Patent ID: 7171152

Claim:
An image-forming apparatus comprising a plurality of toner image-forming units that form toner images by developing electrostatic latent images by means of a developer containing a nonmagnetic toner and a magnetic carrier, that transfers and superimposes the toner images formed in respective toner image-forming units one by one to give a final superimposed image on a recording medium, fuses the superimposed toner image on the recording medium, and forms the fused toner image on the recording medium, wherein: each of the toner image-forming units further comprises a photoreceptor, a developing device that supplies the developer above to the surface of the photoreceptor and develops an electrostatic latent image borne on the surface of the photoreceptor by using a magnetic carrier and a developer containing a nonmagnetic toner both in the same electrostatic charge polarity, a plurality of cleaning rolls each having a magnetic particle layer of magnetic particles at the surface, which are located in the state freely rotatable and in contact with or in the neighborhood of the surface of the photoreceptor and absorb nonmagnetic toners present on the surface of the photoreceptor on the magnetic particle layer thereof by rotation, the plurality of cleaning rolls each further comprise a first cleaning roll to which a direct-current bias having the opposite electrostatic charge polarity to that of the nonmagnetic toner is applied and a second cleaning roll to which a direct-current bias having the same electrostatic charge polarity as that of the nonmagnetic toner; and the photoreceptor is rotating at a peripheral velocity of approximately 200 mm/sec or more.