Image-forming apparatus and image-forming method

An image-forming method that, in a system wherein a plurality of toner image-forming units for forming toner images by developing electrostatic latent images on the electrostatic latent image-bearing bodies by using a nonmagnetic toner and a developer containing a magnetic carrier are installed, comprises the steps of forming a toner image in each toner image-forming unit;

• transferring the toner image onto a recording medium;
• and fixing the transferred toner image on the recording medium;
• wherein the image-forming method further comprises the steps of:
• developing the electrostatic latent image borne on the surface of the photoreceptor by supplying the developer to the surface of the photoreceptor which is rotating at a peripheral velocity of approximately 200 mm/sec or more and by using a magnetic carrier and a developer containing a nonmagnetic toner both in the same electrostatic charge polarity;
• transferring the toner image obtained in the developing step above;
• and
• removing the nonmagnetic toners remaining on the surface of the photoreceptor (cleaning step);
• and
• the cleaning is conducted by 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 the plurality of cleaning rolls each further comprise a first cleaning roll and a second cleaning roll,
• applying a direct-current bias having the opposite electrostatic charge polarity to that of the nonmagnetic toner to the first cleaning roll, and
• applying a direct-current bias having the same electrostatic charge polarity as that of the nonmagnetic toner to the second cleaning roll.