| 摘要 |
PURPOSE:To appropriately control toner concentration in the case of not using an image forming device, etc., for a long time by counting the stopping time of the power source of a device main body, comparing the counted value with a reference value and altering an ordinary control level and a toner exhaustion level. CONSTITUTION:The toner concentration of a developing part 5 is detected by a toner concentration sensor 50. At least the ordinary control level and the toner exhaustion level at the time of ordinarily forming an image are stored in a storage means 62. A toner concentration control means 63 compares an output from a sensor 50 with the content of the storage means 62 and based on the compared result, the toner replenishing means 18 of the developing part 5 is driven 64 and a state where toner is exhausted is displayed 65. The stopping time of the device main body is counted by a timer 40 and a level alteration means 61 compares the counted value by the timer 40 and the specified reference value, then the stored ordinary control level and the stored toner exhaustion level are altered based on the compared result. |
