| 摘要 |
PURPOSE:To improve the drawing speed by forming the beam of peculiar shape by combination of a variable arranging beam and some kinds of peculiar area beam instead of drawing all patterns including obliqueness and roundness by dividing them into minute rectangules. CONSTITUTION:The conventional type optical system is provided with a selection coil 50 and a beam-axis aligning coil 51. On a second arranging aperture plate 30, a proper number of peculiar apertures having high frequency of use are arranged in addition to a rectangular aperture. Formation of the variable rectangular beam is carried out by a deflector 9. At this time, the electrical current flown into the coils 50 and 51 is 0. When selecting a peculiar basic figure, deflecting function of the deflector 9 is released and the current corresponding to the selection coil 50 is flown to deflect the beam as shown by 2'. In this case, the current of corresponding quantity is flowed into the coil 51 in order to correct the displacement of the beam from the optical axis after passing through the second aperture. |
