| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a transparent polycrystal ceramic in which a sintered body has an extremely little content of scattering bodies, a high linear transmission factor and a little scattering, and to provide a light-emitting device having no color dispersion and a high light-emitting efficiency. <P>SOLUTION: The phosphor ceramic plate is a YAG: Ce polycrystal phosphor ceramic plate which emits the light having a wavelength range of from 440 nm to 460 nm as an excitation light, with a chromaticity of such a light being white as synthesizes the excitation light with the light which the ceramic plate emits. The white is in such a region that x-values and y-values on the CIE 1931 chromaticity coordinates are enclosed with the points of (0.24, 0.30), (0.31, 0.26), (0.40, 0.44) and (0.34, 0.48), and additionally the x-values are in the region of from 0.27 or more to 0.395 or less. <P>COPYRIGHT: (C)2010,JPO&INPIT |
