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:
Jun. 28, 2016
Filed:
Apr. 15, 2015
Sumita Optical Glass, Inc., Saitama, Saitama, JP;
Tatsuya Tezuka, Saitama, JP;
Sumita Optical Glass, Inc., Saitama, Saitama, JP;
Abstract
Provided is an optical glass having low specific gravity, low abrasion degree, and high devitrification-proof stability, as well as a preform for precision press molding and an optical element which use such an optical glass. The optical glass has a composition including, in cationic % expression, P: 36 to 40%, Al: 11 to 16%, Mg: 11 to 19%, Ca: greater than 0% and 2% or less, Sr: 0 to 4%, Ba: 25 to 31%, Zn: 0% or more and less than 2.4%, and Y: 2 to 7%, a total amount of Znand Y(Zn+Y) being 3 to 7%. The composition also includes, in anionic % expression, O: 74 to 78%, and F: 22 to 26%. Li, Na, K, La, and Gdare not included. The optical glass further has a refractive index (nd) of 1.58 to 1.60 and an Abbe number (νd) of 67 to 69.