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. 10, 2009
Filed:
Jul. 16, 2007
Kazuo Tachiwana, Tokyo, JP;
Kazuo Tachiwana, Tokyo, JP;
Hoya Corporation, Tokyo, JP;
Abstract
An optical glass having high-refractivity and low-dispersion optical properties and having a low glass transition point so that a heat-treating furnace can be operated for a long period of time. The optical glass has a refractive index nd of at least 1.875, an Abbe's number νd of at least 39.5 and a glass transition point Tg of 700° C. or lower, and contains at least one of LaO, GdO, YOor YbOand at least one of ZrO, TaOor NbO, with a weight ratio of the total content of LaO, GdO, YOand YbOto the total content of SiOand BOof from 3.2 to 5 and the weight ratio of the total content of ZrO, TaOand NbOto the total content of SiOand BOis from 1.1 to 1.5.