Optical glass, precision press-molding preform, optical element and their production processes as well as image-sensing device
AssigneeHoya Corporation
InventorHiroki Takazawa
Life of this patent
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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 νd of 29 or less.
Claims26
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 νd of 29 or less.
Dependencies are inferred from the claim text.