Field emissive display (FED) is a newly developed flat panel display

the phosphors in which are excited by low voltage cathode rays. It is expected that this display would replace the widely used cathode ray tube (CRT) in near future. Y

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SiO

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:Ce is the important candidate blue phosphor for FED. The emission peak of this phosphor is at 410 nm

an eye insensitive wavelength. Questions appear: should this emission peak be moved to longer wavelength to increase the brightness of this phosphor? If this is the case

how does this moving affect the efficiency and the color triangle area of FED device? Chromaticity simulation was tried to answer the questions. The emission spectrum of the blue phosphor was simulated by using Gaussian function. The luminous efficiencies and color coordinates of Y

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O

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:Eu and Y

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Al

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Ol

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:Tb were selected for red and green phosphors. During the calculations

these parameters were kept constant. The color temperature and the brightness of the display were set as 6500K and 300cd/m

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respectively

while the voltage of the electron beams was chosen as 2000V. It is also assumed that the brightness of the phosphors linearly increases with the current density of the electron beams. When the emission peak position and width of the blue phosphor were varied

the color coordinates and brightness efficiency of the blue phosphor were calculated. Furthermore

the brightness efficiency and the color triangle area of the display were calculated. During the calculation

adjusting the current densities of the electron beams to maintain the color temperature and brightness of the display. The decrease of the current density indicates the increase of the efficiency. The simulation gives following results: (1) Increasing the peak wavelength and width enhances the luminous efficiency of the blue phosphor

but reduces the color saturation of it

but if the peak wavelength is kept shorter than 460nm

the color saturation is acceptable for the display. (2) It is better to keep the peak wavelength of the blue phosphor in the range 420～460nm

in which the phosphor possesses saturated blue color; the color triangle shows large area and the display performs high efficiency. (3) The wavelength of Y

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SiO

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:Ce is too short for the display applications. If the wavelength could be shifted to longer wavelength

20～40nm

it would be beneficial to improve FED performance. In some extent

the results obtained in the present simulation are also suitable to other color displays.