DEVELOPMENT DEVICE, PROCESS CARTRIDGE, AND IMAGE FORMING APPARATUS

摘要

PROBLEM TO BE SOLVED: To provide a development device capable of reducing a diameter of a developer carrier to make the whole development device compact, and to provide an image forming apparatus comprising the development device and a process cartridge.SOLUTION: A development device 3 is configured so that developer-carrying poles to generate a magnetic field having strength capable of holding developer 32 on a surface of a development sleeve 34a out of magnetic poles possessed by a magnet roller 34b may consist of only three magnetic poles of: an S1 pole being a development magnetic pole to generate the magnetic field in a development range A where the development sleeve 34a faces a photoreceptor 1; an N2 pole being a pre-development magnetic pole to generate the magnetic field to transport the supplied developer 32 to the development range A; and an N1 pole being a post-development magnetic pole to generate the magnetic field so as to release the developer 32 between the N1 pole and the N2 pole being the pre-development magnetic pole so as to release the developer 32 after having passed through the development range A from the surface of the development sleeve 34a.