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. 02, 2002
Filed:
Aug. 24, 1999
Hongyon Gu, Lexington, MA (US);
Jakob Maya, Brookline, MA (US);
Matsushita Electric Works R & D Laboratories Inc., Woburn, MA (US);
Abstract
A discharge lamp adapted to operate on DC current and being equivalent to an AC-operated ceramic metal halide lamp in different operating positions. The lamp comprises a ceramic arc tube with a fill of mercury, rare gas and metal halides. The arc tube is sealed with an anode and a cathode and has at least one metal heat shield on the cathode side of the ceramic DC metal halide arc tube to achieve operation of the lamp with universal orientation. Each of the two electrodes sealed into the arc tube are different, the anode being formed of tungsten with a ball shaped tip and the cathode being formed of a thoriated tungsten rod and a wound coil of the rod.