Light detection device

Abstract

To detect movement of a subject in high speed.SOLUTION: A light detection device has a first photoelectric conversion part and an event signal generation part. The first photoelectric conversion part of the light detection device is laminated on its semiconductor substrate and performs photoelectric conversion for incident light. The event signal generation part of the light detection device is disposed on its semiconductor substrate, detects a change of incident light luminance in the same direction, as an event on the basis of charge generated by the photoelectric conversion of the first photoelectric conversion part, and generates an event signal which is a signal based on the detected event.SELECTED DRAWING: Figure 7

Description

[Technical field]

[0001] The present disclosure relates to a light detection device. [Background technology]

[0002] A photodetection device in which pixels each made of a photodiode and a transistor are formed on a semiconductor substrate is used as a photodetection device for capturing an image of a subject. For example, a solid-state imaging device has been proposed in which a photodiode is formed in a semiconductor substrate and a semiconductor region constituting the photodiode is extended below the transistor to improve the transfer of charges from the photodiode to the transistor (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2005-223084 A Summary of the Invention [Problem to be solved by the invention]

[0004] When generating video data from images generated by the above-mentioned photodetection device, a system is used that reduces the amount of data by updating only the images in the area where the subject has moved. However, to detect the movement of a subject using the above-mentioned conventional photodetection device, it is necessary to calculate the difference between two consecutive images, which makes it difficult to detect a moving object at high speed.

[0005] Therefore, the present disclosure proposes a light detection device that detects the movement of a subject at high speed. [Means for solving the problem]

[0006] A photodetector according to a first aspect of the present disclosure includes a first photoelectric conversion unit and an event signal generation unit. The first photoelectric conversion unit is stacked on a semiconductor substrate and performs photoelectric conversion of incident light. The event signal generation unit detects a change in luminance of the incident light in the same direction as an event based on charges generated by photoelectric conversion of the first photoelectric conversion unit, and generates an event signal that is a signal based on the detected event.

[0007] A photodetector according to a second aspect of the present disclosure includes a first photoelectric conversion unit, a grayscale signal generation unit, and an event signal generation unit. The first photoelectric conversion unit is stacked on a semiconductor substrate and performs photoelectric conversion of incident light. The grayscale signal generation unit generates a grayscale signal that is a signal corresponding to the luminance of the incident light based on charges generated by photoelectric conversion of the first photoelectric conversion unit. The event signal generation unit detects a change in the luminance of the incident light in the same direction as an event, and generates an event signal that is a signal based on the detected event. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram illustrating an example of a schematic configuration of a light detection device according to an embodiment of the present disclosure. [Diagram 2] 1 is a diagram illustrating an example of the configuration of a pixel according to a first embodiment of the present disclosure. [Diagram 3] FIG. 4 is a diagram illustrating an example of the configuration of a gray-scale signal generating unit according to an embodiment of the present disclosure. [Figure 4] 4 is a diagram illustrating a configuration example of an event signal generating unit according to the first embodiment of the present disclosure. FIG. [Diagram 5] 1 is a circuit diagram illustrating a configuration example of an event signal generating unit according to an embodiment of the present disclosure. [Figure 6] 1 is a circuit diagram illustrating a configuration example of an event signal generating unit according to an embodiment of the present disclosure. [Figure 7] 1 is a cross-sectional view showing a configuration example of a pixel according to a first embodiment of the present disclosure. [Figure 8] FIG. 11 is a cross-sectional view showing a configuration example of a pixel according to a second embodiment of the present disclosure. [Figure 9]FIG. 11 is a cross-sectional view showing a configuration example of a pixel according to a third embodiment of the present disclosure. [Figure 10] FIG. 13 is a diagram illustrating a configuration example of an element according to a third embodiment of the present disclosure. [Figure 11] FIG. 13 is a circuit diagram showing an example configuration of a grayscale signal generating section and an event signal generating section according to a fourth embodiment of the present disclosure. [Figure 12] FIG. 11 is a cross-sectional view showing a configuration example of a pixel according to a fourth embodiment of the present disclosure. [Figure 13] FIG. 11 is a plan view showing a configuration example of an element according to a fourth embodiment of the present disclosure. [Figure 14] FIG. 13 is a diagram illustrating a configuration example of an element according to a fourth embodiment of the present disclosure. [Figure 15] FIG. 13 is a circuit diagram showing another example of the configuration of the grayscale signal generating section and the event signal generating section according to the fourth embodiment of the present disclosure. [Figure 16] FIG. 13 is a circuit diagram showing another example of the configuration of the grayscale signal generating section and the event signal generating section according to the fourth embodiment of the present disclosure. [Figure 17] FIG. 13 is a circuit diagram showing an example configuration of a grayscale signal generating section and an event signal generating section according to a fifth embodiment of the present disclosure. [Figure 18] FIG. 13 is a cross-sectional view showing a configuration example of a pixel according to a fifth embodiment of the present disclosure. [Figure 19] FIG. 13 is a circuit diagram showing another exemplary configuration of the grayscale signal generating section and the event signal generating section according to the fifth embodiment of the present disclosure. [Figure 20] FIG. 13 is a circuit diagram showing another exemplary configuration of the grayscale signal generating section and the event signal generating section according to the fifth embodiment of the present disclosure. [Figure 21] 13 is a circuit diagram showing another example configuration of the grayscale signal generating section and the event signal generating section according to the modified example of the embodiment of the present disclosure. FIG. [Figure 22] FIG. 11 is a cross-sectional view showing a configuration example of a pixel according to a modified example of the embodiment of the present disclosure. [Diagram 23] FIG. 11 is a cross-sectional view showing another example of a pixel configuration according to a modified example of the embodiment of the present disclosure. [Figure 24] FIG. 13 is a diagram illustrating a configuration example of a photoelectric conversion unit according to a modified example of an embodiment of the present disclosure. [Diagram 25] FIG. 13 is a cross-sectional view showing a configuration example of a pixel according to a seventh embodiment of the present disclosure. [Figure 26] FIG. 13 is a cross-sectional view showing another configuration example of a pixel according to the seventh embodiment of the present disclosure. [Figure 27A] 13A to 13C are diagrams illustrating an example of a method for manufacturing a light detection device according to a seventh embodiment of the present disclosure. [Figure 27B] 13A to 13C are diagrams illustrating an example of a method for manufacturing a light detection device according to a seventh embodiment of the present disclosure. [Figure 27C] 13A to 13C are diagrams illustrating an example of a method for manufacturing a light detection device according to a seventh embodiment of the present disclosure. [Figure 27D] 13A to 13C are diagrams illustrating an example of a method for manufacturing a light detection device according to a seventh embodiment of the present disclosure. [Figure 27E] 13A to 13C are diagrams illustrating an example of a method for manufacturing a light detection device according to a seventh embodiment of the present disclosure. [Figure 27F] 13A to 13C are diagrams illustrating an example of a method for manufacturing a light detection device according to a seventh embodiment of the present disclosure. [Figure 27G] 13A to 13C are diagrams illustrating an example of a method for manufacturing a light detection device according to a seventh embodiment of the present disclosure. [Fig. 27H] 13A to 13C are diagrams illustrating an example of a method for manufacturing a light detection device according to a seventh embodiment of the present disclosure. [Figure 27I] 13A to 13C are diagrams illustrating an example of a method for manufacturing a light detection device according to a seventh embodiment of the present disclosure. [Figure 27J] 13A to 13C are diagrams illustrating an example of a method for manufacturing a light detection device according to a seventh embodiment of the present disclosure. [Figure 27K] 13A to 13C are diagrams illustrating an example of a method for manufacturing a light detection device according to a seventh embodiment of the present disclosure. [Figure 27L] 13A to 13C are diagrams illustrating an example of a method for manufacturing a light detection device according to a seventh embodiment of the present disclosure. [Figure 27M] 13A to 13C are diagrams illustrating an example of a method for manufacturing a light detection device according to a seventh embodiment of the present disclosure. [Figure 27N] 13A to 13C are diagrams illustrating an example of a method for manufacturing a light detection device according to a seventh embodiment of the present disclosure. [Figure 27O]13A to 13C are diagrams illustrating an example of a method for manufacturing a light detection device according to a seventh embodiment of the present disclosure. [Figure 27P] 13A to 13C are diagrams illustrating an example of a method for manufacturing a light detection device according to a seventh embodiment of the present disclosure. [Figure 28] FIG. 13 is a cross-sectional view showing a configuration example of a pixel according to an eighth embodiment of the present disclosure. [Figure 29] FIG. 13 is a cross-sectional view showing another configuration example of a pixel according to the eighth embodiment of the present disclosure. [Diagram 30] FIG. 13 is a cross-sectional view showing another configuration example of a pixel according to the eighth embodiment of the present disclosure. [Diagram 31] FIG. 13 is a cross-sectional view showing a configuration example of a pixel according to a ninth embodiment of the present disclosure. [Diagram 32] FIG. 13 is a cross-sectional view showing another configuration example of a pixel according to the ninth embodiment of the present disclosure. [Diagram 33] FIG. 13 is a cross-sectional view showing another configuration example of a pixel according to the ninth embodiment of the present disclosure. [Diagram 34] FIG. 13 is a diagram illustrating a configuration example of a current-voltage conversion circuit according to a modified example of an embodiment of the present disclosure. [Diagram 35] FIG. 13 is a diagram illustrating a configuration example of a current-voltage conversion circuit according to a modified example of an embodiment of the present disclosure. [Diagram 36] FIG. 13 is a diagram illustrating a configuration example of a current-voltage conversion circuit according to a modified example of an embodiment of the present disclosure. [Figure 37] FIG. 13 is a diagram illustrating a configuration example of a current-voltage conversion circuit according to a modified example of an embodiment of the present disclosure. [Figure 38] FIG. 13 is a diagram illustrating a configuration example of a current-voltage conversion circuit according to a modified example of an embodiment of the present disclosure. [Figure 39] FIG. 13 is a diagram illustrating a configuration example of a current-voltage conversion circuit according to a modified example of an embodiment of the present disclosure. [Diagram 40] 6A and 6B are diagrams illustrating an example of generation of a grayscale signal and an event signal according to an embodiment of the present disclosure. [Diagram 41] 1 is a block diagram showing an example of the configuration of an imaging device mounted on an electronic device. [Diagram 42]1 is a block diagram showing a schematic configuration example of a vehicle control system that is an example of a mobile object control system to which the technology according to the present disclosure can be applied. [Diagram 43] FIG. 4 is a diagram showing an example of an installation position of an imaging unit. [Diagram 44] 1 is a diagram showing an example of a schematic configuration of an endoscopic surgery system to which the technology according to the present disclosure (the present technology) can be applied. [Diagram 45] 45 is a block diagram showing an example of the functional configuration of the camera head and the CCU shown in FIG. 44. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. The description will be given in the following order. In the following embodiments, the same components are designated by the same reference numerals, and duplicated description will be omitted. 1. First embodiment 2. Second embodiment 3. Third embodiment 4. Fourth embodiment 5. Fifth embodiment 6. Sixth embodiment 7. Seventh embodiment 8. Eighth embodiment 9. Ninth embodiment 10.Other 11. Configuration of Electronic Devices 12. Mobile application examples 13. Application example to endoscopic surgery system

[0010] 1. First Embodiment [Configuration of the photodetector] FIG. 1 is a diagram showing an example of a schematic configuration of a photodetector according to an embodiment of the present disclosure. As shown in FIG. 1, the photodetector 1 of this example is configured to have a pixel array section (so-called imaging region) 13 in which pixels 12 including a plurality of photoelectric conversion units are regularly arranged two-dimensionally on a semiconductor substrate 11, for example, a silicon substrate, and a peripheral circuit section. The pixel 12 is configured to have, for example, a photodiode serving as a photoelectric conversion unit, and a plurality of pixel transistors (so-called MOS transistors). The plurality of pixel transistors can be configured to have, for example, three transistors, a transfer transistor, a reset transistor, and an amplification transistor. In addition, it can be configured to have four transistors by adding a selection transistor. The pixel 12 can also have a shared pixel structure. This pixel sharing structure is configured to have a plurality of photodiodes, a plurality of transfer transistors, one shared floating diffusion region, and one other shared pixel transistor.

[0011] The peripheral circuit section includes a vertical drive circuit 33, a column signal processing circuit 34, a horizontal drive circuit 35, an output circuit 37, a control circuit 36, and the like.

[0012] The control circuit 36 ​​receives an input clock and data instructing an operation mode, etc., and outputs data such as internal information of the image sensor. That is, the control circuit 36 ​​generates clock signals and control signals that serve as a reference for the operation of the vertical drive circuit 33, the column signal processing circuit 34, the horizontal drive circuit 35, etc., based on a vertical synchronization signal, a horizontal synchronization signal, and a master clock. These signals are then input to the vertical drive circuit 33, the column signal processing circuit 34, the horizontal drive circuit 35, etc.

[0013] The vertical drive circuit 33 is configured, for example, by a shift register, selects the pixel drive line 23, supplies a pulse for driving the pixel to the selected pixel drive wiring, and drives the pixel by row. That is, the vertical drive circuit 33 selects and scans each pixel 12 of the pixel array unit 13 in the vertical direction by row, and supplies a pixel signal based on a signal charge generated in response to the amount of light received in, for example, a photodiode serving as a photoelectric conversion unit of each pixel 12 to the column signal processing circuit 34 through the vertical signal line 24.

[0014] The column signal processing circuit 34 is arranged, for example, for each column of the pixels 12, and performs signal processing such as noise removal for each pixel column on signals output from one row of the pixels 12. That is, the column signal processing circuit 34 performs signal processing such as CDS (Correlated Double Sampling) for removing fixed pattern noise specific to the pixels 12, signal amplification, AD conversion, etc. A horizontal selection switch (not shown) is provided at the output stage of the column signal processing circuit 34 and connected between the output stage and the horizontal signal line 38.

[0015] The horizontal drive circuit 35 is configured, for example, by a shift register, and sequentially outputs horizontal scanning pulses to select each of the column signal processing circuits 34 in turn, and cause each of the column signal processing circuits 34 to output a pixel signal to a horizontal signal line 38.

[0016] The output circuit 37 processes and outputs signals sequentially supplied from each of the column signal processing circuits 34 through a horizontal signal line 38. For example, the output circuit 37 may only perform buffering, or may perform black level adjustment, column variation correction, various digital signal processing, etc. The input / output terminal 39 exchanges signals with the outside.

[0017] [Pixel configuration] 2 is a diagram showing a configuration example of a pixel according to the first embodiment of the present disclosure. The same figure is a block diagram showing a configuration example of a pixel 12. The pixel 12 includes a grayscale signal generating unit 110 and an event signal generating unit 120. The grayscale signal generating unit 110 generates a grayscale signal, which is a signal corresponding to the luminance of incident light, based on charges generated by photoelectric conversion in a photoelectric conversion unit (not shown). This grayscale signal generating unit 110 generates the grayscale signal based on a control signal supplied from a vertical driving circuit 33 via a pixel driving line 23. The generated grayscale signal is transmitted to a column signal processing circuit 34 via a vertical signal line 24.

[0018] The event signal generating unit 120 detects a change in the luminance of incident light in the same direction as an event based on charges generated by photoelectric conversion in a photoelectric conversion unit (not shown), and generates an event signal that is a signal based on the detected event. The event signal generating unit 120 generates the event signal based on a control signal supplied from the vertical driving circuit 33 via the pixel driving line 23. The generated event signal is transmitted to the column signal processing circuit 34 via the vertical signal line 24.

[0019] In addition, a first photoelectric conversion unit 201 and a second photoelectric conversion unit 202 are further arranged in the pixel 12 in the figure. A grayscale signal generation unit 110 in the figure generates a grayscale signal based on charges generated by photoelectric conversion of the second photoelectric conversion unit 202. In addition, an event signal generation unit 120 in the figure detects an event based on charges generated by photoelectric conversion of the first photoelectric conversion unit 201.

[0020] [Configuration of the gradation signal generation section] FIG. 3 is a diagram showing a configuration example of a grayscale signal generating unit according to an embodiment of the present disclosure. The diagram is a circuit showing a configuration example of the grayscale signal generating unit 110. In addition, the diagram further shows a second photoelectric conversion unit 202. The grayscale signal generating unit 110 includes a charge holding unit 203 and MOS transistors 211 to 214. The MOS transistors 211 to 214 can be n-channel MOS transistors. In addition, the pixel driving line 23 connected to the pixel 12 includes a signal line TRG, a signal line RST, and a signal line SEL. In addition, a power supply line Vdd that supplies power is wired to the pixel 12.

[0021] The anode of the second photoelectric conversion unit 202 is grounded, and the cathode is connected to the source of the MOS transistor 211. The drain of the MOS transistor 211 is connected to the source of the MOS transistor 212, the gate of the MOS transistor 213, and one end of the charge holding unit 203. The other end of the charge holding unit 203 is grounded. The drain of the MOS transistor 212 is connected to the power supply line Vdd. The drain of the MOS transistor 213 is connected to the power supply line Vdd, and the source is connected to the drain of the MOS transistor 214. The source of the MOS transistor 214 is connected to the vertical signal line 24. The signal lines TRG, RST, and SEL are connected to the gates of the MOS transistors 211, 212, and 214, respectively.

[0022] The second photoelectric conversion unit 202 is an element that performs photoelectric conversion of incident light. The second photoelectric conversion unit 202 generates and holds electric charges by photoelectric conversion. The second photoelectric conversion unit 202 is disposed on a semiconductor substrate 300, as described later.

[0023] The MOS transistor 211 transfers the charge held in the second photoelectric conversion unit 202 to the charge holding unit 203. The MOS transistor 211 is controlled by a control signal transmitted by a signal line TRG. The MOS transistor 211 corresponds to the transfer transistor described above.

[0024] The charge holding portion 203 is an element that holds electric charges. The charge holding portion 203 can be configured by a semiconductor region formed on a semiconductor substrate.

[0025] The MOS transistor 212 resets the charge holding unit 203. The MOS transistor 212 is controlled by a control signal transmitted through a signal line RST. The MOS transistor 212 corresponds to the above-mentioned reset transistor.

[0026] The MOS transistor 213 is an element that generates a grayscale signal according to the charge held in the charge holding unit 203. The generated grayscale signal is output to a source terminal. The MOS transistor 213 corresponds to the above-mentioned amplifying transistor.

[0027] The MOS transistor 214 is an element that outputs the grayscale signal generated by the MOS transistor 213 to the vertical signal line 24. The MOS transistor 214 is controlled by a control signal transmitted by a signal line SEL. The MOS transistor 214 corresponds to the selection transistor described above.

[0028] The generation of a grayscale signal in the grayscale signal generation unit 110 in the figure can be performed as follows. First, the MOS transistor 212 is made conductive to reset the charge holding unit 203. At this time, the MOS transistor 211 is made conductive. This also resets the second photoelectric conversion unit 202. This resetting of the charge holding unit 203 and the second photoelectric conversion unit 202 is an operation equivalent to an electronic shutter. Next, the MOS transistors 211 and 212 are made non-conductive. This starts exposure.

[0029] After a predetermined exposure period has elapsed, the MOS transistor 212 is made conductive to reset the charge holding unit 203. After the charge holding unit 203 has been reset, the MOS transistor 211 is made conductive to transfer the charge of the second photoelectric conversion unit 202 to the charge holding unit 203. Then, a grayscale signal is generated by the MOS transistor 213. The generated grayscale signal is output to the vertical signal line 24 by making the MOS transistor 214 conductive. This operation of generating a grayscale signal after the exposure period has elapsed is called reading.

[0030] In this way, a grayscale signal is generated by the three processes of electronic shutter, exposure, and readout, and is output from the grayscale signal generating unit 110. As described above, the grayscale signal is generated for each row. At this time, the shutter, exposure, and readout are applied sequentially while shifting the timing for each row. This will be described later with reference to FIG.

[0031] [Event signal generation section configuration] 4 is a diagram showing a configuration example of an event signal generating unit according to the first embodiment of the present disclosure. The figure is a block diagram showing a configuration example of the event signal generating unit 120. The event signal generating unit 120 in the figure includes a current-voltage conversion circuit 140, a differentiation circuit 150, a luminance change detection unit 160, and an output unit 170. Note that the figure further shows a first photoelectric conversion unit 201.

[0032] The first photoelectric conversion section 201 performs photoelectric conversion of incident light, similar to the second photoelectric conversion section 202. The first photoelectric conversion section 201 can be configured by a photoelectric conversion film disposed adjacent to the semiconductor substrate 300.

[0033] The current-voltage conversion circuit 140 converts the photocurrent from the first photoelectric conversion unit 201 into a voltage signal. During this conversion, the current-voltage conversion circuit 140 performs logarithmic compression of the voltage signal. The converted voltage signal is output to the differentiation circuit 150. The configuration of the current-voltage conversion circuit 140 will be described in detail later.

[0034] The differentiation circuit 150 extracts the change in the voltage signal output from the current-voltage conversion circuit 140 and accumulates the extracted change to generate a signal according to the amount of change in the voltage signal. This signal corresponds to a signal according to the change in luminance of the incident light. This signal is called an optical signal. The differentiation circuit 150 outputs the generated optical signal to the luminance change detection unit 160 via a signal line 121. In addition, a control signal is input to the differentiation circuit 150 from the vertical drive circuit 33. This control signal is a signal that resets the circuit that detects the amount of change in the voltage signal. The configuration of the differentiation circuit 150 will be described in detail later.

[0035] The luminance change detection unit 160 detects a luminance change of the incident light. The luminance change detection unit 160 in the figure detects a change in the optical signal output from the differentiation circuit 150 based on a threshold value. That is, when the change in the optical signal exceeds the threshold value, the change in the optical signal is detected as an event. Here, an event in the direction in which the optical signal increases is called an on-event, and an event in the direction in which the optical signal decreases is called an off-event. The luminance change detection unit 160 detects an on-event and an off-event using the voltages of the on-event detection signal and the off-event detection signal supplied from the vertical drive circuit 33 as threshold values. The detection result is output to the output unit 170. The configuration of the luminance change detection unit 160 will be described in detail later.

[0036] The output section 170 outputs the ON event and the OFF event detected by the brightness change detection section 160 based on a control signal from the vertical drive circuit 33 as an event signal.

[0037] [Circuit configuration of event signal generation section] 5 and 6 are circuit diagrams showing configuration examples of the event signal generating unit according to an embodiment of the present disclosure. Fig. 5 is a circuit diagram showing configuration examples of the current-voltage conversion circuit 140 and the differentiation circuit 150. Note that the figure further shows a first photoelectric conversion unit 201. Fig. 6 is a circuit diagram showing configuration examples of the luminance change detection unit 160 and the output unit 170.

[0038] The current-voltage conversion circuit 140 in the figure includes MOS transistors 215 to 217. In the figure, Vdd represents a power supply line Vdd that supplies power. Vb1 represents a signal line Vb1 that supplies a bias voltage. The MOS transistors 215 and 217 can be n-channel MOS transistors. The MOS transistor 216 can be a p-channel MOS transistor.

[0039] The anode of the first photoelectric conversion unit 201 is grounded, and the cathode is connected to the source of the MOS transistor 215 and the gate of the MOS transistor 217. The sources of the MOS transistor 215 and the MOS transistor 216 are connected to a power supply line Vdd, and the gate of the MOS transistor 216 is connected to a signal line Vb1. The source of the MOS transistor 217 is grounded, and the drain is connected to the gate of the MOS transistor 215, the drain of the MOS transistor 216, and an output signal line of the current-voltage conversion circuit 140. One end of the capacitor of the differentiation circuit 150 is connected to this output signal line.

[0040] The MOS transistor 215 is a MOS transistor that supplies a current to the first photoelectric conversion unit 201. A sink current (photocurrent) corresponding to incident light flows through the first photoelectric conversion unit 201. The MOS transistor 215 supplies this sink current. At this time, the gate of the MOS transistor 215 is driven by the output voltage of a MOS transistor 217 described later, and outputs a source current equal to the sink current of the first photoelectric conversion unit 201. Since the gate-source voltage Vgs of the MOS transistor becomes a voltage corresponding to the source current, the source voltage of the MOS transistor 215 becomes a voltage corresponding to the current of the first photoelectric conversion unit 201. As a result, the photocurrent of the first photoelectric conversion unit 201 is converted into a voltage signal.

[0041] The MOS transistor 217 is a MOS transistor that amplifies the source voltage of the MOS transistor 215. The MOS transistor 216 constitutes a constant current load of the MOS transistor 217. An amplified voltage signal is output to the drain of the MOS transistor 217. This voltage signal is output to the differentiation circuit 150 and is also fed back to the gate of the MOS transistor 215. When the Vgs of the MOS transistor 215 is equal to or lower than the threshold voltage, the source current changes exponentially with respect to the change in Vgs. Therefore, the output voltage of the MOS transistor 217 that is fed back to the gate of the MOS transistor 215 becomes a voltage signal that is logarithmically compressed from the photocurrent of the first photoelectric conversion unit 201, which is equal to the source current of the MOS transistor 215.

[0042] [Differential circuit configuration] The differentiation circuit 150 in the figure includes capacitors 204 and 205, MOS transistors 218 and 219, and a constant current circuit 231. The MOS transistors 218 and 219 can be p-channel MOS transistors.

[0043] As described above, one end of the capacitor 204 is connected to the output of the current-voltage conversion circuit 140, and the other end of the capacitor 204 is connected to the gate of the MOS transistor 218, the drain of the MOS transistor 219, and one end of the capacitor 205. The other end of the capacitor 205 is connected to the drain of the MOS transistor 218, the drain of the MOS transistor 219, the sink side terminal of the constant current circuit 231, and the signal line 121. The source of the MOS transistor 218 is connected to the power supply line Vdd, and the gate of the MOS transistor 219 is connected to the signal line AZ. The source side terminal of the constant current circuit 231 is grounded.

[0044] The capacitor 204 corresponds to a coupling capacitor. This capacitor 204 blocks the DC component of the output voltage of the current-voltage conversion circuit 140 and passes only the AC component. In addition, a current based on the change in the output voltage of the current-voltage conversion circuit 140 is supplied to the gate of the MOS transistor 218 via the capacitor 204. The AC component of the output voltage of the current-voltage conversion circuit 140 corresponds to the change in the photocurrent. The MOS transistor 218 and the constant current circuit 231 constitute an inverting amplifier circuit. The change in the output voltage of the current-voltage conversion circuit 140 is input to the gate of the MOS transistor 218 via the capacitor 204, and is inverted and amplified by the MOS transistor 218 and output to the drain. Therefore, a current based on the change in the output voltage of the current-voltage conversion circuit 140 flows through the capacitor 205, and the capacitor 205 is charged and discharged. That is, the change in the output voltage of the current-voltage conversion circuit 140 is integrated. An optical signal, which is a signal according to the amount of change in the voltage signal output by the current-voltage conversion circuit 140, is output to the signal line 121.

[0045] The MOS transistor 219 resets the differentiation circuit 150. By making this MOS transistor 219 conductive, both ends of the capacitor 205 are shorted. The integrated change in the output voltage of the current-voltage conversion circuit 140 is discharged and reset. This reset causes the output voltage of the differentiation circuit 150 to become, for example, the voltage at the midpoint between the power supply line Vdd and the ground line. This reset is controlled by an AZ control signal transmitted by a signal line AZ. Hereinafter, the reset of the differentiation circuit 150 will be referred to as an AZ operation.

[0046] [Configuration of the luminance change detection section] 6, the luminance change detection unit 160 includes MOS transistors 220 to 223. The MOS transistors 220 and 222 can be p-channel MOS transistors. The MOS transistors 221 and 223 can be n-channel MOS transistors. Signal lines ON and OFF from the vertical drive circuit 33 are connected to the luminance change detection unit 160. The signal line ON is a signal line that transmits an ON event detection signal. The signal line OFF is a signal line that transmits an OFF event detection signal.

[0047] The signal line 121 is connected to the gate of the MOS transistor 220 and the gate of the MOS transistor 222. The source of the MOS transistor 220 is connected to the power supply line Vdd, and the drain is connected to the drain of the MOS transistor 221 and the gate of the MOS transistor 225 of the output section 170. The gate of the MOS transistor 221 is connected to the signal line ON, and the source is grounded. The source of the MOS transistor 222 is connected to the power supply line Vdd, and the drain is connected to the drain of the MOS transistor 223 and the gate of the MOS transistor 227 of the output section 170. The gate of the MOS transistor 223 is connected to the signal line OFF, and the source is grounded.

[0048] The circuit of the MOS transistors 220 and 221 constitutes a comparison circuit. The output of this comparison circuit changes depending on the magnitude relationship between the drain current on the sink side of the MOS transistor 221 and the drain current on the source side of the MOS transistor 220. When the output voltage of the differentiation circuit 150 is lower than a threshold based on the voltage of the on-event detection signal, specifically, a voltage obtained by subtracting the threshold voltage from the power supply voltage Vdd, the source current of the MOS transistor 220 becomes smaller than the sink current of the MOS transistor 221. Therefore, the output voltage becomes an L level. On the other hand, when the output voltage of the differentiation circuit 150 becomes higher than the threshold voltage (the voltage obtained by subtracting the threshold voltage from the power supply voltage Vdd), the sink current of the MOS transistor 221 becomes smaller than the source current of the MOS transistor 220. Therefore, the output voltage shifts to an H level. In this way, the comparison circuit consisting of the MOS transistors 220 and 221 compares the output voltage of the differentiation circuit 150 with the threshold voltage of the on-event detection signal, and detects an on-event, which is a change in the direction in which the luminance of the incident light increases. When the on-event detection signal is at a voltage higher than the threshold voltage, for example, the power supply voltage of the power supply line Vdd, the output of the comparator is always at L level. In other words, by applying the threshold voltage as the on-event detection signal, it is possible to detect an on-event.

[0049] The circuit of the MOS transistors 222 and 223 also constitutes a comparison circuit. When the output voltage of the differentiation circuit 150 is lower than a threshold based on the voltage of the off-event detection signal, specifically, a voltage obtained by subtracting the threshold voltage from the power supply voltage Vdd, the output voltage becomes an L level. On the other hand, when the output voltage of the differentiation circuit 150 becomes higher than the threshold voltage (the voltage obtained by subtracting the threshold voltage from the power supply voltage Vdd), the output voltage transitions to an H level. By setting the threshold voltage of the off-event detection signal to a voltage lower than the threshold voltage of the on-event detection signal, the comparison circuit of the MOS transistors 222 and 223 detects an off-event, which is a change in the direction in which the luminance of the incident light decreases. Note that when the off-event detection signal is a voltage lower than the threshold voltage, for example, the ground potential, the output of the comparator is always at an H level. That is, by applying a threshold voltage as the off-event detection signal, it is possible to detect an off-event.

[0050] [Output section configuration] The output section 170 includes MOS transistors 224 to 227. The MOS transistors 224 to 227 can be n-channel MOS transistors. The drain of the MOS transistor 224 is connected to one side of the vertical signal line 24, and the drain of the MOS transistor 226 is connected to the other side of the vertical signal line 24. The gates of the MOS transistors 224 and 226 are commonly connected to a signal line OUT. The source of the MOS transistor 224 is connected to the drain of the MOS transistor 225, and the source of the MOS transistor 225 is grounded. The source of the MOS transistor 226 is connected to the drain of the MOS transistor 227, and the source of the MOS transistor 227 is grounded.

[0051] When an event read signal is input to the signal line OUT, the MOS transistors 224 and 226 become conductive. As a result, the drain voltages of the MOS transistors 225 and 227 are output to the vertical signal line 24. Since the on-event detection signal and the off-event detection signal of the luminance change detection unit 160 are applied to the gates of the MOS transistors 225 and 227, an event signal including an on-event signal and an off-event signal is output to the vertical signal line 24.

[0052] In this manner, the grayscale signal generating unit 110 and the event signal generating unit 120 generate grayscale signals and event signals, respectively. When generating grayscale signals, the vertical driving circuit 33 outputs a selection signal, a reset signal, and a transfer signal to the pixels 12 in the row for which the grayscale signal is to be generated. On the other hand, when generating an event signal, the vertical driving circuit 33 sequentially outputs an on-event detection signal, an off-event detection signal, and an AZ control signal to all the pixels 12 in the pixel array unit 13. Thereafter, the output signal is sequentially output for each row of the pixel array unit 13, and the event signal is output (read out).

[0053] [Cross-sectional structure of pixel] 7 is a cross-sectional view showing a configuration example of a pixel according to the first embodiment of the present disclosure. The figure is a cross-sectional view showing a configuration example of a pixel 12. The pixel 12 in the figure includes a semiconductor substrate 300, a through electrode 341, a wiring region 330, an insulating film 345, a first photoelectric conversion unit 201, a sealing film 391, a color filter 392, and an on-chip lens 393.

[0054] The semiconductor substrate 300 is a semiconductor substrate on which elements such as the second photoelectric conversion unit 202 are arranged. The semiconductor substrate 300 in the figure includes the second photoelectric conversion unit 202, MOS transistors 211 and 212 included in the gradation signal generation unit 110, and the charge retention unit 203. The semiconductor substrate 300 in the figure also includes a MOS transistor 215 included in the event signal generation unit 120.

[0055] The semiconductor substrate 300 may be made of, for example, silicon (Si). The second photoelectric conversion unit 202 and the like are disposed in a well region formed in the semiconductor substrate 300. For convenience, it is assumed that the semiconductor substrate 300 in the figure constitutes a p-type well region. An element can be formed by disposing an n-type or p-type semiconductor region in this p-type well region.

[0056] The rectangle drawn on the semiconductor substrate 300 in the figure represents an n-type semiconductor region. The second photoelectric conversion unit 202 is composed of an n-type semiconductor region 301. Specifically, the second photoelectric conversion unit 202 corresponds to a photodiode composed of a pn junction formed at the interface between the n-type semiconductor region 301 and the surrounding p-type well region.

[0057] The charge holding portion 203 is composed of an n-type semiconductor region 302. This semiconductor region 302 constitutes the above-mentioned FD.

[0058] The MOS transistor 211 is composed of semiconductor regions 301 and 302 and a gate electrode 309. The n-type semiconductor regions 301 and 302 correspond to the source region and drain region of the MOS transistor. The gate electrode 309 is disposed on the front surface side of the semiconductor substrate 300 and has a columnar portion with a depth reaching the n-type semiconductor region 301. A gate insulating film (not shown) is disposed between the gate electrode 309 and the semiconductor substrate 300. When a drive voltage is applied to the gate electrode 309, a channel is formed in the well region adjacent to the gate electrode 309, and the n-type semiconductor regions 301 and 302 are brought into a conductive state. That is, the second photoelectric conversion unit 202 and the charge holding unit 203 are conductive, and the charge of the second photoelectric conversion unit 202 is transferred to the charge holding unit 203.

[0059] An insulating film 320 is disposed on the front surface side of the semiconductor substrate 300. This insulating film 320 is a film that insulates the front surface side of the semiconductor substrate 300. The insulating film 320 is a film made of silicon oxide (SiO 2 ) or silicon nitride (SiN).

[0060] The through electrode 341 is an electrode that penetrates the semiconductor substrate 300. This through electrode 341 connects an element arranged on the back side of the semiconductor substrate 300 to an element arranged on the front side. The through electrode 341 in the figure transmits a signal from the first photoelectric conversion unit 201 to the event signal generation unit 120 arranged on the semiconductor substrate 300. As described above, the through electrode 341 can be made of W, for example.

[0061] The wiring region 330 is disposed on the front surface side of the semiconductor substrate 300, and is a region where wiring and the like of elements are disposed. The wiring region 330 includes an insulating layer 331 and wiring 332. The insulating layer 331 insulates the wiring 332 and the like. The insulating layer 331 is made of, for example, SiO 21. The wiring 332 is a conductor that transmits signals and the like of an element. The wiring 332 can be made of a metal such as W or copper (Cu). The wiring 332 and the semiconductor region can be connected by a contact plug 333. The contact plug 333 is made of a columnar metal. A through electrode 341 is connected to the wiring 332 in the figure. The semiconductor substrate 300 constitutes the semiconductor substrate 11 in FIG. 1.

[0062] The insulating film 345 provides insulation between the semiconductor substrate 300 and the first photoelectric conversion portion 201. The insulating film 345 is, for example, SiO 2 The present invention can be configured as follows.

[0063] The first photoelectric conversion unit 201 is an element disposed adjacent to the semiconductor substrate 300 and performs photoelectric conversion of incident light. The first photoelectric conversion unit 201 in the figure is adjacent to the semiconductor substrate 300 via an insulating film 345. The first photoelectric conversion unit 201 includes a first electrode 361, a photoelectric conversion film 362, and a second electrode 363.

[0064] The photoelectric conversion film 362 is, for example, an organic photoelectric conversion film, and is a film that generates charges according to incident light. The photoelectric conversion film 362 can be made of an organic photoelectric conversion material including, for example, rhodamine dyes, merocyanine dyes, quinacridone, phthalocyanine dyes, coumarin dyes, and tris-8-hydroxyquinoline Al. The second electrode 363 is a transparent electrode disposed adjacent to the photoelectric conversion film 362. The second electrode 363 can be made of, for example, indium tin oxide (ITO). The first electrode 361 is an electrode that reads out the charges generated by the photoelectric conversion film 362.

[0065] The second electrode 363 is grounded by a wiring (not shown). The first electrode 361 is connected to the event signal generator 120 via the through electrode 341.

[0066] The sealing film 391 seals the first photoelectric conversion unit 201. The color filter 392 is an optical filter that transmits light of a predetermined wavelength out of the incident light. The color filter 392 in the figure transmits one of red light, green light, and blue light, and infrared light. The on-chip lens 393 is a lens that focuses the incident light on the second photoelectric conversion unit 202.

[0067] As shown in the figure, the pixel 12 is provided with a first photoelectric conversion unit 201 and a second photoelectric conversion unit 202 stacked together. As described above, the first photoelectric conversion unit 201 performs photoelectric conversion of visible light. The color filter 392 is provided with a color filter that transmits any of red light, green light, and blue light in addition to infrared light. In this case, the pixel 12 is provided with a color filter 392 corresponding to any of infrared light + red light, infrared light + green light, and infrared light + blue light. The first photoelectric conversion unit 201 performs photoelectric conversion of infrared light transmitted by each color filter 392 arranged in the pixel 12. On the other hand, the second photoelectric conversion unit 202 performs photoelectric conversion of visible light transmitted by the first photoelectric conversion unit 201 and the color filter 392.

[0068] In this way, the photodetection device 1 according to the first embodiment of the present disclosure generates a grayscale signal and an event signal in the pixel 12. This makes it possible to detect the movement of a subject at high speed.

[0069] 2. Second embodiment In the photodetector 1 of the above-described first embodiment, the gradation signal generator 110 and the event signal generator 120 are disposed in the pixel 12. In contrast, the photodetector 1 of the second embodiment of the present disclosure differs from the above-described first embodiment in that the gradation signal generator 110 is omitted.

[0070] [Pixel configuration] Fig. 8 is a cross-sectional view showing a configuration example of a pixel according to a second embodiment of the present disclosure. Similar to Fig. 7, the figure is a cross-sectional view showing a configuration example of a pixel 12. The pixel 12 in the figure differs from the pixel 12 in Fig. 7 in that the second photoelectric conversion unit 202 and the grayscale signal generation unit 110 are omitted.

[0071] Other than this, the configuration of the photodetector 1 is similar to the configuration of the photodetector 1 in the first embodiment of the present disclosure, and therefore a description thereof will be omitted.

[0072] In this manner, the photodetection device 1 according to the second embodiment of the present disclosure generates an event signal in the pixel 12. This makes it possible to detect the movement of a subject at high speed.

[0073] 3. Third embodiment In the photodetector 1 of the second embodiment described above, the elements of the event signal generating unit 120 are disposed on the semiconductor substrate 300. In contrast, the photodetector 1 of the third embodiment of the present disclosure differs from the photodetector 1 of the first embodiment described above in that some of the elements of the event signal generating unit 120 are disposed adjacent to the first photoelectric conversion unit 201.

[0074] [Pixel configuration] Fig. 9 is a cross-sectional view showing a configuration example of a pixel according to the third embodiment of the present disclosure. Similar to Fig. 8, this figure is a cross-sectional view showing a configuration example of a pixel 12. The pixel 12 in this figure differs from the pixel 12 in Fig. 8 in that an element 240 is arranged instead of the MOS transistor 215. The element 240 is an element formed of a semiconductor layer arranged adjacent to the first photoelectric conversion unit 201.

[0075] In the pixel 12 in the figure, a transparent semiconductor layer 364, an insulating film 365, a third electrode 366, and an electrode 367 are further disposed below the photoelectric conversion film 362. The element 240 in the figure is composed of these transparent semiconductor layer 364, insulating film 365, third electrode 366, and electrode 367.

[0076] The transparent semiconductor layer 364 constitutes a path for transmitting charges generated by the photoelectric conversion film 362. The transparent semiconductor layer 364 can be made of an oxide semiconductor film such as indium gallium zinc oxide (IGZO). The insulating film 365 is a film for providing insulation between the transparent semiconductor layer 364 and the electrode 367. The insulating film 365 can be made of, for example, SiO 2The electrode 367 may be made of, for example, ITO. The structure of the element 240 will be described with reference to FIG.

[0077] FIG. 10 is a diagram showing a configuration example of an element according to a third embodiment of the present disclosure. The figure is a cross-sectional view showing a configuration example of an element 240. The third electrode 366 is disposed under the transparent semiconductor layer 364. The first electrode 361 in the figure is disposed adjacent to an end of the transparent semiconductor layer 364. The electrode 367 is disposed in a region between the third electrode 366 and the first electrode 361. The electrode 367 is disposed adjacent to the transparent semiconductor layer 364 via an insulating film 365. The charge generated by the photoelectric conversion film 362 moves vertically (in the normal direction of the surface of the semiconductor substrate 300) in the photoelectric conversion film 362 to reach the transparent semiconductor layer 364, and then moves horizontally in the transparent semiconductor layer 364 to be transmitted to the first electrode 361. A voltage for adjusting the movement of the charge in the transparent semiconductor layer 364 is applied to the electrode 367. The input voltage of the event signal generating unit 120 is read out from the third electrode 366.

[0078] As shown in the figure, the third electrode 366 is connected to the gate of the MOS transistor 217 via a through electrode 341. The electrode 367 is connected to the drain terminal of the MOS transistor 217 via a through electrode 342. The first electrode 361 is connected to the power supply line Vdd via a through electrode 343. In this manner, some elements of the event signal generation unit 120 can be formed in the vicinity of the photoelectric conversion film 362 constituting the first photoelectric conversion unit 201. The transparent semiconductor layer 364 is an example of a "semiconductor layer" in the present disclosure.

[0079] Other than this, the configuration of the photodetector 1 is similar to the configuration of the photodetector 1 in the second embodiment of the present disclosure, and therefore a description thereof will be omitted.

[0080] In this way, in the photodetector 1 according to the third embodiment of the present disclosure, some of the elements of the event signal generator 120 can be formed in the vicinity of the photoelectric conversion film 362. This allows the number of elements on the semiconductor substrate 300 to be reduced.

[0081] 4. Fourth Embodiment The photodetector 1 of the first embodiment described above uses the second photoelectric conversion unit 202 and the first photoelectric conversion unit 201. In contrast, the photodetector 1 of the fourth embodiment of the present disclosure differs from the first embodiment described above in that the gradation signal generation unit 110 and the event signal generation unit 120 share a photoelectric conversion unit.

[0082] [Configuration of the gradation signal generator and the event signal generator] 11 is a circuit diagram showing a configuration example of a grayscale signal generating unit and an event signal generating unit according to a fourth embodiment of the present disclosure. The figure is a circuit diagram showing a configuration example of a grayscale signal generating unit 110 and an event signal generating unit 120. For convenience, some signal lines are omitted in the figure.

[0083] The first photoelectric conversion unit 201 is commonly connected to the grayscale signal generation unit 110 and the event signal generation unit 120 in the figure. In addition, a MOS transistor 228 is further arranged in the circuit in the figure. This MOS transistor 228 is an element connected to the first photoelectric conversion unit 201. An n-channel MOS transistor can be used for the MOS transistor 228. The cathode of the first photoelectric conversion unit 201 is connected to the source of the MOS transistor 211 and the source of the MOS transistor 228. The drain of the MOS transistor 228 is connected to the source of the MOS transistor 215 and the gate of the MOS transistor 217. Other wiring is the same as that in the circuits of Figures 3 and 5, so a description thereof will be omitted.

[0084] The MOS transistors 211 and 228 in the figure can be disposed on a semiconductor substrate 300. Note that a circuit formed by the MOS transistors 211 and 228 is a circuit that connects the first photoelectric conversion unit 201 to the gradation signal generation unit 110 and the event signal generation unit 120. This circuit is referred to as a first connection circuit 260.

[0085] [Pixel configuration] Fig. 12 is a cross-sectional view showing a configuration example of a pixel according to a fourth embodiment of the present disclosure. Similar to Fig. 7, the figure is a cross-sectional view showing a configuration example of a pixel 12. The pixel 12 in the figure differs from the pixel 12 in Fig. 7 in that the second photoelectric conversion unit 202 is omitted.

[0086] The MOS transistor 211 of the grayscale signal generating unit 110 in the figure is configured by a flat-plate gate MOS transistor. Also, a MOS transistor 228 is disposed on a semiconductor substrate 300 in the figure. The MOS transistor 211 and the MOS transistor 228 are connected to the first photoelectric conversion unit 201 via a through electrode 341 and a wiring 322.

[0087] [Other configurations of the gradation signal generating unit and the event signal generating unit] 11 uses the first connection circuit 260 configured by MOS transistors 211 and 228. Alternatively, the first connection circuit 260 can be configured by using elements (elements 241 and 242 described later) configured by a semiconductor layer disposed adjacent to the first photoelectric conversion unit 201.

[0088] [Element configuration] FIG. 13 is a plan view showing a configuration example of an element according to a fourth embodiment of the present disclosure. The figure is a plan view showing a configuration example of elements 241 and 242. The third electrode 366 in the figure is configured to be T-shaped in a plan view. The first electrode 361a and the first electrode 361b are respectively arranged at the lower left and lower right of the third electrode 366 in the figure. In addition, an electrode 367a is arranged between the third electrode 366 and the first electrode 361a, and an electrode 367b is arranged between the third electrode 366 and the first electrode 361b. The element 241 includes a first electrode 361a, an electrode 367a, and a third electrode 366. In addition, the element 242 includes a first electrode 361b, an electrode 367b, and a third electrode 366.

[0089] 14 is a diagram showing a configuration example of an element according to a fourth embodiment of the present disclosure. The figure is a cross-sectional view showing a configuration example of elements 241 and 242. The figure is also a diagram showing a schematic shape of a cross section along line a-a' in FIG. 13. As shown in the figure, a first electrode 361a of the element 241 is connected to a source terminal of the MOS transistor 212 via a through electrode 344. Also, a first electrode 361b of the element 242 is connected to a source terminal of the MOS transistor 215 via a through electrode 346.

[0090] [Other circuit configurations of the gradation signal generating unit and the event signal generating unit] 15 is a circuit diagram showing another example of the configuration of the grayscale signal generating unit and the event signal generating unit according to the fourth embodiment of the present disclosure. The same figure is a circuit diagram showing an example of the configuration of the grayscale signal generating unit 110 and the event signal generating unit 120, similar to FIG. 11. The grayscale signal generating unit 110 and the event signal generating unit 120 in the same figure are different from the grayscale signal generating unit 110 and the event signal generating unit 120 in FIG. 11 in that the MOS transistor 211 of the grayscale signal generating unit 110 is omitted. Note that the circuits of the grayscale signal generating unit 110 and the event signal generating unit 120 in the same figure can also be regarded as circuits in which the MOS transistor 211 of the first connection circuit 260 shown in FIG. 11 is omitted.

[0091] In the grayscale signal generating unit 110 shown in the figure, the cathode of the first photoelectric conversion unit 201 is directly connected to the MOS transistor 212 and the charge holding unit 203 .

[0092] Fig. 16 is a circuit diagram showing another example of the configuration of the grayscale signal generating section and the event signal generating section according to the fourth embodiment of the present disclosure. The same figure is a circuit diagram showing an example of the configuration of the grayscale signal generating section 110 and the event signal generating section 120, similar to Fig. 11. The grayscale signal generating section 110 and the event signal generating section 120 in the figure differ from the grayscale signal generating section 110 and the event signal generating section 120 in Fig. 11 in that a second photoelectric conversion section 202 and a MOS transistor 229 are further arranged. An n-channel MOS transistor can be applied to the MOS transistor 229.

[0093] The anode of the second photoelectric conversion unit 202 is grounded, and the cathode is connected to the source of the MOS transistor 229. The drain of the MOS transistor 229 is connected to the drain of the MOS transistor 211.

[0094] The grayscale signal generating unit 110 in the figure can generate a grayscale signal based on charges generated by the first photoelectric conversion unit 201 and the second photoelectric conversion unit 202. For example, when the event signal generating unit 120 does not generate an event signal, the charges generated by the first photoelectric conversion unit 201 and the second photoelectric conversion unit 202 can be transferred to the charge holding unit 203 by making the MOS transistor 228 non-conductive and making the MOS transistors 211 and 229 conductive. This can improve the sensitivity of the grayscale signal generating unit 110.

[0095] Other than this, the configuration of the photodetector 1 is similar to the configuration of the photodetector 1 in the first embodiment of the present disclosure, and therefore a description thereof will be omitted.

[0096] Thus, in the photodetector 1 according to the fourth embodiment of the present disclosure, the gradation signal generator 110 and the event signal generator 120 share the first photoelectric conversion unit 201. This allows the configuration of the semiconductor substrate 300 to be simplified.

[0097] 5. Fifth Embodiment In the photodetector 1 of the first embodiment described above, the first photoelectric conversion unit 201 is connected to the event signal generation unit 120, and the second photoelectric conversion unit 202 is connected to the gradation signal generation unit 110. In contrast, the photodetector 1 of the fifth embodiment of the present disclosure differs from the first embodiment described above in that the first photoelectric conversion unit 201 is connected to the gradation signal generation unit 110, and the second photoelectric conversion unit 202 is connected to the event signal generation unit 120.

[0098] [Circuit configuration of the grayscale signal generation unit and the event signal generation unit] Fig. 17 is a circuit diagram showing a configuration example of a grayscale signal generating unit and an event signal generating unit according to a fifth embodiment of the present disclosure. The same figure is a circuit diagram showing a configuration example of a grayscale signal generating unit 110 and an event signal generating unit 120, similar to Figs. 3 and 5. The grayscale signal generating unit 110 in the figure differs from the grayscale signal generating unit 110 in Fig. 3 in that a first photoelectric conversion unit 201 is connected instead of a second photoelectric conversion unit 202. In addition, the event signal generating unit 120 in the figure differs from the event signal generating unit 120 in Fig. 5 in that a second photoelectric conversion unit 202 is connected instead of a first photoelectric conversion unit 201.

[0099] The cathode of the first photoelectric conversion unit 201 is connected to the source of the MOS transistor 211 of the grayscale signal generation unit 110. The cathode of the second photoelectric conversion unit 202 is connected to the source of the MOS transistor 215 of the event signal generation unit 120.

[0100] [Pixel configuration] 18 is a cross-sectional view showing a configuration example of a pixel according to a fifth embodiment of the present disclosure. As shown in the figure, the grayscale signal generating unit 110 is connected to the first photoelectric conversion unit 201 via a through electrode 341. Meanwhile, the event signal generating unit 120 is connected to the second photoelectric conversion unit 202. Note that the n-type semiconductor region 301 constituting the second photoelectric conversion unit 202 in the figure is configured in a shape in which a part of the region is close to the surface of the semiconductor substrate 300. This region corresponds to the source region of the MOS transistor 215 and is connected to the gate of the MOS transistor 217 via a contact plug 333 and a wiring 332.

[0101] [Other circuit configurations of the gradation signal generating unit and the event signal generating unit] 19 and 20 are circuit diagrams showing other configuration examples of the grayscale signal generation unit and the event signal generation unit according to the fifth embodiment of the present disclosure. The same drawings are circuit diagrams showing configuration examples of the grayscale signal generation unit 110 and the event signal generation unit 120.

[0102] 19 shows an example in which a first photoelectric conversion unit 201 is connected to the gradation signal generation unit 110 and the event signal generation unit 120 via a circuit including a MOS transistor 211 and a MOS transistor 228, similar to the circuit in Fig. 11. The gradation signal generation unit 110 and the event signal generation unit 120 in Fig. 19 differ from the gradation signal generation unit 110 and the event signal generation unit 120 in Fig. 11 in that a second photoelectric conversion unit 202 is further connected to the event signal generation unit 120 via a MOS transistor 230.

[0103] 20 shows an example in which the second photoelectric conversion unit 202 is connected to the grayscale signal generation unit 110 and the event signal generation unit 120 via a circuit of a MOS transistor 211 and a MOS transistor 228. The first photoelectric conversion unit 201 is further connected to the grayscale signal generation unit 110 via a MOS transistor 229.

[0104] 2. The circuit configured by the MOS transistor 211 and the MOS transistor 228 in the figure is a circuit that connects the second photoelectric conversion unit 202 to the gradation signal generation unit 110 and the event signal generation unit 120. This circuit is referred to as a second connection circuit 261.

[0105] Other than this, the configuration of the photodetector 1 is similar to the configuration of the photodetector 1 in the first embodiment of the present disclosure, and therefore a description thereof will be omitted.

[0106] Thus, in the photodetector 1 according to the fifth embodiment of the present disclosure, the first photoelectric conversion unit 201 constituted by the photoelectric conversion film 362 is connected to the gradation signal generation unit 110. Also, the second photoelectric conversion unit 202 formed on the semiconductor substrate 300 is connected to the event signal generation unit 120 to generate an event signal.

[0107] 6. Sixth Embodiment A modification of the photodetector 1 will now be described.

[0108] [Other circuit configurations of the gradation signal generating unit and the event signal generating unit] Fig. 21 is a circuit diagram showing another configuration example of the gradation signal generation unit and the event signal generation unit according to a modified example of the embodiment of the present disclosure. The same figure is a circuit diagram showing a configuration example of the gradation signal generation unit 110 and the event signal generation unit 120, similar to Fig. 20. The gradation signal generation unit 110 and the event signal generation unit 120 in the figure differ from the gradation signal generation unit 110 and the event signal generation unit 120 in Fig. 20 in that a first photoelectric conversion unit 201 is further connected to the event signal generation unit 120 via a MOS transistor 230.

[0109] [Pixel configuration] Fig. 22 is a cross-sectional view showing a configuration example of a pixel according to a modified example of an embodiment of the present disclosure. Similar to Fig. 7, this figure is a cross-sectional view showing a configuration example of a pixel 12. The pixel 12 in this figure differs from the pixel 12 in Fig. 7 in that a color filter 394 is disposed between the first electrode 361 under the photoelectric conversion film 362 and the semiconductor substrate 300.

[0110] The first photoelectric conversion unit 201 in the figure can perform photoelectric conversion of infrared light, red light, green light, and blue light among incident light. This can improve the sensitivity of the first photoelectric conversion unit 201. The first photoelectric conversion unit 201 can also perform photoelectric conversion of red light, green light, and blue light. The second photoelectric conversion unit 202 performs photoelectric conversion of visible light transmitted through the first photoelectric conversion unit 201 and the color filter 394.

[0111] 7. In this case, by thinning the organic photoelectric conversion film 362, a part of the incident visible light transmitted through the color filter 392 is absorbed by the first photoelectric conversion section 201. In addition, the incident visible light transmitted through the first photoelectric conversion section 201 reaches the second photoelectric conversion section 202.

[0112] [Other pixel configurations] Fig. 23 is a cross-sectional view showing another example of the configuration of a pixel according to a modified example of the embodiment of the present disclosure. Similar to Fig. 7, this figure is a cross-sectional view showing an example of the configuration of a pixel 12. The pixel 12 in this figure differs from the pixel 12 in Fig. 7 in that the color filter 392 is omitted.

[0113] The first photoelectric conversion unit 201 in the figure can perform photoelectric conversion of infrared light, red light, green light, and blue light among the incident light. The second photoelectric conversion unit 202 in the figure can perform photoelectric conversion of infrared light. In this case, the gradation signal generation unit 110 generates a gradation signal based on the infrared light. This gradation signal based on the infrared light can be used, for example, as a distance measurement signal for measuring the distance to a subject.

[0114] [Photoelectric conversion section configuration] 24 is a diagram showing a configuration example of a photoelectric conversion unit according to a modified example of the embodiment of the present disclosure. The figure shows a configuration example of the second photoelectric conversion unit 202 and the first photoelectric conversion unit 201. As shown in the figure, the second photoelectric conversion unit 202 and the first photoelectric conversion unit 201 can be configured to have different sizes. The figure shows an example in which the first photoelectric conversion unit 201 is configured to be four times the size of the second photoelectric conversion unit 202. In the example of the figure, the sensitivity of the first photoelectric conversion unit 201 can be improved.

[0115] (7. Seventh embodiment) In the photodetector 1 of the first embodiment described above, a first photoelectric conversion unit 201 having an organic photoelectric conversion film is disposed in each pixel 12. In contrast, the photodetector 1 of the seventh embodiment of the present disclosure differs from the first embodiment described above in that a first photoelectric conversion unit 201 that absorbs visible light of a specific wavelength among visible light contained in incident light is disposed in each pixel 12.

[0116] [Pixel configuration] FIG. 25 is a cross-sectional view showing a configuration example of a pixel according to the seventh embodiment of the present disclosure. The same figure is a cross-sectional view showing a configuration example of a pixel 12, similar to FIG. 7. The pixel 12 in the figure differs from the pixel 12 in FIG. 7 in that a photoelectric conversion film 369 is arranged instead of the photoelectric conversion film 362 constituting the first photoelectric conversion section 201. Note that three pixels 12 (pixel 12a, pixel 12b, and pixel 12c) are shown in the figure. These pixels 12 have different photoelectric conversion films 369 of the first photoelectric conversion section 201. Note that some parts of the pixel 12 in the figure are omitted.

[0117] The configuration will be described by taking pixel 12a as an example. Pixel 12a includes a first photoelectric conversion unit 201 having a photoelectric conversion film 369 and a second photoelectric conversion unit 202 disposed on a semiconductor substrate 300. The first photoelectric conversion unit 201 is connected to an event signal generation unit 120. The second photoelectric conversion unit 202 is connected to a gradation signal generation unit 110. The connection portion of the second photoelectric conversion unit 202 and the gradation signal generation unit 110 can be configured similarly to that shown in FIG. 7. Although not shown, the event signal generation unit 120 and the gradation signal generation unit 110 are also disposed in pixels 12b and 12c, and are connected to the first photoelectric conversion unit 201 and the second photoelectric conversion unit 202, respectively.

[0118] The first photoelectric conversion unit 201 disposed in the pixel 12a etc. absorbs visible light of a specific wavelength among the visible light contained in the incident light to perform photoelectric conversion. The white characters attached to the photoelectric conversion film 369 of the pixel 12a etc. indicate the type of visible light absorbed by the first photoelectric conversion unit 201. In the figure, "R" represents red light. "G" represents green light. "B" represents blue light. That is, the first photoelectric conversion unit 201 of the pixel 12a absorbs red light among the incident light to perform photoelectric conversion. The first photoelectric conversion unit 201 of the pixel 12b absorbs green light among the incident light to perform photoelectric conversion. The first photoelectric conversion unit 201 of the pixel 12c absorbs blue light among the incident light to perform photoelectric conversion. In this way, in the photodetector 1 having the pixel 12a etc. in the figure, the wavelength of visible light absorbed by the first photoelectric conversion unit 201 differs for each pixel 12. The pixel 12a having the first photoelectric conversion unit 201 that absorbs red light, the pixel 12b having the first photoelectric conversion unit 201 that absorbs green light, and the pixel 12c having the first photoelectric conversion unit 201 that absorbs blue light can be arranged in the pixel array unit 13, for example, in a Bayer array.

[0119] The photoelectric conversion film 369 of the first photoelectric conversion unit 201 of the pixel 12a absorbing red light can be made of an organic photoelectric conversion material including, for example, a phthalocyanine dye and a subphthalocyanine dye (subphthalocyanine derivative). The photoelectric conversion film 369 of the first photoelectric conversion unit 201 of the pixel 12b absorbing green light can be made of an organic photoelectric conversion material including, for example, a rhodamine dye, a merocyanine dye, a quinacridone derivative, and a subphthalocyanine dye (subphthalocyanine derivative). The photoelectric conversion film 369 of the first photoelectric conversion unit 201 of the pixel 12c absorbing blue light can be made of an organic photoelectric conversion material including, for example, a coumaric acid dye, tris-8-hydroxyquinolialuminum (Alq3), and a melacyanine dye.

[0120] In the pixel 12 of FIG. 7, the first photoelectric conversion unit 201 absorbs infrared light and performs photoelectric conversion, and the second photoelectric conversion unit 202 performs photoelectric conversion of visible light. In this way, the pixel 12 of FIG. 7 detects infrared light and visible light separately in the first photoelectric conversion unit 201 and the second photoelectric conversion unit 202, which reduces convenience. In addition, in the pixel 12 of FIG. 22, the first photoelectric conversion unit 201 absorbs a part of the incident visible light, and the second photoelectric conversion unit 202 absorbs the remaining visible light and performs photoelectric conversion. That is, the pixel 12 of FIG. 22 detects incident light of the same wavelength by dividing it by the first photoelectric conversion unit 201 and the second photoelectric conversion unit 202, so the sensitivity is reduced. In contrast, in the pixel 12a of FIG. 25, the first photoelectric conversion unit 201 and the second photoelectric conversion unit 202 can be made to correspond to visible light of different wavelengths. Therefore, the first photoelectric conversion unit 201 and the second photoelectric conversion unit 202 can detect visible light with relatively high sensitivity. In addition, since there is no limitation on the wavelength of incident light detected in the first photoelectric conversion unit 201 and the second photoelectric conversion unit 202, it becomes possible to design the unit to match incident light with a wavelength having high quantum efficiency, for example. This improves the degree of freedom in designing the pixel 12.

[0121] [Other pixel configurations] 26 is a cross-sectional view showing another configuration example of a pixel according to the seventh embodiment of the present disclosure. Similar to FIG. 25, this figure is a cross-sectional view showing a configuration example of a pixel 12. The pixels 12 (pixels 12a, 12b, and 12c) in this figure show an example in which the pixel 12 further includes the element 240 described in FIG. 9. As described above, the element 240 is composed of a transparent semiconductor layer 364, an insulating film 365, a third electrode 366, and an electrode 367.

[0122] [Method of manufacturing the photodetector] 27A-27P are diagrams illustrating an example of a manufacturing method of a photodetector according to the seventh embodiment of the present disclosure. The diagrams illustrate manufacturing steps of a pixel 12 portion of the photodetector 1. The diagrams illustrate an example of a manufacturing process of the pixel 12 having an element 240.

[0123] First, a semiconductor region 301 (not shown) and a wiring region 330 (not shown) are arranged on the semiconductor substrate 300. Next, a through electrode 341 and an insulating film 345 are arranged on the semiconductor substrate 300. Next, a third electrode 366 (not shown), a first electrode 361 (not shown), and an insulating film 365 (not shown) that constitute the element 240 are arranged on the back surface side of the semiconductor substrate 300. Next, a material film 401 of the transparent semiconductor layer 364 is arranged (FIG. 27A).

[0124] Next, a material film 402 for the photoelectric conversion film 369 that absorbs red light, a material film 403 for the second electrode 363, and a material film 404 for the sealing film 391 are laminated in this order on the back surface side of the semiconductor substrate 300 (FIG. 27B).

[0125] Next, a resist 405 is placed on the surface of the material film 404. This resist 405 is configured in a shape that covers the region of the pixel 12a that includes the first photoelectric conversion unit 201 that absorbs red light (FIG. 27C).

[0126] Next, the material films 402 to 404 are etched using the resist 405 as a mask (FIG. 27D). As a result, the photoelectric conversion film 369, the second electrode 363, and the sealing film 391 of the first photoelectric conversion unit 201 of the pixel 12a are formed. Next, the resist 405 is removed (FIG. 27E).

[0127] Next, a material film 407 for the photoelectric conversion film 369 that absorbs green light, a material film 408 for the second electrode 363, and a material film 409 for the sealing film 391 are laminated in this order on the back surface side of the semiconductor substrate 300 (FIG. 27F).

[0128] Next, resist 411 is placed on the surface of material film 409. This resist 411 is configured in a shape that covers the region of pixel 12b that includes first photoelectric conversion unit 201 that absorbs green light (FIG. 27G).

[0129] Next, the material films 407 to 409 are etched (etched back) using the resist 411 as a mask (FIG. 27H). As a result, the photoelectric conversion film 369, the second electrode 363, and the sealing film 391 of the first photoelectric conversion unit 201 of the pixel 12b are formed. Next, the resist 411 is removed (FIG. 27I).

[0130] Next, a material film 413 for the photoelectric conversion film 369 that absorbs blue light, a material film 414 for the second electrode 363, and a material film 415 for the sealing film 391 are laminated in this order on the back surface side of the semiconductor substrate 300 (FIG. 27J).

[0131] Next, resist 417 is placed on the surface of material film 415. This resist 417 is configured in a shape that covers the region of pixel 12c that includes first photoelectric conversion unit 201 that absorbs blue light (FIG. 27K).

[0132] Next, the material films 413 to 415 are etched (etched back) using the resist 417 as a mask (FIG. 27L). As a result, the photoelectric conversion film 369, the second electrode 363, and the sealing film 391 of the first photoelectric conversion unit 201 of the pixel 12c are formed. Next, the resist 410 is removed (FIG. 27M).

[0133] Next, a resist 418 is placed on the back surface side of the semiconductor substrate 300. This resist 418 is configured in a shape that covers the regions of the pixels 12 (pixels 12a, 12b, and 12c) (FIG. 27N).

[0134] Next, the material film 401 is etched using the resist 418 as a mask (FIG. 27O). This forms the transparent semiconductor layer 364. Next, the resist 418 is removed (FIG. 27P). After that, the on-chip lens 393 and the like are formed. Through the above steps, the pixel 12 can be manufactured.

[0135] Other than this, the configuration of the photodetector 1 is similar to the configuration of the photodetector 1 in the first embodiment of the present disclosure, and therefore a description thereof will be omitted.

[0136] In this manner, the photodetector 1 according to the seventh embodiment of the present disclosure includes the pixel 12 in which the first photoelectric conversion unit 201 that absorbs visible light of a specific wavelength is disposed. This allows for greater freedom in designing the pixel 12.

[0137] 8. Eighth embodiment The photodetector 7 of the first embodiment described above includes pixels 12 in which first photoelectric conversion units 201 that absorb visible light of a specific wavelength are arranged. In contrast, the photodetector 1 of the eighth embodiment of the present disclosure differs from the first embodiment described above in that it further includes a color filter.

[0138] [Pixel configuration] Fig. 28 is a cross-sectional view showing a configuration example of a pixel according to an eighth embodiment of the present disclosure. Similar to Fig. 25, the figure is a cross-sectional view showing a configuration example of a pixel 12. The pixel 12 in the figure differs from the pixel 12 in Fig. 25 in that a color filter 395 is further disposed.

[0139] The color filter 395 transmits visible light including visible light of a specific wavelength absorbed by the first photoelectric conversion unit 201. The color filters 395 are disposed in the pixels 12a, 12b, and 12c. The letters attached to the color filters 395 in the figure indicate the type of visible light transmitted by the color filters 395. In the figure, "RG" indicates red light and green light. "GB" indicates green light and blue light. "BR" indicates blue light and red light. A complementary color filter can be applied to the color filter 395.

[0140] In the pixel 12a, the color filter 395 transmits red light and green light. The first photoelectric conversion unit 201 of the pixel 12a absorbs the red light and performs photoelectric conversion, and the second photoelectric conversion unit 202 of the pixel 12a absorbs the green light and performs photoelectric conversion. In the pixel 12b, the color filter 395 transmits green light and blue light. The first photoelectric conversion unit 201 of the pixel 12b absorbs the green light and performs photoelectric conversion, and the second photoelectric conversion unit 202 of the pixel 12b absorbs the blue light and performs photoelectric conversion. In the pixel 12c, the color filter 395 transmits blue light and red light. The first photoelectric conversion unit 201 of the pixel 12c absorbs the blue light and performs photoelectric conversion, and the second photoelectric conversion unit 202 of the pixel 12c absorbs the red light and performs photoelectric conversion. The white arrows in the figure represent the trajectories of visible light ("R": red light, "G": green light, and "B": blue light) incident on the pixel 12.

[0141] In this way, by disposing the color filter 395 in the pixel 12, visible light of a wavelength not used in the first photoelectric conversion unit 201 and the second photoelectric conversion unit 202 of each pixel 12 can be attenuated.

[0142] [Other pixel configurations] Fig. 29 is a cross-sectional view showing another configuration example of a pixel according to the eighth embodiment of the present disclosure. Similar to Fig. 28, this figure is a cross-sectional view showing a configuration example of a pixel 12. The pixels 12 (pixels 12a, 12b, and 12c) in this figure show an example in which the pixel 12 further includes the color filter 394 described in Fig. 22.

[0143] Fig. 30 is a cross-sectional view showing another configuration example of a pixel according to the eighth embodiment of the present disclosure. Similar to Fig. 29, this figure is a cross-sectional view showing a configuration example of a pixel 12. The pixels 12 in this figure (pixels 12a, 12b, and 12c) differ from the pixel 12 in Fig. 29 in that the color filter 395 is omitted.

[0144] Other than this, the configuration of the photodetector 1 is similar to the configuration of the photodetector 1 in the seventh embodiment of the present disclosure, and therefore a description thereof will be omitted.

[0145] In this way, the photodetector 1 according to the eighth embodiment of the present disclosure includes the pixel 12 in which the color filter is arranged. This makes it possible to attenuate visible light that is not used in the first photoelectric conversion unit 201 and the second photoelectric conversion unit 202 of the pixel 12. It is possible to reduce noise in the grayscale signal based on visible light.

[0146] 9. Ninth embodiment In the photodetector 1 of the seventh embodiment described above, the first photoelectric conversion unit 201 is connected to the event signal generation unit 120, and the second photoelectric conversion unit 202 is connected to the gradation signal generation unit 110. In contrast, the photodetector 1 of the ninth embodiment of the present disclosure differs from the seventh embodiment described above in that the first photoelectric conversion unit 201 is connected to the gradation signal generation unit 110, and the second photoelectric conversion unit 202 is connected to the event signal generation unit 120.

[0147] [Pixel configuration] Fig. 31 is a cross-sectional view showing a configuration example of a pixel according to a ninth embodiment of the present disclosure. Similar to Fig. 26, this figure is a cross-sectional view showing a configuration example of a pixel 12. As shown in this figure, the grayscale signal generation unit 110 is connected to the first photoelectric conversion unit 201 via the through electrode 341 and the element 240. On the other hand, the event signal generation unit 120 is connected to the second photoelectric conversion unit 202.

[0148] In the pixel 12 in the figure, a grayscale signal is generated based on visible light absorbed by the first photoelectric conversion unit 201, and an event signal is generated based on visible light or infrared light transmitted through the first photoelectric conversion unit 201.

[0149] [Other pixel configurations] Fig. 32 is a cross-sectional view showing another configuration example of a pixel according to the ninth embodiment of the present disclosure. Similar to Fig. 31, this figure is a cross-sectional view showing a configuration example of a pixel 12. The pixels 12 (pixels 12a, 12b, and 12c) in this figure show an example in which the pixel 12 further includes the color filter 395 described in Fig. 28.

[0150] [Other pixel configurations] Fig. 33 is a cross-sectional view showing another configuration example of a pixel according to the ninth embodiment of the present disclosure. Similar to Fig. 32, this figure is a cross-sectional view showing a configuration example of a pixel 12. The pixels 12 (pixels 12a, 12b, and 12c) in this figure show an example in which a color filter 392 is provided instead of the color filter 395.

[0151] Other than this, the configuration of the photodetector 1 is similar to the configuration of the photodetector 1 in the seventh embodiment of the present disclosure, and therefore a description thereof will be omitted.

[0152] As described above, in the photodetector 1 according to the ninth embodiment of the present disclosure, the first photoelectric conversion unit 201 formed by the photoelectric conversion film 369 is connected to the gradation signal generation unit 110. In addition, the second photoelectric conversion unit 202 formed on the semiconductor substrate 300 is connected to the event signal generation unit 120.

[0153] (10. Others) The portions other than the pixel array section 13 will be described.

[0154] [Configuration of current-voltage conversion circuit] 34 to 39 are diagrams illustrating configuration examples of current-voltage conversion circuits according to modified examples of the embodiments of the present disclosure.

[0155] 34 shows an example of a current-voltage conversion circuit 140 configured with a first photoelectric conversion unit 201 and a MOS transistor 215. The MOS transistor 215 configures a constant current circuit.

[0156] Fig. 35 shows an example of a current-voltage conversion circuit 140 having a similar configuration to that of Fig. 5. In place of the MOS transistor 216, a constant current circuit 237 is provided.

[0157] 36 to 39 show examples of the current-voltage conversion circuit 140 in which MOS transistors are additionally connected to the drain side of the MOS transistor 215, etc. By increasing the number of additionally connected MOS transistors, it is possible to increase the amplification factor when converting the change in current of the first photoelectric conversion unit 201 into a voltage. This makes it possible to reduce the influence of noise.

[0158] [How to generate gradation signals and event signals] Fig. 40 is a diagram showing an example of generation of a grayscale signal and an event signal according to an embodiment of the present disclosure. The figure shows the timing of generation of a grayscale signal and an event signal. The upper side of the figure shows the timing of generation of a grayscale signal, and the lower side shows the timing of generation of an event signal. "Vertical synchronization signal 1" in the figure is a signal indicating the division of a frame period in generation of a grayscale signal. Also, "vertical synchronization signal 2" is a signal indicating the division of a frame period in generation of an event signal.

[0159] A grayscale signal is generated by sequentially performing shutter 501, exposure 502, and readout 503 for each row. Grayscale signals are generated for each row from the first row to the last row while shifting the timing of shutter 501, exposure 502, and readout 503, and then the frame period for the grayscale signal is completed.

[0160] On the other hand, for generating an event signal, ON event detection 504, OFF event detection 505, and AZ operation 506 are performed in all pixels 12. Next, readout 507, which is the output of the event signal, is performed sequentially for each row, and the frame period for the event signal is completed. As shown in the figure, generation of the grayscale signal and generation of the event signal can be performed asynchronously at different frame rates.

[0161] (11. Configuration of Electronic Devices) The above-described photodetector 1 can be applied to various electronic devices, such as imaging systems such as digital still cameras and digital video cameras, mobile phones with imaging capabilities, and other devices with imaging capabilities.

[0162] Fig. 41 is a block diagram showing a configuration example of an imaging device mounted on an electronic device. As shown in Fig. 41, an electronic device 701 includes an optical system 702, a photodetector 703, and a DSP (Digital Signal Processor) 704, and is configured by connecting the DSP 704, a display device 705, an operation system 706, a memory 708, a recording device 709, and a power supply system 710 via a bus 707, and is capable of capturing still images and moving images.

[0163] The optical system 702 is configured to have one or more lenses, and guides image light (incident light) from a subject to the photodetector 703 , forming an image on the light receiving surface (sensor portion) of the photodetector 703 .

[0164] The photodetector 703 is applied with the photodetector 1 of any of the configuration examples described above. In the photodetector 703, electrons are accumulated for a certain period according to an image formed on the light receiving surface via the optical system 702. Then, a signal according to the electrons accumulated in the photodetector 703 is input to the DSP 704.

[0165] The DSP 704 performs various signal processing on the signal from the photodetector 703 to obtain an image, and temporarily stores the image data in a memory 708. The image data stored in the memory 708 is recorded in a recording device 709 or supplied to a display device 705 to display the image. In addition, an operation system 706 accepts various operations by a user and supplies operation signals to each block of the electronic device 701, and a power supply system 710 supplies power necessary to drive each block of the electronic device 701.

[0166] (12. Application to moving objects) The technology according to the present disclosure (the present technology) can be applied to various products. For example, the technology according to the present disclosure may be realized as a device mounted on any type of moving body such as an automobile, an electric vehicle, a hybrid electric vehicle, a motorcycle, a bicycle, a personal mobility device, an airplane, a drone, a ship, a robot, etc.

[0167] FIG. 42 is a block diagram showing a schematic configuration example of a vehicle control system, which is an example of a moving object control system to which the technology according to the present disclosure can be applied.

[0168] The vehicle control system 12000 includes a plurality of electronic control units connected via a communication network 12001. In the example shown in Fig. 42, the vehicle control system 12000 includes a drive system control unit 12010, a body system control unit 12020, an outside-vehicle information detection unit 12030, an inside-vehicle information detection unit 12040, and an integrated control unit 12050. Also, as functional configurations of the integrated control unit 12050, a microcomputer 12051, an audio / video output unit 12052, and an in-vehicle network I / F (Interface) 12053 are illustrated.

[0169] The drivetrain control unit 12010 controls the operation of devices related to the drivetrain of the vehicle in accordance with various programs. For example, the drivetrain control unit 12010 functions as a control device for a drive force generating device for generating a drive force of the vehicle, such as an internal combustion engine or a drive motor, a drive force transmission mechanism for transmitting the drive force to the wheels, a steering mechanism for adjusting the steering angle of the vehicle, and a braking device for generating a braking force of the vehicle.

[0170] The body system control unit 12020 controls the operation of various devices mounted on the vehicle body according to 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 head lamps, back lamps, brake lamps, turn signals, and fog lamps. In this case, radio waves or signals of various switches transmitted from a portable device that replaces a key may be input to the body system control unit 12020. The body system control unit 12020 receives the input of these radio waves or signals and controls the door lock device, power window device, lamps, and the like of the vehicle.

[0171] The outside-vehicle information detection unit 12030 detects information outside the vehicle equipped with the vehicle control system 12000. For example, an imaging unit 12031 is connected to the outside-vehicle information detection unit 12030. The outside-vehicle information detection unit 12030 causes the imaging unit 12031 to capture an image outside the vehicle and receives the captured image. The outside-vehicle information detection unit 12030 may perform object detection processing or distance detection processing for a person, a car, an obstacle, a sign, or characters on a road surface, based on the received image.

[0172] The imaging unit 12031 is an optical sensor that receives light and outputs an electrical signal according to the amount of light received. The imaging unit 12031 can output the electrical signal as an image, or as distance measurement information. The light received by the imaging unit 12031 may be visible light or invisible light such as infrared light.

[0173] The in-vehicle information detection unit 12040 detects information inside the vehicle. For example, a driver state detection unit 12041 that detects the state of the driver is connected to the in-vehicle information detection unit 12040. The driver state detection unit 12041 includes, for example, a camera that captures an image of the driver, and the in-vehicle information detection unit 12040 may calculate the degree of fatigue or concentration of the driver based on the detection information input from the driver state detection unit 12041, or may determine whether the driver is dozing.

[0174] The microcomputer 12051 can calculate control target values ​​for the driving force generating device, the steering mechanism, or the braking device based on the information inside and outside the vehicle acquired by the outside-of-vehicle information detection unit 12030 or the inside-vehicle information detection unit 12040, and output a control command to the drive system control unit 12010. For example, the microcomputer 12051 can perform cooperative control aimed at realizing the functions of an ADAS (Advanced Driver Assistance System), including vehicle collision avoidance or impact mitigation, following driving based on the inter-vehicle distance, vehicle speed maintenance driving, vehicle collision warning, vehicle lane departure warning, etc.

[0175] In addition, the microcomputer 12051 can perform cooperative control for the purpose of autonomous driving, which allows the vehicle to travel autonomously without relying on the driver's operation, by controlling the driving force generating device, steering mechanism, braking device, etc. based on information about the surroundings of the vehicle acquired by the outside vehicle information detection unit 12030 or the inside vehicle information detection unit 12040.

[0176] Furthermore, the microcomputer 12051 can output a control command to the body system control unit 12020 based on the information outside the vehicle acquired by the outside-vehicle information detection unit 12030. For example, the microcomputer 12051 can control the headlamps according to the position of a preceding vehicle or an oncoming vehicle detected by the outside-vehicle information detection unit 12030, and perform cooperative control for the purpose of preventing glare, such as switching from high beams to low beams.

[0177] The audio / video output unit 12052 transmits at least one output signal of audio and video to an output device capable of visually or audibly notifying information to passengers in the vehicle or the outside of the vehicle. In the example of Fig. 42, an audio speaker 12061, a display unit 12062, and an instrument panel 12063 are exemplified as the output device. The display unit 12062 may include at least one of an on-board display and a head-up display, for example.

[0178] FIG. 43 is a diagram showing an example of the installation position of the imaging unit 12031.

[0179] In FIG. 43, the imaging unit 12031 includes imaging units 12101, 12102, 12103, 12104, and 12105.

[0180] The imaging units 12101, 12102, 12103, 12104, and 12105 are provided at positions such as the front nose, side mirrors, rear bumper, back door, and the upper part of the windshield in the vehicle interior of the vehicle 12100. The imaging unit 12101 provided at the front nose and the imaging unit 12105 provided at the upper part of the windshield in the vehicle interior mainly acquire images of the front of the vehicle 12100. The imaging units 12102 and 12103 provided at the side mirrors mainly acquire images of the sides of the vehicle 12100. The imaging unit 12104 provided at the rear bumper or back door mainly acquires images of the rear of the vehicle 12100. The imaging unit 12105 provided at the upper part of the windshield in the vehicle interior is mainly used to detect a preceding vehicle, a pedestrian, an obstacle, a traffic light, a traffic sign, a lane, or the like.

[0181] 43 shows an example of the imaging ranges of the imaging units 12101 to 12104. Imaging range 12111 indicates the imaging range of the imaging unit 12101 provided on the front nose, imaging ranges 12112 and 12113 indicate the imaging ranges of the imaging units 12102 and 12103 provided on the side mirrors, respectively, and imaging range 12114 indicates the imaging range of the imaging unit 12104 provided on the rear bumper or back door. For example, an overhead image of the vehicle 12100 viewed from above is obtained by superimposing the image data captured by the imaging units 12101 to 12104.

[0182] At least one of the imaging units 12101 to 12104 may have a function of acquiring distance information. For example, at least one of the imaging units 12101 to 12104 may be a stereo camera made up of a plurality of imaging elements, or may be an imaging element having pixels for detecting a phase difference.

[0183] For example, the microcomputer 12051 can extract, as a preceding vehicle, a three-dimensional object that is the closest three-dimensional object on the travel path of the vehicle 12100 and travels at a predetermined speed (for example, 0 km / h or more) in approximately the same direction as the vehicle 12100, by calculating the distance to each three-dimensional object in the imaging ranges 12111 to 12114 and the change over time of this distance (relative speed with respect to the vehicle 12100) based on the distance information obtained from the imaging units 12101 to 12104. Furthermore, the microcomputer 12051 can set a vehicle distance to be secured in advance in front of the preceding vehicle, and perform automatic brake control (including follow-up stop control) and automatic acceleration control (including follow-up start control). In this way, cooperative control can be performed for the purpose of automatic driving that travels autonomously without relying on the driver's operation.

[0184] For example, the microcomputer 12051 classifies and extracts three-dimensional object data on three-dimensional objects into two-wheeled vehicles, ordinary vehicles, large vehicles, pedestrians, utility poles, and other three-dimensional objects based on distance information obtained from the imaging units 12101 to 12104, and can use the data for automatic obstacle avoidance. For example, the microcomputer 12051 distinguishes obstacles around the vehicle 12100 into obstacles that are visible to the driver of the vehicle 12100 and obstacles that are difficult to see. Then, the microcomputer 12051 determines a collision risk indicating the risk of collision with each obstacle, and when the collision risk is equal to or greater than a set value and a collision is possible, the microcomputer 12051 can provide driving assistance for collision avoidance by outputting an alarm to the driver via the audio speaker 12061 or the display unit 12062, or by performing forced deceleration or avoidance steering via the drive system control unit 12010.

[0185] At least one of the imaging units 12101 to 12104 may be an infrared camera that detects infrared rays. For example, the microcomputer 12051 can recognize a pedestrian by determining whether or not a pedestrian is present in the captured images of the imaging units 12101 to 12104. The recognition of such a pedestrian is performed, for example, by a procedure of extracting feature points in the captured images of the imaging units 12101 to 12104 as infrared cameras, and a procedure of performing pattern matching processing on a series of feature points that indicate the contour of an object to determine whether or not the object is a pedestrian. When the microcomputer 12051 determines that a pedestrian is present in the captured images of the imaging units 12101 to 12104 and recognizes the pedestrian, the audio / image output unit 12052 controls the display unit 12062 to superimpose a rectangular contour line for emphasis on the recognized pedestrian. The audio / image output unit 12052 may also control the display unit 12062 to display an icon or the like indicating a pedestrian at a desired position.

[0186] An example of a vehicle control system to which the technology according to the present disclosure can be applied has been described above. The technology according to the present disclosure can be applied to the imaging unit 12031 in the above-described configuration. Specifically, the photodetector 1 in FIG. 1 can be applied to the imaging unit 12031.

[0187] (13. Application to endoscopic surgery systems) The technology according to the present disclosure (the present technology) can be applied to various products. For example, the technology according to the present disclosure may be applied to an endoscopic surgery system.

[0188] FIG. 44 is a diagram showing an example of a schematic configuration of an endoscopic surgery system to which the technology according to the present disclosure (the present technology) can be applied.

[0189] 44 shows a state in which an operator (doctor) 11131 is performing surgery on a patient 11132 on a patient bed 11133 using an endoscopic surgery system 11000. As shown in the figure, the endoscopic surgery system 11000 is composed of an endoscope 11100, other surgical tools 11110 such as an insufflation tube 11111 and an energy treatment tool 11112, a support arm device 11120 that supports the endoscope 11100, and a cart 11200 on which various devices for endoscopic surgery are mounted.

[0190] The endoscope 11100 is composed of a lens barrel 11101, a region of a predetermined length from the tip of which is inserted into a body cavity of a patient 11132, and a camera head 11102 connected to the base end of the lens barrel 11101. In the illustrated example, the endoscope 11100 is configured as a so-called rigid scope having a rigid lens barrel 11101, but the endoscope 11100 may be configured as a so-called flexible scope having a flexible lens barrel.

[0191] An opening into which an objective lens is fitted is provided at the tip of the lens barrel 11101. A light source device 11203 is connected to the endoscope 11100, and light generated by the light source device 11203 is guided to the tip of the lens barrel by a light guide extending inside the lens barrel 11101, and is irradiated via the objective lens toward an observation target in the body cavity of the patient 11132. The endoscope 11100 may be a direct-viewing endoscope, an oblique-viewing endoscope, or a side-viewing endoscope.

[0192] An optical system and an image sensor are provided inside the camera head 11102, and reflected light (observation light) from an observation target is collected on the image sensor by the optical system. The observation light is photoelectrically converted by the image sensor to generate an electrical signal corresponding to the observation light, i.e., an image signal corresponding to an observation image. The image signal is transmitted to a camera control unit (CCU) 11201 as RAW data.

[0193] The CCU 11201 is configured with a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), etc., and performs overall control of the operations of the endoscope 11100 and the display device 11202. Furthermore, the CCU 11201 receives an image signal from the camera head 11102, and performs various types of image processing on the image signal, such as development processing (demosaic processing), for displaying an image based on the image signal.

[0194] Under the control of the CCU 11201, the display device 11202 displays an image based on an image signal that has been subjected to image processing by the CCU 11201.

[0195] The light source device 11203 is composed of a light source such as an LED (light emitting diode), and supplies the endoscope 11100 with irradiation light when photographing an operation site or the like.

[0196] The input device 11204 is an input interface for the endoscopic surgery system 11000. A user can input various information and instructions to the endoscopic surgery system 11000 via the input device 11204. For example, the user inputs an instruction to change the imaging conditions (type of irradiated light, magnification, focal length, etc.) of the endoscope 11100.

[0197] The treatment tool control device 11205 controls the driving of the energy treatment tool 11112 for cauterizing tissue, incising, sealing blood vessels, etc. The insufflation device 11206 sends gas into the body cavity of the patient 11132 via the insufflation tube 11111 to inflate the body cavity for the purpose of securing the field of view of the endoscope 11100 and securing the working space of the surgeon. The recorder 11207 is a device capable of recording various information related to the surgery. The printer 11208 is a device capable of printing various information related to the surgery in various formats such as text, image, or graph.

[0198] The light source device 11203 that supplies irradiation light to the endoscope 11100 when photographing the surgical site can be composed of a white light source composed of, for example, an LED, a laser light source, or a combination of these. When the white light source is composed of a combination of RGB laser light sources, the output intensity and output timing of each color (each wavelength) can be controlled with high precision, so that the white balance of the captured image can be adjusted in the light source device 11203. In this case, it is also possible to capture images corresponding to each of the RGB colors in a time-division manner by irradiating the observation object with laser light from each of the RGB laser light sources in a time-division manner and controlling the driving of the image sensor of the camera head 11102 in synchronization with the irradiation timing. According to this method, a color image can be obtained without providing a color filter to the image sensor.

[0199] The light source device 11203 may be controlled to change the intensity of the light it outputs at predetermined time intervals. The driving of the image sensor of the camera head 11102 may be controlled in synchronization with the timing of the change in the light intensity to obtain images in a time-division manner, and the images may be synthesized to generate an image with a high dynamic range that is free of so-called blackout and whiteout.

[0200] The light source device 11203 may be configured to supply light of a predetermined wavelength band corresponding to the special light observation. In the special light observation, for example, by utilizing the wavelength dependency of light absorption in body tissue, a narrow band light is irradiated compared to the irradiated light (i.e., white light) during normal observation, and a predetermined tissue such as blood vessels on the mucous membrane surface is photographed with high contrast, so-called narrow band imaging is performed. Alternatively, in the special light observation, a fluorescent observation may be performed in which an image is obtained by fluorescence generated by irradiating an excitation light. In the fluorescent observation, it is possible to irradiate an excitation light to a body tissue and observe the fluorescence from the body tissue (autofluorescence observation), or to locally inject a reagent such as indocyanine green (ICG) into the body tissue and irradiate the body tissue with excitation light corresponding to the fluorescent wavelength of the reagent to obtain a fluorescent image. The light source device 11203 may be configured to supply narrow band light and / or excitation light corresponding to such special light observation.

[0201] FIG. 45 is a block diagram showing an example of the functional configuration of the camera head 11102 and the CCU 11201 shown in FIG.

[0202] The camera head 11102 has a lens unit 11401, an imaging unit 11402, a drive unit 11403, a communication unit 11404, and a camera head control unit 11405. The CCU 11201 has a communication unit 11411, an image processing unit 11412, and a control unit 11413. The camera head 11102 and the CCU 11201 are connected to each other by a transmission cable 11400 so as to be able to communicate with each other.

[0203] The lens unit 11401 is an optical system provided at the connection portion with the lens barrel 11101. Observation light taken in from the tip of the lens barrel 11101 is guided to the camera head 11102 and enters the lens unit 11401. The lens unit 11401 is configured by combining a plurality of lenses including a zoom lens and a focus lens.

[0204] The imaging unit 11402 may include one imaging element (so-called single-plate type) or multiple imaging elements (so-called multiple-plate type). When the imaging unit 11402 is configured as a multiple-plate type, for example, each imaging element may generate an image signal corresponding to each of RGB, and a color image may be obtained by combining the image signals. Alternatively, the imaging unit 11402 may be configured to have a pair of imaging elements for acquiring image signals for the right eye and the left eye corresponding to a 3D (dimensional) display. By performing a 3D display, the surgeon 11131 can more accurately grasp the depth of the biological tissue in the surgical site. Note that when the imaging unit 11402 is configured as a multiple-plate type, the lens unit 11401 may also be provided in multiple systems corresponding to each imaging element.

[0205] Furthermore, the imaging unit 11402 does not necessarily have to be provided in the camera head 11102. For example, the imaging unit 11402 may be provided inside the lens barrel 11101, immediately behind the objective lens.

[0206] The driving unit 11403 is configured by an actuator, and moves the zoom lens and focus lens of the lens unit 11401 by a predetermined distance along the optical axis under the control of the camera head control unit 11405. This allows the magnification and focus of the image captured by the imaging unit 11402 to be appropriately adjusted.

[0207] The communication unit 11404 is configured by a communication device for transmitting and receiving various information to and from the CCU 11201. The communication unit 11404 transmits the image signal obtained from the imaging unit 11402 to the CCU 11201 via the transmission cable 11400 as RAW data.

[0208] Furthermore, the communication unit 11404 receives a control signal for controlling the driving of the camera head 11102 from the CCU 11201, and supplies the control signal to the camera head control unit 11405. The control signal includes information on the imaging conditions, such as information specifying the frame rate of the captured image, information specifying the exposure value at the time of capturing the image, and / or information specifying the magnification and focus of the captured image.

[0209] The image capturing conditions such as the frame rate, exposure value, magnification, and focus may be appropriately specified by a user, or may be automatically set by the control unit 11413 of the CCU 11201 based on an acquired image signal. In the latter case, the endoscope 11100 is equipped with a so-called AE (Auto Exposure) function, AF (Auto Focus) function, and AWB (Auto White Balance) function.

[0210] The camera head control unit 11405 controls the driving of the camera head 11102 based on a control signal received from the CCU 11201 via the communication unit 11404.

[0211] The communication unit 11411 is configured with a communication device for transmitting and receiving various information to and from the camera head 11102. The communication unit 11411 receives an image signal transmitted from the camera head 11102 via the transmission cable 11400.

[0212] Furthermore, the communication unit 11411 transmits, to the camera head 11102, a control signal for controlling the driving of the camera head 11102. The image signal and the control signal can be transmitted by electrical communication, optical communication, or the like.

[0213] The image processing unit 11412 performs various types of image processing on the image signal, which is RAW data sent from the camera head 11102 .

[0214] The control unit 11413 performs various controls related to imaging of the surgical site etc. by the endoscope 11100 and display of the captured image obtained by imaging the surgical site etc. For example, the control unit 11413 generates a control signal for controlling the driving of the camera head 11102.

[0215] Further, the control unit 11413 causes the display device 11202 to display the captured image showing the surgical site, etc., based on the image signal that has been image-processed by the image processing unit 11412. At this time, the control unit 11413 may recognize various objects in the captured image using various image recognition techniques. For example, the control unit 11413 can recognize surgical tools such as forceps, specific living body parts, bleeding, mist when the energy treatment tool 11112 is used, etc., by detecting the shape and color of the edge of an object included in the captured image. When the control unit 11413 causes the display device 11202 to display the captured image, it may use the recognition result to superimpose various types of surgery support information on the image of the surgical site. By superimposing and presenting the surgery support information to the surgeon 11131, the burden on the surgeon 11131 can be reduced and the surgeon 11131 can proceed with the surgery reliably.

[0216] The transmission cable 11400 connecting the camera head 11102 and the CCU 11201 is an electrical signal cable for communication of electrical signals, an optical fiber for optical communication, or a composite cable of these.

[0217] Here, in the illustrated example, communication is performed wired using a transmission cable 11400, but communication between the camera head 11102 and the CCU 11201 may also be performed wirelessly.

[0218] An example of an endoscopic surgery system to which the technology according to the present disclosure can be applied has been described above. The technology according to the present disclosure can be applied to the endoscope 11100 and the imaging unit 11402 of the camera head 11102 among the configurations described above. Specifically, the light detection device 1 in FIG. 1 can be applied to the imaging unit 11402.

[0219] Although an endoscopic surgery system has been described as an example here, the technology disclosed herein may also be applied to other systems, such as a microsurgery system.

[0220] The configuration of the third embodiment of the present disclosure can be applied to other embodiments. Specifically, the color filter 394 in FIG. 22 can be applied to the second to fifth embodiments of the present disclosure. The configuration of the pixel 12 in FIG. 23, which does not include a color filter, can be applied to the second to fifth embodiments of the present disclosure. The first photoelectric conversion unit 201 and the second photoelectric conversion unit 202 in FIG. 24 can be applied to the second to fifth embodiments of the present disclosure.

[0221] The configuration of the third embodiment of the present disclosure can be applied to the other embodiments. Specifically, the element 240 in FIG. 9 can be applied to the second and fifth embodiments of the present disclosure.

[0222] The configuration of the seventh embodiment of the present disclosure can be applied to the other embodiments. Specifically, the first photoelectric conversion unit 201 in FIG. 25 can be applied to the first to sixth embodiments of the present disclosure.

[0223] The configuration of the eighth embodiment of the present disclosure can be applied to other embodiments. Specifically, the first photoelectric conversion unit 201 and the color filter 395 in FIG. 28 can be applied to the first to sixth embodiments of the present disclosure.

[0224] The present technology can also be configured as follows. (1) A first photoelectric conversion unit that is stacked on a semiconductor substrate and performs photoelectric conversion of incident light; an event signal generating unit that detects a change in luminance of the incident light in the same direction as an event based on charges generated by photoelectric conversion of the first photoelectric conversion unit, and generates an event signal that is a signal based on the detected event; A light detection device having: (2) The photodetector according to (1), wherein the event signal generating unit is disposed on the semiconductor substrate. (3) The photodetection device described in (1), wherein the event signal generation unit is an element connected to the first photoelectric conversion unit and includes an element constituted by a semiconductor layer arranged adjacent to the first photoelectric conversion unit. (4) The photodetector according to any one of (1) to (3), further comprising a grayscale signal generating unit that generates a grayscale signal that is a signal corresponding to the luminance of the incident light. (5) The photodetector according to (4), wherein the gradation signal generating unit is disposed on the semiconductor substrate. (6) The photodetector according to (4) or (5), wherein the gradation signal generating section generates the gradation signal based on charges generated by photoelectric conversion of the first photoelectric conversion section. (7) The photodetector according to (6), further comprising a first connection circuit that connects the first photoelectric conversion unit to the event signal generation unit and the gradation signal generation unit. (8) The photodetector device described in (7), wherein the first connection circuit is an element connected to the first photoelectric conversion unit and includes an element constituted by a semiconductor layer arranged adjacent to the first photoelectric conversion unit. (9) the event signal generation unit detects the event based on the charge of the first photoelectric conversion unit supplied via the first connection circuit; The grayscale signal generating section generates the grayscale signal based on the charge of the first photoelectric conversion section supplied via the first connection circuit. The light detection device according to (7) above. (10) The photodetector according to (9) above, further comprising a second photoelectric conversion section disposed on the semiconductor substrate and performing photoelectric conversion of incident light. (11) The photodetection device described in (10), wherein the event signal generation unit generates the event signal based on the charge generated by photoelectric conversion of the second photoelectric conversion unit and the charge of the first photoelectric conversion unit supplied via the first connection circuit. (12) The photodetection device described in (10), wherein the gradation signal generation unit generates the gradation signal based on the charge generated by photoelectric conversion of the second photoelectric conversion unit and the charge of the first photoelectric conversion unit supplied via the first connection circuit. (13) The photodetection device described in (4), wherein the gradation signal generation unit generates the gradation signal based on charges generated by photoelectric conversion of a second photoelectric conversion unit arranged on the semiconductor substrate and performing photoelectric conversion of incident light. (14) The photodetector according to (13), wherein the first photoelectric conversion unit is configured to have a different size from the second photoelectric conversion unit. (15) The photodetector according to (13), wherein the second photoelectric conversion unit performs photoelectric conversion of the incident light that has passed through the first photoelectric conversion unit. (16) The photodetection device according to (13), wherein the event signal generating unit is an element connected to the first photoelectric conversion unit and includes an element constituted by a semiconductor layer arranged adjacent to the first photoelectric conversion unit. (17) A second photoelectric conversion unit disposed on the semiconductor substrate and performing photoelectric conversion of incident light; a second connection circuit that connects the second photoelectric conversion unit to the event signal generation unit and the gradation signal generation unit; Further comprising: the event signal generation unit generates the event signal based on charges generated by photoelectric conversion of the first photoelectric conversion unit and charges of the second photoelectric conversion unit supplied via the second connection circuit; The grayscale signal generating section generates the grayscale signal based on the charge of the second photoelectric conversion section supplied via the second connection circuit. The light detection device according to (4) above. (18) Further comprising a second photoelectric conversion unit disposed on the semiconductor substrate and performing photoelectric conversion of incident light, the first photoelectric conversion unit absorbs visible light having a specific wavelength among visible light contained in the incident light to perform the photoelectric conversion; The second photoelectric conversion unit performs the photoelectric conversion of visible light transmitted through the first photoelectric conversion unit. The light detection device according to (4) above. (19) a color filter that transmits visible light including the specific wavelength of the incident light, the first photoelectric conversion unit performs the photoelectric conversion of the visible light of the specific wavelength that has passed through the color filter; The second photoelectric conversion unit performs the photoelectric conversion of visible light transmitted through the color filter and the first photoelectric conversion unit. The light detection device according to (18) above. (20) A first photoelectric conversion unit that is stacked on a semiconductor substrate and performs photoelectric conversion of incident light; a grayscale signal generating unit that generates a grayscale signal corresponding to the luminance of the incident light based on the charges generated by the photoelectric conversion of the first photoelectric conversion unit; an event signal generating unit that detects a change in the luminance of the incident light in the same direction as an event and generates an event signal that is a signal based on the detected event; A light detection device having: (twenty one) The photodetector according to (20), wherein the gradation signal generating section is disposed on the semiconductor substrate. (twenty two) The photodetector according to (20), wherein the event signal generating unit is disposed on the semiconductor substrate. (twenty three) The photodetector according to (20), further comprising a second photoelectric conversion section disposed on the semiconductor substrate and performing photoelectric conversion of the incident light. (twenty four) a first connection circuit that connects the first photoelectric conversion unit to the event signal generation unit and the gradation signal generation unit; the gradation signal generation unit generates the gradation signal based on the charge of the first photoelectric conversion unit supplied via the first connection circuit; The event signal generating unit detects the event based on the charge generated by photoelectric conversion of the second photoelectric conversion unit and the charge of the first photoelectric conversion unit supplied via the first connection circuit. The light detection device according to (23) above. (twenty five) The photodetector according to (23), wherein the event signal generation unit generates the event signal based on charges generated by photoelectric conversion of the second photoelectric conversion unit. (26) a second connection circuit that connects the second photoelectric conversion unit to the event signal generation unit and the gradation signal generation unit; the gradation signal generation unit generates the gradation signal based on charges generated by photoelectric conversion of the first photoelectric conversion unit and charges of the second photoelectric conversion unit supplied via the second connection circuit; The event signal generating unit detects the event based on the charge of the second photoelectric conversion unit supplied via the second connection circuit. The optical detection device according to (25) above. (27) The photodetector according to (25), wherein the first photoelectric conversion unit is configured to have a different size from the second photoelectric conversion unit. (28) The photodetector according to (25), wherein the second photoelectric conversion unit performs photoelectric conversion of the incident light that has passed through the first photoelectric conversion unit. [Explanation of symbols]

[0225] 1, 703 Photodetector 110 Gradation signal generator 120 Event signal generator 201 First photoelectric conversion unit 202 Second photoelectric conversion unit 260 First Connection Circuit 261 Second Connection Circuit 300 Semiconductor Substrate 392, 394, 395 Color Filters 11402, 12031, 12101~12105 Imaging unit

Claims

1. a first photoelectric conversion unit that is stacked on a semiconductor substrate and performs photoelectric conversion of incident light; an event signal generating unit that detects a change in luminance of the incident light in the same direction as an event based on charges generated by photoelectric conversion of the first photoelectric conversion unit, and generates an event signal that is a signal based on the detected event; A light detection device having

2. The photodetector according to claim 1 , wherein the event signal generator is disposed on the semiconductor substrate.

3. The photodetector according to claim 1 , wherein the event signal generating section comprises an element connected to the first photoelectric conversion section and made of a semiconductor layer disposed adjacent to the first photoelectric conversion section.

4. 2. The light detection device according to claim 1, further comprising a gray-scale signal generating section for generating a gray-scale signal which is a signal corresponding to the luminance of the incident light.

5. The photodetector according to claim 4 , wherein the gray-scale signal generating section is disposed on the semiconductor substrate.

6. The photodetector according to claim 4 , wherein the grayscale signal generating section generates the grayscale signal based on charges generated by photoelectric conversion of the first photoelectric conversion section.

7. 7. The photodetector according to claim 6, further comprising a first connection circuit that connects the first photoelectric conversion unit to the event signal generation unit and the gradation signal generation unit.

8. The photodetector according to claim 7 , wherein the first connection circuit includes an element connected to the first photoelectric conversion unit, the element being made of a semiconductor layer and arranged adjacent to the first photoelectric conversion unit.

9. the event signal generation unit detects the event based on the charge of the first photoelectric conversion unit supplied via the first connection circuit; The grayscale signal generating section generates the grayscale signal based on the charge of the first photoelectric conversion section supplied via the first connection circuit.

8. The optical detection device according to claim 7.

10. The light detection device according to claim 9 , further comprising a second photoelectric conversion section disposed on the semiconductor substrate and performing photoelectric conversion of incident light.

11. The photodetection device according to claim 10 , wherein the event signal generating unit generates the event signal based on the charge generated by photoelectric conversion of the second photoelectric conversion unit and the charge of the first photoelectric conversion unit supplied via the first connection circuit.

12. The photodetection device according to claim 10 , wherein the gradation signal generation unit generates the gradation signal based on charges generated by photoelectric conversion of the second photoelectric conversion unit and charges of the first photoelectric conversion unit supplied via the first connection circuit.

13. The photodetector according to claim 4 , wherein the gradation signal generating section generates the gradation signal based on charges generated by photoelectric conversion of a second photoelectric conversion section disposed on the semiconductor substrate and performing photoelectric conversion of incident light.

14. The photodetector according to claim 13 , wherein the first photoelectric conversion portion is configured to have a different size from the second photoelectric conversion portion.

15. The light detection device according to claim 13 , wherein the second photoelectric conversion section performs photoelectric conversion on the incident light that has passed through the first photoelectric conversion section.

16. The photodetector according to claim 13 , wherein the event signal generating section includes an element connected to the first photoelectric conversion section and made of a semiconductor layer disposed adjacent to the first photoelectric conversion section.

17. a second photoelectric conversion unit disposed on the semiconductor substrate and performing photoelectric conversion of incident light; a second connection circuit that connects the second photoelectric conversion unit to the event signal generation unit and the gradation signal generation unit; Further comprising: the event signal generation unit generates the event signal based on charges generated by photoelectric conversion of the first photoelectric conversion unit and charges of the second photoelectric conversion unit supplied via the second connection circuit; The grayscale signal generating section generates the grayscale signal based on the charge of the second photoelectric conversion section supplied via the second connection circuit.

5. The optical detection device according to claim 4.

18. Further, a second photoelectric conversion unit is disposed on the semiconductor substrate and performs photoelectric conversion of incident light, the first photoelectric conversion unit absorbs visible light having a specific wavelength among visible light contained in the incident light to perform the photoelectric conversion; The second photoelectric conversion unit performs the photoelectric conversion of visible light transmitted through the first photoelectric conversion unit.

5. The optical detection device according to claim 4.

19. a color filter that transmits visible light including the specific wavelength of the incident light, the first photoelectric conversion unit performs the photoelectric conversion of the visible light of the specific wavelength transmitted through the color filter; The second photoelectric conversion unit performs the photoelectric conversion of visible light transmitted through the color filter and the first photoelectric conversion unit.

20. The optical detection device of claim 18.

20. a first photoelectric conversion unit that is stacked on a semiconductor substrate and performs photoelectric conversion of incident light; a grayscale signal generating unit that generates a grayscale signal corresponding to the luminance of the incident light based on the charges generated by the photoelectric conversion of the first photoelectric conversion unit; an event signal generating unit that detects a change in the luminance of the incident light in the same direction as an event and generates an event signal that is a signal based on the detected event; A light detection device having

21. The photodetector according to claim 20 , wherein the gray-scale signal generating section is disposed on the semiconductor substrate.

22. The photodetector according to claim 20 , wherein the event signal generator is disposed on the semiconductor substrate.

23. The light detection device according to claim 20 , further comprising a second photoelectric conversion section disposed on the semiconductor substrate and performing photoelectric conversion of the incident light.

24. a first connection circuit that connects the first photoelectric conversion unit to the event signal generation unit and the gradation signal generation unit; the gradation signal generation unit generates the gradation signal based on the charge of the first photoelectric conversion unit supplied via the first connection circuit; The event signal generating unit detects the event based on charges generated by photoelectric conversion of the second photoelectric conversion unit and charges of the first photoelectric conversion unit supplied via the first connection circuit.

24. The optical detection device of claim 23.

25. The photodetector according to claim 23 , wherein the event signal generating section generates the event signal based on charges generated by photoelectric conversion of the second photoelectric conversion section.

26. a second connection circuit that connects the second photoelectric conversion unit to the event signal generation unit and the gradation signal generation unit; the gradation signal generation unit generates the gradation signal based on charges generated by photoelectric conversion of the first photoelectric conversion unit and charges of the second photoelectric conversion unit supplied via the second connection circuit; The event signal generating unit detects the event based on the charge of the second photoelectric conversion unit supplied via the second connection circuit.

26. The optical detection device of claim 25.

27. The photodetector according to claim 25 , wherein the first photoelectric conversion portion is configured to have a different size from the second photoelectric conversion portion.

28. The light detection device according to claim 25 , wherein the second photoelectric conversion section performs photoelectric conversion on the incident light that has passed through the first photoelectric conversion section.

29. the first photoelectric conversion unit absorbs visible light having a specific wavelength among visible light contained in the incident light to perform the photoelectric conversion; The second photoelectric conversion unit performs the photoelectric conversion of visible light transmitted through the first photoelectric conversion unit.

24. The optical detection device of claim 23.

30. a color filter that transmits visible light including the specific wavelength of the incident light, the first photoelectric conversion unit performs the photoelectric conversion of the visible light of the specific wavelength transmitted through the color filter; The second photoelectric conversion unit performs the photoelectric conversion of visible light transmitted through the color filter and the first photoelectric conversion unit.

30. The optical detection device of claim 29.

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