(19)

(11)

EP 0 169 237 A1

(12)

(43) Date of publication: 29.01.1986 Bulletin 1986/05 (21) Application number: 85900883.0 (22) Date of filing: 15.01.1985

(51) International Patent Classification (IPC):  G02B 6/ 24( . ) G02B 6/ 255( . ) (86) International application number: PCT/US1985/000066 (87) International publication number: WO 1985/003283 (01.08.1985 Gazette 1985/17)

(84) Designated Contracting States: DE FR GB NL (30) Priority: 24.01.1984 US 19840573141 (71) Applicant: AT&T Corp. New York, NY 10013-2412 (US)	(72) Inventor: KRAUSE, John, Thorvald New Providence, NJ 07974 (US) (74) Representative: Johnston, Kenneth Graham, et al  AT&T (UK) Ltd. 5 Mornington Road Woodford Green Essex, IG8 OTU Woodford Green Essex, IG8 OTU (GB)