| 摘要 |
PURPOSE:To improve the efficiency of an electric-discharge lamp remarkably by adjusting the amount of a phosphor applied to the lamp to an optimum value. CONSTITUTION:A calcium halophosphate phosphor 9 is applied almost homogeneously over the inner wall of an outer encircling case 1 and the outer surface of an inner encircling case 2. The amount of the phosphor 9 with which the lamp efficiency of such an electric-discharge lamp becomes high is in the range of 1.3-4.0mg/cm<2>; the optimum range is 1.5-3.5mg/cm<2>. This is exceptionally small compared to the optimum range of the usual fluorescent lamp, which is 6-9mg/cm<2>. It means that the efficiency of above electric-discharge lamp is widely decreased if the same amount as that for the usual fluorescent lamp of the phosphor 9 is applied to above electric-discharge lamp. Therefore, the decreased amount of the applied phosphor 9 serves two ends, and gives a notably large significance by reducing the manufacturing cost as well as by increasing the lamp efficiency. |
