IMAGE FORMATION APPARATUS

PROBLEM TO BE SOLVED: To suppress both discharge noise and deterioration in picture quality.SOLUTION: An image formation apparatus has: an image processing part comprising a plurality of devices each including an electrostatic charging part which is arranged oppositely to an image holder and applied with a DC voltage having an AC voltage of first frequency superposed to electrostatically charge the image holder, an electrostatic latent image formation part which forms an electrostatic latent image on the electrostatically charged image holder through optical scanning based upon image information, a developing part which develops the electrostatic latent image, and a transfer part which transfers the developed image to a recording medium; and switching means of switching the frequency of the alternating voltage in electrostatic charging of at least the electrostatic charging part to a second frequency different from the first frequency.SELECTED DRAWING: Figure 3 【課題】放電騒音の抑制と画質低下との抑制を両立する。【解決手段】像保持体に対向して配置されて第１の周波数の交番電圧が重畳された直流電圧を印加することで像保持体を帯電する帯電部と、帯電された像保持体に画像情報に基づく光走査によって静電潜像を形成する静電潜像形成部と、静電潜像を現像する現像部と、現像された画像を記録媒体へ転写する転写部と、を含む複数のデバイスを備えた画像処理部と、前記画像情報に基づく画像密度が特定の画像密度以上の場合に、少なくとも前記帯電部の帯電実行中の交番電圧の周波数を前記第１の周波数とは異なる第２の周波数に切り替える切替手段を有する。【選択図】図３