(19)

(11)

EP 0 995 271 A1

(12)

(43) Date of publication: 26.04.2000 Bulletin 2000/17 (21) Application number: 98932338.1 (22) Date of filing: 01.07.1998

(51) International Patent Classification (IPC)7: H03M 7/30 (86) International application number: PCT/GB9801/937 (87) International publication number: WO 9901/940 (14.01.1999 Gazette 1999/02)

(84) Designated Contracting States: AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE (30) Priority: 01.07.1997 GB 9713921 (71) Applicant: Hexagen Technology Limited Cambridge CB4 4WA (GB)	(72) Inventor: GILCHRIST, Michael, James Cambridge CB1 2AQ (GB) (74) Representative: Hallybone, Huw George  CARPMAELS AND RANSFORD43 Bloomsbury Square London WC1A 2RA London WC1A 2RA (GB)