| 摘要 |
PURPOSE:To prevent the reduction of the surface potential of a recording sheet passing under plural printing stations and to improve printing quality by arranging a potential reducing member behind a transfer electrifier set to a high voltage. CONSTITUTION:The surface potential of the recording sheet 18 electrified with a high voltage together with a sheet carrying belt 8 by the discharge of the transfer electrifier 11 is reduced by a conductive roller 20. Therefore, the surface potential of the recording sheet 18 is controlled to the prescribed voltage optimum for the attraction of a toner image before the sheet 18 reaches a first printing station 71 so that the toner image at the printing station 7 situated forward in the carrying direction is satisfactorily transferred to the recording sheet 18. Further, even when the surface potential of the recording sheet 18 is reduced the back of the recording sheet 18 and the sheet carrying belt 8 are electrified to the high voltages, therefore, even when it passes under the plural printing stations 71-74, the reduction of the surface potential of the recording sheet 18 is prevented and the toner image at the printing station 7 situated backward in the carrying direction is also transferred to the recording sheet 18 satisfactorily. |
