Patent ID: 7008891
Filing Date: 2006-03-07
Classification: C03C,G02B

Abstract:
1. A crystallized glass for an optical filter substrate, which consists, as represented by mol % based on the following oxides, essentially of: SiO Al TiO Na K Li MgO: 0 to 15%, CaO: 0 to 15%, SrO: 0 to 15%, BaO: 0 to 15%, ZnO: 0 to 15%, B P Y and which has an average linear expansion coefficient α L of from 95×10 −7 /° C. to 130×10 −7 /° C. at from −30° C. to 70° C., and which has a crystal or solid solution of Na 4-x K x Al 4 Si 4 O 16 (1<x≦4) precipitated therein.