| 摘要 |
<p>A sixth grid (G6) forming a main electron lens includes a first anode (G61), an auxiliary electrode (G62), and a second anode (G63). A moderate voltage is applied to a fifth grid (G5), the anode voltage is applied to the first and second anodes (G61, G63), and an intermediate voltage is applied to a middle electrode (GM) and the auxiliary electrode (G62).</p> |
