| 摘要 |
A control circuit for controlling an output phase of a video signal is comprised of a variable type phase shifting circuit for phase-shifting the video signal by a designated phase shifting amount and a fixed type phase shifting circuit for phase-shifting the video signal by a constant phase shifting amount. A signal switch selects video signals from the designated and fixed type phase shifting circuits. The video signal from the fixed type phase shifting circuit is selected only during a predetermined period including at least ancillary data while the video signal from the variable type phase shifting circuit is utilized during other period. Thus, the ancillary data is constantly extracted from the video signal which is phase-shifted by the constant phase-shifting amount so that the inserting position of the ancillary data is not changed, regardless of the output phase amount. Thereby the ancillary data is extracted reliably. In other words, even when the output phase amount is varied, the position of the ancillary data inserted into the video signal can be prevented from being changed.
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