Toshiyasu Oue

Effects of Wall Charge on Firing Voltage and Statistical Delay Time in Alternating-Current Plasma Display Panels

The effects of wall charge on firing voltage, Vf, and the statistical delay time of discharge, ts, in plasma display panels were investigated. Vf, i.e., the ion-induced secondary electron emission, is independent of both the polarity and amount of wall charge. In contrast, ts, i.e., the exoelectron emission, strongly depends on the wall charge and is smaller for a high positive wall charge, revealing the coexistence of trapped electrons and holes in the surface region. Positive charging of the MgO surface of the cathode side is effective to improve the response of the address discharge.

Accumulation and Decay Characteristics of Exoelectron Sources at MgO Protective Layer Surface in Alternating-Current Plasma Display Panels

The accumulation and decay characteristics of exoelectron sources at a MgO protective layer surface in alternating-current plasma display panels (AC-PDPs) were investigated. The positively charged MgO surface provides a larger number of exoelectrons than the negatively charged surface, indicating that electrons trapped in shallow carrier traps coexist with trapped holes, and exoelectrons are emitted through Auger and/or photoionization processes after their recombination. The exoelectron sources are accumulated by sustain discharges and always decay. The halflife of the decay of the exoelectron sources is relatively long, of the order of a few tens of ms, confirming that the exoelectron emission property at the address discharge in a certain television (TV) field is strongly affected by sustain firings in the previous two TV fields or more. The effects of such a long-term decay of the exoelectron sources should be taken into consideration when designing the driving waveforms of AC-PDPs. # 2010 The Japan Society of Applied Physics

Improvement in Discharge Delay Time by Accumulating Positive Wall Charges on Cathode MgO Protective Layer Surface in Alternating-Current Plasma Display Panels

The improvement in discharge delay time by accumulating positive wall charges on a cathode MgO protective layer surface in plasma display panels (PDPs) was investigated. The number of exoelectrons emitted from the cathode MgO surface, which trigger the discharge, increases with the accumulation of positive wall charges on the cathode MgO surface, thereby reducing both the statistical and formative delay times, ts and tf, respectively, of the address discharge. The correlations between exoelectron emission and ts and tf were investigated, revealing that the address discharge is triggered by multiple exoelectrons. In addition, it is found that exoelectron emission plays an important role in wall charge leakage during the address period. The present results confirmed that the accumulation of positive wall charges on the cathode MgO protective layer surface is effective for improving the discharge delay times ts and tf in not only PDPs but also common dielectric barrier discharge.