Abstract: A charging device according to one or more embodiments may include: a charging member that is rotatable and provided to be in contact with a contact member. The charging member includes: a shaft; a surface layer to be in contact with the contact member and containing porous particles; and an elastic layer provided between the shaft and the surface layer. A ratio of convex portions formed by the porous particles on the surface layer to a surface area of the surface layer is 68.4% or more.

Abstract: A charging device includes a charging member that is rotatable and contacts and electrically charges a surface of a charging target member; and a cleaning member that is rotatable and cleans a surface of the charging member, wherein the cleaning member includes a core bar extending in a lengthwise direction, a foam member that is helically wound around the core bar while forming a gap in the lengthwise direction and contacts the charging member, and a first adhesive agent that is provided between the foam member and the core bar, the first adhesive agent contacting a part of the foam member and another part of the foam member that are formed to adjoin each other in the lengthwise direction via the gap.

Abstract: A charging device includes a charging member that is rotatable and contacts and electrically charges a surface of a charging target member; and a cleaning member that is rotatable and cleans a surface of the charging member, wherein the cleaning member includes a core bar extending in a lengthwise direction, a foam member that is helically wound around the core bar while forming a gap in the lengthwise direction and contacts the charging member, and a first adhesive agent that is provided between the foam member and the core bar, the first adhesive agent contacting a part of the foam member and another part of the foam member that are formed to adjoin each other in the lengthwise direction via the gap.

Abstract: An image carrier unit includes an image carrier that makes a rotation and has a photosensitive layer on an outer surface, the photosensitive layer containing a binding resin and at least one type of charge transporting material and covering the surface, and a cleaning blade that has a contact part contacting the surface of the image carrier and removes residue on the surface of the image carrier accompanying the rotation of the image carrier. A photosensitive ratio of a first product to a second product is 183.0 or higher and 233.9 or lower, the first product is obtained from a weight-average molecular weight (A) of the binder resin multiplied by an added ratio (B) of the binder resin in the photosensitive layer, and the second product is obtained from a weight-average molecular weight (C) of the charge transporting material multiplied by an added ratio (D) of the charge transporting material.

Abstract: An image forming apparatus includes a toner image supporting section and a medium transfer section. The toner image supporting section includes first and second toner image supporting member that support first and second toner images at first and second linear speeds, respectively. The medium transfer section transfers, onto a medium, the first and second toner images respectively supported by the first and second toner image supporting members, to thereby cause the first and second toner images to be superimposed on each other. The following conditional expression (1) is satisfied when the medium transfer section transfers the first and second toner images onto the medium, (Vd1?Vt1)/(Vt1>(Vd2?Vt2)/Vt2??(1) where Vd1 is the first linear speed, Vt1 is a first conveyance speed of the medium, Vd2 is the second linear speed, and Vt2 is a second conveyance speed of the medium.

Abstract: An image forming apparatus includes a toner image supporting section and a medium transfer section. The toner image supporting section includes first and second toner image supporting member that support first and second toner images at first and second linear speeds, respectively. The medium transfer section transfers, onto a medium, the first and second toner images respectively supported by the first and second toner image supporting members, to thereby cause the first and second toner images to be superimposed on each other. The following conditional expression (1) is satisfied when the medium transfer section transfers the first and second toner images onto the medium, (Vd1?Vt1)/(Vt1>(Vd2?Vt2)/Vt2 ??(1) where Vd1 is the first linear speed, Vt1 is a first conveyance speed of the medium, Vd2 is the second linear speed, and Vt2 is a second conveyance speed of the medium.

Abstract: An image forming apparatus includes an image forming section, a transferred member, a transfer roller, and a separator. The image forming section forms a developer image. The transferred member is conveyed in a first direction and the developer image is to be transferred on the transferred member. The transfer roller faces the transferred member, and makes a transition between a biasing state in which the transferred member is biased by the transfer roller and a separated state in which the transfer roller is separated away from the transferred member. The separator starts to separate a medium away from the transferred member after the transfer roller starts making a transition from the biasing state to the separated state, the medium being held between the transferred member and the transfer roller in the biasing state.

Abstract: An image forming apparatus includes an image forming section, a transferred member, a transferring member, and a separator. The image forming section forms a developer image by developing a developer. The transferred member is conveyed in a first direction and the developer image is to be transferred on the transferred member. The transferring member faces the transferred member, and makes a transition between a biasing state in which the transferred member is biased by the transferring member and a separated state in which the transferring member is separated away from the transferred member. The separator separates, in the separated state, a medium away from the transferred member, in which the medium is held between the transferred member and the transferring member in the biasing state.

Abstract: Provided is an image forming unit that includes: an image supporting member including a photosensitive layer configured to support a latent image; a developer supporting member configured to support a developer, and perform a development process on the latent image with use of the developer; and a developer feeding member including a surface that comes into contact with the developer supporting member, and configured to feed the developer to the developer supporting member. The developer feeding member includes an elastic layer. The elastic layer has a plurality of cells each including an opening that is exposed on the surface, and an area occupancy rate of the openings in area of the surface is in a range from 40% to 85%.

Abstract: Provided is an image forming unit that includes: an image supporting member including a photosensitive layer configured to support a latent image; a developer supporting member configured to support a developer, and perform a development process on the latent image with use of the developer; and a developer feeding member including a surface that comes into contact with the developer supporting member, and configured to feed the developer to the developer supporting member. The developer feeding member includes an elastic layer. The elastic layer has a plurality of cells each including an opening that is exposed on the surface, and an area occupancy rate of the openings in area of the surface is in a range from 40% to 85%.

Abstract: An image forming apparatus suppressing jitter from occurring includes an image carrier, and a developer carrier supplying a developer to the image carrier, wherein the developer carrier includes an elastic layer having a thickness of 2.5 mm or less and having an MD-1 hardness of 40 degrees or more.

Abstract: A developing device includes a developer bearing body that rotates in a first direction, and a supply brush roller, out of contact with the body, that also rotates in the first direction. A brush contact member has a first contact portion in contact with bristles of the roller above a first horizontal plane passing through a rotational axis of the roller and upstream in the first rotational direction of the roller of a portion of the roller opposing the body. A thickness adjusting member has a second contact portion in contact with the body below a second horizontal plane passing through a rotational axis of the body and downstream in the first rotational direction of the body of the portion of the roller opposing the body. A first vertical plane passing through the first contact portion is closer to the axis of the roller than is a second vertical plane passing through the second contact portion.

Abstract: A developing device includes a developer supporting member abutting against an image supporting member for developing a static latent image on the image supporting member. In a state that a film member is disposed between the image supporting member and the developer supporting member, it is arranged such that the film member is extended with a tensional force N (N) when the image supporting member and the developer supporting member rotate. The tensional force N has a relationship as follows: (A×B×exp(0.32×F?16))/N?11.6 where A (mm) is a difference between an outer diameter of a center portion of the developer supporting member and an outer diameter of an end portion of the developer supporting member; B (mm) is a wobble amount of the end portion of the developer supporting member; and F (degree) is an Asker C hardness of the developer supporting member.

Abstract: A developer bearing body rotates in a first direction. A supply brush roller, out of contact with the body, also rotates in the first direction. A brush contact member has a first contact portion in contact with bristles of the roller above a first horizontal plane passing through a rotational axis of the roller and upstream in the first rotational direction of the roller, of a portion of the roller opposing the body. A thickness adjusting member has a second contact portion in contact with the body below a second horizontal plane passing through a rotational axis of the body and downstream in the first rotational direction of the body, of the portion of the roller opposing the body. A first vertical plane passing through the first contact portion is closer to the axis of the roller than is a second vertical plane passing through the second contact portion.

Abstract: A developing device includes a developer supporting member having an elastic layer and a surface layer, and a supply member for supplying developer to the developer supporting member. The surface layer is formed of a mixture containing at least an acrylic resin and a polyether type urethane resin. The developer supporting member and the supply member are configured so that the following equations are satisfied: 20?A1?80 0.6?D?2.0 45+0.1×A1×D?F×N?65 where A1 is a weight ratio (%) of the acrylic resin relative to a total weight of the acrylic resin and the polyether type urethane resin, F is an Asker F hardness (degree) of a surface of the supply member, and N is an overlap amount (mm) representing a biting amount of the supply member relative to the developer supporting member.

Abstract: A developer material carrying body rotates in contact with an image carrying body on which an electrostatic latent image is formed. The developer material carrying body deposits a developer material to the electrostatic latent image. The developer material carrying body includes a surface having a surface potential (Vo) 0.15 seconds after having been charged, and a relaxation time (?) required for the surface potential changes to change from Vo to Vo/e. The surface potential and relaxation time are related such that 2.0?Vo?10 and 0<?<0.20.

Abstract: A developing device includes a developer supporting member having an elastic layer and a surface layer, and a supply member for supplying developer to the developer supporting member. The surface layer is formed of a mixture containing at least an acrylic resin and a polyether type urethane resin. The developer supporting member and the supply member are configured so that the following equations are satisfied: 20?A1?80 0.6?D?2.0 45+0.1×A1×D?F×N?65 where A1 is a weight ratio (%) of the acrylic resin relative to a total weight of the acrylic resin and the polyether type urethane resin, F is an Asker F hardness (degree) of a surface of the supply member, and N is an overlap amount (mm) representing a biting amount of the supply member relative to the developer supporting member.

Abstract: A developing device includes a developer supporting member abutting against an image supporting member for developing a static latent image on the image supporting member. In a state that a film member is disposed between the image supporting member and the developer supporting member, it is arranged such that the film member is extended with a tensional force N (N) when the image supporting member and the developer supporting member rotate. The tensional force N has a relationship as follows: (A×B×exp(0.32×F?16))/N?11.6 where A (mm) is a difference between an outer diameter of a center portion of the developer supporting member and an outer diameter of an end portion of the developer supporting member; B (mm) is a wobble amount of the end portion of the developer supporting member; and F (degree) is an Asker C hardness of the developer supporting member.

Abstract: In order to obtain the surface shape which is uniform in each of the circumferential direction and the axial direction without being deviated in one direction on the surface, a developer holding body is provided which is arranged so as to face an image holding body, holds a developer as a layer onto a roughened surface, and supplies the developer in order to develop an image which is formed on the image holding body, and wherein the roughening is executed on the basis of a ratio of cutting depths in a plurality of directions.

Abstract: In an electrophotographic image forming apparatus, a contact-type developing roller contacts a photosensitive drum, a developing blade, a supply roller or the like. If the surface of the developing roller is excessively hard, there is a possibility that a pressure applied between the developing roller and the photosensitive drum or the like may increase, and may cause a filming, i.e., a phenomena in which a toner is degraded and welded to the surface of the developing roller. The filming can be prevented when a JIS-A hardness HA (degree) of a resilient layer of the developing roller and a dynamic hardness HS (mN/?m2) of a surface layer of the developing roller satisfy the following relationship: HA×HS<15.