| 摘要 |
PURPOSE:To prevent blocking and cross-linkage securely and to perform stable development of good quality by extending a steel wire at the upstream side of a thickness control member in the conveyance direction of a magnetic developer and nearby the outer peripheral surface of a developing roller and then applying an AC voltage to the steel wire. CONSTITUTION:Magnetic toner 1 is attracted to the surface of a sleeve 5 by an internal magnet roller 6 and conveyed gradually as shown by an arrow while sliding on the surface of the sleeve 5 to form a toner layer. This toner layer is controlled by the thickness control member 8 to constant layer thickness and conveyed to the side opposite a photosensitive drum 3 to develop a latent image on the surface of the photosensitive drum 3. An alternating current is generated at the upstream side of the thickness control member 8 between the steel wire 9 applied with an AC voltage and the sleeve 5 and the magnetic toner 1 itself oscillates by the potential of the magnetic toner 1 on the sleeve 5 associatively with variation of an electric field. Consequently, even if small flocculates are formed in the magnetic toner 1, they are crushed into particles and toner blocking and the deposit of foreign matter are prevented by packing effect, thereby obtaining an image of good quality. |
