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EP-4738873-A1 - PHOTOELECTRIC CONVERSION DEVICE AND PHOTOELECTRIC CONVERSION SYSTEM HAVING PHOTOELECTRIC CONVERSION DEVICE

EP4738873A1EP 4738873 A1EP4738873 A1EP 4738873A1EP-4738873-A1

Abstract

A photoelectric conversion device includes: a photoelectric conversion unit that generates a photon detection signal by using avalanche multiplication; a counter circuit that counts the photon detection signal output from the photoelectric conversion unit; a first period included in one frame; and a second period that is included in the one frame, that follows the first period, and that does not overlap with the first period. A count value based on one photon detection signal by the counter circuit in the first period is greater than a count value based on the one photon detection signal by the counter circuit in the second period.

Inventors

  • MORIMOTO KAZUHIRO
  • SEKINE HIROSHI
  • SASAGO TOMOYA

Assignees

  • Canon Kabushiki Kaisha

Dates

Publication Date
20260506
Application Date
20240628

Claims (19)

  1. A photoelectric conversion device comprising: a photoelectric conversion unit that generates a photon detection signal by using avalanche multiplication; a counter circuit that counts the photon detection signal output from the photoelectric conversion unit; a first period included in one frame; and a second period that is included in the one frame, that follows the first period, and that does not overlap with the first period, wherein a count value based on one photon detection signal by the counter circuit in the first period is greater than a count value based on the one photon detection signal by the counter circuit in the second period.
  2. The photoelectric conversion device according to claim 1, wherein in response to the photoelectric conversion unit outputting the photon detection signal in the first period, a natural number N is added to the counter circuit, wherein in response to the photoelectric conversion unit outputting the photon detection signal in the second period, a natural number M is added to the counter circuit, and wherein the natural number N is greater than the natural number M.
  3. The photoelectric conversion device according to claim 2, wherein the natural number M is 1.
  4. The photoelectric conversion device according to claim 1, wherein the first period is temporally contiguous with the second period.
  5. The photoelectric conversion device according to claim 1, wherein a clock signal is input, the clock signal causing the photoelectric conversion unit to be recharged and to enter a standby state.
  6. The photoelectric conversion device according to claim 5, wherein the first period and the second period come after the clock signal is input.
  7. The photoelectric conversion device according to claim 1, wherein a duration of the first period is shorter than a duration of the second period.
  8. The photoelectric conversion device according to claim 2, wherein in response to the photoelectric conversion unit outputting the photon detection signal in a third period, a natural number L is added to the counter circuit, and wherein the natural number L is less than the natural number M.
  9. The photoelectric conversion device according to claim 2, wherein a value based on a photon detection result in a preceding recharging cycle is added.
  10. The photoelectric conversion device according to claim 2, wherein a value based on a result of detecting a neighboring pixel is added.
  11. The photoelectric conversion device according to claim 2, wherein in response to a photon being detected in the first period but not being detected in the second period, the natural number M is not added to the counter circuit.
  12. The photoelectric conversion device according to claim 1, wherein up to one photon is detected in each of the first period and the second period.
  13. The photoelectric conversion device according to claim 2, wherein the natural number N or the natural number M is set based on a count value of the counter circuit.
  14. The photoelectric conversion device according to claim 1, wherein a duration of the first period and a duration of the second period are set based on a count value of the counter circuit.
  15. The photoelectric conversion device according to claim 2, wherein combination of a duration of the first period and a duration of the second period or combination of the natural number N and the natural number M is set different between a kth frame and a (k+1)th frame.
  16. The photoelectric conversion device according to claim 2, wherein the photoelectric conversion unit has a pixel array in which a plurality of pixels are arranged in a plurality of columns and a plurality of rows, wherein the pixel array has a first pixel group and a second pixel group, and wherein combination of a duration of the first period and a duration of the second period or combination of the natural number N and the natural number M is different between the first pixel group and the second pixel group.
  17. A photoelectric conversion system comprising: The photoelectric conversion device according to any one of claims 1 to 16; and a signal processing unit that generates an image by using a signal output by the photoelectric conversion device.
  18. The photoelectric conversion system according to claim 17, wherein nonlinearity correction is performed.
  19. A movable body including the photoelectric conversion device according to any one of claims 1 to 16, comprising: a control unit that performs control of moving of the movable body by using a signal output by the photoelectric conversion device.

Description

Technical Field The present invention relates to a photoelectric conversion device and a photoelectric conversion system having the photoelectric conversion device. Background Art Photoelectric conversion devices capable of detecting single-photon-level faint light using avalanche (electron avalanche) multiplication are known. Citation List Patent Literature PTL 1: Japanese Patent Laid-Open No. 2023-039400 Summary of Invention Technical Problem In the invention described in PTL 1, exposure time is controlled on a per-pixel basis in such a manner that the quantity of incident light is calculated from information regarding a count value and exposure time. There arises a concern about image quality deterioration due to LED flicker occurrence in the configuration as described above. Solution to Problem The present invention provides, as an aspect thereof, a photoelectric conversion unit, a first period, and a second period. The photoelectric conversion unit generates a photon detection signal by using avalanche multiplication. The counter circuit counts the photon detection signal output from the photoelectric conversion unit. The first period is included in one frame. The second period is included in the one frame, follows the first period, and does not overlap with the first period. A count value based on one photon detection signal by the counter circuit in the first period is greater than a count value based on the one photon detection signal by the counter circuit in the second period. Advantageous Effects of Invention According to the present invention, the sensitivity of a photoelectric conversion device is controlled to appropriately count incident photons, and thereby image quality deterioration may be reduced. Brief Description of Drawings [Fig. 1] Fig. 1 is a schematic chart of a photoelectric conversion device according to an embodiment.[Fig. 2] Fig. 2 is a schematic chart of a PD substrate of the photoelectric conversion device according to the embodiment.[Fig. 3] Fig. 3 is a schematic chart of a circuit board of the photoelectric conversion device according to the embodiment.[Fig. 4] Fig. 4 is an example of a pixel circuit configuration of the photoelectric conversion device according to the embodiment.[Fig. 5] Fig. 5 is a schematic chart illustrating the driving of a pixel circuit of the photoelectric conversion device according to the embodiment.[Fig. 6] Fig. 6 is a chart for explaining the principle of the invention of the present application.[Fig. 7] Fig. 7 is a block diagram of a pixel of the photoelectric conversion device according to a first embodiment.[Fig. 8] Fig. 8 is a chart illustrating an example of a pixel circuit configuration of the photoelectric conversion device according to the first embodiment.[Fig. 9] Fig. 9 is a timing chart of the photoelectric conversion device according to the first embodiment.[Fig. 10] Fig. 10 is a chart illustrating an example of a pixel circuit configuration of a photoelectric conversion device according to a second embodiment.[Fig. 11] Fig. 11 is a timing chart of the photoelectric conversion device according to the second embodiment.[Fig. 12] Fig. 12 is a timing chart of the photoelectric conversion device according to the second embodiment.[Fig. 13] Fig. 13 is a chart illustrating an example of a pixel circuit configuration of a photoelectric conversion device according to a third embodiment.[Fig. 14] Fig. 14 is a timing chart of the photoelectric conversion device according to the third embodiment.[Fig. 15] Fig. 15 is a chart illustrating an example of a pixel circuit configuration of the photoelectric conversion device according to a modification of the third embodiment.[Fig. 16] Fig. 16 is a timing chart of the photoelectric conversion device according to the modification of the third embodiment.[Fig. 17] Fig. 17 is a chart illustrating an example of a pixel circuit configuration of a photoelectric conversion device according to a modification of a fourth embodiment.[Fig. 18] Fig. 18 is a timing chart of the photoelectric conversion device according to the modification of the fourth embodiment.[Fig. 19] Fig. 19 is a chart illustrating an example of a pixel circuit configuration of a photoelectric conversion device according to a modification of a fifth embodiment.[Fig. 20] Fig. 20 is a timing chart of the photoelectric conversion device according to the modification of the fifth embodiment.[Fig. 21] Fig. 21 is a functional block diagram of a photoelectric conversion system according to a sixth embodiment.[Fig. 22A] Fig. 22A is a schematic chart according to a seventh embodiment.[Fig. 22B] Fig. 22B is a schematic chart according to the seventh embodiment.[Fig. 23] Fig. 23 is a functional block diagram of a photoelectric conversion system according to an eighth embodiment.[Fig. 24A] Fig. 24A is a functional block diagram of a photoelectric conversion system according to a ninth embodiment.[Fig. 24B] Fig. 24B is a functional block diagram of the pho