Imaging apparatus and method for suppressing influence of flicker occurring under an artificial light source

Patent metadata

Field	Value
Publication number	US-10708515-B2
Application number	US-201715836567-A
Country	US
Kind code	B2
Filing date	Dec 8, 2017
Priority date	May 10, 2013
Publication date	Jul 7, 2020
Grant date	Jul 7, 2020

Abstract

An imaging apparatus has a first mode in which a detection unit detects a light amount change characteristic from an object between first and second exposures of an imaging unit during a continuous shooting and a determination unit determines an exposure timing of the second exposure based on the detected light amount change characteristic.

First claim

What is claimed is:

1. An imaging apparatus capable of continuous shooting for continuously obtaining a plurality of images in response to a predetermined operation of an instruction member, comprising:
an image sensor; and
at least one processor that executes instructions stored in at least one memory
to detect flicker of a light; and
to control an exposure timing of the image sensor during the continuous shooting so as to synchronize with a phase of the flicker based on a result of a detection of the flicker when the flicker is detected,
wherein, the at least one processor controls the exposure timing of the image sensor during the continuous shooting so that intervals of the exposure timings of the continuous shooting when the flicker is not existing are shorter than intervals of the exposure timings of the continuous shooting when the flicker is existing, and
wherein the at least one processor detects the phase of the flicker, and controls the exposure timing so that each exposure timing of the continuous shooting is synchronized with each feature point of the flicker, in a case where the flicker is detected.

2. The imaging apparatus according to claim 1 , wherein the at least one processor controls the exposure timing so that the timing of each feature point of the flicker is positioned in a center of each exposure period.

3. The imaging apparatus according to claim 1 ,
wherein the at least one processor detects the flicker before a start of the continuous shooting,
wherein, in a case where the flicker is not detected before the start of the continuous shooting, the at least one processor does not control the exposure timing to synchronize with the phase of the flicker, and
wherein, in a case where the flicker is detected before the start of the continuous shooting, the at least one processor controls the exposure timing to synchronize with the phase of the flicker.

4. The imaging apparatus according to claim 3 ,
wherein, the at least one processor detects the phase of the flicker by detecting a light amount a plurality of times during a flickering period.

5. The imaging apparatus according to claim 4 ,
wherein the detecting the light amount is performed at a period of about 1.667 ms.

6. The imaging apparatus according to claim 1 ,
wherein the at least one processor detects the phase of the flicker before starting the continuous shooting, and in a case where the flicker is detected, detects the feature point of the flicker during the continuous shooting.

7. The imaging apparatus according to claim 6 ,
wherein the feature point of the flicker detection is performed in a period between obtaining images during the continuous shooting.

8. The imaging apparatus according to claim 7 ,
wherein the flicker detection is not performed in a period between obtaining the images during the continuous shooting when the flicker is not detected before starting the continuous shooting.

9. The imaging apparatus according to claim 8 ,
wherein the flicker detection is not performed in a period between obtaining the images during the continuous shooting when the phase of the flicker is not detected before starting the continuous shooting,
wherein the flicker detection is performed in a period between obtaining the images during the continuous shooting when the phase of the flicker is detected before starting the continuous shooting, and
wherein the flicker detection in a period between obtaining the images during the continuous shooting is detecting feature point of the flicker.

10. The imaging apparatus according to claim 1 , wherein the flicker detection is performed using a light metering sensor different from the image sensor.

11. A control method for an imaging apparatus which includes an image sensor and is capable of continuous shooting for continuously obtaining a plurality of images in response to a predetermined operation of an instruction member, the control method comprising:
detecting flicker of a light,
controlling an exposure timing of the image sensor during the continuous shooting so as to synchronize with a phase of the flicker when the flicker is detected,
wherein, the controlling the exposure timing of the image sensor during the continuous shooting so that intervals of the exposure timings of the continuous shooting when flicker is not existing are shorter than intervals of the exposure timings of the continuous shooting when the flicker is existing, and
wherein the phase of the flicker is detected, and the exposure timing is controlled so that each exposure timing of the continuous shooting is synchronized with each feature point of the flicker, in a case where the flicker is detected.

12. A non-transitory computer-readable storage medium storing a program for causing a computer to execute a method for controlling an image apparatus which includes an image sensor and is capable of continuous shooting for continuously obtaining a plurality of images in response to a predetermined operation of an instruction member, the control method comprising:
detecting flicker of a light,
controlling an exposure timing of the image sensor during the continuous shooting so as to synchronize with a phase of the flicker when the flicker is detected,
wherein, the controlling controls the exposure timing of the image sensor during the continuous shooting so that intervals of the exposure timings of the continuous shooting when flicker is not existing are shorter than intervals of the exposure timings of the continuous shooting when the flicker is existing, and
wherein the phase of the flicker is detected, and the exposure timing is controlled so that each exposure timing of the continuous shooting is synchronized with each feature point of the flicker, in a case where the flicker is detected.

13. An imaging apparatus includes an image sensor, capable of continuous shooting for continuously obtaining a plurality of frames by capturing an object continuously, comprising:
at least one processor that executes instructions stored in at least one memory
to detect whether flicker of light is existing or not; and
to control an exposure timing of the image sensor so as to synchronize with a feature point of a phase of the flicker based on a result of a detection of the flicker when the flicker is existing,
wherein at least one processor controls the exposure timing of the image sensor of the continuous shooting so that a frame speed of the continuous shooting when the flicker is existing is lower than the frame speed of the continuous shooting when the flicker is not existing.

14. The imaging apparatus according to claim 13 ,
wherein the at least one processor controls the exposure timing of the image sensor of the continuous shooting so that intervals between the plurality of frames when the flicker is existing are longer than the intervals between the plurality of frames when the flicker is not existing.

15. The imaging apparatus according to claim 1 , wherein the feature point of the flicker is a peak or bottom of the phase of the flicker.

16. The imaging apparatus according to claim 13 , wherein the feature point is a peak or bottom of the phase of the flicker.

17. The imaging apparatus according to claim 16 , wherein the at least one processor controls the exposure timing of the of the image sensor of the continuous shooting so that the timing of each feature point of the flicker is positioned in a center of each exposure period when the flicker is existing.

18. The imaging apparatus according to claim 13 ,
wherein the at least one pr

Assignees

• Canon Kk

Inventors

• Nakagawara Naoyuki

Classifications

• H04N23/73

  by influencing the exposure time · CPC title

• H04N23/745 Primary

  Detection of flicker frequency or suppression of flicker wherein the flicker is caused by illumination, e.g. due to fluorescent tube illumination or pulsed LED illumination · CPC title

• H04N5/2353

  Electricity · mapped topic

• H04N5/2357 Primary

  Electricity · mapped topic