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:
Jan. 08, 1980
Filed:
Mar. 06, 1978
Applicant:
Inventors:
Assignee:
NGK Insulators, Ltd., Nagoya, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H01J / ; C04B / ; C04B / ;
U.S. Cl.
CPC ...
313221 ; 106 734 ; 106 732 ;
Abstract
A polycrystalline alumina has at least 50% unit surface area provided by crystals of at least 60 .mu.m, and preferably 100 .mu.m size. This improves the in-line transmission value and hence lamp efficiency in a tube for a high pressure metal vapor lamp having an envelope of alumina.