| 摘要 |
PURPOSE:To achieve compatibility between the prevention of deterioration of the image quality on hygroscopic paper and transfer omission on it and the separation of dry paper, by keeping currents supplied to a separation member almost constant when the sheet of transfer paper is in contact with the separation member having the specific volume resistivity. CONSTITUTION:The sheet of transfer paper P on which a toner image has been transferred is destaticized by the separation roller 15 to which a separation bias is applied from a separation power source 15A, is separated from the surface of a photosensitive drum 5, and is sent out of the device after the transferred toner image is fixed on it. Here, the separation roller 15 is made of urethane foam rubber and its volume resistivity is 10<9>OMEGAcm or less; when the sheet of transfer paper P is in contact with the separation roller 15, the currents supplied to the separation roller 15 are almost maintained at -10muA. In the case of the hygroscopic paper, the transfer currents properly flow in the separation roller 15 via the surface of the transfer paper P, therefore deterioration of image quality and excessive transfer-currents, are prevented. In the case of the dry paper, currents hardly flow in the surface of the transfer paper P, therefore almost all the separation currents contribute to the separation and the separation performance is secured. |
