A toner container includes a container body, an opening, a cover, a toner discharge port, a shutter, a cylindrical structure, protrusions, and an identifier. The shutter is attached to the cover and includes a main shutter covering the toner discharge port. The main shutter moves between a closed position to close the toner discharge port and an open position to open the toner discharge port. The protrusions are on both sides of the cover and protrude in a direction orthogonal to a toner container mounting direction. The identifier is on the cover to indicate a toner color. The cylindrical structure's leading end is downstream of leading ends of the protrusions in the mounting direction. The main shutter's leading end is downstream of the protrusions' leading ends in the mounting direction when the main shutter is in the closed position. The protrusions are downstream of the identifier in the mounting direction.

An example consumable print device component may comprise a surface and a human-indiscernible hardware-based identifier arranged on the surface.

An image forming apparatus includes a sensor configured to detect a remaining amount of a recording agent in a cartridge mounted in the image forming apparatus, an output device configured to output at least one of visual and audio information, and a controller. The controller is configured to, upon a first cartridge being dismounted, store, as a previous remaining amount, a remaining amount of a recording agent in the first cartridge detected by the sensor. The controller is also configured to, upon a remaining amount of a recording agent in a second cartridge that has been mounted in the image forming apparatus after the first cartridge is dismounted decreasing to or below a first threshold value as detected by the sensor, control the output device to output information that varies based on a value of the previous remaining amount.

A process cartridge mountable in and dismountable from an image forming apparatus includes a frame, a storing portion provided on a mounting surface of the frame and configured to store information on the process cartridge, a projection projecting outwardly of the mounting surface in a direction normal to the mounting surface, and an electrical contact portion mounted on the projection and electrically connected to the storing portion.

A toner container includes a container body, an opening, a cover, a toner discharge port, a shutter, a cylindrical structure, protrusions, and an identifier. The shutter is attached to the cover and includes a main shutter covering the toner discharge port. The main shutter moves between a closed position to close the toner discharge port and an open position to open the toner discharge port. The protrusions are on both sides of the cover and protrude in a direction orthogonal to a toner container mounting direction. The identifier is on the cover to indicate a toner color. The cylindrical structure's leading end is downstream of leading ends of the protrusions in the mounting direction. The main shutter's leading end is downstream of the protrusions' leading ends in the mounting direction when the main shutter is in the closed position. The protrusions are downstream of the identifier in the mounting direction.

A drum cartridge includes a first photosensitive drum, a frame, a main body connector, a first toner cartridge connector, a drum-cartridge circuit board, a harness, and a first harness. The harness is electrically connected between the main body connector and the drum-cartridge circuit board. The harness extends in the first direction. The first harness is electrically connected between the first toner cartridge connector and the drum-cartridge circuit board. The first harness extends in the second direction.

A drum cartridge includes a first photosensitive drum, a frame, a main body connector, a first toner cartridge connector, a drum-cartridge circuit board, a harness, and a first harness. The harness is electrically connected between the main body connector and the drum-cartridge circuit board. The harness extends in the first direction. The first harness is electrically connected between the first toner cartridge connector and the drum-cartridge circuit board. The first harness extends in the second direction.

An image forming apparatus includes: a storage unit configured to store correction data; an identifying unit configured to identify a correction amount for a correction target pixel, based on the correction data stored in the storage unit; a correction unit configured to correct an exposure amount of the correction target pixel among a plurality of pixels indicated by image data, from an exposure amount indicated by the image data, based on the correction amount for the correction target pixel; and an image forming unit configured to form an image based on an exposure amount after correction by the correction unit. The correction data includes only a correction amount corresponding to each of representative parameter values of a plurality of parameter values of a first parameter for varying the correction amount.

A toner container includes a container body, an opening, a cover, a toner discharge port, a shutter, a cylindrical structure, protrusions, and an identifier. The shutter is attached to the cover and includes a main shutter covering the toner discharge port. The main shutter moves between a closed position to close the toner discharge port and an open position to open the toner discharge port. The protrusions are on both sides of the cover and protrude in a direction orthogonal to a toner container mounting direction. The identifier is on the cover to indicate a toner color. The cylindrical structure's leading end is downstream of leading ends of the protrusions in the mounting direction. The main shutter's leading end is downstream of the protrusions' leading ends in the mounting direction when the main shutter is in the closed position. The protrusions are downstream of the identifier in the mounting direction.

An image forming apparatus includes an apparatus main body and a replacement unit that is detachable to the apparatus main body. The replacement unit includes a first sensor that detects first environmental information that is an ambient environment of the replacement unit, and a recording part that records the first environmental information as environmental history information, the apparatus main body includes a second sensor that detects second environmental information that is another ambient environment of the apparatus main body, and a control part that controls the replacement unit based on the environmental history information and the second environmental information, when the replacement unit is attached to the apparatus main body, the control part performs a return control based on the environmental history information, which is obtained before the replacement unit is attached, and the second environmental information.