(19)

(11)

EP 0 324 822 A1

(12)

(43) Date of publication: 26.07.1989 Bulletin 1989/30 (21) Application number: 88905995.0 (22) Date of filing: 20.07.1988

(51) International Patent Classification (IPC):  G02F 1/ 133( . ) G02F 1/ 137( . ) G09F 9/ 35( . ) G02F 1/ 13( . ) G02F 1/ 139( . ) (86) International application number: PCT/GB1988/000585 (87) International publication number: WO 1989/000712 (26.01.1989 Gazette 1989/03)

(84) Designated Contracting States: CH DE FR LI (30) Priority: 22.07.1987 GB 19870017362 (71) Applicant: THE GENERAL ELECTRIC COMPANY, p.l.c. London W1A 1EH (GB)	(72) Inventors: WILTSHIRE, Michael, Charles, Keogh Buckinghamshire HP11 1EB (GB) MOSLEY, Alan Herts HP4 1EU (GB) (74) Representative: George, Sidney Arthur  The General Electric Company p.l.c. GEC Patent Department Waterhouse Lane Chelmsford, Essex CM1 2QX Chelmsford, Essex CM1 2QX (GB)