Black level correction circuit for video camera

摘要

A circuit for cancelling the effects of dark current in a video camera by making a correction such that there is no variation in the black level values produced when the gain of a video amplifier for amplifying an image pick-up output is switched between high and low levels in the dark condition. Provision is made to provide correction when the camera is in the stabilized state and also to detect whether a corrected black level value falls within a clip level, typically found in the video amplifier system, in order to obtain proper black level correction.