A toner classification apparatus comprising a classification rotor in which the classification rotor has a vane A which extends from a rotation center direction of the classification rotor to an outer circumference direction thereof and a vane B having a length longer than that of the vane A, the vane A, and the vane B are disposed so as to satisfy a predetermined relationship, and a toner production method comprising a classification step of carrying out a classification process on particles to be classified by using the toner classification apparatus.

An image forming apparatus includes a rotatable photosensitive member, a charging member, an exposure unit, a developing member, a transfer member, and a pre-exposure unit. The pre-exposure unit exposes a surface of the photosensitive member after the toner image is transferred to the recording material and before being charged by the charging member. The pre-exposure unit includes a substrate disposed adjacent to one end of the photosensitive member with respect to a longitudinal direction of the photosensitive member, and in which a first light emitting element and a second light emitting element having directional characteristics narrower than that of the first light emitting element are mounted.

An image forming portion applies a bias voltage in which an AC component is superimposed on a DC component between a first carrying member and a second carrying member, and transfers toner from the first carrying member to the second carrying member to form an image on the second carrying member. An AC setting processing portion performs AC calibration to set a magnitude of the AC component of the bias voltage. A potential measurement processing portion measures a surface potential of the first carrying member or the second carrying member based on a target current flowing between the first carrying member and the second carrying member. A drive processing portion executes the AC calibration before measurement of the surface potential in a case where, when measuring the surface potential, an activation condition is satisfied.

An image forming apparatus is capable of performing a second image forming operation in which a peripheral velocity ratio of a developer bearing member to an image bearing member becomes greater than that in a first image forming operation, and in which a potential difference between a developing bias applied to the developer bearing member and a supply bias applied to a supply member becomes a potential difference at which a urging force causing a developer at the contact portion between the developer bearing member and the supply member to move from the supply member to the developer bearing member becomes smaller than that in the first image forming operation, or becomes a potential difference at which a urging force causing the developer to move from the developer bearing member to the supply member is generated.

In an image forming apparatus, in a case where a power of the apparatus is turned from OFF to ON, a rotation drive unit rotationally drives each of a developing roller, a first conductive roller, and a second conductive roller in a state where a liquid developer supplied to a developer container by a supply device has reached a supply position, and a bias application unit applies a bias to each of the developing roller, the first conductive roller, and the second conductive roller after the developing roller rotates at least once, in the state where the liquid developer supplied to the developer container by the supply device has reached the supply position.

In a cartridge, a housing has a developer accommodating portion and includes a first side wall and a second side wall. A coupling member is disposed at a position opposite to the developer accommodating portion with respect to the first side wall. A detection body is disposed at a position opposite to the developer accommodating portion with respect to the second side wall. A first driving force transmission member is positioned at the same side with the coupling member with respect to the first side wall, and transmits driving force from the coupling member to a rotating member. A second driving force transmission member is positioned at the same side with the detection body with respect to the second side wall, and transmits driving force from the rotating member to the detection body.

A particle conveying device includes a storage portion that stores pressure sensitive adhesive particles that contain at least a binder resin, have a pressure-induced phase transition property, and have a sulfur content in a range of 0.1 mass % or more and 0.5 mass % or less relative to the entire pressure sensitive adhesive particles as measured by X-ray fluorescence; and a conveying member that is disposed in the storage portion and rotates about a shaft that extends in one direction inside the storage portion to thereby convey the pressure sensitive adhesive particles in a direction along the shaft inside the storage portion.

An image forming apparatus includes image forming units. A controller includes an execution section, a measurement section, and a prediction section. The execution section controls execution of a developer refresh operation in which toner is ejected from a developer bearing member to an image bearing member so that a specific image forming unit replenishes a development device with the toner from the developer bearing member. The measurement section measures respective surface potentials of the image bearing members included in other image forming units while the specific image forming unit is executing the developer refresh operation. The prediction section uses measurement results of the respective surface potentials of the image bearing members included in the other image forming units for a prediction on the surface potential of the image bearing member included in the specific image forming unit.

An image forming apparatus includes an image bearing member, a developing member that supplies a developer of a regular polarity, a developer supply member that supplies developer to the developing member, and a control unit that applies a first voltage to the developing member and a second voltage to the developer supply member. The control unit executes an image forming operation, and a rotational operation in which the developer supply member rotates in a state in which the first voltage of a regular polarity is applied thereto. The rotational operation includes a first rotational operation in which a potential difference is a first potential difference and a second rotational operation in which the developing member and the developer supply member rotate in a state in which the second voltage having the same polarity as the regular polarity and having a greater absolute value is applied.

An image forming apparatus includes: an image forming unit comprising: a photosensitive member configured to rotate; a charging unit configured to charge the photosensitive member based on a charging bias; an exposure unit configured to expose the photosensitive member charged by the charging unit with laser light to form an electrostatic latent image on the photosensitive member; and a developing device configured to develop the electrostatic latent image based on a development bias to form an image on the photosensitive member, a reading unit configured to read a test image formed by the image forming unit, and a controller configured to: control the image forming unit to form the test image; control the reading unit to read the test image.