| 摘要 |
<P>PROBLEM TO BE SOLVED: To prevent the image defect caused by a cleaning defect of toner remaining after transfer, for a long period of time. <P>SOLUTION: The toner remaining on a photoreceptor drum 1 after transfer of a toner image is recovered into a developing device 4 by a fog removing bias during developing of the developing device 4. The fog removing bias is required to be controlled to a level at which the recovering efficiency of the toner is enhanced and the adhesion of carriers does not arise. A power source S1 for impressing an electrostatic charge bias is thereupon controlled by a control means 7 according to the result of calculating the image ratio of a means for calculating the image ratio (a video counter) in a control means 7 during image formation, thereby changing the electrostatic charge bias that the power source S1 impresses to an electrostatic charging roller 2. As a result, the fog removing bias is controlled. <P>COPYRIGHT: (C)2004,JPO |
