(19)

(11)

EP 0 540 627 A1

(12)

(43) Date of publication: 12.05.1993 Bulletin 1993/19 (21) Application number: 91913926.0 (22) Date of filing: 26.07.1991

(51) International Patent Classification (IPC):  A01H 4/ 00( . ) G06T 1/ 00( . ) (86) International application number: PCT/GB1991/001266 (87) International publication number: WO 1992/001994 (06.02.1992 Gazette 1992/04)

(84) Designated Contracting States: BE CH DE DK FR GB IT LI NL (30) Priority: 26.07.1990 GB 19900016443 (71) Applicant: BRITISH TECHNOLOGY GROUP LTD London SE1 6BU (GB)	(72) Inventor: McFARLANE, Nigel James Bruce Clophill, Bedford MK45 4DA (GB) (74) Representative: Laight, Martin Harvey  W.H. Beck, Greener & Co. 7 Stone Buildings Lincoln's Inn London WC2A 3SZ London WC2A 3SZ (GB)