Abstract: An electrophotographic apparatus having an electrophotographic photosensitive member, a charging unit, and a developing unit for forming a toner image on a surface of the electrophotographic photosensitive member, wherein the charging unit has a conductive member disposed to be contactable with the electrophotographic photosensitive member; a conductive layer at the surface of the conductive member has a matrix and a plurality of domains dispersed in the matrix; at least a portion of the domains is exposed at the outer surface of the conductive member; the outer surface of the conductive member is constituted of at least the matrix and the domains; a volume resistivity R1 of the matrix is greater than 1.00×1012 ?·cm; a volume resistivity R2 of the domains is smaller than R1; the developing unit contains the toner; and a dielectric loss tangent of the toner is at least 0.0027.

Abstract: An electrophotographic apparatus including an electrophotographic photosensitive member, a charging unit, and a developing unit, wherein the charging unit includes a conductive member disposed to be contactable with the electrophotographic photosensitive member, a conductive layer of the conductive member has a matrix-domain structure, at least some of the domains are exposed at the outer surface of the conductive member, the volume resistivity RI of the matrix is greater than 1.00×1012 ?·cm and not greater than 1.00×1017 ?·cm, the matrix volume resistivity R1 is at least 1.0×105-times the domain volume resistivity R2, and the developing unit includes a toner, the toner includes a binder resin-containing toner particle and an external additive, and the external additive contains fine particles of a hydrotalcite compound.

Abstract: An image forming apparatus at least includes: an image bearing member; a developer container; a developer carrying member; and a controller that controls a power source that applies a voltage to the developer carrying member, wherein the developer carrying member has at least a base and a surface layer, the surface layer has an electron donating portion that mainly donates charge to the developer when the developer and the surface layer makes frictional contact to exchange charge and an electron accepting portion that mainly accepts charge from the developer, and the controller applies an AC voltage to the developer carrying member during a period in which an image forming operation is not performed and the developer carrying member is driven, the AC voltage being different from that applied during an image forming period.

Abstract: An electrophotographic apparatus including an electrophotographic photosensitive member, a charging unit, and a developing unit, wherein the charging unit includes a conductive member disposed to be contactable with the electrophotographic photosensitive member, a conductive layer of the conductive member has a matrix-domain structure, at least some of the domains are exposed at the outer surface of the conductive member, the volume resistivity RI of the matrix is greater than 1.00×1012 ?·cm and not greater than 1.00×1017 ?·cm, the matrix volume resistivity R1 is at least 1.0×105-times the domain volume resistivity R2, and the developing unit includes a toner, the toner includes a binder resin-containing toner particle and an external additive, and the external additive contains fine particles of a hydrotalcite compound.

Abstract: An electrophotographic apparatus having an electrophotographic photosensitive member, a charging unit, and a developing unit for forming a toner image on a surface of the electrophotographic photosensitive member, wherein the charging unit has a conductive member disposed to be contactable with the electrophotographic photosensitive member; a conductive layer at the surface of the conductive member has a matrix and a plurality of domains dispersed in the matrix; at least a portion of the domains is exposed at the outer surface of the conductive member; the outer surface of the conductive member is constituted of at least the matrix and the domains; a volume resistivity R1 of the matrix is greater than 1.00×1012 ?·cm; a volume resistivity R2 of the domains is smaller than R1; the developing unit contains the toner; and a dielectric loss tangent of the toner is at least 0.0027.

Abstract: A method of manufacturing a developer container including a frame configured to define a developer containing portion, a first electrode, and a second electrode arranged on a surface of the frame and having a surface opposed to the first electrode, a developer amount in the developer containing portion being detected based on a capacitance between the first electrode and the second electrode, the method including: holding a conductive resin member constituting the second electrode on a mold configured to mold the frame, a surface of the conductive resin member being in contact with a surface of the mold configured to mold a surface of the frame on a side of the developer containing portion; injecting a resin to be formed into the frame, into the mold on which the conductive resin member is held; and curing the resin to form the frame to which the second electrode is fixed.

Abstract: A developing device includes a rotatable sleeve for carrying a developer including a magnetic material to develop a latent image on an image bearing member, a developer chamber, a rotatable stirring member provided inside the chamber to stir the developer while being in contact with at least a part of an inner surface of the chamber and a magnet generating a magnetic field in at least a part of a contact region between the stirring member and the inner surface. A magnetic flux density of the magnetic field at a first position in the contact region generated by the magnet is different from that in a second position which is adjacent to the first position in a rotational axis direction of the sleeve.

Abstract: A developing device includes a rotatable sleeve for carrying a developer including a magnetic material to develop a latent image on an image bearing member; a developer chamber; and a rotatable stirring member provided inside the chamber to stir the developer while being in contact with at least a part of an inner surface of the chamber; a magnet generating a magnetic field in at lease a part of a contact region between the stirring member and the inner surface, wherein a magnetic flux density of the magnetic field at a first position in the contact region generated by the magnet is different from that in a second position which is adjacent to the first position in a rotational axis direction of the sleeve.

Abstract: A developing apparatus includes a developer bearing member bearing a developer on a surface in a developing operation, a regulating member configured to regulate layer thickness of the developer borne on the developer bearing member, a development chamber provided with the developer bearing member and the regulating member and having an opening, a storage chamber to store the developer, and a conveying member to convey the developer stored in the storage chamber to the development chamber through the opening. When the developing operation is performed, a bottom section of the development chamber is located above a bottom section of the storage chamber in a vertical direction, and a contact region of the developer bearing member in contact with the regulating member is located directly above the opening in the vertical direction.

Abstract: An image forming apparatus includes a control portion configured to perform a cleaning operation including: a first step of causing a developer, which has a reversed polarity and is attracted to a surface of a charging roller, to have a normal polarity under a state in which the developer bearing member is separated from the image bearing member with the contact/separation unit; and a second step of collecting the developer, which has the normal polarity and is attracted to the surface of the image bearing member, to the developer bearing member, by rotating the image bearing member and the developer bearing member under a state in which the developer bearing member is brought into contact with the image bearing member with the contact/separation unit after performing the first step.

Abstract: In a developing apparatus, a cartridge, and an image forming apparatus, the positions of a regulating section, an opening, a bottom section of a development chamber, and a bottom section of a storage chamber are in a specific positional relationship, an optical discharging section is provided in a specific position, or the structure of a regulating member is a specific structure.

Abstract: An image forming apparatus includes an image bearing member, a developer bearing member, a fixing unit including a heating member, a rotary member which is heated by the heating member, and a nip area where the rotary member comes into contact with a sheet, and configured to perform fixing by heating a developer image transferred to the sheet and fixing the developer image to the sheet in the nip area, and a control unit configured to execute, while the fixing is not performed, a mode in which the image bearing member is rotated with the developer bearing member being in a separated position and the heating member is controlled such that a temperature of a portion of a surface of the rotary member, after the rotary member passes through the nip area, is maintained higher than the temperature of the portion during the fixing.

Abstract: A method of manufacturing a developer container including a frame configured to define a developer containing portion, a first electrode, and a second electrode arranged on a surface of the frame and having a surface opposed to the first electrode, a developer amount in the developer containing portion being detected based on a capacitance between the first electrode and the second electrode, the method including: holding a conductive resin member constituting the second electrode on a mold configured to mold the frame, a surface of the conductive resin member being in contact with a surface of the mold configured to mold a surface of the frame on a side of the developer containing portion; injecting a resin to be formed into the frame, into the mold on which the conductive resin member is held; and curing the resin to form the frame to which the second electrode is fixed.

Abstract: In a developing apparatus, a cartridge, and an image forming apparatus, the positions of a regulating section, an opening, a bottom section of a development chamber, and a bottom section of a storage chamber are in a specific positional relationship, an optical discharging section is provided in a specific position, or the structure of a regulating member is a specific structure.

Abstract: An image forming apparatus includes a control portion configured to perform a cleaning operation including: a first step of causing a developer, which has a reversed polarity and is attracted to a surface of a charging roller, to have a normal polarity under a state in which the developer bearing member is separated from the image bearing member with the contact/separation unit; and a second step of collecting the developer, which has the normal polarity and is attracted to the surface of the image bearing member, to the developer bearing member, by rotating the image bearing member and the developer bearing member under a state in which the developer bearing member is brought into contact with the image bearing member with the contact/separation unit after performing the first step.

Abstract: A method of manufacturing a developer container including a frame configured to define a developer containing portion, a first electrode, and a second electrode arranged on a surface of the frame and having a surface opposed to the first electrode, a developer amount in the developer containing portion being detected based on a capacitance between the first electrode and the second electrode, the method including: holding a conductive resin member constituting the second electrode on a mold configured to mold the frame, a surface of the conductive resin member being in contact with a surface of the mold configured to mold a surface of the frame on a side of the developer containing portion; injecting a resin to be formed into the frame, into the mold on which the conductive resin member is held; and curing the resin to form the frame to which the second electrode is fixed.

Abstract: In an axial direction of a developing sleeve that bears magnetic developer on an outer circumferential surface thereof, ends of a sheet-shaped stirring member that stirs the magnetic developer in a container frame to move the magnetic developer toward the developing sleeve are disposed on an outer side of a region in a magnetic field region generated by a magnet roller disposed on an inner side of the developing sleeve. The region has a magnetic field strength equal to or larger than a predetermined magnetic flux density at which the magnetic developer can be borne on the surface of the developing sleeve.

Abstract: A developing apparatus includes a developer bearing member configured to bear a developer on a surface, a regulating member that regulates layer thickness of the developer on the developer bearing member, and a developer conveying member. In addition, a frame has a development chamber in which the developer bearing member and the regulating member are provided, a storage chamber in which the conveying member is provided and the developer is stored, and an opening through which the developer passes into the development chamber. The developing apparatus collects the developer remaining on the developer bearing member into the storage chamber after the developer on the developer bearing member is transferred onto a transfer material. The regulating material includes a step portion that forms a gap between the regulating member and the developer bearing member.

Abstract: An image forming apparatus includes an image bearing member, a developer bearing member, a fixing unit including a heating member, a rotary member which is heated by the heating member, and a nip area where the rotary member comes into contact with a sheet, and configured to perform fixing by heating a developer image transferred to the sheet and fixing the developer image to the sheet in the nip area, and a control unit configured to execute, while the fixing is not performed, a mode in which the image bearing member is rotated with the developer bearing member being in a separated position and the heating member is controlled such that a temperature of a portion of a surface of the rotary member, after the rotary member passes through the nip area, is maintained higher than the temperature of the portion during the fixing.

Abstract: An image forming apparatus includes a control portion configured to perform a cleaning operation including: a first step of causing a developer, which has a reversed polarity and is attracted to a surface of a charging roller, to have a normal polarity under a state in which the developer bearing member is separated from the image bearing member with the contact/separation unit; and a second step of collecting the developer, which has the normal polarity and is attracted to the surface of the image bearing member, to the developer bearing member, by rotating the image bearing member and the developer bearing member under a state in which the developer bearing member is brought into contact with the image bearing member with the contact/separation unit after performing the first step.