(19)

(11)

EP 0 812 439 A1

(12)

(43) Date of publication: 17.12.1997 Bulletin 1997/51 (21) Application number: 96902734.0 (22) Date of filing: 22.01.1996

(51) International Patent Classification (IPC):  G06F 17/ 17( . ) (86) International application number: PCT/US1996/000747 (87) International publication number: WO 1996/023264 (01.08.1996 Gazette 1996/35)

(84) Designated Contracting States: AT BE CH DE DK ES FR GB GR IE IT LI LU MC NL PT SE (30) Priority: 26.01.1995 US 19950378457 (71) Applicant: WATKINS-JOHNSON COMPANY Palo Alto, CA 94304-1223 (US)	(72) Inventors: KLINE, Paul, Asher Germantown, MD 20876 (US) BELL, Dirk, Anderson Alexandria, VA 22310 (US) (74) Representative: Pacitti, Pierpaolo A.M.E., et al  Murgitroyd and Company 373 Scotland Street Glasgow G5 8QA Glasgow G5 8QA (GB)