| 摘要 |
PURPOSE: To prevent an image defect such as the ground fogging by correcting a toner concn. control reference value basing on the used time information of a developing device since the new carrier is used and the relative humidity information of the image forming device. CONSTITUTION: By the control device 8, on inputting the humidity information at every constant interval of time from the humidity sensor 16 disposed in the image forming device, and applying the latest information, the previous information and the before the previous information, the weighted moving average temp. information is obtained. Then, by the control device 8, the driving time of the developing device 5Y, 5M, 5C and 5B is severally counted by the counter 52Y, 52M 52C and 52B. Moreover, at every time the count number of the respective count becomes the specified value, the toner concn. control reference value is corrected by making access to the correcting amount depending on the weighted moving average temp. and the count number stored in the memory, and the respective toner replenishing means 54Y, 54M, 54C and 54B is driven so as to maintain the toner concn. after the correction. Thus, the toner concn. of the developer is properly maintained and the excellent image can be always formed. |
