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:
Mar. 29, 2005
Filed:
Sep. 14, 2001
Arlene Hecker, Beverly, MA (US);
George C. Wei, Weston, MA (US);
Helmar G. Adler, Danvers, MA (US);
Dieter Lang, Bruckmuehl, DE;
Arlene Hecker, Beverly, MA (US);
George C. Wei, Weston, MA (US);
Helmar G. Adler, Danvers, MA (US);
Dieter Lang, Bruckmuehl, DE;
Osram Sylvania Inc., Danvers, MA (US);
Abstract
A ceramic metal halide discharge lamp may be made having a monolithic seal between a sapphire arc tube and a polycrystalline alumina cap. The lamp is made by providing an arc tube of fully dense sapphire and providing a cap made of unsintered compressed polycrystalline alumina doped with magnesium oxide and yttrium oxide. The cap is presintered to remove binder material at a low temperature. The presintered cap is placed on an end of the arc tube to form a close interface. The presintered cap and arc tube are then heated to until the cap is fully sintered onto the arc tube and the sapphire tube grows into the cap. A monolithic seal is formed along the interface as the sapphire grows into the polycrystalline alumina.