Image capturing apparatus, method of controlling the same, and storage medium

Patent metadata

Field	Value
Publication number	US-9531946-B2
Application number	US-201514859667-A
Country	US
Kind code	B2
Filing date	Sep 21, 2015
Priority date	Sep 26, 2014
Publication date	Dec 27, 2016
Grant date	Dec 27, 2016

Abstract

An image capturing apparatus comprising an image forming pixel and a focus detection pixel arranged on a portion of the image forming pixel, an image sensor that converts a subject image formed by an imaging lens into an image signal, and a control unit that switches between a first mode in which, after the image sensor has been exposed, pixels of the image sensor are sequentially read out in an order in which the pixels are arranged, and a second mode in which a signal from the focus detection pixel and a signal from peripheral pixels are read out first.

First claim

What is claimed is:

1. An image capturing apparatus comprising:
an image sensor that has image forming pixels and focus detection pixels arranged at a portion of the image forming pixels, and is configured to convert a subject image formed by an imaging lens into an image signal;
a control unit configured to switch between a first mode in which, after the image sensor has been exposed, pixels of the image sensor are sequentially read out in an order in which the pixels are arranged, and a second mode in which signals from the focus detection pixels and signals from peripheral pixels in a periphery of the focus detection pixels are read out first, and signals from remaining pixels that have not been read out are read out thereafter; and
a correction unit configured to correct pixel signals that correspond to positions of the focus detection pixels using the peripheral pixels.

2. The image capturing apparatus according to claim 1 , wherein the control unit performs control such that after readout of the focus detection pixels and the peripheral pixels, a focus detection operation and driving of the imaging lens are performed in parallel while the remaining pixels that have not been read out are read out.

3. The image capturing apparatus according to claim 1 , wherein the control unit performs control such that after readout of the focus detection pixels and the peripheral pixels, a photometric operation and driving of an aperture of the imaging lens are performed in parallel while the remaining pixels that have not been read out are read out.

4. The image capturing apparatus according to claim 1 , wherein the control unit switches between the first mode and the second mode based on at least one out of shutter speed, sensitivity, and temperature at the time of imaging.

5. The image capturing apparatus according to claim 1 , wherein the control unit switches a method of correcting fixed-pattern noise of the image sensor according to whether the first mode is used or the second mode is used.

6. The image capturing apparatus according to claim 5 , wherein in a case in which the second mode is used, the control unit performs filter processing separately for the focus detection pixels and the peripheral pixels, and for the remaining pixels.

7. The image capturing apparatus according to claim 1 , wherein the control unit changes an area in which the focus detection pixels are to be read out first in the second mode, based on a position of a subject in a screen of the image sensor.

8. A method of controlling an image capturing apparatus comprising an image sensor that has image forming pixels and focus detection pixels arranged at a portion of the image forming pixels and is configured to convert a subject image formed by an imaging lens into an image signal, the method comprising:
switching between a first mode in which, after the image sensor has been exposed, pixels of the image sensor are sequentially read out in an order in which the pixels are arranged, and a second mode in which signals from the focus detection pixels and signals from the peripheral pixels in a periphery of the focus detection pixels are read out first, and signals from the remaining pixels that have not been read out are read out thereafter; and
correcting pixel signals that correspond to positions of the focus detection pixels using the peripheral pixels.

9. A non-transitory computer-readable storage medium storing a computer-executable program for causing a computer to execute a method of controlling an image capturing apparatus comprising an image sensor that has image forming pixels and focus detection pixels arranged at a portion of the image forming pixels and is configured to convert a subject image formed by an imaging lens into an image signal, the method comprising:
switching between a first mode in which, after the image sensor has been exposed, pixels of the image sensor are sequentially read out in an order in which the pixels are arranged, and a second mode in which signals from the focus detection pixels and signals from the peripheral pixels in a periphery of the focus detection pixels are read out first, and signals from the remaining pixels that have not been read out are read out thereafter; and
correcting pixel signals that correspond to positions of the focus detection pixels using the peripheral pixels.

Assignees

• Canon Kk

Inventors

• Okubo Toshiyuki

Classifications

• H04N23/71

  Circuitry for evaluating the brightness variation · CPC title

• H04N23/672 Primary

  based on the phase difference signals · CPC title

• H04N25/42

  by switching between different modes of operation using different resolutions or aspect ratios, e.g. switching between interlaced and non-interlaced mode · CPC title

• H04N25/67

  applied to fixed-pattern noise, e.g. non-uniformity of response · CPC title

• H04N25/704

  Pixels specially adapted for focusing, e.g. phase difference pixel sets · CPC title