Patent ID: 9394194
Filing Date: 2016-07-19
CPC Classification: C03C

Claim Text:
1. Optical glass, which is oxide glass wherein: a total content of Si a total content of La a total content of Ti a content of Li a content of Ge is lower than 5.0 mass % as a quantity of GeO no Pb is comprised; a cation ratio of a content of Si a cation ratio of the total content of La a cation ratio of a content of Y Nb which has a refractive index nd within a range of higher than 1.920 and equal to or lower than 2.000, an Abbé number vd ranging from 31.5 to 34.0, and a yield point of higher than 645° C.; and wherein a deviation ΔPg,F from a normal line of a partial dispersion ratio Pg,F obtained from the following equation is equal to or lower than 0.0005: wherein, in the equation, Pg,F denotes a partial dispersion ratio given by (ng−nF)/(nF−nC) using various refractive indexes ng, nF, and nC at spectral lines g, F, and c; and vd denotes the Abbé number.