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US 12,699,218 B2Granted
Optical glass, optical element blank, and optical element
AssigneeHoya Corporation
InventorShungo Kuwatani
Life of this patent
Estimating the term…
Abstract
An optical glass which has a refractive index nd of 1.80 to 2.00 and an Abbe number νd of 17 to 22, contains 25 to 40 mass % of P2O5, 15 to 40 mass % of Nb2O5, 10 to 35 mass % of TiO2, 3 to 12 mass % of B2O3, 0 to 15 mass % of BaO, greater than 0 mass % and 10 mass % or less of Li2O, greater than 0 mass % and 15 mass % or less of a total of Li2O, Na2O, K2O, and Cs2O [Li2O+Na2O+K2O+Cs2O], has a mass ratio [TiO2/(Nb2O5+TiO2+WO3+Bi2O3+Ta2O5)] of TiO2 to the total of Nb2O5, TiO2, WO3, Bi2O3, and Ta2O5 of 0.33 to 0.60, and does not substantially contain F.
Claims20
Optical glass,
- wherein a refractive index nd is 1.80 to 2.00,
- an Abbe's number νd is 17 to 22,
- a content of P2O5 is 25 to 40% by mass,
- a content of Nb2O5 is 15 to 40% by mass,
- a content of TiO2 is 10 to 35% by mass,
- a content of B2O3 is 3 to 12% by mass,
- a content of BaO is 0 to 5% by mass,
- a content of Li2O is greater than 0% by mass and 10% by mass or less,
- a total content [Li2O+Na2O+K2O+Cs2O] of Li2O, Na2O, K2O, and Cs2O is greater than 0% by mass and 15% by mass or less,
- a mass ratio [TiO2/(Nb2O5+TiO2+WO3+Bi2O3+Ta2O5)] of the content of TiO2 to a total content of Nb2O5, TiO2, WO3, Bi2O3, and Ta2O5 is 0.37 to 0.60, and
- F is not substantially contained.
8 more elements
Phosphate optical glass containing Nb2O5 and TiO2,
- wherein a mass ratio [(P2O5+B2O3+SiO2+Al2O3)/(TiO2+Nb2O5+WO3+Bi2O3)] of the total content of P2O5, B2O3, SiO2, and Al2O3 to the total content of TiO2, Nb2O5, WO3, and Bi2O3 is 0.50 to 0.85,
- an Abbe's number νd is 17 or more, and
- a refractive index nd and a specific gravity d satisfy Expression (1) described below:
- nd≥0.5×d+0.225 (1).
1 more element
Dependencies are inferred from the claim text.