| 摘要 |
PURPOSE: To always set stable toner concentration by correcting the detected result on the toner concentration in a developing device in accordance with the change of a parameter which exerts an influence on toner consumption and setting toner supply amount. CONSTITUTION: A toner concentration detecting sensor 10 set in a developing device 4 is connected to the input side of a correction circuit 20, and an image forming device control circuit 11 is connected to the output side thereof. A reference value concerning the increase/decrease of the toner consumption is registered in the correction circuit 20. The decrease condition of the toner in developer is fetched and compared with the registered reference value, and the toner supply amount obtained from the detected value of the toner concentration in the developing device 4 is corrected so as to adjust the toner supply amount in a toner supply device 4E by the control circuit 11. As for the toner decrease condition used in the correction circuit 20, the size of an image forming area and temperature and humidity in the device which exert the influence on the toner consumption are used as the parameter. |
