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:
Sep. 21, 1999
Filed:
Feb. 25, 1994
Cha-Mei Tang, Potomac, MD (US);
Antonio C Ting, Silver Spring, MD (US);
Thomas A Swyden, Falls Church, VA (US);
The United States of America as represented by the Secretary of the Navy, Washington, DC (US);
Abstract
A field emitter for producing an electron beam includes at least one cold cathode unit. Each of the cold cathode units includes an emitter cone having an emitter tip and a gate spaced apart from the emitter tip for extracting electrons from the emitter tip in a propagation direction upon application of a positive dc voltage on the gate with respect to the emitter tip. The gate forms a gate cavity for propagation of the extracted electrons therethrough. Each of the cold cathode units further includes at least one lens electrode disposed further in the propagation direction from the emitter tip than the gate, the at least one lens electrode forming at least one lens cavity for propagation of the extracted electrons therethrough. The at least one lens electrode is for focusing the extracted electrons in part of the gate cavity, part of the at least one lens cavity, and part of the region therebetween.