Photoelectric conversion apparatus, imaging system, and mobile body

Abstract

A photoelectric conversion apparatus includes a light-receiving unit, in which a voltage applied to the light-receiving unit is controlled by a recharge pulse and the light-receiving unit is configured to convert incident light into a light-receiving pulse; a first counting unit configured to generate a first count value by using the light-receiving pulse in a period from a first recharge pulse to a second recharge pulse of the recharge pulse; and a second counting unit, in which a detection pulse that is active in a part of the period and inactive in another part of the period is input to the second counting unit, wherein the second counting unit generates a second count value by using the light-receiving pulse and the detection pulse in the period.

Description

Technical Field

[0001] This invention relates to photoelectric conversion devices, camera systems, and mobile bodies. Background Technology

[0002] A photon-counting photoelectric conversion device is known that digitally counts the number of photons incident on a light-receiving unit undergoing avalanche multiplication and outputs the count value as a digital signal from the pixel. A representative example of this technology is called a single-photon avalanche diode (SPAD).

[0003] The device described in Patent Document 1 performs imaging by detecting the incidence of photons during the time intervals between periodically repeating pulses output from an avalanche photodiode. The device obtains a count value corresponding to the number of photons incident on a pixel by counting the number of times the result indicating photon incidence is acquired. Existing technical documents Patent documents

[0004] Patent Document 1: Japanese Patent Application Publication No. 2020-123847 Summary of the Invention The problem the invention aims to solve

[0005] However, when the device captures images of a subject whose brightness changes frequently during periods of potential avalanche multiplication, there is a possibility that the device may not be able to obtain pixel values ​​that adequately reflect the actual condition of the subject as perceived by visual recognition. Solution for solving the problem

[0006] To achieve the above objectives, one aspect of the present invention relates to a photoelectric conversion device comprising: a light-receiving unit, wherein a voltage applied to the light-receiving unit is controlled by a recharge pulse and the light-receiving unit is configured to convert incident light into a light-receiving pulse; a first counting unit configured to generate a first count value by using the light-receiving pulse during a period from a first recharge pulse to a second recharge pulse of the recharge pulse; and a second counting unit, wherein a detection pulse valid in a portion of the period and invalid in another portion of the period is input to the second counting unit, wherein the second counting unit generates a second count value during the period by using the light-receiving pulse and the detection pulse.

[0007] Another aspect of the present invention relates to a photoelectric conversion device comprising: a light-receiving unit, wherein a voltage applied to the light-receiving unit is controlled by a recharge pulse and the light-receiving unit is configured to convert incident light into a light-receiving pulse; a counting unit configured to perform either a first counting process or a second counting process; and a switching unit having the function of switching between the first counting process and the second counting process according to a switching signal, wherein, as the first counting process, a count value is changed according to the generation of the light-receiving pulse during a period from a first recharge pulse to a second recharge pulse of the recharge pulse, and wherein, as the second counting process, a count value is changed according to the light-receiving pulse and a detection pulse that is valid in a part of the period and invalid in another part of the period. Advantages of the invention

[0008] According to the present invention, correction values ​​can be created based on the imaging results. Attached Figure Description

[0009] Figure 1 This is a schematic diagram of a photoelectric conversion device according to an embodiment. Figure 2 This is a schematic diagram of the pixel substrate of the photoelectric conversion device according to an embodiment. Figure 3 This is a schematic diagram of the circuit board of the photoelectric conversion device according to an embodiment. Figure 4 This is a diagram illustrating an example configuration of the pixel circuit of a photoelectric conversion device according to an embodiment. Figure 5A This is a schematic diagram illustrating the driving of the pixel circuit of a photoelectric conversion device according to an embodiment. Figure 5B This is a schematic diagram illustrating the driving of the pixel circuit of a photoelectric conversion device according to an embodiment. Figure 6 This is a block diagram illustrating an example configuration of a camera device according to the first embodiment. Figure 7 This is a timing diagram of the camera processing according to the first embodiment. Figure 8 This is a block diagram illustrating an example configuration of the detection counting unit according to the first embodiment. Figure 9 This is a diagram illustrating the correction values ​​used for the processing performed by the pixel value correction unit according to the first embodiment. Figure 10 This is a block diagram illustrating an example configuration of a camera device according to the second embodiment. Figure 11 This is a timing diagram of the camera processing according to the second embodiment. Figure 12 This is a block diagram illustrating an example configuration of the counting unit according to the second embodiment. Figure 13A This is a functional block diagram of the photoelectric conversion system according to the third embodiment. Figure 13B This is a functional block diagram of the photoelectric conversion system according to the third embodiment. Figure 13C This is a functional block diagram of the photoelectric conversion system according to the third embodiment. Detailed Implementation

[0010] The embodiments described below are merely examples embodying the technical spirit of the invention and are not intended to limit the invention. In each drawing, for clarity, the dimensions and positional relationships of the components may be exaggerated. In the following description, the same reference numerals are applied to the same constituent elements, and their descriptions may be omitted.

[0011] In the following description, embodiments of the invention are described in detail with reference to the accompanying drawings. In the following description, terms describing specific directions and positions (e.g., "up," "down," "right," "left," and other terms including these terms) are used as needed. These terms are used to facilitate understanding of the embodiments described with reference to the accompanying drawings, and the meaning of these terms should not be construed as limiting the technical scope of the invention.

[0012] In this specification, a plan view refers to a view seen from a direction perpendicular to the light incident surface of the semiconductor layer. Furthermore, 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 in a microscopic view, the plan view is defined using the light incident surface of the semiconductor layer in a macroscopic view as a reference.

[0013] When the term "impurity concentration" is used simply in this specification, it refers to the net impurity concentration obtained by subtracting the value compensated by impurities of the opposite conductivity type. In other words, "impurity concentration" indicates the net doping concentration. Regions where the P-type added impurity concentration is higher than the N-type added impurity concentration are P-type semiconductor regions. Conversely, regions where the N-type added impurity concentration is higher than the P-type added impurity concentration are N-type semiconductor regions.

[0014] In the following embodiments, there are cases where the components of the described circuit are connected. In such cases, even if another component is present between the components of interest, the components of interest are considered to be connected to each other unless otherwise stated. For example, suppose component A is connected to one node of a capacitor component C with multiple nodes, and component B is connected to another node of the capacitor component C. In this case, unless otherwise stated, components A and B are considered to be connected to each other.

[0015] Reference Figures 1 to 5A and Figure 5B The common configurations of corresponding embodiments of the photoelectric conversion device and its driving method according to the present invention are described.

[0016] Figure 1 This is a diagram illustrating the configuration of a photoelectric conversion device 100 according to an embodiment of the present invention. Hereinafter, a stacked photoelectric conversion device is used as an example of the photoelectric conversion device 100. In other words, a photoelectric conversion device comprising two substrates (i.e., sensor substrate 11 and circuit substrate 21) stacked and electrically connected to each other is described as an example. However, the photoelectric conversion device is not limited to the above-described photoelectric conversion device. For example, the photoelectric conversion device may be a photoelectric conversion device in which the constituent elements in the sensor substrate 11 and the circuit substrate are arranged on a common semiconductor layer. Hereinafter, a photoelectric conversion device comprising the constituent elements in the sensor substrate 11 and the circuit substrate arranged on a common semiconductor layer is referred to as a non-stacked photoelectric conversion device.

[0017] The sensor substrate 11 includes a first semiconductor layer and a first wiring structure, the first semiconductor layer including a photoelectric conversion element 102. The circuit substrate 21 includes a second semiconductor layer and a second wiring structure, the second semiconductor layer including circuitry such as the signal processing circuit 103 described below. The photoelectric conversion device 100 includes a second semiconductor layer, a second wiring structure, a first wiring structure, and a first semiconductor layer stacked sequentially.

[0018] Figure 1 An example of a back-illuminated photoelectric conversion device is shown, wherein light is incident on a first surface and a circuit board is disposed on a second surface opposite to the first surface. In the case of a non-stacked photoelectric conversion device, the surface on which transistors for signal processing circuitry are disposed is referred to as the second surface. In the case of a back-illuminated photoelectric conversion device, the first surface of the semiconductor layer opposite to the second surface is the light incident surface. Furthermore, in the case of a front-illuminated photoelectric conversion device, the second surface of the semiconductor layer is the light incident surface.

[0019] In the following description, although the sensor substrate 11 and the circuit substrate 21 are described as diced chips, these substrates are not limited to chips. For example, the substrate can be a wafer. Furthermore, the substrate can be diced into chips after being stacked in a wafer state, or it can be stacked and bonded in a chip state after being diced into chips.

[0020] Pixel region 12 is disposed on sensor substrate 11, and circuit region 22 for processing signals detected from pixel region 12 is disposed on circuit substrate 21.

[0021] Figure 2This is a diagram illustrating the arrangement of sensor chip 11. Pixels 101, each including a photoelectric conversion unit 102, are arranged in two dimensions to form pixel region 12. The photoelectric conversion unit 102 includes an avalanche photodiode (hereinafter referred to as "APD").

[0022] Typically, pixel 101 is the pixel used to form an image. However, in cases where pixel 101 is used for time-of-flight (TOF) purposes, pixel 101 does not always have to form an image. In other words, pixel 101 can be a pixel used to measure the arrival time and intensity of light.

[0023] Figure 3 This is a diagram illustrating the configuration of circuit chip 21. Circuit chip 21 includes components for controlling the circuit chip 21. Figure 2 The photoelectric conversion unit 102 processes the charge after photoelectric conversion, and includes a signal processing unit 103, a readout circuit 112, a control pulse generation unit 115, a horizontal scanning circuit unit 111, a signal line 113, and a vertical scanning circuit unit 110.

[0024] Figure 2 Each photoelectric conversion unit 102 in the image is electrically connected to a connection wire provided for each pixel. Figure 3 The corresponding signal processing unit 103 in the middle.

[0025] The vertical scanning circuit unit 110 receives control pulses supplied from the control pulse generation unit 115 and supplies the control pulses to each pixel. Logic circuits such as shift registers or address decoders are used in the vertical scanning circuit unit 110.

[0026] The control pulse generation unit 115 includes a signal generation unit 215 for generating a control signal P_CLK for the switch described below. As described below, the signal generation unit 215 generates a pulse signal for controlling the switch. For example, as... Figure 4 As shown in Figure A, the signal generation unit 215 can generate a control signal P_CLK shared by pixels in the pixel region, or as shown in Figure A. Figure 4 As shown in Figure B, a control signal P_CLK can be generated for each pixel. When the pulse signal P_CLK is generated jointly, at least one of the pulse signal period, pulse number, and pulse width of the signal P_EXP used to control the exposure period is generated jointly in association with the exposure period. Furthermore, when controlling the control signal P_CLK for each pixel, the 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 used to control the exposure period. For example, the control pulse generation unit 115 may include a frequency divider circuit. In this way, control can be performed simply, and the increase in the number of components can be reduced.

[0027] The signals output from the photoelectric conversion unit 102 of each pixel are processed by the signal processing unit 103. The signal processing unit 103 includes a counter and a memory, and the digital values ​​are stored in the memory.

[0028] The horizontal scanning circuit unit 111 inputs control pulses to the signal processing unit 103 for sequentially selecting each column, so as to read the signal from the memory of the corresponding pixel in which the digital signal is stored.

[0029] For the selected column, the signal processing unit 103 of the pixel selected by the vertical scanning circuit unit 110 outputs a signal to the signal line 113.

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

[0031] exist Figure 2 In the pixel region 12, the array of pixels 100 can be arranged in one dimension. The function of the signal processing unit 103 does not always have to be provided individually for each pixel 101. For example, a signal processing unit 103 can be shared by multiple pixels 101 and can perform signal processing sequentially.

[0032] Figure 4 It includes Figure 2 and Figure 3 An example of a block diagram of the equivalent circuit. In Figure 2 In the process, the photoelectric conversion unit 102, including APD 201, is arranged on the sensor chip 11, and other components are arranged on the circuit chip 21.

[0033] APD 201 performs photoelectric conversion to generate charge pairs corresponding to the incident light. A voltage VL (first voltage) is supplied to the anode of APD 201. Furthermore, a voltage VH (second voltage) higher than the voltage VL supplied to the anode is supplied to the cathode of APD 201. A reverse bias voltage that causes avalanche multiplication in APD 201 is supplied to each of the anode and cathode. By supplying the aforementioned voltage, avalanche multiplication occurs due to the charges generated according to the incident light, thereby generating an avalanche current.

[0034] With a reverse bias voltage supplied to the anode and cathode, the APD operates in either Geiger mode or linear mode. In Geiger mode, the APD operates with a potential difference between the anode and cathode greater than the breakdown voltage. In linear mode, the APD operates with a potential difference between the anode and cathode that is close to, less than, or equal to the breakdown voltage. An APD operating in Geiger mode is called a single-photon avalanche diode (SPAD). For example, the voltage VL (first voltage) is -30V, and the voltage VH (second voltage) is 1V. The APD 201 can operate in either linear or Geiger mode. The potential difference of the SPAD is greater than that of the APD operating in linear mode, making its voltage withstand capability more significant.

[0035] Switch 202 is connected to the control line used to supply the drive voltage VH and to APD 201. Switch 202 is connected to one of the anode and cathode nodes of APD.

[0036] Then, switch 202 switches the potential difference between the anode and cathode of the APD between a first potential difference used to induce avalanche multiplication and a second potential difference used not to induce avalanche multiplication. Hereinafter, switching from the second potential difference to the first potential difference is also referred to as turning on switch 202, and switching from the first potential difference to the second potential difference is also referred to as turning off switch 202. Switch 202 functions as a quenching element. When signal multiplication occurs due to avalanche multiplication, switch 202 functions as a load circuit (quenching circuit) to suppress avalanche multiplication by suppressing the voltage supplied to APD 201 (i.e., quenching operation). Furthermore, switch 202 is also used to restore the voltage supplied to APD 201 back to voltage VH by applying a current corresponding to the voltage drop caused by the quenching operation (i.e., recharging operation). In other words, switch 202 functions as a control circuit for controlling the occurrence of avalanche multiplication in APD 201.

[0037] For example, a metal-oxide-semiconductor (MOS) transistor can be used as switch 202. A control signal P_CLK supplied from signal generation unit 215 to switch 202 is applied to the gate electrode of the MOS transistor used as switch 202. In this embodiment, the voltage applied to the gate electrode of switch 202 is controlled so that switch 202 is controlled to be turned on and off.

[0038] The signal processing unit 103 includes a waveform shaping unit 210, a counter circuit 211, and a selection circuit 212. In this specification, the signal processing unit 103 may include 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 of the cathode of the APD 201 acquired during photon detection and outputs a pulse signal. The input side of the waveform shaping unit 210 is referred to as node A, and the output side is referred to as node B. The waveform shaping unit 210 changes the output potential from node B based on whether the input potential to node A is a predetermined value or greater than or less than a predetermined value. For example, in... Figure 5A and Figure 5B In this circuit, when the input potential to node A becomes a high potential greater than or equal to a predetermined threshold, the output potential from node B becomes a low level. Then, when the input potential to node A becomes a low potential below the predetermined threshold, the output potential from node B becomes a high level. For example, an inverter circuit is used as waveform shaping unit 210. Figure 4 In the illustrated example, an inverter is used as waveform shaping unit 210. However, circuits comprising multiple inverters connected in series or other circuits with waveform shaping effects may also be used.

[0040] Quenching and recharging operations using switch 202 can be performed based on avalanche multiplication occurring in APD 201. However, depending on the photon detection timing, the charge generated in the APD may not be identified as an output signal. For example, the case where node A goes low due to avalanche multiplication occurring in the APD and a recharging operation is performed will be described. Typically, the determination threshold of 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 enters the APD, avalanche multiplication occurs in the APD when the potential of node A is below the determination threshold due to the recharging operation and is at a potential where avalanche multiplication may occur in the APD, and the voltage of node A decreases. In other words, since the potential of node A decreases at a voltage below the determination threshold, no potential change occurs across the determination threshold, so the output potential from node B does not change. Therefore, even if avalanche multiplication occurs, the detected photon will not be identified as a signal. In particular, under high illumination, photons continuously enter the APD within a short period, so the incident light is not easily identified as a signal. Therefore, even with high illuminance, the output signal may deviate from the actual number of incident photons.

[0041] On the other hand, by applying a control signal P_CLK to switch 202 to switch its on and off states, the incident light can be identified as a signal even when photons continuously enter the APD within a short period of time. Figure 5A and Figure 5B The document describes the configuration of using a pulse signal with a repetitive period as the control signal P_CLK. In other words, in Figure 5A and Figure 5BThe configuration for switching the on and off states of switch 202 at a predetermined clock frequency is described. However, even if the pulse signal is not a signal with a repetitive period, the effect of suppressing the increase in power consumption of the photoelectric conversion device can be achieved.

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

[0043] Control pulse pSEL via Figure 4 Drive line 214 in Figure 3 (Not shown in the example) From Figure 1 The vertical scanning circuit unit 110 is supplied to the selection circuit 212, causing the electrical connection between the counter circuit 211 and the signal line 113 to be turned on and off. For example, a buffer circuit for the output signal is included in the selection circuit 212.

[0044] Electrical connections can be switched using transistors that function as switches located between switch 202 and APD 201 or between photoelectric conversion unit 102 and signal processing unit 103. Similarly, the supply of voltage VH or voltage VL to photoelectric conversion unit 102 can be electrically switched using switches such as transistors.

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

[0046] like Figure 5AAs shown, switch 202 can be implemented with a single transistor, and both the quenching and recharging operations can be performed by a single transistor. With this configuration, the number of circuits can be reduced compared to the case where the quenching and recharging operations are performed by different circuit elements. In particular, when each pixel includes a counter circuit and the signal from the SPAD is read out for each pixel, the circuit area used for the switch can be reduced to accommodate the counter circuit. Therefore, the effect of implementing switch 202 with a single transistor becomes significant.

[0047] At time t1, the control signal P_CLK changes from high to low, turning on the switch and initiating the APD's recharging operation. Therefore, the potential at the APD's cathode becomes high. Then, the potential difference between the anode and cathode of the APD enters a state where avalanche multiplication may occur. The cathode potential is the same as the potential at node A. Therefore, when the cathode potential changes from low to high, the potential at node A becomes greater than or equal to a predetermined threshold at time t2. At this time, the pulse signal output from node B reverses from high to low. Subsequently, the potential difference between the drive voltage VH and the drive voltage VL is applied to APD 201. The control signal P_CLK goes high, and the switch turns off.

[0048] Next, when a photon is incident on APD 201 at time t3, avalanche multiplication occurs in APD 201, and the voltage of the cathode decreases. In other words, the voltage at node A decreases. As the voltage drop increases further and the voltage difference applied to APD 201 decreases, the avalanche multiplication in APD 201 stops at time t2, and the voltage level at node A no longer decreases beyond a certain value. Therefore, the voltage level at node A does not decrease beyond a certain value. When the voltage at node A falls below a predetermined threshold in the middle of the voltage drop at node A, the voltage at node B changes from low to high. In other words, the portion of the output waveform at node A that exceeds the predetermined threshold is shaped by the waveform shaping unit 210 and output as a signal from node B. Then, the signal is counted by the counter circuit, and the count value of the counter signal output from the counter circuit is incremented by one least significant bit (LSB).

[0049] Although photons are incident on the APD during the time interval between time t3 and time t4, the voltage level at node A does not exceed a predetermined threshold because the switch is turned off and the voltage applied to APD 201 does not become a potential difference that could lead to avalanche multiplication.

[0050] At time t4, the control signal P_CLK changes from high to low, turning on the switch. As a result, the current compensating for the voltage drop flows from the drive voltage VH into node A, causing the voltage at node A to return to its original level. At this time, the voltage at node A becomes greater than or equal to a predetermined threshold at time t5, causing the pulse signal output from node B to reverse from high to low.

[0051] At time t6, node A stabilizes at its original voltage level, and the control signal P_CLK changes from low to high. Therefore, the switch is turned off. Thereafter, similar to the situation from time t1 to time t6, the potential of the corresponding node and the signal line change according to the control signal P_CLK and the incidence of photons.

[0052] The photoelectric conversion devices according to various embodiments will be described below. (First Embodiment)

[0053] refer to Figures 6 to 8 The invention is described according to a first embodiment. The configurations described in the following embodiments are merely examples, and the invention is not limited to the configurations described below.

[0054] Figure 6 This is a block diagram illustrating a configuration example of a photoelectric conversion device 605. The photoelectric conversion device 605 includes a light-receiving unit 601, a first counting unit 602, a second counting unit 603, and a pixel value correction unit 604.

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

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

[0057] The second counting unit 603 counts the number of detected photons by using a light-receiving pulse and a detection pulse output from the light-receiving unit 601. The detection count value, as a result of this counting, is called the second count value.

[0058] In addition, the pixel value correction unit 604 corrects the first count value with the second count value and outputs the corrected value as the pixel value from the photoelectric conversion device 605.

[0059] In such Figure 2 In the case where the light-receiving units 601 are arranged in a pixel array with multiple rows and columns, the first counting unit 602, the second counting unit 603, and the pixel value correction unit 604 are similarly arranged in multiple rows and columns. The second counting unit 603 and the pixel value correction unit 604 do not necessarily need to be arranged in an array corresponding to the pixel array, and any number of second counting units 603 and pixel value correction units 604 can be arranged around the perimeter of the pixel array. In this case, one second counting unit 603 and one pixel value correction unit 604 can be shared and operated by multiple light-receiving units 601.

[0060] Furthermore, the pixel value correction unit 604 can perform correction processing through pipelined processing around the pixel array while reading data stored in the first counting unit 602 and the second counting unit 603. Although Figure 6 The photoelectric conversion device 605 shown includes a pixel value correction unit 604, but the pixel value correction unit 604 may be arranged outside the photoelectric conversion device 605.

[0061] As described above, by arranging the second counting unit 603 and the pixel value correction unit 604 in a number smaller than that of the light receiving unit 601, the circuit size of the photoelectric conversion device 605 can be reduced.

[0062] Next, refer to Figure 7 The timing diagram is used to describe in detail the components including... Figure 6 The light-receiving unit 601 in the middle performs the generation of light-receiving pulses and Figure 6 The operation process of the first counting unit 602 and the second counting unit 603 in the process.

[0063] Figure 7 (A) illustrates the relationship between time and the light intensity of the light source as the subject. The light source has periods of high and low light intensity in a periodic, continuous manner. For example, the light source is an LED light source using pulse width modulation (PWM) dimming. The timing diagram is described with respect to the case where the ratio of the period of high light intensity to the unit period (hereinafter referred to as the duty cycle) is 10%.

[0064] Figure 7 Example (B) illustrates a recharge pulse input to the light-receiving unit 601. The avalanche photodiode is recharged during the high period of this pulse. Through the above operation, it is possible to provide... Figure 7 The continuous exposure period is shown in (C). An 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 light from... Figure 7The light source shown in (A) emits photons and generates photons as shown in (A). Figure 7 The light pulse shown in (D) is at this time. Figure 7 As shown in (E), the first count value of the first counting unit 602 is incremented by 1.

[0065] Furthermore, the counting method is not limited to the method described above, and the first counting unit can add a value other than 1 to a single light-receiving pulse, or the amount of count change can be changed depending on which point in time within any exposure period the light-receiving pulse is generated. For example, if the light-receiving pulse is generated in the early stage of any exposure period, the pixel value correction unit 604 corrects the count value of the first counting unit to a larger value under the assumption that the subject is in a bright state. Conversely, when the light-receiving pulse is generated in the later stage of any exposure period, the pixel value correction unit 604 corrects the count value of the first counting unit to a smaller value under the assumption that the subject is in a dark state. As an example, a method to be performed when the exposure period has 1000 subframes is described. The value n is set to the value to be added to the first count value based on the light-receiving pulse generated in the period before the center timing in the exposure period (i.e., the period from subframe 1 to subframe 500). The value m is set to be added to the first count value based on the light-receiving pulse generated in the period following the center timing during the exposure period (i.e., the period from subframe 501 to subframe 1000). In this case, the value n is greater than the value m.

[0066] If it is necessary to improve the sensitivity of the photoelectric conversion device, a value greater than 1 can be added to the count value of the first counting unit. Furthermore, if it is necessary to improve high dynamic range (HDR) performance, the value to be added to the count value of the first counting unit can be changed according to the timing of the pulse rise during the subframe period.

[0067] exist Figure 7 In the example shown, the number of subframes is set to 1000, a light pulse is generated for each subframe, and the value of the first counting unit is incremented by 1. By changing the sum of the values ​​according to the aforementioned light timing, pixel values ​​that appropriately reflect the actual condition of the subject as visible to the human eye can be obtained.

[0068] exist Figure 7 In the example shown, one or more photons are received in each subframe. However, depending on the shooting conditions, photons may not be received in some subframes. However, when the brightness of the light source changes frequently between subframes, a large number of photons flow into the light-receiving unit 601 during a specific subframe period. Therefore, there are cases where pixel values ​​that adequately reflect the actual condition of the subject as visible to the human eye cannot be obtained.

[0069] To solve the above problems, such as Figure 7As shown in (F), a detection pulse that is valid (high) only in a portion of the subframe time period and invalid (low) in another portion of the subframe time period is input to the second counting unit 603. The detection pulse can be generated in the camera device or can be input from outside the camera device. The detection pulse can be generated synchronously with the recharge pulse.

[0070] An example of the configuration of the second counting unit is in Figure 8 As illustrated in the example, the light-receiving pulse and the detection pulse, which are inputs from the light-receiving unit 601, are input to the AND circuit 801, and the output of the AND circuit 801 is input to the counter circuit 802.

[0071] Using this circuit configuration, such as Figure 7 As shown in (G), the second counting unit 103 can count the detection count value as the logical product of the light pulse and the detection pulse.

[0072] exist Figure 7 In the example shown, because the earliest timing of the detection pulse in the subframe period is higher, the number of subframes with high light intensity of the light source is counted as the second count value.

[0073] Similar to time t701, at time t702, the first and second count values ​​increment by 1.

[0074] At times t703, t704, and t705, the detection pulse is low because the light source has low light intensity and the rise time of the light pulse is slow. Therefore, the first count value increases, but the second count value does not increase.

[0075] The operation for incrementing both the first and second count values ​​is performed in the same manner as at times t701, t706, and t707. Furthermore, the operation for incrementing only the first count value without incrementing the second count value is performed in the same manner as at times t703, t708, and t709.

[0076] exist Figure 7 In the example shown, after a time equivalent to 1000 subframes, a first count value of 1000 and a second count value of 100 can be obtained. In this case, it can be seen that the light intensity of the light source is high in 100 of the 1000 subframes, and information indicating a 10% duty cycle for the light source can be obtained. In this specification, an example of photon reception occurring and the first count value increasing during each subframe period has been described. However, depending on the state of the light source, there may be subframe periods where no photon reception occurs.

[0077] exist Figure 7In the example shown, detection pulses are input in all subframe periods. However, for any number of subframes, detection pulses can be input all at once. In this case, the duty cycle of the light source can be calculated by using the number of detection pulse inputs as the denominator and the second count value as the numerator. The larger the number of detection pulses, the larger the circuit size of the counter circuit 802. Although the duty cycle of the light source may become less accurate when the number of detection pulses is reduced by inputting one detection pulse for each arbitrary subframe, the circuit size of the counter circuit can be reduced.

[0078] Furthermore, although embodiments have been described based on a configuration where one pixel includes one second counting unit, one pixel can include multiple second counting units. In this case, detection pulses with different high-level durations are input to each second counting unit, and a second count value is counted for each detection pulse. In this way, the duty cycle can be calculated for various brightness levels, making the correction value to be used by the pixel value correction unit 604 more desirable. Furthermore, by extending the high-level duration of the detection pulse, the intensity of the light source corresponding to the second count value can be changed. In this way, the second count value corresponding to the light intensity requiring correction can be counted according to the environment in which the imaging is performed.

[0079] Next, refer to Figure 9 This describes the method for creating correction values ​​to be used by the pixel value correction unit 604. Figure 9 This is a table illustrating a method for creating correction values, which has the duty cycle of the light source on the vertical axis and a first count value on the horizontal axis. The gain, which is used as the correction value to be multiplied by the first count value, is switched based on the duty cycle of the light source and the first count value. The duty cycle of the light source is obtained by using the number of detected pulse inputs as the denominator and the second count value as the numerator. For simplicity, the range of the first count value is equally divided into high (first count value 1000 to 668), medium (first count value 667 to 333), and low (first count value 332 to 0) ranges. The values ​​of the first count values ​​included in these ranges can be appropriately determined. Similarly, the range of the duty cycle of the light source is also described as high (100% to 66%), medium (66% to 33%), and low (33% to 0%), and the values ​​of the duty cycles included in the respective ranges can be appropriately set.

[0080] When the first count value is high, the pixel value correction unit 604 does not perform correction processing regardless of the duty cycle level of the light source. This is because the acquired pixel value is likely to appropriately reflect the actual condition of the subject.

[0081] When the first count value is moderate and the duty cycle of the light source is high, the acquired pixel value is likely to appropriately reflect the actual condition of the subject. Therefore, the pixel value correction unit 604 does not perform correction processing. It is expected that the above situation is unlikely to occur in actual shooting.

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

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

[0084] When the first count value is low and the duty cycle is high to medium, the acquired pixel value is likely to appropriately reflect the actual condition of the subject. Therefore, the pixel value correction unit 604 does not perform correction processing. However, it is anticipated that the above-mentioned imaging conditions are unlikely to occur in actual situations.

[0085] In the example above, a correction value is calculated such that the change in the first count value increases as the second count value decreases. When the second count value is the first value, the first count value after correction is the first corrected count value, and when the second count value is the second value, which is less than the first value, the first count value after correction is the second corrected count value, which is greater than the first corrected count value.

[0086] The above example is merely an example, and the value determined based on the first count value and the duty cycle of the light source can be used as a correction value to be used by the pixel value correction unit 604. Although the absolute value of the gain is calculated based on the characteristics of the duty cycle and the count value, a combination of the magnitude relationship of the duty cycle and the gain intensity, or a combination of the magnitude relationship of the count value and the gain magnitude relationship, is maintained under the corresponding imaging conditions. The correction value can be an additive value to be added to the first count value, instead of the gain multiplied by the first count value. In the above description, the correction value is set by dividing the duty cycle and the first count value into three modes respectively. However, the number of modes can be increased or decreased.

[0087] As described above, the photoelectric conversion device according to this embodiment can correct pixel values ​​when capturing images of subjects whose brightness changes within a frame. (Second Embodiment)

[0088] refer to Figure 10 The second embodiment of the present invention will be described. Since the basic functional block diagram of the camera device includes many parts common to the first embodiment, only the parts that differ from the first embodiment 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 correction unit 1004.

[0090] The light-receiving pulse and detection pulse output from the light-receiving unit 1001 are input to the switching unit 1002, and the light-receiving pulse and detection pulse are processed according to the switching signal.

[0091] The counting unit 1003 is a circuit that has both the functions of the first counting unit and the second counting unit 603 according to the first embodiment.

[0092] refer to Figure 11 The timing diagram is used to describe in detail the process of... Figure 10 The light-receiving unit 1001 in the middle performs the generation of light-receiving pulses and Figure 10 The operation of the switching unit 1002 and the counting unit 1003. Figure 11 The timing diagram and Figure 7 The difference between timing diagrams in the text and those in the text is that timing diagrams include... Figure 11 The shared count value shown in (M) and Figure 11 The switching signal shown in (N).

[0093] The shared count value is the value obtained by counting by counting unit 1003, and counting unit 1003 performs the task of acquiring the value in a time-division manner. Figure 7 The first counting process and the method for obtaining the first count value in the first count value. Figure 7 The second count processing of the second count value in the middle.

[0094] Figure 12 The diagram illustrates a configuration example of counting unit 1003. Counting unit 1003 includes an AND circuit 1201, a counter circuit 1202, and a selector 1203. The circuit configuration is... Figure 8 The difference in the circuit configuration of the second counting unit 803 is that the 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 counting unit and the second counting unit 603 of the photoelectric conversion device according to the first embodiment can be implemented by a single counting unit 1003, thereby reducing the circuit size of the pixel circuit.

[0096] In the following text, see references Figure 11 The operation of the photoelectric conversion device according to this embodiment is described using a timing diagram. In the photoelectric conversion device according to this embodiment, the switching signal is 0 (low) during the time period 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 counting unit 1003 counts the second count value used to calculate the duty cycle.

[0097] The switching signal changes from 0 (low) to 1 (high) at time t1110. At this time, the light 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] The pixel value correction unit 1104 can correct the first count value obtained from time t1111 to time t1119 by using a correction value based on the second count value obtained from counting from time t1101 to time t1109.

[0099] exist Figure 11 In this example, the number of subframes used to count the second count value for calculating the duty cycle is set to 1000. However, the number of subframes can be less than or greater than 1000. By reducing the number of subframes, the proportion of time spent counting the actual first count value can be increased, thereby increasing the frame rate of the camera device.

[0100] As described above, compared with the first embodiment, the photoelectric conversion device according to this embodiment can reduce the circuit size. (Third Embodiment)

[0101] The third embodiment can be applied to each of the first and second embodiments. Figure 13A This is a schematic diagram illustrating an apparatus 9191 including a semiconductor device 930 according to this embodiment.

[0102] The photoelectric conversion devices described in the above embodiments can be used in semiconductor device 930. A device 9191 including semiconductor device 930 is described in detail. In addition to semiconductor device 910, semiconductor device 930 may also include a package 920 for housing semiconductor device 910. Package 920 may include a substrate member to which semiconductor device 910 is fixed and a cover member made of a material such as glass, arranged facing semiconductor device 910. Package 920 may also include bonding members, such as bonding wires and bumps, for connecting terminals disposed on the substrate member to terminals disposed on semiconductor device 910.

[0103] Apparatus 9191 may 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 operates in association with the semiconductor device 930. For example, the optical device 940 is a lens, shutter, or mirror, and includes an optical system for directing light to the semiconductor device 930. The control device 950 controls the semiconductor device 930. For example, the control device 950 is a semiconductor device such as an application-specific integrated circuit (ASIC).

[0104] Processing device 960 processes signals output from semiconductor device 930. Processing device 960 is a semiconductor device such as a central processing unit (CPU) or ASIC used to configure an analog front-end (AFE) or digital front-end (DFE). Display device 970 is an electroluminescent (EL) display device or liquid crystal display device that displays information (images) acquired by semiconductor device 930. Storage device 980 is a magnetic or semiconductor device that stores information (images) acquired by semiconductor device 930. Storage device 980 is a volatile memory such as static random access memory (SRAM) or dynamic random access memory (DRAM), or a non-volatile memory such as flash memory or hard disk drive.

[0105] Mechanical device 990 includes a movable unit or propulsion unit such as a motor or engine. Device 9191 displays signals output from semiconductor device 930 on display device 970, or transmits signals to an external unit via a communication device (not illustrated) included in device 9191. Therefore, in addition to the storage circuitry and computing circuitry included in semiconductor device 930, device 9191 may also include storage device 980 and processing device 960. Mechanical device 990 can be controlled based on signals output from semiconductor device 930.

[0106] Device 9191 is suitable for electronic devices, such as information terminals with camera capabilities (e.g., smartphones or wearable devices) or cameras (e.g., interchangeable lens cameras, compact cameras, camcorders, or surveillance cameras). Mechanical devices 990 in the camera can drive components of optical devices 940 for zooming, focusing, and shutter operations. Alternatively, mechanical devices 990 in the camera can move semiconductor devices 930 for image stabilization operations.

[0107] Furthermore, device 9191 can be a transportation device, such as a vehicle, ship, or aircraft. The mechanical equipment 990 within the transportation device can be used as a mobile device. Device 9191 as a transportation device is suitable for transporting semiconductor equipment 930 or for assisting and / or automating driving or manipulation via camera functionality. Processing equipment 960 for assisting and / or automating driving operations (operations) can perform processing for operating the mechanical equipment 990 as a mobile device based on information acquired by semiconductor equipment 930. Alternatively, device 9191 can be a medical device such as an endoscope, a measuring device such as a range sensor, an analytical device such as an electron microscope, office equipment such as a copier, or industrial equipment such as a robot.

[0108] According to the above embodiments, advantageous pixel characteristics can be obtained. Therefore, the value of the semiconductor device can be increased. This increased value, as mentioned herein, includes at least one of adding functionality, improving performance, enhancing characteristics, increasing reliability, increasing manufacturing yield, reducing environmental impact, reducing cost, decreasing size, and reducing weight.

[0109] Therefore, if the semiconductor device 930 according to this embodiment is used in device 9191, the value of the device can be increased. For example, excellent performance can be obtained when the semiconductor device 930 is mounted on a transport device to capture images of the exterior of the transport device or measure the external environment. Therefore, in the process of manufacturing and selling the transport device, deciding to mount the semiconductor device according to this embodiment on the transport device is beneficial to improving the performance of the transport device itself. In particular, the semiconductor device 930 is suitable for a transport device that uses information acquired by the semiconductor device to assist and / or automate driving operations performed by the transport device.

[0110] refer to Figure 13B and Figure 13C The photoelectric conversion system and the moving body according to this embodiment are described below.

[0111] Figure 13AThis is a diagram illustrating an example of a photoelectric conversion system related to a vehicle-mounted camera. The photoelectric conversion system 8 includes a photoelectric conversion device 80. The photoelectric conversion device 80 is a photoelectric conversion device (camera device) according to any of the embodiments described above. The photoelectric conversion system 8 includes: an image processing unit 801 for performing image processing on multiple image data acquired by the photoelectric conversion device 80; and a disparity acquisition unit 802 for calculating disparity (phase difference of a disparity image) from the multiple image data acquired by the photoelectric conversion system 8. The photoelectric conversion system 8 also includes: a distance acquisition unit 803 for calculating the distance to a target subject based on the calculated disparity; and a collision determination unit 804 for determining the possibility of a collision based on the calculated distance. Here, the disparity acquisition unit 802 and the distance acquisition unit 803 are examples of distance information acquisition units that acquire distance information indicating the distance to a target subject. In other words, distance information refers to information related to disparity, defocus, and the distance to the target subject. The collision determination unit 804 can determine the possibility of a collision by using any of these types of distance information. The distance information acquisition unit can be implemented by specially designed hardware or by a software module. Furthermore, the distance information acquisition unit can be implemented by a field-programmable gate array (FPGA), an application-specific integrated circuit (ASIC), or a combination of these components.

[0112] The photoelectric conversion system 8 is connected to the vehicle information acquisition device 810, enabling the photoelectric conversion system 8 to acquire vehicle information such as vehicle speed, yaw rate, and steering angle. Furthermore, a control electronic control unit (ECU) 820, serving as a control device, is connected to the photoelectric conversion system 8. The control ECU 820 outputs a control signal to apply braking force to the vehicle based on the determination results obtained by the collision determination unit 804. An alarm device 830, used to warn the driver based on the determination results obtained by the collision determination unit 804, is also connected to the photoelectric conversion system 8. For example, if the collision determination unit 804 determines that a collision is highly likely, the control ECU 820 performs vehicle control to avoid a collision and / or reduce damage by applying the brakes, releasing the accelerator pedal, or suppressing engine output. The alarm device 830 warns the user by emitting an alarm sound, displaying an alarm message on the screen of the vehicle navigation system, or generating vibrations in the seatbelt or steering wheel.

[0113] In this embodiment, the photoelectric conversion system 8 captures peripheral views of the vehicle, such as the front and rear views of the vehicle.

[0114] Figure 13CThis diagram illustrates a photoelectric conversion system used to capture a front view (viewing range 850) of a vehicle. The vehicle information acquisition device 810 sends instructions to the photoelectric conversion system 8 or the photoelectric conversion device 80. With this configuration, ranging accuracy can be further improved.

[0115] The above example describes control for preventing a vehicle from colliding with another vehicle. However, this embodiment can also be applied to control of a vehicle autonomously following another vehicle or to control an autonomous vehicle while preventing it from leaving its lane. Furthermore, the photoelectric conversion system can be applied not only to vehicles such as automobiles, but also to mobile bodies (mobile devices) such as ships, aircraft, or industrial robots. In addition to mobile bodies, the photoelectric conversion system can also be applied to devices such as intelligent transportation systems (ITS) that widely employ subject recognition.

[0116] The above embodiments can be appropriately modified without departing from the spirit of the technology. The disclosure of this specification includes not only what is described herein, but also everything that can be grasped from this specification and the accompanying drawings. Furthermore, the disclosure of this specification includes supplements to the concepts described herein. In other words, for example, if this specification includes the description "A is greater than B," it can be considered that even if the description "A is not greater than B" is omitted, this specification still discloses the description "A is not greater than B." This is because "A is greater than B" is described based on the premise that "A is not greater than B."

[0117] The disclosure in this embodiment includes the following configurations and methods. (Configuration 1)

[0118] A photoelectric conversion device includes: a light-receiving unit, wherein a voltage applied to the light-receiving unit is controlled by a recharge pulse and the light-receiving unit is configured to convert incident light into a light-receiving pulse; a first counting unit configured to generate a first count value by using the light-receiving pulse during a time period from a first recharge pulse to a second recharge pulse in the recharge pulse; and a second counting unit, wherein a detection pulse valid for a portion of the time period and invalid for another portion of the time period is input to the second counting unit. The second counting unit generates a second count value during the time period by using the light-receiving pulse and the detection pulse. (Configuration 2)

[0119] According to the photoelectric conversion device described in configuration 1, the second counting unit outputs the logical product of the received light pulse and the detected pulse as the second counting value. (Configuration 3)

[0120] According to configuration 1 or 2 of the photoelectric conversion device, the correction value for the correction processing of the first count value is generated by using the second count value and the first count value. (Configuration 4)

[0121] According to the photoelectric conversion device of configuration 3, when the second count value is a first value, the first count value after the correction process is a first correction count value; and when the second count value is a second value less than the first value, the first count value after the correction process is a second correction count value greater than the first correction count value. (Configuration 5)

[0122] According to any one of configurations 1 to 4, the amount of change in the first count value changes according to the timing of generating the light-receiving pulse during the exposure period. (Configuration 6)

[0123] According to the photoelectric conversion device described in configuration 5, 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. (Configuration 7)

[0124] According to any one of configurations 1 to 6, the photoelectric conversion device further includes a switch connected in series between the light-receiving unit and a node for supplying a driving voltage to the light-receiving unit, wherein the recharge pulse is a clock signal input to the switch. (Configuration 8)

[0125] The photoelectric conversion device according to configuration 2 further includes a switch connected in series between the light-receiving unit and a node for supplying a driving voltage to the light-receiving unit, wherein the recharge pulse is a clock signal input to the switch, and wherein the detection pulse is a signal input synchronously with the clock signal. (Configuration 9)

[0126] According to any one of configurations 1 to 8, the photoelectric conversion device wherein the light-receiving unit is an avalanche photodiode. (Configuration 10)

[0127] A photoelectric conversion device includes: a light-receiving unit, wherein a voltage applied to the light-receiving unit is controlled by a recharge pulse and the light-receiving unit is configured to convert incident light into a light-receiving pulse; a counting unit configured to perform either a first counting process or a second counting process; and a switching unit having the function of switching between the first counting process and the second counting process according to a switching signal. As the first counting process, a count value is changed based on the generation of the light-receiving pulse during a time period from a first recharge pulse to a second recharge pulse of the recharge pulse. As the second counting process, a count value is changed based on the light-receiving pulse and a detection pulse that is valid in a portion of the time period but invalid in another portion of the time period. (Configuration 11)

[0128] According to the photoelectric conversion device of configuration 10, the logical product of the light-receiving pulse and the detection pulse is counted as a count value. (Configuration 12)

[0129] According to the photoelectric conversion device of configuration 10, the correction value for correcting the count value is generated by using the count value obtained by the first counting process and the count value obtained by the second counting process. (Configuration 13)

[0130] According to the photoelectric conversion device of configuration 12, when the count value obtained by the second counting process is a first value, the count value obtained by the first counting process after the correction process is a first corrected count value; and when the count value obtained by the second counting process is a second value less than the first value, the count value obtained by the first counting process after the correction process is a second corrected count value greater than the first corrected count value. (Configuration 14)

[0131] According to any one of configurations 10 to 13, the photoelectric conversion device further includes a switch connected in series between the light-receiving unit and a node for supplying a driving voltage to the light-receiving unit, wherein the recharge pulse is a clock signal input to the switch. (Configuration 15)

[0132] The photoelectric conversion device according to configuration 11 further includes a switch connected in series between the light-receiving unit and a node for supplying a driving voltage to the light-receiving unit, wherein the recharge pulse is a clock signal input to the switch, and wherein the detection pulse is a signal input synchronously with the clock signal. (Configuration 16)

[0133] According to any one of configurations 10 to 15, the photoelectric conversion device wherein the light-receiving unit is an avalanche photodiode. (Configuration 17)

[0134] A photoelectric conversion system includes: a photoelectric conversion device according to any one of configurations 1 to 16; and a signal processing unit configured to generate an image by using a signal output from the photoelectric conversion device. (Configuration 18)

[0135] A mobile body includes: a photoelectric conversion device according to any one of configurations 1 to 16; and a control unit configured to control the movement of the mobile body by using a signal output from the photoelectric conversion device.

[0136] This invention is not limited to the embodiments described above, and various changes and modifications can be made without departing from the spirit and scope of the invention. Therefore, the appended claims are added to disclose the scope of the invention.

[0137] This application claims priority to Japanese Patent Application 2024-049500, filed on March 26, 2024, the entire contents of which are incorporated herein by reference. List of reference numerals

[0138] 601 Light Receiving Unit 602 First Counting Unit 603 Second Counting Unit

Claims

1. A photoelectric conversion device, comprising: A light-receiving unit, wherein the voltage applied to the light-receiving unit is controlled by a recharge pulse and the light-receiving unit is configured to convert incident light into a light-receiving pulse; A first counting unit is configured to generate a first count value by using the light-receiving pulse during the period from the first recharge pulse to the second recharge pulse of the recharge pulse. as well as A second counting unit is provided, wherein a detection pulse that is valid in a portion of the time period and invalid in another portion of the time period is input to the second counting unit. The second counting unit generates a second count value during the time period by using the light-receiving pulse and the detection pulse.

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

3. The photoelectric conversion device according to claim 1, wherein, The correction value used for the correction processing of the first count value is generated by using the second count value and the first count value.

4. The photoelectric conversion device according to claim 3, in, When the second count value is the first value, the first count value after the correction process is the first corrected count value; and Wherein, when the second count value is a second value that is less than the first value, the first count value after the correction process is a second correction count value that is greater than the first correction count value.

5. The photoelectric conversion device according to claim 1, wherein, The change in the first count value varies depending on the timing of the generation of the light-receiving pulse during the exposure period.

6. The photoelectric conversion device according to claim 5, wherein, The sum of the first count value in the period before the center timing of the exposure period is greater than the sum of 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 includes a switch, the switch being connected in series between the light-receiving unit and a node for supplying a driving voltage to the light-receiving unit. in, The recharge pulse is a clock signal input to the switch.

8. The photoelectric conversion device according to claim 2 further includes a switch, the switch being connected in series between the light-receiving unit and a node for supplying a driving voltage to the light-receiving unit. in, The recharge pulse is a clock signal input to the switch, and The detection pulse is a signal that is input synchronously with the clock signal.

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

10. A photoelectric conversion device, comprising: A light-receiving unit, wherein the voltage applied to the light-receiving unit is controlled by a recharge pulse and the light-receiving unit is configured to convert incident light into a light-receiving pulse; A counting unit, configured to perform either a first counting process or a second counting process; as well as The switching unit has the function of switching between the first counting process and the second counting process according to a switching signal. Wherein, as the first counting process, the count value is changed according to the generation of the light-receiving pulse during the time period from the first recharge pulse to the second recharge pulse of the recharge pulse, and In this second counting process, the count value is changed based on the light-receiving pulse and the detection pulse that is valid in one part of the time period but invalid in another part of the time period.

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

12. The photoelectric conversion device according to claim 10, wherein, The correction value used to correct the count value is generated by 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 according to claim 11, in, When the count value obtained by the second counting process is the first value, the count value obtained by the first counting process after the correction process is the first corrected count value; and Wherein, when the count value obtained by the second counting process is a second value that is less than the first value, the count value obtained by the first counting process after the correction process is a second correction count value that is greater than the first correction count value.

14. The photoelectric conversion device according to claim 10 further includes a switch, the switch being connected in series between the light-receiving unit and a node for supplying a driving voltage to the light-receiving unit. in, The recharge pulse is a clock signal input to the switch.

15. The photoelectric conversion device according to claim 11 further includes a switch, the switch being connected in series between the light-receiving unit and a node for supplying a driving voltage to the light-receiving unit. in, The recharge pulse is a clock signal input to the switch, and The detection pulse is a signal that is input synchronously with the clock signal.

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

17. A photoelectric conversion system, comprising: The photoelectric conversion device according to any one of claims 1 to 16; as well as A signal processing unit is configured to generate an image using a signal output from the photoelectric conversion device.

18. A mobile body, comprising: The photoelectric conversion device according to any one of claims 1 to 16; as well as A control unit is configured to control the movement of the moving body by using signals output from the photoelectric conversion device.

Images