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

Sharp Kabushiki Kaisha Corporation

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

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

The Secretary of State for Defence in Her Majesty'3 S Government of the

Madeline J Bradshaw

Edward P Raynes

Ian Charles Sage

George W Gray

Kenneth J Toyne

David Lacey

Lawrence Kam Chan

Richard M Scrowston

Victoria Brimmell

John Clifford Jones

Damien Gerard McDonnell

Adam Jackson

John A Jenner

Amarjit Kaur Samra

Jennifer Constant

David I Bishop

Paul Anthony Gass

Ibrahim G Shenouda

A liquid crystal device is provided with a pair of substrates (12, 16) containing a liquid crystal material (22). A wall structure comprising, for example, a plurality of walls (14) is provided between the two substrates. The wall structure provides mechanical strength to the device and resistance to flow of liquid crystal material which can cause deterioration in the device performance. The walls may extend in two mutually different directions (FIG. 8, 40) to provide mechanical strength and resistance to flow in two directions while the device can still be readily filled. The device is particularly applicable to a ferroelectric liquid crystal device.

Liquid crystal device

Optically active compounds of formula (I), where X has a structure (II) and B is C.sub.1-12 alkyl, a chiral group or a group having a general structure (III), where R and R' are H, C.sub.1-12 alkyl, alkoxy, alkylcarbonyloxy, or alkoxycarbonyl, each ring (IV) and (V) is the same or different, A and D are single bonds or bridging groups, each a and d is 0 or 1; Z, Z' are CN, Cl, F, Br or CF.sub.3 ; provided when Z is CN or Cl, then when B is alkyl X-Y is not (VI) or (VII). Ferroelectric smectic liquid crystal mixtures containing these compounds are also described. ##STR1##

Chiral liquid crystal compounds

This invention relates to novel chiral cyano-containing compounds suitable for use in ferroelectric smectic liquid crystal mixtures.

A method, device, and material for providing a fast switching liquid crystal display employs the ferro electric effect of chiral smectic liquid crystal material. To provide a uniform appearance the liquid crystal material is arranged to have a long cholesteric pitch at a temperature close to a smectic/cholesteric phase transistion temperature. This long cholesteric pitch allows liquid crystal molecules to cool from the cholesteric to smectic phase with a uniform alignment. The smectic material is contained in a cell between walls (2, 3) bearing electrodes (5, 6) and surface treated to provide homogeneous alignment of liquid crystal material (7).

Smectic liquid crystal devices

Amides having the following structure: ##STR1## used in ferroelectric smectic liquid crystal mixtures, especially as pitch compensators and liquid crystal compositions containing them.

Amide liquid crystal compounds: mixtures and devices using them

A liquid crystal display is arranged to provide very low minimum light trmission in one of its two switchable states. This makes it useful for a shutter (FIG. 1) and for high contrast digital displays (FIG. 2). A layer of a chiral smectic liquid crystal material is contained between two cell walls carrying electrode structures. The liquid crystal material has the following phases with temperature: isotropic.revreaction.cholesteric.revreaction.chiral smectic.revreaction.solid. The cholesteric pitch is large. The cell walls are surface treated to provide a parallel alignment of liquid crystal molecules. Crossed polarizers are arranged either side of the cell walls, one aligned with its optical axis parallel to the surface alignment of the adjacent cell wall. The device is switched by means of .+-.-d.c. voltage pulses and utilizes the ferro electric effect.

Biphenyl egters of formula (I), ##STR1## wherein formula (II) represents formula (III) or formula (IV), R.sub.1 represents C.sub.3 -C.sub.12 alkyl, alkoxy, alkylcarbonyloxy, alkoxycarbonyl or alkoxycarbonyloxy, j is O or 1 R.sub.2 represents C.sub.3 -C.sub.12 alkyl or alkoxy, one of Q.sub.1 or Q.sub.2 is fluorine and the other is hydrogen, provided that when j is O and formula (II) is formula (III) and both R.sub.1 and R.sub.2 are n-alkyl, then the total number of carbon atoms in R.sub.1 and R.sub.2 is more than 12. These compounds may be used as constituents of liquid crystal mixtures which show a room temperature ferroelectric smectic phase, and a number of such mixtures are described.

Biphenyl esters and liquid crystal materials and devices containing them

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Madeline J Bradshaw