Patent ID: 7251442

Claim:
An image forming apparatus comprising: an image forming section for forming a toner image with toner particles having a first electric polarity; an intermediate transfer body for bearing the toner image; a first transfer section for transferring the toner image from the image forming section to the intermediate transfer body; a second transfer section for transferring the toner image from the intermediate transfer body to a recording medium; a charger for applying an electric charge to the toner image on the intermediate transfer body before the toner image is transferred to the recording medium; and a charge control section for applying a voltage to the charger, the voltage being suitable for lowering an electric surface potential of a high density portion of the toner image and for substantially preventing an electric surface potential of a low density portion of the toner image from lowering; a sensor for sensing an electric surface potential of at least one of the intermediate transfer body or a portion where toner particles are adhered on the intermediate transfer body; and a control section for, based on the surface electric potential sensed by the sensor, controlling the charge control section to adjust the voltage applied to the charger.