| 摘要 |
PURPOSE:To obtain the titled optical glass for the pressed lens having a comparatively low softening point, a medium refractive index, and a low dispersive characteristic by incorporating oxides such as BaO and Li2O into an essential component of P2O5. CONSTITUTION:The glass having the following composition is used as the optical glass for the pressed lens without requiring grinding or polishing after press- molding. The glass contains 34-45mol% P2O5, 0-4mol% B2O3, 0-5mol% Al2O3, 4-20mol% Li2O, 28-45mol% BaO, 0-8mol% SrO, and 0-7mol% ZnO where P2O5+B2O3+Al2O3<=45mol%. The optical glass for the pressed lens having optical characteristics such as >=1.60 nd, >60nud, a comparatively low softening temp., a medium refractive index, and low dispersion can be obtained.
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