Focus circuit for multi-tube image pick-up apparatus

摘要

In a multi-tube image pick-up apparatus, such as, a color television camera, having image pick-up tubes of the electro-magnetic focusing type with their respective focusing coils connected in series with each other for minimizing the power consumption thereof; a main focus current control circuit is connected in series with the series-connected focusing coils for controlling a main focus current so as to maintain an adjustably predetermined value thereof, and individual focus current control circuits respectively corresponding to the image pick-up tubes are connected in parallel with the respective focusing coils for controlling the individual focus current flowing through each of the focusing coils without influencing the individual focus currents through the other coils.