| 摘要 |
PURPOSE:To make toner concentration accurate and to always keep it constant by detecting the toner concentration and writing it in a memory so that the toner concentration is controlled and performing the replenishment of toner instead of the formation of an image when the residual of the toner becomes equal to a specified value or under it. CONSTITUTION:A voltage in accordance with the toner concentration of the developer of reference concentration measured in an inductance sensor 34 is converted in an A/D converter 36 and written in a nonvolatile memory 37, so that an initial setting action is completed. When a copying process is performed, the toner concentration is gradually lowered. Now, a detection output from the sensor 34 is impressed on one terminal of a comparator 39 and the detected voltage of the sensor at the time of getting the reference toner concentration written in the memory 37 is impressed on the other terminal thereof, then the voltage in accordance with difference between both of them is outputted. Based on the output, a toner replenishment indication means 40 designates that the replenishment of the toner should be performed to a toner auxiliary means 35. When the residual of the toner becomes small, a toner residual sensor 33 detects it and a CPU 30 makes a display part 32 display it. Thus, the replenishment of the toner is performed. |
