Patent ID: 7502576

Claim:
A development apparatus including a developer recycle carry path for supplying, for the purpose of developing, toner to be contained in a developer, while recycling and carrying the developer, and a toner supply path that is branch-connected to the developer recycle carry path, the toner being refilled into the developer recycle carry path via the toner supply path, wherein the development apparatus comprises: developer introduction means for guiding some of the developer that is recycled and carried in the developer recycle carry path into the toner supply path, and for mixing with the toner in the toner supply path, wherein the developer recycle carry path comprises: a first developer path in which a first screw axle, provided with a first external peripheral helical blade, is disposed, for carrying the developer by the rotation of the first screw axle; and a second developer path in which a second screw axle, provided with a second external peripheral helical blade, is disposed, for carrying the developer by the rotation of the second screw axle; wherein the developer recycle carry path is a path wherein the first developer path and the second developer path are connected via two opening portions such that the developer is cyclically carried between the first development path and the second development path; wherein the toner supply path is a path that is provided in the vicinity of one of the openings, is connected to the first developer path as a branch from the developer recycle carry path and as an extension of the first developer path, and is a path in which a third screw axle, provided with a third external peripheral helical blade, is disposed; wherein the third external peripheral helical blade is coaxial with the first external peripheral helical blade, and wherein the path carries the toner to the developer recycle carry path via the third external peripheral helical blade; wherein the developer introduction means comprises a cut-out portion formed in the first external peripheral helical blade of the first developer path in the vicinity of the one of the opening portions; and wherein the first and second screw axles are configured to be opposably rotated.