Analysis of microdischarge characteristics induced by synchronized auxiliary address pulse based on cross-sectional infrared observation in AC plasma display panel

The microdischarge characteristics induced by an auxiliary address pulse with the synchronized application of sustain pulses are investigated based on cross-sectional infrared (IR) (823 nm) observations taken using an image-intensified charge-coupled device (ICCD) camera. The IR observations reveal that the application of an auxiliary short pulse with an optimal amplitude and width to the address electrode enhances the intensity of the IR emission. Furthermore, the cross-sectional IR observations demonstrate that the effective infrared emission region is extended toward the address electrode. In addition, a numerical analysis using a two-dimensional fluid simulation is also applied to investigate the discharge mechanism relative to the amplitude and width of the auxiliary address pulse. As a result, the improvement in the luminance and luminous efficiency was found to be caused by a face discharge between the address and the sustain (or scan) electrodes, where the face discharge plays an important role in supplying priming particles to the surface discharge and lengthening the discharge path, which in turn intensifies the surface discharge.

I. Introduction

Despite the suitability of flat panel devices for digital high-definition television, the luminous efficiency of plasma display panels (PDPs) is still low. Yet, improving the luminous efficiency of a PDP is very difficult, because the spacing between the PDP cells are too small to produce an efficient discharge. Moreover, in a typical three-electrode PDP structure with coplanar sustain electrodes, the discharge volume is predominantly formed in the vicinity of the surface of the front panel (called a surface discharge), resulting in a small discharge volume and inefficient use of the phosphor layer deposited on the address electrode. Therefore, enlarging the discharge volume toward the address electrode would be expected to improve the discharge efficiency and use of the phosphor layer, thereby improving the luminance and luminous efficiency of the PDP cells with a small spacing. As such, the current authors previously reported that the synchronized application of an auxiliary short pulse to the address electrode during the sustain period did have an impact on improving the luminance and luminous efficiency in an alternating current plasma display panel (ac-PDP) [1], [2]. Recently, several research results on the analysis of the changes in the micro-discharge characteristics according to the application of various auxiliary address pulses have been reported based on direct measurement of the microdischarge volume [3], [4]. However, direct observation of the microdischarge phenomena, particularly a cross-sectional view, with respect to the use of a synchronized auxiliary pulse is still needed to gain a better understanding of the fundamental discharge physics to improve the luminance and luminous efficiency of the microdischarge cells.