A paper pickup mechanism includes a mechanical frame, a pickup roller module, a feeding roller module, a driving device, a separation roller module and an energy storage element. The mechanical frame has a platform. The pickup roller module is pivoted to and connected to the mechanical frame. The feeding roller module is pivoted to and connected to the mechanical frame. The driving device is mounted to the mechanical frame. The separation roller module is pivoted to and connected to the mechanical frame. The energy storage element is mounted between the mechanical frame and the separation roller module. When the separation roller module rotates together with the feeding roller module in a forward direction, the energy storage element accumulates energies. When more than one piece of paper is fed into the paper pickup mechanism, the energy storage element releases the energies.

A sheet conveyor includes a separation roller, a retard roller forming a nip with the separation roller, and a load application device configured to apply a load to the retard roller. The load application device includes a motor, a first drive train, a second torque limiter isolated from the first drive train, and a controller. The first drive train includes a plurality of gears for transmitting a driving force from the motor to the retard roller, a first torque limiter, and a clutch disposed between the motor and the first torque limiter. The second torque limiter is configured to communicate with the retard roller. The controller is configured to, during conveyance of a sheet, control the clutch to allow transmission of the driving force from the motor for a predetermined time period and to interrupt transmission of the driving force from the motor after expiration of the predetermined time period.

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.

A document conveyance device includes a feed roller, a separation roller, a first motor for generating a first drive force for driving the separation roller, a planet gear, a drive gear, a second motor for generating a second drive force, and a position switching mechanism for switching a position of the planet gear from a first position in which the planet gear is separated from the drive gear and does not transmit the first drive force to the separation roller to a second position in which the planet gear engages with the drive gear and transmits the first drive force to the separation roller, based on the second drive force. The position switching mechanism includes a support member for supporting the planet gear, and a transfer mechanism for moving the support member so that the planet gear engages with the drive gear, based on the second drive force. The further movement of the planet gear is prevented after the planet gear engaged with the drive gear.

The sheet feeding apparatus includes an encoder configured to output a signal according to the rotation state of a retard roller, a feed motor configured to drive a pick-up roller, and a control unit configured to control the feed motor, make the pick-up roller feed a first sheet, and change the timing at which the pick-up roller is made to feed a second sheet following the first sheet, based on a signal output from the encoder after the trailing edge of the first sheet passes a separation nip portion.

A sheet feeding device includes a stacking portion, a first roller, a second roller, a third roller rotatable to provide peripheral movement in a predetermined direction and to provide peripheral movement in a direction opposite to the predetermined direction, a detecting unit, a driving unit for executing a feeding operation by the first roller, and a control unit for providing an instruction to the driving unit so as to continue or stop the feeding operation. The predetermined rotational frequency is larger than 0 and is smaller than a rotational frequency of the third roller in a period in which the third roller is rotated in the predetermined direction in a state in which a single recording material is fed to the nip.

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 sheet supplier, including: a tray including a sheet support surface; a sheet supply roller configured to supply an uppermost one of sheets; a rotational member configured to contact a lowermost one of the sheets; a presser configured to press the supply roller relative to the rotational member; and a supporter configured to support the rotational member by a contact portion such that the rotational member is rotated by a movement of the lowermost sheet and to limit a movement of the rotational member caused by a force of the lowermost sheet in a sheet supply direction; wherein, where static friction coefficients between the supply roller and the uppermost sheet, between the sheets on the support surface, between the rotational member and the lowermost sheet, and between the rotational member and the contact portion are respectively defined as 2, 3, and 4, the following expressions are satisfied: 1>4>2, 3>4.

A sheet feeder includes a stacker to stack sheets and a separation and conveyance device to separate one sheet from the sheets fed from the stacker and convey the sheets one by one. The separation and conveyance device includes a feed roller that rotates in a direction to feed the sheet and a separation roller to press against the feed roller via the sheet. The separation roller has an apparent hardness different from an apparent hardness of the feed roller and is configured to form an indentation in the feed roller.

A stack of media items are urged along a transport path that includes a bend in the track of the transport path. A first phase of separating the media items from the stack includes pre-separating the media items from the stack as the media items are urged along the bend. A second phase includes separating a leading media item from the stack by urging the leading media item exiting the first phase between opposing rollers to transport the leading media item along the transport path within a value media depository.