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 includes 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 .