Patent ID: 6628261
Filing Date: 2003-09-30
Classification: G09G

Abstract:
A liquid crystal display apparatus comprising:a plurality of switching elements arranged at intersections between a scanning line and a signal line; a scanning circuit for controlling a voltage of the scanning line; a first substrate having formed thereon a signal circuit for controlling a voltage of the signal line; a second substrate having a transparent electrode formed on one side thereof; a liquid crystal held between the first substrate and the second substrate; a first D/A converter which converts a digital video signal into a positive analog voltage; a second D/A converter which converts a digital Video signal into a negative analog voltage; a first drive circuit for driving the signal line by sampling the positive analog signal at a predetermined timing; and a second drive circuit supplied with a negative analog voltage for driving the signal line by sampling the negative analog voltage, wherein the first drive circuit comprises: a first sample/hold circuit for sampling the positive analog signal, a first comparator circuit for comparing an output of the first sample/hold circuit with the voltage of the signal line, a first switch for controlling the output voltage of the signal line, first voltage supply means for supplying a voltage to the first switch, and a first control circuit for controlling the first switch in accordance with an output of the first comparator circuit; and wherein the second drive circuit comprises: a second sample/hold circuit for sampling the negative analog voltage, a second comparator circuit for comparing an output of the second sample/hold circuit with the voltage of the signal line, a second switch for controlling the output voltage of the signal line, a second voltage supply means for supplying a voltage to the second switch, and a second control circuit for controlling the second switch in accordance with an output of the second comparator circuit.