Patent ID: 7491667
Filing Date: 2009-02-17
Classification: C03B,C03C

Abstract:
1. An optical glass comprising, by % by weight, 14 to 30% of B 10 to 40% of La 1 to 30% of Gd 6 to 26% of ZnO, 0 to 20% of WO 0 to 20% of Ta 0 to 10% of Nb 0 to 8% of TiO 0 to 10% of SiO provided that the content of SiO 2 is 0 to 1.9% when the content of Li 2 O is over 0%, 0 to 5% of Li 0 to 5% of Na 0 to 5% of K 0 to 5% of MgO, 0 to 5% of CaO, 0 to 5% of SrO, 0 to 5% of BaO, 0 to 10% of Y 0 to 10% of Yb 0 to 10% of ZrO 0 to 10% of Bi 0 to 1% of Sb and the optical glass is devoid of F and PbO having a refractive index (nd) of over 1.82 but not more than 1.86, an Abbe's number (νd) of 30 to 39.5 and a glass transition temperature (Tg) of 630° C. or lower.