| 摘要 |
<p>A power source to drive a deflecting output unit is fixed, thereby simplifying so that it is possible to cope with two or more different horizontal frequencies. A resonance capacitor 4a and an auxiliary resonance capacitor 4b are serially connected and a variable capacitive switching element 7 to short-circuit the capacitor 4b is connected. When a tracing period changes from Tt to Tt' (Tt < Tt') in correspondence to a change from a first horizontal frequency on the high side to a second horizontal frequency on the low side, by turning on the variable capacitive switching element 7, the capacitor 4b is short-circuited and a capacitance is increased from C1 C1'/(C1 + C1') to C1, thereby enabling (Tr' =Tr Tt'/Tt) to be satisfied. Even when a fixed power source is used, a voltage of a retrace pulse does not change and a fluctuation of another voltage such as an anode voltage or the like which is formed from the retrace pulse can be prevented. <IMAGE></p> |
