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:
Feb. 13, 2001
Filed:
Sep. 29, 1999
Michiko Morishita, Sagamihara, JP;
Kabushiki Kaisha Ohara, , JP;
Abstract
Ophthalmic and optical glasses have a composition in weight percent of 4.5-9.5% SiO,, 10-19.5% B,O,, 0-3% Al,O,, 0-5% GeO,, 18—less than 23% La,O,, 0.3—less than 2% Gd,O,, 5.5-13.5% TiO,, 0-7.5% ZrO,, 15-21% Nb,O,, 0-1.5% Ta,O,, 0.3-5% WO,, with the proviso that (Ta,O,+WO,)/B,O,is 0.5 or below in the ration terms of weight, 2.1-10% ZnO, 0-5% MgO, 7-12.5% CaO, 0-5% SrO, 0-4% BaO, ≧0.1% Li,O+Na,O+K,O in which 0-1% Li,O, 0-1% Na,O and 0-1% K,O, 0-0.5% As,O,and 0-0.5% Sb,O,and have a specific gravity of 4.1 or below, and optical constants of a refractive index (nd) exceeding 1.88 and up to 1.93 and an Abbe number j(&ngr; d) within a range from 28 to 31. A preferable range of Nb,O,is 15.5—less than 20.5% and a more preferable range of Nb,O,is less 15.5-20%.