Patent ID: 7433617

Claim:
An image forming apparatus, comprising: a plurality of developing units to form a color image using at least a two pass developing process by developing a plurality of electrostatic latent images with toners having different colors and polarities during a first pass of the developing process; an exposing unit to form a tri-level potential on a photosensitive medium; and a control unit to control one of a development voltage applied time and a collection voltage applied time without changing the other of the development voltage applied time and the collection voltage applied time by applying a development applied voltage to at least one of the plurality of developing units operating during the first pass of the developing process, by dividing the development applied voltage into a development voltage, a collection voltage, and at least one intermediate voltage, and by selectively applying the intermediate voltage to the at least one of the developing units during a time period of the development voltage or during a time period of the collection voltage to the second developing unit.