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:
Aug. 18, 2009
Filed:
Oct. 11, 2005
Kazutaka Hayashi, Akishima, JP;
Kazutaka Hayashi, Akishima, JP;
Hoya Corporation, Tokyo, JP;
Abstract
Provided is an optical glass for precision press-molding is free from degradations in product quality caused by a surface altered layer such as fogging, browning, etc., and a precision press-molding preform and an optical element provided are formed of the above glass. The optical glass is a glass which contains BO, LaOand ZnO and is used as a glass material for precision press-molding, and contains, by mol %, 20 to 60% of BO, 0 to 20% of SiO, 22 to 42% of ZnO, 5 to 24% of LaO, 0 to 20% of GdO, provided that the total content of LaOand GdOis 10 to 24%, 0 to 10% of ZrO, 0 to 10% of TaO, 0 to 10% of WO, 0 to 10% of NbO, 0 to 10% of TiO, 0 to 10% of BiO, 0 to 10% of GeO, 0 to 10% of GaO, 0 to 10% of AlO, 0 to 10% of BaO, 0 to 10% of YOand 0 to 10% of YbO, has an Abbe's number (νd) of 40 or more and is substantially free of lithium.