Patent ID: 7204939

Claim:
A plasma display device having a plasma display panel in which a plurality of discharge cells having one of one color and a plurality of colors are disposed, phosphor layers having a color corresponding to said respective discharge cells are disposed in arrays, and said phosphor layers are excited by ultraviolet light to emit light, wherein said phosphor layers have a blue phosphor, and said blue phosphor is selected from a group of compounds consisting of Ba 1−x MgAl 10 O 17 :Eu x and Ba 1−x−y Sr y MgAl 10 O 17 :Eu x , wherein part of a divalent Eu ion constituting said phosphor is made trivalent in an oxidizing atmosphere, the amount of the trivalent Eu ion ranges from 0.1 to 15% of the divalent ion, and wherein 0.03≦x≦0.20 and 0.1≦y≦0.5.