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:
May. 13, 1986
Filed:
Jun. 15, 1983
Ruichen Liu, Berkeley Heights, NJ (US);
Michael G Thomson, Berkeley Heights, NJ (US);
AT&T Bell Laboratories, Murray Hill, NJ (US);
Abstract
An electron emission system includes a high-brightness field-emitter cathode. Advantageously, the tip of the cathode is shaped to minimize structural variations caused by surface tension forces. In addition, an electrode assembly associated with the cathode is designed to establish electric field forces that are opposite and at least approximately equal to the surface tension forces acting on the tip. The electric field forces can be adjusted to establish a highly stable operating condition without altering the value of electron beam energy for which the overall system was designed. Moreover, the current density of the beam at a writing surface can be selectively varied without changing prescribed operating parameters of the cathode. The resulting system is characterized by excellent emission stability, low noise and a useful operating life of at least several thousand hours.