Abstract: Provided is a developing member capable of sufficiently securing a toner conveyance amount, thereby being capable of suppressing a reduction in image density, even when a solid black image or an image having a high print percentage is continuously output. The developing member includes an electro-conductive substrate and an electro-conductive layer thereon, an outer surface of the developing member includes a first, second and third regions, when surface potentials of the respective regions with scanning probe microscope, and measured surface potential of the respective regions are defined as V1, V2, and V3, respectively, V1 is ?0.70 V to ?0.50 V, 1.30?V1/V2?25.00, and V3 is 0.00 V to 0.50 V.

Abstract: An electrophotographic member has an electro-conductive substrate, an elastic layer on the substrate and a coating layer on the elastic layer. The elastic layer has an elastic modulus of 0.5 MPa to 3.0 MPa and the coating layer has an elastic modulus of 5.0 MPa to 100.0 MPa as measured in an environment of a temperature of 30° C. and a relative humidity of 80%.

Abstract: Provided is a developing member capable of sufficiently securing a toner conveyance amount, thereby being capable of suppressing a reduction in image density, even when a solid black image or an image having a high print percentage is continuously output. The developing member includes an electro-conductive substrate and an electro-conductive layer thereon, an outer surface of the developing member includes a first, second and third regions, when surface potentials of the respective regions with scanning probe microscope, and measured surface potential of the respective regions are defined as V1, V2, and V3, respectively, V1 is ?0.70 V to ?0.50 V, 1.30?V1/V2?25.00, and V3 is 0.00 V to 0.50 V.

Abstract: The developing member includes a substrate, and an electroconductive layer on the substrate, wherein the electroconductive layer has electrically insulating domains on an outer surface thereof, the domains being independent from each other, the developing member has an outer surface including a surface of the electroconductive layer and surfaces of the domains, and wherein, when each of the domains is orthographically projected onto the surface of the electroconductive layer, defining respective areas of projected images of the domains as S, and defining respective areas of convex envelopes of the projected images as H, at least one domain satisfies the relation represented by 0.05?S/H?0.80.

Abstract: A developing apparatus, includes: a developer bearing member configured to bear a developer; and a regulating member that is disposed in contact with a surface of the developer bearing member, and configured to regulate the developer borne on the developer bearing member. On the surface of the developer bearing member, a conductive portion having a first surface roughness and first electric resistance, and a dielectric portion having a second surface roughness, which is smaller than the first surface roughness, and second electric resistance, which is larger than the first electric resistance, are disposed. In a case where the developer borne on the developer bearing member is charged by friction with the regulating member, a charging polarity of the dielectric portion is the same polarity as a charging polarity of the developer.

Abstract: Provided is a developing roller comprising an electroconductive substrate and an electroconductive layer thereon, the electroconductive layer retaining resin particles so that at least a part of each of the resin particles is exposed on an outer surface of the developing roller; the outer surface of the developing roller constituted by electrically insulating domains and an electroconductive matrix, assuming that a square region 200-?m in a side is put on the outer surface of the developing roller, the square region including the domains, among the domains in the square region at least two of them satisfying specific condition, and assuming that the outer surface of the developing roller is charged, and creating a potential map of the charged outer surface of the developing member, the two domains satisfying the specific condition being ascertained in the potential map.

Abstract: Provided is an electrophotographic developing member capable of sufficiently increasing a density of an image initially output from a standby state. The developing member includes: a substrate; a porous electroconductive elastic layer on the substrate; and an electroconductive solid layer on the electroconductive elastic layer, in which an outer surface of the developing member includes a first region having an electrical insulating surface and a second region having an electroconductive surface, the first region and the second region are arranged to be adjacent to each other, and the first region is constituted by an electrical insulating portion disposed on an outer surface of the electroconductive solid layer.

Abstract: Provided is a developing roller comprising an electroconductive substrate and an electroconductive layer thereon, the electroconductive layer retaining resin particles so that at least a part of each of the resin particles is exposed on an outer surface of the developing roller; the outer surface of the developing roller constituted by electrically insulating domains and an electroconductive matrix, assuming that a square region 200-?m in a side is put on the outer surface of the developing roller, the square region including the domains, among the domains in the square region at least two of them satisfying specific condition, and assuming that the outer surface of the developing roller is charged, and creating a potential map of the charged outer surface of the developing member, the two domains satisfying the specific condition being ascertained in the potential map.

Abstract: A developing roller is capable of preventing the generation of a difference in image density between a central portion and an end portion of an electrographic image. The developing roller has an electro-conductive mandrel and an electro-conductive layer on the mandrel, the electro-conductive layer has a crown shape in which an outer diameter of a central portion in a direction along the mandrel is larger than outer diameters of both end portions in the direction along the mandrel, an outer surface of the developing roller includes a first region having an electrically insulating property and a second region having a higher conductive property than the first region, and the first region and the second region are disposed adjacent to each other.

Abstract: To provide a developing roller having improved toner conveying force in a high-temperature and high-humidity environment. The developing roller has a substrate and an electro-conductive layer on the substrate. The outer surface of the developing roller has an electrical insulating first region and an electro-conductive second region adjacent to the first region and at the same time has at least one groove in the first region.

Abstract: The electrophotographic member comprises: an electroconductive substrate; and an electroconductive layer on or above the substrate, an outer surface of the electrophotographic member having electrically insulating first regions and an electroconductive second region, each of the first regions being adjacent to the second region, wherein assuming that a square region having a side length of 300 ?m is put on an outer surface of the electrophotographic member, in the square regions, the first regions are included, and assuming that Voronoi tessellation is conducted with respect to the first regions in the square region to create Voronoi polygons, a coefficient of variation of S1/SV is from 0.10 to 1.00, where SV denotes a plane area of each of the Voronoi polygons, and S1 denotes a plane area of one of the first regions included in each of the Voronoi polygons.

Abstract: Provided is an electrophotographic member in which density unevenness of an image is less likely to occur even in the case of outputting an image after standing in a high-temperature and high-humidity environment for a long period of time. The electrophotographic member includes: an electroconductive substrate; an electroconductive elastic layer on or above the substrate; and an insulating portion on the elastic layer, an outer surface of the electrophotographic member being composed of an outer surface of the insulating portion and an outer surface of the elastic layer that is not covered with the insulating portion, wherein the elastic layer contains a urethane resin as a first resin, and the elastic layer has a region from the outer surface of the elastic layer constituting the outer surface of the electrophotographic member to a depth of 1 ?m, the region further containing a second resin.

Abstract: The electrophotographic member comprises: an electroconductive substrate; and an electroconductive layer on or above the substrate, an outer surface of the electrophotographic member having electrically insulating first regions and an electroconductive second region, each of the first regions being adjacent to the second region, wherein assuming that a square region having a side length of 300 ?m is put on an outer surface of the electrophotographic member, in the square regions, the first regions are included, and assuming that Voronoi tessellation is conducted with respect to the first regions in the square region to create Voronoi polygons, a coefficient of variation of S1/SV is from 0.10 to 1.00, where SV denotes a plane area of each of the Voronoi polygons, and S1 denotes a plane area of one of the first regions included in each of the Voronoi polygons.

Abstract: Provided an electrophotographic member capable of causing less fog in an H/H environment even when used in a torque-reduced image forming apparatus. The member comprises an electro-conductive substrate, an electro-conductive layer thereon and insulating parts, the member having a surface having an electrical insulating first region and an electro-conductive second region, the first region and the second region being adjacent to each other, a total area of the second region in a square region put on an outer surface of the member is 30% to 80% of an area of the square region; two or more of the 200 straight lines drawn in the square region at an interval of 5 ?m pass the second region at least once, and, the number of line segment LS having a length of 200 ?m or more is 5% or less of the total number of the line segment LS.

Abstract: To provide an electrophotographic member causing less change in toner conveyance even used in a high-temperature and high-humidity environment. The electrophotographic member has an electro-conductive substrate, an elastic layer on the substrate and a coating layer on the elastic layer. The elastic layer has a first protrusion on a surface thereof on a side opposite to a side facing the substrate. The electrophotographic member has, on an outer surface thereof, a second protrusion derived from the first protrusion. The outer surface of the electrophotographic member has one or more of electrical insulating first region(s) and an electro-conductive second region. The elastic layer has an elastic modulus of 0.5 MPa or more to 3.0 MPa or less and the coating layer has an elastic modulus of 5.0 MPa or more to 100.0 MPa or less as measured in an environment of a temperature of 30° C. and a relative humidity of 80%.

Abstract: The developing roller includes an electro-conductive substrate and a covering layer on the electro-conductive substrate, the covering layer including a matrix and an electro-conductive particle dispersed in the matrix, an arithmetic mean value of the current value is 300 pA or less and the standard deviation of the current value is 0.1-fold or less of the current value, a standard deviation of a potential is 3.0 V or more, and an arithmetic mean value of a volume resistivity is 1010 ?·cm or less, and a standard deviation of the volume resistivity is 1-fold or more of the arithmetic mean value of the volume resistivity.

Abstract: The developing member includes a substrate, and an electroconductive layer on the substrate, wherein the electroconductive layer has electrically insulating domains on an outer surface thereof, the domains being independent from each other, the developing member has an outer surface including a surface of the electroconductive layer and surfaces of the domains, and wherein, when each of the domains is orthographically projected onto the surface of the electroconductive layer, defining respective areas of projected images of the domains as S, and defining respective areas of convex envelopes of the projected images as H, at least one domain satisfies the relation represented by 0.05?S/H?0.80.

Abstract: Provided is an electrophotographic member which can suppress adhesion of the toner component and fogging even in the case of printing a large number of sheets. The electrophotographic member includes an electroconductive support and an elastic layer and has convex portions composed of the elastic layer on a surface of the electrophotographic member and a filled portion containing a resin at a valley portion between the convex portions, the filled portion has a height lower than heights of the convex portions, and the surface of the electrophotographic member has a specific Martens hardness.

Abstract: Provided is an electrophotographic member which can suppress adhesion of the toner component and fogging even in the case of printing a large number of sheets. The electrophotographic member includes an electroconductive support and an elastic layer and has convex portions composed of the elastic layer on a surface of the electrophotographic member and a filled portion containing a resin at a valley portion between the convex portions, the filled portion has a height lower than heights of the convex portions, and the surface of the electrophotographic member has a specific Martens hardness.

Abstract: A developing apparatus includes a developer carrying member, a developing frame member to rotatably supporting the developer carrying member, and a regulating member provided on the developing frame member and regulating developer carried on the developer carrying member. The regulating member includes a projecting part projected towards the developer carrying member and having an abutting part that abuts the developer carrying member, and an opposing surface facing the developer carrying member. The opposing surface is positioned on an upstream side of the projecting part and arranged to connect the projecting part with a distal end of the regulating member at a free end side of the regulating member. In addition, the opposing surface is a surface having no point of reverse curve, and the distance between the opposing surface and the developer carrying member is constant or decreasing with distance from the projecting part.