EP-4738870-A1 - PHOTOELECTRIC CONVERSION DEVICE AND PHOTOELECTRIC CONVERSION SYSTEM HAVING SAID PHOTOELECTRIC CONVERSION DEVICE

Abstract

A photoelectric conversion device includes a photoelectric conversion element configured to generate a photon detection signal by avalanche multiplication; a circuit configured to control a first state in which a first terminal of the photoelectric conversion element is connected to a power-supply voltage and a second state in which resistance between the first terminal and the power-supply voltage is higher than in the first state; a counter circuit connected to the photoelectric conversion element; a waveform shaping circuit disposed between the photoelectric conversion element and the counter circuit; and a gating circuit connected between an output node of the waveform shaping circuit and an input node of the counter circuit and configured to control whether or not to input an output signal of the waveform shaping circuit to the counter circuit.

Inventors

• SEKINE, HIROSHI
• MORIMOTO, KAZUHIRO

Assignees

• Canon Kabushiki Kaisha

Dates

Publication Date

20260506

Application Date

20240614

Claims (20)

1. A photoelectric conversion device comprising: a photoelectric conversion element configured to generate a photon detection signal by avalanche multiplication; a circuit configured to control a first state in which a first terminal of the photoelectric conversion element is connected to a power-supply voltage and a second state in which resistance between the first terminal and the power-supply voltage is higher than in the first state; a counter circuit connected to the photoelectric conversion element; a waveform shaping circuit disposed between the photoelectric conversion element and the counter circuit; and a gating circuit connected between an output node of the waveform shaping circuit and an input node of the counter circuit and configured to control whether or not to input an output signal of the waveform shaping circuit to the counter circuit.
2. The photoelectric conversion device according to claim 1, wherein during one standby state, there are a first period in which an output signal of the waveform shaping circuit is counted and a second period in which the gating circuit is controlled so as not to count an output signal of the waveform shaping circuit.
3. The photoelectric conversion device according to claim 1, wherein in the second state, the first terminal and the power-supply voltage are not connected.
4. The photoelectric conversion device according to claim 1, comprising: a pulse generation circuit, wherein the pulse generation circuit outputs a judge signal that controls whether or not the gating circuit counts an output signal of the waveform shaping circuit.
5. The photoelectric conversion device according to claim 4, wherein a signal output from the waveform shaping circuit and the judge signal are input to the gating circuit.
6. The photoelectric conversion device according to claim 5, wherein one count period of the counter circuit is a period from a start of the second state until a pulse of the judge signal is input to the gating circuit.
7. The photoelectric conversion device according to claim 5, wherein the gating circuit includes an AND circuit, and the output signal of the waveform shaping circuit and the judge signal are input to the AND circuit.
8. The photoelectric conversion device according to claim 5, wherein a period during which counting by the counter circuit is performed is defined by a period in which a level of the judge signal is High, or by a period in which the level of the judge signal is Low.
9. The photoelectric conversion device according to claim 8, wherein the processing circuit includes a D latch, and the output signal of the waveform shaping circuit and the judge signal are input to the D latch.
10. The photoelectric conversion device according to claim 1, comprising: a second counter circuit connected to an output node of the photoelectric conversion element.
11. The photoelectric conversion device according to claim 10, wherein in response to a single input of an output signal of the waveform shaping circuit, the counter circuit outputs a first count value, and the second counter circuit outputs a second count value, and counting of the first count value and counting of the second count value are performed with an overlap in time.
12. The photoelectric conversion device according to claim 11, comprising: a signal processing circuit configured to process the first count value and the second count value and output a single count value.
13. A photoelectric conversion device comprising: a photoelectric conversion element configured to generate a photon detection signal by avalanche multiplication; a resistor element provided between a first terminal of the photoelectric conversion element and a power-supply voltage; a counter circuit connected to an output node of the photoelectric conversion element; a waveform shaping circuit disposed between the photoelectric conversion element and the counter circuit; and a gating circuit disposed between an output node of the waveform shaping circuit and an input node of the counter circuit and configured to control whether or not to input an output signal of the waveform shaping circuit to the counter circuit, wherein during one standby state, there are a first period in which an output signal of the waveform shaping circuit is counted and a second period in which the gating circuit is controlled so as not to count an output signal of the waveform shaping circuit; and the photoelectric conversion device comprises a circuit configured to count a number of the first periods in which the output signal of the waveform shaping circuit has been counted.
14. The photoelectric conversion device according to claim 13, wherein the resistor element is a quench element.
15. The photoelectric conversion device according to claim 14, comprising: a pulse generation circuit, wherein the pulse generation circuit outputs a judge signal for controlling whether or not the gating circuit counts the output signal of the waveform shaping circuit.
16. The photoelectric conversion device according to claim 15, wherein a signal output from the waveform shaping circuit and the judge signal are input to the gating circuit.
17. The photoelectric conversion device according to claim 16, wherein a period during which counting by the counter circuit is performed is defined by a period in which a level of the judge signal is High, or by a period in which the level of the judge signal is Low.
18. The photoelectric conversion device according to claim 17, wherein the processing circuit includes a D latch, and the output signal of the waveform shaping circuit and the judge signal are input to the D latch.
19. A photoelectric conversion system comprising: the photoelectric conversion device according to any one of claims 1 to 18; and a signal processing unit configured to generate an image by using a signal output from the photoelectric conversion device.
20. A moving body comprising: the photoelectric conversion device according to any one of claims 1 to 18; and a control unit configured to control movement of the moving body by using a signal output from the photoelectric conversion device.

Description

Technical Field The present invention relates to a photoelectric conversion device and to a photoelectric conversion system including the photoelectric conversion device. Background Art Photoelectric conversion devices utilizing avalanche (electron avalanche) multiplication and capable of detecting faint light at a single photon level are known. Citation List Patent Literature PTL 1: Japanese Patent Laid-Open No. 2020-123847 Summary of Invention Technical Problem PTL 1 discloses a photoelectric conversion device that performs so-called clock-recharge driving. In the photoelectric conversion device described in PTL 1, in order to prevent pile-up under high illuminance, there are cases where the sensitivity of each pixel is adjusted, for example, to a low sensitivity. In this case, there is a concern of deterioration in image quality if the period of photon detection is shortened or the clock frequency is lowered. Solution to Problem One aspect of the present invention is a photoelectric conversion device that includes a photoelectric conversion element configured to generate a photon detection signal by avalanche multiplication; a circuit configured to control a first state in which a first terminal of the photoelectric conversion element is connected to a power-supply voltage and a second state in which resistance between the first terminal and the power-supply voltage is higher than in the first state; a counter circuit connected to the photoelectric conversion element; a waveform shaping circuit disposed between the photoelectric conversion element and the counter circuit; and a gating circuit connected between an output node of the waveform shaping circuit and an input node of the counter circuit and configured to control whether or not to input an output signal of the waveform shaping circuit to the counter circuit. Another aspect of the present invention is a photoelectric conversion device that includes a photoelectric conversion element configured to generate a photon detection signal by avalanche multiplication; a resistor element provided between a first terminal of the photoelectric conversion element and a power-supply voltage; a counter circuit connected to an output node of the photoelectric conversion element; a waveform shaping circuit disposed between the photoelectric conversion element and the counter circuit; and a gating circuit disposed between an output node of the waveform shaping circuit and an input node of the counter circuit and configured to control whether or not to input an output signal of the waveform shaping circuit to the counter circuit, wherein, during one standby state, there are a first period in which an output signal of the waveform shaping circuit is counted and a second period in which the gating circuit is controlled so as not to count an output signal of the waveform shaping circuit; and the photoelectric conversion device includes a circuit configured to count a number of the first periods in which the output signal of the waveform shaping circuit has been counted. Advantageous Effects of Invention The present invention makes it possible to perform sensitivity adjustment of a photoelectric conversion device while suppressing deterioration in image quality. Brief Description of Drawings [Fig. 1] Fig. 1 is a schematic configuration diagram of a photoelectric conversion device according to a first embodiment.[Fig. 2] Fig. 2 is a circuit-diagram configuration example of a photoelectric conversion device according to the first embodiment.[Fig. 3] Fig. 3 is an operation sequence chart of a photoelectric conversion device according to the first embodiment.[Fig. 4] Fig. 4 is a circuit-diagram configuration example of a photoelectric conversion device according to a second embodiment.[Fig. 5] Fig. 5 is an operation sequence chart of a photoelectric conversion device according to the second embodiment.[Fig. 6] Fig. 6 is a circuit-diagram configuration example of a photoelectric conversion device according to a third embodiment.[Fig. 7] Fig. 7 is an operation sequence chart of a photoelectric conversion device according to the third embodiment.[Fig. 8] Fig. 8 is a schematic diagram of a photoelectric conversion device of a photoelectric conversion device according to a fourth embodiment.[Fig. 9] Fig. 9 is a circuit-diagram configuration example of a photoelectric conversion device according to the fourth embodiment.[Fig. 10] Fig. 10 is an operation sequence chart of a photoelectric conversion device according to the fourth embodiment.[Fig. 11] Fig. 11 is a schematic diagram of a photoelectric conversion device of a photoelectric conversion device according to a fifth embodiment.[Fig. 12] Fig. 12 is a circuit-diagram configuration example of a photoelectric conversion device according to the fifth embodiment.[Fig. 13] Fig. 13 is an operation sequence chart of a photoelectric conversion device according to the fifth embodiment.[Fig. 14] Fig. 14 is a functional block diagram o