| 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 a reference voltage or threshold data being reference concentration data when the developer of reference toner concentration is supplied with a detection voltage from a toner concentration sensor. CONSTITUTION:When the developer of reference toner concentration is supplied to a developing tank 4, a control circuit 22 obtains the detection voltage from the toner concentration sensor 11 as reference concentration data and threshold data by adding additional data to the reference concentration data, and stores them in a memory 21. Then, the control circuit compares the data in the memory 21 with the detection voltage transmitted from the toner concentration sensor 11. Consequently, the signal controlling toner concentration to the reference value is generated, and the abnormal replenishment of the toner replenishing system can be detected. |
