Abstract: Provided is an electrophotographic belt having a cylindrical film as a base layer. The cylindrical film contains crystalline polyester and carbon black, and a content of the carbon black in the cylindrical film is 2.0% by mass or more. Fc1 is 0.30 or more, and ?c1 being ?10° to +10°, where Fc1 denotes an average degree of arrangement of the carbon black in the circumferential direction observed in a cross section in a direction along a circumferential direction of the cylindrical film, and ?c1 denotes an average arrangement angle of the carbon black in the circumferential direction observed in a cross section in a direction along a circumferential direction of the cylindrical film.

Abstract: An intermediate transfer belt includes a single-layer body including a resin layer or a multilayer body including the resin layer serving as a top surface layer. The surface of the resin layer has an arithmetic average surface height Sa of 0.005 ?m or more and 0.020 ?m or less. The surface of the resin layer has a maximum height Sz of 0.050 ?m or more and 0.200 ?m or less. The surface of the resin layer has recesses having a depth of 0.050 ?m or more, the recesses being arranged at a regular interval, and the interval of the recesses is 0.20 ?m or more and 0.80 ?m or less.

Abstract: The crystallinity of a thermoplastic resin is 8% or more and 25% or less, the average primary particle size of carbon black is 10 nm or more and 30 nm or less, the content of the carbon black is 15.0 parts by mass or more and 30.0 parts by mass or less with respect to 100 parts by mass of an intermediate transfer belt, and (Li+Lo+Lc)/3?100 nm, where Li, Lo, and Lc are values of an L-function indicating a dispersibility of the carbon black with respect to the thermoplastic resin in an inner peripheral surface region of the intermediate transfer belt, in an outer peripheral surface region, and in a central region that is a central portion of the intermediate transfer belt in a thickness direction of the intermediate transfer belt, respectively.

Abstract: An image forming apparatus includes: a rotating body; a sprocket provided coaxially with the rotating body, the sprocket being configured to rotate integrally with the rotating body; a chain including a holder configured to hold a leading end portion of a recording medium, the chain being wound on the sprocket, the chain being configured to rotate so as to transport the recording medium; an annular shaped transfer belt supported by an opposing member opposing the rotating body at an opposing position, the transfer belt being configured to sandwich the recording medium transported by the chain between the transfer belt and the rotating body at the opposing position, in which an image on an outer peripheral surface of the transfer belt is transferred to the recording medium in response to a transfer bias being applied between the rotating body and the opposing member; and a forming member that supports the transfer belt on an upstream side of the opposing position in a transport direction, the forming member be

Abstract: In an image forming apparatus, in a case in which a second toner image to be transferred to a same recording material as a first toner image is to be transferred is formed on the photosensitive member after the first toner image is formed on the photosensitive member and the first toner image is formed on an area of the photosensitive member including at least a part of a position of the second toner image one cycle before with respect to a movement direction of the surface of the photosensitive member, a control unit changes a value of a transfer current at a time of transferring the first toner image to a transfer-receiving member between a first value and a second value of which an absolute value is greater than an absolute value of the first value, based on image information regarding the second toner image.

Abstract: Provided is an electrophotographic belt that can suppress the occurrence of a cleaning failure even when used for a long time period. The electrophotographic belt includes a surface layer containing a first acrylic resin, wherein resin particles are present on an outer surface thereof, wherein the resin particles each contain a second acrylic resin and a fluorine resin, and wherein the second acrylic resin and the fluorine resin are exposed to an outer surface of each of the resin particles.

Abstract: The present disclosure relates to a method of producing an intermediate transfer blanket. The method includes spray-coating a blanket body with a release layer composition including a curable polysiloxane polymer and solid particles of an electrically conductive material. The blanket body is subjected to motion during spray-coating, such that the release layer composition is subjected to shear forces as it deposits on the blanket body.

Abstract: An endless-shaped electrophotographic belt with a cleaning blade provides improvement in transfer remaining toner wiping properties. The electrophotographic belt has an endless shape including, on an outer circumferential surface thereof, grooves and lands. The grooves extend in a circumferential direction of the belt and the lands are positioned between the grooves. The belt further has on the outer circumferential surface, one or more convex portion(s) between at least one of the grooves and one of the lands adjacent to the one of the grooves, and in a cross section of the belt in a direction orthogonal to a direction of which the grooves extend, the convex portion(s) projects more than the lands.

Abstract: This substance adhesion simulation system includes an input unit for inputting a model of a device, and information of a presence state of a substance which may be able to adhere to the device, and a processing unit which estimates an adhesion state of the substance to the device by using the information, which is input to the input unit, and the substance is in a liquid state, a gas state, a mist state, a powder state, a dust state, or a state combining the liquid state and the mist state.

Abstract: An image forming apparatus includes a transferor, a first detector to detect an image formed on the transferor, a second detector to detect an image formed on a recording medium, and circuitry. The circuitry is configured to generate first gradation correction data based on a detection result obtained by the first detector, generate second gradation correction data based on a detection result obtained by the second detector, and control gradation correction for the image formed on the recording medium using the first and second gradation correction data. Further, the circuitry is configured to prioritize one of the first and second gradation correction data based on at least one of a characteristic of the recording medium and a characteristic of the image in the gradation correction during consecutive printing in which images are consecutively formed on recording media.

Abstract: A system printing comprises: a movable intermediate transfer member in the form of a flexible, substantially inextensible, belt guided to follow a closed path, an image forming station for forming an ink image, a drying station for drying the ink image to leave an ink residue film, first and second impression stations spaced from one another in the direction of movement of the belt, each impression station comprising an impression cylinder for supporting and transporting a substrate and a pressure cylinder for urging the belt against the substrate supported on the impression cylinder, and a transport system including a perfecting system for selectively inverting the substrate during transportation between the two impression stations; and a treatment station situated between the second impression station and the image forming station, the treatment station configured to apply a treatment agent comprising polyethylenimine (PEI) to pre-treat the belt.

Abstract: An intermediate transfer belt includes, on a surface in contact with a photosensitive drum and a cleaning blade, a plurality of grooves formed along a moving direction of the intermediate transfer belt in a width direction which intersects the moving direction of the intermediate transfer belt. Further, the intermediate transfer belt includes a plurality of first regions in which adjacent grooves in the width direction are arranged at a predetermined interval, and a second region which is positioned between the plurality of first regions and in which an interval between adjacent grooves in the width direction is different from the predetermined interval. The second region is arranged outside, in the width direction of the intermediate transfer belt, a range in which a patch toner is to be formed in concentration correction.

Abstract: An image forming apparatus includes an intermediary transfer member; a first image forming portion including a first developing device and a detecting portion; a second image forming portion including a second developing device; a contact-and-separation mechanism capable of setting a first state and a second state; and an executing portion capable of executing an operation in a first monochromatic mode in the first state and capable of executing an operation in a second monochromatic mode in the second state. When a toner amount in the first developing device is below a predetermined amount on the basis of the detecting portion during an image forming operation for continuously forming the black image in the operation in the first monochromatic mode, the executing portion continuously executes the image forming operation in the second state.

Abstract: A conveyor belt assembly may include a conveyor belt having an elastomeric layer, a chain adjacent a side edge of the conveyor belt and a flexible bridge extending between and connected to the chain and the conveyor belt along the side edge. The chain, bridge and conveyor belt may be driven to revolve by a sprocket engaging the chain.

Abstract: An image forming apparatus is operable in a first mode in which a control unit is in a rest state and a second mode in which electric power is supplied to the control unit. The image forming apparatus changes the mode of the operation to the second mode of an operation in response to change of detection of a detecting portion from presence of the sheet on a manual feeding tray to absence thereof during execution of the operation in the first mode with a pressing mechanism being in the second position, and then in response to receipt of input of a predetermined instruction about an image forming operation by a receiving portion in the second mode, the control unit controls the moving mechanism so that the pressing mechanism moves from the low pressure position to a nip-forming position.

Abstract: An image forming apparatus is operable in a first mode in which a control unit is in a rest state and a second mode in which electric power is supplied to the control unit. The image forming apparatus changes the mode of the operation to the second mode of the operation in response to detection of putting of the sheet on the manual feeding tray during execution of the operation in the first mode with the pressing mechanism being in the second position, and then in response to receipt of input of a predetermined instruction about an image forming operation by a receiving portion in the second mode, the control unit controls the moving mechanism so that the pressing mechanism moves from the low pressure position to a nip-forming position.

Abstract: The intermediate transferring belt is to be mounted in an electrophotographic image-forming apparatus. The intermediate transferring belt includes the following, in sequence, a substrate; an elastic layer; and a surface layer. The surface layer has an elongation of 5% or more and a stress of 5MPa or more at an elastic limit determined by a stress-strain curve obtained according to JIS K7161.

Abstract: Provided is an intermediate transfer member used in an electrophotographic image forming apparatus having a unit of primary-transferring a toner image carried on an electrostatic latent image carrier to an intermediate transfer member, and then secondary-transferring the primary-transferred toner image onto a transfer material from the intermediate transfer member, wherein a surface of the intermediate transfer member has a hardness in the range of 150 to 350 MPa, and an elastic modulus in the range of 200 to 600 MPa, which are measured by a nano indentation method, and also has a hardness of 0.5 to 2.0 MPa specified in terms of universal hardness.

Abstract: A control device includes an image-formation command section and a first reception section. The image-formation command section commands an image forming section to form multiple latent images based on one input image onto an image bearing member in accordance with different light emission patterns by using a light source including multiple light emitting members, develop the latent images, and output the multiple developed images to a medium. The first reception section receives a designation by a user with respect to one of the multiple light emission patterns after the multiple images are output. Each light emission pattern indicates which of the multiple light emitting members included in the light source is to emit light.

Abstract: The present invention relates to an electrophotographic intermediate transfer member that, even if an image is repeatedly and continuously transferred, can retain its transfer performance and can obtain an excellent image for a long time. The electrophotographic intermediate transfer member has a base layer and a surface layer, the surface layer has a matrix-domain structure in the cross section in the thickness direction, the matrix is formed of a binder resin, the domains contains a perfluoropolyether, and a microhardness of a surface of the electrophotographic intermediate transfer member measured by an ultramicro-hardness meter is 50 MPa or more.

Abstract: Provided is a transfer device including a primary transfer roller that selectively takes a contact position where an intermediate transfer belt is brought into contact with an image holding member, and a separation position where the intermediate transfer belt is separated from the image holding member, a tension applying roller on which the intermediate transfer belt is wound thereon together with a driving roller and which is urged in a direction receding from the driving roller, and a relaxing member that is attached to a shaft portion of the tension applying roller, is urged by an urging unit in a direction approaching the driving roller, and relaxes an urging force of the tension applying roller in a direction receding from the driving roller when the primary transfer roller is at the separation position.

Abstract: An image recording method includes recording an intermediate image by applying an ink to an intermediate transfer body, and transferring the intermediate image onto a recording medium while heating the intermediate image. The ink contains a coloring material and polymer fine particles each including a core constituted by a crystalline polymer and a shell constituted by an amorphous polymer. In transferring the intermediate image, the intermediate image is heated to a temperature equal to or higher than a melting point of the crystalline polymer constituting the core and equal to or higher than a glass transition point of the amorphous polymer constituting the shell.

Abstract: An intermediate transfer member for use in an image-recording method that includes applying a reaction liquid to an intermediate transfer member, forming an intermediate image by applying an ink to the intermediate transfer member to which the reaction liquid has been applied, and transferring the intermediate image to a recording medium. The intermediate transfer member has protruding structures having an average height of 3.0 ?m or less on a surface thereof. An average ratio R of surface areas of the intermediate transfer member to a unit area of a surface of the intermediate transfer member and an average ratio S of a total surface area of upper portions of the protruding structures to a unit area of the surface of the intermediate transfer member satisfy the following formula (1): S? 1/24·(10R?13)??(1) wherein R?1.3, and 0?S?1.

Abstract: A printing system is disclosed which comprises an image forming station 12 at which an ink that includes an organic polymeric resin and a coloring agent is applied to an outer surface of an intermediate transfer member 10 to form an ink image, a drying station 14 for drying the ink image to leave a residue film of resin and coloring agent; and an impression station 16 at which the residue film is transferred to a substrate. The intermediate transfer member 10 comprises a thin flexible substantially inextensible belt and the impression station 16 comprises an impression cylinder 20 and a pressure cylinder 18 having a compressible outer surface for urging the belt against the impression cylinder to cause the residue film resting on the outer surface of the belt 10 to be transferred onto a substrate passing between the belt 10 and the impression cylinder 20 during engagement with the pressure cylinder.

Abstract: In accordance with the invention, there are image forming apparatuses, fuser members, and methods of making fuser members. The fuser member can include a substrate and an electrospun layer disposed over the substrate, the electrospun layer including a structure selected from a group consisting of a fiber-on-fiber structure, a bead-on-fiber structure, and a pop-corn structure, wherein the fuser member includes a top surface that is both hydrophobic and oleophobic.

Abstract: An image forming apparatus includes an image carrier and a cleaning device. The image carrier is rotated to carry a toner image. The cleaning device includes a cleaning member and an auxiliary cleaning member. To the cleaning member, a bias of a reversed polarity to a polarity of a remained toner adhered on a surface of the image carrier is applied. The auxiliary cleaning member is located at an upstream side from the cleaning member in a rotating direction of the image carrier. According to advance of whitening of the surface of the image carrier, the auxiliary cleaning member is made to come into contact with the surface of the image carrier or contact pressure of the auxiliary cleaning member with the surface of the image carrier is increased.

Abstract: An endless belt for an image forming device includes a base member that is shaped in a loop and is to be rotated around a center of the loop, and a reinforcement tape that is attached to a side of the base member, has two ends that are overlapped with each other, and has a bonding portion between the two ends in the overlapped portion. The bonding portion has an outer portion, an inner portion and a center portion between the inner and outer portions. A length of the center portion in a rotating direction of the base member is greater than a length of the inner portion and a length of the outer portion.

Abstract: An image forming apparatus includes a toner receiving member, and a toner receiver driving section. The toner receiving member supplements toner of a correction patch that falls from and spatters from an intermediate transfer belt. A toner receiver driving section movably supports the toner receiving member. A control section inserts the toner receiving member between a sheet-side transfer roller and the intermediate transfer belt when the sheet-side transfer roller is spaced apart from the intermediate transfer belt.

Abstract: An image forming apparatus includes: an image bearing member for bearing a toner image; a movable intermediary transfer member onto which the toner image is to be transferred from the image bearing member; and a cleaning member, contacting a surface of the intermediary transfer member, for scraping off a toner from the surface of the intermediary transfer member which moves. At the surface of the intermediary transfer member, a plurality of grooves are formed along a surface movement direction of the intermediary transfer member. The surface of the intermediary transfer member has an average in-plane roughness of 10 nm or more and 30 nm or less in an area of a square of an average particle size of the toner.

Abstract: An image forming apparatus includes a housing and a transfer unit. The transfer unit detachably attachable relative to the housing includes a drive roller, a driven roller disposed opposite the drive roller, a belt formed into a loop and entrained around the drive roller and the driven roller, a frame to support the shaft of the drive roller, and a support member to movably support the shaft of the driven roller to be parallel to an axial direction of the drive roller and movable in a first direction different from the axial direction. A positioning member disposed in the housing holds the shaft of the drive roller parallel, and a restriction member restricts movement of the driven roller in the first direction to keep the shaft of the driven roller parallel to the shaft of the drive roller as the transfer unit is mounted in the image forming apparatus.

Abstract: Image forming apparatus includes: main body casing having first and second side walls opposite to each other, and upper portion having opening; top cover swingably supported on the upper portion of the main body casing at a position near the second side wall and configured to openably close the opening; endless belt disposed below the top cover and having first end portion closer to the first side wall and second end portion closer to the second side wall; photoconductor drum disposed under the endless belt; development unit disposed under the photoconductor drum and configured to supply developer to the photoconductor drum; and fixing device disposed above the second end portion of the endless belt. The endless belt is configured to be swingable about axis of rotation provided near the second side wall such that the first end portion of the endless belt is swingable in an upper-lower direction.

Abstract: An image forming apparatus includes: a transfer unit that is detachably attachable to a housing of the image forming apparatus and includes: a transfer member configured to contact the image carrier; a movable frame that supports the transfer member and configured to rotate around a fulcrum shaft; a driving input member coaxially arranged with the fulcrum shaft and configured to connect to a first driving transmitting member, and a second driving transmitting member supported by the movable frame and configured to transmit a driving force inputted by the driving input member to the transfer member. The image forming apparatus further includes a contact/separation unit configured to press the transfer member against the image carrier and to separate the transfer member from the image carrier by moving the movable frame around the fulcrum shaft while the transfer unit is attached to the image forming apparatus.

Abstract: Concerned with a cylindrical conductive belt for electrophotography which has made permanent curl less occur. The conductive belt has a continuous phase containing a thermoplastic polyester resin and discontinuous phases each containing any one or both selected from a polyether-ester amide and a polyether amide, and the discontinuous phases are present in such way as to extend in the peripheral direction of the belt; the belt having a crystallinity that is lower on the outer-peripheral surface side than on the inner-peripheral surface side.

Abstract: A belt assembly includes a belt, a plurality of support rollers, and a shaft-end retainer. The belt is formed into an endless loop, entrained about and stretched taut between the plurality of support rollers with a rotary shaft. The plurality of support rollers includes a first support roller and a second support roller. The shaft-end retainer including a first retainer and a second retainer is disposed at each end of the rotary shaft of the plurality of support rollers. The first retainer detachably holds an end of the rotary shaft of the first support roller. The second retainer detachably holds an end of the rotary shaft of the second support roller and includes a second-retainer opening from which the end of the rotary shaft of the second roller is detachable from and attachable to the second retainer in a direction perpendicular to the rotary shaft of the second support roller.

Abstract: An image forming apparatus includes an image bearing member which bears a toner image, an intermediate transfer member which bears the toner image transferred from the image bearing member, an endless recording material-conveying member which conveys a recording material, and a transfer portion which transfers the toner image to the recording material conveyed from the intermediate transfer member by the recording material-conveying member, wherein a perimeter of the intermediate transfer member is set to substantially an integral multiple of a perimeter of the recording material-conveying member.

Abstract: An image forming apparatus includes an image bearing member unit including a toner image carrying member, a transfer unit including a movable endless belt for transferring the toner image from the carrying member onto a transfer material, a plurality of stretching members for stretching the endless belt, and a supporting portion, provided at an end portion with respect to a widthwise direction, for supporting the stretching members. In addition, a main assembly frame is provided at a position opposing the supporting portion and includes a positioning portion for determining positions of the plurality of stretching members, wherein the supporting portion is movable relative to the main assembly frame.

Abstract: An object of the present invention is to provide: an electrophotographic member which enhances image quality, prevents the lowering of a grade of an image even when images have been repeatedly output, and can remarkably enhance the stability of the grade of the image; an intermediate transfer member; and an image forming apparatus. The electrophotographic member includes a base layer and a surface layer, wherein the surface layer has a binder resin, perfluoropolymer fine particles, a fluorocarbon resin dispersing agent and a particular fluorine compound, wherein the perfluoropolymer fine particle has a fluorine compound carried on its surface.

Abstract: A composition that includes a polyalkylene glycol silicone phosphate and carbon black, and where there is formed between the carbon black and the silicone phosphate an ionic attachment and processes thereof.

Abstract: It has been difficult to ensure satisfactory secondary transfer performance while ensuring satisfactory primary transfer performance by passing a current in the circumferential direction of an intermediate transfer belt from a current supply member. To satisfy a relationship of Rv>Rs, where Rv is resistance in the thickness direction of an intermediate transfer belt and Rs is resistance in the circumferential direction of the intermediate transfer belt over the distance between an image carrier located most upstream and an image carrier located most downstream in the movement direction of the intermediate transfer belt.

Abstract: A method of forming a silicone release layer on a substrate, for an intermediate transfer member of a digital offset printing system, the method including: a) providing a curable first primer on the substrate; b) providing a curable second primer on the substrate; c) providing a curable silicone release formulation on the curable first and second primers; and d) curing the first primer, the second primer and the release formulation.

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 including a conveyance unit to convey a transfer medium, a first image forming unit to form a monochrome image transferred at a first transfer position onto the transfer medium, and a second image forming unit disposed downstream from the first image forming unit in a direction of conveyance of the transfer medium, including an intermediate transfer body to form a multi-colored toner image on the intermediate transfer body. The multi-colored toner image is transferred onto the transfer medium at a second transfer position. The conveyance unit is separated from the intermediate transfer body at the second transfer position in a monochrome mode to form the monochrome image using only the first image forming unit, and contacts the intermediate transfer body at the second transfer position in a full-color mode to form a full-color image using both the first and second image forming units.

Abstract: It has been difficult to ensure satisfactory secondary transfer performance while ensuring satisfactory primary transfer performance by passing a current in the circumferential direction of an intermediate transfer belt from a current supply member. To satisfy a relationship of Rv>Rs, where Rv is resistance in the thickness direction of an intermediate transfer belt and Rs is resistance in the circumferential direction of the intermediate transfer belt over the distance between an image carrier located most upstream and an image carrier located most downstream in the movement direction of the intermediate transfer belt.

Abstract: A transfer device includes an intermediate transfer belt, and a plurality of intermediate transfer rollers. A most upstream side intermediate transfer roller which is located most upstream in a moving direction of the intermediate transfer belt has a rotational axis arranged downstream from a rotational axis of a most upstream side photoreceptor drum which is located most upstream in the moving direction of the intermediate transfer belt when the most upstream side intermediate transfer roller is in its pressing position, while a most downstream side intermediate transfer roller which is located most downstream in the moving direction of the intermediate transfer belt has a rotational axis arranged upstream from a rotational axis of a most downstream side photoreceptor drum which is located most downstream in the moving direction of the intermediate transfer belt when the most downstream side intermediate transfer roller is in its pressing position.

Abstract: An object is to provide an intermediate transfer belt and a method for producing the same which inhibits fine toner dots in white area in an environment of low temperature and low humidity and further, inhibits roughness of image with long-term use. An intermediate transfer belt for an electrophotographic image forming apparatus comprising a polyimide having a dispersed conductive filler, wherein the polyimide contains a unit structure represented by Formula (1); wherein X represents a group selected from Formulas (a) to (e), n, m, l each represents 0 or 1, and at least one of m and l is 1, wherein p in Formula (c) and q in Formula (e) each is an integer of 1 to 5.

Abstract: An image forming apparatus includes a main body, a sheet stack unit, an endless intermediate transfer member, a first transfer member for transferring a toner image onto the sheets conveyed from the sheet stack unit, at a nip formed between the intermediate transfer member and the first transfer member, and a second transfer member. In addition, a first voltage applying device applies a voltage to the first transfer member, a second voltage applying device applies a voltage having an opposite polarity to the second transfer member, and a controller controls the first and second voltage applying devices.

Abstract: A first transfer inner roller and a first transfer outer roller are arranged such that the leading edge of a recording material is pressed against an intermediate transfer member on the downstream side of an upstream side transfer portion to change a traveling direction of the recording material.

Abstract: An intermediate transfer member that includes a fluorinated polyamic acid and a conductive component.

Abstract: An image forming apparatus includes a transfer belt, a pressure receiving roller, a suspension roller, a secondary transfer roller, and an endless support belt. The support belt is stretched over at least one of the pressure receiving roller and the suspension roller. When pressing the transfer belt between the pressure receiving roller and the secondary transfer roller, and nipping paper between the transfer belt and the secondary transfer roller, an angle defined by the portion, upstream from the secondary transfer roller, of the transfer belt and an imaginary line connecting the pressure-receiving-roller axis with the secondary-transfer-roller axis is less than 90 degrees. A part of the support belt is held between the transfer belt and at least one of the two rollers over which the support belt is stretched.

Abstract: An image formation apparatus includes an image carrier; a driving source generating a driving force for the image carrier; a drive transmission unit; a driving control unit controlling the driving source; an image formation unit forming an image on a surface of the image carrier; a transfer nip between a transfer member and the surface of the image carrier; a driving-force exerting unit exerting a driving force on any one of the image carrier and a first drive transmission member on a drive transmission path, and a specific drive transmission member imparting weakest spring characteristics among drive transmission members to a drive transmission system; a detecting unit detecting an estimation parameter used in estimating a driving-load-torque variation amount of the image carrier; a torque-variation-amount estimation unit; and a driving-force control unit controlling the driving force to cancel the driving-load-torque variation.