Patent ID: 8476177
Filing Date: 2013-07-02
Classification: C03C,G02B

Abstract:
1. A lead-free and arsenic-free optical glass having a refractive index n d of 1.945≦n d ≦1.97, an Abbe number ν d of 33≦ν d ≦36, and an internal transmittance of >80% at 410 nm and at a thickness of 10 mm, wherein said optical glass has a composition comprising respective components in the following amounts expressed in % of corresponding cations of said respective components in said composition, with reference to a sum of all cations in the composition: wherein a ratio of B 3+ to La 3+ is 1.1 to 1.6, a ratio of B 3+ to Σ Si 4+ +B 3+ is greater than 0.5, and the glass is free of Ti 4+ , Th 4+ , Zn 2+ , F − and Hf 4+ , and wherein the glass contains less than 6 ppm of platinum.