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:
Apr. 01, 2008
Filed:
Oct. 19, 2006
Masaru Kuribayashi, Akishima, JP;
Masahiro Nonoguchi, Tachikawa, JP;
Naohisa Osaka, Ome, JP;
Yoji Kobayashi, Akiruno, JP;
Masaru Kuribayashi, Akishima, JP;
Masahiro Nonoguchi, Tachikawa, JP;
Naohisa Osaka, Ome, JP;
Yoji Kobayashi, Akiruno, JP;
Rigaku Corporation, Tokyo, JP;
Abstract
A coiled filament for an X-ray tube has a varied coil pitch to obtain a good uniformity of the longitudinal temperature distribution. The filament has a central region including plural turns having a same coil pitch, and end regions which include plural turns each of which has a coil pitch smaller than the coil pitch of the central region. The coil pitches of the plural turns of the end regions are reduced one by one by a same variation from a turn close to the central region toward an outermost turn. A value of Δp/p is within a range of 0.015 to 0.1 and k/n is within a range of 0.3 to 0.8, where p is the coil pitch of the central region, Δp is the coil pitch variation of the end regions, n is a total number of turns of the filament, and k is a sum of numbers of turns of the end regions. The k/n preferably satisfies the following equation:=0.72−4.66(Δ)±0.12.