Device for generating backscatter histogram data for determining diffuse backscatter in optical time-of-flight measurement and method

Description

[0001] The present invention relates generally to a device for generating backscattering histogram data for determining diffuse backscattering in an optical time-of-flight measurement and to a method for generating backscattering histogram data for determining diffuse backscattering in an optical time-of-flight measurement.

[0002] In general, various methods for optical time-of-flight measurement are known, which can be based on the so-called time-of-flight principle, in which the time of flight of a light signal emitted and reflected by an object is measured in order to determine the distance to the object based on the time of flight.

[0003] It is known to use sensors in the automotive environment based on the so-called LIDAR (Light Detection and Ranging) principle, in which pulses are periodically emitted to scan the environment and the reflected pulses are detected. A corresponding method and device are known, for example, from WO 2017 / 081294.

[0004] US 2019 / 0361098 A1 discloses a method for processing lidar measurement pulses, while US 2019 / 0265333 A1 relates to a device for measuring distances. WO 2019 / 102751 also relates to a measuring unit for distance measurement, whereas US 2018 / 0329061 A1 describes an optical system for determining distances.

[0005] In general, the type of light signals detected in LIDAR applications can vary, for example, depending on whether the emitted light signal is reflected by a solid object (object backscatter) or backscattered by airborne particles (diffuse backscatter), such as in fog or exhaust gases. The recorded backscatter data can be used to draw conclusions about the ambient conditions.

[0006] Although solutions for recording backscatter data in optical time-of-flight measurements are known from the prior art, it is an object of the present invention to provide a device and a method for generating backscatter histogram data for determining backscatter in an optical time-of-flight measurement.

[0007] This task is solved by the device and the method according to the independent claims.

[0008] According to a first aspect, the present invention provides a device for generating backscatter histogram data for determining diffuse backscattering in an optical time-of-flight measurement, comprising: at least one histogram accumulation unit having a plurality of signal inputs for receiving time-correlated histogram data, wherein the histogram accumulation unit is configured to generate backscatter histogram data based on the time-correlated histogram data received at the signal inputs. For determining diffuse backscattering, time intervals that lie above a certain time threshold (this corresponds to a distance threshold, e.g., of 20 m) are not considered for generating the backscatter histogram data.

[0009] According to a second aspect, the present invention provides a method for generating backscatter histogram data for determining diffuse backscatter in an optical time-of-flight measurement, comprising: receiving a plurality of time-correlated histogram data; and generating backscatter histogram data based on the received time-correlated histogram data. For the determination of diffuse backscatter, the time intervals that lie above a certain time threshold (this corresponds to a distance threshold, e.g., of 20 m) are not considered for generating the backscatter histogram data.

[0010] Further advantageous embodiments of the invention emerge from the subclaims, the drawings and the following description of preferred embodiments of the present invention.

[0011] As mentioned, some embodiments relate to a device according to claim 1.

[0012] As stated above, conclusions about environmental conditions can be drawn from backscatter data in LIDAR measurements. With more precise knowledge of the environmental conditions (e.g., fog, etc.), the driving style can be adapted to the environmental conditions, for example in autonomous vehicles, thus increasing safety. Furthermore, precise knowledge of diffuse backscatter in LIDAR measurements also allows (more precise) detection of solid objects in some embodiments. This allows, for example, traffic situations to be determined more precisely, which also increases the safety and reliability of autonomous vehicles.

[0013] Therefore, in some embodiments, the device is used in a LIDAR system or the like and is used, for example, in the automotive environment, without the invention being limited to these cases.

[0014] In some embodiments, LIDAR data typically contains signal contributions from backscatter, light reflection from objects, ambient light, stray light signals from other light sources in the environment, and the like. This data can be represented in a histogram, which is generally known.

[0015] Accordingly, the generation of backscattering histogram data means that the generated backscattering histogram data according to the invention contain at least the signal contribution of the diffuse backscattering or are formed in such a way that they can basically contain the signal contribution of the diffuse backscattering and are therefore basically suitable for determining the diffuse backscattering in an optical distance measurement.

[0016] According to the invention, the optical time-of-flight measurement is based on the so-called TCSPC (time correlated single photon counting) measuring principle, particularly in embodiments based on LIDAR. According to the invention, light pulses are emitted periodically, which are typically a few nanoseconds long and mark a start time of a measurement. During the time until the next light pulse (measurement time), the light reflected from objects or backscattered light is detected by a light-detecting receiving element (e.g., a single photon avelanche diode (SPAD)). According to the invention, the measurement time is divided into a plurality of short time intervals (e.g., 500 ps). Each time interval can then be assigned a time point that corresponds to a time interval from the start time (e.g.,For time intervals of 500 ps, a time of 250 ps can be assigned to a first time interval and a time of 750 ps can be assigned to a second time interval, etc.).

[0017] Depending on the distance to the object or the point of backscattering, the light reaches the light-detecting receiving element at different times.

[0018] In doing so, it generates an electrical signal in the light-detecting receiving element. Using a time-to-digital converter (TDC), which is generally known, the electrical signal can then be assigned to one of the time intervals. By counting the electrical signals ("events") assigned to a time interval, so-called histograms or time-correlated histograms (also called TCSPC histograms) are created. These histograms can also be present as pure data and stored, for example, as value pairs consisting of the time interval and the associated number of entries (events). The time intervals, together with the number of events assigned to each time interval ("bin"), accordingly form histogram data, which can generally be represented by digital signals (or analog signals).These therefore typically contain signal contributions from diffuse backscattering, light reflection from objects, ambient light, stray light signals from other light sources in the environment and the like.

[0019] The device contains at least one histogram accumulation unit having a plurality of signal inputs. In some embodiments, the maximum number of histogram accumulation units is given by the number of light-detecting receiving elements in a system for optical time-of-flight measurement (e.g., LIDAR system). The histogram accumulation unit can fundamentally be or comprise an electronic circuit that receives digital signals or data, such as the time-correlated histogram data, via the signal inputs and carries out the generation of backscatter histogram data described herein. The electronic circuit can contain electronic components, digital memory elements, and the like to perform the functions described herein. The electronic circuit can be implemented by an FPGA (Field Programmable Gate Array), DSP (Digital Signal Processor), or the like.In other embodiments, the histogram accumulation unit is implemented by a memory and a microprocessor. In further embodiments, the histogram accumulation unit is implemented by software, wherein in such embodiments, the signal inputs correspond to the parameters / attributes of a software function / method. The generation of the backscatter histogram data then corresponds to the execution of a sequence of instructions for performing specific arithmetic operations on a computer, so that after all instructions have been processed, backscatter histogram data is available. In some embodiments, the histogram accumulation unit is also implemented by a mixture of hardware- and software-based components, across which the functionalities described herein are distributed accordingly.

[0020] The histogram accumulation unit receives time-correlated histogram data at the or each signal input. Histogram data need not always be received at every signal input, and in some embodiments, there are also additional signal inputs at which, for example, no histogram data is received or only after appropriate configuration.

[0021] Time-correlated histogram data is data generated based on the electrical signals of the light-detecting receiving elements within the (corresponding) measurement time. As mentioned above, these typically contain signal contributions from diffuse backscattering, light reflection from objects, ambient light, stray light signals from other light sources in the environment, and the like.

[0022] In some embodiments, the received time-correlated histogram data at each signal input is provided by time-correlated histogram data from a light-detecting receiving element. In other embodiments, the received time-correlated histogram data at each signal input is provided by the sum of time-correlated histogram data from multiple light-detecting receiving elements. In further embodiments, the received time-correlated histogram data at each signal input is provided by multiple time-correlated histogram data from multiple light-detecting receiving elements.

[0023] Based on the time-correlated histogram data received at the signal inputs, backscatter histogram data is generated.

[0024] Typically, the amount of light detected due to diffuse backscattering is small compared to ambient light, e.g., daylight, and the amount of light reflected from objects, so determining diffuse backscattering can be difficult and inaccurate, particularly with time-correlated histogram data. Therefore, in some embodiments, the device is used to generate backscattering histogram data for determining diffuse backscattering in an optical time-of-flight measurement.

[0025] In some embodiments, the backscattering histogram data corresponds to an accumulation of time-correlated histogram data from multiple light-detecting receiving elements. The accumulation of time-correlated histogram data can be advantageous for determining diffuse backscattering, as the signal-to-noise ratio (SNR) of the diffuse backscattering contribution is increased compared to other signal contributions. This allows for a better determination of diffuse backscattering in some embodiments.

[0026] This basically follows from the fact that the diffuse backscatter in an optical time-of-flight measurement is typically higher at short distances (e.g. 5 m) than at long distances (e.g. 200 m) and can decrease continuously.

[0027] In contrast, the ambient light is usually constant during the measurement time and thus typically provides a constant contribution across all time intervals. Likewise, the signal contributions from reflections from objects are often sharp peaks, meaning that the reflected light is only detected in one or a few time intervals because the light pulse can be received with a reduced amplitude but with a nearly identical pulse duration. For typical pulse durations of, for example, 10 ns, a time resolution of 250 ps may be required for precise location determination.

[0028] In diffuse backscattering from, for example, fog or particles in the air, continuous backscattering can occur during the light propagation at low intensity. The light pulse can be greatly expanded or temporally smeared. For example, with a 10 ns light pulse with a geometric extension of 1.5 m, diffuse backscattering can be generated over a 1.5 m depth range at any time. Therefore, in some embodiments, a significantly reduced temporal resolution is sufficient.

[0029] Consequently, in some embodiments, the time resolution (distance resolution, e.g., 16 cm for determining backscatter compared to 4 cm for object detection) can be selected to be smaller for determining diffuse backscatter. This can be taken into account in such embodiments by accumulating the time-correlated histogram data from multiple time intervals into one time interval.

[0030] Furthermore, the contributions of diffuse backscatter are typically similar across the entire field of view of the LIDAR system, since, for example, fog is not spatially sharply defined. In contrast, objects are often only present in a narrow area of the field of view, with the field of view describing a spatial region that is detected. Therefore, in some embodiments, the spatial resolution can be selected to be smaller for determining diffuse backscatter. This can be taken into account in such embodiments by accumulating the time-correlated histogram data from multiple light-detecting receiving elements.

[0031] This is advantageous because it reduces the amount of data required to determine backscatter, thus reducing the required computing and storage capacity. This also promotes lower power consumption.

[0032] Therefore, according to the invention, the histogram accumulation unit generates the backscattering histogram data by adding the received time-correlated histogram data.

[0033] The number of events detected in a time interval can be summed from all received time-correlated histogram data, generating backscatter histogram data that contains the exact sum of all events in each time interval. Preferably, the time-correlated histogram data are accumulated or summed as integers to make diffuse backscattering, which in some embodiments is weak, measurable. This is advantageous because the SNR of the diffuse backscattering contribution can be increased compared to other contributions, as described above.

[0034] In some embodiments, the histogram accumulation unit calculates an arithmetic mean from the received time-correlated histogram data to generate the backscatter histogram data.

[0035] As described above, the received time-correlated histogram data are added and divided by the number of signal inputs. This may be advantageous in some embodiments that have a fixed-point or floating-point number implementation (in contrast to embodiments that accumulate integers).

[0036] In some embodiments, the histogram accumulation unit accumulates the received time-correlated histogram data of multiple time intervals into one time interval to generate the backscatter histogram data.

[0037] As mentioned above, the distance resolution (time resolution) for the determination of diffuse backscattering can be reduced to save computational and storage resources, since the signal contribution of diffuse backscattering can decay continuously and typically does not exhibit sharp peaks.

[0038] Therefore, the number of events from multiple time intervals can be accumulated, preferably added, in one time interval. In such embodiments, the accumulated time intervals are preferably temporally consecutive time intervals (time points), and the time interval in which the accumulation takes place is preferably a time interval that lies between the minimum and maximum time points of the accumulated time intervals.

[0039] According to the invention, the histogram accumulation unit is further configured to disregard received time-correlated histogram data of time intervals that are above a certain time threshold for generating the backscatter histogram data.

[0040] Diffuse backscattering in an optical time-of-flight measurement is typically undetectable at long distances because the amount of light is too small. Therefore, time intervals for determining diffuse backscattering that exceed a certain time threshold can be neglected to save memory and computing resources.

[0041] In embodiments, this can be achieved when generating the backscatter histogram data from received time-correlated histogram data by, for example, only taking into account those time intervals that are below the time threshold value when adding the received time-correlated histogram data as described above.

[0042] In some embodiments, the histogram accumulation unit is further configured to weight the received time-correlated histogram data for generating the backscatter histogram data.

[0043] A weighting of the received time-correlated histogram data can, for example, be a multiplication of individual time-correlated histogram data by a factor greater than or less than one (e.g., different for each signal input). In such embodiments, time-correlated histogram data multiplied by a factor greater than one receives a higher weight for generating the backscatter histogram data, and conversely, a factor less than one results in a lower weight for generating the backscatter histogram data (without limiting the present invention to this example of weighting).

[0044] This can be advantageous if, for example, some time-correlated histogram data contain larger contributions from objects or ambient light, making it more difficult to determine diffuse backscatter from these time-correlated histogram data. Accordingly, such time-correlated histogram data can be multiplied by a factor less than one.

[0045] In some embodiments, the histogram accumulation unit is further configured to output the backscattering histogram data for determining the diffuse backscattering. The backscattering histogram data can then be output, for example, to a processor, FPGA, or the like for determining the backscattering.

[0046] According to the invention, the device comprises a receiving matrix with a plurality of light-detecting receiving elements, each of the light-detecting receiving elements being configured to detect light and to generate an electrical signal in response thereto.

[0047] The receiving matrix is basically a three-dimensional body, in particular a plate-shaped body, wherein several light-detecting receiving elements are arranged in a plane on a surface or on parts of the surface, as is basically known.

[0048] The receiving matrix can preferably be integrated on a semiconductor chip (e.g., an ASIC - "Application Specific Integrated Circuit"), wherein the semiconductor chip can comprise multiple light-detecting receiving elements such as SPADs and multiple TDCs. In other embodiments, the receiving matrix can be a printed circuit board on which multiple light-detecting receiving elements are mounted, wherein a light-detecting receiving element is, for example, a SPAD or the like.

[0049] In principle, the light-detecting receiving element can detect very small amounts of light (e.g. single photons) with high time resolution and generate an electrical signal in response.

[0050] In some embodiments, each of the light-detecting receiving elements can be activated and deactivated. For example, if SPADs are provided as light-detecting receiving elements, light detection can be interrupted by changing the electrical voltage applied to the light-detecting receiving element. In such embodiments, the light-detecting receiving element does not generate an electrical signal when light is incident. This is advantageous because certain areas of the field of view can be masked out for determining backscatter.

[0051] In some embodiments, the light-detecting receiving elements in the receiving matrix are arranged in columns and rows (as is generally known), wherein in some embodiments, without loss of generality, the same number of light-detecting receiving elements are provided in each row.

[0052] An arrangement of the light-detecting receiving elements in columns and rows generally means an arrangement in a grid-like pattern, with the column and row spacing preferably being constant. Constant should not be understood as exact, but rather also includes a manufacturing-related tolerance of the column and row spacing in the arrangement of the light-detecting receiving elements. The number of rows and columns is generally not limited and is typically based on a specific requirement in the exemplary embodiments, e.g., the resolution, the amount of data to be processed, the accuracy, etc.

[0053] The arrangement of the light-detecting receiving elements in the receiving matrix in columns and rows is advantageous because it requires less space and is therefore more cost-effective. Furthermore, the receiving matrix can be manufactured more cost-effectively in such embodiments.

[0054] Furthermore, it is advantageous to arrange the same number of light-detecting receiving elements in a row, since in such embodiments each area of the field of view has the same spatial resolution and can also be manufactured more cheaply.

[0055] In some embodiments, the device comprises a plurality of evaluation units, wherein one evaluation unit is connected to the light-detecting receiving elements in a column or one evaluation unit is connected to the light-detecting receiving elements in a row.

[0056] An evaluation unit can be or contain an electronic circuit, which can contain electronic components, digital memory elements, and the like to perform the functions described herein. The electronic circuit can also be implemented by an FPGA (Field Programmable Gate Array), DSP (Digital Signal Processor), or the like.

[0057] The evaluation unit is connected to the light-detecting receiving elements in such a way that the electrical signals from the light-detecting receiving elements are transmitted to the evaluation unit. In some embodiments, the evaluation unit is connected to the light-detecting receiving elements via a multiplexer. The evaluation unit can read a row or column as a whole, or it can read only the activated light-detecting receiving elements.

[0058] The evaluation unit can include a time-to-digital converter to temporally classify the electrical signals of the light-detecting receiving elements and generate time-correlated histogram data for each of the light-detecting receiving elements of a row or column. In other embodiments, the time-correlated histogram data of a column or row are accumulated in the evaluation unit. The evaluation unit can output the time-correlated histogram data.

[0059] Therefore, in some embodiments, each of the evaluation units is configured to generate the time-correlated histogram data based on the electrical signals of the light-detecting receiving elements.

[0060] Consequently, in some embodiments, only the light-detecting receiving elements that are activated are taken into account for generating the time-correlated histogram data.

[0061] Accordingly, in some embodiments, each signal input of a histogram accumulation unit is connected to one of the evaluation units, so that the time-correlated histogram data are transmitted from the evaluation unit to the corresponding histogram accumulation unit.

[0062] The method steps explained above or herein can also be the subject of a method for generating backscattering histogram data for determining diffuse backscattering in an optical time-of-flight measurement.

[0063] Some embodiments relate to a method according to claim 11.

[0064] The method may be carried out in part by the device described herein or by a computer, processor, electronic circuit, or the like. Embodiments of the invention will now be described by way of example and with reference to the accompanying drawings, in which: Fig. 1illustrates a diagram of an embodiment of a device; Fig. 2 shows time-correlated histogram data received from two evaluation units in two histograms (top left and bottom left) and shows the backscatter histogram data generated from them in a histogram accumulation unit in one histogram (right); and Fig. 3 a flowchart of an embodiment of a method is illustrated.

[0065] Fig. 1 illustrates a diagram of an embodiment of a device 1.

[0066] The device 1 has a receiving matrix 2 on which several light-detecting receiving elements (ENxM, in this embodiment E0,0 to E127,255) are arranged in rows (Z0 to Z127) and columns (S0 to S255). In each of the N = 128 rows (Z0 to Z127), M = 256 light-detecting receiving elements (E0,0 to E127,255) are arranged (corresponding to the M = 256 columns (S0 to S255)). The light-detecting receiving elements (E0,0 to E127,255) are SPADs in this embodiment.

[0067] The device 1 further comprises a plurality of evaluation units (A0 to A127), each evaluation unit (A0 to A127) being connected to the light-detecting receiving elements (E0,0 to E127,255) of a row (Z0 to Z127) via a multiplexer (not shown). In each row (Z0 to Z127), at a given time, only the two light-detecting receiving elements (E0,0 and E0,1 to E127,0 and E127,1) in columns S0 and S1 are activated (illustrated by the second circle within the light-detecting receiving elements (E0,0 and E0,1 to E127,0 and E127,1)). The activated light-detecting receiving elements (E0,0 and E0,1 to E127,0 and E127,1) generate electrical signals upon light detection, from which time-correlated histogram data are generated using a time-to-digital converter (not shown) in each of the evaluation units (A0 to A127).In this embodiment, the time-correlated histogram data of the two activated light-detecting receiving elements (E0,0 and E0,1 to E127,0 and E127,1) are added in the evaluation units (A0 to A127) to generate and output time-correlated histogram data. In other embodiments, any number of the M = 256 light-detecting receiving elements (E0,0 to E127,255) can be activated in each row, e.g., E0,0 to E0,10, E1,0 to E1,10, E2,0 to E2,10,..., E127,0 to E127,10.

[0068] Device 1 further comprises several histogram accumulation units (HAO to HAX). Each histogram accumulation unit (HAO to HAX) has P = 16 signal inputs (not explicitly shown), with each signal input connected to a respective evaluation unit (A0 to A127). Therefore, with N = 128 lines (Z0 to Z127), X = N / P = 8 histogram accumulation units are required in this embodiment, which accordingly accumulate the time-correlated histogram data from P = 16 evaluation units (A0 to A127). The time-correlated histogram data output by the evaluation units (A0 to A127) are transmitted to the histogram accumulation units (HA0 to HA6X) so that they are received at the signal inputs. The histogram accumulation units (HA0 to HAX) generate backscatter histogram data based on the received time-correlated histogram data.In this embodiment, the time-correlated histogram data received at each signal input is added to generate the backscatter histogram data.

[0069] Fig. 2 shows the time-correlated histogram data (ZHDO to ZHDP) received by two evaluation units (A0 and A1) as examples for two of 16 histograms (top left and bottom left) and shows the backscatter histogram data (RHDO) generated from them in a histogram accumulation unit (HAO) in a histogram (right).

[0070] The device 1 in this embodiment is analogous to the device 1 from Fig. 1 configured.

[0071] In Fig. 2 illustrates how the time-correlated histogram data (ZHDO to ZHDP) generated by 16 evaluation units (A0 to A15) are accumulated.

[0072] The horizontal axis is the time axis, which is divided into several equal time intervals ("bins"). Depending on the time of light detection ("event"), the event is assigned to one of the time intervals. The number of events detected within the time interval is represented by the height of a bar on the vertical axis. The number of events in each time interval of the time-correlated histogram data (ZHDO to ZHDP) is added to generate the backscatter histogram data (RHDO).

[0073] The large bar in the fifth time interval of the time-correlated histogram data (ZHDO) from the first evaluation unit (A0) corresponds to a small object that is only registered in a small area of the field of view. However, the contribution of diffuse backscatter is present in the entire field of view in front of the object at short distances, and is therefore also present in the two example time-correlated histogram data (ZHDO to ZHDP). The addition of the 16 time-correlated histogram data (ZHDO to ZHDP) increases the SNR in the backscatter histogram data (RHDO) compared to the contribution from objects and ambient light. This makes the backscatter histogram data (RHDO) more suitable for determining diffuse backscatter in an optical time-of-flight measurement.

[0074] Fig. 3 illustrates a flowchart of an embodiment of a method 20.

[0075] At 21, a plurality of time-correlated histogram data is received as set forth herein.

[0076] At 22, based on the received time-correlated histogram data, backscatter histogram data is generated as set forth herein. Reference symbol

[0077] 1Device 2Receiving matrix 20Procedure 21Receiving multiple time-correlated histogram data 22Generating backscattering histogram data based on the received time-correlated histogram data A0 to A127Evaluation units ENxM, E0.0 to E127.255Light-detecting receiving elements HA0 to HAX Histogram accumulation units RHD0Backscattering histogram data S0 to S255Columns Z0 to Z127Rows ZHD0 to ZHDPTime-correlated histogram data

Claims

1. Device (1) for generating backscatter histogram data (RHDO) for determining diffuse backscatter in an optical transit time measurement, wherein the device (1) comprises a receiving matrix with several light-detecting receiving elements, wherein the optical transit time measurement is based on TCSPC, time correlated single photon counting, so that light pulses are emitted periodically and the measurement time until reception is measured by one of the light-detecting receiving elements, wherein the measurement time is divided into time intervals, wherein each of the light-detecting receiving elements is configured for detecting light and for generating an electrical signal in response thereto, wherein the electrical signal is assigned to one of the time intervals using a time-to-digital converter, wherein time-correlated histogram data is generated by counting the electrical signals that are assigned to a time interval, wherein the time-correlated histogram data comprises signal contributions from diffuse backscatter, wherein the device comprises at least one histogram accumulation unit (HAO to HAX) which has a plurality of signal inputs for receiving the time-correlated histogram data (ZHDO to ZHDP), wherein the histogram accumulation unit (HAO to HAX) is configured to generate backscatter histogram data (RHDO) based on the time-correlated histogram data (ZHDO to ZHDP) received at the signal inputs, wherein the histogram accumulation unit (HAO to HAX) the backscatter histogram data (RHDO) are generated by adding the received time-correlated histogram data (ZHDO to ZHDP), characterized in that the histogram accumulation unit (HAO to HAX) is further configured not to take into account received time-correlated histogram data (ZHDO to ZHDP) of time intervals which are above a certain time threshold for the generation of the backscatter histogram data (RHDO). .

2. Device (1) according to claim 1, wherein the histogram accumulation unit (HAO to HAX) calculates an arithmetic mean from the received time-correlated histogram data (ZHDO to ZHDP) to generate the backscatter histogram data (RHDO).

3. Device (1) according to one of the preceding claims, wherein the histogram accumulation unit (HAO to HAX) accumulates the received time-correlated histogram data (ZHDO to ZHDP) of several time intervals in one time interval to generate the backscatter histogram data (RHDO).

4. Device (1) according to one of the preceding claims, wherein the histogram accumulation unit (HAO to HAX) is further configured to weight the received time-correlated histogram data (ZHDO to ZHDP) for generating the backscatter histogram data (RHDO).

5. Device (1) according to one of the preceding claims, wherein the histogram accumulation unit (HAO to HAX) is further configured to output the backscatter histogram data (RHDO) for determining the backscatter.

6. Device (1) according to claim 1, wherein each of the light-detecting receiving elements (ENxM, E0,0 to E127,255) can be activated and deactivated.

7. Device (1) according to claim 1 or 6, wherein the light-detecting receiving elements (ENxM, E0,0 to E127,255) are arranged in the receiving matrix (2) in columns (S0 to S255) and in rows (Z0 to Z127), wherein an equal number of light-detecting receiving elements (ENxM, E0,0 to E127,255) is provided in each row (Z0 to Z127).

8. Device (1) according to claim 7, further comprising: several evaluation units (A0 to A127) for outputting the time-correlated histogram data (ZHDO to ZHDP), wherein one evaluation unit each (A0 to A127) is connected with the light-detecting receiving elements (ENxM, E0,0 to E127,255) in a column (S0 to S255) or one evaluation unit each (A0 to A127) is connected with the light-detecting receiving elements (ENxM, E0,0 to E127,255) in a row (Z0 to Z127), wherein each of the evaluation units (A0 to A127) is configured for generating the time-correlated histogram data (ZHDO to ZHDP) based on the electrical signals of the light-detecting receiving elements (ENxM, E0,0 to E127,255).

9. Device (1) according to claim 8 insofar as it depends on claim 6, wherein only the light-detecting receiving elements (ENxM, E0,0 to E127,255) which are activated are taken into account for the generation of the time-correlated histogram data (ZHDO to ZHDP).

10. Device (1) according to one of the preceding claims, wherein each signal input is connected with an evaluation unit (A0 to A127), so that the time-correlated histogram data (ZHDO to ZHDP) are transmitted from the evaluation unit (A0 to A127) to the corresponding histogram accumulation unit (HAO to HAX).

11. Method (20) for generating backscatter histogram data for determining diffuse backscatter in an optical runtime measurement, wherein the light runtime measurement is based on TCSPC, time correlated single photon counting, so that light pulses are emitted periodically and the measurement time until reception by a light-detecting receiving element is measured, wherein the measurement time is divided into time intervals, wherein the method comprises: Detecting light and generating an electrical signal by means of light-detecting receiving elements of a receiving matrix, Assigning the electrical signal to one of the time intervals using a time-to-digital converter, Counting the electrical signals that are assigned to a time interval and thus generating time-correlated histogram data, wherein the time-correlated histogram data comprise signal contributions from diffuse back-scattering, receiving (21) the time-correlated histogram data, and generating (22) backscatter histogram data based on the received time-correlated histogram data, wherein the backscatter histogram data (RHDO) is generated by adding the received time-correlated histogram data (ZHDO to ZHDP), characterized in that received time-correlated histogram data (ZHDO to ZHDP) of time intervals that are above a certain time threshold are not taken into account for the generation of the backscatter histogram data (RHDO).