Abstract: A belt device includes a plurality of rollers, a belt stretched and supported around the plurality of rollers, a roller shaft included in one of the plurality of rollers and configured to rotate along with the one of the plurality of rollers, a shaft inclination member slidably supported by the roller shaft, a cleaning member opposed to the one of the plurality of rollers via the belt, a bearing configured to rotatably support the roller shaft, and a support configured to rotatably support the bearing. The shaft inclination member is configured to incline the roller shaft in conjunction with movement in which the belt moves in a width direction of the belt device. The cleaning member is configured to clean the belt. The bearing is configured to stationarily support the cleaning member.

Abstract: An image forming apparatus includes an endless belt, an inner roller, an upstream roller, a pressing member, and a guiding member. In a cross-section perpendicular to a rotational axis of the inner roller, a downstream free end of the guiding member is disposed downstream of a pressing portion normal line Lc with respect to a feeding direction of the sheet, where L is a reference line which is a common tangent of the inner roller and the upstream roller in a contact portion relative to the belt, Ld is a pressing portion tangent line, parallel with the reference line, of the belt in a region where the pressing member contacts the belt, and Lc is the pressing portion normal line passing through a contact point between the belt and the pressing portion tangent line Ld and perpendicular to the reference line L.

Abstract: An image forming apparatus has a plurality of image forming portions, an intermediate transfer belt having an elastic layer, a plurality of primary transfer members, a contact-separation mechanism, a secondary transfer member, a driving device, a voltage applying device, and a control portion. The contact-separation mechanism is switchable between an all-color pressure state where the primary transfer members are all in pressed contact with the image carrying members via the intermediate transfer belt and an all-color apart state where the primary transfer members are all away from the intermediate transfer belt. At first power-on, the control portion starts driving the image carrying members and the intermediate transfer belt in the all-color apart state, then transits to the all-color pressure state, and then ejects toner from the developing device to the image carrying members to reduce the surface friction coefficient on the image carrying members and the intermediate transfer belt.

Abstract: An image forming apparatus includes an apparatus body including an image bearing member configured to bear a toner image, a transfer unit including a transfer portion configured to transfer the toner image borne on the image bearing member onto a sheet, the transfer unit being pivotably supported with respect to the apparatus body, an opening/closing unit disposed at a position farther from the apparatus body than the transfer unit is, and openably and closably supported with respect to the apparatus body, and a positioning portion pivotably supported with respect to the apparatus body and configured to position the transfer unit with respect to the apparatus body. The positioning portion is entirely disposed further on an outer side in the apparatus body than a pivot center of the transfer unit in a horizontal direction.

Abstract: An image forming apparatus includes: an image carrier that carries an image formed on an outer circumferential surface thereof and that circularly moves; a circulating member that circularly moves and receives a transfer of the image from the image carrier on an outer circumferential surface thereof that is in contact with the outer circumferential surface of the image carrier or on a recording material; a first driving unit that drives the image carrier to circularly move; a second driving unit that drives the circulating member to circularly move by a driving force independent from a driving force of the first driving unit; a load detector that detects a driving load of at least one of the first and second driving units; and a driving adjuster that regulates the driving by the second driving unit so that the load detected by the load detector becomes a predetermined load.

Abstract: An image forming apparatus includes: a cover configured to be pivotal between a closed position and an open position to open an opening portion through which an intermediate transfer unit is removable, wherein when the cover is moved from an intermediate position to the open position, a secondary transfer unit is changed by using a self-weight of the secondary transfer unit from a first relative position to a second relative position, and wherein when the cover is located in the open position and the intermediate transfer unit is supported in a first position by a guiding portion, a secondary transfer unit interferes with the intermediate transfer unit if located in the first relative position, but does not interfere with the intermediate transfer unit if located in the second relative position.

Abstract: A separation cam is disposed on a shaft of an opposing roller. The separation cam rotates about the shaft in response to a separation unit separating an intermediate transfer belt from a photosensitive drum, and the separation cam thereby separates a secondary transfer roller from the intermediate transfer belt.

Abstract: A transfer device includes a rubbing member provided in contact with a transfer belt, a supporting member supporting the rubbing member, and a damping member configured to damp vibration of the transfer device. The damping member is fastened to the supporting member, and an end of the damping member in a width direction that is orthogonal to a direction of rotation of the transfer belt is a free end.

Abstract: An image forming apparatus includes: a transfer member that transfers a toner image to a continuous sheet, the transfer member having a lower hardness than a member opposed thereto with the continuous sheet therebetween when the continuous sheet is transported; and a moving unit that moves the transfer member in a direction intersecting the direction in which the continuous sheet is transported.

Abstract: A sheet conveying device, which is included in an image forming apparatus, includes first and second sheet conveying bodies to contact each other, a cover to move relative to an apparatus body of the image forming apparatus, and a connecting body to connect the cover and the second sheet conveying body. The second sheet conveying body separates from the first sheet conveying body along with an opening movement of the cover. The connecting body includes a first connecting portion connected to the cover and a second connecting portion connected to the second sheet conveying body. At least one of a connection with the cover and a connection with the second sheet conveying body is released when the cover is closed. The connecting body is brought into connection with the cover or the second sheet conveying body.

Abstract: A cleaning apparatus removes a toner and a paper dust remaining on an intermediate transfer belt. The pressure reducing member includes a fitting hole and an outer peripheral portion. The fitting hole is fitted to a rotation shaft of a rotation roller rotating at which the intermediate transfer belt is stretched. The outer peripheral portion is in a cam shape and has a diameter dimension larger than a diameter of the rotation roller. The outer peripheral portion is located around the fitting hole. The outer peripheral portion includes a first outer peripheral portion and a second outer peripheral portion. The first outer peripheral portion has a predetermined first radius and does not contact the supporting member when not reducing the pressure. The second outer peripheral portion has a predetermined cam radius larger than the first radius. The second outer peripheral portion contacts the supporting member when reducing the pressure.

Abstract: A field replaceable transfer belt unit for toner-based printers includes a transfer belt and rollers for moving the transfer belt in a loop during a print operation, including a first roller configured to be driven by a driver shaft of a printer. The field replaceable transfer belt unit includes a rotatable handle for removing and replacing the field replaceable transfer belt unit from the printer. The rotatable handle is in communication with a drive cam that rotates to selectively engage and disengage the drive shaft with the first roller. Rotating the handle also secures the transfer belt unit to the printer.

Abstract: An image forming apparatus includes a transfer unit which includes a belt member having an outer peripheral surface which contacts an image holding member, and a transfer member, and the belt member is wound around both of the image holding member and the transfer member, wherein a toner to be used includes a binder resin containing an amorphous resin and a crystalline resin and has specific physical properties described in the specification, and paraffin wax having a melting temperature of 60° C. to 80° C., and an absolute value of a difference between the melting temperature of the crystalline resin and the melting temperature of the paraffin wax is 10° C. or less.

Abstract: A pressing apparatus includes a presser including a second member configured to come close to or separate from a first member; an elastic member configured to apply force in a direction in which the second member comes close to the first member to the presser, the elastic member being mounted on the presser; an actuator configured to apply force in a direction in which the second member comes close to the first member or separates from the first member to the presser, the actuator being mounted on the presser; an acquirer configured to acquire a parameter containing at least one of a position of the presser, a speed of the presser, and force applied by the actuator to the presser; and a controller configured to feedback-control the actuator based on the parameter.

Abstract: A belt device includes a belt unit including a plurality of rotators and a belt looped around the plurality of rotators. The belt device further includes a frame including a plurality of support portions to support the belt unit, a biasing member to bias the belt unit supported by the frame in a predetermined direction, and an adjuster to adjust a position of at least one of the plurality of support portions.

Abstract: A separating claw unit includes: a separating claw provided beside and against a surface of an image carrier on which a toner image to be transferred to a recording paper sheet in a nip area between the image carrier and a transfer section is to be formed, the separating claw being configured to separate the recording paper sheet having passed through the nip area off the surface of the image carrier in a direction away from the surface of the image carrier; and a cushion guide provided next to the separating claw to extend beyond the separating claw in the direction away from the surface of the image carrier, held elastically and displaceably away from the surface of the image carrier, and configured to come into contact with the recording paper sheet to guide the recording paper sheet downstream in a direction of conveyance of the recording paper sheet.

Abstract: A drive transmitting device includes a first rotator, a second rotator, a rotation driver, and a linker. The first rotator is rotatable. The second rotator is rotatable in a state where the second rotator comes into pressure contact with the first rotator. The rotation driver rotates the first rotator. The linker links speed change operation with pressure change operation, the speed change operation being operation to change a speed ratio of a surface of the first rotator and a surface of the second rotator, the pressure change operation being operation to change pressure force of the second rotator to the first rotator.

Abstract: A sheet conveying apparatus, includes: a first roller; an opening-closing member that is movable between an open position and a close position; a second roller; an urging member; a restraint member switching between a restraint state in which a rotation shaft of the second roller is restrained and a release state in which the rotation shaft is released from the restraint, by being moved, wherein, during the movement of the opening-closing member from the open position to the close position, the restraint member keeps the rotation shaft in the restraint state; and a releasing member that is moved by driving force from the drive source when the opening-closing member is in the close position and the rotation shaft is in the restraint state, the releasing member switching the rotation shaft to the release state by moving the restraint member as being engaged with the restraint member.

Abstract: A detachable device includes: a detachable member that is provided to be attachable to and detachable from an apparatus main body in which a first rotating member is provided and that includes a second rotating member which is brought into press-contact with the first rotating member; a moving member that is provided in the apparatus main body, that holds the detachable member at an attachment position to the apparatus main body so as to maintain a press-contact load between the first rotating member and the second rotating member, and that is movable to a position at which the detachable member is not held by the moving member; and a release member as defined herein.

Abstract: A belt feeding device includes a belt, a first roller, an opposing roller, a second roller, and a brush roller. (|D2s?D2m|/2)×10???(|D2s?D2m|/2)×(b/(a+b)) is satisfied, where D2m is a minimum diameter of the first roller, D2s is a maximum diameter of the first roller, ? is an entering amount of the opposing roller into the brush roller with respect to a reference line A between a portion of the first roller having the minimum diameter D2m and the second roller, a is a distance between a line passing through a rotation center of the first roller and a line passing through a rotation center of the opposing roller, and b is a distance between a line passing through a rotation center of the second roller and a line passing through the rotation center of the opposing roller.

Abstract: A transfer unit includes a transfer target member, a first transfer device, and a holding member. The transfer target member has an image region to which an image is transferred and a non-image region to which the image is not transferred and which exists along an edge of the transfer target member. The transfer target member is transported in a path passing through a contact position where the transfer target member is brought into contact with an image holding body, which has a surface on which the image is held, so as to allow the image to be transferred to the transfer target member. The first transfer device transfers the image from the image holding body to the transfer target member. The holding member is brought into contact with the non-image region so as to hold the transfer target member without contact with the image region.

Abstract: A sheet conveyance apparatus includes first and second conveyance rollers, a holding member configured to rotatably hold the second conveyance roller, and an urging member to urge the holding member in a pressing direction. In addition, a reduction portion reduces a force applied to an openable member by the urging member when the openable member is opened or closed. The reduction portion includes a swingable member swingably supported by the openable member and movable to a first position, at which the swingable member causes the second conveyance roller to be pressed against the first conveyance roller, and a second position at which the swingable member causes the second conveyance roller to be separated from the first conveyance roller. The urging member is disposed between the swingable member and the holding member and urges the swingable member to swing toward an abut portion.

Abstract: An image forming apparatus including a cleaning unit removably mountable to an apparatus main body under a state of being supported by a transfer unit, and movable with respect to the transfer unit in a longitudinal direction of a cleaning member under a state of not being mounted to the apparatus main body. The apparatus main body includes a frame unit portion configured to position a cartridge with respect to the apparatus main body in an axial direction of a photosensitive drum. The frame unit portion is configured to position the cleaning member with respect to the apparatus main body in the longitudinal direction under a state in which the transfer unit is mounted to the apparatus main body.

Abstract: A drum unit of an image forming apparatus including a flange that is integrally provided with the photoconductor drum. A frame rotatably supports the photoconductor drum and covers its side. A gear portion is integrally formed with an outer circumferential surface of the flange. An outer diameter of the gear portion is larger than a diameter size of the photoconductor drum. A guide member is provided on an upper surface of the frame and guides the edge portion upward when the drum unit is pulled out of the apparatus main body. An upper surface of the guide member includes first and second guide surfaces. The first guide surface is located more on a side of a center of the photoconductor drum than the edge position, and the second guide surface is located more on the side of the insertion direction than the edge position.

Abstract: The image formation apparatus includes a transport frame including a maximum front-to-back medium width passage area defined in an area between a first back side passage line and a first front side passage line, and allowing a continuous medium of a maximum front-to-back width to pass therethrough, and a minimum front-to-back medium width passage area defined in an area located inside the maximum front-to-back medium width passage area between a second back side passage line and a second front side passage line, and allowing a continuous medium of a minimum front-to-back width to pass therethrough, in a state where the transport frame is drawn out most frontward and a toner replenishment door is opened most wide downward, when the toner replenishment door is seen downward projectively, at least a portion of the first back side passage line being covered with the toner replenishment door.

Abstract: An image forming device includes a cover member, a conveying unit, a first rotor, a second rotor, a bearing unit, a biasing member, and a link member. The cover member includes a hook, and an opening/closing lever that moves the hook. The conveying unit is disposed on the inner side of the cover member, and is rotatably supported between an opened position and a closed position to the main body of the image forming device. The link member is swingably supported on the conveying unit, and is configured to engage with the bearing unit. By operating the opening/closing lever in a state where the conveying unit is in a closed position, the link member is pressed against the hook to swing so that the first rotor of the bearing unit should move in a direction away from the second rotor against biasing force from the biasing member.

Abstract: An image forming apparatus includes an image bearing member to bear a toner image charged with a predetermined polarity, and a power source to apply a bias to a transfer portion to transfer the toner image from the image bearing member to a recording medium, a polarity of the bias being changed alternately. The toner image formed with toner of a plurality of colors is transferred in a color mode and the toner image formed with toner of a single color is transferred in a monochrome mode. The bias includes a peak voltage with a polarity that returns toner from the recording medium to the image bearing member. An absolute value of the peak voltage in the color mode is equal to or greater than an absolute value of the peak voltage in the monochrome mode.

Abstract: A transfer device includes a transport belt that contacts with a photoreceptor, and transports a recording medium; a transfer roll that transfers the toner image formed on a surface of the photoreceptor to the recording medium while pressing the recording medium to the photoreceptor through the transport belt; an adjusting unit that adjusts a pressing force of the transfer roll against the recording medium; and a controller that controls the adjusting unit so that a first pressing force is stronger than a second pressing force. The first pressing force is the pressing force after the recording medium starts to pass through a transfer position of the transfer roll and is moved by a predetermined distance. The second pressing force is the pressing force when the recording medium starts to pass through the transfer position.

Abstract: An image forming apparatus includes an image forming section, a transferred member, a transfer roller, and a separator. The image forming section forms a developer image. The transferred member is conveyed in a first direction and the developer image is to be transferred on the transferred member. The transfer roller faces the transferred member, and makes a transition between a biasing state in which the transferred member is biased by the transfer roller and a separated state in which the transfer roller is separated away from the transferred member. The separator starts to separate a medium away from the transferred member after the transfer roller starts making a transition from the biasing state to the separated state, the medium being held between the transferred member and the transfer roller in the biasing state.

Abstract: A positioning member is configured to be fixed to a main assembly frame of an image forming apparatus and configured to position a fixing device. The positioning member includes a mounting portion, a first projected portion configured to be inserted into a first hole of the main assembly frame, a second projected portion configured to be inserted into a second hole of the main assembly frame, and a third projected portion configured to be inserted into a third hole of the main assembly frame. The third projected portion includes a snap-off facilitating portion that snaps off in order to permit movement of the positioning member relative to the main assembly frame.

Abstract: An image forming apparatus includes: an open/close member provided to an image forming apparatus body so as to be openable and closable by turning about a turning support point; and a second transfer member attached to the open/close member to be positioned at an operation position with a positioning projecting portion contacting a positioning recessed portion of the image forming apparatus body. A distance between the turning support point and an outer peripheral end of the positioning projecting portion at a time when the open/close member is opened is shorter than the distance with the second transfer member at the operation position. The second transfer member is guided to the operation position, when the open/close member is closed, with the positioning projecting portion first contacting a guide surface of the positioning recessed portion. The guide surface is located on a downstream side along a turning direction of the open/close member.

Abstract: An image forming apparatus is provided. The image forming apparatus includes a main body; a first unit detachably attachable to the main body; a second unit which is arranged adjacent to the first unit and which is detachably attachable to the main body; and a cover which is located on the front side of the second unit relative to the detaching direction of the first and second units while supported by the second unit and which is openable and closable, wherein opening the cover permits detaching of the first unit from the main body and attaching of the first unit to the main body.

Abstract: An image forming apparatus is designed to be capable of easily suppressing a variation of an inclination of a sensor relative to an endless belt and capable of high accuracy and stabilized sensing operation. The image forming apparatus includes a belt unit having an endless belt supported to be rotatable in a circumferential direction, an image forming unit for forming an image on the belt unit, and an optical sensor for detecting light projected onto the endless belt. The image forming apparatus further includes a sensor supporting member for supporting the sensor, and a positioning portion including, as a unit, a first positioning portion for positioning the belt unit by being contacted by the belt unit and a second positioning portion positioning the sensor supporting member by being contacted by the sensor supporting member.

Abstract: An image forming apparatus includes a belt-shaped image bearer, a transferer, a guide unit, and a plurality of contact members. The belt-shaped image bearer has an image bearing surface to bear an image thereon. The transferer forms a transfer section between the transferer and the image bearer, to transfer the image onto a recording medium. The guide unit is disposed upstream from the transfer section in a delivery direction of the recording medium, to guide the recording medium toward the transfer section. The plurality of contact members are disposed side by side at positions opposing the guide unit and in contact with a non image bearing surface of the image bearer opposite to the image bearing surface.

Abstract: An image forming apparatus includes: a guide groove for a rotation shaft; a positioning groove provided on a guide surface, for the rotation shaft, in the guide groove; a pressing member provided so as to be rotatable about a support shaft provided at the opening side with respect to the positioning groove, and configured to press the rotation shaft in a groove depth direction of the positioning groove; and a lower surface portion configured to apply a first pressing force in the groove depth direction to the rotation shaft in a fit-in state where the rotation shaft is located at a fit-in position, and apply a second pressing force in the inserting direction to the rotation shaft against the first pressing force in an escape state where the rotation shaft is located at an escape position.

Abstract: An image forming apparatus includes an output gear that is driven by a drive source, a transmitting member that meshes with the output gear in such a manner as to be capable of advancing toward and retracting from a driving object and transmits a rotational driving force to the driving object, a guiding portion provided coaxially with the output gear and that guides the transmitting member in a direction of advancement or retraction of the transmitting member, and a locking member provided between the output gear and the transmitting member and that limits a movement of the transmitting member from a side of the output gear toward the driving object.

Abstract: A belt-shaped member includes an endless belt-shaped base member that has a circumferential edge and that is supported by plural support members. The belt-shaped member also includes a meandering preventing member that is provided along the circumferential edge of the base member and that has a bonding surface bonded to the base member. When a diameter of at least one of the plural support members is 25 mm or less, a protective film having a thickness of from 5 to 20 ?m is formed on the bonding surface of the meandering preventing member.

Abstract: In accordance with one embodiment, an image forming apparatus includes an image forming section and a transfer roller. A support body supports the image carrier in a main body opposite to the transfer roller. A holding member positioned in the support body holds the transfer roller. The holding member includes at least one groove in a portion of the holding member that holds the transfer roller. At least one conductive member is positioned in, and protruding from, the at least one groove so that a part of the conductive member makes electrical contact with the transfer roller when the transfer roller is held in the holding member. A power supply section applies transfer bias between the image carrier and the transfer roller through the conductive member.

Abstract: An image forming apparatus includes an image bearer, a nip forming device, a contact-and-separation device, a thickness information retrieving device, and a controller. The contact-and-separation device moves the image bearer and the nip forming device to contact and separate from each other. The controller controls the contact-and-separation device based on information on a thickness of a recording medium obtained by the thickness information retrieving device such that in a case in which a thickness of a preceding recording medium and a thickness of a successive recording medium are different in continuous printing in which a plurality of recording media is printed out continuously, the contact-and-separation device adjusts a space between the image bearer and the nip forming device when the preceding recording medium exits the transfer nip to a preset size corresponding to the thickness of the successive recording medium that enters the transfer nip.

Abstract: A recording apparatus includes a recording section, a transportation unit, and a supporting frame. The recording section performs recording on paper. The transportation unit includes a transportation belt and a moving section. The transportation belt can transport the paper by turning. The moving section causes the transportation belt to move between a recording position, at which the recording is performed by the recording section, and a retracted position, which is more distant from the recording section than the recording position is. The supporting frame supports the transportation unit inside. A first opening portion is formed in the supporting frame. Through the first opening portion, the transportation unit supported inside the supporting frame can be drawn out from the inside of the supporting frame to the outside of the supporting frame in a state in which the transportation belt has been moved to the retracted position.

Abstract: An image forming apparatus includes a door movably holding a transfer unit; a first roller movably held by the door and a second roller provided on the main body for conveying a recording material; a transfer positioning member provided on the main body to be interlocked with rotation of the door, the transfer positioning member positioning the transfer unit with respect to the main body with the transfer member being in contact with the image bearing member; and a roller positioning member provided on the main body to be interlocked with rotation of the door, the roller positioning member positioning the first roller with respect to the main body with the first roller being in contact with the second roller.

Abstract: Provided is a transfer mechanism including a rotor that configures a transfer section which transfers an image including a flat pigment to a recording medium, a second gear that engages with a first gear provided in a support, a to-be-supported object that is provided with the rotor and the second gear, is supported by the support through a shaft portion of the rotor, and is allowed to move around the shaft portion in a direction in which engagement of the second gear with the first gear becomes weaker, and a member that presses or pulls the to-be-supported object in a direction in which the engagement becomes stronger.

Abstract: An image forming apparatus includes an image bearer, an image forming device, a transfer member, and a contact-and-separation device. The contact-and-separation device starts a contact operation to move the transfer member to contact the image bearer according to an entry of a recording medium into a transfer nip. The thinner the recording medium, the faster a contacting speed at which the transfer member moves to contact the image bearer. The thicker the recording medium, the slower the contacting speed.

Abstract: An image-forming apparatus includes a main body, a belt unit detachably attachable to the main body, a coupling and a first restricting part. The belt unit includes: a first roller defining an axis extending in an axial direction, a second roller opposing the first roller in a first direction perpendicular to the axial direction, and a belt looped over the first roller and the second roller. The coupling is configured to move in the axial direction to come into engagement with the first roller for inputting a drive force into the first roller. The first restricting part is provided on the main body and is configured to restrict the first roller from moving in a second direction perpendicular to the axial direction and the first direction when the belt unit is attached to the main body.

Abstract: The image forming apparatus configured such that a primarily-transferred toner image is secondarily transferred onto a recording material at a secondary transfer portion formed between a transfer belt and a secondary transfer roller, includes a belt unit configured to support the transfer belt in a rotatable manner; and a sheet feeding unit configured to feed the recording material toward the secondary transfer portion. Both the belt unit and the sheet feeding unit are positioned and fixed on the same main stay, so that higher printing accuracy is achieved in consideration of a mutual positional relationship between the sheet feeding portion and the image forming portion.

Abstract: An image forming apparatus is provided. The image forming apparatus, in a case in which a toner on a transfer belt is checked through a sensing unit, is capable of preventing a rotation of a guide roller, which is configured to guide the transfer belt, by use of a regulation device, so that a check error occurring due to vibration of the guide roller is reduced. Thus, the toner on the transfer belt is checked with increased accuracy and precision.

Abstract: A belt unit for use with an image forming apparatus includes a belt member, a belt supporting unit, and a cleaning unit. The cleaning unit includes attached portions engaged with attaching portions of the belt supporting unit to mount the cleaning unit in an attached position, a connecting portion connectable with a connected portion on the belt supporting unit, and a contact portion that contacts a horizontal surface when the cleaning unit is placed on the horizontal surface. When the belt supporting unit is in a standing state in which one of its side units is directed downward and a direction of rotation axis of supporting rollers is directed in a vertical direction, the cleaning unit is placed on the horizontal surface and the connected portion, and the connecting portion are connected, the cleaning unit maintains the belt supporting unit in the standing state.

Abstract: An image forming apparatus includes a lever configured to move a secondary transfer roller from an endless belt. The lever is arranged between a primary transfer surface of the endless belt, which opposes a plurality of image bearing members between an opposing roller and a stretching roller, and a surface opposing the primary transfer surface. The lever is engaged with the secondary transfer roller to separate the secondary transfer roller from the endless belt. Such a simple contact-separation configuration for the secondary transfer roller achieves reduction in size and space of the image forming apparatus.

Abstract: In a case where a belt unit is not attached to an apparatus body, when an opening and closing member is closed against the apparatus body, a switching member cannot press a switch, and image formation operation is prohibited. In a case where the belt unit is attached to the apparatus body, when the opening and closing member is closed against the apparatus body, the switching member presses the switch, and the prohibition of the image formation is released.

Abstract: A member moving mechanism includes a moving member, a moved member, a belt member, an openable-closable cover that is rotatable about a rotation shaft with the openable-closable cover engaged with the moving member, and a first biasing member. The moving member moves in a first negative direction with a biasing force of the first biasing member when the openable-closable cover rotates in an opening direction, while the moving member moves in a first positive direction against the biasing force of the first biasing member when the openable-closable cover rotates in a closing direction. The moving member has a boss formed to abut a first-positive-direction side of the engaging piece projecting from the rotation shaft. A biasing force in the opening direction is applied to the openable-closable cover by the boss pressing the engaging piece in the first negative direction with the biasing force of the first biasing member.