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:
May. 15, 2012
Filed:
Oct. 06, 2009
Hidetaka Sawada, Tokyo, JP;
Fumio Hosokawa, Tokyo, JP;
Hidetaka Sawada, Tokyo, JP;
Fumio Hosokawa, Tokyo, JP;
JEOL Ltd., Tokyo, JP;
Abstract
An aberration corrector has two stages of multipole elements each of which has a thickness along the optical axis. Each multipole element produces a static electric or magnetic field of 3-fold symmetry and a static electromagnetic field of 2- or 3-fold symmetry superimposed on the static electric or magnetic field. In each of the multipole elements, the static electromagnetic field is so set that magnetic and electric deflecting forces on an electron beam accelerated by a given accelerating voltage substantially cancel out each other. Thus, chromatic aberration is corrected. Also, spherical aberration is corrected by the static electric or magnetic fields of 3-fold symmetry produced by the multipole elements.