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. 27, 1998
Filed:
Nov. 29, 1995
Osamu Inoue, Himeji, JP;
Toshiyuki Shima, Himeji, JP;
Ushiodenki Kabushiki Kaisha, Tokyo, JP;
Abstract
A mercury lamp of the short arc type in which tantalum can absorb impurity gases to a sufficient degree even if the inside of the arc tube reaches a high temperature is achieved by providing an arc tube, within which mercury and an inert gas are encapsulated, with a pair of electrodes disposed opposite each other within the arc tube, each of the electrodes being supported by a respective terminal post, tantalum being provided on the terminal post of one of the electrodes, and by ensuring that both of the relationships (D2/D1)>1.3 and the relationship 0.2.ltoreq.(D2/D1).sup.2 /L.ltoreq.0.5 are satisfied at the same time, where D1 is an outer diameter of the terminal post in millimeters, D2 is an outer diameter of the electrode supported by the respective terminal post in millimeters, and L is a distance between a tip of the electrode on which the tantalum is provided and the tantalum on the terminal post of that electrode.