Patent ID: 8682226

Claim:
A development device mounted on an electrophotographic image forming apparatus including a photoconductive drum in which an electrostatic latent image is formed on a surface thereof, the development device comprising: a developer tank in which a developer containing a toner and a carrier is stored; a toner replenishing port through which the toner is replenished to the developer tank; a development roller that is provided in the developer tank, the development roller rotating while bearing the developer in order to supply the toner to the surface of the photoconductive drum, in which the electrostatic latent image is formed; a developer conveying path that is provided between the development roller and a position in which the toner in the developer tank is replenished; and a developer conveying spiral member that is rotatably provided in the developer conveying path to convey the developer in the developer conveying path to the development roller, wherein the developer conveying path includes: a first developer conveying path on the toner replenishing port side and a second developer conveying path on the development roller side, the first and the second developer conveying path being partitioned by a partition wall parallel to a shaft center direction of the development roller; and a pair of communicating paths that communicates the first developer conveying path and the second developer conveying path on both sides in the shaft center direction, the developer conveying spiral member includes: a first developer conveying spiral member that is disposed in the first developer conveying path; and a second developer conveying spiral member that is disposed in the second developer conveying path, each of the first and second developer conveying spiral members includes: a rotary shaft; and a spiral blade that is fixed to a circumferential surface of the rotary shaft, at least one of the first and second developer conveying spiral members further includes an end blade that is provided at one end of the rotary shaft, the end blade includes: a spiral blade portion that is fixed to the circumferential surface of the rotary shaft; and a circumferential agitating plate portion that is fixed to a circumferential portion of the spiral blade portion, wherein a radial inner edge of the circumferential agitating plat portion is attached to a radial outer edge of the spiral blade portion, the developers are conveyed in opposite directions each other in the first and second developer conveying paths by the first and second developer conveying spiral members, and the developer is circulated between the first and second developer conveying paths.