| 摘要 |
PURPOSE:To control toner concentration reliably with high accuracy by agitating and conveying a developer for a specific period from operation is started without operating a toner supply means regardless of developer toner concentration information. CONSTITUTION:The developer at a developer storage part is agitated and conveyed by agitating and conveying means 8 and 9 for the specific period after the power source is turned on or from the point of time when the operation of a developing device is started after the power source is turned on without operating the toner supply means regardless of toner concentration information on the developer at the developer storage part which is detected by the developer toner concentration detecting means 15 of a developing device. Namely, the preliminary agitation and conveyance period T of the developer agitating and conveying means 8 and 9 is only set to several - tens of seconds in general as shown in the timing chart of the power-on operation, operation of the developer agitating and conveying means 8 and 9, a toner supply means, and a developing stroke. Further, toner may be supplied without fail not only when the power source is turned on, but also when toner concentration is detected. |
