| 摘要 |
PURPOSE:To prevent the occurrence of a frequency fluctuation in a phase-locked point by providing a circuit that generates a detection current in a period when the output of a voltage controlled oscillator is shifted from the fixed width to a dividing signal in the phase-locked point. CONSTITUTION:As for a phase difference between a horizontal synchronizing pulse and the dividing signal of the voltage controlled oscillator, the polarity of the detection current is switched within a horizontal synchronizing period according to the position of the period at the circuits of transistors TRs 6-10. By changing the voltages of output terminal capacitors C1 and C2 in the circuit, a negative feedback loop as the control voltage of the voltage controlled oscillator is formed. A pulse having a fixed width to the dividing signal of the voltage controlled oscillator at the phase locked point of the output of the voltage controlled oscillator from a horizontal synchronizing pulse (a) is generated with a monostable multivibrator and a pulse signal generated in the period shifted from the phase locked point is generated at the circuit of TRs 15-20, thereby generating the detection current only in the period. |
