(19)

(11)

EP 0 389 592 A1

(12)

(43) Date of publication: 03.10.1990 Bulletin 1990/40 (21) Application number: 89909835.0 (22) Date of filing: 25.08.1989

(51) International Patent Classification (IPC):  G02B 6/ 12( . ) C08L 49/ 00( . ) G02F 1/ 065( . ) G02F 1/ 355( . ) C08F 38/ 00( . ) G02B 6/ 13( . ) G02F 1/ 35( . ) G02F 1/ 361( . ) (86) International application number: PCT/GB1989/000990 (87) International publication number: WO 1990/002348 (08.03.1990 Gazette 1990/06)

(84) Designated Contracting States: AT BE CH DE FR GB IT LI LU NL SE (30) Priority: 25.08.1988 GB 19880020211 (71) Applicant: PLESSEY OVERSEAS LIMITED Ilford Essex IG1 4AQ (GB)	(72) Inventors: TRUNDLE, Clive 27 Hillside Avenue Northants (GB) GOODWIN, Martin, John Northampton (GB) CARR, Neil Northampton (GB) (74) Representative: Pritchard, Evan  Intellectual Property Department The Plessey Company plc Vicarage Lane Ilford Essex IG1 4AQ Ilford Essex IG1 4AQ (GB)