Patent ID: 9720351
Date: 2017-08-01
CPC Classifications: G03G

Claim:
1. An image forming apparatus comprising: an intermediate transfer belt that rotates and carries a toner image which is to be primarily transferred, the toner image being secondarily transferred onto a sheet at a secondary transfer position, the intermediate transfer belt being tensioned by multiple inner rollers; multiple first type photoconductive drums that are arranged to have a common tangent plane to drum surfaces on the outer peripheral side of the intermediate transfer belt; multiple first type transfer rollers that are arranged at positions which face the multiple first type photoconductive drums on the inner peripheral side of the intermediate transfer belt and transfer toner images which are formed on the multiple first type photoconductive drums onto the intermediate transfer belt; a second type photoconductive drum that is arranged on the outer peripheral side of the intermediate transfer belt at a position which is farther separated from the secondary transfer position than the multiple first type photoconductive drums and at a position where the drum surface of the second type photoconductive drum is not tangent to the common tangent plane from the same direction as the multiple first type photoconductive drums; a second type transfer roller that is arranged on the inner peripheral side of the intermediate transfer belt at a position which faces the second type photoconductive drum and transfers a toner image which is formed on the second type photoconductive drum onto the intermediate transfer belt; a single roller that is arranged on the inner peripheral side of the intermediate transfer belt between the second type transfer roller and one transfer roller of the multiple first type transfer rollers which is the closest to the second type transfer roller, the single roller being different from two inner rollers of the multiple inner rollers, the two inner rollers being most-distant from each other in the multiple inner rollers inside the intermediate transfer belt; and a roller moving unit that is configured to move the single roller in a first direction and a second direction, the first direction being along the common tangent plane, the second direction being orthogonal with respect to the common tangent plane, the roller moving unit changing the state of abutting of the multiple first type photoconductive drums and the second type photoconductive drum on the intermediate transfer belt by pressing and moving the single roller to the inner peripheral face of the intermediate transfer belt.