An image forming apparatus includes first and second image forming portions and a belt. The first and second image forming portions include first and second image bearing members, and first and second transferring members, respectively. The belt nips and feeds a recording material. The first image forming portion is disposed upstream of the second image forming portion in a moving direction of the recording material, and a plurality of members including the first and second image bearing members are integrally assembled and are mountable on or dismountable from a main assembly of the image forming apparatus. A film thickness of a surface of the first image bearing member is larger than a film thickness of a surface of the second image bearing member, circumferential speed ratios or contact pressures of rotating components differ, and/or mass ratios of components of respective developers differ.

A printing drum mounting system and method of assembling the mounting system. The mounting system comprising a rotatable shaft; a first mount and a second mount arrangeable on the shaft to clamp a printing drum therebetween, wherein the first mount comprises a first engaging surface to form a mating contact with a corresponding first end surface of the printing drum and the second mount comprises a second engaging surface to form a mating contact with a corresponding end surface of the printing drum; a double-walled flexure to flexibly mount the first engaging surface and the shaft, the flexure to provide the first engaging surface with a single degree of freedom of axial movement relative to the shaft and to maintain mating contact between the first engaging surface and the first end surface of the printing drum as the printing drum thermally expands and contracts; and a releasable fixing to align and rigidly engage the second engaging surface relative to the shaft.

A rotating force transmitting part for an electrophotographic photosensitive drum for a main assembly of the electrophotographic image forming apparatus, wherein the main assembly of the electrophotographic image forming apparatus includes a driving shaft, to be driven by a motor, having the rotating force applying portion, and wherein the electrophotographic photosensitive drum is dismountable from the main assembly of the electrophotographic image forming apparatus in a direction substantial perpendicular with an axial direction of the driving shaft, the rotating force transmitting part includes a coupling member engageable with the rotational force applying portion to receive a rotational force for rotating the electrophotographic photosensitive drum in the state in which electrophotographic photosensitive drum is mounted to the main assembly of the electrophotographic image forming apparatus, wherein the coupling member being capable of taking a rotational force transmitting angular position for transmitting the rotational force for rotating the electrophotographic photosensitive drum to the electrophotographic photosensitive drum and a disengaging angular position in which the coupling member is inclined away from the axis of the electrophotographic photosensitive drum from the rotational force transmitting angular position, wherein when the process cartridge is dismounted from the main assembly of the electrophotographic image forming apparatus in a direction substantially perpendicular to the axis of the electrophotographic photosensitive drum, the coupling member moves from the rotational force transmitting angular position to the disengaging angular position.

The present invention relates to a single-layer type electrophotographic photoreceptor for positive charging, comprising: a conductive support; and a photosensitive layer disposed on the conductive support and comprising a binder resin, a charge generation material, a hole transport material and a specific electron transport material within the same layer, wherein the photosensitive layer contains a specific aromatic compound.

To provide an image forming device that can effectively predict a replacement timing of a photoconductor drum. A toner image is to be formed on the photoconductor drum. The charger is configured to charge the photoconductor drum. The potential sensor is configured to measure a charge potential of the photoconductor drum. The memory stores a manufacturing date of the photoconductor drum and a failure threshold value of the charge potential related to a failure of the photoconductor drum. The processor is configured to calculate an elapsed time from the manufacturing date based on the manufacturing date, update the failure threshold value based on the elapsed time, and predict a replacement timing of the photoconductor drum based on the updated failure threshold value.

An image forming apparatus includes a drum cartridge and developing cartridge. The drum cartridge may include a photosensitive drum rotatable about a first axis extending in an axial direction. The developing cartridge may include a developing roller rotatable about a second axis extending in the axial direction. The image forming apparatus may include a main casing including a slot extending in the axial direction. The image forming apparatus may include a first inner surface positioned inside of the slot, and a second inner surface positioned inside of the slot farther from the cover in the axial direction than the first inner surface from the cover in the axial direction. The first and second inner surfaces may be configured to press the developing roller toward the photosensitive drum.

A photoconductive drum for an electrophotographic image forming device according to one example embodiment includes a cylindrical drum member. A shaft defines a rotational axis of the photoconductive drum. An end cap is positioned at an axial end of the drum member. An electrical contact is positioned against an axially inboard side of the end cap. The electrical contact electrically connects the shaft to the drum member. The electrical contact includes a plurality of projections that contact an inner circumferential surface of the drum member. A plurality of grooves are formed in an outer circumferential surface of the end cap.

A drawer includes: a photosensitive drum; a drawer frame; a connector; a drawer memory; and a holder. The photosensitive drum is rotatable about a drum axis extending in a first direction. The drawer frame holds the photosensitive drum. The drawer frame has an outer surface. The connector has a plurality of terminals arrayed in an arraying direction. The drawer memory stores information on the photosensitive drum. The drawer memory is electrically connectable to at least one of the plurality of terminals. The holder is positioned at the outer surface of the drawer frame and holds the connector. The holder is movable relative to the drawer frame in the arraying direction of the plurality of terminals.

A drum cartridge includes: a drum frame to which a developing cartridge is attachable; a photosensitive drum rotatable about an axis extending in a first direction; a memory having an electrical contact surface; and a resilient member positioned between the electrical contact surface and the drum frame. The resilient member is configured to expand and compress in a second direction crossing the electrical contact surface between a first state and a second state, the resilient member having a shorter length in the second state than in the first state. A distance between the drum frame and the electrical contact surface in the second direction when the resilient member is in the second state is smaller than a distance between the drum frame and the electrical contact surface in the second direction when the resilient member is in the first state.

A rectifying device includes: a first flow channel member that has an annular first flow channel through which a fluid flows in an axial direction, the first flow channel being provided between an inner peripheral wall and an outer peripheral wall; a second flow channel member that has a second flow channel between the inner peripheral wall and the outer peripheral wall, the second flow channel being provided upstream of the first flow channel in a flowing direction of the fluid and being connected with the first flow channel along an entire circumference; an inflow section that is provided at the second flow channel member and that allows the fluid to flow into a circumferential area of the second flow channel located away from the first flow channel in the axial direction; a first guide wall that is provided within the second flow channel at a position located away from the inflow section in a circumferential direction and that guides the fluid flowing toward a first side in the circumferential direction through the second flow channel toward the first flow channel; and a second guide wall that is provided within the second flow channel at a position adjacent to the first guide wall in the circumferential direction, the second guide wall guiding the fluid flowing toward a second side in the circumferential direction through the second flow channel toward the first flow channel and being disposed in a direction intersecting the first guide wall.