| 摘要 |
PURPOSE:To improve the efficiency of a maintenance work by providing a means for controlling process based on the physical value of electrophotographic process, for storing process setting value and the physical value and for erasing information when a prescribed period passes. CONSTITUTION:The surface potential of a photosensitive drum is measured by a surface electrometer 90 provided between the exposure position of a copying machine and an image eraser. A toner concentration sensor 80 measures a toner weight ratio to the overall weight of a developer from the magnetic permeability of a developer. Based on these measured values, a first CPU 201 controlls the process. The process setting value at the time of the control and the above measured values are stored by a RAM 210 and displayed on a message display part 117 as required. The stored information is erased when the period set by the timing means of a second CPU 221 in advance passes. Thus, the capacity reduction of a storage means is performed and process for obtaining proper image quality is readily applied. |
