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. 12, 1991
Filed:
Feb. 16, 1990
Applicant:
Inventors:
Jan Hasker, Eindhoven, NL;
Jacobus E Crombeen, Eindhoven, NL;
Petrus A Van Dorst, Eindhoven, NL;
Johannes Van Esdonk, Eindhoven, NL;
Pieter Hokkeling, Eindhoven, NL;
Josef J Van Lith, Eindhoven, NL;
Assignee:
U.S. Philips Corporation, New York, NY (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H01J / ;
U.S. Cl.
CPC ...
445 50 ;
Abstract
For maintaining a monolayer of scandium which is necessary for a satisfactory emission on the surface of a scandate cathode, at least the top layer of the cathode is provided with scandium coated with a scandium oxide film. Even after repeated ion bombardment the emission is found to recover up to approximately 90% of the initial value at a current density of ca. 100 A/cm.sup.2.