An image forming apparatus includes: an image forming unit; a first re-conveyance guide that guides a sheet on which an image is formed in a re-conveying direction; a second re-conveyance guide that guides the sheet from the first re-conveyance guide toward the image forming unit; a side guide provided at one end portion of the second re-conveyance guide in a widthwise direction to regulate the sheet; a side chute provided at one end portion of the first re-conveyance guide in the widthwise direction; and an engaging portion provided on the second re-conveyance guide. The engaging portion is engaged with a first engaging portion extending downward from an upstream end portion of the side guide in the re-conveying direction and is engaged with a second engaging portion provided on a downstream end portion of the side chute in the re-conveying direction.

A sheet conveyance apparatus that conveys a sheet along a curved path shorter than the sheet and corrects skew of the sheet, includes: a conveyance roller that sends the sheet into the curved path; a guide that guides the sheet along the curved path; and a gate that is hinders advance of the leading end, generates a moment about a normal of the sheet passing through the leading end, and allows advance of the leading end by being pushed away by the leading end, wherein the guide includes a projection projecting toward a movement space for the sheet on a surface facing the movement space, and the projection abuts a center portion of the sheet in a longitudinal direction and generates a moment about an axis parallel to an advance direction of a portion that has come into contact with the projection.

There is provided an intermediate unit including a transportation path along which a medium, on which printing has been performed by a printing unit that performs printing on the medium by using liquid, is transported to a post processing unit that performs post processing on the medium. The transportation path includes first and second inversion paths in which the medium is inverted upside down, respectively, the second inversion path being provided with a decurling unit that corrects curl of the medium, the first inversion path being not provided with the decurling unit, the first and second inversion paths being selectively used to invert the medium upside down according to printing data for the medium.

An upstream roller pair and a downstream roller pair are disposed on a first conveyance path and configured to perform a reverse conveyance operation on a sheet. The upstream roller pair includes a first roller and a second roller abutting with each other. The downstream roller pair is configured to nip and convey a sheet by a third roller and a fourth roller in a state that areas in a width direction where a plurality of first rotary members contact a first surface of a sheet do not overlap with areas in the width direction where a plurality of second rotary members contact a second surface of a sheet opposite to the first surface.

A medium transporting device provided in a printer includes a curved path in which a paper sheet after recording is curved and inverted, a plurality of first ribs that extend in a medium transportation direction in a facing area facing a recording head, that are provided at intervals in a width direction intersecting the medium transportation direction, and that form cockling on the paper sheet, a plurality of second ribs that are provided on an outer curved portion of the curved path, and a plurality of third ribs that are provided on an inner curved portion of the curved path. The plurality of second ribs and the plurality of third ribs are disposed at positions in the width direction that correspond to a mountain portion and a valley portion of the cockling of the paper sheet that is formed by the plurality of first ribs.

In one example, a sheet media alignment system includes: a guide (12) defining a curved media path (14) that extends from an upstream part of the guide to a downstream part of the guide; a movable blocker (16, 56) to block the curved media path (14) at the downstream part of the guide, the blocker movable into and out of a blocking position in which the blocker is spaced from the downstream part of the guide a first distance; and a driver (24, 58) upstream from the curved media path to drive a media sheet into the guide along the curved media path and into the blocker. The driver is spaced from the upstream part of the guide a second distance greater than the first distance such that a media sheet driven into the blocker will buckle between the driver and the guide before it will buckle between the guide and the blocker.

An image forming apparatus includes a main body, an image forming unit, a sheet tray disposed below the image forming unit, and a retransport assembly configured to transport a sheet along a retransport path including first, second, and third retransport path portions in a transport direction. The retransport assembly includes a portion of the sheet tray defining the first retransport path portion, a connecting unit and a retransport unit, which are disposed below the sheet tray. The connecting unit defines the second retransport path portion connected to an upstream end of the third retransport path portion in the transport direction. The retransport unit is movable between a stored position and a pulled-out position. The retransport unit at the stored position defines the first retransport path portion connected to an upstream end of the second retransport path portion in the transport direction.

A medium transporting device provided in a printer includes a curved path in which a paper sheet after recording is curved and inverted, a plurality of first ribs that extend in a medium transportation direction in a facing area facing a recording head, that are provided at intervals in a width direction intersecting the medium transportation direction, and that form cockling on the paper sheet, a plurality of second ribs that are provided on an outer curved portion of the curved path, and a plurality of third ribs that are provided on an inner curved portion of the curved path. The plurality of second ribs and the plurality of third ribs are disposed at positions in the width direction that correspond to a mountain portion and a valley portion of the cockling of the paper sheet that is formed by the plurality of first ribs.

There is provided a printing apparatus that is capable of reducing an occurrence of transport disorder of a medium when transporting the medium unwound from an unwinding unit that holds a roll body.

The printing apparatus performs printing on the medium unwound from the roll body having the medium wound into a cylindrical shape, the printing apparatus including: an unwinding unit 40 that rotatably holds the roll body and unwinds the medium by rotating the roll body; a transport unit that transports the medium unwound from the unwinding unit 40; and a printing unit that performs printing on the medium transported by the transport unit. The unwinding unit 40 includes a first rotary body 441 that is integrally rotatable with the roll body by engaging with a first end of the roll body, a second rotary body 451 that is integrally rotatable with the roll body by engaging with a second end of the roll body, a first motor 442 that rotatably drives the first rotary body 441, and a second motor 452 that rotatably drives the second rotary body 451.

A paper conveyance device includes: an upstream roller and a downstream roller being arranged at an interval in a paper conveyance path; paper conveyance guides being arranged between the upstream and downstream roller in the paper conveyance path to guide both surfaces of paper along the paper conveyance path during paper conveyance; drivers that drive the upstream and downstream roller independently; and a processor that measures the load torques on the upstream and downstream roller, that judges whether or not the paper is rubbing against one of the paper conveyance guides with reference to the load torques on the upstream and downstream roller, the load torques being obtained by the processor, and that performs controlled paper conveyance with reference to the load torques on the upstream and downstream roller depending on the result of the judgment being obtained by the processor.