(19)

(11)

EP 0 375 716 A1

(12)

(43) Date of publication: 04.07.1990 Bulletin 1990/27 (21) Application number: 88907429.0 (22) Date of filing: 12.08.1988

(51) International Patent Classification (IPC):  G01N 35/ 00( . ) H01J 37/ 20( . ) H01J 37/ 02( . ) (86) International application number: PCT/SE1988/000407 (87) International publication number: WO 1989/001698 (23.02.1989 Gazette 1989/05)

(84) Designated Contracting States: AT BE CH DE FR GB IT LI LU NL SE (30) Priority: 21.08.1987 SE 19870003250 (71) Applicants: ANDERSSON, Jan Peter S-133 00 Saltsjöbaden (SE) NYBOM, Rolf S-161 55 Bromma (SE)	(72) Inventors: ANDERSSON, Jan Peter S-133 00 Saltsjöbaden (SE) NYBOM, Rolf S-161 55 Bromma (SE) (74) Representative: Ström, Tore, et al  Ström & Gulliksson AB Studentgatan 1 P.O. Box 4188 S-203 13 Malmö S-203 13 Malmö (SE)