FLICKER INDEX METHOD FOR EVALUATING FLICKER IN COLOR PDPs

Objective In order to red uc e the flicker in color plasma display panel (PDP), the highly peaked light outpu t at certain positions and the strong luminance difference among subfields, whic h cause flicker in PDP, is analyzed; and a flicker index method is developed to evaluate flicker in PDP based on the flicker theory and the electroencephalograp h response model for luminance. Methods This method considers f licker as a main result of the fundamental frequency component of luminance supe rimposed on the DC-component, the flicker index is defined as ratio between the positive square roots of the sum of the two square components. Results & Conclusion The calculation results of flicker index indicate that flicker can be obviously weakened via increase of subfield number, symmetrical s election and homogeneous interlaced distribution of major weight subfields . Fli cker can be further reduced by choosing the suitable subfield order according to gray scale region of image.

Breakdown Voltage Research of Penning Gas Mixture in Plasma Display Panel

Paschen law and equations, which ignore the influence of the Penning ionization on the electron ionization coefficient （α）, are always used as the approximation of the breakdown voltage criterion of the Penning gas mixture in current researches of discharge characteristics of the plasma display panel （PDP）. It is doubtful that whether their results match the facts. Based on the Townsend gas self-sustaining discharge condition and the chemical kinetics analysis of the Penning gas mixture discharging in PDP, the empirical equation to describe the breakdown of the Penning gas mixture is given. It is used to calculate the breakdown voltage curves of Ne-Xe/MgO and Ne-Ar/MgO in a testing macroscopic discharge cell of AC-PDP. The effective secondary electron emission coefficients （γeff） of the MgO protective layers are derived by comparing the breakdown voltage curves obtained from the empirical equation with the experimental data of breakdown voltages. In comparison with the results calculated by the Paschen law and the equation which ignore the influence of the Penning ionization on α , the results calculated by the empirical equation have better conformity with experimental data. The empirical equation characterizes the breakdown of the Penning gas mixture in PDP effectively, and gives a convenient way to study its breakdown characteristics and the secondary electron emission behaviors.

Effects of Linear Falling Ramp Reset Pulse on Addressing Operation in AC PDP

The effects of linear falling ramp reset pulse related to addressing operation in an alternating current plasma display panel （AC PDP） were studied. The wall charge waveforms were measured by the electrode balance method in a 12-inch coplanar AC PDP. The wall charge waveforms show the relationship between the slope ratio of the falling ramp reset pulse and the wall charges at the end of the falling ramp reset pulse which influences the addressing stability. Then the effects of the slope ratio of the linear falling ramp reset pulse on the addressing voltage and addressing time were investigated. The experimental results show that the minimum addressing voltage increases with the increase of the slope ratio of the falling ramp reset pulse, and so does the minimum addressing time. Based on the experimental results, the optimization of the addressing time and the slope ratio of the falling ramp pulse is discussed.

New red phosphor (Y,Gd,Lu)BO_3:Eu^(3+) for PDP applications

Highly efficient phosphors under vacuum ultraviolet excitation are still demanded for the development of plasma display panels and Hg-free fluorescent lamps. The phosphors of Eu3＋ doped （Y, Gd, Lu）BO3 were synthesized with solid state reaction method and the contents of y3＋ Gd3＋, and Lu3＋ for plasma display panel red phosphor were optimized under vacuum ultraviolet excitation. Two new potential candidates, which were （Y1-S-TGdsLuT）BO3： Eu^3＋ （0〈S〈0.2, 0〈T〈0.1） and （GdlYJLuK）BO3： Eu3＋ （0.5〈I〈0.7, 0.2〈J〈0.4, 0〈K〈0.1）, were olgtained. The mechanism of luminescence improvement was discussed upon the analysis of crystal microstructure and excitation spectra.