A power circuit supplies a plurality of voltages to a display-device-driving circuit for time-division-driving a display device. Each of the plurality of voltages are output via a constant-voltage circuit constituted by a regulator for dividing a voltage supplied from a power source and keeping the divided voltages at a certain voltage level, whereby a stable power source consuming a small amount of power when supplying power to a driving circuit as a power source for a display device to be time-division-driven can be obtained.