Patent ID: 7359661

Claim:
A developing device, comprising: a carrying roller configured to carry a developer; a storing section configured to store the developer; a supplying roller configured to supply the developer to the carrying roller by contacting the developer to the carrying roller, the supplying roller extending substantially parallel to the carrying roller; a first conveying unit configured to convey the developer stored in the storing section to the supplying roller, the first conveying unit comprising a pump including a stator having a through-hole, and a rotor disposed in the through-hole of the stator and spirally extended such that a cavity to convey the developer is formed between an outer peripheral surface of the rotor and an inner peripheral surface of the through-hole of the stator, the rotor being configured to convey the developer in the cavity in an axial direction of the rotor by eccentrically rotating; a distributing member configured to distribute onto the supplying roller the developer conveyed by the first conveying unit so that the developer comes down freely from the distributing member under the influence of gravity onto the supplying roller; and an air supplying unit configured to supply air to the developer conveyed by the pump to scatter and fluidize the developer.