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. 03, 1987
Filed:
Apr. 03, 1985
Shigeaki Ohmi, Tokorozawa, JP;
Seiichi Shingaki, Akishima, JP;
Hiroyuki Sakai, Akishima, JP;
Yoshiyuki Asahara, Higashiyamato, JP;
Hoya Corporation, Tokyo, JP;
Abstract
A process for producing a glass product having .DELTA.n, the difference between the central and peripheral portions of the glass, greater than 0.04. This process utilizes a porous glass body which is produced via a phase separation technique. A dopant selected from the group consisting of (1) TlNO.sub.3, (2) TlNO.sub.3 and an alkali metal compound and (3) TlNO.sub.3, Pb(NO.sub.3).sub.2 and an alkali metal compound is then permeated into the micropores of the porous glass product. A concentration gradient of the dopant is then formed by leaching out a portion of the dopant from the micropores. After the dopant is solidified in the mircopores, the porous glass product is dried. A heat-treatment step then serves to collapse the micropores. A glass product having a gradient of refractive indices is therby obtained.