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:
Oct. 27, 1992
Filed:
Jul. 08, 1991
Applicant:
Inventors:
Michihisa Kyoto, Yokohama, JP;
Akira Urano, Yokohama, JP;
Yoichi Ishiguro, Yokohama, JP;
Minoru Watanabe, Yokohama, JP;
Assignee:
Sumitomo Electric Industries, Ltd., Osaka, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C03C / ;
U.S. Cl.
CPC ...
65-312 ; 65DI / ; 65-314 ; 65 182 ; 65 301 ;
Abstract
A method for producing a glass preform for use in the fabrication of an optical fiber, which includes the steps of forming a glass soot preform from a glass-forming raw material and heating the soot preform in an atmosphere containing SiF.sub.4 under a pressure higher than 2 atm. for a period of time sufficient to add fluorine during the time between the formation of the soot preform and the vitrification of it, fluorine is added at a high rate and in a larger amount.