Source driver circuit of liquid crystal display device

Abstract

Provided is a technology for preventing noisy data from being displayed before valid data is inputted when power is turned on in a liquid crystal display. A source driver circuit for a liquid crystal display includes: a power supply voltage input unit configured to divide a first power supply voltage and a second power supply voltage, such that a middle level of the second power supply voltage is lower than a level of the first power supply voltage; a power supply voltage comparison unit configured to compare division voltages inputted from the power supply voltage input unit, and output an output voltage of a high level in a time period in which the middle level of the second power supply voltage is higher than the level of the first power supply voltage; a Schmitt trigger configured to output the output voltage of the power supply voltage comparison unit as a reset signal while preventing a sensitive response to external environment; and a specific voltage supply unit configured to output a voltage of a specific level in a time period between the input of the reset signal from the Schmitt trigger and the input of a first gate start pulse.