Patent ID: 6753278
Filing Date: 2004-06-22
Classification: C03C

Abstract:
An optical glass having an index of refraction (nd) greater than or equal to 1.71, an AbbÃ©number (&ngr;d) greater than or equal to 39 and a density (&rgr;) less than or equal to 4.7 g/cm3, wherein said optical glass consists of (in percent by weight on an oxide basis):La2O330 to 45B2O330 to 40Al2O30 to 5PbO0.1 to 5â€‚â€‰Li2Oâ€‚0 to 10Na2Oâ€‚0 to 10K2Oâ€‚0 to 10Rb2Oâ€‚0 to 10Cs2Oâ€‚0 to 10MgO0 to 8CaO0 to 8SrO0 to 8BaO0 to 8ZnOâ€‚1 to 10TiO20 to 5ZrO2â€‚1 to 10Y2O31 to 8Yb2O30.1 to 2â€‚â€‰Gd2O30.1 to 5â€‚â€‰Nb2O60.1 to 10â€‰With MgO + CaO + SrO + BaOâ€‚0 to 10With Li2O + Na2O +]K2Oâ€‚0 to 10Rb2O + Cs2O;and from 0 to 1.5 percent by weight of at least one refining agent, wherein said at least one refining agent is selected from the group consisting of Sb2O3, As2O3, SnO2 and CeO2.