OPTICAL SCANNER AND ITS ADJUSTING METHOD

摘要

PROBLEM TO BE SOLVED: To suppress recording defects brought about by deviation of scanning units from normal positions due to the temperature change or the like with respect to an optical scanner where a plurality of the scanning units constituted to perform scanning with deflectors are arranged in the main scanning direction. SOLUTION: With respect to the optical scanner where a plurality of scanning units provided with semiconductor lasers 1 and polygon mirrors 2 which deflect laser light to scan a scan object face are arranged in the main scanning direction, laser light from polygon mirrors is detected by photo detection sensors 5a to 5e provided in reference positions for prescribing the scan widths of respective scanning units on the scan object face in trial scan performed in the absence of a medium M, and the start position and the end position of recording scan are set on the basis of detection timings of laser light in the reference positions. In this case, the polygon mirrors are moved forward and backward in the direction orthogonal to the scan object face so that a proper number of pixels may be arranged between the reference positions.