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: In a two-component developing unit, by devising the layout of magnetic poles 6 (particularly a pickup magnetic pole 6b and a trimming magnetic pole 6c) of a magnet member 5 arranged inside a developer carrier 3, an excess portion of a developer G picked up onto the surface of the developer carrier 3 is allowed to drop in the vicinity of the height of the rotational center O of the developer carrier 3, and only the developer G restricted to a predetermined layer thickness is carried and transported to a development region m. A charging member 9 is disposed over a periphery of the developer carrier 3, as required. In addition, the layout of the magnetic poles 6 of the magnet member 5 arranged inside the developer carrier 3 is set variably between the time of development and the time of nondevelopment, and the amount of developer carried on the surface of the developer carrier and transported to the development region m is set to substantially zero at the time of nondevelopment.

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 means 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 developing device for an image forming apparatus includes a developing roller for conveying toner deposited thereon to a developing region where it faces a photoconductive element. A magnet brush roller conveys a two-ingredient type developer, which consists of toner and magnetic particles, deposited thereto to a toner supplying region where it faces the developing roller. In the toner supplying region, only the toner is supplied from the magnet brush roller to the developing roller. The distribution of the number of toner particles for an amount of charge differs from the developing roller to the magnet brush roller.

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 electrophotographic image forming method includes a charging step, an exposure step, a developing step and a transfer step in the rotation of an electrostatic latent image bearing member, in which a process speed of the electrostatic latent image bearing member is 200 to 500 mm/sec, an outer diameter of the electrostatic latent image bearing member is 15 to 35 mm, an outer diameter of a developer bearing member is 10 to 25 mm, and a magnetic single component developer of which the residual magnetization in a measured magnetic field of 796 kA/m is 0.5 to 5.0 Am2/kg is used as the developer. The electrophotographic image forming method can provide a good image quality without causing scattering of toner in downsizing, weight reduction of an electrophotographic apparatus and speed-up of an electrophotographic process.

Abstract: An image developing apparatus includes a latent image carrying member and a developer carrying member. The developer carrying member carries developer which forms a magnetic brush on a surface thereof and causes the magnetic brush to brush a surface of the latent image carrying member in the developing region so that the latent image on the latent image carrying member is visualized. In the apparatus, a developing nip is formed relatively small so that a time period in which a toner of the magnetic brush moves to the developer carrying member back from the latent image carrying member is reduced and a density of the magnetic brush is increased. A developing magnetic pole of the developer carrying member has specific half-angle and attenuation rate values.

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: 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: 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 device of the present invention includes a developing container containing a developer having non-magnetic toner and magnetic carriers, a developer carrying member for bearing and carrying the developer in the developing container, and a magnetic field generating device for generating 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 formed on the developer carrying member by the magnetic field generating device, and the image bearing member and the developer carrying member move in opposite directions at a closest portion therebetween, and 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: 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 photoconductor. The magnet brush comprises a mixture of toner and hard magnetic carriers.

Abstract: An electrophotographic image forming method includes a charging step, an exposure step, a developing step and a transfer step in the rotation of an electrostatic latent image bearing member, in which a process speed of the electrostatic latent image bearing member is 200 to 500 mm/sec, an outer diameter of the electrostatic latent image bearing member is 15 to 35 mm, an outer diameter of a developer bearing member is 10 to 25 mm, and a magnetic single component developer of which the residual magnetization in a measured magnetic field of 796 kA/m is 0.5 to 5.0 Am2/kg is used as the developer. The electrophotographic image forming method can provide a good image quality without causing scattering of toner in downsizing, weight reduction of an electrophotographic apparatus and speed-up of an electrophotographic process.

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 0.3 mm or above, but 0.6 mm or below.

Abstract: An image forming apparatus of the present invention includes a developing device of the type causing a developer to form a magnet brush on the surface of a developer carrier in a developing region or nip for development. The magnet brush contacts and thereby develops a latent image formed on an image carrier. The apparatus of the present invention increases image density and faithfully reproduces even low-contrast images with a low-cost configuration. Further, the apparatus reduces image defects, including granularity and the omission of the trailing edge of an image, even if the range over which the magnet brush and image carrier contact is reduced.

Abstract: A developing device includes a developing container for containing therein a developer provided with a carrier and a toner, a conveying device for conveying the developer in the developing container, a developer bearing member for bearing thereon the developer conveyed by the conveying device, the developer bearing member conveying the developer to a developing portion for developing a latent image formed on an image bearing member, a magnetic field generating device provided in the developer bearing member for generating a magnetic field, the magnetic field generating device being provided with a first magnetic pole and a second magnetic pole provided so as to be adjacent to the downstream side of the first magnetic pole in the direction of rotation of the developer bearing member and having the same polarity as the first magnetic pole, and a regulating device for regulating the layer thickness of the developer on the developer bearing member at a location substantially opposed to the second magnetic pole.

Abstract: A developing apparatus comprises a hollow cylindrical sleeve which is rotationally driven and a magnetic shaft which is rotationally driven inside the sleeve. The magnetic shaft causes the magnetic toner to adhere to the peripheral surface of the sleeve by the magnetic force. The magnetic toner adhering to the peripheral surface is supplied to the developing position by rotation of the sleeve and adheres to the 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: 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.

Abstract: An electrophotograph development apparatus for developing an electrostatic latent image formed on an electrostatic latent image carrier body with magnetic developer includes a developer carrier body having a magnetic roller, and a thin layer forming member for forming the magnetic developer on the developer carrier body into a thin layer. A magnetic pole of the magnetic roller is disposed at a position of a &thgr; degree in an upper stream side relative to a rotational direction of the developer carrier body from a contact point of the thin film forming member and the developer carrier body, and &thgr; is in a range of 0 degree≦&thgr;≦10 degree. A relation between a surface roughness Rz′ of the developer carrier body and a surface roughness Rz of the thin layer forming member is represented by −10 &mgr;m≦(Rz-Rz′)≦5 &mgr;m.

Abstract: In a developing system containing a combination of forward-rotating and a backward-rotating developing rollers, a steady quantity of developing agent should be supplied to the developing rollers for high-quality printed images. This requirement can be satisfied by placing a doctor blade between an intersection point, where a line connecting the central axis of one of the developing rollers and its polarity reversing position meets a line connecting the central axis of the other of the developing rollers and its polarity reversing position, and the developing roller pair.

Abstract: In a developing roll, grooves of a length direction of a developing roll are formed on a surface of the developing roll on conditions that a ratio of a groove depth to a groove width is set to one or more and a ratio of a groove pitch to a groove width is set to two or more and a groove depth is set to three times or more a carrier particle size, and a magnetic pole of the inside of the developing roll is provided in a position of a doctor blade for regulating the amount of carriage of a developer roll, and further a magnetic force on the surface of the developing roll of the position of the doctor blade is set to 0.06 T or less.

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: A toner of toner particles containing at least one binder, at least one colorant, and preferably one or more external additives is advantageously formed into a developer and used in a magnetic brush development system to achieve consistent, high quality copy images. The toner particles, following triboelectric contact with carrier particles, exhibit a charge per particle diameter (Q/D) of from 0.6 to 0.9 fC/&mgr;m and a triboelectric charge of from 20 to 25 &mgr;C/g. The toner particles preferably have an average particle diameter of from 7.8 to 8.3 microns. The toner is combined with carrier particles to achieve a developer, the carrier particles preferably having an average diameter of from 45 to 55 microns and including a core of ferrite substantially free of copper and zinc coated with a coating comprising a polyvinylidenefluoride polymer or copolymer and a polymethyl methacrylate polymer or copolymer.

Abstract: A magnetic member is arranged at a position on the downstream side with respect to the rotational direction of a developing sleeve, outside the developer conveyance path where the magnetism from the magnetic member has no influence on the magnetic field of the developing magnetic pole. When the magnetic member is arranged with its N pole facing the developing sleeve, the magnetic attractive force from the magnetic member weakens the developer's attraction to the peripheral surface of the developing sleeve. When the magnetic member is arranged with its S pole facing the developing sleeve, the developer being conveyed along the developer conveyance path is magnetized in such a direction as to repel the peripheral surface of the developing sleeve.

Abstract: Method for producing a firm, motion-resistant connection between mating surfaces of a male member, such as a shaft or hub, and a female member such as a bore. One or more thin ribs of pressure-deformable composition, such as integral soft metal or plastic, are formed on one of the mating surfaces, which ribs deform and spread between the surfaces when the male member is forced into the bore to connect the members. According to a preferred embodiment, the shaft is the fixed core shaft of a xerographic toner developer roller within a toner cartridge and/or the hub of a bearing support member for the shaft, and the bore is a central core shaft-engaging bore in the hub and/or a hub-engaging bore in the cartridge housing, and the connection is an electroconducting connection providing near-zero capacitance.

Abstract: A developing device for an image forming apparatus includes a developing roller for conveying toner deposited thereon to a developing region where it faces a photoconductive element. A magnet brush roller conveys a two-ingredient type developer, which consists of toner and magnetic particles, deposited thereto to a toner supplying region where it faces the developing roller. In the toner supplying region, only the toner is supplied from the magnet brush roller to the developing roller. The distribution of the number of toner particles for an amount of charge differs from the developing roller to the magnet brush roller.

Abstract: The present invention provides for a developing device comprising a developing roller configured to supply developer to a developing portion, a first conveying path configured to guide a moving of the developer and from which the developer is supplied by the developing roller to the developing portion, a first mixer configured to mix the developer while the developer is moving along the first conveying path, a second conveying path configured to guide the moving of the developer, wherein a residual developer left on the developing roller is recovered to the second conveying path and conveyed to the first conveying path, a second mixer configured to mix the developer while the developer is moving along the second conveying path, and a partition member arranged between the developing roller and the first conveying path to prevent leakage of the developer from between the developing roller and the first conveying path to the second conveying path directly, wherein one end of the partition member is brought in co

Abstract: Electrostatic latent images are developed with a toner in such a configuration that an electrostatic-latent-image-bearing member is disposed to face a developer-bearing member which bears thereon a developer consisting of a magnetic carrier and a toner by relatively moving the developer-bearing member and the electrostatic-latent-image-bearing member at different velocities, with the development being carried out under conditions represented by formula (1): 1 0.

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: A developing device includes a rotatable developer carrying member for carring a developer; a magnet roller provided in the developer carrying member; a first electrode portion connected electrically with the developer carrying member, the first electrode portion being rotatable with the developer carrying member; a second electrode portion provided with a contact portion in sliding contact with the first electrode portion, the contact portion being disposed outside a longitudinal end portion of the magnet roller substantially at a center of rotation of the developer carrying member.

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: When the structure is arranged such that one of the repulsion poles is used as a developer layer thickness regulation pole, screw pitch-shaped density unevenness occurred at the rear end of a solid black image.

Abstract: An object of the present invention is to provide a developing apparatus which can prevent reduction in image density due to paper powder. A further object of the present invention is to provide a developing apparatus that has a developing container, a toner carrying member, and a toner container, wherein the toner container has a space portion which disposed below the toner carrying member and which is not substantially replenished with the toner.

Abstract: An image forming apparatus of the present invention includes a developing roller accommodating a magnet roller therein. The magnet roller includes a main pole forming a magnetic flux whose attenuation ratio is 40% or above in the direction normal to the developing roller. The axis A of the developer carrier, the axis B of the image carrier and the peak C of the magnetic force of the main pole in the above direction are positioned such that an angle between a line AB and a line AC is substantially zero degree.

Abstract: The present invention relates to a developing apparatus which has an upstream developer bearing member for developing a latent image formed on an image bearing member and a downstream developer bearing member for developing a latent image on an image bearing member, and the downstream developer bearing member is provided downstream of the upstream developer bearing member in a moving direction of the image bearing member.

Abstract: A developing device includes: a multiple number of magnetic poles fixed at predetermined positions; a developer sleeve which rotatably encloses the magnetic poles; a doctor blade for regulating the thickness of the developer layer on the developer sleeve; and an agitating roller arranged adjacent to the developer sleeve and agitating and supplying the developer. In this arrangement, the magnetic poles include a development magnetic pole for developing the static latent image on the photoreceptor drum, and a developer conveyance magnetic pole positioned downstream, with resect to the rotational direction of the developer sleeve, of the development magnetic pole. A magnetic element is arranged opposing the developer sleeve outside the developer flow path where the magnetic field of the developer conveyance pole is not effective.

Abstract: Disclosed is a two-component developing agent comprising toner which includes a second magnetic powder added in an amount of 4 wt % or less with respect to the weight of toner particles which contains a first magnetic powder and a binder resin, and manganese-magnesium-based carrier.

Abstract: A developing device of this invention that includes a developing sleeve extending substantially parallel to a substantially cylindrical image carrier and opposed for rotation to an outer peripheral surface of the image carrier with a given developing gap therefrom, a magnet roller located for reverse rotation in the developing sleeve with a given gap therefrom, and a developing bias applying member for applying a given developing bias between the image carrier and the developing sleeve. The magnet roller has a plurality of magnetic poles of different polarities that are arranged alternately along its outer peripheral surface.

Abstract: A developing device for an image forming apparatus includes a developer carrier such as a developing sleeve having a magnetic field generating device therein which carries and conveys a developer containing toner and magnetic carrier particles. The developing device also includes a first regulating member such as a blade which regulates the developer being carried and conveyed by the developer carrier, and a developer storing section stores developer scraped off the developer carrier by the first regulating member. The developer storing section includes a second regulating member arranged upstream of the first regulating member with respect to a direction in which the developer carrier conveys the developer. The developing device further includes a toner storing section provided adjacent to the developer storing section to supply toner to the developer carrier.

Abstract: In the particular embodiment disclosed in the specification, an electrostatic image forming arrangement includes a photoreceptor in the form of a continuous belt which is moved past four development stations each containing a different colored toner which incorporates ferromagnetic material. At each development station a developer roll conveys toner in closely spaced relation to the surface of the photoreceptor and a DC-biased AC voltage is applied to the developer roll to cause the toner to be transferred to an electrostatic image on the photoreceptor. A magnet member mounted on the opposite side of the photoreceptor produces a magnetic field which holds toner on the image-receiving surface permitting a greater range of variation for the DC-biased AC toner transfer voltage.

Abstract: A method of fabricating a developer bearing body includes the steps of preparing metallic base material blasting the surface of the metallic base material using spherical particles and plating the surface of the metallic base material blasted, wherein a thickness of the plating layer is two or more times as large as a particle diameter in volume average of the developer.

Abstract: An apparatus for non-interactive, dry powder development of electrostatic Images composed of solid areas and fine lines areas on an imageable surface including a housing containing developer material; a first magnetic roll, spaced a first predefined distance from the image, for transporting the developer material from the housing to develop solid areas of the image, the magnetic roll including an magnetic core and a cylindrical sleeve enclosing and rotating about the magnetic core; and a second magnetic roll, spaced a second predefined distance from the image, for transporting the developer material from the housing to develop fine line areas of the image, the magnetic roll including an magnetic core and a cylindrical sleeve enclosing and rotating about the magnetic core.

Abstract: An image forming apparatus including a rotatable image supporter having photoconductive properties, an optical image irradiating device configured to irradiate the image supporter with a light beam to form an electrostatic latent image thereon, and a developing device including a developer, which includes a magnetic carrier and a toner, and a developer supporter which bears the developer on the surface thereof and configured to feed the developer to a developing area between the image supporter and the developer supporter to develop the electrostatic latent image, wherein a ratio of a toner content in a first portion of the developer in the developing area relatively close to the surface of the image supporter to a toner content in a second portion of the developer in the developing area relatively close to the surface of the developer supporter is not less than about 0.6, measured when the developer contacts a continuous non-image area formed on the image supporter.

Abstract: A magnetic carrier for a developer used in electrostatically forming a visual image, comprising a magnetic core material, an electrically-conductive particle-containing resin layer and electrically-conductive particles externally added to the electrically-conductive particle-containing resin layer, the magnetic carrier having a magnetization (.sigma..sub.1000) of 61-100 emu/g at 1 kOe magnetic field, a specific volume resistance of 10.sup.6 .OMEGA..multidot.cm or less, and an average particle size of 10-100 .mu.m. The magnetic carrier of low specific volume resistance has a high durability and provides high quality images. In particular, when the magnetic carrier is applied to an image forming process by rear side exposure, the residual toner on the image-bearing member can be effectively removed without using an additional cleaning means, and high quality images free from the background fogging and contamination can be produced.

Abstract: A developer carrying member for carrying a developer is includes a substrate and a resin coat layer which is formed on the surface of the substrate and contains a binder resin and a conductive fine powder. The binder resin is composed of a copolymer having a monomeric unit of a methyl methacrylate monomer (M) and a monomeric unit of a nitrogen-containing vinyl monomer (N). A copolymerization molar ratio of the methyl methacrylate monomer (M) to the nitrogen-containing vinyl monomer (N) in the copolymer fulfills the following condition: M:N=4:1 to 999:1. The binder resin has a weight-average molecular weight (Mw) of from 3,000 to 50,000.

Abstract: A development system is which includes a developer roll with a magnetic sleeve. The sleeve has a static magnetic field pattern for transporting developer material to a development zone; and a magnetic system for generating a superimposed alternating magnetic field to agitate developer material in the development zone in order to produce a charged toner cloud intended for the non-interactive development of latent electrostatic images.

Abstract: Provided is an image-forming method including a step of forming a layer of a developer on a surface of a developer support member disposed facing a latent image support member, a developing step of developing an electrostatic latent image on the latent image support member using the layer of the developer formed to obtain a toner image, a transferring step of transferring the toner image onto a transfer material and a fixing step of fixing the transferred toner image, wherein the developer support member has therein a development magnetic pole in which a magnetic force of a main pole is 100 mT or more, said developer having a toner and a carrier which has a volume average particle diameter of 50 .mu.m or less, and image formation method is conducted at a process speed of 200 mm/sec or more.

Abstract: A developing device develops a latent image formed on a latent image holding body. The developing device includes a developing roller conveying, with rotation of the developing roller, developer adhered thereto to a developing area in which the latent image on the latent image holding body should be developed, the developer including toner and carriers, a limit member, provided so as to face the developing roller, limiting a height of a layer of the developer on the developing roller, a toner container storing the toner, a toner supply mechanism supplying the toner in the toner container to the developing roller, and a partition member forming a space between the partition member and the developing roller, the toner supplied from the toner container being moved in the space with rotation of the developing roller.

Abstract: An apparatus for the development of electrostatic images includes a developer storing section, a developing sleeve, a first magnetic field generating member, a developer layer thickness regulator, a second magnetic field generating member and a developer conveying member. The second magnetic field generating member faces the developing sleeve and forms an attracting magnetic field to attract the carrier particles from the developing sleeve. The second magnetic field generating member, moreover, has a closer section located close to the developing sleeve and a farther section located far from the developing sleeve, the farther section being located downstream of the closer section with regard to the conveying direction.

Abstract: A plurality of electrostatic images are formed on a moving tensioned belt formed with an electrically conductive base having a non-conductive image-carrying surface layer. The images are developed by passing the belt through toner development stations, each of which includes a development unit including a magnetic roller and a backing member, in opposed position to the magnetic roller, over which the belt passes. Under non-ideal conditions, the image quality in terms of image density and uniformity of image density and rendition of sharp image transitions, is substantially improved by applying an alternating electrical field between the magnetic roller and the belt, with a peak-to-peak voltage greater than 800 volts.