| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an ecologically minded optical glass in which PbO, Tl<SB POS="POST">2</SB>O, TeO<SB POS="POST">2</SB>and As<SB POS="POST">2</SB>O<SB POS="POST">3</SB>are not used, and preferably fluorine and Gd<SB POS="POST">2</SB>O<SB POS="POST">3</SB>are not used. <P>SOLUTION: The lead- and arsenic-free optical glass having a refractive index n<SB POS="POST">d</SB>of ≥1.91 to ≤2.05, and an Abbe number v<SB POS="POST">d</SB>of ≥19 to ≤25 includes (in wt.% on an oxide basis) 55-70% of Bi<SB POS="POST">2</SB>O<SB POS="POST">3</SB>, 13-21% of GeO<SB POS="POST">2</SB>, 0-9% of SiO<SB POS="POST">2</SB>, 0-10% of B<SB POS="POST">2</SB>O<SB POS="POST">3</SB>, 0-5% of Li<SB POS="POST">2</SB>O, 0-5% of Na<SB POS="POST">2</SB>O, 0-5% of K<SB POS="POST">2</SB>O, 0-6% of Cs<SB POS="POST">2</SB>O, 0-10% of MgO, 0-10% of CaO, 0-10% of SrO, 0-10% of BaO, 0-10% of ZnO, 0-5% of Ti<SB POS="POST">2</SB>O, 0-7% of La<SB POS="POST">2</SB>O<SB POS="POST">3</SB>, 0-6% of WO<SB POS="POST">3</SB>, 0-6% of Nb<SB POS="POST">2</SB>O<SB POS="POST">5</SB>, 0-5% of the total alkali metal oxides, 0-10% of the total alkaline earth metal oxides, and 0-8% of the total of La<SB POS="POST">2</SB>O<SB POS="POST">3</SB>, WO<SB POS="POST">3</SB>, Nb<SB POS="POST">2</SB>O<SB POS="POST">5</SB>and TiO<SB POS="POST">2</SB>, and 0-2% of conventional clarifying agents, and has a Bi<SB POS="POST">2</SB>O<SB POS="POST">3</SB>to GeO<SB POS="POST">2</SB>ratio of not greater than 5. <P>COPYRIGHT: (C)2012,JPO&INPIT |
