(19)

(11)

EP 0 437 591 A1

(12)

(43) Date of publication: 24.07.1991 Bulletin 1991/30 (21) Application number: 90912626.0 (22) Date of filing: 03.08.1990

(51) International Patent Classification (IPC):  G02B 26/ 00( . ) H01J 29/ 12( . ) G02B 26/ 08( . ) (86) International application number: PCT/GB1990/001218 (87) International publication number: WO 1991/002280 (21.02.1991 Gazette 1991/05)

(84) Designated Contracting States: AT BE DE DK ES FR GB IT NL SE (30) Priority: 03.08.1989 GB 19890017771 (71) Applicant: RANK BRIMAR LIMITED Manchester M24 1SN (GB)	(72) Inventors: LEYLAND, John, Derek Oldham Greater Manchester Ol4 4LR (GB) WALTERS, Frank Bury Greater Manchester BL8 2JA (GB) (74) Representative: Beresford, Keith Denis Lewis, et al  BERESFORD & Co. 2-5 Warwick Court High Holborn London WC1R 5DJ London WC1R 5DJ (GB)