Patent ID: 7691293

Claim:
A red light-emitting phosphor capable of emitting red light upon excitation with light having a wavelength of from 350 nm to 420 nm, wherein the red light-emitting phosphor is represented by the following compositional formula (1): A (1-x) Eu (1-x-y) Ln y D 2x M 2 O 8 (1) A is at least one element selected from the group consisting of Li, Na, K, Rb and Cs, Ln is at least one element selected from rare earth elements including Y but excluding Eu, D is at least one element selected from the group consisting of Mg, Ca, Sr and Ba, M is at least one element selected from Mo and W, x is a positive number satisfying 0.1≦x≦0.7, y is 0 or a positive number satisfying 0<y≦0.5, and x+y is a number satisfying 0<x+y≦0.7.