Capacitive load charge-discharge device and liquid crystal display device having the same

Abstract

A pixel charge-discharge circuit charges and discharges a series circuit of a capacitor by alternately connecting two types of auxiliary capacitance wires to a high voltage source and a low voltage source by using four types of switches. The high voltage source and the low voltage source are positive voltage sources, and a potential of the high voltage source is greater than that of the low voltage source. The low voltage source serving as a sink-current-flowing voltage source includes a stored energy adjustment section. The stored energy adjustment section discharges electrostatic energy from the high voltage source by turning ON and OFF two types of switches and causes the electrostatic energy to be balanced by energy supplied from the series circuit. In this way, a capacitive load charge-discharge device can be achieved which uses homopolar voltage sources as both a high voltage source and a low voltage source and is capable of stabilizing a constant voltage function of each of the voltage sources, while generating less heat, when a capacitive load is charged and discharged by alternately reversing the direction of a current.