Optical glass
AssigneeKabushiki Kaisha
InventorKoji Shimizu
Life of this patent
Estimating the term…
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.
Claims25
An optical glass comprising SiO2, B2O3 and La2O3 and one or more oxides selected from the group consisting of ZrO2, Nb2O5 and Ta2O5, where the total amount of Gd2O5+Nb2O5 is less than 10 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.
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 17-28% and
- Li2O
- 0-3%
- 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.
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 16-28% and
- Li2O
- 0-3%
- 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.
An optical glass comprising Ta2O5 and Nb2O5, being free of F and having a specific gravity within a range from 4.60 to 5.25 wherein a total amount of Ta2O5 and Nb2O5 to the total mass of the glass composition is 18-23%.
Dependencies are inferred from the claim text.