A developer container includes a developer accommodating portion, a rotatable member, and a flexible sheet member. The developer container further includes an elastically deformable elastic member. With respect to a longitudinal direction of the developer accommodating portion, between an end portion of the rotatable member and an inside surface of the developer accommodating portion, a gap is formed to permit movement of the rotatable member relative to the developer accommodating portion. In an unused state, the sheet member is elastically deformable together with the elastic member by the movement of the rotatable member relative to the developer accommodating portion in the longitudinal direction.

A developer accommodating unit for accommodating a developer for image formation includes a flexible container provided with an opening 35a for permitting discharge of the developer, a frame for accommodating the flexible container and for accommodating the developer to be discharged from the flexible container, and an urging member 21 for urging a developer accommodating bag toward the frame for accommodating the developer accommodating bag 16. By this, it is possible to satisfactorily effect discharge of the developer from the flexible developer accommodating bag 16.

A powder accommodating container includes a powder accommodating portion that accommodates powder, a sealing section that openably seals a supply port by being removed from the powder accommodating portion, and a breaking section that has a film-shaped member that breaks the powder in the powder accommodating portion by being removed from the powder accommodating portion in a case of opening the supply port, is fixed to plural places in the powder accommodating portion such that the film-shaped member is removable, and is fixed to the powder accommodating portion such that a force required for removing a tip of the film-shaped member from the powder accommodating portion is larger than other portions.

A developer container includes a developer accommodating portion, a rotatable member, and a flexible sheet member. The developer container further includes an elastically deformable elastic member. With respect to a longitudinal direction of the developer accommodating portion, between an end portion of the rotatable member and an inside surface of the developer accommodating portion, a gap is formed to permit movement of the rotatable member relative to the developer accommodating portion. In an unused state, the sheet member is elastically deformable together with the elastic member by the movement of the rotatable member relative to the developer accommodating portion in the longitudinal direction.

A developing apparatus includes a developer bearing member bearing and feeding developer including toner and carrier, a first feeding screw arranged in a first chamber and feeding the developer in a first direction, and a second feeding screw arranged in a second chamber and including a first blade portion feeding the developer in a second direction, a second blade portion arranged downstream of the first blade portion and feeding the developer in the first direction, and a third blade portion arranged downstream of the second blade portion. A sealing sheet is arranged upstream of a developer discharging portion and seals initial developer contained in a developing container; and an unsealing mechanism unseals the sealing sheet sealing the initial developer, wherein the sealing sheet is arranged downstream of the second blade portion and upstream of the third blade portion in the second direction.

A developing apparatus includes a developer container, a conveyance screw, a wall portion, and a sheet member. The wall portion forms a first chamber and a second chamber respectively comprising an opening portion that is opened to a conveyance screw side. The sheet member sealing an opening portion of the first chamber when developer is stored in the first chamber, the sheet member configured to be peeled off from the opening portion of the first chamber. The second chamber includes a sheet discharge port that communicates the second chamber and an outer side of the developer container, a portion of the sheet member reaching the outer side of the developer container through the sheet discharge port in a state sealing the opening portion of the first chamber. The sheet discharge port is arranged above the opening portion of the first chamber.

An image forming apparatus includes a developing device that is mountable and dismountable and has a sealing member for sealing to be removed at a time of start using the developing device. The image forming apparatus further includes a winding shaft, a drive source, a detector, and a controller. The winding shaft rotates for removal processing for removing the sealing member. The drive source drives the winding shaft. The detector detects a value corresponding to a load torque applied to the drive source. The controller notifies of an error in a case where the value detected by the detector has become smaller than a predetermined value before a predetermined period of time elapses from start of the drive by the drive source.

An image forming apparatus is provided which can reduce occurrence of unusual noise. The image forming apparatus includes a driving motor configured to drive a developer bearing member and a control unit which can control the driving motor between a first driving speed and a second driving speed higher than the first driving speed. In a case where the first driving speed is equal to the driving speed of the image forming operation, the control unit controls the driving motor to drive at the second driving speed while an unsealing operation is being performed.

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 developer accommodating unit for accommodating a developer for image formation includes a flexible container provided with an opening 35a for permitting discharge of the developer, a frame for accommodating the flexible container and for accommodating the developer to be discharged from the flexible container, and an urging member 21 for urging a developer accommodating bag toward the frame for accommodating the developer accommodating bag 16. By this, it is possible to satisfactorily effect discharge of the developer from the flexible developer accommodating bag 16.