Four-level voltage supply for liquid crystal display
AssigneeSharp Kabushiki Kaisha
InventorsShitaro Hashimoto, Yuuichi Sato
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Abstract
A liquid crystal display enabling circuitry wherein the backplate electrode of a liquid crystal display is activated by a four-level voltage while the respective segment electrodes thereof are activated by a two-level voltage. This includes at least two input terminals, five output terminals, a voltage dividing resistor network and complementary MOSFET switching means and thereby provides the four-level voltage for the backplate electrode and the four-level voltage for the segment electrodes. In addition, this may be implemented with MOS integrated circuitry technology (and not bipolar integrated circuitry technology).
Claims11
Voltage supply circuitry for supplying to a liquid crystal display first, second and third voltage levels in addition to a reference level, comprising:
- first and second input terminals, the first input terminal being connected to the first voltage level and the second input terminal being connected to the reference level;
- first, second, third, fourth and fifth output terminals for providing desired voltage levels to the liquid crystal display;
- impedance means interposed between the first input terminal and the second input terminal for producing the second and third voltage levels;
- connection means for always providing the first and reference levels to the first output terminal and the fifth output terminal respectively;
- and
- switching means for selectively providing the first, second, third and reference voltage levels to the second, third and fourth output terminals.
Dependencies are inferred from the claim text.