A medium transporting apparatus including a paddle that comes in contact with a medium discharged on a first tray including an upstream end matching member and that rotates to move the medium towards the upstream end matching member, and a low frictional resistance member configured to switch between an advanced state advanced from outside a medium mount region of the first tray to a first region, and a retracted state retracting from the first region to an outside of the medium mount region. The low frictional resistance member is, after a first medium is mounted on the first tray, switched from the retracted state to the advanced state, and is interposed between the first medium and a second medium when, after discharging the first medium, moving the second medium discharged from a pair of discharge rollers towards the upstream end matching member with the paddle.

A sheet stacker includes a pair of sheet holders, a sheet leading-edge aligner, a sheet stacking member, and control circuitry. A downstream side of the pair of sheet holders in a conveyance direction of a conveyed sheet is lowered along the conveyance direction. Each one of the pair of sheet holders is movable in an orthogonal direction to the conveyance direction. The pair of sheet holders hold both side-end portions of the sheet in the orthogonal direction. The sheet stacking member is disposed below the pair of sheet holders. A downstream side of the sheet stacking member in the conveyance direction is lowered along the conveyance direction. The sheet stacking member stacks the sheet dropped from the pair of sheet holders after a leading edge of the sheet is aligned by the leading-edge aligner. The control circuitry controls operations of the leading-edge aligner and the pair of sheet holders.

Provided are: a sheet feed device that is capable of suppressing the occurrence of a sheet feeding fault by changing the pressing contact force of a retard roller against a feed roller; and an image formation device equipped with the same. This sheet feed unit (50) is provided with: a pickup roller (29); a feed roller (31); a retard roller (32); a holding member (40) that holds the retard roller (32); a first biasing member (42) that biases the holding member (40); and a pressing contact force changing mechanism (60) that changes the pressing contact force of the retard roller (32) against the feed roller (31). The pressing contact force changing mechanism (60) has: a rotary shaft (61) disposed parallel to the axial direction of the retard roller (32); a cam member (70) that rotates with the rotary shaft (61); and a movable member (80) that contacts the cam member (70), moves in the axial direction in conjunction with the rotation of the cam member (70), and changes the biasing force generated by the first biasing member (42).

An image forming apparatus includes a stacking unit, a feeding unit, an image forming unit, a discharge stacking unit, a detecting unit, a double-side feeding passage, and a controller. In a case that subsequent to a current recording material, a subsequent recording material is discharged, the controller determines a feeding timing of the subsequent recording material depending on a discharge interval time from discharge of the current recording material on the discharge stacking unit to discharge of the subsequent recording material on the discharge stacking unit, and determines the discharge interval time on the basis of print information of at least the subsequent recording material.

A sheet stacker includes a pair of sheet holders, a sheet leading-edge aligner, a sheet stacking member, and control circuitry. A downstream side of the pair of sheet holders in a conveyance direction of a conveyed sheet is lowered along the conveyance direction. Each one of the pair of sheet holders is movable in an orthogonal direction to the conveyance direction. The pair of sheet holders hold both side-end portions of the sheet in the orthogonal direction. The sheet stacking member is disposed below the pair of sheet holders. A downstream side of the sheet stacking member in the conveyance direction is lowered along the conveyance direction. The sheet stacking member stacks the sheet dropped from the pair of sheet holders after a leading edge of the sheet is aligned by the leading-edge aligner. The control circuitry controls operations of the leading-edge aligner and the pair of sheet holders.

A paper stacking device includes: a stacker on which paper is stacked; a paper ejector that ejects the paper; an aligning plate that is provided on a side of the paper, and aligns a side end of the paper; a paper floating member that is provided in the aligning plate, and supports, from below, the side end of the paper; and a blower that is provided on the side of the paper across the aligning plate, and blows air, wherein the aligning plate includes a blowing opening through which air from the blower is blown, the paper floating member is switched between: a paper floating position; and a retreat position, when the paper floating member is located in the paper floating position, the blowing opening is opened, and when the paper floating member is located in the retreat position, the blowing opening is shielded.

A sheet stacking device includes a stacker, a detector, a blower, and a moving device. A sheet is stacked on the stacker. The detector detects a stacking amount of the sheet on the stacker. The blower blows air to the sheet stacked on the stacker. The moving device moves the blower with respect to the stacker based on the stacking amount of the sheet detected by the detector.

Provided are: a sheet feed device that is capable of suppressing the occurrence of a sheet feeding fault by changing the pressing contact force of a retard roller against a feed roller; and an image formation device equipped with the same. This sheet feed unit (50) is provided with: a pickup roller (29); a feed roller (31); a retard roller (32); a holding member (40) that holds the retard roller (32); a first biasing member (42) that biases the holding member (40); and a pressing contact force changing mechanism (60) that changes the pressing contact force of the retard roller (32) against the feed roller (31). The pressing contact force changing mechanism (60) has: a rotary shaft (61) disposed parallel to the axial direction of the retard roller (32); a cam member (70) that rotates with the rotary shaft (61); and a movable member (80) that contacts the cam member (70), moves in the axial direction in conjunction with the rotation of the cam member (70), and changes the biasing force generated by the first biasing member (42).

A cleaning device cleans a conveyance face of a conveyance member conveying a sheet. The cleaning device includes a delivery roller, a pressure roller, a fixed roller and a winding roller. The delivery roller supports a web roll that a belt shaped web is wound into a roll. The pressure roller brings the web delivered from the web roll into pressure-contact with the conveyance face. The fixed roller keeps an extending angle of the web passed from between the conveyance member and the pressure roller constant. The winding roller winds the used web passed the fixed roller into a roll.

A sheet stacking device includes a stacker, a detector, a blower, and a moving device. A sheet is stacked on the stacker. The detector detects a stacking amount of the sheet on the stacker. The blower blows air to the sheet stacked on the stacker. The moving device moves the blower with respect to the stacker based on the stacking amount of the sheet detected by the detector.