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:
Jul. 27, 2004
Filed:
Oct. 28, 2002
Applicant:
Inventors:
Yoshinori Aiura, Hyogo, JP;
Yukio Yasuda, Hyogo, JP;
Assignee:
Ushio Denki Kabushiki Kaisya, Tokyo, JP;
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H01J 1/706 ; H01J 6/106 ;
U.S. Cl.
CPC ...
H01J 1/706 ; H01J 6/106 ;
Abstract
A short arc type mercury lamp in which a cathode and an anode are disposed opposite one another inside an arc tube, at least a noble gas and mercury are filled into the arc tube, cathode contains thorium oxide, a cone-shaped part that continues on from a cathode body is formed on the cathode, and a protruding part that continues on from the cone-shaped part is formed, wherein the number of grain boundaries on a straight line that passes through the approximate center of an arbitrary section in the radial direction of the protruding part is at least 0.5 per mm but not more than 100 per mm.