An imaging system includes a rotatable image carrier; a rotatable developer carrier, a storage container, and an air flow generator. The developer carrier transfers toner to the image carrier at a developing region located between the image carrier and the developer carrier. The storage container stores the developer carrier. The air flow generator is separated from the storage container by a gap, and rotates in a rotational direction that is opposite to a rotational direction of the developer carrier, to channel an air flow through the gap when the air flow generator rotates.

A developing device includes a developer roller that is rotatable about an axis, to carry a developer to a development region; a rectifier member extending in a direction parallel to an axial direction of the developer roller. The rectifier member includes a developer collecting part that is spaced apart by a predetermined distance from a surface of the developer roller, and a rectifying part to guide air from within the developing device via the developer collecting part toward an upstream side of the development region, in a rotational direction of the developer roller.

An image forming apparatus includes a photosensitive member, a charging member, an exposing device, a developing device, a transfer member, a brush, a voltage applying portion, and a control portion controlling a surface potential of the photosensitive member at the brush contacting position. When a value of subtracting a value of the surface potential of the photosensitive member in the brush contacting position from a value of the brush voltage is defined as a contacting position potential difference, the control portion controls the surface potential of the photosensitive member in the brush contacting position so that the contacting position potential difference is changed from a first potential difference to a second potential difference in a predetermined direction which is either one of an increasing direction or a decreasing direction, and then the contacting position potential difference is changed from the second potential difference to a third potential difference in the predetermined direction.

A cartridge for an electrophotographic image forming apparatus includes a developing roller, a rotatable member for transmitting a rotational force to the developing roller, a coupling member, and a frame. The coupling member is capable of moving between a first coupling member position in which the coupling axis is substantially coaxial with the rotational axis of the rotatable member and a second coupling member position in which the coupling axis is not coaxial with the rotational axis of the rotatable member. When the frame is in a first frame position, the coupling member is in the first coupling member position and a rotational force receiving portion of the coupling member engages with a rotational force applying portion of the apparatus, and, when the frame is in the second frame position, the coupling member is in the second coupling member position and the rotational force receiving portion engages with the rotational force applying portion.

An example developing device includes a housing to contain a developer and having an opening, a developing sleeve provided in the housing and partially exposed to the outside of the housing through the opening, a magnetic member including a plurality of magnetic poles and located inside the developing sleeve, and an elastic member blocking an inflow of air through a space between a downstream edge of the opening in a rotation direction of the developing sleeve and an outer circumferential surface of the developing sleeve. The elastic member includes a fixed portion fixed to the housing at a position adjacent to the downstream edge of the opening and an extension portion extending from the fixed portion in a bent form in the rotation direction of the developing sleeve to be elastically in contact with the surface of the developing sleeve.

When, in a state where a developer borne by a developer bearing member is sandwiched by an opposing portion of an image bearing member and the developer bearing member, C denotes capacitance between the image bearing member and the developer bearing member, ΔV denotes a development contrast, Q/S denotes a charge amount per unit area of the developer borne by the developer bearing member, and Δv denotes a peripheral velocity ratio which is a ratio of a peripheral velocity of the developer bearing member to a peripheral velocity of the image bearing member, a first peripheral velocity ratio is set so that |Q/S×Δv|≦|C×ΔV| is satisfied, and a second peripheral velocity ratio which is larger than the first peripheral velocity ratio is set so that |Q/S×Δv|>|C×ΔV| is satisfied.

A developing device includes a developing housing that contains developer; a developer carrier that transports the developer; a layer-thickness regulating member that is provided for an upstream gap between the developer carrier and the developing housing and that regulates a layer thickness of the developer; and a sealing member that is provided for a downstream gap between the developer carrier and the developing housing. The sealing member is fixed to the developing housing at one side and is in contact with the developer on the developer carrier at the other side. The sealing member has cuts extending from a free end of the sealing member by approximately 60% or more of a dimension of the sealing member from the free end to a fixed end in the width direction, and is at an angle of approximately 30° or less with respect to a reference line.

An example developing device includes a housing to contain a developer and having an opening, a developing sleeve provided in the housing and partially exposed to the outside of the housing through the opening, a magnetic member including a plurality of magnetic poles and located inside the developing sleeve, and an elastic member blocking an inflow of air through a space between a downstream edge of the opening in a rotation direction of the developing sleeve and an outer circumferential surface of the developing sleeve. The elastic member includes a fixed portion fixed to the housing at a position adjacent to the downstream edge of the opening and an extension portion extending from the fixed portion in a bent form in the rotation direction of the developing sleeve to be elastically in contact with the surface of the developing sleeve.

A wet type developing device including a developing roller and an anilox roller, the wet type developing device includes: a dual purpose roller being opposite to the surface of the anilox roller, leaving a gap therebetween, upstream of a region of contact between the surfaces of the anilox roller and the developing roller and being in contact with the surface of the developing roller upstream of the region of contact between the surfaces of the anilox roller and the developing roller and being rotationally driven. A surface part of the dual purpose roller is made of a porous member that has flexibility and elasticity.

A developing cartridge includes a developing roller with a shaft, a housing with a wall portion, a developing electrode, a first contact portion, a second contact portion, and a connecting portion. The developing electrode includes a first contact portion contacting the shaft and has a first surface against which an apparatus electrode of an image forming apparatus body slides, a second contact portion disposed next to the first contact portion, and a second surface configured to contact an electrode of the image forming apparatus. The connecting portion includes a first inclined surface connecting the first surface and the second surface with each other and being contiguous with the first surface. The first inclined surface is inclined toward the second contact portion from the first contact portion such that the first inclined surface extends in a direction away from the wall portion.