| 摘要 |
<p>An optical glass comprising, by mass%,
12 to 40 % of SiO 2 ,
15 % or more but less than 42 % of Nb 2 O 5 ,
2 % or more but less than 18 % of TiO 2 ,
(provided that Nb 2 O 5 /TiO 2 is over 0.6),
0.1 to 20 % of Li 2 O,
0.1 to 15 % of Na 2 O, and
0.1 to 25 % of K 2 O,
and having an Abbe's number vd of 20 to 30, a ”g,F of 0.016 or less and a liquidus temperature of 1,200°C or lower.</p> |
