Liquid crystal matrix display
AssigneeKabushiki Kaisha Suwa Seikosha
InventorMasami Murata
Life of this patent
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Abstract
A liquid crystal matrix display provides scanning in a plurality of modes wherein the number of scanning electrodes simultaneously driven is varied. Higher driving duty cycles are used as the number of simultaneously driven scanning electrodes increases. Energy consumption is reduced and the quality is improved. A change-over circuit lowers the driving voltage during simultaneous scanning.
Claims13
In a liquid crystal matrix display having picture elements formed at the overlapped intersections of a plurality of first electrodes with a plurality of second electrodes, the improvement therein comprising:
- first circuit means for selecting among and generating driving signals for said plurality of first electrodes;
- second circuit means for generating driving signals for said plurality of second electrodes, the voltage difference of said driving signals at said picture elements determining individually the ON or OFF state of each said picture element, said voltage difference providing an AC multiplexed drive, said multiplex signals being synchronized by a clock signal;
- said first circuit means including switch means for controlling the mode of operation of said first circuit means, said first circuit means being subject to operate in at least two modes dependent upon the state of said switch means, in each said mode the number of said first electrodes simultaneously selected and driven by the same signal differing, said first circuit means being adapted to increase the driving duty cycle of said multiplexed signal when the quantity of said simultaneously driven first circuit electrodes increases in accordance with the state of said switch means, simultaneous driving of selected electrodes reducing the number of required driving signals in a fixed time period for said selected electrodes, power being conserved by simultaneous operation of a greater number of picture elements at higher duty cycles.
In a liquid crystal matrix display having picture elements formed at the overlapped intersections of a plurality of first electrodes with a plurality of second electrodes, the improvement therein comprising:
- first circuit means for selecting among and generating driving signals for said plurality of first electrodes;
- second circuit means for generating driving signals for said plurality of second electrodes, the voltage difference of said driving signals at said picture elements determining individually the ON or OFF state of each said picture element;
- said first circuit means including first switching means for controlling the mode of operation of said first circuit means, said first circuit means being subject to operate in at least two modes dependent upon the state of said first switching means, in each said mode the number of said first electrodes simultaneously selected and driven by the same signal differing, said first circuit means being adapted to increase the driving duty cycle of said difference signal when the quantity of said simultaneously driving first circuit electrodes increases in accordance with the state of said first switching means, simultaneous driving of selected electrodes reducing the number of required driving signals in a fixed time period for said selected electrodes, power being conserved by simultaneous operation of a greater number of picture elements at higher duty cycles,
- said first circuit means for selecting and driving further including means for raising and lowering the driving voltage for said selected first electrodes and for applying a relatively lower voltage to said modes having greater duty cycles, whereby power is further conserved
Dependencies are inferred from the claim text.