| 摘要 |
PURPOSE:To prevent scattering and dropping of a developer, or generation of flaws, etc. due to rubbing of the developer on a developed image forming surface, by obstructing bristles of the developer of the part facing a photosensitive body on a developing sleeve at the time of non-development. CONSTITUTION:When both a developing sleeve 24 and a magnet roll 47 are rotated in the right direction, a developer 48 is carried by a small quantity in the right direction on a layer A in the civinity of the sleeve 24, and rotated in the left direction on a layer B of the outside circumferential part and the greater part is carried. When a revolving speed of the roll 47 remains unchanged and a revolving speed of the sleeve 24a is increased, only the layer A is formed, and a layer corresponding to the layer B is not formed. It is because the sleeve 24 rotates at a high speed, therefore, the developer 48 cannot move in the opposite direction against the rotating force. Also, when the sleeve is rotated at a higher speed, the developer 48 is not carried to the part facing a photosensitive body 11, and bristle formation of the developer 48 can be obstructed. At the time of non-development, the sleeve 24 is rotated at a high speed so that the developer 48 does not contact the photosensitive body 11. |
