An image forming apparatus includes a drawer unit, a sheet inverting unit, a sheet guide plate, and a projection. The drawer unit is drawable from an apparatus body. The sheet inverting unit is disposed in the apparatus body, and pulls a sheet into a lower portion of the drawer unit to invert the sheet. The sheet guide plate is disposed on the sheet inverting unit to face the drawer unit, and includes a recess extending in a pull-out direction of the drawer unit that crosses a direction in which the sheet is transported. The projection protrudes toward the recess from a portion of a lower surface of the drawer unit facing the sheet guide plate near a pull-out start point in the pull-out direction and on a rear of a transport area of the sheet.

A medium transport device includes a first roller that applies a transporting force to a medium, a second roller that applies a transporting force to the medium transported from the first roller, a third roller that applies a transporting force to the medium transported from the second roller, a first rotor that transmits rotational torque to the third roller, a first shaft that is provided away from the first rotor at a first interval, and a second shaft that is provided away from the first rotor at the first interval and at a position different from a position of the first shaft. A shaft center of the first shaft and a shaft center of the second shaft are positioned on a circular arc, the center of which is a rotation center of the second roller.

A sheet conveyance apparatus includes first and second conveyance paths, a conveyance roller pair, first and second conveyance guides, and a holding unit. The reverse unit reverses a sheet having passed through the first conveyance path. The second conveyance path conveys the sheet having passed through the first conveyance path between the reverse unit and the first conveyance path. The conveyance roller pair nips and convey the reversed sheet. The first conveyance guide forms the second conveyance path and the second conveyance guide forms the second conveyance path. The holding unit moveably holds the first conveyance guide. The first conveyance guide moves between a first position located at a first distance from the second conveyance guide and a second position located at a second distance. The sheet reversed by the reverse unit is conveyed toward the conveyance roller pair by the first conveyance guide located at the first position.

An image forming apparatus includes an image forming portion configured to form an image on a sheet; a pair of conveyance rotary members arranged downstream of the image forming portion in a sheet conveyance direction and configured to convey the sheet, on which the image is formed, by a conveyance nip; and a guide portion configured to guide the sheet to the conveyance. The guide portion includes a first guide member formed into a sheet shape and having a first stiffness and an abutment surface configured to abut the sheet and a second guide member formed into a sheet shape and having a second stiffness higher than the first stiffness and arranged on a side opposite to the abutment surface of the first guide member, wherein a downstream edge of the first guide member is closer to the conveyance nip than a downstream edge of the second guide member.

An image forming apparatus includes an image forming portion, a sheet reversing roller portion, a first sheet feeding passage, a second sheet feeding passage, a sheet a guiding member forming a retraction feeding passage for guiding upward a leading end of the sheet fed from the reversing roller portion rotating in the first direction and then for guiding the sheet, guided upward, in a direction crossing a vertical direction, the guiding member having an inner surface curved to guide one side of the sheet, and a preventing member for preventing a droop of the leading end of the sheet by contact with the sheet guided in the direction crossing the vertical direction by the sheet guiding member.

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 relay conveyance device includes a relay conveyance path arranged between an image forming apparatus and a post processing device to convey a sheet from the image forming apparatus to the post processing device, two reversing units reversing a surface side and a back-face side of the sheet, and a control device controlling conveyance of the sheet on the relay conveyance path. The relay conveyance path includes two reverse paths respectively passing through the two reversing units, a branch section branching into the two reverse paths at an upstream side, and a confluence section joining the two reverse paths. The control device controls the branch and confluence sections to convey the sheet while alternately switching the two reverse paths, measures an interval time between the sheets passing through the confluence section, and controls conveyance of the sheet in the two reverse paths so as to uniformize the interval time.

A sheet conveying device includes a first sheet conveyance passage, a second sheet conveyance passage, and a branching guide. The first sheet conveyance passage is a passage through which a sheet passes in a first direction. The second sheet conveyance passage shares a part of the first sheet conveyance passage and branches off from the first sheet conveyance passage in a second direction opposite the first direction of the first sheet conveyance passage. The branching guide is disposed at a position where the first sheet conveyance passage meets the second sheet conveyance passage. The branching guide is configured to move between a first position for the first direction and a second position for the second direction. A plurality of branching guides including the branching guide is spaced apart in a width direction of the sheet and separately switchable between the first position and the second position.

An image forming apparatus, including a main chassis having a discharge tray and a switchback tray in an upper position with respect to the discharge tray; an image forming unit; a discharge roller to discharge a recording sheet conveyed through the image forming unit onto the discharge tray; a duplex conveyer to invert the sheet and convey the inverted sheet to return to the image forming unit; and a switchback roller being rotatable in a normal direction to convey the sheet toward the switchback tray and a reverse direction to convey the sheet to the duplex conveyer; is provided. The main chassis includes a pair of walls, each of which extends in a vertical direction and in a conveying direction of the sheet and is arranged in adjacent to the switchback tray such that the switchback tray is interposed between the pair of walls.

A medium transporting apparatus includes a first medium transport path in which a transport roller pair is provided, a second medium transport path for feeding a medium fed downstream in a medium transport direction from the transport roller pair to an upstream position of the transport roller pair in the first medium transport path, and a medium detection unit for detecting passage of a medium in the first medium transport path, in which a position at which the medium detection unit detects a medium is switched between a transport direction upstream position and a transport direction downstream position of the transport roller pair according to whether or not a medium is transported on the second medium transport path.