TV camera system comparing line sync. pulse phase - generates raster reset pulse for counter in camera head driven by line frequency oscillator for synchronisation

摘要

Video signals (5) from a camera head (1) are conveyed by a cable (3) of unknown length to a control unit (2) for processing by a line and field sync. separator (6), field locking circuit (8) and phase comparator (7). Line sync. pulses from the head (1) and clock generator (9) are compared, and a correction voltage (UPh) is added (16) to a raster reset pulse (RR) for feedback (11) to the line timebase generator (12). USE/ADVANTAGE - Esp. for high-definition TV. Compensation for both line and field rate phase delays is feasible for any length of cable between camera head and control unit.