| 摘要 |
PURPOSE:To prevent a thermionic emission characteristic from deterioration as well as to secure stable luminance for hours, by making up a part of a cathode to have a sulfide phosphor layer and, what is more, a part of a getter to have such one making at least one type of Fe and Zn as a main component. CONSTITUTION:A cathode 8 is one being coated with, for example, an oxided substance on its W fine wire surface, while at least a phosphor layer 10 in a display pattern uses various types of fluorescence. In addition, a first getter 12 is installed in a part of a cathode supporting body 7a being one side of a corner part inside an envelope 1. This first target 12 has a getter ring 15 molded in ringlike form with such materials as Ba-Mg and so on by a holding member of Ni, Fe, etc., and a supporting body 16 supporting the getter ring on the cathode supporting body 7a. On the other hand, a second getter 13 is installed in a part of a cathode supporting body 7b and this second getter 13 has a supporting body 18 supporting a getter ring 17, which molded in disclike form by a cadding material composed of at least one type of Fe and Zn produced in a hot pressing method, on the cathode supporting body 7b. |
