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:
Feb. 09, 2010
Filed:
May. 15, 2006
Kenji Okada, Yotsukaido, JP;
Koichi Harada, Yachiyo, JP;
Shunichirou Hirafune, Sakura, JP;
Munehisa Fujimaki, Sakura, JP;
Kenji Okada, Yotsukaido, JP;
Koichi Harada, Yachiyo, JP;
Shunichirou Hirafune, Sakura, JP;
Munehisa Fujimaki, Sakura, JP;
Fujikura Ltd., Tokyo, JP;
Abstract
A drawing method for a bare optical fiber, comprises the steps of: melting an optical fiber preform using a heating device and drawing the bare optical fiber; and naturally cooling down the bare optical fiber or forcibly cooling down the bare optical fiber by a cooling device after the heating and melting step, wherein a temperature history during the drawing the optical fiber preform to obtain the bare optical fiber in the heating device satisfies a relational expression: T≦−0.01X+12 where a time period when the heated and molten portion of the optical fiber preform heated and molten by the heating device reaches 1800° C. or higher is T (min) and a OH group concentration in a cladding layer of the optical fiber preform is X (wtppm).