| 摘要 |
PROBLEM TO BE SOLVED: To prevent defective electrification from occurring because toner left after transfer is moved to an electrifying roller in an image forming device constituted so that the toner left after the transfer is recovered by a developing device. SOLUTION: Since the toner left on the surface of a photoreceptor drum 1 after a toner image is transferred is electrified to positive polarity, it is necessary that the toner left after the transfer is electrified to negative polarity in order to be moved to a developing roller 2 by back contrast between the drum 1 and the roller 2. When a positive-polarity electrifying bias is impressed on the electrifying roller 8 at an electrifying time, one part of the positive- polarity toner left after the transfer is moved to the surface of the roller 8. Then, the toner left after the transfer and attached to the surface of the roller 8 is triboelecrtrified to the negative polarity by making the circumferential velocity of the surface of the drum 1 and the circumferential velocity of the surface of the drum 8 different and returned to the surface of the drum 1 from the surface of the roller 8. Then, the toner left after the transfer and electrified to the negative polarity is recovered by the roller 2. |
