IMAGE FORMATION APPARATUS, IMAGE FORMATION CONTROL METHOD AND IMAGE FORMATION CONTROL PROGRAM

PROBLEM TO BE SOLVED: To reduce image quality degradation due to fine irregularities on a polygon mirror reflection surface.SOLUTION: An image formation apparatus comprises: an image carrier on which an image is formed with exposure of an optical beam; a light source which generates the optical beam emitted in accordance with image data; an optical scan unit which scans the optical beam in the first scan direction in the image carrier with plural reflection surfaces of a rotationally-driven rotary polygon mirror; a second scan direction drive unit which relatively moves the image carrier and the optical beam in the second scan direction orthogonal to the first scan direction; a reflection surface specification unit which identifies each reflection surface of the rotary polygon mirror; a storage unit which stores irradiation shape information generated from the irradiation shape on the image carrier surface of the optical beam reflected at each position of each surface of the rotary polygon mirror; and an image processing unit which corrects the pixel value of the target pixel of the image data by referring to the irradiation shape information and the pixel value of the proximity pixel so that the exposure intensity on the image carrier surface of the target pixel becomes the state corresponding to the original pixel value with the irradiation shape information of the proximity pixel, and supplies the image data after correction to a light source.SELECTED DRAWING: Figure 1 【課題】ポリゴンミラー反射面の微細な凹凸に起因する画質劣化を軽減させる。【解決手段】光ビームの露光で画像形成される像担持体と、画像データに応じて発光する光ビームを発生する光源と、回転駆動される回転多面鏡の複数の反射面により像担持体において光ビームを第一走査方向に走査する光走査部と、第一走査方向と直交する第二走査方向に像担持体と光ビームとを相対的に移動させる第二走査方向駆動部と、回転多面鏡の各反射面を識別する反射面特定部と、回転多面鏡の各面の各位置で反射された光ビームの像担持体面における照射形状から生成された照射形状情報を記憶する記憶部と、近接画素の照射形状情報により、注目画素の像担持体面における露光強度が本来の画素値に対応した状態になるように、照射形状情報と近接画素の画素値とを参照して、画像データの当該注目画素の画素値を補正し、補正後の画像データを光源に供給する画像処理部とを備える。【選択図】図１