Abstract: An electrophotographic apparatus comprising an electrophotographic photosensitive member, a charging device, and a developing device, wherein the charging device comprises a conductive member arranged to be capable of contacting the electrophotographic photosensitive member, a conductive layer on the conductive member outer surface comprises a matrix and a plurality of domains dispersed in the matrix, at least some of the domains are exposed at the conductive member outer surface, the matrix has a volume resistivity of larger than 1.00×1012 ?·cm and is 1.0×105 times or more one of the domains, the developing device comprises the toner comprising a toner particle, fine particles A and B, the fine particle A has a volume resistivity of 1.0×103 to 1.0×1010 ?·cm, and the fine particle B is silica fine particle and having a volume resistivity of 1.0×1011 to 1.0×1017 ?·cm.

Abstract: An electrophotographic apparatus comprising an electrophotographic photosensitive member, a charging device, and a developing device, wherein the charging device comprises a conductive member arranged to be capable of contacting the electrophotographic photosensitive member, a conductive layer on the conductive member outer surface comprises a matrix and a plurality of domains dispersed in the matrix, at least some of the domains are exposed at the conductive member outer surface, the matrix has a volume resistivity of larger than 1.00×1012 ?·cm and is 1.0×105 times or more one of the domains, the developing device comprises the toner comprising a toner particle, fine particles A and B, the fine particle A has a volume resistivity of 1.0×103 to 1.0×1010 ?·cm, and the fine particle B is silica fine particle and having a volume resistivity of 1.0×1011 to 1.0×1017 ?·cm.

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: An image forming apparatus in which a developer bearing member is disposed below a cleaning member, which cleans a charging member, so as to overlap with the cleaning member when viewed in a vertical direction and includes a base body and an elastic layer covering the base body and having a width in a longitudinal direction of the developer bearing member that accommodates the entire region of the cleaning member in the longitudinal direction. In the longitudinal direction, the cleaning member is disposed at a position where the entire region thereof in the longitudinal direction is accommodated in the width of the elastic layer.

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: An image forming apparatus in which a developer bearing member is disposed below a cleaning member, which cleans a charging member, so as to overlap with the cleaning member when viewed in a vertical direction and includes a base body and an elastic layer covering the base body and having a width in a longitudinal direction of the developer bearing member that accommodates the entire region of the cleaning member in the longitudinal direction. In the longitudinal direction, the cleaning member is disposed at a position where the entire region thereof in the longitudinal direction is accommodated in the width of the elastic layer.

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: An image forming apparatus in which a developer bearing member is disposed below a cleaning member, which cleans a charging member, so as to overlap with the cleaning member when viewed in a vertical direction and includes a base body and an elastic layer covering the base body and having a width in a longitudinal direction of the developer bearing member that accommodates the entire region of the cleaning member in the longitudinal direction. In the longitudinal direction, the cleaning member is disposed at a position where the entire region thereof in the longitudinal direction is accommodated in the width of the elastic layer.

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: An image forming apparatus in which a developer bearing member is disposed below a cleaning member, which cleans a charging member, so as to overlap with the cleaning member when viewed in a vertical direction and includes a base body and an elastic layer covering the base body and having a width in a longitudinal direction of the developer bearing member that accommodates the entire region of the cleaning member in the longitudinal direction. In the longitudinal direction, the cleaning member is disposed at a position where the entire region thereof in the longitudinal direction is accommodated in the width of the elastic layer.

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: An image forming apparatus includes an image bearing member, a charging apparatus, an exposure apparatus configured to expose the image bearing member charged by the charging apparatus to form an electrostatic latent image, a developing apparatus provided with a developer accommodation section and configured to develop the electrostatic latent image, a signal output unit configured to output a first signal for exposing a printing part of the image bearing member and a second signal for exposing a non-printing part of the image bearing member, a counting apparatus configured to receive the electric signal output from the signal output unit and count the first signals and the second signals, and a calculation apparatus configured to obtain a use amount of the developer by the developing apparatus from count values of the first signals and the second signals counted by the counting apparatus.

Abstract: A developing device usable with an image forming apparatus includes a developer carrying member for carrying a developer, a developer accommodating portion for accommodating a developer, and a guiding member having an inclined surface contacting the developer carrying member. The inclined surface guides a developer to a contact portion where the inclined surface contacts the developer carrying member to cause the developer to be carried on the developer carrying member. A regulating member regulates an amount of the developer carried on the developer carrying member. An inclination angle of the inclined surface is in a range not less than an angle of rest of the developer and less than 90 degrees.

Abstract: An image forming apparatus includes an image bearing member, a developing device, a holding unit, and a detection device. The image bearing member supports an electrostatic latent image. The developing device includes a developer bearing member having a first electrode member and supporting a developer to develop the electrostatic latent image. The developing device includes a supply member having a second electrode member and supplying the developer to the developer bearing member at a nip portion. The holding unit holds and change the developing device to a first posture and to a second posture where the deposited developer falls off the first posture. The detection device detects a remaining developer amount in the developing device based on a capacitance C1 between the first and second electrode members in the first posture and a capacitance C2 between the first and second electrode members in the second posture.

Abstract: An image forming apparatus includes an image bearing member, a charging apparatus, an exposure apparatus configured to expose the image bearing member charged by the charging apparatus to form an electrostatic latent image, a developing apparatus provided with a developer accommodation section and configured to develop the electrostatic latent image, a signal output unit configured to output a first signal for exposing a printing part of the image bearing member and a second signal for exposing a non-printing part of the image bearing member, a counting apparatus configured to receive the electric signal output from the signal output unit and count the first signals and the second signals, and a calculation apparatus configured to obtain a use amount of the developer by the developing apparatus from count values of the first signals and the second signals counted by the counting apparatus.

Abstract: An image forming apparatus includes an image bearing member; a charging device; an exposure device configured to expose intermittently for each unit area of the image bearing member charged by the charging device to form a latent image; a developing device configured to develop the latent image with developer; a signal output portion configured to output a first electric signal when the exposure device exposes a print area of the image bearing member, and output a second electric signal, which instructs the exposure device to shorten an exposure time per unit area more than an exposure time of the first electric signal, when the exposure device exposes a non-print area of the image bearing member; and a count portion, to which the first and the second electric signals are input from the signal output portion, configured to measure only the first electric signal without measuring the second electric signal.

Abstract: In an image forming apparatus, when no image is being formed, an image bearing member is rotated at least one rotation, in a state in which a transfer bias is controlled such that a potential on a surface of the image bearing member on the upstream side in the rotational direction of a cleaning apparatus is a polarity opposite to that of a developer.

Abstract: An image forming apparatus includes a holding unit configured to change a developing device to first and second orientations. Whether a developer in the developing device is unevenly distributed in a longitudinal direction of the developing device is detected based on a capacitance C1 between first and second electrode members in the first orientation and a capacitance C2 between the first and second electrode members in the second orientation.

Abstract: A color image forming apparatus includes an image bearing member for carrying an electrostatic latent image, a plurality of developing devices for developing the electrostatic latent image, a supporting member for moving the developing devices sequentially to a developing position opposing the image bearing member, and a detecting device for detecting developer remainder in the developing device. In addition, a determining portion determines the developer remainder. In the developing device in which the detecting operation is effected after the developing operation, the determining portion determines the developer remainder from the information relating to the detected developer remainder. In the developing device of the developing devices for which the detecting operation is effected before the developing operation, the determining portion determines the developer remainder from the information relating to the detected developer remainder and a deduced consumption amount.