An image forming apparatus includes an apparatus housing, and an imaging module that is removably installed in the apparatus housing. The imaging module includes an image carrier unit that is capable of carrying an image, an image writer unit that writes an image on the image carrier unit, and a module housing that registers and removably holds the image carrier unit and the image writer unit. A fastening unit that registers the module housing with respect to the apparatus housing and that removably fastens the module housing is disposed between the apparatus housing and the module housing.

A bearing which supports one end side of a driving roller includes a first restriction portion which is restricted from rotating and moving with respect to a first frame, and a bearing which supports the other end side of the driving roller includes a second restriction portion which is restricted from rotating and moving with respect to a second frame. As viewed from a direction perpendicular to a width direction of an intermediate transfer belt, a phase of shape of the first restriction portion in a state of being held by the first frame and a phase of shape of the second restriction portion in a state of being held by the second frame are equal to each other.

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.

A developing cartridge includes: a developing roller; a casing having an outer surface; a first shaft rotatable about a rotational axis; a first arm; and a cam. The first arm and the cam extend radially outward from an outer periphery of the first shaft and pivotally movable along with rotation of the first shaft. The cam has: one end connected to the first shaft; another end positioned farther from the rotational axis than the one end is farther from the rotational axis; and a pressure contact surface inclined so as to approach the outer surface of the casing as extending from the one end toward the another end. When a pressing force is applied to the pressure contact surface, the first arm pivotally moves from a first position to a second position along with: pivotal movement of the cam; and the rotation of the first shaft.

Power receiving unit and process cartridge are provided. The power receiving unit of a process cartridge is detachably mounted in an image formation apparatus configured with a power output unit that is swingable. An outer circumference of the power output unit contains a recessed portion, and the power receiving unit is engaged with the power output unit to receive a driving force. The power receiving unit includes a protrusion. The protrusion is disposed inside the power receiving unit. The protrusion is engaged with the recessed portion of the power output unit to receive the driving force. When the power receiving unit moves along an axial direction thereof and is in a contact engagement with the power output unit, the protrusion abuts against a front end of the power output unit to cause the power output unit to be tilted and swung.

A mountable unit set usable with an electrophotographic-image-forming apparatus includes a cartridge and an attachment. A cartridge includes a photosensitive drum and a coupling member for receiving a driving force for rotating the photosensitive drum, from a driving shaft. An attachment includes a cylindrical portion for being mounted to a periphery of the driving shaft to suppress tilting of the driving shaft. Tilting of a driving-force transmitting member is suppressed.

A cartridge frame includes a protruding rib protruding toward a first frame, a first bearing supporting one end of a photosensitive drum in an axial direction, and a second bearing supporting an other end of the photosensitive drum in the axial direction. The first frame includes a first guide rail configured to, when a process cartridge is attached to an apparatus main body, guide the protruding rib to slide along the first guide rail. A second frame includes a second guide rail configured to, when the process cartridge is attached to the apparatus main body, guide the second bearing to slide along the second guide rail. A size of the first guide rail in a width direction perpendicular to both the axial direction and an attachment direction of the process cartridge is smaller than a size of the second guide rail in the width direction.

An image forming apparatus includes a photoconductor, a bearing body, an abutting portion, a support frame, an exposure device, and an urging body. The photoconductor includes a shaft portion at an end portion. The bearing body is configured to receive the shaft portion. The abutting portion is coupled to the bearing body. The support frame is configured to support the abutting portion and the bearing body. The exposure device faces the photoconductor, abuts on the abutting portion, and includes a light source exposing the photoconductor to light. The urging body is configured to press the exposure device toward the support frame, urge the abutting portion toward the bearing body and the shaft portion, and urge the bearing body toward the support frame.

An image forming apparatus includes a photoconductive body, a light source, a deflector to deflect a light beam from the light source, a scanning optical system to image the deflected light beam onto the photoconductive body, a developing unit to supply developer to the photoconductive body, an optical sensor to detect the deflected light beam, a moving mechanism to move the developing unit to a first position and to a second position, and a controller configured to start driving the deflector, when the developing unit is in the second position, the light source to emit the light beam, thereby obtaining a detection signal of the light beam from the optical sensor, and after obtaining the detection signal of the light beam from the optical sensor, control the moving mechanism to move the developing unit to the first position.

In some examples, a print materials container can include a dispense mechanism to dispense print materials directly to an in-situ reservoir of a printing device, a lock feature to engage a fill port during connection of the dispense mechanism to the fill port, and a valve integrated with the dispense mechanism for connecting the dispense mechanism to the fill port of the reservoir and comprising an output opening offset from a center axis of a tip of the dispense mechanism. The valve can open responsive to rotation of the valve opening with respect to the lock feature such that opposite openings align.