Optical glass, hot-molded article and method of manufacturing the same, optical element and method of manufacturing the same
AssigneeHoya Corporation
InventorMasanori Aniya
Life of this patent
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Abstract
An optical glass includes P2O5, B2O3 and a rare earth oxide as essential components, and in a glass composition based on oxides, the P2O5 content is in the range of over 0 weight % and less than 0.79 weight %, the B2O3 content is in the range of 20-40 weight % and the total content of the rare earth oxide and an oxide selected from the group including of Ta2O5, WO3, TiO2, Nb2O5 and Bi2O3 is in the range of 35-70 weight %. Further, this optical glass has a refractive index (nd) in the range of 1.72-1.83, an Abbe number (υd) in the range of 45-55 and a glass transition temperature (Tg) of 640° C. or less.
Claims13
An optical glass comprising P2O5, B2O3, and a rare earth oxide as essential components, wherein in a glass composition based on oxides,
- P2O5 content is in the range of over 0 weight % and less than 0.79 weight %,
- B2O3 content is in the range of 20 to 40 weight %, and
- the total content of the rare earth oxide and an oxide selected from the group consisting of Ta2O5, WO3, TiO2, Nb2O5 and Bi2O3 is in the range of 35 to 70 weight %,
- the optical glass having
- a refractive index nd of 1.72 to 1.83,
- an Abbe number νd of 45 to 55, and
- an optical glass transition temperature Tg of 640° C. or less.
An optical glass comprising, in a glass composition based on oxides,
- over 0 but less than 0.79 weight % of P2O5,
- 20 to 40 weight % of B2O3, and
- 35 to 60 weight % of a rare earth oxide,
- the optical glass having
- a refractive index nd of 1.72 to 1.83,
- an Abbe number νd of 45 to 55, and
- an optical glass transition temperature Tg of 640° C. or less.
Dependencies are inferred from the claim text.