New Sustain Waveform for Improving Luminous Efficiency in Wide-Gap Plasma-Display Panel

The three-electrode microdischarge characteristics of ac-plasma-display panels (PDPs) are analyzed with a wide sustain discharge gap of 180 mum. In particular, the luminous efficiency variation is examined as a parameter of the operating frequency. It is found that the luminous efficiency decreases with an increase in the operating frequency. In other words, a failure discharge mode for luminous efficiency occurs at a high frequency up to 200 kHz, originating from a self-erasing discharge and the space-charge behavior under high sustaining frequency conditions. Thus, based on an analysis of the failure mode of a wide-gap discharge, a new sustain waveform is proposed to improve the luminous efficiency at a high operating frequency. As a result of adopting the proposed sustain waveform, a luminous efficiency of 2.4 lm/W is obtained at a sustain voltage of 170 V in a 42-in high-definition wide-gap PDP.