An image forming apparatus includes a developing roller, a photo-interrupter, and a separation mechanism. The developing roller is movable between a contact position and a separated position. The photo-interrupter includes a light emitting element and a light receiving element. The separation mechanism includes a cam configured to move the developing roller between the contact position and the separated position. The cam includes a phase detection wall extending in a circumference direction. The phase detection wall has a first slit and a second slit. The first slit allows the light emitted from the light emitting element to pass therethrough when the developing roller is at the separated position. The second slit allows the light emitted from the light emitting element to pass therethrough when the developing roller is at the contact position. A size of the first slit in the circumferential direction is different from that of the second slit.

To develop a conventional structure of a toner cartridge. Toner cartridge includes a container and an open/close member. The container includes an accommodating portion, a discharge opening and a cartridge side guide. the open/close member includes a closing portion and an engaging portion and is movable between a closing position and an opening position. When the toner cartridge is dismounted from a receiving apparatus, the engaging portion receives a force for moving the open/close member from the opening position toward the closing position, the engaging with a receiving apparatus side guide of the receiving apparatus.

A process cartridge includes a frame, a photosensitive drum supported by the frame, a developing roller supported by the frame, and a coupling operatively connected to the photosensitive drum. A helical gear is positioned at the side of the process cartridge, the helical gear being rotatable about an axis thereof. A stopper is positioned at the side of the process cartridge, with the stopper having a surface extending in an axial direction of the photosensitive drum and facing the axis of the photosensitive drum. As measured in an axial direction of the photosensitive drum, at least a part of exposed teeth of the helical gear is positioned farther an end of the photosensitive drum than a tip of the projection of the coupling is positioned from the end of the photosensitive drum.

An example power delivery device includes a drive shaft to connect with a load, a first motor connected with the drive shaft through a first reducer, and at least one second motor connected with the drive shaft through a second reducer, wherein a first final driven gear of the first reducer is directly connected with the drive shaft, and a second final driven gear of the second reducer is connected with the drive shaft through a one-direction connector.

Provided is an Oldham coupling having a play in a rotational direction and being capable of transmitting a driving force.

An Oldham coupling 1 includes a developing drive gear 99 that is a first hub, a drive coupling 89 that is a second hub, and an intermediate member 3 that transmits a driving force between the developing drive gear 99 and the drive coupling 89. The developing drive gear 99 includes a protruded portion 99a that is fitted to a recessed portion 3a of the intermediate member 3 to transmit a driving force between the developing drive gear 99 and the intermediate member 3. When seen in a rotational axis direction of the Oldham coupling 1, the shape of a protruded portion 89a is a substantially rhombic shape.

To develop a conventional structure of a toner cartridge. The toner cartridge includes a container and an open/close member. The container includes an accommodating portion for accommodating toner, and a discharge opening. The open/close member includes a closing portion for closing the discharge opening, and a closing force receiving portion. The open/close member a movable relative to the container between a closing position for causing the closing portion to the close the discharge opening and an opening position for causing the closing portion to open the discharge opening. The open/close member including a leading end portion and a trailing end portion which are on downstream and upstream sides of the open/close member with respect to a closing direction in which the open/close member moves to close the discharge opening, respectively. An open/close member extends from the leading end portion to the trailing end portion in a range exceeding 180° of a circumference of the container, as the toner cartridge is seen in the longitudinal direction of the container. The closing force receiving portion receives a force for moving the open/close member from the opening position to the closing position when the toner cartridge is dismounted from the receiving apparatus.

An image forming apparatus includes an image forming unit having a plurality of members, a control unit, and a sound collecting unit. The control unit controls operations of the plurality of members in a first operation mode in which the image forming unit forms an image on a recording material. The sound collecting unit collects a sound that arises in the image forming apparatus during the first operation mode execution to generate a sound signal. When it is determined, based on the generated sound signal, that an abnormal sound has arisen, the control unit determines a source of the abnormal sound by transitioning to a second operation mode after the first operation mode has ended and causing, in the second operation mode, one or more members, from the plurality of members, that are possible sources of the abnormal sound to operate separately from the remaining plurality of members.

An example cartridge may be detachably attached to a main body of an image forming apparatus. The cartridge includes a rotation member and a driven coupler to receive a rotation force to rotate the rotation member. The driven coupler includes a power transmission member connected to the rotation member, an extension member extending from the power transmission member and including an outer diameter portion, a hollow portion, and a through portion, a protrusion member located at the hollow portion and movable between a protrusion position for receiving the rotation force and a retreat position, a switching member inserted into the hollow portion and movable between first and second positions for locating the protrusion member at the protrusion position and the retreat position, respectively, and an elastic member to apply an elastic force to the switching member in a direction for location at the second position.

A replaceable unit for an electrophotographic image forming device includes a housing having a reservoir for holding toner. An electrical connector is positioned on a first side of the housing. The electrical connector includes an electrical contact for contacting a corresponding electrical contact in the image forming device and a magnetic sensor electrically connected to the electrical contact. The electrical connector is movable between a first position and a second position. When the electrical connector moves from the first position to the second position, the electrical contact of the replaceable unit moves from a retracted position to an operative position. When the electrical connector moves from the first position to the second position, the magnetic sensor moves from a misaligned position to an aligned position with a point in a path of movement of a magnet for sensing a magnetic field of the magnet.

An image forming apparatus includes: a photosensitive drum; a developing roller; a separation mechanism for moving the developing roller between a contacting position contacting the photosensitive drum and a separated position separated from the photosensitive drum; a first tray; a first sheet feed mechanism for feeding a sheet from the first tray toward the photosensitive drum; a first sheet sensor for detecting passage of the sheet at a prescribed position; and a controller. The controller of the image forming apparatus is configured to perform: when a printing operation is performed onto the sheet ted from the first tray, feeding the sheet in the first tray to the prescribed position and maintain the sheet; moving, on or after the first sheet sensor detects the sheet, the developing roller to the contacting position.