Abstract: A developing device for developing a latent image formed on an image carrier includes a developer carrier having a developer carrying surface. The developer carrying surface includes a plurality of grooves to carry the developer. Dispersion D (%) in depth of the plurality of grooves is calculated according to an equation, D (%)={(A−B)/2}/C, where A is a maximum depth of the plurality of grooves, B is a minimum depth of the plurality of grooves, and C is an average depth of the plurality of grooves. The dispersion D (%) is at most approximately 30%.

Abstract: An image forming apparatus includes a latent image carrier that carries an electrostatic latent image, a developer carrier that carries a two-component developer containing toner and magnetic particles, and an electric field forming device that forms a developing electric field to develop the electrostatic latent image with the toner in a developing region where the developer carrier faces the latent image carrier. A magnetic brush is formed by magnetically adsorbing the two-component developer onto the surface of the developer carrier to develop the latent image with the toner in the magnetic brush. A developing gap between the developer carrier and the latent image carrier in the developing region is set so as not to press the toner in the magnetic brush against the surface of the developer carrier that faces a non-image portion of the latent image carrier and set so as not to fix the toner onto the developer carrier.

Abstract: To control bending of a magnetic field generation unit provided inside a developer carrying member, a developing apparatus for developing an electrostatic image formed on an image bearing member according to the present invention includes: a developer container which contains a magnetic developer; first and second developer carrying members which carry the developer in the developer container to the image bearing member; and first and second magnetic field generation units which are fixedly arranged in the first and second developer carrying members. In the developing apparatus, the first magnetic field generation unit and the second magnetic field generation unit form a magnetic field for delivering the developer from the first developer carrying member to the second developer carrying member, and the developing apparatus further includes a magnetic unit which exerts a magnetic force, which resists a magnetic force caused by the magnetic field, on the first and second magnetic field generation units.

Abstract: A developing device including a developer supporter, and a napping unit for napping the developer on the developer supporter by magnetic poles. The napping unit further includes a developing main magnetic pole installed at a location opposite to a latent image supporter, and a developing auxiliary magnetic pole located at a downstream side of the developing main magnetic pole in a rotational direction of the developer supporter. The developing main magnetic pole has a half-value width equal to or less than 22°. The composite magnetic flux density of the developing main magnetic pole and the developing auxiliary magnetic pole is equal to or greater than 80 mT. In this way, the disclosure can prevent voids in a back end from occurring to improve the fine line reproduction, and additionally, the carrier adhesion can be also prevented.

Abstract: A developing apparatus prevents or reduces splashing of toner and carrier caused by abnormal outward airflows generated at downstream positions of a developing unit casing thereof through interactions between behaviors of magnetic brushes and local portions of the developing unit casing. The developing apparatus includes a developer carrying member, a first permanent magnet, a developing unit casing, a second permanent magnet, which is built in the developer carrying member at a fixed position at the downstream side from the first permanent magnet with respect to the rotational direction of the developer carrying member. The developing unit casing has a concave structure to form a low pressure area at a position facing the second permanent magnet. The low pressure area suppresses an increase in the speed of the airflow therein that causes the abnormal outward airflows.

Abstract: In a developing device for an image forming apparatus of the present invention, a main magnetic pole for development has an angle of 60° or below between opposite pole transition points respectively positioned upstream and downstream thereof in a direction of developer conveyance. A flux density between the main magnetic pole and the magnetic pole downstream of the main magnetic pole in the normal direction has a peak value that is 80% of the maximum flux density of the main pole in the normal direction or above. With this configuration, it is possible to reduce various defective images at the same time.

Abstract: The development is performed under a condition that |Q2|−|Q1|/|Q1≦±0.45. Here, Q1 denotes an average amount of charge on toner held on a development roller and carried toward a development region immediately before development. Q2 denotes an average amount of charge on toner immediately before development held and carried toward the development region in the state immediately after development of an electrostatic latent image on a development drum. This is effective to allow the amount of charge q/m on toner held on the development roller to have a variation rate of 45% or below and an afterimage rate R within 2%.

Abstract: An image-forming apparatus which includes an image developer configured to develop a latent electrostatic image and to have a developer, a developer bearing member which has a magnet therein, has the developer on a surface thereof, and rotates with carrying the developer, and a developer limiting member which faces the developer bearing member, and controls an amount of the developer, and a latent electrostatic image support configured to contain a filler in its outermost layer. In the image-forming apparatus, the developer is a double-component developer which contains a magnetic carrier and a toner, the magnetic carrier has a coating layer which is formed of a binder resin having particles retained on a surface of the magnetic carrier, and a ratio of a particle diameter D1 of the particles to a film thickness h1 of the binder resin satisfies a relation of: 1<D1/h1<10.

Abstract: The toner of the present invention is suitably used in SLIC development system where a liner velocity of a developer-bearing member is 150 to 500 cm/sec. The toner has resin particles containing at least a coloring agent, and a charge controlling agent fine articles, and a ratio M/T of the amount M (% by weight) of an element in the surface of toner particles as determined by X-ray photoelectron spectroscopy (XPS) to the amount T (% by weight) of the element in the entire toner particles of 20 to 500, which element is present only in a charge control agent among components of the toner and is an element belonging to one of the first, second, third, fourth, and fifth periods of the long form of periodic table of elements except hydrogen, carbon, oxygen, and rare gas elements.

Abstract: A developing apparatus includes a first developing system for developing a latent image formed on an image bearing member with a first developer including magnetic toner. The first developing system includes a first developer carrying member for carrying and feeding the first developer to the image bearing member and a first magnetic field generating device disposed in the first developer carrying member. The developing apparatus further includes a second developing system develops a latent image formed on the image bearing member with a second developer including a magnetic carrier and non-magnetic toner while the developer contacts the image bearing member. The second developing system includes a second developer carrying member for carrying and feeding the developer to the image bearing member and a second magnetic field generating device disposed in the second developer carrying member. A magnetization intensity M&sgr; (Am2/kg) of the magnetic toner in an external magnetic field of 795.

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 toner suitable for use in electrophotography, etc., is composed of toner particles each containing a binder resin, a colorant and a wax component. The toner has a number-average particle size of 2-6 &mgr;m and a standard deviation in particle size of below 2.6 based on a number-basis distribution of circle-equivalent diameters, an average circularity of 0.970-0.995 and a standard deviation in circularity of below 0.030 based on a circularity frequency distribution, and a residual monomer content of at most 500 ppm. The toner particles have such a microtexture as to provide a particle cross section as observed through a transmission electron microscope (TEM) exhibiting a matrix of the binder resin and a particle of the wax dispersed in a discrete form in the matrix of the binder resin.

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 carrier grains retaining the toner grains thereon, deposited on a developer carrier in the form of brush chains. Assume that the brush chains on the developer carrier has a height of h as measured at a zero field point where the magnetic field formed by a main magnet is zero, and that a gap for development that is the shortest distance between the developer carrier and the image carrier is a, then a and h are equal to each other. Image quality is estimated by varying the combination of an angle &thgr; between the gap and the zero field point, the outside diameter of the image carrier and the outside diameter of the developer carrier and the height h. A desirable or an optimum range of the results of estimation are selected to set various conditions.

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: A developing device for developing a latent image formed on an image carrier includes a developer carrier having a developer carrying surface. The developer carrying surface includes a plurality of grooves to carry the developer. Dispersion D (%) in depth of the plurality of grooves is calculated according to an equation, D (%)={(A−B)/2}/C, where A is a maximum depth of the plurality of grooves, B is a minimum depth of the plurality of grooves, and C is an average depth of the plurality of grooves. The dispersion D (%) is at most approximately 30%.

Abstract: A developing method of the present invention is practicable with a developing unit of the type including a rotatable, nonmagnetic sleeve and a rigid metering member. A two ingredient type developer made up of magnetic carrier grains and toner grains is magnetically deposited on the sleeve. The metering member meters the amount of the developer deposited on the sleeve. The sleeve has surface roughness Rz ranging from 5 &mgr;m to 20 &mgr;m. The carrier grains each are covered with a coating layer containing at least binder resin and grains. The ratio of the diameter D of the individual grain contained in the coating layer to the thickness h of the binder resin layer lies in the range of 1<D/h<10. The carrier grains have a weight-mean grain size ranging from 20 &mgr;m to 60 &mgr;m.

Abstract: In order to provide an image forming apparatus capable of forming a quality image by restricting a distance between a developing roll and a magnetic roll with a simple structure, an image forming apparatus comprises a magnetic roll 1 and a developing roll 2 that are disposed in parallel with a predetermined distance and a developing unit 50 that develops an electrostatic latent image on a photosensitive body drum 3 disposed on the image forming apparatus main body using a toner thin layer formed on the surface of the developing roll by means of the magnetic roll, wherein a member for holding rotational axes having a pair of openings for holding, which fits and holds rotatably and integrally each of rotational axes of the magnetic roll and the developing roll is provided, the opening for holding of the developing roll being capable of swinging around the axis center of the opening for holding of the magnetic roll.

Abstract: In a developing device of the present invention, in a developing zone where an image carrier and a developer carrier face each other, the developer carrier carrying a developer thereon moves at a linear velocity of 150 mm/sec or above, but below 500 mm/sec. The amount of the developer conveyed to the developing zone by the developer carrier is between 65 mg/cm2 and 95 mg/cm2. A magnetic flux generated on the developer carrier in the developing zone by a magnetic pole has a flux density having an attenuation ratio of 40% in the direction normal to the developer carrier. The flux density in the direction normal to the developer carrier, as measured on the surface, is between 100 mT and 200 mT. Magnetic grains, which constitute the developer together with toner grains, have a saturation magnetization value of 40×10−7×4&pgr; Wb·m/kg or above, but below 50×10−7×4&pgr; Wb·m/kg.

Abstract: In a developing assembly including a two-component developer container and a developer-carrying member, the developer-carrying member has at least a substrate and a resin coat layer formed on the substrate surface, and the resin coat layer contains at least a binder resin and solid particles for making the resin coat layer surface uneven. The solid particles satisfying an average circularity of 0.

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: There is disclosed a developing device including a toner hopper, a toner supply source, a toner table on which a toner is laid, an agitator for carrying the toner to the toner table from the toner hopper, a magnet roller disposed above the toner table, a developing sleeve which covers an outer periphery of the magnet roller, holds a magnetic carrier, allows the toner of the toner table to be adsorbed onto the magnetic carrier, and shifts and attaches the toner to an electrostatic latent image of a photosensitive drum, a doctor blade disposed close opposite to the developing sleeve, and a developer returning member which is disposed between the developing sleeve and the toner hopper and is positioned in a position higher than a position of the toner table to prevent the toner cut/removed by the doctor blade from dropping toward the toner hopper and to return the cut/removed toner to the toner table, and which has a tip end displaced toward the developing sleeve from the boundary of the toner table and the tone

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 soft magnetic 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 said magnetic assembly; and a vibrating member positioned in between the magnetic assembly and the sleeve at a predefined position around the donor roll, the vibrating member fluidizing the developer material on the donor member to prevent developer bed freezing, to prevent long-range carrier bead chain formation, and to smooth developer bed height-banding on the donor member before a development zone.

Abstract: A developing device of the present invention uses 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 &mgr;m to 8.0 &mgr;m while the toner grains having grain sizes of 5 &mgr;m and below occupy 40 number % to 80 number % 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, image reproducibility.

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 soft magnetic 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 said magnetic assembly; and a vibrating member positioned in between the donor roll and the sleeve at a predefined position around the donor roll, the vibrating member fluidizing the developer material on the donor member to prevent developer bed freezing, to prevent long-range carrier bead chain formation, and to smooth developer bed height-banding on the donor member before a development zone.

Abstract: In a development system there is provided 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 said magnetic assembly; a trim bars positioned about the donor roll at a predefined position and spacing around the donor roll, the trim bar including a vibrating member for disrupting the developer bed and reducing developer bed height of the developer material on the donor member to a predefine developer bed height within the development nip.

Abstract: A developing apparatus of an electric photographic printer supplies a two-element developing agent to develop an electrostatic latent image formed on a photosensitive medium.

Abstract: A developing device developing a latent image on a latent image carrier with a developer, and including a casing having an opening facing the latent image carrier and a developer carrier. Also included is a magnetic field generating device including a first magnetic pole generating a magnetic field causing the developer to rise on the developer carrier in a form of a magnet brush in a developing region, and a second magnetic pole generating a magnetic field at a downstream side of the first magnetic pole in a rotating direction of the developer carrier. Further, a toner-scattering restraining device is provided on an end portion of the casing at the downstream side of the developing region, and a magnetic member provided on a side of the toner-scattering restraining device facing the latent image carrier. A peak of a magnetic flux density set by the second magnetic pole in its normal direction is located outside of the opening.

Abstract: The invention relates generally to apparatus for electrostatic image development and, in particular, apparatus that implement a magnetic brush with a drum photoconductor. According to an aspect of the invention, a method and apparatus for developing an electrostatic image are provided implementing a drum photoconductor and a magnetic brush contacting the drum photoconductor. The magnetic brush includes a mixture of toner and hard magnetic carriers.

Abstract: A magnetic toner with a negative polarity for developing latent electrostatic images is made of toner particles, each toner particle containing a binder resin, a magnetic powder, and a charge control agent, the surface of the magnetic toner satisfying the relationship of 2×10−7≦C/Sw≦10×10−7, provided C≦8×10−3, wherein C is an amount (g/g) of the charge control agent dissolved in a solvent comprising water and methanol, and Sw is a specific surface area (cm2/cm3) of the toner particles determined from a weight-average particle diameter of the toner particles. An image forming apparatus has an electrostatic image bearing member, and a unit for developing the electrostatic image with the above magnetic toner, the unit having a developer holding member provided with a magnet, and a developer container.

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 the developing device of the image forming apparatus, a two-component developer is used which satisfies conditions that volume mean particle diameter dt of the toner is 3˜5 &mgr;m (Condition 1), volume mean particle diameter dc of the carrier is 5dt˜10dt (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 of a rotary sleeve is arranged in the vicinity of the closest position of the rotary sleeve and the 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 of the main magnetic pole.

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 process cartridge detachably mountable to a main assembly of an electrophotographic image forming apparatus, the process cartridge includes an electrophotographic photosensitive drum; a developing roller for developing an electrostatic latent image formed on the photosensitive drum; a magnet disposed inn the developing roller; a drum frame supporting the photosensitive drum; a developing device frame supporting the developing roller and the magnet; an engaging member mounted to one longitudinal end of the developing device frame in engagement with one end of the developing roller and with one end of the magnet, the engaging member is provided with a projected portion at an opposite end from the end where it is in engagement with one end of the developing roller and one end of the magnet; an elastic member urging the projected portion by its elastic force so as to urge the developing roller to the photosensitive drum.

Abstract: In a developing assembly having a developer container, a developer-carrying member, a developer layer thickness control member, a magnetic-field formation means and an agitation means, 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, and the developer-carrying member has been subjected to surface blasting with spherical particles to have a surface having a ten-point average roughness Rz of from D/6 to D/2 where D is the average particle diameter of the magnetic carrier.

Abstract: A developing device includes a developing container containing a developer having non-magnetic toner and magnetic carriers. A developer carrying member bears and carries the developer contained in the developing container. A magnetic field generating device generates a magnetic field provided in the developer carrying member, wherein an electrostatic latent image formed on an image bearing member is developed with a magnetic brush, which is formed on the developer carrying member by the magnetic field generating device. The image bearing member and the developer carrying member move in opposite directions at a closest portion therebetween. A peak position of a magnetic force Fr generated by the magnetic field generating device in a direction vertical to a surface of the developer carrying member is disposed in the vicinity of the closest portion and downstream in a rotation direction of the developer carrying member from the closest portion.

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: Toner particles having at least one toner resin and at least one polyalkylene wax or a wax having a percent crystallinity of 80% or more are described. The wax that is present in the toner particles has a polydispersity of 2.0 or higher or a percent crystallinity of 80% or more, and also preferably has a number average molecular weight of about 2,000 or higher and/or a melting temperature onset of from about 115° C. to about 130° C. Development systems using the toner particles of the present invention are further described. Also, improvements in various properties associated with development systems are further described such as reduced toner dust levels as well as improved toner image abrasion resistance.

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 hard carriers and 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: The development is performed under a condition that |Q2|−|Q1|/|Q1≦±0.45. Here, Q1 denotes an average amount of charge on toner held on a development roller and carried toward a development region immediately before development. Q2 denotes an average amount of charge on toner immediately before development held and carried toward the development region in the state immediately after development of an electrostatic latent image on a development drum. This is effective to allow the amount of charge q/m on toner held on the development roller to have a variation rate of 45% or below and an afterimage rate R within 2%.

Abstract: The present invention provides a developing apparatus which has a developer carrying member opposed to an image bearing member for bearing a latent image and adapted to carry magnetic developer, a magnet provided within the developer carrying member and having one end secured to a frame of the apparatus, and a bearing fitted on other end of the magnet and adapted to rotatably support the developer carrying member, wherein a fitting portion between the magnet and the bearing has a non-circular shape.

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: In a developing device for an image forming apparatus of the present invention, a main magnetic pole for development has an angle of 60° or below between opposite pole transition points respectively positioned upstream and downstream thereof in a direction of developer conveyance. A flux density between the main magnetic pole and the magnetic pole downstream of the main magnetic pole in the normal direction has a peak value that is 80% of the maximum flux density of the main pole in the normal direction or above. With this configuration, it is possible to reduce various defective images at the same time.

Abstract: When image formation is performed by an apparatus comprising: a magnetic roll for generating a magnetic brush by carrier having toner adhering triboelectrically thereto, a developer roll on the surface of which a thin layer of the toner supplied by the magnetic brush is formed, and a photoreceptor onto which the toner of thin layer jumps selectively in accordance with the latent image thereon; positively chargeable toner of which charge amount is controlled in 5˜20 &mgr;C/g is used, the surface potential of the photoreceptor is set to a range above 0 to 250 V, and the after exposure potential which is the potential right after the photoreceptor is exposed is in a range of 0˜ to 100 V.

Abstract: A developing apparatus is provided which includes a hollow cylindrical sleeve which is rotationally driven and a magnetic shaft which is rotationally driven inside the sleeve. The magnetic shaft causes magnetic toner to adhere to a peripheral surface of the sleeve by magnetic force. The magnetic toner adhering to the peripheral surface is supplied to a developing position by rotation of the sleeve and adheres to an electrostatic latent image formed on the surface of a photosensitive body. The center of rotation of the magnetic shaft is deviated from the center of rotation of the sleeve nearer to the photosensitive drum, and frontward along the direction of rotation of the sleeve from a line connecting the center of rotation of the sleeve and the center of rotation of the photosensitive body.

Abstract: A magnetic brush development station includes, a housing forming a reservoir for developer materials. A plurality of augers are located in the housing for mixing developer material. A development roller is mounted within the housing for delivering developer material from the reservoir to a development zone. The development roller includes a core magnet inside a shell, having relative rotation. The core magnet extends less than the entire length of the development roller such that a developer nap on the shell does not extend to the respective ends. A metering skive controls the quantity of developer material delivered from the reservoir. A metering skive is positioned parallel to a longitudinal axis of the development roller at a location upstream in the direction of shell rotation prior to the development zone. A magnetic seal is located in association with the skive at each end to substantially prevent leakage of developer material.

Abstract: A developing device includes first developing means for developing a latent image formed on an image bearing member with a developer comprising magnetic toner, said first developing means including a first developer carrying member for carrying and feeding the developer to the image bearing member and first magnetic field generating means disposed in said first developer carrying member; and second developing means for developing a latent image formed on the image bearing member with a developer comprising magnetic carrier and non-magnetic toner while the developer being in contact with the image bearing member, said second developing means including a second developer carrying member for carrying and feeding the developer to the image bearing member and second magnetic field generating means disposed in said second developer carrying member, wherein a magnetization intensity M&sgr; (Am2/kg) of the magnetic toner in an external magnetic field of 795.

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: The development apparatus develops a latent image formed on a photo-conductor using a developer composed of a toner and a magnetic currier particle. A development sleeve carries the developer on an outer surface thereof so as to transfer the developer to the photo-conductor. A developer application mechanism applies the developer to the outer surface of the development sleeve. A plurality of magnets are provided inside the development sleeve so as to generate a magnetic field so that a magnetic brush is formed by the developer. The magnetic brush is brought into contact with said latent image carrier in a development area where the developer carrier is contiguous to the latent image carrier and the magnetic field between the latent image carrier and the developer separates the toner from the magnetic carrier of the magnetic brush. The wherein the magnetic brush is separated from the latent image carrier outside the development area.

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: Apparatus and methods for electrographic image development, wherein the image development process is optimized by setting the developer mass flow velocity with reference to the imaging member velocity, for example, where the developer mass 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.