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:
Jun. 22, 1993
Filed:
Aug. 31, 1992
Applicant:
Inventors:
Assignee:
Sumitomo Electric Industries, Ltd., Osaka, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C03B / ;
U.S. Cl.
CPC ...
65-312 ; 65 182 ; 65900 ; 65DI / ;
Abstract
A method for producing a glass preform, which method comprises forming a soot preform of glass fine particles comprising SiO.sub.2 by flame hydrolysis or solution hydrolysis of a starting glass material and sintering the soot preform in an atmosphere containing at least SiF.sub.4 to obtain a glass preform which is free from an increase in absorption due to impurities and has sufficiently low attenuation of light transmission.