Apparatus for cleaning a transfer device of an image forming apparatus

摘要

A contact type image transferring system and method incorporated in an image forming apparatus for cleaning residual toner on a transfer roller. The transfer roller is in contact with a photoconductive drum and forms a nip between the roller and the drum. A sheet of paper passes through the nip and a toner image on the drum is transferred to the sheet of paper. A power source applies a first bias current which has the same polarity as regularly charged toner to the transfer roller from when the image carrier starts its rotation after an inputting of a print start request until the sheet reaches the nip. Then the power source applies a second bias current having the same polarity as the first bias current to the transferring device when the sheet is at the nip to transfer the toner image on the image carrier to the sheet.