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.

If a user is not familiar with the operation for the developer supply container, the rotating operation for the developer supply container may be insufficient, so that developer supply container does not reach a predetermined operating position, with the result of abnormal developer supply. by increasing a rotation load of a second gear 6 which is in an operable connection with a drive gear member 12 of the developer receiving apparatus 10 by a function of a locking member 7, the developer supply container 1 mounted to the developer receiving apparatus 10 is rotated toward the supply position. After the developer supply container 1 rotates to the supply position, the locking by the locking member 7 is released, by which the rotation load applied to the second gear 6 is reduced, so that drive transmission, thereafter, to the feeding member 4 for developer supply is smooth.

A cartridge includes a shutter that opens and closes when the cartridge is attached and detached to a developing unit or image forming apparatus. The cartridge includes a casing having a chamber with a first opening at one end portion allowing toner to flow out of the casing. The cartridge includes a cover that covers the first opening, movable with the casing and having a second opening allowing toner to flow out of the cover. The shutter is located at the one end portion and has a protrusion further from the one end portion than the cover. The developing unit supports the protrusion when the cartridge is mounted thereon, and the casing pivots with the cover relative to the developing unit between a first position where the shutter closes the second opening and a second position where a third opening of the shutter overlaps the second opening.

A toner container includes a container body, a first bearing portion, and a rotational member. The container body in which toner is stored includes a pair of side walls that face one another across a specific distance. The first bearing portion is provided in an inner surface of at least one side wall of the pair of side walls. The rotational member includes a rotational shaft that is rotatably supported by the first bearing portion. The first bearing portion includes a terminal end portion on one side and an open portion on another side, and further includes a first long groove in which the rotational shaft is inserted, and a projection protruding from a groove bottom surface that extends from the open portion to the terminal end portion of the first long groove.

If a user is not familiar with the operation for the developer supply container, the rotating operation for the developer supply container may be insufficient, so that developer supply container does not reach a predetermined operating position, with the result of abnormal developer supply. by increasing a rotation load of a second gear 6 which is in an operable connection with a drive gear member 12 of the developer receiving apparatus 10 by a function of a locking member 7, the developer supply container 1 mounted to the developer receiving apparatus 10 is rotated toward the supply position. After the developer supply container 1 rotates to the supply position, the locking by the locking member 7 is released, by which the rotation load applied to the second gear 6 is reduced, so that drive transmission, thereafter, to the feeding member 4 for developer supply is smooth.

A cartridge includes a shutter that opens and closes when the cartridge is attached and detached to a developing unit or image forming apparatus. The cartridge includes a casing having a chamber with a first opening at one end portion allowing toner to flow out of the casing. The cartridge includes a cover that covers the first opening, movable with the casing and having a second opening allowing toner to flow out of the cover. The shutter is located at the one end portion and has a protrusion further from the one end portion than the cover. The developing unit supports the protrusion when the cartridge is mounted thereon, and the casing pivots with the cover relative to the developing unit between a first position where the shutter closes the second opening and a second position where a third opening of the shutter overlaps the second opening.

A cartridge includes a shutter that opens and closes when the cartridge is attached and detached to a developing unit or image forming apparatus. The cartridge includes a casing having a chamber with a first opening at one end portion allowing toner to flow out of the casing. The cartridge includes a cover that covers the first opening, movable with the casing and having a second opening allowing toner to flow out of the cover. The shutter is located at the one end portion and has a protrusion further from the one end portion than the cover. The developing unit supports the protrusion when the cartridge is mounted thereon, and the casing pivots with the cover relative to the developing unit between a first position where the shutter closes the second opening and a second position where a third opening of the shutter overlaps the second opening.

A cartridge includes a shutter that opens and closes when the cartridge is attached and detached to a developing unit or image forming apparatus. The cartridge includes a casing having a chamber with a first opening at one end portion allowing toner to flow out of the casing. The cartridge includes a cover that covers the first opening, movable with the casing and having a second opening allowing toner to flow out of the cover. The shutter is located at the one end portion and has a protrusion further from the one end portion than the cover. The developing unit supports the protrusion when the cartridge is mounted thereon, and the casing pivots with the cover relative to the developing unit between a first position where the shutter closes the second opening and a second position where a third opening of the shutter overlaps the second opening.

One or more toner bottles are provided for supplying toners to development apparatuses. The toner bottles each include bottle portions and displacement sensors. The bottle portions accommodate the toners and are rotated by a drive force of a drive source. The displacement sensors are positioned on sides of the bottle portions and detect deflection amounts of the sides of the bottle portions to determine how much toner is remaining in each toner bottle.

A toner container includes a container body, a first bearing portion, and a rotational member. The container body in which toner is stored includes a pair of side walls that face one another across a specific distance. The first bearing portion is provided in an inner surface of at least one side wall of the pair of side walls. The rotational member includes a rotational shaft that is rotatably supported by the first bearing portion. The first bearing portion includes a terminal end portion on one side and an open portion on another side, and further includes a first long groove in which the rotational shaft is inserted, and a projection protruding from a groove bottom surface that extends from the open portion to the terminal end portion of the first long groove.