| 摘要 |
<P>PROBLEM TO BE SOLVED: To suppress the occurrence of carrier adhesion and scumming even if a small-diameter developing roller is used in an image forming apparatus which has a developing means for developing a latent image on an image carrier by a developer composed of a toner and the carrier and a transfer means for transferring the toner image formed by the developing means to a transfer material, has a nonmagnetic sleeve rotating together with the fixed magnet in the developing means, and has a developing roller arranged to face the developer carrier. <P>SOLUTION: The image forming apparatus is so constituted that the external diameter of the developing roller 51 is ≤18 mm; the developing main pole angle θ of the fixed magnet is inclined 5 to 10° to the upstream side in the rotating direction of the developing roller from a straight line connecting the center of the developing roller and the point nearest to the image carrier in the developing roller; the average grain size of the carrier constituting the developer is 35 to 40 μm; and the electric resistance value measured by a magnetic brush shape of the carrier is 5×10<SP>6</SP>to 5×10<SP>7</SP>Ω. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
