The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 21, 1999
Filed:
Feb. 27, 1998
Katsushige Tsuno, Tokyo, JP;
Jeol Ltd., Tokyo, JP;
Abstract
There is disclosed a small-sized omega-type energy filter having reduced drift lengths and an increased merit function. Four magnetic fields M.sub.1, M.sub.2, M.sub.3, and M.sub.4 deflect the electron beam into an .OMEGA.-shaped orbit from the entrance window plane to the slit plane. The distance L.sub.4 from the exit end surface of the third field M.sub.3 to the entrance end surface of the fourth field M.sub.4 is set no greater than 50 .sqroot.U*/.sqroot.U*(200) mm. The deflection angle .PHI. is set to a range of from 120.degree.-50.degree. to 120.degree.+5.degree.. The distance L.sub.3 from the central plane between the second field M.sub.2 and the third field M.sub.3 to the entrance end surface of the third field M.sub.3 is set such that 20 .sqroot.U*/.sqroot.U*(200) mm .gtoreq.10.sqroot.U*/.sqroot.U*(200) mm. The distance L.sub.5 from the exit end surface of the fourth field M.sub.4 to the slit plane is set such that 30 .sqroot.U*/.sqroot.U*(200) mm.ltoreq.L.sub.5 .ltoreq.50 .sqroot.U*/.sqroot.U*(200) mm.