Patent ID: 8022971

Claim:
A data driver for driving a data line, the data driver comprising: a data signal generator having channels and being configured to generate a data signal, each channel of the data signal generator being provided with a first digital-to-analog converter and a second digital-to-analog converter; and a buffer unit that receives the data signal from the data signal generator, the buffer unit providing the data signal to the data line, wherein: the first digital-to-analog converter is configured to select first and second reference voltages from among a plurality of reference voltages depending on upper bits of data: the second digital-to-analog converter is configured to divide the first and second reference voltages into a plurality of voltages and supply tiny one voltage of the first and second reference voltages and the divided voltages to an output terminal as the data signal depending on lower bits of the data, the second digital-to-analog converter including a second switch and a capacitor, the second switch is coupled between one of the first reference voltage and a first electrode of the capacitor, the second switch receiving the first reference voltage and being configured to selectively couple the first reference voltage to the first electrode of the capacitor, the first electrode of the capacitor is coupled to the output terminal, and the output terminal is coupled to the buffer unit, such that the output terminal is between the first electrode and the buffer unit, a second electrode of the capacitor is coupled to a variation voltage, the variation voltage being received from a source external to the second digital-to-analog converter and varying a voltage of the capacitor that is applied to the output terminal, the second reference voltage has a voltage higher than the first reference voltage, the second digital-to-analog converter is configured to supply an intermediate gray scale voltage to the output terminal prior to supplying the data signal, the intermediate gray scale voltage being controlled by the variation voltage and having a voltage between the first and second reference voltages, and the second digital-to-analog converter is configured to supply the first reference voltage to the output terminal, without passing the first reference voltage through a voltage divider, the variation voltage that is supplied to the second electrode of the capacitor being varied so as to vary the first reference voltage at the output terminal.