Patent ID: 7689152
Filing Date: 2010-03-30
Classification: G03G

Abstract:
1. An image forming apparatus comprising: a first transfer section for transferring a toner image, which is formed on an image carrier by utilizing a charging section, an exposing section and a developing section, onto an intermediate transfer member having a belt shape; and a second transfer section for transferring the toner image transferred on the intermediate transfer member onto a recording material by applying an electric field between a second transfer roller being provided outside the intermediate transfer member and a backup roller being provided inside the intermediate transfer member, the second transfer roller and the backup roller sandwiching an intermediate recording member and the recording material; wherein a bias voltage having a same polarity as a polarity of toner forming the toner image to be transferred is applied to the backup roller through a metal shaft of the backup roller when transfer operation is conducted by the second transfer section, and bias voltage having an opposite polarity to the polarity of toner is applied to the backup roller through the metal shaft of the backup roller when transfer operation is not conducted by the second transfer section; wherein a metal shaft of the second transfer roller is constantly grounded and further provided is a second charging section for charging a surface of the second transfer roller; wherein the second charging section charges the surface of the second transfer roller with a same polarity as a polarity of toner forming the toner image to be transferred when a transfer operation by the second transfer section is not conducted; wherein the second charging section comprises s corona discharging electrode.