Low Cost Plasma Display Panel

ABSTRACT

Plasma Display Panel (PDP) is a very new technology for digital entertainment presently ruling the market, although it is very expensive. Most of the expense in the cast is due to the driver circuit which uses high voltage switching devices (since it uses an H-bridge driver). Here a new technique is presented wherein a cost effective PDP sustainer can be used. It uses a voltage balancing technique by which the driver cost can be reduced by 20%-30% as compared with that of the conventional H-bridge driver by using low voltage switches. The energy that is used is recovered also by using the current injection method (CIM). Here the current is build up before the energy recovery operations. The polarity of the panel electrode should be changed, and the build up current in the inductor is used to change the panel polarity of the panel electrode, this will improve the energy recovery operations. Here the final output light can also be improved and be made more stable by independently controlling the rising and falling slopes of the sustain voltages. Hence this technique can create a low cost PDP.

Introduction

Nowadays, digital televisions are becoming very popular, because of certain new technologies and trends in the entertainment market like the Home Theatre Systems, DTH systems. Different types of digital displays have been developed, but the display that rules over other displays is the Plasma Display Panel (PDP), since it has many advantages over other forms of displays such as its

· Wide view angle

· Large screen

· High brightness

· Thinness

· Portability

Which are very hard to find in other displays. Due to its great advantages it is expected to make a huge deal in the display market, but because of its biggest disadvantage it does not even move out of the stores, which is its cost. It is very expensive to attract customers. Hence this one issue must be solved.

Fig. 1 shows the simplified PDP structure with three electrodes. It consists of two glass plates with chemically stable rare gases filled between them. The scanning and sustaining electrodes are built on the front glass, which is coated with a dielectric layer and the addressing electrode is on the rear glass. A desired color light can be obtained by exciting

the phosphors on the addressing electrode to emit visible light with the ultraviolet photons generated by gas discharge

The operation of a PDP is divided into three periods of setup,

addressing, and sustaining periods. During the setup period, all

of the PDP cells are erased and prepared to carry out addressing

by forming adequate wall charges. After that, selective write

discharges to form an image are ignited by applying data and

scanning pulses to the addressing and scanning electrodes, respectively. Since addressing discharge itself emits an insufficient visible light, high-voltage ac square pulses are continuously applied between sustaining and scanning electrodes for strong light emission of selective cells. The high-voltage pulses can be generated using a simple full-bridge driver, as shown in Fig. 2, and most of the PDP power is consumed during this sustaining period. Since a dielectric layer is encrusted on sustaining and scanning electrodes, capacitance between two electrodes exits inherently. When a sustaining pulse is applied to electrodes, an amount of energy CpVs²is dissipated in switches and parasitic resistances of wire during charging and discharging transients, where Cp is panel capacitance and Vs is sustain voltage. If an average frequency of sustaining pulse is, then the total dissipated power is 2CpVsf² . Without proper methods to recover the energy, a large amount of surge current causes electromagnetic interference (EMI) and the heating problem of switching devices. To solve the problems, an energy recovery circuit (ERC) using the series LC resonant concept. It features high efficiency and good circuit flexibility to cope with various driving methods.