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. 05, 1994
Filed:
Dec. 24, 1992
Applicant:
Inventors:
Futoshi Ishizaki, Sagamihara, JP;
Muneo Nakahara, Sagamihara, JP;
Hiroshi Shishido, Sagamihara, JP;
Katsuhiko Yamaguchi, Sagamihara, JP;
Assignee:
Kabushiki Kaisha Ohara, Kanagawa, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C03C / ; C03C / ;
U.S. Cl.
CPC ...
501 67 ; 501 77 ; 501 79 ; 501903 ;
Abstract
An optical glass which is a SiO.sub.2 --B.sub.2 O.sub.3 --(TiO.sub.2 +ZrO.sub.2)--SrO--BaO--R'.sub.2 O system of a specific composition range exhibits optical constants of a refractive index (Nd) of 1.57-1.75 and Abbe number (.nu.d) of 30-55, is free of PbO and has improved stability against devitrification and tinting and improved chemical durability.