| 摘要 |
PROBLEM TO BE SOLVED: To provide a developing method capable of preventing an abnormal image quality generated by the fact that a development sleeve is faster than the moving speed of an electrostatic latent image, and to improve the following qualities: 1 image density, 2 scumming, 3 pinhole defects at back end of solid, 4 pinhole defects at back end of half tone, 5 line aspect ratio (= longitudinal line width/lateral line width), 6 carrier adhesion to ground section (counter charge (charging polarity of toner and charge of reverse polarity) type carrier adhesion), 7 carrier adhesion to solid section, and 8 granularity. SOLUTION: In a two-component contact development method, a non-magnetic toner and a dry type two-component developer constituted by core material particles having magnetism and an electrophotographic developer carrier where the particle surface is covered with a resin layer are supplied to a development region with the development sleeve rotating in the same direction as an image carrier and a plurality of magnetic poles rotating in the same direction as the image carrier installed inside the development sleeve, and a direct current bias is applied to visualize the electrostatic latent image. When the development region width is L [mm], the moving speed of a photosensitive body is Vp [mm/sec], the number of magnetic poles is K, and the rotation speed of the magnetic poles is N [rpm], (L/Vp)×(KN/60)>2 is satisfied. COPYRIGHT: (C)2009,JPO&INPIT |
