Patent ID: 8580148

Claim:
A fluorescent material, comprising: an alkaline earth metal aluminate phosphor of a type exhibiting fluorescence, said alkaline earth metal aluminate phosphor comprising: bivalent europium as an activator; barium and/or strontium; magnesium; aluminum; and at least one element (e) selected from the group consisting of indium, tungsten, niobium, bismuth, molybdenum, tantalum, thallium and lead, wherein the fluorescent material is obtained by a process comprising the steps of (2-1) of mixing a fired product (A) with a compound (B), said fired product (A) comprising barium and/or strontium (a), magnesium (b), aluminum (c) and europium (d), said compound (B) comprising at least one compound selected from the group consisting of indium compounds, tungsten compounds, niobium compounds, bismuth compounds, molybdenum compounds, tantalum compounds, thallium compounds and lead compounds; and a step (2-2) of firing, in an oxidizing atmosphere, the mixture obtained in the step (2-1) or a fired product of the mixture obtained in the step (2-1), said step (2-2) being preceded, at least once, by firing in a reducing atmosphere.