Patent ID: 6809712
Filing Date: 2004-10-26
Classification: G09G

Abstract:
A drive circuit of an active-matrix type liquid crystal display (LCD), for supplying a picture signal, whose polarity is alternately changed like an alternating current, to each electrode of liquid crystal elements of the LCD, comprising:a clip circuit for clipping the amplitude range of the voltage of the picture signal input from an input terminal; a polarity inversion circuit for receiving the picture signal whose amplitude range was clipped by the clip circuit, and for converting the picture signal so that an inverted signal and a non-inverted signal are alternately assigned to each dot; and a video amplifier for amplifying the voltage level of the converted picture signal by a predetermined amplification degrees wherein the clip circuit comprises two serially connected diodes, and predetermined control voltages are respectively applied to the cathode of one of the two diodes and the anode of the other diode, and the contact between the two diodes is connected to an input terminal of the polarity inversion circuit.