| 摘要 |
<p>PURPOSE:To avoid deviation in a center focus when the amplitude of a modulation wave is changed by providing a clip circuit between a modulation waveform generating circuit for dynamic focus and a capacitor connecting to the center focus. CONSTITUTION:A clip circuit 2 clipping a modulation waveform at a level is provided between a modulation wave generating circuit 1 and a coupling capacitor Cl(3). When a parabolic waveform outputted from the waveform generating circuit 1 is given to the clip circuit 2, the upper portion of the waveform is clipped when the level is large. Thus, a change in a center part of the parabolic waveform is extremely decreased. Thus, even when the level of the modulation waveform is changed, the deviation in the level of the center DC focus is avoided and the focus is simply adjusted.</p> |
