| 摘要 |
PURPOSE:To prevent toner from passing under the edge of a cleaning blade by striking the surface of an image carrier on the upstream side of the blade with electrostatically charged particles of grain size much larger than that of toner. CONSTITUTION:A conductive roller 4 is arranged on the upstream side of a magnetic roller 8 and applied with an AC voltage, and a mixture of a powder body 5a which has 30-100mu grain size severe times as large as that of normal toner and a powder body 5b which has grain size about 10 times as large as that of said powder body is put in the space where the roller 4 is present. Those two kinds of charged powder bodies are conveyed successively by the roller 4 and the blade 11 cuts off the powder body 5b having the large grain size, so that only the small-sized powder body 5a is carried to the part where the roller 4 and image carrier 1 face each other. This small-sized powder body 5a jumps in the presence of an AC electric field to enter reciprocal motion between the roller 4 and the surface of the image carrier 1. The motion of the powder body 5a attracts part of residual toner sticking on the surface of the image carrier because of a difference in charging polarity. |
