| 摘要 |
PURPOSE:To rotate a fur brush in a low speed to display a high cleaning capacity for a long time by operating two fur brushes alternately and giving a charge, which is most suitable for individual fur brushes, to the surface of a toner image carrier before the cleaning process. CONSTITUTION:Before the start of copying, only the second fur brush BR9 is set to 300rpm by a driving control part 18. -100muA is given to a electrostatic precharger 7, and a shutter 16 closes a duct 13a of the first fur brush BR8. Copying is performed, and a proper load is given to a photosensitive drum 1 by the charger 7, and the drum 1 is cleaned by the BR9. Mechanical cleaning of the BR9 is supported electrostatically by the charge of the charger 7 to hold the cleaning rate 100%. The removed toner is discharged through ducts 13a and 14a by flicker bars 11 and 12. After the copying process with the BR9 is executed 1,000 times, this copying process is switched to the copying process with BR8. In this case, the shutter 16 is turned to apply +100muA to a charger 17, and this process is executed 15,000 times. Thus, BRs 9 and 8 are driven alternately in a low speed in accordance with an optimum operating ratio. |
