Smectic liquid crystal display cell
AssigneeThomson-CSF
InventorsMichel Hareng, Serge Le Berre
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Abstract
The invention provides a liquid crystal display cell in which particles having a preferential light absorption direction, particles which may be the molecules of a dichroic pigment, are inserted in the body of a layer of a mesomorphic material in a smectic state. The write-in can be made by a thermo-optical process. The molecular orientation of the smectic material controls the particles orientation, so that the variation in the light scattering coefficient commonly used with smectic layers are replaced by variations in the absorption coefficient, easier to use and provide a better contrast.
Claims6
A liquid crystal cell comprising:
- two plates, at least one of them being transparent;
- a layer of a material having a smectic mesomorphic state;
- said layer being inserted between said plates and containing in dispersion particles exhibiting a preferential light absorption direction;
- means for providing heat pulses to at least a selected part of said layer;
- said layer being in said smectic state at least in the absence of said heat pulses and the molecular orientation of said material in said smectic state controlling the orientation of said particles.
Dependencies are inferred from the claim text.