Abstract: A developing device, process cartridge and image forming apparatus of a premix developing system, with which developer splashed by the transport member is not discharged from the device, fluctuations of the amount of developer discharged to the outside are not produced, and the output image quality is stable. This developing device is provided with a pocket part, which is installed in a depressed manner facing the outside in relation to the transport route formed by the transport member, and into and out of which part of the developer transported in the transport route flows. This pocket part is provided with a discharge port for discharging developer to outside the device when the surface of the developer flowing into the pocket part exceeds a specified height.

Abstract: A developing unit according to an embodiment of the present disclosure includes a developer container, a stirring member, a magnetic roller, a developing roller, a developer supply port, and a developer discharge portion. The developer discharge portion includes a discharge blade having a spiral blade and conveying an excess developer, a developer discharge port through which the excess developer conveyed by the discharge blade is discharged outside of the developer container, and an air outlet through which an airflow in the developer container passes toward the outside of the developer container. The developer discharge port is located at a position lower than the upper surface of the developer present in the developer discharge portion; and the air outlet is located at a position higher than the upper surface of the developer present in the developer discharge portion.

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: An image forming apparatus includes: a photosensitive member that is configured to carry a developer image; a developing roller that is configured to supply developer to the photosensitive member; a transfer member that is configured to transfer the developer image carried on the photosensitive member to a transfer medium; and a control unit that is configured to execute a collection mode upon receiving a printing instruction for executing a printing operation but before initiating the printing operation, wherein the control unit in the collection mode is configured to: discharge the developer of one or more circumferences of the developing roller, which has been carried on the developing roller, to the photosensitive member; and collect the discharged developer by the developing roller.

Abstract: A toner supplying method for supplying toner from a toner container to a developing part that causes toner to adhere to a latent image formed on a latent image carrying member and develops the latent image, includes detecting a toner amount in the developing part as being equal to or less than a predetermined toner amount value; forming a fog detecting image in a case where the toner amount in the developing part is equal to or less than the predetermined toner amount value, and detecting fog; and determining based on the detected fog whether to execute a toner ejecting process of ejecting the toner remaining in the developing part toward the latent image carrying member before supplying the toner to the developing part from the toner container.

Abstract: An image forming apparatus includes a latent image carrier, a development device, a discharge port through which developer is discharged, a discharge port detector, and a controller that determines whether to permit driving of the development device in a direction reverse to a normal direction or to terminate discharge of developer based on detection results by the discharge port detector in discharge of developer. The development device includes a developer carrier, a developer supply member disposed in a supply compartment facing the developer carrier, a developer collection member disposed in a collection compartment lower than the supply compartment, a developer agitation member disposed in an agitation compartment disposed at a height similar to that of the collection compartment, to transport developer in a direction opposite conveyance direction by the developer supply member and the developer collection member.

Abstract: A developing device for supplying a developer to an image bearing member is provided with a housing configured to define a passage for movement of the developer and a replenishment path configured to communicate with the passage and supply the developer to the passage; a conveyor configured to move the developer in the passage and the replenishment path; and a switching device configured to switch one moving direction to another moving direction of the developer by the conveyor to selectively move the developer toward the replenishment path.

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: An image forming apparatus includes: an image carrier that carries an electrostatic latent image; a development device that includes a toner carrier which is disposed opposite to the image carrier, carries and supplies toner to the image carrier, and develops the electrostatic latent image formed on a surface of the image carrier; and a control means that performs a refresh process in which toner is ejected from the toner carrier to the image carrier in a time an image is not formed, and a toner ejection pattern which is formed by ejecting a line image a plurality of times that has an acute angle to a main scan direction at predetermined intervals in a circumferential direction of the image carrier over a total width of a development region.

Abstract: An image forming device includes an image carrier, an exposing part, a developing member; a developer reserving part; a detection part to detect a developer remaining amount; a first count part to count a rotation number of the image carrier; a second count part to count an exposing dot number; a first calculation part to calculate a print duty for a print sheet based on the rotation number of the image carrier and the exposing dot number; and a discarding part in which when the developer remaining amount is equal to or less than a standard remaining amount, and when the print duty is less than a standard duty, developer is to discard more than the case in which the developer remaining amount is more than the standard remaining amount.

Abstract: An image forming apparatus for forming a visual image on a recording medium includes a toner replacing device that replaces toner stored in a developing device with fresh toner, and a determiner that determines if a recording medium selected by a user necessitates replacement of the toner. The toner replacing device replaces the toner with fresh toner when the determiner determines that the recording medium necessitates replacement of the toner before the latent image is formed on a photoconductive member.

Abstract: A developing apparatus includes a developer container to store a developer, a conveyance member to convey the developer, and a discharge port to discharge the developer. The discharge port is at a position that is on one end side from a central portion of the conveyance member with respect to an axial direction of the conveyance member. A first region of the conveyance member may include a portion facing the discharge port that has a conveyance capacity that is lower than a conveyance capacity of a second region or has a conveyance capacity that is zero. The conveyance member includes a positioning unit that is provided on the one end side thereof in the axial direction to position the conveyance member in the axial direction by abutting on the developer container, and an urging unit to urge the positioning unit with respect to the developer container.

Abstract: An image forming apparatus includes first and second developer carrying members and a control device. The apparatus is operable in a first mode where an image of a single color is formed using the first developer carrying member and is operable in a second mode, wherein an image of a plurality of colors is formed using the first and second developer carrying members. The control device controls a first discharging operation for discharging developer from the first developer carrying member and a second discharging operation for discharging developer from each of the first and second developer carrying members. When the apparatus executes only the first mode, the control device performs more image formations, in a period between completion of the second discharging operation and start of the first discharging operation, compared to a period between completion of the first discharging operation and start of a subsequent first discharging operation.

Abstract: A developer collection container includes: a developer collection container main body that forms a developer collection chamber in which developer is collected; a first developer conveyance member, provided inside the developer collection container main body, that conveys the developer by rotating about a shaft; and a second developer conveyance member, provided below the first developer conveyance member with respect to a gravitational direction in the developer collection container main body, that conveys the developer by rotating about a shaft, the developer collection container main body having a collected developer introduction member that introduces the developer to the developer collection chamber being provided between the first developer conveyance member and the second developer conveyance member with respect to the gravitational direction.

Abstract: An image forming apparatus includes an image bearing member for bearing a latent image; a developing device, including a developer carrying member for carrying and feeding a developer including toner and a carrier to a developing position in which the developer opposes the image bearing member, for developing the latent image formed on the image bearing member; a discharging portion for permitting discharge of an excessive developer present in the developing device by supplying the developer into the developing device; a feeding member for feeding the developer in the developing device; a controller for controlling a forced discharging operation for discharging the excessive developer from the discharging portion by changing a driving condition of at least one of the developer carrying member and the feeding member; and a detecting device for detecting information correlating to flowability of the developer in the developing device.

Abstract: A developer accommodating container is provided with a first accommodating portion in which a first feeding member is arranged, a second accommodating portion in which a second feeding member is arranged, a first communication portion communicating the first accommodating portion and the second accommodating portion in their one end sides, a second communication portion and a third communication portion communicating the first accommodating portion and the second accommodating portion at two positions in the other end sides so as to be shifted their positions in a feeding direction of the developer, a discharge portion arranged between the second communication portion and the third communication portion in the second accommodating portion, and provided for discharging the developer, and a replenishing portion arranged in a downstream side in the feeding direction of the developer than the third communication portion in the first accommodating portion, and provided for replenishing the developer.

Abstract: An apparatus and method that determines toner age in a printing apparatus. The method can include placing an imaging surface cleaner in contact with an imaging surface. The method can include placing a toner patch on the imaging surface. The method can include rotating the imaging surface in a process direction. The method can include measuring a frictional interaction between the imaging surface cleaner and the imaging surface as the toner patch passes the imaging surface cleaner. The method can include determining whether toner should be purged based on the measured frictional interaction. The method can include purging the toner if the toner should be purged.

Abstract: A powder transporting device includes: a dropping path through which developer drops; a loosening member that is arranged in the dropping path, and loosens the developer applied on an inner wall of the dropping path; a supporting portion that is provided on the inner wall of the developing path, and supports the loosening member; a rotary member that includes: a rotary center; and a reciprocation applying portion that is located at a position eccentric from the rotary center, the rotary member being arranged within the dropping path and rotationally driven; and a reciprocation applied portion that is provided on the loosening member, and is brought into contact with the reciprocation applying member, wherein the loosening member is moved along the inner wall of the dropping path by contact between the reciprocation applying member and the reciprocation applied portion while the rotary member rotates.

Abstract: An image forming apparatus is provided with a developing unit for attaching developer to a static latent image formed through charging and exposing to form a developer image; an image supporting member for supporting the developer image formed with the developing unit; a removing member disposed to abut against the image supporting member for removing developer; a drive unit for driving the image supporting member; a drive control unit for controlling the drive unit; and a fixing unit for fixing the developer image to a medium. It is configured such that the drive control unit controls the drive unit to temporarily stop before developer is discharged.

Abstract: A developing apparatus includes a tank configured to contain a developing agent including a toner and a carrier, the tank having a discharge port configured to discharge the developing agent overflowing from the tank, a supplier configured to develop a latent image by using the toner contained in the tank, a replenisher configured to contain the developing agent and to replenish the developing agent into the tank, and a controller configured to estimate an amount of the developing agent in the tank in according with the amount of the supplied developing agent and the amount of the replenished developing agent and to execute a forced discharge for forcibly discharging the developing agent contained in the tank from the discharge port based on the estimated amount of developing agent.

Abstract: An image forming apparatus calculates the amount of staying toner based on the amount of drive of the developer roller and the amount of toner consumed for a print job performed. When the amount of staying toner exceeds a threshold, the toner is discharged. The threshold used upon completion of image stabilization is larger than that used upon completion of a print job. Even when performing image stabilization temporarily increases the amount of staying toner in the developing device, immediate toner discharge based on that condition is prevented. Thus, toner consumption can be minimized.

Abstract: A developing device, process cartridge and image forming apparatus of a premix developing system, with which developer splashed by the transport member is not discharged from the device, fluctuations of the amount of developer discharged to the outside are not produced, and the output image quality is stable. This developing device is provided with a pocket part, which is installed in a depressed manner facing the outside in relation to the transport route formed by the transport member, and into and out of which part of the developer transported in the transport route flows. This pocket part is provided with a discharge port for discharging developer to outside the device when the surface of the developer flowing into the pocket part exceeds a specified height.

Abstract: An image forming apparatus which performs toner discharge control for held toners of respective colors, comprises: an image carrier; a transfer member on which toner images of the respective colors formed on the image carrier are transferred and superposed; a calculation unit configured to calculate toner amounts used to form the toner images of the respective colors; and a control unit configured to superpose toners of at least two colors onto the transfer member when the toner amounts calculated by the calculation unit are smaller than a predetermined consumption amount, wherein the control unit decides a combination of colors of the toners to be superposed in accordance with differences between the toner amounts and the predetermined consumption amount.

Abstract: A developing device and an image forming apparatus capable of carrying out image formation for a long period by making fluctuations in toner concentration and volume level of the developer inside a trickle developing device that uses a two-component developer as small as possible.

Abstract: An image forming apparatus is provided that holds counter information obtained by integrating a consumption of a consumable that depends on usage of service provided by the image forming apparatus. A log corresponding to the usage of the service is set in job log information with a synchronization flag set off. The log in the job log information, for which the synchronization flag is set off, is set on. The counter information and the job log information are output after the synchronization flag for the log having the synchronization flag set off has been set on.

Abstract: A waste developer collecting device comprising: a collecting container; a collecting opening; a conveying unit; a filter; a partition wall; and an air inlet.

Abstract: A developing device, process cartridge and image forming apparatus of a premix developing system, with which developer splashed by the transport member is not discharged from the device, fluctuations of the amount of developer discharged to the outside are not produced, and the output image quality is stable. This developing device is provided with a pocket part, which is installed in a depressed manner facing the outside in relation to the transport route formed by the transport member, and into and out of which part of the developer transported in the transport route flows. This pocket part is provided with a discharge port for discharging developer to outside the device when the surface of the developer flowing into the pocket part exceeds a specified height.

Abstract: A developing device capable of conveying discharged developer to the outside of the device well by preventing developer from firmly adhering within a discharge conveyance path, as well as an image forming apparatus and a process cartridge having this developing device.

Abstract: The image forming apparatus includes a discharge execution section for forcedly discharging toner from a developing device and forming a toner image on a photosensitive drum, in which a primary transfer roller transfers the toner image formed on the photosensitive drum by the discharge execution section by applying, to a predetermined area part of the toner image, a first transfer bias having a predetermined transfer efficiency with respect to an intermediate transfer belt and applying, to a part excluding the predetermined area part of the toner image, a second transfer bias whose transfer efficiency is at least smaller than the predetermined transfer efficiency of the first transfer bias.

Abstract: In an embodiment, a contact pivoting plate, which comes into contact with a developer swelled by a discharge mixer, is provided in a case. The contact pivoting plate is pivoted according to a detection result of a temperature and humidity sensor to change the magnitude of resistance by the contact pivoting plate with respect to a flow of the developer. The height of the swell of the developer is suppressed from fluctuating according to an environmental change. The fluctuation in an amount of an excess developer discharged from a discharge port is suppressed to replace a deteriorated carrier in a development container with a new carrier little by little.

Abstract: A development device includes a developer carrier facing an image carrier, a first developer transport path and a second developer transport path disposed vertically, a closably openable developer discharge port provided in the second developer transport path, a detector to detect whether the developer carrier carries the developer, a driving unit to drive the first and the second transporters, and a controller. The first developer transport path and the second developer transport path include a first transporter and a second transporter, respectively, to transport the developer in a longitudinal direction. The controller starts rotating the developer carrier and the first transporter and the second transporter in normal directions and opens the developer discharge port simultaneously. When a predetermined time period has elapsed after determining that no developer is carried on the developer carrier, the controller starts rotating the first transporter and the second transporter in reverse.

Abstract: An image forming apparatus includes a developer image forming portion for forming a developer image; a primary transfer member for transferring the developer image to an intermediate transfer member; a secondary transfer member for transferring the developer image to a recording medium; a medium transportation unit for transporting the recording medium to a secondary transfer position; a contact cleaning member for cleaning the secondary transfer member; a voltage control unit for applying a transfer voltage to the primary transfer member and the secondary transfer member; and a control unit for controlling the developer image portion, the primary transfer member, the secondary transfer member and the medium transportation unit. The control unit is arranged to perform a developer discarding operation, in which the developer image portion forms a discard developer image, and the discard developer image is transferred to the intermediate transfer member and to the secondary transfer member.

Abstract: An image forming apparatus includes an image carrier, a development device, a developer collection device, a detector, and a controller. The image carrier carries a latent image. The development device develops the latent image into a toner image, and includes a developer carrier opposing the image carrier and carrying a developer. The developer collection device collects the developer from the development device when the development device is driven. The detector detects a state in which the developer carrier does not carry the developer. The controller starts driving the image carrier, starts driving the development device to cause the developer collection device to start collecting the developer, and stops driving the image carrier when the detector detects the state in which the developer carrier does not carry the developer, to collect the developer from the development device.

Abstract: An image forming apparatus includes a process including at least a developing section and an image bearing body. A calculating section calculates a number of the dots formed on the image bearing body. A rotation calculating section calculates a number of rotations of the image bearing body for forming the number of dots on the image bearing body in accordance with the print data. A controller makes a decision to determine whether the number of dots formed on the image bearing body is larger than a first reference when the number of rotations is larger than a second reference. If the answer is YES, then the controller forms a developer image formed of dots equivalent to a difference between the first reference and the number of dots. Then, the developer image is discarded.

Abstract: An apparatus and method that determines toner age in a printing apparatus. The method can include placing an imaging surface cleaner in contact with an imaging surface. The method can include placing a toner patch on the imaging surface. The method can include rotating the imaging surface in a process direction. The method can include measuring a frictional interaction between the imaging surface cleaner and the imaging surface as the toner patch passes the imaging surface cleaner. The method can include determining whether toner should be purged based on the measured frictional interaction. The method can include purging the toner if the toner should be purged.

Abstract: A developing device includes: a housing that stores a developing agent including toner and a carrier and that is replenished with the toner and the carrier; an agitation conveyance member that rotates the developing agent to thus agitate and convey the developing agent; a developing agent supply member that supplies to a developing area the conveyed developing agent; a first outlet that discharges a superfluous developing agent, which is in excess of first set storage capacity, of the stored developing agent and that is connected to a recovery device for transferring and collecting the superfluous developing agent; a second outlet that discharges an excessive developing agent, which is in excess of second set storage capacity that is larger in amount than the first set storage capacity, of the stored developing agent; a container that stores the excessive developing agent; and a detection unit that detects the stored excessive developing agent.

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 includes a developer tank configured to contain a developer including a toner and a carrier, the developer tank having a discharge port which is provided in a lateral side surface of the developer tank and configured to discharge the developer, a developing agent supplier configured to develop a latent image by using the toner contained in the developer tank, and a plate-shaped member configured to be formed in a direction of height from a lower end of the discharge port and partially cover the discharge port to regulate the discharge of the developer.

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: A developing device having a housing that houses two-component developer containing carrier and toner, replenishing replenishment carrier to the housing while gradually ejecting developer to outside from an outlet. The developing device includes: transport passage provided in the housing so that developer is transported therein; transport member provided in the housing and rotates to transport the developer; ejection passage having diverged from the transport passage so that a part of the developer transported in the transport passage is conveyed therein to the outlet; and restriction unit configured to restrict an amount of ejected developer so that a first amount of developer is ejected from the outlet when the transport member rotates at a first speed, and a second amount of developer is ejected when it rotates at a second speed. The second amount is smaller than the first amount. The second speed is higher than the first speed.

Abstract: In a method or system for controlling an electrophotographic printer or copier that has at least one developer station, a toner discharge from the developer station is detected during the print operation and a developer regeneration process is started when the detected toner discharge fulfills a predetermined first regeneration criterion. A charge image is generated on the photoconductor, the charge image is developed by the developer station, and the developed image is removed by a cleaning device without being transferred as printed onto a recording medium. New toner is introduced into the developer station. Also in accordance with the method or system for controlling an electrophotographic printer or copier that has at least two developer stations, during a print operation the print data is used to determine which developer stations are needed for printing of the data.

Abstract: A toner supplying method for supplying toner from a toner container to a developing part that causes toner to adhere to a latent image formed on a latent image carrying member and develops the latent image, includes detecting a toner amount in the developing part as being equal to or less than a predetermined toner amount value; forming a fog detecting image in a case where the toner amount in the developing part is equal to or less than the predetermined toner amount value, and detecting fog; and determining based on the detected fog whether to execute a toner ejecting process of ejecting the toner remaining in the developing part toward the latent image carrying member before supplying the toner to the developing part from the toner container.

Abstract: In order to provide an image forming apparatus capable of maintaining the image quality by making smooth flowability of a surplus developer, which is discharged according to supply of a new developer (toner and carrier), toward a collection box, there are provided a stirring screw that electrify toner by stirring the toner together with a carrier; a casing that supports the stirring screw and stores a developer in which the toner and the carrier are mixed; a inlet used to supply the developer to the casing; a guide that guides the surplus developer discharged from the casing downward; and a reciprocating member that moves on a flow surface of the guide along which the surplus developer flows.

Abstract: A waste developer collecting device comprising: a collecting container; a collecting opening; a conveying unit; a filter; a partition wall; and an air inlet.

Abstract: A developing apparatus includes a developer container that contains a developer and a supply device that supplies a supply developer to the developer container. A feeding member that feeds the developer is disposed close to a discharge opening in the developer container, which allows the discharge of the developer contained in the developer container. The feeding member has a developer feeding power in an opposing area, in which the developer feeding member is opposed to the discharge opening, larger than a developer feeding power in an upstream-side area, which is upstream of the opposing area with respect to a developer feeding direction. Further, the feeding member has a developer feeding power in a downstream-side area, which is downstream of the opposing area with respect to the developer feeding direction, equal to or larger than the developer feeding power in the opposing area.

Abstract: According to one embodiment, a deteriorated carrier included in a developer circulating in a developer tank is extracted. The extracted deteriorated carrier is guided to an outflow port.

Abstract: A development apparatus 8 has developer transport members 26 and 27 respectively contained in containers 22 and 23 and transporting developer while stirring the developer and passing the developer to each other at a passing portion 41 and a passing portion 42, thereby causing the developer to circulate in a developer tank 21. The passing portion 41 is formed at a location of a partition 21c adjacent to a developer discharging mechanism 34 and the passing portion 42 is formed at a location of the partition 21c away from the developer discharging mechanism 34. The passing portions 41 and 42 have configurations in which a transport force acting on the developer at the passing portion 41 is greater than the transport force acting on the developer at the passing portion 42.

Abstract: An image forming apparatus includes a latent image carrier, a development device, a discharge port through which developer is discharged, a discharge port detector, and a controller that determines whether to permit driving of the development device in a direction reverse to a normal direction or to terminate discharge of developer based on detection results by the discharge port detector in discharge of developer. The development device includes a developer carrier, a developer supply member disposed in a supply compartment facing the developer carrier, a developer collection member disposed in a collection compartment lower than the supply compartment, a developer agitation member disposed in an agitation compartment disposed at a height similar to that of the collection compartment, to transport developer in a direction opposite conveyance direction by the developer supply member and the developer collection member.

Abstract: A developer collection device includes: a collection unit including: a collection container that contains a developer to be collected; an upstream connection part that is formed with an inlet port through which the developer flows in; and a collection conveying part that conveys the developer flown in through the inlet port toward the collection container; and a connection unit including: an upstream connection port that is connected to an upstream conveying path; a connection conveying part that conveys the developer flown in through the upstream connection port in a developer conveying direction; and a connection outlet port that is formed at a downstream end in the developer conveying direction, wherein the connection unit is configured to be movable between an extracted position and a retracted position.