Patent ID: 7091145

Claim:
Lead-free and arsenic-free optical glass with a refractive index n d of 1.84≦n d ≦1.96 and an Abbé number ν d of 27≦ν d ≦36, and having a composition free of arsenic and lead and, in percent by weight based on oxide content, comprising: SiO 2 1 to 8, B 2 O 3 13 to 19.5, La 2 O 3 34 to 50, MgO 0 to 6, CaO 0 to 6, BaO 0 to 6, ZnO 0 to 9, TiO 2 4 to 13, ZrO 2 0 to 11, Nb 2 O 5 6 to 14.5, wherein a sum total amount of MgO+CaO+BaO+ZnO is from 1 to 10.