Abstract: A developing unit includes a casing, a developer carrier, a developer conveying path, a developer conveying member, and a layer thickness regulator. The developer carrier is driven to rotate in the casing and carries a toner on the circumferential surface. The developer conveying member is located in the developer conveying path and driven to rotate so as to convey the developer in a second direction and to supply the toner to the developer carrier. The layer thickness regulator is spaced from the developer carrier, and regulates a layer thickness of the developer supplied to the developer carrier. The developing unit is configured to satisfy a condition of 2.0<Vd/Vs<7.0, where Vd denotes a circumferential velocity of the developer carrier and Vs denotes a circumferential velocity of the developer conveying member.

Abstract: In a development device, a developer carrier arranged in a housing containing a one-component developer has a circumferential surface carrying the developer. A developer conveying path includes one conveying path along the developer carrier in a first direction and another conveying path in a second direction opposite to the first direction. The developer is circulated and conveyed between the conveying paths. A developer conveying member is arranged in the one conveying path and rotationally driven to convey the developer along the first direction and to supply the developer to the developer carrier. A layer thickness adjusting member is arranged at a distance from the circumferential surface to adjust a layer thickness of the developer supplied to the developer carrier. The developer carrier has a circumferential speed Vd and the developer conveying member has a circumferential speed Vs so that a circumferential speed ratio Vd/Vs satisfies a relationship represented by 1.3?Vd/Vs?5.0.

Abstract: A developing apparatus according to one aspect of the present disclosure includes a developing roller, a development housing, a first agitating screw, a toner supply inlet, a downstream-side reduction wall, and an upstream-side reduction wall. The developing roller is driven to rotate in the development housing, and carries toner on the circumferential surface thereof. Toner is circulated and conveyed in a first conveying path and a second conveying path in the development housing. The first agitating screw is disposed in the first conveying path, and conveys toner in a first direction. The downstream-side reduction wall is disposed downstream of the toner supply inlet. Further, the upstream-side reduction wall is disposed upstream of the toner supply inlet. An accumulation portion for toner is formed downstream and upstream of the toner supply inlet due to the downstream-side reduction wall and the upstream-side reduction wall.

Abstract: An image forming apparatus includes an image carrier, a developing part, a storing part and an adjusting part. The image carrier includes a surface. An electrostatic latent image formed on the surface is developed by a toner, thereby forming a toner image on the surface. The developing part contains the toner supplied from a toner cartridge and supplies the toner to the image carrier. The storing part stores information relating to a replacement rate when a first toner in the developing part is replaced by a second toner, in a case where kinds of the first toner contained in the developing part and the second toner being supplied from the toner cartridge are different. The adjusting part adjusts density of the toner image on the basis of the replacement rate when a toner cartridge containing the first toner is replaced by another toner cartridge containing the second toner.

Abstract: In an image forming apparatus, a developer containing case containing a developer includes a first storage storing developer information indicating a composition of the developer. A developing part receives the developer from the developer containing case. An acquiring part acquires the developer information in the first storage, when the developer containing case is installed to an installed part. A decision part decides whether or not a composition of the developer in existing developer information in a second storage is different from another composition of the developer in newly acquired developer information. An electric charge amount measuring part measures an electric charge amount of the developer in the developing part. A developer replacement controlling part controls discharge and replenishment of the developer in the developing part on the basis of the measured electric charge amount, when the decision part decides that both the compositions are different.

Abstract: A developing device includes an applying portion for applying a bias at a first voltage value and a first frequency, to a toner bearing member during a development period in which toner particles are supplied to an image bearing member. A controller executes a removal control to remove attached matter adhering to a bearing surface of the toner bearing member during a non-development period. Upon executing the removal control, the controller first causes residual toner particles to separate from the bearing surface. Subsequently, the controller controls the applying portion to cause a second bias at a second voltage value higher than the first voltage value or at a second frequency higher than the first frequency to be applied to the toner bearing member while bringing a developer layer on a developer bearing member into contact with the bearing surface.