Sharpcut filter glass and sharpcut filter

摘要

Glass suited to use in sharpcut filters cutting ultraviolet radiation, and sharpcut filters. The sharpcut filter glass comprises, given as weight percentages: SiO₂ 50 to 70%, Al₂O₃ 0 to 5%, Li₂O 0 to 10%, Na₂O 0 to20 %, K₂O 0 to 20%, where Li₂O+Na₂O+K₂O comprises 10 to 30%, ZnO 8 to 20%, CeO₂ 1 to 5 %. The glass essentially does not comprise Pb, As, and Ti. The sharpcut filter exhibits, according to JIS B7113, the transmission threshold wavelength falling within a range of from 365 to 385 nm and the wavelength inclination range being less than or equal to 35 nm.