| 摘要 |
PURPOSE:To decrease heat deterioration of a fluorescent lamp and to lessen the lowering of efficiency due to ambient temperature, by the application of fluorescent material of cerium-terbium activation lanthanum silicate-phosphate, represented by the chemical formula, (La, Ce, Tb)2O3.aSiO2.bP2O5. CONSTITUTION:Chemical constitution of the fluorescent material applied to the fluorescent lamp is represented by the chemical formula, (La, Ce, Tb)2O3.aSiO2. bP2O5, where a and b are limited within the ranges: 0<a<=0.6 and 0.7<=b<1.0. Such a fluorescent material suffers little lowering of luminance in a high-temperature atmosphere, and the lamp of the present invention operates quite well in the high-temperature atmosphere even if the same is applied to a linear lamp. The lamp also undergoes little heat deterioration during a high-temperature forming process; besides, it exhibits little lowering of efficiency if lighted in high temperature. |
