signal and the sum signal. However, other possibilities also exist. The evaluation device can be configured to form the one or more quotient signals. The evaluation device can further be configured to determine the at least one longitudinal coordinate by evaluating the at least one quotient signal.

[0131] The evaluation device can in particular be configured to use at least one predetermined relationship between the quotient signal Q and the longitudinal coordinate to determine the at least one longitudinal coordinate. For the reasons stated above and because of the dependence of the properties of the light spot on the longitudinal coordinate, the quotient signal Q is typically a monotonic function of the longitudinal coordinate of the object and / or the size of the light spot, e.g., the diameter or the equivalent diameter of the light spot. Thus, for example, especially when using linear optical sensors, a simple quotient can be calculated from the sensor signal s Mitte and the sum signal s Summe Q=S Mitte / s Summebe a monotonically decreasing function of distance. Without wishing to be bound by this theory, it is assumed that this is due to the fact that in the preferred setup described above, both the center signal s Mitte as well as the sum signal s Summe decrease quadratically with increasing distance from the light source, as the amount of light reaching the detector decreases. However, the center signal s Mitte faster than the sum signal s Summe, since in the optical setup used in the experiments the light spot grows in the image plane and is thus distributed over a larger area. The quotient of the center signal and the sum signal therefore decreases continuously with increasing diameter of the light beam or the light spot on the light-sensitive surfaces of the optical sensors of the matrix. Furthermore, the quotient is generally independent of the total power of the light beam, since the total power of the light beam flows into both the center signal and the sum sensor signal. Consequently, the quotient Q can form a secondary signal that provides a clear relationship between the center signal and the sum signal and the size or diameter of the light beam. On the other hand, since the size or diameter of the light beam depends on a distance between the object from which the light beam propagates towards the detector and the detector itself, i.e.Since the signal distribution depends on the longitudinal coordinate of the object, a unique relationship can exist between the center signal and the sum signal on the one hand, and the longitudinal coordinate on the other. For the latter, reference can be made, for example, to WO 2014 / 097181 A1. The predetermined relationship can be determined by analytical considerations, e.g., by assuming a linear combination of Gaussian light beams, by empirical measurements, e.g., by measuring the combined signal and / or the center signal and the sum signal or secondary signals derived therefrom as a function of the longitudinal coordinate of the object, or by both.

[0132] Thus, the evaluation device can generally be configured to determine the longitudinal coordinate by evaluating the quotient signal Q as the combined signal. This determination can be performed in one step, e.g., by directly combining the center signal and the sum signal and deriving the longitudinal coordinate therefrom, or can be performed in multiple steps, e.g., by first deriving the combined signal from the center signal and the sum signal and then deriving the longitudinal coordinate from the combined signal. Both options, i.e., the option that steps c) and d) represent separate and independent steps, and the option that steps c) and d) are combined in whole or in part, are encompassed by the present invention.

[0133] As described above, the optical sensors can in particular be or comprise photodetectors, preferably inorganic photodetectors, particularly preferably inorganic semiconductor photodetectors, most preferably silicon photodetectors. The optical sensors can be particularly sensitive to the infrared spectral range. All optical sensors of the matrix or at least one group of the optical sensors of the matrix can be identical. Groups of identical optical sensors of the matrix can in particular be provided for different spectral ranges, or all optical sensors can be identical with regard to spectral sensitivity. Furthermore, the optical sensors can be identical in their size and / or in their electronic or optoelectronic properties.

[0134] The array can be composed of independent optical sensors. Thus, a matrix can be composed of inorganic photodiodes. Alternatively, however, a commercially available array can be used, such as a CCD detector, such as a CCD detector chip, and / or a CMOS detector, such as a CMOS detector chip.

[0135] Thus, the optical sensors of the detector can generally form a sensor array or be part of a sensor array, such as the matrix mentioned above. Thus, for example, the detector can comprise an array of optical sensors, e.g. a rectangular array with m rows and n columns, where m and n are independently positive integers. Preferably, there are more than one column and more than one row, i.e. n>1, m>1. Thus, for example, n can be 2 to 16 or higher and m can be 2 to 16 or higher. Preferably, the ratio between the number of rows and the number of columns is close to 1. For example, n and m can be chosen such that 0.3 ≤ m / n ≤ 3, e.g. by selecting m / n = 1:1, 4:3, 16:9 or similar. The array can, for example, be a square array with an equal number of rows and columns, e.g. by selecting m=2, n=2 or m=3, n=3 or the like.

[0136] As described above, the matrix can in particular be a rectangular matrix with at least one row, preferably a plurality of rows and a plurality of columns. For example, the rows and columns can be aligned substantially perpendicularly, wherein with regard to the term "substantially perpendicular" reference can be made to the above definition. For example, tolerances of less than 20°, in particular less than 10° or even less than 5°, can be acceptable. In order to enable a wide field of view, the matrix can in particular have at least 10 rows, preferably at least 50 rows and particularly preferably at least 100 rows. Likewise, the matrix can have at least 10 columns, preferably at least 50 columns and particularly preferably at least 100 columns. The matrix can comprise at least 50 optical sensors, preferably at least 100 optical sensors and particularly preferably at least 500 optical sensors.The matrix may comprise a number of pixels in the range of several megapixels. However, other embodiments are also possible. Thus, as described above, in structures where axial rotational symmetry is expected, circular or concentric arrangements of the optical sensors of the matrix, which may also be referred to as pixels, may be preferred.

[0137] As further described above, the sensor element can preferably be aligned substantially perpendicular to an optical axis of the detector. With regard to the term "substantially perpendicular", reference is again made to the above-mentioned definition and tolerances. The optical axis can be a straight optical axis or curved or even split, e.g., by using one or more deflection elements and / or by using one or more beam splitters, wherein the substantially perpendicular alignment in the latter cases can refer to the local optical axis in the respective branch or beam path of the optical structure.

[0138] The detector can be configured to determine at least one item of distance information of the object using methods that operate with triangulation and / or structured light. In known 3D sensor devices, such as methods that operate with triangulation or structured light, regular, constant, or periodic patterns are unsuitable due to correspondence problems, since each measured point must be assigned to a reference point of a reference pattern. The at least one light beam propagating from the object to the detector can be configured to generate at least one reflection pattern on the matrix of optical sensors.The term "reflection pattern" refers to at least one image determined by the optical sensors in response to illumination of the light-sensitive surfaces by the light beam propagating from the object to the detector, which was generated in response to the illumination by the illumination pattern. The reflection pattern may comprise at least one reflection feature that depends on the corresponding illumination feature of the illumination pattern. The detector may be configured to determine the longitudinal coordinate of an object point for at least one reflection feature of the reflection pattern from the quotient signal. Thus, the detector may be configured to pre-classify the at least one reflection feature of the reflection pattern.This allows the use of lighting patterns that include a regular and / or constant and / or periodic pattern, such as a triangular pattern, a rectangular pattern, a hexagonal pattern, or a pattern with additional convex tiles. The lighting pattern can include as many features per area as possible, so hexagonal patterns may be preferred.

[0139] The evaluation device may be configured to perform at least one image analysis and / or image processing to identify the reflection feature. The image analysis and / or image processing may use at least one feature detection algorithm. The image analysis and / or image processing may comprise one or more of the following: filtering; selecting at least one region of interest; forming a difference image between an image generated by the sensor signals and at least one offset; inverting sensor signals by reversing an image generated by the sensor signals; forming a difference image between an image generated by the sensor signals at different times; background correction; decomposition into color channels; decomposition into hue, saturation, and brightness channels; frequency decomposition; singular value decomposition; application of a Canny edge detector;an application of a Laplacian-Gaussian filter; an application of a Gaussian difference filter; an application of a Sobel operator; an application of a Laplacian operator; an application of a Scharr operator; an application of a Prewitt operator; an application of a Roberts operator; an application of a Kirsch operator; an application of a high-pass filter; an application of a low-pass filter; an application of a Fourier transform; an application of a Radon transform; an application of a Hough transform; an application of a wavelet transform; a thresholding operation; a creation of a binary image. The region of interest can be determined manually by a user or automatically, e.g., by detecting an object in an image generated by the optical sensors.

[0140] The evaluation device can be configured to determine at least one reference feature in at least one reference pattern that corresponds to the at least one reflection feature. The term "reference pattern" refers to a comparison image at a specific spatial position having at least one reference feature. As described above, the evaluation device can be configured to perform image analysis and identify features of the reflection pattern. The evaluation device can be configured to identify at least one reference feature in the reference pattern that has a substantially identical longitudinal coordinate to the selected reflection feature. The term "substantially identical" refers to a match within 10%, preferably 5%, particularly preferably 1%. The reference feature corresponding to the reflection feature can be determined using epipolar geometry.For a description of epipolar geometry, see, for example, Chapter 2 in X. Jiang, H. Bunke: “Three-dimensional Computer Vision” Springer, Berlin Heidelberg, 1997. In epipolar geometry, it can be assumed that the reference pattern and the reflection pattern are images of the object determined at different spatial positions and / or spatial orientations with a fixed distance. The distance can be a relative distance, also referred to as the baseline. The evaluation device can be set up to determine an epipolar line in the reference pattern. The relative position of the reference pattern and the reflection pattern can be known. For example, the relative position of the reference pattern and the reflection pattern can be stored in at least one memory unit of the evaluation device.The evaluation device can be configured to determine a straight line running from the selected reflection feature to the real feature from which it originates. Thus, the straight line can include possible object features corresponding to the selected reflection feature. The straight line and the baseline span an epipolar plane. Since the reference pattern is determined in a different relative constellation than the reflection pattern, the corresponding possible object features can be mapped onto a straight line, the so-called epipolar line, in the reference pattern. The epipolar line can be the intersection between the epipolar plane and the reference pattern.

[0141] Thus, a feature of the reference pattern that corresponds to the selected feature of the reflection pattern lies on the epipolar line.

[0142] Depending on the distance to the object, the reference feature corresponding to the image position of the reflection feature may be shifted within the reference pattern compared to the image position in the reflection pattern. The reference pattern may comprise at least one shift region in which the reference feature corresponding to the selected reflection feature can be imaged. The shift region may comprise only one reference feature. The shift region may extend along the epipolar line. The evaluation device may be configured to determine the reference feature along the epipolar line. The evaluation device may be configured to determine the longitudinal coordinate z for the reflection feature and an error interval ±ε from the quotient signal Q in order to determine a shift region along the epipolar line corresponding to z±ε.The evaluation device can be configured to compare the selected reflection feature with at least one reference feature within the displacement region. Here, the term "matching" refers to determining and / or evaluating the corresponding reference and reflection features. The evaluation device can be configured to compare the selected feature of the reflection pattern with the reference feature within the displacement region using at least one evaluation algorithm, taking into account the determined longitudinal coordinate z. The evaluation algorithm can be a linear scaling algorithm. Preferably, the detector can be configured to pre-classify the selected reflection feature based on the quotient signal Q such that a clear assignment to a reference feature is possible.In particular, illumination features of the illumination pattern can be arranged such that corresponding reference features of the reference pattern have the greatest possible relative distance from one another on the epipolar line. The illumination features of the illumination pattern can be arranged such that only a few reference features are positioned on the epipolar line. The illumination pattern can, for example, comprise at least one hexagonal pattern. Preferably, the illumination pattern can comprise at least one hexagonal pattern, wherein the pattern is rotated relative to the baseline. Preferably, the illumination pattern can comprise at least one shifted hexagonal pattern, wherein individual points of the hexagonal pattern are shifted by a random distance from the regular position, for example, orthogonally to the epipolar line of the point.The displacement of the individual points can be less than half the distance between two parallel epipolar lines, preferably less than a quarter of the distance between two parallel epipolar lines. The displacement of the individual points can be performed in such a way that two points are not displaced over each other.

[0143] The evaluation device can be configured to determine a displacement of the reference feature and the reflection feature. The evaluation device can be configured to determine the displacement of the matched reference feature and the selected reflection feature. Here, the term "displacement" refers to the difference between an image position in the reference image and an image position in the reflection image. The evaluation device can be configured to determine longitudinal information of the matched feature based on a predetermined relationship between a longitudinal coordinate and the displacement. Here, the term "longitudinal information" refers to information relating to the longitudinal coordinate z TriangThe longitudinal information can, for example, be a distance value. The evaluation device can be configured to determine the predetermined relationship using triangulation methods. If the position of the selected reflection feature in the reflection pattern and the position of the matched reference feature and / or the relative displacement of the selected reflection feature and the matched reference feature are known, the longitudinal coordinate of the corresponding object feature can be determined by triangulation. Thus, the evaluation device can be configured to select a reflection feature, e.g., sequentially and / or column by column, and to determine the corresponding distance value for each possible position of the reference feature by means of triangulation. The displacement and the corresponding distance value can be stored in at least one memory device of the evaluation device.The evaluation device can, for example, comprise at least one data processing device, such as at least one processor, at least one DSP, at least one FPGA, and / or at least one ASIC. For storing the at least one predetermined or determinable relationship between the longitudinal coordinate z and the displacement, the at least one data storage device can, for example, be provided to provide one or more check tables for storing the predetermined relationship.

[0144] The detector may comprise at least one FiP sensor configured to generate the so-called FiP effect, as described in WO 2015 / 024871 or WO 2016 / 120392. For example, at least one optical sensor of the matrix of optical sensors may be configured to generate a so-called FiP signal. For example, each of the optical sensors of the matrix may be configured to generate the at least one FiP signal. The matrix of optical sensors may, for example, be a pixelated FiP sensor. Additionally or alternatively, the FiP signal may be determined from the sensor signals of the matrix, e.g., extracted and / or simulated, and the quotient described above may be determined from the sensor signals.

[0145] As explained above, by evaluating the center signal and the sum signal, the detector can be enabled to determine at least one longitudinal coordinate of the object, including the possibility of determining the longitudinal coordinate of the entire object or one or more parts thereof. In addition, other coordinates of the object, including one or more transverse coordinates and / or rotational coordinates, can also be determined by the detector, in particular by the evaluation device. Thus, for example, one or more transverse sensors can be used to determine at least one transverse coordinate of the object.As described above, the position of the at least one optical sensor from which the center signal emanates can provide information about the at least one transverse coordinate of the object, wherein, for example, a simple lens equation can be used for the optical transformation and for deriving the transverse coordinate. Additionally or alternatively, one or more additional transverse sensors can be used and included in the detector. Various transverse sensors are well known in the art, such as the transverse sensors disclosed in WO 2014 / 097181 A1 and / or other position-sensitive devices (PSDs), such as quadrant diodes, CCD or CMOS chips, or the like. Additionally or alternatively, the detector according to the present invention can, for example, comprise one or more PSDs described in R.A. Street (ed.): Technology and Applications of Amorphous Silicon (Amorphous Silicon - Technologies and Applications) Springer-Verlag Heidelberg, 2010, pp. 346-349. Other embodiments are also possible. These devices can in principle also be implemented in the detector according to the invention. For example, a part of the light beam can be split within the detector by at least one beam splitter element. The split part can, for example, be guided to a transversal sensor, such as a CCD or CMOS chip or a camera sensor, and a transversal position of a light spot generated by the split part on the transversal sensor can be determined, whereby at least one transversal coordinate of the object is determined.Consequently, the detector according to the present invention can be either a one-dimensional detector, such as a simple distance measuring device, or it can be designed as a two-dimensional detector or even as a three-dimensional detector. Furthermore, as explained above or explained in more detail below, a three-dimensional image can also be created by one-dimensional scanning of a landscape or environment. Consequently, the detector according to the invention can in particular be a one-dimensional, a two-dimensional, or a three-dimensional detector. The evaluation device can further be configured to determine at least one transverse coordinate x, y of the object. The evaluation device can be set up to combine the information of the longitudinal coordinate and the transverse coordinate and determine a position of the object in space.

[0146] The detector can be configured to evaluate a single light beam or a plurality of light beams. In the event that a plurality of light beams propagate from the object to the detector, means for distinguishing the light beams can be provided. Thus, the light beams can have different spectral properties, and the detector can comprise one or more wavelength-selective elements for distinguishing the different light beams. Each of the light beams can then be evaluated independently. The wavelength-selective elements can be or comprise, for example, one or more filters, one or more prisms, one or more gratings, one or more dichroic mirrors, or any combination thereof. In order to distinguish two or more light beams, the light beams can furthermore additionally or alternatively be modulated in a specific manner.Thus, for example, the light beams can be frequency-modulated, and the sensor signals can be demodulated to partially distinguish the sensor signals originating from the different light beams according to their demodulation frequencies. These methods are generally known to a person skilled in the field of high-frequency electronics. In general, the evaluation device can be configured to distinguish between different light beams with different modulations.

[0147] The illumination source may be configured to generate and / or project a point cloud such that a plurality of illuminated regions are created on the array of optical sensors, e.g., the CMOS detector. Furthermore, disturbances may occur on the array of optical sensors, such as disturbances due to speckles and / or extraneous light and / or multiple reflections. The evaluation device may be configured to determine at least one region of interest, e.g., one or more pixels illuminated by the light beam, which are used to determine the longitudinal coordinate of the object. For example, the evaluation device may perform a filtering method, e.g., a blob analysis and / or object detection method.

[0148] Preferably, the illumination source can be a movable and / or mobile illumination source. For example, the illumination source can be moved during the measurement to illuminate the object from different positions and / or angles. However, embodiments are also possible in which the illumination source can be positioned in at least one fixed position, for example, during an entire measurement period. The evaluation device can be configured for illumination sources with an unclear position, e.g., due to high manufacturing tolerances and / or user interaction and / or user assembly or the like.

[0149] The illumination source can illuminate the object with a convergent and / or divergent and / or collimated light beam.

[0150] In a further preferred embodiment, the detector may comprise: - at least two optical sensors, each optical sensor having a light-sensitive surface, each light-sensitive surface having a geometric center, the geometric centers of the optical sensors being spaced from an optical axis of the detector by different spatial offsets, each optical sensor being configured to generate a sensor signal in response to illumination of its respective light-sensitive surface by a light beam propagating from the object to the detector; and - at least one evaluation device configured to determine at least one longitudinal coordinate z of the object by combining the at least two sensor signals.

[0151] In this further preferred embodiment, the optical sensors can be arranged such that the light-sensitive surfaces of the optical sensors differ in terms of their spatial offset and / or their surface areas.

[0152] The light-sensitive surfaces of the optical sensors can overlap or not overlap, as seen from the object, meaning they can be arranged next to each other without overlapping. The light-sensitive surfaces can be spaced apart from each other or directly adjacent to each other.

[0153] The detector may comprise more than two optical sensors. In any case, i.e. if the detector comprises exactly two optical sensors and if the detector comprises more than two optical sensors, the optical sensors may comprise at least a first optical sensor spaced from the optical axis by a first spatial offset and at least one second optical sensor spaced from the optical axis by a second spatial offset, wherein the first spatial offset and the second spatial offset differ from one another. If, in addition to the first and second optical sensors, further optical sensors are provided, these additional optical sensors may likewise satisfy the condition or, alternatively, be spaced from the optical axis by the first spatial offset, the second spatial offset, or another spatial offset.The first and second spatial offsets may differ, for example, by at least a factor of 1.2, preferably by at least a factor of 1.5, particularly preferably by at least a factor of 2. The spatial offsets may also be zero or assume negative values, provided that the above-mentioned conditions are met.

[0154] As explained above, each light-sensitive surface has a geometric center. Each geometric center of each light-sensitive surface can be spaced from the optical axis of the detector, for example, the optical axis of the beam path or the respective beam path in which the respective optical sensor is located.

[0155] As already mentioned, the optical sensors can be arranged in one and the same plane, which preferably runs perpendicular to the optical axis. However, other configurations are also possible. Thus, two or more of the optical sensors can also be spaced in a direction parallel to the optical axis.

[0156] The optical sensors can, for example, be partial diodes of a segmented diode, with a center of the segmented diode being eccentric to the optical axis of the detector. In this case, the term “partial diode” can include multiple diodes connected in series or parallel. This example is quite simple and inexpensive to implement. For example, double-cell diodes or quadrant diodes are widespread and commercially available at low cost, and control methods for these double-cell diodes or quadrant diodes are generally known. In this case, the term “double-cell diode” generally refers to a diode with two partial diodes in one housing. Double-cell and quadrant diodes can have two or four separate light-sensitive areas, in particular two or four active areas. For example, the double-cell diodes can each form independent diodes with the full functionality of a diode.For example, each of the double-cell diodes can have a square or rectangular shape, and the two diodes can be arranged in a plane such that the two sub-diodes together form a 1 × 2 or 2 × 1 matrix with a rectangular shape. However, the present invention proposes a new approach for evaluating the sensor signals of the double-cell diodes and the quadrant diode, which is explained in more detail below. In principle, however, the optical sensors can be sub-diodes of a quadrant diode, with a center of the quadrant diode being eccentric to the optical axis of the detector. Here, the term "quadrant diode" generally refers to a diode with four sub-diodes in one housing. For example, the four sub-diodes can each form independent diodes with the full functionality of a diode.For example, the four sub-diodes can each have a square or rectangular shape, and the four sub-diodes can be arranged in a plane such that the four sub-diodes together form a 2 × 2 matrix with a rectangular or square shape. In another example, the four sub-diodes together can form a 2 × 2 matrix with a circular or elliptical shape. For example, the sub-diodes can be located next to each other, with a minimal distance between them. However, the distance between neighboring diodes can also be varied to improve the dynamic range of the quotient signal. For example, the distance between two neighboring diodes can be increased by an opaque mask. This can reduce the light on one of the diodes relative and / or absolutely compared to the neighboring diode, which can increase a quotient of the signal from the two diodes.

[0157] When using a quadrant diode with a 2×2 matrix of sub-diodes, the center of the quadrant diode can be eccentric or offset from the optical axis. Thus, for example, the center of the quadrant diodes, which can be an intersection of the geometric centers of the optical sensors of the quadrant diode, can be eccentric from the optical axis by at least 0.2 mm, preferably by at least 0.5 mm, particularly preferably by at least 1.0 mm, or even 2.0 mm. Similarly, when using other types of optical sensor configurations with a plurality of optical sensors, an overall center of the optical sensors can be offset from the optical axis by the same distance.

[0158] As explained above, double-cell and quadrant diodes can have two or four separate light-sensitive areas, in particular two or four active areas. The light-sensitive areas can be separated by a dividing line. The dividing line, for example of two Si diodes, can be arranged parallel to the baseline of the detector, in particular parallel to a spot movement on the optical sensors. However, other arrangements are also possible. The quadrant diode can, for example, comprise two dividing lines. The dividing lines can be arranged orthogonally to each other. The orthogonal arrangement of the dividing lines makes it possible to adjust the quotient signal independently for near-field and far-field applications.In addition to determining the quotient signal from sensor signals of two optical sensors of the quadrant diode, the evaluation device can be configured to determine a second quotient using at least three or all four sensor signals of the quadrant diode. The two quotients can be formed such that two different distance ranges are covered. The two quotient signals for the near field and the far field can have an overlap region in which both quotient signals enable a meaningful determination of the longitudinal distance z. The quotient signal can be determined, for example, by dividing the sensor signals of two upper quadrants, also called the upper segment, by the sensor signals of two lower quadrants, also called the lower segment.Using the quotient signal from sensor signals determined from two sensor surfaces whose dividing line runs parallel to the detector baseline can allow the quotient to be determined without distance-dependent movement of the light spot. In particular, for example, if the dividing line between the upper and lower segments runs parallel to the baseline, the quotient signal determined from the upper segment divided by the lower segment can be used in the near field, where the light spot may only illuminate a left or right segment of the quadrant diode. In this case, determining the quotient signal by dividing sensor signals from the left and right segments may not be possible. However, determining the quotient by dividing the sensor signals from the upper and lower segments can provide a reasonable distance measurement.The quotient signal, determined by dividing the sensor signals from the left and right segments, can be used for far-field measurement, with the light spot illuminating both the left and right segments. Furthermore, the evaluation device can be configured to determine the quotient signal by dividing the sensor signals from opposite or adjacent segments. The evaluation device can be configured to combine the acquired sensor signals from the quadrants to enable distance measurement over a large area with high resolution.

[0159] In principle, the light-sensitive areas of the optical sensors can have any desired area or size. However, especially with regard to simplified evaluation of the sensor signals, the light-sensitive areas of the optical sensors are preferably essentially the same, e.g., within a tolerance of less than 10%, preferably less than 5%, or even less than 1%. This is particularly the case with typical commercially available quadrant diodes.

[0160] The detector can comprise at least one quadrant diode with four quadrants. For example, an upper left quadrant of the quadrant diode can be designated "ol", a lower left quadrant "ul", an upper right quadrant "or", and a lower right quadrant "ur". The light spot can move from the left in a short distance range to the left in a long distance range. The detector can comprise at least one neutral density filter. The quadrants of the short distance range can be covered by the neutral density filter. In the short distance range, the quotient ol / ul can be used to determine the longitudinal coordinate z. In the long range, a quotient or / ur and / or a quotient from a combination of all quadrants can be used.The neutral density filter allows objects at close ranges to illuminate the optical sensors more brightly through constant gain without the amplifier saturating. At the same time, it is possible to capture more of the signal at long distances. The neutral density filter thus improves the detector's dynamic range.

[0161] In particular, as explained in more detail below, the evaluation device can be configured to determine the at least one longitudinal coordinate z of the object using at least one known, determinable, or predetermined relationship between sensor signals and / or a secondary signal derived therefrom and the longitudinal coordinate. Thus, the evaluation device can be configured to determine at least one combined sensor signal from the at least two sensor signals, i.e., from the at least one sensor signal from at least one first optical sensor and from the at least one sensor signal from at least one second optical sensor.

[0162] The detector may comprise at least one FiP sensor configured to generate the so-called FiP effect, as described in WO 2015 / 024871 or WO 2016 / 120392. The double cell or quadrant diode may, for example, be configured to generate a so-called FiP signal. As described, for example, in WO 2015 / 024871 or WO 2016 / 120392, the FiP signal can be used to determine depth information over a wide distance range. The FiP sensor may be configured to exhibit a positive and / or negative FiP effect. According to the FiP effect, the longitudinal sensor signal, with the same overall power, may exhibit at least one pronounced maximum for one or a plurality of focusing operations and / or for one or a plurality of specific light spot sizes on the sensor region or within the sensor region.For comparison purposes, an observation of a maximum of the longitudinal sensor signal in a condition where the material in question is struck by a light beam with the smallest possible cross-section, e.g., when the material is at or near a focal point influenced by an optical lens, can be referred to as a "positive FiP effect." The negative FiP effect describes an observation of a minimum of the longitudinal sensor signal under a condition where the material in question is struck by a light beam with the smallest available beam cross-section, in particular, when the material is at or near a focal point influenced by an optical lens. The negative FiP effect can be used to tune small image effects at long distances. Image changes such as position, size, shape, sharpness, etc. may disappear at long distances, while the negative FiP effect increases.Furthermore, no luminance dependence may be introduced because both cells are located at the same longitudinal position and thus receive an identical photon density.

[0163] As explained above, the detector may comprise at least one illumination source. A distance perpendicular to an optical axis of the detector between the illumination source and the double-cell or quadrant diode may be small. The distance perpendicular to the optical axis of the detector between the illumination source and the double-cell or quadrant diode may be less than 0.1 m, preferably less than 0.05 m, and more preferably less than 0.025 m. The illumination source and the optical axis may be separated by a small baseline. The illumination source may be spaced a minimum distance from the optical axis. The minimum distance from the optical axis may be determined by further detector elements such as the size and position of the double-cell or quadrant diode and the at least one optional transmission device.The baseline may be less than 0.1 m, preferably less than 0.05 m, and more preferably less than 0.025 m. The baseline may be, for example, 21 mm. Preferably, the illumination source may be arranged directly next to the transmission device. For example, the transmission device may be flattened so that the illumination source can be positioned even closer to the optical axis. The illumination source may be arranged behind the transmission device.

[0164] As used herein, the term "combining" may generally refer to any operation in which two or more components, such as signals, are mathematically combined to form at least one combined combined signal and / or compared to form at least one comparison signal or comparison result. As explained in more detail below, the combined sensor signal or the secondary signal may be or include at least one quotient signal.

[0165] If more than two sensor signals are present, more than one quotient signal can be generated, e.g. by forming quotient signals from more than one pair of sensor signals.

[0166] For example, if more than two optical sensors are present, the aforementioned quotient can be calculated between two of the sensor signals generated by these optical sensors or between more than two of the sensor signals. Instead of using the first of the sensor signals and the second of the sensor signals in the above-mentioned formulas, combined sensor signals can also be used to calculate the quotient.

[0167] The quotient signal Q is generally an example of an asymmetry parameter that indicates an asymmetry or asymmetric distribution of the light spot generated by the light beam on the light-sensitive surface. The quotient of the two or more optical sensors, such as the two or more photodiodes, can provide a combined signal that typically depends monotonically on the distance between the detector and the object from which the light beam travels to the detector, as shown below by experimental data. In addition to or alternatively to the quotient signal, other types of combined functions can be used that implement the sensor signals from two or more sensors in the setup of the present invention and which can also exhibit a dependence on the distance between the object and the detector.For example, the asymmetry or asymmetry parameter of the light spot can be an indication of the width of a light beam. If this asymmetry parameter depends only on distance, the measurement can be used to determine distance.

[0168] In typical setups, commercially available quadrant diodes such as quadrant photodiodes are used for positioning, i.e., for adjusting and / or measuring a transverse coordinate of a light spot in the plane of the quadrant photodiode. For example, the positioning of laser beams using quadrant photodiodes is well known. However, a typical prejudice holds that quadrant photodiodes are only used for xy positioning. According to this assumption, quadrant photodiodes are not suitable for measuring distances. However, the findings mentioned above, which used a quadrant photodiode eccentric with respect to an optical axis of the detector, show something different, as demonstrated in further measurements below.As already mentioned, with quadrant photodiodes, the asymmetry of the light spot can be measured by shifting the quadrant diode slightly off-axis, for example, by the offset mentioned above. This allows a monotonically z-dependent function to be generated, e.g., by forming the quotient signal Q from two or more of the sensor signals from two or more sub-photodiodes, i.e., quadrants, of the quadrant photodiode. In principle, only two photodiodes are necessary for the measurement. The other two diodes can be used for noise suppression or to achieve a more accurate measurement.

[0169] In addition to or as an alternative to using a quadrant diode or quadrant photodiode, other types of optical sensors can also be used. Thus, offset optical sensors can be used, as shown below.

[0170] The use of quadrant diodes offers a number of advantages over known optical detectors. Quadrant diodes are used in a wide variety of applications in combination with LEDs or active targets and are commercially available at a very low cost, with different optical properties such as spectral sensitivities, and in various sizes. No specific manufacturing process needs to be specified, as commercially available products can be implemented in the detector according to the present invention.

[0171] The detector according to the present invention can be used in particular in multilayer optical storage disks, as disclosed in International Patent Application PCT / IB2015 / 052233, filed on March 26, 2015. Measurements performed using the detector according to the invention can be used in particular to optimize the focus position in optical storage disks.

[0172] As explained in more detail below, distance measurement with the detector according to the invention can be improved by implementing one or more additional distance measuring means in the detector and / or by combining the detector with other types of distance measuring means. Thus, for example, the detector can comprise or be combined with at least one triangulation distance measuring device. Thus, distance measurement can be improved by utilizing a combination of the measuring principle described above and a triangulation distance measurement. Furthermore, means for measuring one or more other coordinates, such as the x and / or y coordinates, can be provided.

[0173] If a quadrant diode is used, it can also be used for additional purposes. Thus, the quadrant diode can also be used for conventional xy measurements of a light spot, as is commonly known in optoelectronics and laser physics. Thus, for example, the position of the lens or detector can be adjusted using the conventional xy position information of the quadrant diode in order to optimize the position of the light spot for the distance measurement. As a practical example, the light spot may initially be located exactly in the center of the quadrant diode, which typically does not allow the aforementioned distance measurement using the quotient function Q. Therefore, conventional quadrant photodiode methods can initially be used to achieve an eccentric position of the light spot on the quadrant photodiode so that, for example, the spot position on the quadrant diode is optimal for the measurement.Thus, for example, the different eccentricity of the optical sensors of the detector can simply be a starting point for a movement of the optical sensors relative to the optical axis, so that the light spot is eccentric with respect to the optical axis and with respect to a geometric center of the arrangement of the optical sensors.

[0174] Thus, the optical sensors of the detector can generally form a sensor array or be part of a sensor array, such as the quadrant diode mentioned above. The case m=2, n=2 is the case of the quadrant diode or optical quadrant sensor, which is one of the preferred cases for practical reasons, since quadrant photodiodes are widely used.

[0175] As a starting point, a geometric center of the optical sensors within the array can be eccentric with respect to the optical axis, e.g. by the offset mentioned above. In particular, the sensor array can be movable relative to the optical axis, e.g. along a gradient, preferably automatically, such as by moving the sensor array, e.g. in a plane perpendicular to the optical axis, and / or by moving the optical axis itself, e.g. by shifting the optical axis in a parallel translation and / or tilting the optical axis. Thus, the sensor array can be shifted to adjust a position of a light spot generated by the light beam in the plane of the sensor array. Additionally or alternatively, the optical axis can be shifted and / or tilted by suitable elements, e.g. by one or more deflection elements and / or one or more lenses.The movement can, for example, be carried out using one or more suitable actuators, such as one or more piezo actuators and / or one or more electromagnetic actuators and / or one or more pneumatic or mechanical actuators, which, for example, move and / or translate the arrangement and / or move and / or translate and / or tilt one or more optical elements in the beam path in order to move the optical axis, such as parallel translation of the optical axis and / or tilting the optical axis. The evaluation device can, in particular, be set such that it controls a relative position of the sensor arrangement to the optical axis, e.g. in the plane perpendicular to the optical axis.An adaptation procedure can be carried out in such a way that the evaluation device is configured such that it first determines the at least one transverse position of a light spot generated by the light beam on the sensor arrangement based on the sensor signals and then moves the arrangement relative to the optical axis, such as by moving the arrangement and / or the optical axis, e.g. by moving the arrangement in the plane to the optical axis until the light spot is eccentric and / or by tilting a lens until the light spot is eccentric. In the present case, a transverse position can be a position in a plane perpendicular to the optical axis, which can also be referred to as the xy plane. For measuring the transverse coordinate, the sensor signals of the optical sensors can be compared, for example.For example, if it is determined that the sensor signals are equal and thus that the light spot is symmetrical to the optical sensors, for example, in the center of the quadrant diodes, the array can be shifted and / or a lens tilted to eccentrically position the light spot in the array. Thus, as described above, positioning the array eccentrically with respect to the optical axis, for example, by eccentrically positioning the center of the quadrant photodiode with respect to the optical axis, can merely be a starting point to avoid the typical situation in which the light spot is on the optical axis and thus centered. By positioning the array eccentrically with respect to the optical axis, the light spot should therefore be eccentric.If this turns out not to be the case, so that the light spot happens to be located in the center of the array and illuminates all optical sensors evenly, the aforementioned shifting of the array relative to the optical axis can be performed, preferably automatically, to position the light spot eccentrically on the array. This allows for reliable distance measurement.

[0176] Furthermore, in a scanning system with a moving light source, the position of the light spot on the quadrant diode is not necessarily fixed. This is still possible, but may require the use of other calibrations depending on the xy position of the spot in the diode.

[0177] Furthermore, the use of the aforementioned quotient signal Q represents a very reliable method for distance measurements. Typically, Q is a monotonic function of the longitudinal coordinate of the object and / or the size of the light spot, e.g., the diameter or equivalent diameter of the light spot. For example, when using linear optical sensors, the quotient Q=s1 / s2 is a monotonically decreasing function of the size of the light spot. Without wishing to be bound by this theory, it is assumed that this is due to the fact that, in the preferred configuration described above, the sensor signals, e.g., the aforementioned first signal s1 and the aforementioned second signal s2, decrease quadratically with increasing distance from the light source, since the amount of light reaching the detector decreases.However, due to the eccentric positioning, one sensor signal decreases more quickly than the other because, in the optical setup used in the experiments, the light spot grows in the image plane and is thus distributed over a larger area. However, as the light spot spreads, the proportion of light illuminating the one or more optical sensors outside the center of the light spot increases compared to a very small light spot. The quotient of the sensor signals therefore changes continuously, i.e. it increases or decreases with increasing diameter of the light beam or light spot. Furthermore, the quotient can be made largely independent of the total power of the light beam because the total power of the light beam is a factor in all sensor signals.Consequently, the quotient Q can form a secondary signal that provides a unique relationship between the sensor signals and the size or diameter of the light beam.

[0178] As explained above, quadrant photodiodes, in particular, can be used. For example, commercially available quadrant photodiodes can be integrated to provide four optical sensors, such as one or more quadrant photodiodes from Hamamatsu Photonics Deutschland GmbH, D-82211 Herrsching am Ammersee, Germany, such as quadrant Si PIN photodiodes of type S4349, which are sensitive in the UV to near-IR spectral range. If an array of optical sensors is used, the array can be a bare chip or an encapsulated array, e.g., encapsulated in a TO-5 metal package. Additionally or alternatively, a surface-mounted device can be used, such as the TT Electronics OPR5911, available from TT Electronics plc, Fourth Floor, St Andrews House, West Street, Woking, Surrey, GU21 6EB, England. It should be noted that other optical sensors can also be used.

[0179] It should also be noted that in addition to the possibility of using exactly one quadrant photodiode, two or more quadrant photodiodes can also be used. For example, a first quadrant photodiode can be used for the distance measurement described above, which provides the two or more optical sensors. A further quadrant photodiode can be used, e.g. in a second partial beam path branched off from the beam path of the first quadrant photodiode, for a transverse position measurement, e.g. for the use of at least one transverse coordinate x and / or y. The second quadrant photodiode can, for example, be arranged axially with respect to the optical axis.

[0180] Furthermore, it should be noted that in addition to the possibility of using one or more quadrant photodiodes, one or more quadrant photodiodes or further photodiode arrays may also be replaced or imitated by separate photodiodes arranged close to one another or assembled together, preferably in a symmetrical shape such as a rectangular matrix, e.g., a 2 × 2 matrix. However, other arrangements are possible. In such an arrangement or assembly, the photodiodes may be arranged or assembled in a package or holder, e.g., all photodiodes in a single package or holder, or groups of photodiodes in one package or holder, or each of the photodiodes in a separate package or holder. Furthermore, the photodiodes may also be assembled directly on a printed circuit board.In such arrangements or compositions, the photodiodes can be arranged such that the distance between the active regions of the photodiodes has a specific value of less than one centimeter, preferably less than one millimeter, more preferably as small as possible. In order to avoid optical reflections, distortions or the like that could impair the measurement, the space between the active regions can either be empty or filled with a material, preferably with a light-absorbing material such as a black polymer, e.g. black silicon, black polyoxymethylene or the like, more preferably with an optically absorbing and electrically insulating material, e.g. black ceramic or insulating black polymers such as black silicon or the like. Furthermore, the specific value of the photodiode distance can also be determined by adding a specific building block, e.g.a plastic separator between the photodiodes. Other embodiments are possible. Replacing quadrant photodiodes with individual diodes arranged in a similar configuration, e.g., in a 2 × 2 rectangular array with minimal spacing between the active regions, can further reduce the cost of the optical detector.

[0181] Furthermore, two or more diodes of a quadrant diode can be connected in parallel or in series to form a single light-sensitive area.

[0182] The optical sensors can each be, in particular, uniform sensors, each having a single light-sensitive surface. The optical sensors can therefore, in particular, be non-pixelated optical sensors.

[0183] In a further preferred embodiment, the detector may comprise: - at least one first optical sensor having a first light-sensitive surface, the first optical sensor being configured to generate at least one first sensor signal in response to illumination of the first light-sensitive surface by a light beam propagating from the object to the detector; - at least a second optical sensor with: ◯ at least one fluorescent waveguiding film forming a second light-sensitive surface, wherein the fluorescent waveguiding film is aligned with the object such that at least one light beam propagating from the object towards the detector generates at least one light spot in the second light-sensitive surface, wherein the fluorescent waveguiding film contains at least one fluorescent material, wherein the fluorescent material is arranged to generate fluorescent light in response to illumination by the light beam; and ◯ at least one photosensitive element located at at least one edge of the fluorescent waveguiding film and capable of detecting fluorescent light guided through the fluorescent waveguiding film from the light spot to the photosensitive element, and capable of generating at least one second sensor signal in response to the illumination of the second photosensitive area by the light beam, wherein the first photosensitive area is smaller than the second photosensitive area; and - at least one evaluation device configured to determine at least one longitudinal coordinate z of the object by evaluating the first and second sensor signals.

[0184] In this further preferred embodiment, the optical sensors can be arranged such that the light-sensitive surfaces of the optical sensors differ in terms of their spatial offset and / or their surface areas. The first and second light-sensitive surfaces can, in particular, be aligned with the object.

[0185] In particular, the light beam propagating from the object to the detector can completely illuminate the first light-sensitive surface, such that the first light-sensitive surface is located entirely within the light beam, wherein a width of the light beam is greater than the light-sensitive surface of the first optical sensor. In contrast, the light beam propagating from the object to the detector can preferably create a light spot on the second light-sensitive surface that is smaller than the second light-sensitive surface, such that the light spot is located entirely within the second light-sensitive surface. A shadow generated by the first optical sensor can be located within the light spot on the second light-sensitive surface.Thus, in general, the first optical sensor with the smaller first light-sensitive surface can be located in front of the second optical sensor as seen from the object, wherein the first light-sensitive surface is completely located within the light beam and the light beam creates a light spot on the second light-sensitive surface that is smaller than the second light-sensitive surface, and wherein a shadow is further created by the first optical sensor within the light spot. The situation can be easily adapted by a person skilled in the art by selecting one or more suitable lenses or elements that have a focusing or defocusing effect on the light beam, e.g. by using a suitable transmission device, as explained in more detail below. A light spot is generally a visible or recognizable round or non-round illumination of an article, surface, or object by a light beam.

[0186] The first and second optical sensors may be sensitive to the ultraviolet and / or visible and / or infrared spectral range. The first and second optical sensors may be sensitive to the same spectral range or have different spectral sensitivities.

[0187] In this context, the term "fluorescent waveguiding film" generally refers to an element that exhibits both waveguiding and fluorescent properties. The term "waveguiding" generally refers to the property of one or more elements to guide light in the ultraviolet and / or visible and / or infrared spectral range by internal reflection, in particular by total internal reflection. The term "fluorescence" generally refers to the property of an element or material to emit secondary light, also called fluorescent light, in the ultraviolet and / or visible and / or infrared spectral range in response to excitation by electromagnetic radiation, also referred to as primary radiation or excitation radiation, such as primary light or excitation light.In most cases, the emitted light, fluorescent light, or secondary light, has a longer wavelength and lower energy than the primary radiation. The primary radiation typically induces the presence of excited states in the fluorescent material, e.g., so-called excitons. Typically, the decay times of excited states for photon emissions with energies from the UV to the near-infrared range are in the range of 0.5 to 20 nanoseconds. However, other examples are possible within the scope of the present invention. Similarly, herein, the term "fluorescent material" refers generally to a material with fluorescent properties. The term "fluorescent light" refers generally to the secondary light generated during the aforementioned fluorescence process.

[0188] For possible embodiments of the fluorescent waveguiding foil, reference can generally be made to the so-called "Q-Foil Technology," as disclosed, for example, in the above-mentioned article by P. Bartu, R. Koeppe, N. Arnold, A. Neulinger, L. Fallon, and S. Bauer, "Conformable large-area position-sensitive photodetectors based on luminescence collecting silicone waveguides," J. Appl. Phys. 107, 123101 (2010). Fluorescent waveguiding foils and / or second optical sensors as disclosed herein can also be used within the second optical sensor within the scope of the present invention.

[0189] The fluorescent waveguiding foil may, as explained in more detail below, in particular be or comprise an element that has a foil-like shape or is a foil. As used herein, a "foil" generally refers to an element that has a lateral dimension, such as a diameter or equivalent diameter, that significantly exceeds a thickness of the element, for example by at least a factor of 5, preferably by at least a factor of 10, or more preferably by at least a factor of 20, a factor of 50, or even a factor of 100. The foil may be flexible, deformable, or rigid.

[0190] As explained in more detail below, the fluorescent waveguiding film may in particular be or comprise a transparent material, in particular a transparent film. The transparency may be a transparency of at least 50 to 70% in the visible spectral range or in a part thereof, e.g., in a range from 500 nm to 700 nm. Other embodiments are also possible.

[0191] As used herein, the term "sensitive area" generally refers to a two- or three-dimensional region of an element, in particular the fluorescent waveguiding film or the optical sensor, that is sensitive to external influences and, for example, elicits at least one response in response to an external stimulus. In this case, the sensitive area may be particularly sensitive to optical excitation. The sensitive area may, in particular, be part of a surface or the volume of the fluorescent waveguiding film, for example, the entire surface of the fluorescent waveguiding film or a part thereof.

[0192] Furthermore, the term "fluorescent waveguiding foil is aligned with the object" generally refers to the situation where the surface of the fluorescent waveguiding foil or a part of this surface, in particular the sensitive area, is fully or partially visible from the object. In particular, at least one connecting line between at least one point of the object and at least one point of the sensitive area can form an angle with a surface element of the sensitive area or the fluorescent waveguiding foil that differs from 0°, for example, an angle in the range of 20°-90°. However, other embodiments are also possible.

[0193] Most preferably, however, the at least one fluorescent waveguiding film, the sensitive surface or a part thereof is oriented substantially perpendicular to an optical axis of the optical sensor and / or the detector.

[0194] Furthermore, as used herein, the term "edge" of the fluorescent waveguiding film generally refers to a boundary of the at least one fluorescent waveguiding film, e.g., a side boundary or a side edge or a front or back side of the fluorescent waveguiding film. As one skilled in the art will recognize, the term "edge" of the fluorescent waveguiding film may generally refer to an interface between the fluorescent waveguiding film and a surrounding atmosphere, such as air. In particular, the edge may be a boundary of a second photosensitive area formed by the fluorescent waveguiding film. The term "located at" generally refers to the photosensitive elements being located either directly at the edge or in close proximity to the edge.For example, at least 50% of the light emerging from the edge toward the photosensitive element can be collected by the respective photosensitive element without being lost through scattering, beam broadening, or other losses. For example, the photosensitive element can be located at a position no more than 10 mm, preferably no more than 5 mm, from the edge. However, it should be noted that other embodiments for connecting the fluorescent light are also possible. Preferably, all photosensitive elements are arranged in the same way relative to their respective edges of the fluorescent waveguiding film in order to create similar measurement conditions for all photosensitive elements.

[0195] The at least one photosensitive element located at the at least one edge of the fluorescent waveguiding film can, for example, lie entirely or partially in the same plane as the fluorescent waveguiding film and / or lie entirely or partially in a different plane. In the latter case, as will be explained in more detail below, an optical coupling between the edge of the fluorescent waveguiding film and the at least one photosensitive element can be achieved, for example, by using at least one optical coupling element. If a plurality of photosensitive elements are present in the second optical sensor, at least one of the photosensitive elements can be located in the same plane as the fluorescent waveguiding film, and at least one of the photosensitive elements can be located outside the plane of the fluorescent waveguiding film.Furthermore, a viewing direction of the at least one light-sensitive element can be oriented parallel to the plane of the fluorescent waveguiding film or differently, e.g., perpendicular to this plane. When reference is made here to a "plane" of the fluorescent waveguiding film, this designation does not necessarily mean that the fluorescent waveguiding film is completely flat. Thus, the fluorescent waveguiding film can also be curved or bent, for example, and the plane of the fluorescent waveguiding film at the location of the at least one light-sensitive element can be a local tangential plane.

[0196] In the present case, the term “edge” of the fluorescent waveguiding film can refer to a straight line or a straight boundary region of the fluorescent waveguiding film, hereinafter also referred to as “straight edge”, or it can also refer to a non-straight line or a non-straight boundary region of the fluorescent waveguiding film, such as a corner of the fluorescent waveguiding film. Thus, the at least one photosensitive element or, if a plurality of photosensitive elements is present, at least one of the photosensitive elements can also be located at at least one corner of the fluorescent waveguiding film, for example at at least one corner of the second photosensitive surface formed by the fluorescent waveguiding film. Thus, the edge can in particular comprise an edge or part of an edge of the fluorescent waveguiding film, such as, for example,B. a corner and / or a straight edge section. Additionally or alternatively, the edge can also comprise a flat surface of the fluorescent waveguiding foil, such as a front or back side.

[0197] As already described above, in order to improve the feed of fluorescent light, which is guided from the light spot to the at least one photosensitive element, into the at least one photosensitive element, at least one optical coupling can be carried out by using at least one optical coupling element between the fluorescent waveguiding film and the respective photosensitive element.Thus, the at least one light-sensitive element or, if a plurality of light-sensitive elements are present, at least one of the light-sensitive elements can be optically coupled to the fluorescent waveguiding layer by at least one optical coupling element configured to at least partially decouple the fluorescent light guided by the fluorescent waveguiding film from the fluorescent waveguiding layer and preferably to at least partially couple it into the light-sensitive element. As used herein, the term "optical coupling element" generally refers to any element configured to disrupt and / or reduce and / or interrupt total internal reflection within the fluorescent waveguiding film that occurs during waveguiding within the fluorescent waveguiding film.Thus, the optical coupling element can, for example, be any transparent element whose refractive index lies between the refractive index of the fluorescent waveguiding film and the photosensitive element and / or the ambient atmosphere, such as air. For example, if a refractive index of the fluorescent waveguiding film is denoted by n1 and a refractive index of the photosensitive element is denoted by n2, the refractive index n3 of the optical coupling element can be n1 <n3<n2 oder n1> n3>n2.

[0198] The optical coupling element can be in direct contact with the fluorescent waveguiding film, e.g., with at least one surface of the fluorescent waveguiding film, e.g., a surface facing the object and / or a surface facing away from the object. Furthermore, the optical coupling element can also be in direct contact with the at least one photosensitive element. Furthermore, an independent optical coupling element can be provided for each photosensitive element, or alternatively, a plurality of photosensitive elements can share a common optical coupling element, or alternatively, a plurality of optical coupling elements can be coupled to one photosensitive element.

[0199] A person skilled in the art will be aware of various possibilities for optical coupling, which can also be used for coupling fluorescent light from the fluorescent waveguiding film into the photosensitive element. Thus, the at least one optical coupling element can, for example, comprise at least one element selected from the group consisting of: a part of a transparent adhesive that attaches the photosensitive element to the fluorescent waveguiding film; an etched part within the fluorescent waveguiding film, such as within a surface of the fluorescent waveguiding film, such as a surface facing the object and / or facing away from the object; a scratch in the fluorescent waveguiding film, such as a scratch in the surface of the fluorescent waveguiding film, such asa surface facing the object and / or facing away from the object; a prism. Additionally or alternatively, other optical coupling elements are generally known and can also be used within the scope of the present invention. In the simplest case, the at least one light-sensitive element can simply be adhered or glued to a surface of the fluorescent waveguiding film, e.g., using at least one transparent adhesive or bonding agent, e.g., a transparent epoxy resin. Other optical coupling options are also possible.

[0200] The first optical sensor and the second optical sensor can in particular have a substantially identical electrical capacitance. When reference is made to the capacitance of an optical sensor, this generally means the capacitance C as can be determined in a resonant circuit, as a person skilled in the art will recognize. If the first optical sensor or alternatively the second optical sensor is incorporated into a resonant circuit, the resonant circuit can, for example, have substantially the same resonant frequency. In the present case, the term “substantially identical” generally refers to the fact that the capacitance of the first optical sensor and the capacitance of the second optical sensor differ by no more than a factor of 10, preferably by no more than a factor of 5 or even by no more than a factor of 2.Furthermore, when reference is made to the capacitance of the second optical sensor, this refers to the capacitance of the at least one light-sensitive element of the second optical sensor, since the light-sensitive element determines the electrical behavior and, in particular, the high-frequency behavior of the second optical sensor. If a plurality of light-sensitive elements are present in the second optical sensor, this refers to the capacitance of at least one of these light-sensitive elements.

[0201] As described above, e.g. with reference to the first preferred embodiment, at least one predetermined or determinable relationship between the first and second sensor signals and the longitudinal coordinate can be used to evaluate the first and second sensor signals. With regard to the evaluation of the first and second sensor signals, reference can be made to the description of the first preferred embodiment. Thus, the evaluation device can be configured in particular to derive a quotient signal Q by dividing the first and second sensor signals, by dividing multiples of the first and second sensor signals, or by dividing linear combinations of the first and second sensor signals. The evaluation device can be configured to determine the longitudinal coordinate by evaluating the quotient signal Q.

[0202] In the configuration described above, Q can generally be a monotonic function of the longitudinal coordinate of the object and / or the size of the light spot, e.g., the diameter or equivalent diameter of the light spot. Thus, for example, when using linear optical sensors, the quotient Q=s1 / s2 is a monotonically decreasing function of the size of the light spot. This is due to the fact that, in the preferred configuration described above, the first photosensitive area is fully illuminated and is preferably located in the center of the light spot, e.g., on the optical axis. Consequently, as the diameter of the light spot increases, the peak intensity of the illumination, which may be located primarily in the first photosensitive area, decreases, and thus the first sensor signal also decreases.However, the second sensor signal can be more or less independent of the size of the light spot, as long as the light spot, apart from the shadow created by the first optical sensor, is located on the second light-sensitive surface. Consequently, the second sensor signal can remain more or less constant. The quotient of the first and second sensor signals therefore decreases continuously with increasing diameter of the light beam or the light spot on the first and second light-sensitive surfaces. The quotient is also largely independent of the total power of the light beam, since the total power of the light beam is included in both the first sensor signal and the second sensor signal. Consequently, the quotient Q can form a secondary signal that provides a clear relationship between the first and second sensor signals and the size or diameter of the light beam. On the other hand, since the size or diameter of the light beam is dependent on the wavelength of the light beam, the quotient Q can be used to determine the relationship between the first and second sensor signals and the wavelength of the light beam.Since the diameter of the light beam depends on a distance between the object from which the light beam propagates towards the detector and the detector itself, i.e. on the longitudinal coordinate of the object, a unique relationship can exist between the first and second sensor signals and the longitudinal coordinate. For the latter, reference can be made, for example, to WO 2014 / 097181 A1. The predetermined relationship can be determined by analytical considerations, e.g. by assuming a linear combination of Gaussian light beams, by empirical measurements, e.g. by measuring the first and second sensor signals or a secondary signal derived therefrom as a function of the longitudinal coordinate of the object, or by both.

[0203] The first optical sensor and the second optical sensor can be positioned in various ways. Thus, in a first example, the first optical sensor is arranged in front of the second optical sensor, such that the light beam first passes through the first optical sensor and then reaches the second optical sensor. Alternatively, however, a reverse order is also possible. Thus, alternatively, the second optical sensor can be placed in front of the first optical sensor, such that the light beam first reaches the second optical sensor, completely or partially passes through the second optical sensor, and then reaches the first optical sensor. The latter is possible primarily because the fluorescent waveguiding film of the second optical sensor can be designed to be completely or partially transparent in this or other embodiments, in particular in the spectral range of the light beam.Thus, the smaller first optical sensor can be placed on a back side of the second optical sensor from the perspective of the object.

[0204] The second optical sensor, and in particular the fluorescent waveguiding film of the second optical sensor, can be placed in various positions in one or more beam paths. Thus, for example, the second optical sensor and / or the fluorescent waveguiding film of the second optical sensor can be placed near a focal point in the beam path. Alternatively, the second optical sensor can also be placed one, two, or more than two Rayleigh wavelengths away from the focal point, particularly to improve the summation function.

[0205] As described above, the second optical sensor comprises at least one light-sensitive element from which the at least one second sensor signal originates. In this case, exactly one light-sensitive element can be used, for example, to collect at least a portion of the fluorescent light and, in response thereto, to generate a second sensor signal. Alternatively, however, the second optical sensor can also comprise two, three, four, or more light-sensitive elements, which are preferably located at at least two edges of the fluorescent waveguiding film, for example, at at least two opposite portions of an edge of the fluorescent waveguiding film. The light-sensitive elements can be capable of detecting fluorescent light that is guided through the fluorescent waveguiding film from the light spot to the light-sensitive elements and of each generating at least one sensor signal.So there can be a multitude of second sensor signals.

[0206] If at least two light-sensitive elements are provided which are located on at least two edges of the fluorescent waveguiding film, there are a multitude of possibilities. Thus, the at least two light-sensitive elements can be located, for example, at one or more of the following locations: on at least two straight edges of the fluorescent waveguiding film, such as at least two opposite edges, such as opposite edge sections; on at least two corners of the fluorescent waveguiding film, such as at least two opposite corners; on at least one corner of the fluorescent waveguiding film and on at least one straight edge, such as at least one straight edge section, of the fluorescent waveguiding film. Other possibilities are generally possible.

[0207] The detector and preferably the evaluation device can be configured in particular to combine at least two of these second sensor signals into at least one common second sensor signal. This at least one common second sensor signal can be used, in particular, in conjunction with the first second sensor signal to determine the longitudinal coordinate. Furthermore, at least one common second sensor signal can be used to acquire additional information, e.g., at least one piece of information about a transverse position of the object or a part thereof, as will be explained in more detail below.

[0208] Thus, the evaluation device for combining the at least two second sensor signals may comprise at least one summing device configured to sum the sensor signals of the at least two light-sensitive elements and thus to form a sum signal S. For example, the sum signal may be derived using the following formula: S=∑ici,si, where s i denotes the second sensor signals, with i = 1...N, where N is a positive integer indicating the number of light-sensitive elements, or a smaller positive integer, and where c i respective calibration coefficients.

[0209] As described above, the evaluation device can be configured in particular to determine the at least one longitudinal coordinate z of the object using at least one predetermined relationship between the first sensor signal, the at least one second sensor signal, and the longitudinal coordinate z. If, as described above, a plurality of second sensor signals is given, at least one combined second sensor signal can be used in this relationship. Thus, in particular, the sum signal S can be used. Thus, for example, the evaluation device can be configured in particular to determine the at least one longitudinal coordinate z using at least one predetermined relationship between the first sensor signal, the sum signal S of the second sensor signals, and the longitudinal coordinate z.

[0210] In addition to the at least one longitudinal coordinate, the detector can also be configured to determine at least one transverse coordinate of the object and / or a part thereof. For this purpose, the detector can comprise at least one transverse optical sensor. Various transverse sensors are well known in the art, such as the transverse sensors disclosed in WO 2014 / 097181 A1 and / or WO 2014 / 198629 A1 and / or other position-sensitive devices (PSDs), such as quadrant diodes, CCD or CMOS chips, or the like. Thus, the detector according to the present invention can, for example, comprise one or more PSDs disclosed in R.A. Street (ed.): Technology and Applications of Amorphous Silicon, Springer-Verlag Heidelberg, 2010, pp. 346-349. Other embodiments are also possible. For example, a portion of the light beam can be split within the detector by at least one beam splitter element.The split-off part can, for example, be directed to a transverse sensor, such as a CCD or CMOS chip or a camera sensor, and a transverse position of a light spot generated by the split-off part on the transverse sensor can be determined, thereby determining at least one transverse coordinate of the object. Preferably, however, the at least one second optical sensor can itself be used as a transverse optical sensor to determine at least one transverse coordinate of the object. This configuration is particularly advantageous when a plurality of light-sensitive elements are used in the second optical sensor, e.g., in different positions and at different edges of the fluorescent waveguiding film. The evaluation device can be configured to determine at least one transverse coordinate x, y of the object by evaluating the sensor signals of the light-sensitive elements.The evaluation device may be configured to combine the longitudinal coordinate and transverse coordinate information and determine a position of the object in space.

[0211] Thus, the evaluation device can further be configured to determine at least one transverse coordinate x, y of the object by evaluating the second sensor signals of the light-sensitive elements. To determine the at least one transverse coordinate in one or more directions, the sensor signals of the light-sensitive elements can be compared. The sensor signal of a respective light-sensitive element, which represents the fluorescent light guided from the light spot and thus from the location of the fluorescent light generation through the fluorescent waveguiding film to the light-sensitive elements, thus depends, as will be apparent to one skilled in the art, on a distance between the light spot and the respective light-sensitive element.In general, with increasing distance between the light spot and the photosensitive element, the sensor signal of the respective photosensitive element decreases, for example due to losses in waveguiding and / or due to scattering of the fluorescent light. By comparing the sensor signals of the photosensitive elements located at different, known positions, the lateral or transverse position of the light spot on the fluorescent waveguiding film can be determined and from this, for example using a known or determinable relationship between the transverse position of the light spot and the transverse coordinate of the object, the transverse coordinate of the object. Here, too, empirical relationships and / or semi-empirical relationships and / or analytical relationships can be used, such as the lens equation, which is basically known to a person skilled in the art.

[0212] Thus, the evaluation device can be configured in particular for the evaluation of at least two second sensor signals from at least two different light-sensitive elements. These at least two second sensor signals can, for example, be compared in order to determine a transverse position of the light spot on the fluorescent waveguiding foil and / or to directly derive a transverse position of the object. Thus, for example, a difference between at least two second sensor signals can be determined in order to derive at least one item of information about a transverse position of the object. Consequently, the evaluation device can comprise at least one subtraction device configured to form at least one difference signal D between second sensor signals generated by at least two of the light-sensitive elements. The second sensor signals can comprise at least one second sensor signal s 21and at least one second sensor signal s 22 wherein the at least one difference signal D is proportional to a·s 21 - b s 22 is: D∼a⋅s21−b⋅s22, where a, b are real coefficients, preferably with a=1 and b=1. Additionally or alternatively, the at least one difference signal D can be derived according to the following formula: D=(a⋅s21−b⋅s22) / (a⋅s21+b⋅s22).

[0213] The subtraction device can in particular be configured to generate at least a first difference signal D x from which at least a first transverse coordinate x of the object is derived. Additionally or alternatively, the subtraction device may be configured to generate at least a second difference signal D y from which at least a second transverse coordinate y of the object is derived. Thus, the first difference signal D xfrom at least two second sensor signals s x1 , s x2 generated by at least two light-sensitive elements located at opposite edges of the waveguiding foil in a first dimension. The second difference signal D y can consist of at least two second sensor signals s y1 , s y2 generated by at least two light-sensitive elements located at opposite edges of the waveguiding foil in a second dimension. The at least one first difference signal D x can be derived using the following formula Dx=(a⋅sx1−b⋅sx2) / (a⋅sx1+b⋅sx2), and the at least one second difference signal D y can be derived using the following formula Dy=(c⋅sy1−d⋅sy2) / (c⋅sy1+d⋅sy2), where a, b, c, d are real coefficients, preferably with a=1, b=1, c=1 and d=1.

[0214] In particular, if the second optical sensor comprises a plurality of photosensitive elements, the second optical sensor may comprise at least two photosensitive elements located at opposite edges of the fluorescent waveguiding film, as described above. The photosensitive elements may comprise at least a first pair of photosensitive elements located at opposite edges of the fluorescent waveguiding film in a first dimension of a coordinate system, and the photosensitive elements may further comprise at least a second pair of photosensitive elements located at opposite edges of the fluorescent waveguiding film in a second dimension of the coordinate system.

[0215] Further optional details may relate to the at least one fluorescent waveguiding film and / or to the second light-sensitive surface. Thus, for example, the second light-sensitive surface may in particular be a homogeneous light-sensitive surface. The second light-sensitive surface may therefore not be physically divided into sub-areas, such as pixels. In contrast, the sensitive surface may be a homogeneous region exhibiting uniform fluorescence.

[0216] The second light-sensitive surface can in particular be a large sensitive surface. Thus, for example, the second light-sensitive surface can have a surface area of at least 5 mm 2 , preferably at least 10 mm 2 , particularly preferably at least 100 mm 2 , particularly preferably at least 400 mm 2 The sensitive area can, for example, have a surface of 5 mm 2 up to 10,000 mm2 have, e.g. 100 mm 2 up to 2500 mm 2 The large-area design of the sensitive surface is advantageous in many respects. In particular, by increasing the surface area of the second light-sensitive surface, the resolution in determining the transverse coordinates can be increased. Furthermore, the field of view of the detector, e.g., the viewing angle, can be increased by using a large second light-sensitive surface.

[0217] The fluorescent waveguiding film can, in particular, comprise at least one flat film. However, slight curvatures can still be tolerated. In other embodiments, however, the fluorescent waveguiding film can also be configured as a curved fluorescent waveguiding film, for example, to achieve certain optical effects that might be desired in certain applications. Thus, one of the advantages of the present detector can be that the fluorescent waveguiding film can, in particular, be curved or flexible, or have a specific geometry.

[0218] The fluorescent waveguiding film can have a thickness of 10 µm to 3 mm, preferably a thickness of 100 µm to 1 mm, e.g., a thickness of 50 µm to 2 mm. The thickness of the waveguiding film can, in particular, be a dimension of the waveguiding film along an optical axis of the detector. The thickness can be adjusted to improve the waveguiding properties of the fluorescent light.

[0219] The fluorescent waveguiding foil can be completely or partially rigid or alternatively completely or partially flexible or deformable.

[0220] The fluorescent waveguiding film may comprise at least one matrix material. As used herein, the term "matrix material" generally refers to a material that forms the main part of the fluorescent waveguiding film and defines the main body of the fluorescent waveguiding film. The matrix material may, for example, be a material capable of incorporating one or more additional materials, e.g., by mixing, chemical bonding, dispersion, or dissolution. Thus, the at least one fluorescent material may be mixed into the matrix material and / or dispersed in the matrix material and / or chemically bonded to the matrix material and / or dissolved in the matrix material.

[0221] The matrix material can, in particular, be or comprise at least one plastic. The plastic can, in particular, be or comprise at least one polymer material. The plastic can, for example, be or comprise at least one material selected from the group consisting of polycarbonate, poly(methyl methacrylate), polystyrene, polyurethane, polypropylene, polyethylene terephthalate, and polyvinyl chloride. However, other materials are also possible.

[0222] The fluorescent material may, in particular, comprise any fluorophore. In particular, the at least one fluorescent material may comprise at least one fluorescent dye. A variety of fluorescent dyes are generally known to those skilled in the art. As described above, most of these fluorescent dyes exhibit the aforementioned saturation effects, so that the fluorescence is a nonlinear function of the excitation. For example, the fluorescent dye may be saturated by the light beam, so that the total power of the fluorescent light generated by the fluorescent dye is a nonlinear function of the intensity of the light beam. In particular, the total power of the fluorescent light may be disproportionate to the intensity of the light beam.

[0223] The fluorescent dye may in particular comprise at least one organic fluorescent dye. However, inorganic dyes may be used additionally or alternatively. The fluorescent dye may be selected from the group consisting of: a xanthene derivative, preferably fluorescein and / or rhodamine and / or Oregon Green and / or eosin and / or Texas Red and / or a derivative of any component thereof; a cyanine derivative, preferably cyanine and / or indocarbocyanine and / or oxacarbocyanine and / or thiacarbocyanine and / or merocyanine and / or a derivative of any component thereof; a squaraine derivative or a ring-substituted squaraine, preferably seta and / or SeTau and / or square dyes and / or a derivative of any component thereof; a naphthalene derivative, preferably a dansyl and / or prodane derivative thereof; a coumarin derivative;an oxadiazole derivative, preferably pyridyloxazole and / or nitrobenzoxadiazole and / or benzoxadiazole or a derivative of any component thereof; an anthracene derivative, preferably anthraquinone and / or DRAQ5 and / or DRAQ7 and / or CyTRAK Orange or a derivative of any component thereof; a pyrene derivative, preferably Cascade Blue; an oxazine derivative, preferably Nile Red and / or Nile Blue and / or Cresyl Violet and / or Oxazine 170 and / or a derivative of any component thereof; an acridine derivative, preferably proflavine, acridine orange, acridine yellow or a derivative of any component thereof; an arylmethine derivative, preferably auramine and / or crystal violet and / or malachite green and / or a derivative of any component thereof; a tetrapyrrole derivative, preferably porphine and / or phthalocyanine and / or bilirubin; a rylene dye or a derivative thereof, such as a perylene dye; a naphthalene imide or perylene imide;a naphthylene benzimidazole dye, as published in WO 2012 / 168395 A1; or a derivative of any of the listed substances. However, it should be noted that other dyes may be used additionally or alternatively.

[0224] Further optional details regarding the detector relate to the at least one light-sensitive element or to the plurality of light-sensitive elements. Thus, the at least one light-sensitive element may comprise, for example, at least one photodiode, preferably at least one inorganic photodiode, such as a silicon photodiode. The at least one light-sensitive element may comprise at least one elongated light-sensitive element extending along at least one segment of an edge or edge portion of the waveguiding foil.

[0225] As explained above, the fluorescent waveguiding film can, in particular, be a rectangular, preferably a square, fluorescent waveguiding film. In this configuration, the light-sensitive elements can be located, for example, at each of the four edges, e.g., at each of the four straight edge sections or edge regions, of the waveguiding film. Other embodiments are also possible.

[0226] The first and second optical sensors can each be independently opaque, transparent, or semi-transparent. However, for simplicity, opaque sensors that do not transmit the light beam can be used, as these opaque sensors are generally readily available commercially. However, the fluorescent waveguiding film can be fully or partially transparent.

[0227] The first optical sensor can, in particular, be a uniform sensor with a uniform light-sensitive surface. Thus, the first optical sensor can, in particular, be a non-pixelated optical sensor. Alternatively, however, the at least one first optical sensor can also comprise one or more pixelated sensors, each with two or more pixels. Other embodiments are also possible.

[0228] As explained in more detail below, the at least one second optical sensor can similarly comprise exactly one second optical sensor or a plurality of optical sensors. Furthermore, the at least one fluorescent waveguiding film of the second optical sensor can be exactly one coherent fluorescent waveguiding film. Alternatively, the at least one second optical sensor can also comprise a plurality of second optical sensors. The latter alternative can be realized, for example, by providing a plurality of fluorescent waveguiding films. Thus, a plurality of fluorescent waveguiding films can be provided, each having one or more light-sensitive elements. Other embodiments are also possible.

[0229] The detector, e.g., the second optical sensor, may further comprise at least one optical filter element, preferably at least one optical short-pass filter. Thus, for example, only photons capable of exciting fluorescent light can be transmitted to the fluorescent waveguiding film. However, other embodiments are also possible.

[0230] The first and second optical sensors can, in particular, be arranged linearly in one and the same beam path of the detector. Thus, for example, the first and second optical sensors can be arranged concentrically to an optical axis of the detector, wherein in particular the first optical sensor is placed in front of the second optical sensor. However, it should be noted that other embodiments are also possible, for example embodiments in which the first optical sensor and the second optical sensor are placed in separate and different beam paths, wherein the beam path of the detector is divided by one or more beam-splitting elements. However, the linear design in which the first and second optical sensors are arranged in one and the same beam path is preferred due to the simple optical design and the small volume required for the detector.Thus, the present invention enables in particular a simple, efficient and cost-effective optical structure.

[0231] As described above, the first optical sensor can in particular be a semiconductor sensor, preferably an inorganic semiconductor sensor, more preferably a photodiode, and most preferably a silicon photodiode. For example, the first optical sensor can be a unitary sensor with a single light-sensitive surface. As an example, a commercially available silicon photodiode can be used.

[0232] In a further preferred embodiment, the detector may comprise: - at least one angle-dependent optical element arranged to generate at least one light beam having at least one beam profile depending on an angle of incidence of an incident light beam propagating from the object towards the detector and illuminating the angle-dependent optical element; - at least two optical sensors, each optical sensor having at least one light-sensitive surface, each optical sensor being designed to generate at least one sensor signal in response to illumination of its respective light-sensitive surface by the light beam generated by the angle-dependent optical element, - wherein the at least one evaluation device is configured to determine at least one longitudinal coordinate z of the object by evaluating the quotient signal Q of the sensor signals.

[0233] The angle-dependent optical element can comprise at least one optical element selected from the group consisting of: at least one optical fiber, in particular at least one multiply bifurcated optical fiber, in particular at least one bifurcated optical fiber; at least one diffractive optical element, at least one angle-dependent reflective element, at least one diffractive grating element, in particular a blazed grating element; at least one aperture stop; at least one prism; at least one lens; at least one lens arrangement, in particular at least one microlens arrangement; at least one optical filter; at least one polarization filter; at least one bandpass filter; at least one liquid crystal filter, in particular a tunable liquid crystal filter; at least one shortpass filter; at least one longpass filter; at least one notch filter; at least one interference filter;at least one transmission grating; at least one nonlinear optical element, in particular a birefringent optical element;

[0234] At least one of the light-sensitive surfaces can be aligned with the object. In particular, at least one connecting line between at least one point of the object and at least one point of the respective light-sensitive surface can form an angle with a surface element of the light-sensitive surface that is different from 0°, for example an angle in the range of 20° to 90°, preferably 80 to 90°, for example 90°. If the object is located on the optical axis or near the optical axis, the light beam propagating from the object to the detector can thus run substantially parallel to the optical axis. Additionally or alternatively, at least one of the light-sensitive surfaces can be aligned differently from the alignment with the object. For example, at least one of the optical sensors can be aligned perpendicularly or at any angle to the optical axis and with respect to the object.The angle-dependent optical element can be configured to generate the light beam such that it impinges on the light-sensitive surfaces. For example, if at least one of the light-sensitive surfaces is oriented at an arbitrary angle to the optical axis, the angle-dependent optical element can be configured to direct the light beam onto the light-sensitive surface.

[0235] Here, the term "angle-dependent optical element" refers to an optical element configured to generate the at least one light beam with at least one beam profile that depends on the angle of incidence of the incident light beam propagating from the object to the detector and illuminating the angle-dependent optical element. In particular, the angle-dependent optical element may be configured to influence and / or change and / or adapt the beam profile of the incident light beam. The angle-dependent optical element may, for example, have angle-dependent transmission properties and / or angle-dependent reflection properties and / or angle-dependent absorption properties. The light beam generated by the angle-dependent optical element may comprise at least one transmitted light beam and / or at least one reflected light beam.The angle of incidence can be measured with respect to an optical axis of the angle-dependent optical element.

[0236] An electromagnetic wave that strikes a first side, e.g. a surface and / or an entrance, of the angle-dependent optical element can be partially absorbed and / or reflected and / or transmitted depending on the properties of the angle-dependent optical element. The term “absorption” refers to a reduction in the power and / or intensity of the incident light beam by the angle-dependent optical element. For example, the power and / or intensity of the incident light beam can be converted into heat or another form of energy by the angle-dependent optical element. In the present case, the term “transmission” refers to a part of the electromagnetic wave that is measurable outside the angle-dependent optical element in a half-space with angles of 90° and more with respect to the optical axis.Transmission can, for example, be a remaining part of the electromagnetic wave that impinges on the first side of the angle-dependent optical element, penetrates the angle-dependent optical element, and exits the angle-dependent optical element at a second side, such as an opposite side and / or an exit. The term "reflection" refers to a part of the electromagnetic wave that is measurable outside the angle-dependent optical element in a half-space with angles less than 90° with respect to the optical axis. The reflection can, for example, a change in the direction of a wavefront of the incident light beam due to an interaction with the angle-dependent optical element.

[0237] The total power of the electromagnetic wave incident on the angle-dependent optical element can be split by the angle-dependent optical element into at least three components, i.e., an absorption component, a reflection component, and a transmission component. A transmittance can be defined as a power of the transmission component normalized by the total power of the electromagnetic wave incident on the angle-dependent optical element. An absorbance can be defined as a power of the absorption component normalized by the total power of the electromagnetic wave incident on the angle-dependent optical element. A reflectance can be defined as a power of the reflection component normalized by the total power of the electromagnetic wave incident on the angle-dependent optical element.

[0238] Here, the term “angle-dependent transmission” refers to the fact that the transmittance depends on the angle of incidence at which the incident light beam propagating from the object to the detector strikes the angle-dependent optical element. As explained above, the angle of incidence can be measured with respect to an optical axis of the angle-dependent optical element. The angle-dependent optical element can be arranged behind at least one transmission device in the direction of propagation. The transmission device can, for example, comprise at least one collimating lens. The angle-dependent optical element can be designed such that it attenuates rays that impinge at a larger angle compared to rays that impinge at a smaller angle. The transmittance can, for example, be highest for light rays parallel to the optical axis, i.e. at 0°, and decrease at larger angles.In particular, the transmittance can drop sharply to zero at at least one critical angle. Thus, light rays with a large angle of incidence can be cut off.

[0239] In this case, the term "angle-dependent absorption" refers to the fact that the absorption coefficient depends on the angle of incidence at which the incident light beam propagating from the object to the detector strikes the angle-dependent optical element. In this case, the term "angle-dependent absorption" refers to the fact that the absorption coefficient depends on the angle of incidence at which the incident light beam propagating from the object to the detector strikes the angle-dependent optical element. For example, the photon energy and / or intensity of the light beam propagating from the object to the detector may be reduced depending on the angle of incidence.

[0240] In this case, the term “angle-dependent reflection” refers to the fact that the degree of reflection depends on the angle of incidence at which the incident light beam propagating from the object to the detector hits the angle-dependent optical element.

[0241] The angle-dependent optical element comprises, for example, at least one optical fiber. The optical fiber can be designed such that the transmittance for incident light rays parallel, i.e. at an angle of 0°, to the optical fiber is highest, whereby reflection effects can be neglected. The optical fiber can be designed such that at larger angles, e.g. at angles of 1° to 10°, the transmittance decreases uniformly to approximately 80% of the transmittance for parallel light rays and remains constant at this level up to an acceptance angle of the optical fiber. In the present case, the term “acceptance angle” can refer to an angle above which total internal reflection within the optical fiber is not possible, so that the light rays are reflected out of the optical fiber. The optical fiber can be designed such that the transmittance can drop steeply to zero at the acceptance angle.Light rays with a large angle of incidence can be cut off.

[0242] The optical fiber can be configured to transmit at least portions of the incident light beam that are not absorbed and / or reflected between two ends of the optical fiber. The optical fiber can have a length and be configured to enable transmission over a distance. The optical fiber can comprise at least one material selected from the group consisting of: silicon dioxide, aluminum silicate glass, germanium silicate glass, fluorozirconate, rare earth-doped glass, fluoride glass, chalcogenide glasses, sapphire, doped variants, in particular for silicon dioxide glass, phosphate glass, PMMA, polystyrene, fluoropolymers such as poly(perfluorobutenyl vinyl ether), or the like. The optical fiber can be a single- or multimode fiber. The optical fiber can be a step-index fiber, a polarizing fiber, a polarization-maintaining fiber, a plastic optical fiber, or the like.The optical fiber may comprise at least one fiber core surrounded by at least one fiber cladding having a lower refractive index than the fiber core. The fiber cladding may also be double or multiple cladding. The fiber cladding may comprise a so-called outer cladding. The fiber cladding may be coated with a so-called buffer configured to protect the optical fiber from damage and moisture. The buffer may comprise at least one UV-cured urethane-acrylate composite and / or at least one polyimide material. In one embodiment, a refractive index of the fiber core may be higher than the refractive index of the fiber cladding material, and the optical fiber may be configured to guide the incoming light beam by total internal reflection below the acceptance angle.In one embodiment, the optical fiber may comprise at least one hollow-core fiber, also called a photonic bandgap fiber. The hollow-core fiber may be configured to guide the incident light beam substantially within a so-called hollow region, with a small portion of the light beam being lost due to propagation into the fiber's cladding material.

[0243] The optical fiber may include one or more fiber connectors at the end of the fiber. The optical fiber may include end caps, such as coreless end caps. The optical fiber may include a fiber coupler, a fiber Bragg grating, a fiber polarizer, a fiber amplifier, a fiber-coupled diode laser, a fiber collimator, a fiber junction, a fiber splice, a fiber connector, a mechanical splice, a fusion splice, or the like. The optical fiber may include a polymer coating.

[0244] The optical fiber may comprise at least two or more fibers. The optical fiber may be at least one multiply bifurcated optical fiber, in particular at least one bifurcated optical fiber. The bifurcated optical fiber may, for example, comprise two fibers, in particular at least a first fiber and at least one second fiber. The first fiber and the second fiber may be arranged close to one another at an inlet end of the bifurcated optical fiber and split into two limbs separated by a distance at an outlet end of the bifurcated optical fiber. The first and the second fiber may be designed as fibers with identical properties or as fibers of different types. The first fiber may be configured to generate at least a first transmitted light beam, and the second fiber may be configured to generate at least a second transmitted light beam.The bifurcated optical fiber can be arranged such that the incident light beam enters the first fiber at a first angle of incidence and the second fiber at a second angle of incidence different from the first angle, so that the transmittance for the first transmitted light beam and the second transmitted light beam is different. One of the optical sensors can be arranged at an exit end of the first fiber and the other optical sensor at an exit end of the second fiber. The optical fiber can comprise more than two fibers, for example, three, four, or more fibers.For example, the multi-bifurcated fiber may comprise multiple fibers, each fiber comprising a core and / or a sheath and / or a buffer and / or a cladding, and one or more fibers may be partially or fully bundled by a further cladding such as a polymer tube to ensure that the fibers remain close to each other, for example at one end of the fiber.

[0245] The detector may comprise a plurality of optical fibers, e.g., a plurality of single optical fibers or a plurality of multi-bifurcated optical fibers. The detector may, for example, comprise a plurality of single optical fibers, e.g., optical fibers with identical properties. The optical fibers, e.g., the single optical fibers or the multi-bifurcated optical fibers, may be arranged such that the incident light beam can enter each of the optical fibers at different angles of incidence, such that the transmittance is different for each of the optical fibers. At least one optical sensor may be arranged at the exit ends of each optical fiber. Alternatively, at least two or more of the optical fibers may use the same optical sensor.

[0246] The illumination source can be configured to illuminate the object through the angle-dependent optical element. The optical fiber can comprise at least one illumination fiber configured to transmit at least one incident light beam generated by the illumination source such that it illuminates the object. The illumination source can be configured to couple the at least one light beam generated by the illumination source into the illumination fiber. The detector can comprise at least one coupling element, e.g. at least one input coupling element and / or at least one output coupling element, which can be arranged in front of and / or behind the optical fiber. The coupling element can be or comprise at least one transmission device.

[0247] The detector may comprise a further coupling element, in particular a further coupling element, which is configured to couple the light beam traveling from the object to the detector into the illumination fiber. The further coupling element may be arranged upstream of the optical fiber in the propagation direction of the light beam traveling from the object to the detector. The further coupling element may be or comprise at least one transmission device.

[0248] If the detector comprises a plurality of optical fibers, the detector may comprise one illumination source or a plurality of identical illumination sources and / or a plurality of different illumination sources. For example, the plurality of illumination sources may comprise at least two illumination sources that generate light with different properties such as color or modulation frequencies. In one embodiment, at least two of the optical fibers of the plurality of optical fibers may be illuminated by the same illumination source and / or two identical illumination sources. At least one optical sensor may be arranged at the exit ends of each optical fiber illuminated by the same illumination source and / or by identical illumination sources. Alternatively, at least two or more of the optical fibers illuminated by the same illumination source may use the same optical sensor.Such a detector, in which the same illumination source and identical optical sensors are used for a plurality of optical fibers, can be used as a proximity sensor. In one embodiment, at least two of the optical fibers of the plurality of optical fibers can be illuminated with at least two different illumination sources. At least one optical sensor can be arranged at the exit ends of each optical fiber. Alternatively, at least two or more of the optical fibers can use the same optical sensor.

[0249] As explained above, the distance perpendicular to an optical axis of the detector between the illumination source and the optical sensors can be small. The baseline can be less than 0.1 m, preferably less than 0.05 m, particularly preferably less than 0.025 m. For example, the baseline can be 21 mm. In particular, if the angle-dependent optical element is an optical fiber, the baseline can even be smaller than a radius of the transmission device.

[0250] The angle-dependent optical element may, for example, be an optical fiber. The illumination source may be guided by an optical fiber, wherein the illumination beam may exit the optical fiber behind the transmission device within a baseline that is smaller than the radius of the transmission device. The illumination source may be configured to generate at least one illumination light beam, wherein the optical fiber guiding the illumination beam may be attached to the transmission device, for example by a polymer or an adhesive or the like, in order to reduce reflections at interfaces with larger differences in refractive index. The detector may, for example, be a compact device without further optical elements, wherein the illumination source may be placed as close as possible to an edge of the transmission device.Thus, the baseline can be approximately half the diameter of the transmission device, in particular the lens diameter and the housings of the lens and light source. For example, the detector can be an even more compact device, wherein a mirror, in particular a small mirror, can be positioned in front of the transmission device, in particular at a center, for example a geometric center, or close to the center of the transmission device, in order to couple the illumination beam into the beam path. Thus, the baseline can be less than half the diameter of the transmission device. The illumination source can be arranged so that the baseline is as small as possible.By arranging the illumination source such that the propagation direction of the illumination light beam is substantially parallel to the optical axis and such that the illumination source and the optical axis are separated by the small baseline, very compact devices are possible. For example, a distance from the center of the transmission device to the illumination source, in particular along a connecting line from the center of the transmission device to the illumination source, can preferably be less than 2.5 times the distance from the center of the transmission device to an edge of the transmission device, more preferably less than 1.5 times the distance from the center to the edge of the transmission device, and most preferably less than 1 time the distance from the center to the edge of the transmission device.The transmission device can have any shape; in particular, non-circular shapes are possible. For short distances, the aperture of the illumination source can be small and the baseline small. For long distances, the aperture of the illumination source can be large and the baseline small. This is in contrast to triangulation methods, which require a large baseline for long distances. Furthermore, due to the necessary spatial extent of the baseline, triangulation-based systems have a minimum detection range that is significantly greater than zero, e.g., 20 cm from the detector system. Such a large baseline can result in the illumination light scattered by the object possibly not reaching the light-sensitive surface of the optical sensor behind the transmission device.Furthermore, in triangulation-based systems, the use of a small baseline would reduce the minimum detection range, but at the same time also reduce the maximum detection range. Furthermore, triangulation-based systems require a large number of light-sensitive surfaces and sensor signals, e.g., sensor signals from at least one detector row. According to the invention, the determination of the longitudinal coordinate z is possible with a reduced number of sensor signals, in particular with fewer than 20, preferably fewer than 10, and particularly preferably fewer than 5 sensor signals. The illumination source and the angle-dependent optical element can be arranged behind the transmission device in the propagation direction of the light beam traveling from the object to the detector, as will be described in more detail below.The distance perpendicular to the optical axis of the detector between the illumination source and the optical sensors may be smaller than the radius of the transmission device.

[0251] The illumination source and the optical sensors and / or the illumination source and the angle-dependent optical element and / or the optical sensors can be arranged with a relative spatial offset to the optical axis of the detector. Such an arrangement can improve the tendency of the quotient and thus the accuracy of the distance measurement. In particular, a gradient in a Q-distance diagram increases with increasing spatial offset, so that similar distances can be differentiated more precisely. For example, either the illumination source or the optical sensors can be arranged on the optical axis and the other(s) can be spaced from the optical axis. For example, both the illumination source and the optical sensors can be spaced from the optical axis by at least a different distance, in particular perpendicular to the optical axis.For example, the at least two fibers of a multi-forked optical fiber may be arranged at different distances from the optical axis. The angle-dependent optical element is configured to simulate a greater than actual distance perpendicular to an optical axis between the illumination source and the optical sensors without moving the illumination source and / or the optical sensors.

[0252] The transmission device may, for example, comprise one or more lenses, in particular one or more refractive lenses, and / or one or more convex mirrors. In this example, the focal length may be defined as the distance between the center of the thin refractive lens and the principal focal points of the thin lens. For a converging thin refractive lens, e.g., a convex or biconvex thin lens, the focal length may be considered positive and indicate the distance at which a collimated light beam incident on the thin lens as a transmission device can be focused to a single spot. In addition, the transmission device may comprise at least one wavelength-selective element, for example, at least one optical filter. In addition, the transmission device may be designed to impart a predefined beam profile to the electromagnetic radiation, e.g.,at the location of the sensor region and in particular the sensor surface. The above-mentioned optional embodiments of the transmission device can, in principle, be implemented individually or in any desired combination.

[0253] As an alternative to the linear arrangement of the two optical sensors, the optical sensors can also be arranged in different beam paths of the detector. The angle-dependent optical element can be configured to generate the first light beam and the second light beam. The first light beam and the second light beam can be generated with different transmittances. The first optical sensor can be configured to generate the first sensor signal in response to the illumination of the first light-sensitive surface by the first light beam generated by the angle-dependent optical element. The second optical sensor can be configured to generate the second sensor signal in response to the illumination of the second light-sensitive surface by the second light beam generated by the angle-dependent optical element.For example, as explained above, the angle-dependent optical element can comprise at least one multiply bifurcated optical fiber, which can be arranged such that the incident light beam can enter the first fiber at the first angle of incidence and the second fiber at the second angle of incidence, different from the first angle, such that the transmittance is different for the first light beam, in this case a first transmitted light beam, and the second light beam, in this case a second transmitted light beam. Either the first or the second optical sensor can be arranged at the exit end of the first fiber, and the other optical sensor at the exit end of the second fiber.

[0254] At least one sensor element may comprise a matrix of optical sensors, the optical sensors each having a light-sensitive surface, each optical sensor being configured to generate at least one sensor signal in response to illumination of the light-sensitive surface by the light beam generated by the angle-dependent optical element.

[0255] The detector can, for example, comprise two sensor elements, in particular at least a first sensor element and at least one second sensor element, which are arranged in different beam paths of the detector. The angle-dependent optical element can be configured to generate the first light beam and the second light beam. The first light beam and the second light beam can be generated with different transmittances. The first sensor element can be configured to generate the first sensor signal in response to illumination by the first light beam generated by the angle-dependent optical element. The second sensor element can be configured to generate the second sensor signal in response to illumination by the second light beam generated by the angle-dependent optical element.For example, as explained above, the angle-dependent optical element can comprise at least one multiply bifurcated optical fiber arranged such that the incident light beam can enter the first fiber at the first angle of incidence and the second fiber at the second angle of incidence, different from the first angle, such that the transmittance is different for the first transmitted light beam and the second transmitted light beam. Either the first or the second sensor element can be arranged at the exit end of the first fiber, and the other sensor element can be arranged at the exit end of the second fiber.

[0256] The detector may comprise at least two optical sensors, each optical sensor having a light-sensitive surface, each light-sensitive surface having a geometric center, the geometric centers of the optical sensors being spaced from an optical axis of the detector by different spatial offsets, each optical sensor being configured to generate a sensor signal in response to illumination of its respective light-sensitive surface by the light beam generated by the angle-dependent optical element.

[0257] The evaluation device can be configured to determine at least one longitudinal coordinate z of the object by combining the at least two sensor signals. In this further embodiment, the optical sensors can be arranged such that the light-sensitive surfaces of the optical sensors differ in terms of their spatial offset and / or their surface areas.

[0258] The detector may have a single beam path along which a light beam can travel from the object to the optical sensors, or it may have a plurality of beam paths. If, for example, the angle-dependent optical element comprises at least one multi-bifurcated optical fiber, each of the fibers of the multi-bifurcated optical fiber may represent an independent beam path. For example, there may be a single beam path or the beam path may be divided into two or more sub-beam paths. In the latter case, each sub-beam path may have its own optical axis, and the above-mentioned condition may generally refer to each beam path independently. The optical sensors may be located in one and the same beam path or sub-beam path. Alternatively, the optical sensors may also be located in different sub-beam paths.In the event that the optical sensors are distributed over different sub-beam paths, the above-mentioned condition can be described such that at least one first optical sensor is located in at least one first sub-beam path, which is offset by a first spatial offset from the optical axis of the first sub-beam path, and at least one second optical sensor is located in at least one second sub-beam path, which is offset by at least a second spatial offset from the optical axis of the second sub-beam path, wherein the first spatial offset and the second spatial offset differ from one another.

[0259] As explained above, each light-sensitive surface has a geometric center. Each geometric center of each light-sensitive surface can be spaced from the optical axis of the detector, for example, the optical axis of the beam path or the respective beam path in which the respective optical sensor is located.

[0260] As already mentioned, the optical sensors can be arranged in one and the same plane, which preferably runs perpendicular to the optical axis. However, other configurations are also possible. Thus, two or more of the optical sensors can also be spaced in a direction parallel to the optical axis.

[0261] The optical sensors can, for example, be sub-diodes of a segmented diode, with a center of the segmented diode being eccentric to the optical axis of the detector. For example, double-cell diodes or quadrant diodes are widely used and commercially available at low cost, and driving methods for these double-cell diodes or quadrant diodes are well known. For example, the double-cell diodes can each form independent diodes with the full functionality of a diode. For example, each of the double-cell diodes can have a square or rectangular shape, and the two diodes can be arranged in a plane such that the two sub-diodes together form a 1 × 2 or 2 × 1 rectangular matrix.However, the present invention proposes a new approach for evaluating the sensor signals of the double-cell diodes and the quadrant diode, which is explained in more detail below. In principle, however, the optical sensors can be sub-diodes of a quadrant diode, with a center of the quadrant diode being eccentric to the optical axis of the detector. For example, the four sub-diodes can each form independent diodes with the full functionality of a diode. For example, the four sub-diodes can each have a square or rectangular shape, and the four sub-diodes can be arranged in a plane such that the four sub-diodes together form a 2 × 2 matrix with a rectangular or square shape. In another example, the four sub-diodes together can form a 2 × 2 matrix with a circular or elliptical shape.For example, the sub-diodes can be located next to each other, with a minimal distance between them.

[0262] When using a quadrant diode with a 2×2 matrix of sub-diodes, the center of the quadrant diode can be eccentric or offset from the optical axis. Thus, for example, the center of the quadrant diodes, which can be an intersection of the geometric centers of the optical sensors of the quadrant diode, can be eccentric from the optical axis by at least 0.2 mm, preferably by at least 0.5 mm, particularly preferably by at least 1.0 mm, or even 2.0 mm. Similarly, when using other types of optical sensor configurations with a plurality of optical sensors, an overall center of the optical sensors can be offset from the optical axis by the same distance.

[0263] According to a further aspect of the present invention, a detector system for determining a position of at least one object is disclosed. The detector system comprises at least one detector according to the present invention, for example according to one or more of the embodiments disclosed above or according to one or more of the embodiments disclosed in further detail below. The detector system further comprises at least one beacon device configured to direct at least one light beam toward the detector, wherein the beacon device can be attached to the object and / or held by the object and / or integrated into the object. Further details about the beacon device, including possible embodiments, are described below.Thus, the at least one beacon device may be or comprise at least one active beacon device comprising one or more illumination sources such as lasers, LEDs, light bulbs, or the like. The light emitted by the illumination source may, for example, have a wavelength of 300-500 nm. Alternatively, as described above, the infrared spectral range may also be used, for example in the range from 780 nm to 3.0 µm. In particular, the near-infrared range, in which silicon photodiodes can be used, in particular in the range from 700 nm to 1000 nm, may be used. The light emitted by the one or more beacon devices may be unmodulated or, as described above, modulated to distinguish two or more light beams.Additionally or alternatively, the at least one beacon device can be configured to reflect one or more light beams towards the detector, for example by comprising one or more reflective elements. Furthermore, the at least one beacon device can be or comprise one or more scattering elements that can scatter a light beam. Elastic or inelastic scattering can be used here. If the at least one beacon device is configured to reflect and / or scatter a primary light beam towards the detector, the beacon device can be configured to leave the spectral properties of the light beam unaffected, or alternatively, it can be configured to change the spectral properties of the light beam, for example by modifying a wavelength of the light beam.

[0264] According to a further aspect of the present invention, a human-machine interface for exchanging at least one piece of information between a user and a machine is disclosed. The human-machine interface comprises at least one detector system according to the embodiments disclosed above and / or according to one or more of the embodiments disclosed in further detail below. The at least one beacon device is configured such that it can be attached either directly or indirectly to the user or held by the user. The human-machine interface is designed such that it determines at least one position of the user by means of the detector system, wherein the human-machine interface is designed such that it assigns at least one piece of information to the position.

[0265] According to a further aspect of the present invention, an entertainment device for performing at least one entertainment function is disclosed. The entertainment device comprises at least one human-machine interface according to the embodiment disclosed above and / or according to one or more of the embodiments disclosed in further detail below. The entertainment device is configured such that at least one piece of information can be input by a player via the human-machine interface. The entertainment device is further configured to change the entertainment function according to the information.

[0266] According to a further aspect of the present invention, a tracking system for tracking a position of at least one moving object is disclosed. The tracking system comprises at least one detector system according to one or more of the embodiments relating to a detector system, as disclosed above and / or in further detail below. The tracking system further comprises at least one tracking controller. The tracking controller is configured to track a series of positions of the object at specific times.

[0267] According to another aspect of the present invention, a camera for imaging at least one object is disclosed. The camera comprises at least one detector according to one of the embodiments relating to a detector, as disclosed above or in further detail below.

[0268] According to a further aspect of the present invention, a readout device for optical storage media is proposed. The readout device comprises at least one detector according to one of the preceding embodiments relating to a detector. A readout device for optical storage media here refers to a device capable of optically retrieving information stored on optical storage media such as optical storage disks, e.g., CCD, DVD, or Blu-ray discs. Thus, the above-described measuring principle of the detector according to the invention can be used to detect data modules in an optical storage medium, such as, for example, optical storage disks.For example, if a reflective data module is present and reflects the illuminating light beam, the detector detects not only the reflected light beam according to the measuring principle described above, but also a distance between the detector and the reflective data module—i.e., a depth of the reflective data module within the optical storage medium. Thus, the detector can be used, for example, to detect different layers of information modules or data modules within the optical storage medium. This allows, for example, two-layer or three-layer discs, or even discs with more than three layers, to be produced and read.

[0269] According to a further aspect of the present invention, a scanning system for determining a depth profile of a scene is provided, which may also include determining at least one position of at least one object. The scanning system comprises at least one detector according to the invention, such as at least one detector as disclosed in one or more of the embodiments listed above and / or in one or more of the embodiments below. The scanning system further comprises at least one illumination source configured to scan the scene with at least one light beam, which may also be referred to as an illumination light beam or scanning light beam.As used herein, the term "scenery" generally refers to a two-dimensional or three-dimensional region visible to the detector such that at least one geometric or spatial property of the two-dimensional or three-dimensional region can be evaluated with the detector. Furthermore, as used herein, the term "sampling" generally refers to a successive measurement in different regions. Thus, the scanning may in particular include at least a first measurement in which the illumination light beam is aligned or directed in a first manner and at least a second measurement in which the illumination light beam is aligned or directed in a second manner that is different from the first manner. The scanning may be continuous or stepwise.Thus, the illuminating light beam can be directed continuously or stepwise onto different regions of the scene, and the detector can be sensed to generate at least one piece of information, such as at least one longitudinal coordinate, for each region. To scan an object, for example, one or more illuminating light beams can continuously or stepwise generate light spots on the surface of the object, with longitudinal coordinates being generated for the light spots. Alternatively, however, a light pattern can also be used for scanning. The scanning can be a point scan or a line scan, or even scanning with more complex light patterns. The illumination source of the scanning system can be separate from the optional illumination source of the detector.Alternatively, the illumination source of the scanning system may be wholly or partially identical to or integrated into the at least one optional illumination source of the detector.

[0270] Thus, the scanning system may comprise at least one illumination source configured to emit the at least one light beam configured to illuminate the at least one point on the at least one surface of the at least one object. As used herein, the term "point" refers to an area, in particular a small area, on a portion of the surface of the object that can be selected, for example, by a user of the scanning system to be illuminated by the illumination source.Preferably, the point may have a size which, on the one hand, can be as small as possible so that the scanning system can determine as accurately as possible a value for the distance between the illumination source included in the scanning system and the part of the surface of the object on which the point may be located, and which, on the other hand, can be as large as possible so that the user of the scanning system or the scanning system itself, in particular by means of an automatic procedure, can detect the presence of the point on the relevant part of the surface of the object.

[0271] For this purpose, the illumination source can comprise an artificial illumination source, in particular at least one laser source and / or at least one incandescent lamp and / or at least one semiconductor light source, for example at least one light-emitting diode, in particular an organic and / or inorganic light-emitting diode. The light emitted by the illumination source can, for example, have a wavelength of 300-500 nm. Additionally or alternatively, light in the infrared spectral range can also be used, for example in the range from 780 nm to 3.0 µm. In particular, light in the part of the near-infrared range in which silicon photodiodes can be used, in particular in the range from 700 nm to 1000 nm, can be used. Due to their generally defined beam profiles and other handling properties, the use of at least one laser source as the illumination source is particularly preferred.The use of a single laser source may be preferred, particularly in cases where it may be important to provide a compact scanning system that can be easily stored and transported by the user. The illumination source may thus preferably be a component of the detector and may therefore in particular be integrated into the detector, for example into the housing of the detector. In a preferred embodiment, in particular the housing of the scanning system may comprise at least one display configured to provide the user with distance-related information, for example in an easily readable form. In a further preferred embodiment, in particular the housing of the scanning system may additionally have at least one button configured to operate at least one function of the scanning system, for example to set one or more operating modes.In a further preferred embodiment, in particular the housing of the scanning system may additionally comprise at least one fastening unit which may be configured to fasten the scanning system to a further surface, such as a rubber foot, a base plate or a wall mount, such as a base plate or mount with a magnetic material, in particular to increase the accuracy of the distance measurement and / or the handling of the scanning system by the user.

[0272] In particular, the illumination source of the scanning system can thus emit a single laser beam, which can be configured to illuminate a single point on the surface of the object. By using at least one of the detectors according to the invention, at least one item of information about the distance between the at least one point and the scanning system can thus be generated. In this case, the distance between the illumination system comprised by the scanning system and the individual point generated by the illumination source can preferably be determined, e.g., with the aid of the evaluation device comprised in the at least one detector. However, the scanning system can also further comprise an additional evaluation system, which can be configured in particular for this purpose.Alternatively or additionally, a size of the scanning system, in particular of the housing of the scanning system, can be taken into account and thus alternatively the distance between a specific point on the housing of the scanning system, such as a front or rear edge of the housing, and the individual point can be determined. The illumination source can be configured to generate and / or project a point cloud; for example, the illumination source can comprise at least one digital light processing (DLP) projector and / or at least one LCoS projector and / or at least one spatial light modulator and / or at least one diffractive optical element and / or at least one arrangement of light-emitting diodes and / or at least one arrangement of laser light sources.

[0273] Alternatively, the illumination source of the scanning system may emit two individual laser beams, which may be configured to form a respective angle, e.g., a right angle, between the directions of emission of the beams, thereby illuminating two corresponding points located on the surface of the same object or on two different surfaces on two separate objects. However, other values for the respective angle between the two individual laser beams are also possible. This feature can be used in particular for indirect measurement functions, for example, to derive an indirect distance that may not be directly accessible, e.g., because one or more obstacles are located between the scanning system and the point, or because it is otherwise difficult to reach.For example, it may be possible to determine a value for the height of an object by measuring two individual distances and deriving the height using the Pythagorean equation. In particular, to be able to maintain a predefined position relative to the object, the scanning system may further comprise at least one position adjustment unit, in particular an integrated bubble level, which can be used by the user to maintain the predefined position.

[0274] As a further alternative, the illumination source of the scanning system may emit a plurality of individual laser beams, for example an array of laser beams, which may be spaced a respective distance, in particular a regular distance, from one another and which may be arranged to generate an array of points located on the at least one surface of the at least one object. For this purpose, specially designed optical elements such as beam splitters and mirrors may be provided, which may enable the described array to be generated from the laser beams. In particular, the illumination source may be directed to scan a surface or volume by using one or more movable mirrors to redirect the light beam in a periodic or non-periodic manner.

[0275] Thus, the scanning system can provide a static array of the one or more points on the one or more surfaces of the one or more objects. Alternatively, the illumination source of the scanning system, in particular the one or more laser beams, such as the arrangement of laser beams described above, can be configured to provide one or more light beams that can have a varying intensity over time and / or that can be subject to a changing emission direction over time, in particular by moving one or more mirrors, such as the micromirrors included in said arrangement of micromirrors.Consequently, the illumination source may be configured to scan a portion of the at least one surface of the at least one object as an image using one or more light beams with changing characteristics generated by the at least one illumination source of the scanning device. In particular, the scanning system may use at least one line scan and / or one line scan, for example, to scan the one or more surfaces of the one or more objects sequentially or simultaneously. Thus, the scanning system may be configured to measure angles by measuring three or more points, or the scanning system may be adapted to measure corners or narrow regions, such as a roof gable, which may be difficult to access with a conventional measuring rod. As non-limiting examples, the scanning system may be used in safety laser scanners, e.g.in manufacturing environments, and / or in 3D scanning devices for determining the shape of an object, e.g. in connection with 3D printing, body scanning, quality control, in construction applications, e.g. as a distance meter, in logistics applications, e.g. to determine the size or volume of a package, in household applications, e.g. in robotic vacuum cleaners or lawn mowers, or in other types of applications that may include a scanning step. As non-limiting examples, the scanning system may be used in applications related to industrial safety curtains. As non-limiting examples, the scanning system may be used for sweeping, vacuuming, mopping or waxing or for yard maintenance functions such as mowing or raking.As non-limiting examples, the scanning system may use an LED illumination source with collimated optics and be configured to shift the frequency of the illumination source to a different frequency for more accurate results and / or use a filter to attenuate certain frequencies while allowing others to pass. As non-limiting examples, the scanning system and / or the illumination source as a whole, or just a specific optics package, such as a mirror, beam splitter, or the like, may be rotated using a special motor so that the scanning system has a full 360-degree view during operation or can even be moved and / or rotated out of plane to further increase the scanned area. Furthermore, the illumination source may be actively steered in a predetermined direction.To enable the rotation of wired electrical systems, slip rings, optical data transmission or inductive couplings can also be used.

[0276] As a non-limiting example, the scanning system may be mounted on a tripod and directed at an object or region with multiple corners and surfaces. One or more flexibly movable laser sources are attached to the scanning system. The one or more laser sources are moved to illuminate points of interest. The position of the illuminated points relative to the scanning system is measured when a specific button on the scanning system is pressed, and the position information is transmitted to a mobile phone via a wireless interface. The position data is stored in a mobile phone application. The laser sources are moved to illuminate additional points of interest, whose position is measured and transmitted to the mobile phone application. The mobile phone application can convert the set of points into a 3D model by connecting neighboring points with planar surfaces.The 3D model can be saved and further processed. The distances and / or angles between the measured points or surfaces can be displayed directly on a display connected to a scanning system or on the mobile phone to which the position data is transmitted.

[0277] As a non-limiting example, a scanning system may include two or more flexible, movable laser sources for projecting spots and a further movable laser source for projecting a line. The line may be used to arrange the two or more laser spots along a line, and the scanner's display may show the distance between the two or more laser spots, which may be arranged along the line, e.g., at the same distance. With two laser spots, a single laser source may be used, while the distance of the projected spots is varied using one or more beam splitters or prisms, where a beam splitter or prism can be moved to move the projected laser spots apart or closer together.Furthermore, the scanning system may be configured to project further patterns such as a right angle, a circle, a square, a triangle, or the like, along which a measurement may be performed by projecting laser spots and measuring their position.

[0278] As a non-limiting example, the scanning system may be configured as a line scanning device. In particular, the scanning device may comprise at least one row or array of sensors. Triangulation systems require a sufficient baseline, so detection may not be possible at close range. Near-field detection may be possible if the laser spot is tilted toward the transmission device. However, tilting causes the light spot to move out of the field of view, limiting detection in far-field regions. These near- and far-field problems can be overcome by using the detector according to the invention. In particular, the detector may comprise a CMOS array of optical sensors. The scanning system may be configured to detect a plurality of light beams propagating from the object to the detector on the CMOS array.The light beams can be generated at different locations on the object or by moving the illumination source. The scanning system can be configured to determine at least one longitudinal coordinate for each of the light points by determining the quotient signal Q, as described in more detail above and below.

[0279] As a non-limiting example, the scanning system may be configured to support the use of tools such as woodworking or metalworking tools, such as a saw, drill, or the like. Thus, the scanning system may measure distance in two opposite directions and display the two measured distances or the sum of the distances on a display. Furthermore, the scanning system may be configured to measure the distance to the edge of a surface such that, when the scanning system is placed on the surface, a laser spot is automatically moved away from the scanning system along the surface until the distance measurement shows a sudden change due to a corner or edge of a surface. Thus, it is possible to measure the distance of the end of a wooden board while the scanning device is on the board but away from its end.Furthermore, the scanning system can measure the distance of the end of a board in one direction and project a line, circle, or point at a certain distance in the opposite direction. The scanning system can be configured to project the line, circle, or point at a distance that depends on the distance measured in the opposite direction, e.g., depending on a predetermined sum distance. This makes it possible to work with a tool such as a saw or drill at the projected position while placing the scanning system at a safe distance from the tool, and simultaneously perform machining with the tool at a predetermined distance from the edge of the board. Furthermore, the scanning system can be configured to project points, lines, or the like in two opposite directions at a predetermined distance.If the sum of the distances is changed, only one of the projected distances changes.

[0280] As a non-limiting example, the scanning system may be configured to be placed on a surface, for example, a surface on which a task is performed, such as cutting, sawing, drilling, or the like, and to project a line onto the surface at a predetermined distance, which may be adjusted, for example, using buttons on the scanning device.

[0281] As non-limiting examples, the scanning system may be used in safety laser scanners, e.g. in manufacturing environments, and / or in 3D scanning devices for determining the shape of an object, e.g. in connection with 3D printing, body scanning, quality control, in construction applications, e.g. as a distance meter, in logistics applications, e.g. to determine the size or volume of a package, in household applications, e.g. in robotic vacuum cleaners or lawn mowers, or in other types of applications that may include a scanning step.

[0282] The transmission device can, as explained above, be designed such that it feeds light propagating from the object to the detector to the optical sensor, preferably sequentially. As explained above, this feeding can be effected optionally by imaging or non-imaging properties of the transmission device. In particular, the transmission device can also be designed such that it collects the electromagnetic radiation before it is fed to the optical sensor. The transmission device can also be wholly or partially a component of at least one optional illumination source, for example by the illumination source being designed such that it provides a light beam with defined optical properties, for example with a defined or precisely known beam profile, for example at least one linear combination of Gaussian beams, in particular at least one laser beam with a known beam profile.

[0283] The beacon devices and / or the at least one optional illumination source can generally emit light in at least one of the following ranges: in the ultraviolet spectral range, preferably in the range from 200 nm to 380 nm; in the visible spectral range (380 nm to 780 nm); in the infrared spectral range, preferably in the range from 780 nm to 3.0 micrometers, particularly preferably in the part of the near infrared range in which silicon photodiodes are applicable, in particular in the range from 700 nm to 1000 nm. For thermal imaging applications, the target object can emit light in the far infrared spectral range, preferably in the range from 3.0 micrometers to 20 micrometers. The at least one illumination source is, for example, configured to emit light in the visible spectral range, preferably in the range from 500 nm to 780 nm, particularly preferably at 650 nm to 750 nm or at 690 nm to 700 nm.For example, at least one illumination source is configured to emit light in the infrared spectral range. However, other options are also possible.

[0284] The light beam can be fed into the optical sensor in particular such that a light spot, e.g. with a round, oval or otherwise configured cross-section, is generated on the optional sensor surface of the optical sensor. The detector can, for example, have a field of view, in particular a solid angle range and / or a spatial range, within which objects can be detected. The transmission device can preferably be designed such that the light spot, for example in the case of an object arranged within a field of view of the detector, is arranged entirely on a sensor region and / or on a sensor surface of the optical sensor. To ensure this condition, a sensor surface with an appropriate size can, for example, be selected.

[0285] According to a further aspect, the present invention discloses an inertial measuring unit for use in an electronic device. The electronic device may be a mobile electronic device. The electronic device may be a camera. The electronic device may be a mobile phone. The inertial measuring unit is arranged to receive data determined by at least one inertial measuring unit comprising at least one detector according to the present invention, e.g. according to one or more of the embodiments relating to a detector as disclosed above or disclosed in further detail below. Here, the term “data determined by the at least one detector” refers to at least one item of information about the at least one longitudinal coordinate, e.g.The inertial measurement unit is further configured to receive data determined by at least one further sensor selected from the group consisting of: a wheel speed sensor, a yaw rate sensor, a tilt sensor, an orientation sensor, a motion sensor, a magnetohydrodynamic sensor, a force sensor, an angle sensor, an angular rate sensor, a magnetic field sensor, a magnetometer, an accelerometer, and a gyroscope.

[0286] Here, the term “data determined by the at least one further sensor” refers to at least one piece of information selected from the group consisting of: angle information, speed information, information about a rotation rate, information about an inclination. The inertial measurement unit is configured to determine, by evaluating the data from the detector and the at least one further sensor, at least one property of the electronic device selected from the group consisting of: position in space, relative or absolute movement in space, rotation, acceleration, orientation, angular position, inclination, rotation rate, speed. The inertial measurement unit can comprise at least one processor. The processor can be configured to evaluate data recorded by the further sensor.In particular, the processor can be configured to measure a spatial position and / or a spatial orientation and / or movement and / or speed. The inertial measurement unit can comprise a plurality of further sensors. The inertial measurement unit can be configured to fuse information determined from at least two of the further sensors. The inertial measurement unit can be configured to fuse information from at least two further sensors using at least one Kalman filter. As described above, the detector can be configured to provide an absolute measurement of the longitudinal coordinate z. The processor, e.g. the evaluation device described above, can be configured to fuse the information from the at least two further sensors taking into account the longitudinal coordinate z.The various sensor signals can be combined in a Kalman filter or a linear quadratic estimator to account for the inherent measurement errors and inaccuracies of each sensor signal. Combining these sensor signals in a Kalman filter can lead to improved estimation, e.g., for measuring the longitudinal coordinate.

[0287] According to a further aspect, the present invention discloses a method for determining a position of at least one object using a detector, for example a detector according to the present invention, such as according to one or more of the embodiments relating to a detector as disclosed above or as disclosed in further detail below. However, other types of detectors may also be used. The method comprises the following method steps, wherein the method steps may be carried out in the order given or in a different order. Furthermore, there may be one or more additional method steps that are not listed. Furthermore, one, several or even all method steps may be repeated.

[0288] The procedure includes the following steps: - Providing at least two optical sensors, each optical sensor having a light-sensitive surface, each optical sensor being configured to generate a sensor signal in response to illumination of its respective light-sensitive surface by the light beam, the detector comprising at least one transmission device, the transmission device having at least one focal length in response to the light beam propagating from the object to the detector; - illuminating each of the light-sensitive surfaces of at least two optical sensors of the detector with a light beam propagating from the object to the detector, whereby each of the light-sensitive surfaces generates at least one sensor signal; and - Evaluating the sensor signals and thereby determining at least one longitudinal coordinate z of the object, wherein the evaluation comprises deriving a quotient signal Q of the sensor signals.

[0289] The longitudinal coordinate z of the object can be determined in at least one measuring range independent of the object size in an object plane.

[0290] Deriving the quotient signal Q may comprise dividing the sensor signals and / or dividing multiples of the sensor signals and / or dividing linear combinations of the sensor signals.

[0291] The method may comprise adjusting the measurement range by adjusting one or more parameters selected from the group consisting of: a longitudinal distance between the object and the transmission device z0; the focal length of the transmission device f; a diameter of an exit pupil of the transmission device E x; a longitudinal distance between the transfer device and the photosensitive surface z s ; a distance between the transmission device and an image of the object z i ; an object size O Größe of the object in the object plane.

[0292] The transmission device may have an optical axis. Regarding embodiments of the transmission device, reference is made to the embodiments of the transmission device described above with reference to a first aspect.

[0293] For details, options, and definitions, reference can be made to the detector described above. Thus, the method may, in particular, as described above, comprise using the detector according to the present invention, for example, according to one or more of the embodiments mentioned above or described in further detail below.

[0294] In a first preferred embodiment, the method may comprise the following method steps, wherein the method steps may be performed in the specified order or in a different order. Furthermore, one or more additional method steps may be present that are not listed. Furthermore, one, several, or even all method steps may be repeated.

[0295] The procedural steps can be as follows: - illuminating at least a first light-sensitive surface of at least a first optical sensor of the detector with a light beam propagating from the object to the detector, and thereby generating at least a first sensor signal; - illuminating at least one second light-sensitive surface of at least one second optical sensor of the detector with the light beam and thereby generating at least one second sensor signal, wherein the first light-sensitive surface is smaller than the second light-sensitive surface; and - Evaluating the first and second sensor signals and thereby determining at least one longitudinal coordinate z of the object.

[0296] In particular, evaluating the first and second sensor signals may comprise deriving the quotient signal Q by dividing the first and second sensor signals, by dividing multiples of the first and second sensor signals, or by dividing linear combinations of the first and second sensor signals. Furthermore, determ...

Claims

[1] A portable device with an optical detector comprising: a. an illumination source for generating an illumination pattern for illuminating an object, the illumination pattern comprising a regular and / or constant and / or periodic pattern; b. an array of optical sensors, each optical sensor being designed to generate at least one sensor signal in response to illumination of the object of its respective light-sensitive surface by the light beam, and c. an evaluation device for determining a region of interest. [2] The portable device of claim 1, wherein the illumination pattern includes a triangular pattern, a rectangular pattern, or a hexagonal pattern. [3] The portable device of claim 1, wherein the illumination pattern includes a rotated hexagonal pattern and / or a shifted hexagonal pattern. [4] The portable device of any one of claims 1 to 3, wherein the illumination source includes one or more of: a digital light processing (DLP) projector, an LCoS projector, a spatial light modulator, a diffractive optical element, an array of light emitting diodes, an array of laser light sources. [5] The portable device according to any one of claims 1 to 4, wherein the illumination source is configured to directly generate the illumination pattern. [6] The portable device of any one of claims 1 to 5, wherein the illumination source includes a projector configured to generate a point cloud such that the illumination pattern includes a plurality of points. [7] The portable device of any one of claims 1 to 6, wherein the illumination source is configured to generate and / or project a point cloud to create a plurality of illuminated regions on the array of optical sensors. [8] The portable device according to any one of claims 1 to 7, wherein the portable device additionally includes an optical element comprising a diffractive optical element, the optical element being arranged to supply the light propagating from the object to the detector to the optical sensors to the optical sensor, this supplying being effected by imaging or non-imaging properties of the transmission device. [9] The portable device according to any one of claims 8, wherein the illumination source is located behind the optical element in the direction of light propagation. [10] The portable device according to any one of claims 1 to 9, wherein the array of optical sensors includes at least one element selected from the group consisting of a CCD sensor element, a CMOS sensor element, a photodiode, a photocell, a photoconductor, a phototransistor, or any combination thereof. [11] The portable device according to any one of claims 1 to 10, wherein the array of optical sensors comprises a matrix of CCD detectors and / or CMOS detectors. [12] The portable device according to any one of claims 1 to 11, wherein the distance between the illumination source and the array of optical sensors is less than 0.025 meters. [13] The portable device according to any one of claims 1 to 12, wherein the evaluation device is arranged to determine and use one or more light-sensitive areas illuminated by the light beam to determine a longitudinal coordinate of the object. [14] The portable device according to any one of claims 1 to 13, wherein the evaluation device is configured to perform a filtering method or an object recognition method. [15] The portable device according to any one of claims 1 to 14, wherein the evaluation device is configured to evaluate the sensor signals by a. Determining at least one optical sensor with the highest sensor signal and forming at least one center signal; b. Evaluating the sensor signals of the optical sensors of the matrix and forming at least one sum signal; c. Determining at least one combined signal by combining the center signal and the sum signal; and d. Determining at least one longitudinal coordinate z of the object by evaluating the combined signal [16] The portable device according to any one of claims 1 to 15, wherein the optical detector is configured to determine at least one item of distance information of the object using triangulation and / or structured light methods. [17] The portable device according to any one of claims 1 to 16, wherein the light beam propagating from the object to the detector is arranged to produce at least one reflection pattern on the array of optical sensors, the reflection pattern comprising at least one reflection feature that depends on the corresponding illumination feature of the illumination pattern, the evaluation device being arranged to perform at least one image analysis to identify the reflection feature. [18] The portable device according to any one of claims 1 to 17, wherein the portable device is configured to perform facial recognition and identification. [19] The wearable device according to any one of claims 1 to 18, wherein the wearable device is configured to perform gaze detection, gaze tracking, tracking of hands, arms or objects used in connection with a virtual or augmented reality application. [20] The portable device according to any one of claims 1 to 19, wherein the portable device is configured to perform gesture recognition of hand movements or movements of parts of a hand.

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