| 摘要 |
PURPOSE:To improve the cleaning effect of the transfer roller of a photoreceptor unit in an image forming device. CONSTITUTION:An electrostatic charger 23 having a positive polarity, an exposure part by a scanner unit, a developing device 10 forming a toner image having the positive polarity, and a transfer roller 8 transferring a toner image on a photoreceptor drum 7 to paper at a transfer part by impressing transfer bias voltage having a negative polarity are arranged in order on the outer periphery of the rotating photoreceptor drum 7. When the paper does not exist at the transfer part, a controller controls so that cleaning bias voltage having the positive polarity is impressed on the transfer roller 8 so as to transfer electrostatically charged toner to the drum 7, and the area of the drum 7 passing the transfer part is electrostatically charged to be in the positive polarity by the charger 23 and then the voltage of nearly the same potential is impressed on the electrostatically charged area by a developing device 10. |
