| 摘要 |
PURPOSE:To prevent the dispersion of impurities from glass surface to phosphor layer without lowering the visible light transmittivity of glass by forming a layer formed of titanium oxide minute powder as protective film on glass surface and forming phosphor particle layer on the titanium oxide layer. CONSTITUTION:On the inner surface of an outer-shell glass bulb 1, a first layer 2 is formed which is formed of titanium dioxide powder having particle diameter of 0.1mu or less. The thickness of this layer is 0.05-0.4mu. On this titanium dioxide powder layer 2 (1st layer), the second layer 3 formed of phosphor particles is coated. |
