| 摘要 |
PURPOSE:To prevent the mixing ratio of toner from becoming abnormal at abnormal humidity by stopping the supply of the toner when the humidity is not within a prescribed range and by supplying a constant amount of toner for every copying operation. CONSTITUTION:When the output voltage value of humidity sensor 19 is lower than reference voltage Vb, the output side of comparator 21 is held at a low level and the output side of NAND circuit NAND is changed from a high level to the low level via INV2 to supply the output to AND1 as an input, so that AND1 will close the gate. When the output voltage value of humidity sensor 19 is lower than reference voltage value Vb, toner supply control operation performed corresponding to the detection result of sensor 5 for the amount of sticking toner is invalidated. On the other hand, while the output voltage of humidity sensor 19 is lower than reference voltage Vb, a constant amount of toner is supplied to continue copying operation. |
