Abstract: In one embodiment, in a development apparatus in which at least a first screw conveyor has been provided in a case, a developer affixing prevention member that prevents a developer from affixing to the first screw conveyor is disposed in the vicinity of a toner resupply port provided in the case. More specifically, the developer affixing prevention member is formed with a torsion coil spring formed from the wire rod whose middle has been wound in a coil-like shape, and in a state with the wound portion of this torsion coil spring supported by a support plate of the case, one arm portion is fixed to the support plate, and another arm portion is extended so as to contact a fin and a rotating shaft of the first screw conveyor.

Abstract: An image forming apparatus and method charges and exposes a latent image carrier to form a latent image. Bias is applied to liquid developer on a developer carrier, and liquid developer collected by a developer carrier cleaning member is stored in a collected developer storing portion. The state of the collected liquid developer is determined based on a state of bias application or detected image data, and a stirring amount of a conveying member that stirs the collected liquid developer is controlled based on the determined state to improve a property of the collected liquid developer conveyed to a storing unit.

Abstract: A developing device for developing with a developer a latent image formed on an image bearing member includes a container for containing the developer; a stirring member, rotatably supported by the container, for stirring the developer in the container; a magnetic member for forming a magnetic field in a gap between the container and a rotation shaft located at an end portion of the stirring member so as to magnetically confine magnetic particles in the gap; a seal member, provided outside the magnetic member with respect to a rotation shaft direction of the stirring member, contacting a peripheral surface of the rotation shaft of the stirring member; and a non-magnetic preventing portion, provided between the magnetic member and the seal member, for preventing the magnetic particles confined by the magnetic member from spreading toward the seal member.

Abstract: A developer storing apparatus which includes a developer storing portion for receiving and storing a developer. The developer storing apparatus also includes a developer carrying member including a rotary shaft and a spiral blade rotatably disposed in the developer storing portion and configured to carry the developer in the developer storing portion in a predetermined direction, an agitating member extending outside the spiral blade rotatably disposed in the developer storing portion and configured to agitate the developer in the developer storing portion, and a driving force transmitting portion that transmits a driving force to the developer carrying member.

Abstract: Methods for operating a development station are provided. In one aspect a method comprises the steps of: applying a first force at a first end of an auger and a second force at a second end of the auger with the first force and the second force being sufficient to rotate the auger against a drag exerted by the developer and the replenishment toner. Both the first force and the second force are less than a third force applied to a single driven end of an alternative auger to rotate the alternative auger against the drag and wherein the auger has a first yield strength at the first end and a second yield strength at the second end that are less than a third yield strength required to receive the third force at the driven end of the alternative auger.

Abstract: In one aspect, methods are provided for operating a development station. In one aspect a method comprises the steps of applying a first force at a first end of an auger and applying a second force at a second end of the auger with the first force and the second force being sufficient to rotate the auger against a drag exerted by a developer and a replenishment toner being moved by rotation of the auger; and, tensioning the auger along a length of the auger by urging the first end of the auger away from the second end and by urging the second end of the auger away from the first end.

Abstract: Development stations are provided. In one aspect, a development station has a housing having a recirculation path an auger being rotatable to move the developer along at least part of the recirculation path. A drive transmission has a first output mechanically linked for movement with a first end of the auger and a second output mechanically linked for movement with a second end of the auger and distributes a force at an input end between a first force provided at the first output and at a second force provided at the second output to rotate the auger against a drag. The first force and the second force are less than a third force to drive an alternative auger from a driven end. The auger has a first end yield strength and a second end yield strength that are each less than a driven end yield strength of the alternative auger.

Abstract: Development stations are provided. In one aspect a development station has a housing having a recirculation path and an auger being rotatable to move the developer along at least part of the recirculation path. A first actuator drives a first end of the auger and a second actuator drives a second end. A first sensor senses a rotational position of the first end while a second sensor senses a rotational position of the second end of the auger. An auger controller causes the actuators to act so that a first force and a second force rotate the auger against a drag. The first force and the second force are less than a third force to drive an alternative auger from a driven end. The auger has a first end yield strength and a second end yield strength that are less than a driven end yield strength of the alternative auger.

Abstract: Development stations are provided. In one aspect a development station has a housing having a recirculation path and an auger being rotatable to move the developer along part of the recirculation path. A first output is at a first end of the auger through which a first urging force urging the first end of the auger away from the second end can be applied and a second output at a second end of the auger through which a second urging force urging the second end away from the first end can be applied. At least one actuator generates an input force from which at least one of the first force and the second force can be provided; and a separator provides the first urging force and the second urging force to create a tension in the auger.

Abstract: A process cartridge for use in an image forming apparatus includes an image bearing member and a developing unit. The developing unit includes a developer bearing member to bear developer including toner and carrier, a casing forming a developer container containing the developer, a screw having a shaft with a spiral screw blade, a toner density sensor to detect a density of the toner on a detection surface, and a detection surface agitating member fixedly mounted on the shaft of the screw at a position facing a detection surface to scrape away the developer accumulated on the detection surface as the screw rotates. The detection surface agitating member includes an elastic sheet elastically deformable to scrape away the developer accumulated on the detection surface and disposed at a substantially same angle to an axial direction of the shaft of the screw as the spiral screw blade.

Abstract: A toner transport screw that is capable of maintaining a smooth and stable transport function. The toner transport screw, in which a helical blade is disposed on the circumference of a rotating shaft, has at least one spiral direction reversal part formed by connecting the respective ends of a first blade part and a second blade part, the directions of spiral of the first blade part and the second blade part being in opposite directions. A passage, which allows the toner to pass through the blades in the circumferential direction of the rotating shaft, is formed in the spiral direction reversal part.

Abstract: A developer cartridge includes a housing for accommodating developer, a rotation shaft rotatably supported by the housing and passing across an inside of the housing. Also, the cartridge includes a supply opening formed in a wall of the housing opposite in a diameter direction of the rotation shaft, and a return opening formed in a wall of the housing at a position displaced from the supply opening in an axial direction of the rotation shaft. In addition, the cartridge includes a first agitation blade supported by the rotation shaft and passing through a position opposite the return opening along an inner surface of the housing from above to below the position opposite the return opening along with a rotation of the rotation shaft, and a second agitation blade supported by the rotation shaft and passing through a position opposite the supply opening along an inner surface of the housing.

Abstract: Disclosed are a developing unit, in which a developing agent storing part is closed by an agitating member, and an image forming apparatus having the same. The developing unit includes a developing agent storing part to store a developing agent, a developing part connected to the developing agent storing part, and an agitating member rotatably provided in a channel between the developing agent storing part and the developing part to transfer the developing agent stored in the developing agent storing part to the developing part, wherein the channel is closed by the agitating member.

Abstract: An image forming method and apparatus, the apparatus including a latent image carrier configured to carry a latent image thereon, a developing unit disposed facing the latent image carrier to develop the latent image with developer, a developer container containing the developer and attachable to the image forming apparatus, a developer detector configured to detect the presence of the developer in the developing unit, and a developer supply controller, and a disengagement detector configured to detect whether or not an intermediate transfer member is disengaged from the latent image carrier. The developer supply controller prohibits supply of the developer from the developer container to the developing unit when the developer detector detects that the developer is present in the developing unit, and when the disengagement detector detects that the intermediate transfer member is not disengaged from the latent image carrier.

Abstract: A developer station and method for an electrographic printer is provided that reduces developer agitation. The developer station includes a sump for holding a reservoir of magnetic developer including a toner and carrier and a magnetic auger mounted above the sump and including a rotatable magnetic core surrounded by a substantially cylindrical rotatable toning shell rotatably mounted with respect to the core, the shell being adjacent to the photoconductor member and defining a nip and a conveyance device for transporting developer in the developer station in a flow direction. The conveyance device has a tapered auger including a shaft and one or more blades such that the developer volume in the flow direction is controlled to maintain a uniform developer level in the sump as well as a conveyance controller for controlling the conveying device, including the tapered auger such that the tapered auger preferentially creates an uniform layer of developer on the toning shell.

Abstract: A developing device, process cartridge, and image forming apparatus, include at least one developing roller. A plurality of transport members with screw and shaft portions, transport developing agent housed within the device in a longitudinal direction, and form a circulation path. A discharge aperture, formed in a transport path wall of one transport member, discharges developing agent to the outside when a surface of the developing agent transported by one of the plurality of transport members exceeds a predetermined height. The one transport member is adjacent to the developing roller that supplies the developing agent and includes, in a part in the longitudinal direction, an area on which the screw portion is not formed. The discharge aperture is disposed opposite to the area on which the screw portion is not formed, and the length of the discharge aperture is formed smaller than that of the area in the longitudinal direction.

Abstract: There are provided a developing unit and a developer stirring and transporting method in which the amount of developer in the developing unit can always be kept at a specified amount without being influenced by a use environment. A developing unit 10 includes a developing roller 12, a containing unit 16 to contain the developer and having a discharge port 14 to discharge the overflown developer in its side wall, a stirring and transporting member 20 to stir and transport the developer along a passage 18 formed in the containing unit 16, and a guide unit 22 provided in the passage 18 correspondingly to the discharge port 14 of the containing unit 16 and to guide the developer transported in the passage 18 by the stirring and transporting member 20 to the discharge port 14 side.

Abstract: A developing unit includes a developing unit body having a toner inlet and a developing roller mounted in the developing unit body. A toner feeding unit for feeding is provided to feed the toner from the toner inlet to the developing roller. A doctor blade is integrally formed with the developing unit body for controlling the thickness of the toner supplied to the developing roller.

Abstract: A developing device that can suitably discharge developer from the developing device by the amount of developer in the developing device increased by carrier supplemented into the developing device, including: a supply transport screw and a receiving transport screw, the rotational axes of which are mutually parallel in relation to an image support member and which are arranged in a top and bottom positional relationship, and an inclined transport screw which is arranged at an incline between one end of the supply transport screw and the other end of the receiving transport screw; supply means for supplying new carrier into a casing; and a discharge port and discharge means for discharging part of the developer housed in the casing to the outside, the discharge port being provided on the part of the casing corresponding to the upper part of the inclined transport screw.

Abstract: A toner agitating unit is located in a toner hopper that houses toner used for developing a latent image. The toner agitating unit includes a rotary shaft and an agitating member. The agitating member is a flat plate made of resin. The agitating member has a plurality of slits extending from an outer edge of the agitating member toward the rotary shaft.

Abstract: A powder conveying apparatus, comprising a powder container for storing powder and a powder agitating/conveying member provided in the powder container, wherein the powder agitating/conveying member includes: a shaft revolving around the axis; a primary conveying blade provided on the external surface of the shaft in such a manner that the powder is conveyed in the first direction toward one side of the axial direction, by revolution in one rotational direction around the axis of the shaft; and a secondary conveying element provided on the external surface of the shaft and located radially inner than a radially outer end of the primary conveying blade in the diameter direction in such a manner that conveying force is applied to part of the powder, which is conveyed in the first direction by the primary conveying blade, in the second direction toward the other side of the axial direction.

Abstract: A developing device includes a developing roller that carries a two-component developer from a developer container to an image carrier, a first screw carrying a developer, and a second screw carrying the developer in a direction opposite to a direction in which the first screw carries the developer. The first screw and the second screw circularly convey the two-component developer while stirring the two-component developer to supply the two-component developer to the developing roller. A rotation speed of the second screw and a rotation speed of the developing roller can be drive-controlled independently, and a ratio of a rotation speed between the second screw and the developing roller is variable.

Abstract: A toner cartridge includes a toner receptacle that houses toner, a plurality of stirring members housed in the toner receptacle, a plurality of gears meshing with each other on outside of the toner receptacle, and a phase display section. The stirring members are arranged next to each other in the toner receptacle and rotate to stir the toner. Each of the stirring members has a scraper that scrapes off the toner adhering to an inner surface of the toner receptacle. The gears rotate to rotate the stirring members in an interlocked manner with each other. The phase display section shows a meshing position of the gears so that the gears mesh with each other at a position where a phase difference along a rotating direction of the stirring members occurs between the scrapers of the stirring members that are next to each other.

Abstract: A developer transportation device includes a storage portion for storing developer; a transportation member formed of an elastic material and disposed in the storage portion to be freely rotatable for transporting the developer upon rotating; and a rotation transmission member for transmitting a rotation to the transportation member. The transportation member may be provided with an abutting portion abutting against a wall portion of the storage portion when the transportation member rotates.

Abstract: A developer tank of a developing device is partitioned into a first conveyance path, a second conveyance path, a first communicating path and a second communicating path with a partition. A first developer conveying member that conveys a developer in a first developer conveying direction is provided in the first conveyance path. A second developer conveying member that conveys the developer in a second developer conveying direction is provided in the second conveyance path. In the first developer conveying member, a double spiral blade is provided on a downstream side in the first developer conveying direction from a first conveying blade of the first developer conveying member, the double spiral blade including an inner spiral blade that conveys the developer in a first direction and an outer spiral blade that conveys the developer in a second direction.

Abstract: An apparatus for moving waste toner within a printer cartridge includes an auger having a radially inward facing surface, the radially inward facing surface defining an opening having an inner diameter. An elongated drive shaft has an outer surface defining an outer diameter, the outer diameter of the drive shaft being greater than the inner diameter of the auger. The radially inward facing surface of the auger engages the outer surface of the drive shaft with a first pressure when the drive shaft is rotated within the opening of the auger in a first direction with a first load applied on the auger.

Abstract: A developer storage case includes: a storage case that includes a discharge opening formed in the horizontal direction side surface thereof, that is formed in a flat shape having a horizontal direction width larger than the vertical direction height thereof, and that stores a developer therein; a delivery member that has a center of rotation disposed shifted to the discharge opening, that is rotatably supported on one end wall of the storage case, and that delivers the developer stored within the storage case; and a drive transmission member that is supported on the end portion of the delivery member, and that drives and rotates the delivery member.

Abstract: An image forming apparatus, a developing unit thereof and a method of controlling the developing unit. The image forming apparatus includes a photosensitive body on which an electrostatic latent image is formed, a light scanning unit which scans a beam onto the photosensitive body, a developing unit which includes a housing having an agitating space and a supply space, the agitating space and the supply space communicating with each other through two gates to circulate a developer, an agitating auger rotatably mounted in the agitating space to transfer the developer, a supply auger rotatably mounted in the supply space to transfer the developer, and a magnetic roller which receives the developer by the supply auger and adheres the developer to the photosensitive body, a rotation control unit which controls rotation of the agitating auger and the supply auger, and a transfer unit which transfers a visible image formed on the photosensitive body onto a printing medium.

Abstract: A developing device includes a developing vessel for storing a developer, a first conveying passage, a second conveying passage, a first conveying member and a second conveying member to supply toner to a photoreceptor drum. The first conveying member includes a first rotary shaft and a first multi-helically structured blade. The first multi-helically structured blade includes a first inner helical blade and ring-shaped first outer helical blade. The first inner helical blade is formed so that the radius of the helical blade varies cyclically. The second helical pitch of the first outer helical blade is smaller than the first helical pitch of the first inner helical blade. The first outer helical blade inscribes the outer periphery of the first inner helical blade at its minimum radius portions.

Abstract: A developing device that can discharge developer by an amount of developer in the developing device increased by a carrier supplemented into the developing device includes a supply transport screw and a receiving transport screw in a top and bottom positional relationship, the rotational axes of the supply transport screw and the receiving transport screw are mutually parallel in relation to an image support member. The developing device also includes an inclined transport screw arranged at an incline between one end of the supply transport screw and an other end of the receiving transport screw. The developing device also includes a supply unit for supplying new carrier into a casing and a discharge port and discharge unit for discharging part of the developer housed in the casing to the outside, the discharge port provided on a part of the casing corresponding to an upper part of the inclined transport screw.

Abstract: A developing device including a developing unit configured to develop an electrostatic latent image formed on a latent image bearing member with a developer comprising a toner and a carrier, and a circulation unit configured to collect the developer from the developing unit and return the developer to the developing unit. The circulation unit includes a container including a main body having an inverted cone shape, a supply opening provided in a top thereof, and a discharge opening provided in a bottom thereof, configured to hold a part of the developer and provided on an upstream side from the developing unit relative to a direction of circulation of the developer. The container includes a plurality of agitation members configured to agitate the developer collected from the developing unit and fresh toner so that a plurality of flows of the developer is produced in the container.

Abstract: In a development device for containing a developer and developing an electrostatic latent image formed on an image carrier, a supplier supplies fresh developer to the development device. A developer carrier carries the developer to be supplied to the electrostatic latent image formed on the image carrier. A plurality of conveyance members conveys the developer contained in the development device in an axial direction of the development device to form a circulation path. An outlet is provided in a wall of a conveyance path formed by one of the plurality of conveyance members and discharges the developer to an outside of the conveyance path. A discharge conveyance member forms a discharge conveyance path to convey the developer discharged from the outlet in the axial direction of the development device and to discharge the developer to an outside of the development device.

Abstract: The developer delivering device includes a first delivering path, a second delivering path, a helical delivering blade disposed in the second delivering path, and a developer breaking member disposed in a connecting portion of the first delivering path and the second delivering path. The developer breaking member includes a breaking portion disposed opposite to a side wall of the second delivering path in a developer delivering direction of the second delivering path, a contact portion that is in contact with the helical delivering blade and extended in the developer delivering direction between the breaking portion and a center of the rotation of the helical delivering blade, and a coupling portion. The breaking portion has a first breaking portion and a second breaking portion. The contact portion has a first contact portion and a second contact portion. The coupling portion couples the first contact portion to the second contact portion.

Abstract: A developing device and a developer cartridge are provided. The developing device includes a first housing that receives a developing roller; a second housing that is disposed adjacent to and detachable from the first housing and stores developer; first and second communication paths that allow an inside of the first housing to communicate with an inside of the second housing and an agitator that is provided within the second housing and conveys the developer from the first communication path toward the second communication path. The developing cartridge includes a housing that stores developer and an agitator including a rotational shaft that is disposed in one direction and a first blade that is provided at a midpoint in the axial direction of the rotational shaft and conveys the developer from the midpoint in the axial direction of the rotational shaft to both end portions of the rotational shaft.

Abstract: An image forming apparatus includes a photosensitive member and a developing device. The developing device includes a developing roller to supply a developer to the photosensitive member and a casing defining an external appearance of the developing device. A first auger section is defined in the casing to agitate and convey the developer, and a second auger section is defined in the casing and divided from the first auger section. A developer delivery unit is provided on the outside of the casing to deliver the developer from the first auger section to the second auger section.

Abstract: A developing unit is configured to develop an electrostatic latent image born on an image bearing member with a developer that has been charged by mixing and agitating toner and magnetic carrier. The developing unit comprises a developing hopper; a developer bearing member; and at least a pair of agitating and conveying members rotationally driven in the developing hopper. The agitating and conveying members are arranged substantially parallel to the developer bearing member and each rotational shaft of the agitating and conveying members is embedded with a magnetic source element whose magnetic poles are laid out so as to produce a magnetic field radially oriented in a particular fixed direction with respect to the agitating and conveying member.

Abstract: A developing device that circulates developer in a circulation passage having first and second conveyance passages, so that the developer is supplied to a developing roller along the first or second conveyance passages, comprising: a first conveyance member in the first conveyance passage driven to rotate to convey the developer in a first conveyance direction; a communicating passage through which the developer flows from the first to second conveyance passages; a second conveyance member in the second conveyance passage driven to rotate to convey the developer in a second conveyance direction; a discharge passage extending from an end portion of the first conveyance passage located downstream in the first conveyance direction; and a passing developer amount changing mechanism configured to change an amount of developer passing through the communicating passage, according to a pressure applied to the developer at a junction between the first conveyance passage and the discharge passage.

Abstract: The development device includes a development member and a circulation member. The development member develops an electrostatic latent image formed on a latent image carrier with a developer including toner and a carrier to make the electrostatic latent image visible. The circulation member receives the developer discharged from the development member and conveys the developer back to the development member. The circulation member includes a container provided upstream from the development member in a conveyance direction of the developer to store the developer. The container includes an agitator provided inside the container and agitates and mixes the developer and fresh toner supplied to the container. The agitator includes a rotatable agitation member in which one or more holes are formed through which the developer passes to mix the fresh toner and the developer to be agitated in the container.

Abstract: A control unit is provided with an excitation current output section for outputting an excitation current to a stepping motor, a first level judging section for judging a drive stop time level indicating the duration of a time during which the stepping motor is not driven, a storage storing a plurality of starting torque values required to start driving the stepping motor and a plurality of drive stop time levels while relating them to each other, and a controller for obtaining the starting torque value corresponding to the drive stop time level judged by the first level judging section by referring to the storage, calculating an excitation current value which gives the obtained starting torque value and outputting an excitation current having the calculated excitation current value.

Abstract: A developing device and an image forming apparatus which suppress unevenness of image density are provided. A developing device includes a developer tank storing a developer, a first conveying member and a second conveying member conveying the developer, and a developing roller bearing the developer thereon. In the developing device, the first conveying member is constituted by a first rotating shaft and a plurality of first conveying blades provided along a first imaginary spiral surrounding the outer periphery of the first rotating shaft and advancing in the axial direction of the first rotating shaft at a predetermined lead angle ?X. The individual first conveying blades are separated from each other in the axial direction and are provided along the portion of less than one cycle of the first imaginary spiral.

Abstract: A developing unit includes a developer consumption calculator calculating consumptions of developer in zones and storing the consumption in each zone into a corresponding storage region; a consumption shift unit shifting the consumption stored in the storage region corresponding to each zone to a storage region corresponding to a zone located on a downstream side in a developer conveyance direction in response to the conveying of the developer by the circulation conveyance member; a supply amount setting unit setting a supply amount from a developer supply portion based on the consumption stored in the storage region corresponding to the zone corresponding to the developer supply position; and a developer supply controller controlling supply of the developer from the developer supply portion based on the set supply amount.

Abstract: There is provided a developer conveyance member that conveys a contained developer from one end side of a delivery region to other end of the delivery region while agitating the contained developer in a developer container, in which the developer is contained. Around a rotation shaft of the developer conveyance member, a spiral wing toward from one end side to other end side is formed. A plurality of paddle parts for conveying the developer in a direction that is perpendicular to a shaft core are formed around the rotation shaft in a delivery region. The paddle parts are arranged with their positions deviated in a circumferential direction.

Abstract: A developing device includes a developing vessel for storing a developer, a first conveying passage, a second conveying passage, a first conveying member, a second conveying member and a developing roller for supplying toner to a photoreceptor drum. The first conveying member has a first rotary shaft and a first conveying blade formed on the periphery of the first rotary shaft. The first conveying blade has a large-diametric ring-shaped helical blade and a small-diametric helical blade, forming a double-helical structure. Alternatively, the first conveying blade is formed of helical blades being different in phase; each helical blade is formed so that the radius varies on a cycle of the rotational angle of 180 degrees.

Abstract: Provided is a developing device including: a developing container including a developer replenishing port from which the developer is replenished, and a developer discharge port which is provided on a downstream side of one of the conveyance paths and from which surplus developer is discharged; and a discharge regulating portion provided to one of the plurality of stirring members which is arranged in the one of the conveyance paths, in which the discharge regulating portion includes a regulating member arranged so as to face the developer discharge port, for regulating movement of the developer to the developer discharge port side, and a decelerating conveyance member arranged between the helical blade and the regulating member, for partially reducing a conveying speed of the developer in the one of the conveyance paths.

Abstract: A toner cartridge inserted in an image forming apparatus and supplying toner to the image forming apparatus comprises a container which contains the toner and provided with a discharging opening for discharging the contained toner, the container having a shape with a predetermined curvature at a bottom part, a conveying member which conveys the toner in the container to the discharging opening, an agitating member which rotates centering on a rotational axis in the container, and agitates the toner contained in the container and a sheet member provided in the agitating member such that a front edge part abuts the bottom part of the container, the sheet member having the front edge part which is formed with a part having substantially the same curvature as the bottom part of the container.

Abstract: An image forming apparatus, a process cartridge, and a developing unit includes a developer carrying member to carry developer, first and second rotary members arranged in parallel to each other and configured to rotate to agitate and convey the developer, and an enclosure having an inside space to contain the developer, the inside space being divided by a partition with communication openings formed therein at opposite ends thereof into a first chamber configured to maintain the developer above a first level and to hold the first rotary member therein which supplies the developer to the developer carrying member while agitating and conveying the developer, and a second chamber configured to communicate with the first chamber through the communication openings, to maintain the developer at a second level lower than the first level, and to hold the second rotary member therein which circulates the developer with the first chamber through the communication openings.

Abstract: The toner cartridge is provided with: a toner storing container of a rectangular shape having a toner feeding opening in an angular portion of the toner storing container; a stirring conveying member that is disposed so as to rotate in a predetermined rotation direction in the toner storing container and stirs and conveys toner in the toner storing container toward the toner feeding opening; a waste toner storing container that stores reclaimed toner; and a partition member that is held by the toner storing container, partitions between the toner storing container and the waste toner storing containers and has a bearing portion axially supporting a rotating shaft of the stirring conveying member and extending into inside of the waste toner storing container. The toner stored in the toner storing container has an average value of a shape factor (SF1) of about 130 or less.

Abstract: A developing device includes a rotator that rotates around a shaft, and a bearing element that supports the shaft to a housing. A sliding element formed of a composite material that contains self-lubricating thermoplastic olefin resin as a base material is used as the bearing element. The sliding element formed of the composite material has at least a ratio of numerical values of “Rockwell hardness”/“bending elastic modulus” in a range from 25 to 45, and provides a sliding surface of which a frictional coefficient is lower than that of the sliding element formed of the base material.

Abstract: A rotator for powder conveyance includes a substantially linear rotary supporting shaft and plural stirring/conveying pieces. The plural stirring/conveying pieces are separated from each other and arranged in a longitudinal direction along the rotary supporting shaft, are placed at positions separated from a central axis of the rotary supporting shaft in a radial direction of the rotary supporting shaft, have a spiral configuration along an outer peripheral surface of the rotary supporting shaft, and are respectively connected to the rotary supporting shaft via a connecting piece at plural points.

Abstract: The developer replenishment apparatus includes a first developer container for accommodating the developer for replenishment, a first conveyance member disposed in the first developer container to discharge the developer for replenishment through a first opening of the first developer container, a second developer container for receiving the developer for replenishment discharged from the first opening, an agitating member disposed in the second developer container to agitate the developer for replenishment, a second conveyance member disposed in the second developer container to discharge the developer for replenishment through a second opening of the second developer container toward the developing apparatus, and a driving device which does not drive the second conveyance member but drives the agitating member when driving the first conveyance member. The bulk density of the developer is thereby stabilized to make possible replenishment with the developer at high accuracy.