| 摘要 |
PROBLEM TO BE SOLVED: To provide an image forming device capable of accurately detecting residual toner, even in a developing device provided with a stirring bar. SOLUTION: A developing sleeve 3 and an electrode 5 are electrostatically connected in a developing container. An AC bias induced in the electrode 5 with an AC bias source 101, an AC bias resistance 102 and the developing sleeve 3 is divided by voltage dividing resistances 104 and 105 and then, inputted to a buffer circuit 106 and further, a detector 107, to obtain a toner quantity voltage. Further, the maximum value of the toner quantity voltage periodically fluctuated by the stirring bar during an image forming processing period is obtained for each copying paper by a peak holding circuit 601. Then, the maximum value is compared with a reference voltage from a prescribed reference voltage source 603 by a voltage comparator 604, to detect a toner quantity. |
