Optical glass having an anomalous dispersion
AssigneeKabushiki Kaisha Ohara
InventorsJunko Ishioka, Masahiro Onozawa
Life of this patent
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Abstract
An optical glass having a positive anomalous dispersion comprises, in mass %, 1 SiO2 40-60% B2O3 3-9% TiO2 3-15% Nb2O5 0.1-5.0% Al2O3 3-15% WO3 0.5-5.0% MgO 0-3% CaO 0-3% SrO 0-3% BaO 0-3% K2O exceeding 10% and up to 21% Na2O 0-10% Sb2O3 0-1% and a fluoride or fluorides of a metal element or elements 3-10%, contained in the above metal oxides, a total amount of F contained in the fluoride or fluorides is free of PbO and As2O3 except for unavoidable mixing of these compounds as impurities, has optical constants of a refractive index (nd) within the range from 1.48 to less than 1.55 and an Abbe number (νd) within the range from 45 to 55, and has an anomalous dispersion (Δθg,F) of +0.0010 or over.
Claims10
An optical glass having a positive anomalous dispersion comprising, in mass %,
- 9 SiO2 40-60% B2O3 3-9% TiO2 3-15% Nb2O5 0.1-5.0% Al2O3 3-15% WO3 0.5-5.0% MgO 0-3% CaO 0-3% SrO 0-3% BaO 0-3% K2O exceeding 10% and up to 21% Na2O 0-10% Sb2O3 0-1% and a fluoride or fluorides of a metal element or elements 3-10%, contained in the above metal oxides, a total amount of F contained in the fluoride or fluorides
- being free of PbO and As2O3 except for unavoidable mixing of these compounds as impurities, having optical constants of a refractive index (nd) within the range from 1.48 to less than 1.55 and an Abbe number (νd) within the range from 45 to 55, and having an anomalous dispersion (Δθg,F) of +0.0010 or over.
An optical glass having a positive anomalous dispersion comprising, in mass %,
- 10 SiO2 40-60% B2O3 3-9% TiO2 + WO3 4-20% in which TiO2 3-15% and WO3 0.5-5.0% Nb2O5 0.1-5.0% Al2O3 3-15% MgO 0-3% CaO 0-3% SrO 0-3% BaO 0-3% K2O + Na2O less than 25% in which K2O exceeding 10% and up to 21% and Na2O 0-10% Sb2O3 0-1% and a fluoride or fluorides of a metal element or elements 3-10%, contained in the above metal oxides, a total amount of F contained in the fluoride or fluorides
- being free of PbO and AS2O3 except for unavoidable mixing of these compounds as impurities, having optical constants of a refractive index (nd) within the range from 1.48 to less than 1.55 and an Abbe number (νd) within the range from 45 to 55, and having an anomalous dispersion (Δθg,F) of +0.0010 or over.
Dependencies are inferred from the claim text.