To reduce, at the time of sheet replenishment, breakage of a floating regulation member that regulates floating of a sheet floated by air blowing in a sheet storage apparatus that loosen stored sheets by means of air blowing. Air is blown to sheets stored in a storage part to loosen the sheets. One of a pair of side regulation members for regulating both ends of the sheets stored in the storage part has a floating regulation member for regulating floating of a sheet floated by means of air blowing. The floating regulation member is configured to be turnable in a sheet stacking direction about a rotation axis provided to one of the side regulation members on the side at which the floating regulation member is provided. A load applied to the floating regulation member differs between when the floating regulation member is turned upward and when it is turned downward.

One embodiment of the present disclosure provides a post-processing apparatus for an image forming apparatus which arranges paper ejected from an ejection part of an image forming apparatus on a fence for post-processing. The post-processing apparatus includes a paddle guide which includes a paddle arm to which a paddle wing is coupled and a pusher positioned adjacent to the ejection part and stands by at a home position until the paper is ejected, a driving part which vertically moves the paddle guide, rotates when the paper is ejected from the ejection part to move the paddle guide downward so that the pusher presses the paper downward and drops the paper on a stacking base, and a paddle wing which vertically moves according to a vertical movement of the paddle guide, moves downward according to a downward movement of the paddle guide, arranges the paper dropped on the stacking base toward the fence positioned adjacent to the stacking base, and then, moves upward with an upward movement of the paddle guide according to operation of the driving part, wherein vertical movements of the pusher and the paddle wing are performed by a vertical movement of the paddle guide performed due to single unit periodic operation of the driving part.

An image forming apparatus includes a photosensitive drum, a light exposure device, a developing device, a fixing unit disposed opposite to the light exposure device relative to the developing device, a sheet supply tray disposed below the developing device, an ejection tray disposed above the developing device and having a sheet receiving surface inclined downward, relative to a horizontal direction, toward the charger, and a sheet conveying path through which a sheet is conveyed from the sheet supply tray to the ejection tray. A lowest end portion of the sheet receiving surface is disposed below an upper end of the charger in the vertical direction. The charger is disposed opposite to the developing device relative to the lowest end portion of the sheet receiving surface.

A sheet conveying device includes a blocking member having a blocking surface with which a leading end of a sheet that is being conveyed comes into contact for obliquity correction. The blocking member is rotated by being pushed by the sheet against an urging force of a positioning unit that positions the blocking member to be in the standby position. The blocking member is rotatable to be in a sheet-passage-allowing orientation in which the sheet is allowed to pass. When a trailing end of the sheet that is being conveyed has passed the blocking member, the blocking member that is in the sheet-passage-allowing orientation rotates in a same direction as a sheet conveyance direction and is positioned to be in a standby position.

The sheet feeding device includes a feed roller, a separation pad and a guide part. The feed roller is configured to feed a sheet by being rotated while coming into pressure contact with the sheet. The separation pad is configured to form a separation nip by being in pressure contact with the feed roller and to separate the fed sheet at the separation nip. The guide part is configured to guide a leading edge of the sheet to the separation nip. The apex part is formed along a feeding direction of the sheet on both outer sides of the feed roller in a width direction perpendicular to the feeding direction. The apex part projects in a direction closer to the feed roller than an extension line of the separation nip between a pressure contact position of the feed roller and the sheet and the separation nip.

A sheet conveying device includes a pair of rollers including a first roller and a second roller to hold a sheet conveyed between the first and second rollers; a biasing member to bias the first roller toward the second roller; a biasing force changer to change a biasing force of the biasing member; control circuitry to, when a predetermined changing condition is met, cause the changer to change the biasing force and cause the rollers to convey the sheet; an operation detector to detect a changing operation of the changer; and a notification device to notify an abnormality of the changing operation when the operation detector detects the abnormality. When the operation detector detects the abnormality, the control circuitry performs sheet conveyance control to cause the rollers to convey the sheet without causing the changer to change the biasing force, regardless of whether the predetermined changing condition is met.

A paper sheet sensing device includes: a sheet thickness sensor that includes a reference member and a displacement sensor, and senses a sheet thickness of a conveyed recording medium by bringing the reference member into contact with the recording medium and sensing a position of a height of the reference member with the displacement sensor, the position of the height having changed with the recording medium; a first attacher to which the sheet thickness sensor is attached; a conveyor that nips and conveys the recording medium, and is disposed adjacent to the sheet thickness sensor at a predetermined distance equal to or shorter than a length of the recording medium being conveyed, in a conveyance direction of the recording medium; and a displacement preventer that prevents a change in an output of the displacement sensor due to a shift of a relative position of the height of the reference member.

A manual sheet feeding device includes: a sheet feeding rotary body configured to separate and feed recording media placed on a manual sheet feeding unit one by one; a shielding unit configured to cover an outer side surface of the sheet feeding rotary body, the shielding unit having an aperture for exposing at least a part of the sheet feeding rotary body to an outside; and an opening and closing unit configured to open and close the aperture of the shielding unit.

Techniques for determination of size of printable medium are described. In an example, a printing device includes an adjuster that is movable based on a size of a printable medium to be fed to the printing device. A first element is coupled to the adjuster and moves with the adjuster to indicate a position of the adjuster. A second element is movable relative to the adjuster. A position signal indicative of a distance between the second element and the first element is generated. The position signal can be used to determine the size of the printable medium.

A medium reversing and discharging device includes a discharger that discharges a medium in a paper discharge direction from a discharge outlet, a holder that holds and reverses the medium, and a driver that moves the holder such that when a first plane along a portion of the medium in contact with the discharge outlet does not intersect with a second plane along a portion of the medium held by the holder on a downstream side in the paper discharge direction of the discharge outlet a moving speed at which the holder moves is lower than a discharge speed at which the medium is discharged from the discharge outlet.