A sheet conveying device, which is included in an image forming apparatus, includes a plurality of position detectors, a leading end detector, and a position adjuster. The plurality of position detectors is configured to detect a position of a sheet. The leading end detector is configured to detect a leading end of the sheet. The position adjuster is configured to, based on a detection result obtained by the plurality of position detectors, rotate in a rotation direction of the sheet within a plane of conveyance of the sheet to change the position of the sheet the position adjuster grips the sheet under conveyance to cause the leading end detector to rotate with the position adjuster in the rotation direction of the sheet within the plane of conveyance of the sheet.

A sheet conveying device includable in an image forming apparatus that uses a method of conveying a conveyance target medium and a method of forming an image, includes a position detector, a position adjuster, and circuitry. The position detector is configured to detect a position of a conveyance target medium. Based on a detection of the position of the conveyance target medium by the position detector, the position adjuster moves in at least one of a width direction of the conveyance target medium and a rotation direction of the conveyance target medium within a plane of conveyance of the conveyance target medium and repeatedly adjusts the position of the conveyance target medium while conveying the conveyance target medium. The circuitry changes a conveying speed of the conveyance target medium, according to a change of the position of the conveyance target medium after adjusted by the position adjuster.

A sheet conveying device, which is included in an image forming apparatus, includes a detector to detect a lateral end face of a sheet, a first pair of rollers to hold and convey the sheet and swing in a direction parallel to a plane of the sheet, a second pair of rollers to convey the sheet together with the first pair of rollers, and a controller to rotate the first pair of rollers to multiple angles, detect time changes at each angle at the lateral end face while conveying the sheet, and determine a home position corresponding to a position where respective rates of the time changes of the sheet at the first and second nip regions are substantially identical to each other or a home position having a least difference of rates of the time changes of the sheet at the first and second nip regions.

A sheet conveying device, which is included in an image forming apparatus, includes a pair of rollers configured to convey a sheet in a sheet conveyance passage, a detector configured to optically detect an attitude of the sheet, one of a rotation device to rotate the pair of rollers in a direction parallel to a plane of the sheet and a moving device to move the pair of rollers in a width direction, and a controller configured to correct the attitude of the pair of rollers at a time interval, based on a detection result obtained by the detector. The controller performs the correcting operation by setting, according to reflectance of the sheet, at least one of a light emission time of the detector, the time interval of the correcting operation, light emission intensity of the detector and a conveying speed of the sheet.

An image forming apparatus, including: a sheet cassette; an image former; a fixer; a discharge tray; a conveyor configured to convey a sheet along a conveyance passage; a return conveyor configured to convey the sheet from a branch position between the fixer and the discharge tray to a merge position between the sheet cassette and the image former along a return passage which is branched from the conveyance passage at the branch position, passes below the sheet cassette, and merges with the conveyance passage at the merge position; a switchback roller disposed between the branch position and the discharge tray in the conveyance passage and configured to convey the sheet to the discharge tray when it rotates forwardly and to the return passage when it rotates backwardly; and an intermediate conveyance roller disposed in the return passage at a height level intermediate between the fixer and the sheet cassette.

A sheet conveying device, which is included in an image forming apparatus and a post processing device, includes a position detector configured to detect a position of a sheet, a sheet conveying body, a fixed body, a movable body configured to move, relative to the fixing body, between a first position and a second position different from the first position, and an index mounted on the fixed body. The sheet conveying device further includes a data storing device, a conveyance positional deviation calculator configured to calculate a positional deviation amount of the sheet to the reference sheet conveyance position, a detected positional deviation calculator configured to calculate a positional deviation amount of the position detector to the index based on a result of the position detector, and a reference position detector configured to correct the reference sheet conveyance position based on a result of the detected positional deviation calculator.

A sheet conveying device, which is included in an image forming apparatus and a post processing device, includes a position detector configured to detect a position of a sheet, a sheet conveying body, a fixed body, a movable body configured to move, relative to the fixing body, between a first position and a second position different from the first position, and an index mounted on the fixed body. The sheet conveying device further includes a data storing device, a conveyance positional deviation calculator configured to calculate a positional deviation amount of the sheet to the reference sheet conveyance position, a detected positional deviation calculator configured to calculate a positional deviation amount of the position detector to the index based on a result of the position detector, and a reference position detector configured to correct the reference sheet conveyance position based on a result of the detected positional deviation calculator.

A sheet conveying device, which is included in an image forming apparatus and a post processing device, includes a position corrector and either one of a rolling body and a contact resistance reducer. The position corrector is configured to convey a sheet and correct a position of the sheet. The rolling body is disposed at least one of an upstream side and a downstream side of a sheet conveyance passage from the position corrector in a sheet conveying direction and is configured to roll in at least a direction intersecting the sheet conveying direction. The contact resistance reducer is configured to reduce contact resistance generated due to contact of the sheet to a neighboring part when the position of the sheet is corrected by the position corrector.

A sheet conveying device, which is included in an image forming apparatus, includes a drive device, a pair of sheet holding rollers to convey a sheet in a sheet conveying direction, a gate to which a leading end of the sheet contacts, a first detector disposed upstream from the pair of sheet holding rollers to detect a position of the sheet and a second detector disposed downstream from the pair of sheet holding rollers to detect a position of the sheet. The pair of sheet holding rollers performs a primary correction to detect and correct a lateral displacement amount of the sheet by moving the pair of sheet holding rollers while holding the sheet, and then performs a secondary correction to detect and correct at least one of a subsequent lateral displacement of the sheet and an angular displacement of the sheet.

A sheet conveying device, which is included in an image forming apparatus, includes a sheet holding roller to move while holding a sheet, a detector to perform a primary detection to detect a sheet position before the sheet holding roller holds the sheet and a secondary detection to detect a sheet position downstream from the sheet position detected by the primary detection, and a controller configured to cause the sheet holding roller to perform a first drive to move the sheet holding roller in at least one direction of a width direction of the sheet and a rotation direction in a sheet conveying surface based on a result of the primary detection and a second drive to move the sheet holding roller opposite to the at least one direction of the first drive, based on a result of the secondary detection.