Focusing and focal width adjuster for video camera with zoom lens produces time window which is supplied to focusing circuit and zoom control circuit to provide vertical scanning gap of video signal

摘要

From the vertical synchronizing impulse which is obtained as a direct signal from the camera electronics or is extracted from the video signal through an extraction circuit a time window is produced which is supplied to the focusing circuit (1-4) and the zoom control circuit. The focusing circuit supplies the generated focus signal to the piezoelectric actor of the drive device and the zoom control circuit supplies the focal width adjusting signal to the zoom drive only within the vertical scanning gap indicated by the time window. The focusing circuit has a micro processor (1,4) which produces the input signal for the electronic potentiometer (3) as a multi-bit signal.