(19)

(11)

EP 1 057 011 A1

(12)

(43) Date of publication: 06.12.2000 Bulletin 2000/49 (21) Application number: 99908387.6 (22) Date of filing: 23.02.1999

(51) International Patent Classification (IPC)7: G01N 29/04 (86) International application number: PCT/US9903/919 (87) International publication number: WO 9944/049 (02.09.1999 Gazette 1999/35)

(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: 26.02.1998 US 76090 P 16.04.1998 US 82018 P 16.04.1998 US 82012 P 11.09.1998 US 151432 20.11.1998 US 197165 20.11.1998 US 196674 (71) Applicant: Perceptron, Inc. Hatboro, PA 19040 (US)	(72) Inventors: SCHAFER, Mark, E. Norristown, PA 19401 (US) ROSS, Robert, J. Madison, WI 53719 (US) (74) Representative: W.P. THOMPSON & CO.  Eastcheap HouseCentral Approach Letchworth,Hertfordshire SG6 3DS Letchworth,Hertfordshire SG6 3DS (GB)