Patent ID: 7838450

Claim:
An optical glass obtained by melting a glass material composition comprising, in mass % on element basis of a total mass of glass materials: P introduced from a complex phosphate material 1.0-5.0% Al introduced from a material which comprises a complex 3.0-19.0% phosphate and/or a fluoride Mg introduced from a material which comprises a complex 0.3-4.0% phosphate and/or a fluoride Ca introduced from a material which comprises a complex 3.0-less than phosphate and/or a fluoride 17.5% Sr introduced from a material which comprises a complex 8.0-19.0% phosphate and/or a fluoride Ba introduced from a material which comprises a complex 4.8-18.0% phosphate and/or a fluoride where (Sr + Ba) which is a sum in mass % 20.0-35.0% Y introduced from a material which comprises a fluoride 0.5-6.0% La introduced from a material which comprises a fluoride 0-4.0% Gd introduced from a material which comprises a fluoride 0-4.0% Li introduced from a material which comprises a fluoride 0-2.0% Na introduced from a material which comprises a fluoride 0-2.0% K introduced from a material which comprises a fluoride 0-1.0% F introduced from a material which comprises a fluoride 40-55% Cl introduced from a chloride material 0-1.0% Br introduced from a bromide material 0-1.0% I introduced from an iodide material 0-1.0% O introduced from complex phosphate and oxide materials 0.5-8% Si less than 0.2% B less than 0.5% Sb 3% or below wherein (Si +B +P +Al)/F is adjusted to a value within a range from 0.27 to 0.35 and Ba/Sr is adjusted to a value within a range from 0.6 to 1.0 wherein the optical glass has a refractive index (nd) within a range from 1.41 to 1.47 and an Abbe number (νd) within a range from 90 to 100.