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:
May. 25, 1976
Filed:
Jan. 03, 1975
Applicant:
Inventors:
Tetsuro Izumitani, Hino, JA;
Hiroji Sagara, Tokyo, JA;
Assignee:
Hoya Glass Works, Ltd., Tokyo, JA;
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C03C / ; C03C / ; C03C / ; C03C / ;
U.S. Cl.
CPC ...
106 / ; 106 53 ; 106 54 ; 106 / ;
Abstract
A thorium oxide-free B.sub.2 O.sub.3 --La.sub.2 O.sub.3 --Gd.sub.2 O.sub.3 --Ta.sub.2 O.sub.5 system optical glass is improved in stability to devitrification and in optical constants by introducing at least one of a divalent metal oxide such as ZnO, CdO, PbO, BaO, SrO, CaO, and MgO into the optical glass composition or replacing Ta.sub.2 O.sub.5 of the optical glass composition with a divalent metal oxide. If desired, the glass may be free of CdO.