Patent ID: 8379139

Claim:
A focus control apparatus for exercising focus control in an image pickup apparatus, the focus control apparatus comprising: a first contrast signal generator for extracting a first high frequency component depending upon a first cutoff frequency from a video signal and generating a first contrast signal of the video signal on the basis of the extracted first high frequency component; a second contrast signal generator for extracting a second high frequency component depending upon a second cutoff frequency which is higher than the first cutoff frequency from the video signal and generating a second contrast signal of the video signal on the basis of the extracted second high frequency component; and a controller for using a quotient obtained by dividing a value of the first contrast signal by a value of the second contrast signal as a parameter and exercising focus control on the basis of the parameter, wherein the first and second cutoff frequencies are set so as to cause a value of the parameter to assume a peak when a focus lens in the image pickup apparatus is located at positions of a predetermined distance behind an in-focus position and decrease when the focus lens is located behind the peak, wherein the predetermined distance is a distance which takes account of an amount of travel of the focus lens during a time difference occurring until the focus control is started in the controller based on the parameter, and wherein the focus control is conducted such that, after the focus lens is moved based on the parameter, the focus lens is moved based on a value other than the value of the parameter.