Patent ID: 8262935

Claim:
A phosphor comprising a composition represented by the formula: (M 2 x ,M 3 y ,M 4 z ) m M 1 O 3 X (2/n) , wherein M 1 is Si and optionally includes at least one element selected from the group consisting of Ge, Ti, Zr, and Sn; wherein M 2 is Ca and optionally includes at least one kind of element selected from the group consisting of Mg, Ba, and Zn; wherein M 3 is Sr and optionally includes at least one kind of element selected from the group consisting of Mg, Ba, and Zn; wherein X is at least one kind of halogen element; wherein M 4 is Eu 2+ and optionally includes at least one element selected from the group consisting of rare-earth elements and Mn; wherein m is in a range of 6/6≦m≦8/6; n is in a range of 5≦n≦7; and x, y, and z satisfies x+y+z=1, where 0<x<1,0<y<1, and 0.01≦z≦0.3; and wherein the ionic radii of principal elements of M 2 , M 3 , and M 4 satisfy M 2 <M 3 ≅M 4 , and x, y, and z satisfies 0.50<x/(y+z)<0.8.