| 摘要 |
PURPOSE:To keep properly the inversion state of a PAL phase by comparing a selection output of a selecting means for introducing alternatively an output signal of a PAL phase inverting means and a chroma component of an input signal with a signal showing a normal PAL phase inversion state and by switching the selection state at the time of dissidence of said output and the signal. CONSTITUTION:A chroma input signal (b) and a signal (c) obtained by PAL phase inverting the signal (b) by means of a PAL phase invertor 1 are impressed to a switch 2. An output (k) is introduced as a corrected chroma signal and its phase is compared with that of a reference subcarrier in a PD (phase comparator) 3. The compared output (d) is extracted by a switch 4 only for a burst period and turns out to be a clock input of a D-FF (delayed flip-flop) 6 through a level comparator 5, while a signal level of a reference PAL pulse (g) is latched. The reference PAL pulse (g) denotes the normal PAL phase inversion state of a chroma signal and a binary level signal having one horizontal period. An output (h) of the D-FF6 and the pulse (g) becomes a clock input of an FF8, and a Q output (j) controls the switch 2.
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