Patent ID: 6961535

Claim:
In a developing device included in an image forming apparatus and including a plurality of developing rollers adjoining each other in a direction of rotation of an image carrier for causing a toner of a two-component type developer to deposit on a latent image which is formed on said image carrier due to a magnetic polarity to thereby develop said latent image, wherein a downstream most developing roller positioned at a most downstream side in said direction of rotation comprises: a sleeve; and a multiple-pole magnet roller held stationary inside of said sleeve, wherein said magnet roller comprises: a plurality of first magnets different in magnetic polarity from each other; and a second magnet buried in one of said plurality of first magnets, said one of said plurality of first magnets forming a magnetic pole, wherein a flux density on a surface of said sleeve of said most downstream developing roller, as measured at the magnetic pole in a radial direction, is 120 mT or above.