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:
Jun. 24, 2003
Filed:
Mar. 15, 2001
Applicant:
Inventors:
Assignee:
NEC Microwave Tube, Ltd., Kanagawa-ken, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H01J 2/534 ; H01J 2/304 ;
U.S. Cl.
CPC ...
H01J 2/534 ; H01J 2/304 ;
Abstract
A method and device are provided for preventing deterioration of a cold cathode in an electron tube device that utilizes the cold cathode as an electron source. In accordance with the expression defining the beam current of the electron tube device, Ib<P&mgr;×Va , where P&mgr; represents the perveance of an electron gun and Va represents a voltage impressed upon an accelerating electrode, the electric potential of the accelerating electrode or an adjacent electrode is maintained at the highest level of all electrodes in the electron tube at all times.