MULTI-BEAM SCANNING OPTICAL DEVICE

摘要

PROBLEM TO BE SOLVED: To accurately correct an interval between plural beams without adding a new optical element as a multi-beam scanning optical device. SOLUTION: This multi-beam scanning optical device is constituted so that the laser beams LBa and LBb radiated from laser diodes 10a and 10b are coupled by a beam splitter 11 and simultaneously used for scanning a photoreceptor drum (surface to be scanned) 40 in a sub-scanning direction Z at the prescribed interval based on the rotation of a polygon mirror 14. Then, a detector 20 detecting the interval between the beams LBa and LBb is installed at a position being optically equivalent to the surface to be scanned. By displacing the position of the splitter 12 based on the detected value of the detector 20, the interval between the beams is corrected.