Patent ID: 7480164

Claim:
A display system comprising: a display panel having first and second electrodes; and a display controller on a semiconductor substrate, the display controller coupled to the first and the second electrodes of the display panel, the display controller comprising: a power supply circuit coupled to receive an external source voltage and generating a positive voltage higher than the external source voltage and a negative voltage lower than a ground potential, the positive voltage and the negative voltage being applied to the second electrodes of the display panel; a first wiring feeding the negative voltage as a bias voltage to the semiconductor substrate; a second wiring supplying the ground potential; a switch element coupled between the first wiring and the second wiring; a circuit which generates a first control signal to make the switch element conduct temporarily in accordance with a second control signal for starting up the power supply circuit; and a terminal coupled to receive the negative voltage generated from the power supply circuit; and a diode whose anode coupled to the terminal of the display controller and whose cathode coupled to the ground potential.