| 摘要 |
PURPOSE:To use small-diameter developing sleeves having the same outside dimensions by providing developing devices with developer carriers having the same shape and providing crest control plates in peripheral edge parts so that their angular positions from magnets related to development are different in respective developing devices. CONSTITUTION:Developing rolls consisting of magnetic rolls 121 having the same constitution and developing sleeves 111A and 111B which are rotated on the outside of these rolls 121 and have the same shape are attached to upper and lower developing devices 11A and 11B, and crest control plates 122A and 122B are made different from each other only in angle of attachment. For example, the control plate 122A is an angle alpha=100 deg. above a main magnet N1 in the rotation direction of the developing sleeve 111A, and the control plate 122B is the angle alpha=90 deg. above the main magnet N1 in the rotation direction of the developing sleeve 111B. As the result, a correct development processing is performed with a fixed density in developing devices 11A and 11B independently of positional relations of upper and lower positions of these devices. Thus, small-diameter developing sleeves 111A and 111B having the same shape can be used in developing devices 11A and 11B, and the device is made compact and the performance is improved.
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