| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus for forming a recorded image of high image quality free from banding at all process speed by preventing a driving system for a transfer roll from resonating with the engagement vibration of a gear for driving the transfer roll. <P>SOLUTION: In the image forming apparatus provided with the transfer roll for finally transferring a toner image from an intermediate transfer body to a recording sheet, and having several steps of process speed in accordance with the kinds of recording sheet and image forming conditions, the apparatus is provided with an auxiliary driving means including a motor and a transmission gear, for rotary-driving the transfer roll, and among the several steps of process speed, the transfer roll is driven by the auxiliary driving means at the 1st process speed, on the other hand, the transfer roll is separated from the auxiliary driving means at the process speed other than the 1st process speed, and the transfer roll is rotated together with the intermediate transfer body, besides, the engagement frequency of the transmission gear at the 1st process speed is set in a frequency region whose frequency is different from the resonance frequency of the auxiliary driving means. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
