Abstract: An image forming apparatus includes: an image bearing member, a developing device, and a controller configured to execute an operation in a forced consumption mode. The controller includes a difference calculating portion, an integrating portion, and a flag. In a case where the flag is set when a predetermined time is elapsed after the integrated value exceeds the predetermined threshold, the image formation on the predetermined number of the recording materials is effected and then the controller executes the operation in the forced consumption mode, and in a case where the flag is reset when the predetermined time is elapsed after the integrated value exceeds the predetermined threshold, the image formation on the predetermined number of the recording materials is effected and then the controller continues an image forming operation without executing the operation in the forced consumption mode.

Abstract: A toner level detection assembly for an electrophotographic image forming device according to one example embodiment includes a rotatable shaft is positioned within a toner reservoir. A magnet is connected to the shaft and is rotatable with the shaft around an axis of rotation of the shaft. The magnet is pivotable independent of the shaft about a pivot axis that is spaced radially from the axis of rotation such that a radial distance of the magnet from the axis of rotation varies as the magnet pivots about the pivot axis. A first magnetic sensor is positioned to sense the magnet within a first range of radial distances from the axis of rotation. A second magnetic sensor is positioned to sense the magnet within a second range of radial distances from the axis of rotation.

Abstract: A toner supply device includes a toner container, a detector, and a determiner. The toner container is configured to contain toner to be supplied to a developing device. The toner container is capable of discharging a prescribed amount of toner contained therein. The detector is configured to detect an amount of toner to be supplied to the developing device. The determiner is configured to estimate a timing at which toner remaining in the toner container is completely consumed, based on a driving amount applied for discharging toner from the toner container during a time period from when the prescribed amount of toner is discharged from the toner container until when the detector detects an amount of toner equal to the prescribed amount of toner.

Abstract: An image forming apparatus is provided which can properly manage individual information after replacement and history of replacement on the apparatus side. If individual information is successfully read from a toner cartridge storing the individual information, the image forming apparatus records the individual information in an apparatus-side memory. At a predetermined timing of when there is a possibility that the toner cartridge is replaced, the image forming apparatus attempts to read information from the toner cartridge. If the reading fails and the individual information recorded in the apparatus-side storage is not information read from the toner cartridge, the image forming apparatus writes new individual information about the toner cartridge to the apparatus-side storage, and records information generated on the apparatus side in the written individual information.

Abstract: A developing apparatus includes a partition member disposed in a first chamber above a discharge space communicated to the discharge port positioned downstream of a return conveyance portion in the first direction, and configured to divide a space within a first chamber in a gravity direction. The partition member is configured to extend from a wall portion on a downstream side of a developer container to a position corresponding to a downstream end of a return conveyance portion or to a position further upstream beyond the position corresponding to the downstream end of the return conveyance portion in the first direction. A surface, opposed to a first conveyance screw, of the partition member is positioned downward in the gravity direction than an upper end of a first communication port and upward in the gravity direction than the first conveyance screw.

Abstract: An image forming apparatus includes an image bearing member, a developing device, and a controller capable of executing an operation in a forced consumption mode in which toner is consumed without being transferred onto a recording material. The controller includes a difference calculating portion configured to calculate a difference between an image amount of a predetermined image forming number and a reference value. The reference value is set i) at a first reference value when information on an average image amount per predetermined image forming number or per predetermined driving time of the developing device is less than a value corresponding to a predetermined reference image amount, and is set ii) at a second reference value lower than the first reference value when the information on the average image amount is not less than a predetermined reference image amount.

Abstract: The voltage detection apparatus includes a transformer, in which a primary side and a secondary side are insulated from each other and the primary side connected in parallel with a first line and a second line, configured to output from the secondary side a voltage supplied to the primary side according to an alternating voltage; a detection circuit configured to detect a frequency of an alternating voltage; and a correction unit configured to acquire information corresponding to a voltage output from the transformer and information corresponding to a frequency detected by the detection circuit, and that corrects the information corresponding to the voltage according to the information corresponding to the frequency.

Abstract: An image forming apparatus includes a correction amount calculator, a fluidity measuring unit, and an external additive amount calculator. The correction amount calculator calculates a correction amount of fluidity to correct the fluidity of a two-component developer. The fluidity measuring unit measures the fluidity of the two-component developer. The external additive amount calculator corrects the measured fluidity on the basis of the correction amount of fluidity, calculates the amount of an external additive of a toner from the corrected fluidity of the two-component developer, and determines the state of the external additive.

Abstract: An image forming apparatus comprises an expendable item having a specific function, installed replaceably with respect to a main body of the image forming apparatus, wherein there are several types of expendable items, and an engine control unit. The engine control unit judges end of lifetime of the expendable item by using one of a plurality of lifetime judgment methods. The engine control unit selects a lifetime judgment method used in the judgment, according to a type of the expendable item. It makes possible to provide an image forming apparatus capable of appropriately determining the reaching of the lifetime end of expendable items.

Abstract: An image forming apparatus includes a controller configured to, each time a development roller of a developing device rotates by a particular rotational amount, increment a counter value stored in a storage, calculate a remaining amount of developer in the developing device, when the counter value is less than a first value, setting a remaining amount threshold to a first threshold, whereas, when the counter value is equal to or more than a second value, setting the remaining amount threshold to a second threshold, the second value being equal to or more than the first value, the second threshold being less than the first threshold, and when the calculated remaining amount is less than the set remaining amount threshold, control a transporter to transport developer stored in a developer box to the developing device.

Abstract: An image forming apparatus includes a developing unit attachment part to which developing units are to be attached, each of the developing units being associated with a first criteria for performing developer refreshing and a second criteria for performing developer refreshing, wherein the second criteria is defined so as to be met prior to the first criteria, and a controller configured to control a timing of developer refreshing executed for each of the developing units according to the first and second criteria values thereof, and a first developer tank that is located at a position higher than the developing unit and configured to contain the developer. When the first criteria for performing developer refreshing is met for at least one of the developing units, the controller causes developer refreshing to be performed for all developing units whose first or second criteria is met.

Abstract: An image forming apparatus comprises a controller, an adjustment unit configured to adjust an image forming condition based on an adjustment condition corresponding to a profile of a toner adhesion amount in a sheet conveying direction, and an image forming unit configured to form an image on a sheet with the adjusted image forming condition while conveying the sheet.

Abstract: An image forming apparatus includes a development current detector that detects an actual measurement value of a development current, a development current calculator that calculates a provisional calculation value of a development current based on an image formation condition, and an image-defect determiner that determines whether or not an image defect occurs, based on the actual measurement value of the development current detected by the development current detector and the provisional calculation value of the development current calculated by the development current calculator.

Abstract: A process unit has an image carrying unit having an image carrying member configured to be rotatable about a first axis extending in a first direction, and a developing agent removing member, a developing unit having a developing agent carrying member configured to be rotatable about a second axis parallel to the first axis, and a waste developing agent collecting unit configured to collect the developing agent removed by the removing member from the image carrying member. The waste developing agent collecting unit is arranged on one side in the first direction with respect to the developing unit such that the waste developing agent collecting unit faces the developing unit, and the developing unit is connected to the waste developing agent collecting unit such that the developing unit being movable in a second direction which is perpendicular to the first direction with respect to the waste developing agent collecting unit.

Abstract: An image forming apparatus includes an image bearing member, a developing device that develops an electrostatic latent image formed on the image bearing member, a toner bottle having a storage portion storing the toner and a discharge portion made of resin and discharging the toner stored in the toner storage portion, and an attachment portion attached with the toner bottle. A driving portion drives the storage portion, a controller controls the driving portion, and a memory disposed in the toner bottle memorizes information regarding component dimensions of a molded discharge portion of the toner bottle. An information reading portion reads information regarding the component dimensions of the molded discharge portion, and the controller controls the driving portion so that a discharge amount of the toner from the discharge portion becomes a specific toner amount targeted based on the information regarding the component dimensions of the molded discharge portion.

Abstract: An image forming output control device includes a duplicate image information detector to receive instruction information from a processing execution control apparatus, compare image information included in a plurality of objects being unit images constituting the instruction information, and detect a plurality of duplicate image information objects, in which the image information is duplicate with each other, in the objects in which identification information for identifying the objects is different from each other; a drawing information generation controller to control a drawing information generator to generate drawing information according to the instruction information; and a drawing result storage unit to store drawing result information being a drawing result of the image information.

Abstract: An image forming apparatus includes an image former which forms an image on an image carrying member with toner stored in a storage, a toner supplier which supplies toner to the storage by driving a conveyance member, a density measurer which causes the image former to form an image having a predetermined density at a predetermined timing and measures density of the formed image, a corrector which corrects a driving amount of the conveyance member based on the density measured by the density measurer, and a changer which changes a timing when the density measurer measures the density in response to an event that a predetermined condition is satisfied.

Abstract: An image forming apparatus includes: an image carrier; a developing device forming a toner image on the image carrier; a transfer section arranged at downstream from the developing device in a rotation direction of the image carrier and transfers the toner image onto a recording sheet; a fixing section arranged at downstream from the transfer section in a conveyance direction of the recording sheet and fixes the toner image transferred to the recording sheet on the recording sheet; an air path guiding air taken from an outside of the image forming apparatus to the developing device; and a control section that, when operating the developing device under a cooling mode for cooling the developing device, controls the developing device and causes the developing device to reduce an amount of developer on a developing roller so as to be smaller than that of under image forming operation.

Abstract: An image forming apparatus includes: an image former that develops, with toner, an electrostatic latent image formed on an image carrier on the basis of a job and prints a first image on continuous paper and; a hardware processor that controls the image former to print a second image on continuous paper in a case where at least either image information or continuous printing distance information of the first image formed by the image former satisfies a predetermined condition, wherein the hardware processor notifies a user of print information indicating a print position of the second image formed by the image former.

Abstract: A developing cartridge is disposed in an image forming apparatus. The developing cartridge includes a developing portion; a toner storing portion; a partition wall positioned between the developing portion and the toner storing portion and provided with a toner supply section; a first agitating member inside the developing portion; and a second agitating member inside the toner storing portion, wherein at least one of the first agitating member and the second agitating member comprises an elastic member to be in contact with the partition wall.

Abstract: An image reading apparatus capable of performing accurate image correction is provided. The image reading apparatus is provided with a colorimeter which colorimetrically measures an image formed on a sheet based on the optical spectrum in a visible light range, a reference plate located in a position facing the colorimeter with a chromatic reflecting surface, a temperature detection unit configured to detect the temperature of the reference plate, the determination unit configured to determine whether or not the colorimeter is in a normal condition based on the temperature of the reference plate detected by the temperature detection unit and the optical spectrum in the visible light range.

Abstract: A video count value is acquired per unit area predetermined in a direction in which a recording medium is conveyed, based on recording target image data. When an image has been formed on an area of the recording medium from which the video count value has been acquired, control is performed by using the acquired video count value so that a developing unit is replenished with an amount of toner corresponding to the video count value acquired from the area.

Abstract: An image forming apparatus includes an image bearing member, a developing device, a supplying device, and a control unit. The image bearing member bears a latent image. The developing device develops the latent image with a toner. The supplying device supplies toner to the developing device. The control unit executes a discharge operation to consume toner transferred onto the image bearing member from the developing device without transferring the toner onto a recording medium. The control unit executes the discharge operation where first deterioration integrated information exceeds a first executing threshold, and where second deterioration integrated information exceeds a second executing threshold that is larger than the first executing threshold.

Abstract: A process cartridge includes a first cartridge and a second cartridge. The first cartridge includes a first wall having a first opening, a first shutter configured to open and close the first opening, and a first operating portion configured to operate together with the first shutter. The second cartridge is mountable onto and demountable from the first cartridge and contains a developer. The second cartridge includes a second wall facing the first wall and having a second opening corresponding to the first opening, a second shutter configured to open and close the second opening, and a second operating portion configured to operate together with the second shutter. The first cartridge further includes a third operating portion. When the second cartridge is mounted onto the first cartridge, the first operating portion and the third operating portion operate together through the second operating portion.

Abstract: An image forming apparatus includes an image bearing member; a developing device; a supply device that supplies the developing device with toner; a density detector that detects information about a toner density serving as a ratio of toner and carrier of the developer of the developing device; and a controller that is able to execute a remaining amount determination mode which interrupts the image forming operation and performs a toner supply operation on the developing device from the supply device, based on the detection result of the density detector. The controller at least selectively executes a first state that immediately prohibits the image formation, a second state that allows the image forming operation, and a third state that executes the mode again, based on the detection result of the density detector acquired after the start of execution of the mode.

Abstract: A developer container includes a conveyance member having at least a first sheet member and a second sheet member and configured to convey the developer, a deformation portion provided to contact the first sheet member and configured to elastically deform the first sheet member, and a release portion configured to release elastic deformation of the first sheet member to cause the developer on the first sheet member to fly toward an opening, wherein a containing chamber includes a recessed portion as viewed in a lengthwise direction of the containing chamber and wherein the second sheet member is in contact with a wall inside the recessed portion when the developer on the first sheet member is positioned at the release portion.

Abstract: A powder detection device includes a detection unit, a cleaning unit, and a drive unit. The detection unit includes detection surfaces provided in a storage container and enables detection of powder through the detection surfaces. The cleaning unit removes the powder from the detection surfaces by sliding along the detection surfaces. The drive unit reciprocates the cleaning unit along a path extending through the detection surfaces and differentiates a speed at which the cleaning unit is moved in a first direction along the path from a speed at which the cleaning unit is moved in a second direction opposite to the first direction.

Abstract: A method and a device for detecting a rubbing cloth, the method includes rubbing a coloring sheet with the rubbing cloth; and detecting the rubbing cloth according to a pattern in a rubbed region. The device includes a base platform, a coloring sheet is provided on the base platform; and a rubbing roller, a rubbing cloth to be detected is provided on an outer surface of the rubbing roller, the rubbing roller is disposed in parallel to the base platform and the rubbing roller is configured to rub on the coloring sheet. By coloring the rubbing cloth with the coloring sheet, and detecting the rubbing cloth with a pattern in a rubbed region, the quality of the rubbing cloth can be detected by observing the depth and the arrangement of the pattern.

Abstract: A lock device includes a lock cover, a restricting portion, a drive source, a biasing portion, and a pressing portion. The lock cover is opened and closed when a developer storing portion storing developer is attached or detached. The restricting portion, when the lock cover is closed, is engaged with the lock cover in such a way as to restrict the lock cover from being opened. The drive source drives the restricting portion in such a way as to release an engagement between the restricting portion and the lock cover. The biasing portion biases the restricting portion in a direction opposite to a direction in which the drive source drives the restricting portion. The pressing portion presses the lock cover in an opening direction in conjunction with an operation of the drive source to release the engagement between the restricting portion and the lock cover.

Abstract: A biasing portion biases a restricting portion in a direction opposite to a direction in which a drive source drives the restricting portion. Each of a lock cover and the restricting portion includes an engaging portion that has a contact surface, and when the lock cover is closed, the contact surfaces of the lock cover and the restricting portion are engaged with each other while facing each other. The contact surfaces of the lock cover and the restricting portion are not parallel to each other in a state where the lock cover is closed, and as the lock cover is displaced in an opening direction of the lock cover when the drive source is not driving the restricting portion, one or both of the engaging portions are bent and the contact surfaces become parallel to each other.

Abstract: A control device may obtain, at each of a plurality of sets of date-and-time, a current value related to a current remaining amount of a print material used by the print performing unit. The control device may calculate N1 change values by using a plurality of current values obtained at the plurality of sets of date-and-time, each change value being related to a change per unit time of a remaining amount of the print material. The control device may specify a first greatest change value among the N1 change values. The control device may perform a first prediction process that includes calculating a first future value by using the first greatest change value, the first future value being related to a future remaining amount of the print material, and a first output process using the first future value in a case where the first prediction process is performed.

Abstract: Image formation is properly performed by suppressing an influence on a transfer property in the image formation due to variation in a toner particle charge amount. An image forming apparatus comprises a developing device for performing development using developer including a charged toner particle, a toner supply container for supplying the toner particle to a development unit, and a CPU for controlling a toner particle amount supplied to the developing device. The CPU calculates a toner consumption amount consumed by the development. Then, from the result, the CPU calculates a toner supply amount which makes the toner charge amount in the developing device constant. Then, the CPU supplies the toner of the calculated amount to the developing device.

Abstract: An image forming apparatus includes at least a load unit, a driving unit that drives the load unit, and a controller that controls the driving unit. The controller determines that at least one of the load unit and the driving unit malfunctions if a velocity change time period that the driving unit has taken to reach a second velocity from a first velocity is off a predetermined threshold value.

Abstract: A replaceable unit for an electrophotographic image forming device according to one example embodiment includes a housing having a reservoir for storing toner. A rotatable shaft is positioned within the reservoir and has an axis of rotation. A first magnet and a second magnet are connected to the shaft and rotatable around the axis of rotation in response to rotation of the shaft. The first magnet and the second magnet are detectable by a magnetic sensor when the replaceable unit is installed in the image forming device. A polarity of the first magnet is oriented opposite a polarity of the second magnet relative to the shaft. An amount of angular offset between the first magnet and the second magnet varies depending on an amount of toner in the reservoir.

Abstract: An image forming apparatus includes an image bearer, a charging, a charge power supply to supply a charging bias to the charging device, a developing device, a toner adhesion amount detector, an environment detector, and a controller to determine whether to execute a charging bias adjustment process in which the charging device charges the image bearer to have different potentials, the developing device supplies the toner to the image bearer according to the different potentials, the toner adhesion amount detector detects the amount of toner adhering to the image bearer, and the controller adjusts the charging. The controller includes a memory device to store the environment data, and is configured to compare the environment data with previous environment data stored in the memory device, and determine not to execute the charging bias adjustment process when an environment change amount is not greater than a threshold.

Abstract: An image forming apparatus of the present disclosure includes a developing device and a toner storage container. The toner storage container is detachable and attachable with respect to an apparatus main body. The toner storage container includes a supply screw which conveys toner by rotating forward, and a first engagement unit coupled via a gear train to a rotation shaft of the supply screw. The apparatus main body includes a second engagement unit which engages with the first engagement unit to restrain detachment/attachment of the toner storage container by engaging with the first engagement unit. In a case where an amount of toner in the toner storage unit has become equal to or less than a predetermined amount, a control unit makes the supply screw rotate backward to thereby release engagement between the first and second engagement units.

Abstract: According to one embodiment, an estimation unit corrects ambient temperatures or ambient humidities measured by an environment measurement unit on the basis of calculating an estimated temperature or humidity from measured temperatures or humidities and temperature correction values or humidity correction values, so as to estimate ambient temperatures or ambient humidities of other photoconductors of which the ambient temperatures or the ambient humidities are not measured. A control unit determines image formation conditions for the image forming units forming images on the photoconductors of which the ambient temperatures or the ambient humidities are not measured, on the basis of the ambient temperatures or the ambient humidities estimated by the estimation unit.

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: A developing cartridge includes: a casing; a developer carrier; and a receiving member. The casing includes a support portion. The receiving member receives a drive force from an external drive source to transmit the drive force to the developer carrier. The receiving member has a cylindrical configuration. The support portion rotatably supports the receiving member. The receiving member includes: a receiving portion; a transmission portion; and a fitting portion. The receiving portion has an outer edge in a radial direction of the receiving member. The transmission portion defines an outer circumferential edge of the receiving member. The fitting portion is positioned inward of the transmission portion in the radial direction and fitted with the support portion. The outer edge of the receiving portion is positioned inward of the transmission portion in the radial direction and outward of the fitting portion in the radial direction.

Abstract: An information processing device may accept an input of a first print instruction. The information processing device may send first print data to a printer in response to accepting the input of the first print instruction. The information processing device may store second print data in the memory in a print stand-by state. The information processing device may receive a push notification from the push notification server. The push notification may include first information that is related to first print processing using the first print data and outputted from the printer. The information processing device may send the second print data to the printer in response to receiving the first information.

Abstract: Control is performed so that a current value gradually shifts, corresponding to a sensor value. More specifically, when a predicted value of a remaining toner amount is calculated, processing for correcting a consumed toner amount corresponding to the sensor value is performed for a consumed toner amount.

Abstract: A developer cartridge may include a gear configured to be movable between an engagement position in which the gear engages an auger or supply gear to provide toner from a toner container to a developing unit and a disengaged position in which the gear does not engage the auger or supply gear. The gear may be moved by a cam and/or cam gear from the engagement position to the disengaged position and vice versa. The cam gear may include toothless and toothed portions to allow the developer cartridge to maintain the movable gear in either the engagement position or the disengaged position. In some arrangements, an urging member such as a spring may bias the cam gear in a rotation direction, while a lever may provide a counteracting force when the movable gear is to be maintained in a particular position.

Abstract: An image forming apparatus includes a developing unit attachment part to which developing units are to be attached, each of the developing units being associated with a first criteria for performing developer refreshing and a second criteria for performing developer refreshing, wherein the second criteria is defined so as to be met prior to the first criteria, and a controller configured to control a timing of developer refreshing executed for each of the developing units according to the first and second criteria values thereof. When the first criteria for performing developer refreshing is met for at least one of the developing units, the controller causes developer refreshing to be performed for all developing units whose first or second criteria is met.

Abstract: A molded resin product for use with an image forming apparatus includes: a base portion formed of a resin material; a positioning portion provided on the base portion; and a movable member formed by injection molding so as to be movable relative to the base portion. When the molded resin product is connected to a connection part, the positioning portion positions the molded resin product and the connection part relative to each other, and the movable member is contactable to a contact portion of the connection part.

Abstract: A toner container according to one example embodiment includes a housing having a reservoir for holding toner. A rotatable shaft is positioned in the reservoir and has a rotational axis. A toner agitator is rotatably coupled to the rotatable shaft. A first electrical conductor and a second electrical conductor are positioned on the housing. The first electrical conductor and the second electrical conductor form a capacitor having a capacitance that changes in response to a change in an amount of toner in the reservoir between the first electrical conductor and the second electrical conductor. The first electrical conductor includes a rod positioned in the reservoir at the rotational axis of the rotatable shaft and extending along the rotational axis of the rotatable shaft.

Abstract: A toner cartridge according to one embodiment includes a housing having a toner reservoir. An outlet port in fluid communication with the reservoir is positioned on a front of the housing near a first side of the housing. An interface gear is exposed on the front of the housing near a second side of the housing. A magnet is movable in response to rotation of the interface gear. An engagement member is positioned on an exterior of the top of the housing proximate the second side of the housing. The engagement member is aligned with a point in a path of movement of the magnet. The engagement member has a front surface that is unobstructed to contact and push a magnetic sensor in the image forming device to an operating position of the magnetic sensor during insertion of the toner cartridge into the image forming device.

Abstract: An image formation apparatus includes a toner bottle, a sub hopper configured to temporarily store toner supplied from the toner bottle, a development apparatus configured to receive supply of the toner from the sub hopper, a first detector configured to detect a remaining amount of toner in the toner bottle, a second detector configured to detect an empty space for toner in the sub hopper, and a controller configured to have the toner supplied from the toner bottle to the sub hopper each time the empty space in the sub hopper exceeds a threshold value Th1. When the remaining amount of toner in the toner bottle is smaller than a threshold value ThA, the controller lowers the threshold value Th1 to a threshold value Th2.

Abstract: There is provided an image forming apparatus that can detect a replacement of toner cartridge and can accurately manage information after the replacement even if serial numbers of the toner cartridges before and after the replacement are identical to each other. Each toner cartridge is provided with a nonvolatile memory that can record cartridge information, such as printed page count value (i.e., total number of printed sheets) and beginning-of-use date and time. The image forming apparatus includes a device built-in memory that can store and update the cartridge information. The image forming apparatus refers to and compares the cartridge information about two cartridges that are likely to be replaced at arbitrary timing and identifies the replacement of the toner cartridge if any discordance is confirmed.

Abstract: When cartridge replacement has occurred, reference use information that is acquired for the first time after occurrence of the cartridge replacement and reference time information indicative of when the reference use information is acquired are stored. Every time target use information, which is acquired after the reference use information is acquired, is acquired, a first period, which is defined from a particular time until printing by a printing execution section using printing agent in a presently-connected cartridge is estimated to become impossible, is computed based on the target use information, target time information indicative of time when the target use information is acquired, the reference use information, and the reference time information. When the first period is shorter than a first set period, output information corresponding to the state of use of the presently-connected cartridge is outputted.

Abstract: An image forming apparatus includes: an image bearing member, a developing device, and a controller configured to execute an operation in a forced consumption mode. The controller includes a difference calculating portion, an integrating portion, and a flag. In a case where the flag is set when a predetermined time is elapsed after the integrated value exceeds the predetermined threshold, the image formation on the predetermined number of the recording materials is effected and then the controller executes the operation in the forced consumption mode, and in a case where the flag is reset when the predetermined time is elapsed after the integrated value exceeds the predetermined threshold, the image formation on the predetermined number of the recording materials is effected and then the controller continues an image forming operation without executing the operation in the forced consumption mode.