| 摘要 |
PURPOSE:To generate a signal controlling toner concentration to a reference value and to detect the abnormal replenishment of a toner replenishing system by comparing toner concentration data transmitted from a toner concentration sensor with reference concentration data corresponding to reference toner concentration read out of a memory. CONSTITUTION:The memory 21 previously stores the reference concentration data corresponding to the reference toner concentration, and outputs the reference concentration data according to a read instructing signal from a control circuit 22. It compares the toner concentration data transmitted from the toner concentration sensor 11 after it is A/D-converted with the reference concentration data read out of the memory 21. Thus, toner concentration is detected to generate the signal controlling toner concentration to the reference value, thereby detecting the abnormal replenishment of the toner replenishing system. |
