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 photosensitive body (11) having a charge transport layer (11d) as a surface layer. The charge transport layer (11d) as the surface layer is charged and exposed so that a latent image is formed thereon. In order to form a basic dot whose diameter is from 10 ?m to 25 ?m, a thickness t (?m) of the charge transport layer (11d) and a diameter D (?m) of the basic dot satisfy the relationship of t?D/2.

Abstract: A driving apparatus of a detachable developing apparatus, and the detachable developing apparatus using the driving apparatus. The driving apparatus includes: a coupling member including a coupling drive which is connected to a driving element and to which driving power is transferred from the driving element, a coupling gear to which driving power is transferred from the coupling drive, and a coupling disc positioned between the coupling drive and the coupling gear for flexibly connecting the coupling drive and the coupling gear; and a power transferring portion including a plurality of gears to transfer driving power from the coupling member to the developing element and the toner supply element. At least one of the plurality of gears is a reduction gear for reducing a load applied to the coupling member from the developing element and the toner supply element.

Abstract: A toner image carrying member can be rotationally driven, and a plurality of grooves are formed on an outer peripheral surfaces of the toner image carrying member, the plurality of grooves extending along a rotation direction of the toner image carrying member and arranged in an orthogonal direction perpendicular to the rotation direction, and the configuration of the outer peripheral surface of the toner image carrying member in the orthogonal direction is a periodic uneven-configuration. Also disclosed is a method for manufacturing the toner image carrying member and an electrophotographic apparatus having the toner image carrying member.

Abstract: An image-forming apparatus includes a toner-supplying roller and a developing roller that receives toner from the toner-supplying roller, the toner having either a glass transition point not higher than 67° C. or a softening point not higher than 120° C. The developing roller and toner-supplying roller are configured to meet a parameter F given by 1×105<F<7×105 and F=?×?×Asp×(Vsp+Vdv) where ? is an angle of slide (degrees) of the developing roller, ?is a nip (mm) formed in the toner-supplying roller in contact with the developing roller, Asp is a hardness (degrees) of a surface of the toner-supplying roller, the hardness being measured with an Asker Type F durometer, Vsp is a circumferential speed (mm/sec) of the toner-supplying roller, and Vdv is a circumferential speed (mm/sec) of the developing roller and is higher than 150 mm/sec.

Abstract: A developing roller for use in an image-forming apparatus includes a substrate, a silicone-based elastic layer formed on the substrate, and a surface-coating layer formed at the outermost surface. The surface-coating layer has a thickness of not less than 3.5 ?m with an amount of detection of silicon-atom-containing substances on the surface of the developing roller being set to not more than 2.5, and a developing device equipped with the developing roller.

Abstract: An developing device comprising a developing roller for developing an electrostatic latent image on a photo conductor; a developing roller driving unit for rotating the developing roller in a forward direction and in a backward direction respectively while development is performed and not performed; a thickness regulating member, which is pressed against a surface of the developing roller, for regulating a thickness of developer adhered to the surface of the developing roller; and a suppression unit for suppressing a pressing force of the thickness regulating member when the developing roller is rotated in the backward direction.

Abstract: A donor member useful in ionographic or electrophotographic apparatuses and useful in hybrid scavengeless development units, having a substrate and an outer coating having a nano-size powder.

Abstract: A developing device is provided with: a developer containing section that is for containing a developer and that has a predetermined coefficient of thermal expansion; a developing roller for bearing the developer contained in the developer containing section; a roller-supporting member that is for rotatably supporting the developing roller, that has a coefficient of thermal expansion which is different from the coefficient of thermal expansion of the developer containing section, and that is structured by connecting at least three members; and a gap for preventing the roller-supporting member and the developer containing section from interfering with one another when the roller-supporting member and the developer containing section expand/contract due to a change in temperature.

Abstract: A developing roller for use in an image-forming apparatus, the roller including: a substrate; an elastic layer formed on the substrate; a primer layer formed on the elastic layer; and a surface-coating layer formed at the outermost surface, wherein the primer layer includes a conductive substance. A developing device is equipped with the developing roller.

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 developing device includes a removing roller positioned vertically above a supplying roller and in contact with a developing roller. Positively charged toner is supplied from the supplying roller to the developing roller and then supplied to a photosensitive drum for developing an electrostatic latent image thereon. Toner remaining on the developing roller that was not supplied to develop the latent image is removed by the removing roller. Some of the toner stripped by the removing roller falls down toward the supply roller and is again supplied to the developing roller.

Abstract: A developing apparatus including: a developer carrying member for carrying a developer, the developer carrying member being provided with an elastic layer and adapted to develop, with a developer, an electrostatic image formed on an image bearing member; wherein the developer includes a toner, the toner has a shape factor SF-1 of 100 or more but less than 130, the toner has a storage modulus G? (140° C.) at 140° C. of 2.0×103 dN/m2 or more but less than 2.0×104 dN/m2, the toner has a temperature, when the toner has a viscosity of 1.0×103 Pa·s in a flow tester temperature elevation method, of 115° C. or more but less than 130° C., and, in a surface roughness of the developer carrying member, a center-line mean roughness Ra, a ten-point mean roughness Rz and a mean spacing Sm of irregularities satisfy following relationships (1): 0.06 ? Rz / Sm ? 0.4 0.8 ? Ra ? 2.0 ? ? ( ? ? ? m ) } .

Abstract: A developing apparatus includes a developing roller and a sealing member. The developing roller applies toner to an electrostatic latent image to develop the electrostatic latent image. The sealing member presses the developing roller to seal the developer. The apparatus includes a developing roller with a shaft and a resilient layer formed on the shaft. The developing roller rotates about the shaft. The resilient layer covers the outer circumferential surface of the developing roller and is in contact with the sealing member. The resilient layer has a diameter that becomes larger nearer longitudinal ends of the developing roller. The diameter has a maximum value and a minimum value. The difference between the maximum value and the minimum value is such that 10 ?m<??<300 ?m, where ?? is a difference between the maximum value and the minimum value.

Abstract: A developer supplying device including a developer holding unit configured to hold a developer, a developer transfer device configured to electrostatically transfer the developer from the developer holding unit, and a charging member having holes piercing therethrough from the developer holding unit, to abrasively charge the developer by contacting the developer with walls of the holes while the developer is electrostatically transferred through the holes by the developer transfer device.

Abstract: A heat development apparatus for heat developing a heat-developable recording material from one surface side by a heating unit, while transporting the heat-developable recording material by a transportation unit, the apparatus comprising: a transportation path from a beginning end to a terminal end of a heating region in which the heat developing is made by the heating unit, the transportation path being formed in an annular path having a substantially equal length with a transportation length of the heat-developable recording material, so that the beginning end and the terminal end of the heating region are arranged in proximity with each other.

Abstract: A developer carrier includes: an opposing region that opposes a latent image-carryable region on an image carrier, and a solid portion that is solid at an end portion of the developer carrier in a longitudinal direction of the developer carrier. An end of the solid portion, which is on a side of a center of the developer carrier in the longitudinal direction, is located closer to the center of the developer carrier than an edge of the opposing region.

Abstract: Graft polymer curatives comprise a side chain having an average molecular weight of at least about 500, a main chain having an average molecular weight of less than about 200, and diol functionality on the main chain. The graft polymer curative is formed via free radical polymerization of at least one ethylenically-unsaturated monomer with a chain transfer agent or initiator.

Abstract: A conductive elastomer composition having rubber-like elasticity and flexibility and thermoplastic-resin-like moldability and realizing a high conductivity. The conductive elastomer composition includes a thermoplastic elastomer composition (A) containing a compound (A1) composed of a thermoplastic resin and/or a thermoplastic elastomer and a compound (A2), composed of a crosslinkable rubber and/or a crosslinkable thermoplastic elastomer, dispersed in the compound (A1) by dynamically crosslinking the compound (A2); and an ionic-conductive agent (B), containing a metal salt and a polyether-containing block copolymer resin, dispersed in the thermoplastic elastomer composition (A). The conductive elastomer composition may contain carbon black (C).

Abstract: A shaft coupling device for coupling a first shaft and a second shaft together includes a grip unit to be attached to the first shaft and including a grip portion configured to grip the second shaft, the grip portion having an end with notches of a length being parallel with an axial direction of the first shaft. The shaft coupling device also includes a grip force acting unit to be attached to the second shaft and configured to cause a grip force for gripping the second shaft to act on the grip portion by moving the grip portion in a radial direction of the second shaft.

Abstract: An image forming device includes a developer bearing member, a photosensitive member, a developing-bias applying portion, a pressing-force adjusting portion, and a density adjusting portion. The photosensitive member is disposed in contact with the developer bearing member. An electrostatic latent image is formed on the photosensitive member and developed by the developer supplied from the developer bearing member for forming a developer image. The developing-bias applying portion applies a developing bias to the developer bearing member. The pressing-force adjusting portion adjusts the pressing force between the developer bearing member and the photosensitive member.

Abstract: A toner cartridge used with an electrophotographic image forming apparatus includes a developing roller that develops an electrostatic latent image formed on an outer circumferential surface of a photosensitive drum, a toner supplying roller that supplies toner onto the developing roller, a main chamber that stores the toner, a guide member that is disposed under the toner supplying roller to receive the toner and to guide the toner toward the developing roller, a toner recovery chamber that is formed under the guide member to form a space where the toner remaining on the guide member, which is not supplied to the developing roller, can accumulate, a recovery roller that rotates in the toner recovery chamber to return the toner in the toner recovery chamber to the main chamber, and a toner blocking film that is installed on a lower portion of the guide member to prevent the toner from directly leaking to the toner recovery chamber.

Abstract: An image forming apparatus includes an image bearing body and a developing section. An electrostatic latent image is formed on the image bearing body. The developing section includes a developing member and a toner supplying member. The developing member is in contact with the image bearing body and applies toner to the electrostatic latent image. The toner supplying member is in contact with the developing member and has a peripheral surface that moves relative to the developing member. The toner has substantially spherical particles and is supplied from above the developing section and has a saturated apparent density not more than 0.4217 g/ml. The amount of the toner deposited on the developing member is in the range of 0.5 to 1.0 mg/cm2. The layer of the toner deposited on the developing member has a surface potential in the range of ?50 to ?250 V.

Abstract: In a developing roller having a shaft member, a conductive elastic layer provided on the shaft member, and a conductive resin layer constituting a most-surface layer, the conductive resin layer contains a condensed polycyclic organic pigment as exemplified by at least one selected from the group consisting of a quinacridone pigment, a threne pigment, a perylene pigment and a perinone pigment. The developing roller can effectively keep ghosts from occurring and can achieve high image density in a low-temperature and low-humidity environment.

Abstract: An electroconductive rubber roller (10) whose outermost layer consists of a rubber layer (1) made of a rubber composition containing an ionic-conductive rubber as a main component thereof. The surface of the rubber layer consists of an oxide film; and the rubber composition contains a dielectric loss tangent-adjusting filler to set a dielectric loss tangent of the electroconductive rubber roller to 0.1 to 1.5. Weak electroconductive carbon black and/or calcium carbonate treated with fatty acid can be used as the dielectric loss tangent-adjusting filler.

Abstract: To provide an method for forming an image capable of effectively suppressing a toner from deteriorating and also capable of keeping the quality of an image for a long period of time, even when the method is applied to an apparatus with as high process speed. The prevent invention provides an method for forming an image, in which a developing unit is used, which includes: a rotatable cylindrical toner bearing member having a diameter represented as Rd (mm); and a rotatable cylindrical toner-supplying member having a diameter Rs (mm), the diameters Rd and Rs satisfying the following relational expression (1): 1?Rs?Rd?10??(1) and in which the nonmagnetic one-component toner having an degree of aggregation of 5 to 30% and an electric resistivity of 1×1014 to 1×1018 ?·cm at an electric field of 1×104 V/cm is used.

Abstract: The electrophotographic image formation apparatus of the present invention adopts a developer roller, which is made of aluminum and has an aluminum oxide film of at least 5 ?m in thickness formed on surface thereof. In the image formation apparatus, a gap between the developer roller and a photoreceptor drum 3 is set in a range of 150 to 300 ?m. The image formation method of the present invention regulates a frequency of AC voltage in a non-development state to be higher than that in a development state, when an AC voltage is applied onto the developer roller to cause flight of toner from the developer roller to the photoreceptor, and selectively makes charged toner fly onto the electrostatic latent image for development. The present invention provides the effective development technique to prevent leakage of the applied voltage between the developer roller and the photoreceptor drum.

Abstract: Polyurethane elastomers are formed from first and second graft curatives, each graft curative having a molecular weight of at least about 800, wherein the first and second graft curatives are substantially immiscible with one another, and wherein the polyurethane elastomer exhibits a hardness of less than about 40 Shore A according to ASTM D2240-86 and a compression set of less than about 8% according to ASTM D395-89, method B, at a temperature of about 70° C. for about 22 hours. Rolls are manufactured using such polyurethane elastomers, particularly rolls that are suitable for use in image forming devices, such as electrophotographic print applications.

Abstract: In a developing assembly comprising a developer-carrying member and a developer quantity control blade kept in pressure contact with the developer-carrying member, the developer-carrying member has a deformation percentage D of 0.5% or less in the direction of pressure contact, and the developer quantity control blade has a ten-point average roughness Rz of from 0.3 ?m to 20 ?m at its surface on the side kept in contact with the developer-carrying member (a charge control face). The developing assembly can prevent faulty images such as lines and uneven images due to the deformation of developer-carrying member even though any deformation due to the pressure contact of the developer quantity control blade has taken place in the developer-carrying member while the developing assembly is stopped.

Abstract: A developing apparatus includes a rotatable, developer carrying body for carrying a one-component developer and a rotatable, agitating member for agitating the one-component developer. The one-component developer is magnetic toner at least containing a bonding resin and magnetic iron oxide. When wettability of the magnetic toner relative to a mixture solution of methanol and water is measured at the transmittance of light having a wavelength of 780 nm, a methanol concentration at the transmittance of 80% is within the range of 45 to 65 volume %, and wherein 0.1?b/a?0.2 is established where a (rps) denotes the rotation speed of the developer carrying body, and b (rps) denotes the rotation speed of the agitating member.

Abstract: A developing device for developing an electrostatic latent image formed on an electrophotographic photoreceptor includes a hollow developing roller, a support member inserted in the hollow developing roller to support the developing roller, a flange member having a first engaging portion engaging with an outer surface of the support member and a second engaging portion engaging with an inner surface of the developing roller, and a gap-holding member disposed at one end of the developing roller, the gap-holding member having an abutment abutting against the electrophotographic photoreceptor for maintaining a gap between the developing roller and the electrophotographic photoreceptor. The abutment overlaps with the second engaging portion in the longitudinal direction of the developing roller.

Abstract: A developer roller (5) is rotated rapidly for high speed printing, which can cause excessive heating at end seal (1). Heat damage to toner (24) is avoided by providing gaps (30a, 30b) under the seals (1) which reduce the stiffness of developer roller (5) and thereby reduce frictional heating.

Abstract: In a device for transporting toner in an electrophotographic printing or copying device, a rotatable cylinder has a cylinder sheath. The cylinder such includes a metallic layer having a surface with a roughness search that at least one of peaks and columns are provided along with recesses. The recesses of the surface are filled with plastic. Also, the cylinder sheath may include a layer of a porous ceramic material having a roughness.

Abstract: A developer bearing member for bearing toner, the developer bearing member having a multitude of depressions on its surface, and each of the depressions has a multitude of protrusions on its surface. A method for forming the developer bearing member where a surface of the developer bearing member is treated by a blasting treatment, an etching treatment, and electroless plating. Alternatively, the surface of the developer bearing member can be treated with a blasting treatment using particles having a multitude of depressions.

Abstract: A roller spacing device roller mechanisms having rollers in close contact under a given pressure to separate first and second rollers by a constant distance to keep the rollers from touching when roller mechanisms are not used for a long period of time. The roller spacing device comprises a spacing member shiftably mounted between first and second positions on a shaft having a partial D-cut portion and associated with one of the roller members to be separated. The spacing member has a spacing nose overlapped in the second position with an outer circumferential surface of a driving gear connected to the other roller member to separate the first roller member from the second roller member by the constant distance; and a shifting unit shifting the spacing member between first and second positions on the shaft.

Abstract: An image drum cartridge includes supporting walls, on which a photoconductive drum rotates, a position selector, a developing roller that rotates relative to the position selector, a developing blade that forms a thin layer of toner on the developing roller, and a slideable member that urges the developing blade against the developing roller. The position selector is mounted on the supporting walls and movable between first and second positions. The position selector causes the developing roller to move to an operative position where a nip is formed between the photoconductive drum and the developing roller. The position selector causes the developing roller to move to an inoperative position where no nip is formed between the photoconductive drum and the developing roller. The developing roller has a first rotational axis and the position selector has a second rotational axis away from the first rotational axis.

Abstract: An image forming apparatus or toner cartridge component thereof uses a bias voltage contact device that fits into an electrobushing which transmits the electrical contact has been invented. Thus, now a bushing can also act as an electrical contact and thereby a spring is not a requirement. The cylindrical bias voltage contact fits into a developer roller and has a smaller portion that is also cylindrical and fits into an electrobushing. The electrobushing is contacted electrically to the power supply of the image forming apparatus. The cylindrical bias voltage contact may have a cylindrical portion that fits into the developer roller by press fit with the new feature where the cylindrical portion has more than one diameter for obtaining a better press fit.

Abstract: The long magnet includes a magnet block made of a mixture of rare earth magnetic powder, thermoplastic resin particles, fluidity additive, pigment, wax and charge control agent, and a reinforcing member to reinforce the magnet block. At least part of the reinforcing member is arranged inside of the magnet block.

Abstract: A developing device for developing an electrostatic latent image formed on an electrophotographic photoreceptor includes a hollow developing roller, a support member inserted in the hollow developing roller to support the developing roller, a flange member having a first engaging portion engaging with an outer surface of the support member and a second engaging portion engaging with an inner surface of the developing roller, and a gap-holding member disposed at one end of the developing roller, the gap-holding member having an abutment abutting against the electrophotographic photoreceptor for maintaining a gap between the developing roller and the electrophotographic photoreceptor. The abutment overlaps with the second engaging portion in the longitudinal direction of the developing roller.

Abstract: Gear (52) and resin body (2) supported on shaft (1) and between frame members (14a) and (14b) are protected from contacting a frame member. Frame (14a) has a partial hole (22) with an opening (24) and a cavity (26), which is open at the hole (22) and on the side toward the opening (24). A bearing (18) has a inner body (30) which internally is partially circular with diameter substantially the same as opening (22). The outer portion of body (30) forms an outwardly extending nub (34). Wall (36) extends across body (30). The part (38) of bearing 18 opposite body 30 has an extended part (38a) to serve as an electrical contact. A shaft end (5a) past a circular ledge (3a) is supported by bearing (18). The nub (34) fits in the cavity (26) and the wall (36) defines the proper position of rotation of the bearing. This protects gear (52) from being dislodged from its position on shaft (1).

Abstract: The electrophotographic image formation apparatus of the present invention adopts a developer roller, which is made of aluminum and has an aluminum oxide film of at least 5 &mgr;m in thickness formed on surface thereof. In the image formation apparatus, a gap between the developer roller and a photoreceptor drum 3 is set in a range of 150 to 300 &mgr;m. The image formation method of the present invention regulates a frequency of AC voltage in a non-development state to be higher than that in a development state, when an AC voltage is applied onto the developer roller to cause flight of toner from the developer roller to the photoreceptor, and selectively makes charged toner fly onto the electrostatic latent image for development. The present invention provides the effective development technique to prevent leakage of the applied voltage between the developer roller and the photoreceptor drum.

Abstract: An image forming apparatus includes an image bearing body and a developing section. An electrostatic latent image is formed on the image bearing body. The developing section includes a developing member and a toner supplying member. The developing member is in contact with the image bearing body and applies toner to the electrostatic latent image. The toner supplying member is in contact with the developing member and has a peripheral surface that moves relative to the developing member. The toner has substantially spherical particles and is supplied from above the developing section and has a saturated apparent density not more than 0.4217 g/ml. The amount of the toner deposited on the developing member is in the range of 0.5 to 1.0 mg/cm2. The layer of the toner deposited on the developing member has a surface potential in the range of −50 to −250 V.

Abstract: There are disclosed an elastic member which comprises (A) polyurethane foam obtained by agitationally mixing a foaming agent, a foam stabiizer and a urethane prepolymer synthesized from a polyol and a polyisocyanate in the presence of a modified silicone, or (B) polyurethane foam obtained by agitationally mixing a polyol, a polyisocyanate, a modified silicone oil bearing a functional group reactive with a polyisocyanate, a foaming agent and a foam stabiizer comprising a polyether modified silicone containing 50 to 100% by weight of a polyoxyethylene unit in the polyether moiety; image formation equipment equipped with the above elastic member; and a toner supply roller which is composed of a foamed elastic member mounted on a developing apparatus and which has a compression spring constant in the range of 0.25 to 5.0 N/mm and a surface friction resistance in the range of 0.4 to 1.2 N.

Abstract: The present invention provides a conductive member used for a charging unit a development unit, a transfer unit, and a cleaning unit, which are used for electrophotographic apparatus or an electrostatic recording process. The conductive member includes an elastic layer and a resin layer, wherein the resin layer is formed on the outer side of the elastic layer directly or indirectly via another layer. When the surface of the resin layer being in a state not containing any conductive agent is charged due to corona discharge generated by applying a voltage of 8 kV to a corona discharger disposed with a gap of 1 mm put between the surface of the resin layer and the corona discharger, a surface potential of the resin layer after an elapse of 0.3 sec is in a range of 50 V or less and a surface potential of the resin layer after an elapse of 10 sec is in a range of 5 V or less.

Abstract: A developer apparatus includes a developer carrying member, for carrying a developer to a developing portion, the developer carrying member including an electroconductive base and a resistance layer provided thereon; a developer feeding member for being supplied with a voltage to supply the developer to the developer carrying member; wherein a surface moving speed of the developer carrying member Vp [mm/sec], a resistance R1 (&OHgr;) of the developer carrying member when an electric current applied the developer carrying member is 0.

Abstract: To provide an method for forming an image capable of effectively suppressing a toner from deteriorating and also capable of keeping the quality of an image for a long period of time, even when the method is applied to an apparatus with as high process speed.

Abstract: An image forming apparatus includes a latent image bearing member and a developing device for performing a two-level developing operation according to a threshold value of a potential on the latent image bearing member using a one-component developer including toner particles. The developing device has a conveyor to convey the developer to a developing area where the conveyor is spaced from the opposing latent image bearing member by a developing gap. The developing device also has a thin layer forming device to form the developer on the conveyor into a uniform thin layer. A developing bias voltage is applied to the conveyor when the two-level developing operation is performed and developing conditions are established such that an amount of the developer that is moved to and adheres to the latent image bearing member image area is saturated.

Abstract: A non-magnetic toning system for inclusion in a magnetic toning system is disclosed. Further the invention is directed to the process of color imaging, which can be divided into two main categories: (1) line, highlight, or imaging, wherein a permanent toned image of a color, including black, is produced using toner particles of a single color; and (2) process, or “near photographic” color imaging, wherein a permanent toned image is produced by selectively blending or mixing toner particles of two or more primary colors. The invention is directed to an interchangeable Non-Magnetic Toning System (“NMTS”) using specific toners in compatible printing machines. The NMTS using specific toners will be useful in printing machines currently on the market using magnetic toning systems.

Abstract: A developing apparatus includes a developer carrying member for carrying a developer to develop an electrostatic latent image formed on and image bearing member, the developer carrying member having an elastic property; scraping/supplying member, contacted into the developer carrying member, for supplying the developer to the developer carrying member and for scraping the developer off the developer carrying member, the scraping/supplying member having an elastic property, wherein the developer carrying member has a hardness which is higher than that of the scraping/supplying member, and wherein the developer carrying member and the scraping/supplying member satisfy that in a state in which the scraping/supplying member is out of contact with the developer carrying member, a radius of curvature of the scraping/supplying member is larger than a radius of curvature of the developer carrying member at a position of contact between the scraping/supplying member and the developer carrying member.

Abstract: A developing apparatus has a developer supporting member 41 with a surface roughness RZ in the range from 3.0 to 5.5 &mgr;m and a one-component developer T with a bulk density in the range from 0.35 to 0.55 g/ml, and an image is developed by forming a layer of the developer T on the developer supporting member 41. This makes it possible to form a thin toner layer stably despite changes in ambient conditions, and to prevent low image density and fogging. The absolute value of the amount of electric charge with which the developer T is charged is preferably in the range from 3.0 to 10.0 &mgr;C/g. The developer supporting member 41 is made preferably of stainless steel.