| 摘要 |
A power supply circuit supplies a liquid crystal energizing circuit with desired potentials for the purposes of energizing a liquid crystal display in accordance with combinations between first, second, third and reference potentials. The power supply circuit includes a first input terminal connected to a constant voltage source for supplying the first potential, a second input terminal connected to the reference potential, first, second, third, fourth and fifth output terminals for supplying the liquid crystal energizing circuit with desired potentials, impedance means connected between the first input terminal and the second input terminal for deriving the second potential and the third potential therefrom, means for always supplying the first output terminal and the fifth terminal with the first potential and the reference potential respectively, and switching means for determining whether the second, third and fourth output terminals are respectively with the first, second and third potentials or with the second, third and reference potentials. The last named switching means contain only P channel MOS transistors (or N channel MOS transistors).
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