Patent ID: 7904002

Claim:
A developing device for developing an electrostatic latent image formed on an image bearer with a developer that has been triboelectrically-charged by mixing and agitation of two components, toner and magnetic carrier, comprising: a developing hopper for storing the developer; an agitation and conveying member that is rotated inside the developing hopper for conveying the developer while agitating; a developer support which supports the developer that has been mixed and agitated inside the developing hopper and supplies the developer whilst rotating to a developing area located opposing the image bearer; a layer thickness-regulating member for regulating the layer thickness of the developer being conveyed by the developer support; a flow-guide plate member for flowing down the surplus developer that was rejected by the layer thickness-regulating member to a place located away from the layer thickness-regulating member; a plurality of diffusing elements arranged upright on the flow-guide plate member for flowing down the surplus developer in a predetermined direction whilst diffusing the developer with respect to the longitudinal direction of the developer support; and a downflow direction turning mechanism that controls the diffusing elements so as to periodically turn the downflow direction of the surplus developer regulated by the diffusing elements every time a predetermined period of time has elapsed while the developer support is driven.