| 摘要 |
A color subcarrier reproducing circuit reproduces a color subcarrier on the basis of a color burst signal in a color television signal in which phase reference data synchronized with the color burst signal is inserted in a predetermined position in a vertical blanking period, and provides a first clock signal whose frequency is equal to the frequency of the color subcarrier and a second clock signal whose frequency is four times the subcarrier frequency. The second clock signal is frequency-divided by first and second frequency dividers to produce a reproduced horizontal sync signal, and frequency-divided by first and third frequency dividers to produce a reproduced vertical sync signal. A phase reference data reproducing circuit reproduces the phase reference data from the color television signal using the first clock signal as a sampling signal. On detecting that the phase reference data reproduced by the phase reference data reproducing circuit has a predetermined pattern, a pattern detecting circuit resets the first to third frequency dividers, thereby keeping the phases of the horizontal and vertical sync signals in sync with the phase reference data.
|
