| 摘要 |
PROBLEM TO BE SOLVED: To improve reactive power recovering efficiency at a low cost without adversely affecting a gas discharge characteristic by forming the potential difference between a scanning electrode and a maintenance electrode to a waveform changing first at the edge on the side where a gas discharge is generated and gently at the edge on a side where the gas discharge is not generated. SOLUTION: The second maintenance pulse to be impressed on the scanning electrode Yi and the first maintenance pulse to be impressed to the maintenance electrode X are so formed as to overlap partly on each other on a time base. In other words, the output period p2 of the second maintenance pulse and the output period p1 of the first maintenance pulse are in the state of partly overlapping on each other. The inductance Lv constituting the reactive power recovering circuit on the side where the maintenance rises first is set relatively small to make both of the voltage changing rates on the rise and fall side of the second maintenance pulse (b) fast. The inductance Lv is set relatively large on the side rising afterward to make both of the voltage changing rates on the rising and falling side of the first maintenance pulse slow. |
