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:
Sep. 06, 2005
Filed:
Jun. 10, 2003
Yasushi Aoki, Tokyo, JP;
Masahiro Katoh, Toyama, JP;
Yasushi Aoki, Tokyo, JP;
Masahiro Katoh, Toyama, JP;
NEC Corporation, Tokyo, JP;
A.L.M.T. Corporation, Tokyo, JP;
Abstract
A high-pressure discharge lamp comprises a lamp tube made of quartz glass and having a central portion formed in a spherical shape, and a pair of opposing tungsten electrodes inserted into the lamp tube. At least one of the tungsten electrodes is made of a tungsten material which contains more than 10 ppm of one of Co and Ni, or 10 ppm of Co and Ni in total, or a tungsten material which contains 20 ppm or more of at least two of Fe, Co and Ni in total, or a tungsten material which contains 20 ppm or more of Fe. Fe, Co and Ni belong to iron-group metals. The inter-electrode distance, i.e., distance between the leading ends of both tungsten electrodes is set to approximately 1-2 mm or less.