Stc, Inc

The Secretary of State for Defence in Her Britannic Majesty's Government

Thorn Emi Plc

The Secretary of State for Defence

Matthew F Bone

David Coates

Anthony Bernard Davey

George W Gray

Kenneth J Toyne

David Lacey

William A Crossland

Daniel J Young

Adam Jackson

Richard M Scrowston

Lawrence Kam Chan

Peter W Ross

Paul W Surguy

Neil Collings

Ian Coulson

Peter A Gemmell

Frances C Saunders

Johnathan R Hughes

A method is disclosed for addressing a matrix-array type liquid crystal layer. The cell has a plurality of pixels which are defined by regions of overlap between two sets of electrodes which sandwich a liquid crystal layer, each pixel having two states. The response time for switching between the two states is dependent upon the voltage across the liquid crystal layer, with a minimum occurring at a particular voltage. The method includes applying a strobe waveform to a selected member of a first set of the electrodes while a data waveform is applied to each member of the second set of electrodes. A waveform for switching a pixel defined by the selected member comprises a switching pulse of a given voltage magnitude and given duration. A waveform for not switching a pixel defined by the selected member comprises a non-switching pulse of a voltage magnitude greater than the given voltage magnitude of the switching pulse and a duration less than the given duration of the switching pulse.

Method of addressing a ferroelectric liquid crystal display

A ferroelectric liquid crystal cell is provided with one alignment layer (14) constituted by rubbed nylon which promotes planar alignment in a specific azimuthal direction and the other alignment layer (15) constituted by a polymer with flexible side chains which promotes planar alignment without any preferred azimuthal direction.

Ferroelectric liquid crystal cells

Bistable switching between clear and scattering states is provided by a liquid crystal cell whose liquid crystal layer is constituted by a random orientation planar aligned ferroelectric smectic exhibiting a pitch length comparable with the wavelength of visible light.

Liquid crystal cell utilizing a ferroelectric liquid crystal having a

##STR1## Ferroelectric smectic liquid crystal mixtures are provided consisting of two constituents; a smectic host and another containing a chiral compound in which rotation of the chiral center relative to the molecular core is sterically hindered, so that the chiral compound induces a high Ps in the mixture. A preferred class of chiral compounds is those derived from naturally occurring compounds with chiral groups, especially .alpha.-hydroxycarboxylic acids, amino acids and terpenoids, e.g. with chiral groups (I), (II), (III). The chiral group is incorporated into a compound containing a mesogenic combination of groups, e.g. with chains of cyclic groups and some mesogenic combinations are described.

Compounds for ferroelectric liquid crystal devices

Bistable operation of ferroelectric liquid crystal smectic I* or smectic F* display cells is disclosed which uses a greater liquid crystal layer thickness than is achievable with smectic C* material while yet retaining bistability of operation.

Ferroelectric liquid crystal cells having a helical liquid crystal

Terpenoid derivatives and liquid crystal materials and devices

Bistable operation of ferroelectric liquid crystal smectic I* or smectic F* cells is disclosed which uses a greater liquid crystal layer thickness than is achievable with smectic C* material while yet retaining bistability of operation. One or more such cells are employed in two-dimensional information processing apparatus.

Two-dimensional optical information processing apparatus

Growing community of inventors

Bishop's Stortford, United Kingdom

Matthew F Bone