Color burst automatic detection device

摘要

A synchronization separation circuit extracts a synchronization timing signal from a video signal, and a burst gate pulse generator generates a timing pulse signal for gating a color burst signal period. In the color burst signal period restricted by the timing pulse signal, a first counter counts up cycles of a color burst signal at a first timing as a rising edge of the color burst signal and a second counter counts up cycles of the color burst signal at a second timing as a falling edge of the color burst signal. A color burst determination circuit receives count values to determine presence/absence of a color burst signal superimposed on the video signal.