| 摘要 |
PURPOSE:To improve the contact between an electron discharging substance and electrode members by using an electron discharging substance containing not less than two kinds of oxides which form a solid solution, and making the mean grain diameter of an oxide of a high content to be a given times the other oxides. CONSTITUTION:An electron discharging substance 18 prepared by mixing yttrium oxide and lanthanum oxide has a reduced melting point since lanthanum oxide and yttrium oxide form a solid solution. As a result, the contact between the substance 18 and electrode members 15, 16 and 17 is improved, and the separation of the substance 18 from the members 15, 16 and 17 caused during the lighting of an electric- discharge lamp is decreased. The mean diameter of the former yttrium oxide is made 0.2-50 times that of the former lanthanum oxide so as to make actual area of these two compounds to be increased. As a result, a homogeneous solid solution can be formed, and sufficiently close contact between the substance 18 and the members 15, 16 and 17 can be realized. A small amount of either tungsten powder or molybdenum powder may be added to the substance 18. |
