Patent ID: 7951733

Claim:
A blue-violet light blocking glass comprising a copper (I) halide and silver, which further comprises 20 to 85% by weight of SiO 2 ; 2 to 75% by weight of B 2 O 3 ; not more than 10% by weight of Al 2 O 3 ; 2 to 30% by weight of at least one member selected from the group consisting of Li 2 O, Na 2 O, K 2 O, Rb 2 O and Cs 2 O; 1 to 15% by weight of at least one member selected from the group consisting of MgO, CaO, SrO, BaO and ZnO; not more than 10% by weight of at least one member selected from the group consisting of PbO, Nb 2 O 5 , ZrO 2 , La 2 O 3 , Y 2 O 3 , Ta 2 O 3 and Gd 2 O 3 ; not more than 5% by weight of at least one member selected from the group consisting of Sb 2 O 3 and As 2 O 3 ; not more than 5% by weight of SnO 2 ; 0.01 to 10% by weight of a copper (I) halide; and 0.001 to 1% by weight of silver calculated on a metal basis.