(19)

(11)

EP 0 807 275 A1

(12)

(43) Date of publication: 19.11.1997 Bulletin 1997/47 (21) Application number: 96900353.0 (22) Date of filing: 15.01.1996

(51) International Patent Classification (IPC):  G01N 21/ 88( . ) G02B 27/ 02( . ) (86) International application number: PCT/GB1996/000071 (87) International publication number: WO 1996/024084 (08.08.1996 Gazette 1996/36)

(84) Designated Contracting States: BE DE DK ES FR GB IE IT NL SE (30) Priority: 03.02.1995 GB 19950002197 (71) Applicant: BRITISH TECHNOLOGY GROUP LIMITED London SE1 6BU (GB)	(72) Inventor: ROSS, David, William Edinburgh EH10 7DZ (GB) (74) Representative: Trevor-Briscoe, David William  Patents Department British Technology Group Ltd 101 Newington Causeway London SE1 6BU London SE1 6BU (GB)