| 摘要 |
PURPOSE:To increase the stability and reliability of carrier reproduction circuit, by digitally performing the correction of carrier reproduction even during the period of video information transmission. CONSTITUTION:The reference clock CLK 5 is frequency-divided with the frequency dividing ratio set with latch circuits 8, 7 at frequency-dividers 20a, 20b, to obtain the reproduction carrier 13. The phase of the carrier 13 starts delaying in comparison with the reception signal 14, and when the delay signal 16a is continuously produced from the phase comparison circuit 16, the switch 19 is switched and the frequency-dividing output S3 small in the frequency dividing ratio from the frequency-divider 20a is fed to the frequency divider 20b to advance the phase of the carrier 13. Inversely, when the phase of the carrier 13 is advanced, the switch 18 is open and the count operation of the frequency-divider 20a is stopped, allowing to make delay the phase of the carrier 13. |
