PROBLEM TO BE SOLVED: To provide a developing device which hitherto makes a first developer supplying unit and a second developer supplying unit into the same driving in order to stabilize the bulk height on the first developer supplying unit side and to always appropriately maintain a developer capacity but into the independent driving and changes the rotating speed of the second developer supplying unit according to the developer capacity of the first developer supplying unit, and an image forming apparatus including the same.;SOLUTION: A developing device includes a developing roller that supplies two-component developer from a developer container to an image carrier, and a first developer supplying unit and a second developer supplying unit arranged in parallel, one closer to the developing roller than the other is to the developing roller. The first developer supplying unit and the second developer supplying unit circularly convey the two-component developer while stirring the two-component developer to supply the two-component developer to the developing roller. The device includes a first adjusting section to deform so as to adjust the developer supplying capacity from the first developer supplying unit to the second developer supplying unit and a second adjusting section to deform so as to adjust the developer supplying capacity from the second developer supplying unit to the first developer supplying unit.;COPYRIGHT: (C)2008,JPO&INPIT
展开▼