Patent ID: 9602717
Date: 2017-03-21
CPC Classifications: G02B,H04N

Claim:
1. An image capture device that includes an imaging element that images a subject through an imaging optical system including a focus lens, the imaging element including a first signal detector that detects a signal based on one beam among a pair of beams that passes through different portions in a pupil region of the imaging optical system, and a second signal detector that detects a signal based on the other beam among the pair of beams, and the image capture device comprising: a focus controller that performs any one of a first focus control for moving the focus lens to a focusing position determined based on detection signals of the first signal detector and the second signal detector and a second focus control for moving the focus lens along an optical axis direction by an arbitrary distance in a predetermined movement range and moving the focus lens to a focusing position determined based on contrast of images captured by the imaging element at respective movement positions; a focus control determinator that determines which one of the first focus control and the second focus control is to be performed based on information generated using the detection signals of the first signal detector and the second signal detector; a controller that variably controls, in the case where it is determined that the second focus control is to be performed, at least the arbitrary distance, among the movement range and the arbitrary distance in the movement range, based on the information; and an information generator that generates, based on correlation operation results between detection signals from the first signal detector and detection signals from the second signal detector, output from a first pair of a first signal detector group including a plurality of first signal detectors arranged along a phase difference detection direction in the first signal detector and the second signal detector and a third signal detector group including the second signal detectors arranged at the same distance in a direction orthogonal to the phase difference detection direction with respect to the respective signal detectors of the first signal detector group, and based on correlation operation results between detection signals from the first signal detector and detection signals from the second signal detector, output from a second pair of a second signal detector group including a plurality of first signal detectors arranged at the same distance in the same direction with respect to the respective signal detectors of the first signal detector group and arranged along the detection direction and fourth signal detector group including the second signal detectors arranged at the same distance in a direction opposite to a direction orthogonal to the phase difference detection direction with respect to the respective signal detectors of the second signal detector group, a reliability determination value for determining reliability of the correlation operation results as the information, wherein the focus control determinator determines which one of the first focus control and the second focus control is to be performed according to the size of the reliability determination value, and wherein the controller determines, in the case where it is determined that the second focus control is to be performed, a factor for the determination that the second focus control is to be performed according to the size of the reliability determination value, and reduces, in the case where the factor is based on a frequency of a subject image, the arbitrary distance compared with a case where the factor is not based on the frequency of the subject image.