Patent ID: 8080491

Claim:
An optical glass having an Abbe number (ν d ) and a refractive index (n d ) in a region indicated by a shape bound by connecting three points, A(53, 1.70), B(53, 1.87), and C(40, 1.87) with straight lines on an orthogonal xy-coordinate system with the x-axis designating the Abbe number and the y-axis designating the refractive index, and having the refractive index, n d , of no less than 1.794; and comprising no less than 25% and no more than 65% of a combination of a SiO 2 component and a B 2 O 3 component, no less than 20% and no more than 55% of a Ln 2 O 3 component (Ln represents at least one species selected from the group consisting of La, Gd, Dy, Yb, and Lu), no more than 35% of the B 2 O 3 component, no more than 15% of a ZnO component, and a ratio of the La 2 O 3 component to the Ln 2 O 3 component being no more than 0.6, and a ratio of a sum of Al 2 O 3 , GeO 2 , Ga 2 O 3 , and P 2 O 5 components to a sum of the SiO 2 and B 2 O 3 components being no less than 0.15 and no more than 0.8, by mol % on the basis of oxides.