Patent ID: 9667852
Date: 2017-05-30
CPC Classifications: H04N

Claim:
1. An image pickup apparatus comprising: an image sensor configured to photoelectrically convert an object image formed by an imaging optical system; a calculation unit configured to, as a scan operation, extract a specific frequency component from an image signal output from an imaging area of the image sensor corresponding to a focus detection area, to calculate a focus evaluation value based on the specific frequency component obtained by one scan operation of the focus detection area; and a control unit configured to drive a focus adjustment unit included in the imaging optical system based on the focus evaluation value, to perform an in-focus operation, wherein the focus adjustment unit is configured to adjust a focusing state of the object image, wherein a change curve representing a change amount of the focus evaluation value obtained by one scan includes a first slope portion before inversion of a sign of an inclination of the change curve at a peak value on the change curve and a second slope portion after inversion of a sign of an inclination of the change curve at the peak value on the change curve, and wherein the control unit determines whether the focus evaluation value corresponding to the peak value on the change curve is used for the in-focus operation, based on a comparison of an inclination of the first slope portion and an inclination of the second slope portion to a threshold value.