When a process cartridge is mounted, air introduced to inside an image forming apparatus via an intake unit flows in a space surrounded by a housing of the process cartridge, a contact unit, and an arm unit, and is exhausted via an exhaust unit. When another process cartridge having a housing larger in size than a housing of the process cartridge is mounted, the air introduced to inside the image forming apparatus via the intake unit flows in a space surrounded by the housing of the another process cartridge having the larger housing, a contact unit, and the arm unit, and is exhausted via the exhaust unit.

A process cartridge includes a frame and a photosensitive drum supported by the frame, with the photosensitive drum being rotatable about an axis thereof. A coupling is operatively connected to the photosensitive drum such that a driving force can be transferred from the coupling to the photosensitive drum. A developing roller is supported by the frame, with the developing roller being rotatable about an axis thereof. A gear is positioned at a side of the process cartridge, with the gear being rotatable about an axis thereof. The gear has a plurality of teeth, with at least some of the teeth being exposed teeth that are uncovered by the frame and exposed to outside of the process cartridge, and with a tip of at least one of the exposed teeth facing the axis of the photosensitive drum. As measured in the axial direction of the photosensitive drum, the teeth of the gear are shorter than the projection of the coupling.

A lubricant solid contains, in a content of 92 mass% or more and 100 mass% or less, a lubricant having a polygonal network bond structure.

The electro-conductive member has an electro-conductive support, and an electro-conductive layer, in which the electro-conductive layer has a matrix including a first rubber cross-linked product and domains dispersed in the matrix, each of the domains includes a second rubber cross-linked product and electro-conductive particles, an outer surface of the electro-conductive member has concave portions, a surface of at least a part of the domains is exposed to the outer surface of the electro-conductive member at bottom portions of the concave portions, a volume resistivity of the matrix is greater than 1×10.sup.12 Ωcm, a volume resistivity of the electro-conductive layer is 1×10.sup.5 Ωcm to 1×10.sup.8 Ωcm, and A2 is 20 times or more of A1.

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 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.

A process cartridge includes a photosensitive drum supported by the frame. A coupling is operatively connected to the photosensitive drum such that a driving force can be transferred from the coupling to the photosensitive drum, and a developing roller is supported by the frame. A first gear is operatively connected to the photosensitive drum and the developing roller such that the driving force can be transmitted from the coupling to the developing roller. A second gear is positioned at a side of the process cartridge, with the second gear having a plurality of teeth, with at least some of the teeth being exposed teeth that are uncovered by the frame and exposed to outside of the process cartridge, and with a tip of at least one of the exposed teeth facing an axis of the photosensitive drum.

An electrostatic charge image developing green toner contains green toner particles containing a binder resin, an azomethine fluorescent pigment having an emission peak in a wavelength region of 500 nm or more and 550 nm or less in an emission spectrum, and a non-fluorescent pigment having a reflection peak in a wavelength region of 480 nm or more and 540 nm or less in a reflection spectrum, in which a mass-based ratio M2/M1 of a content M2 of the non-fluorescent pigment to a content M1 of the azomethine fluorescent pigment is 0.05 or more and 1.5 or less, and a total content of the azomethine fluorescent pigment and the non-fluorescent pigment with respect to a total amount of the green toner particles is 5% by mass or more and 15% by mass or less.

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 process cartridge includes a frame having a slit and a recess formed therein at a side of the process cartridge. A photosensitive drum is supported by the frame, with the photosensitive drum being rotatable about an axis thereof, the photosensitive drum including a first end and a second end opposite to the first end. A developing roller is also supported by the frame, the developing roller being rotatable about an axis thereof. A coupling is operatively connected to the photosensitive drum, with the coupling being rotatable about an axis thereof. A helical gear is positioned at the side of the process cartridge, with the helical gear being rotatable about an axis thereof. The helical gear has a plurality of teeth, with at least some of the teeth being exposed teeth that are uncovered by the frame and exposed to outside of the process cartridge.