Abstract: The location of a printing device is determined. Environmental conditions in which the printing device operated when printing a print job are determined based on the determined location. An environmental adjustment factor for the printing device is determined based on the determined environmental conditions. A predicted print material usage of the printing device in printing the print job is adjusted based on the determined environmental adjustment factor.

Abstract: A system for an electrophotographic image forming device includes a toner container having a reservoir for storing toner and an impact member configured to selectively impart an impulse force on the toner container to cause vibration of the toner container. A sensor is configured to sense the vibration of the toner container upon the impact member imparting the impulse force on the toner container. Processing circuitry in communication with the sensor is configured to determine an estimate of an amount of toner in the reservoir based on the sensed vibration of the toner container.

Abstract: An apparatus includes a developer container to and from which a replenishment container is attachable and detachable and which includes an accommodating portion and a replenishment port, a transfer portion configured to transfer a developer image on an image bearing member onto a recording material, a supporting tray including a supporting surface configured to support the recording material thereon, and a discharge portion configured to discharge the recording material, onto which the developer image has been transferred, on the supporting surface, wherein the supporting surface has an opening portion opening such that the replenishment port is exposed through the supporting surface, and wherein an opening/closing member configured to be movable between a closed position where the opening/closing member covers the replenishment port and serves as a part of the supporting surface and an open position where the replenishment port is exposed is provided.

Abstract: A replaceable unit for an electrophotographic image forming device includes a housing having a reservoir for holding toner. An electrical connector is positioned on a first side of the housing. The electrical connector includes an electrical contact for contacting a corresponding electrical contact in the image forming device. The electrical contact of the replaceable unit is electrically connected to processing circuitry mounted on the housing. The electrical connector is movable between a first position and a second position. The electrical contact of the replaceable unit moves outward from the first side of the housing along a side-to-side dimension of the housing when the electrical connector moves from the first position to the second position. The electrical contact of the replaceable unit faces downward when the electrical connector is in the second position permitting the corresponding electrical contact to contact the electrical contact of the replaceable unit from below.

Abstract: A printing device includes: a communication interface communicable with a server; and a controller. The controller is configured to perform: a communication status monitoring process to monitor a communication state with the server; a consumable determination process; and a transition process. The consumable determination process is to determine whether a particular consumable is included in one or more of consumables attached to the printing device, the particular consumable being a consumable that meets a prescribed condition required for transition to a specific printing state where specific printing under a contract with the server is allowed. The transition process is to execute the transition to the specific printing state in a case where: the communication state is determined to be communicable with the server in the communication status monitoring process; and the particular consumable is determined to be included in the one or more of consumables in the consumable determination process.

Abstract: The present disclosure provides a toner cartridge. The toner cartridge includes a toner hopper containing toner, a waste toner bin containing waste toner, and a developing part disposed in the toner hopper. The toner hopper and the waste toner bin are movably connected; and the toner hopper is capable of moving from a first position to a second position relative to the waste toner bin. When the toner hopper is at the first position, the developing part is electrically connected to a printer and capable of receiving a developing voltage signal sent by the printer; and when the toner hopper is at the second position, the developing unit is electrically disconnected from the printer and not capable of receiving the developing voltage signal sent by the printer or not capable of sending an electrical signal to the printer.

Abstract: An image forming apparatus to and from which a replenishment container accommodating toner is attachable and detachable includes an opening/closing portion moving from a closed position to an open position in a case where the toner replenishment container attached to a replenishment port is rotated, and a locking membered to move between a restricting position restricting movement of the opening/closing portion from the closed position to the open position, and an allowing position in which the movement of the opening/closing portion from the closed position to the open position is allowed. In addition, a controller, in a case where a replenishment operation, in which toner is supplied from the replenishment container to the replenishment port, displays, on a display, a ratio corresponding to an amount of toner accommodated in the developer container after the replenishment operation.

Abstract: A printing device includes a controller configured to receive print setting information, determine whether or not printing is set to accumulation printing, perform the printing, in a case where it is determined that the printing is not set to the accumulation printing, and perform a print preparation processing of performing a predetermined preparation operation before printing, in a case where it is determined that the printing is not set to the accumulation printing. The controller is configured to accumulate print job data without performing the print preparation processing, in a case where it is determined that the printing is set to the accumulation printing.

Abstract: An image forming apparatus includes a memory and a controller. The memory stores first mode information indicating whether the apparatus is set to a contract mode or a normal mode, and second mode information indicating whether a print permission mode is active or inactive. The controller sets the second mode information to active information indicating that the print permission mode is active in a state in which the first mode information indicates the normal mode, sets the second mode information to inactive information indicating that the print permission mode is inactive in a state in which the first mode information indicates the contract mode, and rewrites the second mode information to the active information when an instruction to activate the print permission mode is received in a state in which the first mode information indicates the contract mode and the second mode information is set to the inactive information.

Abstract: Provided is a disclosure for using indicia to handle information for use in material preparation and analysis equipment.

Abstract: An image forming apparatus includes a developer container to accommodate developer containing toner, a developer bearing member to rotate while bearing the developer accommodated in the developer container and develop the electrostatic latent image borne on an image bearing member into a developer image, a detection portion to output remainder amount information corresponding to an amount of the developer accommodated in the developer container, and a notification portion capable of notifying a first state indicating that a remainder amount of the developer accommodated in the developer container is a first amount or more and a second state indicating that the remainder amount of the developer accommodated in the developer container is less than the first amount. The notification portion notifies one of a plurality of states including the first state and the second state on a basis of the remainder amount information output from the detection portion.

Abstract: An active acoustic system includes a thin-film sheet having an array of piezoelectric microstructures embossed in the film. Each piezoelectric microstructure may act as a speaker and/or a microphone. A control circuit is configured to individually address the piezoelectric microstructures to provide a separate voltage signal to, or receive a separate voltage signal from, each piezoelectric microstructure.

Abstract: An in-vehicle software updating method includes: acquiring, after starting a software update, a voltage measurement value of an in-vehicle power source; and acquiring a progress rate in the software update in a case in which the voltage measurement value is equal to or less than a second threshold. In a case in which the progress rate is less than a set value, the software update is interrupted. In a case in which the progress rate is equal to or greater than the set value, an operation mode of the zone control unit is switched to a power saving mode, and a second predicted voltage value of the in-vehicle power source at the update completion time is calculated. The software update is continued in a case in which the second predicted voltage value is greater than a first threshold.

Abstract: A non-transitory computer-readable storage medium storing a program executable by a computer of a device, the program, when executed by the computer, causing the device to perform: causing a reader of the device to read a code image; determining, based on code information indicated by the code image and identification information of a consumable item of a printer stored in a first memory, whether to register the identification information of the consumable item indicated by the code information; registering the identification information in a second memory in a case where the determining determines to register the identification information; and displaying, on a display of the device, unique information of a consumable item whose identification information is registered in the second memory in a display mode different from a display mode of unique information of a consumable item whose identification information is not registered in the second memory.

Abstract: A system for accurately managing the consumables of a network of printers. The system monitors the printers in the network, collects data relating to operation of the printers, determines the current state of the printers regarding at least one consumable, and uses the data and the current state of the printers to predict when at least one consumable of at least one printer of the network will need to be replaced.

Abstract: Examples of the present disclosure relate to a container. The container has a chamber for storing build material for a three-dimensional printing system. The container comprises an opening coaxial with the chamber for coupling to the three-dimensional printing system. The container is configured such that rotation of the chamber in a first direction conveys build material in the chamber to the three-dimensional printing system and rotation of the chamber in a second direction conveys the build material away from the three-dimensional printing system.

Abstract: An information processing apparatus that makes it possible to obtain a result of prediction of a consumption degree (remaining amount) of a consumable at a desired timing. The information processing apparatus is capable of communicating with an image forming apparatus that forms an image using toner supplied from a toner container mounted thereon. A reception unit receives first information on a consumption amount of the toner by the image forming apparatus. A controller acquires date information on a designated date, and determines second information on a consumption amount of the toner by the designated date, based on the first information in an amount corresponding to a predetermined number of days before a certain day before the designated date.

Abstract: A replaceable unit includes a communication unit to perform communication with a main body, and a non-volatile memory storing code information indicating whether a configuration of an error detection code is a first configuration or a second configuration. The communication unit stores, in a volatile memory, the code information, executes the communication in accordance with the code information in the volatile memory, and, upon receiving a change command, updates the code information stored in the volatile memory. The first configuration uses an error detection code of a first code length, the second configuration uses an error detection code of a second code length longer than the first code length, and the first configuration is used for the change command in order to change from the first configuration to the second configuration.

Abstract: An apparatus includes a photoconductor, an exposure device, a developing device, a toner concentration sensor, a supply motor, and a processor. The exposure device exposes the photoconductor based on image data. The developing device forms a toner image on the photoconductor with toner supplied from a toner cartridge. The toner concentration sensor detects a toner concentration in the developing device. The supply motor supplies the toner from the toner cartridge to the developing device based on the toner concentration. The processor detects a toner container supply abnormality based on a toner supply rate and a print rate of the image data, the toner supply rate being calculated based on a pixel count value that is an integrated value of pixel values of the image data and a supply motor count value that is an integrated value of drive times of the supply motor.

Abstract: An example operation method of an image forming apparatus includes determining a state of a toner refill operation of injecting toner from a toner reload kit (TRK) into a cartridge in the image forming apparatus, based on completion of injecting toner from the TRK into the cartridge, controlling the TRK to store information indicating a toner refill completion in a memory of the TRK, based on completion of injecting toner from the TRK into the cartridge, updating information of an amount of remaining toner of the cartridge based on an amount of the toner injected into the cartridge from the TRK, and based on the information indicating the toner refill completion being stored in the memory of the TRK, unlocking a locking apparatus in the image forming apparatus so the TRK may be removed from the cartridge.

Abstract: An image forming apparatus, to form an image on a recording material using a recording agent supplied from a container detachably mounted to the image forming apparatus, includes a cover configured to cover a region in which the container is stored. A display instruction is received from a user to display a procedure for replacing the container. A display unit is caused to display the container replacing procedure based on receiving the display instruction. In a case where it is determined that the container replacing procedure is displayed on the display unit, performing control includes performing control to prevent a notification, prompting the user to close the cover, from being issued even if the cover is opened.

Abstract: An image forming apparatus includes an image forming portion, a first release processing portion, and a second release processing portion. The image forming portion includes a storage portion storing developer and forms an image by using the developer stored in the storage portion. The first release processing portion releases regulation on removal of a developer storage portion when a storage amount of the developer stored in the storage portion is equal to or smaller than a second threshold smaller than a first threshold. The second release processing portion releases the regulation on the removal of the developer storage portion based on the remaining amount of the developer that is acquired when the storage amount of the developer stored in the storage portion is larger than the second threshold.

Abstract: Examples disclosed herein relate to capturing an identifying characteristic of a printer, displaying a plurality of documents suitable for printing on the printer, receiving a selection of at least one document of the plurality of documents suitable for printing on the printer, and causing the selected at least one document to be delivered to the printer according to the identifying characteristic.

Abstract: An image forming apparatus, including: a photoconductor; a developing device; a developer storage; a supplier configured to supply developer; an optical sensor; and a controller configured to execute: a developing process of developing an electrostatic latent image on the photoconductor; a usage-amount obtaining process of obtaining a usage amount of the developer; a supplying process of supplying the developer to the developing device every time when the obtained usage amount becomes equal to or greater than a first threshold; and a detecting process of detecting, by the optical sensor, an amount of the developer in the developing device every time when the obtained usage amount becomes equal to or greater than a second threshold larger than the first threshold, and wherein the controller is configured to execute the detecting process in a period different from a period in which the developing process is being executed.

Abstract: An image forming apparatus includes a release processing portion, a regulation processing portion, and a second restriction processing portion. The release processing portion releases regulation on removal of a developer storage portion when a storage amount of developer stored in an image forming portion is equal to or smaller than a second threshold smaller than a first threshold. The regulation processing portion regulates removal of the developer storage portion when the storage amount of the developer stored in the image forming portion is larger than the second threshold and removal of the developer storage portion has not been regulated. The second restriction processing portion imposes restriction on processing of the regulation processing portion when the regulation on the removal of the developer storage portion is released and a restriction condition is satisfied.

Abstract: An image forming apparatus includes: a development device which develops an electrostatic latent image formed on a photosensitive drum into a toner image; a charger which charges the photosensitive drum; a development power supply which applies a prescribed bias voltage to the development device; and a calculating section which calculates a surface potential of the photosensitive drum based on a development current flowing in the development device. The calculating section calculates, as the surface potential, a bias voltage at which a non-charging development current that flows in the development device in an uncharged state in which the charger has not charged the photosensitive drum is equal to a charging development current that flows in the development device in a charged state in which the charger has charged the photosensitive drum.

Abstract: A toner container information acquiring method includes: measuring a toner amount contained in a resin forming a toner container; and acquiring information regarding mechanical strength of the toner container based on the measured toner amount.

Abstract: An image forming apparatus forms a coverage rate adjustment patch having a coverage rate corresponding to a difference between a coverage rate measured by a coverage rate measurement unit and a coverage rate of an adjustment image pattern together with an adjustment image pattern by using the exposure device and the developing device in the calibration.

Abstract: A toner supply device for supplying toner to a developing device includes a toner container containing toner to be supplied to the developing device and a remaining amount sensor for detecting the remaining amount of toner in the toner container. The toner container includes a cylindrical rotating container having a spiral conveying rib formed on the inner peripheral surface thereof and a paddle provided so as to be slidable on the inner peripheral surface of the rotating container. The remaining amount sensor detects the remaining amount of toner on the upstream side on or before the contact position of the paddle in the toner conveying direction.

Abstract: An information processing apparatus that makes it possible to obtain a result of prediction of a consumption degree (remaining amount) of a consumable at a desired timing. The information processing apparatus is capable of communicating with an image forming apparatus that forms an image using toner supplied from a toner container mounted thereon. A reception unit receives first information on a consumption amount of the toner by the image forming apparatus. A controller acquires date information on a designated date, and determines second information on a consumption amount of the toner by the designated date, based on the first information in an amount corresponding to a predetermined number of days before a certain day before the designated date.

Abstract: A method of converting developer in a printer cartridge, comprising the steps: providing a developer unit of a printer cartridge; removing a first mixture of a developer and a first toner from the developer unit; sieving the first mixture of the developer and the first toner; removing the first toner from the first mixture of the developer and the first toner; mixing a second toner to the developer to create a second mixture of the developer and the second toner, wherein the second toner is a different toner than the first toner; and adding the second mixture of the developer and the second toner into the developer unit of the printer cartridge.

Abstract: In some examples, an apparatus can include a supply reservoir including print substance, and a rotary valve having a central rotary axis, where the central rotary axis is perpendicular to a height of the supply reservoir, where the rotary valve is in a closed position such that the print substance is unable to be supplied from the supply reservoir.

Abstract: An image forming apparatus, including: a photoconductor; a developing device; a developer storage; a supplier configured to supply developer; an optical sensor; and a controller configured to execute: a developing process of developing an electrostatic latent image on the photoconductor; a usage-amount obtaining process of obtaining a usage amount of the developer; a supplying process of supplying the developer to the developing device every time when the obtained usage amount becomes equal to or greater than a first threshold; and a detecting process of detecting, by the optical sensor, an amount of the developer in the developing device every time when the obtained usage amount becomes equal to or greater than a second threshold larger than the first threshold, and wherein the controller is configured to execute the detecting process in a period different from a period in which the developing process is being executed.

Abstract: The image forming apparatus includes a developing device, a toner container, a first mechanism, a toner sensor, and a controller. The developing device adheres toner to an electrostatic latent image on a photoconductor to form a toner image. The toner container supplies toner to the developing device. The first mechanism causes a toner interface to undulate in the toner container. The toner sensor detects a capacitance between a first electrode and a second electrode arranged apart from the first electrode. The controller determines a remaining amount of toner in the toner container based on detection information from the toner sensor.

Abstract: An image forming apparatus includes a body on which a development cartridge is mountable to form a toner image by supplying toner in the development cartridge to an electrostatic latent image formed, a communicating portion provided on an outer surface of the body to be coupled with a toner refill cartridge to form a connection with the development cartridge to perform a toner refill of the toner in the development cartridge through the connection with the development cartridge, a sensor to detect a remaining toner amount remaining in the development cartridge, and a controller to estimate, based on the sensor detecting the remaining toner amount, an estimated toner remaining rate of the development cartridge, which is an estimated rate of the toner remaining in the development cartridge based on toner consumption, according to the toner refill.

Abstract: An image forming system includes a recording processing portion, an acquirement processing portion, and an output processing portion. The recording processing portion records a consumed amount of a consumable consumed by an image forming apparatus per predetermined unit time. The acquirement processing portion acquires prediction data that indicates a predicted consumed amount of the consumable per the unit time for a time period from a predetermined standard time, based on a comparison result between: a first record result corresponding to a first time period extending to a reference time; and a second record result corresponding to a predetermined second time period extending to the standard time, among a record result recorded by the recording processing portion, the reference time being a predetermined specific time period earlier than the standard time. The output processing portion outputs the prediction data acquired by the acquirement processing portion.

Abstract: A process cartridge includes a photosensitive drum; a developing roller; a developer supplying roller, provided in contact with the developing roller; a driving force receiving portion provided at a shaft end of the supplying roller; a first driving force transmitting portion; a second driving force transmitting portion; flexible sheets provided adjacent to an engaging portion between the first portion and the second portion to intermittently contact the second portion with rotation of the second portion, wherein a rotational direction of the roller is opposite to that of the roller, and a peripheral speed of the roller is larger than that of the roller.

Abstract: An image forming apparatus includes an image forming unit, a toner detection sensor, a storage unit, and a control unit. The image forming unit includes an image carrier, a charging device, an exposure device, and a developing device. The toner detection sensor detects toner in the developing device. The control unit predicts transition of the toner deterioration degree in the developing device using the toner consumption amount and the cumulative operating time stored in the storage unit, and a predetermined toner deterioration model. The control unit is capable of measuring the toner deterioration degree based on amplitude of an output value of the toner detection sensor, and corrects the toner deterioration model, if the measured value of the toner deterioration degree is apart from the predicted value of the toner deterioration degree by a predetermined value or more.

Abstract: According to an embodiment, an image forming apparatus includes an image bearing body, a developing unit, a supplying unit, a detecting unit, and a control unit. The supplying unit supplies a recording agent from a recording agent cartridge to the developing unit. The detecting unit detects a residual amount of the recording agent. The control unit controls, if the recording agent cartridge is not replaced, the supplying unit to supply the recording agent to the developing unit if the detected residual amount decreases to a first residual amount or less and controls, if the recording agent cartridge is replaced, the supplying unit to supply the recording agent in the recording agent cartridge after the replacement to the developing unit if the detected residual amount of the recording agent in the recording agent cartridge before the replacement decreases to a second residual amount or less.

Abstract: A printing device includes: an RFID reader including a reader antenna; a cassette mounting portion in which a plurality of types of cassettes can be selectively mounted; a memory storing correlations between the types of cassettes and standard ranges concerning a return energy; and a controller. Each cassette includes an RFID tag storing cassette information related to the cassette. The RFID tag includes a tag antenna configured to communicate with the reader antenna. Communication sensitivity between the reader antenna and the tag antenna when the cassette is mounted in the cassette mounting portion is different for each type of cassette. The controller performs: communicating via the RFID reader with the RFID tag of the cassette mounted in the cassette mounting portion; and determining whether a value of the return energy received by the RFID reader in the communicating falls within any one of the standard ranges indicated by the correlations.

Abstract: An image forming apparatus includes a toner container, and a main body which the toner container is attachable to and detachable from. The main body includes an image forming unit including a photosensitive drum, a toner containing portion, and a development roller, an attaching portion in which the toner container is at a first position for allowing supply of the toner, an opening portion of the main body, an acquisition unit acquiring a correlation value correlating with a toner remaining amount, an opening/closing member moving between an open position and a closed position, a detection unit detecting the opening/closing member, a movement mechanism executing moving operation for moving the toner container from the first position to a second position, and a control unit controlling the movement mechanism to execute the moving operation in a case where both of a first condition and a second condition are satisfied.

Abstract: According to one embodiment, an image forming apparatus includes a developing device, an environment sensor, a memory, and a processor. The developing device stores a developer containing a toner and a carrier. The environment sensor measures an environment parameter. The memory stores end time environment information indicating an environment parameter of a date and time when printing is ended. The processor discharges the toner stored in the developing device when a difference between the environment parameter indicated by the end time environment information and the environment parameter measured by the environment sensor exceeds a predetermined threshold value, and puts the toner into the developing device.

Abstract: According to one embodiment, an apparatus includes a photoconductor, an exposure device, a developing device, a toner concentration sensor, a supply motor, and a processor. The exposure device exposes the photoconductor based on image data. The developing device forms a toner image on the photoconductor with toner supplied from a toner cartridge. The toner concentration sensor detects a toner concentration in the developing device. The supply motor supplies the toner from the toner cartridge to the developing device based on the toner concentration. The processor detects a toner container supply abnormality based on a toner supply rate and a print rate of the image data, the toner supply rate being calculated based on a pixel count value that is an integrated value of pixel values of the image data and a supply motor count value that is an integrated value of drive times of the supply motor.

Abstract: An image forming apparatus includes a main assembly; an openable member, provided with a portion-to-be-engaged, for covering a mounting portion; an engaging member provided on the main assembly for engaging with the portion-to-be-engaged of the openable member positioned at a closed position so as to restrict movement of the openable member relative to the main assembly; a locking portion for locking the engaging member in an engaged state with the portion-to-be-engaged by restricting movement of the engaging member; an electric driving portion for unlocking the locking portion; a discriminating portion for discriminating that a consumable mounted is in an exchange state in which the consumable is to be exchanged; and a controller for driving the electric driving portion so as to unlock the locking portion when the controller receives, from the determining portion, a signal for determining that the consumable is in the exchange state.

Abstract: According to one embodiment, the image forming apparatus includes a storage unit, an image forming unit, a first electrode, a second electrode, a to-be-detected unit, a moving unit, a measuring unit, and a processor. The storage unit stores a recording material. The image forming unit forms an image with the recording material supplied from the storage unit. The to-be-detected unit is in the storage unit and is movable so that at least one of the distance to the first electrode and the distance to the second electrode changes. The moving unit moves the to-be-detected unit in the storage unit. The measuring unit measures the capacitance between the first electrode and the second electrode. The processor controls the image forming unit based on the abnormality detected based on the capacitance.

Abstract: An image forming apparatus to which a containing a recording material is attached removably includes a specifying unit configured to specify a usage amount of the recording material that has been used for printing in a predetermined period, and a prediction unit configured to predict a remaining period for using the attached container, based on a remaining amount of the recording material contained in the attached cartridge and the specified usage amount. The specified usage amount does not include a usage amount of the recording material which has been used in the predetermined period by the image forming apparatus which has been in a predetermined state.

Abstract: An image forming apparatus and method for determining a toner level and providing a notification are provided. The method of operating an image forming apparatus includes counting a number of times a lower toner hopper receives toner from an in-situ refillable upper toner hopper, calculating an estimate of toner volume transferred from the lower toner hopper to a surface of a photosensitive drum, determining an amount of toner consumed from the in-situ refillable upper toner hopper based on the number of times the lower toner hopper receives toner from the in-situ refillable upper toner hopper and the estimate of toner volume transferred from the lower toner hopper to the surface of the photosensitive drum, and generating an upper toner hopper refill notification when the amount of toner consumed from the in-situ refillable upper toner hopper is determined to exceed a threshold value.

Abstract: An image forming apparatus includes an image bearing member, a developing cartridge, a control portion configured to cause the image forming unit to form the toner image in one mode selected from a plurality of modes including a first image forming mode for forming a first toner image whose maximum loading amount is a first loading amount and a second image forming mode for forming a second toner image whose maximum loading amount is a second loading amount different from the first loading amount, a detection unit, and a display portion configured to display information related to the number of sheets of a recording material on which the first toner images can be formed in the first image forming mode and information related to the number of sheets of a recording material on which the second toner images can be formed in the second image forming mode.

Abstract: An image forming apparatus includes an image bearing member, a development cartridge configured to store developer and including a developer bearing member bearing and conveying the stored developer to a position where an electrostatic latent image formed on the image bearing member is developed, a detection unit configured to detect a developer amount within the development cartridge, and a display portion configured to display information indicating that the developer within the development cartridge is insufficient to form an image per size of a recording member, based on a remaining developer amount within the development cartridge detected by the detection unit.

Abstract: An image forming apparatus includes an image carrying member, a developing device, a toner holder, a toner holder mount portion, and a locking member. The toner holder is dismountably mounted in the toner holder mount portion and stores toner for the developing device. The toner holder mount portion has a pair of side support rails supporting a side face of the toner holder. The locking member is adjacent to an end part, in the toner holder mounting direction, of at least one side support rail, and is swingable between a first position restraining mounting and dismounting of the toner holder and a second position allowing mounting and dismounting of the toner holder. The locking member, in the second position, is on the extension line of the side support rails and, together with the side support rails, guides the toner holder to and from the toner holder mount portion.