| 摘要 |
PURPOSE:To obtain an excellent copy image of high quality which has a good hue and no fog by controlling toner supply to a developing means according to the result of comparative arithmetic. CONSTITUTION:The A/D converter 11 of a developer concentration controller receives an analog voltage signal outputted by a photodetector, converts it into a digital signal, and outputs the signal. An arithmetic circuit 13 receives the digital signal from the A/D converter 11 and performs specific arithmetic processing. Further, a memory circuit 15 is stored with various data like data indicating, for example, the reference value of developer concentration. Then a comparator 17 compares data outputted from the memory 15 with processed data outputted from the arithmetic circuit 13 and determines whether or not a toner supply command signal for replenishing toner into a developing device is outputted according to the result of the comparative arithmetic. Consequently, the concentration value of the developer in the developing device is not affected and an excellent copy image which has the good hue and no fog is obtained. |
