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. 13, 2021
Filed:
Feb. 07, 2019
Applicant:
Ushio Denki Kabushiki Kaisha, Tokyo, JP;
Inventors:
Masashi Dan, Tokyo, JP;
Tomoyoshi Arimoto, Tokyo, JP;
Takumi Yamane, Tokyo, JP;
Taro Arimoto, Tokyo, JP;
Shinji Nikawa, Tokyo, JP;
Assignee:
Ushio Denki Kabushiki Kaisha, Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H01J 61/06 (2006.01); H01J 61/073 (2006.01);
U.S. Cl.
CPC ...
H01J 61/0735 (2013.01);
Abstract
A high-pressure discharge lamp includes a cathode body composed of a cathode made of tungsten or tungsten alloy and a lead rod inserted in a lead rod insertion hole of the cathode. The cathode has a carbonized layer made of tungsten carbide (WC) formed on a surface thereof exposed to a discharge space (except for a tip portion thereof) and on an inner surface of the lead rod insertion hole. The carbonized layer contains carbon in an amount of 0.44 g/cc to 0.53 g/cc.