Abstract: Provided is a developing apparatus including a developer carrying member, a developer container, and a regulating member to regulate the thickness of the developer. The regulating member includes a support member such that one end is fixed to the developer container, the other end is a free end, and the support member extends in a direction opposite to the rotating direction of the developer carrying member, and a contact member to be fixed to the other end of the support member and to contact the developer carrying member. The contact member includes a contact curved surface along a peripheral surface of the developer carrying member, and an opposite surface to face the developer carrying member. The contact pressure of the contact curved surface applied to the developer carrying member decreases as a location on the developer carrying member approaches downstream side in the rotating direction.

Abstract: A relation between a first thickness of a resin layer in an upstream portion of a contact nip in which the resin layer that covers a supporting member of a regulating blade makes contact with a developing roller and a second thickness of the resin layer in a downstream portion of the contact nip is set such that the second thickness is smaller than the first thickness. A potential difference having the same polarity as a toner charging polarity toward the supporting member is created between the supporting member and the developing roller.

Abstract: A regulating portion includes a first contact portion, a second contact portion, opposed surface portion, and a second opposed surface portion. When, in a plane orthogonal to the rotation axis direction of a developer bearing member, the fixed end and the free end of a supporting member are connected by an imaginary straight line, a contact position where the first contact portion contacts the developer bearing member is located on the downstream side, in the rotation direction of the developer bearing member, of a point of contact of a tangent line parallel to the imaginary straight line with the outer periphery of the developer 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: The present invention relates to an image forming apparatus that forms an image by consecutively superposing toner images that have been formed on a plurality of photosensitive drums, on an intermediate transfer member or a transfer medium. The image forming apparatus is made compact and operates at a low cost. Since a current supply member supplies a current in a rotational direction of an intermediate transfer belt, multiple first transfer portions do not need corresponding voltage sources. Even in the case where a charging member supplies a current, the potential of the intermediate transfer belt is maintained at a predetermined potential by a constant-voltage element connected to support rollers.

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.

Abstract: Provided is a developer carrying member which depends on a sheet-passing speed to a small extent while maintaining satisfactory developability, and can stably suppress a fogging amount with time. The developer carrying member includes: an electro-conductive mandrel; and an electro-conductive elastic layer, in which: the elastic layer contains a resin j, an electro-semiconductive particle p, and an electro-conductive particle c; and when an electroconductivity of the resin j is defined as ?j, a dielectric constant of the resin j is defined as ?j, an electroconductivity of the electro-semiconductive particle p is defined as ?p and a dielectric constant of the electro-semiconductive particle p is defined as ?p, ?j, ?j, ?p, and ?p satisfy relationships represented by the following formulae (1) and (2), ?j, ?j, ?p and ?p being calculated by an AC impedance method. ?j<?p<0.

Abstract: A developing device includes: a developing container, a developer carrying member, and a plate-like elastic member. An angle formed between a reference surface passing through a surface of the elastic member continuous to a contact portion of the elastic member with the developer carrying member and downstream of the contact portion with respect to the movement direction of the developer carrying member and a tangent plane of the developer carrying member under no load at a contact position between the elastic member and the developer carrying member is 10° or more and 45° or less. The elastic member includes a first region including the contact portion and a second region provided continuously from the first region toward the supporting portion of the elastic member and lower in rigidity than the first region. The second region is provided downstream of the reference surface with respect to the movement direction.

Abstract: In an image forming apparatus having a photosensitive drum that carries a toner image, a developing roller is provided to be capable of rotating while carrying toner and supplies the toner to the photosensitive drum in order to develop a latent image, and a voltage applying device applies a voltage to the developing roller. The developing roller includes a conductive base layer and a surface layer covering the base layer, and a surface charge density of the developing roller is equal to or smaller than a surface charge density of the toner.

Abstract: The present invention relates to an image forming apparatus that forms an image by consecutively superposing toner images that have been formed on a plurality of photosensitive drums, on an intermediate transfer member or a transfer medium. The image forming apparatus is made compact and operates at a low cost. Since a current supply member supplies a current in a rotational direction of an intermediate transfer belt, multiple first transfer portions do not need corresponding voltage sources. Even in the case where a charging member supplies a current, the potential of the intermediate transfer belt is maintained at a predetermined potential by a constant-voltage element connected to support rollers.

Abstract: A developing roller that is capable of carrying toner on a surface thereof, and that supplies the toner carried on the surface to a surface of a photosensitive drum when a voltage is applied thereto, includes: a rubber layer; and a surface layer that covers the rubber layer, contains alumina, and has a higher volume resistivity than the rubber layer.

Abstract: A developing roller that is capable of carrying toner on a surface thereof, and that supplies the toner carried on the surface to a surface of a photosensitive drum when a voltage is applied thereto, includes: an elastic layer; and a surface layer that covers the elastic layer and contains aluminum oxide, wherein the aluminum oxide of the surface layer contains tetracoordinated aluminum atoms and hexacoordinated aluminum atoms existing in a higher proportion than the tetracoordinated aluminum atoms.

Abstract: Provided is a developer carrying member which depends on a sheet-passing speed to a small extent while maintaining satisfactory developability, and can stably suppress a fogging amount with time. The developer carrying member includes: an electro-conductive mandrel; and an electro-conductive elastic layer, in which: the elastic layer contains a resin j, an electro-semiconductive particle p, and an electro-conductive particle c; and when an electroconductivity of the resin j is defined as ?j, a dielectric constant of the resin j is defined as ?j, an electroconductivity of the electro-semiconductive particle p is defined as ?p and a dielectric constant of the electro-semiconductive particle p is defined as ?p, ?j, ?j, ?p, and ?p satisfy relationships represented by the following formulae (1) and (2), ?j, ?j, ?p and ?p being calculated by an AC impedance method. ?j<?p<0.

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: The present invention relates to an image forming apparatus that forms an image by consecutively superposing toner images that have been formed on a plurality of photosensitive drums, on an intermediate transfer member or a transfer medium. The image forming apparatus is made compact and operates at a low cost. Since a current supply member supplies a current in a rotational direction of an intermediate transfer belt, multiple first transfer portions do not need corresponding voltage sources. Even in the case where a charging member supplies a current, the potential of the intermediate transfer belt is maintained at a predetermined potential by a constant-voltage element connected to support rollers.

Abstract: In an image forming apparatus having a photosensitive drum capable of carrying a toner image, a developing roller that is provided to be capable of rotating while carrying toner, and that supplies the toner to the photosensitive drum by contacting the photosensitive drum, a regulating blade that regulates a layer thickness of the toner carried on the developing roller, and a voltage applying device for applying a voltage to the developing roller and the regulating blade. The developing roller includes a conductive base layer and a surface layer covering the base layer, and a surface charge density of the developing roller is equal to or smaller than a surface charge density of the toner.

Abstract: A developing roller that is capable of carrying toner on a surface thereof, and that supplies the toner carried on the surface to a surface of a photosensitive drum when a voltage is applied thereto, includes: an elastic layer; and a surface layer that covers the elastic layer and contains aluminum oxide, wherein the aluminum oxide of the surface layer contains tetracoordinated aluminum atoms and hexacoordinated aluminum atoms existing in a higher proportion than the tetracoordinated aluminum atoms.

Abstract: In an image forming apparatus having a photosensitive drum that carries a toner image, a developing roller that is provided to be capable of rotating while carrying toner, and that supplies the toner to the photosensitive drum in order to develop a latent image, and voltage applying device for applying a voltage to the developing roller, the developing roller includes a conductive base layer and a surface layer covering the base layer, and a surface charge density of the developing roller is equal to or smaller than a surface charge density of the toner.

Abstract: A developing roller that is capable of carrying toner on a surface thereof, and that supplies the toner carried on the surface to a surface of a photosensitive drum when a voltage is applied thereto, includes: a rubber layer; and a surface layer that covers the rubber layer, contains alumina, and has a higher volume resistivity than the rubber layer.

Abstract: In an image forming apparatus having a photosensitive drum capable of carrying a toner image, a developing roller that is provided to be capable of rotating while carrying toner, and that supplies the toner to the photosensitive drum by contacting the photosensitive drum, a regulating blade that regulates a layer thickness of the toner carried on the developing roller, and voltage applying device for applying a voltage to the developing roller and the regulating blade, the developing roller includes a conductive base layer and a surface layer covering the base layer, and a surface charge density of the developing roller is equal to or smaller than a surface charge density of the toner.