A sheet feeding device includes: a feeding unit that is provided to be movable in a forward-backward direction to move forward or backward relative to a sheet placing unit on which a sheet is placed, and feeds the sheet; a moving unit that moves the feeding unit in the forward-backward direction; a contact unit that is provided to be movable, with which the sheet placed on the sheet placing unit is brought into contact; a limitation unit that limits movement of the contact unit; and a releasing unit that, when the moving unit moves the feeding unit in a direction away from the sheet placing unit, with the movement of the feeding unit, releases limitation on the movement of the contact unit by the limitation unit.

In a sheet conveyor, a stopper piece of a sheet stopper temporarily stops a sheet supported on a sheet tray, and a pickup roller conveys the sheet from the sheet tray in a sheet conveying direction. A first sheet sensor disposed upstream of a registration roller and downstream of the stopper piece in the sheet conveying direction detects a leading edge of the sheet, and a second sheet sensor disposed downstream of the registration roller detects the leading edge of the sheet. A first contact member of the first sheet sensor receives the leading edge of the sheet. A second contact member of the second sheet sensor receives the leading edge of the sheet. The stopper piece, the first contact member, and the second contact member are offset from each other in a direction perpendicular to the sheet conveying direction and unaligned with each other in the sheet conveying direction.

In a sheet conveyor, a stopper piece of a sheet stopper temporarily stops a sheet supported on a sheet tray, and a pickup roller conveys the sheet from the sheet tray in a sheet conveying direction. A first sheet sensor disposed upstream of a registration roller and downstream of the stopper piece in the sheet conveying direction detects a leading edge of the sheet, and a second sheet sensor disposed downstream of the registration roller detects the leading edge of the sheet. A first contact member of the first sheet sensor receives the leading edge of the sheet. A second contact member of the second sheet sensor receives the leading edge of the sheet. The stopper piece, the first contact member, and the second contact member are offset from each other in a direction perpendicular to the sheet conveying direction and unaligned with each other in the sheet conveying direction.

Regarding a restricting member that includes a contact face configured to be brought into contact with at least one portion of edges of a bundle of media mounted on a medium mounting section, and that is configured to be switched to either a blocking attitude for blocking advancement of the edges of the bundle of media into a nip portion between a feeding roller and a separating roller or an opening attitude for permitting the advancement of the edges of the bundle of media into the nip portion, the restricting member allows, in the blocking attitude, an edge shape of the bundle of media in contact with the contact face to be formed into a shape that fills in a tapered space tapering toward the nip portion.

A sheet feeder includes: a wheel for issuing a lowermost sheet out to a sheet processing unit; a grate for spacing the sheet apart from the wheel at a raised position and bringing the sheet into contact with the wheel at a lowered position; and a drive device for driving the grate up and down. The drive device includes: a link mechanism for movably supporting the grate; a spring for urging the grate to the lowered position; a grate raising/lowering cam for periodically driving the grate up/down; and a skip feed cam that is driven by a control device, separately from a drive system of the grate raising/lowering cam, and that, at a timing where reached is a phase at which the grate raising/lowering cam does not put the grate in the raised position, retains the grate at the raised position in order to skip feeding of the sheet.

A sheet feeder includes: a wheel for issuing a lowermost sheet out to a sheet processing unit; a grate for spacing the sheet apart from the wheel at a raised position and bringing the sheet into contact with the wheel at a lowered position; and a drive device for driving the grate up and down. The drive device includes: a link mechanism for movably supporting the grate; a spring for urging the grate to the lowered position; a grate raising/lowering cam for periodically driving the grate up/down; and a skip feed cam that is driven by a control device, separately from a drive system of the grate raising/lowering cam, and that, at a timing where reached is a phase at which the grate raising/lowering cam does not put the grate in the raised position, retains the grate at the raised position in order to skip feeding of the sheet.

A sheet feeding apparatus includes a sheet supporting portion including a supporting surface, an abutment portion against which a leading edge of the sheet abuts, a feeding rotator configured to feed the sheet, a first friction member provided on the supporting surface so as to face the feeding rotator, the first friction member including a first friction surface having a static friction coefficient greater than that of the supporting surface, a trailing end supporting portion configured to support a trailing end portion of the sheet curved upward, and a second friction member disposed upstream of the first friction member in the sheet feeding direction on the supporting surface, the second friction member including a second friction surface which has a static friction coefficient greater than that of the supporting surface and is configured to be in contact with the sheet supported by the supporting surface.

A sheet feeder comprises a sheet stacking unit which stacks sheets, a sheet pickup unit which picks up a sheet from one side of the stacked sheets on the sheet stacking unit, a sheet separating and feeding unit which separately feeds sheets one by one to a conveyance path, an orientation holding unit which holds a feed orientation of a sheet, and a biasing unit which biases the orientation holding unit from a retracted position to a projecting position. A projection amount of the orientation holding unit from an inclined surface increases as the number of stacked sheets decreases, and the projection amount from the inclined surface decreases as the number of stacked sheets increases.

A sheet feeder comprises a sheet stacking unit which stacks sheets, a sheet pickup unit which picks up a sheet from one side of the stacked sheets on the sheet stacking unit, a sheet separating and feeding unit which separately feeds sheets one by one to a conveyance path, an orientation holding unit which holds a feed orientation of a sheet, and a biasing unit which biases the orientation holding unit from a retracted position to a projecting position. A projection amount of the orientation holding unit from an inclined surface increases as the number of stacked sheets decreases, and the projection amount from the inclined surface decreases as the number of stacked sheets increases.

A sheet feeding device comprising: a stacking member on which a sheet is stacked; a first conveying portion that conveys a sheet stacked on the stacking member; a second conveying portion that separates and conveys a sheet conveyed by the first conveying portion; a stopper member that stops a sheet whose front end is abutted against the stopper member at an upstream of the second conveying portion in a sheet conveying direction, wherein the stopper member can be at a first position where the sheet can be stopped and a second position where the sheet can pass the stopper member, and wherein the stopper member can move from the first position toward the second position such that a sheet conveyed by the first conveying portion reaches the second conveying portion while maintaining a state where the front end of the sheet is abutted to the stopper member.