Patent ID: 7074732

Claim:
A zinc-containing optical glass with a refractive index (n d ) being in the range of from about 1.52 to about 1.66 and an Abbe number (V d ) being substantially in the range of from about 35 to about 54, said zinc-containing optical glass comprising, on an oxide basis, the composition of: Percentage Material by weight SiO 2 38â€“58 ZnO 0.3â€“42 PbO 0â€“<30 sum of ZnO + PbO >30â€“55 Li 2 O 0â€“<3 Na 2 O 0â€“14 K 2 O 0â€“12 sum of â‰§2 Li 2 O + Na 2 O + K 2 O F 0â€“3 MgO 0â€“6 CaO 0â€“<5 SrO 0â€“6 BaO 0â€“<0.9 B 2 O 3 0â€“<1 Al 2 O 3 0â€“<1.5 ZrO 2 0â€“<2 Cs 2 O 0 to about 2.5; â‰§0% by weight of at least one refining agent.