Abstract: An image forming apparatus includes an apparatus body, an image bearing member, and a process unit attached to the apparatus body. The process unit includes a frame including a storage portion configured to store developer, a developer bearing member configured to supply developer to the image bearing member to develop an electrostatic latent image. and a circuit board attached to the frame. The circuit board includes a light emitting portion configured to emit light, and a light receiving portion configured to receive the light emitted from the light emitting portion and having passed through an interior of the storage portion.

Abstract: A developing device includes a developer carrier to carry a developer, and a developer conveyor to supply the developer to the developer carrier. The developer conveyor includes a shaft extending in an axial direction to rotate in a rotational direction, a helical blade having a conveying surface to convey the developer around the shaft along the axial direction, and a protrusion attached to a rear surface of the helical blade, which faces the conveying surface, and having a leading surface extending from an upstream end to a downstream end in the rotational direction of the shaft.

Abstract: In an image forming apparatus, an agitator agitates the toner in a target agitation amount before the image forming portion forms the image. The target agitation amount represents an amount of actions of agitation imparted upon the toner by the agitator. A processor is configured to: obtain at least one of a degradation level of the toner, the image to be formed, a non-agitation time period during which the agitator has not agitated the toner; set the target agitation amount based on the at least one of the degradation level of the toner, the image to be formed, and the non-agitation time period; perform agitating the toner in the target agitation amount by the agitator; and control the image forming portion to form the image after the agitator agitates the toner in the target agitation amount.

Abstract: In an image forming apparatus that is provided with a developing unit to develop an electrostatic latent image formed on an image carrier as a toner image, the developing unit is provided with a developer reservoir that is disposed between a supplying roller to feed developer agitated by an agitating member into the developer reservoir and a developing roller to cause the developer in the developer reservoir to adhere onto the latent image on the image carrier so as to be developed as the toner image. A control section controls driving of the supplying roller, independently from driving of the agitating member.

Abstract: In a method or digital printer to print a recording material with toner particles applied with a liquid developer, toner concentration of the liquid developer is determined via measurement with aid of ultrasonic pulses. At least one ultrasonic pulse is generated by discharging an ultrasound emitter charged with a charge voltage. The ultrasonic pulse permeates the liquid developer and is received by an ultrasound receiver which generates a reception signal corresponding to the received ultrasonic pulse. With a control device, the charge voltage is regulated to a value such that a representative value of the reception signal corresponds to a predetermined desired value. The toner concentration is determined from the regulated charge voltage.

Abstract: An image forming apparatus includes: a developing device having a developing vessel, a developing roller and a toner supply port; a toner supply device; a toner supply detecting sensor for detecting the toner concentration inside the developing vessel; a toner concentration controller for directing toner supply; a toner empty detector; and a sheet conveyance detecting sensor. The toner concentration controller has a toner supply device control function; and a toner supply stopping function of stopping toner supply when the last sheet of image printout being executed has passed by the predetermined position in the sheet conveyance path.

Abstract: An image forming apparatus is provided. The image forming apparatus includes a developing unit which contains a mixture of toner and carrier, a toner sensor which is disposed in the developing unit, and a controller which determines a control voltage for the toner sensor using change information on a change in a quantity of electric charge which changes according to a time during which the image forming apparatus is used or paused, and drives the toner sensor using the determined control voltage and compensates for an output value of the toner sensor. Accordingly, toner can be prevented from being supplied excessively.

Abstract: A development device includes a development housing, a first developer conveyance member, a developer bearer, and a developer amount detector to detect an amount of developer in the development housing. The developer amount detector includes a light-emitting element, a right-receiving element, a first light guide including a first end from which light enters and a second end disposed inside the development housing, and a second light guide including a first end positioned inside the development housing across a predetermined distance from the second end of the first light guide and a second end from which the light exits. The second end of the first light guide and the first end of the second light guide are arranged in an axial direction of the first developer conveyance member with a light transmission path therebetween partly inside a locus of rotation of the first developer conveyance member.

Abstract: An image forming apparatus that includes an exposure portion to expose a surface of an image carrier to form an electrostatic latent image; a developing device which includes an agitating roller to agitate developer, a developing roller to transfer toner of the developer on a surface of the image carrier and a toner concentration sensor to detect a toner concentration, the developing device developing the electrostatic latent image formed on the image carrier to form a toner image; a drive source to independently drive to rotate the developing roller and the agitating roller; and a control unit to control the drive source to change a rotational frequency of at least one of the developing roller and the agitating roller depending on the toner concentration detected by the toner concentration sensor.

Abstract: In a new printer, a toner cartridge is mounted in the state where there is no toner in a reserve tank, and toner of the amount of filling toner D therein is supplied with the amount of full accommodation toner E for filling up the reserve tank by a toner supply mechanism. The toner of the amount of remaining surplus toner F remains in the toner cartridge. The amount of toner consumption G is measured by a dot counter during a printing execution. In the case where a toner density sensor detects a toner decreasing, the toner is supplied to a developing unit from the reserve tank. When it becomes G>F, it display-informs a user of “toner cartridge exchange is allowed”. Hereby, it enables to exchange the toner cartridge without stopping operation of the main body of the image forming apparatus using a two-component developer.

Abstract: Provided is a printing apparatus in which a printed material of a same page is printed in almost same color tone even in a case where calibration execution conditions are satisfied in executing printing processing and concentration correction information is updated. A decision portion decides, when a calibration execution portion executes calibration in executing print image data generation processing based on print setting information of N-up printing, poster printing and the like, whether print image data of N-up printing, poster printing and the like is generated using concentration correction information before update or concentration correction information after update based on print setting information analyzed by a data analyzing portion. Then, based on the decision results, the print image data generation portion generates print image data of N-up printing, poster printing and the like.

Abstract: In the present invention, for a developing apparatus provided with a sensor for detecting the toner density of a developer, retention of the developer near the sensor face can be suppressed by increasing the force with which the developer present near the sensor face is carried in a shaft direction of a stirring/carrying member.

Abstract: An image forming apparatus prevents printed images from being degraded in image quality due to failure of the toner concentration to fall within a proper range, by correcting the deviations of the amount of toner consumption and the amount of toner supply depending on the individuality of each image forming apparatus and that enables exact identification of the cause of a fault associated with toner concentration, and providing an image forming method using the apparatus. A toner supply device supplies toner to a developing vessel through an opening in accordance with an instruction from a controller. The presence or absence of toner falling is detected based on the variation of the output from a magnetic permeability sensor when toner is supplied. The controller monitors the output voltage level of the magnetic permeability sensor and adjusts the input gain in accordance with the output voltage level to thereby control toner concentration.

Abstract: There are provided a powder supply element adapted to supply powders containing at least toner; developing element adapted to develop an electrostatic latent image by agitating and conveying a developer containing the powders that are supplied by the powder supply element; a toner amount detecting element that is placed in the middle of a conveyance path to connect the powder supply element with the developing element and detects a toner amount per unit volume to be supplied to the developing element; and control element that controls a correction amount with respect to a reference supply amount due to the powder supply element on the basis of a toner amount per unit volume that is detected by the toner amount detecting element.

Abstract: A developer to develop an electrostatic latent image satisfying the requirements of 0.85?Q60/Q600 and 10?Q600?20, where Q60 (??C/g) represents a charge amount of the developer when a sample, made by adding the developer to a carrier such that the concentration of the developer is 5%, is shaken for 60 seconds, and Q600 (??C/g) represents a charge amount of the developer when shaken for 600 seconds under the same conditions.

Abstract: An image forming apparatus includes a toner carrier, a toner image forming unit, and a toner concentration sensor. The toner carrier includes a transparent film. The toner image forming unit forms a toner image onto the toner carrier. The toner concentration sensor senses the concentration of toner on the toner carrier. The toner concentration sensor includes first and second light emitting elements and a light receiving element. The light emitting elements each radiate light directly or indirectly to the toner carrier. The light receiving element receives reflecting light originating from the light emitting elements. The first light emitting element radiates light having a wavelength of a predetermined reflectance resulting from direct radiation to the toner carrier. The second light emitting element radiates light having a wavelength that causes a lower reflectance resulting from direct radiation to the toner carrier than a reflectance resulting from radiation to the toner.

Abstract: The developer supplying device supplies a supplementary developer including a toner and a carrier in a predetermined weight ratio. The developer supplying device includes a supplementary developer container containing the supplementary developer, and a supplementary developer feeding passage configured to feed the supplementary developer from the supplementary developer container to a developing device. The supplementary developer container is replaced when the supplementary developer is substantially exhausted. The developer supplying device further includes a carrier concentration determining device provided on the supplementary developer feeding passage to determine the concentration of the carrier in the supplementary developer fed through the supplementary developer feeding passage, and a residual supplementary developer amount estimating device configured to estimate the amount of the supplementary developer remaining in the supplementary developer container.

Abstract: An image forming apparatus includes: a developing device; a toner supply device; and a toner supply detecting sensor; and a toner concentration controller that directs toner supply. The toner concentration controller includes: a memory that stores the difference between the outputs from toner supply detecting sensor before and after toner supply; a toner supply quantity determinater that determines that the amount of toner remaining in the toner supply device is low and the amount of toner supply is low when the output difference or output ratio of the sensor is lower than a supply reference value; and an image quality adjustment controller that shortens the interval of time between adjustment of electrical potential on toner concentration correction in the above case.

Abstract: An image forming apparatus having a development apparatus that includes: a developer storing part; a developer supply mechanism; and a surplus developer removing section; wherein the developer supply mechanism includes: a toner storing part; a carrier storing part; a developer conveying path and a conveying mechanism, both are arranged between the toner storing part and the developer storing part, and between the carrier storing part and the developer storing part; wherein the developer conveying path includes a toner ejection outlet through which a toner stored in the toner storing part is ejected and a carrier ejection outlet through which a carrier stored in the carrier storing part is ejected, and a supplying developer ejection outlet through which a supplying developer is ejected to the developer storing part; and wherein the conveying mechanism is adapted to convey the toner and the carrier while stirring them.

Abstract: Density-correction-table lists showing an amount of density changes in respective density levels of images that exist after an image having a predetermined density has been printed on a predetermined number of sheets are maintained. The amount of density changes in the respective density levels for an image ratio that exists after the predetermined number of sheets have been printed on and for the predetermined number of sheets that have been printed on are obtained with reference to values in the maintained density-correction-table lists. A density correction characteristic is determined using the obtained amount of density changes.

Abstract: The change in an output voltage when a control voltage is changed is calculated, and the change in the control voltage divided by the calculated change in the output voltage is defined as a sensitivity coefficient. The sensitivity coefficient is recalculated for each predetermined time interval or whenever a predetermined condition is satisfied, and the control voltage is corrected based on the recalculated sensitivity coefficient. Example of the predetermined condition include the time of start-up of the apparatus, the time at which the accumulated number of printed sheets reaches a predetermined number, and the time of carrying out process control.

Abstract: According to one embodiment, an image forming apparatus includes: an image forming section including a developing device; a toner-cartridge holding section configured to detachably house a toner cartridge that stores a toner supplied to the developing device and includes a storage medium which stores information concerning the toner; a reading device configured to read the information stored in the storage medium; a toner detecting section configured to detect that the toner is supplied to the developing device; a toner-density comparing section configured to compare densities of the toner and a carrier after the detection by the toner detecting section; and a storage device configured to store information concerning use in the reading device and the storage medium if the toner-density comparing section determines that the toner density reaches a predetermined value.

Abstract: A first developer container having a toner supplying opening is provided in a developing unit. A toner concentration sensor is arranged downstream of the toner supplying opening to detect toner concentration in developer. A supply controlling unit is provided to determine an excess or a shortage in the amount of supplied toner based on image information correspondingly to a detection result by the toner concentration sensor, and to correct the driving amount of a toner supplying unit that has been determined based on the image information correspondingly to the recognized excess or shortage in the amount of supplied toner.

Abstract: The color printing control device outputs color material reduction processed data generated by applying a color material reduction process to each pixel of bitmaps converted to color material colors to be used in printing, when it is judged that the color material reduction printing mode is specified. The color material reduction process includes chroma conversion that reduces chroma and under-color removal/black generation that replaces at least a portion of achromatic components generated by overlaying of a plurality of color materials.

Abstract: To provide a technology that can realize appropriate developer supply processing according to conditions within a developing unit by a simple method. In an image forming apparatus that visualizes an electrostatic latent image formed on a photoconductor with a developing unit, information on an amount of consumption of a developer in the developing unit is acquired, first developer supply information indicating an amount of developer to be supplied to the developing unit is calculated based on the acquired information, information on concentration of the developer contained within the developing unit is acquired, second developer supply information indicating an amount of developer to be supplied to the developing unit is calculated based on the acquired information, and information indicating an amount of developer to be supplied to the developing unit is determined based on the calculated first and second developer supply information.

Abstract: In accordance with an embodiment of the embodiment of the invention, an image forming apparatus includes: an electrostatic image-bearing member; and a developing device. The developing device includes a developer-carrying member disposed to face the electrostatic image-bearing member, and a developer carried on the developer-carrying member. The developer includes a carrier having a volume-average particle size dc (?m) and a toner having a volume-average particle size dt (?m) of at most 5 ?m and contained at a weight ratio C with respect to the carrier of from 5 to 10% and is controlled so as to provide a surface coverage F of the carrier with the toner of from 30 to 80% as calculated according to Formula (I): F=(¼)×(dc/dt)×(pc/pt)×C, wherein pc denotes a true specific gravity (?) of the carrier, pt denotes a toner absolute specific gravity (?), and C denotes a weight ratio (?) of the toner to the carrier.

Abstract: A developing apparatus has: a developer container including a developer transportation unit that transports, while mixing, a developer containing a toner and a carrier along an axis of rotation by a rotatable mixing transportation member; and a cover member provided in part of the developer transportation unit so as to cover an upper portion of the mixing transportation member. A preset case disposed on top of the developer transportation unit has: a developer feed port provided on that bottom surface of the preset case which lies on a side of the developer container; and a sealing member that seals a developer feed port, the sealing member being mounted so as to be removable, when putting the preset case to use, longitudinally of the mixing transportation member. The developer feed port is provided except for a position that lies opposite to the cover member.

Abstract: A development device includes a toner-containing chamber for containing supplied toner having an interior wall, a developer-containing chamber for containing developer including toner and carrier communicating with the toner-containing chamber; and a transport screw to transport the supplied toner from the toner-containing chamber to the developer-containing chamber, disposed in the toner-containing chamber so that there is no gap between the outer edge of the transport screw and the interior wall of the toner-containing chamber in a portion lower than a level of the supplied toner in the toner-containing chamber.

Abstract: There are provided a powder supply means 23 adapted to supply powders containing at least toner; developing means 11 adapted to develop an electrostatic latent image by agitating and conveying a developer containing the powders that are supplied by the powder supply means 23; a toner amount detecting means 31 that is placed in the middle of a conveyance path to connect the powder supply means 23 with the developing means 11 and detects a toner amount per unit volume to be supplied to the developing means 11; and control means 6 that controls a correction amount with respect to a reference supply amount due to the powder supply means 23 on the basis of a toner amount per unit volume that is detected by the toner amount detecting means 31.

Abstract: A pressing wall is provided in a part of the entire area of the first carrying chamber in which a first screw member is housed. The area is opposed to a bottom wall of the first carrying chamber on the lower side in the gravity direction of the first screw member and opposed to the side walls of the first carrying chamber on both lateral sides orthogonal to a rotation axis direction of the first screw member. In the area, a toner concentration of a K developer being carried is detected by a K toner concentration sensor. The pressing wall comes into contact with, from above in the gravity direction, the K developer, which moves from a lower side to an upper side in the gravity direction according to the rotation of the first screw member, and presses the K developer downward in the gravity direction.

Abstract: A method of changing a color developer in a developer housing of xerographic marking system are disclosed, and may include supplying a chart divided into a plurality of color family sections or quadrants, selecting a new color to be installed in a developer housing corresponding to the color family section, purging old toner from the developer housing until a concentration of old toner is reduced to about 0.1% to 6.0% from its nominal concentration, installing a container of a new color developer in the developer housing, and running the marking system until the required concentration of the new color developer is attained.

Abstract: An image forming apparatus capable of reducing the number of toner concentration detection errors caused by variation in the volume of a toner includes a reverse vane for transferring developer in an opposite direction and protruding from the rotary shaft member in a region where a lower side faces a bottom wall of a first transfer chamber and two lateral sides that are orthogonal to the rotary axis direction face respective side walls of the first transfer chamber, and a toner concentration detection sensor is disposed to detect the toner concentration of the developer as the developer is transferred between the reverse transfer vane and a location of the screw vane adjacent to the reverse transfer vane.

Abstract: An image forming apparatus includes a toner image forming section including a developing device having a developer tank for storing a two-component developer, a transfer section, a fixing section, a recording medium feeding section, and a discharging section. The image forming apparatus further includes a toner concentration detecting section for detecting the toner concentration in the developer tank, a printing speed switching section, a toner concentration calculating section for correcting a detection result obtained by the toner concentration detecting section according to a speed of printing to calculate the toner concentration, and a toner replenishment control section for replenishing the toner into the developer tank according to a calculation result by the toner concentration calculating section.

Abstract: An image forming apparatus includes an optical sensor configured to optically detect a density of a reference pattern image, a toner density sensor configured to detect a density of toner in a developing unit, a storing unit configured to store an image area coverage of an output image, a determining unit configured to determine whether a state of toner accommodated in a toner supplying unit is an almost empty state and an empty state or neither based on detection results obtained by the sensors, a controlling unit configured to continuously perform a toner state check when the image area coverage of the output image is greater than a predetermined image area coverage value and the density of the reference pattern image is greater than a predetermined density level after the determination of the state of toner is the almost empty state or the empty state or neither.

Abstract: A developing device includes: a developer carrier; a first housing chamber; a second housing chamber; a first inflow portion; a first conveying member; a second conveying member; and a concentration detecting member.

Abstract: An image forming apparatus and a toner replenishment control method according to the present invention are configured such that a concentration of toner in a developer detected by a toner concentration detection sensor is measured and the measured toner concentration value is stored. These are configured such that regions of image data corresponding to an electrostatic latent image on an image bearing member to be developed by the developer are specified and an amount of toner to be consumed in the developer is predicted based on the image data of the specified regions, then a post-development concentration value of toner in the developer is estimated based on the measured toner concentration value and the predicted toner consumption amount, and control of replenishment of toner to the developer is carried out based on the estimated post-development toner concentration value and a toner setting concentration value that has been set in advance.

Abstract: A solid-concentration measuring apparatus includes an ultrasonic transmitter, an ultrasonic receiver, and a response-time integrator. The ultrasonic transmitter transmits a single-pulse ultrasonic wave to a liquid toner. The ultrasonic receiver receives the single-pulse ultrasonic wave. The ultrasonic transmitter transmits again a single-pulse ultrasonic wave after a predetermined time has passed from when the ultrasonic receiver receives the single-pulse ultrasonic wave. The response-time integrator measures a response time from transmission to reception of each single-pulse ultrasonic wave, and integrates the response time with respect to each set of N pulses (N>1). A solid concentration of the liquid toner is calculated based on the integrated response time.

Abstract: A black developer is conveyed in a first conveyance chamber in a rotation axis direction while agitating with rotation of a first screw member. A black-toner-concentration detecting sensor detects a toner concentration of the black developer by having contact with the black developer conveyed inside the first conveyance chamber. An average of peak amounts of a pressing force on the black developer, which is conveyed inside the first conveyance chamber by the first screw member, with respect to the black toner-concentration detecting sensor is set within a range of 9.8 15 [N/m2] to 9.8 100 [N/m2].

Abstract: An image forming apparatus in which a predetermined image density can be obtained by correcting a toner density control target value without consuming toner. The toner density of the developer is controlled so that an output value Vt of a magnetic permeability sensor approaches a target output value Vtref. In addition, the target output value Vtref is corrected in accordance with image coverage history information of output images transferred to a transfer paper and image coverage ratio history information of output images determined from the image coverage thereof and the size of the transfer paper. This history information comprises, for example, a cumulative average value of the image coverage or the image coverage ratio per transfer paper. It may also comprise a moving average value of the image coverage or the image coverage ratio per transfer material.

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

Abstract: A toner-concentration controller includes a controller configured to control a toner supply amount in accordance with a detection result of a toner-concentration of two-component toner, and a sensor unit configured to detect the toner-concentration of two-component toner. The sensor unit includes a correction mechanism to correct an output signal of the sensor unit by changing an external-input voltage, based on relationship data between an output voltage change of the sensor unit and a toner-concentration of unused developer, to control the toner supply amount when the toner-concentration of the two-component toner deviates a predetermined amount from the toner-concentration of the unused developer. The sensor unit is configured to detect the toner-concentration of the unused developer from unused two-component toner based on a change in the external-input voltage.

Abstract: Of carrier liquids extracted by an carrier liquid extracting device from a liquid developer obtained by mixing together yellow, cyan, magenta, and black liquid developers, the carrier liquid of particularly high purity is recycled for concentration control of the yellow liquid developer and the carrier liquid of purity a little lower than the aforementioned purity is recycled for concentration control of the cyan, magenta, and black liquid developers. A carrier liquid extracted from the yellow liquid developer is recycled for the concentration control of the yellow liquid developer, and a carrier liquid extracted from the liquid developer obtained by mixing together the cyan, magenta, and black liquid developers is recycled for the concentration control of the cyan, magenta, and black liquid developers. This permits efficient use of carrier liquids to be recycled without having an influence on the image quality.

Abstract: When the temperature of the liquid toner has fluctuated by T1 or more (Step S3: YES), the equation obtained by measuring the liquid toner is modified (Steps S4 through S7). This equation is obtained based on the output voltage value of the concentrated toner liquid sensor 27, which has the same specifications as those of the liquid toner sensor 24, and the output voltage value of the carrier liquid sensor 29, which has the same specifications as those of the liquid toner sensor 24 (S4 through S6). The output voltage value of the liquid toner sensor 24 is entered into the modified equation to calculate the toner solids content of the liquid toner of the storage tank 18 (Step S8). Control of the concentration of the liquid toner is carried out based on the calculated toner solids content (Step S9).

Abstract: A developer supply cartridge including toner, carrier for charging the toner, a case housing the toner and the carrier, an openable partition dividing an inside of the case into a first area filled with the toner and a second area filled with the carrier, and a supply port provided in the first area, the supply port for discharging the developer including the toner and the carrier from the case.

Abstract: A digital color copier includes: a toner concentration storage which stores a detected toner concentration of each developer block of multiple developer blocks across an image forming width; a toner consumption predictor for predicting a first predicted toner consumption of toner consumed from developer of every developer block during a first circulation; a toner concentration estimator for estimating, for every developer block, a toner supply point estimate as the toner concentration at a point where toner is supplied, by subtracting the first predicted toner consumption from the associated detected toner concentration and setting up a toner supply target value of the toner to be supplied from a toner supply device to a developing device in accordance with the predicted toner consumption during a second circulation of the developer inside the developing device that follows the first circulation.

Abstract: A plurality of chambers are adapted to accommodate a plurality of cartridges each containing toner to be used for printing. A mode changer is operable to change an operation mode of the printing apparatus in accordance with a combination of respective colors of toner in the cartridges accommodated in the chambers. A first detector is operable to detect a residual amount of toner in each of the cartridges. A second detector is operable to detect the respective colors of toner in the cartridges when the operation mode is changed. A controller is operable to generate an image data including a plurality of first identifiers each indicative of the residual amount of toner in one of the cartridges and a plurality of second identifiers each indicative of one of the colors of toner and associated with one of the first identifiers. A display is adapted to display the image data.

Abstract: A tool used in the TC measurement in the field includes a venturi shaped container that when connected to vacuum pressure from a portable vacuum cleaner takes advantage of cyclone separator functionality to assist in separation of fine toner from carrier beads with the toner being caught in the vacuum cleaner and the carrier beads being caught by a plurality of screens covering an opening in the bottom of the container.

Abstract: A developer agitation screw is provided with a blade to gather developer onto the sensor surface of a toner concentration sensor. A toner concentration control unit detects the maximum value of the output of the toner concentration sensor within each predetermined period of time, the predetermined period of time being longer than the period in which developer is gathered on the sensor surface of the toner concentration sensor by the blade. The obtained maximum value is used as a characteristic value to control the toner concentration.

Abstract: An image forming apparatus includes an latent image carrier configured to carry a latent image thereon, a developing unit disposed facing the latent image carrier to develop the latent image with developer, a developer container containing the developer and attachable to the image forming apparatus, a developer detector configured to detect the presence of the developer in the developing unit, and a developer supply controller. The developer supply controller prohibits supply of the developer from the developer container to the developing unit when the developer detector detects that the developer is present in the developing unit.

Abstract: An object of the present invention is to provide a remaining amount of toner detecting apparatus capable of highly accurately detecting the remaining amount of toner with a simple configuration, a toner cartridge in which the remaining amount of toner is highly accurately detected with a simple configuration, and an image forming apparatus which enables the operator to easily recognize time to resupply toner and is capable of forming an image of high image quality. A holding member (22) is flexible, one end (22a) in the longitudinal direction is connected to a stirring member (11), and the other end (22b) in the longitudinal direction holds a detection auxiliary member (21) disposed in a housing (8). Consequently, the holding member (22) and the detection auxiliary member (21) rotate as the stirring member (11) rotates.