Abstract: A developing device has a first and a second developer conveyance path configured to convey and circulate the two-component developer; a first and a second conveyance member each having a helical blade for conveying the developer in one direction; a first communicating path for guiding the developer in the first developer conveyance path to the second developer conveyance path; a second communicating path. The second developer conveyance path includes a second upstream side end section having a bottom in a conical shape having an inner diameter conically increasing. The helical blade of the second conveyance member has a second conical helix portion having an outer diameter conically increasing along an inner wall surface of the bottom of the second upstream side end section. The bottom of the second upstream side end section is at a level lower than a bottom of the first developer conveyance path.

Abstract: A developing device includes: a first conveying passage (developer conveying passage) through which a developer containing a toner and a magnetic carrier is conveyed; a first conveying member (developer conveying member) provided in the first conveying passage for agitating and conveying the developer in a predetermined direction; and a toner supply pipe for leading supplementary toner to the first conveying passage. The developing device further includes electromagnets for forming a magnetic field inside the toner supply pipe to create a magnetic brush shutter by means of the electromagnets.

Abstract: A development device includes a development mechanism, an agitation unit connected to the development mechanism, to agitate and mix together developer collected from the development mechanism and fresh toner, and a transport member to transport the agitated developer from the agitation unit to a development portion. The development mechanism includes a developer carrier to carry developer, multiple supply ports disposed at different positions in an axial direction of the developer carrier, through which the agitated developer is supplied to the development mechanism, a discharge port, a developer supply member to supply developer to the developer carrier while transporting the developer in the direction parallel to the axial direction of the developer carrier, and a developer collection member to collect the developer from the developer carrier.

Abstract: A development device includes a development portion to develop a latent image; an agitation container to contain developer; a circulation system through which the developer is circulated between the development portion and the agitation container; a developer replenishing device to supply fresh developer to the agitation container; an agitator, provided inside the agitation container, to agitate and mix the developer collected from the development portion and the fresh developer from the developer replenishing device; and a developer escape chamber to discharge surplus developer in the agitation container, projecting from and continuous with the agitation container, the developer escape chamber defining a communication pathway in a side of the agitation container between the agitation container and the developer escape chamber through which the developer is moved between the agitation container and the developer escape chamber and having a discharge opening whose lower end is positioned higher than the commun

Abstract: A developing unit, which is incorporated in an image forming apparatus, includes a developer case to accommodate a two-component developer including toner and carrier, a developer bearing member bearing the two-component developer to supply the developer to an image, a developer supply path formed inside the developer case to supply the developer along the developer bearing member, an agitation and conveyance member disposed in the developer supply path, a toner collecting mechanism to collect toner after development, and a collected toner conveyance path formed inside the developer case and including a collected toner conveying member. The collected toner conveyance path and the developer supply path are arranged in communication with each other in the vicinity of one end portion of the collected toner conveyance path in a direction of conveyance of collected toner so as to circulate toner unused for development.

Abstract: Two-component developer in an electrophotographic (EP) printer is replenished. Image data are received and a corresponding latent image is produced. Toner is supplied to the latent image by bringing developer containing toner particles and carrier particles into proximity with the latent image on the photoreceptor using a toning member, so that toner particles are removed from the developer to produce depleted developer. The depleted developer is transported to a return channel, along which it is moved at a channel speed. A processor automatically estimates, as a replenishment amount of toner to be added to the return channel, the amount of toner supplied to the latent image in a diagonal swath on the photoreceptor defined by the process surface speed and the channel speed using the received image data. The replenishment amount of toner is added to the depleted developer in the return channel to replenish the developer.

Abstract: Two-component developer in an electrophotographic (EP) printer is replenished. A replenishment amount of toner is added to depleted developer in a return channel by a replenishment system adjacent to the source end of the return channel. The amount of toner replenished is an estimate of the amount of toner supplied to the latent image in a diagonal swath on the photoreceptor defined by the process surface speed of the photoreceptor and the channel speed of the return channel using the received image data, or using measurements of the respective potentials of the latent image or the respective densities of the visible image at a plurality of points in the diagonal swath on the photoreceptor.

Abstract: Two-component developer in an electrophotographic (EP) printer is replenished. A replenishment amount of toner is added to depleted developer a plurality of points along the length of a return channel. The amount of toner replenished is an estimate of the amount of toner supplied to the latent image in a cross-track swath on the photoreceptor having a length defined by the process surface speed using the received image data, or using measurements of the respective potentials of the latent image or the respective densities of the visible image at a plurality of points in the cross-track swath on the photoreceptor.

Abstract: Provided is a developing device including: a first helical blade; a second helical blade formed at the same blade pitch as a blade pitch of the first helical blade; a developer discharge port for discharging surplus developer; and a regulating member formed in a reverse phase with respect to the first helical blade. When a proximity portion is at a position facing a communication portion, a blade apex portion of the second helical blade is arranged to fall within a range of from a position facing an end surface portion of the communication portion on a downstream side of the second conveyance path to a position immediately before a position facing the proximity portion, which is reached in accordance with a phase shift of the second helical blade. A first stirring member and a second stirring member are driven at the same rotational speed.

Abstract: An approach is provided for managing the processing of print data at a printing device based upon available consumable resources. A printing device includes a print process configured to determine consumable resources that are currently available at the printing device. The print process is further configured to determine which print data is to be processed based upon the consumable resources currently available at the printing device and the consumable resources required to completely process each of the print data. Print data that can be completely processed using the currently available consumable resources are selected for processing. The print process may also be configured to cause a notification to be provided to a client device to indicate the consumable resources currently available at a printing device and/or that insufficient consumable resources were available to process particular print data and to recommend other consumable resources to process the particular print data.

Abstract: A developing device includes: a developing vessel for storing a developer D containing a toner and a magnetic carrier; a first conveying passage for conveying the developer; a first conveying member provided in the first conveying passage for agitating and conveying the developer in a predetermined direction; a developing roller; a toner supply port for supplying toner to the first conveying passage; and an electromagnet arranged at the outer periphery of the toner supply port, and is constructed such that the toner supply port is formed over the first conveying member and the electromagnet intermittently attracts the developer residing under the toner supply port.

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: According to one embodiment, a developing device includes: a developing roller configured to supply a developer to a photoconductive drum; a first mixer configured to mix a fresh toner supplied from a toner supply section and the developer; a second mixer configured to supply the developer mixed by the first mixer to the developing roller; and a magnet roller including a magnet on an inside thereof and configured to remove foreign matters from the developer collected.

Abstract: A development device includes a development roller, a developer storage, a first rotating member, a second rotating member, and a rotation speed adjuster. The development roller carries a developer containing non-magnetic toner and magnetic carrier. The developer storage stores the developer. The first rotating member is provided in the developer storage at a position near the development roller. The second rotating member is provided in the developer storage at a position farther from the development roller than the first rotating member is. The first rotating member and the second rotating member agitate and convey the developer stored in the developer storage to supply the agitated developer to the development roller. The rotation speed adjuster adjusts a rotation speed of the second rotating member depending on an amount of new toner supplied to the developer storage.

Abstract: A developing device 2 includes: a partition member 117 for partitioning an internal space of the developing device 2 into a first carrying path P and a second carrying path Q; and a sliding member 128 which is provided downstream from a developing area in a rotational direction of a developing roller 114 and carries, by use of its inclined plane, a residual developer that remains on a surface of the developing roller 114 from the developing roller 114 toward the first carrying path P. Further, a supply opening 115a via which a toner is supplied is provided above the first carrying path P. The partition member 117 has, downstream from the inclined plane of the sliding member 128, a carrying wall surface section 117c for carrying a part of the residual developer received from the sliding member 128 toward the second carrying path Q. The carrying wall surface section 117c has an opening section 117a that is a through-hole facing the first carrying path P.

Abstract: A developing unit of an image forming apparatus includes a developer cartridge detachably mounted on the developing unit, a developing case in which a developing member and a first supply member are provided, a developer supply passage to supply a developer stored in the developer cartridge to the developing case, and a developer supplement unit mounted in a portion connecting the developing case and the developer supply passage, to agitate the developer supplied through the developer supply passage and to supply the agitated developer to the developing case.

Abstract: A developing device includes: a developing tank for storing a developer containing a toner and a magnetic carrier, the developing tank including, inside thereof, a first developer carrying path; and a first stirring carrying member that rotates so that the first stirring carrying member carries the developer included in the first developer carrying path while stirring the developer. A toner supply opening is formed in a developing tank cover. An upper part of an inner wall surface of a side in which a developer sinks which inner wall surface faces downward rotation of the first stirring carrying member inclines from a direction perpendicular to a horizontal surface toward the first developer carrying path. An angle ? made by (i) a tangential line of the upper inner wall surface at a position of the upper inner wall surface which position is at a height of a top part of an outer circumference of the first stirring carrying member and (ii) a horizontal line is not less than 100° but not more than 150°.

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: 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: An image forming apparatus having an image carrier; an electrostatic latent image forming device that forms an electrostatic latent image on the image carrier; a development device having a housing section that stores toner therein, a stirring device for stirring the toner inside the housing section, and a toner, carrier that develops the electrostatic latent image into a toner image by imparting the toner to the image carrier; a voltage applying device that applies a development bias voltage between the image carrier and the toner carrier; a control device that makes the electrostatic latent image forming device and the development device form a test toner image on the image carrier; and a sensing device that senses a toner adhering amount of the test toner image.

Abstract: An image forming apparatus includes: an electrostatic latent image bearing member; a toner cartridge; a developing member; a transfer member; a developing device; a toner-circulating member; a drive-force output unit; and a circulating-member driving unit. The toner cartridge is removably coupled to the developing device. The toner-circulating member is incorporated in the developing device and circulates toner between the developing device and the toner cartridge. The drive-force output unit is provided in the toner cartridge and is configured to output to the developing device a drive force for driving the toner-circulating member. The circulating-member driving unit is provided in the developing device and is configured to drive the toner-circulating member upon receiving the drive force outputted from the drive-force output unit while the toner cartridge is being coupled to the developing device.

Abstract: A developing device includes a developer carrying member; a first feeding path in which a developer is to be supplied and fed to the developer carrying member at a position in which the first feeding path opposes the developer carrying member; a second feeding path, communicating with the first feeding path, for forming a circulation path with the first feeding path; a discharge opening for permitting discharge of an excessive developer in the developing device; a first supply opening, located downstream of the first feeding path opposing the developer carrying member with respect to a developer feeding direction and located upstream of the discharge opening with respect to the developer feeding direction, for permitting supply of a first developer containing at least toner; and a second supply opening, located upstream of the first feeding path with respect to the developer feeding direction and located downstream of the discharge opening with respect to the developer feeding direction, for permitting supply

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: A toner cartridge includes: a toner holding container having an outlet formed thereon; a partition wall separating the inside of toner holding container to a toner discharging portion in which the outlet is formed and a toner stirring portion other than the toner discharging portion; a toner discharging member axially and rotatably supported in the toner discharging portion for carrying the toner contained in the toner discharging portion to the outlet; a toner stirring member axially and rotatably supported in the toner stirring portion for stirring and carrying to the toner discharging portion the toner in the toner stirring portion; and an upper lid with a recess formed to surround, like a tunnel, the toner discharging member at a portion above the outlet, together with the partition wall and the toner holding container.

Abstract: An image forming apparatus includes: an electrostatic latent image bearing member; a toner cartridge; a developing member; a transfer member; a developing device; and a circulating member. The toner cartridge is removably coupled to the developing device. The developing device incorporates the developing member. The circulating member is capable of operating while the toner cartridge remains coupled to the developing device, to circulate the toner between the developing device and the toner cartridge irrespective of whether the developing member is operating.

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 novel development device includes a developer roller, a developer reservoir, a rotatable conveyor, and a replenisher unit. The developer roller is configured to supply toner particles to the electrostatic latent image. The developer reservoir is configured to hold the developer therewithin for application to the developer roller. The rotatable conveyor is configured to rotate within the developer reservoir to convey the developer toward the developer roller. The replenisher unit has a tubular member terminating at a port opening in the developer reservoir. The replenisher unit is configured to direct a particulate material through the tubular member into the developer reservoir via the port. The particulate material is toner particles, carrier particles, or a mixture of toner particles and a given amount of carrier particles. The port is submerged in the developer within the developer reservoir as the rotatable conveyor rotates.

Abstract: An image forming apparatus includes an image carrier on which a latent image is formed, a charging device that charges the image carrier, an exposing device that irradiates the image carrier, thereby forming a latent image on the image carrier, a developing device that develops the latent image into a visible image by using a monocomponent developer that is carried and transferred by a developer carrier and that is charged to a predetermined polarity, and a toner supply container that is installed in the developing device for toner supply. Used old toner is conveyed from the developing device to the toner supply container and mixed with unused new toner within the toner supply container and thus a mixed toner is produced, and the mixed toner is supplied to the developing device.

Abstract: An image forming apparatus includes a first cabinet, a toner carrier, an image carrier, a second cabinet disposed adjacent to the first cabinet, a toner amount detector and an empty decision unit. An inside of the first cabinet is communicated to an inside of the second cabinet through a plurality of openings. A spacing between one outer edge of one opening provided in one end side and another outer edge in a direction opposite to the longitudinal direction of another opening provided in another end side has a width not less than a width of an image forming region. The empty decision unit decides that a remaining state of a suspension polymerization toner in the second cabinet is the empty state before the amount of suspension polymerization toner in the second cabinet becomes smaller than the amount of suspension polymerization toner in the first cabinet.

Abstract: In an image forming apparatus and an image density control method that are capable of suppressing the amount of toner consumed for a purpose other than image formation and responding to variation in the development ability of a development device due to environmental variation and the like such that a constant image density is obtained, the image density is maintained at a substantially fixed level by first target output value correcting means in accordance with a toner replacement amount and without consuming toner, and adjustment of the image density accompanying variation in the development ability due to environmental variation and the like is dealt with by second target output value correcting means in accordance with a toner pattern detection result.

Abstract: A developing unit of an image forming apparatus includes a developer cartridge detachably mounted on the developing unit, a developing case in which a developing member and a first supply member are provided, a developer supply passage to supply a developer stored in the developer cartridge to the developing case, and a developer supplement unit mounted in a portion connecting the developing case and the developer supply passage, to agitate the developer supplied through the developer supply passage and to supply the agitated developer to the developing case.

Abstract: A developing device includes a developing tank having a developing region tank and an agitating region tank, a partition wall member, a first agitating and conveying member, a second agitating and conveying member, a first intermediate wall member, a second intermediate wall member and a sensor, and an opening portion is formed. In the developing device, a third agitating and conveying member extending in a longitudinal direction of the agitating region tank is provided between the second agitating and conveying member and the second intermediate wall member in a transverse direction of the agitating region tank.

Abstract: A developing device includes a developer holding member that carries a developer; an upper developer housing section that houses the developer; a lower developer housing section that has a bottom surface lower than a bottom surface of the upper developer housing section and houses the developer; a toner supply section that includes an upper toner supply part, a lower toner supply part, and a toner transport section; an upper conveying section that includes a rotation shaft, a first conveying member, a second conveying member, and a diameter direction conveying part; and a lower conveying section that conveys at least one of the developer and the toner in a direction opposite to the conveying direction by the first conveying member.

Abstract: A developing unit for visualizing an electrostatic latent image formed on a photoreceptor drum with a toner, includes: a hopper for storing a developer; a developing roller for supplying the toner to a photoreceptor drum on which an electrostatic latent image is formed; and an agitating and conveying portion. In the developing unit, the agitating and conveying portion includes first and second agitating and conveying belts, each having toner agitating blades for agitating and conveying the toner. The first and second agitating and conveying belts are rotatably arranged in the hopper with their rotational axes set approximately vertically so as to rotate the toner agitating blades approximately horizontally.

Abstract: A development apparatus includes three developer conveyance paths with separate functions for the supply, recovery and agitation of a developer, respectively, in which a reduction in size of the apparatus can be achieved. An image forming apparatus includes the development apparatus. By a development region width of a supply opening for delivering developer from a downstream end in the direction of conveyance of an agitation conveyance path to an upstream end in the direction of conveyance of a supply conveyance path and a surplus opening for delivering developer from the downstream end in the direction of conveyance of the supply conveyance path to the upstream end in the direction of conveyance of the agitation conveyance path, a space saving of the upper part of the development apparatus can be achieved and a space saving of the development apparatus as a whole can be achieved compared with a conventional development apparatus.

Abstract: An image forming apparatus is provided which includes a developing apparatus configured to form a developer image; a supply apparatus configured to supply developer to the developing apparatus; a detector configured to detect an amount of developer consumed during an image forming process; and a controller configured to perform an addition calculation for the amount of developer consumed, and for employing a value obtained by the addition calculation and a supply threshold value to determine whether developer should be supplied to the developing apparatus, wherein the controller sets the supply threshold value in accordance with an operating state of the developing apparatus.

Abstract: A developing unit, which incorporates a developer carrier and can be used in an image forming apparatus incorporated in an image forming system, includes an agitator to agitate a developer including a toner therein, a toner conveyer to convey the developer agitated by the agitator, and a developer carrier disposed facing an image carrier at a development area located between the developer carrier and the image carrier to carry the agitated developer conveyed by the toner conveyer toward a surface thereof to develop a latent image formed on the image carrier into a toner image with the developer at the development area. An adhesion force exerted between the surface of the developer carrier and a toner particle is 100 nN or smaller. The developing unit further includes a supplementary particle supplier and a developer container to mix supplementary particles with the developer therein.

Abstract: In a trickle developing device that uses a two-component developer, a simple configuration is adopted to prevent carrier from being discharged without being used. The developing device having stirring members for conveying and stirring developer and a developer holder, comprises a developer replenishing tank for replenishing developer to a developer tank and a trickle discharging mechanism, wherein the initial filling amount of the developer-tank-contained developer to be filled initially into the developer tank is less than a full filling amount.

Abstract: A container for containing a developer in a first chamber and second chamber partitioned by partitions is provided, fresh toner is supplied to the first chamber of the container, toner recovered from an image carrying member is supplied to the second chamber adjacent to the first chamber, and a path is provided in the partitions to flow the developer between the first and second chambers. A filter having a plurality of oblique slits is attached to the path, and the flow of foreign matter contained in the developer in the second chamber to the first chamber through the path is restricted.

Abstract: An apparatus and method for homogenizing developer allow variations in image quality between marking engines to be reduced. The apparatus includes a developer homogenizer in communication with the marking engines which receives developer from the first marking engine and developer from the second marking engine and combines them. A first portion of the combined developer is returned to the first marking engine for forming images therewith and a second portion of the combined developer is returned to the second marking engine for forming images therewith.

Abstract: A pixel count section calculates a coverage rate corresponding to toner consumption. A control coefficient value setting section determines, based on the coverage rate, a stop threshold value representing reference concentration for toner replenishment and replenishment extension time. A magnetic permeability sensor measures permeability representing toner concentration in a housing portion. A toner concentration control section starts toner replenishment when an output value from the magnetic permeability sensor varies from a value less than a start threshold value to the start threshold value or above, and stops toner replenishment after lapse of replenishment extension time from the time at which an output value varied from a value greater than the stop threshold value to the stop threshold value.

Abstract: An agent transport unit for transporting an agent from a first container to a second container includes a transport route and a pump. The transport route connects the first container and second container, and includes at least one of a first route, a second route, and a third route. The first route extends in a substantially horizontal direction, the second route extends in a substantially vertical direction, and the third route extends in a substantially inclined direction with a repose angle equal to or less than that of the agent. The pump supplies a gas flow into the transport route to transport the agent in the transport route.

Abstract: A developing device includes: a first conveying passage (developer conveying passage) through which a developer containing a toner and a magnetic carrier is conveyed; a first conveying member (developer conveying member) provided in the first conveying passage for agitating and conveying the developer in a predetermined direction; and a toner supply pipe for leading supplementary toner to the first conveying passage. The developing device further includes electromagnets for forming a magnetic field inside the toner supply pipe to create a magnetic brush shutter by means of the electromagnets.

Abstract: A developing apparatus is disclosed that includes a developer carrier for carrying a developer used for developing a latent image, a developer supplying chamber having a developer supplying member for supplying the developer to the developer carrier by rotation, a developer storing chamber positioned above the developer supplying chamber for storing the developer and supplying the developer to the developer supplying chamber, and a partitioning member positioned between the developer supplying chamber and the developer storing chamber. The partitioning member has an opening through which the developer is supplied from the developer storing chamber to the developer supplying chamber. The developing apparatus includes a conveying member positioned above the partitioning member for conveying the developer in a substantially horizontal direction.

Abstract: A toner supply device includes: a toner supply assembly having a toner bottle for holding toner; and a toner supply assembly mounting mechanism having the toner bottle mounted, for feeding toner supplied from the toner bottle to a developing unit. In this toner supply device, toner supplied from the toner supply assembly is fed to the developing unit after it being agitated. The toner supply assembly mounting mechanism includes: guide rails for guiding the toner supply assembly when it is mounted; and a stopper for positioning and holding the toner supply assembly. The toner supply assembly has an abutment surface which is guided by the guide rails and positioned and held by the stopper.

Abstract: A toner cartridge is to be attached to a developing device. The developing device is provided with a developing roller comprising a rotational axis extending along a horizontal direction, a first casing, and a first transporting member. The first casing includes a developing chamber for accommodating the toner to be supported by the developing roller, a first feed opening for feeding the toner from the toner cartridge to the developing chamber, and a first return opening for returning the toner from the developing chamber to the toner cartridge. The first transporting member is located within the developing chamber. The first transporting member transports the toner within the developing chamber from the first feed opening to the first return opening. The first feed opening and the first return opening are offset along the horizontal direction. The first feed opening is located higher the first return opening.

Abstract: A development device includes a development roller, a developer storage, a first rotating member, a second rotating member, and a rotation speed adjuster. The development roller carries a developer containing non-magnetic toner and magnetic carrier. The developer storage stores the developer. The first rotating member is provided in the developer storage at a position near the development roller. The second rotating member is provided in the developer storage at a position farther from the development roller than the first rotating member is. The first rotating member and the second rotating member agitate and convey the developer stored in the developer storage to supply the agitated developer to the development roller. The rotation speed adjuster adjusts a rotation speed of the second rotating member depending on an amount of new toner supplied to the developer storage.

Abstract: A developer is appropriately replenished at the desired toner concentration even with bare minimum stirring. A developer container (11) in which a developer containing toner and carrier is received, a developer replenishing container (23) in which a developer containing toner and carrier is received and which replenishes the developer container (11) with the developer, a replenishment path (25) which connects a upper portion of the developer container 11 with an lower portion of the developer replenishing container (23), stirring member (24) for stirring the developer in the developer replenishing container (23), toner concentration detecting member (27) for detecting the toner concentration of the developer in the replenishment path (25), and control unit (6) for stirring the developer in the developer replenishing container (23) by controlling driving of the stirring member (24) on the basis of the toner concentration detected by the toner concentration detecting member (27) are provided.

Abstract: A developing apparatus includes: an agitating chamber agitating a developer; a developing chamber provided with an inlet to which the developer is supplied from the agitating chamber and an outlet from which the developer is returned to the agitating chamber; a developer carrying member; a rotatable developer supplying member supplying the developer to the developer carrying member; a developer conveying member, provided above the center of rotation of the developer supplying member in the developing chamber, for conveying the developer in a longitudinal direction of the developer carrying member, wherein, in a vertical cross-sectional area of a region vertically above the center of rotation of the developer supplying member of the developing chamber, excluding a developer conveying region by the developer conveying member, a cross-sectional area S1 upstream in the developer conveying direction and a cross-sectional area S2 downstream in the developer conveying direction satisfy a relationship of S1<S2.