Patent ID: 7713441

Claim:
A phosphor made of a compound represented by the following formula (II), which comprises, as a matrix, a compound of a garnet structure and which contains, as a luminescent center ion, a metal element in the matrix: M 11 a1 M 21 b1 X 1 c1 M 31 d1 M 41 3 O e1 (II) wherein M 11 is Na and/or Li, M 21 is a bivalent metal element, X 1 is a metal element as a luminescent center ion composed mainly of Ce, M 31 is a trivalent metal element excluding X 1 , M 41 is a tetravalent metal element, and a1, b1, c1, d1 and e1 are numbers satisfying the following formulae, respectively: 0.001<a1<0.5 2.5<b1<3.3 0.005<c1<0.5 1.5<d1<2.5 e 1={( a 1 +b 1)×2+( c 1 +d 1)×3+12}/2.