Abstract: A developing device including a developer containing magnetic toner grains and includes a main pole for development disposed in a sleeve. Flux density generated by the magnetic pole in a direction normal to the surface of the sleeve outside of the surface has an attenuation ratio of 50% or above. The toner grains have a weight mean grain size of 6.0 ?m to 8.0 ?m while the toner grains having grain sizes of 5 ?m and below occupy 40% to 80% of the entire developer. The toner grains have magnetization strength of 10 emu/g to 25 emu/g in a magnetic field of 5 kOe or magnetization strength of 7 emu/g to 20 emu/g in a magnetic field of 1 kOe. The toner grains reduce toner scattering and image defects despite that they are magnetic, thereby implementing ultrahigh resolution.

Abstract: A developing method of the present invention uses a sleeve accommodating a stationary magnet roller formed with a plurality of magnetic poles and facing an image carrier. The sleeve is rotated to convey a developer, which is made up of toner grains and magnetic carrier grains and deposited on the sleeve, to a developing zone for thereby feeding the toner grains from a magnet brush formed by the developer to a latent image formed on the image carrier. When the developing zone is seen from the image carrier side, the ratio of the total area of voids present at the tips of the magnet brush to the total area of the developing zone is selected to be 25% or less.

Abstract: A carrier including a magnetic core material and a layer located on a surface of the magnetic core material, wherein the carrier satisfies the following relationships (1) to (3): 0.90≦(&sgr;a/&sgr;b)<1.00 (1); 200≦(&sgr;b·&rgr;c)≦400 (2); 10≦(&sgr;b/&rgr;c)≦20 (3), wherein &sgr;b represents a magnetization of the carrier at 1,000 Oe, &sgr;a represents a magnetization of the carrier after frictionized with a cylindrical sleeve under a specific condition and &rgr;c represents a true specific gravity of the carrier, wherein the carrier has a weight-average particle diameter of about 25 to about 65 &mgr;m and includes carrier particles having a weight-average particle diameter not greater than about 12 &mgr;m in an amount of not greater than about 0.3% by weight, wherein a ratio between the weight-average particle diameter and a number-average particle diameter of the carrier is about 1 to about 1.3, and wherein an electric resistance is from about 1.0×109 to about 1.

Abstract: Apparatus and methods for electrographic image development, wherein the image development process is optimized by subjecting the developer to magnetic field maxima, thereby imparting to the developer a velocity component in a direction perpendicular to the process direction, ensuring that the toner particles thus accelerated have sufficient kinetic energy to overcome the binding energy binding the toner particles to the carrier particles in the developer, and to be deposited on a receiver bearing an electrostatic latent image. The optimized image is developed to completion, where development to completion is characterized by a proportionality between the cube of the toner charge to mass ratio and a quantity consisting of the magnitude of the voltage of the toning shell minus the magnitude of the voltage of the toned image.

Abstract: A clearance regulating amount L by a clearance regulating member 4, which is provided above a developing roller 3 on a side closer to a photosensitive drum 1, is determined at a size not greater than a height T of a developer at a magnetic pole just downstream of the clearance regulated position. Thus, the scattering of the developer from a developing unit 2 is significantly reduced.

Abstract: A method and apparatus for image forming includes a hybrid developing apparatus that supplies surly charged toner to a developing roll. The apparatus includes a developing roll that is electrically conductive at least on its surface. The image forming apparatus and the method have a constitution capable of applying an alternating current bias having a duty ratio in the range of 10 to 50% and a direct current bias superposed thereon. The developing roll is directly confronted with a latent image bearing body through an insulative toner thin layer at the nearest region of the developing roll and the latent image bearing body. An independent bias is applied to each of the developing roll and the magnetic roll, and the toner is refreshed by the varying duty ratio of the alternate current bias and the direct current bias after developing.

Abstract: A developer carrier used for an SLIC developing system. Characteristic values contributing to provide high image quality, which cannot be covered by the stipulations of the attenuation ratio and half-value width of the flux density are clarified. The developer carrier is constituted to be composed of the developing sleeve for carrying and transporting the developer, and a magnetic roll disposed in the developing sleeve, having a plurality of magnetic poles P1-P5. A narrow nip for development is realized by narrowing the width of the pole for development P1 forming the magnet brush by raising the developer in the developing region facing the latent image carrier, and by narrowing the rising region of the developer in the developing region and the flux density attenuation ratio of the pole for development P1 is 40% or more. The half-value width of the flux density of the pole for development P1 is 22% or less, and the flux density variation rate is 4.

Abstract: An image forming apparatus develops a latent image formed on an image carrier with a developer that forms a magnet brush on a developer carrier. The developer carrier is made up of a sleeve and a stationary magnet roller accommodated in the sleeve. The magnet roller includes a main pole for causing the developer to form the magnet brush and auxiliary poles for helping the main pole exert a magnetic force. An electric field including an oscillation component is formed between the image carrier and the developer carrier. A particular ratio is set up between a distance between the image carrier and the developer carrier, as measured at the boundary of a nip, and the shortest distance between them, between the above shortest distance and the shortest distance between the developer carrier and a metering member, or between the shortest distance between the image carrier and the developer carrier and the amount of developer scooped up to the image carrier.

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 developing agent carrying member including magnets is disposed facing an image carrying member, a two-component developing agent containing toner and magnetic carrier is carried in a form of a layer on a surface of the developing agent carrying member, speed difference is generated between the developing agent carrying member and the magnets so as to cause a magnetic brush to flow while forming the magnetic brush on a developing agent layer at least in a facing region where the developing agent carrying member and the image carrying member face one another, and free toner separated from magnetic carrier in a flow of the magnetic brush adheres onto a latent image formed on the image carrying member, whereby developing is performed. A line-shaped latent image is developed with the toner starting from a middle portion thereof in a width direction of the line-shaped latent image.

Abstract: An image forming method including providing a developer including a toner and a magnetic carrier, a developer carrier configured to convey the developer deposited thereon, and magnetic field generating means fixed within the developer carrier, and forming a magnetic field which forms a magnet brush between the image carrier and the developer carrier such that the magnet brush rises, contacts the image carrier and collapses within a range in which the magnetic field is more intense than an electric field capable of separating the toner and the magnetic carrier from each other by using the magnetic field generating means. The magnetic brush rubs the image carrier to thereby develop a latent image formed on the image carrier.

Abstract: A developing device includes a developing agent carrying member which rotates in the same direction as a latent image carrying member while carrying a developing agent. A casing is provided to form a developing agent storing space therein for storing developing agent and has an opening whereby a portion of the surface of the developing agent carrying member faces the latent image carrying member. A developing agent restricting member is provided upstream of a developing region within the casing such that a gap is formed between the developing agent restricting member and the developing agent carrying member to restrict the amount of developing agent supplied to the developing region. Means for generating a magnetic field are provided so that the developing agent forms a magnetic brush closing off the space between the surface of the developing agent carrying member and the inner wall of the casing.

Abstract: A developing method of the present invention develops a latent image formed on an image carrier with a developing device including at least a developer carrier and a doctor blade. The developer carrier magnetically causes a two-ingredient type developer made up of toner grains and magnetic carrier grains to deposit thereon and conveys it to a developing zone where the developer carrier faces the image carrier. The doctor blade regulates the thickness of the developer forming a layer on the developer carrier. The ratio of a dynamic torque W (kgf·cm) to act on the developer while the developing device is in operation to an amount of toner grains M (g) contained in the developer is selected to be 4.0×10−2 or below.

Abstract: Development systems and methods for developing using magnetic toner are disclosed. The present invention further discloses developers used in development systems as well as the toner used in developer for magnetic ink character recognition printing. With respect to the development system, a development system is disclosed which includes a supply of dry developer mixture which contains magnetic toner particles and hard magnetic carrier particles. The development system further includes a non-magnetic, cylindrical shell for transporting the developer between the supply and the development zone, wherein the shell can be rotatable or stationary. A rotating magnetic core of a pre-selected magnetic field strength and means for rotating at least the magnetic core to provide for the transport of the toner particles from the shell to an electrostatic image also provided as part of the development system.

Abstract: A development system having a magnetic developer material that features novel coated carrier particles. In embodiments of the invention, the coated carrier particles incorporate a coating of sufficiently resilient characteristic so as to maintain the encapsulation of the respective carrier core while withstanding the mechanical action of a development material stripping device which would otherwise cause fragmentation of the carrier particles. Preferably, the carrier coating is of a sufficiently thick and/or a resilient nature such that the desired encapsulation is maintained.

Abstract: A developing apparatus of an electric photographic printer supplying a two-element developing agent to develop an electrostatic latent image formed on a photosensitive medium includes: a housing; a developing agent supplying roller; a developing agent mixing roller; a developing sleeve to transfer mixed developing agent to the photosensitive medium through a developing area formed between the developing sleeve and the photosensitive medium; a fixing magnet disposed inside of the developing sleeve to have a plurality of magnetic poles arranged from the developing area in a circular direction about a center of the fixing magnet; and a magnetic bar disposed on an inside surface of the housing to face one of the magnetic poles of the fixing magnet through the developing sleeve to form a magnetic force brush preventing the developing agent from being scattered as the developing agent passes through the developing area.

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 &mgr;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: Development systems and methods for developing using toner are disclosed. The present invention further discloses developers used in development systems. With respect to the development system, a development system is disclosed which includes a supply of dry developer mixture which contains toner particles and hard magnetic carrier particles. The development system further includes a non-magnetic, cylindrical shell for transporting the developer between the supply and the development zone, wherein the shell can be rotatable or stationary. A rotating magnetic core of a pre-selected magnetic field strength and means for rotating at least the magnetic core to provide for the transport of the toner particles from the shell to an electrostatic image also provided as part of the development system. The development system of the present invention further includes a fuser roll which is coated with a silicone rubber or other low surface energy elastomer or resin.

Abstract: An image formation apparatus develops an electrostatic latent image with a two-component developer consisting of magnetic carriers and toners by using a development apparatus and a latent image supporter including a filler in an outermost layer thereof, the development apparatus having a developer supporter, which has an internally fixed magnetic body and rotates while supporting a developer on a surface thereof, and a developer quantity controller controlling a quantity of the developer which is supported by the developer supporter facing the magnetic body and controlling a height of magnetic brushes and consisting of materials having rigidity or rigidity and magnetic properties, wherein a ratio (Gp/Gd) of a development gap to a doctor gap between the developer supporter and the controller is from 0.7 to 1.0, and a weight-averaged particle diameter of a developer carrier is from 20 to 60 &mgr;m.

Abstract: An electrographic development machine that utilizes magnetic toner particles includes a dielectric film member for carrying an electrostatic image thereon. A toner roller is disposed upon a first side of the dielectric film member. The toner roller has a core and an outer shell. The core includes a plurality of toner roller magnets, each of which have a respective north and south pole. The toner roller magnets are disposed such that adjacent pairs thereof have poles of opposite polarity disposed proximate the shell. The toner roller provides the dielectric film member with a supply of developer material. The machine further includes means for altering or balancing the magnetic forces acting on the developer.

Abstract: A developing device capable of obviating carrier deposition on an image carrier and uniformly distributing toner on a developer carrier is disclosed. A developer deposited on the developer carrier and moved away from a metering member rises in the form of a magnet brush, falls down, and again rises in accordance with the movement of the developer carrier. The toner of the developer is efficiently agitated in the axial direction of the developer carrier in a narrow zone between the first metering member and a developing 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.

Abstract: An image forming apparatus of the present invention includes a lubricator for applying a lubricant to an image carrier or a process unit around the image carrier to thereby reduce friction. The apparatus of the present invention insures a uniform halftone image, prevents the trailing edge of an image from being lost, and faithfully reproduces even a horizontal line.

Abstract: The invention relates generally to processes for electrostatic image development, and setpoints that provide uniform image development. In particular, an apparatus and process having a magnetic brush that implements a rotating magnetic core within a shell is disclosed. The process implements one or more of the following optimum setpoints: a range of shell surface speeds that provide uniform toning density, a range of shell surface speeds that prevent toner plate-out, a skive spacing that minimizes sensitivity to variation, a magnetic core speed that minimizes sensitivity to variation, and an imaging member spacing that minimizes sensitivity to variation.

Abstract: In a development system including a developer transport adapted for depositing developer material on an imaging surface having an electrostatic latent image thereon, including: a housing defining a chamber storing a supply of developer material including 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; the magnetic assembly generating a developer bed having a predefined developer bed height; a grid, interposed between the donor roll and the imaging surface within the predefined bed height, the grid having apertures for permitting carrier and toner therethrough; and means for biasing a region between the grid and the imaging surface at a voltage potential so that toner is ejecting towards the imaging surfa

Abstract: Development systems and methods for developing using magnetic toner are disclosed. The present invention further discloses developers used in development systems as well as the toner used in developer for magnetic ink character recognition printing. With respect to the development system, a development system is disclosed which includes a supply of dry developer mixture which contains magnetic toner particles and hard magnetic carrier particles. The development system further includes a non-magnetic, cylindrical shell for transporting the developer between the supply and the development zone, wherein the shell can be rotatable or stationary. A rotating magnetic core of a pre-selected magnetic field strength and means for rotating at least the magnetic core to provide for the transport of the toner particles from the shell to an electrostatic image also provided as part of the development system.

Abstract: A developing apparatus has a developer supporting member 41 with a surface roughness RZ in the range from 3.0 to 5.5 &mgr;m and a one-component developer T with a bulk density in the range from 0.35 to 0.55 g/ml, and an image is developed by forming a layer of the developer T on the developer supporting member 41. This makes it possible to form a thin toner layer stably despite changes in ambient conditions, and to prevent low image density and fogging. The absolute value of the amount of electric charge with which the developer T is charged is preferably in the range from 3.0 to 10.0 &mgr;C/g. The developer supporting member 41 is made preferably of stainless steel.

Abstract: A developing device of the present invention includes a developing roller provided with a plurality of magnetic poles. The magnetic poles include a main pole and two auxiliary poles positioned at both sides of the main pole for helping the main pole form a magnetic force. The auxiliary poles reduce the half width of the main pole. An AC-biased DC bias for development is applied to the developing roller and disturbs carrier grains close to the developing roller. Images free from various defects including granularity and local omission are achievable with the developing device.

Abstract: In a magnet brush type developing method of the present invention, at least one position where brush chains formed by magnetic carrier grains rise exists in a portion where an electric field formed between a facing zone where an image carrier and a developer carrier face each other has a strength E (V/m) expressed as:

Abstract: In an image forming apparatus, a magnet brush forming device includes at least a first magnetic pole facing an image carrier carrying a latent image and a second magnetic pole positioned downstream of the first magnetic pole in the direction of rotation of a developer carrier. When a magnet brush formed on a developer carrier by the first magnetic pole forms a nip between it and the image carrier, flux density in the direction normal to the developer carrier has an attenuation ratio of 40% or above. The second magnetic pole has an upstream half-value point located downstream of a point upstream of and angularly spaced from the edge of a developer storing member by 15°. Flux density in the normal direction and flux density in the tangential direction between the first and second magnetic poles have vectors the sum of which is 85 mT or above.

Abstract: An image formation apparatus develops an electrostatic latent image with a two-component developer consisting of magnetic carriers and toners by using a development apparatus and a latent image supporter including a filler in an outermost layer thereof, the development apparatus having a developer supporter, which has an internally fixed magnetic body and rotates while supporting a developer on a surface thereof, and a developer quantity controller controlling a quantity of the developer which is supported by the developer supporter facing the magnetic body and controlling a height of magnetic brushes and consisting of materials having rigidity or rigidity and magnetic properties, wherein a ratio (Gp/Gd) of a development gap to a doctor gap between the developer supporter and the controller is from 0.7 to 1.0, and a weight-averaged particle diameter of a developer carrier is from 20 to 60 &mgr;m.

Abstract: An electrophotographic image forming apparatus of the present invention frees images from various defects including the thinning of horizontal lines, the omission of the trailing edge an image, background contamination, granularity particular to a halftone image, carrier scattering, and image noise. Further, the apparatus of the present invention solves problems ascribable to patches used to sense image density. Moreover, the apparatus of the present invention faithfully reproduces tonality and has a high developing ability.

Abstract: In a xerographic development apparatus using a magnetic brush formed from magnetic carrier particles, a magnetic strip disposed downstream of the development zone along the direction of motion of the photoreceptor retains a separate, small brush of carrier particles near the photoreceptor. The brush acts as a barrier separating a flow of “dirty” air (laden with airborne toner particles) upstream of the strip, and a flow of clean air downstream of the strip.

Abstract: In a development system including a developer transport adapted for depositing developer material on an imaging surface having an electrostatic latent image thereon, including: 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; the magnetic assembly generating a developer bed having predefine developer bed height; a grid, interposed between said and the imaging surface within the predefined bed height, the grid having apertures for permitting carrier and toner therethrough; and means for biasing a region between the grid and the imaging surface at a voltage potential so that toner is ejecting towards the imaging surface after ton

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 1 C = 2.

Abstract: A developing device for an image forming apparatus of the present invention includes a developing roller made up of a sleeve and a magnet roller and a doctor facing the surface of the sleeve. The edge of the doctor faces the sleeve at a particular position selected to stabilize the amount of a developer to be scooped up, protect the developer from deterioration, and allow an adequate amount of charge to deposit on the developer by friction.

Abstract: A developing method of the present invention uses a sleeve accommodating a stationary magnet roller formed with a plurality of magnetic poles and facing an image carrier. The sleeve is rotated to convey a developer, which is made up of toner grains and magnetic carrier grains and deposited on the sleeve, to a developing zone for thereby feeding the toner grains from a magnet brush formed by the developer to a latent image formed on the image carrier. When the developing zone is seen from the image carrier side, the ratio of the total area of voids present at the tips of the magnet brush to the total area of the developing zone is selected to be 25% or less.

Abstract: Development systems and methods for developing using chemically prepared toners are disclosed. The present invention further discloses developers used in development systems. The use of chemically prepared toners with hard magnetic carrier particles with a non-magnetic, cylindrical shell for transporting developers provides excellent benefits with respect to image quality by reducing granularity and by providing a typically constant, stable developer life as shown by the consistent level of charge to mass over time during operation.

Abstract: A process for developing which includes the step of developing a latent electrostatic image on a latent electrostatic image support by a developing agent supplied on a development sleeve, where the developing agent is supplied with a density of 1.3 g/cm3 to 2.0 g/cm3 at the closest part between the support and the sleeve, the support is contacted with magnetic brushes formed of the developing agent on the sleeve, so that the magnetic brushes have a width of 2 mm or less at a linearly contacting surface, in a direction where the surface rotates and the developing agent contains toners, and carriers having magnetic core particles and resin layers to cover its surface, the carriers have a weight average particle diameter of 25 &mgr;m to 45 &mgr;m, contain 60 wt % or more of the particles having a diameter of less than 44 &mgr;m, and 7 wt % or less of particles having a diameter of less than 22 &mgr;m.

Abstract: A developing device of the present invention includes an image carrier for forming a latent image thereon, and a developer carrier for depositing a developer thereon in the form of a magnet brush. The magnet brush is caused to contact the latent image to thereby develop it. The developer carrier includes a main magnetic pole for development and an auxiliary magnetic pole adjoining the main pole and helping the main pole exert a magnetic force. The developer carrier and said image carrier are spaced by a gap of 0.35 mm or above, but 0.5 mm or below. The developer carrier has a carrier packing ratio of 15% or above, but 45% or below, measured at the developing region.

Abstract: Apparatus and methods for electrographic image development, wherein the image development process is optimized by setting the average developer bulk flow velocity with reference to the imaging member velocity, for example, where the average developer bulk velocity is about the same as the imaging member velocity, or within preferred ranges, such as between about 40% to about 130% of the imaging member velocity.

Abstract: In a developing assembly having a developer container, a developer-carrying member, a developer layer thickness control member, a magnetic-field formation device and an agitation member, the developer is a two-component developer which contains at least a binder resin, a colorant, an organometallic compound and a wax and has wax-dispersed non-magnetic toner particles with an average particle diameter of from 2 &mgr;m to 10 &mgr;m and a magnetic carrier. The developer-carrying member is a member which has been subjected to surface blasting with spherical particles to have a surface having a ten-point average roughness Rz in a range from D/6 to D/2 where D is the average particle diameter of the magnetic carrier. The magnetic carrier has a magnetization intensity in a range of 8 Am2/kg to 50 Am2/kg in a magnetic field of 7.95775 kA/m.

Abstract: An image forming apparatus is provided for obtaining excellent developing properties using toner with small particle diameters and for forming high-quality visual images. In a developing device of an image forming apparatus, a two-component developer is used which satisfies conditions that volume mean particle diameter dt of a toner is 3˜5 &mgr;m (Condition 1), volume mean particle diameter dc of a carrier is 5 dt˜10 dt (Condition 2), and a weight ratio Rw of the toner and the carrier is 1.6 (dt/dc) ×(&rgr;t/&rgr;c)˜2.4 (dt/dc)×(&rgr;t/&rgr;c) (Condition 3, where &rgr;t and &rgr;c are density of the toner and the carrier, respectively). A main magnetic pole M of a rotary sleeve is arranged in the vicinity of the closest position of the rotary sleeve and an image forming body, and the closest distance D between the rotary sleeve and the image forming body satisfies a condition that D is 0.5 H˜0.8 H for the free tip height H of a magnetic brush B of the main magnetic pole M.

Abstract: A developing method of the present invention develops a latent image formed on an image carrier with a two-ingredient type developer, which consists of toner grains and magnetic carrier grains for supporting the toner grains. A developer carrier faces the image carrier and accommodates magnetic field forming device therein for causing the developer to deposit on the developer carrier. The developer is conveyed to a developing zone formed between the image carrier and the developer carrier. The latent image is developed by a magnet brush including free toner grains, which part from brush chains formed by the carrier grains when the brush chains start rising on the developer carrier in the developing zone. The method insures a high-density, smooth solid image. A device for practicing the method is also disclosed.

Abstract: A device (100) for the transport of particles (30), in particular development particles (30) with a first magnetic roller (11) and a second magnetic roller (22), in which the first magnetic roller (11) and the second magnetic roller (22) form a gap, and with a photographic element (1) for the particles (30), which moves through the gap, while the magnetic rollers (11, 22) turn in the same direction.

Abstract: An image forming apparatus of the present invention includes a developing device including a rotatable, nonmagnetic developer carrier and a magnetic field forming device. In a developing region where the developer carrier faces an image carrier, the magnetic field forming device causes a developer made up of toner and magnetic grains to rise on the developer carrier in the form of a magnet brush. In the developing region, the magnet brush on the developer carrier is caused to move at a higher speed than the surface of the image carrier in the same direction as and in contact with the surface of the image carrier, thereby developing the latent image. The toner of the developer is magnetic toner. Flux density set up in the developing region outside of the surface of the developer carrier in a normal direction has an attenuation ratio of 50% or above.

Abstract: A developing roller of the present invention is made up of a nonmagnetic sleeve and a magnet roller disposed in the sleeve. The magnet roller includes a cylindrical magnet produced by molding a mixture of magnetic powder and a high polymer, and a single rare-earth magnet block mounted on the magnet at a position corresponding to a main magnetic pole for development. The cylindrical magnet is magnetized such that magnetic poles adjoining the main magnetic pole are opposite in polarity to the main pole. The main pole and each pole adjoining it make an angle of 45° or less therebetween.

Abstract: A developing device that develops a latent image with a two-component developer includes a developer carrier, a first developer conveying screw that conveys the developer from a first to a second end of the first developer conveying screw and transfers the developer to the developer carrier, and a second developer conveying screw that conveys the developer from a first to a second end of the second developer conveying screw and conveys the developer from the second end of the second developer conveying screw to the first end of the first developer conveying screw.

Abstract: A developing device of the present invention includes a developing roller including a sleeve and a magnet roller accommodated in the sleeve. The surface of the sleeve s configured such that the center portion, including an image forming range corresponding to the image forming range of an image carrier, in the direction of width perpendicular to the direction of movement of the above has a higher developer conveying ability than opposite end portions outward of the center portion. Opposite ends of the magnetic pole of the magnet roller in the direction of width face the opposite end portions of the sleeve.

Abstract: An image forming apparatus has a non-magnetic rotatable cylinder having a diameter of 10 mm to 25 mm, a plurality of magnetic field generating means which is inside the non-magnetic cylinder and fixed, a developing container which houses a two component developer containing a magnetic carrier and a non-magnetic toner and has the non-magnetic cylinder rotatably mounted at an opening portion thereof, agitating conveyer means which is inside the developing container and agitates the two component developer and conveys it to the non-magnetic cylinder, and an image bearing member arranged in opposition to the non-magnetic cylinder at intervals. The image forming apparatus is an image forming apparatus which conveys the two component developer by the rotation of the non-magnetic cylinder, and an electrostatic latent image on the image bearing member is magnetic-brush-developed.