Patent ID: 7443373

Claim:
A semiconductor device having a function of driving a gate line of a liquid crystal display panel, the device comprising: a polarity inverting circuit for inverting polarities of a positive voltage and a negative voltage for driving said gate line; a state setting circuit capable of changing and controlling, to a high-impedance state, an output circuit for driving said gate line; and at least one control terminal for controlling states of said polarity inverting circuit and said state setting circuit, wherein an inside or outside of the semiconductor device is provided with: a resistor network or a portion of said resistor network changing and controlling, to a positive voltage output and a high-impedance state or to a negative voltage output and a high-impedance state, outputs of a plurality of output terminals each driving said gate line; and a switch means capable of separating said resistor network or the portion of said resistor network at a time of an normal operation.