| 摘要 |
PURPOSE:To prevent soiling of inside of the device due to scattering of residual developer and to obtain a good copy by determining interrelation between effective width of cleaning of a cleaning member, electrostatic charge effective width of a corona electrifier, length of a photosensitive body and developing width of a developing device properly. CONSTITUTION:When L1 denotes electrostatic charge effective length of the corona electrifier 3, L2 denotes cleaning effective width of the cleaning member 11, and L3 denotes the width of a photosensitive body 2 and nearly equal width of a developing roller 14, their relation is determined to become L1<L2<L3. As cleaning effective width of the cleaning member 11 is larger than charge effective width L1 on the photosensitive body 2, a toner image is formed mainly in the electrostatic charge effective width L1, and developer 15 remains in the limit. Accordingly, the developer does not spill down from both ends of the cleaning member 11 and scraped up nicely. Further, as it is swept down by a magnetic brush 14a of the developing roller 14 having width nearly equal to the photosensitive body 2, residual developer 15A on the photosensitive body 2 is recovered to its both ends surely by the magnetic brush 14a into the developing device 5, and does not fall down or scatter in the device. |
