Patent ID: 6512549
Filing Date: 2003-01-28
Classification: H04N

Abstract:
A focus detection apparatus comprising:(A) a plurality of band-pass filters for extracting predetermined frequency components from an image pickup signal, (B) switching means for switching said plurality of band pass filters, wherein said switching means switches said plurality of band-pass filters in correspondence with a frequency of the horizontal synchronization signal; (C) horizontal peak hold means for holding a peak value of an output from the band-pass filter selected by said switching means in synchronism with a horizontal synchronization signal; (D) vertical peak hold means for holding peak values of an output from said horizontal peak hold means corresponding to each of said band-pass filters in a vertical direction in synchronism with the horizontal synchronization signal of a video signal, wherein said vertical peak hold means switches a plurality of vertical peak hold circuits to be interlocked with switching of said plurality of band-pass filters in synchronism with the horizontal synchronization signal; and (E) focus detection means for detecting a focusing state on the basis of the outputs from said horizontal and vertical peak hold means.