Photoelectric conversion device

Abstract

To provide a photoelectric conversion device capable of improving a frame rate.SOLUTION: A photoelectric conversion device Includes: a light receiving unit including a plurality of pixels each configured to generate a signal based on incident light; and a plurality of pixel control units each configured to control an exposure period during which the signal based on the incident light is generated in a corresponding pixel among the plurality of pixels. The plurality of pixel control units include a first pixel control unit and a second pixel control unit. The first pixel control unit controls a first exposure period in a first pixel among the plurality of pixels on the basis of a first exposure control signal, generates a second exposure control signal by delaying the first exposure control signal, and outputs the second exposure control signal to the second pixel control unit. The second pixel control unit controls a second exposure period in a second pixel among the plurality of pixels on the basis of the second exposure control signal.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to a photoelectric conversion device. [Background technology]

[0002] Patent Document 1 discloses a distance measuring device that measures the distance to an object by emitting light from a light source and receiving light, including reflected light from the object, with a light receiving element. Patent Document 1 discloses a method of repeatedly performing measurements while changing a gating period during which photons are detected by the light receiving element. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] US Patent Application Publication No. 2017 / 0052065 Summary of the Invention [Problem to be solved by the invention]

[0004] In the distance measurement method disclosed in Patent Document 1, it is necessary to repeatedly emit and receive light while changing the gating period, so the time required for one distance measurement may be long. Therefore, in this distance measurement method, it may be difficult to improve the frame rate.

[0005] An object of the present invention is to provide a photoelectric conversion device capable of improving the frame rate. [Means for solving the problem]

[0006] According to one disclosure of the present specification, there is provided a photoelectric conversion device comprising: a light receiving unit including a plurality of pixels, each of which generates a signal based on incident light; and a plurality of pixel control units, each of which controls an exposure period during which a signal based on the incident light is generated at a corresponding pixel among the plurality of pixels, wherein the plurality of pixel control units include a first pixel control unit and a second pixel control unit, the first pixel control unit controls a first exposure period at a first pixel among the plurality of pixels based on a first exposure control signal, generates a second exposure control signal by delaying the first exposure control signal and outputs it to the second pixel control unit, and the second pixel control unit controls a second exposure period at a second pixel among the plurality of pixels based on the second exposure control signal. Effect of the Invention

[0007] According to the present invention, a photoelectric conversion device capable of improving the frame rate is provided. [Brief description of the drawings]

[0008] [Figure 1] 1 is a hardware block diagram showing an example of a schematic configuration of a distance measuring device according to a first embodiment. [Diagram 2] 1 is a functional block diagram showing a schematic configuration example of a distance measuring device according to a first embodiment. [Diagram 3] 4A to 4C are diagrams illustrating an outline of distance measurement frame acquisition according to the first embodiment. [Figure 4] 4 is a flowchart showing the operation of the distance measuring device according to the first embodiment. [Diagram 5] 4 is a diagram showing a more specific configuration of a pixel control unit and a pixel according to the first embodiment. FIG. [Figure 6] 4 is a timing chart showing an example of the operation of the distance measuring device according to the first embodiment. [Figure 7] FIG. 11 is a diagram illustrating the configuration of a pixel control unit and a pixel according to a second embodiment. [Figure 8] FIG. 13 is a diagram illustrating the configuration of a pixel control unit and a pixel according to a third embodiment. [Figure 9]13 is a timing chart showing an example of the operation of the distance measuring device according to the third embodiment. [Figure 10] FIG. 11 is a schematic diagram showing the overall configuration of a photoelectric conversion device according to a fourth embodiment. [Figure 11] FIG. 13 is a schematic block diagram showing an example of the configuration of a sensor substrate according to a fourth embodiment. [Figure 12] FIG. 13 is a schematic block diagram showing an example of the configuration of a circuit board according to a fourth embodiment. [Figure 13] FIG. 13 is a schematic block diagram showing an example of the configuration of one pixel of a photoelectric conversion unit and a pixel signal processing unit according to a fourth embodiment. [Figure 14] 13A to 13C are diagrams illustrating the operation of the avalanche photodiode according to the fourth embodiment. [Figure 15] 13A and 13B are schematic diagrams and drive timing charts of a pixel array according to a fifth embodiment. [Figure 16] 13A and 13B are a schematic diagram and a drive timing chart of a pixel array according to a sixth embodiment. [Figure 17] FIG. 13 is a schematic diagram of a device according to a seventh embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The same elements or corresponding elements in multiple drawings are denoted by the same reference numerals, and the description thereof may be omitted or simplified.

[0010] [First embodiment] 1 is a hardware block diagram showing an example of a schematic configuration of a distance measuring device 1 according to this embodiment. The distance measuring device 1 includes a light emitting device 2, a signal processing circuit 3, and a light receiving device 4. Note that the configuration of the distance measuring device 1 shown in this embodiment is merely an example, and is not limited to the configuration shown in the figure.

[0011] The distance measuring device 1 is a device that measures the distance to the object X to be measured using a technology such as LiDAR (Light Detection And Ranging). The distance measuring device 1 measures the distance from the distance measuring device 1 to the object X based on the time difference between when the light emitted from the light emitting device 2 is reflected by the object X and when it is received by the light receiving device 4. The distance measuring device 1 can also measure the distance to a plurality of points in a two-dimensional manner by emitting laser light to a predetermined distance measuring range including the object X and receiving the reflected light with a pixel array. This allows the distance measuring device 1 to generate and output a distance image. Such a method is sometimes called Flash LiDAR.

[0012] The light received by the light receiving device 4 includes ambient light such as sunlight in addition to the reflected light from the object X. Therefore, the distance measuring device 1 performs distance measurement with reduced influence of ambient light by using a method in which the incident light is counted in each of a plurality of periods (bin periods) to generate a frequency distribution and determines that the reflected light is incident in the period when the amount of light is at its peak.

[0013] The light emitting device 2 is a device that emits light such as laser light to the outside of the distance measuring device 1. The signal processing circuit 3 may include a processor that performs arithmetic processing of digital signals, a memory that stores digital signals, etc. The memory may be, for example, a semiconductor memory.

[0014] The light receiving device 4 generates a pulse signal including a pulse based on the incident light. The light receiving device 4 is, for example, a photoelectric conversion device including an avalanche photodiode as a photoelectric conversion element. In this case, when one photon is incident on the avalanche photodiode and an electric charge is generated, one pulse is generated by avalanche multiplication. However, the light receiving device 4 may be, for example, a device using a photoelectric conversion element using another photodiode.

[0015] 2 is a functional block diagram showing an example of a schematic configuration of the distance measuring device 1 according to this embodiment. The distance measuring device 1 has a light emitting unit 20, a light receiving unit 40, a control unit 31, a frequency distribution holding unit 32, and an output unit 33.

[0016] The light receiving section 40 has a plurality of pixels 41 arranged in a plurality of rows and a plurality of columns. Each of the plurality of pixels 41 includes a photoelectric conversion element and a pixel circuit for reading out a signal from the photoelectric conversion element. In the following description, the photoelectric conversion element is assumed to be an avalanche photodiode.

[0017] The light receiving unit 40 also has a plurality of pixel control units 42 arranged to correspond to the plurality of pixels 41, respectively. That is, the plurality of pixel control units 42 are also arranged to form a plurality of rows and a plurality of columns, similar to the plurality of pixels 41. The pixel control unit 42 controls an exposure period during which a signal is generated in the corresponding pixel 41 based on incident light.

[0018] The light receiving section 40 and the light emitting section 20 correspond to the light receiving device 4 and the light emitting device 2, respectively, in Fig. 1. The control section 31, the frequency distribution holding section 32, and the output section 33 correspond to the signal processing circuit 3 in Fig. 1.

[0019] The control unit 31 outputs a light emission control signal that controls the timing of light emission to the light emitting unit 20. The control unit 31 also outputs an exposure control signal according to the distance measurement and a signal for scanning the pixels 41 to the light receiving unit 40. The control unit 31 also outputs a control signal that controls the operation of the frequency distribution holding unit 32. This control signal has a function of controlling, for example, the timing of the start and end of a frame.

[0020] The exposure control signal output from the control unit 31 is input to the pixel control unit 42 in the leftmost column (first column) of the light receiving unit 40. The pixel control unit 42 outputs the exposure control signal to the corresponding pixel 41, and also outputs the exposure control signal to the pixel control unit 42 in the adjacent column (second column). The pixel control unit 42 in the first column has a function of delaying the exposure control signal by a predetermined time and outputting it to the pixel control unit 42 in the second column.

[0021] The photoelectric conversion element of the pixel 41 converts light into an electrical signal when a photon is detected within an exposure period during which an exposure control signal output from the pixel control unit 42 is enabled. The pixel circuit of the pixel 41 outputs the electrical signal converted in the photoelectric conversion unit to a pixel output signal line. The light receiving unit 40 has a vertical scanning circuit (not shown) that receives a control pulse supplied from the control unit 31 and supplies the control pulse to each pixel 41. A logic circuit such as a shift register or an address decoder may be used for the vertical scanning circuit. The signal output from the photoelectric conversion unit of each pixel 41 is processed in the pixel circuit of each pixel 41. The pixel circuit is provided with a memory, and the memory holds a digital signal indicating whether or not the pixel 41 receives light. This digital signal is a 1-bit signal that constitutes a microframe.

[0022] The digital signals output from the multiple pixels 41 are respectively stored in the frequency distribution storage unit 32. Since the measured distance is proportional to the flight time of light, the time from light emission specified by the exposure control signal to light reception by the light receiving unit 40 corresponds to the measured distance. In this embodiment, multiple microframe measurements are performed for each distance. Then, multiple distance measurements are performed while changing the time from light emission to activation of the exposure control signal. The frequency distribution storage unit 32 accumulates the microframes for each class according to the distance, thereby generating a frequency distribution in which the distance is set as a class, the number of times light is received as a frequency, and the classes and the frequencies are associated with each other. The frequency distribution storage unit 32 has a memory that stores the frequency distribution.

[0023] The output unit 33 is an interface that outputs information in a predetermined format to the outside of the distance measuring device 1. The information held in the frequency distribution holding unit 32 may be output directly to an external signal processing device via the output unit 33. Alternatively, the frequency distribution holding unit 32 may perform peak detection processing to detect peaks from the frequency distribution to generate distance information, and the output unit 33 may output the distance information to an external signal processing device.

[0024] As described above, the light receiving section 40 of this embodiment is capable of delaying the exposure control signal input to the pixel 41 in the first row and second column by a predetermined time from the exposure control signal input to the pixel 41 in the first row and first column. In this case, the multiple pixels 41 can perform exposure operations in different periods, so that light can be received in multiple exposure periods with one emission of light. In other words, multiple distances are measured with one emission of light. This reduces the resolution in the light receiving surface of the light receiving section 40, but can improve the frame rate.

[0025] FIG. 3 is a diagram showing an outline of distance measurement frame acquisition according to the present embodiment. In FIG. 3, the acquisition period of a distance measurement frame corresponding to one distance measurement result, a subframe used to generate the distance measurement frame, and a microframe used to generate the subframe are shown by arranging blocks in the horizontal direction. The horizontal direction in FIG. 3 indicates the passage of time, and one block indicates the acquisition period of one distance measurement frame, subframe, or microframe. FIG. 3 also shows a control signal for controlling the light emission period of the light emitting unit 20 and an exposure control signal for controlling the exposure period in the light receiving unit 40. Note that in the following description of FIG. 3 and FIG. 4, a driving method in which multiple pixels 41 perform exposure operations in different periods to measure multiple distances with one light emission is not considered.

[0026] 3 shows multiple frame periods FL_1, FL_2, ... included in one ranging period. Frame period FL_1 indicates the first frame period in one ranging period, and frame period FL_2 indicates the second frame period in one ranging period. A frame period is a period during which the ranging device 1 performs one ranging and outputs a signal indicating the distance (ranging result) from the ranging device 1 to the object X to the outside.

[0027] One ranging frame is generated from multiple subframes. In the "frame period" of Fig. 3, multiple subframe periods SF_1, SF_2, ..., SF_n included in one frame period and a peak output period POUT in which a peak is determined from the frequency distribution and output is shown. The subframe period SF_1 indicates the first subframe period in one frame period, and the subframe period SF_2 indicates the second subframe period in one frame period. In this embodiment, the number of subframes is n per frame (n is an integer equal to or greater than 2). The subframe period SF_n indicates the nth subframe period in one frame period.

[0028] One subframe is generated from multiple microframes. In the "subframe period" of FIG. 3, multiple microframe periods MF_1, MF_2, ..., MF_m included in one subframe period are shown. Microframe period MF_1 indicates the first microframe period in one subframe period, and microframe period MF_2 indicates the second microframe period in one subframe period. In this embodiment, the number of microframes is m per subframe (m is an integer of 2 or more). Microframe period MF_m indicates the mth microframe period in one subframe period. The number m of microframes corresponds to the number of times the light reception results are integrated.

[0029] "Light Emission" and "Exposure Control Signal" in FIG. 3 indicate the light emission period of the light emission unit 20 and the exposure control signal input to the light receiving unit 40 in one microframe period. The light emission unit 20 emits light during the light emission period LA when "light emission" is at a high level. When light is incident on a pixel 41 of the light receiving unit 40 during the exposure period LB when the "exposure control signal" is at a high level, the pixel 41 detects the incident light. The period T_k from the start of the light emission period LA to the start of the exposure period LB corresponds to the flight time of light from light emission to light reception. In other words, the length of the period T_k corresponds to the distance measurement distance in the corresponding microframe. Note that k is the number of the corresponding subframe period and is an integer from 1 to n.

[0030] In each of the multiple microframe periods MF_1, MF_2, ..., MF_m, the length of the period T_k from the start of the light emission period LA to the start of the exposure period LB is the same. That is, in one subframe period, light reception data is read out m times (microframe acquisition). When a photon is detected at least once in one microframe period in each pixel 41, the pixel outputs "1" as light reception data. Data indicating the number of microframes in which a photon was detected is generated by accumulating the m microframes acquired in one subframe period.

[0031] In each of the multiple subframe periods SF_1, SF_2, ..., SF_n, the lengths of the periods T_1, T_2, ..., T_n are different from each other. As a result, a frequency distribution of received light at different distances is obtained in each of the multiple subframe periods SF_1, SF_2, ..., SF_n. In the peak output period POUT, a peak (maximum value) is detected from the frequency of each of the subframe periods SF_1, SF_2, ..., SF_n. The length of the period T_k corresponding to this peak is proportional to the distance from the distance measuring device 1 to the object X.

[0032] Fig. 4 is a flowchart showing the operation of the distance measuring device 1 according to this embodiment. Fig. 4 shows the operation from the start to the end of a distance measuring period. One loop of processing from step S11 to step S19 shows the processing for acquiring one subframe in Fig. 3. One loop of processing from step S11 to step S17 shows the processing for acquiring one microframe in Fig. 3.

[0033] In step S11, the control unit 31 controls the light emitting unit 20 to emit pulsed light within a predetermined distance measurement range. The control unit 31 also controls the light receiving unit 40 to start an exposure process for detecting incident light. If the process of step S11 is the first time, the period (exposure control signal interval) corresponding to the interval between light emission and light reception is set to T_1.

[0034] In step S12, if a photon is incident on a pixel 41 during the exposure period (YES in step S12), the process proceeds to step S13, where the pixel 41 generates a photon detection signal (light reception pulse) indicating the detection of a photon. The photon detection signal is stored as light reception data in the memory in the pixel 41. For a pixel 41 to which no photon is incident during the exposure period (NO in step S12), the process proceeds to step S14. The processes in steps S12 and S13 are performed in parallel in each pixel 41.

[0035] In step S14, the light reception data is read out to the frequency distribution holding section 32 for each predetermined unit area of ​​the pixels 41 under the control of the control section 31 for readout scanning.

[0036] In step S15, the light reception data for each pixel 41 is added in the frequency distribution storage unit 32. As a result, a frequency distribution for each pixel 41 is generated.

[0037] In step S16, the control unit 31 determines whether or not the reading of all pixel data in the read target area has been completed. If the reading has not been completed (NO in step S16), the process proceeds to step S14, where the reading area is changed and reading is continued. If the reading has been completed (YES in step S16), the process proceeds to step S17.

[0038] In step S17, the control unit 31 determines whether the number of acquired microframes in the subframe is m or more. If the number of acquired microframes is less than m (NO in step S17), the process proceeds to step S11, where the next microframe is acquired. If the number of acquired microframes is m or more (YES in step S17), the process proceeds to step S18. Through this process, m microframes are acquired and accumulated.

[0039] In step S18, the control unit 31 determines whether the exposure control signal interval is T_n (the exposure control signal interval in the final subframe). If the exposure control signal interval is not T_n (NO in step S18), the process proceeds to step S19. If the exposure control signal interval is T_n (YES in step S18), the process proceeds to step S20.

[0040] In step S19, the control unit 31 changes the setting value of the exposure control signal interval to a value for the next subframe. For example, if the exposure control signal interval is T_1, the control unit 31 changes the exposure control signal interval to T_2. Then, the process proceeds to step S11, where the next subframe is acquired.

[0041] In step S20, a frequency distribution with n types of exposure control signal intervals from T_1 to T_n has been acquired in the frequency distribution storage unit 32. The frequency distribution storage unit 32 or an external signal processing device performs a peak detection process to detect peaks in the frequency distribution and generate distance information. This peak detection process may be, for example, a process of acquiring the maximum value of the frequency across the acquired multiple classes and calculating the distance from the distance measuring device 1 to the object X based on the exposure control signal interval corresponding to the maximum value. More specifically, when the exposure control signal interval corresponding to the peak is T_p and the speed of light is c (approximately 300,000 km / s), the distance Y can be calculated by Y=c×T_p / 2.

[0042] In step S21, the control unit 31 determines whether or not to end the distance measurement. If it is determined that the distance measurement is to be ended (YES in step S21), this process ends. If it is determined that the distance measurement is not to be ended (NO in step S21), the process proceeds to step S11, and the next distance measurement frame is acquired.

[0043] Next, the control of the exposure period in the pixel control unit 42 and the pixel 41 will be described in more detail with reference to Fig. 5 and Fig. 6. Fig. 5 is a diagram showing a more specific configuration of the pixel control unit 42 and the pixel 41 according to the embodiment.

[0044] FIG. 5 illustrates nine pixels 41 arranged in three rows and three columns, and nine pixel controllers 42 corresponding to the pixels 41. In FIG. 5, pixel controllers 42a, 42b, 42c and pixels 41a, 41b, 41c are arranged in the first row. In the second row, pixel controllers 42d, 42e, 42f and pixels 41d, 41e, 41f are arranged. In the third row, pixel controllers 42g, 42h, 42i and pixels 41g, 41h, 41i are arranged. That is, in FIG. 5, in order to distinguish each of the nine elements, "a" to "i" are added to the end of the reference numerals of each element. The pixel controller 42a has a latch 421a, a selection circuit 422a, and a delay circuit 423a. The other pixel controllers 42b to 42i also have similar circuit elements.

[0045] 5 shows signal lines of the exposure control signals EX1, EX2, EX3 and the selection signal SEL output from the control unit 31. The exposure control signal EX1 is commonly input to the pixel control units 42a, 42b, and 42c of the first row. The exposure control signal EX2 is commonly input to the pixel control units 42d, 42e, and 42f of the second row. The exposure control signal EX3 is commonly input to the pixel control units 42g, 42h, and 42i of the third row. The selection signal SEL is commonly input to the nine pixel control units 42a to 42i. That is, a selection signal SEL of a common level is input to the selection circuits 422a to 422i of the pixel control units 42a to 42i.

[0046] The configurations of the first to third rows are the same except for the exposure control signal input, so the configuration of the first row will be mainly described below. The exposure control signal EX1 is input to a first input terminal of the selection circuit 422a, a second input terminal of the selection circuit 422a, a first input terminal of the selection circuit 422b, and a first input terminal of the selection circuit 422c. In FIG. 5, the terminal with "0" in the circuit symbol of each selection circuit is called the first input terminal, and the terminal with "1" in the circuit symbol is called the second input terminal. Each selection circuit enables either the input signal of the first input terminal or the second input terminal and outputs it from the output terminal according to the level of the signal input to the control terminal.

[0047] The selection signal SEL is input to the latches 421a, 421b, and 421c in common. The latches 421a, 421b, and 421c have a function of holding a 1-bit signal. That is, the latches 421a, 421b, and 421c hold a value of "0" or "1" according to the level of the selection signal SEL. The values ​​held in the latches 421a, 421b, and 421c are input to the control terminals of the selection circuits 422a, 422b, and 422c, respectively. Each of the selection circuits 422a, 422b, and 422c outputs a signal input to a first input terminal when the value input to the control terminal is "0," and outputs a signal input to a second input terminal when the value input to the control terminal is "1." Note that the selection signal SEL may hold a value in the latches 421a, 421b, and 421c, for example, when the distance measuring device 1 is started up.

[0048] The output terminal of the selection circuit 422a is connected to the control terminal of the pixel 41a and the input terminal of the delay circuit 423a. The output terminal of the delay circuit 423a is connected to a second input terminal of the selection circuit 422b. The exposure control signal output from the selection circuit 422a is input to the pixel 41a to control the exposure period of the pixel 41a, and is also input to the pixel control unit 42b via the delay circuit 423a.

[0049] The output terminal of the selection circuit 422b is connected to the control terminal of the pixel 41b and the input terminal of the delay circuit 423b. The output terminal of the delay circuit 423b is connected to a second input terminal of the selection circuit 422c. The exposure control signal output from the selection circuit 422b is input to the pixel 41b to control the exposure period of the pixel 41b, and is also input to the pixel control unit 42c via the delay circuit 423b. The connection relationship between the pixel control unit 42c and the pixel 41c is generally similar, so a description thereof will be omitted.

[0050] FIG. 6 is a timing chart showing an example of the operation of the distance measuring device 1 according to the present embodiment. FIG. 6 shows the operation when the latches 421a to 421i are holding a value of "1" due to the selection signal SEL. The high level period of "light emission" in FIG. 6 shows the light emission period of the light emitting unit 20. "EX1", "EX2", and "EX3" in FIG. 6 show the levels of the exposure control signals EX1, EX2, and EX3, respectively. "EX1b", "EX1c", "EX2e", "EX2f", "EX3h", and "EX3i" in FIG. 6 show the levels of the exposure control signals input to the pixels 41b, 41c, 41e, 41f, 41h, and 41i, respectively. With reference to FIG. 6, the operation will be described when the latches 421a to 421i are holding a value of "1" due to the selection signal SEL, and the second input terminals and output terminals are conductive in the selection circuits 422a to 422i.

[0051] 6, the delay times Td of the delay circuits 423a to 423i are all equal and correspond to the time between time t11 and time t13. The pulse widths of the exposure control signals EX1, EX2, and EX3 are set equal to the delay times Td. The intervals between time t13 and time t21 are each equal to the delay times Td. The delay times of the selection circuits 422a to 422i and the wiring are ignored.

[0052] During the period from time t11 to time t12, the light-emitting unit 20 emits light. During the period from time t11 to time t13, the exposure control signal EX1 becomes high level. The exposure control signal EX1 (first exposure control signal) is input to the pixel 41a via the selection circuit 422a without delay. In this manner, in the pixel 41a (first pixel) corresponding to the pixel control unit 42a (first pixel control unit) of the first column, exposure (counting of light-receiving pulses based on incident light) is performed during the period from time t11 to time t13 (first exposure period). In the example of FIG. 6, the timing of light emission of the light-emitting unit 20 and the start time of exposure based on the exposure control signal EX1 are simultaneous, but this is not limited to this. Due to gate shift, exposure based on the exposure control signal EX1 may start after a predetermined time has elapsed from the timing of light emission of the light-emitting unit 20.

[0053] The exposure control signal EX1 is input to the pixel 41b via the selection circuit 422a, the delay circuit 423a, and the selection circuit 422b. The delay time of this path is Td. An exposure control signal (second exposure control signal) in which the rising and falling edges of the exposure control signal EX1 are delayed by Td is input to the pixel 41b. In this manner, in the pixel 41b (second pixel) corresponding to the pixel control unit 42b (second pixel control unit) of the second column, exposure is performed during the period from time t13 to time t14 (second exposure period). Time t13, which is the start time of the second exposure period, is later than time t11, which is the start time of the first exposure period.

[0054] The exposure control signal EX1 is input to the pixel 41c via the selection circuit 422a, the delay circuit 423a, the selection circuit 422b, the delay circuit 423b, and the selection circuit 422c. The delay time of this path is 2Td. The exposure control signal in which the rising and falling edges of the exposure control signal EX1 are delayed by 2Td is input to the pixel 41c. In this way, in the pixel 41c corresponding to the pixel control unit 42c of the third column, exposure is performed during the period from time t14 to time t15.

[0055] In the period from time t15 to time t16, the exposure control signal EX2 becomes high level. The exposure control signal EX2 is set to become high level at a time 3Td later than the exposure control signal EX1. The exposure control signal EX2 is input to the pixel 41d via the selection circuit 422d without delay. In this way, in the pixel 41d corresponding to the pixel control unit 42d of the first column, exposure is performed in the period from time t15 to time t16.

[0056] As with the above-described pixels 41b and 41c, the delay circuits 423d and 423e delay the rising and falling edges of the exposure control signal EX2 by Td and 2Td, respectively, before inputting them to the pixels 41e and 41f. As a result, the pixel 41e in the second column is exposed during the period from time t16 to time t17, and the pixel 41f in the third column is exposed during the period from time t17 to time t18.

[0057] In the period from time t18 to time t19, the exposure control signal EX3 becomes high level. The exposure control signal EX3 is set to become high level 6Td later than the exposure control signal EX1. The exposure control signal EX3 is input to the pixel 41g via the selection circuit 422g without delay. In this way, in the pixel 41g corresponding to the pixel control unit 42g of the first column, exposure is performed in the period from time t18 to time t19.

[0058] As with the above-described pixels 41b and 41c, the delay circuits 423g and 423h delay the rising and falling edges of the exposure control signal EX3 by Td and 2Td, respectively, before inputting them to the pixels 41h and 41i. As a result, the pixel 41h in the second column is exposed during the period from time t19 to time t20, and the pixel 41i in the third column is exposed during the period from time t20 to time t21.

[0059] The nine pixels in three rows and three columns shown in Fig. 5 are treated as one macro pixel. These nine pixels are sequentially exposed in nine different periods. This allows the macro pixel to measure nine different distance ranges with one light emission. That is, the time required for each distance measurement can be shortened. Therefore, according to this embodiment, a photoelectric conversion device capable of improving the frame rate is provided.

[0060] In addition, the distance measuring device 1 of this embodiment can also perform a second driving method that prioritizes the resolution in the light receiving surface instead of the first driving method that prioritizes the frame rate as shown in FIG. 6. In the second driving method, the selection signal SEL holds the value "0" in the latches 421a to 421i, and the first input terminals and output terminals in the selection circuits 422a to 422i are conductive. Furthermore, in the second driving method, the exposure control signals EX1, EX2, and EX3 become high level at the same timing. In this case, the exposure control signals EX1, EX2, and EX3 are input to the corresponding pixels without delay, not via the delay circuits 423a to 423i. Therefore, in the second driving method, exposure is performed simultaneously in nine pixels 41a to 41i. Since light can be received individually in the nine pixels 41a to 41i during the same period, the resolution in the light receiving surface is improved by applying the second driving method compared to the first driving method.

[0061] In the first exposure method shown in FIG. 6, the frame rate is improved, but the resolution in the light receiving surface of the light receiving unit 40 is reduced. In contrast, in the second driving method, distance measurement can be performed with emphasis on the resolution in the light receiving surface rather than the frame rate. Therefore, in the configuration of this embodiment, appropriate distance measurement can be performed by considering the trade-off between frame rate and resolution by changing the driving method. In addition, since the latch and selection circuit arranged for each pixel perform this switching, there is an advantage that the degree of congestion of wiring is unlikely to increase even when the number of pixels is large. However, the second driving method may not be performed, and only the first driving method may be performed. In other words, the latches 421a to 421i and the selection circuits 422a to 422i are not essential.

[0062] Although the frequency distribution storage unit 32 of the present embodiment is premised on storing all microframes, it may be configured not to store some of the data. For example, the storage capacity may be reduced by adopting a method such as storing only the maximum value among a plurality of subframes.

[0063] In the example shown in Fig. 6, the interval between the exposure periods of the pixels 41a to 41i is equal to the delay time of the delay circuits 423a to 423i. Although this is not essential, by setting it in this way, it is possible to reduce overlaps or gaps between the exposure periods of the pixels 41a to 41i, and the accuracy of distance measurement can be improved. Also, in the example shown in Fig. 6, the lengths of the exposure periods of the pixels 41a to 41i are all equal. Although this is not essential, by setting it in this way, it is possible to measure distances with a certain distance resolution.

[0064] [Second embodiment] In this embodiment, a modified example will be described in which one pixel control unit 42 is arranged to correspond to a pixel group including a plurality of pixels 41. In this embodiment, the description of elements common to the first embodiment may be omitted or simplified.

[0065] FIG. 7 is a diagram showing the configuration of a pixel control unit 42 and a pixel 41 according to the present embodiment. In this embodiment, one pixel 41 in FIG. 5 of the first embodiment is replaced with a pixel group 43. One pixel group 43 includes nine pixels 41 arranged in three rows and three columns. The pixel control unit 42 controls the nine pixels in one pixel group 43 to operate in a common exposure period. FIG. 7 shows nine pixel control units 42a to 42i and nine pixel groups 43a to 43i arranged in three rows and three columns, which can be driven in the same way as in the first embodiment.

[0066] In addition, the multiple pixels 41 belonging to the pixel group 43 in this embodiment are treated as equivalent to one pixel. This is called binning processing. In the binning processing, signals based on photons incident on the multiple pixels 41 are added up and counted, and a frequency distribution is generated by treating the multiple pixels 41 belonging to the pixel group 43 as the same pixel. That is, in this frequency distribution, the frequencies output from the multiple pixels treated as the same pixel are processed as a common class indicating the same distance. By performing this binning processing, although the resolution in the light receiving surface decreases, the effective light receiving area increases, and therefore the probability of receiving reflected light from the object X increases. This makes it possible to expand the distance range that can be measured.

[0067] In this embodiment, the number of pixel control units 42 is smaller than the number of pixels 41. This reduces the total area occupied by the multiple pixel control units 42 compared to the configuration of the first embodiment, and allows the intervals between the pixels 41 to be smaller. This provides the effects of improving sensitivity by expanding the light receiving area, increasing the number of pixels 41, and reducing the size of the distance measuring device 1. It is also possible to increase the area of ​​the delay circuit 423 to improve the control accuracy of the exposure period.

[0068] According to this embodiment, a photoelectric conversion device capable of improving the frame rate is provided, similarly to the first embodiment. In addition, at least one of the above-mentioned quality improvement effects can be obtained by reducing the area occupied by the pixel control unit 42.

[0069] [Third embodiment] In this embodiment, a modified example will be described in which one pixel control unit 42 is arranged to correspond to a plurality of pixels 41 in one column. In this embodiment, the description of elements common to the first embodiment may be omitted or simplified.

[0070] 8 is a diagram showing the configuration of a pixel control unit 42 and a pixel 41 according to the present embodiment. In the first embodiment, one pixel control unit 42 controls one pixel 41, but in the present embodiment, one pixel control unit 42 controls three pixels 41 in the same column. That is, pixel control unit 42a controls pixels 41a, 41d, and 41g, pixel control unit 42b controls pixels 41b, 41e, and 41h, and pixel control unit 42c controls pixels 41c, 41f, and 41i. A horizontal exposure control signal EXH is input to the pixel control units 42a, 42b, and 42c.

[0071] In the light receiving unit 40 of the present embodiment, AND circuits 45a to 45i are arranged to correspond to the plurality of pixels 41a to 41i, respectively. Each of the AND circuits 45a to 45i is a logic circuit that outputs a logical product of input signals at a first input terminal and a second input terminal from an output terminal.

[0072] The output terminal of the selection circuit 422a is connected to the first input terminals of the AND circuits 45a, 45d, and 45g and the input terminal of the delay circuit 423a. The output terminal of the selection circuit 422b is connected to the first input terminals of the AND circuits 45b, 45e, and 45h and the input terminal of the delay circuit 423b. The output terminal of the selection circuit 422c is connected to the first input terminals of the AND circuits 45c, 45f, and 45i and the input terminal of the delay circuit 423c. The vertical exposure control signal EXV1 (third exposure control signal) is input from the control unit 31 to the second input terminals of the AND circuits 45a, 45b, and 45c. The vertical exposure control signal EXV2 is input from the control unit 31 to the second input terminals of the AND circuits 45d, 45e, and 45f. The vertical exposure control signal EXV3 is input from the control unit 31 to the second input terminals of the AND circuits 45g, 45h, and 45i. In this manner, in this embodiment, the exposure periods of the multiple pixels 41a to 41i are controlled based on a combination of the horizontal exposure control signal EXH and the vertical exposure control signals EXV1, EXV2, and EXV3.

[0073] FIG. 9 is a timing chart showing an example of the operation of the distance measuring device 1 according to this embodiment. FIG. 9 shows the operation when the value "1" is held in the latches 421a to 421c by the selection signal SEL. The high level period of "light emission" in FIG. 9 indicates the light emission period of the light emitting unit 20. "EXH", "EXV1", "EXV2", and "EXV3" in FIG. 9 indicate the levels of the horizontal exposure control signal EXH and the vertical exposure control signals EXV1, EXV2, and EXV3, respectively. "EXHb" and "EXHc" in FIG. 9 indicate the levels of the horizontal exposure control signals output from the selection circuits 422b and 422c, respectively.

[0074] In the example of Fig. 9, the delay times Td of the delay circuits 423a to 423c are all equal and correspond to the time between time t11 and time t13. The pulse width of the horizontal exposure control signal EXH is set equal to the delay time Td. The pulse widths of the vertical exposure control signals EXV1, EXV2, and EXV3 are set three times the delay time Td. The intervals between time t13 and time t21 are each equal to the delay time Td. The delay times of the selection circuits 422a to 422c, the AND circuits 45a to 45i, and the wiring are ignored.

[0075] In this embodiment, the horizontal exposure control signal EXH is at a high level during the period from time t11 to time t13, the period from time t15 to time t16, and the period from time t18 to time t19. This horizontal exposure control signal EXH is delayed by Td by the delay circuits 423a and 423b, as in the example of FIG. 6. That is, the exposure control signal output from the pixel control unit 42a is at a high level during the period from time t11 to time t13, the period from time t15 to time t16, and the period from time t18 to time t19. The exposure control signal output from the pixel control unit 42b is at a high level during the period from time t13 to time t14, the period from time t16 to time t17, and the period from time t19 to time t20. The exposure control signal output from the pixel control unit 42c is at a high level during the period from time t14 to time t15, the period from time t17 to time t18, and the period from time t20 to time t21.

[0076] The vertical exposure control signal EXV1 is at high level from time t11 to time t15, the vertical exposure control signal EXV2 is at high level from time t15 to time t18, and the vertical exposure control signal EXV3 is at high level from time t18 to time t21. In other words, the vertical exposure control signal EXV2 is delayed by 3 Td from the vertical exposure control signal EXV1, and the vertical exposure control signal EXV3 is delayed by 3 Td from the vertical exposure control signal EXV2.

[0077] The exposure control signal output from the AND circuit 45a to the pixel 41a is the logical product of two signals ("EXH" and "EXV1" in FIG. 9) input to the AND circuit 45a. Therefore, the pixel 41a in the first row and first column receives an exposure control signal that is at a high level during the period from time t11 to time t13.

[0078] The exposure control signal output from the AND circuit 45b to the pixel 41b is the logical product of the two signals ("EXHb" and "EXV1" in FIG. 9) input to the AND circuit 45b. Therefore, the pixel 41b in the first row and second column receives an exposure control signal that is at a high level during the period from time t13 to time t14.

[0079] Similarly, the exposure control signals generated by the AND circuits 45c to 45i are input to the other pixels 41c to 41i. That is, the high-level period of the exposure control signals input to the pixels 41a to 41i is the same as that of the first embodiment shown in Fig. 6, and exposure is performed in different periods in the pixels 41a to 41i. Therefore, distance measurement similar to that of the first embodiment can be performed in this embodiment as well.

[0080] In this embodiment, one pixel control unit 42 is shared by multiple pixels 41, and therefore the number of pixel control units 42 is smaller than the number of pixels 41. As a result, similar to the second embodiment, the total area occupied by the multiple pixel control units 42 is reduced, and the intervals between the pixels 41 can be made smaller.

[0081] According to this embodiment, a photoelectric conversion device capable of improving the frame rate is provided, similarly to the first embodiment. In addition, the area occupied by the pixel control unit 42 is reduced, resulting in an effect of improving quality.

[0082] The vertical exposure control signals EXV2 and EXV3 may be generated by, but are not limited to, the control unit 31. For example, the vertical exposure control signals EXV2 and EXV3 may be generated by delaying the vertical exposure control signal EXV1 using a circuit similar to the pixel control unit 42.

[0083] [Fourth embodiment] In this embodiment, a specific configuration example of a photoelectric conversion device including an avalanche photodiode that can be applied to the distance measuring device 1 will be described. The configuration example of this embodiment is just an example, and the photoelectric conversion device that can be applied to the distance measuring device 1 is not limited to this.

[0084] FIG. 10 is a schematic diagram showing the overall configuration of a photoelectric conversion device 100 according to this embodiment. The photoelectric conversion device 100 has a sensor substrate 11 (first substrate) and a circuit substrate 21 (second substrate) that are stacked on each other. The sensor substrate 11 and the circuit substrate 21 are electrically connected to each other. The sensor substrate 11 has a pixel region 12 in which a plurality of pixels 101 are arranged to form a plurality of rows and a plurality of columns. The circuit substrate 21 has a first circuit region 22 in which a plurality of pixel signal processing units 103 are arranged to form a plurality of rows and a plurality of columns, and a second circuit region 23 arranged on the periphery of the first circuit region 22. The second circuit region 23 may include a circuit for controlling the plurality of pixel signal processing units 103. The sensor substrate 11 has a light incident surface that receives incident light and a connection surface that faces the light incident surface. The sensor substrate 11 is connected to the circuit substrate 21 on the connection surface side. That is, the photoelectric conversion device 100 is a so-called back-illuminated type.

[0085] In this specification, "planar view" refers to a view from a direction perpendicular to the surface opposite to the light incident surface. Also, a cross section refers to a surface in a direction perpendicular to the surface opposite to the light incident surface of the sensor substrate 11. Note that the light incident surface may be rough when viewed microscopically, and in such a case, the planar view is defined based on the light incident surface when viewed macroscopically.

[0086] In the following description, the sensor substrate 11 and the circuit substrate 21 are described as being diced chips, but the sensor substrate 11 and the circuit substrate 21 are not limited to being chips. For example, the sensor substrate 11 and the circuit substrate 21 may be wafers. In addition, when the sensor substrate 11 and the circuit substrate 21 are diced chips, the photoelectric conversion device 100 may be manufactured by stacking them in a wafer state and then dicing them, or may be manufactured by stacking them after dicing.

[0087] 11 is a schematic block diagram showing an example of the arrangement of the sensor substrate 11. A plurality of pixels 101 arranged in a plurality of rows and a plurality of columns are arranged in the pixel region 12. Each of the plurality of pixels 101 has a photoelectric conversion unit 102 including an avalanche photodiode (hereinafter referred to as APD) as a photoelectric conversion element within the substrate.

[0088] The conductivity type of the charge pair generated in the APD and used as the signal charge is called the first conductivity type. The first conductivity type refers to a conductivity type in which the charge of the same polarity as the signal charge is the majority carrier. The conductivity type opposite to the first conductivity type, that is, the conductivity type in which the charge of the opposite polarity to the signal charge is the majority carrier, is called the second conductivity type. In the APD described below, the anode of the APD is at a fixed potential, and a signal is taken out from the cathode of the APD. Therefore, the semiconductor region of the first conductivity type is an N-type semiconductor region, and the semiconductor region of the second conductivity type is a P-type semiconductor region. The cathode of the APD may be at a fixed potential, and the signal may be taken out from the anode of the APD. In this case, the semiconductor region of the first conductivity type is a P-type semiconductor region, and the semiconductor region of the second conductivity type is an N-type semiconductor region. In the following, a case in which one node of the APD is at a fixed potential will be described, but the potentials of both nodes may be fluctuating.

[0089] 12 is a schematic block diagram showing a configuration example of the circuit board 21. The circuit board 21 has a first circuit area 22 in which a plurality of pixel signal processing units 103 are arranged to form a plurality of rows and a plurality of columns.

[0090] Further, a vertical scanning circuit 110, a horizontal scanning circuit 111, a readout circuit 112, pixel output signal lines 113, an output circuit 114, and a control signal generating unit 115 are arranged on the circuit board 21. The multiple photoelectric conversion units 102 shown in Fig. 11 and the multiple pixel signal processing units 103 shown in Fig. 12 are electrically connected to each other via connection wiring provided for each pixel 101.

[0091] The control signal generating unit 115 is a control circuit that generates control signals for driving the vertical scanning circuit 110, the horizontal scanning circuit 111, and the readout circuit 112, and supplies these circuits with these signals. In this way, the control signal generating unit 115 controls the drive timing of each circuit.

[0092] The vertical scanning circuit 110 supplies a control signal to each of the pixel signal processing units 103 based on the control signal supplied from the control signal generation unit 115. The vertical scanning circuit 110 supplies a control signal to each pixel signal processing unit 103 for each row via a drive line provided for each row of the first circuit area 22. As will be described later, there may be multiple drive lines for each row. The vertical scanning circuit 110 may include logic circuits such as a shift register and an address decoder. In this way, the vertical scanning circuit 110 selects a row for outputting a signal from the pixel signal processing unit 103.

[0093] A signal output from the photoelectric conversion unit 102 of the pixel 101 is processed by a pixel signal processing unit 103. The pixel signal processing unit 103 counts pulses output from the APD included in the photoelectric conversion unit 102 to acquire and hold a digital signal.

[0094] It is not necessary that one pixel signal processing unit 103 is provided for each pixel 101. For example, one pixel signal processing unit 103 may be shared by a plurality of pixels 101. In this case, the pixel signal processing unit 103 provides a signal processing function to each pixel 101 by sequentially processing the signals output from each photoelectric conversion unit 102.

[0095] The horizontal scanning circuit 111 supplies a control signal to the readout circuit 112 based on the control signal supplied from the control signal generation unit 115. The pixel signal processing unit 103 is connected to the readout circuit 112 via a pixel output signal line 113 provided for each column of the first circuit region 22. The pixel output signal line 113 of one column is shared by a plurality of pixel signal processing units 103 of the corresponding column. The pixel output signal line 113 includes a plurality of wirings, and has at least a function of outputting a digital signal from each pixel signal processing unit 103 to the readout circuit 112 and a function of supplying a control signal for selecting a column for outputting a signal to the pixel signal processing unit 103. The readout circuit 112 outputs a signal to a storage unit or a signal processing unit outside the photoelectric conversion device 100 via the output circuit 114 based on the control signal supplied from the control signal generation unit 115.

[0096] The photoelectric conversion units 102 in the pixel region 12 may be arranged one-dimensionally. Moreover, the function of the pixel signal processing unit 103 does not necessarily have to be provided for each pixel 101. For example, one pixel signal processing unit 103 may be shared by a plurality of pixels 101. In this case, the pixel signal processing unit 103 provides a signal processing function to each pixel 101 by sequentially processing signals output from each photoelectric conversion unit 102.

[0097] 11 and 12, a first circuit region 22 in which a plurality of pixel signal processing units 103 are arranged is arranged in a region overlapping the pixel region 12 in a plan view. A vertical scanning circuit 110, a horizontal scanning circuit 111, a readout circuit 112, an output circuit 114, and a control signal generating unit 115 are arranged so as to overlap between an end of the sensor substrate 11 and an end of the pixel region 12 in a plan view. In other words, the sensor substrate 11 has the pixel region 12 and a non-pixel region arranged around the pixel region 12. In the circuit substrate 21, a second circuit region 23 (described above in FIG. 10) in which the vertical scanning circuit 110, the horizontal scanning circuit 111, the readout circuit 112, the output circuit 114, and the control signal generating unit 115 are arranged is arranged in a region overlapping the non-pixel region in a plan view.

[0098] The arrangement of the pixel output signal lines 113, the readout circuits 112, and the output circuits 114 are not limited to those shown in Fig. 12. For example, the pixel output signal lines 113 may be arranged to extend in the row direction and shared by a plurality of pixel signal processing units 103 in the corresponding row. The readout circuits 112 may be arranged so that the pixel output signal lines 113 in each row are connected to each other.

[0099] Fig. 13 is a schematic block diagram showing a configuration example of one pixel of the photoelectric conversion unit 102 and pixel signal processing unit 103 according to this embodiment. Fig. 13 shows a more specific configuration example including the connection relationship between the photoelectric conversion unit 102 arranged on the sensor substrate 11 and the pixel signal processing unit 103 arranged on the circuit substrate 21. Note that in Fig. 13, the drive lines between the vertical scanning circuit 110 and the pixel signal processing unit 103 in Fig. 12 are shown as drive lines 213, 214, and 215.

[0100] The photoelectric conversion unit 102 has an APD 201. The pixel signal processing unit 103 has a quenching element 202, a waveform shaping unit 210, a counter circuit 211, a selection circuit 212, and a gating circuit 216. It is sufficient that the pixel signal processing unit 103 has at least one of the waveform shaping unit 210, the counter circuit 211, the selection circuit 212, and the gating circuit 216.

[0101] The APD 201 generates charges according to incident light by photoelectric conversion. A voltage VL (first voltage) is supplied to the anode of the APD 201. A cathode of the APD 201 is connected to a first terminal of the quench element 202 and an input terminal of the waveform shaping unit 210. A voltage VH (second voltage) higher than the voltage VL supplied to the anode is supplied to the cathode of the APD 201. As a result, a reverse bias voltage is supplied to the anode and cathode of the APD 201 such that the APD 201 performs avalanche multiplication. When charges are generated by incident light in the APD 201 to which the reverse bias voltage is supplied, the charges undergo avalanche multiplication, generating an avalanche current.

[0102] In addition, there are two operation modes when a reverse bias voltage is supplied to the APD 201: Geiger mode and linear mode. The Geiger mode is a mode in which the APD 201 operates with a potential difference between the anode and cathode that is greater than the breakdown voltage, and the linear mode is a mode in which the APD 201 operates with a potential difference between the anode and cathode that is close to or less than the breakdown voltage.

[0103] An APD operated in Geiger mode is called a SPAD (Single Photon Avalanche Diode). In this case, for example, the voltage VL (first voltage) is −30 V, and the voltage VH (second voltage) is 1 V. The APD 201 may be operated in either linear mode or Geiger mode. In the case of a SPAD, the potential difference is larger than that of an APD in linear mode, and the effect of avalanche multiplication is more pronounced, so a SPAD is preferable.

[0104] The quench element 202 functions as a load circuit (quench circuit) during signal multiplication by avalanche multiplication. The quench element 202 suppresses the voltage supplied to the APD 201 to suppress avalanche multiplication (quench operation). The quench element 202 also returns the voltage supplied to the APD 201 to the voltage VH by passing a current corresponding to the voltage drop caused by the quench operation (recharge operation). The quench element 202 can be, for example, a resistive element.

[0105] The waveform shaping unit 210 shapes the potential change of the cathode of the APD 201 obtained when a photon is detected, and outputs a pulse signal. For example, an inverter circuit is used as the waveform shaping unit 210. Although an example using one inverter as the waveform shaping unit 210 is shown in Fig. 13, the waveform shaping unit 210 may be a circuit in which a plurality of inverters are connected in series, or may be another circuit having a waveform shaping effect.

[0106] The gating circuit 216 is a circuit that performs gating such that the pulse signal output from the waveform shaping unit 210 passes only for a predetermined period. During the period during which the pulse signal can pass through the gating circuit 216, photons incident on the APD 201 are counted by the counter circuit 211 at the rear stage. Therefore, the gating circuit 216 controls the exposure period during which a signal is generated based on the incident light in the pixel 101. The period during which the pulse signal passes is controlled by a control signal supplied from the vertical scanning circuit 110 via the drive line 215. FIG. 13 shows an example in which one AND circuit is used as the gating circuit 216. A pulse signal and a control signal are input to two input terminals of the AND circuit. The AND circuit outputs the logical product of these to the counter circuit 211. Note that the gating circuit 216 may have a circuit configuration other than an AND circuit as long as it can realize gating. In addition, the waveform shaping unit 210 and the gating circuit 216 may be integrated by using a logic circuit such as a NAND circuit.

[0107] The counter circuit 211 counts the pulse signals output from the waveform shaping unit 210 via the gating circuit 216, and holds a digital signal indicating the count value. When a control signal is supplied from the vertical scanning circuit 110 via the drive line 213, the counter circuit 211 resets the held signal. The counter circuit 211 can be, for example, a 1-bit counter.

[0108] A control signal is supplied to the selection circuit 212 from the vertical scanning circuit 110 shown in Fig. 12 via a drive line 214 shown in Fig. 13. In response to this control signal, the selection circuit 212 switches between electrical connection and non-connection between the counter circuit 211 and the pixel output signal line 113. The selection circuit 212 includes, for example, a buffer circuit for outputting a signal corresponding to a value held in the counter circuit 211.

[0109] 13, the selection circuit 212 switches between electrical connection and disconnection between the counter circuit 211 and the pixel output signal line 113, but the method of controlling the signal output to the pixel output signal line 113 is not limited to this. For example, a switch such as a transistor may be disposed at a node between the quench element 202 and the APD 201, between the photoelectric conversion unit 102 and the pixel signal processing unit 103, or the like, and the signal output to the pixel output signal line 113 may be controlled by switching between electrical connection and disconnection. Alternatively, the signal output to the pixel output signal line 113 may be controlled by changing the value of the voltage VH or voltage VL supplied to the photoelectric conversion unit 102 using a switch such as a transistor.

[0110] Fig. 14(a), Fig. 14(b) and Fig. 14(c) are diagrams for explaining the operation of the APD 201 according to this embodiment. Fig. 14(a) is a diagram showing the APD 201, the quench element 202 and the waveform shaping unit 210 extracted from Fig. 13. As shown in Fig. 14(a), a connection node between the APD 201, the quench element 202 and the input terminals of the waveform shaping unit 210 is referred to as nodeA. Also, as shown in Fig. 14(a), the output side of the waveform shaping unit 210 is referred to as nodeB.

[0111] FIG. 14(b) is a graph showing the time change of the potential of nodeA in FIG. 14(a). FIG. 14(c) is a graph showing the time change of the potential of nodeB in FIG. 14(a). In the period from time t0 to time t1, a voltage of VH-VL is applied to the APD 201 in FIG. 14(a). When a photon is incident on the APD 201 at time t1, avalanche multiplication occurs in the APD 201. As a result, an avalanche current flows through the quench element 202, and the potential of nodeA drops. Thereafter, the amount of potential drop becomes larger, and the voltage applied to the APD 201 gradually decreases. Then, at time t2, the avalanche multiplication in the APD 201 stops. As a result, the voltage level of nodeA does not drop below a certain value. Thereafter, during the period from time t2 to time t3, a current that compensates for the voltage drop from the node of voltage VH flows to nodeA, and at time t3, nodeA settles to its original potential.

[0112] In the above process, the potential of node B becomes high during the period when the potential of node A is lower than a certain threshold. In this way, the waveform of the drop in the potential of node A caused by the incidence of a photon is shaped by the waveform shaping unit 210 and output as a pulse to node B.

[0113] According to this embodiment, a photoelectric conversion device using an avalanche photodiode that can be applied to the distance measuring device 1 is provided.

[0114] [Fifth embodiment] The method of making the exposure periods of a plurality of pixels different by using a delay circuit, as described in the first to third embodiments, can be applied to various configurations. In the following embodiments, examples of such applications will be described. In the following embodiments, when the timing of the gate pulse differs between pixels, the method of delaying the gate pulse by using the delay circuit of the above-described embodiments can be applied.

[0115] In the first embodiment, a pixel array having three rows and three columns as one unit is described, but in the following modified example, an example of a pixel array having two rows and two columns as one unit is described. This embodiment is an example of a pixel configuration and driving method that is substantially similar to the first embodiment except for the pixel array unit, and an example of a driving method for a pixel array having two rows and two columns as one unit is described. In this embodiment, the description of elements common to the above-mentioned embodiments may be omitted or simplified.

[0116] In this embodiment, the pixels in the light receiving section 40 are divided into four types of pixel groups. The exposure period for reading out the microframes differs for each pixel group. A specific example will be described with reference to Fig. 15(a) and Fig. 15(b). Fig. 15(a) is a schematic diagram showing the arrangement of pixel groups in a pixel array (pixel arrangement portion of the light receiving section 40) according to this embodiment, and Fig. 15(b) is a drive timing diagram showing the timing of gate pulses (exposure period) according to this embodiment.

[0117] The pixel array of this embodiment includes a first pixel group 327A ("A" in FIG. 15(a)), a second pixel group 327B ("B" in FIG. 15(a)), a third pixel group 327C ("C" in FIG. 15(a)), and a fourth pixel group 327D ("D" in FIG. 15(a)). As shown in FIG. 15(a), the first pixel group 327A, the second pixel group 327B, the third pixel group 327C, and the fourth pixel group 327D form a two-dimensional repeated array with four pixels forming one block.

[0118] "Light Emitted" in FIG. 15(b) indicates the light emission timing of the light emitting unit 20. As shown in FIG. 15(b), the light emitting unit 20 emits light at a constant cycle. This cycle corresponds to the length of one microframe period during which one microframe is acquired. G_A " to "P G_D " indicates the timing of the exposure control signal. G_A ", "P G_B ", "P G_C " and "P G_D " indicate different exposure control signals for controlling the first pixel group 327A, the second pixel group 327B, the third pixel group 327C, and the fourth pixel group 327D, respectively. Hereinafter, a pulse corresponding to a period during which the exposure control signal temporarily becomes high level is referred to as a gate pulse. Gate pulses synchronized with the light emission timing L01 corresponding to the first pixel group 327A, the second pixel group 327B, the third pixel group 327C, and the fourth pixel group 327D are respectively referred to as gate pulses G01, G02, G03, and G04. The gate pulses G01, G02, G03, and G04 become high level after a predetermined time has elapsed since the light emission of the light-emitting unit 20, but the periods during which they become high level within one microframe period are different from each other. In other words, the gate pulses G01, G02, G03, and G04 become high level at the time when the first time, the second time, the third time, and the fourth time, which are different from each other, have elapsed since the light emission of the light-emitting unit 20. The first to fourth times are all shorter than the length of a microframe period.

[0119] In this way, by varying the timing of the gate pulses G01, G02, G03, and G04, it is possible to vary the exposure time in each of the first pixel group 327A, the second pixel group 327B, the third pixel group 327C, and the fourth pixel group 327D. Therefore, it is possible to measure four types of distance measurement points within one microframe period.

[0120] As described above, one subframe is generated by adding up a plurality of microframes. That is, the first pixel group 327A, the second pixel group 327B, the third pixel group 327C, and the fourth pixel group 327D output signals for generating subframes of different distance measurement points. When one subframe is generated, at the start of the next subframe period, the timing of the gate pulse in the first pixel group 327A is gate shifted by a predetermined time interval from the timing of the gate pulse in the current subframe period. Similarly, the second pixel group 327B, the third pixel group 327C, and the fourth pixel group 327D are also gate shifted. By such gate shift, a predetermined period corresponding to each subframe period can be set as an exposure period.

[0121] In this way, by making the exposure time different for each of the multiple pixel groups and performing gate shifting for each of the multiple pixel groups for each subframe period, the number of gate shifts required to measure the required number of ranging points is reduced. This reduces the total period of the multiple subframes, i.e., the length of the frame period. Therefore, it is possible to improve the frame rate without reducing the number of ranging points (distance resolution). As described above, according to this embodiment, a photoelectric conversion device with an improved frame rate is provided.

[0122] In this embodiment, the number of types of pixel groups is set to four, but the number of types of pixel groups may be at least two, and the effect of improving the frame rate can be obtained even if the number is other than four. Also, the number of photoelectric conversion elements included in one pixel group may be at least one. That is, for two photoelectric conversion elements (first photoelectric conversion element and second photoelectric conversion element), the above-mentioned effect can be obtained as long as the first exposure period of the first photoelectric conversion element and the second exposure period of the second photoelectric conversion element are different from each other in one microframe period. Also, the arrangement of the pixel groups is not limited to that shown in FIG. 15(a) and can be changed as appropriate.

[0123] In this embodiment, although the frame rate can be improved by arranging multiple pixel groups, the in-plane resolution of the ranging image may be reduced. Therefore, a method may be further applied in which pixels with missing information in the ranging image are supplemented with surrounding pixels to reduce the effect on the in-plane resolution.

[0124] [Sixth embodiment] In this embodiment, another example of the arrangement of the pixel groups and the timing of the gate pulses described in the fifth embodiment will be described. Descriptions of elements common to the above-mentioned embodiments may be omitted or simplified as appropriate.

[0125] FIG. 16(a) is a schematic diagram showing an arrangement of a pixel group in a pixel array according to this embodiment, and FIG. 16(b) is a drive timing diagram showing the timing of gate pulses according to this embodiment.

[0126] The pixel array of this embodiment includes a first pixel group 328A ("A" in FIG. 16(a)), a second pixel group 328B ("B" in FIG. 16(a)), a third pixel group 328C ("C" in FIG. 16(a)), and a fourth pixel group 328D ("D" in FIG. 16(a)). The first pixel group 328A and the second pixel group 328B are configured to be sensitive to light of a first wavelength. The third pixel group 328C and the fourth pixel group 328D are configured to be sensitive to light of a second wavelength different from the first wavelength. More specifically, a first color filter that transmits light of the first wavelength is arranged in the first pixel group 328A and the second pixel group 328B, and a second color filter that transmits light of the second wavelength is arranged in the third pixel group 328C and the fourth pixel group 328D. Note that the ranges of the first wavelength and the second wavelength in this embodiment may both be, for example, in the infrared region.

[0127] The light-emitting unit 20 of this embodiment is configured to emit light of the first wavelength and light of the second wavelength separately with different cycles. "Light emission (first wavelength)" in FIG. 16(b) indicates the timing of light emission of the first wavelength by the light-emitting unit 20. "Light emission (second wavelength)" in FIG. 16(b) indicates the timing of light emission of the second wavelength by the light-emitting unit 20. As shown in FIG. 16(b), the light of the first wavelength and the light of the second wavelength have different lengths of light emission cycles. In the example of FIG. 16(b), the length of the light emission cycle of the light of the second wavelength is twice the length of the light emission cycle of the light of the first wavelength.

[0128] For the first pixel group 328A and the second pixel group 328B, gate pulses G05 and G06 are input at a timing synchronized with the emission timing L02 of the light of the first wavelength. For the third pixel group 328C and the fourth pixel group 328D, gate pulses G07 and G08 are input at a timing delayed by one period of the emission of the first wavelength from the emission timing L03 of the light of the second wavelength. Therefore, the acquisition period of the microframes for the first pixel group 328A and the second pixel group 328B is different from the acquisition period of the microframes for the third pixel group 328C and the fourth pixel group 328D. By setting in this way, the first pixel group 328A and the second pixel group 328B are used as pixel groups for distance measurement of a short distance (first distance range), and the third pixel group 328C and the fourth pixel group 328D are used as pixel groups for distance measurement of a long distance (second distance range). This makes it possible to measure a plurality of different distance measurement ranges within the same subframe period. In addition, in general, in methods that repeatedly acquire and add microframes of 1-bit signals, the distance measurement range is limited by the repetition period of the light emission pulse, but the method of this embodiment can acquire signals from both short and long distances, making it possible to measure distances over a wide range.

[0129] As described above, according to this embodiment, in addition to obtaining the same effects as the fifth embodiment, a photoelectric conversion device is provided that can simultaneously acquire a plurality of different distance measurement ranges without reducing the frame rate.

[0130] In this embodiment, the bit depth of the signal of the subframe obtained from the pixel group for short distance measurement and the bit depth of the signal of the subframe obtained from the pixel group for long distance measurement may be different from each other. When the number of additions of the signal for short distance measurement is 64 times, a subframe for short distance with 6 bit depth is obtained. In this case, since the number of times of emission of the light of the second wavelength is half the number of times of emission of the light of the first wavelength, the number of times of addition of the signal for long distance measurement is 32 times at most. Therefore, the subframe for long distance has a 5 bit depth. In this way, when the bit depths of the two signals are different, the bit depth may be adjusted.

[0131] In this embodiment, the light emitting unit 20 emits light of two different wavelengths, but it may be three or more. The ratio of the periods of the light of different wavelengths is not limited to two times, and can be set appropriately. Furthermore, the period between the emission timings of the light of the first wavelength is shorter than the period between the emission timings of the light of the second wavelength. Therefore, for example, when an object is approaching, it may be impossible to distinguish between the reflected light based on the n-th emission and the reflected light based on the n+1-th emission. Therefore, it is also possible to control the light intensity of the n-th emission and the light intensity of the n+1-th emission. This makes it possible to distinguish which timing of the emission is the reflected light.

[0132] [Seventh embodiment] 17(a) and 17(b) are block diagrams of devices related to the vehicle-mounted distance measuring device in this embodiment. The device 80 has a distance measuring unit 803, which is an example of the distance measuring device 1 in the above-mentioned embodiment, and a signal processing device (processing device) that processes a signal from the distance measuring unit 803. The device 80 has a distance measuring unit 803 that measures the distance to an object, and a collision determination unit 804 that determines whether or not there is a possibility of collision based on the measured distance. Here, the distance measuring unit 803 is an example of a distance information acquisition means that acquires distance information to the object. That is, the distance information is information related to the distance to the object, etc. The collision determination unit 804 may use the distance information to determine the possibility of collision.

[0133] The device 80 is connected to a vehicle information acquisition device 810, and can acquire vehicle information such as vehicle speed, yaw rate, and steering angle. In addition, the device 80 is connected to a control ECU 820, which is a control device that outputs a control signal to generate a braking force for the vehicle based on the judgment result of the collision judgment unit 804. In addition, the device 80 is also connected to an alarm device 830 that issues an alarm to the driver based on the judgment result of the collision judgment unit 804. For example, when the judgment result of the collision judgment unit 804 indicates that there is a high possibility of a collision, the control ECU 820 performs vehicle control to avoid a collision and reduce damage by applying the brakes, releasing the accelerator, suppressing engine output, etc. The alarm device 830 warns the user by sounding an alarm such as a sound, displaying alarm information on the screen of a car navigation system, etc., and applying vibrations to a seat belt or steering wheel. These devices of the device 80 function as a mobile object control unit that controls the operation of controlling the vehicle as described above.

[0134] In this embodiment, the device 80 measures distances around the vehicle, for example, in front or behind. Fig. 17(b) shows the device when measuring distances in front of the vehicle (distance measurement range 850). A vehicle information acquisition device 810 as a distance measurement control means sends an instruction to the device 80 or distance measurement unit 803 to perform a distance measurement operation. With this configuration, the accuracy of distance measurement can be further improved.

[0135] Although the above describes an example of control to prevent collision with other vehicles, the present invention can also be applied to control of automatic driving by following other vehicles, control of automatic driving to prevent deviation from lanes, etc. Furthermore, the device is not limited to vehicles such as automobiles, but can be applied to moving bodies (moving devices) such as ships, aircraft, artificial satellites, industrial robots, and consumer robots. In addition, the present invention can be applied to devices that use object recognition or biometric recognition, such as intelligent transport systems (ITS) and surveillance systems, in addition to moving bodies.

[0136] [Modified embodiment] The present invention is not limited to the above-described embodiments and can be modified in various ways. For example, an example in which a part of the configuration of any of the embodiments is added to another embodiment, or an example in which a part of the configuration of any of the embodiments is replaced with a part of the configuration of another embodiment, is also an embodiment of the present invention.

[0137] The disclosure of this specification includes the complement of the concepts described in this specification. In other words, if the specification states, for example, that "A is B" (A=B), the specification is deemed to disclose or suggest that "A is not B" even if the statement that "A is not B" (A≠B) is omitted. This is because when it states that "A is B," it is assumed that the case that "A is not B" is taken into consideration.

[0138] The disclosure of this specification includes the following configurations. (Configuration 1) a light receiving section including a plurality of pixels each of which generates a signal based on incident light; a plurality of pixel control units each controlling an exposure period during which a signal is generated based on the incident light in a corresponding pixel among the plurality of pixels; having the plurality of pixel control units include a first pixel control unit and a second pixel control unit, the first pixel control unit controls a first exposure period of a first pixel among the plurality of pixels based on a first exposure control signal, generates a second exposure control signal by delaying the first exposure control signal, and outputs the second exposure control signal to the second pixel control unit; The second pixel control unit controls a second exposure period of a second pixel of the plurality of pixels based on the second exposure control signal. A photoelectric conversion device comprising: (Configuration 2) The second pixel control unit controls the second exposure period based on the second exposure control signal so that a start time of the second exposure period is later than a start time of the first exposure period. 2. The photoelectric conversion device according to configuration 1. (Configuration 3) the second pixel control unit has a selection circuit that enables one of the first exposure control signal and the second exposure control signal based on a selection signal; when the first exposure control signal is enabled, the second pixel control unit controls the second exposure period based on the first exposure control signal so that a start time of the second exposure period coincides with a start time of the first exposure period; When the second exposure control signal is enabled, the second pixel control unit controls the second exposure period based on the second exposure control signal so that a start time of the second exposure period is later than a start time of the first exposure period. 2. The photoelectric conversion device according to configuration 1. (Configuration 4) Each of the plurality of pixel control units has the selection circuit, The selection signal having a common level is input to the selection circuit of each of the plurality of pixel control units. 4. The photoelectric conversion device according to configuration 3. (Configuration 5) A light emitting portion; a control unit that controls the timing of light emission in the light emitting unit and the first pixel control unit; Further comprising 5. The photoelectric conversion device according to any one of configurations 1 to 4. (Configuration 6) The control unit outputs the first exposure control signal to the first pixel control unit so that the first exposure period starts simultaneously with a timing of light emission in the light emitting unit or after a predetermined time has elapsed. 6. The photoelectric conversion device according to configuration 5. (Configuration 7) a frequency distribution holding unit that holds a frequency distribution based on a frequency of a signal based on the incident light in the first exposure period and a frequency of a signal based on the incident light in the second exposure period. 7. The photoelectric conversion device according to any one of configurations 1 to 6. (Configuration 8) One of the plurality of pixel control units controls exposure periods of two or more pixels to be the same; The frequency distribution holding unit sets the frequencies of the signals output from the two or more pixels as a common class in the frequency distribution. 8. The photoelectric conversion device according to configuration 7. (Configuration 9) The pixels are arranged in a plurality of rows and a plurality of columns, The first pixel and the second pixel are arranged in the same row but in different columns. 9. The photoelectric conversion device according to any one of configurations 1 to 8. (Configuration 10) the first pixel control unit is arranged to supply the first exposure control signal to two or more pixels in a first column including the first pixel; The second pixel control unit is arranged to supply the second exposure control signal to two or more pixels in a second column including the second pixel. 10. The photoelectric conversion device according to configuration 9. (Configuration 11) Further, an AND circuit is provided corresponding to each of the plurality of pixels, The third exposure control signal and the first exposure control signal are input to the AND circuit of the first column, The third exposure control signal and the second exposure control signal are input to the AND circuit of the second column. 11. The photoelectric conversion device according to configuration 10. (Configuration 12) The third exposure control signal is input in common to a plurality of the AND circuits in one row. 12. The photoelectric conversion device according to claim 11, (Configuration 13) the third exposure control signal is commonly input to the AND circuits in a first row of the plurality of rows, the delayed third exposure control signal is input to the AND circuits in a second row of the rows; 13. The photoelectric conversion device according to configuration 11 or 12. (Configuration 14) The interval between the start time of the first exposure period and the start time of the second exposure period is equal to the length of the first exposure period. 14. The photoelectric conversion device according to any one of configurations 1 to 13. (Configuration 15) The length of the first exposure period is equal to the length of the second exposure period. 15. The photoelectric conversion device according to any one of configurations 1 to 14. (Configuration 16) The plurality of pixels include pixels sensitive to light of a first wavelength and pixels sensitive to light of a second wavelength different from the first wavelength. 16. The photoelectric conversion device according to any one of configurations 1 to 15. (Configuration 17) The plurality of pixels generate signals for distance measurement in a first distance range based on the light of the first wavelength, and generate signals for distance measurement in a second distance range different from the first distance range based on the light of the second wavelength. 17. The photoelectric conversion device according to claim 16, (Configuration 18) A period in which a signal for measuring distance in the first distance range is generated is different from a period in which a signal for measuring distance in the second distance range is generated. 18. The photoelectric conversion device according to claim 17, (Configuration 19) The first wavelength and the second wavelength are both in the infrared region. 19. The photoelectric conversion device according to any one of configurations 16 to 18. (Configuration 20) A mobile object, The photoelectric conversion device according to any one of configurations 1 to 19, a moving object control unit that controls the moving object based on distance information acquired by the photoelectric conversion device; A moving object comprising:

[0139] The present invention can also be realized by a process in which a program for implementing one or more of the functions of the above-described embodiments is supplied to a system or device via a network or a storage medium, and one or more processors in a computer of the system or device read and execute the program. The present invention can also be realized by a circuit (e.g., ASIC) for implementing one or more of the functions.

[0140] It should be noted that the above-mentioned embodiments are merely examples of the implementation of the present invention, and the technical scope of the present invention should not be interpreted as being limited by these embodiments. In other words, the present invention can be implemented in various forms without departing from its technical concept or main features. [Explanation of symbols]

[0141] 1 Ranging device 40 Light receiving part 41 pixels 42 Pixel control unit

Claims

1. A light-receiving unit including multiple pixels, each of which generates a signal based on incident light, A plurality of pixel control units, each controlling the exposure period during which a signal based on the incident light is generated in a corresponding pixel among the plurality of pixels, It has, The plurality of pixel control units include a first pixel control unit and a second pixel control unit, The first pixel control unit controls the first exposure period for the first pixel among the plurality of pixels based on the first exposure control signal, generates a second exposure control signal by delaying the first exposure control signal, and outputs it to the second pixel control unit. The second pixel control unit controls the second exposure period for the second pixel among the plurality of pixels based on the second exposure control signal. The second pixel control unit has a selection circuit that activates either the first exposure control signal or the second exposure control signal based on a selection signal. When the first exposure control signal is enabled, the second pixel control unit controls the second exposure period based on the first exposure control signal so that the start time of the second exposure period coincides with the start time of the first exposure period. When the second exposure control signal is enabled, the second pixel control unit controls the second exposure period based on the second exposure control signal such that the start time of the second exposure period is later than the start time of the first exposure period. A photoelectric conversion device characterized by the following features.

2. Each of the plurality of pixel control units has the selection circuit, Each of the selection circuits in the plurality of pixel control units is input to the selection signal at a common level. The photoelectric conversion device according to feature 1.

3. Light-emitting part, A control unit that controls the timing of light emission in the light-emitting unit and the first pixel control unit, It further possesses The photoelectric conversion device according to feature 1.

4. The control unit outputs the first exposure control signal to the first pixel control unit so that the first exposure period starts simultaneously with the timing of light emission in the light-emitting unit or after a predetermined time has elapsed. The photoelectric conversion device according to feature 3.

5. The device further includes a frequency distribution holding unit that holds a frequency distribution based on the frequency of the signal based on the incident light during the first exposure period and the frequency of the signal based on the incident light during the second exposure period. The photoelectric conversion device according to feature 1.

6. One of the plurality of pixel control units controls the exposure period of two or more pixels to be the same, The frequency distribution holding unit sets the frequencies of the signals output from the two or more pixels as a common class in the frequency distribution. The photoelectric conversion device according to feature 5.

7. The aforementioned plurality of pixels are arranged to form a plurality of rows and a plurality of columns, The first pixel and the second pixel are located in different columns of the same row. The photoelectric conversion device according to feature 1.

8. The first pixel control unit is configured to supply the first exposure control signal to two or more pixels in the first row, including the first pixel. The second pixel control unit is configured to supply the second exposure control signal to two or more pixels in the second row, which includes the second pixel. The photoelectric conversion device according to feature 7.

9. The system further includes AND circuits arranged in correspondence to each of the aforementioned plurality of pixels, The AND circuit in the first row receives the third exposure control signal and the first exposure control signal. The second row of the AND circuit receives the third exposure control signal and the second exposure control signal. The photoelectric conversion device according to feature 8.

10. The third exposure control signal is input in common to multiple AND circuits in one row. The photoelectric conversion device according to feature 9.

11. The third exposure control signal is commonly input to the multiple AND circuits in the first row of the multiple rows. The delayed third exposure control signal is input to the multiple AND circuits in the second row of the multiple rows. The photoelectric conversion device according to feature 10.

12. The interval between the start time of the first exposure period and the start time of the second exposure period is equal to the length of the first exposure period. The photoelectric conversion device according to feature 1.

13. The length of the first exposure period is equal to the length of the second exposure period. The photoelectric conversion device according to feature 1.

14. The plurality of pixels include pixels that are sensitive to light of a first wavelength and pixels that are sensitive to light of a second wavelength different from the first wavelength. The photoelectric conversion device according to feature 1.

15. The plurality of pixels generate a distance measuring signal for a first distance range based on light of a first wavelength, and generate a distance measuring signal for a second distance range different from the first distance range based on light of a second wavelength. The photoelectric conversion device according to feature 14.

16. The period during which the distance measurement signal for the first distance range is generated and the period during which the distance measurement signal for the second distance range is generated are different from each other. The photoelectric conversion device according to feature 15.

17. Both the first and second wavelengths are in the infrared region. The photoelectric conversion device according to feature 14.

18. It is a mobile object, A photoelectric conversion device according to any one of claims 1 to 17, A mobile body control unit that controls the mobile body based on distance information acquired by the photoelectric converter, A mobile body characterized by having the following features.

Images