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:
Sep. 14, 2004
Filed:
Nov. 20, 2001
Kunio Fukai, Shizuoka, JP;
Akihiro Nagata, Shizuoka, JP;
Koito Manufacturing Co., Ltd., Tokyo, JP;
Abstract
An arc tube and method of fabricating the arc tube for a discharge lamp. The arc tube includes an arc tube main body at which a sealed glass bulb serving as a discharge portion sandwiched by pinch seal portions is formed at a portion of a glass tube W along the longitudinal direction thereof, and a cylindrical shroud glass which is welded on and integrated with the arc tube main body so as to cover the sealed glass bulb , the front and rear end portions of the shroud glass may be joined, for example, by welding on shroud glass welded portions with circular cross sections provided at the front and rear end sides of the arc tube main body , respectively. The inner peripheral surface of the diameter reduced portion of the shroud glass tube , which is molten, soften and deformed inside along the radial direction, contacts closely to the circular outer peripheral surface on the arc tube main body side, so that a space can not be formed at the welding portion of the shroud glass (adhesion surface). Thus, the atmosphere does not enter into the sealed space surrounded by the shroud glass , and accordingly, devitrification is prevented.