Study On An Equivalent Circuit Model For SM-PDP

Plasma display panel(PDP) technology has achieved many excellent performances and it has been regarded as one of the best candidates for HDTV(high-definition television), a home entertainment terminal with very good display performance. PDP has many advantages, such as self-luminescent, store-effect, extreme non-linear electric characteristic, high luminance and luminance efficacy, comparatively simple structure, which make it suitable for large screen and high definition display application. Today, the surface discharge structure is widely adopted, which provides good display quality and has been put into mass production. However the surface discharge structure is still not the best one because of some problems and difficulties, the high fabrication cost and low luminance efficacy, for example. These problems are keeping PDP out of the common consumer market, the largest market area of all. Therefore, many research center and manufacturers keep studying the working principle of PDP and finding ways to optimize the structure with lower cost and higher luminance efficacy. The color motion pictures of PDP are generated by gas discharge with continent AC waveforms. The process is quite complicate and the size of each discharge cell is quite small. So it is very difficult to study by means of experimental measurement or direct-view. One fluid method is widely utilized that cam simulate the discharge process by computer calculation. However this method still has many limitations in studying the discharging process and cannot be handled by common engineers in PDP design. Therefore, the equivalent circuit model is presented. It is suitable for engineering application and can optimize the PDP driving system. Now most work focuses on developing practical equivalent circuit and simulating method for optimizing PDP driving circuit and driving scheme.After the analysis and comparison to the available PDP equivalent circuit models for the surface-discharge structure, the equivalent circuit model for SM-PDP has been proposed according to its special structure. In this model, capacitance is considered as the core component, thyristor is added to present the non-linear characteristic during discharge. The influence of the metal shadow mask on discharge was considered as well. A stable simulation environment and simulation process had been established. From the comparison of the practical drive waveforms to the simulation results, this model has been proved as a precise and reasonable one. Some modification was also proposed on this model to present the property during weak gas-discharge.With the equivalent circuit model of SM-PDP, the discharge characteristics have been further analyzed, including the relationship between the wall charge and the electrical characteristics during discharge, and the main factors to determine the sustain voltage margin with the WVIO curve of the wall voltage. Four main practical driving waveforms, including the sustain waveform, the erasing waveform, the address waveform and the priming waveform, were studied respectively based upon above results.With the equivalent circuit model of SM-PDP, the principle and importance of energy recovery circuit (ERC) can be clearly explained. The modification and optimization on ERC and the whole display systems have been presented as well. In the new driving system, the ramped priming waveform was introduced. The simulation of the new driving system was presented.