An end seal for an electrophotographic image forming device according to one example embodiment includes an elastomeric body having a blade seal portion for sealing against a rear surface of a doctor blade and a curved rotary seal portion that extends from a bottom end of the blade seal portion for sealing against an outer surface of a rotatable developer roll. The end seal includes a cutout in an inner axial side of the body positioned at a point where the rotary seal portion and the blade seal portion meet.

A process cartridge detachably mountable to a main assembly of an image forming apparatus includes an image bearing member; a developer carrying member for developing an electrostatic image on the image bearing member; a first gear provided on the developer carrying member and a second gear driving-connected to the first gear; and a supporting portion for rotatably supporting the second gear. The supporting member is mounted on a frame of the process cartridge through a vibration damping member having a vibration transmission performance lower than that of at least the supporting portion.

A process unit (10) which is detachably attachable to an image forming apparatus, including: a photosensitive drum (20); a flange (211); a rotational axis for rotating integrally with the photosensitive drum (20) (the outer diameter of the rotating axis is less than the outer diameter of the photosensitive drum (20); a drum supporting (43) portion which rotatably supports the rotational axis; and a seal brush (100) which seals at least a part of a space formed between the drum supporting portion (43) and the flange (211).

A development device used for an image forming apparatus includes a frame member, a developer bearing member configured to develop a latent image formed on an image bearing member using developer, and an edge portion sealing member provided between an edge portion in a rotational axis direction of the developer bearing member and the frame member to prevent the developer from leaking to an outside of the development device from between the edge portion and the frame member, and including, in a state of being compressed between the edge portion and the frame member, a layer that includes an aggregate of a plurality of foam cells in which a foam cell communicating with an adjacent cell via a communication hole and a foam cell not communicating with an adjacent cell are mixed in a direction from an inside of the development device to the outside thereof.

A developing device includes: a developing device body including a vent opening that releases internal pressure, and a filter member including a filter that closes the vent opening, the filter member detachably attached to the developing device body; wherein the filter member is subjected to an attaching operation and a detaching operation, relative to the developing device body, in a state where an inner surface of the filter is in a predetermined first posture with the inner surface facing upward; and wherein the filter member is held on the developing device body in a state where the inner surface of the filter is in a predetermined second posture different from the first posture.

A developing device includes a plurality of conveyance passages, an opening portion, and a filter. Developer is conveyed in the plurality of conveyance passages in a longitudinal direction of the developing device. The opening portion is disposed in one conveyance passage of the plurality of conveyance passages and communicates with an outside of the developing device. The filter is fitted in the opening portion and has both a collecting ability to collect the developer and a ventilation ability to ventilate the one conveyance passage to the outside of the developing device. The collecting ability of the filter is higher in a high-bulk portion in which bulk of the developer increases in the one conveyance passage than in a low-bulk portion in which the bulk of the developer decreases in the one conveyance passage. The ventilation ability of the filter is lower in the high-bulk portion than in the low-bulk portion.

An optical scanning device includes a housing, a transmissive member, a linear member, a drive portion, a guide rail, a cleaning holder, a cleaning member, a detection portion, and a control portion. The detection portion includes a light emitter that emits light in a juxtaposition direction of the transmissive member and a light receiver that receives the light emitted from the light emitter. The cleaning holder includes a light blocking portion that is located, when the cleaning holder reaches one end part of a movement path thereof, between the light emitter and the light receiver so as to block the light emitted from the light emitter, with a gap formed between the light blocking portion and the housing. The housing includes a light leakage prevention portion formed between the light emitter and the light receiver.

A developer storing device according to the present disclosure includes a developer container and a container support portion which retains the developer container at an attachment position. The container support portion includes a bottom surface support portion and a stopper member. The developer container includes a container body, an inlet, an engagement portion, and a step portion. The inlet is provided on an upper surface of the container body. The engagement portion is provided more on a side of a drawing direction than the inlet on the upper surface of the container body, and engages with the stopper member to restrict a movement of the developer container in the drawing direction. The step portion causes, while the inlet passes by the stopper member when the developer container is inserted or drawn out, the container body to be displaced downwardly so that the inlet is separated from the stopper member.

A developing device includes a developing container, a developing roller, a regulating blade, a seal member, and a resin member. The regulating blade includes a mounting plate and a blade plate. The developing container has a facing part facing a step part due to thickness difference between the mounting plate and the blade plate. The seal member has a resin placement area, and is squeezed between the regulating blade and the facing part. The resin placement area is an area that penetrates the seal member and is surrounded by the seal member. The resin placement area overlaps the step part.

A developer container detachably attached at a predetermined mounting position includes: a developer accommodating chamber, a filter that allows passage of air and suppresses passage of the developer, and an air chamber that is partitioned from the developer accommodating chamber by the filter, and switching between a first state and a second state can be made, the first state being a state in which a driving force of a motor is transmitted to an air supply portion that supplies the air to the air chamber, and is not transmitted to a movement mechanism that moves a restricting member between a restricting position for restricting movement of the developer container and an allowing position for allowing the movement of the developer container, and the second state being a state in which the driving force is transmitted to the movement mechanism and is not transmitted to the air supply portion.