| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an optical glass having a small Abbe number (ν<SB POS="POST">d</SB>), a small partial dispersion ratio (θg, F) and high transparency to visible light, while having a refractive index (n<SB POS="POST">d</SB>) in a desired range. <P>SOLUTION: The optical glass contains in terms of mol%, ≥25.0% and ≤55.0% of a B<SB POS="POST">2</SB>O<SB POS="POST">3</SB>component, ≥6.0% and ≤30.0% of a Ln<SB POS="POST">2</SB>O<SB POS="POST">3</SB>component (in the formula, Ln shows one kind or more selected from a group consisting of La, Gd, Y and Yb), and >0% and ≤25.0% of a Nb<SB POS="POST">2</SB>O<SB POS="POST">5</SB>component, with respect to the glass total material amount of a composition in terms of oxides, wherein the content of a ZrO<SB POS="POST">2</SB>component is ≤10.0%, and the partial dispersion ratio (θg, F) has relations with the Abbe number (ν<SB POS="POST">d</SB>) satisfying (-0.00162×νd+0.63822)≤(θg, F)≤(-0.00275×νd+0.68125) in the range of νd≤31, and satisfying (-0.00162×νd+0.63822)≤(θg, F)≤(-0.00162×νd+0.64622) in the range of νd>31. <P>COPYRIGHT: (C)2013,JPO&INPIT |
