| 摘要 |
PURPOSE:To facilitate the removal of a toner which has been mixed into a developing device, and to contrive the improvement of the picture quality by forming a toner image of two colors or more on a photosensitive body, and attracting selectively and electrostatically a mixed toner electrified to the opposite polarity to the toner used for its developing device, to a prescribed part on the photosensitive body, when the toner of the toner image formed previously has been mixed into the developing device in the subsequent developing process. CONSTITUTION:Materials of a toner and a carrier are selected in advance so that the toner of a developing device 6 is electrified to the positive polarity, and the mixed toner is electrified to the negative polarity. A photosensitive body 1 suspends the formation of an electrostatic latent image at the time of a cleaning work of the developing device 6, and during that time, the position electrode of a DC power source 64 is connected thereto. Also, a developing roller 61 is grounded. In this state, the photosensitive body 1 rotates in the direction as indicated with an arrow 63. In such a way, the mixed toner 32 electrified to the negative polarity is attracted electrostatically to the photosensitive body 1. On the other hand, the toner 31 electrified to the positive polarity sticks to the carrier 30 as it is and remains in a second developing device 6. In such a way, the mixed toner 32 which has been attracted selectively to the photosensitive body 1 is removed from the outer peripheral surface of the photosensitive body 1 by a cleaning device thereafter.
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