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US 8,410,008 B2Granted
Optical glass
AssigneeHoya Corporation
InventorsTomoaki Negishi, Xuelu Zou
Life of this patent
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Abstract
An optical glass that is an oxide glass having a very high refractive index in spite of its low-dispersion property, having excellent glass stability and having less susceptibility to coloring.
Claims16
An optical glass that is an oxide glass and that comprises, by cationic %,
- 0 to 30% of Si4+,
- 10 to 50% of B3+,
- less than 5% of total of Li+, Na+ and K+,
- less than 1% of total of Mg2+, Ca2+ and Sr2+,
- 0 to 8% of Ba2+,
- 0.1 to 15% of Zn2+,
- 10 to 50% of La3+,
- 0.1 to 20% of Gd3+,
- 0 to 15% of Y3+,
- 0 to 10% of Yb3+,
- 0 to 20% of Zr4+,
- 0.1 to 22% of Ti4+,
- 0 to 20% of Nb5+,
- 0 to 8% of Ta5+,
- 0 to 5% of W6+,
- 0 to 4% of Ge4+,
- 0 to 10% of Bi3+, and
- 0 to 10% of Al3+,
- the cationic ratio of the content of Si4+ to the content of B3+, Si4+/B3+, being less than 1.0, the optical glass having a refractive index nd of 1.930 to 2.2, an Abbe's number νd of 26 to 45, and a glass transition temperature Tg of 630° C. or higher.
16 more elements
Dependencies are inferred from the claim text.