Abstract: An image forming apparatus includes a rotatable image bearing member, a developing member, a transfer member, and a brush contacting a surface of the image bearing member in a contact portion downstream of a transfer portion and upstream of a developing portion with respect to a rotational direction of the image bearing member. The toner which is not transferred onto a toner image receiving member is collected by the developing member. In a charging series, the toner is positioned on the same side as a normal charge polarity of the toner relative to the brush. In the contact portion, a maximum value of a contact pressure of 0.7 gf/mm2 or more and 3.5 gf/mm2 or less, a maximum contact area ratio is 18% or more and 74% or less, and a Clark-Evans index of the brush is 1 or more.

Abstract: An image forming apparatus includes a rotatable image bearing member, a developing member, a transfer member, and a brush contacting a surface of the image bearing member in a contact portion downstream of a transfer portion and upstream of a developing portion with respect to a rotational direction of the image bearing member. The toner which is not transferred onto a toner image receiving member is collected by the developing member. In a charging series, the toner is positioned on the same side as a normal charge polarity of the toner relative to the brush. In the contact portion, a maximum value of a contact pressure of 0.7 gf/mm2 or more and 3.5 gf/mm2 or less, a maximum contact area ratio is 18% or more and 74% or less, and a Clark-Evans index of the brush is 1 or more.

Abstract: A developing device includes a developing container having an accommodation chamber for a developer and a developing chamber communicating with the accommodation chamber through a communication port, a conveyance member configured to convey the developer toward the communication port by a sheet, the conveyance member including a rotation shaft and the sheet which is flexible and has a first end fixed to the rotation shaft so as to rotate in the accommodation chamber, a light transmitting member provided in the developing container and positioned above the communication port, and an abutting portion configured to abut on a second end of the sheet such that the sheet is maintained in a bent state until the second end passes in front of the communication port from its upstream end in a rotation direction of the conveyance member and then reaches the light transmitting member.

Abstract: An image-forming apparatus to execute an image-forming operation includes an image bearing member, a charging member to charge at a charging portion a surface of, and a developing member to supply at a developing portion toner to, the image bearing member. When a rotating image bearing member stops rotating, a surface potential of the image bearing member formed on the developing portion is defined as V1, a developing voltage applied to the developing member is defined as V2, a charging voltage applied to the charging member is defined as V3, and a surface potential of the image bearing member formed on the charging portion is defined as V4. A first potential difference, which is a potential difference between V2 and V1, and a second potential difference, which is a potential difference between V3 and V4, are controlled based on information about a number of execution times of the image-forming operation.

Abstract: An image forming apparatus includes a rotatable image bearing member, a developing member, a transfer member, and a brush contacting a surface of the image bearing member in a contact portion downstream of a transfer portion and upstream of a developing portion with respect to a rotational direction of the image bearing member. The toner which is not transferred onto a toner image receiving member is collected by the developing member. In a charging series, the toner is positioned on the same side as a normal charge polarity of the toner relative to the brush. In the contact portion, a maximum value of a contact pressure of 0.7 gf/mm2 or more and 3.5 gf/mm2 or less, a maximum contact area ratio is 18% or more and 74% or less, and a Clark-Evans index of the brush is 1 or more.

Abstract: 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.

Abstract: Provided is an image forming apparatus, including: an image bearing member; an exposure unit; a developing member which is rotatable at a rotation speed different from the image bearing member; a developer supply member; a developing voltage-applying unit; a supply voltage-applying unit; and a control unit. The control unit controls execution of: an image forming operation in which a developer image is formed by supplying developer on the image bearing member; and a cleaning operation which removes a substance adhered to the image bearing member using the developing member. In the cleaning operation, the control unit controls the developing voltage-applying unit or the supply voltage-applying unit so that the cleaning force using the developing member becomes stronger than that in the image forming operation.

Abstract: An image forming apparatus includes a rotatable image bearing member, a charging member, a developing member, a transfer member, an exposure unit, and a controller. The controller executes a preparatory operation in which before an image forming operation, rotation of the image bearing member is started and a charging voltage and a developing voltage are increased stepwise. In the preparatory operation, the controller carries out control so as to start application of the charging voltage at a voltage value not less than a discharge start voltage of the charging member before a surface region of the image bearing member positioned in a developing portion at a time of a start of the rotation of the image bearing member reaches a charging portion in a state which a surface of the image bearing member is exposed to light by the exposure unit.

Abstract: Provided is an image forming apparatus, including: an image bearing member; an exposure unit; a developing member which is rotatable at a rotation speed different from the image bearing member; a developer supply member; a developing voltage-applying unit; a supply voltage-applying unit; and a control unit. The control unit controls execution of: an image forming operation in which a developer image is formed by supplying developer on the image bearing member; and a cleaning operation which removes a substance adhered to the image bearing member using the developing member. In the cleaning operation, the control unit controls the developing voltage-applying unit or the supply voltage-applying unit so that the cleaning force using the developing member becomes stronger than that in the image forming operation.

Abstract: 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.

Abstract: A process cartridge is provided, which is configured to recover, with a developing member, developer remaining on an image bearing member after transfer of a developer image to a transfer receiving member, wherein a charging member has a shaft that is conductive and an elastic layer supported on the shaft and being in contact with the image bearing member; the elastic layer has a matrix containing a first rubber, and a plurality of domains containing a second rubber and an electron-conductive agent and interspersed within the matrix. The electric resistance of the domains is lower than the electric resistance of the matrix. The matrix is exposed on an outer surface of the elastic layer and forms multiple depressed portions, and the domains include a domains exposed at a bottom section of the depressed portion.

Abstract: A process cartridge is provided, which is configured to recover, with a developing member, developer remaining on an image bearing member after transfer of a developer image to a transfer receiving member, wherein a charging member has a shaft that is conductive and an elastic layer supported on the shaft and being in contact with the image bearing member; the elastic layer has a matrix containing a first rubber, and a plurality of domains containing a second rubber and an electron-conductive agent and interspersed within the matrix. The electric resistance of the domains is lower than the electric resistance of the matrix. The matrix is exposed on an outer surface of the elastic layer and forms multiple depressed portions, and the domains include a domains exposed at a bottom section of the depressed portion.

Abstract: A cleaning device, including: a cleaning frame; a cleaning member having one end and the other end, an image bearing member being capable of rotating and bearing a developer image formed of a developer so as to remove the developer remaining on the image bearing member after transfer of the developer image from the image bearing member; and a sheet member having flexibility and having one end and the other end; wherein a work function W (D) of the developer and a work function W (S) of the sheet member satisfy 0?W(D)?W(S)?0.23 and the developer includes inorganic particles, and at least one kind of the inorganic particles has an average primary particle diameter of 50 nm or larger.

Abstract: A cleaning device has: a cleaning frame; a cleaning member which, after transfer through contact with an image bearing member, removes a developer remaining on the image bearing member; and a sheet member having flexibility and coming into contact with the image bearing member at an upstream side of a contact position between the cleaning member and the image bearing member in the rotation direction of the image bearing member. An external additive is an inorganic salt having a charging polarity on the positive side with respect to the developer, and work functions ?(S), ?(A), ?(T) of the sheet member, the external additive and the developer satisfy 0?|?(A)??(S)|<0.57; and ?(A)<?(T).

Abstract: A cleaning device has: a cleaning frame; a cleaning member which, after transfer through contact with an image bearing member, removes a developer remaining on the image bearing member; and a sheet member having flexibility and coming into contact with the image bearing member at an upstream side of a contact position between the cleaning member and the image bearing member in the rotation direction of the image bearing member. The external additive is an inorganic salt having a charging polarity on the positive side with respect to the developer, and work functions ?(S), ?(A), ?(T) of the recovery member, the external additive and the developer satisfy 0?|?(A)??(S)|<0.57; and ?(A)<?(T).

Abstract: A cleaning device, including: a cleaning frame; a cleaning member having one end and the other end, the image bearing member being capable of rotating and bearing a developer image formed of a developer so as to remove the developer remaining on the image bearing member after transfer of the developer image from the image bearing member; and a sheet member having flexibility and having one end and the other end; wherein a work function W (D) of the developer and a work function W (S) of the sheet member satisfy 0?W(D)?W(S)?0.23 and the developer includes inorganic particles, and at least one kind of the inorganic particles has an average primary particle diameter of 50 nm or larger.

Abstract: A nip portion is formed between a transfer member and an image bearing member. During an image transfer operation, a first transfer voltage is applied so that a first charging voltage is applied to the surface of the image bearing member forming the nip portion. Before paper enters, a second transfer voltage is applied so that a third charging voltage is applied to the surface of the image bearing member forming the nip portion. A void is formed by the image bearing member, the transfer member and the paper within the nip portion. Before an image transfer operation and the void is formed, one of the first and second transfer voltages and a third transfer voltage is applied so that a second charging voltage having a same polarity as the first charging voltage and being lower in absolute value is applied to the surface of the image bearing member.

Abstract: A nip for holding paper is formed between a transfer member and an image bearing member. During an image transfer operation, a first transfer voltage is applied thereto so that a first charging voltage is applied to the surface of the image bearing member forming the nip portion. Before paper enters thereto, a second transfer voltage is applied thereto so that a third charging voltage is applied to the surface of the image bearing member forming the nip portion. A void is formed by the image bearing member, the transfer member and the paper within the nip. Before an image transfer operation and the void is formed, one of the first, second and third transfer voltages is applied so that the second charging voltage having a same polarity as the first charging voltage and being lower in absolute value is applied to the surface of the image bearing member.

Abstract: Provided is a toner, including a toner particle having a core particle containing a binder resin and a colorant. The toner particle has a protrusion on a surface thereof, and the protrusion contains an olefin-based polymer having a cyclic olefin structure. When an average radius of curvature of the protrusion, an average particle diameter of the core particle, a projected area of the toner particle, and a projected area of the protrusion that are calculated from a planar projected image of an image of the toner particle photographed with a scanning electron microscope are represented by Rs (?m), Rc (?m), S, and S1, respectively, the average radius of curvature Rs of the protrusion is 0.004Rc ?m or more and 0.100Rc ?m or less, and an average of a surface coverage “100×S1/S” % is 5% or more and 90% or less.

Abstract: A developing device includes: a developing container for accommodating developer, a developer carrying member, and a plate-like elastic member. In a state in which the elastic member contacts the developer carrying member without being deformed, an angle formed between a flat reference surface passing through a surface of the elastic member which is continuous to a contact portion of the elastic member with the developer carrying member and which is downstream of the contact portion with respect to the movement direction and a tangent plane of the developer carrying member and a contact position between the elastic member and the developer carrying member is 10° or more and 45° or less, and the elastic member includes a first region including the contact portion and a second region which is provided continuously from the first region toward the supporting portion and which is lower in rigidity than the first region.