| 摘要 |
PURPOSE:To transport uniformly a magnetic toner and to simplify the constitution of the permanent magnet shaft in a non-magnetic cylindrical sleeve by providing freely rotatably said sleeve around the permanent magnet shaft and providing a permanent magnet layer magnetized to multiple poles to the outside or inside peripheral surface of the cylindrical sleeve. CONSTITUTION:The permanent magnet shaft 12 having a magnetic pole for development facing always a photosensitive drum 6 is fixedly provided and the non-magnetic cylindrical sleeve 10 is freely rotatably provided around the shaft 12. The permanent magnet layer 11 magnetized to multiple poles is provided to the outside or inside peripheral surface of the sleeve 10. The magnetic pole width of the multipolar permanent magnet layer 11 is set at 1-6.5mm and the ratio of the moving speed of the latent image on the drum 6 with respect to the peripheral speed of the layer 11 is set at 0.2-0.36. |
