LIQUID CRYSTAL DISPLAY DRIVE CIRCUIT WHICH CAN DRIVE NORMALLY WHITE TYPE LIQUID CRYSTAL PANEL AND NORMALLY BLACK TYPE LIQUID CRYSTAL PANEL

摘要

PURPOSE: To provide a liquid crystal drive circuit which is capable of reducing power and also is capable of simplifying of the circuit constitution. CONSTITUTION: In this liquid crystal drive circuit, a first amplifier group 310, 330 accepts the negative-polarity video signal subjected to a conversion processing or the positive-polarity video signal subjected to the conversion processing and a second amplifier group 320, 340 accepts the positive-polarity video signal when the first amplifier group 310, 330 accepts the negative-polarity video signal and accepts the negative-polarity video signal when the first amplifier group 310, 330 accepts the positive-polarity video signal. A first bias voltage source 352 generates a first bias voltage and a second bias voltage source 353 generates a second bias voltage. A bias switch 351 applies the first bias voltage or the second bias voltage to the first group 310, 330 and supplies the second bias voltage to the second group 320, 340 when the first bias voltage is applied to the first group 310, 330 and, also, applies the first bias voltage to the second group 320, 340 when the second bias voltage is applied to the first group 310, 330.