A first cover is pivotable between a first cover closed position and a first cover open position about a first pivot axis located at a pivotal end. A process cartridge includes a reception port configured to receive toner from a toner container. A cover main body includes a first portion and a second portion. The first portion extends in a vertical direction in a state where the first cover is located at the first cover closed position. The second portion is connected to an upper end of first portion and extends in a second direction in a state where the first cover is located at the first cover closed position. At least part of the first cover faces the reception port in a state where the process cartridge is attached to a main housing and the first cover is located at the first cover closed position.

A toner cartridge includes: a body to contain toner and including a toner outlet to discharge the toner to the outside; an agitating member to rotate about a central axis of the body and agitate the toner contained in the body; a shutter member to move along the central axis with respect to the body, and having an open position to open the toner outlet and a blocked position to block the toner outlet; a driving force receiver exposed to the outside through the toner outlet when the shutter member is in the blocked position, and to rotate by receiving a driving force from the outside; and a driving shaft to transmit a rotational force of the driving force receiver to the agitating member.

An image forming apparatus includes a developing device, a container, a toner replenishment device, a toner conveyance detection portion, and a control portion. The toner replenishment device includes a plurality of toner replenishment paths through which toner in the container is conveyed and replenished to the developing device. The toner conveyance detection portion detects a toner conveyance error in toner conveyance performed by using the plurality of toner replenishment paths. In a case where the toner conveyance detection portion has detected a toner conveyance error in one of the toner replenishment paths that is in use, the control portion switches to another one of the toner replenishment paths to convey the toner.

A toner cartridge includes: a body to contain toner and including a toner outlet to discharge the toner to the outside; an agitating member to rotate about a central axis of the body and agitate the toner contained in the body; a shutter member to move along the central axis with respect to the body, and having an open position to open the toner outlet and a blocked position to block the toner outlet; a driving force receiver exposed to the outside through the toner outlet when the shutter member is in the blocked position, and to rotate by receiving a driving force from the outside; and a driving shaft to transmit a rotational force of the driving force receiver to the agitating member.

A toner container (32) includes a rotatable container body (33). The container body includes an opening portion (33c) and a plurality of projections (33a). The opening portion is on a first end, which is opposite a second end, of the container body in a rotation axis direction. The plurality of projections are each protrude inward and have a slope inclined with respect to the rotation axis direction. The plurality of projections are disposed such that, out of two adjacent projections in the rotation axis direction, one projection closer to the first end of the container body in the rotation axis direction overlaps the other projection closer to the second end of the container body in the rotation axis direction, in an area of the one projection closer to the second end and an area of the other projection closer to the first end in the rotation axis direction.

A developer supply container includes a container unit and a discharge passage forming unit. The container unit includes a containing member including an opening portion, and a connecting member including an engaged portion and a connected portion connected to the opening portion of the containing member. The discharge passage forming unit includes an engaging portion configured to be engageable with the engaged portion, and a discharge passage which is configured to communicate with the accommodating space via the opening portion and through which the toner can be discharged to an outside.

An image forming apparatus includes a toner container housing, an image forming device, a tuning fork, a vibration generator, a communication circuit, and a terminal. The toner container housing houses a toner bottle storing toner. The toner bottle includes an electrode on a surface of the toner bottle. The image forming device receives the toner in the toner bottle to form a toner image. The vibration generator vibrates the tuning fork. The communication circuit is electrically connected to the tuning fork. The terminal is coupled to the tuning fork and is contactable with the electrode to electrically connect the communication circuit and the electrode of the toner bottle in the toner container housing via the tuning fork. The vibration generator vibrates the tuning fork to vibrate the terminal contacting the electrode.

An image forming apparatus includes: a body comprising a developing device, and a mounting unit from which a toner refill cartridge is detachable and which is connected to the developing device and delivers toner accommodated in the toner refill cartridge to the developing device. The body includes a housing having a communication hole so that the toner refill cartridge is mounted on the mounting unit from outside the image forming apparatus. The image forming apparatus includes a drive unit to provide a driving force to the toner refill cartridge so that toner is supplied from the toner refill cartridge to the developing device: a detecting unit to acquire a detected value corresponding to an amount of toner in the toner refill cartridge; and a controller to control an operation of the drive unit based on the detected value.

A method for cleaning a toner cartridge includes the steps of taking a toner cartridge provided at a first end and a second end thereof with a first opening and a second opening respectively, engaging an air-blowing connector with the first opening, inserting the second end of the toner cartridge into a tubular barrel which is provided with a conduit extending along an axial direction and an air nozzle connected with the conduit, and drawing air from the tubular barrel to create a negative pressure inside the tubular barrel, and introducing air into the toner cartridge through the air-blowing connector, and the conduit and the air nozzle to generate an airflow to carry residual toner inside the toner cartridge through the second opening into the tubular barrel to be extracted. Accordingly, the method may effectively remove residual toner from the toner cartridge.