(19)

(11)

EP 0 670 052 A1

(12)

(43) Date of publication: 06.09.1995 Bulletin 1995/36 (21) Application number: 94906428.0 (22) Date of filing: 15.11.1993

(51) International Patent Classification (IPC):  G02B 3/ 00( . ) G03B 27/ 50( . ) G03F 7/ 20( . ) G02B 5/ 18( . ) G03F 7/ 00( . ) (86) International application number: PCT/US1993/010945 (87) International publication number: WO 1994/011781 (26.05.1994 Gazette 1994/12)

(84) Designated Contracting States: CH DE FR GB IT LI NL SE (30) Priority: 17.11.1992 GB 19920024080 30.08.1993 US 19930114732 (71) Applicants: BROOK, John Basingstoke, Hants RG24 84D (GB) PAGE, Joseph La Jolla, CA 92307 (US)	(72) Inventors: HUGLE, William Bell CH-6614 Brissago (CH) DANDLIKER, René CH-2000 Neuchâtel (CH) HERZIG, Hans, Peter CH-2000 Neuchâtel (CH) (74) Representative: Gibson, Stewart Harry  URQUHART-DYKES & LORD, Three Trinity Court, 21-27 Newport Road Cardiff CF2 1AA Cardiff CF2 1AA (GB)