| 摘要 |
A power source circuit which supplies liquid driving potentials VH, V3, V2, VC, -V2, -V3, VL, etc., to a liquid display and can reduce the power consumption of the display. The potentials VCC and GND of the input power source are used, as they are, as the potentials V3 and VC, and the high potentials VH and VL are supplied from a charge pump circuit. The charge pump composed of a negative-direction voltage-sextupler (2), etc., performs charge-pumping by utilizing a pulse-like clock LP. The power source circuit is also provided with a boosting/dropping magnification changing means. Two pumping capacitors are prepared so as to eliminate uneven display by performing the charge-pumping at every horizontal interval. When the supply of the potential VCC, etc., is discontinued, the residual charge of the potentials VH and VL are released. The potentials VCC and GND are used not only as the driving voltage of liquid crystals, but also as the power supply voltage to the logic section of a driver.
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