A sheet feeding mechanism includes a feeding path, at least one card feeding roller mounted to the feeding path, at least one paper feeding roller coaxial with the at least one card feeding roller, at least one card idle roller contacting with the at least one card feeding roller, at least one paper idle roller contacting with the at least one paper feeding roller, at least one elastic unit connected to the feeding path, and a stroke limiting unit. The at least one elastic unit is fastened to the feeding path. The at least one elastic unit has a stretching stroke. The stroke limiting unit controllably shortens the stretching stroke.

A sheet processing system for automated sheet adjustment includes a sensor system which captures at least a first image of a sheet of print media as the sheet is conveyed on a main transport path between a print media supply module and a marking device of an image rendering module. A control module computes a lateral error for the sheet, based on the captured at least first image, and computes an adjustment based on the computed lateral error. A sheet transport path adjustment mechanism translates a first portion of the main transport path relative to a second portion of the main transport path, based on the computed adjustment.

A rotation device rotates a sheet on an upstream side of, in a sheet conveyance orientation, a working device positioned in a middle of a conveyance path, thereby changing an orientation of the sheet. An information acquiring portion acquires sheet size information and sheet orientation information representing a size and the orientation of the sheet in a sheet storing portion, and working position information representing a working position on the sheet. A rotation control portion controls the rotation device in accordance with the sheet orientation information and the working position information. The working control portion controls the working device in accordance with the orientation of the sheet after passing through the rotation device, and the sheet size information and the working position information.

A rotation device rotates a sheet on an upstream side of, in a sheet conveyance orientation, a working device positioned in a middle of a conveyance path, thereby changing an orientation of the sheet. An information acquiring portion acquires sheet size information and sheet orientation information representing a size and the orientation of the sheet in a sheet storing portion, and working position information representing a working position on the sheet. A rotation control portion controls the rotation device in accordance with the sheet orientation information and the working position information. The working control portion controls the working device in accordance with the orientation of the sheet after passing through the rotation device, and the sheet size information and the working position information.

An image forming device includes a tray on which a sheet is to be placed and including a plurality of first electrodes arranged along a first direction, a sheet guide including a conductor and movable along the first direction to different positions relative to the first electrodes, a detection circuit electrically connected to each of the first electrodes and configured to detect an amount of electric charge in each of the first electrodes, a printer configured to form an image on the sheet supplied from the tray, and a processor configured to determine a size of the sheet placed on the tray based on amounts of electric charge detected by the detection circuit, and control the printer to form an image on the sheet using the determined size.

An image forming apparatus includes a sheet storage unit including a sheet tray on which one or more sheets are to be stacked, a sensor configured to detect that the sheet storage unit is being operated, and a processor configured to execute a predetermined process after the sensor detects that the sheet storage unit has been operated, and a predetermined condition relating to an occurrence of the sheet conveyance error is satisfied.

A sheet transport device includes a processor configured to change lifting control for lifting sheets on a tray, which are to be floated up and handed over, from normal state control to small-quantity state control in a case where it is detected that the remaining number of sheets on the tray is small.

A sheet transport device includes a processor configured to change lifting control for lifting sheets on a tray, which are to be floated up and handed over, from normal state control to small-quantity state control in a case where it is detected that the remaining number of sheets on the tray is small.

A sheet feeding device includes a sheet stacking unit, a long sheet stacking unit, a first guide, a first detector, and a closing unit. The sheet stacking unit is movable up and down. Sheets are stacked on the sheet stacking unit. The long sheet stacking unit is detachably mounted on the sheet stacking unit. Long sheets are stacked on the long sheet stacking unit. The first guide is movable along a feeding direction through a groove. The first guide is deformable into a shape that does not interfere with the long sheet stacking unit. The first guide guides a rear end portion of the sheets in the feeding direction. The first detector is provided in the first guide. The first detector detects the sheets stacked on the sheet stacking unit. The closing unit is detachably attached to the groove in the sheet stacking unit. The closing unit closes the groove.

A sheet feeding device includes a sheet stacking unit, a long sheet stacking unit, a first guide, a first detector, and a closing unit. The sheet stacking unit is movable up and down. Sheets are stacked on the sheet stacking unit. The long sheet stacking unit is detachably mounted on the sheet stacking unit. Long sheets are stacked on the long sheet stacking unit. The first guide is movable along a feeding direction through a groove. The first guide is deformable into a shape that does not interfere with the long sheet stacking unit. The first guide guides a rear end portion of the sheets in the feeding direction. The first detector is provided in the first guide. The first detector detects the sheets stacked on the sheet stacking unit. The closing unit is detachably attached to the groove in the sheet stacking unit. The closing unit closes the groove.