(19)

(11)

EP 0 542 834 A1

(12)

(43) Date of publication: 26.05.1993 Bulletin 1993/21 (21) Application number: 91914417.0 (22) Date of filing: 01.08.1991

(51) International Patent Classification (IPC):  G03B 35/ 00( . ) H04N 13/ 00( . ) G02B 27/ 22( . ) H04N 13/ 04( . ) (86) International application number: PCT/GB1991/001318 (87) International publication number: WO 1992/003021 (20.02.1992 Gazette 1992/05)

(84) Designated Contracting States: AT BE CH DE DK ES FR GB IT LI LU NL SE (30) Priority: 01.08.1990 GB 19900016902 (71) Applicant: DELTA SYSTEM DESIGN LIMITED London WC2H 9AJ (GB)	(72) Inventor: ASHBEY, James, Amachi London SW17 9LW (GB) (74) Representative: Harland, Linda Jane  c/o Reddie & Grose 16 Theobalds Road London WC1X 8PL London WC1X 8PL (GB)