| 摘要 |
<P>PROBLEM TO BE SOLVED: To prevent unstabilization of image density in the case of restarting the drive of an image forming apparatus which is left to be in a non-active state for a long time, regarding the image forming apparatus equipped with a two-component developing system developing unit. <P>SOLUTION: The image forming apparatus includes: a toner concentration sensor for detecting toner concentration of two-component developer by a permeability detection system; a control part capable of changing an input control voltage to be imparted to the toner concentration sensor; an agitating screw and an agitating paddle for making the developer flow in the developing unit; a stop time counting part for counting the stop time when the agitating screw and the agitating paddle are in the non-active state. The control part 62 offsets the input control voltage when the stop time is equal to or exceeding a prescribed time during an image forming period (S104 and S105), and the control part 62 controls the offset amount of the input control voltage to be zero after an operation of forming the prescribed amount (TH 2 sheets) of images is performed. <P>COPYRIGHT: (C)2008,JPO&INPIT |
