Focus detector, and lens apparatus and image pickup apparatus including the same

摘要: A focus detector for detecting a defocus amount of an image pickup optical system based on displacement between two images formed by beams divided from the and passed through pupil areas, including: lenses; phase difference sensors photoelectrically converting subject lenses into signals; correlation computing unit dividing signals reference number-of-pixels to compute each area; waveform coincidence degree in area which is computed unit; unit.