Oscillator circuit suitable for picture-in-picture system.

摘要

Disclosed herein is an oscillator circuit used for a PIP system which displays a child picture image without distortion even when the image method of the child picture image is different from that of a parent picture image. The oscillator circuit employed in such a system comprises a programmable frequency divider for frequency dividing an output of a voltage-controlled oscillator with a frequency dividing ratio to produce a frequency-divided signal and a control circuit for controlling the oscillation frequency of the oscillator 201 according to a phase difference between the frequency-divided signal and a horizontal synchronizing signal. The frequency dividing ratio for the frequency divider is changed according to the image method of the child picture image. <IMAGE>