| 摘要 |
PURPOSE:To execute a development by which a picture density and a picture quality are good and stable by setting substantially a relative speed of a photosensitive drum and a developing roller to ''0'', and also setting a velocity ratio of a magnetic roller and the developing roller to a specified range. CONSTITUTION:A magnetic roller 22 for carrying a two component developer G by sticking it like a brush by a magnetic force, and a developing roller 23 for separating and sticking only a toner T and carrying it are provided in a casing 20 of a developing device 8. Also, the relative speed of the photosensitive drum 4 and the developing roller 23 is ''0'' substantially, and also the velocity ratio of the magnetic roller 22 and the developing roller 23 is set so as to be within a range of 2:1 through 6:1. By setting such a velocity ratio, it is possible to execute the development by which the picture density and the picture quality are good and stable. |
