IMAGE CAPTURING APPARATUS AND CONTROL METHOD THEREOF

• US 20190327424A1
• Filed: 04/18/2019
• Published: 10/24/2019
• Est. Priority Date: 04/23/2018
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Sasaki, Ken, Takeda, Nobuhiro
• Granted Patent: US 11,076,108 B2
• Time in Patent Office: Days
• CPC Class Codes: G01J 2001/442 Single-photon detection or photon counting
• CPC Class Codes: H04N 23/76 by influencing the image signals
• CPC Class Codes: H04N 25/532 by controlling global shutters in CMOS SSIS
• CPC Class Codes: H04N 25/773 comprising photon counting circuits, e.g. single photon detection [SPD] or single photon avalanche diodes [SPAD]

Abstract

An image capturing apparatus comprises an image sensor including a plurality of pixels, each pixel being configured to include a sensor unit that outputs a signal pulse in response to a single photon being received, and a counter that counts the signal pulses and outputs a count value; and a control unit configured to control a pulsewidth of the signal pulses in accordance with shooting conditions of the image capturing apparatus or a state of the image capturing apparatus.

Claims

1. An image capturing apparatus comprising:

an image sensor including a plurality of pixels, each pixel being configured to include a sensor unit that outputs a signal pulse in response to a single photon being received, and a counter that counts the signal pulses and outputs a count value; and

at least one processor or circuit configured to function as a control unit configured to control a pulsewidth of the signal pulses in accordance with shooting conditions of the image capturing apparatus or a state of the image capturing apparatus.

2. The image capturing apparatus according to claim 1,

wherein the shooting conditions include at least one of the magnitude of a gain with which the count value is multiplied and a length of a period in which the signal pulses are counted.

3. The image capturing apparatus according to claim 1,

wherein the state of the image capturing apparatus includes at least one of an illuminance of the image capturing apparatus, an amount of increase in the count value per unit of time, a magnitude of an aperture diameter that limits light incident in the image capturing apparatus, and a temperature of the image capturing apparatus.

4. The image capturing apparatus according to claim 1,

wherein the image capturing apparatus comprises a plurality of the control units;

and

the plurality of the control units change the pulsewidths of the signal pulses in each of image capturing regions, in accordance with the shooting conditions or the state.

5. The image capturing apparatus according to claim 4,

wherein the plurality of the control units change the pulsewidths of the signal pulses on a pixel-by-pixel basis, in accordance with the shooting conditions or the state.

6. The image capturing apparatus according to claim 1,

wherein the sensor unit includes an avalanche photodiode and a quenching element;

and

the control unit changes the pulsewidth of the signal pulses by changing a voltage applied to the quenching element.

7. The image capturing apparatus according to claim 1,

wherein the sensor unit includes an avalanche photodiode and a quenching element;

and

the control unit changes the pulsewidth of the signal pulses by changing a resistance value of the quenching element.

8. The image capturing apparatus according to claim 7,

wherein the quenching element includes a plurality of MOS transistors;

and

the control unit changes the resistance value of the quenching element by changing gate voltages of the MOS transistors.

9. The image capturing apparatus according to claim 1,

wherein the sensor unit includes a buffer that outputs the signal pulses;

and

the control unit changes the pulsewidth of the signal pulses by changing response characteristics of the buffer.

10. An image capturing apparatus comprising:

an image sensor including a plurality of pixels, each pixel being configured to include a sensor unit that outputs a signal pulse in response to a single photon being received, a counter that counts the signal pulses and outputs a count value, and a counter controller that controls the counter to not count signal pulses in a predetermined period after the occurrence of the signal pulse; and

at least one processor or circuit configured to function as a control unit configured to control the predetermined period in accordance with shooting conditions of the image capturing apparatus or a state of the image capturing apparatus.

11. The image capturing apparatus according to claim 10,

wherein the shooting conditions include at least one of the magnitude of a gain with which the count value is multiplied and the length of a period in which the signal pulses are counted.

12. The image capturing apparatus according to claim 10,

wherein the state of the image capturing apparatus includes at least one of an illuminance of the image capturing apparatus, an amount of increase in the count value per unit of time, a magnitude of an aperture diameter that limits light incident in the image capturing apparatus, and a temperature of the image capturing apparatus.

13. The image capturing apparatus according to claim 10,

wherein the image capturing apparatus comprises a plurality of the control units;

and

the plurality of the control units change the predetermined period in each of image capturing regions, in accordance with the shooting conditions or the state.

14. The image capturing apparatus according to claim 13,

wherein the plurality of the control units change the predetermined period on a pixel-by-pixel basis, in accordance with the shooting conditions or the state.

15. A method for controlling an image capturing apparatus,

the image capturing apparatus comprising:

an image sensor including a plurality of pixels, each pixel being configured to include a sensor unit that outputs a signal pulse in response to a single photon being received, and a counter that counts the signal pulses and outputs a count value, and

the method comprising;

controlling a pulsewidth of the signal pulse in accordance with shooting conditions of the image capturing apparatus or a state of the image capturing apparatus.

16. A method for controlling an image capturing apparatus,

the image capturing apparatus comprising:

an image sensor including a plurality of pixels, each pixel being configured to include a sensor unit that outputs a signal pulse in response to a single photon being received, a counter that counts the signal pulses and outputs a count value, and a counter controller that controls the counter to not count signal pulses in a predetermined period after the occurrence of the signal pulse, and

the method comprising;

controlling the predetermined period in accordance with shooting conditions of the image capturing apparatus or a state of the image capturing apparatus.