Abstract: An image forming apparatus has a rotary in which first and second cartridges are attached. The image forming apparatus has first and second developing units. The first and second developing units include a first and second containers containing first and second developers supplied from the first and second cartridges respectively, and first and second developing members to develop electrostatic latent images formed on a photosensitive member using the first and second developers. The image forming apparatus performs at least two times an acceleration/deceleration operation in which the rotary accelerates and thereafter decelerates, during a period in which the rotary rotates from the first feeding orientation to the first developing orientation.

Abstract: A developer cartridge is attachable/detachable to/from an image forming apparatus. The image forming apparatus has a rotary containing the cartridge; and a control unit to control the drive unit to rotate the rotary. The control unit rotates the rotary to a first rotational phase for replacing the cartridge; rotates the rotary to a second rotational phase when developing an image; and rotates the rotary in the first rotational phase so as to pass through a third rotational phase more than once and then reach the second rotational phase when performing an image forming operation for a first time after the cartridge is replaced. When the rotary is located in the third rotational phase, the direction from the discharge opening of the cartridge toward the receiving opening is a downward direction.

Abstract: In an image forming apparatus, a developing roller accommodating unit includes a developing roller and has an opening of a length smaller than a length of the developing roller in a direction of a rotation axis of the developing roller. A replenishment operation determination unit determines to perform a replenishment operation if a predetermined condition is satisfied. A pixel number determination unit determines, based on information on a number of pixels in an image to be formed, a number of pixels in both a first area and a second area obtained by dividing an image formation area. The predetermined condition is at least one of that the first number of pixels in the first area is greater than a first threshold and that the second number of pixels in the second area is greater than a second threshold different from the first threshold.

Abstract: An image forming apparatus includes an image bearing member, a developing unit including a developing member and a supplying member, a developing voltage applying portion, a supplying voltage applying portion and a control portion. During non-image formation in a state in which the developing member and the supplying member rotate, the control portion is capable of controlling the developing voltage applying portion and the supplying voltage applying portion so as to perform a preliminary operation in which a first potential difference and a second potential difference different from the first potential difference are formed between the developing member and the supplying member by being alternately switched for a plurality of number of times based on toner amount information regarding a toner amount in the developing unit.

Abstract: An image forming apparatus includes a rotary rotatable about a rotation axis extending in an axial direction, a toner cartridge supported by the rotary and having a discharge opening, the toner cartridge configured to discharge toner from the discharge opening; and a developing unit supported by the rotary and including a receiving opening configured to receive the toner discharged from the discharge opening, a storage chamber configured to store the toner received from the receiving opening, and a developing roller configured to bear the toner stored in the storage chamber, wherein the developing unit includes a guide portion, and the guide portion is configured to guide the toner stored in the storage chamber to be away from the receiving opening in the axial direction when the rotary rotates.

Abstract: An image forming apparatus including: a photosensitive drum; a rotary configured to be rotatable around an axial direction; a toner cartridge configured to be supported by the rotary and have a discharge opening discharging toner, and a developing unit configured to be supported by the rotary, develop an electrostatic latent image formed on the photosensitive drum at a development position, and have a discharged receiving opening receiving toner, an accommodating chamber accommodating the received toner, a developing roller, a supply roller rotating around a roller axis along the axial direction and supplying the housed toner to the developing roller, and a guide portion, in which the guide portion guides toner moving in a direction intersecting the axial direction away from the receiving opening, is used.

Abstract: An image forming apparatus includes a main assembly including a photosensitive drum, a developing unit, and a rotary, and includes a toner cartridge. The toner cartridge includes a frame extending in a longitudinal direction and including an accommodating chamber, a first discharge opening through which the toner discharged from the accommodating chamber to the developing unit passes, and a second discharge opening through which the toner discharged from the accommodating chamber to the developing unit passes. The second discharge opening is provided in a position different in position from the first discharge opening with respect to the longitudinal direction, and a partitioning portion for partitioning the accommodating chamber into a plurality of spaces including a first space and a second space separated from the first space. The first discharge opening communicates with the first space. The second discharge opening communicates with the second space.

Abstract: An image-forming apparatus, wherein, in a non-image-forming operation, a control unit executes the following control processing: i) not discharging electric charge between the charging member and the image bearing member and applying a first voltage having a first polarity with respect to a potential on the image bearing member to the charging member; ii) after performing the processing of i), applying a second voltage having a polarity opposite to the first polarity with respect to the potential; and iii) after performing the processing of ii), controlling a third voltage having a second polarity with respect to the potential to be applied to the charging member and controlling a fourth voltage having a polarity opposite to the second polarity with respect to the potential to be applied to the charging member, and controlling electric charge to be discharged between the charging member and the image bearing member.

Abstract: An image forming apparatus includes an image bearing member, a rotary including a developing chamber and a developing member, and a toner cartridge. The developing chamber includes a partition wall for partitioning the developing chamber into a first region including the developing member and a second region. The toner is supplied from the toner cartridge to the developing chamber by communication between a receiving opening provided in the developing chamber and a discharge opening provided in the toner cartridge. The toner accommodated in the toner cartridge and the toner accommodated in the first region are moved to the second region by rotation of the rotary and then are mixed in the second region.

Abstract: When a cartridge is in a posture in which it is installed in an image forming apparatus and used for image formation, a developing chamber is positioned below a storage chamber. At least a portion of an opening is located above a supply roller. A stirring shaft is located above the opening. A second stirring sheet member is provided on the side opposite to a first stirring sheet member with respect to an imaginary line passing through the center of rotation of the stirring shaft. The first stirring sheet member and the second stirring sheet member each have a length that allows the other ends thereof to reach the opening when the stirring shaft rotates.

Abstract: An image forming apparatus includes a photosensitive member, a charging member, an exposing device, a developing device, a transfer member, a brush, a voltage applying portion, and a control portion controlling a surface potential of the photosensitive member at the brush contacting position. When a value of subtracting a value of the surface potential of the photosensitive member in the brush contacting position from a value of the brush voltage is defined as a contacting position potential difference, the control portion controls the surface potential of the photosensitive member in the brush contacting position so that the contacting position potential difference is changed from a first potential difference to a second potential difference in a predetermined direction which is either one of an increasing direction or a decreasing direction, and then the contacting position potential difference is changed from the second potential difference to a third potential difference in the predetermined direction.

Abstract: An image forming apparatus includes an image bearing member, a charging member, a development member, a transfer member, a charging voltage application unit, a development voltage application unit, and a control unit. The development member collects toner that remains on a surface of the image bearing member after a toner image is transferred from the image bearing member surface to transfer material. The control unit controls application of a development voltage to apply, to the development member in a cleaning operation, a development voltage having a polarity that is opposite to a normal polarity, and controls application of a charging voltage to apply, to the charging member, a charging voltage having the normal polarity such that a potential difference formed at a charging portion between the applied charging voltage and a surface potential formed at the image bearing member surface is lower than or equal to a discharge start voltage.

Abstract: An image forming apparatus includes a charging unit that charges an image bearing member, a developing unit that forms a toner image on an latent image formed on the image bearing member, a transfer unit that transfers the toner image onto a transfer material, a charge neutralizer that neutralizes a charge of the image bearing member downstream of a transfer portion and upstream of a charging portion in a rotating direction of the image bearing member, a conductive collecting unit that collects a material adhering on the image bearing member downstream of the transfer portion and upstream of the charging portion, wherein the developing unit collects residual toner on the image bearing member, an voltage application unit sets a potential difference between the voltage applied to the collecting unit and the surface electric potential of the image bearing member not more than a discharge threshold.

Abstract: A fixing apparatus includes a first rotary member, a heating element, a second rotary member, a nip member, a reflection member, and a support member. The support member configured to transit to a pressurized state and a non-pressurized state, the pressurized state being a state in which a first position and a second position of the support member are pressurized in a pressurization direction toward the second rotary member, the non-pressurized state being in which the pressurized state of the support member is released. The support member includes a contact surface in contact with the reflection member in the pressurized state. The contact surface takes such a posture that a center position between the first and second positions in the rotation axial direction is close to the second rotary member rather than the first and second positions in a case where the support member is in the non-pressurized state.

Abstract: An image forming apparatus is used, which includes a developer bearing member that transports developer to an electrostatic latent image formed on an image bearing member, a supply roller including a foam elastic member that supplies the developer to the developer bearing member, a power source device that applies a developing voltage to the developer bearing member and applies a supply voltage to the supply roller; a power source control unit that controls supply of the developer from the supply roller to the developer bearing member by controlling the developing voltage and the supply voltage; and an image control unit that controls formation of the electrostatic latent image based on image information. The image control unit controls, based on a first value, a change amount of the supply voltage in a period during which image formation is performed.

Abstract: An image forming apparatus includes a photosensitive member, a charging member, an exposing device, a developing device, a transfer member, a brush, a voltage applying portion, and a control portion controlling a surface potential of the photosensitive member at the brush contacting position. When a value of subtracting a value of the surface potential of the photosensitive member in the brush contacting position from a value of the brush voltage is defined as a contacting position potential difference, the control portion controls the surface potential of the photosensitive member in the brush contacting position so that the contacting position potential difference is changed from a first potential difference to a second potential difference in a predetermined direction which is either one of an increasing direction or a decreasing direction, and then the contacting position potential difference is changed from the second potential difference to a third potential difference in the predetermined direction.

Abstract: An image-forming apparatus, wherein, in a non-image-forming operation, a control unit executes the following control processing: i) not discharging electric charge between the charging member and the image bearing member and applying a first voltage having a first polarity with respect to a potential on the image bearing member to the charging member; ii) after performing the processing of i), applying a second voltage having a polarity opposite to the first polarity with respect to the potential; and iii) after performing the processing of ii), controlling a third voltage having a second polarity with respect to the potential to be applied to the charging member and controlling a fourth voltage having a polarity opposite to the second polarity with respect to the potential to be applied to the charging member, and controlling electric charge to be discharged between the charging member and the image bearing member.

Abstract: An image forming apparatus includes a photosensitive member, a charging member, an electrostatic image forming portion, a developing member, a transfer member, a transfer voltage source, a brush member, a brush voltage source, and a controller capable of executing a cleaning operation. The controller carries out control so that the cleaning operation includes a first operation in which a potential difference is formed between the transfer member and the photosensitive member so that toner charged to a normal charge polarity is moved from the transfer member toward the photosensitive member, and a second operation in which a potential difference is formed between the brush member and the photosensitive member so that the toner charged to the normal charge polarity is moved from the photosensitive member toward the brush member.

Abstract: An image forming apparatus includes a photosensitive member, a charging member, an exposing device, a developing device, a transfer member, a brush, a voltage applying portion, and a control portion controlling a surface potential of the photosensitive member at the brush contacting position. When a value of subtracting a value of the surface potential of the photosensitive member in the brush contacting position from a value of the brush voltage is defined as a contacting position potential difference, the control portion controls the surface potential of the photosensitive member in the brush contacting position so that the contacting position potential difference is changed from a first potential difference to a second potential difference in a predetermined direction which is either one of an increasing direction or a decreasing direction, and then the contacting position potential difference is changed from the second potential difference to a third potential difference in the predetermined direction.

Abstract: An image-forming apparatus, wherein, in a non-image-forming operation, a control unit executes the following control processing: i) not discharging electric charge between the charging member and the image bearing member and applying a first voltage having a first polarity with respect to a potential on the image bearing member to the charging member; ii) after performing the processing of i), applying a second voltage having a polarity opposite to the first polarity with respect to the potential; and iii) after performing the processing of ii), controlling a third voltage having a second polarity with respect to the potential to be applied to the charging member and controlling a fourth voltage having a polarity opposite to the second polarity with respect to the potential to be applied to the charging member, and controlling electric charge to be discharged between the charging member and the image bearing member.