| 摘要 |
PURPOSE:To accurately carry out judgement of existence of toner without bringing up the cost or enlarging the size of the device and to avoid image formation in a state of toner deficiency. CONSTITUTION:In a state of end of toner, when a cover switch 121 is turned ON or OFF, crack 106b is driven by CPU (control means) 300 and toner replenishing operation is executed. At this time, whether the toner is fed or not is judged based on the quantity of variation of detected signal of a P sensor S1, and if the judgment is made that the toner is fed, control is carried out so that the end of toner state is cancelled so that the image forming operation can be carried out. |
