| 摘要 |
<P>PROBLEM TO BE SOLVED: To control the number of times that toner is supplied, until a toner concentration reaches a predetermined value, by forcibly stopping an image forming operation when residual quantity of toner in a toner hopper has become small. <P>SOLUTION: When a difference between a measurement value and a reference value exceeds a predetermined value A (S103), it is determined that toner in developer is insufficient, and a supply roller is rotated for m seconds to supply toner to a developing device (S105 to S108). When an amount of toner remaining in the toner hopper has become small and a difference between a measurement value and the reference value exceeds a predetermined value B (S104), it is determined that toner in developer is significantly insufficient, and the supply roller is rotated for n seconds to supply toner to the developing device (S105 to S108). When an amount of toner in the toner hopper has become smaller and a difference between a measurement value and the reference value exceeds the predetermined value C (S109), the image forming operation is forcibly stopped (S114), and the supply roller is rotated until a difference between the measurement value of a magnetic permeability sensor S and the reference value becomes zero (S115 to S118). <P>COPYRIGHT: (C)2007,JPO&INPIT |
