| 摘要 |
<P>PROBLEM TO BE SOLVED: To set a permeability sensor to a permeability sensor characteristic suitable for controlling toner concentration by adjusting the offset and gain of the permeability sensor. <P>SOLUTION: A control unit detects a mixture having a toner concentration for comparison in a toner stirring chamber of a developing device, whenever the drive frequency of the permeability sensor is changed to a plurality of stages. A stirring member of the developing device is operated to obtain a mixture having a proper development toner concentration and then the mixture is detected whenever the drive frequency is changed to the plurality of stages. The value of the gain being a difference between the detection value of the mixture having the toner concentration for comparison and the detection value of the mixture having the proper development toner concentration is calculated for each drive frequency, and the drive frequency closer to the value of the reference of the gain stored in a storage part is set to the drive frequency of the permeability sensor. An output adjustment signal of the permeability sensor is set so as to make the detection value of the mixture having the proper development toner concentration by the permeability sensor driven at the drive frequency coincident with the output value of the reference of the offset stored in the storage part. <P>COPYRIGHT: (C)2013,JPO&INPIT |
