| 摘要 |
PURPOSE:To prevent the occurrence of a stripe-like nonuniformity on a copy due to defective developer agitation by opening and closing a shutter mechanism before a developing magnet roller and carrier magnet roller are stopped. CONSTITUTION:A shutter 30 is opened and closed at a time when a device is warmed up, a driving system stops and developing action is finished. After a latent image on a photosensitive belt 6 is developed, the shutter 30 is opened and closed a prescribed number of times, then it is finally closed. The developer is recovered in the upper part of the shutter mechanism 30, and after that the driving systems of the developing magnet roller 24 and the carrier magnet roller 27 stop so as to prepare next developing action. The developer existing in the opening A part between the shutter 30 and a developer tank main body 21 is sufficiently agitated by the opening and closing action caused by the rotation of the shutter 30, and therefore uniformal tonner density can be obtained in general. Thereby, the copy nonuniformity due to the defective developer agitation can be prevented. |
