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:
Nov. 02, 1999
Filed:
Sep. 25, 1997
Hideo Makishima, Tokyo, JP;
NEC Corporation, Tokyo, JP;
Abstract
In a field emission cathode type electron gun, a plurality of cathode segments and a plurality of gate control circuits are provided. Each of the gate control circuits is connected to one of the cathode segments. Each of the cathode segments includes a cathode electrode, a gate electrode, an insulating layer therebetween, and a plurality of cone-shaped emitters formed within openings perforated in the gate electrode and the insulating layer. Each of the gate control circuits detects a current flowing through one of the cathode segments and controls a voltage of the gate electrode of the respective cathode segments in accordance with the detected current, so that the detected current is brought close to a definite value.