An image forming apparatus includes first and second image bearing members, first and second developing members. The controller controls to execute first and second controls based on an image information in a case that the first developing member is separated from the first image bearing member when an operation in which the image is sequentially transferred to a transferred member from the first and second image bearing members is terminated. The first developing member is started to separate from the first image bearing member in the first control after an end of an image forming area on the first image bearing member in a moving direction passes through the first transfer position, and in the second control after the end of the image forming area on the first image bearing member in the moving direction passes through the developing position and before the end of the image forming area reaches the first transfer position.

A toner includes: toner base particles including a binder resin, a colorant, an inorganic filler, and a release agent; and an external additive. An average circularity of the toner is 0.974 or more but 0.985 or less. A surface roughness parameter Sz of a surface of the toner is 200 nm or more but 500 nm or less, the surface roughness parameter Sz being measured with an atomic force microscope (AFM).

An imaging system includes a rotatable image carrier; a rotatable developer carrier, a storage container, and an air flow generator. The developer carrier transfers toner to the image carrier at a developing region located between the image carrier and the developer carrier. The storage container stores the developer carrier. The air flow generator is separated from the storage container by a gap, and rotates in a rotational direction that is opposite to a rotational direction of the developer carrier, to channel an air flow through the gap when the air flow generator rotates.

An image forming apparatus includes a main casing, a cartridge, and a controller. The cartridge is attachable to the main casing. The cartridge includes a cartridge memory configured to store identification information. The controller is configured to perform a rewriting process to rewrite the identification information to information indicating that the cartridge is the normal cartridge, in a case where the controller receives a cancellation instruction to instruct to cancel the service contract and the identification information, which is stored in a cartridge memory of the cartridge attached to the main casing, indicates that the cartridge is the contract cartridge.

An image forming apparatus includes: an image carrier body to be transported; an image forming unit that forms an image on the image carrier body; a change roller that is in contact with an inner peripheral surface of the image carrier body so as to be rotatable around a rotation axis and that is capable of changing an angle of the rotation axis with respect to a width direction of the image carrier body; a flywheel provided at the change roller; and a driving mechanism that applies a driving force for changing an angle of the rotation axis with respect to the width direction to an applied portion that moves together with the change roller. A direction of the driving force applied to the applied portion by the driving mechanism is opposite to a direction in which the applied portion moves due to gravity acting on the flywheel.

An image forming apparatus includes a developing case housing a developer. A doctor blade is separated from an outer surface of a developing sleeve, the both ends of the doctor blade in a longitudinal direction are fixed to a developing case, and the doctor blade includes a through hole in the central portion in the longitudinal direction. An adjusting portion adjusts the distance between the doctor blade and the outer surface of the developing sleeve. A rotating portion is provided on one surface of the base portion, inserts the through hole, and rotates with respect to the doctor blade and the developing case.

A developing cartridge may include: a casing for accommodating developer therein; a developing roller rotatable about an axis extending in a first direction and positioned at one side of the casing in a second direction; a storage medium having an electric contact surface; and a holder movable relative to the casing in the second direction with the electric contact surface between a first position and a second position, the holder having an outer surface at which the electric contact surface is positioned.

Provided is an electrophotographic developer set having a toner and a powder adhesive, wherein the toner comprises a thermoplastic resin A; the powder adhesive comprises a thermoplastic resin B and a wax A; the wax A has two or more ester groups in the molecule; the thermoplastic resin B has an ester group; and in a viscoelasticity measurement, with Gt′(100) (Pa) being a storage elastic modulus at 100° C. of the toner, and Gb′(100) (Pa) being a storage elastic modulus at 100° C. of the powder adhesive, Gb′(100) is 1.00×10.sup.5 Pa or less, and Gt′(100)/Gb′(100) is 1.20 or more, as well as a method for producing a bonded product using the above electrophotographic developer set.

The image forming apparatus includes a drum cartridge having a photosensitive drum and a drum drive input member; a developing cartridge configured to be movably mounted to the drum cartridge, the developing cartridge comprising a developing roller disposed so as to face the photosensitive drum and a developing drive input member; a drum drive transmission member configured to engage with the drum drive input member and configured to transmit drum driving force to the drum drive input member while permitting a positional gap of the drum drive input member within a predetermined range; and a developing drive transmission member configured to engage with the developing drive input member and configured to transmit developing driving force to the developing drive input member while permitting a positional gap of the developing drive input member within a predetermined range.

In a toner container, a powder container that includes a container body configured to store toner, and is rotated by input of rotational drive of a drive output section of an image forming device while being set in the image forming device, the toner container includes an incompatible hole group, as a container-side engagement portion, on a front end surface facing downstream in an insertion direction when inserted in a direction parallel to a rotational center line of the rotational drive and set in the image forming device, the incompatible hole group has a hole shape that is engaged with a body-side projection portion of the drive output section protruding upstream in the insertion direction, and the rotational drive is input by rotation of the drive output section with the incompatible hole group and the body-side projection portion engaged with each other.