(19)

(11)

EP 0 695 438 A1

(12)

(43) Date of publication: 07.02.1996 Bulletin 1996/06 (21) Application number: 94911284.0 (22) Date of filing: 05.04.1994

(51) International Patent Classification (IPC):  G01N 21/ 88( . ) G01N 21/ 95( . ) G11B 7/ 26( . ) G01B 11/ 30( . ) G03F 7/ 30( . ) (86) International application number: PCT/GB1994/000720 (87) International publication number: WO 1994/023343 (13.10.1994 Gazette 1994/23)

(84) Designated Contracting States: AT BE CH DE DK ES FR GB GR IE IT LI LU MC NL PT SE (30) Priority: 07.04.1993 GB 19930007239 (71) Applicant: NIMBUS COMMUNICATIONS INTERNATIONAL LIMITED Monmouth, Gwent NP5 3SR (GB)	(72) Inventors: REYNOLDS, Gerald, Alfred, John Monmouth Gwent NP5 3SR (GB) HALLIDAY, Jonathan Gwent NP5 3SR (GB) (74) Representative: Calderbank, Thomas Roger, et al  MEWBURN ELLIS York House 23 Kingsway London WC2B 6HP London WC2B 6HP (GB)