A page registration system may include, in an example, a media edge sensor to detect a location of an edge of a print media along a media feed path and in a direction non-parallel to the media feed path and a calibration sensor downstream of the media edge sensor to detect changes in the location of the edge of the print media in the direction non-parallel to the media feed path, and provide calibration data to the page registration system to correct changes in the location of the edge of the print media in the direction non-parallel to the media feed path.

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.

An image forming apparatus includes: a pair of rollers for conveying paper; a rocking mechanism for rocking the pair of rollers in a second direction orthogonal to a first direction, the first direction being a paper conveying direction; an upstream pair of rollers provided upstream of the pair of rollers in the paper conveying direction for conveying the paper; an upstream rocking mechanism corresponding to the upstream pair of rollers for rocking the upstream pair of rollers in the second direction; a first paper detector for detecting an end position of the paper in the second direction; and a controller controlling the rocking mechanism based on the paper end position to effect first rocking correction in which the pair of rollers is rocked, wherein the controller controls the upstream rocking mechanism to effect second rocking correction in which only the upstream pair of rollers is rocked.

An image forming apparatus includes: a pair of rollers for conveying paper; a rocking mechanism for rocking the pair of rollers in a second direction orthogonal to a first direction, the first direction being a paper conveying direction; an upstream pair of rollers provided upstream of the pair of rollers in the paper conveying direction for conveying the paper; an upstream rocking mechanism corresponding to the upstream pair of rollers for rocking the upstream pair of rollers in the second direction; a first paper detector for detecting an end position of the paper in the second direction; and a controller controlling the rocking mechanism based on the paper end position to effect first rocking correction in which the pair of rollers is rocked, wherein the controller controls the upstream rocking mechanism to effect second rocking correction in which only the upstream pair of rollers is rocked.

An inkjet recording apparatus includes a conveyance unit which conveys a recording medium, a recording unit which is disposed opposite the conveyance unit and ejects ink onto a recording medium conveyed by the conveyance unit, an edge position detection sensor which detects edge positions on both sides of the recording medium in a recording-medium width direction, and a control unit which controls ink ejection performed by the recording unit. The recording unit has a recording head where a large number of ink ejection nozzles are arrayed along the recording-medium width direction. The control unit calculates a center position of the recording medium from the edge positions on both sides in the recording-medium width detected by the edge position detection sensor, and shifts a use range of the ink ejection nozzles based on a distance between the center position calculated and a reference center position.

An inkjet recording apparatus includes a conveyance unit which conveys a recording medium, a recording unit which is disposed opposite the conveyance unit and ejects ink onto a recording medium conveyed by the conveyance unit, an edge position detection sensor which detects edge positions on both sides of the recording medium in a recording-medium width direction, and a control unit which controls ink ejection performed by the recording unit. The recording unit has a recording head where a large number of ink ejection nozzles are arrayed along the recording-medium width direction. The control unit calculates a center position of the recording medium from the edge positions on both sides in the recording-medium width detected by the edge position detection sensor, and shifts a use range of the ink ejection nozzles based on a distance between the center position calculated and a reference center position.

According to an example, an apparatus to prevent media transport jams may include an actuator to load and advance a media within a media path width. The apparatus may also include a first sensor and a second sensor to detect respective edges of the media, in which the first sensor and the second sensor may be positioned outside of a media action area and on opposite sides of the media path width. The apparatus may further include a controller to prevent the actuator from advancing the media along the media path in response to a detection of one or both of the first edge of the media by the first sensor and the second edge of the media by the second sensor.

A sheet position correction device includes a detection unit, a skew correcting portion, a moving unit, and a control unit. The detection unit is configured to detect inclination of a sheet, and a position of a sheet in a width direction. The skew correcting portion is configured to convey the sheet, and correct skewing of the sheet. The moving unit is configured to move the skew correcting portion in the width direction. The control unit is configured to perform control such that skew correction of the sheet by the skew correcting portion and movement of the skew correcting portion by the moving unit are performed in parallel based on a detection result of the detection unit.

A sheet transport device includes a transport path along which a sheet is transported in one direction; a sheet butting portion provided at one side of the transport path; a sheet rotating section; and a sheet butting section. When a short sheet is transported along the transport path, the sheet rotating section rotates the short sheet such that a leading end is directed to the other side of the transport path, and when a long sheet is transported, the sheet rotating section rotates the long sheet such that an angle of inclination with respect to the one direction is reduced. The sheet butting section moves the short sheet rotated by the sheet rotating section toward the one side to make the side edge of the short sheet butt against the sheet butting portion, while allowing the long sheet to pass therethrough without moving the long sheet toward the one side.

A sheet transport device includes a transport path along which a sheet is transported in one direction; a sheet butting portion provided at one side of the transport path; a sheet rotating section; and a sheet butting section. When a short sheet is transported along the transport path, the sheet rotating section rotates the short sheet such that a leading end is directed to the other side of the transport path, and when a long sheet is transported, the sheet rotating section rotates the long sheet such that an angle of inclination with respect to the one direction is reduced. The sheet butting section moves the short sheet rotated by the sheet rotating section toward the one side to make the side edge of the short sheet butt against the sheet butting portion, while allowing the long sheet to pass therethrough without moving the long sheet toward the one side.