A cleaning device, including: a cleaning frame; a cleaning member having one end and the other end, an image bearing member being capable of rotating and bearing a developer image formed of a developer so as to remove the developer remaining on the image bearing member after transfer of the developer image from the image bearing member; and a sheet member having flexibility and having one end and the other end; wherein a work function W (D) of the developer and a work function W (S) of the sheet member satisfy 0W(D)W(S)0.23 and the developer includes inorganic particles, and at least one kind of the inorganic particles has an average primary particle diameter of 50 nm or larger.

A cleaning device, including: a cleaning frame; a cleaning member having one end and the other end, the image bearing member being capable of rotating and bearing a developer image formed of a developer so as to remove the developer remaining on the image bearing member after transfer of the developer image from the image bearing member; and a sheet member having flexibility and having one end and the other end; wherein a work function W (D) of the developer and a work function W (S) of the sheet member satisfy 0W(D)W(S)0.23 and the developer includes inorganic particles, and at least one kind of the inorganic particles has an average primary particle diameter of 50 nm or larger.

An image forming system includes an image carrier to rotate, a developer carrier to rotate, a container to contain the developer carrier, and a developer retainer separated from the rotatable developer carrier by a first gap of closest proximity, separated from the rotatable image carrier by a second gap of closest proximity, and separated from the container by a third gap of closest proximity. The first gap is less than the second gap and the third gap.

An image forming apparatus includes a housing in which an exhaust port is formed, a fan, a duct extending in an exhausting direction and configured to accommodate the fan, the duct including a downstream end in the exhausting direction, and an exhaust filter disposed between the duct and the exhaust port in the exhausting direction, the exhaust filter including a first surface facing the exhaust port and a second surface facing the duct. Dimensions of the duct each orthogonal to the exhausting direction are smaller than dimensions of the exhaust filter each orthogonal to the exhausting directions. A perimeter of the downstream end of the duct in the exhausting direction is in contact with the second surface of the exhaust filter.

A cartridge attachable to a main body of an image forming apparatus, the cartridge including a developer bearing member, a frame supporting the developer bearing member, a developing blade including a regulating member and a support member, and a collecting member. The collecting member includes a containing portion. The collecting member includes an opening opposing the developer bearing member. The containing portion extends in a rotational axis direction of the developer bearing member, and a sectional area of a longitudinal end portion area of the containing portion, orthogonal to the rotational axis direction, corresponding to a longitudinal end portion of the developer bearing member is larger than that of a longitudinal middle portion area of the containing portion.

A developer unit for an electrophotographic image forming device includes a developer roll rotatably mounted on a housing. The developer roll includes a roll body cylindrically disposed around a shaft and forming an outer circumferential surface of the developer roll. An axial end of the roll body includes an undercut forming a hollow region in the axial end of the roll body. An elastomeric end seal has a curved rotary seal portion that is sandwiched between a portion of the housing and the outer circumferential surface of the developer roll at the axial end of the developer roll. An interference between the curved rotary seal portion of the end seal and the outer circumferential surface of the developer roll decreases along an axial dimension of the developer roll in a direction from an axially outboard edge of the end seal toward an axially inboard edge of the end seal.

An image forming system includes an image carrier to rotate, a developer carrier to rotate, a container to contain the developer carrier, and a developer retainer separated from the rotatable developer carrier by a first gap of closest proximity, separated from the rotatable image carrier by a second gap of closest proximity, and separated from the container by a third gap of closest proximity. The first gap is less than the second gap and the third gap.

An image forming apparatus includes a cover, a cooperating member, a switching member, a detector, and a controller. The cover opens and closes an aperture in a main body of the image forming apparatus. The cooperating member moves to an activated position when the cover is opened for the first time. The activated position is a position where the cooperating member is enabled to cooperate with the cover. The switching member moves in cooperation with the cover through the cooperating member in the activated position as the cover is opened and closed. The detector detects an open state or a closed state of the cover according to the movement of the switching member. The controller determines that image formation is enabled when the detector has detected the closed state of the cover.

A cartridge attachable to a main body of an image forming apparatus, the cartridge including a developer bearing member, a frame supporting the developer bearing member, a developing blade including a regulating member and a support member, and a collecting member. The collecting member includes a containing portion. The collecting member includes an opening opposing the developer bearing member. The containing portion extends in a rotational axis direction of the developer bearing member, and a sectional area of a longitudinal end portion area of the containing portion, orthogonal to the rotational axis direction, corresponding to a longitudinal end portion of the developer bearing member is larger than that of a longitudinal middle portion area of the containing portion.

A process unit includes an image bearing body, a flange provided on an end portion of the image bearing body, and a supporting portion that rotatably supports a rotational axis portion provided on the flange. A seal is provided that to seal at least a part of a space formed between the supporting portion and the flange.