There is provided a power circuit for a display-device-driving circuit for supplying a plurality of voltages to a driving circuit for time-division-driving a display device, wherein 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 divided voltages at a certain voltage level, whereby a stable power source consuming a small power to a driving circuit as a power source for a display device to be time-division-driven can be obtained.