Provided is a roll body capable of effectively suppressing the occurrence of a telescope phenomenon even if the ambient temperature during transportation and storage of the roll body becomes higher than that during production of the roll body. A roll body RB according to the present invention configured by winding a belt-shaped web around a winding core that thermally expands or contracts due to an influence of a surrounding environment is characterized in that a linear expansion coefficient of the web in a thickness direction is in a range of 60 to 150 times a linear expansion coefficient of the web in a longitudinal direction, and the winding core has a linear expansion coefficient in a range of 20×10.sup.−6/K to 100×10.sup.−6/K and a Young's modulus in a range of 0.2 GPa to 0.5 GPa.

An image forming apparatus includes a paper discharging tray and a paper detection part disposed at an upstream end of the paper discharging tray in a paper discharge direction. The paper detection part includes a base end member provided rotatably around a first axis extending in a direction perpendicular to a paper discharge direction and a tip member pivoted to the base end member to rotate around a second axis parallel to the first axis, and extending downwardly to incline toward an upstream side of the paper discharge direction in a state where the base end member is not subjected to pressure from the paper being discharged. The base end member is disposed to face a discharge opening when being at the reference position, and the image forming apparatus stops discharging paper from the discharge opening when the base end member rotates by a predetermined threshold or more with respect to the reference position.

An image forming apparatus includes a paper discharging tray and a paper detection part disposed at an upstream end of the paper discharging tray in a paper discharge direction. The paper detection part includes a base end member provided rotatably around a first axis extending in a direction perpendicular to a paper discharge direction and a tip member pivoted to the base end member to rotate around a second axis parallel to the first axis, and extending downwardly to incline toward an upstream side of the paper discharge direction in a state where the base end member is not subjected to pressure from the paper being discharged. The base end member is disposed to face a discharge opening when being at the reference position, and the image forming apparatus stops discharging paper from the discharge opening when the base end member rotates by a predetermined threshold or more with respect to the reference position.

An elastic roller is capable of elastic deformation at low load, lightweight and low-cost, and the surface speed of the roller has been made stable. At a drawing showing the view from the side of pipe 2 and flange 3 which make up roller 1, roller 1 which has pipe 2 and flange 3 is supported by shaft 8 which is inserted therein along axis 8a of shaft 8, the situation being such that elastic deformation occurs upon being pressed downward by pressure P from pressure-applying body 11 above pipe. None of the four outermost ribs 7a disposed in outermost gap 6a between outermost ring 4a of flange 3 and middle ring 4b which is mutually adjacent thereto and toward the interior therefrom is present in the upper portion of pipe 2.

A feeding device includes a sheet tray, a transport device, a sheet sensor, and a control device. On the sheet tray, a sheet is placed. The transport device transports the sheet placed on the sheet tray. The sheet sensor is located upstream of the transport device in a sheet transport direction, and outputs curvature information indicating a curvature status of the sheet being transported by the transport device. The control device includes a processor, and acts as a measuring device and a calculation device, when the processor executes a control program. The measuring device measures a curvature amount of the sheet, on a basis of the curvature information. The calculation device calculates rigidity of the sheet, on a basis of the curvature amount.

A feeder includes a conveyance path, a conveyance roller that conveys a sheet along the conveyance path, a transmitter that emits a space propagating energy, a receiver that receives a reflected energy obtained by reflection of the space propagating energy, and an actuator mounted pivotably on a pivot shaft and including first and second legs extending in different directions from the pivot shaft. The first leg is disposed to extend to the conveyance path and abut against the sheet being conveyed along the conveyance path. The second leg has a reflective surface crossing a path of the space propagating energy. The actuator is pivoted by abutment of the sheet against the first leg. The reflective surface is formed so that the reflected energy obtained by the reflection of the space propagating energy on the reflective surface enters the receiver regardless of an angle of pivotal movement of the actuator.

To ensure reliable and productive processing of printed sheets into stacks, a sheet stacker includes: a flipping device for flipping a sheet with respect to the sheet's orientation before being received by the flipping device onto a stack support or a stack of sheets on the stack support; a sensor assembly for detecting an out-of-plane deformation of a top sheet with respect to the underlying stack support or a stack of sheets on the stack support at least for each sheet added to the stack; and a controller configured to determine from data from the sensor assembly whether the top sheet was successfully flipped and stacked.

The present invention provides a sheet diverting unit for selectively diverting a sheet towards a first receiving path or a second receiving path, comprising an inlet path for advancing a sheet in a sheet supply direction towards a diverter; the diverter comprising a shaft, a deflector being connected to said shaft and extending between said shaft and a tip, and an actuator arranged for rotating the shaft thereby selectively pivoting the deflector between a first deflector position for directing the sheet into the first receiving path and a second deflector position for directing the sheet into the second receiving path; said deflector comprising a guiding edge and a second edge, said second edge arranged facing a second trajectory to the second receiving path in the second deflector position for directing the sheet into the second receiving path and said guiding edge arranged facing a straight first trajectory to the first receiving path thereby said guiding edge facing a guiding element in the first deflector position for guiding the sheet into the first receiving path; wherein the guiding edge comprises a recess portion, wherein the recess portion is arranged inwardly away from the straight first trajectory to the first receiving path when the deflector is arranged in the first deflector position, wherein the recess portion is arranged for extending substantially from the guiding element towards the shaft when the deflector is arranged in the second deflector position.

The present invention provides a sheet diverting unit for selectively diverting a sheet towards a first receiving path or a second receiving path, comprising an inlet path for advancing a sheet in a sheet supply direction towards a diverter; the diverter comprising a shaft, a deflector being connected to said shaft and extending between said shaft and a tip, and an actuator arranged for rotating the shaft thereby selectively pivoting the deflector between a first deflector position for directing the sheet into the first receiving path and a second deflector position for directing the sheet into the second receiving path; said deflector comprising a guiding edge and a second edge, said second edge arranged facing a second trajectory to the second receiving path in the second deflector position for directing the sheet into the second receiving path and said guiding edge arranged facing a straight first trajectory to the first receiving path thereby said guiding edge facing a guiding element in the first deflector position for guiding the sheet into the first receiving path; wherein the guiding edge comprises a recess portion, wherein the recess portion is arranged inwardly away from the straight first trajectory to the first receiving path when the deflector is arranged in the first deflector position, wherein the recess portion is arranged for extending substantially from the guiding element towards the shaft when the deflector is arranged in the second deflector position.

A printer includes a printing unit, a casing, a scanner unit disposed in an upper portion of the casing, and a discharge unit that, below the scanner unit, is connected to the casing pivotably between a closed position and an open position and that a sheet of paper is discharged to. The discharge unit includes a placement surface for the sheet and a medium support unit capable of supporting the sheet from below while in a state of being protruded from the placement surface. The medium support unit is displaceable between a maximum protruded position and a minimum protruded position. When the amount of protrusion of the medium support unit from the placement surface when the discharge unit is in the open position is less than the amount of protrusion of the medium support unit in the maximum protruded position from the placement surface.