A sheet conveying device, which is included in an image forming apparatus and a post processing device, includes multiple position detectors and a position corrector. The multiple position detectors are aligned along a sheet conveying direction and configured to detect a side end of a sheet. The position corrector is configured to convey the sheet and correct a position of the sheet based on a positional deviation amount of the sheet, obtained by a detection result of the multiple position detectors. The positional deviation amount of the sheet is obtained by an extreme downstream position detector in the sheet conveying direction, of the multiple position detectors. A position of a subsequent sheet is corrected based on a sum of the positional deviation amount of the sheet and a positional deviation amount of the subsequent sheet.

An image recording apparatus for recording an image on a sheet includes a recording section which records the image on the sheet in a transport passage for transporting the sheet in a transport direction and multiple plates which are spaced apart from each other in a widthwise direction. These multiple plates include a first type of plate and a second type of plate. Plates of a first type of plate are configured to overlap a sheet when viewed in a direction perpendicular to the transport direction and the widthwise direction, while plates of the second type of plate do not.

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.

A medium carrying device includes a first stopper, a second stopper, a lever, and a mechanism that, when the lever is positioned in a blocking area, places the first stopper at a first blocking position and places the second stopper at a second blocking position, when the lever is positioned in a opening area, releases the first stopper to be positioned at a first opening position and releases the second stopper to be positioned at a second opening position. When the lever is positioned at a boundary position in between the blocking area and the opening area, a lever portion of the lever gets positioned in between a first stopper portion of the first stopper positioned at the first blocking position and a second stopper portion of the second stopper positioned at the second blocking position.

A roll paper holder is provided which rotatably holds belt-like paper to be conveyed towards a printing section when a roll of paper is obtained by winding the paper on an upstream side in a conveyance direction with respect to the printing section. The roll paper holder includes a side wall section in contact with both side ends of the roll of paper in a width direction to prevent the roll of paper from moving in the width direction. The holder further includes at least one protrusion located outside a range where it can contact with the side end of the roll paper to be held having the largest diameter in the side wall section. The at least one protrusion is configured to protrude by a predetermined dimension from a portion contacting with the side end to control a position of the paper in the width direction.

A medium carrying device includes a first stopper, a second stopper, a lever, and a mechanism that, when the lever is positioned in a blocking area, places the first stopper at a first blocking position and places the second stopper at a second blocking position, when the lever is positioned in a opening area, releases the first stopper to be positioned at a first opening position and releases the second stopper to be positioned at a second opening position. When the lever is positioned at a boundary position in between the blocking area and the opening area, a lever portion of the lever gets positioned in between a first stopper portion of the first stopper positioned at the first blocking position and a second stopper portion of the second stopper positioned at the second blocking position.

An image recording apparatus for recording an image on a sheet includes a recording section which records the image on the sheet in a transport passage for transporting the sheet in a transport direction and multiple plates which are spaced apart from each other in a widthwise direction. These multiple plates include a first type of plate and a second type of plate. Plates of a first type of plate are configured to overlap a sheet when viewed in a direction perpendicular to the transport direction and the widthwise direction, while plates of the second type of plate do not.

A sheet processing device has a moveable beam (36) that moves in the vertical direction, a gripper bar (30) for gripping a sheet that travels through the sheet processing device (10), and a gripper bar locking device (40) that can lock the gripper bar (30) in a precise position. The gripper bar locking device (40) has a locking lever (68) that is pivoting between a rest position and a locking position. The locking lever (68) is connected to a vertical linear guide coupled with the moveable beam (36) resulting in a precise, compact and simple system to lock the gripper bar.

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.

A sheet conveying device, which is incorporated in an image forming apparatus, includes a first detector to detect an angle deviation of a recording medium to a sheet conveying direction, a second detector to detect a lateral shift of the recording medium to a width direction, a third detector to detect at least one of the angle deviation and the lateral shift after correction of the angle deviation detected by the first detector and the lateral shift detected by the second detector, and a rotary body to perform a primary movement by (1) rotating in the sheet conveying direction and returning to a reference position and by (2) moving in the width direction and returning to the reference position, and a secondary movement by performing at least one of (1) and (2) after the primary movement.