Abstract: An image forming apparatus includes first and second image forming portions. The first and second image forming portions forms a toner image. The second image forming portion forms a toner image so that the toner image is superimposed on the toner image formed by the first image forming portion. The second image forming portion includes an image bearing member, a cleaning member that removes transfer residual toner existing on the image bearing member at an abutting position, and a supply unit that supplies abrasive particles or toner to the abutting position. The image forming apparatus includes a controller that controls the amount of toners or abrasive particles, which are supplied by the supply unit, in accordance with the amount of toner used in the first and second image forming portions.

Abstract: In an electrographic printing device a plurality of printing groups each have a respective plurality of developer stations. A plurality of toner reservoirs are each connected via a respective toner transport channel with one or more of the developer stations. Each of the toner reservoirs outside of the printing groups is stored in a respective toner transport unit. Each of the toner reservoirs is provided with a first circuit having a memory in which is stored at least a color filled into the respective toner reservoir. A respective second circuit with a memory is associated with each of the toner transport units. These memories have stored therein at least the respective toner color filled into the respective stored toner reservoir. A respective third circuit with a memory is provided for each developer station, the respective third circuit memory having stored therein at least a toner color filled into the respective developer station.

Abstract: Background development in a multi-color electrophotographic printer is reduced. A print job including a plurality of separations is received. Each separation has an image area and a non-image area. A printer is provided, including a development member for supplying toner to a photoreceptor for each separation. A developing and a non-developing zone are determined for each separation, corresponding to the image area and non-image area, respectively. Developer is automatically supplied to the development members, and automatically removed developer from the respective non-developing zone of each development member.

Abstract: An image forming apparatus includes an image carrier, a developer carrier, a runout measurement information storage unit to store runout measurement information of the image carrier and the developer carrier, including runout amounts on the circumference of the image and developer carriers in a development area, a development gap measurement information storage unit to store information obtained by measuring a development gap when runout measurement points of the image and developer carriers face each other, and a development electric field strength control unit to obtain each development electric field strength based on the runout measurement information and the development gap measurement information, and determine control contents of development electric field strength control to cause the entire development electric field strengths to fall within an acceptable range of a target electric field strength to perform the control contents.

Abstract: A rotational speed of an image bearing member on a downstream side is controlled so as to reduce a detection time difference between a leading end section of first electrostatic latent image indexes of an image bearing member and a leading end section of second electrostatic latent image indexes of a transfer medium in an area of a leading end margin preceding an effective image area.

Abstract: There is provided an apparatus for developing a latent image recorded on an imaging surface, including: a housing defining a reservoir storing a supply of developer material comprising toner; a donor member positioned in the housing, spaced from the imaging surface, for transporting toner on an outer surface of the donor member to a region opposed from the imaging surface, a print quality system for monitoring a plurality of xerographic actuator parameters, the print quality system generating a feedback signal if at least one of a plurality of xerographic actuator parameters is beyond a predefined threshold limit; and system for translating the donor member from a first predefined spacing to a second predefined spacing from the imaging surface in response to the feedback signal from the print quality system.

Abstract: An image forming apparatus includes a controller that starts a forced drive stop sequence for stopping image formation at least by stopping rotation of a developer carrier in a first direction when a number of printed sheets reach a threshold. The forced drive stop sequence rotates the developer carrier in a second direction for a prescribed time period when the image formation is stopped. The forced drive stop sequence stops the rotation of the developer carrier in the second direction and resumes the image formation after the prescribed time has elapsed.

Abstract: Methods for printing are provided. In one aspect a primary imaging member having a pattern of engine pixel locations with image modulated differences of potential and with first toner having a first toner difference of potential is moved to a second development station. A second development difference of potential of the first polarity at the second development station forms a second net development difference of the second development difference of potential less any image modulated difference of potential at the individual engine pixel location and less any difference of potential relative to ground of any first toner at the individual engine pixel location. The second development difference of potential is greater than the first development difference of potential so that second toner that is different from the first toner, is developed onto the first toner using the second net development difference of potential.

Abstract: Methods for printing are provided. In one aspect, the method includes providing a primary imaging member having engine pixel locations with a ratio modulated difference of potentials, establishing a first development difference of potential to form a first net development difference of potential between the first development difference of potential and the engine pixel location and providing a first charged toner such that the second toner develops at the engine pixel location. Establishing a second development difference of potential that is greater than the first difference of potential proximate the engine pixel location such that a determined amount of first toner develops at the engine pixel locations according to a second net development difference of potential. Wherein the range of second toner potentials is such that a determined range of ratios of second toner amounts and the determined first toner amount provide ratio modulated differences of potential.

Abstract: Methods for printing are provided. In one aspect a primary imaging member having a pattern of engine pixel locations with image modulated differences of potential and with first toner having a first toner difference of potential is moved to a second development station. A second development difference of potential of the first polarity at the second development station forms a second net development difference of the second development difference of potential less any image modulated difference of potential at the individual engine pixel location and less any difference of potential relative to ground of any first toner at the individual engine pixel location. The second development difference of potential is greater than the first development difference of potential so that second toner that is different from the first toner is developed onto the first toner using the second net development difference of potential.

Abstract: An image forming apparatus includes a first image forming unit for forming a first developer image; a second image forming unit for forming a second developer image; a transfer unit for transferring at least one of the first developer image and the second developer image; a separation contacting unit for moving at least one of the first image forming unit and the second image forming unit to a first position and a second position; a density measurement unit for measuring a first image density and a second image density of the first developer image; and a control unit including a density calculation unit for calculating a difference between the first image density and the second image density and a density correction unit for correcting a density of the first developer image according to the difference.

Abstract: An image forming apparatus and a control method of the image forming apparatus. The image forming apparatus includes a photosensitive medium, a charger to charge the photosensitive medium, an exposing unit to expose light to the photosensitive medium to form a latent image on the photosensitive medium, a developing unit which is disposed opposite to the photosensitive medium to develop the latent image into a visible image, a density sensing unit to sense a density of an area of the photosensitive medium, and a controller to determine whether a preset developing condition corresponds to a background image generating condition based on the density sensed by the density sensing unit and to adjust the developing condition based on the determination.

Abstract: A supply control unit is configured to, in a successive image-forming operation, perform a process of successively generating a driving control pattern for a toner supply device based on image information of each page, and synthesizing an unused portion of the driving control pattern which is obtained by eliminating a portion of the driving control pattern already reflected on a driving control of the toner supply device from the driving control pattern generated based on image information of a previous page with a driving control pattern generated based on a subsequent page.

Abstract: An image forming apparatus includes: a cartridge attachment portion; an image forming unit; a reading unit; and a control unit. A toner cartridge configured to accommodate toner is removably attached to the cartridge attachment portion. The toner cartridge includes a cartridge mechanism unit mechanically driven and a storage medium for storing torque information including information indicating torque used for a mechanical drive of the cartridge mechanism unit. The image forming unit is configured to print an image on a surface of a printing medium using toner accommodated in the toner cartridge. The reading unit is configured to read the torque information from the toner cartridge attached to the cartridge attachment portion. The control unit is configured to determine a number of printing media to be printed by the image forming unit per unit time, according to the torque information read by the reading unit.

Abstract: An image forming apparatus includes a sensor that detects a property of a developer material, a transport unit that contacts the developer material and moves the developer material toward a recording medium, and a controller that receives the data regarding the property of the developer material from the sensor unit and sets both a voltage and a velocity of the transport unit, wherein the voltage and the velocity is determined based on data regarding the detected property of the developer material received from the sensor.

Abstract: An image forming apparatus includes a developing device, a detection mode execution unit, and a notice signal generating unit. The developing device supplies a toner bearing member with toner in a container by rotating a toner supply member in a contact manner with the toner bearing member. The detection mode execution unit executes a detection mode in which a predetermined period for changing a toner amount in the foam layer by rotating the toner supply member is provided, a capacitance C1 between the first and second electrode members is detected before the predetermined period, and a capacitance C2 between the first and second electrode members is detected after the predetermined period. The notice signal generating unit generates a low toner amount notice signal in response to an absolute value |C1?C2| of a difference between the capacitances C1 and C2 being smaller than a predetermined threshold.

Abstract: There is provided an image forming apparatus that accurately obtains the dynamic characteristic of the apparatus when a foreign substance is adhered to a driving roller for driving an endless belt, such as a facing roller. To accomplish this, the image forming apparatus uses an optical sensor to detect information of a foreign substance on the facing roller. When it is determined that there is no foreign substance information, the image forming apparatus executes profile detection of an intermediate transfer belt using the nominal circumference of the facing roller. When the optical sensor detects foreign substance information, the image forming apparatus measures the circumference of the facing roller, and performs profile detection of the intermediate transfer belt using the measured circumference of the facing roller.

Abstract: In an image forming apparatus, an image forming contrast potential for obtaining the maximum density is set by reading a specific pattern transferred and formed on a sheet. A photosensor detects the density of a specific pattern formed on an image carrier at the image forming contrast potential, and the detection result is stored. A correction amount for the image forming contrast potential is calculated on the basis of the relationship between the stored detected density, and the density, detected by the optical sensor, of the specific pattern formed on the image carrier at a predetermined timing. The image forming contrast potential is adjusted by the correction amount.

Abstract: An image forming apparatus which forms an image on an image carrier along with rotation of a developing sleeve that carries a toner and carrier contained in a two-component developer, comprises: forming unit configured to form a density detection toner image on the image carrier using the toner; detection unit configured to detect a density of the density detection toner image formed; prediction unit configured to predict a toner charge amount in the two-component developer; correction unit configured to correct the toner charge amount in the two-component developer using a value obtained from a relationship between the toner charge amount predicted by the prediction unit and the density of the toner image that is detected by the detection unit; and control unit configured, when forming the density detection toner image by the forming unit, to control to increase a development efficiency, compared to image formation based on image data.

Abstract: In a method to control a development process and an electrographic process, at least one developer station inks a latent image on a carrier with a toner. The toner is extracted from a mixture of toner and toner particles and wherein first toner is supplied to the mixture. A characteristic value is determined for a status of the mixture from a model calculation in which a toner exchange rate and an operating aging rate are linked. The development process is at least one of monitored, controlled, or regulated depending on the characteristic value. Also in a related method for controlling a development process, a characteristic value is determined for a status of the mixture from a model calculation in which a change of a toner consumption rate for the toner within a time interval during operation of the developer station and a time constant are taken into account. At least one of monitoring, controlling, or regulating the development process depends on the characteristic value.

Abstract: In an image forming apparatus, a control portion forms a restoring toner image (restoring toner band) at a position, in which the refreshing toner image overlaps with a control image with respect to a longitudinal direction of a secondary transfer roller, during post-rotation after image formation in an image forming job is completed. The restoring toner band is formed in a length corresponding to 3 full circumferences of the secondary transfer roller for one-sheet image forming job, 2 full circumferences of the secondary transfer roller for 5-sheet image forming job, and one full circumference of the secondary transfer roller for 10-sheet image forming is job. In the case of an image forming job on 50 sheets or more, a lowering in cleaning performance of a secondary transfer member cleaning device for the secondary transfer roller is not caused to occur, so that the restoring toner band is not formed.

Abstract: An image forming apparatus that includes a latent image carrier, a latent image forming unit, a developing unit, a toner supplier, a toner concentration detector, a prediction calculator, and a toner supply controller. The toner supplier includes a single driving source and supplies toner to a two-component developer at a predetermined supply position by driving a toner supply member with the driving source. The toner concentration detector detects a toner concentration in the developer at a predetermined detection position located upstream of the supply position. The prediction calculator predicts changes in the toner concentration in the developer over time at a prediction position located at the supply position or downstream of the supply position and upstream of a developer feed position to the developer carrier when toner is not supplied. The toner supply controller adjusts an amount of the toner supplied based on the prediction.

Abstract: The present invention aims to prevent a problem that an image on a document sheet is erased due to misdetection of a line-shaped noise. A copy machine 1 compares RGB values of a target pixel with averaged RGB values (Step S103). If only one of the RGB values has a difference that is greater than a prescribed value Ref2 (Step S103: YES), the copy machine 1 extracts the target pixel as a line-shaped noise pixel, and moves to a line-shaped noise correction (Step S108) while holding the address of the target pixel in a line-shaped noise address storing area 49b. If two of the RGB values have differences (Step S103: NO, Step S104: YES) and a difference between these two of the RGB values is no greater than a prescribed value Ref3 (Step S105: YES), the copy machine 1 extracts the target pixel as a line-shaped noise pixel, and moves to the line-shaped noise correction (Step S108) while holding the address of the target pixel in the line-shaped noise address storing area 49b.

Abstract: An image forming apparatus includes a drum; a developing device, including a developer carrying member for carrying a developer including a non magnetic toner and a magnetic carrier and for conveying the developer to a developing position in which the developer carrying member opposes the drum; a detecting portion for detecting information correlating to a toner charge amount of the developer in the developing device; and a controller capable of executing an operation in a mode, wherein drive of the developer carrying member in a first period in which a non image formation area of the drum corresponding to an internal between a recording material and a subsequent recording material passes through the developing position is stopped or lowered in speed less than that in a second period in which an image area corresponding to the recording material passes through the developing position.

Abstract: An image forming apparatus includes an image bearing member, a developer bearing member, a conveying member circulating and conveying a developer, an executing portion which can make the image forming apparatus execute a first mode in which image formation is performed at a first image forming speed and a second mode in which image formation is performed at a second image forming speed lower than the first image forming speed, and a controlling portion which, in case that a mode is switched between the first mode and the second mode, gradually changes a target drive speed of the conveying member so that the drive speed of the conveying member is gradually changed from the drive speed of the conveying member in the mode before switching to the drive speed in a steady state in the mode after switching.

Abstract: The present image forming apparatus forms a reference developing material image on an image carrier using an exposure unit and a developing unit before executing auto tone correction processing, and detects the density of the reference developing material image formed on the image carrier. If the detection result indicates that the toner charge amount of the developing material contained in the developing unit is within a predetermined range, auto tone correction processing is executed, whereas if the detection result of the density detecting unit indicates that the toner charge amount of the developing material contained in the developing unit is outside the predetermined range, adjustment processing for adjusting the toner charge amount of the developing material contained in the developing unit to be within the predetermined range is executed before execution of auto tone correction processing.

Abstract: A duty ratio Du (%), denoted by (T2/(T1+T2))×100, is in the range of 60?Du?80; a magnetic carrier has a resistivity ? which decreases in accordance with an increasing electric field strength, and a relative dielectric constant ? which increases in accordance with an increasing electric field strength; a product of a time constant ?0??(s) of electric charge decay in an electric field strength E2D decided by a second peak voltage V2 and a dark potential VD, and an electric field strength E2D satisfies a relation of 20??0?? E2D (s·V/cm); and a time constant ?0??(s) and a relative dielectric constant ? in an electric field strength E1L, which is decided by a first peak voltage V1 and a bright potential VL, satisfy the following relations: ?0??(s)?6.0×10?4, and 30??.

Abstract: The invention provides a wet development device, wet development method and image forming apparatus having the device by which appropriate cleaning can be performed, the wear of the blade or developing roller can be reduced, and good images can be obtained without toner contamination even when the amount of toner for development or that of electric charge of the toner is changed for changing the density or gradation of image or type of paper. The toner in the developer is electrically charged to an arbitral charging amount by a discharging section and provided for the development and the charge of the toner is eliminated after development by that a discharging section is provided before cleaning the developer remaining on the developing roller and the output of the discharging section is appropriately controlled corresponding to the output of the discharging section.

Abstract: An image forming apparatus includes a toner supply member which is in contact with the toner carrier and is provided within the container, has a foam layer on its surface, rotates in a predetermined direction for image formation and supplies the toner to the toner carrier and has a contact area with the toner carrier with an uppermost stream position in the predetermined direction of the contact area being higher than a lowermost stream position and has a period when the toner supply member rotates in the opposite direction of the predetermined direction to increase the toner amount contained in the foam layer.

Abstract: A method and apparatus transfer a material from first roller within a container to at least one second roller, and transfer the material from the second roller to at least one third roller. The second roller and the third roller form a loading nip at a location where the second roller is closest to the third roller. The method and apparatus transfer the material from the third roller to at least one recipient device, and measure current flow between the second roller and the third roller using a measurement device. Then, the method alters the relative rotation rate difference between the first roller and the second roller based on the current flow to maintain a predetermined density of the material at the loading nip using a controller.

Abstract: An image forming apparatus includes a photoreceptor drum, a developing roller, and a control section. The photoreceptor drum is configured to form an electrostatic latent image on a surface thereof in accordance with image data. The developing roller has a surface for bearing a two-component developer at least a partial region of which faces the photoreceptor drum and is configured to be driven so as to feed the developer to the photoreceptor drum. The control section is configured to detect a print coverage for image data to be used during continuous formation of images in accordance with plural image data items and then set a relative velocity of the developing roller to the photoreceptor drum to a higher value when the print coverage is relatively high and set the relative velocity to a lower value when the print coverage is relatively low.

Abstract: At least a portion of an intermediate transfer member (34) includes a release layer (50) facing outwardly from and supported by a supportive portion. The release layer (50) includes an inner layer (70) and an outer layer (72) over and in contact with the inner layer (70), The inner layer (70) has a thickness of between about 1 ?m and about 8 ?m and a bulk swelling of between 120% and 350%. The outer layer (72) has a thickness of less than about 5 ?m and a bulk swelling of less than 120%.

Abstract: An image forming apparatus, which has a plurality of image forming units, comprises a plurality of cartridges adapted to supply developer; a plurality of supply members adapted to supply developer to the image forming units from a plurality of the cartridges; a drive unit adapted to drive a plurality of the supply members; and a control unit adapted to supply developer from a plurality of the cartridges by selectively operating a plurality of the supply members based on the amount of developer accommodated in the cartridges.

Abstract: In a disclosed developing device, a developing part includes a developer carrier for circulating a developer inside the developing part and for supplying the developer to an image carrier, a developer supply member for supplying the developer to the developer carrier, and a developer collection member for collecting the developer which is not used. A developer stirring part is arranged at a different position from a position of the developing part. A developer conveyance part carries the developer by an air conveyance in a developer conveyance path from the developer stirring part to the developing part. A developer detection part includes an opening which communicates between the developer supply member and the developer collection member, is arranged at a downstream side in a flow direction of the developer below and near the developer supply member, and detects whether the developer exists in a vicinity of the developer supply member.

Abstract: A control unit decreases the potential difference according to an increase in the drive amounts of the image bearing member and the developer bearing member, based on a first information about a drive amount of the image bearing member and second information about a drive amount of the developer bearing member, in a case that an integrated value of the first information and the second information from initial installation or replacement of the developing device is greater than a predetermined value.

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

Abstract: Printers are provided for printing using large particle toner. One printer has a printer controller causing a first imaging module to form first toner image using a first toner particle having a first charge-to-mass ratio and a median volume weighted diameter between 3 um and 9 um and having a first charge-to-mass ratio and, a second imaging module to form a second toner image using second toner particles having a median volume weighted diameter that is greater than 20 um and a charge-to-mass ratio that is between ? to ½ of the first charge to mass ratio of the first toner times the ratio of the median volume weighted diameter of the first toner to the median volume weighted diameter of the second toner. The first toner image is transferred to a receiver using a first electrostatic field and the second toner image is transferred using a second electrostatic field.

Abstract: An image forming apparatus including a latent image bearing member a surface of which is rotated, a charging device, an irradiating device, a developing device, a transfer device, and a control unit. The control unit controls the image forming apparatus to perform subsequent image formation in accordance with a subsequent image forming request when determining that the subsequent image forming request is present at a predetermined determination time after completion of previous image formation, and controls the image forming apparatus to shut down certain predetermined operations including at least rotation of the surface of the latent image bearing member and application of a charging bias from the charging device and a developing bias from the developing device in accordance with a predetermined shutdown sequence when determining that the subsequent image forming request is not present at the predetermined determination time.

Abstract: An image forming apparatus includes: a development member carrying developer for forming a toner image on an image carrier; a cleaning member in contact with the development member for removing the developer left on the development member; a carrying member provided in contact with the development member, for carrying the supplied developer to the development member; a driving part driving at least one of the carrying member and the development member; and a regulating mechanism for separating the cleaning member and the development member from each other. The driving part causes preliminary rotation of the development member and the carrying member with the cleaning member separated from the development member, before starting main rotation for image formation.

Abstract: An apparatus and method for calculating toner amount including receiving print setting information, performing image processing on print data based on the print setting information received by the reception unit to form an image, calculating a print data feature quantity of the print data based on the formed image, and calculating a toner amount in a case where the print setting information is changed based on difference information between the print setting information before it is changed and after it is changed, and the calculated print data feature quantity based on the image formed by the image formation unit using the print setting information before it is changed.

Abstract: An image forming apparatus includes an image bearing member for carrying a developed image; a developer carrying member for carrying a developer to be supplied to the image bearing member; a cleaning blade for removing the developer from the image bearing member; a control device for executing, at predetermined timing during a non-image-formation period, sequence controls for moving a developer from the sleeve to the drum and removing a developer moved to the drum by the cleaning blade; and a removing device capable of removing the developer in a position before developer moved to the image bearing member by the cleaning blade, wherein the sequence controls includes a first sequence control and a second sequence control, and wherein an amount of the developer removed by the cleaning blade is controlled such that the amount is smaller in the first sequence control than in the second sequence control.

Abstract: An image forming apparatus includes an image bearing member; a plurality of developing devices, contactable to the image bearing member, for developing a latent image on the image bearing member with toner; a rotatable member for rotatably supporting the plurality of developing devices; a detecting device for detecting a position of the image bearing member, wherein on the basis of an output of the detecting device, the rotatable member is rotated; and a control device for changeably controlling a period from timing of detection by the detecting device to timing of contact of one of the plurality of developing device, rotated by the rotatable member, to the image bearing member.

Abstract: In a rotary-type image forming apparatus, rotation of a rotary is temporarily stopped at a position where a coupling member and a drive transmission member are engageable with each other, and a developing roller is set in a rotating state. Subsequently, the rotary is rotated so as to bring the developing roller into contact with a surface of a photosensitive drum.

Abstract: According to one embodiment, an image forming apparatus includes an image forming part to form an image with one of a color unerasable developer and a color erasable developer, and a control part to automatically select the color erasable developer when test printing is selected.

Abstract: An image forming apparatus is provided that reduces the occurrence of downtime in the case in which the interval between sheets needs to be expanded, and also suppresses the degradation of a photosensitive drum and a developing roller, when continuously forming images. The image forming apparatus of the present invention predicts the start timing of image formation onto the next printing material, and performs control of the positional relationship between the photosensitive drum and the developing roller without decreasing productivity, based on a result of the prediction. Further, the image forming apparatus performs control of the rotating operation of the photosensitive drum, based on the above prediction result.

Abstract: An image forming system includes an image forming station for forming a transparent image on a recording material with transparent toner; a selecting portion for selecting one of image forming modes including a first image forming mode for forming a transparent image having a high glossiness and a second image forming mode for forming a transparent image having a glossiness lower than that in the first image forming mode; and a setting portion for setting a toner amount, per unit area, of the transparent image in accordance with the image forming mode selected by the selecting portion.

Abstract: An image forming apparatus includes an image bearing member for bearing a image; a developing container for accommodating a developer comprising toner and carrier; a rotatable developer carrying member, provided in an opening of the developing container, for developing an electrostatic latent image formed on the image bearing member; a feeding device for feeding the developer in the developing container toward the developer carrying member; detecting device for detecting information relating to a consumption amount of the developer; and a controller for executing, when a image formation is continuously effected for a plurality of recording materials, a operation in a mode in which on the basis of a result of detection of the detecting device, the image forming operation is interrupted, and a operating condition of at least one of the feeding device and the developer carrying member is changed.

Abstract: A developing apparatus including a developing container for containing developer, the developing container having an opening portion, a developer carrying member for carrying the developer at the opening portion, a detecting member for detecting a developer amount, the detecting member detecting a capacitance between the developer carrying member and the detecting member, and a force receiving portion for receiving a force and moving the developing container between a first position in which a developing operation is performed by the developer carrying member and a second position in which the developing operation is not performed, wherein the capacitance can be detected in the second position, and the detecting member is a rotatable developer supplying member for supplying the developer to the developer carrying member, the developer supplying member including a foam layer in which the developer can enter.

Abstract: In an image forming apparatus, when backside contamination of a recording material occurs, a control portion carries out control so that a plurality of restoring toner bands having a length L1 longer than a circumference L3 of a secondary transfer roller is formed at an interval L2 at positions in which the restoring toner bands can overlap with control images with respect to a longitudinal direction of the secondary transfer roller and then is transferred onto the secondary transfer roller through an intermediary transfer belt. The restoring toner bands transferred onto the secondary transfer roller stagnate on a fur brush rubbing against the secondary transfer roller to remove an electric discharge product deposited on the secondary transfer roller. The toner stagnating on the fur brush is inverted in charge polarity and then is re-transferred onto the intermediary transfer belt through the secondary transfer roller.

Abstract: A development device includes a development portion, to develop a latent image formed on a latent image carrier with developer, disposed close to the latent image carrier; a developer agitation container to agitate the developer, provided separately from the development portion; a transport system connecting the development portion and the developer agitation container, through which the developer is transported from the developer agitation container to the development portion by air; and a developer retainer to temporarily retain the developer, disposed downstream from the transport system, to which the developer remaining in the transport system escapes.