Light detection device

Abstract

The present technology relates to a light detection device comprising: a plurality of avalanche photodiodes arranged in a two-dimensional array, comprising first and second avalanche photodiodes; a first transistor connected to an anode or a cathode of the first avalanche photodiode; and a second transistor connected to an anode or a cathode of the second avalanche photodiode; in a first mode, the first transistor is in an on state, the second transistor is in an on state; in a second mode, the first transistor is in an on state, the second transistor is in an off state, wherein the light detection device is arranged to switch between the first mode and the second mode, and wherein the first avalanche photodiode and the second avalanche photodiode are located in a same row of the two-dimensional array. For example, the present technology can be applicable to an image sensor.

Description

[0001] This application is a divisional application of patent application No. 201880008273.7, with the title "Solid-state imaging device and driving method thereof", filed on August 3, 2018. TECHNICAL FIELD

[0002] The present technology relates to a solid-state imaging device and a driving method thereof, and more particularly, to a solid-state imaging device and a driving method thereof that enable imaging with lower power consumption. BACKGROUND

[0003] A SPAD (Single Photon Avalanche Diode), which is a photodiode technology that has readout sensitivity at a single photon level through electron multiplication (see, for example, Patent Literature 1).

[0004] LIST OF CITATIONS

[0005] PATENT LITERATURE

[0006] Patent Literature 1: US 2015 / 0054111 A1 SUMMARY

[0007] PROBLEMS

[0008] Incidentally, a SPAD has a structure in which an avalanche section in a semiconductor that detects one photon, and electrons photoelectrically converted from one photon pass through the section and are multiplied by tens of thousands of times. Therefore, a solid-state imaging device using SPAD pixels is suitable for imaging in a dark scene with a small amount of light.

[0009] On the other hand, in the case where a solid-state imaging device using SPAD pixels is used for imaging in a bright scene with a large amount of light, tens of thousands of photons are incident and multiplied, and hundreds of millions of electrons are generated. As a result, power consumption becomes very large, and it is desirable to reduce power consumption.

[0010] The present technology was made in view of the above circumstances, and an object thereof is to provide a solid-state imaging device using SPAD pixels that enables imaging with lower power consumption.

[0011] SOLUTION TO PROBLEM

[0012] According to one aspect of the present technology, a solid-state imaging device includes a pixel array section on which a plurality of SPAD (Single Photon Avalanche Diode) pixels are arranged two-dimensionally, wherein in a case where an illuminance becomes a first illuminance that is higher than a reference illuminance, a portion of the plurality of SPAD pixels arranged on the pixel array section is thinned out.

[0013] According to one aspect of the present technology, a driving method of a solid-state imaging device including a pixel array section on which a plurality of SPAD pixels are arranged two-dimensionally includes, in a case where an illumination changes to a first illumination that is higher than a reference illumination, sparsifying a part of the plurality of SPAD pixels arranged on the pixel array section.

[0014] In a solid-state imaging device and a driving method according to one aspect of the present technology, in a case where an illumination changes to a first illumination that is higher than a reference illumination, a part of a plurality of SPAD pixels arranged on a pixel array section is sparsified.

[0015] The solid-state imaging device according to one aspect of the present technology can be an independent device, or can be an internal block that constitutes one device.

[0016] Advantages of the Invention

[0017] According to one aspect of the present technology, imaging can be performed with lower power consumption.

[0018] Note that the effects described here are not necessarily limiting, and can be any effect described in the present disclosure. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 is a block diagram showing a configuration example of an embodiment of a solid-state imaging device to which the present technology is applied.

[0020] Figure 2 is a diagram showing a first example of driving a plurality of SPAD pixels arranged on a pixel array section.

[0021] Figure 3 is a diagram showing a second example of driving a plurality of SPAD pixels arranged on a pixel array section.

[0022] Figure 4 is a cross-sectional view showing a first example of a structure of a SPAD pixel.

[0023] Figure 5 is a cross-sectional view showing a second example of a structure of a SPAD pixel.

[0024] Figure 6 is a plan view showing a third example of a structure of a SPAD pixel.

[0025] Figure 7 is a cross-sectional view showing a third example of a structure of a SPAD pixel.

[0026] Figure 8 is a plan view showing a fourth example of a structure of a SPAD pixel.

[0027] Figure 9is a sectional view showing a fourth example of the structure of a SPAD pixel.

[0028] Figure 10 is a graph showing an example of the probability of avalanche occurrence by the voltage difference between the anode and the cathode of a SPAD.

[0029] Figure 11 is a flowchart illustrating the flow of a SPAD pixel drive control process.

[0030] Figure 12 is a plan view showing another example of the structure of a SPAD pixel.

[0031] Figure 13 is a plan view showing another example of the structure of a SPAD pixel.

[0032] Figure 14 is a block diagram showing a configuration example of an electronic device including a solid-state imaging device to which the present technology is applied.

[0033] Figure 15 is a graph showing a use example of a solid-state imaging device to which the present technology is applied.

[0034] Figure 16 is a block diagram showing an example of the schematic configuration of a vehicle control system.

[0035] Figure 17 is a graph that helps explain an example of the mounting positions of an outside-vehicle information detection section and an imaging section. DETAILED DESCRIPTION

[0036] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. Embodiments of the present technology will be described in the following order.

[0037] 1. Configuration of solid-state imaging device

[0038] 2. Embodiments of the present technology

[0039] 3. Modified examples

[0040] 4. Configuration of electronic device

[0041] 5. Use example of solid-state imaging device

[0042] 6. Application example of mobile body

[0043] <1. Configuration of solid-state imaging device>

[0044] (Configuration example of solid-state imaging device)

[0045] Figure 1 is a block diagram showing a configuration example of an embodiment of a solid-state imaging device to which the present technology is applied.

[0046] The solid-state imaging device 10 is an image sensor that receives incident light from an object, converts the amount of incident light imaged on an imaging surface into an electrical signal in units of pixels, and outputs it as a pixel signal.

[0047] In Figure 1 The solid-state imaging device 10 includes a pixel array section 21, a control circuit 22, and a readout circuit 23.

[0048] In the pixel array section 21, a plurality of SPAD (single photon avalanche diode) pixels are arranged two-dimensionally (in a matrix). Here, the SPAD pixel is a pixel including a single photon avalanche photodiode (SPAD). The single photon avalanche photodiode has a structure in which an avalanche section in a semiconductor that detects one photon passes through an electron photo-converted from one photon, and the electron is multiplied (amplified) by several tens of thousands of times.

[0049] The control circuit 22 controls the operation of each section of the solid-state imaging device 10.

[0050] In addition, the control circuit 22 outputs a control signal (pulse) for driving the SPAD pixel via a pixel drive line, thereby controlling the driving of the plurality of SPAD pixels arranged two-dimensionally on the pixel array section 21. For example, the control circuit 22 controls the driving of the plurality of SPAD pixels arranged two-dimensionally on the pixel array section 21 based on the detection result of the illuminance.

[0051] The readout circuit 23 sequentially scans the plurality of SPAD pixels arranged two-dimensionally on the pixel array section 21, and reads out the pixel signal generated by each SPAD pixel via a signal line. The readout circuit 23 outputs the read-out pixel signal to a signal processing section (not shown) of the next stage.

[0052] The solid-state imaging device 10 is configured as described above.

[0053] <2. Embodiment of the present technology>

[0054] Incidentally, the solid-state imaging device 10 has the pixel array section 21 on which a plurality of SPAD pixels are arranged two-dimensionally. When imaging in a bright place, for example, several tens of thousands of photons are incident and multiplied, thereby generating several hundred million electrons. Therefore, it is desirable to reduce power consumption. According to the present technology, the power consumption is reduced by the following method.

[0055] Specifically, in the solid-state imaging device 10, in a case where the illuminance is higher than a reference illuminance, a part of the plurality of SPAD pixels arranged on the pixel array section 21 is thinned. Therefore, it is possible to perform imaging at lower power consumption.

[0056] Note that, depending on the threshold value, the illuminance, for example, can be divided into three stages: high illuminance, middle illuminance lower than the high illuminance, and low illuminance lower than the middle illuminance. Specifically, for example, the high illuminance is set to about 10,000 lux, the middle illuminance is set to about 1,000 lux, and the low illuminance is set to about 0.01 lux.

[0057] Further, depending on the threshold value, the illuminance, for example, can be divided into two stages: high illuminance and low illuminance lower than the high illuminance. In other words, depending on the threshold value, the illuminance is divided into multi-stage illuminance.

[0058] (First example of driving SPAD pixels)

[0059] Figure 2 A first example of driving a plurality of SPAD pixels arranged on a pixel array section 21 of Figure 1 is shown.

[0060] Figure 2 A pixel arranged in the upper left region of 16 rows and 16 columns is shown, for example, as seen from the light incident side, among a plurality of SPAD pixels 100 arranged two-dimensionally on the pixel array section 21.

[0061] Note that, in Figure 2 , each row number and each column number corresponding to the i-th row and the j-th column of the SPAD pixels 100 are indicated in the left region and the upper region. In the following description, the i-th row and the j-th column of the plurality of SPAD pixels 100 arranged on the pixel array section 21 are indicated as SPAD pixels 100(i, j).

[0062] In addition, as a color filter, a red (R) color filter is disposed. A pixel that receives a pixel signal of light corresponding to a red (R) component from light that has passed through the R color filter is indicated as an R pixel.

[0063] Similarly, a pixel that receives a pixel signal of light corresponding to a green (G) component from light that has passed through the G color filter is indicated as a G pixel. In addition, a pixel that receives a pixel signal of light corresponding to a blue (B) component from light that has passed through the B color filter is indicated as a B pixel.

[0064] Specifically, in the pixel array section 21, the plurality of SPAD pixels 100 are two-dimensionally and regularly arranged as R pixels, G pixels, or B pixels to form a Bayer array. Note that the Bayer array is an arrangement pattern in which G pixels are arranged in a checkerboard pattern and R pixels and B pixels are alternately arranged for one column in the remaining portion.

[0065] Here, in the pixel array section 21, the SPAD pixel 100(3, 3) is observed. This SPAD pixel 100(3, 3) is a B pixel, and also a thinned pixel to which the word "OFF" is added.

[0066] The sparse pixel is a pixel that is thinned out among the plurality of SPAD pixels 100 arranged two-dimensionally on the pixel array section 21 at high illuminance. The SPAD pixel 100(3, 3) becomes a sparse pixel at high illuminance according to driving control from the control circuit 22.

[0067] In the pixel array section 21, the SPAD 100(2, 9), the SPAD pixel 100(4, 7), the SPAD pixel 100(4, 13), the SPAD pixel 100(6, 2), the SPAD pixel 100(6, 7), the SPAD pixel 100(6, 14), the SPAD pixel 100(7, 13), and the SPAD pixel 100(8, 5) are set as sparse pixels, similarly to the SPAD pixel 100(3, 3).

[0068] Further, in the pixel array section 21, the SPAD pixel 100(9, 16), the SPAD pixel 100(10, 4), the SPAD pixel 100(10, 13), the SPAD pixel 100(11, 1), the SPAD pixel 100(11, 5), the SPAD pixel 100(11, 9), the SPAD pixel 100(13, 3), the SPAD pixel 100(13, 13), the SPAD pixel 100(14, 6), the SPAD pixel 100(14, 9), and the SPAD pixel 100(15, 15) are set as sparse pixels, similarly to the SPAD pixel 100(3, 3).

[0069] Thus, in the pixel array section 21, at high illuminance, any of the plurality of SPAD pixels 100 is irregularly (randomly) set as a sparse pixel for each pixel unit. Then, since a part of the plurality of SPAD pixels 100 arranged two-dimensionally on the pixel array section 21 is thinned out for each pixel unit at high illuminance, it is possible to reduce power consumption.

[0070] Note that the pixel signal corresponding to the position of the sparse pixel can be acquired by performing predetermined signal processing (for example, correction processing) using the image signal acquired from the pixels around the sparse pixel, for example, on the signal processing circuit of the next stage.

[0071] (Second Example of Driving SPAD Pixels)

[0072] Figure 3 A second example of driving a plurality of SPAD pixels arranged on the pixel array section 21 of Figure 1 is shown.

[0073] In the pixel array section 21 of Figure 3 , similarly to Figure 2The pixel array section 21 illustrated in FIG. 1 is a Bayer array in which a plurality of SPAD pixels 100 are two-dimensionally and regularly arranged as R pixels, G pixels, or B pixels.

[0074] Further, in the pixel array section 21 of the present embodiment, a part of the plurality of SPAD pixels 100 is thinned out (turned off). However, the thinned-out pixels are not configured for each pixel unit but for each block unit including a plurality of pixels. Figure 3

[0075] For example, in the pixel array section 21, one block is constituted by the SPAD pixels 100 of 4 x 4 pixels including the SPAD pixels 100(1, 1) to 100(1, 4), the SPAD pixels 100(2, 1) to 100(2, 4), the SPAD pixels 100(3, 1) to 100(3, 4), and the SPAD pixels 100(4, 1) to 100(4, 4). The SPAD pixels 100 in the block are turned into thinned-out pixels at high illuminance.

[0076] Further, for example, in the pixel array section 21, one block is constituted by the SPAD pixels 100 of 4 x 4 pixels including the SPAD pixels 100(1, 5) to 100(1, 8), the SPAD pixels 100(2, 5) to 100(2, 8), the SPAD pixels 100(3, 5) to 100(3, 8), and the SPAD pixels 100(4, 5) to 100(4, 8). The SPAD pixels 100 in the block are normal pixels, and are any one of R pixels, G pixels, or B pixels even at high illuminance.

[0077] Similarly, in the pixel array section 21, for the 4 x 4 pixel block, a first block including normal SPAD pixels 100 and a second block including SPAD pixels 100 turned into thinned-out pixels at high illuminance are alternately repeated in the column direction and the row direction.

[0078] Thus, in the pixel array section 21, at high illuminance, any of the plurality of SPAD pixels 100 is regularly turned into a thinned-out pixel for each block unit. Then, since a part of the plurality of SPAD pixels 100 two-dimensionally arranged on the pixel array section 21 is thinned out for each block unit at high illuminance, power consumption can be reduced.

[0079] (First Example of Structure of SPAD Pixel)

[0080] Figure 4 FIG. 2 is a cross-sectional view illustrating a first example of a structure of the SPAD pixel 100.

[0081] In the SPAD pixel 100, the SPAD 101 is a photodiode that generates a signal according to the amount of incident light. Figure 4 ​In the single photon avalanche photodiode 110 of the SPAD pixel 100, a voltage that generates avalanche multiplication is applied, for example, on the anode 111 or the cathode 112. The pn junction between the n-well that receives incident light and the p+ diffusion layer causes avalanche multiplication to occur.

[0082] In the single photon avalanche photodiode 110, the transistor 121 is connected to the anode 111. A drive signal from the control circuit 22 is input to the gate of the transistor 121 to control the on / off of the transistor 121.

[0083] By the control circuit 22, if the brightness is low or medium other than high illuminance, the SPAD pixel 100 that becomes a sparse pixel at the time of high illuminance is allowed to have a predetermined level of a drive signal input to the gate of the transistor 121. Thus, the target SPAD pixel 100 is driven as an R pixel, a G pixel, or a B pixel.

[0084] In addition, by the control circuit 22, if the brightness is high, the SPAD pixel 100 that becomes a sparse pixel at the time of high illuminance is allowed to have a predetermined level of a drive signal input to the gate of the transistor 121. Thus, the target SPAD pixel 100 becomes a sparse pixel.

[0085] Note that, by the control circuit 22, the SPAD pixel 100 that becomes a normal pixel is allowed to have a predetermined level of a drive signal input to the gate of the transistor 121. Thus, regardless of high illuminance, medium illuminance, or low illuminance, the target SPAD pixel 100 is always driven as an R pixel, a G pixel, or a B pixel.

[0086] Thus, in the SPAD pixel 100, the transistor 121 is connected to the anode 111 of the single photon avalanche photodiode 110 and controls the voltage thereof. Thus, for each pixel unit or each block unit, at the time of high illuminance, it is possible to cause a part of the SPAD pixels 100 among a plurality of SPAD pixels arranged on the pixel array section 21 to be sparse.

[0087] (Second Example of Structure of SPAD Pixel)

[0088] Figure 5 is a cross-sectional view that shows a second example of the structure of the SPAD pixel 100.

[0089] In Figure 5 In the SPAD pixel 100, the transistor 122 is connected to the cathode 112 of the single photon avalanche photodiode 110. A drive signal from the control circuit 22 is input to the gate of the transistor 122 to control the on / off of the transistor 122.

[0090] Therefore, in the SPAD pixel 100, the transistor 122 is connected to the cathode 112 of the single photon avalanche photodiode 110 and controls the voltage thereof. Therefore, for each pixel unit or each block unit, it is possible to make a part of the plurality of SPAD pixels 100 arranged on the pixel array section 21 sparse at high illuminance.

[0091] (Third Example of Structure of SPAD Pixel)

[0092] Figure 6 is a plan view showing a third example of the structure of the SPAD pixel 100.

[0093] Figure 6 The SPAD pixel 100 of the structure of the SPAD pixel 100 has a structure in which the avalanche section 131, which is a multiplication region of the single photon avalanche photodiode 110, is divided into a plurality, and the anode 111 and the cathode 112 are connected to each divided avalanche section 131.

[0094] Here, the avalanche section 131 is divided into four to form divided avalanche sections 131-1 to 131-4, and cathodes 112-1 to 112-4 are connected to the respective divided avalanche sections 131-1 to 131-4.

[0095] Figure 7 A cross-sectional view taken along the line A-A' of the SPAD pixel 100 is shown. Figure 6

[0096] In the single photon avalanche photodiode 110 of the SPAD pixel 100, the cathode 112-1 is connected to the divided avalanche section 131-1. The transistor 122-1 is connected to the cathode 112-1, and controls the on / off operation according to the drive signal from the control circuit 22. Figure 7 On the other hand, the cathode 112-4 is connected to the divided avalanche section 131-4. The transistor 122-4 is connected to the cathode 112-4, and controls the on / off operation according to the drive signal from the control circuit 22.

[0097] By the control circuit 22, if the brightness is high, it is allowed to input a predetermined level of the drive signal to the gate of the transistor 122-1 to 122-4 with respect to the SPAD pixel 100 which becomes a sparse pixel at high illuminance. Therefore, the target SPAD pixel 100 becomes a sparse pixel.

[0098] At this time, in the SPAD pixel 100, it is allowed to input a predetermined level of the drive signal to each gate of the transistors 122-1 to 122-4, thereby controlling the drive of each divided avalanche section 131-1 to 131-4.

[0099] Therefore, in the SPAD pixel 100, the transistor 122 is connected to the cathode 112 of the single photon avalanche photodiode 110 and controls the voltage thereof. Therefore, for each pixel unit or each block unit, it is possible to make a part of the plurality of SPAD pixels 100 arranged on the pixel array section 21 sparse at high illuminance.​

[0100] For example, at low or medium illuminance, all four of the divided avalanche portions 131-1 to 131-4 are used (i.e., the utilization rate at this time is equal to "4 / 4"). However, at high illuminance, only three of the divided avalanche portions 131-1 to 131-4 are used (i.e., the utilization rate at this time is equal to "3 / 4").

[0101] Note that such sparse control for each divided avalanche portion unit can be performed for all of the plurality of SPAD pixels 100 arranged on the pixel array portion 21, or can be performed for only a part of the SPAD pixels 100.

[0102] Therefore, in a case where the avalanche portion 131 of the SPAD pixel 100 is divided into a plurality, the transistors 122-1 to 122-4 are connected to the cathodes 112-1 to 112-4 of the respective divided avalanche portions 131-1 to 131-4 and control the voltage thereof. Therefore, for each divided pixel unit (divided avalanche portion unit), at high illuminance, it is possible to sparsify a part of the plurality of SPAD pixels 100 arranged on the pixel array portion 21.

[0103] (Fourth Example of Structure of SPAD Pixel)

[0104] Figure 8 is a plan view showing a fourth example of the structure of the SPAD pixel 100.

[0105] Similarly to the third example described above, Figure 8 The SPAD pixel 100 of has a structure in which the avalanche portion 131 is divided into four, and the anode 111 and the cathode 112 are connected to the avalanche portions 131-1 to 131-4.

[0106] Figure 9 shows a cross-sectional view taken along the line A-A' of Figure 8 shows a fourth example of the structure of the SPAD pixel 100.

[0107] In the single-photon avalanche photodiode 110 of Figure 9 the cathode 112-1 is connected to the divided avalanche portion 131-1. In addition, the gate electrode 141-1 is configured to cover a part of the upper portion of the divided avalanche portion 131-1.

[0108] Here, the wiring contact is connected to the upper portion of the gate electrode 141-1. The gate electrode 141-1 performs on / off operation in accordance with a drive signal applied via the contact, so that electrons are transported from the divided avalanche portion 131-1 to the cathode 112.

[0109] The overflow drain (OFD) 142-1 is configured to drain unnecessary electrons so that the electrons do not leak to the adjacent avalanche portion 131 (e.g., the divided avalanche portions 131-2 ~ 131-4) when the gate electrode 141-1 is turned off.

[0110] On the other hand, the cathode 112 is connected to the gate electrode 141-4, and the overflow drain 142-4 is disposed on the divided avalanche portion 131-4. The gate electrode 141-4 performs on / off operation in accordance with the drive signal applied via the contact so that the electrons are transmitted from the divided avalanche portion 131-4 to the cathode 112.

[0111] By the control circuit 22, if the brightness is high, the SPAD pixel 100 that becomes a sparse pixel at the time of high illuminance is allowed to apply a predetermined level of drive signal to the gate electrodes 141-1 ~ 141-4. Thus, the target SPAD pixel 100 becomes a sparse pixel.

[0112] At this time, in the SPAD pixel 100, a predetermined level of drive signal is allowed to be input to each of the gate electrodes 141-1 ~ 141-4, thereby controlling the drive of each of the divided avalanche portions 131-1 ~ 131-4.

[0113] For example, at the time of low or medium illuminance, all four of the divided avalanche portions 131-1 ~ 131-4 (i.e., the utilization rate at this time is equal to "4 / 4") are used. However, at the time of high illuminance, only one of the divided avalanche portions 131-1 ~ 131-4 (i.e., the utilization rate at this time is equal to "1 / 4") is used.

[0114] Note that this sparse control for each of the divided avalanche portion units can be performed on all of the plurality of SPAD pixels 100 arranged on the pixel array portion 21, or can be performed on only a part of the SPAD pixels 100.

[0115] Thus, in the case where the avalanche portion 131 of the SPAD pixel 100 is divided into a plurality, the gate electrodes 141-1 ~ 141-4 are disposed with respect to the cathode 112 and the corresponding divided avalanche portions 131-1 ~ 131-4 connected thereto and control the voltage thereof. Thus, for each of the divided pixel units (divided avalanche portion units), at the time of high illuminance, it is possible to sparsify a part of the plurality of SPAD pixels 100 arranged on the pixel array portion 21.

[0116] (Example of driving by utilizing avalanche occurrence probability)

[0117] Figure 10is a graph showing an example of the avalanche occurrence probability by the voltage difference between the anode and the cathode of the single photon avalanche photodiode 110.

[0118] In Figure 10 , the horizontal axis indicates the voltage difference between the anode and the cathode, and the vertical axis indicates the avalanche occurrence probability.

[0119] As Figure 10 indicated, the smaller the voltage difference between the anode and the cathode, the lower the avalanche occurrence probability. On the other hand, the larger the voltage difference between the anode and the cathode, the higher the avalanche occurrence probability.

[0120] In other words, when the voltage difference between the anode and the cathode is large enough, for example, all the electrons can generate avalanche multiplication. However, when the voltage difference becomes small, for example, the number of electrons that generate avalanche multiplication becomes about half.

[0121] Here, the voltage difference between the anode and the cathode is controlled so that the avalanche occurrence probability is 100% at low illumination, for example. On the other hand, the voltage difference between the anode and the cathode is controlled so that the avalanche occurrence probability decreases at high illumination. Thus, imaging can be performed with lower power consumption at high illumination.

[0122] (Flow of SPAD pixel drive control processing)

[0123] Next, the flow of the SPAD pixel drive control processing performed by the control circuit 22 will be described with reference to the flowchart of Figure 11

[0124] In step S11, the control circuit 22 acquires the detection result of the illumination.

[0125] Here, as a method of detecting the illumination, various detection methods can be employed. For example, the detection result of the illumination can be acquired from the output from the illumination sensor or the analysis result of the image acquired from the output of the solid-state imaging device 10 (for example, whether the image is too bright to be saturated or the like), and the like.

[0126] In step S12, the control circuit 22 determines whether the illumination is high by comparing the detection result of the illumination acquired in the processing of step S11 with a threshold value, on the basis of the detection result of the illumination acquired in the processing of step S11.

[0127] Note that, in the determination processing, depending on the threshold value, the detection result of the illumination can be determined, for example, by three stages of high illumination, medium illumination, and low illumination or by two stages of high illumination or low illumination.

[0128] In step S12, in the case where it is determined that the illumination is high, the processing proceeds to step S13. In step S13, the control circuit 22 determines the sparse pixel.

[0129] ​Here, for example, the control circuit 22 determines which unit, such as a pixel unit, a block unit, and a divided avalanche unit, spars a part of the plurality of SPAD pixels 100 arranged on the pixel array unit 21 based on preset information or the like, and further determines which SPAD pixel 100 is an actual sparse pixel.

[0130] In other words, here, it can also be said that among the plurality of SPAD pixels 100 arranged on the pixel array unit 21, the valid SPAD pixel 100 and the invalid SPAD pixel 100 are respectively determined at high illuminance.

[0131] After the processing in step S13 ends, the processing proceeds to the processing in step S14. Note that in step S12, in a case where the illuminance is determined to be low or medium and not high, the processing in step S13 is skipped, and the processing proceeds to the processing in step S14.

[0132] In step S14, the control circuit 22 controls the driving of the plurality of SPAD pixels 100 arranged on the pixel array unit 21.

[0133] Here, since the information about the unit for sparsification and the sparse pixel is determined by the processing in step S13 at high illuminance, for example, based on the information, the control circuit 22 can control the driving of the plurality of SPAD pixels 100 arranged on the pixel array unit 21.

[0134] The flow of the SPAD pixel driving control processing has been described above.

[0135] In the SPAD pixel driving control processing, since it is possible to sparsify a part of the plurality of SPAD pixels 100 arranged on the pixel array unit 21 for a predetermined unit (for example, a pixel unit, a block unit, or a divided avalanche unit) at high illuminance, it is possible to perform imaging with lower power consumption.

[0136] <3. Modification>

[0137] (Other example of the structure of the SPAD pixel)

[0138] Figure 12 is a plan view showing another example of the structure of the SPAD pixel 100.

[0139] In the above description, the structure in which the avalanche unit 131 of the SPAD pixel 100 is divided into four has been shown. Any division number can be used by dividing the avalanche unit 131. For example, if the avalanche unit 131 is divided into two, the structure is as shown in Figure 12 .

[0140] Specifically, in Figure 12In this case, the avalanche section 131 is divided into two, forming a divided avalanche section 131-1 and a divided avalanche section 131-2. Here, similarly to the fourth example described above, the gate electrode 141-1 is disposed on the divided avalanche section 131-1, and the gate electrode 141-2 is disposed on the divided avalanche section 131-2, thereby sparsifying a part of the SPAD pixels 100 for each divided pixel unit (divided avalanche section unit).

[0141] Note that the number of divisions of the avalanche section 131 is exemplified as four and two. The number of divisions is arbitrary, and can be divided into three, eight, ten, one hundred, and the like.

[0142] Figure 13 is a plan view showing another example of the structure of the SPAD pixel 100.

[0143] The above description shows that the avalanche section 131 of the SPAD pixel 100 is divided into four, so that the area of the divided avalanche sections 131-1 to 131-4 is almost the same. However, the area of each of the divided avalanche sections 131-1 to 131-4 can be different.

[0144] For example, as shown in Figure 13 , in the SPAD pixel 100, the divided avalanche section 131-1 has the largest area, and the divided avalanche section 131-3, the divided avalanche section 131-2, and the divided avalanche section 131-4 have smaller areas in this order.

[0145] Further, here, similarly to the fourth example described above, the gate electrodes 141-1 to 141-4 are disposed on the divided avalanche sections 131-1 to 131-4, thereby sparsifying a part of the SPAD pixels 100 for each divided pixel unit (divided avalanche section unit).

[0146] Note that in the structure of the SPAD pixel 100 shown in Figure 12 and Figure 13 , similarly to the fourth example described above, the overflow drain 142 can be disposed. In addition, as the structure of the SPAD pixel 100 shown in Figure 12 and Figure 13 , similarly to the third example, each of the divided avalanche sections 131-N (N: an integer of one or more) can be connected to a different cathode 112-N.

[0147] (Other examples of driving the SPAD pixel)

[0148] In the above description, in Figure 2In the pixel array section 21 illustrated, when any of the plurality of SPAD pixels 100 becomes a sparse pixel irregularly (randomly) for each pixel unit at high illuminance, power consumption can be reduced. Here, it is not limited to making the pixels irregularly sparse for each pixel unit, but it can be made regularly sparse for each pixel unit.

[0149] According to the above description, in Figure 3 In the pixel array section 21 illustrated, when any of the plurality of SPAD pixels 100 becomes a sparse pixel regularly for each block unit at high illuminance, power consumption can be reduced. Here, it is not limited to making the pixels regularly sparse for each block unit, but it can be made irregularly (randomly) sparse for each block unit.

[0150] Further, the number of pixels (sparse pixels) that are made sparse from the plurality of SPAD pixels 100 arranged on the pixel array section 21 at high illuminance is arbitrary.

[0151] (Other examples of sectional structure of SPAD pixel)

[0152] In the single photon avalanche photodiode 110, the anode can be formed on the first surface side as a light incident surface or on the second surface side opposite to the first surface, and the cathode can be formed on the second surface side or the first surface side. In other words, the anode and the cathode of the single photon avalanche photodiode 110 can be disposed on the surface of the semiconductor, for example, or can be disposed on the front surface and the back surface.

[0153] (Other examples of sensor)

[0154] The above description shows an image sensor (for example, a CMOS (Complementary Metal Oxide Semiconductor) image sensor) for acquiring image data as the solid-state imaging device 10. However, it can be used as other sensors such as a distance sensor (for example, a sensor that measures a distance by a TOF (Time of Flight) method).

[0155] (Other examples of arrangement pattern of SPAD pixel)

[0156] In the above description, the Bayer array is shown as the arrangement pattern of the plurality of SPAD pixels 100 arranged on the pixel array section 21. However, other arrangement patterns can be employed. In addition, it is shown that the SPAD pixels 100 are R pixels, G pixels, or B pixels. However, for example, it can include a W pixel of white (W), an IR pixel of infrared (IR), or the like.

[0157] (Other examples of control circuit)

[0158] The above description shows that the control circuit 22 controls the driving of the plurality of SPAD pixels 100 arranged on the pixel array section 21. However, an external device different from the solid-state imaging device 10 can control the driving of the SPAD pixels 100. Therefore, other means can control the driving of the SPAD pixels 100.

[0159] <4. Configuration of Electronic Device>

[0160] Figure 14 is a block diagram showing a configuration example of an electronic device including the solid-state imaging device to which the present technology is applied.

[0161] The electronic device 1000 is an imaging device such as a digital still camera and a video camera, a mobile terminal device such as a smart phone and a tablet terminal, and the like.

[0162] The electronic device 1000 includes a solid-state imaging device 1001, a DSP circuit 1002, a frame memory 1003, a display section 1004, a recording section 1005, an operation section 1006, and a power supply section 1007. In the electronic device 1000, the DSP circuit 1002, the frame memory 1003, the display section 1004, the recording section 1005, the operation section 1006, and the power supply section 1007 are connected to each other via a bus 1008.

[0163] The solid-state imaging device 1001 corresponds to the above-described solid-state imaging device 10 Figure 1 ), the structure of the plurality of SPAD pixels arranged two-dimensionally on the pixel array section 21 Figure 1 ) adopts the above-described structure (for example, the first to fourth examples of the structure of the SPAD pixel 100), and its driving can be controlled by the above-described driving (for example, the first example to the second example of the driving of the SPAD pixel 100).

[0164] The DSP circuit 1002 is a camera signal processing circuit that processes a signal supplied from the solid-state imaging device 1001. The DSP circuit 1002 outputs image data acquired by processing the signal from the solid-state imaging device 1001. The frame memory 1003 temporarily holds the image data processed by the DSP circuit 1002 in units of frames.

[0165] The display section 1004 includes a panel-type display device such as a liquid crystal panel and an organic EL (electroluminescence) panel, and displays a moving image or a still image imaged by the solid-state imaging device 1001. The recording section 1005 records image data of a moving image or a still image imaged by the solid-state imaging device 1001 on a recording medium such as a semiconductor memory and a hard disk.

[0166] The operation section 1006 outputs an operation command with respect to various functions included in the electronic device 1000 according to an operation of a user. The power supply section 1007 supplies various power sources to be supplied as an operation power source of the DSP circuit 1002, the frame memory 1003, the display section 1004, the recording section 1005, and the operation section 1006 as appropriate.

[0167] The electronic device 1000 is configured as described above. As described above, the present technology is applicable to the solid-state imaging device 1001. Specifically, the solid-state imaging device 10( Figure 1 ) can be applicable to the solid-state imaging device 1001. By applying the present technology to the solid-state imaging device 1001, since a part of the plurality of SPAD pixels 100 arranged on the pixel array section 21 is thinned out for a predetermined unit (for example, a pixel unit, a block unit, or a divided avalanche section unit) at high illuminance, imaging can be performed with lower power consumption.

[0168] <5. Usage example of solid-state imaging device>

[0169] Figure 15 is a view showing a usage example of the solid-state imaging device to which the present technology is applicable.

[0170] The solid-state imaging device 10( Figure 1 ) can be used for various cases of sensing light such as visible light, infrared light, ultraviolet light, and X-rays, as described below. Specifically, as shown in Figure 15 , the solid-state imaging device 10 can be used not only in the field of devices for taking images for appreciation, but also in, for example, the field of transportation, the field of home electric appliances, the field of medical care, the field of security, the field of beauty care, the field of sports, the field of agriculture, and the like.

[0171] Specifically, in the field of appreciation, for example, the solid-state imaging device 10 can be used for a device for taking images for appreciation (for example, the electronic device 1000 of Figure 14 , such as a digital camera, a smartphone, and a mobile phone with a camera function.

[0172] In the field of transportation, for example, the solid-state imaging device 10 can be used for a device for transportation, such as a vehicle-mounted sensor for taking an image of the front, the rear, the surroundings, the inside, or the like of a vehicle, a monitoring camera for monitoring a traveling vehicle and a road, and a distance measuring sensor for measuring an inter-vehicle distance or the like, for safe driving such as automatic parking, for recognizing a state of a driver, or the like.

[0173] In the field of home appliances, for example, the solid-state imaging device 10 can be used in home appliance devices, such as televisions, refrigerators, and air conditioners, to capture the user's posture and operate the appliance based on that posture. Additionally, in the field of healthcare, for example, the solid-state imaging device 10 can be used in healthcare devices, such as endoscopes or devices for angiography by receiving infrared light.

[0174] In the security field, for example, the solid-state imaging device 10 can be used in security devices, such as surveillance cameras for crime prevention or cameras for personal identification. In the beauty and skincare field, for example, the solid-state imaging device 10 can be used in beauty and skincare devices, such as skin measuring instruments for photographing skin and microscopes for photographing the scalp.

[0175] In the field of sports, for example, the solid-state imaging device 10 can be used in sports devices, such as wearable cameras or action cameras for sports purposes. Additionally, in the field of agriculture, for example, the solid-state imaging device 10 can be used in agricultural devices, such as cameras for monitoring the condition of fields and crops.

[0176] <6. Examples of applications of moving objects>

[0177] The technology disclosed herein (the Technology) can be applied to a variety of products. For example, the Technology disclosed herein can be implemented as a device to be installed on any type of mobile body such as automobiles, electric vehicles, hybrid electric vehicles, motorcycles, bicycles, personal mobility devices, airplanes, drones, ships, and robots.

[0178] Figure 16 This is a block diagram illustrating a schematic configuration example of a vehicle control system, which is an example of a mobile body control system to which the technology is applicable according to an embodiment of the present disclosure.

[0179] The vehicle control system 12000 includes multiple electronic control units connected together via a communication network 12001. Figure 16 In the example shown, the vehicle control system 12000 includes a drive system control unit 12010, a main system control unit 12020, an external information detection unit 12030, an internal information detection unit 12040, and a comprehensive control unit 12050. Furthermore, as functional components of the comprehensive control unit 12050, a microcomputer 12051, an audio / image output unit 12052, and an in-vehicle network interface (I / F) 12053 are shown.

[0180] The drive system control unit 12010 controls the operations of devices related to the drive system of the vehicle in accordance with various programs. For example, the drive system control unit 12010 functions as a control device for a drive force generation device such as an internal combustion engine or a drive motor that generates drive force of the vehicle, a drive force transmission mechanism that transmits the drive force to wheels, a steering mechanism that adjusts a steering angle of the vehicle, a brake device that generates a braking force of the vehicle, or the like.

[0181] The body system control unit 12020 controls the operations of various devices mounted to the vehicle body in accordance with various programs. For example, the body system control unit 12020 functions as a control device for a keyless entry system, a smart key system, a power window device, or various lamps such as a head lamp, a back lamp, a brake lamp, a turn signal lamp, a fog lamp, or the like. In this case, radio waves transmitted from a portable device or signals of various switches for replacing a key can be input to the body system control unit 12020. The body system control unit 12020 receives the input of the radio waves or the signals and controls a door lock device, a power window device, a lamp, or the like of the vehicle.

[0182] The outside -vehicle information detecting unit 12030 detects information outside the vehicle on which the vehicle control system 12000 is mounted. For example, the outside-vehicle information detecting unit 12030 is connected with an imaging section 12031. The outside-vehicle information detecting unit 12030 causes the imaging section 12031 to capture an image of the outside of the vehicle and receives the captured image. The outside-vehicle information detecting unit 12030 can perform object detection processing or distance detection processing such as a person, a car, an obstacle, a sign, a word on a road, or the like, on the basis of the received image.

[0183] The imaging section 12031 is an optical sensor that receives light and outputs an electrical signal corresponding to the amount of received light. The imaging section 12031 can output the electrical signal as an image or output the electrical signal as ranging information. Further, the light received by the imaging section 12031 can be visible light or invisible light such as infrared rays.

[0184] The in-vehicle information detecting unit 12040 detects information about the inside of the vehicle. For example, the in-vehicle information detecting unit 12040 is connected with a driver state detecting unit 12041 that detects a state of a driver. For example, the driver state detecting unit 12041 includes a camera that captures an image of the driver, and on the basis of detection information input from the driver state detecting unit 12041, the in-vehicle information detecting unit 12040 can calculate a degree of fatigue or concentration of the driver, or can determine whether the driver is dozing off.

[0185] For example, the microcomputer 12051 can calculate a control target value of a driving force generation device, a steering mechanism, or a braking device on the basis of information about the inside and outside of the vehicle obtained by the outside information detection unit 12030 or the in-vehicle information detection unit 12040, and can output a control command to the drive system control unit 12010. For example, the microcomputer 12051 can perform cooperative control to achieve the function of an advanced driver assistance system (ADAS) including collision avoidance or collision mitigation of the vehicle, follow-up running based on the distance between vehicles, vehicle speed maintenance running, vehicle collision warning, lane departure warning of the vehicle, and the like.

[0186] In addition, the microcomputer 12051 can perform cooperative control to achieve automatic driving in which the vehicle autonomously travels without depending on the operation of the driver, or the like, by controlling the driving force generation device, the steering mechanism, the braking device, and the like on the basis of information about the surroundings of the vehicle obtained by the outside information detection unit 12030 or the in-vehicle information detection unit 12040.

[0187] In addition, the microcomputer 12051 can output a control command to the body system control unit 12020 on the basis of information about the outside of the vehicle obtained by the outside information detection unit 12030. For example, the microcomputer 12051 controls a headlamp in accordance with the position of a preceding vehicle or an oncoming vehicle detected by the outside information detection unit 12030 to perform cooperative control to achieve glare prevention such as switching a high beam to a low beam.

[0188] The sound / image output section 12052 transmits at least one of a sound and an image output signal to an output device capable of visually or aurally notifying information to a vehicle occupant or outside of the vehicle. In Figure 16 In the example, as the output device, an audio speaker 12061, a display section 12062, and an instrument panel 12063 are illustrated. For example, the display section 12062 can include at least one of a vehicle-mounted display and a head-up display.

[0189] Figure 17 FIG. 12 is a diagram showing an example of a mounting position of the imaging section 12031.

[0190] In Figure 17 In the example, as the imaging section 12031, imaging sections 12101, 12102, 12103, 12104, and 12105 are included.

[0191] Each of the imaging sections 12101, 12102, 12103, 12104, and 12105 is provided at a position such as the front of the vehicle 12100, a side mirror, a rear bumper, a rear door, the upper side of a windshield in the vehicle interior, or the like. The imaging section 12101 provided in the front of the vehicle and the imaging section 12105 provided on the upper side of the windshield in the vehicle interior mainly obtain images of the front of the vehicle 12100. The imaging sections 12102 and 12103 provided in the side mirrors mainly obtain images of the side of the vehicle 12100. The imaging section 12104 provided in the rear bumper or the rear door mainly obtains an image of the rear of the vehicle 12100. The imaging section 12105 provided on the upper portion of the windshield in the vehicle interior is mainly used to detect a preceding vehicle, a pedestrian, an obstacle, a traffic signal, a traffic sign, a lane, or the like.

[0192] Incidentally, Figure 17 Examples of imaging ranges of the imaging sections 12101 to 12104 are shown. The imaging range 12111 represents the imaging range of the imaging section 12101 provided in the front of the vehicle, the imaging ranges 12112 and 12113 respectively represent the imaging ranges of the imaging sections 12102 and 12103 provided in the side mirrors, and the imaging range 12114 represents the imaging range of the imaging section 12104 provided in the rear bumper or the rear door. For example, image data captured by the imaging sections 12101 to 12104 are superimposed on each other, and thus an overhead view image of the vehicle 12100 is obtained.

[0193] At least one of the imaging sections 12101 to 12104 can have a function of acquiring distance information. For example, at least one of the imaging sections 12101 to 12104 can be a stereo camera including a plurality of image pickup elements, or can be an imaging element having pixels for phase difference detection.

[0194] For example, based on distance information obtained from the imaging sections 12101 to 12104, the microcomputer 12051 calculates distances to each of the three-dimensional objects within each of the imaging ranges 12111 to 12114 and temporal changes in the distances (relative speeds with respect to the vehicle 12100), and thus can extract, as a preceding vehicle, a three-dimensional object located on a travel route of the vehicle 12100, in particular, a closest three-dimensional object, and traveling at a predetermined speed (for example, 0 km / h or more) in substantially the same direction as the vehicle 12100. In addition, the microcomputer 12051 can set a distance between vehicles that is ensured in advance in front of the preceding vehicle, and can perform automatic brake control (including follow-up travel stop control), automatic acceleration control (including follow-up travel start control), or the like. In this way, coordinated control of automatic driving or the like in which the vehicle autonomously travels without depending on the operation of the driver can be performed.

[0195] For example, based on distance information obtained from the imaging sections 12101 to 12104, the microcomputer 12051 can extract three-dimensional object data on a three-dimensional object by classifying the three-dimensional object into a two-wheeled vehicle, a general vehicle, a large vehicle, a pedestrian, and other three-dimensional objects such as a utility pole, and automatically avoid an obstacle using the extracted data. For example, the microcomputer 12051 identifies obstacles around the vehicle 12100 as obstacles that can be visually recognized by a driver of the vehicle 12100 and obstacles that are difficult to visually recognize. Then, the microcomputer 12051 judges a collision risk indicating a degree of danger of collision with each obstacle, and when the collision risk is equal to or higher than a set value and there is a possibility of collision, the microcomputer 12051 can perform a collision avoidance enabling driving assist by outputting a warning to the driver via the audio speaker 12061 and the display section 12062 or performing forced deceleration or evasive steering via the drive system control unit 12010.

[0196] At least one of the imaging sections 12101 to 12104 can be an infrared camera for detecting infrared rays. For example, the microcomputer 12051 can recognize a pedestrian by judging whether a pedestrian is present in a captured image of the imaging sections 12101 to 12104. For example, the recognition of a pedestrian is performed by a process of extracting a feature point in a captured image of the imaging sections 12101 to 12104 as an infrared camera and a process of performing pattern matching processing on a series of feature points indicating the outline of an object to judge whether the object is a pedestrian. When the microcomputer 12051 judges that a pedestrian is present in a captured image of the imaging sections 12101 to 12104 and recognizes the pedestrian, the sound / image output section 12052 controls the display section 12062 to display a superimposed quadrangular outline to emphasize the recognized pedestrian. In addition, the sound / image output section 12052 can control the display section 12062 to display an icon or the like indicating the pedestrian at a desired position.

[0197] The above describes an example of a vehicle control system to which the technology according to the present disclosure can be applied. The technology according to the present disclosure can be applied to the imaging section 12031 configured as described above. Specifically, the solid-state imaging device 10 of Figure 1 the technology according to the present disclosure can be applied to the imaging section 12031. By applying the technology according to the present disclosure to the imaging section 12031, since a part of the plurality of SPAD pixels arranged on the pixel array is thinned out for a predetermined unit (for example, a pixel unit, a block unit, or a divided avalanche section unit) at a high illuminance, imaging can be performed with lower power consumption.

[0198] Note that the embodiments of the present technology are not limited to the above-described embodiments. Various modifications and changes can be made to the present technology without departing from the spirit and scope of the present disclosure.

[0199] Further, the present technology can have the following configurations. (1)

[0201] A solid-state imaging device including:

[0202] a pixel array section on which a plurality of SPAD (single photon avalanche diode) pixels are arranged two-dimensionally, wherein

[0203] in a case where an illuminance becomes a first illuminance that is higher than a reference illuminance, sparsifying a part of the SPAD pixels among the plurality of SPAD pixels arranged on the pixel array section. (2)

[0205] The solid-state imaging device according to (1), wherein

[0206] in the pixel array section, the sparse pixels that are a part of the SPAD pixels are sparsified for a pixel unit or a block unit including a plurality of pixels. (3)

[0208] The solid-state imaging device according to (2), wherein

[0209] the sparse pixels are regularly or irregularly arranged on the pixel array section for the pixel unit or the block unit. (4)

[0211] The solid-state imaging device according to (1) or (2), wherein

[0212] the sparse pixels are sparsified by controlling a voltage of an anode or a cathode of each SPAD. (5)

[0214] The solid-state imaging device according to (1), wherein

[0215] the SPAD pixels have a plurality of divided avalanche sections of a SPAD, and each divided avalanche section unit for the divided avalanche sections is sparsified. (6)

[0217] The solid-state imaging device according to (5), wherein

[0218] each divided avalanche section is sparsified by controlling a voltage of an anode or a cathode. (7)

[0220] The solid-state imaging device according to (5), wherein

[0221] each divided avalanche section is sparsified by controlling a gate electrode arranged on an upper portion of the divided avalanche section. (8)

[0223] The solid-state imaging device according to (7), further comprising:

[0224] An overflow drain for discharging unnecessary electrons with respect to the respective divided avalanche sections. (9)

[0226] The solid-state imaging device according to any one of (1) to (8), wherein

[0227] The potential difference between the anode and the cathode of the SPAD is controlled by using a relationship with an avalanche occurrence probability with respect to the sparse pixels of a part of the SPAD pixels. (10)

[0229] The solid-state imaging device according to any one of (1) to (9), wherein

[0230] The illuminance is classified into a plurality of stages including a first illuminance depending on a reference threshold value. (11)

[0232] The solid-state imaging device according to (10), wherein

[0233] The illuminance is classified into two stages of a first illuminance and a second illuminance lower than the first illuminance depending on the threshold value. (12)

[0235] The solid-state imaging device according to (10), wherein

[0236] The illuminance is classified into three stages of a first illuminance, a second illuminance lower than the first illuminance, and a third illuminance lower than the second illuminance depending on the threshold value. (13)

[0238] The solid-state imaging device according to any one of (1) to (12), wherein

[0239] In the SPAD of the SPAD pixel,

[0240] The anode is formed on the first surface side as a light incident surface or on the second surface side opposite to the first surface, and

[0241] The cathode is formed on the second surface side or the first surface side. (14)

[0243] A driving method of a solid-state imaging device including a pixel array section on which a plurality of SPAD pixels are two-dimensionally arranged, the method including:

[0244] In a case where the illuminance becomes a first illuminance higher than a reference illuminance, a part of the plurality of SPAD pixels arranged on the pixel array section is thinned.

[0245] List of reference signs

[0246] 10 solid-state imaging device

[0247] 21 pixel array unit

[0248] 22 control circuit

[0249] 23 readout circuit

[0250] 100 SPAD pixel

[0251] 110 single photon avalanche photodiode (SPAD)

[0252] 111 anode

[0253] 112, 112-1 to 112-4 cathode

[0254] 121 transistor

[0255] 122 transistor

[0256] 131 avalanche portion

[0257] 131-1 to 131-4 divided avalanche portions

[0258] 141-1 to 141-4 gate electrodes

[0259] 142-1 to 142-4 overflow drains

[0260] 1000 electronic apparatus

[0261] 1001 solid-state imaging device

[0262] 12031 imaging unit

Claims

1. A light detection device comprising: a plurality of avalanche photodiodes arranged in a two-dimensional array, the plurality of avalanche photodiodes including a first avalanche photodiode and a second avalanche photodiode; a first transistor connected to an anode or a cathode of the first avalanche photodiode; and a second transistor connected to an anode or a cathode of the second avalanche photodiode; wherein, in a first mode, the first transistor is in an on state and the second transistor is in an on state, wherein, in a second mode, the first transistor is in an on state and the second transistor is in an off state, wherein the light detection device is configured to switch between the first mode and the second mode, and wherein the first and second avalanche photodiodes are located in a same row of the two-dimensional array, wherein the plurality of avalanche photodiodes further includes a third avalanche photodiode, and a third transistor is connected to an anode or a cathode of the third avalanche photodiode, wherein the third transistor is in an on state in the first mode and the second mode, and wherein the second avalanche photodiode is located between the first and third avalanche photodiodes. The light detection device is configured to transition from the first mode to the second mode depending on an amount of incident light.

2. The light detecting device according to claim 1, wherein The light detection device is configured to transition from the first mode to the second mode if the amount of incident light exceeds a predetermined threshold.

3. The light detecting device according to claim 1, wherein The plurality of avalanche photodiodes are disposed on a first side of a semiconductor substrate as a light incident surface, and the anode or the cathode of the first avalanche photodiode and the anode or the cathode of the second avalanche photodiode are disposed on a second side opposite the first side.

4. The light detecting device according to claim 1, wherein The anode or the cathode of the first avalanche photodiode and the anode or the cathode of the second avalanche photodiode are configured by a shared electrode.

5. The light detecting device according to claim 1, wherein 6. The light detection device of claim 1, further comprising a control circuit configured to output a signal to a gate of the second transistor.

7. The light detection device of claim 1, further comprising a white color filter array disposed above the plurality of avalanche photodiodes.

8. The light detection device of claim 1, further comprising a Bayer-arranged color filter array disposed above the plurality of avalanche photodiodes.

9. A light detection device comprising: a plurality of avalanche photodiodes arranged in a two-dimensional array, the plurality of avalanche photodiodes including a first group of avalanche photodiodes and a second group of avalanche photodiodes; a first transistor connected to an anode or a cathode of a first avalanche photodiode of the first group of avalanche photodiodes; and a second transistor connected to an anode or a cathode of a second avalanche photodiode of the second group of avalanche photodiodes; wherein, in a first mode, the first transistor is in an on state and the second transistor is in an on state, wherein, in a second mode, the first transistor is in an on state and the second transistor is in an off state, ​ wherein in the second mode, the first transistor is in an on state and the second transistor is in an off state, wherein a first number of avalanche photodiodes of the first group of avalanche photodiodes is greater than a second number of avalanche photodiodes of the second group of avalanche photodiodes, wherein the plurality of avalanche photodiodes further comprises a third group of avalanche photodiodes, and a third transistor is connected to anodes or cathodes of the third group of avalanche photodiodes, wherein the third group of transistors is in an on state in the first mode and the second mode, and wherein the second group of avalanche photodiodes is located between the first group of avalanche photodiodes and the third group of avalanche photodiodes.

10. The light detecting device according to claim 9, wherein The second group of avalanche photodiodes is randomly arranged in a two-dimensional array.

Images