| 摘要 |
PURPOSE:To provide a charged-beam optical mirror tube, which can be simplified, can have an increased stability, can be manufactured at a low cost, and can change the dimension and the shape of a beam without any need of providing a lens used for forming a cross-over at the deflection center of the deflectors. CONSTITUTION:A planking deflector 22, a beam-positioning deflector 23 and an objective lens 17 are installed under a capacitor lens 21. Aperture masks 11 and 12 and deflectors 13-16 are installed between the avove deflectors 22 and 23. A cross-over (Q1) formed by an electron gun, which is not illustrated in the figure, is imaged on the aperture mask 11 by means of the capacitor lens 21, and a cross-over (Q2) is formed on the mask 11. By constituting a charged-beam optical mirror tube in such a manner as above, usual electron-beam deflection can be carried out by subjecting an electron beam to deflection scanning by means of the beam-positioning deflector 23, and by planking the electron beam by means of the planking deflecting plate 22. |
