| 摘要 |
PURPOSE:To obtain a stable gate pulse by preparing signals to set a timing of gate pulse's first and last transitions after dividing a reference color subcarrier wave through a divider on the basis of horizontal scanning reference pulse. CONSTITUTION:A phase inversion circuit 43 outputs the reference color subcarrier wave fsc by inverting its phase every each horizontal cycle and its fsc is added to the divider 44. Furthermore, a horizontal phase detecting circuit 45 performs a phase detection of a saw-tooth-wave SAW obtained out of a flight-back-trans 50's pulse as well as a complex synchronizing signal CS. And in a reset pulse producing circuit 46; when a base potential of transistor Q7 becomes higher than that of transistor Q6, a reset pulse RSP will transit and is inputted to reset terminals of the divider 44 and a gate circuit G7. Accordingly gate circuits G10 and G11 decide a rising time t1 of the gate pulse GP and a dividing output inputting in a gate circuit G5 will determine a rising time t2 of the gate pulse GP.
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