An example image forming apparatus includes a printing engine to perform a printing work by using toner filled in a toner cartridge, a communication device to communicate with a circuit board attached to a toner refill apparatus that refills toner in the toner cartridge by using a plurality of terminals, and a processor to identify a connection state of the toner refill apparatus based on a voltage value of at least one of the plurality of terminals.

An image forming apparatus is capable of being attached with a toner supply container. The toner supply container stores a toner that is to be supplied to a developing portion. An attachment location of the toner supply container isbelow a light scanning portion in a vertical direction.

An image forming apparatus is capable of being attached with a toner supply container. The toner supply container stores a toner that is to be supplied to a developing portion. An attachment location of the toner supply container is below a light scanning portion in a vertical direction.

A powder container is detachably attached to an image forming apparatus or a removable component in the image forming apparatus. The powder container includes an operation device and a rotation portion to rotate with operation of the operation device. The rotation portion is configured to contact a wall of the image forming apparatus or the removable component in a state in which the rotation portion maintains a posture in a direction of attachment of the powder container to the image forming apparatus or the removable component and is rotatable together with an engagement portion, which is opposed to the wall, of the image forming apparatus or the removable component while engaging the engagement portion, without hindering the powder container from moving in the direction of attachment, to restrain the powder container from moving in a direction of detachment from the image forming apparatus or the removable component.

A developer container includes a developer chamber configured to store a developer, a discharge port configured to discharge the developer in the developer chamber to a developing device, a developer conveyance path configured to transport the developer in the developer chamber to the discharge port, a supply port configured to supply the developer in the developer chamber to the developer conveyance path, a conveyor disposed in the developer conveyance path and configured to transport the developer to the discharge port, a partition between the developer conveyance path and the developer chamber, and a communication port disposed in the partition between the discharge port and the supply port and connecting the developer conveyance path with the developer chamber.

In the case that a developer supply container is provided with a feeding portion for feeding a developer by receiving a rotational force and a pump portion for discharging the developer by reciprocation, and the rotational force and a reciprocating force are received from a main assembly side of an image forming apparatus, there is a liability that a driving connection is not properly established between a portion of the developer supply container for receiving the reciprocating force and a portion of the main assembly side for applying the reciprocating force.

The developer supply container is provided with a drive converting mechanism for converting the rotational force received from the main assembly side to a force for operating a volume changing type pump.

A developer supply includes a developer container body configured to accommodate developer, a gear portion configured and positioned to receive a force for rotating the developer container body, and a pump portion configured and positioned to act upon the developer container body to discharge the developer out of the developer supply container, with the pump portion having a volume that changes with reciprocation of the pump portion. A weight is configured and positioned to reciprocate the pump portion with a rotation of the developer container body by the force received by the gear.

An image forming apparatus includes: a latent image carrier on which a latent image is formed; a developing device that develops the latent image formed on the latent image carrier, using developer; a supply member that supplies the developer to the developing device; and a hardware processor that: performs control of the supply member; and acquires an atmospheric pressure value in a position where the image forming apparatus is installed, wherein the hardware processor changes a method of controlling the supply member based on the atmospheric pressure value acquired by the hardware processor.

A powder container is detachably attached to an image forming apparatus or a removable component in the image forming apparatus. The powder container includes an operation device and a rotation portion to rotate with operation of the operation device. The rotation portion is configured to contact a wall of the image forming apparatus or the removable component in a state in which the rotation portion maintains a posture in a direction of attachment of the powder container to the image forming apparatus or the removable component and is rotatable together with an engagement portion, which is opposed to the wall, of the image forming apparatus or the removable component while engaging the engagement portion, without hindering the powder container from moving in the direction of attachment, to restrain the powder container from moving in a direction of detachment from the image forming apparatus or the removable component.

A developer container includes a developer chamber configured to store a developer, a discharge port configured to discharge the developer in the developer chamber to a developing device, a developer conveyance path configured to transport the developer in the developer chamber to the discharge port, a supply port configured to supply the developer in the developer chamber to the developer conveyance path, a conveyor disposed in the developer conveyance path and configured to transport the developer to the discharge port, a partition between the developer conveyance path and the developer chamber, and a communication port disposed in the partition between the discharge port and the supply port and connecting the developer conveyance path with the developer chamber.