Examples include: a leveling system for a top feeder of a printer, where the top feeder includes a media positioning arrangement. The leveling system has a detector for detecting reflected light and generating a three-dimensional image comprising media positioning regions corresponding to the media positioning arrangement on a top sheet of a media stack installed into the top feeder. Also, the leveling system has an actuator configured to adjust heights of different points of the bottom of the media stack. Further, it has a controller for selecting, based on the three-dimensional image, adjustments to the heights for improving leveling of at least one of the media positioning regions; and controlling the actuator to implement the adjustments.

Examples include: a leveling system for a top feeder of a printer, where the top feeder includes a media positioning arrangement. The leveling system has a detector for detecting reflected light and generating a three-dimensional image comprising media positioning regions corresponding to the media positioning arrangement on a top sheet of a media stack installed into the top feeder. Also, the leveling system has an actuator configured to adjust heights of different points of the bottom of the media stack. Further, it has a controller for selecting, based on the three-dimensional image, adjustments to the heights for improving leveling of at least one of the media positioning regions; and controlling the actuator to implement the adjustments.

A sheet stacker includes a housing, a fence, a first distance measurement sensor, and a second distance measurement sensor. The fence is movable in a fence moving direction on the housing and is configured to regulate a position of an end of a sheet. The first distance measurement sensor is configured to measure a distance between the fence and a first portion of the housing, the first portion being on one side of the housing with respect to the fence in the fence moving direction. The second distance measurement sensor is configured to measure a distance between the fence and a second portion of the housing, the second portion being on another side of the housing with respect to the fence in the fence moving direction.

A medium conveying apparatus includes a plurality of feed rollers, each feed roller rotating independently at a respective speed to feed a medium, a first sensor located on a downstream side of the plurality of feed rollers in a medium conveying direction and also in a central part in a direction perpendicular to the medium conveying direction, to detect the medium, a second sensor and a third sensor located on both sides of the first sensor in the direction perpendicular to the medium conveying direction, to respectively detect the medium, and a processor to change the speed of one of the plurality of feed rollers at least until the first sensor detects the medium when any of the second sensor or the third sensor detects the medium and the first sensor does not detect the medium within a predetermined time.

A medium conveying apparatus includes a plurality of feed rollers, each feed roller rotating independently at a respective speed to feed a medium, a first sensor located on a downstream side of the plurality of feed rollers in a medium conveying direction and also in a central part in a direction perpendicular to the medium conveying direction, to detect the medium, a second sensor and a third sensor located on both sides of the first sensor in the direction perpendicular to the medium conveying direction, to respectively detect the medium, and a processor to change the speed of one of the plurality of feed rollers at least until the first sensor detects the medium when any of the second sensor or the third sensor detects the medium and the first sensor does not detect the medium within a predetermined time.

A sheet transport system for moving a sheet in a transport direction while adjusting a position of the sheet in a lateral direction normal to the transport direction to a target position, includes first and second pinch roller sets spaced apart from one another in the transport direction, each pinch roller set including two pairs of pinch rollers spaced apart from one another in the lateral direction, each pair forming a nip for pinching and driving the sheet with an individually controllable speed; a detection system for detecting a position of the sheet in the lateral direction while the sheet is pinched by the first pinch roller set; and a control system configured for carrying out the following actions: by controlling the speeds of the pinch rollers of the first pinch roller set before the sheet has reached the second pinch roller set, rotating the sheet by a first rotation angle for adjusting a given reference point on a leading part of the sheet to its target position; and when the sheet has left the first pinch roller set and while the reference point travels along a path segment that is symmetric with respect to the second pinch roller set, rotating, by controlling the speeds of the pinch rollers of the second pinch roller set, the sheet by a second rotation angle for aligning a leading edge of the sheet in the lateral direction.

A sheet conveying device includes a position detector configured to detect a position of a side end portion of a conveyance target medium, a position adjuster configured to move 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 sheet conveyance, while conveying the conveyance target medium, and adjust a position of the conveyance target medium, according to the position of the side end portion of the conveyance target medium detected by the position detector, a transfer rotary body disposed downstream from the position adjuster in a sheet conveying direction and having a receiver mounted on the rotary body to receive the conveyance target medium, and circuitry configured to change a rotation speed of the transfer rotary body according to the position of the conveyance target medium after adjusted by the position adjuster.

A sheet conveying device includes a position detector configured to detect a position of a side end portion of a conveyance target medium, a position adjuster configured to move 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 sheet conveyance, while conveying the conveyance target medium, and adjust a position of the conveyance target medium, according to the position of the side end portion of the conveyance target medium detected by the position detector, a transfer rotary body disposed downstream from the position adjuster in a sheet conveying direction and having a receiver mounted on the rotary body to receive the conveyance target medium, and circuitry configured to change a rotation speed of the transfer rotary body according to the position of the conveyance target medium after adjusted by the position adjuster.

The image forming apparatus includes a transfer section that transfers an image to a sheet; a sheet conveying member that is provided on an upstream side of the transfer section in a conveying direction of the sheet and that conveys the sheet; and a hardware processor that controls displacement of the sheet conveying member such that the sheet is displaced in a width direction of the sheet. The hardware processor causes a detector that detects an edge of the sheet in the width direction to detect the edge of the sheet after displacement of the sheet conveying member has been started, and causes the displacement to be terminated on the basis of the detected result such that the edge of the sheet reaches a target position.

The image forming apparatus includes a transfer section that transfers an image to a sheet; a sheet conveying member that is provided on an upstream side of the transfer section in a conveying direction of the sheet and that conveys the sheet; and a hardware processor that controls displacement of the sheet conveying member such that the sheet is displaced in a width direction of the sheet. The hardware processor causes a detector that detects an edge of the sheet in the width direction to detect the edge of the sheet after displacement of the sheet conveying member has been started, and causes the displacement to be terminated on the basis of the detected result such that the edge of the sheet reaches a target position.