Patent ID: 8303847

Claim:
A phosphor given by a general composition formula expressed by MmAaBbOoNn:Z, (wherein element M is one or more kinds of elements having bivalent valency, element A is one or more kinds of elements having tervalent valency, element B is one or more kinds of elements having tetravalent valency containing at least Si, O is oxygen, N is nitrogen, and element Z is one or more kind of activating agent, satisfying m>0, a>0, b>0, o≧0, and n>0), wherein when the ratio of element B atoms to total numbers of atoms in a depth of 50 nm from a particle surface is set at M(B) 50 at %, and the ratio of the element B atoms to the total numbers of atoms in a depth of d nm which is obtained by measuring a range of the depth from 50 nm to 1950 nm from the particle surface by an interval of 100 nm is set at M(B) d at %, a value of M(B) d obtained by measuring the range of the depth from 50 nm to 1950 nm from the particle surface at a prescribed interval satisfies: −10<(M(B) d −M(B) 50 )/M(B) 50 ×100<10, expressions of 5.0<(a+b)/m<9.0, 0≦a/m<2.0, 0≦o<n, and n=(2/3)m+a+(4/3)b−(2/3) o, are satisfied, and a peak wavelength of an emission spectrum is in a range from 400 nm to 500 nm, under excitation of light in a wavelength range from 250 nm to 430 nm.