OPTICAL GLASS, GLASS GOB FOR PRESS FORMING, OPTICAL PART, AND METHODS FOR MANUFACTURING GLASS SHAPED ARTICLE AND OPTICAL PART

摘要

PROBLEM TO BE SOLVED: To provide an optical glass having a high light transmissivity, a high refractive index, and an excellent manufacturing stability.;SOLUTION: The optical glass contains, as glass components, at least one of CaO and SrO, SiO₂, B₂O₃, La₂O₃, Nb₂O₅, TiO₂, and BaO, and is substantially composed of SiO₂ of 1-18%, B₂O₃ of 3-24% (wherein the content of B₂O₃ vs. that of SiO₂, viz. B₂O₃/SiO₂, is 1), La₂O₃ of 10-50%, Nb₂O₅ of 1-30%, TiO₂ of 1-30%, BaO of 6% and ≤25%, CaO of 7%, SrO of ≤6%, MgO of 0-13% (wherein the total content of BaO, CaO, SrO and MgO is ≤40%), ZnO of 0-15%, ZrO₂ of 0-15%, Al₂O₃ of 0-10%, Gd₂O₃ of 0-20%, Y₂O₃ of ≥0% and 2%, Yb₂O₃ of 0-5%, Ta₂O₅ of 0-18%, Bi₂O₃ of 0-20%, GeO₂ of 0-10%, Sb₂O₃ of ≥0% and 2%, and SnO₂ of ≥0% and 2% in wt.%; and has a refractive index (n_d) of 1.8, an Abbe's number (ν_d) of 28-40, and a density of ≥4.2 g/cm³.;COPYRIGHT: (C)2006,JPO&NCIPI