Image pickup element and image pickup method

Abstract

The present invention reduces the occurrence of a delay in detecting a valid address event that should inherently be detected. An image pickup element includes a plurality of pixels (100), a pixel address event detection unit (120), a region address event detection unit (320), and a pixel selection unit (310). The pixels (100) each include a photoelectric conversion unit (110) for performing photoelectric conversion of incident light. The pixel address event detection unit (120) is provided with respect to each pixel and detects a pixel address event that is an address event of a relevant pixel based on a change in the amount of charge generated by photoelectric conversion. The region address event detection unit (320) detects a region address event that is an address event in a predetermined region based on a change in the amount of charge generated by photoelectric conversion in a plurality of pixels included in the predetermined region among the plurality of pixels. The pixel selection unit (310) selects a pixel (100) based on the detected pixel address event and region address event and causes the selected pixel to output a pixel address event detection result.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to an image pickup element and an image pickup method. BACKGROUND

[0002] In recent years, an asynchronous image pickup device provided with an address event detection circuit in each pixel is used. The address event detection circuit detects an address event in which the light amount of a pixel exceeds a threshold value in real time.

[0003] When the occurrence of an address event is detected, each address event detection circuit outputs a request signal for requesting output of a detection signal indicating the occurrence of the address event to an arbitration circuit called an arbiter. The arbiter gives the right to select to the address event detection circuit in the order of early transmission of the request signal, and enables the light receiving element signal to be output (for example, Patent Literature 1).

[0004] LIST OF CITATIONS

[0005] PATENT LITERATURE

[0006] Patent Literature 1: JP 2016-533140 A SUMMARY

[0007] TECHNICAL PROBLEM

[0008] However, since the above-described image pickup device is arbitrated in the order of early detection of an address event, although such an address event is detected, the generation of an image based on an address event having a high priority can be delayed. Specifically, even in the case where an effective address event that is initially detected such as an event accompanying movement of an observation target is detected, an address event caused by noise and the like that is detected first is preferentially processed. Therefore, there is a problem that a delay occurs in the detection of an effective address event that is initially to be detected.

[0009] Therefore, the present disclosure proposes an image pickup element and an image pickup method capable of suppressing a delay from occurring in the detection of an effective address event that is initially detected.

[0010] SOLUTION TO PROBLEM

[0011] To solve the above problems, an image pickup element according to an embodiment of the present disclosure includes: a plurality of pixels provided with a photoelectric conversion unit that performs photoelectric conversion of incident light; a pixel address event detection unit arranged in each of the plurality of pixels and detecting a pixel address event, the pixel address event being an address event of each of the plurality of pixels and being detected based on a change in an amount of charge generated by the photoelectric conversion; a region address event detection unit detecting a region address event, the region address event being an address event in a predetermined region and being detected based on a change in an amount of charge generated by the photoelectric conversion in a plurality of pixels included in the predetermined region among the plurality of pixels; and a pixel selection unit selecting a pixel from the plurality of pixels based on the detected pixel address event and the detected region address event, and causing the selected pixel to output a detection result of the pixel address event. BRIEF DESCRIPTION OF DRAWINGS

[0012] Figure 1 is a block diagram illustrating a configuration example of an image pickup device according to an embodiment of the present disclosure.

[0013] Figure 2 is a diagram illustrating a configuration example of an image pickup element according to an embodiment of the present disclosure.

[0014] Figure 3 is a diagram illustrating a configuration example of a pixel array unit and an arbiter according to a first embodiment of the present disclosure.

[0015] Figure 4 is a diagram illustrating a configuration example of a pixel address event detection unit according to the first embodiment of the present disclosure.

[0016] Figure 5 is a diagram illustrating a configuration example of a current-voltage conversion circuit according to the first embodiment of the present disclosure.

[0017] Figure 6 is a diagram illustrating a configuration example of a buffer, a subtracter, and a quantizer according to the first embodiment of the present disclosure.

[0018] Figure 7 is a diagram illustrating a configuration example of a region address event detection unit according to the first embodiment of the present disclosure.

[0019] Figure 8 is a diagram illustrating a configuration example of a current-voltage conversion circuit according to the first embodiment of the present disclosure.

[0020] Figure 9 is a block diagram illustrating a configuration example of a pixel selection unit according to the first embodiment of the present disclosure.

[0021] Figure 10 is a diagram illustrating an example of image data generation processing according to the first embodiment of the present disclosure.

[0022] Figure 11 is a diagram illustrating an example of detection result output processing according to the first embodiment of the present disclosure.

[0023] Figure 12 is a diagram illustrating a configuration example of a pixel array unit and an arbiter according to the first modification of the first embodiment of the present disclosure.

[0024] Figure 13 is a diagram illustrating a configuration example of a pixel array unit and an arbiter according to the second modification of the first embodiment of the present disclosure.

[0025] Figure 14 is a diagram illustrating a configuration example of a pixel array unit and an arbiter according to the second embodiment of the present disclosure.

[0026] Figure 15 is a diagram illustrating an example of image data generation processing according to the second embodiment of the present disclosure.

[0027] Figure 16 is a diagram illustrating a configuration example of an arbiter according to the third embodiment of the present disclosure.

[0028] Figure 17 is a diagram illustrating a configuration example of a pixel array unit and an arbiter according to the fourth embodiment of the present disclosure.

[0029] Figure 18 is a diagram illustrating a configuration example of an image signal generation unit according to the fourth embodiment of the present disclosure. DETAILED DESCRIPTION

[0030] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. The description will be given in the following order. In addition, in each of the following embodiments, the same parts are labeled with the same reference numerals and repetitive explanation is omitted.

[0031] 1. First Embodiment

[0032] 2. Second Embodiment

[0033] 3. Third Embodiment

[0034] 4. Fourth Embodiment

[0035] <First Embodiment>

[0036] [Configuration of Image Pickup Device]

[0037] Figure 1is a block diagram illustrating a configuration example of an image pickup device according to an embodiment of the present disclosure. Figure 1 A configuration example of the image pickup device 1 is shown.

[0038] The image pickup device 1 according to the embodiment includes an image pickup lens 5, an image pickup element 2, a recording unit 3, and a control unit 4. The image pickup device 1 is assumed to be a camera mounted on a wearable device, a vehicle-mounted camera, or the like.

[0039] The image pickup lens 5 is an example of an optical system, and captures incident light from an object to form an image on an image pickup surface of the image pickup element 2.

[0040] The image pickup element 2 is also called an event-based vision sensor (EVS), and detects, for each of a plurality of pixels, an address event that is an absolute value of a luminance change amount exceeding a threshold value. The address event includes, for example, an ON event indicating that a luminance increase amount exceeds an upper limit threshold value, and an OFF event indicating that a luminance decrease amount falls below a lower limit threshold value that is smaller than the upper limit threshold value.

[0041] Then, the image pickup element 2 generates a detection signal representing a detection result of the address event of each pixel. Each detection signal includes an ON event detection signal V CH ( Figure 6 ) indicating the presence or absence of an ON event, and an OFF event detection signal V CL ( Figure 6 ) indicating the presence or absence of an OFF event.

[0042] Further, the image pickup element 2 also generates an image signal for each pixel for which the detection signal is generated. The generated image signal is subjected to a prescribed signal processing such as image recognition processing, and the processed image data is output to the recording unit 3 via a signal line 6.

[0043] The recording unit 3 records the image data from the image pickup element 2. The control unit 4 controls the image pickup element 2 to cause the image pickup element 2 to capture the image data. At this time, the control unit 4 outputs a control signal to the image pickup element 2 via a signal line 7.

[0044] [Configuration of image pickup element]

[0045] Figure 2 is a block diagram illustrating a configuration example of an image pickup element according to an embodiment of the present disclosure. Figure 2 is a block diagram illustrating a configuration example of the image pickup element 2. Figure 2 The image pickup element 2 in is configured to include a pixel array unit 10, a control circuit 20, an arbiter 30, and a signal processing unit 40.

[0046] The pixel array unit 10 is configured by arranging a plurality of pixels 100. Figure 2 The pixel array unit 10 in FIG. 1 shows an example in which the pixels 100 are arranged in a two-dimensional matrix. Each of the pixels 100 includes a photoelectric conversion unit that performs photoelectric conversion of incident light and detects an address event based on an amount of change in electric charge generated by the photoelectric conversion. Hereinafter, the address event detected in the pixel 100 is referred to as a pixel address event.

[0047] The pixel 100 that has detected the pixel address event outputs a detection signal of the pixel address event to the control circuit 20 and the signal processing unit 40 described later. The control circuit 20 outputs a control signal to the pixel 100 that has output the detection signal to reset the pixel address event detected in the pixel 100. Further, the signal processing unit 40 performs predetermined signal processing on the detection signal.

[0048] Before outputting the detection signal, the pixel 100 transmits an output request of the detection signal to the arbiter 30 described later. The arbiter 30 selects the pixel 100 that has transmitted the request and outputs a response to the request. The response allows the output of the detection signal.

[0049] The arbiter 30 selects the pixel 100 based on the pixel address event and the area address event described above. Here, the area address event is an address event detected based on an amount of change in electric charge generated by photoelectric conversion of the pixels 100 included in a predetermined area among the plurality of pixels 100 arranged in the pixel array unit 10. The area address event can be detected, for example, based on an amount of change in total electric charge generated by the pixels 100 included in the predetermined area. Details of the configuration of the pixel 100 will be described later.

[0050] The control circuit 20 is a circuit that controls the reset of the pixel address event in each of the pixels 100 of the pixel array unit 10. The control circuit 20 resets the pixel address event detection unit 120 by outputting a control signal for resetting the subtracter 123 of the pixel address event detection unit 120 arranged in the pixel 100 described later.

[0051] The arbiter 30 selects the pixel 100 that has transmitted the request. The arbiter 30 selects the pixel 100 based on the pixel address event and the area address event as described above. As described above, the pixel 100 that has detected the address event outputs the detection signal to the control circuit 20 and the signal processing unit 40. It is necessary to supply the control signal to one pixel 100 exclusively. This is to prevent collision when the detection signal is output in a plurality of pixels 100. Therefore, the arbiter 30 arbitrates a plurality of pixels 100 that have detected the pixel address event. Specifically, the arbiter 30 selects one pixel 100 from among the pixels 100 that have detected the pixel address event and returns a response to the selected pixel 100. The response indicates the result of the selection.

[0052] When requests are transmitted from a plurality of pixels 100, the arbitrator 30 may select pixels 100 in the order in which the requests have been transmitted. Here, the arbitrator 30 may give priority to selecting specific pixels 100. For example, the arbitrator 30 may give priority to selecting pixels 100 included in an area where the above-mentioned area address event has been detected, rather than pixels 100 included in the area. The area where the area address event is detected is an area where a change in the brightness of the incident light is detected in many pixels 100. In this area, it can be estimated that a change such as movement has occurred in the object of the image pickup element 2. In other words, it is estimated that an address event such as an event accompanying the movement of the observation target is detected in the area. Therefore, by preferentially selecting the pixels 100 in this area, an image of the observation target accompanying the movement can be acquired at an early stage.

[0053] On the other hand, after the generation of image signals of the pixels 100 included in the area where the area address event has been detected is completed, responses are output to the pixels 100 that have not been selected by the arbitrator 30. For example, the pixels 100 where the pixel address event has been detected due to the influence of noise, etc. may be given a lower priority. The details of the configuration of the arbitrator 30 will be described later.

[0054] The signal processing unit 40 performs predetermined signal processing on the detection signals from the pixels 100. For example, the signal processing unit 40 may arrange the detection signals into image signals in a two-dimensional matrix and generate image data having two bits of information for each pixel 100. In addition, the signal processing unit 40 can perform signal processing such as image recognition processing on the generated image data.

[0055] [Configuration of pixel array unit and arbiter]

[0056] Figure 3 : is a diagram showing a configuration example of a pixel array unit and an arbitrator according to the first embodiment of the present disclosure. Figure 3 A configuration example of the pixel array unit 10 and the arbiter 30 is shown. Figure 3 The pixel 100 of the pixel array unit 10 includes a photoelectric conversion unit 110 and a pixel address event detection unit 120 .

[0057] Photoelectric conversion unit 110 performs photoelectric conversion of incident light. Photoelectric conversion unit 110 may include a photodiode. Through this photoelectric conversion, a charge corresponding to the brightness of the incident light is generated. By applying a voltage to photoelectric conversion unit 110, a photocurrent, which is a current corresponding to the generated charge, can be supplied to an external circuit.

[0058] The pixel address event detection unit 120 detects a pixel address event. By detecting a change in the above-mentioned photocurrent, a change in the electric charge generated by photoelectric conversion can be detected, and a pixel address event can be detected based on the amount of change in the electric charge. Furthermore, the pixel address event detection unit 120 supplies the photocurrent of the photoelectric conversion unit 110 to the region address event detection unit 320. Details of the configuration of the pixel address event detection unit 120 will be described later.

[0059] Figure 3 The arbitrator 30 in the region address event detection unit 320 includes a region address event detection unit 320 and a pixel selection unit 310.

[0060] The region address event detection unit 320 detects a region address event based on the amount of change in the electric charge generated by photoelectric conversion by the pixels 100 included in a region, the region address event being an address event in a predetermined region among the plurality of pixels 100 of the pixel array unit 10. This region address event can be detected, for example, based on a change in the photocurrent in all the pixels 100 included in the predetermined region, and can be detected based on a change in the total photocurrent of all the pixels 100 included in the region. Note that, in the case where the region address event is detected based on a change in the total photocurrent of all the pixels 100 included in the region, the region address event detection unit 320 can be configured to detect a region address event based on a change in the total photocurrent of all the pixels 100 included in the region, and can be configured to detect a region address event based on a change in the total photocurrent of all the pixels 100 included in the region. Figure 3 The pixel array unit 10 in the region address event detection unit 320 illustrates one example in which a region 591, which is the above-mentioned predetermined region, is arranged in a two-dimensional matrix for each row of pixels 100. The region address event detection unit 320 is provided for each region 591, and the photocurrent is supplied from the pixels 100 included in the region. The photocurrent is supplied via the signal line 103. Details of the configuration of the region address event detection unit 320 will be described later.

[0061] The pixel selection unit 310 selects the pixel 100 based on the pixel address event and the region address event. Furthermore, the pixel selection unit 310 causes the selected pixel 100 to output a detection result of the pixel address event. The pixel selection unit 310 can select the pixel 100 in which the pixel address event is detected from among the pixels 100 included in the region 591 in which the region address event is detected.

[0062] The exchange of signals and the like in the pixel 100 will be described with reference to Figure 3 When the pixel address event detection unit 120 of the pixel 100 detects a pixel address event, a request for outputting a detection signal of the pixel address event is output to the pixel selection unit 310. The request is output via the signal line 102. Furthermore, when a region address event is detected in its own region 591, the region address event detection unit 320 outputs a request to the pixel selection unit 310. The pixel selection unit 310 selects the pixel 100 based on the pixel address event and the region address event, and outputs a response to the selected pixel 100. The response is output via the signal line 101.

[0063] The pixel 100 that outputs the response from the pixel selection unit 310 outputs a detection signal of the pixel address event to the signal processing unit 40 and the control circuit 20. This detection signal is output via the signal line 104. The control circuit 20 outputs a control signal to the pixel 100 that has output the detection signal, to reset the pixel 100. As a result, the detection of the pixel address event in the reset pixel 100 is stopped, and the output of the request is stopped.

[0064] Further, the pixel selection unit 310 also outputs the response to the region address event detection unit 320 including the region 591 of the selected pixel 100. The region address event detection unit 320 to which the response is output is reset, and the output of the request is stopped.

[0065] Note that the configuration of the region 591 is not limited to this example. For example, the region 591 can be provided for each of a plurality of rows arranged in the pixel array unit 10, such as every two rows of the pixel 100.

[0066] [Configuration of the pixel address event detection unit]

[0067] Figure 4 is a diagram that shows a configuration example of the pixel address event detection unit according to the first embodiment of the present disclosure. Figure 4 A configuration example of the pixel address event detection unit 120 is shown. Figure 4 The pixel address event detection unit 120 in includes a current-voltage conversion circuit 121, a buffer 122, a subtracter 123, a quantizer 124, and a transfer control unit 125.

[0068] The current-voltage conversion circuit 121 converts the photo current from the photoelectric conversion unit 110 into a voltage signal. In the conversion, the current-voltage conversion circuit 121 performs logarithmic compression of the voltage signal. The converted voltage signal is output to the buffer 122. Details of the configuration of the current-voltage conversion circuit 121 will be described later.

[0069] The buffer 122 corrects the voltage signal output from the current-voltage conversion circuit 121, and outputs the corrected signal to the subtracter 123. In the pixel 100 according to the embodiment, it is possible to improve the driving force for driving the subsequent stage and to ensure isolation of noise accompanying the switching operation in the subsequent stage by the buffer 122.

[0070] The subtracter 123 obtains an amount of change of the corrected signal output from the buffer 122 by subtraction processing. Then, the subtracter 123 outputs the obtained amount of change as a difference signal to the quantizer 124. Details of the configuration of the subtracter 123 will be described later.

[0071] The quantizer 124 converts (i.e., quantizes) the analog difference signal into a digital detection signal by comparing the difference signal output with a predetermined threshold value. The quantizer 124 according to the present embodiment compares the difference signal with each of an upper threshold value and a lower threshold value, and outputs the comparison result as a two-bit detection signal to the transfer control unit 125.

[0072] The transfer control unit 125 controls transfer of the detection signal to the signal processing unit 40 and the control circuit 20. When the detection signal is output from the quantizer 124, the transfer control unit 125 outputs a request to the pixel selection unit 310. Thereafter, when a response is output from the pixel selection unit 310, the transfer control unit 125 outputs the detection signal to the signal processing unit 40 and the control circuit 20.

[0073] [Structure of voltage-current conversion circuit]

[0074] Figure 5 is a diagram illustrating a configuration example of a current-voltage conversion circuit according to the first embodiment of the present disclosure. Figure 5 is a circuit diagram illustrating a configuration example of the current-voltage conversion circuit 121.

[0075] Figure 5 The current-voltage conversion circuit 121 in includes MOS transistors 501 to 505. Note that, Figure 5 The photoelectric conversion unit 110 is further illustrated in Figure 5 In, a power supply line Vdd supplies power. A signal line Vbl supplies a bias voltage. For the MOS transistors 501 to 503, p-channel MOS transistors can be used. For the MOS transistors 504 and 505, n-channel MOS transistors can be used.

[0076] The anode of the photoelectric conversion unit 110 is grounded, and the cathode is connected to the source of the MOS transistor 504 and the gate of the MOS transistor 505. The source of the MOS transistor 505 is grounded, and the drain is connected to the gate of the MOS transistor 504, the drain of the MOS transistor 503, and the signal line 129. The gate of the MOS transistor 503 is connected to the signal line Vbl, and the source thereof is connected to the power supply line Vdd. The drain of the MOS transistor 504 is connected to the drain and gate of the MOS transistor 501 and the gate of the MOS transistor 502. The source of the MOS transistor 501 and the source of the MOS transistor 502 are commonly connected to the power supply line Vdd. The drain of the MOS transistor 502 is connected to the signal line 103.

[0077] The MOS transistor 504 is a MOS transistor that supplies a current to the photoelectric conversion unit 110. An absorption current (photocurrent) according to incident light flows through the photoelectric conversion unit 110. The MOS transistor 504 supplies the absorption current. Here, the gate of the MOS transistor 504 is driven by an output voltage of the MOS transistor 505 that will be described later, and a source current equal to a constant current of the photoelectric conversion unit 110 is output. Since the gate-source voltage Vgs of the MOS transistor is a voltage corresponding to the source current, the source voltage of the MOS transistor 504 is a voltage corresponding to the current of the photoelectric conversion unit 110. As a result, the current of the photoelectric conversion unit 110 is converted into a voltage signal.

[0078] The MOS transistor 505 is a MOS transistor that amplifies the source voltage of the MOS transistor 504. Further, the MOS transistor 503 constitutes a constant current load of the MOS transistor 505. The amplified voltage signal is output to the drain of the MOS transistor 505. The voltage signal is output to the signal line 129, and is fed back to the gate of the MOS transistor 504. When the gate-source voltage Vgs of the MOS transistor 504 is equal to or lower than a threshold voltage, the change in the source current with respect to the gate-source voltage Vgs changes in an exponential manner. Therefore, the output voltage of the MOS transistor 504 fed back to the gate of the MOS transistor 505 is a voltage signal obtained by logarithmically compressing the photocurrent of the photoelectric conversion unit 110 into the source current of the MOS transistor 504.

[0079] The MOS transistor 501 is connected between the power supply line Vdd and the drain of the MOS transistor 504, and the gate and the drain are short-circuited. Therefore, the drain current of the MOS transistor 501 (i.e., the photocurrent of the photoelectric conversion unit 110) flows through the MOS transistor 504. The MOS transistor 502 forms a current mirror circuit with the MOS transistor 501, and a current substantially equal to the drain current of the MOS transistor 501 flows. As a result, the photocurrent of the photoelectric conversion unit 110 is copied and supplied to the signal line 103 connected to the drain of the MOS transistor 502.

[0080] [Configuration of amplifier, differential detection unit, and quantizer]

[0081] Figure 6 is a diagram illustrating a configuration example of a buffer, a subtracter, and a quantizer according to the first embodiment of the present disclosure. Figure 6 is a circuit diagram illustrating a configuration example of the buffer 122, the subtracter 123, and the quantizer 124. In Figure 6 In the configuration example of the differential detection unit 121, the signal lines Vb2 and Vb3 supply bias voltages, respectively. The signal lines Vbon and Vboff supply a power voltage corresponding to the above-described Figure 1The upper threshold value of the increase in luminance and the upper threshold value of the decrease in luminance are set to the same value. For the MOS transistors 511 to 515, p-channel MOS transistors can be used. For the MOS transistors 521 to 524, n-channel MOS transistors can be used.

[0082] The signal line 129 is connected to the gate of the MOS transistor 521, and the source of the MOS transistor 521 is grounded. The gate of the MOS transistor 511 is connected to the signal line Vb2, and the source of the MOS transistor 511 is grounded to the power supply line Vdd. The drain of the MOS transistor 511 is connected to the drain of the MOS transistor 521 and one end of the capacitor 531. The other end of the capacitor 531 is connected to the gate of the MOS transistor 512, the source of the MOS transistor 513, and one end of the capacitor 532. The other end of the capacitor 532 is connected to the drain of the MOS transistor 512, the drain of the MOS transistor 513, the drain of the MOS transistor 522, the gate of the MOS transistor 514, and the gate of the MOS transistor 515.

[0083] The source of the MOS transistor 512 is connected to the power supply line Vdd, and the gate of the MOS transistor 513 is connected to the signal line 105. The source of the MOS transistor 522 is grounded, and the gate is connected to the signal line Vb3. The source of the MOS transistor 514 and the source of the MOS transistor 515 are commonly connected to the power supply line Vdd. The drain of the MOS transistor 514 is connected to the drain of the MOS transistor 523 and the signal line 128 (VCH). The source of the MOS transistor 523 is grounded, and the gate is connected to the signal line Vbon. The drain of the MOS transistor 515 is connected to the drain of the MOS transistor 526 and the signal line 128 (VCL), and the source of the MOS transistor 524 is grounded, and the gate is connected to the signal line Vboff.

[0084] The buffer 122 includes the MOS transistors 511 and 521. The voltage signal input via the signal line 129 is amplified by the MOS transistor 521 and output to the subtracter 123. The MOS transistor 511 constitutes a drain load of the MOS transistor 521.

[0085] The subtracter 123 includes the MOS transistors 512, 513, and 522, and the capacitors 531 and 532. The MOS transistor 512 configures an inverting amplifier. Note that the MOS transistor 522 constitutes a constant current load. The capacitor 532 and the MOS transistor 513 connected in parallel configure a feedback circuit of the inverting amplifier including the MOS transistor 512. Further, the capacitor 531 corresponds to a coupling capacitor connected to the input of the inverting amplifier. The input of the inverting amplifier is a virtual ground. For convenience, the potential of the virtual ground terminal is set to zero. The voltage signal output from the buffer 122 and applied to the capacitor 531 is denoted by Vinit In the initial state, the MOS transistor 513 is in an on state, and both ends of the capacitor 532 are short-circuited.

[0086] Here, when the capacitor 531 has a capacitance C1, the charge Q accumulated in the capacitor 531 init It is expressed by the following expression (1). On the other hand, since both ends of the capacitor 532 are short-circuited, the accumulated charge is zero.

[0087] Q init = C1 × V init (1)

[0088] Next, consider that the MOS transistor 513 is turned off and the voltage on the buffer 322 side of the capacitor 531 becomes V after , the charge Q accumulated in capacitor 531 after It is represented by the following expression (2).

[0089] Q after = C1 × V after (2)

[0090] On the other hand, when the capacitor 532 has a capacitance C2 and the output voltage is represented by Vout, the charge Q2 accumulated in the capacitor 532 is represented by the following expression (3).

[0091] Q2 = -C2 × V out (3)

[0092] Here, since the total amount of charge of the capacitor 531 and the capacitor 532 does not change, the following expression (4) is established.

[0093] Q init = Q after + Q2 (4)

[0094] Then, when Expressions (1) to (3) are substituted into the above Expression (4) and converted, the following Expression (5) is obtained.

[0095] V out = -(C1 / C2) × (V after -Vi init ) (5)

[0096] The above expression (5) represents a subtraction operation of the voltage signals, and the gain of the subtraction result is C1 / C2. Generally, it is desirable to maximize the gain, and thus it is preferable to design the capacitance C1 to be large and the capacitance C2 to be small. On the other hand, when the capacitance C2 is too small, kTC noise increases, and the noise characteristic can deteriorate. Thus, the reduction of the capacitance C2 is limited within a range in which noise is tolerable.

[0097] In this way, the change in the input signal is subtracted and output. The change in the input signal is integrated in the capacitor 532. When the reset signal is input to the gate of the MOS transistor 513 via the signal line 105, the MOS transistor 513 becomes conductive, the charge of the capacitor 532 is discharged, and the integrated change in the input signal is reset.

[0098] The MOS transistors 514, 515, 523, and 524 configure the quantizer 124. The MOS transistors 514 and 523 configure comparators, and compare the output signal of the subtracter 123 with the bias voltage Vbon representing the upper limit threshold value. As a result of the comparison, when the output signal of the subtracter 123 exceeds Vbon, the on event detection signal VCH is output to the transfer control unit 125 as a detection signal. Further, the MOS transistors 515 and 524 configure comparators, and compare the output signal of the subtracter 123 with the bias voltage Vboff representing the lower limit threshold value. As a result of the comparison, when the output signal of the subtracter 123 is less than Vboff, the off event detection signal VCL is output to the transfer control unit 125 as a detection signal.

[0099] [Configuration of area address event detection unit]

[0100] Figure 7 is a diagram illustrating a configuration example of an area address event detection unit according to the first embodiment of the present disclosure. Figure 7 A configuration example of the area address event detection unit 320 is illustrated. Figure 7 The area address event detection unit 320 in includes a current-voltage conversion circuit 321, a buffer 322, a subtracter 323, a quantizer 324, and a transfer control unit 325.

[0101] The photoelectric current of the pixel 100 included in the area 591 is input to the current-voltage conversion circuit 321, and the total photoelectric current is converted to a voltage signal and logarithmically compressed.

[0102] The transfer control unit 325 exchanges a request and a response with the pixel selection unit 310. In addition, the transfer control unit 325 outputs a reset signal to the subtracter 323 at the time of inputting the response. The other configuration of the transfer control unit 325 can be similar to the configuration of the transfer control unit 125 described in Figure 4 .

[0103] The buffer 322, the subtracter 323, and the quantizer 324 can have configurations similar to those of the buffer 122, the subtracter 123, and the quantizer 124 described in Figure 4

[0104] [Structure of voltage-current conversion circuit]

[0105] Figure 8 is a diagram illustrating a configuration example of a current-voltage conversion circuit according to the first embodiment of the present disclosure. Figure 8 is a circuit diagram illustrating a configuration example of the current-voltage conversion circuit 321. The current-voltage conversion circuit 321 includes MOS transistors 541 to 543 and a plurality of current mirror circuits 550.

[0106] The current-voltage conversion circuit 321 is similar to the current-voltage conversion circuit 321 described in Figure 5

[0107] The current mirror circuit 550 includes MOS transistors 551 and 552. For the MOS transistors 551 and 552, n-channel MOS transistors can be used. The current mirror circuit 550 includes an input terminal Ii and an output terminal Io. The input terminal Ii is connected to the drain of the MOS transistor 551, the gate of the MOS transistor 551, and the gate of the MOS transistor 552. The source of the MOS transistor 551 and the source of the MOS transistor 552 are grounded. The drain of the MOS transistor 552 is connected to the output terminal Io.

[0108] In the current mirror circuit 550 of Figure 8

[0109] The voltage signal output from the current-voltage conversion circuit 321 is processed by the buffer 322, the subtracter 323, and the quantizer 324 to detect a region address event.

[0110] ​​​[Configuration of pixel selection unit]

[0111] Figure 9 is a block diagram illustrating a configuration example of a pixel selection unit according to the first embodiment of the present disclosure. Figure 9 A configuration example of the pixel selection unit 310 is illustrated. Figure 9 The pixel selection unit 310 in the region 590 includes a region arbiter 311 and a pixel arbiter 312.

[0112] The region arbiter 311 arbitrates requests from the region address event detection units 320. The region arbiter 311 arbitrates requests from a plurality of region address event detection units 320 and outputs a response as an arbitration result. For example, this arbitration can be performed by selecting the region address event detection units 320 in the order of arrival of the requests. Further, the region arbiter 311 outputs the region 591 corresponding to the selected region address event detection unit 320 to the pixel arbiter 312.

[0113] The pixel arbiter 312 arbitrates requests from the pixel address event detection units 120. The pixel arbiter 312 arbitrates requests from a plurality of pixel address event detection units 120 and outputs a response as an arbitration result. For example, this arbitration can be performed by preferentially selecting requests from the pixel address event detection units 120 included in the region 591 selected by the region arbiter 311. Specifically, when the region arbiter 311 selects the region 591, the pixel address event detection units 120 can be selected in the order of arrival of the requests from the pixels 100 included in the region to output a response. Further, in the case where the region arbiter 311 does not select the region 591, the pixel address event detection units 120 can be selected in the order of arrival of the requests from all the pixels 100 of the pixel array unit 10 to output a response. In this way, the pixel selection unit 310 can select the pixels 100 based on the pixel address event and the region address event.

[0114] [Image data generation processing]

[0115] Figure 10 is a diagram illustrating an example of image data generation processing according to the first embodiment of the present disclosure. Figure 10An example of the image data generation processing in the image pickup element 2 is shown. First, the pixel address event detection units 120 detect the pixel address events in all the pixels 100 arranged in the pixel array unit 10, and the pixel selection unit 310 determines whether or not a pixel address event is detected (step S101). The pixel address event can be determined to be detected when the pixel address event is detected and a request is output from any of the pixel address event detection units 120 of the pixels 100 arranged in the pixel array unit 10. The pixel selection unit 310 waits until the pixel address event is detected and the request is output (step S101, No). Note that the processing in step S101 is an example of the pixel address event detection step described in the claims.

[0116] When the pixel address event is detected (step S101, Yes), the pixel selection unit 310 determines whether or not a region address event is detected (step S102). The region address event can be determined to be detected when the region address event is detected and a request is output from any of the plurality of region address event detection units 320. Note that the processing in step S102 is an example of the region address event detection step described in the claims.

[0117] When the region address event is not detected (step S102, No), the pixel selection unit 310 detects the pixel address event and selects the pixel address event detection unit 120 that has output the request (step S103). When there are a plurality of pixel address event detection units 120 that have output the request, the pixel selection unit 310 can select the pixel address event detection unit 120 in the order of arrival of the request.

[0118] Next, the pixel selection unit 310 outputs a response to the selected pixel address event detection unit 120 of the pixel 100 (step S104). The pixel address event detection unit 120 that outputs the response performs the detection result output processing (step S110). Thereafter, the processing proceeds to step S101.

[0119] In step S102, when the region address event is detected (step S102, Yes), the pixel selection unit 310 selects the region address event detection unit 320 that has output the region address event (step S105). When there are a plurality of region address event detection units 320 that have output the request, the pixel selection unit 310 can select the region address event detection unit 320 in the order of arrival of the request.

[0120] Next, the pixel selection unit 310 outputs a response to the selected region address event detection unit 320 (step S106).

[0121] Next, the pixel selection unit 310 determines whether a pixel address event has been detected in the pixels 100 in the selected area (step S107). If a pixel address event has been detected, that is, if a request has been output from the pixel address event detection unit 120 of the pixel 100 in the selected area (step S107, yes), the pixel selection unit 310 selects the pixel address event detection unit 120 that has output the request (step S108). If there are multiple pixel address event detection units 120 that have output requests, the pixel selection unit 310 may select the pixel address event detection unit 120 in the order in which the requests arrived.

[0122] Next, the pixel selection unit 310 outputs the response to the selected pixel address event detection unit 120 (step S109). The pixel address event detection unit 120 that outputs the response performs a detection result output process (step S110). Thereafter, the process starting from step S107 is repeated again.

[0123] If no pixel address event is detected in step S107 (step S107, No), it can be determined that detection results have been output from all pixels 100 in which pixel address events in the selected area have been detected. In this case, the process proceeds to step S101 again. Note that the processes in steps S103 and S108 are examples of the selection steps described in the claims.

[0124] [Test result output processing]

[0125] Figure 11 2 is a diagram illustrating an example of a detection result output process according to the first embodiment of the present disclosure. Figure 11 Shown Figure 10 An example of the detection result output process (step S110) in FIG. Figure 11 The processing in FIG1 represents an example of the processing in the pixel address event detection unit 120. First, the transmission control unit 125 of the pixel address event detection unit 120 to which the pixel selection unit 310 has output a response outputs a detection signal to the signal processing unit 40 and the control circuit 20 (step S111). As a result, the signal processing unit 40 generates image data. In addition, the control circuit 20 generates a control signal and outputs it to the subtractor 123. The subtractor 123 is reset by the control signal (step S112). Then, the detection result output processing ends. It should be noted that the processing in step S111 is an example of the detection result output step described in the claims.

[0126] With the above-described processing, image data can be generated based on the detected pixel address events and area address events.

[0127] [First embodiment variant (1)]

[0128] Figure 12 is a diagram illustrating a configuration example of a pixel array unit and an arbiter according to the first variant of the first embodiment of the present disclosure. Figure 12 Similarly to Figure 3 The configuration of the pixel array unit 10 and the arbiter 30 is illustrated. The pixel array unit is similar to Figure 3 The difference from the pixel array unit 10 in is that a region is formed for each column of pixels 100 arranged in the pixel array unit 10. For the sake of convenience, the illustration of the control circuit 20 and some signal lines is omitted to simplify the pixels 100.

[0129] Figure 12 The region 592 in is a region arranged for each column of pixels 100 arranged in a two-dimensional matrix. A region address event detection unit 330 is provided for each region 592. Figure 12 The region address event detection unit 330 in is arranged for each region 593. The photoelectric current from the pixels 100 included in the region 593 is input to the region address event detection unit 340, and the region address event of the region 593 can be detected.

[0130] Note that the configuration of the region 591 is not limited to this example. For example, a region 592 can be provided for each of a plurality of columns (such as every two columns of pixels 100) arranged in the pixel array unit 10.

[0131] [First embodiment variant (2)]

[0132] Figure 13 is a diagram illustrating a configuration example of a pixel array unit and an arbiter according to the second variant of the first embodiment of the present disclosure. Figure 13 The configuration of the pixel array unit 10 and the arbiter 30 is illustrated similarly to Figure 12 The pixel array unit is similar to Figure 12 The difference from the pixel array unit 10 in is that a region is formed for each block of two rows and two columns of pixels 100 arranged in the pixel array unit 10.

[0133] Figure 13 The region 593 in is a region arranged for every four pixels 100 of two rows and two columns of pixels 100 arranged in a two-dimensional matrix. Figure 13 The region address event detection unit 340 in is arranged for each region 593. The photoelectric current from the pixels 100 included in the region 593 is input to the region address event detection unit 340, and the region address event of the region 593 can be detected.

[0134] Note that the configuration of the region 591 is not limited to this example. For example, the region 593 can be set for each block of a different size of the pixels 100 arranged in the pixel array unit 10.

[0135] As described above, the image pickup element 2 according to the first embodiment of the present disclosure selects the pixels 100 based on the pixel address events and the region address events, and outputs the detection signal based on the pixel address events of the selected pixels 100. Thus, different processing can be performed for each region. For example, the regions can be prioritized based on the detected region address events. The region in which the region address event is detected can be set to high priority, so that image data of a region having a large change in luminance can be generated with priority. Thus, a delay in detection of an effective event such as movement of an observation object can be suppressed. Further, the region in which the region address event is detected can also be designated as a region of interest (ROI).

[0136] On the other hand, an ineffective event such as noise is detected as a single pixel address event for each pixel 100. By lowering the priority of the ineffective event, noise and the like can be suppressed.

[0137] <Second Embodiment>

[0138] In the above-described first embodiment, the pixels 100 in the region in which the region address event is detected are preferentially selected to detect the pixel address events. On the other hand, the second embodiment of the present disclosure differs from the above-described first embodiment in that the pixels 100 in a region different from the region in which the region address event is detected are preferentially selected.

[0139] The pixel selection unit 310 in the second embodiment of the present disclosure sets the priority of the region 591 in which the region address event is detected to be low. For example, the pixel selection unit 310 can omit detection of the pixel address events of the pixels 100 included in the region 591 in which the region address event is detected. As a result, generation of image data of a region having a large change in luminance can be stopped.

[0140] [Configuration of Pixel Array Unit and Arbiter]

[0141] Figure 14 is a diagram showing a configuration example of a pixel array unit and an arbiter according to the second embodiment of the present disclosure. Figure 12 Similar to Figure 3 The configuration of the pixel array unit 10 and the arbiter 30 is shown. The pixel array unit is different from Figure 3 The pixel array unit 10 in the second embodiment of the present disclosure is different from that in the first embodiment in that the pixel selection unit 310 outputs a reset signal to the pixel address event detection unit 120. For convenience, one pixel 100 is shown as being included in the region 591 in Figure 14the pixel array unit 10 in the example.

[0142] Figure 14 The pixel selection unit 310 in the example outputs a reset signal to the pixel address event detection unit 120 arranged in the region 591 in which a region address event is detected.

[0143] When the reset signal is input, Figure 14 The pixel address event detection unit 120 in the example stops outputting a request. For example, when the reset signal is input, Figure 14 The pixel address event detection unit 120 in the example can reset its own subtracter 123.

[0144] [Image data generation processing]

[0145] Figure 15 is a view showing an example of image data generation processing according to the second embodiment of the present disclosure. Like Figure 10 similarly, Figure 15 shows an example of image data generation processing in the image pickup element 2. This processing is different from Figure 10 the image data generation processing in the example in that the processing of outputting a reset signal to the pixel address event detection unit 120 is performed after the processing in step S108 (step S121).

[0146] In the example, Figure 15 In the example, the pixel selection unit 310 can stop the output of the detection signal of the pixel address event detection unit 120 in the region 591 by outputting a reset signal to all of the pixels 100 in the region 591 in which a region address event has been detected. On the other hand, in the example, Figure 15 In the example, when a pixel address event is detected in the pixels 100 included in a region 591 different from the region 591 in which a region address event has been detected, the pixel selection unit 310 can output a response. As a result, when a portion of the region 591 of the image pickup element is irradiated with strong light due to flicker or the like, the generation of image data of that region can be stopped.

[0147] Since the configuration of the image pickup element 2 other than this is similar to that of the first embodiment of the present disclosure, the description thereof will be omitted.

[0148] As described above, the image pickup element 2 according to the second embodiment of the present disclosure resets the pixel address event detection unit 120 included in the region in which a region address event is detected, and detects a pixel address event in a region different from the region in which a region address event is detected. As a result, the generation of image data based on the pixels 100 in which a pixel address event is detected due to flicker or the like can be suppressed.

[0149] <Third Embodiment>

[0150] In the above-described first embodiment, the pixels 100 in the region in which the region address event is detected are preferentially selected to detect the pixel address event. On the other hand, the third embodiment of the present disclosure differs from the above-described first embodiment in that a standby state is set until an address event in a specific region is detected.

[0151] [Configuration of Arbitrator]

[0152] Figure 16 is a diagram illustrating a configuration example of an arbitrator according to the third embodiment of the present disclosure. Figure 16 A configuration example of the arbitrator 30 is illustrated. Figure 16 The arbitrator 30 in the image pickup element 2 differs from the arbitrator 30 in the image pickup element 2 Figure 3 The arbitrator 30 in the image pickup element 2 differs from the arbitrator 30 in the image pickup element 2

[0153] The specific region address event detection unit 350 detects an address event based on an amount of change in electric charge generated by photoelectric conversion in the photoelectric conversion unit 110 included in the specific region among all the pixels 100 arranged in the pixel array unit 10. Figure 16 The specific region address event detection unit 350 in the image pickup element 2 illustrates an example of detecting an address event using the pixel array unit 10 as a specific region. The photoelectric current of all the pixels 100 included in the pixel array unit 10 is input to the specific region address event detection unit 350. Figure 16 The specific region address event detection unit 350 in the image pickup element 2, and detects an address event when the amount of change in the total photoelectric current exceeds a predetermined threshold value. The specific region address event detection unit 350 that has detected an address event can output a request similarly to the region address event detection unit 320.

[0154] The standby control unit 360 controls a standby state in which the detection result of the pixel address event is stopped from being output. The standby control unit 360 controls the standby state based on the address event detected by the specific region address event detection unit 350. Specifically, the standby control unit 360 can switch the image pickup element 2 to the standby state in a case where no request is output from the specific region address event detection unit 350 for a predetermined period of time. The transition to the standby state can be performed, for example, by stopping the output of the response from the pixel selection unit 310 to the pixel address event detection unit 120. When a request is output from the specific region address event detection unit 350 after the transition to the standby state, the standby control unit 360 can return the image pickup element 2 from the standby state to the normal state in which the image data is generated.

[0155] Since the configuration of the image pickup element 2 other than this point is similar to that of the first embodiment of the present disclosure, the description thereof will be omitted.

[0156] As described above, the image pickup element 2 according to the third embodiment of the present disclosure can reduce power consumption in the image pickup element 2 by detecting an address event based on a change in total photoelectric current of the photoelectric conversion unit included in the specific region in the pixel array unit 10 and controlling a standby state.

[0157] <Fourth Embodiment>

[0158] In the above-described first embodiment, the image data is generated from the detection signal of the pixel address event output from the pixel 100. On the other hand, the fourth embodiment of the present disclosure differs from the above-described first embodiment in that the image data is generated from an image signal generated based on incident light.

[0159] [Configuration of pixel array unit and arbiter]

[0160] Figure 17 is a diagram illustrating a configuration example of a pixel array unit and an arbiter according to the fourth embodiment of the present disclosure. Figure 12 Similarly to Figure 3 The configuration of the pixel array unit 10 and the arbiter 30 is illustrated. The pixel array unit differs from Figure 3 the pixel array unit 10 in the first embodiment in that a photoelectric conversion unit 130 and an image signal generation unit 140 are further arranged in the pixel 100.

[0161] The photoelectric conversion unit 130 can include a photodiode similar to the photoelectric conversion unit 110.

[0162] The image signal generation unit 140 generates an image signal based on the charge generated by photoelectric conversion in the photoelectric conversion unit 130. The image signal generation unit 140 is controlled by the control signal output from the control circuit 20, generates the image signal, and outputs the image signal to the signal processing unit 40.

[0163] When a response is output from the pixel selection unit 310, Figure 17 the pixel address event detection unit 120 in the first embodiment outputs the detection signal to the control circuit 20. The control circuit 20 outputs the control signal to the image signal generation unit 140 of the pixel 100 that has output the detection signal. As a result, the image signal is generated and output. The image pickup element 2 can generate the image signal in the pixel 100 in which the address event is detected.

[0164] [Configuration of image signal generation unit]

[0165] Figure 18 is a diagram illustrating a configuration example of an image signal generation unit according to the fourth embodiment of the present disclosure. Figure 18is a circuit diagram showing a configuration example of the image signal generation unit 140. The image signal generation unit 140 includes a charge holding unit 571 and MOS transistors 561 to 564. For the MOS transistors 561 to 564, n-channel MOS transistors can be used. Note that, in Figure 18 The photoelectric conversion unit 130 is further shown in

[0166] The anode of the photoelectric conversion unit 130 is grounded, and the cathode is connected to the source of the MOS transistor 561. The drain of the MOS transistor 561 is connected to the source of the MOS transistor 562, the gate of the MOS transistor 563, and one end of the charge holding unit 571. The other end of the charge holding unit 571 is grounded. The drains of the MOS transistors 562 and 563 are commonly connected to a power supply line Vdd, and the source of the MOS transistor 563 is connected to the drain of the MOS transistor 564. The source of the MOS transistor 564 is connected to the signal line 106. The gates of the MOS transistors 561, 562, and 564 are connected to a transfer signal line TR, a reset signal line RST, and a selection signal line SEL, respectively. Note that the transfer signal line TR, the reset signal line RST, and the selection signal line SEL constitute the signal line 105.

[0167] The MOS transistor 561 is a transistor that transfers the charge generated by the photoelectric conversion in the photoelectric conversion unit 130 to the charge holding unit 571. The transfer of the charge by the MOS transistor 561 is controlled by a signal transferred by the transfer signal line TR. The charge holding unit 571 is a capacitor that holds the charge transferred by the MOS transistor 561. The MOS transistor 563 is a transistor that generates a signal based on the charge held in the charge holding unit 571. The MOS transistor 564 is a transistor that outputs the signal generated by the MOS transistor 563 to the signal line 12 as an image signal. The MOS transistor 564 is controlled by a signal transferred by the selection signal line SEL.

[0168] The MOS transistor 562 is a transistor that resets the charge holding unit 571 by releasing the charge held in the charge holding unit 571 to the power supply line Vdd. The reset of the MOS transistor 562 is controlled by a signal sent by the reset signal line RST, and is performed before the MOS transistor 561 transfers the charge. Note that, at this reset, the photoelectric conversion unit 130 can also be reset by turning on the MOS transistor 561. In this way, the image signal generation unit 140 converts the charge generated by the photoelectric conversion unit 130 into an image signal.

[0169] Since the configuration of the image pickup element 2 except for this is similar to that of the first embodiment of the present disclosure, the description thereof will be omitted.

[0170] As described above, the image pickup element 2 according to the fourth embodiment of the present disclosure arranges the image signal generation unit 140 in the pixel 100 and generates an image signal in the pixel 100 in which a pixel address event has been detected. By updating the image data using the generated image signal, it is possible to update the image of only the region in which the luminance has changed. As a result, it is possible to generate the image data at high speed.

[0171] Note that the configuration of the second embodiment is applicable to other embodiments. Specifically, Figure 14 The pixel selection unit 310 in Figure 12 , Figure 13 and Figure 16 may be applied to the pixel selection unit 310 in

[0172] Note that the configuration of the third embodiment is applicable to other embodiments. Specifically, Figure 16 The specific region address event detection unit 350 and the standby control unit 360 in Figure 12 to Figure 14 may be applied to the pixel selection unit 310 in

[0173] Note that the configuration of the fourth embodiment is applicable to other embodiments. Specifically, Figure 17 The image signal generation unit 140 in Figure 12 and Figure 13 may be applied to the pixel 100 in

[0174] [Effects]

[0175] The image pickup element 2 is provided with a plurality of pixels 100 including a photoelectric conversion unit that performs photoelectric conversion of incident light, a pixel address event detection unit 120 that detects a pixel address event that is an address event of the pixel 100 based on an amount of change in electric charge generated by the photoelectric conversion, a region address event detection unit 320 that detects a region address event that is an address event in a predetermined region among the plurality of pixels 100 based on an amount of change in electric charge generated by the photoelectric conversion in the plurality of pixels 100 included in the predetermined region, and a pixel selection unit 310 that selects the pixel 100 based on the detected pixel address event and the region address event and causes the selected pixel to output a detection result of the pixel address event.

[0176] Accordingly, the pixel 100 can be selected based on the region address event and the pixel address event, and the pixel 100 in which the pixel address event is detected can be selected for each predetermined region.

[0177] Further, in the image pickup element 2, the plurality of pixels 100 are arranged in the shape of a two-dimensional matrix.

[0178] As a result, the pixel 100 in which the pixel address event is detected can be selected for each region having a matrix shape.

[0179] Further, in the image pickup element 2, the predetermined region is arranged for each row of the two-dimensional matrix.

[0180] Therefore, the pixel 100 in which the pixel address event is detected can be selected for each row.

[0181] Further, in the image pickup element 2, the predetermined region is arranged for each column of the two-dimensional matrix.

[0182] As a result, the pixel 100 in which the pixel address event is detected can be selected for each column.

[0183] Further, in the image pickup element 2, the pixel address event detection unit 120 detects the pixel address event based on a change in the photoelectric current, that is, a current according to the charge generated by the photoelectric conversion, and the region address event detection unit 320 detects the region address event based on a change in the photoelectric current of each of the plurality of pixels 100 included in the region.

[0184] Therefore, the address event can be detected by the change in the photoelectric current.

[0185] Further, in the image pickup element 2, the region address event detection unit 320 detects the region address event based on a change in the total photoelectric current of the plurality of pixels 100 included in the region.

[0186] Therefore, the region address event can be detected by the change in the total photoelectric current in the region.

[0187] Further, in the image pickup element 2, the pixel selection unit 310 selects the pixel 100 based on the pixel address event detected in the pixel 100 included in the region in which the region address event is detected.

[0188] As a result, a high priority can be set to the region in which the region address event is detected.

[0189] Further, in the image pickup element 2, the pixel selection unit 310 selects the pixel 100 based on the pixel address event detected in the pixel 100 included in the region different from the region in which the region address event is detected.

[0190] As a result, a low priority can be set to the region in which the region address event is detected.

[0191] Further, in the image pickup element 2, the pixel selection unit 310 selects the pixel 100 based on the pixel address event detected without the region address event being detected.

[0192] As a result, a pixel address event of the pixel 100 can be detected in a region in which a region address event is not detected.

[0193] Further, the image pickup element 2 further includes a specific region address event detection unit 350 that detects an address event in a specific region based on an amount of change in the electric charge generated by photoelectric conversion in a plurality of pixels 100 included in the specific region including the pixel array unit, and a standby control unit 360 that controls a standby state in which output of a detection result of a pixel address event in the pixel 100 is stopped based on a detection result of the specific region address event detection unit 350.

[0194] Therefore, when a pixel address event is not detected, it is possible to shift to the standby state to reduce power consumption.

[0195] Further, in the image pickup element 2, the specific region address event detection unit 350 detects an address event in the pixel array unit 10 as the specific region.

[0196] Therefore, when a pixel address event is not detected in all of the pixels 100 of the pixel array unit 10, it is possible to shift to the standby state.

[0197] Further, in the image pickup element 2, the pixel address event detection unit 120 detects a pixel address event when the amount of change in the generated electric charge exceeds a predetermined threshold value.

[0198] Therefore, it is possible to detect a pixel address event based on a predetermined threshold value.

[0199] Further, in the image pickup element 2, the region address event detection unit 320 detects a region address event in a case where the amount of change in the electric charge generated in a plurality of pixels 100 included in a predetermined region exceeds a predetermined threshold value.

[0200] Therefore, it is possible to detect a region address event based on a predetermined threshold value.

[0201] Further, the image pickup element 2 further includes an image signal generation unit 140 arranged in each of the pixels 100 and generating an image signal that is a signal based on an electric charge generated by photoelectric conversion of incident light, and the pixel selection unit 310 causes the image signal generation unit 140 of the selected pixel 100 to output an image signal as a detection result of a pixel address event.

[0202] Therefore, it is possible to generate an image signal based on a region address event and a pixel address event.

[0203] Further, an image pickup method in the image pickup element 2 includes a pixel address event detection step of detecting a pixel address event that is an address event of a pixel based on an amount of change in electric charge generated by photoelectric conversion in each of a plurality of pixels 100 including a photoelectric conversion unit 110 that performs photoelectric conversion of incident light, a region address event detection step of detecting a region address event that is an address event in a predetermined region based on an amount of change in electric charge generated by photoelectric conversion in a plurality of pixels included in the predetermined region of the plurality of pixels 100, a selection step of selecting a pixel 100 based on the detected pixel address event and region address event, and a detection result output step of causing the selected pixel 100 to output a detection result of the pixel address event.

[0204] Accordingly, the pixel 100 can be selected based on the region address event and the pixel address event, and the pixel 100 in which the pixel address event is detected can be selected for each predetermined region.

[0205] Note that the effects described in this specification are merely examples and are not limiting, and other effects can be provided.

[0206] The present technology can also have the following configuration.

[0207] (1) An image pickup element comprising:

[0208] a plurality of pixels provided with a photoelectric conversion unit that performs photoelectric conversion of incident light;

[0209] a pixel address event detection unit arranged in each of the plurality of pixels and detecting a pixel address event that is an address event of each of the plurality of pixels and that is detected based on an amount of change in electric charge generated by the photoelectric conversion;

[0210] a region address event detection unit detecting a region address event that is an address event in a predetermined region and that is detected based on an amount of change in electric charge generated by photoelectric conversion in a plurality of pixels included in the predetermined region among the plurality of pixels; and

[0211] a pixel selection unit selecting a pixel among the plurality of pixels based on the detected pixel address event and the detected region address event, and causing the selected pixel to output a detection result of the pixel address event.

[0212] (2) The image pickup element according to the above (1), wherein the plurality of pixels are arranged in a shape of a two-dimensional matrix.

[0213] (3) The image pickup element according to the above (2), wherein the predetermined region is arranged for each row of the two-dimensional matrix.

[0214] (4) The image pickup element according to (2) above, wherein the predetermined region is arranged for each column of the two-dimensional matrix.

[0215] (5) The image pickup element according to any one of (1) to (4) above, wherein,

[0216] the pixel address event detection unit detects the pixel address event based on a change in a photo current that is a current corresponding to the electric charge generated by the photoelectric conversion, and

[0217] the region address event detection unit detects the region address event based on a change in a photo current of each of the plurality of pixels in the predetermined region.

[0218] (6) The image pickup element according to (5) above, wherein the region address event detection unit detects the region address event based on a change in a total photo current of the plurality of pixels in the predetermined region.

[0219] (7) The image pickup element according to any one of (1) to (6) above, wherein the pixel selection unit selects the pixel based on the pixel address event detected in the pixel in the predetermined region in which the region address event has been detected.

[0220] (8) The image pickup element according to any one of (1) to (6) above, wherein the pixel selection unit selects the pixel based on the pixel address event detected in the pixel in a region different from the predetermined region in which the region address event has been detected.

[0221] (9) The image pickup element according to any one of (1) to (8) above, wherein, when the region address event is not detected, the pixel selection unit selects the pixel based on the detected pixel address event.

[0222] (10) The image pickup element according to any one of (1) to (9) above, further comprising:

[0223] a specific region address event detection unit that detects the address event in a specific region, the address event being detected based on a change in an amount of electric charge generated by photoelectric conversion in a plurality of pixels in the specific region among the plurality of pixels, the specific region being arranged in a pixel array unit including the plurality of pixels; and

[0224] a standby control unit that controls a standby state in which output of a detection result of the pixel address event from the pixel is stopped, based on a detection result of the specific region address event detection unit.

[0225] (11) The image pickup element according to the above (10), wherein the specific-area address event detection unit detects the address event in the pixel array unit as the specific area.

[0226] (12) The image pickup element according to any one of the above (1) to (11), wherein the pixel address event detection unit detects the pixel address event when a change in the amount of charge generated in the plurality of pixels in the predetermined area exceeds a predetermined threshold value.

[0227] (13) The image pickup element according to any one of the above (1) to (12), wherein the area address event detection unit detects the area address event when a change in the amount of charge generated in the plurality of pixels in the predetermined area exceeds a predetermined threshold value.

[0228] (14) The image pickup element according to any one of the above (1) to (13), further comprising:

[0229] an image signal generation unit arranged in each of the plurality of pixels and generating an image signal that is a signal based on charge generated by photoelectric conversion of the incident light,

[0230] the pixel selection unit causing the image signal generation unit of the selected pixel to output the image signal as a detection result of the pixel address event.

[0231] (15) An image pickup method comprising:

[0232] a pixel address event detection step of detecting a pixel address event of a pixel among a plurality of pixels provided with a photoelectric conversion unit that performs photoelectric conversion of incident light, the pixel address event being detected based on a change in the amount of charge generated by the photoelectric conversion;

[0233] an area address event detection step of detecting an area address event in a plurality of pixels in a predetermined area among the plurality of pixels, the area address event being detected based on a change in the amount of charge generated by photoelectric conversion in the plurality of pixels in the predetermined area;

[0234] a selection step of selecting the pixel based on the detected pixel address event and the detected area address event; and

[0235] a detection result output step of causing the selected pixel to output a detection result of the pixel address event.

[0236] Reference List

[0237] 1 Image pickup device

[0238] 2 image pickup element

[0239] 10 pixel array unit

[0240] 30 arbiter

[0241] 40 signal processing unit

[0242] 100 pixel

[0243] 110, 130 photoelectric conversion unit

[0244] 120 pixel address event detection unit

[0245] 140 image signal generation unit

[0246] 310 pixel selection unit

[0247] 311 area arbiter

[0248] 312 pixel arbiter

[0249] 320, 330, 340 area address event detection unit

[0250] 350 specific area address event detection unit

[0251] 360 standby control unit

[0252] 591 to 593 areas

Claims

1. An image pickup element, comprising: a plurality of pixels provided with a photoelectric conversion unit that performs photoelectric conversion of incident light; a pixel address event detection unit that is disposed in each of the plurality of pixels and detects a pixel address event that is an address event of each of the plurality of pixels and is detected based on a change in an amount of charge generated by the photoelectric conversion; an area address event detection unit that detects an area address event, the area address event being an address event in a predetermined area and being detected based on a change in an amount of charge generated by photoelectric conversion in a plurality of pixels included in the predetermined area among a plurality of pixels; as well as A pixel selection unit selects a pixel from among the plurality of pixels based on the detected pixel address event and the detected area address event, and causes the selected pixel to output a detection result of the pixel address event.

2. The image pickup element according to claim 1, wherein The plurality of pixels are arranged in a two-dimensional matrix shape.

3. The image pickup element according to claim 2, wherein The predetermined area is arranged for each row of the two-dimensional matrix.

4. The image pickup element according to claim 2, wherein The predetermined area is arranged for each column of the two-dimensional matrix.

5. The image pickup element according to claim 1, wherein The pixel address event detection unit detects the pixel address event based on a change in photocurrent, which is a current corresponding to the charge generated by the photoelectric conversion, and the area address event detection unit detects the area address event based on a change in photocurrent of each of the multiple pixels in the predetermined area.

6. The image pickup element according to claim 5, wherein The area address event detection unit detects the area address event based on a change in a total photocurrent of the plurality of pixels in the predetermined area.

7. The image pickup element according to claim 1, wherein The pixel selection unit selects the pixel based on the pixel address event detected in the pixel in the predetermined area where the area address event has been detected.

8. The image pickup element according to claim 1, wherein The pixel selection unit selects the pixel based on the pixel address event detected in the pixel in an area different from the predetermined area in which the area address event has been detected.

9. The image pickup element according to claim 1, wherein When the area address event is not detected, the pixel selection unit selects the pixel based on the detected pixel address event.

10. The image pickup element according to claim 1, further comprising: a specific area address event detection unit that detects the address event in a specific area, the address event being detected based on a change in the amount of charge generated by photoelectric conversion in a plurality of pixels in the specific area among the plurality of pixels, the specific area being arranged in a pixel array unit including the plurality of pixels; as well as A standby control unit controls a standby state in which the output of the detection result of the pixel address event from the pixel is stopped based on the detection result of the specific area address event detection unit.

11. The image pickup element according to claim 10, wherein The specific area address event detection unit detects the address event in the pixel array unit as a specific area.

12. The image pickup element according to claim 1, wherein The pixel address event detection unit detects the pixel address event when the amount of the generated charge changes by more than a predetermined threshold.

13. The image pickup element according to claim 1, wherein The area address event detection unit detects the area address event when a change in the amount of charge generated in the plurality of pixels in the predetermined area exceeds a predetermined threshold value.

14. The image pickup element according to claim 1, further comprising: an image signal generating unit that is arranged in each of the plurality of pixels and generates an image signal that is a signal based on charges generated by photoelectric conversion of the incident light, wherein The pixel selection unit causes the image signal generation unit of the selected pixel to output the image signal as a result of detection of the pixel address event.

15. An image pickup method, comprising: a pixel address event detecting step of detecting a pixel address event of a pixel among a plurality of pixels provided with a photoelectric conversion unit that performs photoelectric conversion of incident light, the pixel address event being detected based on a change in an amount of charge generated by the photoelectric conversion; an area address event detecting step of detecting an area address event in a plurality of pixels in a predetermined area among the plurality of pixels, the area address event being detected based on a change in an amount of charge generated by photoelectric conversion in the plurality of pixels in the predetermined area; a selecting step of selecting the pixel based on the detected pixel address event and the detected region address event; as well as The detection result outputting step causes the selected pixel to output the detection result of the pixel address event.

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