| 摘要 |
PURPOSE:To achieve improved exhaust of a cathode structure for a cathode-ray tube so as to increase the electron-discharging property and the life of a cathode by forming exhaust cuts in the outermost periphery of a plate-like insulating supporter which is used to support the cathode within the cup-like first grid. CONSTITUTION:An insulating supporter 9 has a central hole 91, an annular groove 92 and a few exhaust cuts 93 formed in the outermost periphery. Although distance (d) between the end of the exhaust cut 93 and a central hole 91 is restricted, the area of penetrating holes formed when the supporter 9 is held with an annular supporter can be made large by adjusting width (w) to be large. Therefore the speed of exhaust in the first grid can be maintained sufficiently high, thereby preventing any deterioration of the electron-discharging-property of the cathode. |
