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. 29, 2014
Filed:
May. 17, 2013
Ushio Denki Kabushiki Kaisha, Tokyo, JP;
Yukio Yasuda, Himeji, JP;
Akiko Uchino, Himeji, JP;
Ushio Denki Kabushiki Kaisha, 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. According to the present invention, the bonding strength between the body part and the tip part is increased to the same level as the mechanical strength of tungsten, thus preventing a breakage from being caused on a junction interface. For this, on a section of the cathode electrode taken along a line perpendicular to the junction interface, in an arbitrary portion of 500 μm or more in length along the junction interface, when a length of the arbitrary portion along the junction interface is set to L, and a sum of lengths of tungsten crystal grains, along the junction interface, that are present through the junction interface is set to L, (L/L0)≧0.16 is satisfied.