The Characteristics of CLHS Driving for High Luminance Efficiency in AC PDP

This paper proposes a CLHS (Capacitor Less Half Sustain) driving method that is applied to a long gap panel to reduce the power consumption. In order to reduce the power consumption in moving images, the luminous efficiency should be improved at the low discharge load (<25%). The weight of reactive power consumption tends to increase as the low discharge load decreases. Thus, it is very important to improve the luminous efficiency at low discharge load. It is well known that a long gap panel improves the luminance and the luminous efficiency but it is very difficult to drive the panel due to high driving voltage. It is confirmed that the main factors which cause a long gap panel to increase the minimum driving voltages are not only a long discharge gap but also self-erasing discharge. Self-erasing discharge is generated between the address and sustain electrodes in a sustain period. The CLHS driving method can reduce the reactive power consumption in a sustain period because energy recovery capacitors were removed in the sustain circuit. The CLHS driving method can reduce the minimum driving voltage of the long gap panel because the self-erasing discharge was prevented. When the CLHS driving method was applied to the panel with an ITO gap of 100 µm, V_S and V_A minimum voltages are reduced by about 9 V and 12 V compared with those of the normal driving method. The luminance and the luminous efficiency also increased by about 24.3% and 33.3% at the discharge load of 4% compared with those at the normal condition.