Optical glass
AssigneeNippon Electric Glass Co., Ltd.
InventorsSatoko Konoshita, Takahiro Matano
Life of this patent
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Abstract
The present invention provides an optical glass that has a high refractive index property and excels in a light transmittance property in the visible range and in resistance to devitrification. The optical glass contains from 3 to 18 mass % of SiO2, from 5 to 11.5 mass % of B2O3, from 0 to 7 mass % of Al2O3, from 0 to 11 mass % of CaO, 1 mass % or less of ZnO, from 7 to 20 mass % of TiO2, from 3 to 38 mass % of Nb2O5, from 27 to 49.8 mass % of La2O3, from 6 to 14 mass % of Gd2O3, from 0 to 5 mass % of Y2O3, less than 6 mass % of Ta2O5, and 0.6 mass % or less of WO3, with a ratio of B2O3/SiO2 being from 1 to 2.
Claims20
An optical glass comprising from 3 to 11.5 mass % of SiO2, from 5 to 11.5 mass % of B2O3, from 0 to 7 mass % of Al2O3, from 0 to 11 mass % of CaO, 0.1 mass % or less of ZnO, from 10 to 16 mass % of TiO2, from 3 to 38 mass % of Nb2O5, from 27 to 49.8 mass % of La2O3, from 6 to 14 mass % of Gd2O3, from 0 to 5 mass % of Y2O3, less than 6 mass % of Ta2O5, and 0.6 mass % or less of WO3, with a ratio of B2O3/SiO2 being from 1 to 2.
Dependencies are inferred from the claim text.