(19)

(11)

EP 0 722 571 A1

(12)

(43) Date of publication: 24.07.1996 Bulletin 1996/30 (21) Application number: 94930637.0 (22) Date of filing: 04.10.1994

(51) International Patent Classification (IPC):  G01V 8/ 10( . ) (86) International application number: PCT/US1994/011365 (87) International publication number: WO 1995/010056 (13.04.1995 Gazette 1995/16)

(84) Designated Contracting States: BE DE ES FR GB IE IT LU NL (30) Priority: 05.10.1993 US 19930132102 12.01.1994 US 19940180611 30.09.1994 US 19940312998 (71) Applicant: INTELECTRON PRODUCTS COMPANY Hayward, CA 94545 (US)	(72) Inventors: SANDELL, Donald, R. San Jose, CA 95135 (US) LEE, Wade, P. Hayward, CA 94545 (US) (74) Representative: Shindler, Nigel  BATCHELLOR, KIRK & CO. 2 Pear Tree Court Farringdon Road London EC1R 0DS London EC1R 0DS (GB)