| 摘要 |
Apparatus for synchronising a plurality of independent video signal generators comprises a first input (12) for receiving field or frame synchronising signals from a first video signal generator, a second input (14) for receiving field or frame synchronising signals from a second video signal generator, a comparator (13) for comparing the phase of the first and second synchronisation signals, a master clock generator (1), a slave clock generator (4), the slave clock generator (4) having a frequency different from that of the master clock generator (1), means for applying the master clock signal to a first output (7) for application to the first video signal generator, means for applying the slave clock signal to a second output (9) for application to the second video signal generator, and means (5) for means for applying the master clock signal to the second output (9) in place of the slave clock signal when the synchronising signals from the first and second synchronising signals are in phase. A second comparator (3) is provided for comparing the phase of the master clock (1) and the slave clock (4) so that the operation of the means (5) for applying the master clock (1) to the second output (9) is dependent also on the master (1) and slave (4) clocks being in phase.
|
