| 摘要 |
PROBLEM TO BE SOLVED: To provide a cathode structure which can provide an electron emission characteristic that is stable over a long time since an electron emitter layer is not peeled even if a cathode-ray tube is operated at a high current density, and which is inexpensive and can be mass-produced. SOLUTION: In a cathode structure in which a hat-shaped cathode base 1 made of a high-melting-point metal is securely attached to one end of a cathode sleeve 2 made of a high-melting-point metal and is covered at its top surface with an electron emitter layer 3, the electron emitter layer 3 contains 0.5 to 5.0 wt.% rare earth metal oxides dispersed in alkaline earth metal oxides, the average particle diameters of the rare earth metal oxides as measured by laser diffraction method being 0.5 to 2.0 μm. In this case, the electron emitter layer 3 is made by a two-layered structure consisting of a first layer 5 and a second layer 6, the contents of the rare earth metal oxides in the first layer 5 is zero, and the total contents of the rare earth metal oxides in the first and second layers 5, 6 is selected in a range of 0.5 to 5.0 wt.%. |
