Patent ID: 7538315
Filing Date: 2009-05-26
Classification: H04N

Abstract:
1. An image forming apparatus which forms an image on a photosensitive member by scanning the photosensitive member forward and backward in a main scanning direction with a laser beam reflected by a reciprocating movable mirror which reflects the laser beam emitted from a light source based on image data toward the photosensitive member, comprising: a rotation direction detecting unit adapted to detect a rotation direction of the movable mirror; a laser beam detecting unit adapted to detect the laser beam scanning the photosensitive member in the main scanning direction; and an image correction unit adapted to weight, on the basis of the rotation direction detected by said rotation direction detecting unit, image data of two lines along a sub-scanning direction in correspondence with a scanning length after start of laser scanning for a line of laser scanning to compensate the image to be formed using the movable mirror; correct the image data and output the corrected image data to said light source for control of its emission, wherein said image correction unit changes weighting coefficients in proportion to a scanning time after start of a line of forward or backward laser scanning in the main scanning direction, based on the rotation direction of the movable mirror detected by said rotation direction detecting unit and a detection of the laser beam by said laser beam detection unit, and generates the corrected image data for a line of forward or backward laser scanning in the main scanning direction by weighting image data of two lines neighboring in a sub-scanning direction orthogonal to the main scanning direction with the changed weighting coefficients to compensate the image to be formed using the movable mirror.