Abstract: A developing device includes a developing member including a magnet member on which plural magnetic poles including a developing main magnetic pole are magnetized in a circumferential direction and a developer holder that faces an image supporting member, receives the magnet member, and holds a developer, wherein the distribution of a magnetic attraction force in a circumferential direction has a gradient that increases toward a downstream end from an upstream end of a developing area in a developer transport direction of the developer holder, and the magnetic poles are magnetized on the magnet member so that the amount of the increase of the magnetic attraction force between the upstream end and a middle position of the developing area is larger than that between the middle position and the downstream end.

Abstract: Provided is a developing device including a pair of developer holding members that include a pair of cylinder members, which are disposed close to each other and rotate in the same direction at an adjacent gap at which both cylinder members are in close proximity, and a pair of magnetic force generation sections which are provided inside the pair of cylinder members respectively and generate magnetic forces for holding a developer on the cylinder members, and a pair of developing magnetic poles that are provided in the pair of magnetic force generation sections respectively, are disposed to be opposed to a latent image holding member, and are set to have the same polarity.

Abstract: A developing device includes: a developing housing in which a developer is to be contained; a first developer carrier that is placed opposedly to an image carrier which is rotated while a latent image is formed on a surface of the image carrier, that is supported by the developing housing, and that is rotated while holding the developer on a surface of the first developer carrier; a second developer carrier that is supported movably with respect to the developing housing, that is opposed to the image carrier on an upstream or downstream side of the first developer carrier in a rotation direction of the image carrier, and that is rotated while holding the developer on a surface of the second developer carrier; and a coupling defined herein.

Abstract: A magnet roller includes a magnetic field generator being columnar, a support element being columnar, coaxially provided at both ends of the magnetic field generator, and whose diameter is smaller than that of the magnetic field generator, a level element extending along an axis of the magnetic field generator with a distance from the axis, the distance larger than the diameter of the support element, and a high magnetic power element being a main magnetic pole provided on the level element, extending long along the axis of the magnetic field generator.

Abstract: A method for transferring developer (14) to a development roller (11) in an electrophotographic printing process includes feeding developer from a first channel (12) to the development roller; releasing developer from the development roller to a second channel (15); and wherein a strength of a pickup field of a feed magnet (50) in the development roller increases in a direction of developer flow in the first channel.

Abstract: A developing device includes a developing sleeve, a magnet roller mounted in the developing sleeve, a first conveying screw feeding a developer to the developing sleeve, and a regulating blade regulating a layer thickness of the developer. The developing device further includes a guide member that backs up the developer from the first conveying screw at an upstream side of the regulating blade based on a rotational direction of the developing sleeve and that forms a buffer portion temporarily containing the developer between the regulating blade and the guide member. The guide member is installed so that a direction of a resultant force of a magnetic force and a gravitational force acting on a carrier particle becomes a direction away from a surface of the guide member on a facing surface of the guide member which is opposite to the regulating blade.

Abstract: A development device includes a developer containing part containing two-component developer, a cylindrical developer carrier to carry by rotation the developer to a development range, a first developer transport member disposed in the developer containing part, to supply the developer to the developer carrier while transporting the developer in an axial direction of the developer carrier, and a magnetic field generator disposed inside the developer carrier, having three developer-carrying magnetic poles, consisting of a development pole to generate a first magnetic field in the development range, a pre-development pole to generate a second magnetic field to transport the developer supplied from the developer containing part to the development range, and a post-development pole to generate a third magnetic field disposed between the first magnetic field and the second magnetic field, to transport the developer to a release position where the developer is separated from the developer carrier.

Abstract: An image forming apparatus includes an image carrier, a developing unit, and a developer sucking section. A relationship 0?X?R+kRW (where k=10 to 12) is established, when X (m) is a distance from a center of a transport pole to a position where a straight line crosses a rotating section, R (m) is a chain standing length of developer on the transport pole, W (m/s) is a peripheral velocity of the developing unit, and k is a coefficient. The transport pole is adjacent to a development pole and is situated downstream of the development pole in a direction of rotation of the rotating section. The straight line is situated at a downstream side in the direction of rotation of the rotating section and connects a center of rotation of the developing unit and an end of the developer sucking section.

Abstract: A development roller includes a magnet roller and a rotatably supported development sleeve including inside thereof the magnet roller, the development sleeve is formed in a cylindrical shape and configured such that a shaft center of the cylindrical shape is inconsistent with a rotation axis of the development sleeve, the development sleeve includes an outer surface provided with many circular or elliptical depressions in a planar view, the depressions being regularly arranged at intervals, and a depth of the depression provided in a portion of the outer surface close to the rotation axis is larger than a depth of the depression provided in a portion of the outer surface far from the rotation axis.

Abstract: A development device includes a developer bearer to carry the developer to a development range, a magnetic field generator disposed inside the developer bearer for generating magnetic force, a developer regulator for adjusting an amount of the developer, a developer supply compartment disposed adjacent to the developer bearer, separated by a side wall from a portion where the developer bearer is provided, a developer agitator provided in the supply compartment, and a blocker disposed above the side wall of the supply compartment across a supply gap through which the developer moves from the supply compartment. The magnetic field generator has an attraction magnetic pole and a regulation magnetic pole. The blocker prevents the developer blocked by the developer regulator from moving along a magnetic force line of the regulation magnetic force toward the circumferential surface of the developer bearer.

Abstract: A developing device includes a first developer carrier that carries developer on a peripheral surface thereof; a second developer carrier that carries the developer on a peripheral surface thereof; a supplying section that supplies the developer to the peripheral surface of the first developer carrier; a layer thickness regulating member that regulates a layer thickness of the developer supplied to the peripheral surface of the first developer carrier by the supplying section; a first transfer magnetic pole disposed in an interior of the first developer carrier; a second transfer magnetic pole disposed in an interior of the second developer carrier; a first downstream magnetic pole disposed in the interior of the first developer carrier; and a second downstream magnetic pole disposed in the interior of the second developer carrier.

Abstract: A developing device includes a developer supporting rotator, toner supporting rotator and voltage application unit. The toner supporting rotator is arranged opposite to a developer supporting rotator, supports toner supplied from the developer supporting rotator, and forms a toner layer by a magnetic brush. The voltage application unit causes the toner supported by the toner supporting rotator to an electrostatic latent image on a surface of an image carrier to develop it into a toner image. A longitudinal end portion of the toner supporting side magnetic member is positioned longitudinally more outside than a longitudinal end portion of the developer supporting side magnetic member. A surface of the second rotating sleeve positioned more outside than the end of the developer supporting side magnetic member is composed of a surface of low adherence with lower toner adherence and a higher dielectric constant than those of a surface positioned inside thereof.

Abstract: A developing apparatus, including: a developing sleeve; a magnet configured to cause the sleeve to carry the developer and including a first magnetic pole and a second magnetic pole; a supply chamber configured to supply the developer to the sleeve; a collection chamber configured to collect the developer used for development; a first conveyance member and a second conveyance member provided in the supply chamber and the collection chamber, respectively; and a third conveyance member configured to convey the developer collected in the collection chamber in a direction opposite to a developer conveying direction in the collection chamber, wherein a center of the third conveyance member is arranged below a zone and overlaps the zone, which is defined on a surface of the sleeve between a local maximal peak of a magnetic flux density of the first magnetic pole and a local minimal peak of the magnetic flux density.

Abstract: A longitudinal end portion of an opposing magnetic member of a developer supporting rotator is positioned more longitudinally outside than a longitudinal end portion of a toner supporting side magnetic member. With respect to the opposing magnetic member facing the toner supporting side magnetic member and a downstream magnetic member disposed more downstream than the opposing magnetic member in a rotational direction, a magnetic force generated in a vicinity of both longitudinally end portions thereof is greater than a magnetic force generated longitudinally inside thereof. A housing includes a sealing portion that projects from a position facing a face at a longitudinal end portion of the developer supporting rotator toward the face, such that the sealing portion prevents the toner in a space between the face and an inner face of the housing from scattering outside.

Abstract: A developing device includes a developer bearing member, a layer restricting member, a facing magnet and a nonmagnetic member. The developer bearing member has a sleeve for bearing magnetic toner and a fixed magnet included inside the sleeve. The layer restricting member faces one magnetic pole of the fixed magnet, is arranged at a distance from the sleeve and made of a magnetic material. The facing magnet is arranged upstream of the layer restricting member in a rotation direction of the sleeve and at a distance from the sleeve, includes a first facing surface facing a position overlapping with a position with a maximum magnetic force of the one magnetic pole and has a magnetic pole having the same polarity as the one magnetic pole on the first facing surface. The nonmagnetic member is connected at an upstream side of the facing magnet in the rotation direction.

Abstract: A magnet roller includes a roller-shaped body constructed of a magnetic field generating material, a first support rod provided to a first axial end of the body; and a second support rod provided to a second axial end of the body. At least one of the first and second support rods is constructed of a nonmagnetic material and includes a projecting part projecting outside the body from an end face of the body and a buried part united to the projecting part and positioned inside the body. The buried part includes a reduced-area portion smaller than a base end of the projecting part adjacent to the buried part in cross-sectional area perpendicular to an axial direction of the first and second support rods.

Abstract: A developing device includes a developing roller; a housing that retains the developing roller such that the developing roller has exposed and unexposed portions, end portions of the housing having first faces curved along the unexposed portion and second faces facing inward; a layer-thickness regulating member having an edge near the developing roller; a first magnet including a first magnetic pole that attracts the developer and a second magnetic pole located downstream of the first magnetic pole and upstream of the exposed portion in a rotational direction of the developing roller, the second magnetic pole having a magnetic force of about 60 mT or less; second magnets retained on the first faces; and magnetic plates retained on the second faces and arranged such that developer chains formed thereon at the downstream ends in the rotational direction extend to positions upstream of the edge of the layer-thickness regulating member.

Abstract: Provided is a developing device for developing an electrostatic latent image on an image carrier, the developing device comprising: a housing having an opening; a developing sleeve facing the image carrier through the opening; a magnet roller encased in the developing sleeve and having magnetic poles including (i) a first magnetic pole having a strongest magnetic force of all the magnetic poles and (ii) a second magnetic pole having a magnetic force equal to or larger than a predetermined value and being different from the first magnetic pole; and a positioning member operable to allow the magnet roller to rotate together with the developing sleeve when the magnet roller is in a first rotational position where the first or the second magnetic pole faces an edge of the opening located downstream in a transfer direction of a two-component developer, and to inhibit the rotation of the magnet roller when the magnet roller is in a second rotational position where the first magnetic pole is closest to the image car

Abstract: The image forming apparatus is provided with first spacing members having an outer diameter larger than that of a first developing roller, which first spacing members are disposed at two ends of the first developing roller coaxially with the first developing roller, second spacing members having an outer diameter larger than that of a second developing roller, which second spacing rollers are disposed at two ends of the second developing roller coaxially with the second developing roller, a first retaining member, a second retaining member, a first biasing member, a second biasing member.

Abstract: A developing device includes first and second developing members facing an image bearing member and respectively having substantially-cylindrical first and second sleeves rotationally driven in a circumferential direction and first and second magnet rollers fixedly supported within the first and second sleeves and provided with magnetic poles in the circumferential direction; a supply member supplying a two-component developer onto the first sleeve; a layer regulating member facing the first sleeve and regulating a layer of the two-component developer thereon; and a magnetic member facing the second sleeve with a certain distance therebetween at a position facing a magnetic pole provided downstream of a development pole and upstream of a removal pole, which are included in the magnetic poles of the second magnet roller, in a rotational direction of the second sleeve. The development pole faces the image bearing member. The removal pole removes the two-component developer from the second sleeve.

Abstract: A magnetic roller includes a solid-core roller having magnetic anisotropy in a direction orthogonal to a central axis thereof. The solid-core roller includes a body part, and shaft parts disposed on both ends of the body part, a concave groove provided in an outer circumference face of the body part to extend in an axial direction, and a magnetic block disposed in the concave groove, the magnetic block having a direction of magnetic anisotropy substantially orthogonal to a direction of the magnetic anisotropy of the magnetic roller.

Abstract: A developing device includes : a first developing body that develops a developing agent image on a development surface using a developing agent; a second developing body that develops a developing agent image on the development surface using the developing agent; and a sealing member that is disposed between a region where a first delivery pole and a second delivery pole are opposed to each other and the development surface, and adjacently to the first developing body and the second developing body at distances so small that developing agents formed as magnetic brushes on a first conveyance pole and a second conveyance pole respectively can touch the sealing member to secure sealing to prevent the developing agent from leaking to the outside of a device body.

Abstract: A developing device includes a first developing unit, a second developing unit, a rotating member, a magnetic pole forming member, a first separating pole, a second separating pole, a developer supplying unit, and a path formation member. The developing device is provided with a magnetic structure, in which, when a value of a magnetic flux density at which the developer is separated is a reference separation value, at a side of the first separating pole at the separation area of the second developing unit, a position where a magnetic flux density of a vertical component of a magnetic force becomes less than or equal to the reference separation value is disposed downstream in the direction of rotation of the rotating member of a position where a magnetic flux density of a horizontal component of the magnetic force becomes less than or equal to the reference separation value.

Abstract: A developing device having: a guide member creating a guide channel for guiding the developer being fed thereto while being supported on the developer support; and a regulating member regulating the amount of the developer that has passed through the guide channel, the guide member further creates a reflux channel in a gap from an inner surface of the housing, the reflux channel is connected to the guide channel via a communication channel such that the developer regulated by the regulating member returns toward an upstream end of the guide member, the upstream end of the guide member is disposed in a position opposed to the position where the magnetic flux density of the catch pole peaks, and the magnet assembly further includes a feeding pole that is disposed downstream of the catch pole and upstream of the developing pole, so as to be opposed to the guide channel.

Abstract: A magnet roll for development for a printer, a copying machine, or the like. The magnet roll comprises a metal pipe provided with recesses formed on a surface thereof and portion maintaining an original metal surface, and a magnet inserted into the metal pipe. Recesses on the surface of the metal pipe are formed by etching using a resist formed by an inkjet process, and irregularities based on crystal grains of metal are formed on an inner surface of each of the recesses and can effectively carry toner that is carried by carrier to a portion of latent images.

Abstract: A method for transferring developer (14) to a development roller (11) in an electrophotographic printing process includes feeding developer from a first channel (12) to the development roller; releasing developer from the development roller to a second channel (15); and wherein a strength of a pickup field of a feed magnet (50) in the development roller increases in a direction of developer flow in the first channel.

Abstract: A development system (10) for an electrophotographic printer (100) with multiple augers and containing a development roller (11) and a first channel (12) containing a feed auger (13) and developer (14), where the magnetic strength of the feed pole of the development roller increases in the direction of developer flow (18) in the first channel. This increase in magnetic field strength of the feed pole (50) ensures that a uniform layer of developer is formed on the development roller despite the volume of developer in the first channel decreasing along the length of the first channel in the direction of developer flow.

Abstract: A developing apparatus includes a developer carrying member for carrying a developer containing magnetic particles; a magnetic member, including first and second magnetic poles which have the same magnetic polarity; a magnetic seal provided opposed to the developer carrying member at a side remote from an image bearing member. The magnetic seal has a third magnetic pole which is most closely opposed to a peak position of the first magnetic pole and which has a magnetic polarity opposite to that of the first magnetic pole, and a fourth magnetic pole which is most closely opposed to a peak position of the second magnetic pole and which has a magnetic polarity opposite to that of the second magnetic pole. Between the third and fourth magnetic poles, the magnetic seal has only one magnetic pole having a polarity opposite to that of the third and fourth magnetic poles.

Abstract: A magnet roller according to the present invention comprises: a single metal shaft member; and a pair of first and second semicylindrical resin magnet members each of which is shorter than the metal shaft member and has a first or second annular portion integrally provided at one end portion thereof. Each of first and second central holes is provided at the center of each of the first and second annular portions. The magnet roller according to the present invention is assembled by arranging the first annular portion and the second annular portion so as not face each other, inserting both end portions of the metal shaft member into the first and second central holes from the inner side of the first and second annular portions, and sandwiching the metal shaft member between the first and second semicylindrical resin magnet members in such a manner that both the end portions of the metal shaft member protrude to the outside of the first and second annular portions.

Abstract: A developing device includes a developer carrying member for carrying a developer; a first feeding portion for supplying the developer to the developer carrying member while feeding the developer along the developer carrying member; a second feeding portion, communicating with the first feeding portion at end portions thereof, for feeding the developer in a direction opposite to a developer feeding direction of the first feeding portion while collecting the developer from the developer carrying member; and a partition wall portion for partitioning the first and second feeding portions. The partition wall portion includes an opposing portion opposing the developer carrying member with a spacing. A surface roughness of at least the opposing portion is larger than that of the developer carrying member.

Abstract: A developing device including a developer container and a developer bearing member is provided. The developer container contains a two-component developer comprising toner particles and magnetic carrier particles having a ten-point average surface roughness Rz of 0.5 to 3.0 ?m. The developer bearing member is a cylindrical member containing a magnetic field generator having multiple magnetic poles. The developer bearing member is adapted to bear the two-component developer on a surface thereof and to convey the two-component developer as the surface rotates. The developer bearing member has a ten-point average surface roughness Rz of 10 to 30 ?m. The multiple magnetic poles include three developer bearing poles each adapted to generate a magnetic field having a strength enough for retaining the two-component developer on a surface of the developer bearing member. The three developer bearing poles consist of a developing pole, a pre-developing pole, and a post-developing pole.

Abstract: A developing unit includable in a process cartridge and in an image forming apparatus includes a developer bearing member including a magnetic field generator and a nonmagnetic hollow member, a developer container, an agitation/conveyance member, and a developer regulating member. The magnetic field generator has first and second magnetic poles to generate respective magnetic forces for removing the developer from the developer bearing member after the developer passes the development region. A developer-releasing region releases the developer from the developer bearing member using a release force. The developer is disposed higher than a surface of the developer in the developer storing chamber. A component of a magnetic flux density of the magnetic field generated by the magnetic field generator in a direction normal to the developer-releasing region is directed to a same direction as the first and second magnetic poles across the developer-releasing region without forming a local maximum point.

Abstract: A developing device includes a developing member including a scooping pole generating the magnetic lines of force to scoop up a developer, rotating while holding the developer scooped up by the scooping pole on a surface thereof, and supplying the developer to an image holding body to develop the electrostatic latent image, and an agitation transport unit that is disposed at a position where a developer used for development and separated and falling from the developing member is received, rotates about a rotating shaft extending along a rotating shaft of the developing member, agitates the developer, and transports the agitated developer to a scoop position, wherein the scooping pole is disposed on the downstream side of a line, which connects the rotating shaft of the developing member with the rotating shaft of the agitation transport unit, in a rotation direction of the developing member.

Abstract: A method for reducing high-frequency banding in an electrophotographic development station having a rotating shell and a rotating magnetic core is disclosed. A rotating angular velocity of the rotating shell is adjusted relative to a angular velocity of a photoconductor such that a ratio of these angular velocities is not a ratio of whole numbers.

Abstract: A developing device includes a developing sleeve for carrying a developer containing a magnetic carrier and a non magnetic toner; a magnet, provided in the sleeve and including a plurality of magnetic poles disposed along a circumferential direction of the sleeve, for carrying the developer on the sleeve; and a regulating member, provided opposed to the sleeve with a predetermined spacing in a region in which the magnetic poles different in polarity are adjacent to each other, for regulating an amount of the developer carried on the sleeve. The magnetic poles are disposed so that a circumferential direction component of a magnetic force acting on the magnetic carrier contacting at least a part of an upstream regulating surface of the regulating member with respect to the circumferential direction of rotation of the sleeve is opposite from the circumferential direction of the rotation.

Abstract: An electrostatic printing method in which the toning shell and the magnetic core each rotate in a co-current direction with the imaging member such that the portion of the toning shell adjacent to the image development area moves in a process direction, and the magnetic core rotates in the same direction as the toning shell such that a the average developer bulk velocity (ADBV) of the developer on the toning shell is in the same direction and proportional to the photoconductor velocity.

Abstract: A development roller, including a development sleeve disposed near a photo conductive drum, a magnetic roller disposed in the development sleeve, and a supplying device configured to supply a developer including a toner and a magnetic carrier to the photo conductive drum uniformly, the development sleeve having an outer surface on which the developer including the toner and the magnetic carrier is adsorbed by a magnetic force of the magnetic roller.

Abstract: Described is a developing roller, which makes it possible to appropriately peel developer off the developing roller, even if the developing roller is a small-sized. The developing roller includes a non-magnetic developing sleeve and a magnetic member installed into an inner space of the developing sleeve and having plural magnetic poles including a peeling magnetic pole. When a reference position is defined as such a position that exhibits a maximum value of magnetic flux density to be generated in a normal direction by the peeling magnetic pole, a magnetic-flux density flat region within which the magnetic flux density is kept at substantially a constant value being closely approximate to the maximum value of the magnetic flux density and the reference position is included, exists while fulfilling an Equation indicated as follow: Z?7° where numeral Z indicates an angle of the developing roller in the magnetic-flux density flat region.

Abstract: An image forming apparatus includes: a developing device that allows a developer to be retained on a developer carrier having a magnet member equipped with a plurality of magnetic poles mounted on an inner periphery thereof and rotates the developer carrier to deliver the developer to an image carrier and that forms a toner image by supplying the toner of the developer to the image carrier by applying a developing bias voltage from a bias voltage source between the developer carrier and the image carrier; a transfer device for transferring the toner image formed on the image carrier to a transfer receiving material; a toner recovery device for recovering the toner remaining on the surface of the image carrier after the transfer of the toner image; and a toner return device for returning to the developing device the toner recovered by the toner recovery device.

Abstract: A developing device includes a developing roller; a housing that retains the developing roller such that the developing roller has exposed and unexposed portions, end portions of the housing having first faces curved along the unexposed portion and second faces facing inward; a layer-thickness regulating member having an edge near the developing roller; a first magnet including a first magnetic pole that attracts the developer and a second magnetic pole located downstream of the first magnetic pole and upstream of the exposed portion in a rotational direction of the developing roller, the second magnetic pole having a magnetic force of about 60 mT or less; second magnets retained on the first faces; and magnetic plates retained on the second faces and arranged such that developer chains formed thereon at the downstream ends in the rotational direction extend to positions upstream of the edge of the layer-thickness regulating member.

Abstract: A developing device includes a first screw that supplies a developer to a developing roller while agitating/conveying the developer in a first direction, and a screw that collects residual developer from the developing roller, agitates/conveys the residual developer in a second direction opposite to the first direction, and delivers the residual developer to the first screw. Between two points that a magnetic flux density in a normal direction of a magnetic field formed in a developer separating magnetic pole in the developing roller become substantially zero, a point at a downstream side in a rotating direction of the developing roller is formed at an upstream side to a developing roller rotating direction, than a line joining the center of the developing roller and the center of the second screw.

Abstract: A developing unit includable in a process cartridge and in an image forming apparatus includes a developer bearing member including a magnetic field generator and a nonmagnetic hollow member, a developer container, an agitation/conveyance member, a developer regulating member to regulate the thickness of a layer of the two-component developer. The magnetic field generator has first and second magnetic poles to generate respective magnetic forces for removing the developer from the developer bearing member after the developer passes the development region. The second magnetic pole generates a magnetic force to attract the developer to form a magnetic brush on the developer bearing member. The developer regulating member includes a magnetic member outwardly disposed on an exterior perimeter surface of the developer bearing member upstream from the developer regulating member, and one planar surface of the magnetic member faces the second magnetic pole across an effective development region.

Abstract: A development device including a developer container, a developer bearer, a magnetic field generator, a developer agitator to supply the developer to the developer bearer, and a developer regulator to adjust a layer thickness of the developer carried on the developer bearer. Multiple oval recesses oblique to the axial direction of the developer bearer are formed in the outer circumferential surface of the developer bearer and arranged in a circumferential direction and the axial direction thereof. An upstream inner wall of the recess in the rotational direction of the developer bearer applies a force to the developer as the developer bearer rotates, and an angle between a long axis of the recess and the axial direction is set so that the force applied by the upstream inner wall of the recess has a component in a direction substantially identical to the developer conveyance direction of the developer agitator.

Abstract: A development device configured to develop a latent image with developer including toner and carrier includes a development roller configured to carry the developer. The development roller includes a stationary magnet-fixing member, a plurality of magnets fixed to an interior of the stationary magnet-fixing member to form a plurality of magnetic poles, and a cylindrical rotatable sleeve roller configured to revolve coaxially around the exterior of the magnet-fixing member. Magnetic force distribution of a portion of the plurality of magnetic poles is varied in an axial direction of the development roller at positions corresponding to an image forming area in the axial direction of the development roller, enabling the development device to transport and agitate the developer.

Abstract: A developing device 2 includes a control member 116 for controlling an amount of a developer supplied to an image bearing member 3 by causing a developer captured on a surface of a developing sleeve 119 to be uniform in layer thickness. The control member 116 is arranged to face, via the developing sleeve 119, one (120b) of a plurality of magnetic poles provided inside the developing sleeve 119. Further, the control member 116 is arranged to be in parallel with a developing roller 114 in an axial direction of a magnet fixing shaft 126. The control member 116 is such a non-magnetic member that the nearest part of the non-magnetic member from the developing roller 114 has been caused to be ferromagnetic and has been magnetic-field oriented.

Abstract: A development device includes a developer bearer to carry the developer to a development range, a magnetic field generator disposed inside the developer bearer for generating magnetic force, a developer regulator for adjusting an amount of the developer, a developer supply compartment disposed adjacent to the developer bearer, separated by a side wall from a portion where the developer bearer is provided, a developer agitator provided in the supply compartment, and a blocker disposed above the side wall of the supply compartment across a supply gap through which the developer moves from the supply compartment. The magnetic field generator has an attraction magnetic pole and a regulation magnetic pole. The blocker prevents the developer blocked by the developer regulator from moving along a magnetic force line of the regulation magnetic force toward the circumferential surface of the developer bearer.

Abstract: A development device includes a developer bearer to carry by rotation two-component developer to a development range to develop a latent image formed on a latent image bearer, a magnetic field generator disposed inside the developer bearer, a developer regulator for adjusting an amount of the developer on the developer bearer, positioned upstream from the development range in a rotational direction of the developer bearer and facing the developer bearer across a regulation gap, a supply compartment from which the developer is supplied by a developer agitator to the developer bearer, a collection compartment, a pre-regulation portion adjacent to and upstream from the developer regulator in the rotational direction of the developer bearer, and a developer mobility adjuster that makes mobility of the developer in the pre-regulation portion higher on an upstream side in a developer conveyance direction in the supply compartment.

Abstract: The present invention provides a developing device which is capable of suppressing the generation of a fogging phenomenon and deposition of carrier particles to an electrostatic latent image carrier and developing the electrostatic latent image efficiently, the device includes a development sleeve and a magnet body onto which the sleeve is fitted, and using a two-component developer. An angular position which indicates the peak value of the magnetic flux density in the normal direction produced by a development pole of the magnet body is shifted downstream from the center position of the development pole in the direction of movement of the surface of a photosensitive member in a development region. The present invention also provides an image forming apparatus which can form high-quality images with reduced noise such as fogging by mounting the developing device.

Abstract: A developing device includes: a developing member including a magnetism-generating member having plural magnetic poles polarized in a circumferential-direction thereof, and a rotating member that is rotated about the magnetism-generating member; a developer-pumping pole provided in the magnetism-generating member, and that pumps up the developer, which is supplied from a developer accommodating portion, to the rotating member surface; a developer-peeling-off pole provided in the magnetism-generating member below a rotation axis of the rotating member in a vertical direction on an upstream side of the developer-pumping pole in a rotational-direction of the rotating member, that peels off the developer from the rotating member surface; and a magnetic body provided in at least a portion between a facing position facing the developer-peeling-off pole in a circumferential-direction of the rotating member and an intermediate position between the developer-peeling-off pole and the developer-pumping pole in the circu

Abstract: An image forming apparatus includes: a photoconductive drum; a mixer which stirs a developer; and a developing roller which has plural magnets to supply the stirred developer to the photoconductive drum, and a separation pole that is a magnet arranged opposite the photoconductive drum in relation to a rotational center axis and separating the developer supplied to the photoconductive drum, and which is arranged in a way that a vertical first tangential line on the separation pole side is located outward to the separation pole side from an outer circumference of the mixer.