Patent ID: 7218879

Claim:
An image forming apparatus comprising: an image carrier; a charging device configured to uniformly charge a surface of said image carrier with a charging member, which is applied with a bias of a first polarity for charging; a latent image forming device configured to form a latent image on the surface of said image carrier uniformly charged; a developing device configured to develop the latent image by depositing toner grains of the first polarity on said latent image to thereby form a corresponding toner image; a transferring device configured to form an electric field between said image carrier and a moving member whose surface is movable in contact with said image carrier to thereby transfer the toner image from the surface of said image carrier to said moving member or a recording member nipped between said image carrier and said moving member; a polarity controlling device configured to set residual toner to a second polarity opposite to said first polarity, before the residual toner left on said image carrier by the transferring device is conveyed to a corresponding position to said charging member; and an electric charging device configured to keep the residual toner at a keeping area formed between the charging member and a bias applying blade adjacent the charging member, and configured to charge the residual toner deposited on said charging member to said first polarity; wherein said charging device discharges the residual toner whose polarity is charged to said first polarity onto said image carrier at a predetermined time.