A feeding roller feeds a medium placed at a medium placement portion by forward rotation power supplied from a driving unit. A displacement portion displaces the feeding roller to an abutting position by the forward rotation power supplied from the driving unit and displaces the feeding roller to a separation position by reverse rotation power supplied from the driving unit. A power transmission unit includes a one-way clutch that transmits the forward rotation power, that is supplied from the driving unit, to the feeding roller but does not transmit the reverse rotation power, that is supplied from the driving unit, to the feeding roller.

A post-processing apparatus includes a tray receiving an ejected recording medium, a moving mechanism vertically moving the tray, a driving source driving the moving mechanism, a member pressing, from vertically above, a recording medium ejected to the tray, a rotational-driving mechanism driving the member so that the member rotates in a first direction away from an apparatus body when the tray is moved upward by the moving mechanism and that the member rotates in a second direction toward the apparatus body when the tray is moved downward by the moving mechanism, a rotation-angle limiting unit limiting a rotation angle of the member when the member is driven to rotate in the first direction and to rotate in the second direction, and a rotational-force limiting mechanism idling when a rotational force not lower than a predetermined force is applied to the rotational-driving mechanism.

The feeding apparatus includes a pick-up roller, a feed roller, a separation roller which forms a separation nip portion with the feed roller, an encoder, and an engine control unit. The engine control unit obtains variation in rotation speed of the separation roller based on a detection result of the encoder, and determines a life condition of the separation roller based on the obtained variation in rotation speed of the separation roller.

An image forming apparatus includes image forming units forming images, a movable body moving along a path extending in a direction in which the image forming units are arranged while the images are sequentially formed on the movable body or on a recording material transported by the movable body so as to be superposed with one another, a contact and separation unit moving to a contact position at which the contact and separation unit is in contact with the movable body and to a separation position at which the contact and separation unit is separated from the movable body and changing a load applied to the moving movable body as a position of the contact and separation unit is changed, and a change unit changing the load in a manner opposite to a change in the load upon a change in the position of the contact and separation unit.

A paper-sheet counting machine (10) includes: a recognition and counting unit (24) configured to count paper sheets; a stacking unit (26) configured to stack therein the paper sheets that have been counted by the recognition and counting unit (24), an opening being provided in a front face of the stacking unit (26); a rotary guide unit (28) provided to the stacking unit (26) and configured to allow the paper sheets that have been counted by the recognition and counting unit (24) to be stacked in the stacking unit (26); a shutter (40) configured to close the opening provided in the front face of the stacking unit (26); a shutter drive unit (50) configured to drive the shutter (40) to open and close the opening provided in the front face of the stacking unit (26); and a control unit (70) configured to control the shutter drive unit (50).

There is provided a feed apparatus including a support unit, a feed roller, a swingable arm to support the feed roller, a guide unit, a movable member movable to a retracted position and a protruding position at which the movable member can abut against the sheet supported by the support unit, a driving source, driving transmission units; and a contact-separating mechanism to move the feed roller to a separated position and an abutment position at which the feed roller abuts against the sheet supported by the support unit. In a state in which the movable member is the protruding position and the feed roller is the separated position, a time required to start feeding of the sheet by the feed roller moved from the separated position to the abutment position is longer than a time required to shift the movable member from the protruding position to the retracted position.

In one example, a torque control system for a sheet media pick mechanism to move a top sheet of media from a stack of media sheets into a nip between a pick roller and a separator roller. The torque control system includes a sensor to sense a number of consecutive pick failures and a controller operatively connected to the sensor to reduce a torque applied to the separator roller during a pick attempt after each pick failure in an amount corresponding to the number of consecutive pick failures sensed by the sensor.

The present invention provides an image forming apparatus that reduces image artifacts caused by the back tension of a separating unit. A control unit decreases the number of rotations (the rotational speed) of a resist roller pair after the leading edge of a sheet reaches a transfer position.

A media feeding apparatus includes a feed roller, a separation roller, a torque limiter, a unit, a pressing portion, and a reaction-force generator. The feed roller feeds a medium. The separation roller faces the feed roller and is located on a rotation shaft to which power is not transmitted. The torque limiter is located on the rotation shaft. The separation roller is driven by the feed roller when a torque greater than a predetermined torque is applied to the torque limiter. The unit supports the rotation shaft. The pressing portion applies a pressing force to the unit to swing the unit in a direction in which the separation roller is pressed against the feed roller. The reaction-force generator generates a reaction force to swing the unit in a direction in which the separation roller moves away from the feed roller as the separation roller rotates.

A manual feed tray is located at a side surface of a main housing. A supply roller conveys a sheet on the manual feed tray toward a print engine. A pressure plate is movable between a contact position at which the sheet on the manual feed tray contacts the supply roller and a separated position at which the sheet on the manual feed tray is separated from the supply roller. A push-up cam pushes up the pressure plate from the separated position to the contact position. The push-up cam includes a contact portion configured to contact the pressure plate. A controller is configured to: when performing printing on a plurality of sheets, after moving the pressure plate from the separated position to the contact position, convey the plurality of sheets by intermittently driving the supply roller while maintaining the pressure plate at the contact position.