Patent ID: 7315711

Claim:
An image forming apparatus comprising: an image carrier; charging means for uniformly charging a surface of said image carrier; latent image forming means for forming a latent image on the surface of said image carrier uniformly charged by said charging means; developing means for developing the latent image to thereby produce a corresponding toner image, said developing means comprising stationary magnetic field generating means, which is disposed thereinside, and rotatable with a two-ingredient type developer made up of magnetic carrier grains and toner grains deposited on a surface thereof; and image transferring means for transferring the toner image from said image carrier to an image transfer medium; wherein said developing means bifunctions as cleaning means for collecting residual toner grains left on said image carrier after transfer of the toner image to the image transfer medium, in the event of collection of the residual toner grains, a DC voltage is applied to said image carrier and a developer carrier to thereby form an electric field in a direction in which the residual toner grains move from said image carrier toward said developer carrier, and said magnetic field generating means generates, at a position where said developer carrier faces said image carrier, a magnetic field whose magnetic force in a direction normal to the surface of said developer carrier is between 100 mT and 200 mT.