| 摘要 |
PROBLEM TO BE SOLVED: To allow a safe and stable switching operation of a deflection circuit without an overcurrent in a PWM circuit when an input frequency changes or the like. SOLUTION: When a frequency of a horizontal synchronizing signal changes, a discriminating signal showing the point of the change is delayed by a delay circuit 113, and during this operation, until a horizontal oscillating pulse synchronized with the horizontal synchronizing signal outputted from an oscillation circuit 104 is stabilized, the capacitances of S-shaped correction capacitors 107, 108 and 109 remain large so that a deflecting current from a horizontal output circuit 103 can be reduced and no overcurrent flows to a PWM circuit 101. Besides, corresponding to the discriminating signal delayed by the delay circuit 113, a control circuit 14 performs switching to the S-shaped correction capacitor for performing the optimum distortion correction after the stabilization of the horizontal oscillating pulse so that no overcurrent flows to the PWM circuit 101 and switching operation is performed stably and safely. |
