Patent ID: 8183778

Claim:
A phosphor represented by a general formula: a YO 3/2 ·(3 −a )CeO 3/2 ·b AlO 3/2 ·c GaO 3/2 , where 2.80 ≦a ≦2.99, 1.00 ≦b ≦5.00, 0 ≦c ≦4.00, and 4.00 ≦b+c ≦5.00 are satisfied, wherein a peak whose peak top is located in the range of diffraction angle 2θ of not less than 16.7 degrees but not more than 16.9 degrees is present in an X-ray diffraction pattern obtained by measurement on the phosphor using an X-ray with a wavelength of 0.774 Å.