(19)

(11)

EP 0 855 121 A1

(12)

(43) Date of publication: 29.07.1998 Bulletin 1998/31 (21) Application number: 97935403.0 (22) Date of filing: 13.08.1997

(51) International Patent Classification (IPC):  G02B 27/ 28( . ) H04N 9/ 31( . ) (86) International application number: PCT/CA1997/000567 (87) International publication number: WO 1998/007279 (19.02.1998 Gazette 1998/07)

(84) Designated Contracting States: DE GB (30) Priority: 13.08.1996 CA 19962183188 (71) Applicant: NATIONAL RESEARCH COUNCIL OF CANADA Ottawa, Ontario K1A 0R6 (CA)	(72) Inventors: LI, Li Gloucester, Ontario K1J 7V7 (CA) SULLIVAN, Brian, Thomas Gloucester, Ontario K1J 6S3 (CA) DOBROWOLSKI, Jerzy, A. Ottawa, Ontario K1V 8B6 (CA) (74) Representative: Spence, Anne, et al  FRY HEATH & SPENCE The Old College 53 High Street Horley Surrey RH6 7BN Horley Surrey RH6 7BN (GB)