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:
Mar. 29, 1994
Filed:
Feb. 11, 1993
Shigeo Okayama, Tsukuba, JP;
Agency of Industrial Science and Technology, Tokyo, JP;
Ministry of International Trade and Industry, Tokyo, JP;
Abstract
A lens for a charged particle beam comprises first, second, third and fourth quadrupoles, a first aperture electrode placed in front of the first quadrupole, a second aperture electrode placed between the first quadrupole and the second quadrupole, a third aperture electrode placed between the second quadrupole and the third quadrupole, a fourth aperture electrode placed between the third quadrupole and the fourth quadrupole, a fifth aperture electrode placed behind the fourth quadrupole, means for exciting the quadrupoles to cause them to converge the charged beam to a line near the third aperture electrode, and means for applying voltage to excite the first to fifth aperture electrodes and cause them to produce an octupole lens action for correcting aperture aberration.