Monostable ferroelectric active matrix display
AssigneeAventis Research & Technologies GmbH & Co. KG
InventorsHans-Rolf Dübal, Rainer Wingen, Toshiaki Nonaka
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Abstract
The monostable ferroelectric active matrix display comprises a liquid-crystal layer in the form of a monodomain having an unambiguously defined direction of the layer normal z of the smC* phase, the liquid-crystal layer preferably having a chevron C-1, chevron C-2 or bookshelf geometry.
Claims10
A monostable ferroelectric active matrix display comprising a liquid-crystal layer in the form of a monodomain having an unambiguously defined direction of the layer normal z of the smC* phase, the ratio between the sum of pretilt angle and layer leaning angle and the tilt angle (AR=(LLA+PTA)/TIA) being greater than 0.1 and the absolute value of the dielectric anisotropy DA being less than 3.
A monostable ferroelectric active matrix display comprising a liquid-crystal layer in chevron C1 geometry in the form of a monodomain having an unambiguously defined direction of the layer normal z of the smC* phase, the pretilt angle PTA being at least 5° and the ratio between pretilt angle and layer leaning angle (PTA/LLA) being greater than 0.7.
A monostable ferroelectric active matrix display comprising a liquid-crystal layer in bookshelf geometry in the form of a monodomain having an unambiguously defined direction of the layer normal z of the smC* phase, the pretilt angle PTA being at least 1°.
A monostable ferroelectric active matrix display comprising a liquid-crystal layer in the form of a monodomain having an unambiguously defined direction of the layer normal z of the smC* phase having the following properties:
- a spontaneous polarization P of between 0.1 and 15 nC/cm2,
- a tilt angle TIA of 9° to 45° C.
- an absolute value of the ratio between layer leaning angle and tilt angle of at least 0.2,
- a pitch in the chiral nematic (cholesteric) phase of at least 50 μm within the temperature range of 5° C. above the smectic-nematic phase transition, and
- an absolute value of the dielectric anisotropy DA of less than 3.
Dependencies are inferred from the claim text.