| 摘要 |
The astigmatism of the electron beams (6, 7, 8) generated by an electron gun system (5) are substantially reduced by constructing the lens electrode components (25, 26) between which a focusing lens is formed in an operating electron gun to be inverted replicas of each other. The lens electrode components should be provided with the corresponding sides (45, 46) facing each other and with the corresponding apertures (38, 42) opposite to each other. |
