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. 17, 2002
Filed:
Aug. 31, 1999
Applicant:
Inventor:
Hironori Imura, Tokyo, JP;
Assignee:
NEC Corporation, Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H01J 2/946 ;
U.S. Cl.
CPC ...
H01J 2/946 ;
Abstract
To stabilize an emission current of cold cathode electron gun and extend its product life. A cold cathode electron gun comprises a cold cathode for emitting electrons by field-emission, a gate electrode for controlling the field-emission, a Wehnelt electrode which surrounds the cold cathode and the gate electrode, a first anode for accelerating electrons, and a second anode for constructing an electron lens together with the first anode. An inner diameter of the first anode is greater than a radius of flow of electrons which are emitted in the direction perpendicular to the optical axis of the electron lens.