Patent ID: 7141525

Claim:
A high refractive index, high dispersion optical glass for precision molding, having a yield temperature (At) of at most 580° C., refractive index (nd) of at least 1.89 and Abbe number (νd) of at most 23.0, which is represented, in term of atoms for making up the glass, by the following chemical composition (wt %): P 2 O 5 3 to 20% B 2 O 3 0 to 5% GeO 2 more than 14 to 37% Sum of P 2 O 5 + B 2 O 3 + GeO 2 24 to 43% Li 2 O 0 to 5% Na 2 O 0 to 8% K 2 O 0 to 10% Sum of Li 2 O + Na 2 O + K 2 O 1 to 10% Nb 2 O 5 0 to 50% Bi 2 O 3 12 to 67% BaO 0 to 5% WO 3 0 to 12%.