Abstract: A developer system and method for an electrographic printer is provided that provides a stable and high rate of developer flow to the photoconductor drum of the printer. The system includes a magnetic brush having a magnetic core surrounded by a toning shell that rotatably conveys a layer of developer to the photoconductor element; a sump containing a reservoir of developer, and a self-metering conveyor roller having a maximum magnetic field strength on its outer surface of between about 100 and 1000 gauss, and a minimum magnetic field strength of no less than about 30% of the maximum field strength. A driving assembly rotates the conveyor roller at a saturation speed that saturates the capacity of the conveyor roller to deliver developer to said toning shell. The self-metering conveyor roller obviates the need for a metering skive to provide a stable flow rate of developer, and increases the printing speed of the printer by providing a higher flow rate of developer to the photoconductor drum of the printer.

Abstract: A developer system and method for an electrographic printer is provided that provides a stable and high rate of developer flow to the photoconductor drum of the printer. The system includes a magnetic brush having a magnetic core surrounded by a toning shell that rotatably conveys a layer of developer to the photoconductor element; a sump containing a reservoir of developer, and a self-metering conveyor roller having a maximum magnetic field strength on its outer surface of between about 230 and 1000 gauss, and a minimum magnetic field strength of no less than about 30% of the maximum field strength. A driving assembly rotates the conveyor roller at a saturation speed that saturates the capacity of the conveyor roller to deliver developer to said toning shell. The self-metering conveyor roller obviates the need for a metering skive to provide a stable flow rate of developer, and increases the printing speed of the printer by providing a higher flow rate of developer to the photoconductor drum of the printer.

Abstract: A developing device uses a two-component developer including at least carriers and toners. The toners are supplied to an image bearing member bearing an electrostatic latent image so that a toner image is developed from the electrostatic latent image. The developing device has a developing roller arranged to oppose the image bearing member; and a magnetic roller arranged to oppose the developing roller. The magnetic roller retains the two-component developer to supply toners to the developing roller. The developing roller and the magnetic roller are rotationally driven in directions to be opposite from one another at an opposed position, and a magnetic pole of the magnetic roller and a magnetic pole of the developing roller have magnetic polarities different from one another at the opposed position. A surface roughness of the magnetic roller is greater than a surface roughness of the developing roller.

Abstract: A developing device comprises a feeding and conveying path; a stirring and conveying path; and a recovering and conveying path, and capable of extending the service life of a developer and of forming an image with stable image density. In the developing device, the central position of a stirring rotary shaft that is a rotary shaft of a stirring screw and the central position of a feeding rotary shaft that is a rotary shaft of a feed screw are disposed at almost the same height. A recovering rotary shaft that is a rotary shaft of a recovering screw is so disposed that the central position thereof is higher than the central positions of the stirring rotary shaft and feeding rotary shaft, and lower than a rotation central position of the developing rotary shaft that is a rotary shaft of a developing roller.

Abstract: A developing apparatus for visualizing an electrostatic latent image on an electrostatic latent image bearing member by using a developer including toner and carrier particles, has a developer including toner and carrier particles, a first transport member, a second transport member positioned to oppose to the first transport member across a first region and to the electrostatic latent image bearing member across a second region. A first electric field forming unit forms a first electric field between the first and second transport members to move the toner particles from the first transport member to the second transport member. A second electric field forming unit forms a second electric field between the second transport member and the electrostatic latent image bearing member to move the toner particles from the second transport member to the electrostatic latent image bearing member and thereby to visualize an electrostatic latent image on the image into a visible image.

Abstract: A developer station and method for an electrographic printer is provided that reduces developer agitation. The developer station includes a sump for holding a reservoir of magnetic developer comprising toner and carrier and a magnetic auger mounted above said sump and including a rotatable magnetic core surrounded by a substantially cylindrical rotatable toning shell rotatably mounted with respect to the core, said shell being adjacent to the photoconductor drum and defining a nip and a conveyance device for transporting developer in the developer station in a flow direction. The conveyance device has a tapered auger including a shaft and one or more blades such that the developer volume in the flow direction is controlled to maintain a uniform developer level in the sump as well as a conveyance controller for controlling the conveying device, including the tapered auger such that the tapered auger preferentially creates an uniform layer of developer on the toning shell.

Abstract: A developing unit includes a development roller and a magnetic roller. Sleeves of the development roller and the magnetic roller are driven to rotate in the same circumferential direction. A first magnet is provided on the roller shaft in the sleeve of the development roller and a second magnet is provided on the roller shaft in the sleeve of the magnetic roller. The first and second magnets are opposed to each other so that opposite polarities face each other, and are supported non-rotatably in circumferential directions. The first magnet is supported so that the peak of the magnetic force of the first magnet is positioned upstream in the direction of rotation of the sleeve of the development roller from the straight line connecting the center of the roller shaft of the development roller to the center of the roller shaft of the magnetic roller.

Abstract: An image forming apparatus includes a latent image carrying member, a two-component developer carrying member holding on an outer surface a developer containing carrier beads and toner particles, the two-component developer carrying member having a first magnetic element mounted therein, a toner carrying member carrying a thin toner layer on an outer surface, a toner collecting roller for collecting the toner particles scattered and suspended in the vicinity of the two-component developer carrying member and the toner carrying member, the toner collecting roller having a second magnetic element mounted therein, and a housing accommodating the two-component developer carrying member, the toner carrying member and the toner collecting roller. The toner collecting roller is located face to face with the two-component developer carrying member with the first and second magnetic elements disposed to face each other with oppositely directed polarities.

Abstract: An image forming apparatus including: an image bearing member; and a developer bearing member bearing a developer including a toner and a carrier, the developer bearing member developing an electrostatic image formed on the image bearing member with the developer, and the developer bearing member being applied with an alternate voltage in order to form an alternate electric field between the developer bearing member and the image bearing member, wherein assuming that electric field intensities Eb and Ed be Eb=|(Vp1?VL)/D| and Ed=|(Vp2?VL)/D|, a relationship, 0?K1>K2, is satisfied, where K1: a gradient at Ed, and K2: a gradient at Eb, and wherein a resistivity ?b of the carrier at the electric field intensity Eb satisfies 1.1×106×en<?b<6.0×107 [?·m] (where: e is the base of natural logarithms; and n=4×Eb×10?7).

Abstract: A developing unit using a two-component developer intended to provide an image forming apparatus capable of forming a high-quality image for a long period of time. A developing unit using a developer contains toner, carrier and opposite polarity particles having a polarity opposite to the charging polarity of toner includes separation means for separating the toner or opposite polarity particles, and control mechanism for controlling opposite polarity particle separation ratio in response to the image area ratio and the number of prints.

Abstract: The present invention provides a developing apparatus using a two-component developer, an image forming apparatus, and a method of forming an image capable of forming a high quality image characterized by stable suppression of carrier deterioration and absence of a residual image (memory effect) for a long period of time. The voltage formed by overlapping AD voltage to DC voltage is applied separately to each of the developer carrying member and the toner carrying member. The toner separation field made up of AC field is formed between the developer carrying member and the toner carrying member, and the development electric field made up AC field is formed between the toner carrying member and the image carrying member.

Abstract: A development apparatus and an image forming apparatus capable of minimizing deterioration of a carrier for a long time, even in a case of continuous formation of images of a smaller image area ratio. The charging of toner is assisted by using a developer composed of a mixture of toner and the carrier, to the surface of which is added a reverse polarity particle having a polarity reverse to that of a charged toner. Separation of the toner or reverse polarity particle of the developer prior to a process of development prevents the reverse polarity particle from being consumed in a developing area, whereby an effect thereof is maintained for a long time.

Abstract: An apparatus includes an upstream transport surface TSa which, while facing a circumferential surface DS of a developing roller 33, is disposed upstream of an area (developing area) in the vicinity of a latent image forming surface LS, and a downstream transport surface TSb which, while facing the circumferential surface, is disposed downstream of the developing area. The apparatus forms electric fields on the upstream and downstream transport surfaces for moving a charged developer T from an upstream side toward a downstream side. In the apparatus, the transport speed of developer on the upstream transport surface is higher than that on the downstream transport surface. As a result, there can be lowered a speed at which the developer which has not adhered to the circumferential surface and has reached a downstream end portion of the upstream transport surface flies out toward the vicinity of the developing area.

Abstract: A developing device 2a, which is provided with: a developer tank 16 that houses a developer 24 containing a toner, a carrier for charging the toner and reverse polarity particles that are charged with a polarity reversed to the electrostatic charge polarity of the toner by the carrier; a developer-supporting member 11 that supports the developer supplied from the developer tank on the surface thereof, and transports the developer; and a separating mechanism 22 that separates the toner or the reverse polarity particles from the developer supported on the developer-supporting member, and the reverse polarity particles are collected into the developer tank, is provided, and an image-forming apparatus having such a developing device and an image-forming method applied thereto are also provided.

Abstract: A development device includes a developer carrier, and a developer conveyance path. The developer carrier carries and conveys developer having a magnetic property. The developer carrier includes a plurality of magnetic poles provided inside the development carrier. The developer conveyance path is provided above the developer carrier and conveys the developer by a flow of air such that the developer is conveyed parallel to the developer carrier. The developer conveyance path is provided with a first developer outlet disposed above the developer carrier and open along a direction of conveyance of the developer to discharge the developer to the outside of the developer conveyance path to directly supply the developer to the developer carrier.

Abstract: A compact development apparatus using a two-component developer and an image forming apparatus wherein carrier deterioration is prevented to ensure formation of a high-quality image for a long time. The development apparatus uses the developer made up of a mixture of toner, carrier, and opposite polarity particles to be charged oppositely to the toner wherein the opposite polarity particles contain the particles having a relative dielectric constant of 6.7 or more.

Abstract: A developing cartridge usable with an image forming apparatus, the developing cartridge includes a supporting frame, a developing member which is supported in the supporting frame, and to supply the developer to an electrostatic latent image of a photosensitive body of the image forming apparatus, a supplying member which is supported in the supporting frame, and to supply the developer to the developing member, and an elastic unit which is supported in the supporting frame, and to elastically support the supplying member so that the supplying member can move toward and away from the developing member.

Abstract: An apparatus and method for dispensing toner in an electrostatographic printer includes an apparatus for feeding powder toward the feed apparatus wherein the feed roller includes a tapered feed roller including a shaft and one or more variable height flutes such that there is more developer volume in the direction of flow as well as a conveyance controller for controlling the powder conveying device, including the one or more tapered feed rollers such that the tapered feed roller preferentially uniformly conveys the powder toward the feed apparatus.

Abstract: A developing device including a first developing roller and a roller drive mechanism is disclosed. The first developing roller comprises a tubular sleeve, on the surface of which developer is supplied, and a magnetic roller that comprises a drawing magnetic pole for drawing developer and a peel-off magnetic pole for peeling off developer, both of which are arranged on the inner circumference of the sleeve. The drawing magnetic pole is arranged to be adjacent to and upstream of the peel-off magnetic pole in the first rotational direction, in which the magnetic roller rotates during an image forming operation. The roller drive mechanism rotates the magnetic roller in the first rotational direction during the image forming operation, and can rotate the magnetic roller in a second rotational direction that is opposite the first rotational direction.

Abstract: A development device configured to develop an electrostatic latent image on an image carrying member with a two-component developer having a toner and a carrier, the development device including: a developer carrying member to carry the two-component developer to a development region in which the developer carrying member faces the image carrying member; a developer control member to control a volume of the two-component developer; a plurality of electrodes to be separately disposed in a direction parallel to a rotation axis of the developer carrying member while separated from a surface of the developer carrying member and located between the developer control member and the development region in a rotation direction of the developer carrying member; and a power source to apply a power to the plurality of electrodes to form a periodically changing electric field generating an external force to convey the two-component developer in the rotation axis direction.

Abstract: A first bias Vslv is applied to a development roller 22 and a second bias Vmag is applied to a magnetic roller 23 to perform development; after completion of development, without changing the setting of Vslv, of the AC component Vpp2 of Vmag, the peak voltage value Vpp2 (max) at the side with the same polarity as toner is made lower than during a development period and development-residual toner on the development roller 22 is collected to prevent a lateral streak formed on photoconductor drums 1a to 1d during a non-development period.

Abstract: A developing unit for an image forming apparatus including an agent carrying member, a supply compartment, a supply screw, a recovery compartment, a recovery screw, an agitation compartment, and an agitation screw. The agent carrying member carries and supplies developing agent to an image carrying member. The supply screw in the supply compartment supplies the developing agent to the agent carrying member. The recovery screw in the recovery compartment, provided under the agent carrying member, transports the developing agent dropped from the agent carrying member. The agitation screw in the agitation compartment receives the developing agent from the supply compartment and recovery compartment, and transports the developing agent to the supply compartment. The recovery compartment, supply compartment, and agitation compartment are provided side-by-side in a horizontal direction. A magnetic flux density in a given area of the agent carrying member is set to 10 mT or less.

Abstract: An image forming apparatus is disclosed. The image forming apparatus includes a photosensitive body, a magnetic roller disposed at a predetermined distance from the photosensitive body, and a donor roller disposed between the photosensitive body and the magnetic roller. The donor roller has a diameter larger than the closest distance between the photosensitive body and the magnetic roller. The image forming apparatus includes gap rings and pressing device to maintain desired gaps between the magnetic roller and the donor roller and between the donor roller and the photosensitive body.

Abstract: In a method or system where inking in an electrophotographic printer or copier, a magnetic roller is provided having a rotatable magnetic roller sleeve having a circumferential surface to which a two-component mixture comprising toner particles and ferro-magnetic carrier particles adheres. An applicator element has a circumferential surface to be inked with toner particles and past which the two-component mixture adhering to the circumferential surface of the magnetic roller is guided to produce a toner layer on the applicator element. The magnetic roller has a magnetic rotor which comprises magnetic elements and arranged inside the magnetic roller sleeve. A magnetic rotor and the magnetic roller sleeve are moveable relative to one another.

Abstract: A development system for an electrophotographic machine in which uncharged toner is stored in a housing having an opening. A rotatable dispensing roll is mounted in the housing opening. An overhung metering blade mounted at the housing opening meters a layer of uncharged toner onto the dispensing roll. An ion or electron charging device places a charge on the toner layer residing on the dispensing roll prior to the transportation thereof by the dispensing roll to a captive magnetic brush. The magnetic brush transports the two component developer on the magnetic brush to a development zone for either direct development of a latent image on a moving imaging surface or to coat donor rolls for AC/DC generated toner cloud development of a latent image.

Abstract: An image forming apparatus capable of collecting residual toner from the donor roller by means of a plurality of magnetic rollers and consequently, reducing the occurrences of possible ghost phenomenon caused by the toner residue. The image forming apparatus includes an image receiving member having an electrostatic latent image formed on a surface thereof, a donor roller to receive a toner and form a layer of toner on an outer circumferential surface thereof, the donor roller being arranged to oppose the image receiving member so as to develop with toner the electrostatic latent image of the image receiving member, and a plurality of magnetic rollers each to support magnetic brushes of carrier.

Abstract: A method for determining if an image to be printed is subject to reload artifact, includes providing an image (which may be a low resolution version of the image) to be printed; locating within the image a first area to be printed requiring toner of sufficient quantity to cause reload of the donor roll; locating within the image a second area substantially one rotation of the donor roll subsequent to the first area; determining if the second region is a region of high area toner coverage, wherein high area toner coverage comprises toner coverage exceeding a predetermined threshold value; if the second region is a region of high area toner coverage, determining if the second region contains high frequency content; if the second region contains high frequency content, the second region is not subject to reload artifact; else the second region is subject to reload artifact.

Abstract: An aspect of the invention provides a development device including a rotatable development sleeve which supplies developer to a photosensitive drum, the development sleeve being disposed such that a rotational axis of the development sleeve is orientated toward a vertical direction; a conveying screw which conveys the developer along a rotational axis direction of the development sleeve; and a developer supply guide which guides the developer conveyed by the developer conveying device to the development sleeve. The plural developer supply guides are disposed at predetermined intervals in the rotational axis direction of the development sleeve and between the development sleeve and the conveying screw.

Abstract: A two-component developer including toner and magnetic carriers is provided. The two-component developer is characterized in that when a development device including a developer bearing member bearing the two-component developer is operated under a development condition of an image forming apparatus using a quasi-photoconductor in which a 10 ?m thick layer of tetrafluoroethylene resin is provided to a conductive material, the number of times of light emission occurring in a magnetic brush formed on the developer bearing member due to partial conduction in the magnetic brush is 10 times or less per second at an observation cross section that is perpendicular relative to a rotation axis of the developer bearing member.

Abstract: A developing device uses a two-component developer including at least carriers and toners. The toners are supplied to an image bearing member bearing an electrostatic latent image so that a toner image is developed from the electrostatic latent image. The developing device has a developing roller arranged to oppose the image bearing member; and a magnetic roller arranged to oppose the developing roller. The magnetic roller retains the two-component developer to supply toners to the developing roller. The developing roller and the magnetic roller are rotationally driven in directions to be opposite from one another at an opposed position, and a magnetic pole of the magnetic roller and a magnetic pole of the developing roller have magnetic polarities different from one another at the opposed position. A surface roughness of the magnetic roller is greater than a surface roughness of the developing roller.

Abstract: A magnetic brush development station for a reproduction apparatus has a housing forming, at least in part, a reservoir for developer material; a developer roller mounted within the housing for delivering developer material to a dielectric support member in a development zone; a transport mechanism for transporting developer material from the reservoir to the developer roller; a metering skive for establishing a developer material metering gap; and a mechanism for selectively moving the metering skive to an operative position relative to the developer roller and to a position remote from the developer roller, wherein a build up of contamination at the metering gap between the metering skive and the developer roller can be substantially prevented. A method of removing a skive blockage from a metering skive in a magnetic brush developer station is also disclosed.

Abstract: A developing apparatus, comprises an endless belt shaped donor member; a developer supporting member to carry developer including toner and magnetic carrier and to form a toner layer on the donor member; a first supporting member arranged in the inside of the donor member with a predetermined gap against the developer supporting member and to strain the donor member; a second supporting member arranged in the inside of the donor member with a predetermined gap against the developer supporting member and to strain the donor member; a toner supply bias applying section to apply onto the first supporting member a toner supply bias for supplying toner from the developer supporting member to the donor member; and a toner recovery bias applying section to apply onto the second supporting member a toner recovery bias for recovering toner from the donor member to the developer supporting member.

Abstract: An apparatus for loading one or more donor rolls of a developer unit, comprising a developer housing having a reservoir for a developer material, a rotatable first donor roll that delivers the toner onto a moving photoconductive member, a rotatable first magnetic brush roll that receives the developer material from the reservoir and delivers the toner to the first donor roll, and a rotatable second magnetic brush roll that receives the developer material from the first magnetic brush roll and delivers the toner to the first donor roll. The apparatus may further comprise a rotatable second donor roll that receives the toner from the second magnetic brush roll and delivers the toner onto the photoconductive member, and a rotatable third magnetic brush roll that receives the developer material from the second magnetic brush roll and delivers the toner to the second donor roll.

Abstract: An apparatus for loading one or more donor rolls of a developer unit, comprising a developer housing having a reservoir for a developer material, a rotatable first donor roll that delivers the toner onto a moving photoconductive member, a trim roll that receives developer material from the reservoir and delivers the developer material to a first magnetic brush roller that delivers toner to the first donor roll, and a rotatable second magnetic brush roll that receives the developer material from the first magnetic brush roll and delivers the toner to the first donor roll. The apparatus may further comprise a rotatable second donor roll that receives the toner from the second magnetic brush roll and delivers the toner onto the photoconductive member, and a rotatable third magnetic brush roll that receives the developer material from the second magnetic brush roll and delivers the toner to the second donor roll.

Abstract: In a color image forming apparatus comprising a plurality of developing devices each provided with a developing roller structured with a developing sleeve and a fixed magnetic pole member, an agitating member, a recovering and feeding member, a regulating member and a developing device casing member, at least one of the plurality of developing devices has a different developer storing capacity and a different outer diameter of the recovering and feeding member for the other developing devices and has the same angle allocation values among the plurality of fixed magnetic poles in the fixed magnetic pole member.

Abstract: The present invention provides a developing apparatus that can effectively prevent generation of a ghost due to poor detachment of a developer after development, and generation of unevenness in density between a left part and a right part of an image region due to lack of an amount of the developer transported. The developing apparatus satisfies the relationship r+R?d?3r+R where r denotes a rotational radius of a second developer transporting screw, R denotes a rotational radius of a development roller, and d denotes a center distance between the second developer transporting screw and the development roller. The developing apparatus also satisfies the relationship M0?(mg0×v×l)/0.

Abstract: A development station is disclosed for a reproduction apparatus such as an electrophotographic printing machine. The development station includes a housing that forms a reservoir and a developer roller such as a magnetic brush for delivering developer material to a development zone. A transport roller is provided for moving developer material from the reservoir to the developer roller. The transport roller includes a rotating non-magnetic tubular shell and a stationary elongated magnetic core having an odd number of alternating North and South magnetic poles. There are at least five magnetic poles in the magnetic core, and preferably exactly five magnetic poles.

Abstract: An image forming method, comprising the steps of: agitating a mixture of toner particles and carrier particles so as to electrically charge the toner particles; forming a charged toner layer on a toner conveying roller by extracting the charged toner particles from the mixture; forming an electrostatic latent image on an image carrying member; and conveying the charged toner layer by the toner conveying roller so as to develop the electrostatic latent image on the image carrying member with charged toner; wherein the carrier particles are carrier particles each formed by dispersing magnetic fine powder in a binder resin and have a shape coefficient SF-1 of 1.0 to 1.2, a shape coefficient SF-2 of 1.1 to 2.5, and a volume-based median size of 10 to 100 ?m.

Abstract: The developing device 100 includes a stirrer and transferor 122, 124, a magnetic roller 130, and a developing roller 140, that are disposed in a housing 110 which contains the two-component developing agent including the magnetic carrier and the non-magnetic toner, wherein volumetric mean particle size of the non-magnetic toner is set in a range from 6 to 11 ?m and proportion of toner particles not larger than 4 ?m is set to 8% by number or less, thereby making it possible to prevent imaging defect (ghost) and sticking of the toner onto the developing roller from occurring.

Abstract: A developing apparatus includes a developing roller, a toner-supplying roller, and at least one toner-supplying member. The developing roller develops an electrostatic latent image formed on a photoconductive drum with toner. The toner-supplying roller is formed of a foamed material and rotates in contact with the developing roller to supply the toner to the developing roller. The toner-supplying member is disposed over the toner-supplying roller and opposes an upper surface of the toner-supplying roller. The toner-supplying member approaches the toner-supplying roller periodically to supply the toner to the toner-supplying roller. When the toner-supplying member is closest to the toner-supplying roller, the developer-supplying member and the toner-supplying roller are either in contact with each other or are spaced apart by a distance not longer than 0.8 mm.

Abstract: An image forming apparatus which can stably form an image of high quality by the use of a first developer carrying member and a second developer carrying member. On the first developer carrying member, development is performed by a method whereby a magnetic carrier contacts with an image bearing member, and on the second developer carrying member, development is performed by a method whereby the magnetic carrier does not contact with the image bearing member.

Abstract: A developing apparatus supplies a developer from a developing roller to an image-bearing body that bears an electrostatic latent image thereon. A toner-supplying roller is rotatably supported to oppose the developing roller. A rotating body has recesses formed in its surface, opposing the developer-bearing member. The toner-supplying roller and the rotating body rotate in opposite directions and at different circumferential speeds. The rotating body is formed of a foamed material having cells formed in and open to a surface of the rotating body, the cells having a cell size in the range of 10 to 40 cells/inch. The toner-supplying roller and the rotating body rotate at circumferential speeds such that a ratio between the circumferential speeds is in the range of 1 to 2.5. The rotating body and toner-supplying roller may have a diameter that varies along the length.

Abstract: A two-component developer unit of an electrophotographic image forming apparatus includes a developer rectifier having a lifting guide portion and a developer collection guide portion. The lifting guide portion guides a developer agitated by an agitating unit upward along a circumferential direction of a developer magnet roller. The developer collection guide portion keeps the developer to move down to the lifting guide portion between a developer blade and the lifting guide portion. A non-uniformity of image intensity can be solved without giving an overweight load to the developer and a photoreceptor and without increasing a driving torque of the developer and the photoreceptor.

Abstract: A developing apparatus includes a developer carrying member for carrying a developer; and a developer feeding member, disposed close to or in contact to the developer carrying member, for supplying a developer to the developer carrying member, the developer feeding member being in the form of a wire and is adapted to be supplied with a voltage which is effective to electrically charge the developer to a regular polarity and which is higher than a discharge starling voltage at which electric discharge starts between the developer carrying member and the developer feeding member.

Abstract: An apparatus and method for non-interactive, dry powder development of electrostatic images includes an image bearing member bearing an electrostatic image; two component developer comprising toner and permanently magnetized thickly coated carrier beads, the coated carrier beads having magnetizable core radius r, average radius a, and magnetization Mb, with the ratio r/a being given as K; a developer transporting member having a thickness t for transporting a developer layer of the two component developer, wherein the layer is spaced close to and out of contact with the image bearing member, a multipole magnet member disposed in close proximity to the transporting member and moving relative to it so as to sweep poles across its surface, the magnet member having a periodic magnetization of spatial frequency k and a peak magnetization M0 wherein Mb, t, k, and M0, are chosen such that Mb is sufficiently large to prevent the escape of developer, a quantity C in the equation C = 2.

Abstract: A development system optimized for efficient development of an electrostatic latent image on an imaging surface. The development system includes a development material sump, a magnetic developer roll including a rotatable sleeve having located therein a rotatable magnetic core, and a developer material delivery system for providing a metered supply of developer material to the rotatable sleeve. One or more stationary magnetic shunts are located with respect to the magnetic core, sleeve, and/or developer material delivery system so as to block the magnetic field effective for attracting developer material to the sleeve, thus allowing disengagement of the developer material therefrom at a drop-off zone.

Abstract: A developing device for feeding a developer stored therein to an image carrier of the present invention includes a sleeve facing the image carrier for causing the developer deposited thereon to contact a latent image formed on the image carrier. A regulating member faces the sleeve for regulating the thickness of the developer that forms a layer on the sleeve. A guide member has a guide surface for guiding the developer regulated by the regulating member toward the surface of the image carrier. The guide surface has a conductive surface facing the sleeve. The developing device protects the image carrier from defective images ascribable to impurities, which include deteriorated toner and paper dust, without resorting to a filter mechanism or a bias for collection.

Abstract: In a development system including a developer transport adapted for depositing developer material on an imaging surface having an electrostatic latent image thereon, comprising: a housing defining a chamber storing a supply of developer material comprising carrier and toner; a donor member, mounted partially in the chamber and spaced from the imaging surface, for transporting developer on an outer surface thereof to a region opposed from the imaging surface, the donor member having a magnetic assembly having a plurality of poles, a sleeve, enclosing the magnetic assembly, rotating about the magnetic assembly; a developer bed height of the developer material produce by the rotation of the magnetic assembly on the donor member to a predefine developer bed height within a development nip; and a grid, spaced and interposed between the donor member and the charge retentive surface, the grid having being dispose longitudinal with respect to the charge retentive surface and the donor member, the grid being spaced su

Abstract: A development system optimized for localized agitation of developer material proximate to and within a development zone so as to provide cleaner and more efficient development of an electrostatic latent image on an imaging surface. The development system includes a development material sump, a magnetic developer roll including a rotatable sleeve having located therein an offset rotatable magnetic core, and a developer material delivery system for providing a metered supply of developer material. One or more stationary magnets located within the sleeve provide a static magnetic field pattern effective for attracting developer material to the sleeve and for aiding transport of the developer material therefrom to the development zone.

Abstract: A development system optimized for efficient development of an electrostatic latent image on an imaging surface. The development system includes a development material sump, a magnetic developer roll including a rotatable sleeve having located therein a rotatable magnetic core, and a developer material delivery system for providing a metered supply of developer material to the rotatable sleeve. One or more stationary magnetic shunts are located with respect to the magnetic core, sleeve, and/or developer material delivery system so as to block the magnetic field effective for attracting developer material to the sleeve, thus allowing disengagement of the developer material therefrom at a drop-off zone.