| 摘要 |
PROBLEM TO BE SOLVED: To provide an image forming apparatus that can ensure, when forming an image with a low image area ratio on a recording sheet having a number of concaves and convexes on the surface, sufficient image density at the concave parts on the surface of the recording sheet.SOLUTION: In an image forming apparatus including: an intermediate transfer belt 31 that carries a toner image; toner image forming means for forming a toner image on the intermediate transfer belt 31; a nip forming roller 36 for contacting the intermediate transfer belt 31 to form a transfer nip; and a secondary transfer bias power source 39 that applies a transfer bias comprising a DC component and an AC component to the nip forming roller 36, a control part performs switching of a ratio of the area of an AC waveform in the direction to return a toner to the intermediate transfer belt 31 side across the center value of the minimum value and the maximum value of the AC component of the transfer bias, occupied in the entire area of the AC waveform according to an image area ratio; and the control part controls so that the ratio is reduced as the image area ratio is reduced. |
