Abstract: An image forming apparatus includes: a housing; a drum cartridge as a first cartridge including a photosensitive drum; a second cartridge accommodating toner; and a drawer movable between an inside position where the drawer in its entirety is positioned inside the housing and an outside position where at least a part of the drawer is positioned outside the housing. The drum cartridge is attachable to and detachable from the drawer. The drawer includes: a side plate configured to receive the photosensitive drum; and a locking member supported by the side plate. The locking member is movable relative to the side plate between a locking position where the locking member locks the photosensitive drum to the side plate and an unlocking position where the locking member unlocks the photosensitive drum from the side plate in an attached state of the drum cartridge to the drawer.

Abstract: An image forming apparatus employs a constitution in which, in a case that a relative position between an inner roller and an outer member with respect to a circumferential direction of the inner roller is changed in a period after a preceding recording material passes through a transfer portion and until a recording material subsequent to the preceding recording material reaches the transfer portion during execution of a job for forming and outputting images on a plurality of recording materials, a controller controls a position changing mechanism and a contact and separation mechanism so that a separating operation for separating the outer roller from a belt is performed and then the above-described relative position is changed.

Abstract: In an image forming apparatus, in a case that a relative position between an inner roller and an outer member with respect to a circumferential direction of the inner roller is changed in a period from a state in which the outer member separated from a belt until first transfer in a job for forming and outputting an image on a recording material is started when the job is executed, a controller controls a position changing mechanism and a contact and separation mechanism so that a contact operation for bringing the outer member into contact with the belt is performed after changing the relative position.

Abstract: A belt conveyance apparatus includes an endless belt, bearings, first and second adjustment members, and a stretching member. The first and second adjustment members are each rotatably supported by an outer circumferential surface of the bearings, face an end portion of the endless belt, and include a sliding surface. The stretching member includes a rotation unit. On a first end side or a second end side opposite to the first end side in a belt width direction, a distance from a first end portion which is an end portion of the rotation unit at a position closest to the sliding surface to the sliding surface is shorter than a distance from a second end portion at a position farthest from the sliding surface of the first adjustment member or the second adjustment member to the sliding surface.

Abstract: A belt rotating device includes a belt wound around plural rollers to circulate and move, the plural rollers including a roller to be cleaned; and a first cleaning unit disposed inside the belt, the first cleaning unit being in contact with at least the roller to be cleaned to scrape off foreign matter on the roller to be cleaned, the first cleaning unit being configured to change a contact state with respect to the roller to be cleaned.

Abstract: An image forming apparatus includes a first image forming unit that forms a first toner layer on a medium on which an image is to be formed, a first fixing unit that fixes the first toner layer onto the medium, a second image forming unit that forms a second toner layer on the first toner layer on the medium by using a toner having a melting point lower than a melting point of a toner that is included in the first toner layer, and a second fixing unit that performs, in a state in which a foil layer is superposed on the second toner layer, a fixing operation at a temperature lower than a temperature at which the first fixing unit performs a fixing operation.

Abstract: An intermediate transfer belt includes at least two layers which are a base layer and an inner surface layer having electric resistance lower than electric resistance of the base layer, and an end portion of the inner surface layer is positioned on an outside of an end portion of a development opening portion in a width direction as a direction orthogonal to a circumferential direction of the intermediate transfer belt.

Abstract: An image forming apparatus includes an image holding body, a transfer member, and a controller. The image holding body holds an unfixed image. The transfer member presses a continuous medium against the image holding body and causes the image to be transferred to the medium. The controller allows a cleaning operation in which undesired adhering matter adhering to the transfer member is transferred to the image holding body to be performed when the medium does not exist between the image holding body and the transfer member.

Abstract: An image forming apparatus includes image forming units forming images, a movable body moving along a path extending in a direction in which the image forming units are arranged while the images are sequentially formed on the movable body or on a recording material transported by the movable body so as to be superposed with one another, a contact and separation unit moving to a contact position at which the contact and separation unit is in contact with the movable body and to a separation position at which the contact and separation unit is separated from the movable body and changing a load applied to the moving movable body as a position of the contact and separation unit is changed, and a change unit changing the load in a manner opposite to a change in the load upon a change in the position of the contact and separation unit.

Abstract: Described are techniques for performing migration from a source node to a target node. Application data used by an application is migrated from the source node to the target node. I/O operations from the application directed to the application data are sent to the target node. While migrating the application data, first processing is performed on the target node in connection with I/O operations directed to the application data. The first processing includes monitoring read operations directed to the application data. Migrating the application data includes copying a data portion of the application data from the source node to the target node. The data portion has a logical location in the application data determined in accordance with the read operations. The data portion is prefetched by the migrating and copied to the target node prior to the target node receiving a read requesting data of the data portion.

Abstract: An image forming apparatus includes a latent image bearer to bear a plurality of halftone images having a same image density and a high-density image located one cycle downstream of the latent image bearer from at least one of the plurality of halftone images, a transferor to apply a predetermined transfer voltage to transfer the plurality of halftone images and the high-density image, a transfer electric field forming target to bear the plurality of halftone images and the high-density image transferred from the latent image bearer, a detector to detect image densities of the plurality of halftone images on the transfer electric field forming target, and a controller to determine a primary transfer voltage applied at a time of image formation, based on image density variations of the plurality of halftone images detected by the detector.

Abstract: A transfer assist member comprising a plurality of layers, one of the layers being a check film layer comprising a mixture of a polymer and a conductive component in contact with a layer of a polyalkylene furandicarboxylate.

Abstract: An exposing unit forms a latent-image electric potential on each photosensitive drum. A detecting toner image of each color is transferred to an intermediate transfer belt using a first potential difference between a latent-image electric potential and the potential of an intermediate transfer belt at each primary transfer portion. When the polarity of voltage to be applied from a transfer power source to a secondary transfer roller is to be switched to an opposite polarity while the detecting toner image of each color is passing through each primary transfer portion, the absolute value of a second potential difference between the potential of the intermediate transfer belt and the background electrical potential of each photosensitive drum is made equal to or greater than the absolute value of the first potential difference by a control unit.

Abstract: An image forming apparatus that transfers an image from an image carrier onto a sheet passing between the image carrier rotating and a transfer member includes a fixing unit configured to thermally fix the image on the sheet while nipping and conveying the sheet with a pair of fixing members after the transfer, at least one of the fixing members rotating; a measuring unit configured to measure surface movement speed of the sheet in a non-contact manner while the sheet is being conveyed by the fixing members; and a control unit configured to control rotation speed of the fixing members in accordance with a result of the measurement, to adjust speed of conveyance of the sheet to a target speed determined beforehand for peripheral speed of the image carrier, the control being performed while the sheet being conveyed is in contact with the transfer member and the fixing members.

Abstract: A brilliant toner includes toner particles that contain a binder resin and a brilliant pigment which has a flake shape, wherein an average thickness of the brilliant pigment is greater than 0.5 ?m to 1.5 ?m.

Abstract: The image forming apparatus includes a control unit configured to selectively execute an operation for applying a voltage with a polarity opposite to an original charging polarity of a toner to a first charging member and a second charging member and an operation for applying a voltage with the polarity opposite to the original charging polarity of the toner to one of the first charging member and the second charging member and a voltage with the same polarity as the original charging polarity of the toner to another of the first charging member and the second charging member as a cleaning operation for charging a secondary transfer residual toner to the polarity opposite to the original charging polarity of the toner by using the first charging member and the second charging member to transfer the secondary transfer residual toner onto an image bearing member.

Abstract: Provided is an electrophotographic photoreceptor containing a conductive support having thereon a photosensitive layer and a surface layer laminated in that order, wherein the surface layer contains a conductive filler having a number average primary particle size of 10 to 500 nm in a resin; and the conductive filler is treated with a surface treatment agent containing a fluoroalkyl (meth)acrylate/(meth)acrylic acid copolymer.

Abstract: An image forming apparatus includes an image forming portion for forming a toner image; an intermediary transfer belt for receiving the toner image; a blade for cleaning the belt by removing residual toner therefrom; an ambient condition sensor for detecting an ambient condition; a memory for storing information relating to a use amount of the belt; and a controller for executing an operation in a mode in which a toner is deposited on the belt in an area corresponding to between a preceding sheet and a succeeding sheet during execution of a continuous image forming job for continuously forming the images on the sheets to supply the toner to the blade. The controller controls a frequency of the operations in the mode, on the basis of an output of the sensor during an image formation job and the information stored in the memory.

Abstract: An image forming apparatus includes a transfer unit that transfers a toner image on an image bearer onto a transfer medium. The image forming apparatus includes a control unit that controls a transfer voltage to be output to the transfer unit in accordance with a certain condition. The control unit applies currents having at least two different values while paper is not being fed. The two current values are lower than a current value during paper feeding. The control unit estimates an output voltage on a basis of a voltage detected through the application of the currents. When the estimated output voltage falls below a certain limiter voltage, the control unit controls to bring the output voltage to a value calculated through the certain condition. When the estimated output voltage exceeds the certain limiter voltage, the control unit controls to bring the output voltage to the limiter voltage.

Abstract: An image forming apparatus includes a potential detection portion that determines a surface potential of an image bearing member on the basis of an applied voltage value of a detection voltage applied to a voltage application member by a voltage application portion and a detected current value detected by a current detection portion in response to the applied voltage, and a control unit that sets an image formation condition for performing image formation in order to form a toner image on the image bearing member on the basis of the surface potential determined by the potential detection portion. When the surface potential is determined by the potential detection portion, the voltage application portion applies the detection voltage after applying, to the voltage application member, a voltage having an opposite polarity to an image formation voltage that is applied to the voltage application member during image formation.

Abstract: A TCAM database is partitioned into a plurality of sections. A set of rules to be stored in the TCAM database is analyzed to identify respective subsets of rules that match respective possible bit value combinations corresponding to a subset of bits in the rules, and to identify, in the subsets of rules, two or more subsets that share one or more rules. Then, it is determined whether two or more subsets that include shared rules can be written to a same section in the TCAM database, without exceeding a maximum number of rules that can be written to the same section, when one or more duplicates of one the the shared rules is omitted from the TCAM database. When it is determined that two or more subsets can be written to the same section, the two or more subsets are written to the same section in the TCAM database.

Abstract: An image forming apparatus includes an image bearing member; an electrostatic image forming unit; a developing device; an intermediary transfer member; a rotatable transfer member; a constant-voltage element; a power source; a cleaning device; an executing portion capable of executing a toner image collecting mode after jam clearance; and a controller for controlling the power source in an operation in a collecting mode so that a voltage of an identical polarity to a charge polarity of the toner is applied to the rotatable transfer member to transfer, onto the intermediary transfer member, the toner in an upstream-side end region of the toner image carried on the image bearing member with respect to the rotational direction of the image bearing member, and then a voltage of an opposite polarity to the charge polarity of the toner is applied to the rotatable transfer member.

Abstract: A cleaning blade includes an image region and a non-image region in which Young's moduli at positions separated by a distance of L ?m from an edge portion in contact with an photosensitive drum are respectively defined as YL and Y?L, Y0 and Y?0 are 10 mgf/?m2 or more and 400 mgf/?m2 or less, Y50/Y0 is 0.5 or less, [{(Y0?Y20)/Y0}/(20?0)] is equal to or more than [{(Y20?Y50)/Y0}/(50?20)] and, the Young's modulus Y50 ?the Young's modulus Y?L where L satisfies 0?L ?100 ?m.

Abstract: There is provided a carrier including magnetic core particles; and a coating layer on a surface of each of the magnetic core particles, wherein the coating layer contains electroconductive particles; wherein the electroconductive particles are electroconductive particles in which white inorganic pigments are coated with phosphorus-doped tin or tungsten-doped tin; and wherein a dope ratio of phosphorus or tungsten to tin in the phosphorus-doped tin or tungsten-doped tin is 0.010 to 0.100.

Abstract: An intermediate transfer member that contains a mixture of a polyimide, an optional conductive component, and a fluoroaliphatic phosphate.

Abstract: A drive transmission device includes: a gear, provided with a shaft hole, for transmitting a driving force; a frame to which a fixing shaft for rotatably supporting the gear by engaging with the shaft hole is fixed, wherein during transmission of the driving force, the gear is urged in a radial direction of the shaft hole, and a predetermined region of an outer peripheral surface of the fixing shaft slides on an inner peripheral surface of the shaft hole; and a holding portion, provided in a position closer to a center of the fixing shaft than the predetermined region with respect to a radial direction of the fixing shaft, for holding a lubricant between itself and the shaft hole. The holding portion is disposed only in a position opposite the predetermined region with respect to the center of the fixing shaft.

Abstract: An ink jet printer includes a cleaning blade that cleans the surface of a transport belt that attracts a sheet of recording paper by electrostatic adsorption and transports the attracted recording paper, and a pressing roller. The width of the cleaning blade is smaller than the width of the pressing roller that is located downstream of the cleaning blade, and thus, ink, paper dust, and the like that have escapes from both ends of the cleaning blade to the outside and have not been wiped off are caught by the pressing roller.

Abstract: An image forming apparatus includes an image bearing member; an intermediary transfer member; a controller; and a cleaning unit. The cleaning unit includes a cleaning member for collecting a residual toner in contact with the intermediary transfer member, a charging member, which is provided downstream of the cleaning member with respect to a movement direction of the intermediary transfer member, for electrically charging the residual toner, and an accommodating member for accommodating the residual toner. The controller is capable of executing an operation in a discharging mode in which the toner is discharged from the charging member onto the intermediary transfer member. When the operation in the discharging mode is executed, the cleaning unit collects the toner, discharged from the charging member on the intermediary transfer member, by the cleaning member and then accommodates the collected toner in the accommodating member.

Abstract: The organic photoreceptor includes a conductive support, an organic photosensitive layer, and a surface layer made of a cured resin, which are stacked in this order. The surface layer is obtained by curing a composition containing a radical polymerizable compound for forming the cured resin, metal oxide fine particles having a surface treated with a silane coupling agent, and a silane compound represented by the following general formula (1), wherein R1 to R3 each independently represent a hydrogen atom, an alkyl group having 1 to 10 carbon atoms or an aryl group having 6 to 20 carbon atoms, and at least one of R1 to R3 represents an alkyl group having 1 to 10 carbon atoms or an aryl group having 6 to 20 carbon atoms.

Abstract: An image forming apparatus includes an image bearing member, a transfer member disposed facing the image bearing member to form a transfer region therebetween, a transfer bias application device to apply to the transfer region a transfer bias including a direct current (DC) component and an alternating current (AC) component to transfer the toner image onto the recording medium as the recording medium passes through the transfer region, and a controller operatively connected to the transfer bias application device to allow, during a bias change period in a sheet absent period in which the image bearing member rotates and no recording medium passes through the transfer region, the transfer bias application device to selectively apply to the transfer region one of the transfer bias without the AC component and the transfer bias with a peak-to-peak voltage of the AC component less than that applied in image formation.

Abstract: A transfer member includes a shaft and a body. When a measurement member is brought into contact with an outer surface of the body and voltage applied to the measurement member is changed by electrically connecting the shaft to ground, a time constant ?v is measured based on a change in electric potential occurring on a surface of the measurement member. When a first measurement member is brought into contact with the outer surface, a second measurement member is brought into contact with the outer surface while being spaced apart from the first member by a predetermined distance in a circumferential direction of the outer surface, and voltage applied to the first member is changed by electrically connecting the shaft to ground, a time constant ?s is measured based on a change in electric potential occurring on a surface of the second member. ?v is larger than ?s.

Abstract: An image transfer system includes an endless image bearing belt for carrying an image to be transferred to a web material; a first roll around which the image bearing belt travels; a second roll around which the image bearing belt travels; a biased transfer roll for supporting the web material such that the web material contacts the image bearing belt at a nip located at a nip location between the biased transfer roll and the first roll, and such that the image is transferred from the image bearing belt to the web material; and a pre nip roll for supporting the web material upstream of the nip. The image bearing belt wraps concavely around the first roll, and the first roll and the biased transfer roll are positioned relative to each other such that the web material wraps around a portion of the image bearing belt and the first roll prior to the web material entering the nip and prior to the image being subjected to an electric field.

Abstract: A penetrating hole is positioned facing a concave area between a separation guide and a separation guide of a sheet supporting the separation guides. When the front edge of a printing medium has passed through and emerged from a fixing clasp, water vapor generated from the printing medium by heating from a heating belt catches airflow flowing along a circulation movement surface of the heating belt and is sucked into a spatial region where a frame of the fixing device body is positioned from the penetrating hole.

Abstract: An image forming apparatus includes an image bearing member that bears a toner image; a transfer member that faces the image bearing member, nips a recording medium together with the image bearing member, and allows the recording medium to pass therebetween; a transfer-bias applying unit that applies transfer bias voltage to generate an electric field between the transfer member and the image bearing member; a cleaning member that is disposed in contact with the transfer member and removes toner from the transfer member; a cleaning-bias applying unit that applies cleaning bias voltage between the cleaning member and the transfer member; a transfer-toner-amount estimating unit that estimates an amount of toner to be transferred from the image bearing member to the transfer member when the recording medium does not pass therebetween; and a cleaning-bias controller that controls the cleaning bias voltage in correspondence with the estimated amount of toner.

Abstract: An image forming apparatus includes a toner carrying member for carrying a toner; an image carrying member on which a toner image is formed with the toner; and a plurality of divided electrode portions provided at a position in which the electrode portions oppose the toner carrying member via the image carrying member interposed therebetween. The electrode portions are supplied with a voltage on the basis of image information to move the toner between the toner carrying member and the image carrying member thereby to form the toner image. The electrode portions includes a first electrode portion for forming an image portion and a second electrode portion, adjacent to the first electrode portion, for forming a non-image portion.

Abstract: In a first thermal transfer portion of upstream side, a negative toner image forming portion forms on a photosensitive drum a desired negative toner image which reverses a desired positive toner image selected from all the toner images. The negative toner image forming portion then forms the desired negative toner image on a belt member. The first thermal transfer portion transfers a desired negative foil image from a foil sheet to the belt member so that a desired positive foil image remains on the foil sheet. A second transfer portion transfers the desired positive foil image thus remained on the desired positive toner image formed on the sheet of paper. A cleaning portion removes the desired negative toner image and the desired negative foil image from the belt member.

Abstract: An image forming apparatus includes: a first image forming unit including a first transfer unit forming a first nip with a first photosensitive drum for black; a second image forming unit including a second transfer unit forming a second nip with a second photosensitive drum for a color; and a control device which, when a first sheet and a second sheet are continuously conveyed in corresponding order by the conveyance belt at the monochrome mode, is configured to supply a first transfer current for a first time period during which the first sheet or the second sheet pass through the second nip and supply a second transfer current, which is smaller than the first transfer current, for a second time period that is a sheet interval between the first sheet and the second sheet.

Abstract: An image forming apparatus includes a photosensitive drum for bearing a toner image, a rotatable endless belt provided so that its outer surface opposes the drum, and a rigid transfer roller, provided so as to contact an inner surface of the belt, for transferring the toner image from the drum onto the belt or a recording material conveyed by the belt. A coefficient of static friction of a surface of the transfer roller is smaller than that of the inner surface of the belt. In addition, a stretching roller is provided so as to contact the inner peripheral surface of the belt for stretching the belt, with a coefficient of static friction of a surface of the stretching roller being larger than that of the inner peripheral surface of the belt. A cleaning member cleans the surface of the stretching roller.

Abstract: An image formation method includes: transferring a first developer image for an image formed based on image data and a second developer image for adhesion onto a print medium; folding the print medium with the first and second developer images transferred thereto; and fixing the first and second developer images to the folded print medium.

Abstract: In an image forming apparatus, a voltage applied to a pre-transfer charger is set to the highest voltage, and is then reduced at a position corresponding to a predetermined range from a leading edge of a recording material, to suppress a phenomenon of backward scattering of toner formed just before entering a transfer nip, when a burr formed on the leading edge of the recording material exits the transfer nip.

Abstract: An image forming apparatus including an image forming device, a transfer device, a fixing device, an inverting device, and a processor. The transfer device includes an intermediate transfer member, a nip forming member, and an electric potential difference generator to generate an electric potential difference between the intermediate transfer member and the nip forming member. The processor causes the electric potential difference generator to generate a first electric potential difference containing only a DC component when a toner image is transferred onto a first side of a recording sheet, and to generate a second electric potential difference containing a DC component and a superimposed AC component when the toner image is transferred onto a second side of the recording sheet. The second electric potential difference has an averaged absolute value per unit of time smaller than an absolute value of the first electric potential difference.

Abstract: An image forming apparatus includes an inclining device for inclining the endless belt so as to keep the an endless belt in a normal range in a widthwise direction of the belt; a blade member for pressing against the belt at a pressing portion to clean it; a detecting portion for detecting deviation of the belt from a normal range in a widthwise direction thereof; and an executing portion for executing an operation in a mode in which a lubricant is supplied to the pressing portion, when the detecting portion detects that the belt is deviated from the normal range.

Abstract: An image forming apparatus includes an image bearing member for bearing a toner image, a rotatable endless belt, a first driving member for rotationally driving the endless belt and in contact with an inner peripheral surface of the endless belt, and a second driving member for rotationally driving the endless belt and in contact with an outer peripheral surface of the endless belt. In addition, a tension detecting unit detects a state of tension of the endless belt and a controller controls a rotational speed of the second driving member. A driving force applied from the second driving member to the endless belt is smaller than a driving force applied from the first driving member to the endless belt, and the tension detecting unit includes a metal roller contacting the inner peripheral surface of the endless belt and detects the tension by movement of the metal roller which follows the endless belt.

Abstract: An image forming apparatus having: a toner image carrier; a transfer member; a transfer voltage applying device which applies a bias voltage to the transfer member; a voltage controller which performs constant voltage control on the transfer voltage applying device; a transfer contribution current detecting device; an antistatic member for removing static electricity from the record medium after transfer of a toner image; and an antistatic voltage applying device which applies an AC voltage to the antistatic member. The transfer contribution current detecting device measures current values during a current detection time, which corresponds to an integral multiple of a period of the AC voltage applied to the antistatic member, and detects a transfer contribution current value from the measured values, and the voltage controller controls the bias voltage applied to the transfer member based on the transfer contribution current value.

Abstract: A second thermal transfer portion of upstream side transfers a foil image, to be not printed, from the foil sheet on a waste sheet, conveyed from an image forming apparatus, on which a desired negative toner image is transferred. The foil image, to be printed, remains on the transferred foil sheet. The waste sheet is ejected out of a foil transferring apparatus. A printing sheet of paper on which the desired positive toner image is transferred is conveyed from the image forming apparatus to a first thermal transfer portion of downstream side to meet time when the foil sheet on which the foil image, to be printed, remains reaches the first thermal transfer portion. The first thermal transfer portion transfers the foil image, to be printed, from the foil sheet on the conveyed printing sheet of paper on which the desired positive toner image is transferred.

Abstract: An image forming apparatus includes a control unit configured to form electrostatic latent images for correction on a photosensitive member; a voltage application unit configured to apply a voltage to a process unit; a current detection unit configured to detect a current to the voltage application unit via the process unit when the voltage is applied to the process unit; and a conversion unit configured to convert an output value detected by the current detection unit such that a variation range of the output value detected by the current detection unit at a formation period of the electrostatic latent image for correction becomes larger than a variation range of the output value detected by the current detection unit at a one-rotation period of the photosensitive member on which the electrostatic latent image is not formed.

Abstract: An electrostatic charge image developing toner includes toner particles containing a colorant, a binder resin, and a release agent, and an external additive, wherein the external additive includes particles having oil-treated surfaces and composite particles containing silica and titania, and the toner has a content ratio of titania with respect to silica on the surface of the toner, as measured by X-ray photoelectron spectroscopy, of equal to or less than 5 atomic %.

Abstract: A paper stripping member is removably supported by a supporting member disposed facing a circumferential surface of a photoreceptor drum, and strips a paper sheet off the circumferential surface. The paper stripping member includes an acute-shaped stripping nail, a holding member and a cover member. The holding member is configured removably from the supporting member, and holds the stripping nail in such a manner that the stripping nail extends toward the circumferential surface. The cover member is configured removably from the holding member, and covers at least part of the stripping nail in the extending direction of the stripping nail in a state where the cover member is attached to the holding member.

Abstract: An image forming apparatus having below arrangements. A plurality of image forming units form a plurality of images which are transferred onto a transfer belt. A detection unit detects a position of the transfer belt in a belt width direction. A position adjusting unit adjusts the position of the transfer belt in the belt width direction according to a detected position. A calibration unit calibrates an adjustment amount for adjusting color registration based on a detected position of patterns formed onto the transfer belt. A registration adjusting unit adjusts image forming positions of the plurality of image forming units based on the set adjustment amount. During formation of the patterns and during detection of the formed patterns a control unit controls not to adjust the position of the transfer belt in the belt width direction according to the detected position of the transfer belt.

Abstract: Described herein is a transfer device that transfers a visualized image formed on an image carrier onto a recording medium. The transfer device includes an image carrier that carries a toner image, a contacting member that contacts the image carrier via a recording medium and a power source that outputs a transfer bias to transfer the toner image from the image carrier onto the recording medium at a transfer nip formed between the image carrier and the contacting member. The transfer bias has a direct current component and an alternating current (AC) component superimposed on the direct current component. The transfer device also includes a controller that controls the power source such that the controller controls a level of the direct current component output from the power source by a constant current control.