Patent ID: 9025981
Filing Date: 2015-05-05
Classification: G03G

Abstract:
1. An image forming apparatus comprising: a plurality of image carriers each of which carries a toner image that is formed thereon; an intermediate transfer body that is rotated while facing the image carriers, is disposed so as to be in contact with one or more image carriers among the image carriers, and carries one or more toner images formed on the one or more image carriers; a contact and separation mechanism that causes the intermediate transfer body to be in contact with or separated from the image carriers; a selection member that selects, using the contact and separation mechanism, a first contact state in which all of the image carriers and the intermediate transfer body are in contact with each other or a second contact state in which one or some of the image carriers and the intermediate transfer body are in contact with each other; a plurality of first transfer units each of which includes a transfer member that corresponds to one image carrier among the image carriers and that is in contact with a back surface of the intermediate transfer body, and each of which forms a transfer electric field in a first transfer region between the transfer member and the one image carrier to transfer a toner image onto the intermediate transfer body; a second transfer unit that includes a transfer member disposed so as to face the intermediate transfer body and that forms an electric field in a second transfer region between the transfer member and the intermediate transfer body to transfer toner images that have been transferred onto the intermediate transfer body onto a recording material; and an adjustment member that adjusts first transfer conditions for the first transfer units, wherein the adjustment member includes a load adjustment unit that adjusts a load of at least a downstream first transfer unit corresponding to the image carrier located at a most downstream position in a movement direction of the intermediate transfer body among the one or more image carriers used for image formation so that when the selection member selects the second contact state, (1) the load in the first transfer region of the transfer member of the downstream first transfer unit that is in contact with the intermediate transfer body is set to be higher than when the first contact state is selected, and so that, (2) when there is an upstream first transfer unit that is in contact with the intermediate transfer body located on an upstream side of the downstream first transfer unit in the movement direction of the intermediate transfer body, the load of the downstream first transfer unit is set to be higher than a load in the upstream first transfer unit.