US Patent 7892998 Optical glass and optical element

An optical glass includes, based on a total weight of the optical glass: 15 to 40 weight percent of P2O5; 0 to 10 weight percent of Li2O; 0 to 20 weight percent of Na2O; 0 to 20 weight percent of K2O; more than 2 weight percent and not more than 15 weight percent of TiO2; 0 to 15 weight percent of CaO; 0 to 32 weight percent of BaO; 0 to 20 weight percent of SrO; 0 to 15 weight percent of ZnO, not less than 0 weight percent and less than 3 weight percent of Bi2O3; 0 to 50 weight percent of Nb2O5; not less than 0 weight percent and less than 20 weight percent of WO3; and 0 to 1 weight percent of Sb2O3. A total weight of Li2O, Na2O and K2O is in a predetermined range of weight percents and the optical glass does not comprise B2O3.