A process cartridge is detachably mountable to a main assembly of an electrophotographic image forming apparatus. The cartridge includes an electrophotographic photosensitive drum, a developing roller, a drum unit containing the drum, a developing unit containing the roller and being movable so the roller contacts and is spaced from the drum, and a first force receiver receiving a force from a main-assembly first force applier by movement of a door from open to closed positions when mounting the cartridge and a second force receiver movable from a stand-by position by movement of the first force receiver by a force received from the first force applier. The second force receiver takes a projected position receiving a force from the second force applier to move the developing unit so the roller moves out of contact with the drum, the projected position being higher than the stand-by position.

An image forming apparatus includes a housing having an opening, a cover movable between an open position and a closed position, a first photoconductive drum and a second photoconductive drum, a first exposing head having a first boss and rotatably coupled to the cover, a second exposing head having a second boss and rotatably coupled to the cover, and a cam rotatably coupled to each of the first exposing head and the second exposing head. The cam is configured to rotate each of the first exposing head and the second exposing head. The cam includes (i) a first elongated hole into which the first boss fits and extending a direction intersecting a movement direction in which the cam moves and (ii) a second elongated hole into which the second boss fits and extending in a direction intersecting the movement direction of the cam.

An image forming apparatus includes a formation target that is wound around rotating bodies including a driving roller and transported by the rotating bodies including the driving roller while forming a shape having linear portions each of which forms a different angle, which is an acute angle or an angle of zero degrees, with a horizontal direction when viewed in an axial direction of the driving roller, first image forming bodies that are arranged along one of the linear portions in such a manner as to be spaced apart from each other by a first distance and that form images onto the formation target, and second image forming bodies that are arranged along another one of the linear portions, the other linear portion forming the angle larger than the angle formed by the one linear portion, in such a manner as to be spaced apart from each other by a second distance shorter than the first distance and that form images onto the formation target.

A process cartridge is detachably mountable to a main assembly of an electrophotographic image forming apparatus. The cartridge includes an electrophotographic photosensitive drum, a developing roller, a drum unit containing the drum, a developing unit containing the roller and being movable so the roller contacts and is spaced from the drum, and a first force receiver receiving a force from a main-assembly first force applier by movement of a door from open to closed positions when mounting the cartridge and a second force receiver movable from a stand-by position by movement of the first force receiver by a force received from the first force applier. The second force receiver takes a projected position receiving a force from the second force applier to move the developing unit so the roller moves out of contact with the drum, the projected position being higher than the stand-by position.

An image forming apparatus includes: a medium transport path; a first image transport path that is disposed so as to oppose the medium transport path and along which an image to be formed on the medium is transported; an image forming part that forms the image and is disposed adjacent to the first image transport path; and a second image transport path that is disposed so as to oppose the medium transport path, that is located at a distance from the image forming part, and along which an image to be formed on the medium is transported, the second image transport path, the first image transport path, and the medium transport path, together surrounding the image forming part.

A process cartridge is detachably mountable to a main assembly of an electrophotographic image forming apparatus. The cartridge includes an electrophotographic photosensitive drum, a developing roller, a drum unit containing the drum, a developing unit containing the roller and being movable so the roller contacts and is spaced from the drum, and a first force receiver receiving a force from a main-assembly first force applier by movement of a door from open to closed positions when mounting the cartridge and a second force receiver movable from a stand-by position by movement of the first force receiver by a force received from the first force applier. The second force receiver takes a projected position receiving a force from the second force applier to move the developing unit so the roller moves out of contact with the drum, the projected position being higher than the stand-by position.

An image forming apparatus includes an image bearing member, a developing member, a controller configured to carry out switching control between a first state in which the developing member is caused to act on the image bearing member and a second state in which the developing member is not caused to act on the image bearing member, a transfer member, and a detector configured to read density information of the recording material. The controller detects a fog density on the basis of a difference in density information between a fog non-occurrence region of a non-image region of the recording material in the second state and a fog occurable region of the non-image region of the recording material in the first state.

An image forming apparatus includes an image bearing member, a developing member, a controller configured to carry out switching control between a first state in which the developing member is caused to act on the image bearing member and a second state in which the developing member is not caused to act on the image bearing member, a transfer member, and a detector configured to read density information of the recording material. The controller detects a fog density on the basis of a difference in density information between a fog non-occurrence region of a non-image region of the recording material in the second state and a fog occurable region of the non-image region of the recording material in the first state.

An image forming apparatus includes an image bearing member, a developing member, a controller configured to carry out switching control between a first state in which the developing member is caused to act on the image bearing member and a second state in which the developing member is not caused to act on the image bearing member, a transfer member, and a detector configured to read density information of the recording material. The controller detects a fog density on the basis of a difference in density information between a fog non-occurrence region of a non-image region of the recording material in the second state and a fog occurable region of the non-image region of the recording material in the first state.

An image forming apparatus includes a housing having an opening, a cover movable between an open position and a closed position, a first photoconductive drum and a second photoconductive drum, a first exposing head having a first boss and rotatably coupled to the cover, a second exposing head having a second boss and rotatably coupled to the cover, and a cam rotatably coupled to each of the first exposing head and the second exposing head. The cam is configured to rotate each of the first exposing head and the second exposing head. The cam includes (i) a first elongated hole into which the first boss fits and extending a direction intersecting a movement direction in which the cam moves and (ii) a second elongated hole into which the second boss fits and extending in a direction intersecting the movement direction of the cam.