IMAGE FORMING APPARATUS AND CORRECTION METHOD

• Main Author: YAGUCHI KAZUTAKA
• Format: Patent
• Language: English; Japanese
• Published: 08.08.2016
• Subjects: CINEMATOGRAPHY; ELECTROGRAPHY; ELECTROPHOTOGRAPHY; HOLOGRAPHY; MAGNETOGRAPHY; PHOTOGRAPHY; PHYSICS

PROBLEM TO BE SOLVED: To highly accurately correct contrast in a short time.SOLUTION: An image forming apparatus includes a photoreceptive drum 200, exposure means 220, a transfer roller 241, a transfer voltage application circuit 242, and a current detection circuit 243. A control part 250 which determines a discharge start voltage between the photoreceptive drum 200 and the transfer roller 241 on the basis of a current value detected by the current detection circuit 243 and a voltage applied to the transfer roller 241 by the transfer voltage application circuit 242, to calculate a surface potential of the photoreceptive drum 200 on the basis of the discharge start voltage calculates a target current value corresponding to a predetermined surface potential on the basis of a difference between the predetermined surface potential and the calculated surface potential and adjusts the intensity of exposure to the photoreceptive drum 200 by the exposure means 220 on the basis of the difference between the target current value and the current value detected by the current detection circuit 243.SELECTED DRAWING: Figure 6 【課題】短時間で高精度にコントラストの補正を行うこと。【解決手段】感光ドラム２００と、露光手段２２０と、転写ローラ２４１と、転写電圧印加回路２４２と、電流検知回路２４３と、を備え、電流検知回路２４３により検知される電流値と転写電圧印加回路２４２により転写ローラ２４１に印加される電圧とに基づき感光ドラム２００と転写ローラ２４１との間の放電開始電圧を判断し、放電開始電圧に基づき感光ドラム２００の表面電位を算出する制御部２５０が、所定の表面電位と算出された表面電位との差分に基づき、所定の表面電位に対応する目標電流値を算出し、目標電流値と電流検知回路２４３により検知された電流値との差分に基づき露光手段２２０による感光ドラム２００への露光の強度を調整する。【選択図】図６