Patent ID: 8414795

Claim:
A fluorescent substance having formula (1): (M 1-x EC x ) a M 1 b AlO c N d (1), wherein: M is an element selected from the group consisting of IA group elements, IIA group elements, IIIA group elements, IIIB group elements, rare earth elements, and IVA group elements; EC is an element selected from the group consisting of Eu, Ce, Mn, Tb, Yb, Dy, Sm, Tm, Pr, Nd, Pm, Ho, Er, Cr, Sn, Cu, Zn, As, Ag, Cd, Sb, Au, Hg, Tl, Pb, Bi, and Fe; M 1 is different from M and is selected from the group consisting of tetravalent elements; and x, a, b, c and d are numbers satisfying the conditions of 0<x<0.2, 0.63<a<0.80, 2.1<b<2.63, 0<c≦0.24, and 4<d<5, respectively; and emitting luminescence having a peak in the wavelength range of 620 to 670 nm under excitation by light in the wavelength range of 250 to 500 nm.