| 摘要 |
PURPOSE:To obtain an exact color difference signal without controlling the phase of the line switch of fH/2, by deciding the polarity of an R-Y axis component of a burst signal, and that of a chrominance subcarrier provided to the R-Y demodulator, by means of the phase discriminator, and switching and inverting the static switch at the time of inconformity of the polarities. CONSTITUTION:A chrominance signal whose polarity is inverted to the R-Y axis at every 1 horizontal scanning line is provided to the R-Y demodulator 6, and the first switch 13 for inverting at every scanning line the polarity of a chrominance subcarrier for R-Y demodulation provided to the demodulator 6 is installed. Also, the second switch of static type 17 is provided by cascading it to the switch 13, and it is switched when matching the polarity of the chrominance subcarrier from the chrominance subcarrier 22 for demodulation and the demodulation polarity. The polarity of a burst signal which has been added to the chrominance signal, and that of the chrominance subcarrier for demodulation are decided by the phase discriminator 19, and when the polarity of an R-Y axis component of the burst signal does not coincide with that of the chrominance subcarrier provided to the demodulator 6, the switch 17 is swithced so as to be inverted by the FF18, and an exact R-Y color difference signal is output. |
