Focus detection apparatus, focus detection method, and image capturing apparatus

A focus detection apparatus that performs focus detection based on a phase difference method using signals output from an image sensor including a plurality of focus detection pixels, each focus detection pixel having a plurality of photoelectric portions that share one microlens and receive light beams passing through different pupil regions of an imaging optical system, the focus detection apparatus comprising:

• a setting unit that sets one or more focus detection areas in which the focus detection is performed, such that a subject in an image formed on the image sensor is included therein;
• a detection unit that, if a position of the subject has changed, detects a movement amount of the position of the subject;
• and
• a focus detection unit that performs the focus detection in each focus detection area based on signals output from the focus detection pixels included in the focus detection area,
• wherein the setting unit makes the number of the focus detection areas to be set smaller when the movement amount of the position of the subject is smaller than a preset first threshold than when the movement amount is equal to or larger than the first threshold.

A focus detection apparatus that performs focus detection based on a phase difference method using signals output from an image sensor including a plurality of focus detection pixels, each focus detection pixel having a plurality of photoelectric portions that share one microlens and receive light beams passing through different pupil regions of an imaging optical system, the focus detection apparatus comprising:

• a setting unit that sets one or more focus detection areas in which the focus detection is performed, such that a subject in an image formed on the image sensor is included therein;
• a detection unit that detects whether a size of the subject has changed;
• and
• a focus detection unit that performs the focus detection in each focus detection area by obtaining correlation amounts while shifting signals output from the plurality of photoelectric portions relative to each other,
• wherein the focus detection unit sets a range of the shifting to be smaller when a change amount of the size of the subject detected by the detection unit is smaller than a preset threshold than when the change amount is equal to or larger than the threshold.

An image capturing apparatus, comprising:

• an image sensor including a plurality of focus detection pixels, each focus detection pixel having a first photoelectric portion and a second photoelectric portion that share one microlens and receive light beams passing through different pupil regions of an imaging optical system;
• and
• a focus detection apparatus that performs focus detection based on a phase difference method using signals output from the image sensor, the focus detection apparatus comprising:
• a setting unit that sets one or more focus detection areas in which the focus detection is performed, such that a subject in an image formed on the image sensor is included therein;
• a detection unit that detects whether at least one of a position and a size of the subject has changed;
• a division unit that divides each of the one or more focus detection areas into a plurality of divisional areas in a preset first direction in accordance with a result of the detection by the detection unit;
• and
• a focus detection unit that
• for each divisional area, adds signals output from the first photoelectric portions included in the divisional area in the first direction, adds signals output from the second photoelectric portions included in the divisional area in the first direction, and obtains correlation amounts while shifting a pair of signals obtained through the addition relative to each other, and
• adds the obtained correlation amounts of the divisional areas for each focus detection area, and performs the focus detection based on a result of adding the obtained correlation amounts,
• wherein the division unit makes a divisor used in obtaining the divisional areas smaller when at least one of the position and the size of the subject has changed than when there is no change in the position and the size of the subject.

An image capturing apparatus, comprising:

• an image sensor including a plurality of focus detection pixels, each focus detection pixel having a plurality of photoelectric portions that share one microlens and receive light beams passing through different pupil regions of an imaging optical system;
• and
• a focus detection apparatus that performs focus detection based on a phase difference method using signals output from the image sensor, the focus detection apparatus comprising:
• a setting unit that sets one or more focus detection areas in which the focus detection is performed, such that a subject in an image formed on the image sensor is included therein;
• a detection unit that, if a position of the subject has changed, detects a movement amount of the position of the subject;
• and
• a focus detection unit that performs the focus detection in each focus detection area based on signals output from the focus detection pixels included in the focus detection area,
• wherein the setting unit makes the number of the focus detection areas to be set smaller when the movement amount of the position of the subject is smaller than a preset first threshold than when the movement amount is equal to or larger than the first threshold.

An image capturing apparatus, comprising:

• the image sensor including a plurality of focus detection pixels, each focus detection pixel having a plurality of photoelectric portions that share one microlens and receive light beams passing through different pupil regions of an imaging optical system;
• and
• a focus detection apparatus that performs focus detection based on a phase difference method using signals output from an image sensor, the focus detection apparatus comprising:
• a setting unit that sets one or more focus detection areas in which the focus detection is performed, such that a subject in an image formed on the image sensor is included therein;
• a detection unit that detects whether a size of the subject has changed;
• and
• a focus detection unit that performs the focus detection in each focus detection area by obtaining correlation amounts while shifting signals output from the plurality of photoelectric portions relative to each other,
• wherein the focus detection unit sets a range of the shifting to be smaller when a change amount of the size of the subject detected by the detection unit is smaller than a preset threshold than when the change amount is equal to or larger than the threshold.

A focus detection method for performing focus detection based on a phase difference method using signals output from an image sensor including a plurality of focus detection pixels, each focus detection pixel having a first photoelectric portion and a second photoelectric portion that share one microlens and receive light beams passing through different pupil regions of an imaging optical system, the focus detection method comprising:

• setting one or more focus detection areas in which the focus detection is performed, such that a subject in an image formed on the image sensor is included therein;
• detecting whether at least one of a position and a size of the subject has changed;
• dividing each of the one or more focus detection areas into a plurality of divisional areas in a preset first direction in accordance with a result of the detection;
• for each divisional area, adding signals output from the first photoelectric portions included in the divisional area in the first direction, and adding signals output from the second photoelectric portions included in the divisional area in the first direction;
• for each divisional area, obtaining correlation amounts while shifting a pair of signals obtained through the addition relative to each other;
• for each focus detection area, adding the obtained correlation amounts of the divisional areas;
• and
• performing the focus detection based on a result of adding the obtained correlation amounts, wherein
• in the dividing, a divisor used in obtaining the divisional areas is made smaller when at least one of the position and the size of the subject has changed than when there is no change in the position and the size of the subject.

A focus detection method for performing focus detection based on a phase difference method using signals output from an image sensor including a plurality of focus detection pixels, each focus detection pixel having a plurality of photoelectric portions that share one microlens and receive light beams passing through different pupil regions of an imaging optical system, the focus detection method comprising:

• setting one or more focus detection areas in which the focus detection is performed, such that a subject in an image formed on the image sensor is included therein;
• if a position of the subject has changed, detecting a movement amount of the position of the subject;
• and
• performing the focus detection in each focus detection area based on signals output from the focus detection pixels included in the focus detection area, wherein
• in the setting, the number of the focus detection areas to be set is made smaller when the movement amount of the position of the subject is smaller than a preset first threshold than when the movement amount is equal to or larger than the first threshold.

A focus detection method for performing focus detection based on a phase difference method using signals output from an image sensor including a plurality of focus detection pixels, each focus detection pixel having a plurality of photoelectric portions that share one microlens and receive light beams passing through different pupil regions of an imaging optical system, the focus detection method comprising:

• setting one or more focus detection areas in which the focus detection is performed, such that a subject in an image formed on the image sensor is included therein;
• detecting whether a size of the subject has changed;
• and
• performing the focus detection in each focus detection area by obtaining correlation amounts while shifting signals output from the plurality of photoelectric portions relative to each other, wherein
• in the performing of the focus detection, a range of the shifting is set to be smaller when a change amount of the size of the subject detected is smaller than a preset threshold than when the change amount is equal to or larger than the threshold.