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.

There are provided a developer accommodating portion for accommodating the developer, a discharge portion formed with a discharge opening for discharging the developer accommodated in the developer accommodating portion, and an engaging portion 30. The engaging portion 30 is engaged with an engaged portion 11b with a mounting operation of a developer supply container 1 to displace a developer receiving portion 11 in an upward direction U so that the receiving opening communicates with the discharge opening. The engaging portion 30 has a holding portion 31 which is provided rotatably about a rotation shaft 41 and is provided with holding portion 21 to be engaged with the engaged portion 11b to hold the engaged portion 11b. With the mounting operation, the engaging portion 30 rotates about the rotation shaft 41 so that the engaged portion 11b held by the holding portion 31 moves upward U.

There are provided a rotatable developer accommodating portion accommodating a developer, a discharge end portion provided at a bottom side with a discharge opening for discharging the developer accommodated in the developer accommodating portion, an engaging portion 30 engageable with a portion-to-be-engaged 11b with a mounting operation of the developer supply container 1 to displace the portion-to-be-engaged 11b in an upward direction U to bring the receiving opening into fluid communication with the discharge opening, and a swing shaft 41 rotatably supporting engaging portion 30 provided at such a position that opposite end portions of the engaging portion 30 a rotatable.

A powder container includes a container body to store powder. The container body includes an inner peripheral surface of a spiral shape and rotates around a longitudinal axis to convey the powder by the spiral shape in one direction. The inner peripheral surface has a substantially polygonal shape having rounded corners or a shape in which sides of the substantially polygonal shape are recessed, in cross section orthogonal to a longitudinal direction of the longitudinal axis at a predetermined position. The inner peripheral surface has a region in which the cross-sectional shape at a position shifted from the predetermined position by a predetermined amount within one pitch of the spiral shape in the longitudinal direction is a shape obtained by rotating the substantially polygonal shape having the rounded corners or the shape in which the sides of the substantially polygonal shape are recessed, around the longitudinal axis.

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 toner cartridge includes a first chamber configured to accommodate toner and a second chamber provided with an opening that is configured to discharge the toner. A feeding portion is configured to feed the toner from the first chamber toward the second chamber. An air flow generating portion is configured to generate an air flow and blow the air flow into the second chamber to thereby discharge the toner to outside of the cartridge through the opening. A rotatable coupling including a projection is configured to receive a rotational force from outside of the cartridge, the rotatable coupling being operatively connected to the feeding portion and the air flow generating portion so as to drive the feeding portion and the air flow generating portion with rotation of the rotatable coupling.

The powder container includes a container body containing a powder for image formation, the powder being to be supplied to a powder replenishing device; a conveyor configured to convey the powder from one end in a longitudinal direction to the other end at which a cylindrical container opening is formed, the conveyor being provided inside the container body; a gear configured to rotate the conveyor with an external driving force; a container cover configured to cover the gear, the container cover having a gear exposing hole for partially exposing a gear tooth; and a nozzle receiver configured to guide the conveying nozzle inside of the container body, the nozzle receiver being provided on the container opening. The container cover includes a container engaged portion provided outer than the tooth of the gear in a radial direction.

A toner-and-developer supply device includes a toner container to contain toner and a developer container to contain a developer. The toner container has a toner discharge port, and the toner container is rotatable about a rotational axis to transport the toner toward the toner discharge port. The developer container has a toner-and-developer discharge port. The developer container is rotatably coupled to the toner container to transport the developer toward the toner-and-developer discharge port when the toner container rotates in a given direction relative to the developer container.

An image forming apparatus, includes: plural image forming units each including an image holding member and configured to form an image that is to be transferred to a recording medium on the image holding member using a dry toner, the number of the plural image forming units being at least five; and plural developing devices each of which is provided in each of the plural image forming units and supplied with the dry toner and a dry carrier, each of the plural developing devices including a dry toner adhering unit that has a length equal to or longer than a length of a long side of an A3 size and to which the dry toner adheres, the dry toner adhering unit being configured to cause the dry toner adhering to the dry toner adhering unit to adhere to the image holding member.

A developer storage container includes a storage portion, a communication portion, a scooping portion, and a guide portion. The storage portion conveys developer stored therein in a conveying direction along a rotation axis by being rotated around the rotation axis in a specific direction. The communication portion connects the storage portion to an opening portion facing the conveying direction. The scooping portion includes a scooping surface facing the specific direction at an end of the storage portion on a downstream side in the conveying direction and radially outside the communication portion to scoop up the developer in contact with the scooping surface as the storage portion rotates in the specific direction. The guide portion lies radially inside the scooping portion to be contiguous with the scooping surface and an inner peripheral surface of the communication portion, and guides the developer scooped up by the scooping portion to the communication portion.