Photoelectric conversion device, imaging system, and mobile body

Abstract

This photoelectric conversion device is characterized by comprising: a light receiving unit of which an applied voltage is controlled by means of recharge pulses and which converts incident light into a light reception pulse; a first counting unit for generating a first count value by using the light reception pulse in a period from a first recharge pulse to a second recharge pulse among the recharge pulses; and a second counting unit to which a detection pulse that becomes active in a part of the period and becomes inactive in another part of the period is input, wherein the second counting unit generates a second count value by using the light reception pulse and the detection pulse in the period.

Description

Photoelectric conversion device, imaging system, mobile object

[0001] The present invention relates to a photoelectric conversion device, an imaging system, and a moving object.

[0002] Photon counting type photoelectric conversion devices are known that digitally count the number of photons incident on a photodetector that performs avalanche multiplication and output the counted value as a digital signal from a pixel. A representative example of this technology is called SPAD (Single Photon Avalanche Diode).

[0003] Patent Document 1 describes a device that detects the incidence of photons by detecting pulses output from an avalanche photodiode during the period between periodically repeated pulses, and performs imaging. This device counts the number of times a result indicating the incidence of photons is obtained, thereby obtaining a count value corresponding to the number of photons incident on a pixel.

[0004] JP 2020-123847 A

[0005] However, when capturing an image of a subject whose brightness changes frequently within a period in which avalanche growth may occur, it may not be possible to obtain pixel values ​​that reflect the actual conditions of the subject as viewed.

[0006] In order to achieve the above object, one aspect of the present invention is a photoelectric conversion device having a light receiving unit whose applied voltage is controlled by a recharge pulse and which converts incident light into a light receiving pulse, a first counting unit which generates a first count value using the light receiving pulse from the recharge pulse during a period from a first recharge pulse to a second recharge pulse, and a second counting unit which receives a detection pulse which is active during a portion of the period and inactive during another portion of the period, wherein the second counting unit generates a second count value using the light receiving pulse and the detection pulse during the period.

[0007] Another aspect of the present invention is a photoelectric conversion device having a light receiving unit whose applied voltage is controlled by a recharge pulse and which converts incident light into a received light pulse, a counting unit which performs either a first counting process or a second counting process, and a switching unit which has the function of switching between the first counting process and the second counting process by a switching signal, wherein the first counting process changes the count value in accordance with the generation of the received light pulse in the period from the first recharge pulse to the second recharge pulse among the recharge pulses, and the second counting process changes the count value in accordance with the received light pulse and a detection pulse which is active for a part of the period and inactive for another part of the period.

[0008] According to the present invention, it is possible to create correction values ​​according to the imaging results.

[0009] 1 is a schematic diagram of a photoelectric conversion device according to an embodiment; FIG. 2 is a schematic diagram of a pixel substrate of a photoelectric conversion device according to an embodiment; FIG. 3 is a schematic diagram of a circuit board of a photoelectric conversion device according to an embodiment; FIG. 4 is a configuration example of a pixel circuit of a photoelectric conversion device according to an embodiment; FIG. 5 is a schematic diagram showing driving of a pixel circuit of a photoelectric conversion device according to an embodiment; FIG. 6 is a block diagram showing a configuration example of an imaging device according to a first embodiment; FIG. 7 is a timing chart of imaging processing in the first embodiment; FIG. 8 is a block diagram showing a configuration example of a detection count unit in the first embodiment; FIG. 9 is a diagram explaining correction values ​​used for processing by a pixel value correction unit in the first embodiment; FIG. 10 is a block diagram showing a configuration example of an imaging device according to a second embodiment; FIG. 11 is a timing chart of imaging processing in the second embodiment; FIG. 12 is a block diagram showing a configuration example of a count unit in the second embodiment; FIG. 13 is a functional block diagram of a photoelectric conversion system according to a third embodiment; FIG. 14 is a functional block diagram of a photoelectric conversion system according to the third embodiment;

[0010] The embodiments shown below are intended to embody the technical concept of the present invention and are not intended to limit the present invention. The size and positional relationship of components shown in each drawing may be exaggerated for clarity. In the following description, the same components may be designated by the same reference numerals and their description may be omitted.

[0011] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the following description, terms indicating specific directions or positions (for example, "upper," "lower," "right," "left," and other terms including these terms) will be used as necessary. The use of these terms is intended to facilitate understanding of the embodiments with reference to the drawings, and the meaning of these terms does not limit the technical scope of the present invention.

[0012] In this specification, a planar view refers to a view from a direction perpendicular to the light incident surface of the semiconductor layer. A cross-sectional view refers to a surface perpendicular to the light incident surface of the semiconductor layer. When the light incident surface of the semiconductor layer is a rough surface when viewed microscopically, the planar view is defined based on the light incident surface of the semiconductor layer when viewed macroscopically.

[0013] In this specification, when the term "impurity concentration" is simply used, it means the net impurity concentration minus the amount compensated by impurities of the opposite conductivity type. In other words, "impurity concentration" refers to the net doping concentration. A region where the concentration of P-type added impurities is higher than the concentration of N-type added impurities is a P-type semiconductor region. Conversely, a region where the concentration of N-type added impurities is higher than the concentration of P-type added impurities is an N-type semiconductor region.

[0014] Furthermore, in the following embodiments, connections between elements of a circuit may be described. In this case, even if another element is interposed between the elements of interest, the elements of interest are treated as being connected to each other unless otherwise specified. For example, assume that element A is connected to one node of a capacitive element C having multiple nodes, and element B is connected to the other node. Even in such a case, element A and element B are treated as being connected to each other unless otherwise specified.

[0015] A configuration common to each embodiment of a photoelectric conversion device and a driving method thereof according to the present invention will be described with reference to FIGS. 1 to 5A and 5B.

[0016] FIG. 1 is a diagram showing the configuration of a photoelectric conversion device 100 according to an embodiment of the present invention. The following description will be given taking as an example a case where the photoelectric conversion device 100 is a stacked-type photoelectric conversion device. That is, the description will be given taking as an example a photoelectric conversion device configured by stacking and electrically connecting two substrates, a sensor substrate 11 and a circuit substrate 21. However, the photoelectric conversion device is not limited to this. For example, the photoelectric conversion device may be one in which the components included in the sensor substrate 11 and the components included in the circuit substrate are arranged on a common semiconductor layer, as described below. Hereinafter, a photoelectric conversion device in which the components included in the sensor substrate 11 and the components included in the circuit substrate are arranged on a common semiconductor layer will also be referred to as a non-stacked photoelectric conversion device.

[0017] The sensor substrate 11 has a first semiconductor layer having photoelectric conversion elements 102 (described later) and a first wiring structure. The circuit board 21 has a second semiconductor layer having circuits such as a signal processing circuit 103 (described later) and a second wiring structure. The photoelectric conversion device 100 is configured by laminating the second semiconductor layer, the second wiring structure, the first wiring structure, and the first semiconductor layer in this order.

[0018] 1 illustrates a back-illuminated photoelectric conversion device in which light is incident from a first surface and a circuit board is disposed on a second surface opposite the first surface. In the case of a non-stacked photoelectric conversion device, the surface on which the transistors of the signal processing circuit are disposed is referred to as the second surface. In the case of a back-illuminated photoelectric conversion device, the first surface opposite the second surface of the semiconductor layer serves as the light incident surface. In the case of a front-illuminated photoelectric conversion device, the second surface of the semiconductor layer serves as the light incident surface.

[0019] In the following description, the sensor substrate 11 and the circuit substrate 21 are described as diced chips, but are not limited to chips. For example, each substrate may be a wafer. Furthermore, each substrate may be stacked in the wafer state and then diced, or each chip may be stacked and bonded after being formed into chips.

[0020] The sensor substrate 11 has a pixel region 12 arranged thereon, and the circuit substrate 21 has a circuit region 22 arranged thereon for processing signals detected in the pixel region 12 .

[0021] 2 is a layout diagram of the sensor chip 11. Pixels 101, each having a photoelectric conversion unit 102 including an avalanche photodiode (hereinafter, referred to as an APD), are arranged two-dimensionally to form a pixel region 12.

[0022] The pixel 101 is typically a pixel for forming an image, but when used for TOF (Time of Flight), it does not necessarily have to form an image. That is, the pixel 101 may be a pixel for measuring the time and amount of light that arrives.

[0023] 3 is a configuration diagram of the circuit chip 21. It has a signal processing unit 103 that processes the charges photoelectrically converted by the photoelectric conversion unit 102 in FIG. 2, a readout circuit 112, a control pulse generation unit 115, a horizontal scanning circuit unit 111, signal lines 113, and a vertical scanning circuit unit 110.

[0024] The photoelectric conversion unit 102 in FIG. 2 and the signal processing unit 103 in FIG. 3 are electrically connected via connection wiring provided for each pixel.

[0025] The vertical scanning circuit section 110 receives the control pulses supplied from the control pulse generating section 115 and supplies the control pulses to each pixel. The vertical scanning circuit section 110 uses logic circuits such as a shift register and an address decoder.

[0026] The control pulse generation unit 115 includes a signal generation unit 215 that generates a control signal P_CLK for the switch, as described below. The signal generation unit 215 generates a pulse signal for controlling the switch, as described below. For example, as shown in FIG. 4( a), the signal generation unit 215 may generate a common control signal P_CLK for multiple pixels in the pixel region. Alternatively, as shown in FIG. 4( b), the signal generation unit 215 may generate a control signal P_CLK for each pixel. When generating a common pulse signal P_CLK, at least one of the period, number of pulses, and pulse width of the signal P_EXP that controls the exposure period is generated in common to correspond to the exposure period. Furthermore, when controlling the control signal P_CLK for each pixel, a signal can be generated using both the input signal P_CLK_IN output from the control pulse generation unit 115 and the signal P_EXP that controls the exposure period. The control pulse generation unit 115 preferably includes, for example, a frequency divider circuit. This simplifies control and reduces the need for an increased number of elements.

[0027] The signal output from the photoelectric conversion unit 102 of each pixel is processed by the signal processing unit 103. The signal processing unit 103 is provided with a counter, a memory, etc., and digital values ​​are held in the memory.

[0028] The horizontal scanning circuit unit 111 inputs a control pulse to the signal processing unit 103 to sequentially select each column in order to read out the signal from the memory of each pixel in which the digital signal is held.

[0029] A signal is output to the signal line 113 from the signal processing unit 103 of the pixel selected by the vertical scanning circuit unit 110 for the selected column.

[0030] The signal output to the signal line 113 is output via an output circuit 114 to a recording unit or a signal processing unit outside the photoelectric conversion device 100 .

[0031] 2 , the pixels 100 may be arranged one-dimensionally in the pixel region 12. The function of the signal processing unit 103 does not necessarily need to be provided for each pixel 101, and for example, one signal processing unit 103 may be shared by multiple pixels 101, and signal processing may be performed sequentially.

[0032] Fig. 4 is an example of a block diagram including the equivalent circuits of Fig. 2 and Fig. 3. In Fig. 2, the photoelectric conversion unit 102 having the APD 201 is provided on the sensor chip 11, and the other members are provided on the circuit chip 21.

[0033] The APD 201 generates charge pairs in response to incident light through photoelectric conversion. A voltage VL (first voltage) is supplied to the anode of the APD 201. A voltage VH (second voltage) higher than the voltage VL supplied to the anode is supplied to the cathode of the APD 201. A reverse bias voltage is supplied to the anode and cathode so that the APD 201 performs avalanche multiplication. With such a voltage supplied, the charge generated by the incident light undergoes avalanche multiplication, generating an avalanche current.

[0034] When a reverse bias voltage is supplied, the APD can be operated in either a Geiger mode, where the potential difference between the anode and cathode is greater than the breakdown voltage, or a linear mode, where the potential difference between the anode and cathode is close to or less than the breakdown voltage. An APD operated in the Geiger mode is called a SPAD. 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 the linear mode or the Geiger mode. The potential difference in a SPAD is greater than that in a linear mode APD, and the effect of withstanding voltage is significant.

[0035] The switch 202 is connected to a control line to which a drive voltage VH is supplied and to the APD 201. The switch 202 is connected to one of the anode and cathode nodes of the APD.

[0036] The switch 202 switches the potential difference between the anode and cathode of the APD between a first potential difference that causes avalanche multiplication and a second potential difference that does not cause avalanche multiplication. Hereinafter, switching from the second potential difference to the first potential difference is referred to as "on" of the switch 202, and switching from the first potential difference to the second potential difference is referred to as "off" of the switch 202. The switch 202 functions as a quenching element. The switch 202 functions as a load circuit (quenching circuit) during signal multiplication by avalanche multiplication, suppressing the voltage supplied to the APD 201 and suppressing avalanche multiplication (quenching operation). The switch 202 also functions to return the voltage supplied to the APD 201 to the drive voltage VH by flowing a current equivalent to the voltage drop caused by the quenching operation (recharge operation). That is, the switch 202 functions as a control circuit that controls the generation of avalanche multiplication in the APD 201.

[0037] The switch 202 can be configured, for example, by a MOS transistor. A control signal P_CLK for the switch 202, supplied from the signal generating unit 215, is applied to the gate electrode of the MOS transistor that configures the switch 202. In this embodiment, the on / off state of the switch 202 is controlled by controlling the voltage applied to the gate electrode of the switch 202.

[0038] The signal processing unit 103 has a waveform shaping unit 210, a counter circuit 211, and a selection circuit 212. In this specification, it is sufficient that the signal processing unit 103 has at least one of the waveform shaping unit 210, the counter circuit 211, and the selection circuit 212.

[0039] The waveform shaping unit 210 shapes the potential change at the cathode of the APD 201 obtained upon photon detection and outputs a pulse signal. The node on the input side of the waveform shaping unit 210 is designated nodeA, and the node on the output side is designated nodeB. The waveform shaping unit 210 changes the output potential from node nodeB depending on whether the input potential to node nodeA is equal to or higher than a predetermined value or lower. For example, in FIGS. 5A and 5B , when the input potential to node nodeA is equal to or higher than a determination threshold, the output potential from node nodeB becomes low. When the input potential to node nodeA is lower than the determination threshold, the output potential from node nodeB becomes high. For example, an inverter circuit is used as the waveform shaping unit 210. While FIG. 4 shows an example in which a single inverter is used as the waveform shaping unit 210, a circuit in which multiple inverters are connected in series or another circuit with a waveform shaping effect may also be used.

[0040] Although it is possible to perform a quench operation and a recharge operation using the switch 202 in response to avalanche multiplication in the APD 201, depending on the timing of photon detection, the charge generated in the APD may not be determined as an output signal. For example, assume that avalanche multiplication occurs in the APD, causing the node nodeA to go low, and a recharge operation is being performed. Generally, the decision threshold of the waveform shaping unit 210 is set to a potential higher than the potential difference at which avalanche multiplication occurs in the APD. When a photon is incident on the APD when the potential of the node nodeA is lower than the decision threshold due to the recharge operation and is at a potential at which avalanche multiplication is possible in the APD, avalanche multiplication occurs in the APD, and the voltage of nodeA drops. In other words, because the potential of nodeA drops at a voltage lower than the decision threshold, no potential change occurs across the decision threshold, and the output potential from node nodeB does not change. Therefore, even though avalanche multiplication is occurring, photon detection is not determined as a signal. Particularly under high illuminance, photons enter the APD continuously in a short period of time, making it difficult for the incident light to be recognized as a signal. As a result, even under high illuminance, the actual number of incident photons tends to diverge from the output signal.

[0041] In contrast, by applying a control signal P_CLK to the switch 202 to switch the switch 202 between its on and off states, it is possible to determine a signal even when photons continuously enter the APD in a short period of time. Figures 5A and 5B illustrate an example in which the control signal P_CLK is a pulse signal with a repetitive cycle. In other words, Figures 5A and 5B illustrate a configuration in which the switch 202 is switched on and off at a predetermined clock frequency. However, the effect of suppressing an increase in power consumption of a photoelectric conversion device can be obtained even if the pulse signal is not a signal with a repetitive cycle.

[0042] The counter circuit 211 counts the pulse signal output from the waveform shaping unit 210 and holds the count value. When a control pulse pRES is supplied via a drive line 213, the signal held in the counter circuit 211 is reset.

[0043] 1 via a drive line 214 (not shown in FIG. 3 ) in FIG. 4 , and switches between electrical connection and disconnection between the counter circuit 211 and the signal line 113. The selection circuit 212 includes, for example, a buffer circuit for outputting a signal.

[0044] The electrical connection may be switched by disposing a switch such as a transistor between the switch 202 and the APD 201 or between the photoelectric conversion unit 102 and the signal processing unit 103. Similarly, the supply of the voltage VH or the voltage VL to the photoelectric conversion unit 102 may be electrically switched using a switch such as a transistor.

[0045] 5A and 5B are diagrams schematically illustrating the relationship between the control signal P_CLK of the switch, the potential of node nodeA, the potential of node nodeB, and the output signal. In this embodiment, when the control signal P_CLK is at a high level, the drive voltage VH is not easily supplied to the APD, and when the control signal P_CLK is at a low level, the drive voltage VH is supplied to the APD. The high level of the control signal P_CLK is, for example, 1 V, and the low level of the control signal P_CLK is, for example, 0 V. When the control signal P_CLK is at a high level, the switch is turned off, and when the control signal P_CLK is at a low level, the switch is turned on. The resistance value of the switch when the control signal P_CLK is at a high level is higher than the resistance value of the switch when the control signal P_CLK is at a low level. When the control signal P_CLK is at a high level, recharging is not easily performed even if avalanche multiplication occurs in the APD, so the potential supplied to the APD is a potential equal to or lower than the breakdown voltage of the APD. Therefore, the avalanche multiplication operation in the APD stops.

[0046] As shown in Figure 5A, it is preferable to configure the switch 202 using a single transistor, and to perform the quenching operation and the recharging operation using a single transistor. This makes it possible to reduce the number of circuits compared to when the quenching operation and the recharging operation are performed using different circuit elements. In particular, when each pixel has a counter circuit and the SPAD signal is read out for each pixel, it is preferable to reduce the circuit area used for the switch in order to accommodate the counter circuit, and the effect of configuring the switch 202 using a single transistor is significant.

[0047] At time t1, the control signal P_CLK changes from high to low, turning on the switch and starting the recharge operation of the APD. This causes the potential of the cathode of the APD to transition to high. Then, the potential difference between the potentials applied to the anode and cathode of the APD becomes a state in which avalanche multiplication is possible. The potential of the cathode is the same as that of node nodeA. Therefore, when the potential of the cathode transitions from low to high, the potential of node nodeA becomes equal to or greater than the determination threshold at time t2. At this time, the pulse signal output from node nodeB is inverted, transitioning from high to low. After that, a potential difference of drive voltage VH-drive voltage VL is applied to the APD 201. The control signal P_CLK transitions to high, turning off the switch.

[0048] Next, at time t3, when a photon is incident on APD 201, avalanche multiplication occurs in APD 201, and the voltage at the cathode drops. That is, the voltage at node nodeA drops. When the amount of voltage drop further increases and the voltage difference applied to APD 201 decreases, avalanche multiplication in APD 201 stops, as at time t2, and the voltage level at node nodeA does not drop by more than a certain value. When the voltage at node nodeA drops below the decision threshold, the voltage at node nodeB changes from low to high. That is, the portion of the output waveform at node nodeA that exceeds the decision threshold is waveform-shaped by waveform shaping unit 210 and output as a signal at node B. The portion is then counted by the counter circuit, and the count value of the counter signal output from the counter circuit increases by 1 LSB.

[0049] Between time t3 and time t4, photons are incident on the APD, but the switch is in the off state and the voltage applied to the APD 201 does not have a potential difference that allows avalanche multiplication, so the voltage level of node nodeA does not exceed the decision threshold.

[0050] At time t4, the control signal P_CLK changes from high to low, turning on the switch. Accordingly, a current compensating for the voltage drop from the drive voltage VH flows through node nodeA, causing the voltage at node nodeA to transition back to its original voltage level. At this time, at time t5, the voltage at node nodeA becomes equal to or greater than the determination threshold, causing the pulse signal at node nodeB to invert and transition from high to low.

[0051] At time t6, node nodeA is stabilized to its original voltage level, and the control signal P_CLK changes from low to high. Therefore, the switch is turned off. Thereafter, as described from time t1 to time t6, the potentials of the nodes and signal lines change in response to the control signal P_CLK and the incidence of photons.

[0052] The photoelectric conversion devices of the respective embodiments will be described below.

[0053] (First embodiment) A first embodiment realized by the present invention will be described with reference to Figures 6 to 8. Note that the configurations shown in the following embodiments are merely examples, and the present invention is not limited to the configurations shown in the drawings.

[0054] 6 is a diagram showing an example of the configuration of a photoelectric conversion device 605. The photoelectric conversion device 605 has a light receiving unit 601, a first counting unit 602, a second counting unit 603, and a pixel value correcting unit 604.

[0055] The light receiving unit 601 has the function of photoelectrically converting the received light into a received light pulse. The function of converting light into a received light pulse is realized by a photoelectric conversion element such as the avalanche photodiode described above. The APD 201, switch 202, and waveform shaping unit 210 shown in Figure 4 correspond to the light receiving unit 601, and a clock signal is input to the switch 202 as a recharge pulse.

[0056] The first counting unit 602 has a function of counting the number of light-receiving pulses output from the light-receiving unit 601. In other words, the first counting unit 602 corresponds to the counter circuit 211 in Fig. 4. The pixel count value obtained as a result of this counting is defined as a first count value.

[0057] The second counting unit 603 counts the number of detected photons using the light receiving pulses and detection pulses output by the light receiving unit 601. The detection count value resulting from this counting is called the second count value.

[0058] Furthermore, the pixel value correcting unit 604 corrects the first count value using the second count value, and outputs the corrected value as a pixel value from the photoelectric conversion device 605 .

[0059] 2 , when the light receiving units 601 form a pixel array arranged in multiple rows and multiple columns, the first counting unit 602, the second counting unit 603, and the pixel value correcting unit 604 are also arranged in multiple rows and multiple columns. The second counting unit 603 and the pixel value correcting unit 604 are not limited to being arranged in an array corresponding to the pixel array, and any number of them may be mounted, for example, around the pixel array. In this case, one second counting unit 603 or one pixel value correcting unit 604 may be shared and operated among multiple light receiving units 601.

[0060] Furthermore, correction processing by the pixel value correction unit 604 may be performed by pipeline processing in the periphery of the pixel array while reading out the data held in the first count unit 602 and the second count unit 603. In the description of FIG. 6 , the photoelectric conversion device 605 has the pixel value correction unit 604, but the pixel value correction unit 604 may be implemented outside the photoelectric conversion device 605.

[0061] In this way, by implementing fewer second counting units 603 and pixel value correcting units 604 than the number of light receiving units 601, the circuit scale of the photoelectric conversion device 605 can be reduced.

[0062] Next, the flow of operations from the generation of a light-receiving pulse by the light-receiving unit 601 in FIG. 6 to the first counting unit 602 and the second counting unit 603 will be described in detail using the timing chart in FIG.

[0063] 7A illustrates the relationship between time and light intensity of a light source that is a subject. This light source has a cyclical sequence of high and low light intensity periods. For example, the light source is an LED light source that uses PWM (Pulse Width Modulation) dimming. An example will be described in which the ratio of high light intensity periods to a unit period (hereinafter referred to as the duty ratio) is 10%.

[0064] (B) in FIG. 7 shows a recharge pulse input to the light receiving unit 601. The avalanche photodiode is recharged during the high period of this pulse. This allows for the formation of continuous exposure periods as shown in (C) in FIG. 7. One exposure period from the first recharge pulse to the second recharge pulse is called a subframe. At time t701 during subframe 1, the light receiving unit 601 receives photons irradiated from the light source (A) and generates a received light pulse as shown in (D) in FIG. 7. At this time, as shown in (E) in FIG. 7, the first count value of the first counting unit 602 is incremented by one.

[0065] Note that the counting method is not limited to this, and the first counter may add a value other than 1 corresponding to one received light pulse, and the amount of change in the count may be changed depending on when the received light pulse occurs during an arbitrary exposure period. For example, if a received light pulse occurs early during an arbitrary exposure period, the subject is considered to be in a bright state, and the pixel value corrector 604 corrects the count value of the first counter to a larger value. Conversely, if a received light pulse occurs late during an arbitrary exposure period, the subject is considered to be in a dark state, and the pixel value corrector 604 corrects the count value of the first counter to a smaller value. An example will be described in which there are 1000 subframes during an exposure period. Let n be the value added to the first count value in response to received light pulses during the period from subframe 1 to subframe 500, which is the period before the center timing of the exposure period. Let m be the value added to the first count value in response to received light pulses during the period from subframe 501 to subframe 1000, which is the period after the center timing of the exposure period. In this case, n is greater than m.

[0066] When it is desired to improve the sensitivity of the photoelectric conversion device, a value greater than 1 may be added to the count value of the first count unit. Furthermore, when it is desired to improve HDR performance, the value added to the count value of the first count unit may be changed depending on the timing at which the pulse rises during the subframe period.

[0067] In the example of Fig. 7, there are 1000 subframes, and one light-receiving pulse is generated in each subframe, and the value of the first count unit is incremented by 1. By changing the increment value according to the timing of light reception described above, it is possible to obtain pixel values ​​that correspond to the actual state of the subject as seen by the human eye to some extent.

[0068] 7 shows an example in which one or more photons are received in each subframe, but there may be subframes in which no photons are received depending on the shooting conditions. However, in the case of a light source whose brightness changes frequently between subframes, an extremely large number of photons may flow into the light receiving unit 601 during a specific subframe period, which may result in pixel values ​​that do not reflect the actual state of the subject as seen by the human eye.

[0069] To solve this problem, as shown in (F) of Fig. 7, a detection pulse that is active (high) for only a part of the subframe period and inactive (low) for the other period is input to the second count unit 603. The detection pulse may be generated within the imaging device or input from outside the imaging device. It may also be generated in synchronization with the recharge pulse.

[0070] An example of the configuration of the second counting unit is shown in Fig. 8. The light receiving pulse, which is input from the light receiving unit 601, and the detection pulse are input to an AND circuit 801, and the output of the AND circuit 801 is input to a counter circuit 802.

[0071] With this circuit configuration, the second counting unit 103 can count the detection number count value, which is the logical product of the light receiving pulse and the detection pulse, as shown in FIG. 7(G).

[0072] In the example shown in FIG. 7, the detection pulse goes high at the earliest timing in the subframe period, so the number of subframes in which the light amount of the light source is high is counted as the second count value.

[0073] As at time t701, at time t702, the first count value and the second count value are each incremented by one.

[0074] At times t703, t704, and t705, the light intensity of the light source is low and the rise of the light-receiving pulse is slow, so the detection pulse is low. That is, the first count value is incremented, but the second count value is not incremented.

[0075] At times t706 and t707, the operation of adding count values ​​to both the first count value and the second count value is performed in the same manner as at time t701. Also, at times t708 and t709, the operation of adding only the first count value and not the second count value is performed in the same manner as at time t703.

[0076] In the example shown in Figure 7, after the time equivalent to 1,000 subframes has elapsed, the first count value = 1,000 and the second count value = 100 can be obtained. In this case, it is known that out of the 1,000 subframes, 100 subframes had a strong light intensity from the light source, and information can be obtained that the duty ratio of the light source is 10%. Note that, although this explanation shows an example in which photons are received every time a subframe period is reached and the first count value is incremented, there may also be subframe periods in which no light is received depending on the conditions of the light source.

[0077] 7 shows an example in which a detection pulse is input during every subframe period, but the detection pulse may be input once every multiple subframes of any number. In this case, the light source duty ratio can be calculated by using the number of times the detection pulse is input as the denominator and the second count value as the numerator. The greater the number of detection pulses, the larger the circuit size of the counter circuit 802. If the number of detection pulses is reduced by inputting the detection pulse once every multiple subframes, the accuracy of the light source duty ratio may decrease, but the circuit size of the counter circuit can be reduced.

[0078] Although the above description assumes that one pixel has one second count unit, one pixel may have multiple second count units. In this case, multiple detection pulses with different high periods are input to each second count unit, and a second count value is counted for each detection pulse. This makes it possible to calculate duty ratios for various brightness levels, thereby optimizing the correction value used by the pixel value correction unit 604. Furthermore, by extending the high period of the detection pulse, the intensity of the light source corresponding to the second count value can be changed. This allows the second count value to be calculated in accordance with the light amount that needs to be corrected depending on the imaging environment.

[0079] Next, a method for creating the correction value used by the pixel value correction unit 604 will be described using FIG. 9 . FIG. 9 is a table illustrating a method for creating the correction value, with the light source duty ratio on the vertical axis and the first count value on the horizontal axis. The gain, which is the correction value by which the first count value is multiplied, is switched based on the light source duty ratio and the first count value. The light source duty ratio is calculated by using the number of detection pulses input as the denominator and the second count value as the numerator. For simplicity, the possible range of the first count value is divided equally into large (first count value 1000 to 668), medium (first count value 667 to 333), and small (first count value 332 to 0). The value of the first count value included in each range may be determined appropriately. Similarly, the light source duty ratio will be described as high (100 to 66%), medium (66 to 33%), and low (33 to 0%), but the duty ratio included in each range may be set appropriately.

[0080] If the first count value is high, the pixel value corrector 604 does not perform correction processing regardless of the duty ratio of the light source. This is because there is a high possibility that pixel values ​​that correspond to the actual conditions of the subject are obtained.

[0081] Even when the first count value is medium and the duty ratio of the light source is high, it is highly likely that a pixel value that matches the actual state of the subject has been obtained, so correction processing is not performed by the pixel value correction unit 604. Note that it is expected that such a situation is unlikely to occur in actual image capture.

[0082] If the first count value is medium and the light source duty ratio is medium, the pixel value correction unit applies a relatively low gain to the obtained pixel value. Similarly, if the first count value is medium and the light source duty ratio is low, the pixel value is applied with a higher gain than when the light source duty ratio is medium. Here, when comparing the same count values, the gain when the light source duty ratio is medium is higher than the gain when the light source duty ratio is low.

[0083] When the first count value is small and the duty ratio of the light source is low, a stronger gain is applied than when the pixel value count is medium. Here, when comparing the same duty ratios, the gain when the first count value is small is higher than the gain when the first count value is medium.

[0084] It should be noted that when the first count value is low and the duty is high to medium, it is highly likely that pixel values ​​that correspond to the actual conditions of the subject are obtained, and therefore correction processing is not performed by the pixel value correction unit 604, but it is expected that such imaging conditions are unlikely to occur in practice.

[0085] In the above example, the correction value is calculated so that the smaller the second count value, the larger the change in the first count value. When the second count value is the first value, the first count value after the correction process is set as the first correction count value, and when the second count value is the second value smaller than the first value, the first count value after the correction process is set as the second correction count value larger than the first correction count value.

[0086] This example is merely an example, and the correction value used by the pixel value correction unit 604 may be a value determined based on the first count value and the duty ratio of the light source. The absolute value of the gain is calculated from the characteristics of the duty ratio and the count value, but the combination of the magnitude relationship between the duty ratio and the gain, or the combination of the magnitude relationship between the count value and the gain, is maintained under each imaging condition. The correction value may be an additional value to be added to the first count value rather than a gain to be multiplied by the first count value. Furthermore, in this description, the duty ratio and the first count value are each divided into three patterns and the correction values ​​are set, but the number of classifications may be increased or decreased.

[0087] As described above, the photoelectric conversion device according to this embodiment can correct pixel values ​​when capturing an image of a subject whose luminance changes within a frame.

[0088] Second Embodiment A second embodiment realized by the present invention will be described with reference to Fig. 10. The basic functional block diagram of the imaging device has many parts in common with the first embodiment, so only the differences will be described.

[0089] The photoelectric conversion device 1005 according to the second embodiment includes a light receiving unit 1001 , a switching unit 1002 , a counting unit 1003 , and a pixel value correcting unit 1004 .

[0090] The switching section 1002 receives the light receiving pulse and the detection pulse output from the light receiving section 1001, and processes the light receiving pulse and the detection pulse in response to a switching signal.

[0091] The counting unit 1003 is a circuit that combines the function of the first counting unit in the first embodiment and the function of the second counting unit 603 .

[0092] Using the timing chart of Fig. 11, a detailed description will be given of the flow of operations from the generation of a light-receiving pulse by the light-receiving unit 1001 in Fig. 10 to the switching unit 1002 and counting unit 1003. The differences between the timing chart of Fig. 11 and the timing chart of Fig. 7 are the dual-purpose count value shown in (M) of Fig. 11 and the switching signal shown in (N) of Fig. 11.

[0093] The dual-purpose count value is a value counted by the count unit 1003, and both the first counting process to obtain the first count value in Figure 7 and the second counting process to obtain the second count value are performed in a time-division manner using a switching signal.

[0094] 12 shows an example of the configuration of the count unit 1003. The count unit 1003 has an AND circuit 1201, a counter circuit 1202, and a selector 1203. The difference from the circuit configuration of the second count unit 803 in FIG. 8 is that a selector 1203 is added between the output terminal of the AND circuit 1201 and the input terminal of the counter circuit 1202.

[0095] With this configuration, the functions of the first count unit and the second count unit 603 of the photoelectric conversion device according to the first embodiment are shared by the count unit 1003, thereby reducing the circuit scale of the pixel circuit.

[0096] The operation of the photoelectric conversion device according to this embodiment will be described below using the timing chart in Fig. 11. In the photoelectric conversion device according to this embodiment, the switching signal is set to 0 (Low) from time t1101 to time t1109. At this time, the logical product of the light-receiving pulse and the detection pulse output from the AND circuit 1201 is input to the counter circuit 1201. In other words, the count unit 1003 counts a second count value for calculating the duty ratio.

[0097] At time t1110, the switching signal is changed from 0 (Low) to 1 (High). At this time, a light receiving pulse is input to the counter circuit 1201, and the counting unit 1003 counts the first count value from time t1111 to time t1119.

[0098] In the pixel value correction unit 1104, the first count value counted between time t1111 and time t1119 can be corrected using a correction value based on the second count value counted between time t1101 and time t1109.

[0099] 11, the number of subframes for counting the second count value for calculating the duty ratio is 1000, but the number of subframes may be at least more than this. By reducing the number of subframes, the proportion of the period for actually counting the first count value can be increased, and the frame rate of the imaging device can be improved.

[0100] As described above, the photoelectric conversion device according to this embodiment can reduce the circuit scale compared to the first embodiment.

[0101] Third Embodiment A third embodiment is applicable to either the first embodiment or the second embodiment. Fig. 13A is a schematic diagram illustrating a device 9191 including a semiconductor device 930 according to this embodiment.

[0102] The photoelectric conversion device of each of the above-described embodiments can be used for the semiconductor device 930. An apparatus 9191 including the semiconductor device 930 will be described in detail. The semiconductor device 930 can include, in addition to the semiconductor device 910, a package 920 that houses the semiconductor device 910. The package 920 can include a base to which the semiconductor device 910 is fixed, and a lid such as glass that faces the semiconductor device 910. The package 920 can further include bonding members such as bonding wires or bumps that connect terminals provided on the base to terminals provided on the semiconductor device 910.

[0103] The equipment 9191 can include at least one of an optical device 940, a control device 950, a processing device 960, a display device 970, a storage device 980, and a mechanical device 990. The optical device 940 corresponds to the semiconductor device 930. The optical device 940 is, for example, a lens, a shutter, or a mirror, and includes an optical system that guides light to the semiconductor device 930. The control device 950 controls the semiconductor device 930. The control device 950 is, for example, a semiconductor device such as an ASIC.

[0104] The processing device 960 processes the signal output from the semiconductor device 930. The processing device 960 is a semiconductor device such as a CPU or ASIC for configuring an AFE (analog front end) or a DFE (digital front end). The display device 970 is an EL display device or a liquid crystal display device that displays information (images) obtained by the semiconductor device 930. The storage device 980 is a magnetic device or a semiconductor device that stores information (images) obtained by the semiconductor device 930. The storage device 980 is a volatile memory such as an SRAM or a DRAM, or a non-volatile memory such as a flash memory or a hard disk drive.

[0105] The mechanical device 990 has a moving part or a propulsion part such as a motor or an engine. In the device 9191, the signal output from the semiconductor device 930 is displayed on the display device 970, or transmitted to the outside by a communication device (not shown) provided in the device 9191. For this purpose, the device 9191 preferably further includes a memory device 980 and a processing device 960 in addition to the memory circuit and arithmetic circuit provided in the semiconductor device 930. The mechanical device 990 may be controlled based on the signal output from the semiconductor device 930.

[0106] The device 9191 is also suitable for electronic devices such as information terminals with a photographing function (e.g., smartphones and wearable devices) and cameras (e.g., interchangeable lens cameras, compact cameras, video cameras, and surveillance cameras). The mechanical device 990 in the camera can drive components of the optical device 940 for zooming, focusing, and shutter operation. Alternatively, the mechanical device 990 in the camera can move the semiconductor device 930 for vibration isolation operations.

[0107] Furthermore, the device 9191 may be transportation equipment such as a vehicle, a ship, or an aircraft. The mechanical device 990 in the transportation equipment may be used as a moving device. The device 9191 as transportation equipment is suitable for transporting the semiconductor device 930 or for assisting and / or automating driving (piloting) using a photographing function. The processing device 960 for assisting and / or automating driving (piloting) can perform processing to operate the mechanical device 990 as a moving device based on information obtained by the semiconductor device 930. Alternatively, the device 9191 may be a medical device such as an endoscope, a measuring device such as a distance sensor, an analytical device such as an electron microscope, an office machine such as a copier, or an industrial device such as a robot.

[0108] According to the above-described embodiment, it is possible to obtain good pixel characteristics. Therefore, the value of the semiconductor device can be increased. In this case, increasing the value corresponds to at least one of adding functions, improving performance, improving characteristics, improving reliability, improving manufacturing yield, reducing environmental impact, reducing costs, reducing size, and reducing weight.

[0109] Therefore, if the semiconductor device 930 according to this embodiment is used in the equipment 9191, the value of the equipment can also be improved. For example, by installing the semiconductor device 930 in a transport equipment, excellent performance can be obtained when photographing the exterior of the transport equipment or measuring the external environment. Therefore, when manufacturing and selling transport equipment, deciding to install the semiconductor device according to this embodiment in the transport equipment is advantageous in terms of improving the performance of the transport equipment itself. In particular, the semiconductor device 930 is suitable for transport equipment that performs driving assistance and / or automatic driving of the transport equipment using information obtained by the semiconductor device.

[0110] The photoelectric conversion system and the moving object of this embodiment will be described with reference to FIGS. 13B and 13C.

[0111] FIG. 13A illustrates an example of a photoelectric conversion system for an in-vehicle camera. The photoelectric conversion system 8 includes a photoelectric conversion device 80. The photoelectric conversion device 80 is the photoelectric conversion device (image capture device) described in any of the above embodiments. The photoelectric conversion system 8 includes an image processing unit 801 that performs image processing on multiple pieces of image data acquired by the photoelectric conversion device 80, and a parallax acquisition unit 802 that calculates parallax (phase difference between parallax images) from the multiple pieces of image data acquired by the photoelectric conversion system 8. The photoelectric conversion system 8 also includes a distance acquisition unit 803 that calculates the distance to an object based on the calculated parallax, and a collision determination unit 804 that determines whether or not there is a possibility of a collision based on the calculated distance. Here, the parallax acquisition unit 802 and the distance acquisition unit 803 are examples of distance information acquisition means that acquire distance information to the object. In other words, the distance information includes information related to the parallax, the defocus amount, the distance to the object, etc. The collision determination unit 804 may determine the possibility of a collision using any of this distance information. The distance information acquisition means may be realized by dedicated hardware, a software module, a field programmable gate array (FPGA), an application specific integrated circuit (ASIC), or a combination thereof.

[0112] The photoelectric conversion system 8 is connected to a vehicle information acquisition device 810 and can acquire vehicle information such as vehicle speed, yaw rate, and steering angle. The photoelectric conversion system 8 is also 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 determination result of the collision determination unit 804. The photoelectric conversion system 8 is also connected to an alarm device 830 that issues an alarm to the driver based on the determination result of the collision determination unit 804. For example, if the determination result of the collision determination unit 804 indicates a high possibility of collision, the control ECU 820 performs vehicle control to avoid the collision and mitigate damage by applying the brakes, releasing the accelerator, suppressing engine output, etc. The alarm device 830 warns the user by sounding an alarm, displaying alarm information on a screen of a car navigation system, etc., or vibrating the seat belt or steering wheel.

[0113] In this embodiment, the photoelectric conversion system 8 captures an image of the surroundings of the vehicle, for example, the front or rear.

[0114] 13C shows a photoelectric conversion system for capturing an image of the area ahead of the vehicle (image capturing range 850). A vehicle information acquisition device 810 sends instructions to the photoelectric conversion system 8 or the photoelectric conversion device 80. This configuration can further improve the accuracy of distance measurement.

[0115] 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 a lane, etc. Furthermore, the photoelectric conversion system is not limited to vehicles such as automobiles, but can be applied to moving bodies (moving devices) such as ships, aircraft, and industrial robots. In addition, the present invention can be applied not only to moving bodies but also to a wide range of devices that use object recognition, such as intelligent transport systems (ITS).

[0116] The above-described embodiments can be modified as appropriate without departing from the technical spirit. The disclosure of this specification includes not only what is described in this specification, but also all matters that can be understood from this specification and the drawings attached hereto. The disclosure of this specification also includes the complement of the concepts described in this specification. In other words, if this specification states, for example, that "A is greater than B," it can be said that this specification discloses that "A is not greater than B" even if the statement that "A is not greater than B" is omitted. This is because the statement that "A is greater than B" is based on the premise that the case in which "A is not greater than B" is taken into consideration.

[0117] The disclosure of this embodiment includes the following configurations and methods.

[0118] (Configuration 1) A photoelectric conversion device comprising: a light receiving unit whose applied voltage is controlled by a recharge pulse and which converts incident light into a received light pulse; a first counting unit which generates a first count value using the received light pulse during a period from a first recharge pulse to a second recharge pulse among the recharge pulses; and a second counting unit which receives a detection pulse which is active during a portion of the period and inactive during another portion of the period; wherein the second counting unit generates a second count value using the received light pulse and the detection pulse during the period.

[0119] (Configuration 2) The photoelectric conversion device according to configuration 1, wherein the second counting section outputs a logical product of the received light pulse and the detection pulse as the second count value.

[0120] (Configuration 3) The photoelectric conversion device according to Configuration 1 or 2, wherein a correction value used in the correction process of the first count value is generated using the second count value and the first count value.

[0121] (Configuration 4) The photoelectric conversion device according to Configuration 3, wherein when the second count value is a first value, the first count value after the correction process is a first corrected count value, and further, when the second count value is a second value smaller than the first value, the first count value after the correction process is a second corrected count value larger than the first corrected count value.

[0122] (Configuration 5) The photoelectric conversion device according to any one of configurations 1 to 4, wherein the amount of change in the first count value is changed depending on the timing at which the light-receiving pulse is generated during the exposure period.

[0123] (Configuration 6) A photoelectric conversion device according to configuration 5, characterized in that the value added to the first count value in a period before the center timing of the exposure period is greater than the value added to the second count value in a period after the center timing of the exposure period.

[0124] (Structure 7) A photoelectric conversion device according to any one of Structures 1 to 6, further comprising a switch connected in series between the light receiving unit and a node that supplies a drive voltage to the light receiving unit, and the recharge pulse is a clock signal input to the switch.

[0125] (Configuration 8) The photoelectric conversion device according to Configuration 2, further comprising a switch connected in series between the light receiving unit and a node that supplies a drive voltage to the light receiving unit, wherein the recharge pulse is a clock signal input to the switch, and the detection pulse is a signal input in synchronization with the clock signal.

[0126] (Configuration 9) The photoelectric conversion device according to any one of configurations 1 to 8, wherein the light receiving section is an avalanche photodiode.

[0127] (Configuration 10) A photoelectric conversion device comprising: a light receiving unit whose applied voltage is controlled by a recharge pulse and which converts incident light into received light pulses; and a counting unit which performs either a first counting process or a second counting process; and a switching unit which has the function of switching between the first counting process and the second counting process by a switching signal; the first counting process is a count value which is changed in response to the generation of the received light pulses in the period from the first recharge pulse to the second recharge pulse; and the second counting process is a count value which is changed in response to the received light pulses and a detection pulse which is active for a portion of the period and inactive for another portion of the period.

[0128] (Configuration 11) The photoelectric conversion device according to configuration 10, wherein a logical product of the received light pulse and the detection pulse is counted as a count value.

[0129] (Configuration 12) The photoelectric conversion device described in Configuration 10, characterized in that the correction value used to correct the count value is generated using the count value obtained by the first counting process and the count value obtained by the second counting process.

[0130] (Configuration 13) When the count value obtained by the second counting process is a first value, the count value obtained by the first counting process after correction is a first corrected count value. When the count value obtained by the second counting process is a second value smaller than the first value, the count value obtained by the first counting process after correction is a second corrected count value larger than the first corrected count value. The photoelectric conversion device according to Configuration 12, characterized by the above-mentioned.

[0131] (Configuration 14) A photoelectric conversion device according to any one of Configurations 10 to 13, further comprising a switch connected in series between the light receiving unit and a node that supplies a drive voltage to the light receiving unit, wherein the recharge pulse is a clock signal input to the switch.

[0132] (Configuration 15) The photoelectric conversion device according to Configuration 11, further comprising a switch connected in series between the light receiving section and a node that supplies a drive voltage to the light receiving section, wherein the recharge pulse is a clock signal input to the switch, and the detection pulse is a signal input in synchronization with the clock signal.

[0133] (Configuration 16) The photoelectric conversion device according to any one of configurations 10 to 15, wherein the light receiving section is an avalanche photodiode.

[0134] (Configuration 17) A photoelectric conversion system comprising: the photoelectric conversion device according to any one of configurations 1 to 16; and a signal processing unit that generates an image using a signal output from the photoelectric conversion device.

[0135] (Configuration 18) A moving body including the photoelectric conversion device according to any one of configurations 1 to 16, characterized in that the moving body further includes a control device that controls the movement of the moving body using a signal output by the photoelectric conversion device.

[0136] The present invention is not limited to the above-described embodiments, and various modifications and variations can be made without departing from the spirit and scope of the present invention. Therefore, the following claims are appended to apprise the public of the scope of the present invention.

[0137] This application claims priority based on Japanese Patent Application No. 2024-049500, filed March 26, 2024, the entire contents of which are incorporated herein by reference.

[0138] 601 Light receiving unit 602 First counting unit 603 Second counting unit

Claims

1. A photoelectric conversion device comprising: a light receiving unit whose applied voltage is controlled by a recharge pulse and which converts incident light into a received light pulse; a first counting unit which generates a first count value using the received light pulse during the period from a first recharge pulse to a second recharge pulse; and a second counting unit which receives a detection pulse which is active during a portion of the period and inactive during another portion of the period, wherein the second counting unit generates a second count value using the received light pulse and the detection pulse during the period.

2. The photoelectric conversion device according to claim 1, wherein the second counting section outputs the logical product of the received light pulse and the detection pulse as the second count value.

3. The photoelectric conversion device according to claim 1, characterized in that the correction value used in the correction process of the first count value is generated using the second count value and the first count value.

4. The photoelectric conversion device according to claim 3, characterized in that when the second count value is a first value, the first count value after the correction process is a first corrected count value, and when the second count value is a second value smaller than the first value, the first count value after the correction process is a second corrected count value larger than the first corrected count value.

5. The photoelectric conversion device according to claim 1, wherein the amount of change in the first count value is changed depending on the timing at which the light-receiving pulse is generated during the exposure period.

6. The photoelectric conversion device according to claim 5, characterized in that the value added to the first count value in the period before the center timing of the exposure period is greater than the value added to the second count value in the period after the center timing of the exposure period.

7. The photoelectric conversion device according to claim 1, further comprising a switch connected in series between the light receiving section and a node that supplies a drive voltage to the light receiving section, and the recharge pulse is a clock signal input to the switch.

8. The photoelectric conversion device according to claim 2, further comprising a switch connected in series between the light receiving section and a node that supplies a drive voltage to the light receiving section, wherein the recharge pulse is a clock signal input to the switch, and the detection pulse is a signal input in synchronization with the clock signal.

9. The photoelectric conversion device according to claim 1, wherein the light receiving section is an avalanche photodiode.

10. A photoelectric conversion device comprising: a light receiving unit whose applied voltage is controlled by a recharge pulse and which converts incident light into a received light pulse; a counting unit which performs either a first counting process or a second counting process; and a switching unit which has the function of switching between the first counting process and the second counting process by a switching signal, wherein the first counting process changes a count value in response to generation of the received light pulse in the period from the first recharge pulse to the second recharge pulse among the recharge pulses; and the second counting process changes a count value in response to the received light pulse and a detection pulse which is active for a part of the period and inactive for another part of the period.

11. The photoelectric conversion device according to claim 10, wherein the logical product of the received light pulse and the detection pulse is counted as a count value.

12. The photoelectric conversion device described in claim 10, characterized in that the correction value used to correct the count value is generated using the count value obtained by the first counting process and the count value obtained by the second counting process.

13. The photoelectric conversion device described in claim 11, characterized in that when the count value obtained by the second counting process is a first value, the count value obtained by the first counting process after correction processing is a first corrected count value, and when the count value obtained by the second counting process is a second value smaller than the first value, the count value obtained by the first counting process after correction processing is a second corrected count value larger than the first corrected count value.

14. A photoelectric conversion device according to claim 10, further comprising a switch connected in series between the light receiving section and a node that supplies a drive voltage to the light receiving section, wherein the recharge pulse is a clock signal input to the switch.

15. The photoelectric conversion device according to claim 11, further comprising a switch connected in series between the light receiving section and a node that supplies a drive voltage to the light receiving section, wherein the recharge pulse is a clock signal input to the switch, and the detection pulse is a signal input in synchronization with the clock signal.

16. The photoelectric conversion device according to claim 10, wherein the light receiving section is an avalanche photodiode.

17. A photoelectric conversion system comprising: a photoelectric conversion device according to any one of claims 1 to 16; and a signal processing unit that generates an image using a signal output by the photoelectric conversion device.

18. A mobile body equipped with a photoelectric conversion device according to any one of claims 1 to 16, characterized in that it has a control device that controls the movement of the mobile body using a signal output by the photoelectric conversion device.

Images