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. 17, 2009
Filed:
May. 21, 2004
Applicant:
George C. Wei, Weston, MA (US);
Inventor:
George C. Wei, Weston, MA (US);
Assignee:
OSRAM Sylvania Inc., Danvers, MA (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H01J 9/00 (2006.01); H05B 33/10 (2006.01);
U.S. Cl.
CPC ...
Abstract
Aluminum nitride arc discharge vessels having a high total transmittance may be made by annealing the as-sintered AlN vessel in a nitrogen atmosphere, preferably at a temperature of at least about 1850° C. and for a time of at least about 50 hours. The annealing increases the total transmittance of the vessel to greater than 92% in the wavelength region from about 400 nm to about 700 nm. The annealed AlN discharge vessels are useful for lamp applications, such as metal halide lamps, and offer an improved durability and life over polycrystalline alumina (PCA).