| 摘要 |
PURPOSE:To obtain a digital phase adjusting device stable for temperature or change with lapse of time by varying the phase of a sampling pulse signal in accordance with the phase difference between a burst signal and a digitized chrominance subcarrier. CONSTITUTION:An input analog video signal Pi is supplied to an A/D converter 51 and also supplied to a gate signal generating part 54 to generate a burst flag signal Bf. The burst flag signal Bf is applied to a gate circuit 53 and only burst signal is extracted from the digitized video signal. The extracted burst signal is stored in a memory 55 and phase compared with a sampling pulse from a sampling circuit 56 by a phase difference detecting circuit 57. The detected phase difference signal is supplied to a delay circuit 52 to delay the output of the A/D converter 51 and to obtain the phase difference within 90 deg.. When the phase difference is 90 deg. or less, the phase difference is removed by changing the phase of the sampling pulse. |
