Patents Assigned to The Secretary of State for Defence in Her Britannic Majesty's Government of the United Kingdom of Great Britain and Northern Ireland of Defence Research Agency
  • Patent number: 5611957
    Abstract: Multiplex addressed ferroelectric liquid crystal devices containing liquid crystal mixtures composed of components A, B and C. Component A consists of one or more optically active compounds capable of imparting a spontaneous polarization to the material. Component B is a compound or compounds of the formula: ##STR1## where R.sub.1 and R.sub.2 independently represent straight or branched chain C.sub.3 -C.sub.12 alkyl or alkoxy groups, a, b and c are independently 0, 1 or 2 and the total of a+b+c is not greater than 4. Component C is selected from a range of liquid crystal components.
    Type: Grant
    Filed: July 5, 1995
    Date of Patent: March 18, 1997
    Assignee: The Secretary of State for Defence in her Britannic Majesty's Government of the United Kingdom of Great Britain and Northern Ireland of Defence Research Agency
    Inventors: Damien G. McDonnell, John C. Jones, Ian C. Sage
  • Patent number: 5607620
    Abstract: A novel LCP material based on fumarate and maleate di-esters is disclosed having general formula (I); R.sub.1 and R.sub.2 may may not be the same but have general structure (II); (a)=(b), (c), (d); p=2 to 14; q=0 or 1; r=1 or 2; s=1 or 2; X.dbd.O, CO.sub.2, O.sub.2 C, CH.sub.2 ; Y.dbd.C.sub.2 H.sub.4, O, CO.sub.2, O.sub.2 C; Z.dbd.CN, halogen, R, CO.sub.2 R, OR, O.sub.2 CR, wherein R=chiral or achiral.
    Type: Grant
    Filed: December 6, 1994
    Date of Patent: March 4, 1997
    Assignee: The Secretary of State for Defence in her Britannic Majesty's Government of the United Kingdom of Great Britain and Northern Ireland of Defence Research Agency
    Inventors: Mark A. Verrall, David Coates
  • Patent number: 5578242
    Abstract: Liquid crystal compounds of the formula:R.sup.1 --Z.sup.1).sub.m --(Z.sup.2)--X--(Z.sup.3)--(Z.sup.4).sub.n --R.sup.2These compounds may be mixed with other liquid crystal compounds to give liquid crystal mixtures which may then be used in liquid crystal devices. In the formula X is COS, CSS and CSO; each of Z.sup.1, Z.sup.2, Z.sup.3, and Z.sup.4 are independently phenyl, substituted phenyl, where substitution is lateral substitution selected from F, Cl, Br, NO.sub.2, CN, NCS; naphthalene, substituted naphthalene, where substitution is lateral substitution selected from F, Cl, Br, NO.sub.2, CN, NCS, CH.sub.3 ; thiophene, pyridine and pyrimidine; each of A.sup.1 and A.sup.2 is independently selected from single bond, C.tbd.C, CH.dbd.CH; A.sup.3 is selected from C.tbd.C and single bond; each of R.sup.1 and R.sup.2 are independently selected from CN, NCS, CH.dbd.C(CN).sub.2, C.tbd.C--CN, C.tbd.C--CF.sub.
    Type: Grant
    Filed: April 12, 1995
    Date of Patent: November 26, 1996
    Assignee: The Secretary of State for Defence in Her Britannic Majesty's Government of the United Kingdom of Great Britain and Northern Ireland of Defence Research Agency
    Inventors: John W. Goodby, Michael Hird, Kenneth J. Toyne, Alexander J. Seed, Damien G. McDonnell, Amarjit K. Samra