PURPOSE: To reduce the noise component of the rise part of a signal and to obtain a horizontal output pulse with less jitter by switching the polarity of the horizontal output pulse from a comparator in accordance with a switching signal for oscillation signal in a horizontal oscillation circuit.

CONSTITUTION: When a sawtooth wave is generated in a point A and the reference voltage level of a reference power source 16 in the comparator 13 is set to prescribed level, the horizontal output pulse is generated at the output terminal of the comparator 13. When the voltage of a point D is considerably lower (L-level) than reference voltage (+Vcc), and a transistor 19 in a horizontal output pulse generation circuit 17 is turned on, the inverse signal of the output signal of the comparator 13 is generated at a point E. Then, the voltage of the point D becomes an 'H' level, the transistor 19 is turned off and the voltage of the point E is forcibly set to be the 'L' level. Thus, the horizontal output pulse can be generated by the fall timing of the switching signal obtained at the point D can be generated by the horizontal output pulse generation circuit 17.