PURPOSE: To prevent a rectangular wave between the collector and emitter of a horizontal driving transistor (TR) from having a whisker and make the operation of a horizontal output TR perfect by providing a double integration circuit between the collector and emitter of the horizontal driving TR.

CONSTITUTION: The 1st integration circuit composed of a resistance 4 and a capacitor 5 and the 2nd integration circuit composed of a capacitor 13 are both provided between the collector and emitter of the horizontal driving TR3. This capacitor 13 has a different function from the 1st integration circuit (4, 5) and its numeral is determined (e.g. 560PF) so as to have high integration effect in a relatively high frequency range. Consequently, the voltage between the collector and emitter of the horizontal output driving TR has no whisker and a thermal runaway phenomenon is prevented completely.