| 摘要 |
PURPOSE:To reject toner of opposite polarity and to clean up residual toner, by giving a delay to ON of a bias B(¦B¦>¦A¦) of a bias roll than ON of a bias A of a magnet cleaning roll 2 for a prescribed time and making earlier OFF for a given time. CONSTITUTION:The switching relation between a bias A of a magnet cleaning roll 2 of a cleaner and a bias B of a bias roll 3 is as ¦B¦>¦A¦. The ON of the bias B of the bias roll 3 is delayed by time ts than the ON of the bias A of the magnet cleaning roll 2. On the other hand, the OFF is made earlier than time ts'. With the constitution like this, the toner of opposite polarity in the cleaner is rejected at the ON/OFF of the cleaner, the toner remained on the bias roll 3 is cleaned, the bias roll 3 can be cleaned at all times and the life of the bias roll 3 can be extended remarkably. |
