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:
Dec. 11, 2001
Filed:
May. 01, 2001
Masatoshi Kudoh, Chiba-ken, JP;
Ryuichi Murai, Osaka-fu, JP;
Mitsuhiro Ohtani, Osaka-fu, JP;
Katuyoshi Yamashita, Osaka-fu, JP;
Hideharu Ohmae, Osaka-fu, JP;
Masahiko Konda, Osaka-fu, JP;
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
Method and apparatus for manufacturing an electron gun. A beam spot coefficient is obtained from an electrostatic lens magnification and a spherical aberration coefficient of a set resistance distribution. Then, a first process loop is executed to select another resistance distribution that provides an approximate minimum value of the beam spot coefficient. It is then determined whether the beam spot coefficient is an approximate minimum value. The first process loop is repeatedly executed until the beam spot coefficient is determined to be equal to the approximate minimum value. At this point, a second process loop is executed to confirm the minimum value of the beam spot coefficient using an aberration-independent function that is dependent upon the electrostatic lens magnification and is not dependent upon the spherical aberration coefficient. Processing returns to the first process loop using still another resistance distribution as a selected resistance distribution when the beam spot coefficient is not the approximate minimum value.