IMAGE FORMING APPARATUS

To prevent a harmful effect on an image due to a deterioration of a contact member that is in contact with a recording material simultaneously with a transfer member, while maintaining good transferability.SOLUTION: An image forming apparatus 100 has: an image carrier 10; a transfer member 20; a power supply 21 that outputs voltage to the transfer member 20; a detection unit 241 that detects at least either one of a current value or a voltage value when the voltage is output from the power supply 21 to the transfer member 20; a control unit 210 that controls the power supply; an environment detection unit 300; and a contact member 31 that is provided to be contactable with a recording material P simultaneously with the transfer member 20 at a portion other than a transfer part N2. When an absolute moisture amount obtained based on environment information is equal to or more than a predetermined threshold, the control unit 210 sets a limit voltage Vlimit based on a result of detection performed by the detection unit 241 when the recording material P is not at the transfer part N2, and controls the power supply 21 so that the absolute value of the voltage applied from the power supply 21 to the transfer member 20 becomes equal to or less than the absolute value of the limit voltage Vlimit while the recording material P is simultaneously in contact with the transfer member 20 and the contact member 31.SELECTED DRAWING: Figure 3 【課題】良好な転写性を維持しながら、転写部材と同時に記録材に接触する接触部材の劣化による画像弊害を抑制する。【解決手段】画像形成装置１００は、像担持体１０と、転写部材２０と、転写部材２０に電圧を出力する電源２１と、電源２１から転写部材２０に電圧を出力した際の電流値又は電圧値の少なくとも一方を検知する検知部２４１と、電源を制御する制御部２１０と、環境検知部３００と、転写部材２０と同時に転写部Ｎ２以外で記録材Ｐに接触可能に設けられた接触部材３１と、を有し、制御部２１０は、環境情報に基づいて得られた絶対水分量が所定の閾値以上である場合に、転写部Ｎ２に記録材Ｐが無い状態での検知部２４１の検知結果に基づいてリミット電圧Ｖｌｉｍｉｔを設定し、記録材Ｐが転写部材２０と接触部材３１とに同時に接触している間に電源２１から転写部材２０に印加する電圧の絶対値がリミット電圧Ｖｌｉｍｉｔの絶対値以下となるように、電源２１を制御する構成とする。【選択図】図３