| 摘要 |
This invention relates to a system for focusing and deflecting a beam of charged particles comprising a charged particle gun, means for generating a beam of charged particles and electromagnetically deflecting the emitting direction of the beam and a surface or screen to be illuminated with said beam, characterized by the fact that at least two sets of means for deflecting the charged beam are provided between said beam generating means and said screen, so that the position and direction of incidence of said beam upon said lens or group of lenses can be controlled independently of each other to focus said beam on a desired minute region on said screen. This novel system makes it possible to reduce the size of the focal spot of the beam on the screen and improve the deflection accuracy of such beam.
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