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:
Mar. 02, 1976
Filed:
Jul. 31, 1974
Toshiharu Yamashita, Hachioji, JA;
Hoya Glass Works, Ltd., Tokyo, JA;
Hoya Lens Co., Ltd., Tokyo, JA;
Abstract
A reversible light-sensitive glass, e.g., for eyeglasses, comprising 100 parts of a base glass composition consisting, in weight percent, of 48 to 62% SiO.sub.2, 15 to 22% B.sub.2 O.sub.3, 0 to 11% Al.sub.2 O.sub.3, 0 to 10% ZrO.sub.2, 6<Al.sub.2 O.sub.3 + ZrO.sub.2 <13%, 6 to 16% R.sub.2 O where R represents Li, Na or K, 0.5 to 7% BaO, BaO/R.sub.2 O 0.035 to 0.65, 0 to 2% TiO.sub.2, 0 to 2.5%Nd.sub.2 O.sub.3, 0 to 2.5% Ho.sub.2 O.sub.3, 0 to 2.5% Er.sub.2 O.sub.3, 0.2<Nd.sub.2 O.sub.3 + Ho.sub.2 O.sub.3 + Er.sub.2 O.sub.3 <2.5% and 0.002 to 0.03%CuO, and as light-sensitive components 0.15 to 1.0 part of Ag and more than the Ag chemical equivalent of halogens selected from the group consisting of Cl, Br and I.