Focus adjusting apparatus, focus adjusting method, image capturing apparatus, and storage medium

An image capturing apparatus, comprising:

• an image sensor that outputs as image signal by capturing a subject image formed by an optical system;
• and
• a focus adjusting apparatus that comprises:
• a tracking unit that detects a first area of a subject to be tracked, and reliability of a tracking position from an image signal output from an image sensor that captures a subject image formed on the image sensor by an optical system;
• a focus detection unit that detects focus states of a plurality of focus detection areas based on the image signal that is output from the image sensor;
• a determination unit that determines an in-focus area for which focus adjustment of the optical system is to be performed;
• a prediction unit that predicts a focus state in next focus detection based on a history of focus states of the in-focus area detected by the focus detection unit;
• and
• a selection unit that selects a second area from the plurality of focus detection areas,
• wherein the determination unit determines the first area as the in-focus area in a case where a state in which the reliability is higher than a predetermined first threshold continues for a predetermined time period or longer, and determines the second area as the in-focus area in a case where the state does not continue for the predetermined time period.

A focus adjusting method, comprising:

• detecting a first area of a subject to be tracked, and reliability of a tracking position from an image signal output from an image sensor that captures a subject image formed on the image sensor by an optical system;
• detecting focus states of a plurality of focus detection areas based on the image signal that is output from the image sensor;
• determining an in-focus area for which focus adjustment of the optical system is to be performed;
• predicting a focus state in next focus detection based on a history of focus states of the detected in-focus area;
• and
• selecting a second area from the plurality of focus detection areas,
• determining the first area as the in-focus area in a case where a state in which the reliability is higher than a predetermined first threshold continues for a predetermined time period or longer, and determining the second area as the in-focus area in a case where the state does not continue for the predetermined time period.

A computer-readable storage medium having stored therein a program which is executable by a computer, the program having program codes for realizing the focus adjusting method that comprises:

• detecting a first area of a subject to be tracked, and reliability of a tracking position from an image signal output from an image sensor that captures a subject image formed on the image sensor by an optical system;
• detecting focus states of a plurality of focus detection areas based on the image signal that is output from the image sensor;
• determining an in-focus area for which focus adjustment of the optical system is to be performed;
• predicting a focus state in next focus detection based on a history of focus states of the detected in-focus area;
• and
• selecting a second area from the plurality of focus detection areas,
• determining the first area as the in-focus area in a case where a state in which the reliability is higher than a predetermined first threshold continues for a predetermined time period or longer, and determining the second area as the in-focus area in a case where the state does not continue for the predetermined time period.