Patent ID: 7916161
Filing Date: 2011-03-29
Classification: G02B,H04N

Abstract:
1. An image forming apparatus, comprising: a light scanning device configured to direct laser beams emitted from a plurality of laser light sources onto a plurality of photoconductive members via a focusing device and a deflecting device that deflects the beams in a main scanning direction; an image forming device that forms visible images from images written onto the photoconductive members by the light scanning device; an intermediate transfer member or a recording sheet transport member capable of carrying the visible images formed on the photoconductive members; a sub scan deflecting device that deflects a position of the laser beams irradiated onto the photoconductive members in a sub scanning direction; a sub scan position detection device that detects the sub scan position of the laser beams irradiated onto the photoconductive members; a pattern detection device that detects a pattern formed on the intermediate transfer member or the recording sheet transport member by the image forming device; a memory device that stores a target irradiation position obtained by correcting color registration errors with respect to the laser irradiation position detected by the sub scan position detection device and color registration error correction values obtained from a detection output of the pattern detection device; and a control device that controls the correction of color registration errors between each color, wherein the control device stores the target irradiation position detected by the sub scan position detection device in the memory device, and when in a detection mode, forms a pattern on the intermediate transfer member or the recording sheet transport member by the image forming device, detects the pattern by the pattern detection device, and stores the color registration error correction values obtained from the detection output of the pattern detection device in the memory device, and when forming images, the control device reads the color registration error correction values and the target irradiation position stored in the memory device, and carries out control so that the laser irradiation position after correction in accordance with the correction values is the target irradiation position.