| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a belt-like member holding and driving device, with which excess biased force due to the outer diameter difference between one end side and the other end side in the longitudinal direction of a holding roll can be restrained regardless of whether an outer roll is pressed against the holding roll, and to provide an image transfer device and an image forming apparatus. <P>SOLUTION: The image forming apparatus 1 includes an intermediate transfer belt 20, a drive roll 21 which drives the belt from inside, a backup roll 23 which holds the intermediate transfer belt 20, and a secondary transfer roll 31 which can contact/separate from the backup roll 23 from the outer peripheral side of the intermediate transfer belt 20. It is set to satisfy: μ<1/(2×cos((π-θ)/2)) and μ<F/N, where F is a tension of the intermediate transfer belt 20, θ is an angle of winding to the backup roll 23; N is a pressing force to the backup roll 23 of the secondary transfer roll 31; and μ is a friction coefficient between the intermediate transfer belt 20 and the backup roll 23. <P>COPYRIGHT: (C)2010,JPO&INPIT |
