Abstract: An image forming apparatus includes a photosensitive member, a developing roller, a toner supply roller, and a charging member. The toner supply roller supplies single-component non-magnetic toner to the developing roller for developing a latent image formed on the photosensitive drum. In a toner cleaning mode, the toner supply roller removes the toner from the developing roller. To this effect, the charging member charges up the toner held on the developing roller. A bias circuit and a controller are further provided, wherein the bias circuit applies bias voltages to the developing roller, supply roller, and charging member, and the controller controls the bias circuit to produce the bias voltages such that a potential difference between the charging member and the supply roller is greater than a potential difference between the developing roller and the supply roller in the toner cleaning mode.

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

Abstract: 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: Development device includes an electrostatic conveyance device, a supply device, and a collection device. The electrostatic conveyance device moves toner on a surface thereof in a toner conveyance direction by a phase-shifting electric field. The surface has upstream and downstream side ends where the phase-shifting electric field starts and ends, respectively. The supply device opposes the upstream side end to supply the toner onto the electrostatic conveyance surface. The toner supplied by the supply device onto the electrostatic conveyance surface is moved by the phase-shifting electric field to a development area of the electrostatic conveyance device opposing an image bearing. The collection device opposes the downstream side end and collects the toner moved on the electrostatic conveyance surface to a downstream side of the development area of the electrostatic conveyance device in the toner conveyance direction without contributing to the development.

Abstract: The invention provides, as an aspect thereof, an image formation apparatus that includes: an image carrier that carries a latent image; a toner carrier that has, on a surface of the toner carrier, a concave portion arrayed in a regular pattern so as to carry toner, and develops the latent image that is carried on the image carrier by means of the toner carried in the concave portion; and a voltage application section that applies a development voltage to the toner carrier for the purpose of the development of the latent image. In the configuration of an image formation apparatus according to the above-described aspect of the invention, immediately after that the toner carrier has developed the latent image, which is carried on the image carrier, by means of the toner carried in the concave portion in response to the application of the development bias to the toner carrier by the voltage application section, at least one layer of the toner remains carried in the concave portion.

Abstract: An image developer, including a developer bearer rotatable facing an electrostatic latent image bearer; a developer feeder feeding a developer including a toner to the developer bearer; a developer collector collecting the developer separated and left from the developer bearer after the developer is fed to the electrostatic latent image bearer; a detour route including a developer stirrer and transfer stirring and transferring the developer between the developer feeder and the developer collector; a first opening connecting the developer feeder with the detour route; a second opening connecting the detour route with the developer collector; a developer supplier supplying the developer to the image developer; and a third opening connecting to the developer supplier, wherein the toner has a volume-average particle diameter of from 3 to 8 ?m and a ratio (Dv/Dn) of the volume-average particle diameter (Dv) to a number-average particle diameter (Dn) thereof of from 1.00 to 1.40.

Abstract: An image forming apparatus includes: a plurality of development units having developing-agent carriers which are provided in correspondence to three or more developing agents, and developing electrostatic latent images on surfaces of image carriers to form developing-agent images on the image carriers; and a recovery unit that recovers the developing agent adhering to the developing-agent carrier during non-development operation. The recovery unit is provided for at least the development unit other than the development unit that transfers the developing-agent image first in sequence among the plurality of development units. When one of the plurality of development units performs development by the developing agent whose charge capability is higher than that of the developing agent of the development unit that transfers the developing-agent image later in sequence, the recovery unit starts recovery of the developing agent or performs recovery operation for improving recovery capability of the developing agent.

Abstract: An image forming apparatus includes: a plurality of development units having developing-agent carriers which are provided in correspondence to three or more developing agents, and developing electrostatic latent images on surfaces of image carriers to form developing-agent images on the image carriers; and a recovery unit that recovers the developing agent adhering to the developing-agent carrier during non-development operation. The recovery unit is provided for at least the development unit other than the development unit that transfers the developing-agent image first in sequence among the plurality of development units. When one of the plurality of development units performs development by the developing agent whose charge capability is higher than that of the developing agent of the development unit that transfers the developing-agent image later in sequence, the recovery unit starts recovery of the developing agent or performs recovery operation for improving recovery capability of the developing agent.

Abstract: An image forming apparatus of a contact-type to develop an electrostatic latent image using a single-component nonmagnetic toner includes a photoconductive medium, a developing roller to move and attach toner to the photoconductive medium to develop the electrostatic latent image, a developing unit to support the developing roller to be rotatable, and having a toner receptacle to store the toner, a toner supplying roller to rotate in contact with the developing roller with a predetermined nip with the developing roller to supply the toner in the toner receptacle of the developing unit to the developing roller, and a cleaning unit to remove from the toner supplying roller the toner which remains on the toner supplying roller after the toner is transferred from the toner supplying roller to the developing roller.

Abstract: A developer supply device provided is in contact with a developer carrying device. It comprises a surface member having at least one opening elongated in an axial direction of the developer supply device. The number of cellular walls counted in the circumferential direction is increased without increasing the number of openings so that the power of scraping the developer is increased. As a result, the dirty background on the print is minimized, thus enhancing the image quality.

Abstract: An image forming apparatus according to the present invention has a resin sheet 20 contacting a collecting roller 18 between a developing unit casing 11 and a collecting roller 18, wherein a scraper 18a which is provided on the collecting roller and projected over the total length scrapes toner adhered to the resin sheet 20, and the toner is ejected to a duct mechanism 115 provided under the resin sheet.

Abstract: An image forming apparatus includes: a plurality of development units having developing-agent carriers which are provided in correspondence to three or more developing agents, and developing electrostatic latent images on surfaces of image carriers to form developing-agent images on the image carriers; and a recovery unit that recovers the developing agent adhering to the developing-agent carrier during non-development operation. The recovery unit is provided for at least the development unit other than the development unit that transfers the developing-agent image first in sequence among the plurality of development units. When one of the plurality of development units performs development by the developing agent whose charge capability is higher than that of the developing agent of the development unit that transfers the developing-agent image later in sequence, the recovery unit starts recovery of the developing agent or performs recovery operation for improving recovery capability of the developing agent.

Abstract: A developing device and an image forming apparatus equipped with the developing device are provided to suppress the deterioration in picture quality of an image formed on a sheet due to toner-clump created in a developer vessel. The developing device, comprising: a developing roller adapted to hold toner thereon while rotating and to supply the toner onto a photosensitive surface of a photosensitive body; a toner recovery vessel adapted to accommodate the developing roller therein with facing an opening portion thereof and to supply the toner to be held on the developing roller onto the developing roller while recovering residual toner remaining on the developing roller; and the toner vessel including a protrusion portion protruded toward a roller surface of the developing roller, the protrusion portion being provided at an inner wall part which confronts the roller surface of the developing roller and where the residual toner begins to drop from the developing roller.

Abstract: The developing apparatus which develops a latent image formed on an photosensitive drum by a toner is provided with a developing roller which bears the toner, and an RS roller abutting against to this developing roller so as to perform the removal and supply of the toner on the photosensitive drum, and at the same time, is provided with adjusting means which adjusts a pushed-in amount for the developing roller of the RS roller according to the characteristic of the RS roller.

Abstract: The present invention discloses a cleaning patch and method thereof for cleaning a residual toner in a developing unit. The cleaning patch is composed of a plurality of cleaning regions. Each cleaning region includes a plurality of cleaning toner point alternately arranged in a row, which may reduce the absorbed toner in each cleaning region to improve the image quality.

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 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 developer-supplying system of an image forming apparatus includes a developer-supplying roller supplying a developer onto a developing roller and removing residual developer which is not transferred onto a photosensitive body, but remains on the developing roller after developing, and a residual developer-withdrawing member disposed in a spaced-apart relation with and opposite to the developer-supplying roller to withdraw the residual developer removed from the developing roller by the developer-supplying roller and transferred onto the developer-supplying roller. The developer-supplying system can not only prevent developer-supplying efficiency and residual developer-withdrawal efficiency of the developer-supplying roller from being reduced, but also reduce stress to the developer to prevent the developer from deteriorating.

Abstract: A developing device used with an electrophotographic image forming apparatus and developing method thereof includes a power supplying unit which applies a first electric field to a toner transfer body and a supplying member so that the toner is supplied to the toner transfer body when a development operation is performed, and applies a second electric field to the toner transfer body and the supplying member so that the toner is removed from the toner transfer body when the development operation is not performed, by varying a developing bias and a supplying bias.

Abstract: The present invention provides a developing apparatus comprising a developer bearing member for bearing developer, a spacer provided on a surface at an end portion of the developer bearing member along a longitudinal direction, for maintaining a constant gap between the developer bearing member and an image bearing member for supplying the developer from the developer bearing member, a seal member for regulating leakage of the developer toward the end portion of the developer bearing member along the longitudinal direction, and a developer scraping member provided at a portion overlapping with the seal member along the longitudinal direction of the developer bearing member, contacting the developer bearing member, and wherein the developer bearing member contacts a surface of the spacer.

Abstract: The developing apparatus includes a developer bearing member, a developer removing-feeding member and a circulating member, wherein the developer circulating member has a push-in amount to the removing-feeding member equal to or larger than a push-in amount of the developer circulating member to the developer removing-feeding member, thereby preventing toner fusion or generation of uncharged developer by a deterioration of the developer, and realizing stable development over a prolonged period.

Abstract: A toner including toner particles including a binder resin and a release agent, wherein when the toner is molded into a plate upon application of a pressure of 478 kg/cm2, the toner plate has a surface having a coefficient of static friction of from 0.20 to 0.40. An image forming apparatus including an image bearing member, an image developer to form a toner image on the image bearing member, an image transferer configured to transfer the toner image on a receiving material and a fixer configured to fix the toner image thereon, wherein the apparatus has a waiting time not longer than 15 seconds, and a maximum power consumption not greater than 1.5 KW and 30 W in an image forming state and in a standby state, respectively, wherein the toner is the toner mentioned above.

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 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 toner supply roller comprises a metallic core shaft and an electrically conductive elastic layer formed to surround the outer surface of the shaft. The conductive elastic layer is formed of open-cell polyurethane foam. The polyurethane foam is impregnated with an electrically conductive polymer and a binder.

Abstract: A developer-supplying system of an image forming apparatus includes a developer-supplying roller supplying a developer onto a developing roller and removing residual developer which is not transferred onto a photosensitive body, but remains on the developing roller after developing, and a residual developer-withdrawing member disposed in a spaced-apart relation with and opposite to the developer-supplying roller to withdraw the residual developer removed from the developing roller by the developer-supplying roller and transferred onto the developer-supplying roller. The developer-supplying system can not only prevent developer-supplying efficiency and residual developer-withdrawal efficiency of the developer-supplying roller from being reduced, but also reduce stress to the developer to prevent the developer from deteriorating.

Abstract: A developing device including a housing, a developer bearing member rotatably provided in an opening portion of the housing, a developer containing chamber, and a developer supplying and removing member being in contact with the developer bearing member, and having the function of supplying a developer in the developer containing chamber to the developer bearing member and the function of removing the developer from the developer bearing member, wherein the developer bearing member is disposed above the developer containing chamber, and the developer supplying and removing member has the function of upwardly carrying the developer in the developer containing chamber.

Abstract: A color electrophotographic apparatus includes a photosensitive member, an exposing device for forming an image on the photosensitive member, developing devices for different colors, and a transfer member. The developing devices include a toner storing chamber, a toner carrying member for forming a toner layer, a regulating member for regulating an amount of toner attached to the toner carrying member, a toner supply chamber having a supply member therein, a toner recovery chamber having an rotating member therein, and a separating member for separating the toner supply chamber from the toner recovery chamber so that the toner supply chamber is disposable above the toner recovery chamber.

Abstract: A developing apparatus includes sealing members which are installed on both inside walls of a housing and closely contact the housing, a developer roller, and a blade to prevent the toner contained in the housing from leaking out. Each sealing member includes a first sealing member and a second sealing member. The first sealing member has a side part that elastically and closely contacts one inside wall of the housing and a short side part of the blade, and a front part that elastically and closely contacts the outer circumference of the developer roller. The second sealing member overlaps with the first sealing member and has a front part that elastically and closely contacts an inside surface of the blade and the outer circumference of the developer roller. Therefore, deterioration of a close contact of the sealing members due to compression and deformation of the sealing members may be prevented. Accordingly, a developing apparatus is configured to prevent leakage of toner.

Abstract: The developing apparatus includes a developer bearing member, a developer removing-feeding member and a circulating member, wherein the developer circulating member has a push-in amount to the removing-feeding member equal to or larger than a push-in amount of the developer circulating member to the developer removing-feeding member, thereby preventing toner fusion or generation of uncharged developer by a deterioration of the developer, and realizing stable development over a prolonged period.

Abstract: In order to provide a developing device and a process cartridge that are capable of preventing leakage of developer at low cost, for example, a developing device comprises: a container, having an opening, for containing a developer; a developer carrying member, rotatably disposed in the opening, for carrying developer; and a developer collecting member mounted to the opening of the container so as to be kept out of contact with the developer carrying member.

Abstract: A color electrophotographic apparatus includes a photosensitive member, an exposing device for forming an image on the photosensitive member, developing devices for different colors, and a transfer member. The developing devices include a toner storing chamber, a toner carrying member for forming a toner layer, a regulating member for regulating an amount of toner attached to the toner carrying member, a toner supply chamber having a supply member therein, a toner recovery chamber having an rotating member therein, and a separating member for separating the toner supply chamber from the toner recovery chamber so that the toner supply chamber is disposable above the toner recovery chamber.

Abstract: A developing device including a housing, a developer bearing member rotatably provided in the opening portion of the housing, a developer containing chamber, and a developer supplying and removing member being in contact with the developer bearing member, and having the function of supplying a developer in the developer containing chamber to the developer bearing member and the function of removing the developer from the developer bearing member, wherein the developer bearing member is disposed above the developer containing chamber, and the developer supplying and removing member has the function of upwardly carrying the developer in the developer containing chamber.

Abstract: To prevent irregular print density resulting from an uneven toner layer, a plurality of cylindrical members 31 formed like rollers are arranged in a manner to contact the sponge roller 22. When the residual toner on the surface of the developing roller 21 is scraped off by the sponge roller 22, the cylindrical members 31 push the toner away without allowing the toner to clot inside the sponge roller 22. Consequently, the sponge roller's performance to remove toner from itself to the developing roller 21 can be preserved for a long time.

Abstract: A protection circuit for an electrophotographic image-forming apparatus is disclosed. The protection circuit monitors the operational state between the power supply and scavenger plate of the electrophotographic image-forming apparatus and issues an interrupt signal whenever a de-coupled state is sensed.

Abstract: A ghosting preventing development process cartridge detachably mountable into an electrostatographic reproduction machine is provided. The ghosting preventing development process cartridge includes a housing having walls defining a partially enclosed storage chamber for storing developer material, and a development opening into the storage chamber. The ghosting preventing development process cartridge also includes a donor roll, mounted rotatably outside the chamber and near the development opening, for receiving a layer of developer material from the storage chamber, and for donating portions of such developer material layer within a development nip to image areas of an image being developed thus leaving a spent developer layer on the donor roll downstream of the development nip.

Abstract: A developing apparatus includes a developer carrying member for developing an electrostatic image on an image carrying member with a toner. The apparatus also comprises a clouding means for forming a toner cloud, directed in a direction opposite to a moving direction of the developer carrying member, near the developer carrying member. The apparatus further includes a coating device for coating the developer carrying member with the toner in the toner cloud by force of an electric field.

Abstract: A developing device, includes; a developing roller supporting and conveying mono component toner to a photoreceptor having a static latent image; a supplying roller pressed against the developing roller and rotated so as to supply the toner to the developing roller. In order to perform beneficial supply of the toner to the developing roller, bias voltages are applied so as to generate an electric field which will cause the toner between the developing roller and the supplying roller to be attracted to the developing roller. At a predetermined time before completion of development, the bias voltage applied to the supplying roller is switched so as to create an electric field which will cause the toner to be attracted to the supplying roller. Thus the toner residing between the developing roller and supplying roller after development is removed, whereby it is possible to prevent toner from sticking to that area on the developing roller, after development.

Abstract: A developing apparatus includes a developer carrying member carrying a developer thereon. A developer supplying device supplies the developer to the developer carrying member. A developer collecting device collects any residual developer on the developer carrying member after having passed the developing portion. During a period when the developing operation is not being performed, the developer on the developer carrying member is collected by the developer collecting device with the supply of the developer by the developer supplying device being stopped.

Abstract: A developer scraping member for scraping developer from a developer carrying member has a surface layer having a foamed member, a base layer provided inside of the surface layer, and an intrusion preventing layer provided between the surface layer and the base layer. The intrusion preventing layer prevents the developer, which has intruded into the surface layer, from intruding into the base layer.

Abstract: It is an exemplified object of the present invention to provide a development device and process, and an electrophotographic image-forming device that can more stably supply toner to and collect the toner from a development roller, and charge the toner, and thus can obtain a higher-printing-quality image than was previously possible. To achieve this object, the toner supply and collection are carried out by electric force (potential difference) while preventing the toner from deteriorating by providing a gap between a reset roller and the development roller, whereby a high-quality image-forming is possible even when printing is performed for a long time. Excellency in uniformity of charge in the toner makes it possible to stabilize capability of supplying the toner and to improve image quality.

Abstract: A developing apparatus comprises a toner container. The toner container has a bottom wall for receiving the toner and an opening facing a photosensitive drum. A toner supplying body is located at the opening. The toner supplying body has a peripheral surface to which the toner is adhered. The toner supplying body is rotated, so that the toner adhered to the peripheral surface is supplied to the photosensitive drum. Toner remaining on the peripheral surface is returned to the toner container through a gap between the toner supplying body and the bottom wall. The toner container has a toner restricting portion projected upward from the bottom wall. The toner restricting portion faces the gap at a position a distance from the gap to be inside the toner container.

Abstract: The present invention relates to an image forming apparatus in which a developing device has a developer bearing member for bearing and carrying a developer thereon, which is provided in opposed relationship with an image bearing member; and developer collecting means provided in opposed relationship with the developer bearing member and the image bearing member, and the developer collecting means collects any unused developer on the developer bearing member and any untransferred developer on the image bearing member.

Abstract: A developing apparatus has a developer carrying member for carrying a developer thereon and conveying it to a developing area opposed to an image bearing member, an agitating member for agitating the developer to be supplied to the developer carrying member and a stripping device for stripping off the developer having passed the developing area from the developer carrying member wherein the developer stripped off from the developer carrying member by the stripping device is guided to a position farther from the developer carrying member than a position at which the agitating member is disposed.

Abstract: The present invention relates to a developing apparatus which has a developer bearing member, a sealing member, a developer scraping portion, and a damming portion disposed on the downstream side of the sealing members and on an upstream side of the developer scraping portion in the carrying direction, and adapted for damming the developer scraped off by the developer scraping portion, and a damming surface of the damming portion is provided so as to intersect with the developer scraping portion.