(19)

(11)

EP 0 470 161 A1

(12)

(43) Date of publication: 12.02.1992 Bulletin 1992/07 (21) Application number: 90907242.0 (22) Date of filing: 30.04.1990

(51) International Patent Classification (IPC):  G03B 35/ 00( . ) G03B 35/ 24( . ) G03B 35/ 04( . ) H04N 13/ 00( . ) (86) International application number: PCT/GB1990/000669 (87) International publication number: WO 1990/013848 (15.11.1990 Gazette 1990/26)

(84) Designated Contracting States: AT BE CH DE DK ES FR GB IT LI LU NL SE (30) Priority: 28.04.1989 GB 19890009874 (71) Applicant: DELTA SYSTEM DESIGN LIMITED London WC2H 9AJ (GB)	(72) Inventor: ASHBEY, James, Amachi London SW17 9LW (GB) (74) Representative: Abnett, Richard Charles  REDDIE & GROSE 16 Theobalds Road London WC1X 8PL London WC1X 8PL (GB)