An image forming apparatus includes a drum unit, a process frame, a lock member and an intermediate transferring unit. The drum unit rotatably supports a rotating shaft of a photosensitive drum. The process frame has an attachment part to which the drum unit is attached. The lock member positions the drum unit to the attachment part. The intermediate transferring unit is attached to the process frame after the drum unit is attached. The lock member has a supporting part, an engagement part and a restriction part. Though the supporting part, an end of the rotating shaft is passed. The engagement part is engaged with the process frame between the process frame and the intermediate transferring unit. The restriction part interferes with the intermediate transferring unit between the engagement part and the intermediate transferring unit to prevent the engagement part from being detached from the process frame.

In an example, an apparatus includes a container to hold a quantity of a consumable resource. A mechanical drive coupling is attached to the container. The mechanical drive coupling includes a bore and a locking mechanism integrated into the bore. The locking mechanism locks the container to a drive mechanism when the bore and the drive mechanism are rotatably engaged.

At ends of a frame in an axial direction of a developing roller, a first end portion member and a second end portion member are provided so as to be rotatable around a rotation axis parallel to the axial direction, and at least one of them has one side in a direction orthogonal to the rotation axis on which a force receiving portion is provided, and another side in the direction orthogonal to the rotation axis on which a regulating portion is provided. The force receiving portion receives a biasing force in a mounting direction of the developing apparatus to the apparatus main body from a biasing member. The regulating portion is brought into contact with the apparatus main body to regulate movement of the other side relative to the apparatus main body in a direction opposite to the mounting direction, with a fulcrum being the rotation axis.

An optical scanning device provided with a casing, a plurality of light sources, a deflection scanning unit that deflects and scans light beams from the plurality of light sources onto a plurality of bodies to be scanned, and a plurality of optical units arranged between the deflection scanning unit and the bodies to be scanned, in which optical unit supporting members that support the optical units are provided, the optical unit supporting members support the plurality of optical units arranged at predetermined intervals, and a thermal expansion coefficient of the optical unit supporting members is lower than a thermal expansion coefficient of the casing.

Provided is a locking mechanism in which when the urging force of an urging member is larger than the magnetic force of a magnet in the non-excited state, a plunger can be held at a first position, and when the urging force of the urging member is smaller than the magnetic force of the magnet in the non-excited state, the plunger can be held at a second position.

An image forming apparatus includes a toner container, and a lock drive portion. The toner container is attached to an attachment position set in an apparatus main body. The lock drive portion acquires a identification information from a storage portion, and upon determining, based on the identification information, that the toner container has an attachment compatibility, places a lock member at a lock position, and upon determining that the toner container does not have the attachment compatibility, places the lock member at a unlock position.

A resin holding member is supported by a one link member and another link member at positions further outside from both ends of a lens array and both ends of a circuit board in a rotational axis direction of a photosensitive drum, but further inside from an abutting pin and another abutting pin. Force in the opposite direction from the gravitational direction is applied to a portion of the holding member between the link members in a state where the abutting pins are abutting a drum unit. Accordingly, warping of the holding member is suppressed.

A toner detection device of a waste toner container having a housing includes a rotational wheel, a transmission member and a resilient member. The rotational wheel is rotatably disposed to the housing and provided with a first abutment portion. The transmission member including a second abutment position is connected with the rotational wheel in a way that the transmission member is rotatable with the rotational wheel and moveable relative to the rotational wheel between a first position and a second position. Two ends of the resilient member are respectively abutted against the first and second abutment portions in a way that the second abutment portion approaches the first abutment portion and the transmission member is rotatable relative to the rotational wheel with the transmission member moving from the first position to the second position.

An apparatus main body includes a main casing and a cover configured to rotatably move about a rotational axis located below an opening between an open position and a closed position. A drum cartridge includes a photosensitive drum and is configured to be installed into the apparatus main body through the opening. A developing cartridge includes a developing roller and is configured to be installed into the apparatus main body through the opening. A swing plate is attached swingably to the apparatus main body. The swing plate supports the developing cartridge. The swing plate includes a guide configured to guide installation of the developing cartridge into the apparatus main body. The swing plate is configured to swingably move in a state where the drum cartridge and the developing cartridge are installed in the apparatus main body, thereby causing the developing roller to move relative to the photosensitive drum.

The image forming apparatus includes a cartridge replaceable by detachably mounting to the image forming apparatus, a door that takes a closed state or an open state, a locking pin that switches a state of the regulation unit between a regulating state in which the replacement unit is prevented to be detached from the image forming apparatus and a release state in which the replacement unit is to be detachable from the image forming apparatus, and a lock control unit (a control unit) that makes a determination as to whether or not the state of the regulation unit is to be switched from the release state to the regulating state, at a predetermined timing when initial processing is completed after a power source is turned on or a state of the door becomes the closed state from the open state.