A unit includes a part that is detachably attachable relative to an other unit, wherein the other unit includes an opening through which image forming powder is supplied from or received by the other unit, and a shutter that opens and closes the opening, and a collecting member that collects the image forming powder falling from at least one of the opening and the shutter by making contact with the shutter when detaching the unit from the other unit.

A toner supply container includes a toner container body including a cylindrical portion and an opening, and a sealing member provided at one axial end portion of the container body. The sealing member is movable relative to the container body in an axial direction and includes a sealing portion provided at a side adjacent the container body and a coupling portion provided at a side remote from the container body. The coupling portion includes a supporting portion provided on the sealing portion, an engaging portion provided at a free end of the supporting portion, and a displacing force receiving portion provided on the supporting portion at a position closer to the container body than the engaging portion. The displacing force receiving portion is displaceable with the supporting portion and has a radially outermost part that is more remote from a rotation axis of the container body than a radially outermost part of the engaging portion. The supporting portion, the engaging portion, and the displacing force receiving portion are made of a plastic material.

Provided is a developer container, including: a frame body having an opening; a sealing member configured to seal the opening; an unsealing member configured to unseal the opening by moving the sealing member and accommodated inside the frame body; and a part of the sealing member peelably bonded to an outer peripheral edge of the opening on an opposite side of the unsealing member with respect to the opening.

A seal member 14 which seals a gap among a rotating body 9 provided in an opening of a frame body 13, a blade 18a, and the frame body 13 in an end region in an axial direction of the rotating body 9, the seal member 14 including: a first seal portion 14b which comes into contact with the rotating body 9; a second seal portion 14e which comes into contact with the blade 18a; and a third seal portion 14f which is constituted by a surface formed in a stair shape and sequentially arranged between the first seal portion 14b and the second seal portion 14e and which is capable of reducing a gap formed between the rotating body 9 and the blade 18a due to rotation of the rotating body 9.

A cartridge detachably mountable to a main assembly of an image forming apparatus includes a cartridge frame formed of a resin material; a plurality of resin members molded on the cartridge frame by injection molding of a resin material different from that of the cartridge frame; a plurality of contact surfaces, provided on the cartridge frame, to which metal molds corresponding to the resin members are to be contacted from the same side when the resin members are molded; and a plurality of resin material inlet ports, provided in an opposite side of said cartridge frame from a side where the contact surfaces are provided. The resin material has been flowed into the cartridge frame when the resin members are molded.

A toner container includes a container main body having a toner replenishment port and a shutter mechanism. The shutter mechanism has a shutter member having a discharge port and a cover member supported by the shutter member so as to extend toward the replenishment port. The shutter member is movable in an opening direction from a closing position where the discharge port is retracted from the replenishment port to an opening position where the discharge port is communicated with the replenishment port and in a closing direction from the opening position to the closing position. The cover member has a tip end portion that extends toward the replenishment port as the shutter member moves in the closing direction, comes into contact with a downstream side edge portion of the replenishment port at the closing position and retracts from the replenishment port as the shutter member moves in the opening direction.

A process cartridge includes a photosensitive member and a developing unit. The developing unit includes a frame to store toner, a developing roller to carry the toner, a side seal to contact an end portion of the developing roller and prevent the toner from leaking out, and a sealing sheet to contact a center portion of the developing roller and prevent the toner from leaking out. A toner receiving portion of the frame includes an opening facing the developing roller and is disposed on an upstream side of the side seal and a downstream side of a contact portion where the developing roller contacts the photosensitive member, and moreover is disposed at a position overlapping with the side seal. The developing unit includes a blocking member to block at least a part of the opening, and the blocking member is disposed between the opening and the developing roller.

A cartridge detachably mountable to a main assembly of an image forming apparatus includes a photosensitive drum; a discharging path for permitting movement of a developer removed from the drum, the discharging path including a developer discharge opening and a movable portion through which the developer is movable and which is movable between a retracted position in an upstream side with respect to a developer moving direction through the discharge opening and a advanced position in a downstream side with respect to the developer moving direction; and a sealing portion for closing the discharging path by contacting the movable portion at a position different from that of the discharge opening.

A developing apparatus for use in an image forming apparatus includes a developing frame, a rotatable developing member, a regulation blade to regulate developer borne on a developing member surface, and a seal member to prevent developer from leaking outside the developing frame. The regulation blade includes a support plate, a plate-shaped member, and a regulation member. The seal member is fixed to a facing surface of the plate-shaped member, is arranged at a plate-shaped member end portion, is arranged side by side with the regulation member in a rotational axis direction, contacts an end surface of the regulation member, and is disposed between the plate-shaped member and the developing member in a direction intersecting with the rotational axis direction. The plate-shaped member is welded to a region of the support plate excluding a region outside the end surface of the regulation member in the rotational axis direction.

The developing device includes a developing roller, a developer conveying unit, a developer discharge unit, and an air discharge port. The developer conveying unit includes a developing chamber provided with the developing roller and extending in a longitudinal direction of the developing roller, a stirring chamber arranged in parallel to the developing chamber, and a barrier wall having a first communication port and a second communication port, at respective ends in the longitudinal direction, to connect the developing chamber with the stirring chamber. The developer discharge unit extends from the developer conveying unit in the longitudinal direction of the developing roller and includes a developer discharge port to discharge excess developer. The air discharge port is to house a filter to filter a developer, the air discharge port being provided between the developer conveying unit and the developer discharge unit to discharge air in the developer conveying unit.