| 摘要 |
PURPOSE:To prevent deterioration in cleaning performance with the number of copies by providing a counter which counts copies and a means which varies a bias impressed to a conductive sleeve, reproducing roll, etc., according to the counted value of the counter. CONSTITUTION:The conductive sleeve 2a is formed cylindrically around a cleaning roll 2, and its nap tips are rubbed against the surface of a photosensitive body 1 to remove residual toner on the photosensitive body 1. The toner which is removed and remains in a magnetic brush is recovered by being attracted to the surface of the reproducing roll 3. The bias voltage impressed to the conductive sleeve 2a and reproducing roll 3 in this cleaning operation is supplied from a bias power source 5. On the other hand, the counter 6 which counts copies is provided and its counted value is detected to input a signal for controlling the bias voltage to the bias power source 5. |
