A system for creating a continuous signal in phase synchronization with a burst signal

摘要

1,258,486. Phase locked loops. MATSUSHITA ELECTRIC INDUSTRIAL CO. Ltd. 7 Oct., 1969 [12 Oct., 1968; 11 Nov., 1968 (2); 5 March, 1969; 5 Aug., 1969], No. 49296/69. Heading H3A. In a colour television receiver, the oscillator 25 for decoding colour signals is synchronized by comparing its output with the burst signal in a comparator 24 to provide a retroactive control signal and also by a further control signal derived from a circuit 28 which detects variations in the frequency of the synchronizing signal. The various units may be formed as transistor circuits, Fig. 6 (not shown), and the incoming signal at terminal 19 may be derived from a video tape, Fig. 8 (not shown). The frequency of oscillator 25 may be switched to a lower value for reproducing stills from the video tape.