| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide an optical glass which exhibits high refraction and high dispersion and has a low glass transition temperature and excellent transmittance for light from a near-ultraviolet region to a visible region.SOLUTION: The optical glass has a refractive index of 2.05 or more, an Abbe number of 20 or less, a glass transition temperature of 450°C or lower, and a pigmentation degreeλof less than 500 nm; and the optical glass comprises, in terms of mass%, 77.5 to 90% of BiO, 8.5 to 20% of BO, 0 to 5% of SiO, 0 to 7.5% of TeO, 0.1 to 3% of LiO+NaO+KO, 0.1 to 3% of LiO, 1% or more of MgO+CaO+SrO+BaO+ZnO, 0 to 10% of ZnO, and 0 to 1% of TiO+NbO+WO, and substantially contains none of a lead component, an arsenic component, a fluorine component, and GeO.</p> |
