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. 05, 2024
Filed:
Aug. 02, 2021
Meidensha Corporation, Tokyo, JP;
MEIDENSHA CORPORATION, Tokyo, JP;
Abstract
In a cylindrical guard electrode () provided on the outer peripheral side of an electron generation part () of an emitter (), a distal end section (A)positioned in the emission direction of an electron beam (L) from the electron generation part () includes: a distal end inner-peripheral-side part (A) having an inner-peripheral-side curved surface portion (a) convex in the emission direction; a distal end outer-peripheral-side part (A) having an outer-peripheral-side curved portion (a) convex in the emission direction; and adistal end middle part (A) positioned between the distal end inner-peripheral-side (A) and the distal end outer-peripheral-side part (A). The distal end middle part (A) has a flat surface portion (a) between the inner-peripheral-surface portion (a) and the outer-peripheral-side curved surface portion (a) so as to extend in the direction therebetween.