| 摘要 |
PURPOSE:To make the fluctuation of toner concentration smaller by substantially finely changing a toner supply quantity at shorter toner supply intervals in the case of supplying toner in accordance with the toner concentration. CONSTITUTION:This toner supply device supplies the toner to a developing device 40 in which a latent image on a photosensitive body 11 is developed by developer which contains carrier and toner. Every time the integrated value of image forming time attains a specified value, a foaming member roll 54 is driven for a specified time so as to supply the toner to the developing device 40. The combination of the specified value with the driving time of the roll 54 is set at many stages, and the stage is selected in accordance with toner concentration detected by a sensor. |
