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. 29, 2002
Filed:
May. 23, 2000
Yoshiharu Nishiura, Shiga, JP;
Takashi Yamamoto, Osaka, JP;
Kazuo Takeda, Osaka, JP;
Shiki Nakayama, Osaka, JP;
Hiroshi Nohara, Hyogo, JP;
Matsushita Electric Industrial Co., Ltd, Osaka, JP;
Abstract
A discharge tube is provided inside an outer tube. At least a pair of electrodes is arranged inside the discharge tube, and at least mercury is sealed into the discharge tube. The electrode includes an electrode pin and a metal pipe that surrounds the electrode pin. Because a contact area of the electrode pin and the inner surface of the metal pipe is sufficiently maintained in a stable manner, a tip temperature of the electrode pin can be lowered sufficiently without a variation. As a result, it is possible to obtain a high pressure discharge lamp that has excellent lifetime characteristics and can considerably reduce the variation of the lifetime characteristics between lamps.