| 摘要 |
PURPOSE:To prevent the excessive replenishment of toner without making an operator's waiting time longer by changing a reference voltage compared with an output from a concn. sensor in a prescribed time constant at the time of starting an operation. CONSTITUTION:The toner concn. sensor 1 detects toner concn. and outputs a detection signal, which is inputted in a comparator 2 and compared with the reference voltage, so that the toner concn. is controlled corresponding to the output from the comparator 2. The reference voltage is changed in the prescribed time constant after starting the action and the time constant corresponds to the change of the toner concn., for example, just after starting the action. Thus, the excessive replenishment of the toner just after starting the action can be prevented and the lowering of printing density and the adhesion of carrier to a photosensitive body can be prevented without making the waiting time longer. |
