Patent ID: 6677259
Filing Date: 2004-01-13
Classification: C03C,G02B

Abstract:
Glass-ceramics for light filter having acoefficient of thermal expansion within a range from 95Ã—10âˆ’7/Â°C. to 140Ã—10âˆ’7/Â°C. within a temperature range from âˆ’20Â°C. to +70Â°C., having light transmittance for late thickness of 10 mm which is 60% or over within a wavelength range from 950 nm to 160 nm, containing, as predominant crystal phases, (a) lithium disilicate, and (b) at least one selected from the group consisting of &agr;-quartz, &agr;-quartz solid solution, &agr;-cristobalite and &agr;-cristobalite solid solution, and having a composition which comprises 2-7 weight percent of ZrO2 and is substantially free of Nb2O5, SnO2, MoO3, TiO3, B2O3, Cr2O3, and MnO.