FOCUS DETECTION DEVICE AND IMAGE CAPTURING DEVICE

摘要

PROBLEM TO BE SOLVED: To avoid being influenced by saturation of a phase difference image signal for focus detection when performing a correlation arithmetic operation after bandpass filtering the phase difference image signal.SOLUTION: A focus detection device filters each of output signals from divided PDs (photodiodes) 202 and 203 sharing a microlens 204 to detect a phase difference, and generates a first saturation detection signal 602 which shows a pixel saturation period of a sum output signal from the divided PDs 202 and 203 and a second saturation detection signal 603 which shows an extended version of the pixel saturation period of the first saturation detection signal 602. A signal filtered based on the second saturation detection signal 603 or a mask signal is used as a phase difference image signal, and an assessment is made as to whether a correlation function operation for focus detection should be performed based on the first saturation detection signal 602 or not. A defocus quantity for an optical system used with an image sensor is computed based on the assessment result and the phase difference image signal.