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. 26, 1989
Filed:
Jan. 18, 1989
Applicant:
Inventor:
Jan Zwier, Eindhoven, NL;
Assignee:
U.S. Philips Corp., New York, NY (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H01J / ;
U.S. Cl.
CPC ...
313409 ; 313444 ; 313446 ;
Abstract
The stability of semiconductor cathodes is improved by reducing the effective emitting surface area. This is effected by producing emission patterns by means of separate emission regions, whose overall surface area is much smaller than that of the actual emission patter. Due to the higher emission current and adjustment current, adsorbed particles, which adversely affect the stability of the emission, are rapidly drained.