A powder conveying device includes an inflow portion, a discharge portion, and a conveying screw. Powder flows into the inflow portion from outside of the powder conveying device. The powder flows out from the discharge portion to the outside of the powder conveying device. The conveying screw includes a shaft and conveys the powder from the inflow portion to the discharge portion in a conveying direction. A surface portion of the shaft at at least one of an upstream end or a downstream end of the shaft in the conveying direction, in at least one of the inflow portion or the discharge portion has a lower friction with the powder than another surface portion of the shaft at a position other than the at least one of the upstream end or the downstream end.

An image forming apparatus includes an image carrier, a developing device, a voltage applier, a current detector, a cleaning blade, and a control device. The control device acts as a measurer and an estimator. The measurer changes the DC bias to a first value and a second value, and acquires a first magnitude of the developing current corresponding to the first value, and a second magnitude of the developing current corresponding to the second value, from the current detector. The estimator calculates a current ratio between the first magnitude and the second magnitude, and estimates deterioration status of the cleaning blade, according to the value of the current ratio.

An image forming apparatus includes an image carrier, a developing device, a voltage applier, a current detector, a cleaning blade, and a control device. The control device acts as a measurer and an estimator. The measurer changes the DC bias to a first value and a second value, and acquires a first magnitude of the developing current corresponding to the first value, and a second magnitude of the developing current corresponding to the second value, from the current detector. The estimator calculates a current ratio between the first magnitude and the second magnitude, and estimates deterioration status of the cleaning blade, according to the value of the current ratio.

A developing device includes a developing rotator configured to rotate through a developing region while carrying a magnetic developer, a supply transport member configured to rotate to transport the developer to be supplied to the developing rotator, a non-magnetic movement assist member arranged between the developing rotator and the supply transport member, and having a slope that receives the developer from the supply transport member and moves the developer to the developing rotator, a first adjusting member having a facing surface that faces, with distances, the slope of the movement assist member and a surface of the developing rotator at a part passing over the movement assist member, and configured to adjust a movement amount of the developer from the movement assist member to the developing rotator and a carrying amount of the developer on the surface of the developing rotator, and a second adjusting member having a distance from the surface of the developing rotator at a part passing over the first adjusting member, and configured to adjust the carrying amount of the developer on the surface of the developing rotator before the developer reaches the developing region. A first minimum distance between the slope of the movement assist member and the facing surface of the first adjusting member, a second minimum distance between the facing surface of the first adjusting member and the surface of the developing rotator, and a third minimum distance between the second adjusting member and the surface of the developing rotator are reduced in descending order.

A cartridge attachable to and detachable from an image forming apparatus forming an image on a recording material, the cartridge includes: an image bearing member; a developer container that contains therein a developer; a developing member that is rotatable and carries the developer supplied from the developer container and supplies the developer to the image bearing member; a developer supplying member that is rotatable and provided in the developer container and in contact with the developing member to supply the developer to a surface of the developing member; and a contact member provided in the developer container and in contact with a surface of the developer supplying member, wherein the developer remaining on the image bearing member after image formation is collected to the developing member, and the developer collected to the developing member is collected into the developer container.

A cartridge attachable to and detachable from an image forming apparatus forming an image on a recording material, the cartridge includes: an image bearing member; a developer container that contains therein a developer; a developing member that is rotatable and carries the developer supplied from the developer container and supplies the developer to the image bearing member; a developer supplying member that is rotatable and provided in the developer container and in contact with the developing member to supply the developer to a surface of the developing member; and a contact member provided in the developer container and in contact with a surface of the developer supplying member, wherein the developer remaining on the image bearing member after image formation is collected to the developing member, and the developer collected to the developing member is collected into the developer container.

A powder conveying device includes an inflow portion, a discharge portion, and a conveying screw. Powder flows into the inflow portion from outside of the powder conveying device. The powder flows out from the discharge portion to the outside of the powder conveying device. The conveying screw includes a shaft and conveys the powder from the inflow portion to the discharge portion in a conveying direction. A surface portion of the shaft at at least one of an upstream end or a downstream end of the shaft in the conveying direction, in at least one of the inflow portion or the discharge portion has a lower friction with the powder than another surface portion of the shaft at a position other than the at least one of the upstream end or the downstream end.

A powder conveying device includes an inflow portion, a discharge portion, and a conveying screw. Powder flows into the inflow portion from outside of the powder conveying device. The powder flows out from the discharge portion to the outside of the powder conveying device. The conveying screw includes a shaft and conveys the powder from the inflow portion to the discharge portion in a conveying direction. A surface portion of the shaft at at least one of an upstream end or a downstream end of the shaft in the conveying direction, in at least one of the inflow portion or the discharge portion has a lower friction with the powder than another surface portion of the shaft at a position other than the at least one of the upstream end or the downstream end.

An example image forming apparatus includes a printing unit to print an image on a print medium using toner, a container having a hollow portion to accommodate waste toner discharged from the printing unit, a heater to apply heat to the container such that the waste toner becomes a waste toner viscous body, and a piston inserted in the hollow portion of the container movable between a first position blocking a first end portion of the hollow portion, a second position exposing the waste toner viscous body to a second end portion of the hollow portion to cool the waste toner viscous body to become a waste toner pellet, and a third position beyond the second position to separate the waste toner pellet from the second end portion of the hollow portion.

An image forming apparatus includes an image carrier, a developing device, a voltage applier, a current detector, a cleaning blade, and a control device. The control device acts as a measurer and an estimator. The measurer changes the DC bias to a first value and a second value, and acquires a first magnitude of the developing current corresponding to the first value, and a second magnitude of the developing current corresponding to the second value, from the current detector. The estimator calculates a current ratio between the first magnitude and the second magnitude, and estimates deterioration status of the cleaning blade, according to the value of the current ratio.