FOCUS DETECTION DEVICE, IMAGE CAPTURING DEVICE, AND METHOD OF CONTROLLING FOCUS DETECTION DEVICE

摘要

PROBLEM TO BE SOLVED: To provide an image capturing device capable of accurately detecting focus.SOLUTION: A phase difference acquisition unit acquires an amount of misalignment between images received by a pair of photosensitive element groups arranged along a direction perpendicular to an optical axis as a phase difference. A conversion coefficient correction unit corrects a predefined conversion coefficient for converting the phase difference into a defocus quantity along the optical axis direction in accordance with a degree of brightness of an image. A defocus quantity generation unit generates a defocus quantity using the corrected conversion coefficient and the phase difference.