| 摘要 |
PURPOSE:To heighten sensitivity and definition, by providing anti-charging electroconductive coating films on at least the portions of electrically-insulating support bars which face Y-direction deflecting electrodes, to prevent the charging of the support bars to preclude aberration and bright line bending. CONSTITUTION:Electroconductive coating film 20 are provided on the main and side surfaces of the portions of electrically-insulating support bars 19 which face Y-directiondeflecting electrodes 16 and surround the planted portions 161, 162 thereof. One end 201 of each coating film 20 is located near the planted portion of a second anode 15, within such an area that a voltage applied to the second anode and that applied to the Y-direction deflecting electrodes 16 are not hindered. The other end 202 of each coating film 20 is likewise located near the planted portion 171 of an osilation electrode 17. As a result, the form of an electron beam spot hardly undergoes aberration even if there are floating electrons. Furtheremore, the support bars 19 are kept from being electrically charged to distort a converged electron beam. Sensitivity and definition are thus heightened. |
