| 摘要 |
PURPOSE:To exactly obtain an R-Y 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 inverting the static switch only in case of inconformity of the polarities. CONSTITUTION:This equipment is provided with the first switch 12 which is inverted at every 1 horizontal scanning of a chrominance signal of PAL system, and the second static switch 16 which is switched when matching the R-Y demodulation polarity of the polarity relating to its R-Y axis, and the output of this switch 16 is provided to the R-Y demodulator 6. Also, a chrominance subcarrier of the R-Y axis from the subcarrier oscillator 26 is provided to the demodulator 6 by synchronizing with a burst signal which has been added to the chrominance signal, and the polarity of the chrominance subcarrier provided to this demodulator 6, and that of the chrominance signal are decided by the phase discriminator 23. The switch 16 is inverted by the FF17 at the time of inconformity of the polarities, so that the R-Y color difference signal can be obtained exactly without controlling the phase of the line switch of fH/2. |
