Patent ID: 8503901

Claim:
An image forming apparatus comprising: an image carrier; a latent image forming device for forming an electrostatic latent image on the image carrier; a developing device for developing the electrostatic latent image carried on the image carrier to form a toner image on the image carrier; an electrode which is arranged downstream of the developing device in a moving direction of the image carrier and faces to the image carrier; an electric power source which applies a voltage comprising an alternating current voltage to the electrode; a toner contamination detecting device for detecting toner contamination onto the electrode; an electrode cleaning device for cleaning the electrode; and a controlling section, wherein the controlling section controls the electric power source to apply a voltage comprising an alternating current voltage to the electrode so that the toner image is rearranged by reciprocally moving toner of the toner image between the image carrier and the electrode and allows the electrode cleaning device to clean the electrode when the toner contamination detecting device detects toner contamination on the electrode, and performs the toner rearrangement by the electrode from which the toner contamination is removed; wherein the electrode cleaning device applies an electric voltage comprising an alternating current voltage applied by the electric power source, and the controlling section controls the electric power source according to a detected result of the toner contamination onto the electrode detected by the toner contamination detecting device and thereby controls an electrode condition of the electrode while rearranging the toner; and wherein the control of the electrode condition includes a control on a peak voltage and a frequency of the voltage comprising the alternating current voltage.