Sidley Austin LLP
Optical glass and optical element
The optical glass of the invention comprising: SiO2: 10 to 30%, B2O3: 15 to 35%, Li2O: 0 (inclusive) to 10%, Na2O: 0 (inclusive) to 5%, and K2O: 0 (inclusive) to 5% provided that Li2O+Na2O+K2O: 0 to 15%; MgO: 0 (inclusive) to 25%, CaO: 0 (inclusive) to 25%, BaO: 0 (inclusive) to 25%, SrO: 0 (inclusive) to 25%, and ZnO: 18 to 55% provided that MgO+CaO+BaO+SrO+ZnO: 18 to 55%; and La2O3: 5 to 20%. This optical glass does not substantially contain poisonous materials such as lead and arsenic. This optical glass has given optical constants, has a low Tg, a low TL and a good devitrification resistance, and is suitable for press molding.
Konica Minolta Opto, Inc.
C
C03C
inventional
Toshiharu
Mori