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. 30, 2007
Filed:
Dec. 16, 2004
Applicants:
Michio Takagaki, Shizuoka, JP;
Takeshi Fukuyo, Shizuoka, JP;
Shinichi Irisawa, Shizuoka, JP;
Inventors:
Assignee:
Koito Manufacturing Co., Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H01J 61/06 (2006.01);
U.S. Cl.
CPC ...
Abstract
A mercury-free arc tube for a discharge lamp has a closed chamber filled with rare gas and a metal halide containing at least Na halide or Sc halide and electrodes disposed on both end portions of the closed chamber so as to be opposed to each other, wherein the electrode rod is stepped shape which satisfies relationship of 1.1<A/A<7.3, whereas Ais a cross sectional area of the electrode in a top-end side area protruded into the closed chamber and Ais a cross sectional area of the electrode in a base-end side area fixed to the end portion of the closed chamber.