| 摘要 |
PURPOSE: To compensate pincushion distortion by varying the amplitude of the vibration of a 2nd mirror according to the position of a 1st mirror. CONSTITUTION: A two-dimensional scanner 30 makes the light beam of a stationary light source 32 impinge on a 1st (y)-directional mirror 36 along an optical path 34. The (y)-directional mirror reflects the light along an optical path 38 to direct it to a 2nd (x)-directional mirror 40 which makes it vibrate resonantly. The 2nd mirror reflects the light along a 3rd optical path 41 and directs it to a target plane 44, where a lens 43 focuses the light through an f.θfield- flattening lens 42. The 1st (y)-directional scanner 46 rotates a 1st mirror 36 on an axis 48, so as to control the (y) position of the spot obtained on the target lane 44. A controller 53 drives the scanners 46 and 50 by a raster scanning method which makes the spot scan several hundreds of times in the (x) direction with respect to each (y)-directional scan.
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