Apparatus and method for generating backscatter histogram data for determining diffuse backscatter during optical runtime measurements

Abstract

The invention relates to a device (1) for generating backscattering histogram data (RHD0) for determining diffuse backscatter during an optical runtime measurement, comprising: at least one histogram accumulation unit (HA0 to HAX), the at least one histogram accumulation unit (HA0 to HAX) having a plurality of signal input terminals for receiving time-correlated histogram data (ZHD0 to ZHDP), wherein the histogram accumulation unit (HA0 to HAX) is arranged to generate backscattering histogram data (RHD0) based on the time-correlated histogram data (ZHD0 to ZHDP) received at the signal input terminals.

Description

Technical Field

[0001] The present invention generally relates to a method for generating a method for determining dispersion during optical runtime measurement.

[0002] Backscattering histogram data of backscattering equipment and for measuring the optical run time

[0003] A method for generating backscatter histogram data for determining diffuse backscatter during. Background Art

[0004] Different methods for measuring optical runtime are generally known, which can be based on

[0005] The so-called time-of-flight principle, which measures the transit time of an emitted light signal reflected by an object,

[0006] to determine the distance to an object based on runtime.

[0007] It is known to use in the context of motor vehicles a method based on so-called LIDAR (Light Detection and Detection)

[0008] A sensor based on the principle of distance measurement, which periodically transmits pulses and detects reflected pulses to scan the surrounding area.

[0009] A corresponding method and device are known, for example, from WO 2017 / 081294.

[0010] In LIDAR applications, the type of light signal detected often differs, depending, for example, on whether the emitted light signal is reflected off a solid object (object backscatter) or

[0011] Reflection (diffuse backscatter) from particles in the air (e.g. in fog or exhaust gas)

[0012] From the recorded backscatter data conclusions can be drawn about the environmental conditions. Summary of the invention

[0013] Although it is known from the prior art to record backscatter during optical runtime measurements

[0014] data solution, but the object of the present invention is to provide a method for measuring the optical

[0015] Apparatus and method for determining backscatter during measurement.

[0016] This object can be achieved by means of an apparatus and a method according to the main embodiments described below.

[0017] In a first aspect, the invention provides an apparatus for generating backscatter histogram data for determining diffuse backscatter during an optical runtime measurement, comprising:

[0018] At least one histogram accumulation unit has a plurality of signal inputs for receiving the time-correlated histogram data, wherein the histogram accumulation unit is arranged to generate backscatter histogram data based on the time-correlated histogram data received at the signal inputs.

[0019] In a second aspect, the invention provides a method for generating backscatter histogram data for determining diffuse backscatter during an optical runtime measurement, comprising:

[0020] receiving a plurality of time-correlated histogram data; and generating backscatter histogram data based on the received time-correlated histogram data.

[0021] Further advantages of the invention can be gathered from the dependent claims, the drawings and the following description of preferred exemplary embodiments of the invention.

[0022] As mentioned, several exemplary embodiments relate to an apparatus for generating backscatter histogram data for determining diffuse backscatter during an optical runtime measurement, comprising:

[0023] At least one histogram accumulation unit has a plurality of signal inputs for receiving the time-correlated histogram data, wherein the histogram accumulation unit is arranged to generate backscatter histogram data based on the time-correlated histogram data received at the signal inputs.

[0024] As mentioned at the outset, conclusions can be drawn about environmental conditions from the backscatter data during the LIDAR measurement. For example, in the case of an autonomous motor vehicle, a more precise knowledge of environmental conditions (e.g. fog, etc.) makes it possible to adjust the driving mode accordingly to the environmental conditions, thereby increasing safety. Furthermore, in a number of exemplary embodiments, the precise knowledge of the diffuse backscatter during the LIDAR measurement also enables (more precise) detection of static objects. For example, this makes it possible to determine the traffic situation more precisely, which likewise increases the safety and reliability of the autonomous vehicle.

[0025] To this end, the apparatus in some exemplary embodiments is used in a LIDAR system or similar system, such as in a motor vehicle environment, but the invention is not limited to these situations.

[0026] In some exemplary embodiments, LIDAR data typically contains signal contributions from backscatter, light reflections on objects, ambient light, stray light signals from other light sources in the environment, etc. These data are basically known and can be represented in a histogram.

[0027] Accordingly, the generation of backscatter histogram data may mean that the generated backscatter histogram data at least contains the signal contribution of diffuse backscatter, or that the backscatter histogram data are formed in such a way that they may substantially contain the signal contribution of diffuse backscatter and are therefore substantially suitable for determining diffuse backscatter during optical distance measurement.

[0028] In some exemplary embodiments, the optical runtime measurement is based on the so-called TCSPC (time-correlated signal photon counting) measurement principle, in particular in LIDAR-based exemplary embodiments. In these methods, a light pulse that usually lasts a few nanoseconds is usually emitted and marks the start time of the measurement. During the period until the next light pulse (measurement time), the light reflected by the object or the backscattered light is detected by a light detection receiving element (e.g., a single photon avalanche diode (SPAD)). The measurement time is divided into multiple short time periods (e.g., 500ps) here. Each time period can then be assigned a time corresponding to the time period of the start time (e.g., in a 500ps time period, 250ps of time can be assigned to the first time period, and 750ps of time can be assigned to the second time period, etc.).

[0029] Depending on the distance to the object or to the backscattering point, the light reaches the light detection receiving element at different times.

[0030] An electrical signal is thereby generated in the light detection receiving element. The electrical signal can then be assigned to one of the time periods using a substantially known time-to-digital converter (also referred to as a "TDC" (time-to-digital converter)). Counting the electrical signals ("events") assigned to the time periods produces a so-called histogram or time-correlated histogram (also referred to as a TCSPC histogram), wherein these histograms, for example, can also exist only as pure data and are stored as value pairs consisting of a time period and a corresponding number of entries (things or events). The time period together with the number of events correspondingly assigned to each time period ("bin") forms histogram data, which can be represented substantially by a digital signal (or an analog signal). Therefore, these histogram data typically contain signal contributions from diffuse backscattering, light reflections on objects, ambient light, stray light signals from other light sources in the environment, and the like.

[0031] The device includes at least one histogram accumulation unit having a plurality of signal inputs. In some exemplary embodiments, the maximum number of histogram accumulation units is determined by the number of light detection receiving elements in a system (e.g., a LIDAR system) for optical runtime measurement. The histogram accumulation unit may be substantially or have an electronic circuit in an exemplary embodiment, which receives a digital signal or data (e.g., time-correlated histogram data) through a signal input, and performs the generation of backscattered histogram data described herein. The electronic circuit may include electronic components, digital storage elements, etc., to perform the functions described herein. The electronic circuit may be implemented by an FPGA (field programmable gate array), a DSP (digital signal processor), etc. In other exemplary embodiments, the histogram accumulation unit is implemented by a memory and a microprocessor. In other exemplary embodiments, the histogram accumulation unit is implemented by software, wherein in such exemplary embodiments, the signal input corresponds to a parameter / attribute of a software function / method. The generation of backscattered histogram data corresponds to executing a sequence of commands for performing a specific arithmetic operation on a computer, so that after all commands are processed, backscattered histogram data can be obtained. In some exemplary embodiments, the histogram accumulation unit may also be implemented as a mixture of hardware-based components and software-based components, wherein the functions described herein are distributed over these components accordingly.

[0032] The histogram accumulation unit receives the time-correlated histogram data at the signal input or each signal input. The histogram data here does not always have to be received at each signal input, and some exemplary embodiments provide even more signal inputs, for example, histogram data is not received at some signal inputs, or these signal inputs can only receive histogram data based on corresponding configurations.

[0033] Time-correlated histogram data are those data generated based on the electrical signals of the light detection receiving elements within the (corresponding) measurement time. As mentioned above, these time-correlated histogram data therefore typically contain signal contributions from diffuse backscattering, light reflections on objects, ambient light, stray light signals from other light sources in the environment, etc.

[0034] In some exemplary embodiments, the time-correlated histogram data received at each signal input is defined by the time-correlated histogram data from one light detection receiving element. In other exemplary embodiments, the time-correlated histogram data received at each signal input is defined by the sum of the time-correlated histogram data from multiple light detection receiving elements. In other exemplary embodiments, the time-correlated histogram data received at each signal input is defined by multiple time-correlated histogram data from multiple light detection receiving elements.

[0035] Backscatter histogram data is generated based on the time-correlated histogram data received at the signal input.

[0036] The amount of light detected based on diffuse backscatter is typically low compared to ambient light (e.g., sunlight) and the amount of light reflected off an object, and thus any determination of diffuse backscatter may be difficult and imprecise, particularly with respect to time-correlated histogram data. Therefore, in some exemplary embodiments, the apparatus is configured to generate backscatter histogram data for determining diffuse backscatter during an optical runtime measurement.

[0037] In some exemplary embodiments, the backscatter histogram data here corresponds to the accumulation of time-correlated histogram data from multiple light detection receiving elements. The accumulation of time-correlated histogram data can be advantageous for determining diffuse backscatter because the signal-to-noise ratio (also referred to as "SNR") of the diffuse backscatter contribution is increased compared to other signal contributions. In some exemplary embodiments, this allows for better determination of diffuse backscatter.

[0038] This is basically because during the optical run time measurement, the diffuse backscatter at a short distance (e.g., 5 m) is usually higher than that at a long distance (e.g., 200 m) and can continuously decrease. Therefore, in order to determine the diffuse backscatter, in some exemplary embodiments, it is not necessary to consider the time period exceeding a certain threshold (corresponding to the distance threshold, e.g., 20 m) to generate the backscatter histogram data.

[0039] In contrast, ambient light is typically constant during the measurement time and thus typically produces a constant contribution over all time periods. Similarly, the signal contribution of reflections on an object is typically spiked, meaning that the reflected light is only detected for one or a few time periods, since the light pulse can be received with a reduced amplitude but almost the same pulse duration. For example, at a typical pulse duration (e.g., 10ns), a time resolution of 250ps may be required for precise positioning.

[0040] During diffuse backscattering, such as that on fog or particles in the air, continuous backscattering may occur as the light propagates at low intensities. Here, the light pulse may be greatly expanded or spread out over time. For example, a 10ns light pulse with a given geometric spread of 1.5m may generate diffuse backscattering over a depth range of 1.5m at any time. For this reason, in some exemplary embodiments, a significantly reduced temporal resolution is sufficient.

[0041] Therefore, in some exemplary embodiments, a smaller time resolution (range resolution, e.g., 16 cm for determining backscatter compared to 4 cm for object detection) may be selected to determine diffuse backscatter. In such exemplary embodiments, this may be taken into account by accumulating time-correlated histogram data for multiple time periods in one time period.

[0042] Furthermore, the contribution of diffuse backscatter is typically similar across the entire field of view of the LIDAR system, for example, because fog has no clear spatial boundaries. On the other hand, objects typically exist only within a narrow range of the field of view, where the field of view describes the spatial region being detected. Therefore, in some exemplary embodiments, a smaller spatial resolution may be selected to determine diffuse backscatter. In such exemplary embodiments, this may be taken into account by accumulating time-correlated histogram data from multiple light detection receiving elements.

[0043] This is advantageous because it reduces the amount of data used to determine the backscatter, thereby reducing the required computational and storage capacity. This also helps to reduce power consumption.

[0044] Therefore, in some exemplary embodiments, the histogram accumulation unit generates backscatter histogram data by adding the received time-correlated histogram data.

[0045] Here, the number of events detected in a time period can be summed based on all received time-correlated histogram data, thereby generating backscatter histogram data in which each time period accurately contains the sum of all events in the time period. The time-correlated histogram data is preferably accumulated or summed into integers so that weak diffuse backscatter can be measured in some exemplary embodiments. This is advantageous, as described above, because the SNR of the diffuse backscatter contribution can be increased compared to other contributions.

[0046] In some exemplary embodiments, the histogram accumulation unit calculates an arithmetic mean value based on the received time-correlated histogram data to generate the backscattering histogram data.

[0047] As described above, the received time-correlated histogram data is summed and divided by the number of signal inputs. This may be advantageous in some exemplary embodiments implemented by fixed-point or floating-point numbers (as opposed to exemplary embodiments that accumulate integers).

[0048] In some exemplary embodiments, the histogram accumulation unit accumulates the received time-correlated histogram data of a plurality of time periods into one time period to generate backscattering histogram data.

[0049] In the manner described above, the distance resolution (time resolution) for determining the diffuse backscatter can be reduced, thereby saving computing and storage capacity, since the signal contribution of the diffuse backscatter can decrease continuously and generally has no spikes.

[0050] For this reason, the number of events of multiple time periods can be accumulated, preferably added to one time period. In such an exemplary embodiment, the accumulated time period is preferably a continuous time period (time), and the time period in which the accumulation occurs is preferably a time period between the minimum time and the maximum time of the accumulated time period.

[0051] In some exemplary embodiments, the histogram accumulation unit is further configured to generate the backscatter histogram data without considering time-correlated histogram data received for a time period exceeding a certain time threshold.

[0052] Diffuse backscatter in optical runtime measurements is usually undetectable at long distances due to the low amount of light. For this reason, the time period used to determine the diffuse backscatter can be ignored if it exceeds a certain time threshold to save storage and computing capacity.

[0053] In such exemplary embodiments, when generating backscatter histogram data from received time-correlated histogram data, such exemplary embodiments may be implemented, for example, by considering only those time periods that are below a time threshold when summing the received time-correlated histogram data as described above.

[0054] In some exemplary embodiments, the histogram accumulation unit is further configured to weight the received time-correlated histogram data to generate backscatter histogram data.

[0055] For example, weighting the received time-correlated histogram data may involve, in these exemplary embodiments, multiplying each time-correlated histogram data by a factor greater than or less than 1 (e.g., a different factor for each signal input). In such exemplary embodiments, time-correlated histogram data multiplied by a factor greater than 1 is given a higher weight to generate backscattered histogram data, and conversely, a factor less than 1 produces a lower weight to generate backscattered histogram data (the present invention is not limited to this example of weighting).

[0056] For example, these exemplary embodiments may be advantageous if the contribution of object or ambient light in some time-correlated histogram data is large, making it more difficult to determine diffuse backscatter based on these time-correlated histogram data. Therefore, such time-correlated histogram data may be multiplied by a factor less than 1.

[0057] In some exemplary embodiments, the histogram accumulation unit is further configured to output backscatter histogram data to determine diffuse backscatter. For example, the backscatter histogram data can then be output to a processor, FPGA, etc. to determine backscatter.

[0058] In some exemplary embodiments, the device comprises a receiving matrix having a plurality of light detecting receiving elements, wherein each light detecting receiving element is configured to detect light and generate an electrical signal in response to detecting the light.

[0059] It is known in principle that a receiving matrix is ​​essentially a three-dimensional body, in particular a plate-shaped body, in which a plurality of light-detecting receiving elements are arranged on a surface or on parts of this surface in a plane.

[0060] The receiving matrix may preferably be integrated on a semiconductor chip (e.g., an ASIC "application-specific integrated circuit"), wherein the semiconductor chip may have a plurality of light detection receiving elements, such as SPADs, and a plurality of TDCs. In other exemplary embodiments, the receiving matrix may be a printed circuit board on which a plurality of light detection receiving elements are mounted, wherein the light detection receiving elements may be, for example, SPADs, etc. The light detection receiving elements may basically detect very small amounts of light (e.g., single photons) with high temporal resolution, and generate electrical signals in response to the detected amount of light.

[0061] In some exemplary embodiments, each light detection receiving element can be activated and deactivated. For example, if a SPAD is provided as a light detection receiving element, light detection can be interrupted by a change in the voltage applied to the light detection receiving element. In such an exemplary embodiment, the light detection receiving element does not generate an electrical signal during exposure to incident light. This is advantageous because specific areas of the field of view can be hidden to determine backscatter.

[0062] In some exemplary embodiments, the light detecting receiving elements in the receiving matrix are arranged in columns and rows (as is generally known), wherein without loss of generality, in some exemplary embodiments, the same number of light detecting receiving elements are provided in each row.

[0063] Arranging the light detection receiving elements in columns and rows here basically means arranging them in a grid, wherein the column spacing and row spacing are preferably constant. Constant here should not be interpreted as an exact constant, but also includes production-related tolerances of the column spacing and row spacing in the arrangement of the light detection receiving elements. The number of columns and rows here is basically not limited and in an exemplary embodiment usually depends on specific requirements, for example, on resolution, amount of data to be processed, accuracy, etc.

[0064] Arranging the light detecting receiving elements in the receiving matrix in columns and rows is advantageous because less space is required, making it less expensive. Furthermore, in such an exemplary embodiment, the manufacturing cost of the receiving matrix is ​​low.

[0065] Furthermore, arranging the same number of light detection receiving elements in a row is advantageous because in such an exemplary embodiment each region of the field of view has the same spatial resolution and can also be manufactured at a lower cost.

[0066] In some exemplary embodiments, the device includes a plurality of evaluation units, wherein each evaluation unit is connected to a light detection receiving element in a column, or each evaluation unit is connected to a light detection receiving element in a row.

[0067] The evaluation unit can be an electronic circuit or include an electronic circuit, wherein the electronic circuit can include electronic components, digital storage elements, etc. to perform the functions described herein. The electronic circuit can also be implemented by FPGA (field programmable gate array), DSP (digital signal processor), etc.

[0068] The evaluation unit is connected to the light detection receiving element so that the electrical signal of the light detection receiving element is transmitted to the evaluation unit. In some exemplary embodiments, the evaluation unit is connected to the light detection receiving element through a multiplexer. The evaluation unit can read out a row or a column as a whole, or only read out the activated light detection receiving element.

[0069] The evaluation unit may have a time-to-digital converter to time the electrical signals of the light detection receiving elements and generate time-correlated histogram data for each light detection receiving element in a row or column. In other exemplary embodiments, the time-correlated histogram data of a column or a row is accumulated in the evaluation unit. The evaluation unit may output the time-correlated histogram data.

[0070] This is why, in some exemplary embodiments, each evaluation unit is arranged to generate time-dependent histogram data based on the electrical signals of the light detection receiving elements.

[0071] Therefore, in some exemplary embodiments, only activated light detection receiving elements are considered for generating time-dependent histogram data.

[0072] In some exemplary embodiments, each signal input terminal of the histogram accumulation unit is correspondingly connected to one of the evaluation units, so that the time-dependent histogram data is transmitted from the evaluation unit to the corresponding histogram accumulation unit.

[0073] The method steps mentioned above or described herein may also be subject matter of a method for generating backscatter histogram data for determining diffuse backscatter during optical runtime measurements.

[0074] Some example embodiments relate to a method for generating backscatter histogram data for determining diffuse backscatter during an optical runtime measurement, comprising:

[0075] receiving a plurality of time-correlated histogram data; and

[0076] Backscatter histogram data is generated based on the received time-correlated histogram data.

[0077] For example, the method may be performed by an apparatus described herein, or by a computer, a processor, an electronic circuit, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0078] Exemplary embodiments of the present invention will now be exemplarily described with reference to the accompanying drawings, in which:

[0079] Figure 1 A schematic diagram showing an exemplary embodiment of the device is shown;

[0080] Figure 2 The time-correlated histogram data received by the two evaluation units are shown in two histograms (top left and bottom left), and the backscatter histogram data generated therefrom in the histogram accumulation unit are shown in one histogram (right); and

[0081] Figure 3 A flow chart showing an exemplary embodiment of a method is shown. DETAILED DESCRIPTION

[0082] Figure 1 A schematic diagram of an exemplary embodiment of a device 1 is shown.

[0083] The device 1 has a receiving matrix 2 on which a plurality of light detecting receiving elements (ENxM, in this exemplary embodiment, E0,0 to E127,255) are arranged in rows (Z0 to Z127) and columns (S0 to S255). M = 256 light detecting receiving elements (E0,0 to E127,255) are arranged in each of N = 128 rows (Z0 to Z127) (corresponding to M = 256 columns (S0 to S255)). In this exemplary embodiment, the light detecting receiving elements (E0,0 to E127,255) are SPADs.

[0084] The device 1 also has a plurality of evaluation units (A0 to A127), wherein each evaluation unit (A0 to A127) is connected to a row (Z0 to Z127) of light detection receiving elements (E0,0 to E127,255) via a multiplexer (not shown). In each row (Z0 to Z127), only two light detection receiving elements (E0,0 and E0,1 to E127,0 and E127,1) in columns S0 and S1 are activated at any given time (indicated by the second circle within the light detection receiving elements (E0,0 and E0,1 to E127,0 and E127,1)). When light is detected, the activated light detection receiving elements (E0,0 and E0,1 to E127,0 and E127,1) generate electrical signals, from which time-dependent histogram data are generated with the help of a time-to-digital converter (not shown) in each evaluation unit (A0 to A127). In this exemplary embodiment, the time-correlated histograms of the two activated light detection receiving elements (E0,0 and E0,1 to E127,0 and E127,1) are added to the evaluation unit (A0 to A127) to generate and output the time-correlated histogram data. In other exemplary embodiments, any desired number of light detection receiving elements can be activated in each row of M = 256 light detection receiving elements (E0,0 to E127,255), for example, E0,0 to E0,10, E1,0 to E1,10, E2,0 to E2,10, ..., E127,0 to E127,10.

[0085] The device 1 also has several histogram accumulation units (HA0 to HAX). Each histogram accumulation unit (HA0 to HAX) has P = 16 signal input terminals (not explicitly shown), wherein each signal input terminal is connected to a corresponding evaluation unit (A0 to A127). Therefore, in this exemplary embodiment, X = N / P = 8 histogram accumulation units are required in N = 128 rows (Z0 to Z127), and these histogram accumulation units accumulate the time-correlated histogram data of P = 16 evaluation units (A0 to A127) accordingly. The time-correlated histogram data output by the evaluation unit (A0 to A127) is transmitted to the histogram accumulation unit (HA0 to HAX) so as to receive these time-correlated histogram data at the signal input terminal. Based on the received time-correlated histogram data, the histogram accumulation unit (HA0 to HAX) generates backscattered histogram data. In this exemplary embodiment, the time-correlated histogram data received at each signal input terminal are added to generate backscattered histogram data.

[0086] Figure 2The time-correlated histogram data (ZHD0 to ZHDP) received by two evaluation units (A0 and A1) for two of the 16 histograms (upper left and lower left) are shown by way of example, and the backscattered histogram data (RHD0) generated in the histogram accumulation unit (HA0) from these time-correlated histogram data are shown in one histogram (right).

[0087] The device 1 in this exemplary embodiment is Figure 1 Device 1 in is configured similarly.

[0088] Figure 2 It shows how the time-correlated histograms (ZHD0 to ZHDP) generated by the 16 evaluation units (A0 to A15) are accumulated.

[0089] The horizontal axis is the time axis, which is divided into multiple equal time periods ("Bins"), and events are assigned to one of the time periods according to the time when light is detected ("Events"). The number of events detected in a time period is shown by the height of the bars on the vertical axis. The number of events in each time period of the time-correlated histogram data (ZHD0 to ZHDP) is added together to generate the backscatter histogram data (RHD0).

[0090] Here the large bar in the fifth time segment of the time-correlated histogram data (ZHD0) from the first evaluation unit (A0) corresponds to a small object which is only recorded in a small region of the field of view. However, the contribution of diffuse backscatter is present in the entire field of view before the object at a short distance and is therefore also present in the two exemplary time-correlated histogram data (ZHD0 to ZHDP). Adding the 16 time-correlated histogram data (ZHD0 to ZHDP) increases the SNR in the backscatter histogram data (RHD0) compared to the contribution of the object and the ambient light. This makes the backscatter histogram data (RHD0) more suitable for determining diffuse backscatter during optical runtime measurements.

[0091] Figure 3 A flow chart of an exemplary embodiment of the method 20 is shown.

[0092] As described herein, a plurality of time-correlated histogram data is received at 21 .

[0093] As described herein, backscatter histogram data is generated at 22 based on the received time-correlated histogram data.

[0094] Reference numerals list

[0095] 1 device

[0096] 2Receiving Matrix

[0097] 20 Methods

[0098] 21 Receive multiple time-related histogram data

[0099] 22 Generate backscatter histogram data based on the received time-correlated histogram data

[0100] A0 to A127 Evaluation Units

[0101] ENxM, E0,0 to E127,255 light detection receiving element

[0102] HA0 to HAX Histogram accumulation unit

[0103] RHD0 Backscatter histogram data

[0104] S0 to S255 columns

[0105] Z0 to Z127 rows

[0106] ZHD0 to ZHDP Time-correlated histogram data.

Claims

1. A device for generating backscattering histogram data for determining diffuse backscattering during an optical run-time measurement based on a time-correlated signal photon counting (TCSPC) measurement principle, the device comprising: a receiving matrix having a plurality of light detecting receiving elements, wherein each of the light detecting receiving elements is configured to detect light and generate an electrical signal in response to the detected light, the time from periodically transmitting a pulse to receiving a reflected pulse by the light detecting receiving element is measured as a measuring time, the measuring time is divided into a plurality of time periods, and the electrical signal is assigned to one of the plurality of time periods by a time-to-digital converter; and at least one histogram accumulation unit, the at least one histogram accumulation unit having a plurality of signal inputs for receiving time-dependent histogram data, the time-dependent histogram data being generated by counting the electrical signals assigned to the one time period, wherein the histogram accumulation unit is configured to generate backscatter histogram data based on the time-correlated histogram data received at the signal input, the generated backscatter histogram data comprising at least a signal contribution of diffuse backscattering, wherein the histogram accumulation unit generates the backscattered histogram data by adding the received time-correlated histogram data, and The histogram accumulation unit is further configured to ignore the received time-correlated histogram data of a time period exceeding a specific time threshold to generate the backscattered histogram data.

2. The device according to claim 1, wherein: The histogram accumulation unit calculates an arithmetic mean value according to the received time-correlated histogram data to generate the backscattering histogram data.

3. The device according to claim 1, wherein: The histogram accumulation unit accumulates the received time-correlated histogram data of a plurality of time periods into one time period to generate the backscattering histogram data.

4. The device according to claim 1, wherein: The histogram accumulation unit is further configured to weight the received time-correlated histogram data to generate the backscattered histogram data.

5. The device according to claim 1, wherein: The histogram accumulation unit is further configured to output the backscatter histogram data to determine backscatter.

6. The device according to claim 1, wherein: Each of the light detection receiving elements can be activated and deactivated.

7. The device according to claim 1, wherein: The light detection receiving elements in the receiving matrix are arranged in columns and rows, wherein the same number of light detection receiving elements are provided in each row.

8. The device according to claim 7, further comprising: A plurality of evaluation units, wherein each evaluation unit is connected to the light detection receiving elements in a column, or each evaluation unit is connected to the light detection receiving elements in a row.

9. The device according to claim 8, wherein: Each of the evaluation units is configured to generate the time-correlated histogram data based on the electrical signal of the light detection receiving element.

10. The device according to claim 9, wherein: Only activated light detecting receiving elements are considered for generating the time-dependent histogram data.

11. The device according to claim 8, wherein: Each signal input is connected to one of the evaluation units, so that the time-dependent histogram data are transmitted from the evaluation unit to the corresponding histogram accumulation unit.

12. A method for generating backscattering histogram data for determining diffuse backscattering during an optical runtime measurement, the optical runtime measurement being performed based on a time correlated signal photon counting (TCSPC) measurement principle, the method comprising: Each of the plurality of light detection receiving elements of the receiving matrix detects light and generates an electrical signal in response to the detected light, the time from the periodic emission of a pulse to the reception of a reflected pulse by the light detection receiving element is measured as a measurement time, the measurement time is divided into a plurality of time periods, and the electrical signal is assigned to one of the plurality of time periods by a time-to-digital converter, receiving time-correlated histogram data by at least one histogram accumulation unit, the at least one histogram accumulation unit having a plurality of signal inputs, the time-correlated histogram data being generated by counting the electrical signals assigned to the one time period, wherein the histogram accumulation unit is configured to generate backscattering histogram data based on the time-correlated histogram data received at the signal input, the generated backscattering histogram data comprising at least a signal contribution of diffuse backscattering, and generating the backscattered histogram data by the histogram accumulation unit by adding the received time-correlated histogram data, and The histogram accumulation unit is further configured to ignore the received time-correlated histogram data of a time period exceeding a specific time threshold to generate the backscattered histogram data.

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