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. 24, 2026
Filed:
Mar. 20, 2023
Applicant:
Denka Company Limited, Tokyo, JP;
Inventor:
Daisuke Ishikawa, Tokyo, JP;
Assignee:
Denka Company Limited, Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H01J 37/06 (2006.01); H01J 1/22 (2006.01); H01J 1/90 (2006.01);
U.S. Cl.
CPC ...
H01J 1/90 (2013.01); H01J 1/22 (2013.01); H01J 2201/2896 (2013.01);
Abstract
An emitter includes: an insulator; a pair of conductive terminals attached to the insulator and spaced apart from each other; a heater disposed between tips of the pair of conductive terminals and generating heat when energized; an electron source heated by the heater and made of a first material emitting electrons; a Wehnelt electrode having an inner surface forming an internal space along with a surface of the insulator, and applying a bias voltage across the Wehnelt electrode and the electron source; and a shielding member covering a part of the surface of the insulator in the internal space.