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. 12, 2012
Filed:
Dec. 17, 2009
Atsushi Imamura, Hyogo, JP;
Takashi Yamashita, Hyogo, JP;
Tetsu Takemura, Hyogo, JP;
Nobuhiro Nagamachi, Hyogo, JP;
Atsushi Imamura, Hyogo, JP;
Takashi Yamashita, Hyogo, JP;
Tetsu Takemura, Hyogo, JP;
Nobuhiro Nagamachi, Hyogo, JP;
Ushio Denki Kabushiki Kaisha, Tokyo, JP;
Abstract
An extra-high pressure mercury lamp includes an arc tube made of quartz glass. The lamp includes an arc tube portion and sealing portions connected to the arc tube portion, and encloses 0.15 mg/mmor more of mercury. A pair of electrodes are disposed face to face in the arc tube. Each electrode has a rod portion and a base end portion. The base end portion of each electrode is embedded in one of the sealing portions. One of the pair of electrodes serves as a cathode and includes a head portion, which has a larger diameter than the rod portion. A cylinder portion is connected to a rear end portion of the head portion. The cylinder portion extends in the axis direction of the electrode and surrounds the rod portion. The cylinder portion has an inner surface separated from the rod portion.