Patent ID: 7875206

Claim:
A method for manufacturing the luminescent material comprising a light-emitting element emitting light, the light having a main light emission peak in a wavelength ranging from 310 to 420 nm; and a luminescent layer comprising a luminescent material configured to be irradiated with the light, at least part of the luminescent material being a compound having a composition represented by a following general formula (A): (Sr a1 ,Ba b1 ,Ca c1 ,Re v1 ,Eu w1 ) 2 SiO 4 (A), wherein, Re is at least one selected from a group consisting of Pr and Dy; and a1, b1, c1, v1 and w1 satisfy following relationships: a 1+ b 1+ c 1+ v 1+ w 1=1 (1); 0≦ a 1/(1− v 1− w 1)≦1 (2); 0≦ b 1/(1− v 1− w 1)≦1 (3); 0≦ c 1/(1− v 1− w 1)≦1 (4); 0<v1≦0.15 (5); 0<w1≦0.02 (6) v 1/ w 1>1 (7), the method comprising: heating a raw material in a reducing atmosphere constituted by N 2 /H 2 or Ar/H 2 at a temperature of 1100 to 1500° C. for 3 to 7 hours to obtain a primary sintered product; pulverizing the primary sintered product to obtain a pulverized primary sintered product; housing the pulverized primary sintered product into a container; arranging the container housing the pulverized primary sintered product to a furnace; substituting an atmosphere in the furnace with an inert gas; and heating the pulverized primary sintered product in a reducing atmosphere constituted by N 2 /H 2 or Ar/H 2 containing hydrogen at a concentration of 5% or more and less than 100% at a temperature of 1100 to 1500° C. for 2 to 6 hours to obtain a secondary sintered product.