Optical glass
AssigneeKabushiki Kaisha Ohara
InventorKoji Shimizu
Life of this patent
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Abstract
An optical glass comprising SiO2, B2O3 and La2O3 and one or more oxides selected from the group consisting of ZrO2, Nb2O5 and Ta2O5, having a refractive index of 1.83 or over and an Abbe number of 35 or over and being free of F.
Claims21
An optical glass comprising SiO2, where the amount of SiO2 is 2-9 mass %, B2O3, La2O3, Nb2O5 and Ta2O5, where the Nb2O5 and Ta2O5 are essential components and where the total amount of Ta2O5+Nb2O5 is 18-24 mass %, said optical glass having a refractive index of 1.83 or over and an Abbe number of 35 or over and being free of F, said optical glass further comprising Li2O in an amount of 0.5 mass % or over and having a glass transition temperature (Tg) of 670° or below.
An optical glass comprising, in mass % calculated on oxide basis,
- SiO2
- 2-9% and/or
- B2O3
- 8.0-less than 18% and/or
- La2O3
- 33-50% and/or
- Gd2O3
- 3-20% and/or
- ZrO2
- 4.5-7% and/or
- Nb2O5
- 0.1-3% and/or
- Ta2O5
- 15-25%
- where a total amount of Ta2O5+Nb2O5 is 17-24% and
- Li2O
- 0.5-3% and/or
- WO3
- 0-3% and/or
- ZnO
- 0-10% and/or
- RO
- 0-5%
- where R is one or more elements selected from the group consisting of Mg, Ca, Sr and Ba and/or
- Sb2O3
- 0-1%
- and being free of F and having a refractive index within a range from 1.85 to 1.90 and Abbe number within a range from 40 to 42 and a glass transition temperature (Tg) of 670° or below.
An optical glass comprising, in mass % calculated on oxide basis,
- SiO2
- 3-9%
- B2O3
- 9.5-less than 18%
- La2O3
- 33-45%
- Gd2O3
- 3-18%
- ZrO2
- 5-7%
- Nb2O5
- 0.1-3% and
- Ta2O5
- 15-25%
- where a total amount of Ta2O5+Nb2O5 is 16-24% and
- Li2O
- 0.5-3% and/or
- WO3
- 0-3% and/or
- ZnO
- 0-10% and/or
- RO
- 0-5%
- where R is one or more elements selected from the group consisting of Mg, Ca, Sr and Ba and/or
- Sb2O3
- 0-1%
- and being free of F and having a refractive index within a range from 1.85 to 1.90 and Abbe number within a range from 40 to 42 and a glass transition temperature (Tg) of 670° or below.
Dependencies are inferred from the claim text.