| 摘要 |
PROBLEM TO BE SOLVED: To always make the electrifying property of toner excellent and to prevent fogging from occurring when an image is formed by providing a device with a driving means driving a developing device for a prescribed time before an image forming action is executed when the use history of the developing device being equal to or over the previously set history is detected by a detection means. SOLUTION: The use history of the developing device 5 has been detected, and for example, it is judged that the developing device 5 is comparatively new until the number of printing sheets reaches at 5,000 sheets and a normal printing action is executed. When the number of printing sheets has become over 5,000 sheets, such a control action that the developing device 5 is driven for a prescribed time before the normal printing action is started is executed. In such a way, when the using history of the developing device 5 is detected from the number of printing sheets and the number of printing sheets is over the regulated number of sheets, the developing device 5 is driven for the prescribed time before the normal printing action is started. Thus, the electrifying property of the toner is always kept excellent and the excellent printing action is executed by preventing the fogging from occurring in printing, Besides, since the constitution of the developing device is simple, the device is made compact and light in weight. |
