EP-4738871-A1 - PHOTOELECTRIC CONVERSION DEVICE AND PHOTOELECTRIC CONVERSION SYSTEM

EP4738871A1EP 4738871 A1EP4738871 A1EP 4738871A1EP-4738871-A1

Abstract

A photoelectric conversion apparatus includes a first APD, a first pulse generating circuit that generates a first pulse signal, based on an output from the first APD, a first switch that is provided between a first power supply that applies a first voltage and a first terminal of the first APD, and a second switch that is provided between a second power supply that applies a second voltage and the first terminal of the first APD. When the first switch is turned on, the first APD enters a recharge state. When the first switch is turned off, the first APD enters a standby state. When the second switch is turned on, the first APD enters an inactive state. When the second switch is turned off, the first APD enters an active state. A period during which the first switch is on differs from a period during which the second switch is on.

Inventors

TOJIMA KENZO
MORIMOTO KAZUHIRO

Assignees

Canon Kabushiki Kaisha

Dates

Publication Date: 20260506
Application Date: 20240628

Claims (17)

A photoelectric conversion apparatus comprising: a first avalanche photodiode; a first pulse generating circuit that generates a first pulse signal, based on an output from the first avalanche photodiode; a first power supply that applies a first voltage to a first terminal of the first avalanche photodiode via a first switch; a second power supply that applies a second voltage different from a voltage of the first power supply to a second terminal of the first avalanche photodiode; and a third power supply that applies a third voltage different from the voltage of the first power supply and a voltage of the second power supply to the first terminal via a second switch, wherein a period during which the first switch is on differs from a period during which the second switch is on.
The photoelectric conversion apparatus according to claim 1, wherein when the first switch is turned on, the first avalanche photodiode enters a recharge state, wherein when the first switch is turned off, the first avalanche photodiode enters a standby state, wherein when the second switch is turned on, the first avalanche photodiode enters an inactive state, and wherein when the second switch is turned off, the first avalanche photodiode enters an active state.
A photoelectric conversion apparatus comprising: a first avalanche photodiode; a first pulse generating circuit that generates a first pulse signal, based on an output from the first avalanche photodiode; a first switch that is provided between a first power supply that applies a first voltage and a first terminal of the first avalanche photodiode; and a second switch that is provided between a second power supply that applies a second voltage different from the first voltage and the first terminal of the first avalanche photodiode, wherein when the first switch is turned on, the first avalanche photodiode enters a recharge state, wherein when the first switch is turned off, the first avalanche photodiode enters a standby state, wherein when the second switch is turned on, the first avalanche photodiode enters an inactive state, wherein when the second switch is turned off, the first avalanche photodiode enters an active state, and wherein a period during which the first switch is on differs from a period during which the second switch is on.
The photoelectric conversion apparatus according to claim 3, further comprising: a second avalanche photodiode; a second pulse generating circuit that generates a second pulse signal, based on an output from the second avalanche photodiode; a third switch that is provided between the first power supply that applies the first voltage and a first terminal of the second avalanche photodiode; a fourth switch that is provided between the second power supply that applies the second voltage different from the first voltage and the first terminal of the second avalanche photodiode, wherein when the third switch is turned on, the second avalanche photodiode enters a recharge state, wherein when the third switch is turned off, the second avalanche photodiode enters a standby state, wherein when the fourth switch is turned on, the second avalanche photodiode enters an inactive state, wherein when the fourth switch is turned off, the second avalanche photodiode enters an active state, and wherein a period during which the third switch is on differs from a period during which the fourth switch is on.
The photoelectric conversion apparatus according to claim 4, wherein a second period during which the second avalanche photodiode is in the standby state and in the active state starts after a first period during which the first avalanche photodiode is in the standby state and in the active state, and wherein control is periodically implemented for the second switch and the fourth switch such that the first period starts again after the second period.
The photoelectric conversion apparatus according to claim 5, wherein the first avalanche photodiode and the second avalanche photodiode each include a first semiconductor region of a first conductivity type, a second semiconductor region of a second conductivity type, and a third semiconductor region of the first conductivity type to which a signal charge moves from the first semiconductor region, wherein a reverse bias voltage for avalanche multiplication of the signal charge is applied to the second semiconductor region and the third semiconductor region, and wherein a control unit moves the signal charge to the third semiconductor region of the second avalanche photodiode or the first avalanche photodiode in the active state.
The photoelectric conversion apparatus according to claim 6, wherein the control unit is the second switch.
The photoelectric conversion apparatus according to claim 5, wherein whether the control is implemented is set depending on a photographic condition.
The photoelectric conversion apparatus according to claim 2 or claim 4, further comprising: a counter that counts a pulse signal that is generated by the first pulse generating circuit, wherein a count value of the counter is corrected depending on a ratio of a period during which the first avalanche photodiode is in the standby state and in the active state to an exposure period for acquiring a single image.
The photoelectric conversion apparatus according to claim 2 or claim 4, further comprising: a third avalanche photodiode.
The photoelectric conversion apparatus according to claim 4, further comprising: a first pixel; and a second pixel, wherein a separation portion is provided between the first pixel and the second pixel.
The photoelectric conversion apparatus according to claim 11, wherein an insulating isolation portion is not provided between the first avalanche photodiode and the second avalanche photodiode.
The photoelectric conversion apparatus according to claim 1, wherein the second switch switches from a voltage that is applied to the first avalanche photodiode to a voltage higher than a breakdown voltage of the first avalanche photodiode or a voltage equal to or lower than the breakdown voltage.
The photoelectric conversion apparatus according to claim 4, wherein multiple pixels are arranged in a two-dimensional array in an imaging region, wherein the second switch and the fourth switch are controlled such that the first avalanche photodiode that is included in a pixel within a first region in the imaging region enters the active state, and the second avalanche photodiode that is included in a pixel within a second region in the imaging region enters the inactive state.
The photoelectric conversion apparatus according to claim 14, wherein in the imaging region, the second region is nearer than the first region to an outer peripheral portion.
A photoelectric conversion system comprising: the photoelectric conversion apparatus according to any one of claim 1 to claim 15; and a signal processing unit that generates an image by using a signal outputted by the photoelectric conversion apparatus.
A mobile body comprising: the photoelectric conversion apparatus according to any one of claim 1 to claim 15; and a controller that controls movement of the mobile body by using a signal outputted by the photoelectric conversion apparatus.

Description

Technical Field The present invention relates to structures of a photoelectric conversion apparatus and a photoelectric conversion system. Background Art A known photoelectric conversion apparatus includes pixels including multiple avalanche photodiodes (APDs). PTL 1 discloses an APD, a quenching circuit that is connected to the APD, a signal controlling circuit into which a signal outputted from the APD is inputted, and a pulse generating circuit that is connected to the quenching circuit and the signal control circuit. A pulse signal that is generated by the pulse generating circuit causes the turning on and off of the quenching circuit to be controlled and causes the output signal of the APD to be reset, and a pulse signal depending on an incident photon is outputted even under high luminance. Citation List Patent Literature PTL 1: Japanese Patent Laid-Open No. 2020-123847 Summary of Invention Technical Problem The APD includes a single electrode for collecting electric charges, and all of the electric charges are collected by the electrode such that avalanche multiplication occurs. Accordingly, device characteristics dependent on the avalanche multiplication can be degraded. Solution to Problem According to an aspect of the present invention, a photoelectric conversion apparatus includes: a first avalanche photodiode; a first pulse generating circuit that generates a first pulse signal, based on an output from the first avalanche photodiode; a first switch that is provided between a first power supply that applies a first voltage and a first terminal of the first avalanche photodiode; and a second switch that is provided between a second power supply that applies a second voltage different from the first voltage and the first terminal of the first avalanche photodiode. When the first switch is turned on, the first avalanche photodiode enters a recharge state, when the first switch is turned off, the first avalanche photodiode enters a standby state, when the second switch is turned on, the first avalanche photodiode enters an inactive state, when the second switch is turned off, the first avalanche photodiode enters an active state, and a period during which the first switch is on differs from a period during which the second switch is on. According to another aspect of the present invention, a photoelectric conversion apparatus includes: a first avalanche photodiode; a first pulse generating circuit that generates a first pulse signal, based on an output from the first avalanche photodiode; a first power supply that applies a first voltage to a first terminal of the first avalanche photodiode via a first switch; a second power supply that applies a second voltage different from a voltage of the first power supply to a second terminal of the first avalanche photodiode; and a third power supply that applies a third voltage different from the voltage of the first power supply and a voltage of the second power supply to the first terminal via a second switch. A period during which the first switch is on differs from a period during which the second switch is on. Advantageous Effects of Invention The frequency of use of an electrode for collecting electric charges is reduced, and consequently, device characteristics dependent on avalanche multiplication are inhibited from being degraded. Brief Description of Drawings [Fig. 1] Fig. 1 illustrates the structure of a photoelectric conversion apparatus according to an embodiment.[Fig. 2] Fig. 2 illustrates an example of arrangement of a sensor substrate of the photoelectric conversion apparatus according to the embodiment.[Fig. 3] Fig. 3 illustrates an example of arrangement of a circuit substrate of the photoelectric conversion apparatus according to the embodiment.[Fig. 4A] Fig. 4A is a block diagram including an equivalent circuit of a photoelectric conversion element of the photoelectric conversion apparatus according to the embodiment.[Fig. 4B] Fig. 4B is a block diagram including an equivalent circuit of the photoelectric conversion element of the photoelectric conversion apparatus according to the embodiment.[Fig. 5] Fig. 5 illustrates a relationship between the operation of an APD of the photoelectric conversion apparatus according to the embodiment and an output signal.[Fig. 6] Fig. 6 illustrates an example of the structures of a signal processing circuit and a photoelectric conversion element according to a first embodiment.[Fig. 7A] Fig. 7A is a timing chart illustrating the operation of the signal processing circuit according to the first embodiment.[Fig. 7B] Fig. 7B is a timing chart illustrating the operation of the signal processing circuit according to the first embodiment.[Fig. 8A] Fig. 8A is a schematic diagram of the photoelectric conversion element according to the first embodiment.[Fig. 8B] Fig. 8B is a schematic diagram of the photoelectric conversion element according to the first embodiment.[Fig. 9] Fig. 9 illustrates a sectional view of