Optical glass and optical element
AssigneeSumita Optical Glass, Inc.
InventorsKoichi Tsuchiya, Hideaki Takaku
Life of this patent
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Abstract
An optical glass is provided which does not contain components negatively affecting the environment as environmental loads, and is less colored while having a refractive index maintained moderately high. The optical glass has a composition including, in % by mass, 30% or more and 47% or less of SiO2, 0% or more and 10% or less of B2O3, 3% or more and 12% or less of Na2O, 0% or more and 5% or less of Li2O, 0% or more and 3.8% or less of CaO, 28% or more and 43% or less of BaO, 3% or more and 16% or less of ZnO, 0% or more and 8% or less of ZrO2, 0% or more and 15% or less of La2O3, where Sb2O3 is excluded from the composition, wherein the optical glass does not contain any of PbO, As2O3, and K2O.
Claims17
An optical glass having a composition including only, in % by mass:
- 30% or more and 47% or less of SiO2;
- 0% or more and 10% or less of B2O3;
- 3% or more and 12% or less of Na2O;
- 0% or more and 5% or less of Li2O;
- 0% or more and 3.8% or less of CaO;
- 28% or more and 43% or less of BaO;
- 3% or more and 16% or less of ZnO;
- 0.5% or more and 8% or less of ZrO2;
- and
- 0% or more and 15% or less of La2O3,
- wherein the composition optionally includes Sb2O3,
- where the proportions of SiO2, B2O3, Na2O, Li2O, CaO, BaO, ZnO, ZrO2, and La2O3, are relative to the sum of the contents of the components except for Sb2O3, if included, constituting the composition, and
- the optical glass has a proportion of a content of BaO in a sum of contents of CaO and BaO of 91.5% by mass or more.
Dependencies are inferred from the claim text.