Patent ID: 7916134

Claim:
A power supply circuit which supplies a high-potential drive power voltage to a driver circuit which receives a low-potential drive power voltage in addition to the high-potential drive power voltage and drives a plurality of data lines in a display panel which has a plurality of pixels and a plurality of scanning lines in addition to the data lines, the power supply circuit comprising: a regulator outputs a voltage obtained by regulating an input voltage which is a first voltage or a voltage obtained by dividing the first voltage; a first switching circuit, one end of the first switching circuit being connected with an output node to which the high-potential drive power voltage of the driver circuit is output and the other end of the first switching circuit being connected with output of the regulator; and a second switching circuit, one end of which is connected to the output node; a capacitor, one end of the capacitor being connected to the other end of the second switching circuit, and the other end of the capacitor being connected to a system power line; and a diode connected between the other end of the second switching circuit and a power line of the regulator to which is supplied a power voltage so that a direction from the system power line to the power line of the regulator is a forward direction, wherein: the first switching circuit is turned off, the second switching circuit is turned on, and a charge corresponding to a charge discharged from the data lines is accumulated in the capacitor during a given period in which an output from the driver circuit to the data lines is set to a high impedance state, and polarity of a voltage between a pixel electrode of each of the pixels connected to one of the data lines and a common electrode facing the pixel electrode through an electro-optical material is reversed; and the first switching circuit is turned on, the second switching circuit is turned off, and the regulated voltage is output by the regulator to which a voltage generated by the charge accumulated in the parasitic capacitor is supplied as a power voltage of the regulator.