ELECTRODE FOR DISCHARGE LAMP WITH YTTRIUM AND LANTHANUM OXIDE ELECTRON EMISSION MATERIAL

摘要

W.E. 48,922 An electrode for a discharge lamp, such as a high pressure metal vapor lamp or fluorescent lamp comprises an electrode substrate and an electron emission material on the substrate. The emission material comprises a mixture of yttrium oxide and lanthanum oxide. me molar ratio of lanthanum oxide, yttrium oxide is in the range of 1 : 9 to 19 : 1 and the emission material contains in addition, barium-strontium-calcium tungstate and an alkaline earth metal oxide. The electrode so produced improves the luminous flux maintenance of a metal vapor discharge lamp and reduce the starting voltage of fluorescent lamps in neither case producing black depositions on the ends of the tube.