Patent ID: 7619642

Claim:
An image forming apparatus comprising: a plurality of image carriers which are simultaneously rotated; an image forming unit for forming each of color component images of a plurality of colors on each of corresponding image carriers among said plurality of image carriers, respectively; a transfer medium to which each of color component images formed on each of said image carriers is to be transferred; a position detecting unit for detecting a position, on said transfer medium, of each of color component images transferred to said transfer medium; and a timing adjusting unit for adjusting timing at which each of color component images is to be formed on each of said image carriers, respectively, by said image forming unit based on the positions of each of color component images on said transfer medium detected by said position detecting unit; wherein said image forming unit includes: a plurality of irradiators for, with same timing, emitting light beams corresponding to each of said image carriers, respectively; and a single polygon mirror for reflecting, by a same reflecting surface, the light beams emitted with the same timing from said plurality of irradiators toward the corresponding image carriers, respectively so that each of color component images is formed on each of said corresponding image carriers with same timing; and the each of color component images of a plurality of colors is formed simultaneously on the corresponding image carrier among said plurality of image carriers; and an interval between the color component images transferred to said transfer medium becomes substantially equal to an interval between the corresponding image carriers.