| 摘要 |
<p>In a field emission cathode type electron gun, a plurality of cathode segments and a plurality of gate control circuits (5-1, 5'-1) are provided. Each of the gate control circuits is connected to one of the cathode segments. Each of the cathode segments includes a cathode electrode, a gate electrode (14-1, 14-2, ...), an insulating layer therebetween, and a plurality of cone-shaped emitters (15) formed within openings perforated in the gate electrode and the insulating layer. Each of the gate control circuits detects a current flowing through one of the cathode segments and controlling a voltage of the gate electrode of the respective cathode segments in accordance with the detected current, so that the detected current is brought close to a definite value. <IMAGE></p> |
