| 摘要 |
PURPOSE:To increase beam current for correcting any deflected distortion by a method wherein multiple static lenses in partial regions of a screen lens are irradiated with charged beams by a first deflection means and then pictures are drawn on the material by a second deflecting means. CONSTITUTION:Charged beams 2 are focused on an objective aperture 4 through a focusing lens 3. The beams 2 passing through the aperture 4 are irradiated almost in parallel with the optical axes of multiple static lens in the partial regions of a screen lens 7 by the first deflectors 5. While the second deflectors 6 are impressed with voltage for picture drawing process, the beams 2 are deflected vary rapidly by the first deflector 5 to draw pictures while controlling the blanking of partial regions. The distortion correction by the second deflectors 6 is performed by measuring the distortion from pattern picture-drawn for a test as well as correcting any deflected voltage from mean value. Through these procedures, large current can be supplied by irradiating every partial region with beams 2 to correct any deflected distortion by the second deflecting means.
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