Patent ID: 7846860

Claim:
An optical glass comprising, in percent by weight, 2-11% SiO 2 , 28-45% B 2 O 3 , 2-12% CaO, 3-18% ZnO, 1-8% ZrO 2 , 9-40% La 2 O 3 , 0.5-11% Gd 2 O 3 , 0-10% Y 2 O 3 , 0-3% Al 2 O 3 , at most 8% R 2 O, where R 20 is the total of Li 2 O, Na 2 O and K 2 O, at most 20% R′O, where R′O is the total of MgO, CaO, SrO and BaO, 1-7% Li 2 O, 6-8% SrO, 0-3% WO 3 , 0-2% Nb 2 O 5 , and 0-1% Sb 2 O 3 .