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:
May. 06, 2014
Filed:
May. 17, 2013
Ushio Denki Kabushiki Kaisha, Tokyo, JP;
Koji Fujitaka, Himeji, JP;
Hirohisa Iwabayashi, Himeji, JP;
Ushio Denki Kabushiki Kaisha, Chiyoda-Ku, Tokyo, JP;
Abstract
Disclosed herein is a short arc discharge lamp which has a cathode electrode structure formed by solid-phase bonding a tip part made of thoriated tungsten to a body part made of tungsten. In the present invention, thorium can be reliably diffused onto the surface of the cathode electrode over a long period of time without stagnation of reduction of thorium oxide in the tip part. Therefore, satisfactory emission characteristics can be provided, whereby the arc stability is more reliable. The cathode electrode of the present invention is characterized in that potassium concentration of the body part is higher than potassium concentration of the tip part.