(19)

(11)

EP 0 138 878 A1

(12)

(43) Date of publication: 02.05.1985 Bulletin 1985/18 (21) Application number: 84901121.0 (22) Date of filing: 06.03.1984

(51) International Patent Classification (IPC):  G02B 1/ 04( . ) C03C 25/ 10( . ) C03C 13/ 04( . ) G02B 6/ 02( . ) (86) International application number: PCT/SE1984/000078 (87) International publication number: WO 1984/003776 (27.09.1984 Gazette 1984/23)

(84) Designated Contracting States: CH DE FR GB LI NL (30) Priority: 14.03.1983 SE 19830001379 (71) Applicant: TELEFONAKTIEBOLAGET L M ERICSSON S-126 25 Stockholm (SE)	(72) Inventor: VACHA, Lubos S-135 49 Tyresö (SE) (74) Representative: Wennerholm, Kristian, et al  TELEFONAKTIEBOLAGET L M ERICSSON S-126 25 Stockholm S-126 25 Stockholm (SE)