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:
Jun. 15, 2004
Filed:
Sep. 19, 2002
Michio Takagaki, Shizuoka, JP;
Masaya Shido, Shizuoka, JP;
Shinichi Irisawa, Shizuoka, JP;
Takeshi Fukuyo, Shizuoka, JP;
Koito Manufacturing Co., Ltd., Tokyo, JP;
Abstract
A mercury-free arc tube includes a closed glass bulb held between pinch seal portions located at opposite ends of the close glass bulb; and a pair of electrodes provided in the closed glass bulb so as to be opposite to each other. The closed glass bulb does not contain mercury but contains main light emitting metal halide (NaI and ScI ). A rare gas is enclosed in the closed glass bulb with a charged pressure set to be in a range of from 8 to 20 atmospheres. If necessary, a predetermined buffer metal halide acting as a buffer substance is enclosed in the closed glass bulb. The charged pressure of the rare gas is higher than the conventional charged pressure (6 atmospheres).