Voltage Margin and Luminous Efficiency by Changing Positive and Negative Sustain Voltage in AC Plasma Display Panel

In the AC PDP, drive waveforms are applied to three electrodes, respectively, and positive voltages are alternately used for the two electrodes during the sustain period. When the driving waveforms of two electrodes are corrected in the state where one of the three electrodes is grounded for the low cost of the driving circuit, positive and negative voltages are alternately applied to only one electrode during the sustain period, and an asymmetric discharge is generated differently from the conventional case. An asymmetric discharge indicates a strong discharge once, followed by a weak discharge. It was observed that a strong discharge occurred when negative voltage was applied and a weak discharge occurred when positive voltage was applied. When a positive voltage is applied, the potential difference between the three electrodes is the same as in the conventional case. However, when a negative voltage is applied, the voltage also affects the write electrode, so that the discharge becomes strong. Asymmetric discharges decrease the margin and efficiency of the sustain voltage, so that a symmetrical discharge must be generated. In order to generate the symmetric discharge, we proposed a method of applying positive and negative voltage heights and slopes of the waveform differently, and obtained voltage margin and efficiency similar to the conventional one.