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US 2003/0191007 A1Published application
Optical glass
AssigneeKabushiki Kaisha Ohara
InventorsShinya Mashiko, Masahiro Onozawa
Life of this patent
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Abstract
An optical glass which is free of PbO which causes environmental pollution and also is free of expensive Ta2O5 and Nb2O5 comprises, in mass %, 1 SiO2 40-60% B2O3 1 to less than 5% Al2O3 0-3% TiO2 15.5-19% ZrO2 0-1% WO3 0-5% ZnO 0-5% CaO 0-4% SrO 0-10% BaO 10.5-20% Na2O + K2O 11-20% in which Na2O 0-9% and K2O 6-20% a refining agent 0-1% and has optical constants of a refractive index (nd) within a range from 1.55 to less than 1.67 and an Abbe number (νd) within a range from 30 to 45.
Claims3
An optical glass comprising, in mass %,
- 8 SiO2 40-60% B2O3 1 to less than 5% Al2O3 0-3% TiO2 15.5-19% ZrO2 0-1% WO3 0-5% ZnO 0-5% CaO 0-4% SrO 0-10% BaO 10.5-20% Na2O + K2O 11-20% in which Na2O 0-9% and K2O 6-20% a refining agent 0-1%
- and having optical constants of a refractive index (nd) within a range from 1.55 to less than 1.67 and an Abbe number (νd) within a range from 30 to 45.
An optical glass comprising, in mass %,
- 9 SiO2 45-60% B2O3 1 to less than 5% Al2O3 0-3% TiO2 16-19% ZrO2 0-1% WO3 0-5% ZnO 0-5% CaO + SrO + BaO 11-20% in which CaO 0-4% SrO 0-8% and BaO 11-20% Na2O + K2O 11-20% in which Na2O 0-9% and K2O 6-20% a refining agent 0-1%
- and having optical constants of a refractive index (nd) within a range from 1.55 to less than 1.67 and an Abbe number (νd) within a range from 30 to 45.
Dependencies are inferred from the claim text.