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:
Feb. 09, 1993
Filed:
Nov. 01, 1991
Setsuo Norioka, Tokyo, JP;
Hiroshi Shimada, Tokyo, JP;
JEOL Ltd., Tokyo, JP;
Abstract
A condenser means for focusing an electron beam onto a specimen and a scanning means for scanning the beam in two dimensions on the specimen placed inside a specimen chamber are disposed inside an electron beam column. The top portion of the specimem chamber is connected with the column by an annular member of a high magnetic permeability which surrounds the column. Magnetic flux passed through the top wall of the chamber is made to penetrate the annular member of a high magnetic permeability. The flux is then caused to enter the portion of the upper wall remote from the column, after which the flux leaks out. Thus, leakage of the magnetic flux into the specimem chamber is prevented.