Abstract: Exemplary embodiments provide a direct imaging system and methods for direct marking an image using the system. The disclosed direct imaging system can eliminate the use of at least one of a charge, and/or exposure subsystems in an electrostatographic machine and related processes. Specifically, the direct imaging system can include a direct marking substrate (e.g., a printing substrate) and a development roll member closely spaced from the direct marking substrate. In one embodiment, the development roll member can include a plurality of actuator cells with each actuator cell controllably addressable to eject one or more toner particles adhered thereto. The ejected toner particles can transit the space between the donor roll member and the direct marking substrate, and thereby marking onto the direct marking substrate forming an image.

Abstract: A developing device that can reliably supply toner from a toner supply roller to a developing roller and that does not generate scraping irregularities in the toner thin layer on the developing roller, and a process cartridge and an image forming apparatus having the same. The developing device has: a toner supply chamber; a developing roller provided in the toner supply chamber; a toner supply roller provided in the toner supply chamber for supplying toner to the developing roller; and a layer regulation member for forming the toner on the developing roller into a thin layer, and develops electrostatic latent images on an image carrier by applying bias voltage to the developing roller. An intermediate contact member is interposed between the developing roller and the toner supply roller.

Abstract: A developer container for an image forming apparatus includes a developer accommodating chamber, provided with an opening, for accommodating a developer to be supplied to the opening; a feeding member, provided in the developer accommodating chamber and having an elasticity, for feeding the developer by rotation thereof; a deforming portion, provided in the developer accommodating chamber and contactable to the feeding member, for deforming the feeding member against the elasticity with the rotation of the feeding member; and a restoration portion for permitting the feeding member deformed by the deformed portion to restore elastically, thereby to throw the developer toward the opening, wherein a boundary portion between the deformed portion the restoration portion is disposed below a lower end of the opening.

Abstract: A developing device has a developer bearing member, a housing adapted to accommodate a developer, and a supply roller adapted to supply the developer within the housing for the developer bearing member. The supply roller has an outer circumferencial foam layer made of resin or rubber. The foam layer has an air permeability of 150-200 ml/cm2/s, a hardness of 50-200 N, and an average cell density of 20-40 per 25 mm width.

Abstract: A development device, comprising: a casing; a developer reservoir formed at a bottom part of the casing; a developer supply chamber that accommodates the developer; a developer holding body that is provided to be rotatable about a rotation axis extending in a width direction of the casing and is located on an upper side of the developer reservoir to face an image holding body; a first carry member that is provided in the developer supply chamber to extend in the width direction and to carry the developer to the width direction, a second carry member that is provided on a casing side to extend in the width direction and to carry the developer to the width direction; and a carry substrate that is provided in the casing so that the developer is carried from the developer reservoir to a position facing the developer holding body.

Abstract: A technology capable of suppressing the generation of transfer scattering of a toner image on an intermediate transfer body and contributing to an improvement in image quality in an image forming apparatus employing an intermediate transfer system is provided. An image forming apparatus is configured to include an intermediate transfer body to which a toner imager is transferred from an image carrier, the intermediate transfer body having an elastic surface layer having a center point average roughness of 0.1 times or more of a volume average particle size of a used toner and a ten-point average roughness of not more than the volume average particle size of the used toner; and a development section which develops an electrostatic latent image on the image carrier by using a toner having a shape factor SF-1 in the range of from 100 to 130 and a shape factor SF-2 in the range of from 100 to 140.

Abstract: An image forming apparatus including a photosensitive member on which an electrostatic latent image is formed, an image forming unit to form a visible image on the photosensitive member formed with the electrostatic latent image, and a transfer device to transfer the visible image formed on the photosensitive member onto a printing medium. The image forming unit includes a developing agent storage vessel to store a developing agent therein, a developing unit having a conductive layer to which the developing agent is attached and used to attach the developing agent to the photosensitive member, and a supply unit to supply the developing agent stored in the developing agent storage vessel to the developing unit. The developing unit and the supply unit satisfy a relational expression 1.7?log Sr/log Dr?2.5, where Sr a volume resistance of the supply unit and Dr is a volume resistance of the developing unit.

Abstract: A developer supply device, comprising: a developer holding body having a circumferential surface and a rotation axis extending in a main scanning direction and being placed to face a supply target at a developer supply position; a carrying substrate that has a plurality of electrodes arranged along a direction intersecting with the main scanning direction and that carries a developer in a developer transport direction through a traveling electric field generated by application of a multiphase alternating voltage to the plurality of electrodes, the carrying substrate being located such that an end of the carrying substrate in the developer transport direction is positioned to face the developer holding body; and a voltage application unit configured to apply, to the plurality of electrodes and the developer holding body, the multiphase alternating voltage having alternating components synchronizing with each other.

Abstract: A disclosed developing device includes a developing roller; a supply roller that is in contact with the developing roller and configured to supply toner to the developing roller; a current measuring unit configured to measure an electric current that flows from the developing roller to the supply roller when the toner is supplied from the supply roller to the developing roller; and an error determining unit configured to detect a development error of the developing roller based on the electric current measured by the current measuring unit.

Abstract: Each transport electrode has its longitudinal direction intersecting with a sub-scanning direction. Transport electrodes are disposed in parallel with each other and are arrayed along the sub-scanning direction. A transport-electrode electricity supply wiring section is connected to root portions of the transport electrodes. The root portions are one end portions of the transport electrodes with respect to the longitudinal direction. Toner transport guide members are disposed to cover the transport-electrode electricity supply wiring section and opposite end portions of the transport electrodes; i.e., the root portions and distal end portions.

Abstract: A developing unit includes a developer feeding unit which feeds developer to an image receptor, a casing which supports the developer feeding unit and includes a developer storing part provided in an area to face the developer feeding unit and to store the developer, and a developer feeding plate which is formed with a developer flowing hole through which the developer flows, and is provided to move between the developer storing part and the developer feeding unit.

Abstract: A developing apparatus in which a toner has a volume-average particle diameter R that is in a range of 4.0 ?m?R?6.2 ?m, a developing roller has an arithmetic mean roughness Ra (?m) that is not more than 0.10 times the volume-average particle diameter R of the toner, a voltage applied to a supply roller is of negative polarity, that is, a normal charging polarity of the toner, triboelectrification polarity of the supply roller with respect to the toner is negative, that is, of the normal charging polarity of the toner, and an abutment width S in which the developing roller and the supply roller abut each other is in a range of 2.5 mm?S?5.5 mm.

Abstract: A developer unit according to one aspect of the invention includes: a developer accommodation member configured to accommodate a developer, the developer having charging polarity to a first polarity; a developing roller arranged at the developer accommodation member, the developing roller being configured to carry the developer; a supply roller arranged at the developer accommodation member, the supply roller being configured to supply the developer to the developing roller; and a charging member brought into sliding contact with the supply roller. The charging member at a portion brought into sliding contact with the supply roller is formed of a material which is positioned on a side of the first polarity on a triboelectric series relative to the supply roller.

Abstract: An image forming apparatus including: an image bearing member; and a developer bearing member bearing a developer including a toner and a carrier, the developer bearing member developing an electrostatic image formed on the image bearing member with the developer, and the developer bearing member being applied with an alternate voltage in order to form an alternate electric field between the developer bearing member and the image bearing member, wherein assuming that electric field intensities Eb and Ed be Eb=|(Vp1?VL)/D| and Ed=|(Vp2?VL)/D|, a relationship, 0?K1>K2, is satisfied, where K1: a gradient at Ed, and K2: a gradient at Eb, and wherein a resistivity ?b of the carrier at the electric field intensity Eb satisfies 1.1×106×en<?b<6.0×107 [?·m] (where: e is the base of natural logarithms; and n=4×Eb×10?7).

Abstract: The present invention provides a developing apparatus using a two-component developer, an image forming apparatus, and a method of forming an image capable of forming a high quality image characterized by stable suppression of carrier deterioration and absence of a residual image (memory effect) for a long period of time. The voltage formed by overlapping AD voltage to DC voltage is applied separately to each of the developer carrying member and the toner carrying member. The toner separation field made up of AC field is formed between the developer carrying member and the toner carrying member, and the development electric field made up AC field is formed between the toner carrying member and the image carrying member.

Abstract: Flat field uniformity can be improved in images produced by an image development system having a development roller interposed between a supply of developer and an imaging element. A raw feed of developer is supplied from the developer supply to the development roller to produce both a metered feed of developer and an overfeed of developer, which is returned to the supply, from the raw feed. A plurality of mass densities of developer used in the system and a plurality of developer velocities through the system are determined, and respective product values of those developer mass densities and those developer velocities are thereafter calculated or otherwise determined. A maximum value of the respective product values is identified, and the image development system is then operated so that the maximum product value is produced.

Abstract: An apparatus includes an upstream transport surface TSa which, while facing a circumferential surface DS of a developing roller 33, is disposed upstream of an area (developing area) in the vicinity of a latent image forming surface LS, and a downstream transport surface TSb which, while facing the circumferential surface, is disposed downstream of the developing area. The apparatus forms electric fields on the upstream and downstream transport surfaces for moving a charged developer T from an upstream side toward a downstream side. In the apparatus, the transport speed of developer on the upstream transport surface is higher than that on the downstream transport surface. As a result, there can be lowered a speed at which the developer which has not adhered to the circumferential surface and has reached a downstream end portion of the upstream transport surface flies out toward the vicinity of the developing area.

Abstract: A developing device has a developer material bearing member, a toner bearing member, and an electric field generator adapted to generate an alternate first and second electric fields between the members. The members are driven to move in directions opposite to each other in the opposing region. The first electric field is an oscillating electric field which as a whole biases the toner particles from the developer material bearing member to the toner bearing member. The amount (M/A1) of the toner particles carried per unit area on the toner bearing member is 4 g/m2 or less. A product (Rd×M/A1) of a ratio Rd (Sd/Sp) of the circumferential velocity Sd of the toner bearing member to the circumferential velocity Sp of the electrostatic latent image bearing member and the amount (M/A1) of the toner particles carried per unit area is 4 g/m2 or more.

Abstract: In a hybrid development method using a plurality of toner carriers, a development device and image forming apparatus are provided, wherein high image quality in which toner density is not reduced even in the case of high speed printing and the occurrence of development hysteresis (ghost) is controlled is ensured by accelerating the collection of the post-development residual toner on the toner carrier. The counter-charge having occurred in the developer remains in the developer without decreasing to disappear until the developer moves to the second toner carrier on the downstream-side, wherein this counter-charge is caused by supplying toner to the first toner carrier upstream in the rotating direction of the developer carrier.

Abstract: A developing unit includes a developer receiving vessel and a developer conveyance member as defined herein, the developer conveyance member includes a rotary shaft, a first conveyance member and a second conveyance member as defined herein, the second conveyance member is supported on the rotary shaft and bent in contact with the wall surface of the developer receiving chamber with rotation of the rotary shaft while conveying the developer toward the developer retainer, and the second conveyance member includes a second conveyance member body supported on the rotary shaft and located out of the overlapping range, and a second overlapping portion extending from the second conveyance member body to the other axial end of the overlapping range, designed to be movable relatively to the rotary shaft and disposed adjacently to an upstream side of the first overlapping portion in a rotation direction.

Abstract: Disclosed is a toner supply apparatus that can be employed in an image forming apparatus to supply toner. The toner supply apparatus can include an electrically conductive body, on the surface of which multiple fibers is arranged. The fibers may include nylon 12 fibers containing a conductive material, such as, for example, carbon Hack.

Abstract: An image forming unit includes an image supporting member for forming a latent image; a developer supporting member for attaching developer to the latent image to develop the latent image; a developer supply member facing the developer supporting member for supplying the developer to the developer supporting member; and a first developer pushing member facing the developer supply member to be freely rotatable for supplying the developer to the developer supply member. The first developer pushing member includes a first rod member disposed substantially in parallel to the developer supply member, so that the rod member moves close to the developer supply member equal to or more than 2.50 times when the developer supply member rotates one rotation.

Abstract: The present invention relates to a device or method which may reduce starvation in the transfer of an image forming substance to a developing location within an image forming apparatus. The device may include a first roller having a surface which is capable of supplying an image forming substance to a developing location. A second roller may then be included having a surface in rotating contact with the first roller. The second roller is capable of supplying image forming substance to the first roller. The second roller may comprise foam having a specified porosity, electrical conductivity, and/or be configured to rotate in a desired direction and/or desired speed relative to the first roller.

Abstract: To provide a developer supply roller including: a shaft core; and an elastic layer over the shaft core, wherein the elastic layer is composed of at least a first elastic layer and a second elastic layer, the first elastic layer and second elastic layer made of elastic bodies with different moduli of elasticity, the first layer being an outermost layer of the supply roller, and wherein the relationships 0%?k1?20% and 20%?k2?70% are satisfied, where k1 is the modulus of repulsion elasticity of the first elastic layer and k2 is the modulus of repulsion elasticity (%) of the second elastic layer.

Abstract: In a development apparatus of the hybrid method using a component developer, a development apparatus and a development method are provided that prevent the reduction of density or the occurrence of residual images (ghost images) and can carry out good image forming over a long period of time. A development apparatus has the feature that the surfaces of the toner supporting member and the developer supporting member move in a mutually opposite direction at the part where they are opposite to each others. The development apparatus further employs an electric field in the closest part applied in a direction to recover the toner from the toner supporting member to the developing supporting member, wherein the magnitude of the electric field is in the range from 2.5×106 V/m to 5×106 V/m. The developer of the development apparatus is such that its share (PD) in the space of the closest part of the opposing portion satisfies the following relationship: 0.09?PD?650×Dss.

Abstract: An image forming apparatus includes either one of a process cartridge and a development device. The process cartridge is attachable to and detachable from the image forming apparatus, and integrally includes the development device. The development device includes a developer supplying member and a developer carrying member, at least one of which is formed of an elastic material, and which rotate in contact with each other. The developer supplying member is provided to be displacable in directions of contacting with and separating from the developer carrying member, and is biased toward the developer carrying member by predetermined biasing force.

Abstract: A seamless conductive toner supply brush may comprise conductive fibers flocked onto a metal shaft or rigid conductive core. The shaft/core may be coated with a conductive adhesive and then flocked with fibers about 2-5 mm in length. The brush may be useful as a toner supply brush for supplying toner to a developer member in electrophotographic devices.

Abstract: A developing apparatus has a developer carrying member carrying a developer thereon, a developer supplying member for supplying the developer to the developer carrying member, and a scraping member for contacting the developer carrying member upstream of the closest position between the developer carrying member and the developer supplying member with respect to the movement direction of the developer carrying member to thereby scrape off the developer from the developer carrying member. There is formed a developer supplying portion surrounded by the scraping member, the developer carrying member and the developer supplying member for supplying the developer from the developer supplying member to the developer carrying member, and the developer scraped off by the scraping member is conveyed to a collecting passage differing from the closest position.

Abstract: A developing apparatus including: a developer carrying member carrying a developer with which an electrostatic image on an image bearing member is developed; a developer supplying/removing member having a conductive member and an insulating member on the surface thereof, and provided apart from the developer carrying member to supply and remove the developer to and from the developer carrying member, and moving directions of the developer carrying member and the developer supplying/removing member being opposed in a developer supplying position; and an electric field producing device producing between the developer carrying member and the developer supplying/removing member an oscillating electric field, in which direct potentials of the conductive member and the developer carrying member are the same, or the direct potential of the conductive member, with respect to the direct potential of the developer carrying member, is on the opposite side to a normal charging polarity of the developer.

Abstract: A compact development apparatus using a two-component developer and an image forming apparatus wherein carrier deterioration is prevented to ensure formation of a high-quality image for a long time. The development apparatus uses the developer made up of a mixture of toner, carrier, and opposite polarity particles to be charged oppositely to the toner wherein the opposite polarity particles contain the particles having a relative dielectric constant of 6.7 or more.

Abstract: A developing cartridge usable with an image forming apparatus, the developing cartridge includes a supporting frame, a developing member which is supported in the supporting frame, and to supply the developer to an electrostatic latent image of a photosensitive body of the image forming apparatus, a supplying member which is supported in the supporting frame, and to supply the developer to the developing member, and an elastic unit which is supported in the supporting frame, and to elastically support the supplying member so that the supplying member can move toward and away from the developing member.

Abstract: An apparatus and method for dispensing toner in an electrostatographic printer includes an apparatus for feeding powder toward the feed apparatus wherein the feed roller includes a tapered feed roller including a shaft and one or more variable height flutes such that there is more developer volume in the direction of flow as well as a conveyance controller for controlling the powder conveying device, including the one or more tapered feed rollers such that the tapered feed roller preferentially uniformly conveys the powder toward the feed apparatus.

Abstract: A developing apparatus performs image visualization processing by electrostatically adhering toner carried on a developer carrying member onto an electrostatic latent image formed on an image carrying member. In the developing apparatus, the toner to be supplied to the developer carrying member is directly injected onto the developer carrying members after flying inside an electric field generated immediately before reaching the developer carrying member. The electric field has one of a homopolarity and a reverse polarity to the electrostatic latent image.

Abstract: An image forming apparatus has an electrostatic latent image bearing member capable of bearing an electrostatic latent image thereon, and a developer apparatus having a developer material for visualizing the electrostatic latent image into a visualized image. The developer apparatus includes a developer material bearing member, a housing adapted to accommodate a developer material, and a supply roller adapted to supply the developer material within the housing for the developer material bearing member. The supply roller has an outer circumferential foam layer. The foam layer is made of resin foam or rubber foam and has an air permeability of 5 ml/cm2/s or less, a density of 50-200 kg/m3, and a hysteresis loss ratio of 35-45%.

Abstract: A developing device includes a housing in which nonmagnetic one-component toner is housed, a developing roller which horizontally extends in an opening of the housing, and a feed roller which is set in the housing in pressure contact with the developing roller so as to form a nip portion and which feeds toner to the developing roller. The developing device also includes a feed stabilizing member which is in contact with a lower portion of the feed roller so as to form a second nip portion, and which restricts toner feed quantity. The feed stabilizing member is provided so as to extend from a generally triangular-shaped first region below the first nip portion up to one side of the nip portion opposite to the first region side.

Abstract: A toner supplying roller which is used in a developing apparatus and has the following characteristics: (1) an average diameter of a foam cell opening portion on a surface of a foam elastic member is 100 to 800 ?m, (2) an unopened cell closed by a skin layer of a film thickness of 50 ?m or less is present in the surface of the foam elastic member, and (3) assuming that a surface area of the foam elastic member is A, a total area of the foam cell opening portions is B, and a surface area of the unopened cell is C, the following relationship is satisfied: B A + 0.2 ? B + C A ? 0.95 .

Abstract: Embodiments for toner supply members, particularly toner supply member properties and architectures for controlling toner layer thickness supply to the developer member in image forming devices. In one embodiment the toner supply members have a foamed elastic body.

Abstract: A developing device of an electrophotographic image forming apparatus has a first roller and a second roller disposed in a peripheral contact with the first roller to define a contact region therebetween so that the first roller is capable of supplying and collecting a toner to and from the second roller in the contact region. The first roller has a core and a polyurethane foam layer. The polyurethane foam has an open ratio of cells of 2% or more and 50% or less and a hardness of 1 gf/mm or more and 6 gf/mm or less, the hardness being defined by a load per unit length in a longitudinal direction of the first roller, the load being determined by forcing the peripheral surface of the polyurethane foam layer against a substrate, measuring a load necessary for the polyurethane foam layer to be compressed by 30% in thickness, and dividing the load by a length of the polyurethane foam layer in the longitudinal direction.

Abstract: A developing device capable of facilitating toner delivery upward. The cartridge includes a developing roller, a toner supply roller disposed therebelow, a toner container disposed below the toner supply roller and defining an internal space for accommodating the toner. The container has an upper portion formed with an elongated opening having an upper edge and a lower edge. A conveying member is rotatably disposed in the internal space and in rotational contact with an inner surface of the container for delivering the developing agent upward. The developing agent container including a first wall portion for receiving thereon the developing agent passed through the opening. The first wall portion extends from the lower edge in a downstream direction with respect to a rotational direction of the conveying member toward a position close to a bottommost portion of the toner supply roller.

Abstract: Xerographic imaging modules, xerographic apparatuses including the xerographic imaging modules and methods of making the xerographic imaging modules are disclosed. An embodiment of the xerographic imaging modules includes a photoreceptor roll having a photoconductive surface, a donor roll adjacent the photoreceptor roll for supplying toner to the photoconductive surface, and a toner loading roll adjacent the donor roll for supplying the toner to the donor roll. The toner loading roll includes a core comprised of a foam first material, and a non-porous surface region comprised of the first material. The surface region surrounds the core and forms an outer surface of the toner loading roll.

Abstract: There is provided an image formation device, comprising: a holding body configured to hold thereon developer and to have a center axis extending in a main scanning direction; and a developer supply unit configured to supply the developer to the holding body through a traveling electric field, the developer supply unit having an opening through which a part of the holding body is accommodated in the developer supply unit. In this configuration, the developer supply unit comprises a sliding member configured to slide on at least a part of a surface of the holding body moving toward an outside of the developer supply unit through the opening.

Abstract: An image-forming device includes an image acquiring unit, an image forming unit, a determining unit, and a controller. The image acquiring unit acquires image data for one page. The image forming unit forms an image based on the image data. The image forming unit includes a developing roller, a supply roller, and a bias applying unit. The developing roller carries a developer. The supply roller supplies the developer to the developing roller. The bias applying unit applies a first voltage between the developing roller and the supply roller in a first mode, and applies a second voltage between the developing roller and the supply roller in a second mode. The determining unit determines whether the image data includes a part having density greater than or equal to a prescribed density.

Abstract: A developer conveyer for conveying developer includes a shaft, and a plate structure connected to the shaft. Flexural rigidity of a central part of the plate structure is less than flexural rigidity of a lateral part of the plate structure. Deformation of the central part of the plate structure is greater than deformation of the lateral part of the plate structure so that developer moves from the lateral part to the central part of the plate structure when the shaft drives the plate structure to rotate for conveying the developer.

Abstract: An apparatus includes an upstream transport surface TSa which, while facing a circumferential surface DS of a developing roller 33, is disposed upstream of an area (developing area) in the vicinity of a latent image forming surface LS, and a downstream transport surface TSb which, while facing the circumferential surface, is disposed downstream of the developing area. The apparatus forms electric fields on the upstream and downstream transport surfaces for moving a charged developer T from an upstream side toward a downstream side. In the apparatus, the transport speed of developer on the upstream transport surface is higher than that on the downstream transport surface. As a result, there can be lowered a speed at which the developer which has not adhered to the circumferential surface and has reached a downstream end portion of the upstream transport surface flies out toward the vicinity of the developing area.

Abstract: Provided is an image forming apparatus including at least a latent image bearing member, a latent electrostatic image forming unit, a developing unit which includes at least a developing roller and a supply roller, and a transfer unit, wherein both of a diameter R (mm) of the developing roller and a diameter R? (mm) of the supply roller are 12 mm or less; the toner contains at least a binder resin, a wax, and a colorant with the wax having a melting point of 75° C. or less; an amount of the wax exposed on a surface of the toner is 10 mg/g to 30 mg/g; and when a diameter (mm) of the developing roller is represented by R the toner has a torque T (mNm) satisfying the inequation, 20/R<T<27/R, at a void rate of 58% as measured by a torque measurement method using a conical rotor.

Abstract: A development device including a development roller to bear a development agent including toner, a development agent supplying roller which is provided adjacent to the development roller to supply the development agent to the development roller, a regulation applicator to regulate the layer thickness of the development agent on the development roller and a capture device to capture the development agent finely powdered by the regulation applicator.

Abstract: An object of the present invention is to provide a small-sized developing apparatus which well supplies the developer, does not cause the image degradation for a long term. The developing apparatus comprises a developer containing chamber, a developer supply chamber and developing means which is disposed in said developer supply chamber and develops an electrostatic latent image, a boundary wall which is disposed between said developer containing chamber and said developer supply chamber and has a first and a second opening, and an opening and closing member for opening and closing said first opening. The single component developer is supplied through said second opening into the developer supply chamber. The opening and closing member opens and closes, in response to the toner quantity supplied into the toner supply chamber and allows said single component developer to move in only one direction from said developer supply chamber to said developer containing chamber.

Abstract: A developing device capable of smoothly dispersing a developer in a development container and an image forming apparatus having the developing device. The developing device includes a development container which contains a developer and has an opening, a development roller which is mounted near the opening of the development container, a conveying member which is movably mounted in the development container to supply the developer to the development roller and moves forward and backward in a direction of the opening, and at least one dispersing member which operates according to the forward/backward movement of the conveying member to disperse the developer in the development container.

Abstract: A developer unit according to one aspect of the invention includes: a developer accommodation member configured to accommodate a developer having charging polarity to a first polarity opposite to a second polarity; a developing roller arranged at the developer accommodation member, the developing roller being configured to carry the developer; a supply roller arranged at the developer accommodation member and configured to supply the developer to the developing roller, an image formation width being defined on a surface of the supply roller along an axis direction of the supply roller; and a charging member brought into sliding contact with an outside of the image formation width of the supply roller. The charging member at a portion brought into sliding contact with the supply roller is formed of a material which is positioned on a side of the second polarity on a triboelectric series relative to the supply roller.

Abstract: An image forming apparatus includes either one of a process cartridge and a development device. The process cartridge is attachable to and detachable from the image forming apparatus, and integrally includes the development device. The development device includes a developer supplying member and a developer carrying member, at least one of which is formed of an elastic material, and which rotate in contact with each other. The developer supplying member is provided to be displacable in directions of contacting with and separating from the developer carrying member, and is biased toward the developer carrying member by predetermined biasing force.