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. 18, 1978
Filed:
Dec. 10, 1976
Hiroji Sagara, Akikawa, JA;
Hoya Corporation, Tokyo, JA;
Abstract
A glass for an eye glass lens having a composition comprising, in weight percent, 36 to 50% SiO.sub.2 + Al.sub.2 O.sub.3 + B.sub.2 O.sub.3, but with 20 to 50% SiO.sub.2, 0 to 13% Al.sub.2 O.sub.3 and 0 to 20% B.sub.2 O.sub.3 ; 5 to 35% CaO + MgO, but with 5 to 35% CaO and 0 to 20% MgO; 1 to 20% Li.sub.2 O + Na.sub.2 O + K.sub.2 O, but with 0 to 15% Li.sub.2 O and 0 to 15% Na.sub.2 O + K.sub.2 O; 16 to 34% ZrO.sub.2 + TiO.sub.2 + Nb.sub.2 O.sub.5, but with 0 to 11% ZrO.sub.2, 0 to 3% TiO.sub.2 and 8 to 30% Nb.sub.2 O.sub.5 ; 0 to 15% BaO + SrO + ZnO; and 0 to 15% La.sub.2 O.sub.3 + Ta.sub.2 O.sub.5 + WO.sub.3 ; with the glass having further a refractive index and .gtoreq.1.69, an Abbe number .nu.d.gtoreq.40, and a specific gravity .ltoreq.3.2.