| 摘要 |
PURPOSE:To facilitate the adjustment of optical axes when a device is adjusted and to provide stable plotting precision by adding a detection means of a quadrature error between a plotting table and a scanned laser beam and a means deflecting a laser optical axis in the direction orthogonally intersecting with the scan direction. CONSTITUTION:The laser beam is scanned on a photosensitive material placed on the plotting table 6 by the plotting table 6 and a rotary polygon mirror 4, and various patterns on a printed circuit board are plotted. Then, the quadrature error between the plotting table 6 and the scanned laser beam is detected by the detection means 12 of the quadrature error, and a laser beam deflection means 3 moves a laser light spot in the movement direction of the plotting table 6 based on the detection result. A laser light deflection angle is operated from the quadrature error between the plotting table 6 and the scanned laser beam in a correction process part 12, and the laser beam deflection means 3 is controlled. Thus, the quadrature error occurring from optical axis deviation and the surface inclination error of the rotary polygon mirror 4 is canceled by beforehand deflecting the laser beam. |
