A driving force transmitter, including a coupling member, a cam member, an electromagnetic clutch, a sensor, and a controller, is provided. The coupling member arranged between a driving source and a driven device includes a first shaft, a second shaft, a stationary coupling member, and a movable coupling member which is movable between a separating position and an engaging position. The cam member is rotatable to move the movable coupling member. The electromagnetic clutch connects the cam member with the driving source when electrically powered and disconnects the cam member when not electrically powered. The sensor detects rotational positions of the cam member. The controller switches the electricity to the electromagnetic clutch according to the rotational positions of the cam member.

An image forming apparatus includes: an image-forming mechanism; a reconveying roller; an electric motor; and a transmission mechanism. The transmission mechanism is configured to operate in one of a reverse-rotation transmission mode for reversing a direction of a rotational force received from the electric motor to transmit the reversed rotational force to the reconveying roller and a normal-rotation transmission mode for transmitting the rotational force to the reconveying roller without reversing the direction of the rotational force. The transmission mechanism includes an interrupting unit for interrupting transmission of a rotational force from the reconveying roller to the electric motor at least when a sheet is being conveyed in the image-forming mechanism. The transmission mechanism is configured to interrupt transmission of the rotational force received from the electric motor to the reconveying roller when a sheet is being conveyed in the image-forming mechanism.

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.

An image forming apparatus includes a support portion configured to support a sheet, a roller configured to feed the sheet supported on the support portion, a separation member configured to apply a feeding resistance to the sheet fed by the roller from the support portion, a holder holding the roller, a holder pivoting member configured to pivot the holder between a first position where the roller contacts the sheet and a second position where the roller is separated from the sheet, a clutch mechanism, a clutch-state changing member, a rotator configured to rotate between an off position where the holder is at the second position and the clutch mechanism is at a cut-off state and an on position where the holder is at the first position and the clutch mechanism is at a transmission state, a stopper configured to stop the rotator, and an actuator connected to the stopper.

An image forming device includes: a conveyance unit; an image forming section; a plurality of storage units; and a sheet feeding roller, wherein provided are: one drive source; a first drive transmission system including a first one-way clutch; a second drive transmission system including: a second one-way clutch; and a first transmission interrupting unit; a third drive transmission system including: a third one-way clutch; and a second transmission interrupting unit; and a control unit, and the control unit is configured to: rotationally drive the drive source in the first direction at the time of the sending operation by the first sheet feeding roller; rotationally drive the drive source in the second direction at the time of the sending operation by the second sheet feeding roller; and rotationally drive the drive source in the second direction at the time of the sending operation by the third sheet feeding roller.

A sheet supply device detachably attachable to an image forming apparatus includes: a main body; a sheet supply roller; an external output gear; a clutch mechanism; and first and second transmission mechanisms. The main body is provided with a sheet supply tray on which a sheet is mountable. The sheet supply roller is in contact with a sheet mounted on the sheet supply tray and configured to rotate to supply the sheet toward the image forming apparatus. The external output gear is configured to output a driving force to an outside. The clutch mechanism is configured to transmit and interrupt a driving force from the image forming apparatus. The first transmission mechanism is configured to transmit the driving force received through the clutch mechanism to the sheet supply roller. The second transmission mechanism is configured to transmit the driving force received through the clutch mechanism to the external output gear.

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.

A sheet feeding apparatus includes a sheet receiving plate configured to receive a sheet and pivot in an up-down direction; a feed roller configured to pivot between a contact position where the feed roller contacts the sheet on the sheet receiving plate and a withdrawal position where the feed roller withdraws from the sheet; an urging member configured to urge the sheet receiving plate upward; an abutting portion configured to, when the sheet receiving plate pivots upward, abut the sheet and stop the sheet receiving plate; a moving member configured to, after the sheet abuts the abutting portion, move the sheet receiving plate to a sheet feed position; and a feed roller pivoting mechanism configured to, when the sheet receiving plate pivots upward, withdraw the feed roller to the withdrawal position and to, after the sheet contacts the abutting portion, move the feed roller to the sheet receiving plate.

An image forming apparatus includes a support portion configured to support a sheet, a roller configured to feed the sheet supported on the support portion, a separation member configured to apply a feeding resistance to the sheet fed by the roller from the support portion, a holder holding the roller, a holder pivoting member configured to pivot the holder between a first position where the roller contacts the sheet and a second position where the roller is separated from the sheet, a clutch mechanism, a clutch-state changing member, a rotator configured to rotate between an off position where the holder is at the second position and the clutch mechanism is at a cut-off state and an on position where the holder is at the first position and the clutch mechanism is at a transmission state, a stopper configured to stop the rotator, and an actuator connected to the stopper.

A media conveying apparatus includes a roller provided rotatably around a rotation shaft, a drive shaft mechanically coupled to the rotation shaft, a holder holding the rotation shaft and the drive shaft, a driving source, and a drive coupling to transmit a driving force from the driving source to the drive shaft. The holder has a swing shaft about which the holder swings, and a distance between the drive shaft and the swing shaft is smaller than a distance between the rotation shaft and the swing shaft.