The medium winding device includes a winding shaft, a drive unit for winding the medium around the winding member, a rotating member rotatably disposed, a tension applying member which moves as the drive unit is driven or stopped, a position detecting unit for detecting the position of the tension applying member, an output changing unit, a control unit that determines whether slippage occurs between the winding shaft and the winding member based on the position of the tension applying member and the result of output change by a rotation of the winding shaft. Further, the drive unit includes a torque limiter.

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 paper separation structure includes: an actuating unit being selectable to generate a forward and reverse actuating torque (T); a one-way actuator connected to said actuating unit and being able to break the connection of said actuating unit while said actuating unit generates a reverse actuating torque (T); a breaking unit having a threshold of breaking torque (TL1), and said braking torque (TL1) set lower than said actuating torque (T); and a separating roller connected to said one-way actuator and said braking unit to receive said actuating torque (T) and said braking torque (TL1). With the combination of components mentioned above, the paper separation structure of the present invention has a plurality of torque thresholds for paper separation and can switch between active and passive separation modes according to requirements.

A liquid ejection apparatus includes a conveying unit, a winding unit, a printing unit, and a rotation control unit. The conveying unit is configured to intermittently convey a printing medium by a predetermined feed amount. The winding unit is configured to wind the printing medium conveyed by the conveying unit. The printing unit is configured to perform printing on the conveyed printing medium. The rotation control unit is configured to control the winding unit to rotate in a winding direction at a predetermined timing after the conveying unit has started to convey the printing medium intermittently, and then cause the winding unit to rotate in a reverse direction opposite to the winding direction.

A tension controller includes a drive device configured to rotate a drive shaft, and a drive transmission device configured to transmit a rotation driving force of the drive shaft of the drive device to rotate a rotary shaft of a roll of a conveyance target medium. The drive transmission device including a tension applying device including a variable speed reducing device and a torque limiter, the variable speed reducing device and the torque limiter being disposed between the drive shaft of the drive device and the rotary shaft of the roll of the conveyance target medium. The variable speed reducing device of the tension applying device being configured to change a speed reduction ratio between the rotary shaft of the roll of the conveyance target medium and the torque limiter and to apply a tension force to the conveyance target medium.

A sheet conveying apparatus includes a paper re-feeding path, a switching member, a reversing roller, a paper discharge roller, a motor, and a revolution control mechanism. The switching member can be switched between a first position and a second position. The reversing roller can reverse a revolving direction thereof between a first revolving direction and a second revolving direction. The paper discharge roller revolves in a third revolving direction for conveying the sheet in a third conveying direction. The motor reverses the revolving direction of the reversing roller and switches the position of switching member by reversing the revolving direction thereof. The revolution control mechanism revolves the paper discharge roller in the third revolving direction with the revolution of the motor, regardless of the reversing of the revolving direction of the motor.

A paper sheet folding device (sheet folding device) 160 includes a paper sheet folding unit 60 and a tray unit 110 that is provided on one side surface 161a of a device main body 161 and includes a lower discharge tray 121 on which a paper sheet S discharged through a lower discharge port 85 is loaded. The tray unit 110 is pivotable in an up-down direction about a pivotal shaft 111. A discharge drive mechanism 132 is disposed at a center portion of the tray unit 110 in a paper sheet width direction.

An image forming apparatus is configured such that in a case where images are to be formed on a first surface of a preceding sheet, on a first surface of a succeeding sheet fed to the first conveyance path succeeding to the preceding sheet and on a second surface of the preceding sheet, a first conveyance member is stopped without reversing the preceding sheet to a second conveyance path in a case where the image has been formed on the first surface of the preceding sheet and permission of preparing the image to be formed on the first surface of the succeeding sheet is not issued yet, and the first conveyance member restarts conveyance of the preceding sheet to the second conveyance path based on timing when an image forming unit starts preparing the image to be formed on the first surface of the succeeding sheet.

A drive transmitting device, which is included in an image forming apparatus, includes a drive source, a drive transmitting body, and a rotary shaft. The drive transmitting body has a press-in target portion. The rotary shaft includes a press-in portion mounted on one end of the rotary shaft in an axial direction of the rotary shaft to be pressed into the press-in target portion of the drive transmitting body. The press-in portion includes a flat face and a plurality of circular arc faces having different distances from an axial center of the rotary shaft and being disposed at a same position as at least a portion of the flat face in the axial direction of the rotary shaft. A radius of curvature of one of the plurality of circular arc faces is greater than a radius of curvature of another of the plurality of circular arc faces.

A sheet conveyance device, an image forming apparatus, and a sheet conveying method that convey a sheet in a predetermined sheet conveyance direction make a surface moving speed of a driven roller higher than a surface moving speed of a drive roller when a rotational driving force from the drive roller is transmitted to the driven roller, and by a one-way clutch that is provided at any place in a drive transmission path from the drive roller to the driven roller, restrict relative rotation of the driven roller in a first rotation direction, which is the sheet conveyance direction, with respect to the drive roller while allowing relative rotation of the driven roller in a second rotation direction, which is a direction opposite to the first rotation direction, with respect to the drive roller.