Centering unit for a color television camera apparatus having plural pick-up tubes

摘要

In an automatic centering unit for a color television camera, a signal representing a phase-difference between video signals of different color channels is picked up to produce a correction voltage only when correlation of video signals exists for each selected discrete area on the television screen between predetermined time points having an interval of time of at least a frame period, so that the centering unit allows an accurate and quick operation even if focusing is not sufficient or if noise is contained in the video signal.