Abstract: A developing device includes a developing container, a first stirring conveyance member, a second stirring conveyance member, a developer carrying member including a developing sleeve and a magnet, and a regulation member. The regulation pole in the magnet has a region extending over 10° or more in which a maximum value of a vertical magnetic force is not more than 65 [mT] and a vertical magnetic force gradient is not more than 0.3 [mT/°]. A peak position of the vertical magnetic force gradient of the regulation pole is arranged at a position opposed to the second stirring conveyance member, and when a value of the vertical magnetic force gradient and a value of the vertical magnetic force at the peak position of the vertical magnetic force gradient are indicated as A [mT/°] and K [mT], respectively, A?2.8 and A×K?62.5 are satisfied.

Abstract: A developing device includes a developing container, a developing roller, a supplying roller, a first magnet including a first magnetic pole, a second magnet including a second magnetic pole and a third magnetic pole, and a regulating member provided opposed to the third magnetic pole. During non-image formation, an operation in a mode in which the supplying roller is rotated in a direction opposite to a rotational direction of the supplying roller during image formation is executable. With respect to the rotational direction of the supplying roller during the image formation, a position where a magnet flux density of the third magnetic pole in a tangential direction to an outer peripheral surface of the supplying roller is zero is positioned downstream of an upstream end of the regulating member and upstream of the second magnetic pole.

Abstract: According to one embodiment, there is provided a developer layer regulating member including: a magnetic material extending in an axis direction of a developing roller; a non-magnetic material facing the magnetic material; and first and second spot weld rows that bond the magnetic material to the non-magnetic material. The magnetic material includes a first end located near the developing roller and a second end located on an opposite side of the first end. The first spot weld row extends in the axis direction of the developing roller between the first and second ends of the magnetic material. The second spot weld row extends in the axis direction of the developing roller between the first spot weld row and the second end of the magnetic material.

Abstract: A developing device includes a developing member to carry developer stored by a developing frame, and a regulating blade having a support plate fixed to the developing frame, a plate-like member, and a regulating member. One end portion of the plate-like member is opposed to the developing member, and the other end portion is welded to the support plate. The regulating member is fixed to a plate-like member surface, and contacts the developing member to regulate a developer thickness on a developing surface. The regulating member is provided with a recessed portion recessed at a regulating member end portion. The regulating member end portion is lower than a regulating member central portion. A plate-like member region welded to the support plate is located at the plate-like member other end portion and overlaps the regulating member central portion and the regulating member end portion at which the recessed portion is provided.

Abstract: When the area of a developing frame member corresponding to the maximum image area of an image bearing member is, in a section perpendicular to a rotational axis of a developing rotary member, divided by a straight line passing through the center of rotation of the developing rotary member and the center of rotation of the image bearing member and a perpendicular line passing through the center of rotation of a first conveying screw with respect to the straight line, a gate portion is provided at a bottom portion of the developing frame member in a divided area of the developing frame member not provided with the attachment portion, and a gate portion is not provided at the bottom portion of the developing frame member in a divided area of the developing frame member provided with the attachment portion.

Abstract: An image forming apparatus includes a developing device. The developing device transports a two-component developer by a transporting unit so that the two-component developer passes through a developing roller. The two-component developer is stored in a storage chamber provided with a transporting path. The transporting unit rotates in the transporting path. The developing device causes a portion of the two-component developer to overflow from a discharge port provided at the transporting path, and to discharge the two-component developer. The image forming apparatus has a period in which a first operation is executed, the first operation of reversely rotating the transporting unit at a high speed so that a rotational direction of the transporting unit is an opposite direction to that at a time of development and a rotational speed of the transporting unit is higher than that at the time of development.

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 device includes: a developer carrying member (sleeve); a regulating portion including an edge portion at a closest position to a surface of the sleeve or a flat portion tilted, at the closest position, by an angle of 2 degrees or less relative to a contact flat plane contacting the surface of the sleeve; and a rectifying portion connected with the edge or flat portion. The rectifying portion has a concavely curved surface such that a rate of a decrease in gap between the rectifying portion and the contact flat plane increases toward a downstream side of the developer feeding direction and is formed by smoothly connecting rectilinear or curved lines each of 0.2 mm or less except for the edge portion so that the gap between the rectifying portion and the contact flat plane is monotonically decreases toward the downstream side of the developer feeding direction.

Abstract: A developing device includes an accommodating section that accommodates a developer; a developing section; a transporting section that is disposed below the developing section in a gravitational direction; a flow channel portion that extends from an inner side to an outer side of the accommodating section; a first wall portion that extends towards the transporting section at an end portion on an inner side of the flow channel portion; and a second wall portion that extends towards the transporting section at the end portion on the inner side of the flow channel portion, a distance from the second wall portion to an outer peripheral edge of the transporting section being greater than or equal to a distance from the first wall portion to the outer peripheral edge of the transporting section.

Abstract: A developing apparatus includes 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 having one end fixed to the developer container and the other end free, with the support member extending 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 a downstream side in the rotating direction.

Abstract: An image forming apparatus includes: an image bearing member to which a toner is supplied; a cleaning blade that removes the toner supplied onto the image bearing member; a hardware processor that performs control such that a tonner pattern for cleaning blade inspection is formed on the image bearing member; and a detector for detecting a toner that has slipped through the cleaning blade after the toner pattern has been allowed to reach the cleaning blade. The hardware processor performs control such that a contact portion of the cleaning blade with the image bearing member becomes a state in which slipping of a toner readily occurs, and identifies a defective site in the contact portion on the basis of a detected result by the detector.

Abstract: A developing device has a developing roller, a toner feeding roller, a regulating blade, a casing, a film member, a biasing member, and first and second gears. The casing has an inner wall part facing the developing roller between the regulating blade and an image carrying member. The film member is flexible, and can vibrate in a direction approaching or away from the inner wall part. The biasing member applies a tension to the film member in its longitudinal direction. The first and second gears are coupled to a gear train driving the developing roller or the toner feeding roller, and have formed on their circumferential surfaces first and second protrusions vibrating the film member by intermittently making contact with one edge and the other edge of the film member respectively.

Abstract: The present teachings described a bias charging member and a method of manufacture. The bias charging member includes a conductive core and an outer surface layer disposed on the conductive core. The outer surface layer includes a water soluble polyamide resin, and a water soluble aminoplast resin.

Abstract: A developing device includes a developer bearer disposed facing a latent image bearer in a developing range to transport developer by rotation, a support to support the developer bearer and including a holder mount, a rod-shaped developer regulator disposed facing a surface of the developer bearer across a gap, and a holder secured to the holder mount of the support to hold the rod-shaped developer regulator. The rod-shaped developer regulator extends in an axial direction of the developer bearer.

Abstract: A developing device configured to develop a latent image formed on an image bearing member includes a rotatable developing-agent bearing member configured to bear developing agent, a developing container configured to form a developing-agent storage chamber that stores the developing agent, a developing-agent regulating portion provided in the developing container to regulate an amount of the developing agent born on the developing-agent bearing member, a support portion configured to support the developing-agent bearing member movably relative to the developing-agent regulating portion, and a pressurizing member configured to pressurize the developing-agent bearing member toward the developing-agent regulating portion. A contact portion of the developing-agent regulating portion with the developing-agent bearing member is fixed to the developing container without forming a gap from the developing container on a downstream side in a pressurizing direction of the pressurizing member.

Abstract: An electrostatic charge image developer includes an electrostatic charge image developing toner that includes toner particles, and an external additive which is added to the toner particles and which includes silica particles whose compression aggregation degree is from 60% to 95% and particle compression ratio is from 0.20 to 0.40, and a carrier for developing an electrostatic charge image that has a core including a magnetic member in a binder resin for a core and a coating layer which coders a surface or the core and which includes a resin for a coating layer and has a surface roughness Ra of from 0.25 ?m to 0.4 ?m.

Abstract: A developer container includes a container body, a rotary shaft, a rotary stirrer, and a flexible blade. The container body contains developer and has a discharge port. The rotary stirrer includes a rotary support and rotates about the rotary shaft to stir and transport the developer. The rotary support includes a base end rotatable integrally with the rotary shaft, a free end spaced away from an inner wall of the container body, and a holding surface provided at the free end or at a position shifted toward the rotary shaft away from the free end. The holding surface is parallel to or inclined relative to a rotation direction of the rotary support. The flexible blade includes a base end portion held on the holding surface and a distal end to contact the inner wall and transport the developer to the discharge port.

Abstract: A developer quantity control blade is provided which can sufficiently impart charge to toner and which allows bleeding of a material from a blade member to be suppressed even in application of a voltage. The developer quantity control blade includes a supporting member and a blade member, wherein the blade member is composed of a thermoplastic elastomer composition including a block copolymer having a polyamide structure and a polyether structure, and an ion conductive agent; in the blade member, a quantity of an extraction component to be extracted with methyl isobutyl ketone as a solvent is 0.5% by mass or more and 2.4% by mass or less; and a quantity of a molecule having a molecular weight of 5000 or less in the extraction component is 70% by mass or more.

Abstract: A sliding member includes a base material including a contact area which contacts with a member to be slid, wherein a Young's modulus E1 with respect to the thickness of the contact area from a surface of the contact area is from 10 MPa to 200,000 MPa and a thickness T of the contact area is from 10 nm to 500 nm.

Abstract: A layer thickness regulating member regulates an amount of developer carried on a surface of a developer carrying member and includes a base portion and a layer thickness regulating portion. The base portion includes an upstream base portion and a downstream base portion. A reinforcing rib portion projects from a rear side of the base portion and includes a first reinforcing rib and a second reinforcing rib disposed in a direction crossing the first reinforcing rib. The base portion, the layer thickness regulating portion, and the reinforcing rib portion are integrally molded. The layer thickness regulating portion and the first reinforcing rib are provided at positions spaced from each other with respect to a tangential direction of the developer carrying member.

Abstract: A developing device includes a development roller, a toner supply roller, a casing having an inner wall portion facing toward the development roller, a flexible film member, an urging member, a linkage member, and a linkage member driving mechanism. The flexible film member is disposed on the inner wall portion and has ends in a direction of an axis of the development roller that are opposite to each other. The urging member is connected with one of the ends of the film member and pulls the film member. The linkage member is connected with the other of the ends of the film member. The linkage member driving mechanism drives the linkage member in accompaniment to rotation of a gear to intermittently pull the film member, so that the film member reciprocates in directions parallel to the axis of the development roller.

Abstract: A magnetic roll for transporting a dual component developer mix according to one embodiment includes a core having at least one permanent magnet that has a plurality of circumferentially spaced magnetic poles generating a magnetic field. A cylindrical sleeve is positioned around the core. The sleeve is rotatable relative to the core about a rotational axis in an operative rotational direction. At portions of the magnetic roll positioned axially inward from axial ends of the core, a magnitude of a total magnetic field strength of the magnetic field decreases by 1.5 mT/degree or less in the operative rotational direction at a radius of 0.5 mm beyond an outer circumferential surface of the sleeve throughout an area of ±15 degrees from an angular position of the magnetic roll at which a tangential component of the magnetic field is equal to zero at a release pole of the plurality of magnetic poles.

Abstract: A developing device includes a storing portion, a stirring member, a developing roller, a shield plate, and a guide portion. The storing portion stores developer. The stirring member is rotatably provided in the storing portion and stirs the developer in the storing portion by being rotationally driven in a predetermined first rotation direction. The developing roller is rotatably provided above the stirring member, has a magnet that attracts the developer in the storing portion by a magnetic force, and is rotationally driven in a predetermined second rotation direction. The shield plate is made of a nonmagnetic material and provided at a facing position where the developing roller and the stirring member face each other. The guide portion is provided more on an upstream side in the first rotation direction than the facing position, and guides the developer from the storing portion to the developing roller side.

Abstract: A developing device includes a developer bearing member that bears a developer on its surface to supply the developer to an image bearing member having a first dielectric portion and a second dielectric portion in its surface, a regulating member that regulates a thickness of a layer of the developer carried by the developer bearing member, and a flexible sheet-like charging auxiliary member disposed so as to be in contact with the developer bearing member at a position downstream of a contact portion between the developer bearing member and the image bearing member and upstream of a contact portion between the developer bearing member and the regulating member in a rotational direction of the developer bearing member, where the charging auxiliary member charges the developer carried by the developer bearing member. In a triboelectric series, the charging auxiliary member is positioned between the first and second dielectric portions.

Abstract: A layer thickness regulating member includes: an opposing portion having an opposing surface to a peripheral surface of a developer carrying member; and a layer thickness regulating portion, projected from the opposing surface toward the developer carrying member, for regulating a layer thickness of a developer carried on the developer carrying member. The layer thickness regulating portion is integrally molded with the opposing portion. The layer thickness regulating member is, after being molded in a metal mold, separated by being pushed from a side opposite from the opposing portion of the layer thickness regulating member when the layer thickness regulating member is separated from the metal mold.

Abstract: A developing device to supply toner in a developer, including a development member which receives the developer on an outer circumferential surface thereof and supplies the toner to the image bearing member, a first regulation member including a first regulating portion that forms a first doctor gap between the outer circumferential surface of the development member and the first regulating portion, and a second regulation member disposed on an upstream side of the first regulation member in a rotational direction of the development member and includes a second regulating portion that forms a second doctor gap between the outer circumferential surface of the development member and the second regulating portion, the second doctor gaps at a central portion and both end portions in a longitudinal direction of the development member being different from each other.

Abstract: A developing unit employing a two-component developing agent is shown. The developing unit includes a first regulating member, a second regulating member, and a third regulating member forming first, second, and third regulating gaps respectively with a developing roller. The third regulating member forms a recovery path for recovering excessive developing agent that may not pass through the first and second regulating gaps to an agitating region between the third and second regulating members. A distance between a vertical line passing through an upstream side end portion of the second regulating member based on a rotating direction of the developing roller and a center of the developing roller is greater than a radius of the developing roller, and a downstream end of the third regulating member is located between a regulating pole and a catch pole.

Abstract: A developing device has a developing container, a developer carrier, and a restricting member. The restricting member restricts the layer thickness of developer on the surface of the developer carrier. The restricting member includes a restricting base formed of resin with higher strength than the developing container and a metal foil arranged at a tip part of the restricting base. The metal foil has a downstream face portion fixed to a downstream-side face of the restricting base and a restricting face portion formed by bending the tip of the downstream face portion to an upstream side and arranged to face the developer carrier.

Abstract: This invention is to provide a developing device uniformly developing an image along an axis line of a developing roller and stably obtaining the image with a uniform concentration. The developing device comprises: a developer tank, the developing roller, and a cylindrical layer thickness-regulating member. The layer thickness-regulating member comprises a body part regulating a layer thickness of a developer retained on an outer periphery of the developing roller; a first supporting part having a diameter smaller than that of the body part and supporting the body part at one end of the body part; and a second supporting part having a diameter smaller than or the same as that of the body part and supporting the body part at the other end of the body part.

Abstract: Aspects include an apparatus, a blade assembly, and a method for manufacturing the apparatus with the blade assembly. The apparatus may include a developer carrier for carrying developer and a blade assembly. The blade assembly may include a blade disposed adjacent to the developer carrier and configured to regulate an amount of developer on the developer carrier. The blade may include a weld mark joining the blade to the supporting member. A first dimension of the weld mark in a first direction may be greater than a second dimension of the weld mark in a second direction perpendicular to the first direction, and a third dimension of the weld mark in a third direction may be a dimension of the thickness of the blade. The weld mark may be formed by irradiating a laser beam onto the blade while moving the laser beam or the blade.

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: An image forming apparatus includes an image bearing member where an electrostatic latent image is formed, a developing device developing the electrostatic latent image at a developing position facing the image bearing member, the developing device including a developer bearing member which rotates while bearing developer containing toner and which supplies the image bearing member with the toner, and a regulating member regulating a layer thickness of the developer born by the developer bearing member. In addition, a vibrating member vibrates the regulating member when the vibrating member is driven, and a control unit performs a mode of vibrating the regulating member while rotating the developer bearing member during a non-image forming period and of transferring from the developer bearing member to the image bearing member the toner passing through the regulating member during vibration of the regulating member.

Abstract: A detection device configured to detect a charge amount of toner on a developer carrier includes an assembly with a quartz oscillator and having a first surface and a second surface that are provided in the quartz oscillator. The first surface has a recess and a projection formed in a direction in which the quartz oscillator vibrates. In addition, a capacitor is connected to the assembly, a first measurement unit measures a potential difference between two ends of the capacitor, and a second measurement unit measures a frequency of the quartz oscillator. In a case where an alternating-current power is applied to the assembly, the direction in which the quartz oscillator vibrates is parallel to the first surface.

Abstract: An image forming apparatus is provided which includes a development device that has no developer supply member and with which the decrease in density at a back end of a solid image and occurrence of ghosting are suppressed. A development roller having dielectric portions scattered on a surface thereof is provided and components are configured so that the position of the dielectric portions in a triboelectric series is on the same polarity side, relative to a regulating blade, as the normal charge polarity of the toner.

Abstract: A cleaning device for cleaning a cleaning subject moving in a predetermined direction, having; a cleaning member that rotates in an opposite direction from the predetermined direction at a contact with the cleaning subject, thereby gathering toner from the cleaning subject; and a shielding member that is disposed between the cleaning member and the cleaning subject in the predetermined direction relative to the contact and prevents the toner on the cleaning member from moving to the cleaning subject.

Abstract: A developing device of the present disclosure includes a developing roller, a toner feeding roller, a thickness regulating member, and a casing. The toner feeding roller feeds toner to the developing roller. The thickness regulating member is disposed opposite to the toner feeding roller at a predetermined distance from the toner feeding roller, and the thickness regulating member regulates a thickness of the toner carried on the toner feeding roller. The casing holds therein the developing roller, the toner feeding roller, and the thickness regulating member. The thickness regulating member is formed in a roller shape and rotatable.

Abstract: A developing device having: a developing sleeve in which a magnetic member is inserted, transporting two-component developer to a developing area facing an image carrier; and a restriction member for restricting the amount of developer to be no greater than 250 g/m2. The average of absolute values of magnetic flux density within a restriction area falls within a range of 40 mT to 70 mT under a condition that no developer exists within the restriction area. The restriction area extends along the outer circumferential surface between a closest point on the outer circumferential surface, which is closest to the restriction member, and a point 2 mm upstream from the closest point in a rotational direction of the developing sleeve, and has a height that is half a minimum distance between the closest point and the restriction member.

Abstract: A film member in a development device can vibrate with respect to an internal wall in the development device. An idler gear in the development device includes a projection and is reciprocally movable between a first position and a second position. The first position is a position where the projection is apart from an end edge of the film member in response to a rotation of a toner supply roller when image formation is performed. The second position is a position where the projection overlaps with the end edge of the film member in response to a reverse rotation of the toner supply roller when image formation is not performed. The projection causes the film member to vibrate by intermittently coming into contact with the end edge of the film member along with a rotation of the idler gear at the second position.

Abstract: An image forming apparatus, comprising: an image bearing member where an electrostatic latent image is formed; a developing device developing the electrostatic latent image at a developing position facing the image bearing member, the developing device including a developer bearing member which rotates while bearing developer containing toner and which supplies the image bearing member with the toner; a regulating member regulating a layer thickness of the developer born by the developer bearing member; and a vibrating member vibrating the regulating member when the vibrating member is driven; and a control unit performing a mode of vibrating the regulating member while rotating the developer bearing member during a non-image forming period and of transferring from the developer bearing member to the image bearing member the toner passing through the regulating member during vibration of the regulating member.

Abstract: A developing apparatus includes a developing container for containing a developer; a rotatable developer carrying member provided at the position of the developing container opposed to an image bearing member and configured to carry the developer into a developing zone where the developer carrying member is opposed to the image bearing member; and a guiding portion provided opposed to a carrying region, with respect to an axial direction of the developer carrying member, where the developer carrying member carries the developer, in a side of the developing container remote from the image bearing member, the guiding portion being capable of guiding the developer from an end portion of the developer carrying member with rotation of the developer carrying member.

Abstract: A developing device includes a developing sleeve for carrying a developer for developing an electrostatic latent image formed on an image bearing member, a magnet for carrying the developer on the sleeve, and a regulating member for regulating an amount of the developer carried on the sleeve. Magnetic poles of the magnet are disposed so that a circumferential direction component of a magnetic force acting on a magnetic carrier of the developer contacting at least a part of an upstream regulating surface of the regulating member with respect to the direction of rotation of the sleeve is opposite from the direction of the rotation.

Abstract: A developing apparatus includes a developing unit configured to transfer a developer to an image carrying unit on which an electrostatic image is formed, a supplying unit configured to supply the developer to the developing unit, a regulating unit configured to regulate a thickness of the developer on the developing unit, and a repelling unit disposed between the supplying unit and the regulating unit and configured to repel the developer.

Abstract: Provided is a developing device including an accommodating unit that contains a developer, a transport member that holds the developer on an outer surface and transports the developer outside from the accommodating unit, a layer regulating member that faces the outer surface of the transport member with a gap, extends in a direction intersecting a direction in which the developer is transported, and regulates a layer thickness of the developer, and a removal member that is inserted into the gap, moves along the direction in which the layer regulating member extends, and removes the developer from the gap.

Abstract: Provided is a developing device including a container that contains developer; a developing roller that transports the developer within the container to a photoconductor side; a trimmer having a tip brought close to the developing roller, and provided upstream of the photoconductor in a transporting direction by the developing roller; and a detector provided in the trimmer or in the vicinity of the trimmer of the inner surface of the container to detect the pressure caused by the developer.

Abstract: A developing apparatus includes a grooved developer carrying member configured to carry a developer to a developing region opposing an image bearing member, and a regulating member configured to regulate an amount of the carried developer. The regulating member includes a guide portion configured to guide the developer to a regulating position in which the regulating member is closest to the developer carrying member, with the guide portion being located on an upstream side with respect to the regulating position in a rotation direction of the developer carrying member and being shaped so that a gap between the guide portion and a tangent of the developer carrying member at the regulating position becomes narrower toward a downstream side in the rotation direction.

Abstract: A developing device includes: a developing roller; a toner supplying roller; a regulation blade; a casing; a film member; a bias member; and a protrusion. The casing includes an inner wall portion which opposes the developing roller between the blade roller and the image carrier. The film member is flexible, disposed to oppose an upper surface of the inner wall portion over a predetermined gap and vibratile in a direction to approach or leave the inner wall portion. The bias member is connected to at least one end in a longitudinal direction of the film member and gives tension to the film member. The protrusion is disposed on a gear composing a group of drive gears of the developing roller or the toner supplying roller and intermittently contacts an end edge of the film member thanks to rotation of the gear to vibrate the film member.

Abstract: A developing device includes a first developing roller including a first transport member that transports magnetic developer by rotating while being close to a latent-image carrier rotating in one direction and a first magnet member, a second developing roller including a second transport member that transports the developer by rotating while being close to the latent-image carrier at a position on a downstream side of the first developing roller in the one direction, and a second magnet member, and a regulation member that regulates transport amounts of the developer distributed to the first and second developing rollers to required transport amounts, and opposes the developing rollers with predetermined distances therebetween. The first and second developing rollers are spaced from each other. The regulation member is movably supported in an area closer to the latent-image carrier than a closest position between the first and second developing rollers.

Abstract: A developing device includes a developing roller, a regulating blade, and seal members. The regulating blade extends in a rotation axis direction of the developing sleeve, is disposed opposite to a circumferential surface of the developing sleeve, and regulates a quantity of the toner present on the circumferential surface of the developing sleeve. The seal members are disposed opposite to the circumferential surface of the developing sleeve without being in contact with both ends of the developing sleeve in the rotation axis direction, and inhibit the toner on the circumferential surface from moving to the rotation axis direction ends by magnetic brushes formed between the magnet roller and the seal members. An inner surface part of each seal member which is opposite to the circumferential surface of the developing sleeve has root parts which have crest parts formed in a serrated shape.

Abstract: A developing device of the present disclosure includes a magnetic roller and a developing roller arranged so as to oppose the magnetic roller. Inside the magnetic roller, a regulation pole and a conveyance pole are provided. The regulation pole is turned toward an opposing surface side of an end portion of a regulation blade provided in a developer container. The regulation pole and the conveyance pole are arranged such that in magnetic fields formed by these magnetic poles, a point where no magnetic pole perpendicular to a surface of the magnetic roller is generated is located in a gap between the surface of the magnetic roller and the regulation blade.

Abstract: A layer thickness regulating member includes: an opposing portion opposing a peripheral surface of a developer carrying member; a layer thickness regulating portion, projecting from the opposing portion toward the developer carrying member, for regulating a layer thickness of a developer carried on the developer carrying member; and a rib portion provided in a side, of the opposing portion, opposite from the layer thickness regulating portion. The opposing portion, the layer thickness regulating portion and the rib portion are integrally molded. The rib portion is disposed at a non-overlapping position with a region, at least in an image forming region, corresponding to a region where the layer thickness regulating portion is formed at the opposing portion.