Optical glass, shapable glass material for press-shaping, optical element and process for producing optical element
AssigneeHoya Corporation
InventorKoichiro Shiraishi
Life of this patent
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Abstract
An optical glass that has high-refractivity and high-dispersion properties, that is less colored and that is suitable for a shapable glass material for press-shaping and various optical elements, the optical glass containing, as glass components and by mass %, 10 to 32% of P2O5, 27 to 65% of Nb2O5, 10 to 30% of BaO, 0 to 12% of B2O3, more than 0% but not more than 20% of TiO2, more than 0% but not more than 10% of total of Li2O, Na2O and K2O, and more than 0% but not more than 1%, based on the total content of the said glass components, of Sb2O3, and having a light transmittance that is 50% at a wavelength of 420 nm or shorter.
Claims11
A process for producing an optical element, which comprises (a) softening a shapable optical glass material for press-shaping under heat and (b) press-shaping the softened optical glass;
- wherein the optical glass comprises, as glass components and by mass %, 10 to 32% of P2O5, 27 to 65% of Nb2O5, 10 to 30% of BaO, 0 to 12% of B2O3, more than 0% but not more than 20% of TiO2, more than 0% but not more than 10% of total of Li2O, Na2O and K2O, and more than 0% but not more than 1%, based on the total content of the said glass components, of Sb2O3,
- wherein the amount of BaO and Sb9O3 are adjusted to provide the optical glass with a light transmittance that is 50% at a wavelength of 420 nm or shorter, and
- wherein the optical glass has a refractive index (nd) of at least 1.86 and an Abbe's number (νd) of 24 or less.
Dependencies are inferred from the claim text.