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US 4,040,720 AGranted
Ferroelectric liquid crystal display
AssigneeRockwell International Corporation
InventorPaul K. York
Life of this patent
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Abstract
A ferroelectric liquid crystal display device employs capacitance spoiling layers to minimize unneeded capacitances created by crossovers of "X" and "Y" address lines and to accurately define desired capacitances. The spoiler layers comprise low dielectric constant layers which space electrodes from the ferroelectric at crossover points where capacitance is not needed for device operation.
Claims3
A ferroelectric liquid crystal display device having a plurality of unit display cells, said device comprising:
- a layer of ferroelectric material having an upper and a lower surface;
- a first plurality of electrodes disposed adjacent said lower surface of said layer of ferroelectric material, each electrode in said first plurality of electrodes extending across a plurality of unit display cells;
- a second plurality of electrodes disposed adjacent said lower surface of said layer of ferroelectric material, each electrode of said second plurality of electrodes being restricted to a single unit display cell;
- a third plurality of electrodes disposed adjacent to said upper surface of said layer of ferroelectric material, each electrode of said third plurality extending across a plurality of unit display cells;
- a fourth plurality of electrodes adjacent said upper surface of said layer of ferroelectric material, each electrode of said fourth plurality of electrodes being restricted to a single unit display cell;
- capacitance spoiler means disposed adjacent at least one of said upper and lower surfaces of said layer of ferroelectric material between said ferroelectric and said first or said third plurality of electrodes at those locations at which the electrodes of said first and third pluralities overlap;
- dielectric means disposed adjacent said upper surface of said layer of ferroelectric material, the electrodes of said third plurality of electrodes, and the electrodes of said fourth plurality of electrodes;
- a plurality of distribution electrodes overlying said dielectric means, each of said distribution electrodes in electrical contact with one of said fourth plurality of electrodes;
- a layer of liquid crystal material overlying said plurality of distribution electrodes;
- transparent electrode means overlying said layer of liquid crystal material;
- transparent face plate means overlying said transparent electrode means;
- and
- sealing means sealing the edges of said display device, thereby preventing leakage of said liquid crystal material.
10 more elements
Dependencies are inferred from the claim text.