Patent ID: 6628274
Filing Date: 2003-09-30
Classification: G09G,H03F

Abstract:
A display drive apparatus for driving liquid crystals by applying a voltage to the liquid crystals based on gray-scale data representative of a display, the apparatus comprising:a polarity control circuit that generates a polarity control signal based on a polarity signal; an input selection circuit that selects a predetermined reference voltage for driving the liquid crystals from a plurality of reference voltages provided from an input voltage generation circuit or a plurality of reference voltages generated within the input selection circuit based on an input signal representative of gray-scale data and the polarity control signal; a non-linear operation region identifying circuit that identifies a non-linear operation region in which an output signal from an operational amplifier does not follow an input thereto based on the input signal and the polarity control signal, and outputs an offset current generation control signal for supplementing the current of the output signal of the operational amplifier when an input voltage in the non-linear operation region is subjected to an operation amplification, wherein the operational amplifier inputs the predetermined reference voltage selected by the input selection circuit and outputs at an output terminal an output signal that is operation-amplified according to the predetermined reference voltage; and an offset current generation circuit that supplements the current at the output terminal of the operational amplifier based on the offset current generation control signal outputted from the non-linear operation region identifying circuit.