| 摘要 |
PROBLEM TO BE SOLVED: To easily adjust the gradation of image in a liq. crystal display device of a 5-potential level drive system. SOLUTION: This power circuit 5 outputs five potential voltages as a driving voltage of a liq. crystal display device, which are an upper and a lower selective potential VH, VL, non-selective potential VM at about middle potential of this upper and lower selective potentials, an upper bias potential V0 between the upper selective potential VH and the non-selective potential VM, and the lower bias potential V1 between the non-selective bias VM and the lower selective potential VL. The power circuit is provided with a variable bias voltage output means for outputting the upper and lower bias potential V0, V1 so that the upper and lower bias potential V0, V1 keep a symmetry to the non-selective potential VM. The variable bias potential output means is outputs the upper and lower bias potentials V0, V1 at the same time based on the potential obtained by dividing the potential of controlling signal VCON given from out side.
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