Abstract: An image forming apparatus includes an image bearing member for bearing a toner image, a movable endless transfer belt for transferring the toner image from the image bearing member onto a transfer material, and a transfer device for transferring the toner image from the image bearing member toward the transfer belt. The transfer device includes a transfer member for sliding on an inner surface of the transfer belt in contact with the inner surface, a supporting member for supporting the transfer member, and an urging member for urging the supporting member toward the transfer belt, wherein the transfer member contacts the inner surface of the transfer belt at a contact surface thereof without rotation relative to the supporting member during movement of the transfer belt. The supporting member is rotatable about a center axis during movement of the transfer belt, and the contact surface is convex with predetermined curvature toward the transfer belt.

Abstract: An image forming apparatus includes a rotatable image carrying member, a rotatable transfer member cooperative with the image carrying member, and a fixing unit having a fixing nip for nipping and feeding the recording material discharged from the transfer nip while fixing the toner image. In addition, a bowing amount measuring unit measures a bowing amount of the recording material, a storing portion stores a target bowing amount, and a speed controller controls a feeding speed of the recording material. The storing portion stores a plurality of target bowing amounts, which are selectable depending on kinds of the recording material, and the speed controller controls the feeding speed in the fixing nip, and then controls the feeding speed so that the bowing amount is substantially zero at the time when a trailing edge of the recording material leaves the transfer nip.

Abstract: An image forming apparatus includes an image carrying belt for carrying a toner image; an image forming station for forming toner image on the image carrying belt; a sheet feeding belt for feeding a sheet; a transfer member for transferring the toner image from the carrying belt onto the sheet fed on the feeding belt; and a controller for controlling speeds of the carrying belt and the feeding belt. The controller is capable of controlling a relative speed between the carrying belt and the feeding belt at multiple levels. The image forming station forms a first toner pattern on the carrying belt in a state that the relative speed is at a first level, and forms a second toner pattern on the carrying belt in a state that the relative speed is at a second level which is different from the first level. The transfer member transfers the first toner pattern and the second toner pattern onto the sheet carried on the feeding belt.

Abstract: The image forming apparatus includes an endless and movable transfer material bearing belt, a transfer member, an opposing member and a belt guide member, wherein a conveyance direction of the transfer material in a first area is substantially the same as a conveyance direction of the transfer material in a second area, the first area corresponding to a nip area formed by the opposing member and the transfer member and the second area corresponding to an area in which the belt guide member bringing the transfer material bearing belt and the image bearing belt come into contact with each other. By the virtue of the present invention, a transfer material is restrained from scraping off the leading end of a toner image before the leading end of the toner image enters a transfer nip portion, while suppressing spattering of the toner image on the upstream of the transfer nip portion.

Abstract: A toner image formed on an image bearing member is transferred onto a recording material so as to overflow from an edge portion of the recording material, thereby enabling the toner image to be formed so as to extend to the edge portion of the recording material. To suppress the deposition of the toner in the edge portion of the recording material, a cleaning member for cleaning the edge portion of the recording material obtained after the fixing is provided. In order to make a trailing edge of the recording material come into contact with the cleaning member, the recording material which has passed through a fixing apparatus is temporarily switched back, thereby allowing the trailing edge portion of the recording material to collide with the cleaning member.

Abstract: Sheets fed out from a sheet feeding portion, which is brought into pressure contact with the sheets by the upward movement of a sheet stacking portion to feed out the sheets, are separated and conveyed one by one while being upwardly curved. During the sheet feeding operation, the sheet stacking portion is sequentially moved up, and when the sheet feeding operation is completed, the sheet stacking portion is moved down. Further, a remaining amount indicating member moved with the upward movement of the sheet stacking portion to indicate the remaining amount of sheets is held at a position before the sheet stacking portion is moved down, by a holding mechanism, when the sheet feeding operation is completed and the sheet stacking portion is moved down.

Abstract: An image forming apparatus includes a image carrying member; a transfer member forming a transfer nip for nipping and feeding a sheet while transferring the toner image onto the sheet; a fixing unit having a fixing nip for nipping and feeding the sheet discharged from the transfer nip while fixing the toner image; a bowing amount measuring unit for measuring a bowing amount of the sheet which is fed while being nipped by the transfer nip and fixing nip; and a sheet feeding speed controller, wherein the controller is capable of controlling the feeding speed of the fixing nip on the basis of a result detection of the measuring unit such that the bowing amount is substantially zero at the time when a trailing end of the sheet goes out of the transfer nip.

Abstract: The detachment of a feed roller rotatably supported by a holding portion provided in the main body of an apparatus, and held detachably in the axial direction thereof is restricted by a locking device. The locking device is made movable to a lock position and a lock releasing position for permitting the detachment of the feed roller. Further, when the locking device is in the lock releasing position when a sheet stacking portion is mounted, the locking device is moved to the lock position by a position changeover device in operative association with the mounting operation of the sheet stacking portion.

Abstract: An image forming apparatus includes an image carrying belt for carrying a toner image; an image forming station for forming toner image on the image carrying belt; a sheet feeding belt for feeding a sheet; a transfer member for transferring the toner image from the carrying belt onto the sheet fed on the feeding belt; and a controller for controlling speeds of the carrying belt and the feeding belt. The controller is capable of controlling a relative speed between the carrying belt and the feeding belt at multiple levels. The image forming station forms a first toner pattern on the carrying belt in a state that the relative speed is at a first level, and forms a second toner pattern on the carrying belt in a state that the relative speed is at a second level which is different from the first level. The transfer member transfers the first toner pattern and the second toner pattern onto the sheet carried on the feeding belt.

Abstract: A compact image forming apparatus is provided in which stains on the back of a transfer material can be prevented. In particular, in a marginless print mode in which a toner image can be formed to the edge of a transfer material, a large amount of toner adheres to a transfer-material bearing member. The image forming apparatus includes a collecting member that can temporarily collect the toner adhering to the transfer-material bearing member. The toner that is temporarily collected by the collecting member is transferred to an intermediate transfer member and is cleaned by a cleaning unit.

Abstract: The image forming apparatus includes an endless and movable transfer material bearing belt, a transfer member, an opposing member and a belt guide member, wherein a conveyance direction of the transfer material in a first area is substantially the same as a conveyance direction of the transfer material in a second area, the first area corresponding to a nip area formed by the opposing member and the transfer member and the second area corresponding to an area in which the belt guide member bringing the transfer material bearing belt and the image bearing belt come into contact with each other. By the virtue of the present invention, a transfer material is restrained from scraping off the leading end of a toner image before the leading end of the toner image enters a transfer nip portion, while suppressing spattering of the toner image on the upstream of the transfer nip portion.

Abstract: An image forming apparatus includes an image bearing member for bearing a toner image; a movable endless transfer belt for transferring the toner image from the image bearing member onto a transfer material; and a transfer device for transferring the toner image from the image bearing member toward the transfer belt. The transfer device includes a transfer member for sliding on an inner surface of the transfer belt in contact with the inner surface, a supporting member for supporting the transfer member and an urging member for urging the supporting member toward the transfer belt. The transfer member is contacted to the inner surface of the transfer belt at a contact surface thereof without rotation relative to the supporting member during movement of the transfer belt. The supporting member is rotatable about a center axis thereof so as to be moved in a direction perpendicular to a movement direction of the transfer belt. The contact surface is convex with predetermined curvature toward the transfer belt.

Abstract: The detachment of a feed roller rotatably supported by a holding portion provided in the main body of an apparatus, and held detachably in the axial direction thereof is restricted by a locking device. The locking device is made movable to a lock position and a lock releasing position for permitting the detachment of the feed roller. Further, when the locking device is in the lock releasing position when a sheet stacking portion is mounted, the locking device is moved to the lock position by a position changeover device in operative association with the mounting operation of the sheet stacking portion.

Abstract: The detachment of a feed roller rotatably supported by a holding portion provided in the main body of an apparatus, and held detachably in the axial direction thereof is restricted by a locking device. The locking device is made movable to a lock position and a lock releasing position for permitting the detachment of the feed roller. Further, when the locking device is in the lock releasing position when a sheet stacking portion is mounted, the locking device is moved to the lock position by a position changeover device in operative association with the mounting operation of the sheet stacking portion.

Abstract: Sheets fed out from a sheet feeding portion, which is brought into pressure contact with the sheets by the upward movement of a sheet stacking portion to feed out the sheets, are separated and conveyed one by one while being upwardly curved. During the sheet feeding operation, the sheet stacking portion is sequentially moved up, and when the sheet feeding operation is completed, the sheet stacking portion is moved down. Further, a remaining amount indicating member moved with the upward movement of the sheet stacking portion to indicate the remaining amount of sheets is held at a position before the sheet stacking portion is moved down, by a holding mechanism, when the sheet feeding operation is completed and the sheet stacking portion is moved down.

Abstract: Sheets fed out from a sheet feeding portion, which is brought into pressure contact with the sheets by the upward movement of a sheet stacking portion to feed out the sheets, are separated and conveyed one by one while being upwardly curved. During the sheet feeding operation, the sheet stacking portion is sequentially moved up, and when the sheet feeding operation is completed, the sheet stacking portion is moved down. Further, a remaining amount indicating member moved with the upward movement of the sheet stacking portion to indicate the remaining amount of sheets is held at a position before the sheet stacking portion is moved down, by a holding mechanism, when the sheet feeding operation is completed and the sheet stacking portion is moved down.

Abstract: A compact image forming apparatus is provided in which stains on the back of a transfer material can be prevented. In particular, in a marginless print mode in which a toner image can be formed to the edge of a transfer material, a large amount of toner adheres to a transfer-material bearing member. The image forming apparatus includes a collecting member that can temporarily collect the toner adhering to the transfer-material bearing member. The toner that is temporarily collected by the collecting member is transferred to an intermediate transfer member and is cleaned by a cleaning unit.

Abstract: A toner image formed on an image bearing member is transferred onto a recording material so as to overflow from an edge portion of the recording material, thereby enabling the toner image to be formed so as to extend to the edge portion of the recording material. To suppress the deposition of the toner in the edge portion of the recording material, a cleaning member for cleaning the edge portion of the recording material obtained after the fixing is provided. In order to make a trailing edge of the recording material come into contact with the cleaning member, the recording material which has passed through a fixing apparatus is temporarily switched back, thereby allowing the trailing edge portion of the recording material to collide with the cleaning member.

Abstract: The image forming apparatus includes a lower body, an upper body openable from and closable to the lower body, the upper body including a device for forming an image and a support member for supporting the upper body when the upper body is opened, wherein a fastening portion for fastening the upper body and the support member is exposed when the device is detached from the upper body. Thus an influence of the weight of the upper body can be alleviated and the support member supporting the upper body can thus be safely replaced.

Abstract: Sheets fed out from a sheet feeding portion, which is brought into pressure contact with the sheets by the upward movement of a sheet stacking portion to feed out the sheets, are separated and conveyed one by one while being upwardly curved. During the sheet feeding operation, the sheet stacking portion is sequentially moved up, and when the sheet feeding operation is completed, the sheet stacking portion is moved down. Further, a remaining amount indicating member moved with the upward movement of the sheet stacking portion to indicate the remaining amount of sheets is held at a position before the sheet stacking portion is moved down, by a holding mechanism, when the sheet feeding operation is completed and the sheet stacking portion is moved down.