An example toner refill cartridge includes a body including a toner accommodating portion to accommodate toner and a toner discharge port provided at an end portion of the body in a longitudinal direction to be in communication with the toner accommodating portion, a first member rotatably supported by the body and having a spiral portion extending in the longitudinal direction, a second member located inside the first member and having a guide groove extending in the longitudinal direction, and a plunger having a guide protrusion which passes through the guide groove to engage the spiral portion, to push the toner inside a toner accommodating portion toward a toner discharge port while being moved in the longitudinal direction as the first member is rotated.

A development cartridge which is mountable in an image forming apparatus includes a toner container portion to store toner and a toner refilling portion to receive, from a toner refill cartridge mountable to the toner refilling portion, toner to be stored in the toner container portion. The toner refilling portion includes an inlet shutter rotatable to an inlet position at which the toner is capable of being received by the toner refilling portion from the toner refill cartridge, and a shutter protrusion provided on a surface of the inlet shutter to, while the inlet shutter is rotated, contact an object and cause feedback indicating the inlet shutter is rotated to the inlet position.

An image forming apparatus, to which a supply container storing a developer is detachably attachable and which forms an image on a recording material, includes a photosensitive member that rotates, an optical box, a developer bearing member, and a developer container including a supply port for receiving the developer to be supplied from the supply container. The optical box irradiates the photosensitive member with light and forms an electrostatic latent image on the photosensitive member. The developer bearing member bears the developer and develops the electrostatic latent image by supplying the developer to the photosensitive member. The developer container stores the developer to be borne by the developer bearing member. When viewed in a rotation axial direction of the photosensitive member, a region where the optical box is located and at least a part of a region where the supply port is located overlap each other in a horizontal direction.

An example toner refill cartridge includes a body, a plunger, a weight part, and a weight part container. The body includes a toner chamber to contain toner and a toner discharging portion having an entrance connected to one end of the toner chamber in a length direction and an exit to discharge toner. The plunger includes a piston that is movably inserted into the toner chamber in the length direction and a packing member located at an end of the piston to push the toner toward the toner discharging portion. The weight part is movably accommodated in the toner chamber and has a shape that prevents the weight part from passing through the entrance. The weight part container is provided in the one end of the toner chamber in the length direction such that the weight part can be accommodated therein.

An image forming apparatus includes a storage container in which toner is stored, a replenishment port configured to allow replenishment of toner from the replenishment container outside the image forming apparatus to the storage container therethrough, a replenishment restriction portion, a drive source configured to supply a driving force, and a drive transmission portion configured to take a first operation state, in which the drive transmission portion transmits the driving force of the drive source to the replenishment restriction portion to switch the replenishment restriction portion between a restricting state and an allowing state, and a second operation state, in which the drive transmission portion transmits the driving force of the drive source to a toner conveyance portion to cause the toner conveyance portion to convey toner.

An image forming apparatus and method for determining a toner level and providing a notification are provided. The method of operating an image forming apparatus includes counting a number of times a lower toner hopper receives toner from an in-situ refillable upper toner hopper, calculating an estimate of toner volume transferred from the lower toner hopper to a surface of a photosensitive drum, determining an amount of toner consumed from the in-situ refillable upper toner hopper based on the number of times the lower toner hopper receives toner from the in-situ refillable upper toner hopper and the estimate of toner volume transferred from the lower toner hopper to the surface of the photosensitive drum, and generating an upper toner hopper refill notification when the amount of toner consumed from the in-situ refillable upper toner hopper is determined to exceed a threshold value.

Examples described herein relate to a print particle refill device consistent with the disclosure. For instance, a print particle refill device may comprise a cap disk to form a barrier between the print particle refill device and a receptacle, a first liner adjacent to the cap disk to seal print particles in the print particle refill device, and an actuating liner to wipe print particles, when present, from the receptacle.

An example print component includes a container interface with a guide feature to guide rotation and a rotationally asymmetric key feature. An example toner component includes a recess to receive a toner container, a guide feature to guide rotation of the toner container, and an asymmetric key feature embedded in the guide feature to guide a container material interface towards a component material interface upon rotation. An example container may have a periphery with a rotationally asymmetric surface plane to guide rotation of the container and a protrusion extending from the periphery that has a key feature defined by edges rotationally asymmetric with respect to the periphery. An example container may include a mechanical interface including an asymmetrically-located key feature that, upon rotation of the print material container, generates a sealing force substantially perpendicular to the direction of rotation.

Provided is a toner cartridge. The toner cartridge includes a body, a plunger, a memory unit, and a holder. The body is to accommodate toner and includes a toner discharge portion. The plunger is provided in the body and to push the toner outside of the body via the toner discharge portion. The memory unit includes an electrical contact portion including at least one electrical contact point. The holder facilities loading of the memory unit therein and being rotatable relative to the body between a home position and a rotated position.

A toner refilling interface structure including a toner cartridge, an installation portion, a first toner inlet portion, an inlet shutter, and a locking member. The toner cartridge including a discharge shutter located in or coupled to a body and to switch to a closed position at which a first toner discharge portion of the body is closed and to switch to a discharge position at which the first toner discharge portion is open. The toner cartridge is rotatable about a first rotation axis. The first toner inlet portion is provided in the installation portion to receive toner from the toner cartridge. The inlet shutter is provided in the installation portion to switch to an inflow position at which the first toner inlet portion is open, from a blocked position at which the first toner inlet portion is blocked, by a first rotation of the toner cartridge from an installation position to a first angular position The locking member is provided in the toner cartridge and to lock the discharge shutter at the closed position during the first rotation of the toner cartridge.