Patent ID: 8909112
Filing Date: 2014-12-09
Classification: G03G

Abstract:
1. An image forming apparatus comprising: a conveyance unit to convey a transfer medium; a first image forming unit to form a monochrome image transferred at a first transfer position onto the transfer medium conveyed on the conveyance unit; and a second image forming unit disposed downstream from the first image forming unit in a direction of conveyance of the transfer medium, comprising an intermediate transfer body to form a multi-colored toner image on the intermediate transfer body, with the multi-colored toner image transferred from the intermediate transfer body onto the transfer medium conveyed on the conveyance unit at a second transfer position different from the first transfer position; the conveyance unit separating from the intermediate transfer body at the second transfer position in a monochrome mode to form the monochrome image on the transfer medium using only the first image forming unit, and contacting the intermediate transfer body at the second transfer position in a full-color mode to form a full-color image on the transfer medium using both the first and second image forming units; and the conveyance unit and the intermediate transfer body separated from each other at the second transfer position in the monochrome mode respectively having predetermined electric potentials at the second transfer position, wherein the intermediate transfer body includes: wherein the conveyance unit comprises: wherein the transfer medium is separated from the conveyance belt at the third support member in both the monochrome and full-color modes, wherein positions of the third and fourth support members remain unchanged in both the monochrome and full-color modes, wherein the multiple conveyance support members further comprise a tension roller to move along with movement of the second support roller to maintain the tension of the conveyance belt, and wherein the tension roller is interposed between the third support member and the fourth support member and contacts the conveyance belt at a position other than a conveyance path of the transfer medium.