Patent ID: 8188668

Claim:
An image display apparatus comprising: a rear plate provided with a plurality of electron-emitting devices, each of electron-emitting devices emitting electrons; a face plate disposed opposite the plurality of electron-emitting devices and provided with a plurality of pixels of phosphor, each pixel of phosphor being irradiated with electrons emitted from a corresponding one of the electron-emitting devices to generate light; a driver to scan the plurality of electron-emitting devices to drive the plurality of electron-emitting devices for emitting electrons, wherein the phosphor contains as a combination of a host material and a luminescence center SrGa 2 S 4 :Eu or Sr (1-x) Ba x Ga 2 S 4 :Eu, wherein, when the phosphor contains SrGa 2 S 4 :Eu, a luminescence center concentration expressed as a ratio Eu/Sr, satisfies 0.001≦Eu/Sr≦0.1 such that a maximum electric charge density provided for one pixel of phosphor during one scanning period is 3×10 −8 C/cm 2 or more under a predetermined density of current applied to the pixel of phosphor, and wherein, when the phosphor contains Sr (1-x) Ba x Ga 2 S 4 :Eu, 0≦x≦0.3 is satisfied, and a luminescence center concentration expressed as a ratio Eu/(Sr+Ba), satisfies 0.001≦Eu/(Sr+Ba)≦0.1 such that a maximum electric charge density provided for one pixel of phosphor during one scanning period is 3×10 −8 C/cm 2 or more under a predetermined density of current applied to the pixel of phosphor.