Patent ID: 8592332

Claim:
An optical glass, comprising, denoted as cation percentages: 1 to 10% of Si 4+ , 25 to 40% of B 3+ , 0 to 10% of Li + , 0 to 5% of Na + , 0 to 5% of K + , 0 to 5% of Mg 2+ , 0 to 5% of Ca 2+ , 0 to 5% of Sr 2+ , 0 to 5% of Ba 2+ , 10 to 40% of Zn 2+ , 10 to 25% of La 3+ , 1 to 15% of Gd 3+ , 0 to 5% of Y 3+ , 0 to 5% of Yb 3+ , 0 to 3% of Zr 4+ , 1 to 15% of Ti 4+ , 0 to 5% of Nb 5+ , 0 to 5% of Ta 5+ , 1 to 20% of W 6+ , 0 to 5% of Te 4+ , 0 to 5% of Ge 4+ , 0 to 5% of Bi 3+ , and 0 to 5% of Al 3+ ; wherein the cation ratio of (B 3+ /(B 3+ +Si 4+ )) is 0.70 to 0.96; the cation ratio of (B 3+ /(La 3+ +Gd 3+ +Y 3+ )) is 1.0 to 2.0; the cation ratio of ((B 3+ +Si 4+ )/(La 3+ +Gd 3+ +Y 3+ ) is 1.0 to 3.0; the cation ratio of (B 3+ /(Ti 4+ +Nb 5+ Ta 5+ +W 6+ )) is 0.8 to 4.0; the cation ratio of ((B 3+ +Si 4+ )/(Ti 4+ +Nb 5+ Ta 5+ +W 6+ )) is 1.5 to 5.0; the cation ratio of (Zn 2+ /(Zn 2+ +Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ )) is 0.8 to 1.0; the cation ratio of ((La 3+ +Gd 3+ +Y 3+ )/(Ti 4+ +Nb 5+ Ta 5+ +W 6+ )) is 1.4 to 3.0; the cation ratio of Ti 4+ /W 6+ is 0.1 to 4.0; the cation ratio of ((Ti 4+ +W 6+ )/(Ti 4+ +Nb 5+ Ta 5+ +W 6+ )) is 0.8 to 1.0; having an Abbé number νd of 28 to 34.4 and a refractive index nd of nd≧1.900 over a range of νd≧31.6 and nd≧−0.01 νd+2.216 over a range of νd≦31.6.