An image forming apparatus, including: a photoconductor; a developing device; a developer storage; a supplier configured to supply developer; an optical sensor; and a controller configured to execute: a developing process of developing an electrostatic latent image on the photoconductor; a usage-amount obtaining process of obtaining a usage amount of the developer; a supplying process of supplying the developer to the developing device every time when the obtained usage amount becomes equal to or greater than a first threshold; and a detecting process of detecting, by the optical sensor, an amount of the developer in the developing device every time when the obtained usage amount becomes equal to or greater than a second threshold larger than the first threshold, and wherein the controller is configured to execute the detecting process in a period different from a period in which the developing process is being executed.

A developing cartridge includes: a housing extending in a first direction; a developing roller; a memory held at the housing; a holder holding an electrical contact surface; and a relay component electrically connecting the memory to the electrical contact surface. The developing roller is rotatable about an axis extending in the first direction. The developing roller is positioned at one end portion of the housing in a second direction. The holder is movable relative to the housing in at least one of the second direction and a third direction crossing the first direction and the second direction. The third direction also crosses the electrical contact surface.

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 method includes forming an image with a toner using a photoconductor in which an intermediate layer and a photosensitive layer including a charge generating layer and a charge transport layer are formed overlying an electroconductive substrate, wherein the ionization potential of the surface of the photoconductor and the ionization potential of the surface of the toner satisfy the following relations 1 and 2,
|Ip (the surface of the photoconductor)Ip (the surface of the toner)|5.53 (eV) Relation 1
5.45 (eV)Ip (the surface of the photoconductor)5.53 (eV) Relation 2
where Ip (the surface of the photoconductor) represents the ionization potential of the surface of the photoconductor and Ip (the surface of the toner) represents the ionization potential of the surface of the toner.

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. The electrical contact of the replaceable unit is electrically connected to processing circuitry mounted on the housing. The electrical connector is movable between a first position and a second position. The electrical contact of the replaceable unit moves outward from the first side of the housing along a side-to-side dimension of the housing when the electrical connector moves from the first position to the second position. The electrical contact of the replaceable unit faces downward when the electrical connector is in the second position permitting the corresponding electrical contact to contact the electrical contact of the replaceable unit from below.

A process cartridge including a drum cartridge, a developing cartridge, and a waste toner container, is provided. The drum cartridge includes a photosensitive drum including a photosensitive layer and a rotation axis extending in an axial direction, a drum cleaner arranged to contact the photosensitive drum, a cleaner frame configured to accommodate the drum cleaner therein, and a waste toner conveyer tube connected with the cleaner frame. The developing cartridge is movable to be attached to and detached from the drum cartridge and includes a developer roller. The waste toner container is movable to be attached to and detached from the drum cartridge. When the developing cartridge and the waste toner container are attached to the drum cartridge, the waste toner container is connected with the waste toner conveyer tube and is located on an opposite side of the developing cartridge to the photosensitive drum.

A toner conveyance device includes a conveying screw including a screw portion helically wound around an axis of rotation of the conveying screw in an axial direction of the conveying screw and a wall having an opening. The wall surrounds the conveying screw with a clearance relative to the conveying screw in a radial direction of the conveying screw. The toner conveyance device further includes a film attached to the wall at a predetermined distance away from an edge of the opening in the axial direction of the conveying screw.

A toner cartridge according to one example embodiment includes a first positioning slot positioned on a first side of a housing of the toner cartridge for receiving a first corresponding positioning rib in an image forming device for defining an axial position of a photoconductive drum relative to the image forming device when the toner cartridge is installed in the image forming device. A second positioning slot is positioned on a second side of the housing for receiving a second corresponding positioning rib in the image forming device for defining an axial position of a developer roll relative to the image forming device when the toner cartridge is installed in the image forming device. The first and second positioning slots extend upward from a bottom of the housing near a longitudinal end of the housing.

An image forming apparatus, including: a photoconductor; a developing device; a developer storage; a supplier configured to supply developer; an optical sensor; and a controller configured to execute: a developing process of developing an electrostatic latent image on the photoconductor; a usage-amount obtaining process of obtaining a usage amount of the developer; a supplying process of supplying the developer to the developing device every time when the obtained usage amount becomes equal to or greater than a first threshold; and a detecting process of detecting, by the optical sensor, an amount of the developer in the developing device every time when the obtained usage amount becomes equal to or greater than a second threshold larger than the first threshold, and wherein the controller is configured to execute the detecting process in a period different from a period in which the developing process is being executed.

A first cartridge support is configured to support a drum cartridge. The first cartridge support is configured to move in a first direction between a first position at which the drum cartridge is mounted on a housing and a second position at which the drum cartridge is detachable. A second cartridge support is configured to support a development cartridge. The second cartridge support is configured to move in the first direction between a third position at which the development cartridge is mounted on the drum cartridge and a fourth position at which the development cartridge is detachable. In a state where the second cartridge support is located at the third position, the second cartridge support is located between the first cartridge support located at the first position and a cover located at a closed position with respect to the first direction.