Focus-detection device, method for controlling the same, and image capture apparatus

摘要

Disclosed is a focus-detection device capable of performing phase-difference detection type focus detection using outputs of an image sensor, and a method for controlling the same. Phase differences between image signals each of which based on a light beam that has passed through different partial regions of an exit pupil of an imaging optical system, and an image signal based on a light beam that has passed through the entire region of the exit pupil is detected. Then, a defocus amount of the imaging optical system is computed using the sum of the phase differences.

主权项

1. A focus-detection device comprising:
a first detecting unit configured to detect a first phase difference between a first image signal based on a light beam that has passed through a partial region of an exit pupil of an imaging optical system, and a third image signal based on a light beam that has passed through the entire region of the exit pupil; a second detecting unit configured to detect a second phase difference between a second image signal based on a light beam that has passed through another partial region of the exit pupil, and a fourth image signal based on a light beam that has passed through the entire region of the exit pupil; and a computing unit configured to compute a defocus amount of the imaging optical system using a sum of the first phase difference and the second phase difference, wherein the first detecting unit detects the first phase difference while shifting a section of the first image signal with respect to a fixed section of the third image signal in a predetermined direction, and the second detecting unit detects the second phase difference while shifting a section of the second image signal with respect to a fixed section of the fourth image signal in the predetermined direction.