Discharge characteristics in overlap scan waveforms are studied for lowering the write voltage in AC type plasma displays panel. The write discharge during the write period of the AC PDP occurs when negative pulses are applied to several hundreds of scan lines in time and a positive pulse is selectively applied to the write electrode. As the scan and write pulse widths during the write period are determined by the delay time of the write discharge, a high write voltage is typically used to stably generate the discharge within the pulse width. However, a high write voltage induces the high power consumption and causes the low efficiency of the AC PDP. Meanwhile, when the applied write voltage is decreased for the low power consumption, the discharge delay time will surely increase. If the pulse width of the scan electrode is increased so that the discharge occurs within the pulse width, the wall charge will be stably accumulated in a cell. Therefore, the widths of the write pulses are equal to the conventional time to make the same total write time, and overlapped waveforms in the scan lines are proposed by extending only the widths of the scanning pulses. Even if a low write voltage is applied, the discharge delay time will naturally be delayed, but the write discharge stably is occurred within the pulse width due to the long width of the scan pulse.