Abstract: An optical glass comprising, by mass %, 12 to 40% of SiO2, 15% or more but less than 42% of Nb2O5, 2% or more but less than 18% of TiO2, (provided that Nb2O5/TiO2 is over 0.6), 0.1 to 20% of Li2O, 0.1 to 15% of Na2O, and 0.1 to 25% of K2O, and having an Abbe's number ?d of 20 to 30, a ?Pg,F of 0.016 or less and a liquidus temperature of 1,200° C. or lower.

Abstract: The present invention relates to an optical glass, a preform for precision press molding, methods for manufacturing the same, and an image pickup device. The optical glass of the present invention not only has a high refractive index, a high dispersion property, and good precision press moldability, but also has good stability with respect to devitrification when reheated (referred to as “devitrification stability upon reheating”), and is an optical glass with a good partial dispersion ratio (Pg, F).

Abstract: The present invention relates to an optical glass with a high refractive index and good precision press moldability, and a preform for precision press molding and an optical element that are comprised of the optical glass. The present invention further relates to a method of manufacturing an optical element, a lens unit being equipped with an optical element and an image pickup device being equipped with a lens unit.

Abstract: An optical glass comprising, by mass %, 12 to 40% of SiO2, 15% or more but less than 42% of Nb2O5, 2% or more but less than 18% of TiO2, (provided that Nb2O5/TiO2 is over 0.6), 0.1 to 20% of Li2O, 0.1 to 15% of Na2O, and 0.1 to 25% of K2O, and having an Abbe's number ?d of 20 to 30, a ?Pg,F of 0.016 or less and a liquidus temperature of 1,200° C. or lower.

Abstract: An optical glass comprising, by mass %, 12 to 40% of SiO2, 15% or more but less than 42% of Nb2O5, 2% or more but less than 18% of TiO2, (provided that Nb2O5/TiO2 is over 0.6), 0.1 to 20% of Li2O, 0.1 to 15% of Na2O, and 0.1 to 25% of K2O, and having an Abbe's number ?d of 20 to 30, a ?Pg,F of 0.016 or less and a liquidus temperature of 1,200° C. or lower.

Abstract: An optical glass that is an oxide glass and comprises, by cationic %, 20 to 40% of a total of Si4+ and B3+, 15 to 40% of a total of Nb5+, Ti4+, W6+ and Zr4+, 0.2 to 20% of a total of Zn2+, Ba2+, Sr2+ and Ca2+, and 15 to 55% of a total of Li+, Na+ and K+, the cationic ratio of the content of B3+ to the total content of B3+ and Si4+ being 0.01-0.5, the cationic ratio of the content of Zr4+ to the total content of Nb5+, Ti4+, W6+ and Zr4+ being 0.05 or less, the molar ratio of the total content of Zn2+ and Ba2+ to the total content of Zn2+, Ba2+, Sr2+ and Ca2+ being 0.8-1, the optical glass having a refractive index nd of 1.815 or more and an Abbe's number ?d of 29 or less.

Abstract: The present invention relates to an optical glass with a high refractive index and good precision press moldability, and a preform for precision press molding and an optical element that are comprised of the optical glass. The present invention further relates to a method of manufacturing an optical element, a lens unit being equipped with an optical element and an image pickup device being equipped with a lens unit.

Abstract: The present invention relates to an optical glass with a high refractive index and good precision press moldability, and a preform for precision press molding and an optical element that are comprised of the optical glass. The present invention further relates to a method of manufacturing an optical element, a lens unit being equipped with an optical element and an image pickup device being equipped with a lens unit.

Abstract: The present invention relates to an optical glass, a preform for precision press molding, methods for manufacturing the same, and an image pickup device. The optical glass of the present invention not only has a high refractive index, a high dispersion property, and good precision press moldability, but also has good stability with respect to devitrification when reheated (referred to as “devitrification stability upon reheating”), and is an optical glass with a good partial dispersion ratio (Pg, F).

Abstract: The present invention relates to an optical glass with a high refractive index and good precision press moldability, and a preform for precision press molding and an optical element that are comprised of the optical glass. The present invention further relates to a method of manufacturing an optical element, a lens unit being equipped with an optical element and an image pickup device being equipped with a lens unit.

Abstract: An optical glass that is an oxide glass and comprises, by cationic %, 20 to 40% of a total of Si4+ and B3+, 15 to 40% of a total of Nb5+, Ti4+, W6+ and Zr4+, 0.2 to 20% of a total of Zn2+, Ba2+, Sr2+ and Ca2+, and 15 to 55% of a total of Li+, Na+ and K+, the cationic ratio of the content of B3+ to the total content of B3+ and Si4+ being 0.01-0.5, the cationic ratio of the content of Zr4+ to the total content of Nb5+, Ti4+, W6+ and Zr4+ being 0.05 or less, the molar ratio of the total content of Zn2+ and Ba2+ to the total content of Zn2+, Ba2+, Sr2+ and Ca2+ being 0.8-1, the optical glass having a refractive index nd of 1.815 or more and an Abbe's number ?d of 29 or less.

Abstract: An optical glass comprising, by mass %, 12 to 40% of SiO2, 15% or more but less than 42% of Nb2O5, 2% or more but less than 18% of TiO2, (provided that Nb2O5/TiO2 is over 0.6), 0.1 to 20% of Li2O, 0.1 to 15% of Na2O, and 0.1 to 25% of K2O, and having an Abbe's number ?d of 20 to 30, a ?Pg,F of 0.016 or less and a liquidus temperature of 1,200° C. or lower.