Abstract: A developing roller for providing a magnetic brush for a printer or copier has a substantially cylindrical outer surface. The outer surface includes a regular or irregular array of a number of isolated areas, each isolated area being provided by a recess in the outer surface. Each recess is completely surrounded on all sides and isolated from any neighbouring isolated area by separation zones being part of the substantially cylindrical outer surface.

Abstract: An image forming device comprises a process cartridge. The process cartridge comprises a development roller. The development roller comprises a magnet roller and a developing sleeve 132. The magnet roller is fixed. The depressions 139 each having an oval shape are formed on the external surface of the developing sleeve 132. Both ends of the depressions 139 which are adjacent with each other along the longitudinal direction of the developing sleeve 132 are overlapped with each other and both ends of the depressions 139 which are adjacent with each other along the circumferential direction of the developing sleeve 132 are spaced with each other.

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: Certain embodiments provide a developing device including: a case; a cylindrical sleeve having a development region on the outer circumferential surface and a pair of non-development regions respectively in regions at both ends in an axis direction on the outer circumferential surface; a magnet on the inside of the sleeve; plural grooves each formed between both the ends along the axis direction; a pair of magnetic sheet metals provided spaced apart from the sleeve; and a pair of magnetic seal members provided spaced apart from the sleeve. When average groove depth of the plural grooves in the development region is represented as P, thicknesses t of the magnetic sheet metals are substantially t?10×P (mm) and groove depths d of the plural grooves in the non-development regions of the sleeve are P/10?d?4P/5(mm).

Abstract: A develop roller includes a magnet roller, and a develop sleeve containing the magnet roller and comprising a plurality of depressions in an elliptic shape regularly arranged with an interval in a longitudinal direction on a surface onto which developer is attracted by a magnetic force of the magnet roller, wherein the depressions are arranged such that a longitudinal direction of the depressions is intersected with the longitudinal direction of the develop sleeve, and a downstream side of the depressions are formed to be deeper than an upstream side in a rotary direction of the develop sleeve.

Abstract: A carrier for use in a two component developer for developing an electrostatic latent image is provided. The carrier includes a particulate core material; and a cover layer located on a surface of the core material and including a silicone resin and barium sulfate. The cover layer includes Ba and Si at an atomic ratio of from 0.01 to 0.08 as determined by X-ray photoelectron spectroscopy.

Abstract: A developing roller includes a cylindrical sleeve that holds developer on a peripheral surface thereof, and a magnet roller being provided in the sleeve and having a plurality of magnetic poles. The sleeve includes a plurality of micro-recesses formed on the peripheral surface thereof, and the plurality of micro-recesses are arranged dispersedly in the axial direction and the circumferential direction of the sleeve. The densities of the micro-recesses in both end portions of the sleeve are larger than the density of the micro-recesses in a central portion of the sleeve.

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: A developing roller according to the invention includes a columnar magnet roller, and a cylindrical sleeve that houses the magnet roller. A plurality of fragmented micro recesses is formed on the surface of the sleeve. The micro recesses are arranged dispersively both in an axial direction and in a circumferential direction of the sleeve.

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: A developing unit which forms an image on a photosensitive medium, includes a housing which accommodates a developer, a magnetic cylinder having a catch pole which picks up the developer in the housing by a magnetic force, and a main pole which couples a carrier among the picked-up developer, a sleeve rotatably installed on a circumference of the magnetic cylinder to form a magnetic brush having a predetermined width on the circumference by the developer picked up by the catch pole, and a sealing member provided at opposite end parts in an axial direction of the sleeve to prevent a leak of the developer, wherein a width Ws of the sleeve, a magnetized width WM of the main pole, a magnetized width Wc of the catch pole, and a width WB of the magnetic brush satisfy WS>WM>WB>WC.

Abstract: A developing roller includes a developing sleeve and a magnet roller disposed within the developing sleeve to attract developer to an outer surface of the developing sleeve by magnetic force. The outer surface of the developing sleeve has a plurality of recesses of circular or elliptic shape in plan view regularly or irregularly arranged therein so as not to overlap.

Abstract: A magnetic particle carrying device includes a magnetic field generator and a hollow cylindrical structure. The magnetic field generator generates a magnetic field. The hollow cylindrical structure encases the magnetic field generator and attracts magnetic particles on an external surface of the hollow structure using the magnetic field. The external surface of the hollow cylindrical structure is provided with a plurality of elliptical depressions. The depressions include first type depressions and second type depressions. A long axis of a first type of elliptical depression is substantially extending in an axial direction of the hollow cylindrical structure, and a long axis of a second type of elliptical depression is substantially extending in a circumferential direction of the hollow cylindrical structure. The external surface of the hollow cylindrical structure has more elliptical depressions of the second type than elliptical depressions of the first type.

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 method for reducing high-frequency banding in an electrophotographic development station having a rotating shell and a photoconductor is disclosed. A rotating speed of the rotating shell is adjusted relative to a photoconductor such that a banding reduction ratio is not a ratio of differing low whole numbers. Another method for reducing high-frequency banding in an electrophotographic development station having a rotating shell and a rotating magnetic core is also disclosed. A rotating speed of the rotating shell is adjusted relative to a rotating speed of the rotating magnetic core such that from the point of view of a spot on a dielectric support member (DSM) in a nip region of the DSM, a similar point on the rotating shell is substantially in alignment with the DSM spot in the nip region when a pole flip occurs.

Abstract: An image forming apparatus includes an image bearing member for bearing an electrostatic latent image; a rotatable developer carrying member, provided opposed to the image bearing member, for carrying a developer including toner and a carrier to a position where the developer carrying member is opposed to the image bearing member; a regulating member for regulating the amount of the developer to be carried on the developer carrying member; a driving device for rotating the developer carrying member; a controller for controlling the driving device to execute, at the time of end of image formation, a plurality of continuous operations each including acceleration of a rotational speed of the developer carrying member and deceleration thereof following the acceleration.

Abstract: A developing apparatus in which a first magnet of a first developing sleeve includes a first magnetic pole near a potion opposing to an image bearing member, and a second magnetic pole being downstream of the first magnetic pole; and a second magnet of a second developing sleeve includes a third magnetic pole near a portion opposing to the first sleeve. Assuming that a magnetic force obtained by combining normal direction forces Fr1 and Fr2 of magnetic forces generated by the first and second magnets, respectively, near the first sleeve is Fr, a center direction component of the first sleeve of the force Fr becomes positive between the first magnetic pole and a peak value position of the second magnetic pole, and a center direction component of the force Fr becomes negative between the peak value position and the closest position between both sleeves.

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: Provided is a developing device containing a two-component developer including a magnetic carrier and a toner; a developer bearing member containing a nonmagnetic developing sleeve configured to bear the two-component developer on a surface thereof while rotating; a magnetic field generating unit fixed inside of the nonmagnetic developing sleeve; and a developer amount control member configured to control an amount of the two-component developer borne on the developer bearing member. The magnetic carrier contains a core material and a coating layer coated on the core material, and the coating layer containing a binder resin and conductive particles. The magnetic carrier satisfy a ratio D/h of 1.00<[D/h]?1.95, where D denotes an average primary particle diameter of the conductive fine particles, and h denotes a thickness of the coating layer, and a ratio Ra/D of 1.0<[Ra/D]<10.0, where Ra denotes a surface roughness of the developing sleeve.

Abstract: A developing device is provided for visualizing an electrostatic latent image previously formed on the surface of an image carrier as a toner image. The developing device has a developing roller placed at a position facing the image carrier, carrying a toner on the surface thereof, conveying the toner and flying the conveyed toner onto the surface of the image carrier; and a resin layer coated on the surface of the developing roller. The absolute value of the difference in charge between the toners in the upper and lower layers of the toner layer formed on the developing roller as the toner carried on the developing roller is 6 ?C/g or less.

Abstract: To downsize a developing device in the developing carrier axial direction without generating image concentration irregularities from recirculation of developer in the magnetic roller end regions, an N2 pole and an N3 pole, which are mutually adjacent having the same polarity (N polarity), and which are for generating a magnetic force for removing from a developing sleeve a developer that has passed through a developing region, are provided on a magnetic roller. Magnets of this developing device, which are for generating a magnetic field to displace to the inside in the axial direction magnetic force lines that cause peeling force in the direction of separation from the developing sleeve to act on developer on the developing sleeve, based on the magnetic force of the N2 pole and the N3 pole, and that pass through the axial direction end regions within a developer separation region on the developing sleeve, are provided on the outside of the magnetic roller.

Abstract: A developing device includes a magnet roll magnetized with plural magnetic poles including a main magnetic pole, a sleeve in a cylindrical shape which is arranged so as to be opposed to an image holding body, and a supporting frame that stably supports the magnet roll in a manner of restraining the magnet roll from rotating in the tangential direction, and supports the sleeve so as to rotate in the tangential direction around the magnet roll. The magnet roll is so arranged that the main magnetic pole is opposed to the image holding body, and a point on the peripheral face where magnetic flux density of the main magnetic pole in the tangential direction at a position along the peripheral face of the magnet roll is zero is set at a position predetermined with respect to a position where the magnet roll comes most closely to the image holding body.

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: A developing device includes a developing roller and a blade. The developing roller includes: a developing sleeve which rotates while holding two-component developer composed of toner and magnetic carrier on the outer surface having a plurality of grooves extending in parallel to an axis of the rotation; and a magnetic member, provided inside the developing sleeve in such a manner as to be unrotatable, for attracting the two-component developer onto the outer surface of the developing sleeve. The blade is provided outside the rotating sleeve with a gap from the outer surface of the developing sleeve for scraping off a part of the two-component developer on the outer surface of the developing sleeve. Also, the magnetic member includes a magnet for controlling magnetic flux density in the gap to range from 70 mT to 150 mT. This allows preventing image degradation caused by generation of development memory.

Abstract: Provided is a development device and an image forming apparatus that realize high image quality with improved decrease in density at high speed development and with reduced occurrence of development hysteresis (ghost) in the hybrid developing method having a plurality of toner carriers, by reducing the decrease in the toner supplying ability to the downstream-side toner carrier, which decrease is caused by the supply of toner to the toner carrier on the upstream side in the rotating direction of the developer carrier. By providing a magnetic pole between main magnetic poles, of the developer carrier, facing the toner carriers, a magnetically raised bristle of developer is moved by a magnetic force, while the developer in which development hysteresis due to supplying toner to the upstream-side toner carrier occurred is conveyed to supply toner to the downstream-side toner carrier, whereby the developer layer is stirred.

Abstract: An image forming device comprises a process cartridge. The process cartridge comprises a development roller. The development roller comprises a magnet roller and a developing sleeve 132. The magnet roller is fixed. The depressions 139 each having an oval shape are formed on the external surface of the developing sleeve 132. Both ends of the depressions 139 which are adjacent with each other along the longitudinal direction of the developing sleeve 132 are overlapped with each other and both ends of the depressions 139 which are adjacent with each other along the circumferential direction of the developing sleeve 132 are spaced with each other.

Abstract: Disclosed is an image forming method, containing a development step of developing an electrostatic latent image formed on an electrostatic image supporting material using a toner formed on a development sleeve in the from of a thin layer to form a toner image, wherein a ten-point average roughness Rz on the surface of the development sleeve is from 3.0 to 5.7 ?m, a volume average particle size of toner particles is from 6.0 to 8.0 ?m, the content of a volume average particle size of the toner particles of 5.0 ?m or less is from 2.2 to 11.0% by volume, a shape coefficient SF-1 of the toner particles that is measured by an image-analyzing apparatus satisfies the relation: 115?SF-1?155, and a shape coefficient SF-2 of the toner particles that is measured by an image-analyzing apparatus satisfies the relation: 112?SF-2?150.

Abstract: A developing device and an image forming apparatus capable of restraining density irregularity and restraining a decline in image quality caused by adherence of carrier to a photoreceptor, are provided. An angle ? is in a range of no less than 45 degrees nor more than 57 degrees, which is formed between a plane comprising a central line of magnetic pole formed by a regulating pole in a magnet roller and a rotating central axis of a developing sleeve and a plane comprising a central line of magnetic pole formed by a pumping pole and a rotating central axis of the developing sleeve. Further, an absolute value of the maximum value of strength of the magnetic pole formed by a main pole is in a range of no less than 120 mT nor more than 140 mT.

Abstract: A developing apparatus includes: a developing sleeve that carries a mono-component developer; and a developing blade that abuts on the sleeve to regulate a layer thickness of the developer on the sleeve, wherein surface roughness parameters of the sleeve satisfy: 3.0?Rpk?9.0; and 2?Pc2?10. At an abutment portion between the sleeve and the blade, surface roughness parameters of the blade satisfy: 0.030?Sm?0.170; and 0.10?Rvk×(100?Mr2)/100?1.30, where Sm is a mean spacing of profile irregularities [mm]; Rpk is an initial wear height [?m]; Rvk is an oil retaining depth [?m]; Mr2 is a profile bearing length ratio 2 [%]; and Pc2 denotes the number of profile peaks having a height larger than a count level from a center line per the evaluation length of 1 mm.

Abstract: To downsize a developing device in the developing carrier axial direction without generating image concentration irregularities from recirculation of developer in the magnetic roller end regions, an N2 pole and an N3 pole, which are mutually adjacent having the same polarity (N polarity), and which are for generating a magnetic force for removing from a developing sleeve a developer that has passed through a developing region, are provided on a magnetic roller. Magnets of this developing device, which are for generating a magnetic field to displace to the inside in the axial direction magnetic force lines that cause peeling force in the direction of separation from the developing sleeve to act on developer on the developing sleeve, based on the magnetic force of the N2 pole and the N3 pole, and that pass through the axial direction end regions within a developer separation region on the developing sleeve, are provided on the outside of the magnetic roller.

Abstract: A sleeve constituting a developing roller of a developing device has a cylindrical body with three layers composed of a base layer having rigidity and formed in a mesh-like shape, a filter layer for blocking toner passage, and a conductive layer to which a developing bias voltage is applied, which are arranged in this order from the inside. When a sucking device sucks from an open end of one end portion of the sleeve, an air flow going from the inside of the developing roller through the open end to outside is generated so that a pressure of the internal space of the developing roller becomes smaller compared with the outside. As the peripheral wall has air permeability in its thickness direction, air flows from the outer circumferential portion of the developing roller through the peripheral wall to the inside of the developing roller.

Abstract: A developing device includes a developer carrier opposed to an image carrier for carrying an electrostatic latent image, and a rotatable developer transferring screw for transferring developer to the developer carrier while agitating; the developer carrier includes a magnet roller and a developing sleeve including a rotatable non-electromagnetic cylinder body disposed coaxially with an axis of the magnet roller to contain the magnet roller, and an axis diameter of a center portion of the developer transferring screw is set larger than an axis diameter of each of both end portions of the developer transferring screw.

Abstract: The invention relates generally to processes for electrographic image development. An electrographic development apparatus is provided wherein a film is adjacent a cylindrical toning shell and a mixture of toner and carrier is particles disposed on the cylindrical toning shell in contact with the film. The cylindrical toning shell is closest to the film at a first location, the mixture of toner and carrier particles being movable through the first location with a flow direction. A magnetic core disposed within the cylindrical toning shell offset toward the cylindrical shell such that a magnetic field strength is greater at the second location than the first location.

Abstract: A developing device visualizing an electrostatic latent image previously formed on the surface of an image carrier as toner image, comprising: a developing roller placed at a position facing the image carrier, carrying a toner on the surface thereof, conveying the toner and flying the conveyed toner onto the surface of the image carrier; and a resin layer coated on the surface of the developing roller, wherein the absolute value of the difference in charge between the toners in the upper and lower layers of the toner layer formed on the developing roller as the toner carried on the developing roller is 6 ?C/g or less.

Abstract: A developing roller includes a cylindrical sleeve that holds developer on a peripheral surface thereof, and a magnet roller being provided in the sleeve and having a plurality of magnetic poles. The sleeve includes a plurality of micro-recesses formed on the peripheral surface thereof, and the plurality of micro-recesses are arranged dispersedly in the axial direction and the circumferential direction of the sleeve. The densities of the micro-recesses in both end portions of the sleeve are larger than the density of the micro-recesses in a central portion of the sleeve.

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 magnetic roll having longitudinal grooves machined in its rotating sleeve enables a pair of rolls to be rotated in a direction opposite to the direction of a photoreceptor moving through a development zone and a trim blade to be mounted proximate one of the rolls at a trim gap of approximately 0.5 to 0.7 mm. The magnetic roll includes a stationary core with at least one magnet, and a sleeve having longitudinal grooves that is mounted about the stationary core so that the sleeve rotates about the stationary core. The sleeve has a relatively smooth surface area between the grooves.

Abstract: The present invention provides a developer holding member having a surface layer composed of metal on or above a roughened hollow cylindrical substrate, wherein the specular gloss at 60°, Gs (60°), of the surface layer is in the range of approximately 10 to 40 gloss units, a developing apparatus and image-forming apparatus having the developer holding member, and a method of producing the developer holding member.

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: The present invention provides a developing method and a developing unit which can obtain a favorable image quality and the like even when a surface roughness Rz of a developing sleeve is changed or when an amorphous-silicon photoconductor is used by allowing the magnetic monocomponent toner to effectively jump to a photoconductor from a developing sleeve. To attain such an object, the present invention provides a magnetic monocomponent jumping developing system and a developing unit which uses the method, wherein as the magnetic monocomponent toner, a toner having a volume center particle size which is calculated from the particle size distribution based on volume and falls within a range from 6.0 to 7.8 ?m, having the sphericity which falls within a range from 0.92 to 0.98, and setting a toner quantity having a volume particle size of 5.04 ?m or less to a value which falls within a range from 2.5 to 10.

Abstract: A developing device is provided with a developer accommodating vessel accommodating developer having as primary components a nonmagnetic toner and magnetic particles referred to as a carrier. The carrier is composed of a magnetic material as a core material that is uniformly covered with an insulating synthetic resin. The toner is mixed with the carrier at a weight ratio to the overall weight of the developer of 3-10%. The carrier has an average particle size of 65 ?m or less and a saturation magnetization of at least 70 emu/g. The developing device includes a developing roller and a sleeve roller that rotates about the developing roller. The surface of the sleeve roller is processed with metal shot to achieve a surface roughness of 0.45-1.08 times the average particle size of the carrier, or more specifically a roughness Rz of about 30 ?m.

Abstract: A developing roller includes a developing sleeve and a magnet roller disposed within the developing sleeve to attract developer to an outer surface of the developing sleeve by magnetic force. The outer surface of the developing sleeve has a plurality of recesses of circular or elliptic shape in plan view regularly or irregularly arranged therein so as not to overlap.

Abstract: A developing roller according to the invention includes a columnar magnet roller, and a cylindrical sleeve that houses the magnet roller. A plurality of fragmented micro recesses is formed on the surface of the sleeve. The micro recesses are arranged dispersively both in an axial direction and in a circumferential direction of the sleeve.

Abstract: A developing device includes a developing roller and a blade. The developing roller includes: a developing sleeve which rotates while holding two-component developer composed of toner and magnetic carrier on the outer surface having a plurality of grooves extending in parallel to an axis of the rotation; and a magnetic member, provided inside the developing sleeve in such a manner as to be unrotatable, for attracting the two-component developer onto the outer surface of the developing sleeve. The blade is provided outside the rotating sleeve with a gap from the outer surface of the developing sleeve for scraping off a part of the two-component developer on the outer surface of the developing sleeve. Also, the magnetic member includes a magnet for controlling magnetic flux density in the gap to range from 70 mT to 150 mT. This allows preventing image degradation caused by generation of development memory.

Abstract: An image forming apparatus includes a container configured to contain two-component developer including toner particles and carrier beads. The image forming apparatus further includes a developer carrying member configured to carry thereon the two-component developer and having a magnetic field generating member and a plurality of grooves having a generally V-like shape satisfying h?50+R/2+{(R/2)/sin(?/2)}, in which h represents a depth of the grooves, ? represents an opening angle of the grooves, and R represents a volume-average diameter of the carrier beads.

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 includes: a developer supporter that includes: a magnet member that has a plurality of magnetic poles; and a cylinder member; and a thickness regulation member wherein, of the plurality of the magnetic poles, a magnetic pole, which is placed at a position nearest to the thickness regulation member downstream in a rotation direction of the cylinder member from the thickness regulation member, has a maximum position of a normal magnetic flux density distribution, and the maximum position is placed outside the area of angle ? downstream in the rotation direction of the cylinder member from the thickness regulation member, and wherein the diameter of the cylinder member is D, the projection width is W in a case where the thickness regulation member is projected onto the surface of the cylinder member, and the angle ? is 180×W/(D×?).

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.