FOCUSING DEVICE OF TELEVISION CAMERA OBJECT GLAS

摘要

PURPOSE: To optimize focusing in a short time for every substantial position of an objective lens by using an illuminance signal or a green signal of the entire band without a direct current component as a video signal. CONSTITUTION: A television camera 1 is provided with a zoom objective lens 2, the illuminance signal Y or the green signal G is led out as video signal and supplied to an image region selecting circuit 3. A direct current voltage component of the video signal is removed by a capacitor, and the signal is supplied to a terminal 4. In this case, a microcomputer 8 is programmed to transmit a focusing signal for the lens 2 with a line 9 for adjusting an optimal image sharpness by controlling a lens adjuster of the lens 2. Consequently, focusing is optimized in a short time for every substantial position of the lens 2.