| 摘要 |
PURPOSE: A cathode for a CRT(Cathode Ray Tube) is provided to be capable of increasing the lifetime of the cathode by improving the structure of a metal frame for enlarging the surface area influenced with effective electronic field. CONSTITUTION: A cathode having a metal frame(6) is located at the upper portion of a cylindrical type sleeve. At this time, a cathode heating heater is inserted in the cylindrical type sleeve. At the time, the metal frame slightly containing reductive element such as silicon or magnesium, is mainly made of nickel. A hole is formed at the center portion of the upper surface of the metal frame. Preferably, an electron emitting material layer(3a) containing barium, strontium, and calcium, is formed on the entire inner surface of the metal frame. Preferably, the surface area of the hole is 0.1-10% of the upper surface area of the metal frame.
|
