| 摘要 |
PROBLEM TO BE SOLVED: To provide a synchronous signal separation circuit which certainly separates synchronous signals from signals having a large amount of noises such as weak electrical field signals, ghost-attached signals, and nonstandard signals (particular reproduction of a VTR). SOLUTION: A sink chip level is detected from luminance signals by a minimal level detector 5, and a pedestal level is detected from a pedestal level detector 6 to output these level signals, respectively. A synchronous signal amplitude value abnormality detecting circuit 7 outputs proper range judging signals that show whether a synchronous signal amplitude value that is obtained by level difference between the pedestal level and the sink chip level is within a proper range. Further, an intermediate slice level generator 3 generates an intermediate value between the pedestal level and the sink chip level to output an intermediate new slice level when the proper range judging signals shows that the synchronous signal amplitude value is within the proper range, while outputting immediately previous intermediate slice level as the slice level of the synchronous signal separation circuit 2 when the synchronous signal amplitude value is not within the proper range. COPYRIGHT: (C)2005,JPO&NCIPI
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