| 摘要 |
PURPOSE:To prevent an offset and to prolong time life of a fixing roller by making the driving quantity of a cleaning means less as the rate of an area occupied by a developer image on the region capable of forming an image, of a recording material, is low. CONSTITUTION:On a duty calculator 1, an image duty is calculated based on an image signal, and the result of the calculation is inputted into a motor revolving speed converter 2 and converted into a motor revolving speed. In other words, the optimum driving quantity (motor revolving speed) of a cleaning web on each image duty, obtained in such a manner that the offset is suppressed and the life of the fixing roller is maximized, is determined based on data previously obtained by measurement. The motor revolving speed is transmitted to a motor driver 3, and the motor 4 of the cleaning web, is driven at tone revolving speed. At this time, the driving quantity of the cleaning means is made less as the ratio of the area occupied by the developer image is low on the region capable of forming the image, of the recording material. |
