| 摘要 |
PROBLEM TO BE SOLVED: To prevent the coloring of panel glass due to an electron beam without degrading luminance by filling transparent fine particles among phosphor particles stuck to the inside surface of the panel glass of a projecting picture tube. SOLUTION: In order to stick phosphor particles 4 emitting red, green or blue light to the inside surface of front panel glass 3 of this projecting picture tube, transparent fine particles 10 are filled among the phosphor particles 4. The film thickness of a luminescent layer comprising the phosphor particles 4 and the fine particles 10 is set to 25-35μm so as to provide the maximum luminance. Even the film formed of the fine particles 10 of SiO2 with a specific gravity smaller than the specific gravity of around 4-5.2 of the phosphor particles 4 can sufficiently block an electron beam with the film thickness of 12μm. Since the fine particles 10 are filled among the phosphor particles 4, the electron beam passing the gaps among the phosphor particles 4 impinges on the fine particles 10 and do not reach the panel glass 3, so that electron beam browning can be prevented, and since the fine particles 10 are transparent, the degradation of luminance and the variation of color due to the light emission of the phosphor particles 4 never occur.
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