An image forming apparatus includes a sheet container accommodating a recording medium therein, a sheet separating feeder including a sheet feeding body and a sheet separating body, an image forming part, and a bend applier. The sheet feeding body feeds the recording medium along with a surface movement thereof while the recording medium contacting the surface thereof. The sheet separating body forms a sheet separation nip region with the sheet feeding body and sandwiches the recording medium in the sheet separation nip region. The sheet separating feeder separates and feeds the recording medium contacting the sheet feeding body. The image forming part forms an image on the recording medium. The bend applier having a leading end of an elastic material contacts and bends the recording medium before the sheet separation nip region and generates a wrinkle extending on the recording medium in a sheet conveying direction.

A sheet feeding device includes a stacking member, a feeding unit, and a detachable separation unit. The feeding unit feeds sheets stacked from the stacking member. The separation unit separates the fed sheets one by one. The separation unit includes a rotating member to abut and separate from the feeding unit and to rotate, a biasing member to bias the rotating member toward the feeding unit, and an engaged member to be engaged with an engagement member included in the sheet feeding device. The engagement member can move to a first position where the engagement member is engaged with the engaged member, and a second position away from the engaged member. Where the engagement member moves from the first to the second position when the separation unit is attached to the sheet feeding device, the separation unit moves in a detachment direction using the biasing member.

A retarding roller (a roller) is formed of a synthetic rubber (an industrial rubber material) such as ethylene propylene diene M-class rubber (EPDM) or polyurethane, or alternatively, silicone. The roller core of the retarding roller is cylindrical. M arc-shaped long holes (where M is an integer greater than or equal to 4) are formed in each of N layers (where N is an integer greater than or equal to 2) from a first layer (an outermost layer) to an Nth layer (an innermost layer) which are circular and concentric to a center axial line. In each layer, long holes are formed such that spokes in adjacent layers (an ith layer and an i+1th layer, where i is an integer from 1 to N−1) do not overlap in the circumferential direction.

A holding member is configured to hold a feed member and movable up and down. A lever member is configured to pivot on a pivot shaft and includes a contact portion configured to be in contact with the holding member. An elastic member is connected to the lever member and configured to urge the holding member downward through the lever member. The elastic member is disposed such that, when viewed in an axial direction of the pivot shaft of the lever member, a distance from the pivot shaft to a line of action of a force applied by the elastic member to the lever member in a case where the feed member is located at a first position is shorter than a distance from the pivot shaft to the line of action in a case where the feed member is located at a second position below the first position.

A sheet conveyance apparatus is equipped with a stacking portion on which sheets are stacked, a rotator conveying a sheet by rotating in a contact state with the sheet stacked on the stacking portion, a separating member pressing the rotator and separating the sheets one by one at a contact portion where the rotator and the separating member contact each other, and a holder holding the separating member. A guide portion is rotatably provided with the holder and capable of guiding a front end of the sheet to the contact portion, and a regulating portion regulates the guide portion from rotating in a direction approximating the rotator in a state where the guide portion contacts against the regulating portion. The guide portion can be rotated in a direction separating from the rotator in a state where the separating member presses the rotator.

According to one embodiment, a sheet feed device includes a first roller, a second roller, a torque limiter, a holder, and a driving unit. The first roller conveys a sheet in a first direction while being in contact with a first surface of the sheet. The second roller faces the first roller and is in contact with a second surface which is a back side of the first surface of the sheet in a state of sandwiching the sheet between the second roller and the first roller. The torque limiter imparts an anti-torque to the second roller in order to generate a force on the second surface in a direction opposite to the first direction. The holder rotatably supports the second roller. The driving unit moves the holder and biases the holder toward the first roller.

A sheet feeding device includes a sheet feeding roller, a following roller, a rotational speed detection part, and a control part. The rotational speed detection part is configured to detect a rotational speed of the following roller. The control part is configured to accelerate a rotation of the sheet feeding roller and to adjust a sheet interval. The control part obtains a rotational rate of the following roller to the sheet feeding roller based on the rotational speed of the following roller, obtains an actual linear velocity of the sheet based on the rotational rate of the following roller and a theoretical linear velocity of the sheet after accelerating the rotation of the sheet feeding roller, and then adjusts the sheet interval based on the actual linear velocity of the sheet.

A sheet feeding device includes: an accommodating unit having a placement surface on which the stack of sheets is mounted; an inclined member having an inclined surface inclined relative to the placement surface to extend in an inclined direction and a back surface opposite the inclined surface; a sheet pick-up unit for feeding an uppermost sheet in the stack of sheets toward the inclined member; and a sheet separating member provided on the inclined surface. The sheet separating member includes a plurality of separation pieces and a support portion those made of resin. The support portion supports the separation pieces at positions closer to the back surface than to the inclined surface so that the separation pieces are movable away from the placement surface in the inclined direction and toward the back surface in a normal direction of the inclined surface independently from one another.

A feeding unit includes: a retard roller; a holder section; a protruding section; an accommodating section; a pressing section; a first restricting section; and a second restricting section. The holder section rotatably holds the retard roller. The protruding section serves as a rocking fulcrum of the holder section. The accommodating section accommodates the holder section. The pressing section presses the holder section. The first restricting section restricts movement of the holder section in a retreating direction. The second restricting section restricts movement of the holder section in a direction opposite to the retreating direction. The pressing section is arranged so as to deviate in a Y direction with respect to a virtual line passing through a middle point of the protruding section and a middle point of the first restricting section. The holder section comes into contact with the first restricting section and the second restricting section.

In a first mode, the control unit controls the driving source such that the rotary feeding member starts to move toward the first position based on an elapse of a first time since the detection portion detected a leading edge of the sheet, and positions the rotary feeding member at the first position when a trailing edge of the sheet passes through the separation nip. In a second mode, the control unit controls the driving source such that the rotary feeding member starts to move toward the first position based on an elapse of a second time longer than the first time since the detection portion detected the leading edge of the sheet, and positions the rotary feeding member at a position separated more from the stacking portion than the first position when the trailing edge of the sheet passes through the separation nip.