Dense crown optical glass
AssigneeNippon Kogaku K.K.
InventorShizuo Matsumaru
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Abstract
Dense crown optical glass comprises, in percent by weight: ______________________________________ SiO.sub.2 20-28 B.sub.2 O.sub.3 24-34 BaO 17-32 CaO 5-7 Al.sub.2 O.sub.3 2-6 La.sub.2 O.sub.3 8-19 ______________________________________
Claims2
Dense crown optical glass having excellent chemical durability, a refractive index nd in the range of 1.610-1.625 and an Abbe number .nu.d in the range of 57-61, consisting essentially of, in percent by weight:
- ______________________________________ SiO.sub.2 26.12 B.sub.2 O.sub.3 25.86 BaO 30.52 CaO 6.67 Al.sub.2 O.sub.3 2.81 La.sub.2 O.sub.3 8.02. ______________________________________
Dense crown optical glass having excellent chemical durability, a refractive index nd in the range of 1.610-1.625 and an Abbe number .nu.d in the range of 57-61, consisting essentially of, in percent by weight:
- ______________________________________ SiO.sub.2 27.56 B.sub.2 O.sub.3 24.44 BaO 31.55 CaO 5.66 Al.sub.2 O.sub.3 2.30 La.sub.2 O.sub.3 8.49. ______________________________________
Dependencies are inferred from the claim text.