| 摘要 |
A dropout compensation system used with a video tape recorder, video disc, etc. is disclosed. In conventional modulation systems, a reproduced signal which has been modulated in a modulation system in which the signal information is determined by the zero passage of the carrier, is delayed in the form of the modulated signal, and if a dropout occurs, the reproduced signal is switched to the delayed signal by a first switch thereby to compensate for the dropout. The phase of the modulated signal becomes discontinuous each time the switch is operated, thus causing an offensive spark-like interference upon demodulation. The invention is intended for reducing these noises and comprises a second demodulator for normally demodulating the delayed signal and a second switch operated at a different timing from the first switch in response to the dropout. The noise is extracted by the operation of the second switch and the extracted noise is cancelled by being combined at opposite polarity with the demodulated reproduced signal, which signal contains the noise but has been compensated for the dropout. A noise-removing circuit utilizing the horizontal correlation of the TV signal may be easily added to the configuration of the present invention.
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