| 摘要 |
PROBLEM TO BE SOLVED: To stably carry powder without causing toner clogging even when the toner carrying force of an air pump is lowered in an image forming device where an air pump is used to supply toner. SOLUTION: When the carrying amount of the air pump 106 is lowered with the lapse of time because contact property is lowered due to the permanent set in fatigue (permanent deformation or lowering of Young's modulus) of respective valves in the pump and the carrying amount from a toner tank 100 exceeds the carrying amount of the pump, the toner which can not be carried up is left in tubes 105 and 107 and the pump 106 and causes the clogging. Then, by decreasing the revolving speed of a carrying screw 101, the carrying amount from the tank 100 is decreased according as the carrying amount of the pump 106 is lowered, whereby the lowering of the carrying amount of the pump 106 is restrained and the toner clogging is prevented. |
