| 摘要 |
PURPOSE:An electron emission substance comprising dysprosium oxide and lanthanum oxide for use in a discharge lamp. CONSTITUTION:1 is a light emission tube formed of transparent quartz glass, wherein mercury, starting argon gas and a metallic halide are enclosed. 2a, 2b are electrodes disposed at the ends of the light emission tube so that the electrodes face each other, the electrodes being connected to external lead-in wires 4a, 4b via molybdenum foils 3a, 3b attached to the ends of said light emission tube 1. An electron emission substance 13 applied to the surfaces of an internal coil 11 and an external coil 12 wound on a member 10 forming the electrode, and allowed to stick to the surfaces with a heating process at high temperatures, comprises 0.5-20mol% dysprosium oxide and lanthanum oxide. By using the electrodes containing the substance, no separation of the electron emission substance occurs during the time of which the tube is turned on and being operated. Thus it is possible to obtain a lamp having a long life and the capability of constant electron emission during its lifetime without luminous flux deterioration. |
