Abstract: A developing device for developing an electrostatic latent image formed on an photoreceptor drum with a dual-component developer, includes: a developing hopper for storing the developer; an agitation roller for conveying the developer while agitating; a developing roller which supplies the developer to a developing area located opposing the photoreceptor drum; a layer thickness-regulating member for regulating the layer thickness of the developer being conveyed by the developing roller; a flow-guide plate for flowing down the surplus developer that was rejected to a position away from the layer thickness-regulating member; a multiple number of partitioning ribs arranged upright on the flow-guided plate for flowing down the surplus developer in a predetermined direction whilst diffusing the developer with respect to the longitudinal direction of the developer roller; and a downflow direction control mechanism for controlling the downflow direction of the surplus developer regulated by the partitioning ribs.

Abstract: A layer-thickness restriction member, including: an abutting surface that is for abutting against a developer-bearing body in order to restrict a layer thickness of developer borne by the developer-bearing body; and a flash that is located on a side close to a non-abutting surface that is located on an opposite side from the abutting surface in a thickness direction of the layer-thickness restriction member.

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

Abstract: There is provided a developing device including: a casing; a developing roller held by the casing and carrying a developing agent; and a layer-thickness regulating blade for regulating a layer thickness of the developing agent carried on the developing roller, in which in the state where the developing roller is held by the casing, the tip end portion of the layer-thickness regulating blade abuts against the developing roller at a uniform pressure in the axial direction of the developing roller, and in the state where the developing roller is not held by the casing, the layer-thickness regulating blade is bent toward a disposed position of the developing roller.

Abstract: A developing device comprises a stirring roller 7 having stirring blades 7a for stirring a developer, a developing roller 3 for transferring the developer to an electrostatic latent image, a control member 4 for controlling the amount of developer transferred from the developing roller 3 to the electrostatic latent image, a reflux plate 6 by which the excess developer resulting from control by the control member 4 is flowed back to the stirring roller 7, one end portion of the reflux plate 6 being disposed in the vicinity of the outer periphery of the stirring roller 7, part of the developer stirred by the stirring roller 7 flying toward the reflux plate 6, wherein said one end portion of the reflux plate 6 is disposed at a position remote from the stirring roller 7 over a distance greater then the maximum fly distance of the developer provided by rotation of the stirring roller 7.

Abstract: In a developer station for a printer or copier, a rotating developer roller is provided having a mixture of toner particles and ferromagnetic carrier particles accumulated on a surface of the developer roller as a layer, and a transfer zone at which the toner particles are transferred away from the developer roller. A smoothing device is provided with a smoothing element arranged before the transfer zone, the smoothing element being charged with a mechanical tension in a rest state of the developer roller and designed such that it exerts a force on and over an entire width of the layer formed by the mixture of the toner particles and the carrier particles present on the developer roller and smoothes the layer before the transfer of the toner particles. Within the developer roller at least one magnet is provided. The smoothing element comprises a magnetizable material attracted toward said at least one magnet to create said mechanical tension.

Abstract: A developing apparatus is provided which can suppress a fluctuation in image density in a discontinuous printing mode provided with a pause period. The developing apparatus includes a developer for developing an electrostatic latent image on a photosensitive drum, a developer bearing member for carrying and conveying the developer and a developer layer thickness-regulating unit placed close to the developer bearing member for regulating the amount of the developer carried and conveyed by the developer bearing member, the developer layer thickness-regulating unit being. As the developer, a negatively chargeable, one-component, magnetic toner is used having magnetic toner particles containing a binder resin and a magnetic iron oxide particle, and has a specific saturation magnetization, specific weight-average particle diameter and specific composition.

Abstract: Developer units, electrophotograhic apparatuses, and methods of supplying developer material to photoconductive members in electrophotographic apparatuses are disclosed.

Abstract: This invention, by a layer thickness restricting member, restricts a layer thickness of a developer born on a peripheral surface of a developer bearing member which feeds the developer at a developing region in a developer feeding direction which is opposite to an electrostatic latent image feeding direction, at a position upstream of the developing region in the developer feeding direction. In addition, this invention, by a spike-height restricting member, restricts a spike height of the developer caused to project like spikes on the peripheral surface of the developer bearing member, at a predetermined position upstream of a proximal position at which an electrostatic latent image bearing member and the developer bearing member are closest to each other and downstream of the layer thickness restricting member in the developer feeding direction.

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

Abstract: There is provided according to the present invention a toner layer thickness regulation member capable of suppressing uneven density during forming an image. There is also provided an image forming apparatus capable of forming an excellent image stably by employing such a toner layer thickness regulation member. A toner layer thickness regulation member 1 has a strip metal plate 2 and an elastic member 3 provided in one side of the metal plate 2 in a width direction and arranged in parallel to a longitudinal direction of the metal plate, wherein the elastic member 3 has hardness of more than 55° and hardness relaxation of less than 2.6°. In addition, an image forming apparatus employs the above-mentioned toner layer thickness regulation member 1.

Abstract: A fastening structure which fixes a doctor blade to a holder is provided, which includes a cylindrical portion provided on one surface of the holder with which a doctor blade is overlapped, a through hole having an inner diameter larger than an outer diameter of the cylindrical portion and penetrating through the doctor blade. In the fastening structure, while the cylindrical portion is inserted through the through hole with a gap between an outer circumference of the cylindrical portion and an inner circumference of the through hole, an end portion of the cylindrical portion is pressed to be expanded in an outer circumferential direction and then bent towards the doctor blade, to thereby fix the doctor blade to the holder by supporting it between the end portion and the one surface of the holder.

Abstract: Gap among a leaf spring member of a layer-thickness regulating blade, a back-side member of a blade holder and a blade opposed portion of an upper seal is filled with grease. An internal seal is disposed laterally inward of the grease with a portion thereof sandwiched between the back surface of the leaf spring member and the blade opposed portion of the upper seal. This can prevent the grease from overflowing laterally inward from the gap among the back-side member, the leaf spring member and the upper seal, and can also prevent a toner from entering into a gap among the back-side member, the leaf spring member and the upper seal, thereby preventing the oil content of the grease from mixing into the toner.

Abstract: An image forming apparatus includes a plurality of vibration members configured to vibrate a regulating member that regulates a developer layer thickness on a developer bearing member, and a control unit that can execute a vibration mode which vibrates the plurality of vibration members during different periods so that the plurality of vibration members do not vibrate simultaneously when an image is not being formed.

Abstract: An image forming apparatus includes a process cartridge with an image bearing member configured to bear an image on a surface thereof. A developing device is configured to develop the image formed on the image bearing member by using a developer accommodated in a chamber thereof. The developing device includes a developer bearing member configured to bear the developer on a surface thereof to transfer the developer to the image formed on the image bearing member. A conveying member is configured to agitate and convey the developer in the chamber to the developer bearing member. A regulating member held in contact with the developer brought up from the chamber onto the surface of the developing roller is configured to uniformly distribute the developer on the surface of the developer bearing member.

Abstract: A device for metering toner to a predefined toner bed height on a donor member, including a composite trim bar having a support portion and a cutting portion, adjacent to the donor member, attached to the support portion.

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

Abstract: A magnetic brush development station for a reproduction apparatus with a movable metering skive so as to enable such metering skive to control and prevent contamination at such metering skive. A developer roller is mounted within the housing for delivering developer material to a development zone, the developer roller including a core magnet inside a shell, the core magnet and the shell having relative rotation. A transport mechanism is provided for delivering developer material from the reservoir to the development roller. A metering skive is provided for establishing a developer material metering gap between the metering skive and the developer roller for controlling the quantity of developer material delivered from the reservoir portion of the housing to the development zone.

Abstract: A developer regulating apparatus including: a flexible sheet member, which regulates a thickness of a developer layer on a developing roller; and a holding member having wall surfaces for holding the sheet member in a curved state, wherein when the sheet member is not pressed by the developing roller, an angle of circumference of an arc of the sheet member is not larger than 180 degrees, a perpendicular bisector of a chord corresponding to the arc when the sheet member is pressed by the developing roller is provided downstream in a rotation direction of the developing roller with respect to a normal line of a surface of the developing roller which is parallel to the perpendicular bisector, and a sheet member holding line of the wall surface of the holding member upstream in the rotation direction is provided coplanar with the normal line or upstream of the normal line.

Abstract: A sheet-shaped regulation member is supported by a supporting unit with an elastic force occurring by bending a sheet-shaped regulation member in the longitudinal direction thereof, and a force received as a result of being pressed by a developing roller. Thus, direct contact can be securely made onto a developer bearing member, and a regulation member can be provided which enables easily attaching thereof to the supporting member, as well as enabling a developing apparatus, processing cartridge, and image forming apparatus, to be reduced in size.

Abstract: A developing device includes toner, a casing accommodating the toner, a developing roller rotatably fixed on the casing, an elastic blade making contact with a circumferential surface of the developing roller, a seal member, and a cutout portion in the seal member. The seal member is arranged to make contact with a circumferential surface of end portions of the developing roller between the developing roller and a wall surface of the casing and to make contact with an end surface of a tip end of the elastic blade. The cutout portion is arranged on the seal member and is cut out at a potion at a side making contact with a side surface of the tip end of the elastic blade in an axial direction of the developing roller and a side located closer to the wall surface of the casing than the elastic blade in a radial direction of the developing roller.

Abstract: A developing device having an improved regulating member to regulate the thickness of a developing agent layer and consequently, achieving easy fabrication, reduced fabrication costs and/or reduction in the size of the developing device, and an image forming apparatus having the same, is described. The developing device includes a developing container, which contains a developing agent therein, and which has an opening. A developing roller is installed at the opening of the developing container. A regulator regulates the thickness of a developing agent layer on an outer surface of the developing roller. The regulator includes a main regulating member, which maintains a first distance between an end of the main regulating member and the outer surface of the developing roller, and a preliminary regulating member integrally formed with the developing container at a position ahead of the main regulating member along the rotating direction of the developing roller.

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

Abstract: A developing apparatus having a developing sleeve provided with an elastic layer on its surface, and for developing an electrostatic image formed on an image bearing member with a mono-component magnetic toner having a mean degree of circularity of 0.965 or greater, a magnet provided in the developing sleeve, and a blade for regulating the amount of the developer carried on the developing sleeve satisfies the expressions |Br|/|B|?0.5 and Nsb/(Bs×R)?0.

Abstract: A disclosed developing device includes a developer carrier including a developing sleeve and a magnetic roller provided inside the developing sleeve. The magnet roller includes a regulating magnetic pole and a pump-up magnetic pole that have different polarities from each other. Among an entire region of the moving surface of the developing sleeve in the surface movement direction, a maximum pump-up magnetic force position where the pump-up magnetic force of the pump-up magnetic pole is maximum faces an upstream position with respect to a supplying position at which the developer is supplied from a supplying screw to the developing sleeve.

Abstract: A metering roller for a printing machine utilising a high viscosity ink. The metering roller has an axle, a cylindrical roller body formed on the axle and an annular surface layer. The annular surface layer has a surface of a low surface energy and a pattern of a plurality of ink receiving recesses formed in the annular surface layer. The annular surface layer can be integral with the cylindrical roller body or separate from it and can be a plastic material. The annular surface layer has a surface energy in the range of from 18 to 46 dynes/cm.

Abstract: A developing apparatus, a process cartridge and an electrophotographic image forming apparatus which can obtain a good image, and an end portion regulating member provided in them. The end portion regulating members for regulating the layer thickness of developer passed through interstices between a developing blade for forming a layer of the developer having a predetermined thickness on the surface of a developing roller and magnetic seals provided on the longitudinally opposite end portions of the developing roller in opposed relationship with the surface of the developing roller is provided downstream of the developing blade with respect to the rotating direction of the developing roller.

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

Abstract: A device including a developing roller having a magnet roller for transporting developer, and developing an electrostatic latent image, a regulating member regulating transportation amount of the developer transported to the electrostatic latent image with the development roller, and a reflux plate refluxing excess developer regulated by the regulating member away from the regulating member is constructed to comprise a rubbing member arranged to face the developing roller, at a second gap larger than a first gap defined by the developing roller and the regulating member, and rubbing developer transported to the first gap. The rubbing member carries out preliminary electrification on developer and then the regulating member carries out main electrification on the preliminarily electrified developer.

Abstract: An image forming apparatus having a photoconductive drum to form an electrostatic latent image corresponding to a predetermined image by a laser beam scanned after being electrified to a predetermined electric potential, and a developing roller to rotate together with the photoconductive drum having a developing gap therebetween and to transfer a developer, which is a mixture of a toner and a carrier, to the photoconductive drum to form a toner image on the electrostatic latent image, wherein a linear velocity ratio of a linear velocity of the developing roller to a linear velocity of the photoconductive drum is provided at a predetermined ratio, which provides maximum quality of the toner image.

Abstract: A two-component developer is provided with cylindrical toner particles and magnetic carrier particles having an average sphericity of 0.95 or more. When such a developer is used in development using a two-component developing method, a clear image can be stably obtained for a long period by suppressing a spent phenomenon and an insufficiency of cleaning.

Abstract: In a developing unit including a collecting roller for collecting the developer falling from a developing roller and a developer removing device for removing the developer collected by the collecting roller from the collecting roller, the developer removing device includes a casing for supporting the collecting roller, a scraper for removing the developer adhering to the collecting roller and a scraper supporter for supporting the scraper, and the scraper is supported by pressing it against the casing by the scraper supporter.

Abstract: A developing apparatus having a rotatable developing sleeve having an elastic layer on the surface thereof for carrying a mono-component magnetic developer and urged against a photosensitive drum to develop an electrostatic image formed on the drum with the developer, a non-rotary magnet provided inside the sleeve for magnetically attracting the developer to the sleeve, and a blade having an abutting portion abutting against the sleeve in a counter direction for regulating the amount of the developer on the sleeve, a step portion spaced apart from the abutting portion, and a separating portion provided upstream of the step portion in the rotation direction of the sleeve, wherein the surface of the sleeve to which the separating portion is opposed includes a position satisfying |Br|/|B|?0.5, where B(G): the magnitude of magnetic flux density formed on the surface of the sleeve, and Br(G): a component of the magnetic flux density in a direction perpendicular to the surface of the sleeve.

Abstract: A development subsystem is used to develop developer having semiconductive carrier particles and toner particles. The development subsystem includes a developer housing, for retaining a quantity of developer having semiconductive carrier particles and toner particles, a first magnetic roll having a stationary core with at least one magnet and a sleeve that rotates about the stationary core of the first magnetic roll, a second magnetic roll having a stationary core with at least one magnet and a sleeve that rotates about the stationary core of the second magnetic roll, and a motor coupled to the first and the second magnetic rolls to drive the rotating sleeves of the first and the second magnetic rolls in a direction that is against the direction of a photoreceptor that rotates in proximity to the first and the second magnetic rolls. The first and the second magnetic rolls carry semiconductive carrier particles and toner particles through a development zone formed by the first and the second magnetic rolls.

Abstract: A developing apparatus having a developer carrying member carrying developer including toner, a developer regulating member regulating the layer thickness of the developer carried on the developer carrying member, and a lubricant provided in a contact portion between the carrying member and the regulating member with the developer being not present on the carrying member, wherein the lubricant includes a first polymer particle which is of a spherical shape having an average degree of circularity of 0.90 or greater and is of a polarity opposite to the charging polarity of the toner, and a second polymer particle of a scalelike shape and of the same polarity as the charging polarity of the toner.

Abstract: A magnetic brush development station for a reproduction apparatus with a movable metering skive so as to enable such metering skive to control and prevent contamination at such metering skive. A developer roller is mounted within the housing for delivering developer material to a development zone, the developer roller including a core magnet inside a shell, the core magnet and the shell having relative rotation. A transport mechanism is provided for delivering developer material from the reservoir to the development roller. A metering skive is provided for establishing a developer material metering gap between the metering skive and the developer roller for controlling the quantity of developer material delivered from the reservoir portion of the housing to the development zone.

Abstract: The invention relates to a method and devices for cleaning the surfaces of applicator rollers, photoconductor drums, transfer belts, and photoconductor belts using magnetic roller systems. The invention also relates to methods and systems for cleaning magnetic rollers to whose surfaces toner particles adhere. In a first embodiment, a squeegee/scraper is disposed at a distance to the surface of the roller. In another embodiment, a magnetic stator configuration with two spaced apart magnetic elements is used whose poles have substantially the same active direction.

Abstract: A device for metering toner to a predefined toner bed height on a donor member, including a composite trim bar having a support portion and a cutting portion, adjacent to the donor member, attached to the support portion.

Abstract: A developing unit for an image forming apparatus using a two-property developer that induces a magnetic attraction force based on the slope of a curved line representing the magnetism of each magnetic pole of a magnetic field generating part of a developing roller and determining a developer-regulating position where the changes of the magnetic attraction force are minor based on the magnetic attraction force in order to assure stable transfer of the developer to a photoconductive medium.

Abstract: A development apparatus is provided and includes a developer support, a developer-controlling member, and a developer-residue controlling member. The developer support supports developer on the surface. The developer-controlling member controls the thickness of the developer on the developer support. The developer-residue controlling member is disposed facing the developer support immediately upstream of the developer-controlling member in the direction in which the developer is conveyed by the developer support. The development apparatus also has a space between the developer-residue controlling member and the developer support that decreases in size downstream in the direction in which the developer is conveyed.

Abstract: A developer regulating member abutting against a developer carrying member carrying a mono-component developer to regulate the layer thickness of the developer on the developer carrying member has a supported portion supported by a support member, and an abutting portion abutting against the developer carrying member, the surface roughness parameters of this abutting portion satisfying the following expressions (1) to (5): 0.30?Sm?0.170??(1) Rpk?2.0??(2) Rp?5.0??(3) 0.10?Rvk×(100?Mr2)/100?1.30??(4) Rpk<Rvk,??(5) where Sm is a mean spacing [mm] of profile irregularities prescribed by JIS-B0601-1994, Rp is a maximum profile peak height [?m] prescribed by ISO4287-1997, Rpk is an initial wear height [?m] prescribed by DIN4776, Rvk is an oil retaining depth [?m] prescribed by DIN4776, and Mr2 is a profile bearing length ratio 2 [%] prescribed by DIN4776.

Abstract: A metering blade confronts the developer roller of a toner cartridge with a working face and associated upstream corner that is accurately controlled with respect to the developer roller to achieve a desired gap therebetween. More particularly, the quality of toner metering is determined through an appropriate technique and the angle of the bottom working face and working corner is varied using appropriate computer-controlled machining techniques to adjust the location of the corner with respect to the radial centerline of the roller at all points along the axial direction. In an illustrative embodiment, the blade's working face is formed to create a setback that is compound angle in two orthogonal directions. This compound angle reorients the upstream corner of the working face to compensate for irregular metering and electrostatic differences across the roller surface, particularly where toner is greater on one side of the roller than the other, opposing side.

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

Abstract: A developer transporting amount controlling member that is used in a developing apparatus is disclosed. The developing apparatus includes a recording unit having a surface that sustains an electrostatic latent image and attracts a developer, a developer transporting unit that transports the developer, and a developing unit that guides the developer to the recording unit. The recording unit, the developer transporting unit, and the developing unit have rotational center axes that are parallel to each other. The developer transporting amount controlling member includes a magnetic part and a nonmagnetic part that is harder than the magnetic part and is fixed to the developing apparatus such that a portion of the nonmagnetic part is disposed closest to the developing unit.

Abstract: A developing apparatus includes a developer carrying member for carrying a developer including one component magnetic toner to develop an electrostatic image formed on an image bearing member. The developer carrying member includes an elastic member contactable to the image bearing member; magnetic field generating means, for attracting the developer to the developer carrying member, and a regulating member for regulating an amount of the developer carried on the developer carrying member. The developer is regulated by the regulating member and applied on the developer carrying member at 5-16 g/mk2. At a position where the regulating member is contacted to the developer carrying member, a magnetic flux density B generated by the magnetic field generating means, and a component Br of the magnetic flux density B normal to a surface of the developer carrying member, satisfy, |Br|/|B|?0.5.

Abstract: A developing device includes a developer carrier that carries a developer and a developer restricting member that restricts a layer thickness of the developer on the developer carrier. The developer carrier carries the developer in such a manner that a thickness Tup of a layer of the developer when the layer passes through the developer restricting member and a gap Gd between the developer restricting member and the developer carrier satisfy an inequality 7<Tup/Gd<20.

Abstract: A developing apparatus including a developer carrying member, a developer layer regulating member and a flight developer regulating member, wherein the developer carrying member is provided in opposed relationship with an image bearing member and carries a developer thereon, and in an opposed portion between the image bearing member and the developer carrying member, an oscillating electric field is formed between the image bearing member and the developer carrying member, and the developer is caused to fly from the developer carrying member to the image bearing member, and the developer layer regulating member regulates a layer of developer on the developer carrying member, and the flight developer regulating member is mounted on the developer layer regulating member, and regulates an area in which the developer flies in the opposed portion.

Abstract: A method of developing a latent image formed on an image carrier with toner, including causing a developer carrier, which faces the image carrier and accommodates a magnet therein, to support a developer having a toner and a magnetic carrier supporting the toner and convey the developer to a developing zone between the developer carrier and the image carrier, and providing an apparent coating ratio M of a surface of the developer carrier coated with the developer. The coating ration M is, in a zone upstream of the developing zone in a direction of rotation of the developer carrier, expressed as M=?A2+? (%), where ? denotes a coefficient of the coating ratio, A2 denotes an amount of developer for a unit area, ? denotes a value determined by a powder characteristic of the developer for an apparent coating ratio calculated with A2=0, and the coating ratio M is between 90% and 120%.

Abstract: A device to regulate toner within an image forming apparatus. The regulating member has a first section and a toner regulating edge with at least one gap. The regulating member controls the amount of toner that is distributed on the surface of the toner developer roller by contacting the toner developing roller in a contact region. The gap, having at least one upper edge, may regulate toner on the toner developer roller near the contact region. The toner regulating device may prevent inadvertent toner marks that may appear on printed media.

Abstract: A magnetic toner contains, as a magnetic powder, magnetic iron oxide having an octahedral particle shape and an average particle diameter of 0.21 ?m or larger and containing 18% or more by weight of FeO. The magnetic toner is so prepared as to have a bulk density A (g/cm3) and a magnetic powder content B (% by weight) that fulfill the formulae 0.8?A/B×100?1.6 and 35?B?50. This alleviates the reddishness of images produced with the magnetic toner, and alleviates the disturbance of a thin toner layer on a developing sleeve and thus the fogging resulting therefrom.