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:
Apr. 17, 1979
Filed:
Apr. 17, 1978
Applicant:
Inventor:
Donald R Kerstetter, Emporium, PA (US);
Assignee:
GTE Sylvania Incorporated, Stamford, CT (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H01J / ;
U.S. Cl.
CPC ...
313340 ; 3133 / ;
Abstract
A substrate of substantially pure, hexagonal crystal, .alpha. alumina (sapphire) has a central hub and three radiating spokes. One surface of the substrate has a metallized cathode base thereon and the opposite surface is provided with a metallized heater. Electrical connection to the cathode base and heater are provided via the spokes, which are also appropriately metallized. A suitable electron emissive material is applied to the cathode base.