Abstract: A two-component developing device using a developer containing toner and magnetic carrier particles. The developing device comprises a housing, a developing roller, a magnetic field generator mounted inside the developing roller, and a developer restricting member, and further comprises a developer guide member providing a developer guide path for guiding the developer to the developer amount restricting clearance, providing a developer circulation path for circulating the developer to an upstream end of the guide member, and providing a communication path for bringing the developer guide path into communication with the developer circulation path, an upstream end of the guide member being positioned above the position of a peak of magnetic flux density of the magnetic pole of the magnetic field generator which is closest to a low-magnetic force area downstream of the low-magnetic force area or positioned upstream of such a position and downstream of the low-magnetic force area.

Abstract: A developing device includes a developing roller that carries a developer and faces an image carrier, a housing that supports the developing roller and supplies the developer to the developing roller, and a pressure reducing part that exists downstream of an opposite position to the image carrier in a rotation direction of the developing roller, and is formed in a wall of the housing located downstream of an airflow generated in a gap between the developer on the developing roller and an inner wall of the housing.

Abstract: A developer layer thickness regulating device includes a blade member for regulating a thickness of a layer of a developer on a surface of a developing roller rotatably supported by a developing container for accommodating the developer and includes a supporting member for supporting the blade member. The supporting member is capable of being fastened to a part of the developing container by a fastening member, and a position of the supporting member relative to a part of the developer container is adjustable with respect to a widthwise direction of the blade member, when the supporting member is fastened to the developing container by the fastening member, so as to fasten the blade member at a predetermined position relative to the developing container. The supporting member has a biting portion which is capable of biting into the part of the developing container when the supporting member is fastened by the fastening member.

Abstract: Systems and methods for preventing and/or inhibiting toner scatter inside of laser printer toner cartridges including a shield that is adjacent to the toner regulating member, extends over and adjacent the developing roller, includes triboelectric material of a polarity corresponding to the polarity of the laser printer cartridge during operation and that functions as a physical barrier and as an electrical barrier to direct toner particles that scatter away from the developer roller back toward the developer roller.

Abstract: A development apparatus includes a first developer chamber configured to store and supply the developer, a first developer bearer configured to convey the developer supplied from the first developer chamber to a first development domain, defined by a portion of the first developer bearer facing a latent image bearer, to develop the latent image, a second developer bearer configured to convey the developer passed through the first development domain to a second development domain, defined by a portion of the second developer bearer facing the latent image bearer, to develop the latent image, a second developer chamber configured to recover the developer passing through the second development domain and store the recovered developer, and a transfer prevention member provided between the second developer chamber and the second developer bearer to reduce a transfer of the developer from the second developer chamber to the second developer bearer.

Abstract: A developing device that includes a developing member, a cylindrical layer thickness regulation member and a guide surface. The developing member retains a developer supplied from a developer accommodation portion and, while rotating, supplies the developer to an image-bearing body. The layer thickness regulation member comes up against the developer retained at the surface of the developing member and regulates a layer thickness of the developer. The guide surface guides developer that has been rendered excess by the layer thickness being regulated by the layer thickness regulation member toward the developer accommodation portion. The guide surface is provided such that an angle that is formed between the guide surface and a tangent of the layer thickness regulation member at a point of intersection of a line of extension of the guide surface with the layer thickness regulation member is at least 90°.

Abstract: A developer-controlling member includes a first plate (36) and a second plate (35) attached to the first plate (36), the first and second plates (36, 35) being formed to extend in a longitudinal direction of a developing roller (30) including a magnet roller; a half blanking fitting projection (38) is formed on one of the first and second plates (36, 35), a fitting hole (49) fitting to the fitting projection (38) is formed in the other of the first and second plates (36, 35), and the first and second plates are fastened by caulking the fitting projection.

Abstract: An amount-of-developer regulating apparatus configured to restrict the amount of developer carried on a developer bearing member. The amount-of-developer regulating apparatus includes a flexible developer amount regulation member having a contact portion configured to contact with a developer bearing member, and first and second holding portions configured to hold the developer amount regulation member and to contact with the developer amount regulation member at further upstream and further downstream in a direction where the developer bearing member is rotationally moved than the contact portion. With a pressure distribution of the contact portion as to the developer bearing member, there are a plurality of local maximum values in the direction where the developer bearing member is rotationally moved. Thus, the apparatus can be reduced in size, and also image concentration unevenness after long-term use can be prevented.

Abstract: A developing apparatus contains a developer for developing a latent image formed on an image carrier. The developing apparatus includes a developer carrier disposed opposite to the image carrier; a developer regulating member regulating an amount of the developer carried by the developer carrier; and a developer circulating unit transporting the developer in a circulating path. The developer circulating unit includes a rotatable first transport member supplying the developer to the developer carrier while transporting the developer in a horizontal direction, a shielding member preventing the developer separated from the developer carrier from flowing back toward the first transport member, and a rotatable second transport member collecting the developer separated from the developer carrier while transporting the developer in the horizontal direction. A distance between the second transport member and the developer carrier is greater than a distance between the first transport member and the developer carrier.

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 device and an image forming apparatus capable of suppressing occurrence of development hysteresis and moving a developer on a chute without being retained is provided. The developing device provides a chute that guides a two-component developer regulated by a regulating member in the direction separating from a developing roller. The chute is composed of a rectangular thin plate made of non-magnetic austenitic stainless alloy, and a tip part that is one end part in a short side direction thereof is provided so as to face a surface of the developing roller. The tip part is transformed to a processed induced martensitic phase to be made ferromagnetic, and subjected to magnetic field orientation in an area facing the surface of the developing roller so as to form a repulsive magnetic field.

Abstract: A magnetic brush development station for a reproduction apparatus has a housing forming, at least in part, a reservoir for developer material; a developer roller mounted within the housing for delivering developer material to a dielectric support member in a development zone; a transport mechanism for transporting developer material from the reservoir to the developer roller; a metering skive for establishing a developer material metering gap; and a mechanism for selectively moving the metering skive to an operative position relative to the developer roller and to a position remote from the developer roller, wherein a build up of contamination at the metering gap between the metering skive and the developer roller can be substantially prevented. A method of removing a skive blockage from a metering skive in a magnetic brush developer station is also disclosed.

Abstract: An image forming apparatus includes an image carrier, a developer carrier arranged to face the image carrier to form a developing nip portion, which carries developer containing toner for developing a latent image formed on the image carrier, a developing unit having a developer regulating member that regulates a thickness of a layer of the carried developer, an air sending duct having an air sending path provided on the developing unit, which sends air to the developer carrier and a suction duct having a suction path provided on the developing unit, which sucks air from the developer carrier. The developer regulating member is arranged on an air sending duct side, and the air sending and suction paths are arranged to be connected by forming a space surrounded by a surface of the developer carrier, the developer regulating member and a wall forming the suction path.

Abstract: A developing device includes: a developing roller incorporating a fixed magnet body having a plurality of magnetic poles in a circumferential direction; a regulating member for regulating an amount of toner on the developing roller by means of a magnetic field formed by the regulating member and the fixed magnet body; and a magnetic-field generating member for scraping off, on an upstream of the regulating member in a rotational direction of the developing roller, toner which is not used for development on the developing roller. A relation Bm/Br>1 is satisfied, where Br represents a magnetic flux density of a distal end portion of the regulating member facing a surface of the developing roller and Bm represents a magnetic flux density of a distal end portion of the magnetic-field generating member facing the surface of the developing roller.

Abstract: A two-component developing method, including regulating a two-component developer borne on a developer bearer with a doctor blade; and transferring the regulated two-component developer to the developer bearer to develop a latent image on an image bearer, wherein the two-component developer includes a pulverized toner having a volume-average particle diameter of from 3.0 to 6.0 ?m, including particles having a particle diameter not greater than 4.0 ?m in an amount not less than 30% by number, and including particles having a particle diameter not greater than 2.0 ?m in an amount not greater than 10% by number, and wherein the doctor blade has a surface regulating the developer at an upstream side relative to a rotational direction of the developer bearer, which has a surface roughness Ra not greater than 0.2 ?m.

Abstract: A repulsive magnetic field is formed in a section immediately upstream of a regulating blade, so that generation of a developing-agent stationary layer is suppressed or eliminated. Accordingly, a developing apparatus capable of stably maintaining the layer thickness of developing agent conveyed to a developing area for a long time is provided.

Abstract: According to an embodiment, a developing device includes: a rotatable developing roller which has plural magnets forming magnetic poles; and a regulating member which includes a non-magnetic plate and a magnetic plate extending parallel to an axial direction of the developing roller and arranged facing the developing roller to regulate thickness of a developer layer on the developing roller, the magnetic plate being attached to a central part in the longitudinal direction of the non-magnetic plate to form a magnetic chain between the developing roller and the regulating member stronger at the central part than an end part.

Abstract: A method for measuring geometric deviations of a doctor blade using an apparatus, including initializing the apparatus, mounting the doctor blade to a doctor blade holding device, illuminating the doctor blade with light, positioning a first portion of the doctor blade at an optical axis of a camera, obtaining a first image signal from the camera that corresponds to the first portion of the doctor blade, generating a first doctor blade geometry value associated with the first image signal, and determining if a first geometric deviation of the doctor blade is within acceptable tolerance using the first doctor blade geometry value.

Abstract: A magnetic brush development station for a reproduction apparatus has a housing forming, at least in part, a reservoir for developer material; a developer roller mounted within the housing for delivering developer material to a dielectric support member in a development zone; a transport mechanism for transporting developer material from the reservoir to the developer roller; a metering skive for establishing a developer material metering gap; and a mechanism for selectively moving the metering skive to an operative position relative to the developer roller and to a position remote from the developer roller, wherein a build up of contamination at the metering gap between the metering skive and the developer roller can be substantially prevented. A method of removing a skive blockage from a metering skive in a magnetic brush developer station is also disclosed.

Abstract: A device for metering developer material to a predefined developer material bed height on a donor member, including a trim bar being mounted a predefined spacing from the donor member; and a magnetic member positioned adjacent and along the length of the trim bar, the magnetic member coacting with the trim bar to obtain the predefined developer material bed height on the donor member.

Abstract: A developing device includes a developer storing portion, a developer carrying body, a first regulating member having a first regulating surface regulating a layer thickness of the developer on the developer carrying body, a second regulating member having a second regulating surface that is set so as to gradually become apart from the developer carrying body toward the upstream side with respect to the rotation direction of the developer carrying body to regulate an amount of the developer conveyed to the first regulating surface, the second regulating surface being arranged with a step formed between the second regulating surface and the first regulating surface, and a sheet member so attached to the second regulating surface as to cover at least a portion of the step between the first regulating surface and the second regulating surface.

Abstract: A developing device includes: a developer carrying body which supplies developer to a predetermined image carrying body; a layer thickness regulating member which is made of a magnetic material, which has a layer thickness regulating face opposing the developer carrying body so as to form a predetermined gap between the layer thickness regulating face and the developer carrying body and regulating the layer thickness of the developer on the developer carrying body, and which forms a magnetic path between the layer thickness regulating face and the developer carrying body; an installation member on which the layer thickness regulating member is installed; and an elastic sheet member arranged in the gap in a state of contact with a surface of the developer carrying body.

Abstract: The development device of this invention includes a developer bearing member, a magnet, and a developer regulation member. The magnet is fixedly disposed within the interior of the developer bearing member. The developer regulation member includes at least a magnetic member. And the thickness of this magnetic member along the rotational direction of the developer bearing member is between 0.2 mm and 0.4 mm inclusive. Moreover, if the distance over the developer bearing member, from the position thereupon which the center of the magnetic member along the rotational direction opposes, to the position thereupon at which the magnetism of that magnetic pole which is disposed closest to that position is a maximum, is termed L (mm), and the diameter of the developer bearing member is termed D (mm), then the magnetic member is disposed within the range in which the relationship 0?L/D?0.044 holds.

Abstract: An anti-accumulation section is provided at a section where an inner surface of a developer container abuts a surface of a doctor blade on an upstream side of a rotation direction of a developing roller. An angle between a surface of the anti-accumulation section facing the developing roller and the surface of the doctor blade on the upstream side of the rotation direction of the developing roller is set to be larger than an angle between a circle concentric with a cross section of the developing roller perpendicular to an extending direction of the developing roller and the surface of the doctor blade on the upstream side of the rotation direction of the developing roller at the section where the surface of the anti-accumulation section facing the developing roller and the surface of the doctor blade on the upstream side of the rotation direction of the developing roller abut.

Abstract: A developer carrier has concave portions regularly arranged on the surface thereof and being rotatable with a developer thereon. A contact member is made of an elastic rubber material, is in contact with the surface of the developer carrier, and vibrates with the rotation of the developer carrier. A value obtained by dividing a movement speed of the surface at the time of rotation of the developer carrier by a pitch of the concave portions in a peripheral direction of the developer carrier is smaller than a peak vibrational frequency of the contact member when a loss tangent obtained by dividing a loss elastic modulus of the contact member by a storage elastic modulus is the greatest.

Abstract: A developing device for an image forming apparatus includes both a layer height restricting blade for controlling a thickness of the developer layer on a developer supply roller, and a spike-height restricting blade. The spike-height restricting blade is located downstream from the layer height restricting blade, and upstream from the position at which an electrostatic latent image bearing member and the developer supply roller are closest to each other. Preferably, the tip of the spike-height restricting blade is located downstream from a radial line along which a main magnetic pole of the device projects half of its maximum magnetic field strength.

Abstract: An image forming apparatus for forming a color image has developing devices with different color toners. Each developing device has a toner carrier and a layer thickness-controller facing the carrier. Circularity of toner in a particular color is smaller than that of toners in other colors. The layer thickness-controllers of the developing devices containing toners in other colors contact the carrier at a particular linear pressure. Additionally, the coefficient of variance (CV value) of the particle diameter distribution of toner in a particular color may be defined by the formula CV ? ? VALUE = ( STANDARD ? ? DEVIATION ? ? OF ? ? VOLUME - AVERAGE ? ? PARTICLE ? ? DIAMETER ? ? DISTRIBUTION ) ( ARITHMETIC ? ? VOLUME ? - AVERAGE ? ? PARTICLE ? ? DIAMETER ) × 100 and may exceed the CV value of the toners in other colors.

Abstract: A developing unit mounted to a main frame of an image forming apparatus comprising a photosensitive medium where an electrostatic latent image is formed and provides a toner to the photosensitive medium to form an image, the developing unit including a developing frame, a developing member installed in the developing frame to provide a toner to the photosensitive medium to develop an image, a blade to regulate a toner layer on the developing member, and a position changing part to change a position of the blade on the developing member.

Abstract: A developing device and image forming apparatus that can satisfy stability over time in relation to amount of developer carried, and prevent developer retention, deterioration of developer and developing sleeve adhesion, wherein the amount of developer carried per unit area on the developer carrier in the developing region is 30 mg/cm2 to 60 mg/cm2; the weight mean particle diameter of the toner is 4.5 ?m to 8.0 ?m; the ratio Dw/Dn of the toner weight mean particle diameter (Dw) and the number mean particle diameter (Dn) is 1.20 or less; an irregular roughness pattern having the maximum height Rz of the surface roughness of 20 to 40 ?m and the mean space Sm of the roughness of 100 to 200 ?m is formed on the surface of the developer carrier; and the relationship between the developing gap PG and the gap DG between the developer restricting member and the developer carrier is 1.0?(DG/PG)?3.0.

Abstract: A single component development device including a toner including a resin, a coloring agent, a wax, a charge control agent and an inorganic particulate, a development roller to bear the toner on the surface of the development roller and transfer the toner to an image bearing member and a thin layer forming member to regulate a thickness of the layer of the toner while in contact with the surface of the development roller via the toner borne thereon, wherein a regulating pressure A between the thin layer forming member and the development roller is from 25 to 60 (N/m), a content Z (weight %) of the charge control agent satisfies the following relationship (1) and an average dispersion particle diameter D (nm) of the charge control agent satisfies the following relationship (2): 0.029×A?0.150>Z>0.013×A?0.013??Relationship (1) D<6.3×A?106.3??Relationship (2).

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: An amount-of-developer regulating apparatus configured to restrict the amount of developer carried on a developer bearing member. The amount-of-developer regulating apparatus includes a flexible developer amount regulation member having a contact portion configured to contact with a developer bearing member, and first and second holding portions configured to hold the developer amount regulation member and to contact with the developer amount regulation member at further upstream and further downstream in a direction where the developer bearing member is rotationally moved than the contact portion. With a pressure distribution of the contact portion as to the developer bearing member, there are a plurality of local maximum values in the direction where the developer bearing member is rotationally moved. Thus, the apparatus can be reduced in size, and also image concentration unevenness after long-term use can be prevented.

Abstract: A developing unit including a retainer receiving portion for receiving a developer retainer, a first agitation portion adjacent to the retainer receiving portion, a second agitation portion adjacent to the first agitation portion, a first conveyance member received in the first agitation portion, a second conveyance member received in the second agitation portion, a layer thickness limiting member made of a magnetic material and disposed between the second conveyance member and the developer retainer to limit the layer thickness of a developer retained on the surface of a retaining member, and a blocking portion disposed on the upstream side of the layer thickness limiting member in the rotation direction of the retaining member and in a space located between the layer thickness limiting member and the second agitation portion to block a developer on the upstream side of the layer thickness limiting member from entering the space.

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: An image forming apparatus includes an image bearing member for bearing an electrostatic latent image; a charger for electrically charging the image bearing member by contact of electroconductive magnetic particles carried on a magnetic particle carrying member with the image bearing member; a developing device for developing the electrostatic latent image into a toner image by supplying toner to the electrostatic latent image; a layer thickness detecting device for detecting a thickness of a surface layer of the image bearing member; a supplying device for supplying the magnetic particles to the magnetic particle carrying member with predetermined timing; and a control device for controlling a supply amount of the magnetic particles so that the supply amount of the magnetic particles supplied by the supplying device increases with an increase of an amount of change in thickness, in terms of an absolute value, of the surface layer obtained from a detection result of the layer thickness detecting device.

Abstract: A developing apparatus using a two-component developer constituted by a magnetic carrier and a toner, and an image forming apparatus comprising the developing apparatus. A developing unit and a stirring unit are provided, and in order to suppress toner scattering that may occur after a development operation has been halted for a long time, and thereby suppress contamination of the apparatus interior, the developer in a developing machine is transferred to a stirrer serving as a developer storage unit on the exterior of the developing machine when the development operation ends.

Abstract: An image forming apparatus for developing an electrostatic image formed on a photosensitive drum 1 with a developer, so as to form an image includes: a rotatable developing sleeve 44; a developing blade 46 for restricting a layer of a developer borne on the developing sleeve 44; developing member for developing the electrostatic image formed on the photosensitive drum 1 with the developer; vibrating member 50 for vibrating the developing blade 46; and control member for controlling a drive condition of the vibrating means 50 according to a printing ratio of the image formed.

Abstract: A layer-thickness regulating member may include a thin plate member and a projection member. The projection member includes a first pressure contact portion that comes into pressure-contact with each of seal areas, a second pressure contact portion that comes into pressure-contact with each of side end areas, and a third pressure contact portion that comes into pressure-contact with a central area. A notched portion is formed at a position of the distal end of the thin plate member where each of the second pressure contact portions is formed, by cutting the thin plate member from an end edge of the distal end toward a downstream side of the rotation direction of the developing agent carrier.

Abstract: A developing device supplies developer to an electrostatic latent image bearing body of an image forming apparatus. The developing device includes a container housing with an opening in a position opposite to the electrostatic latent image bearing body and stores developer to be supplied to the electrostatic latent image bearing body. A developing roller is rotatably disposed so that a part of the developing roller is exposed from the opening. A regulator is disposed along an axial direction of the developing roller and has a leading end facing the developing roller to regulate the thickness of developer layer on the developing roller. Two holders support the developing roller and the regulator on the container housing. Each holder includes a developing roller support for supporting an end part of the developing roller and a regulator retainer for retaining the regulator on the container housing.

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: A device for metering developer material to a predefined developer material bed height on a donor member, including a trim bar being mounted a predefined spacing from the donor member; and a magnetic member positioned adjacent and along the length of the trim bar, the magnetic member coacting with the trim bar to obtain the predefined developer material bed height on the donor member.

Abstract: An image forming apparatus includes: a main body, a photosensitive body spreading developer on a printing paper, a developing roller supplying the photosensitive body with the developer, a developer regulating member regulating the amount of the developer supplied for the photosensitive body by the developing roller, the developer regulating member comprising a supporting member coupled to the main body and an elastic metal board having a bent part extended from the supporting member and contacting with the photosensitive body, and a free length of the elastic metal board being adjusted shorter as a draw rate of the elastic metal board material increases. Accordingly, a developing cartridge and an image forming apparatus has a free length of a developer regulating member that is adjustable to keep the density of developer uniform according to material characteristics of the developer regulating member.

Abstract: An embodiment of a developing device may include a housing, magnetic developer, and a developer bearing member. In some embodiments, the developer bearing member may include a magnet member. The magnet member may allow the developer to remain in the housing. A developer regulating member may be positioned proximate the developer bearing member and have one or more cut portions. In some embodiments, the cut portions may be positioned at each end of the developer regulating member in a surface facing the developer bearing member. The developer regulating member may regulate an amount of the developer held on the developer bearing member. A magnetic sealing member may extend along an outer peripheral surface of the developer bearing member at each end and may be positioned proximate the cut portion. In some embodiments, a portion of the magnetic sealing member may be positioned within the cut portion.

Abstract: A blade cleaning jig includes a cleaning portion and a gripping portion. The cleaning portion includes a support body of stainless steel or the like and polishing tape provided on the upper face of this support body, and moreover a cushioning material is inserted between the support body and the polishing tape. A protective member for preventing damage to the surface of a developer roller is attached to the entire lower face of the support body. This protective member is attached bent at a circumferential end portion such that the protective member covers from the lower face of the support body via a circumferential edge portion to an upper face circumferential edge portion.

Abstract: A development device includes a developer carrier, and a developer conveyance path. The developer carrier carries and conveys developer having a magnetic property. The developer carrier includes a plurality of magnetic poles provided inside the development carrier. The developer conveyance path is provided above the developer carrier and conveys the developer by a flow of air such that the developer is conveyed parallel to the developer carrier. The developer conveyance path is provided with a first developer outlet disposed above the developer carrier and open along a direction of conveyance of the developer to discharge the developer to the outside of the developer conveyance path to directly supply the developer to the developer carrier.

Abstract: A regulating member includes a protrusion protruding from a supporting member toward a developing roller. The length of the supporting member in the longitudinal direction is longer than the length of the protrusion in the longitudinal direction. A seal member includes an extending portion extending from a space for carrying developing agent. The extending portion is turned backward along an end of the regulating member with respect to the longitudinal direction thereof toward the supporting member.

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

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

Abstract: A developing unit to develop an image on an image support body and an image forming apparatus employing the same. The developing unit includes a housing to contain a developer having a toner and a carrier, a magnetic cylinder including a catch pole to pick up the developer in the housing and a main pole arranged to face the image support body and to hold the carrier of the developer, a sleeve installed to rotate on the magnetic cylinder and on which a developer layer is formed, a thickness regulating member to regulate a thickness of the developer layer, and a width regulating member to regulate a width of the developer layer on the sleeve.

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.