An attachment and detachment structure attaches and detaches a toner container to and from an attachment unit. The toner container includes a container main body, a rotational member and a power transmission body. The rotational member rotates around an axis to agitate the toner contained in the container main body. The power transmission body is provided outside the container main body and rotates around an axis to transmit a rotational force to the rotational member. The attachment unit includes a contact body which comes into contact with the power transmission body on attachment process and detachment process of the toner container to and from the attachment unit and rotates the power transmission body. The power transmission body comes into contact with the contact body on the attachment process of the toner container to the attachment unit, and is rotated around the axis to rotate the rotational member around the axis.

An attachment and detachment structure attaches and detaches a toner container to and from an attachment unit. The toner container includes a container main body, a rotational member and a power transmission body. The rotational member rotates around an axis to agitate the toner contained in the container main body. The power transmission body is provided outside the container main body and rotates around an axis to transmit a rotational force to the rotational member. The attachment unit includes a contact body which comes into contact with the power transmission body on attachment process and detachment process of the toner container to and from the attachment unit and rotates the power transmission body. The power transmission body comes into contact with the contact body on the attachment process of the toner container to the attachment unit, and is rotated around the axis to rotate the rotational member around the axis.

A developer storage container includes a container body, and a discharge member, wherein the container body includes a first opening on a downstream side in a conveyance direction in which the developer is conveyed, and includes a first side wall, the first side wall includes on an inner surface a protrusion, the discharge member is provided at the first opening to close the first opening, and includes a discharge port, and includes a suppressor, and includes a second side wall, the suppressor includes a plurality of scooping-up members, each of the plurality of scooping-up members includes a scooping-up surface, and a plurality of second openings connecting to the space is provided on the scooping-up surface of any of the plurality of scooping-up members at respective positions different from each other in the conveyance direction.

Providing a toner cartridge capable of restraining toner from leaking through an opening, and improving labor efficiency for assembling the cartridge. The toner cartridge (process cartridge 1) includes a developing frame having a storage chamber configured to store therein toner and formed with an opening to discharge the toner out of the storage chamber, a shaft rotatably supported to the developing frame; and an agitation sheet positioned in the storage chamber and having a base end portion supported to the shaft, the agitation sheet being rotationally movable along with rotation of the shaft. The developing frame includes a first wall formed with the opening, and a second wall configured to support the agitation sheet by nipping the agitation sheet positioned to close the opening between the first wall and the second wall, the second wall permitting the agitation sheet to contact with the first wall and contacting with the agitation sheet through an elastic member.

A developing device develops an electrostatic latent image formed on a photosensitive drum. A bottle rotation sensor detects rotation of a toner bottle that stores toner. A bottle motor drives the toner bottle for rotation to thereby discharge toner from the toner bottle. A hopper-internal toner sensor detects presence/absence of toner stored in a hopper that stores toner discharged from the toner bottle. A replenishment unit replenishes toner stored in the hopper to the developing device. Which of failure of the bottle rotation sensor and rotation failure of the toner bottle has occurred is determined based on a detection result of the bottle rotation sensor and a detection result of the hopper-internal toner sensor.

A developer storage container includes a container body, and a discharge member, wherein the container body includes a first opening on a downstream side in a conveyance direction in which the developer is conveyed, and includes a first side wall, the first side wall includes on an inner surface a protrusion, the discharge member is provided at the first opening to close the first opening, and includes a discharge port, and includes a suppressor, and includes a second side wall, the suppressor includes a plurality of scooping-up members, each of the plurality of scooping-up members includes a scooping-up surface, and a plurality of second openings connecting to the space is provided on the scooping-up surface of any of the plurality of scooping-up members at respective positions different from each other in the conveyance direction.

A developing cartridge includes: a casing; a first gear; a second gear; a cover; a link; and an urging member engaging with the second gear and the link. The second gear is rotatable from a first position to a second position in accordance with the first gear when the second gear engages with the first gear. The link is movable together with rotation of the second gear and pivotally movable relative to the second gear. The link has: a first state where a distal end portion of the link contacts the cover; and a second state where the link pivotally moves relative to the second gear. The first state is provided due to resilient deformation of the urging member in the first position of the second gear. The second state is provided due to a restoring force of the urging member in the second position of the second gear.

An image forming apparatus includes an image carrier; a charging section that charges the surface of the image carrier; an electrostatic-charge-image-forming section that forms an electrostatic charge image on the charged surface of the image carrier; a developing section that contains toner for electrostatic charge image development and develops the electrostatic charge image on the surface of the image carrier into a toner image using the toner; a replenishment toner supplying section that supplies the toner to the developing section, the replenishment toner supplying section including a replenishment toner cartridge, the replenishment toner cartridge containing the toner, having a cap and a body, and detachably attached to the image forming apparatus, the cap being at a first axial end of the replenishment toner cartridge and having an outlet for the replenishment toner to be ejected therethrough, whereas the body having a ridged portion by which the toner inside is moved in the direction from a second axial end of the replenishment toner cartridge to the outlet as the body rotates; a transfer section that transfers the toner image formed on the surface of the image carrier to the surface of a recording medium; and a fixing section that fixes the toner image transferred to the surface of the recording medium. The toner satisfying the following relations: (ln (T1)ln (T2))/(T1T2)0.14; (ln (T2)ln (T3))/(T2T3)0.15; and (ln (T1)ln (T2))/(T1T2)<(ln (T2)ln (T3))/(T2T3), where (T1) represents a viscosity of the toner at 60 C., (T2) represents a viscosity of the toner at 90 C., and (T3) represents a viscosity of the toner at 130 C.

A toner case includes a case main body, a conveying member and a transmitting member. The case main body is configured to store a toner and has a discharge port for the toner. The conveying member is configured to rotate around a rotation axis extending along a rotation axis direction and to convey the toner in the case main body to the discharge port. The transmitting member is configured to transmit rotation to the conveying member. The conveying member is movable along the rotation axis direction with respect to the transmitting member between a coupling position where the conveying member is coupled to the transmitting member and a release position where a coupling of the conveying member to the transmitting member is released.

Providing a toner cartridge capable of restraining toner from leaking through an opening, and improving labor efficiency for assembling the cartridge. The toner cartridge (process cartridge 1) includes a developing frame having a storage chamber configured to store therein toner and formed with an opening to discharge the toner out of the storage chamber, a shaft rotatably supported to the developing frame; and an agitation sheet positioned in the storage chamber and having a base end portion supported to the shaft, the agitation sheet being rotationally movable along with rotation of the shaft. The developing frame includes a first wall formed with the opening, and a second wall configured to support the agitation sheet by nipping the agitation sheet positioned to close the opening between the first wall and the second wall, the second wall permitting the agitation sheet to contact with the first wall and contacting with the agitation sheet through an elastic member.