Imaging optical system, image forming apparatus having the same, and a method therefor

摘要

An image forming apparatus includes a semiconductor laser array to emit a plurality of laser beams through a plurality of independently controllable laser elements according to an image signal, an imaging optical system to magnify the laser beams emitted from the laser array, and a photosensitive drum having an imaging surface to form an electrostatic latent image by being photo-exposed through the imaging optical system. The imaging optical system includes a first mirror group having a plurality of reflection mirrors to reflect the laser beams emitted from the laser array, disposed at a given distance from the laser array, a second mirror group having a plurality of reflection mirrors to reflect the laser beams reflected from the first group, and a third mirror group having a plurality of reflection mirrors to reflect the laser beams reflected from the second group onto the imaging surface