(19)

(11)

EP 1 005 702 A1

(12)

(43) Date of publication: 07.06.2000 Bulletin 2000/23 (21) Application number: 98940959.4 (22) Date of filing: 18.08.1998

(51) International Patent Classification (IPC)7: H01J 35/20, H01J 35/06, H01J 1/30 (86) International application number: PCT/US9817/064 (87) International publication number: WO 9909/580 (25.02.1999 Gazette 1999/08)

(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: 18.08.1997 US 55682 P (71) Applicant: XRT Corp. St. Paul, MN 55113 (US)	(72) Inventors: CHORNENKY, Victor, I. Minnetonka, MN 55345 (US) SCHREINER, Dale, L. Cologne, MN 55322 (US) (74) Representative: Bayliss, Geoffrey Cyril et al BOULT WADE TENNANT,Verulam Gardens70 Gray's Inn Road London WC1X 8BT London WC1X 8BT (GB)