A driving force adjusting pick-up device, includes: a transmitting path; a pick roller disposed in the transmitting path for transmitting papers; an actuating unit connected with the pick roller to adjust the normal force applied to the paper; a separating unit disposed in the transmitting path and located downstream to the pick roller; and a driving force measuring unit which includes a first speed measuring roller disposed upstream to the separating unit and a second speed measuring roller disposed downstream to the separating unit for measuring transmitting speed of the paper upstream and downstream to the separating unit; wherein the driving force measuring unit evaluates the driving force applied to the paper by comparing transmitting speed of the paper upstream and downstream to the separating unit.

A transport device includes a transport roller, a nip section, and first and second transport path surfaces. The transport roller transports a transport target material sent from an accommodating unit. The nip section nips the transport target material with the transport roller, and prevents multi-feed of the transport target material. The first transport path surface is disposed upstream of the nip section in a transport direction to face a transport roller side of the nip section. The first transport path surface includes a top portion protruding toward the transport roller side beyond a nip line between the transport roller and the nip section. The second transport path surface is disposed downstream of the nip section in the transport direction to face the transport roller side of the nip section. The second transport path surface includes a top portion protruding toward the transport roller side beyond the nip line.

A sheet feeding apparatus includes a sheet stacking portion on which a sheet is stacked, and a one-way clutch configured such that (i) in delivering the sheet stacked on the sheet stacking portion toward a separation nip, rotation of a drive shaft in a first rotational direction is transmitted through the one-way clutch, a drive gear and a gear train rotate a pick-up roller without slipping of the one-way clutch, and (ii) after a leading edge of the sheet has reached the separation nip, the pick-up roller is dragged and rotated by the sheet conveyed by a feed roller, rotation of the pick-up roller is transmitted through the gear train to the drive gear, and the drive gear is rotated in the first rotational direction with respect to the drive shaft that is rotated in the first rotational direction while the one-way clutch is slipping.

An image forming apparatus including a print engine to form an image on an image forming medium, a conveyance device to provide printing paper using a feed roller and a conveyance roller installed to face the feed roller to the print engine, a sensor to sense pressure applied to the conveyance roller, and a processor to identify whether double feed occurs on the basis of a signal provided from 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.

In the first mode, the control unit controls the driving source such that the rotary feeding member starts to move toward the first position based on an elapse of a first time since the detection portion detected a leading edge of the sheet, and position the rotary feeding member at the first position when a trailing edge of the sheet passes through the separation nip. In the second mode, the control unit controls the driving source such that the rotary feeding member starts to move toward the first position based on an elapse of a second time longer than the first time since the detection portion detected the leading edge of the sheet, and position the rotary feeding member at a position separated more from the stacking portion than the first position when the trailing edge of the sheet passes through the separation nip.

A sheet feeding apparatus includes a sheet supporting portion, a rotary feeding member, a rotary separation member, a support member configured to support a rotation shaft of the rotary separation member, a swing shaft configured to support the support member, a frame member including a first support portion configured to fix a first end portion of the swing shaft and a second support portion configured to movably support a second end portion of the swing shaft, and an adjustment mechanism including a long hole formed in the second support portion and a fixing member configured to fix the second end portion of the swing shaft to the frame member. The second end portion of the swing shaft can be fixed at a plurality of positions to the second support portion with the fixing member.

A sheet feeding device includes a pickup roller, a feed roller, a retard roller, a conveyance rollers pair. The pickup roller contacts a sheet at a first contact point in a pickup position and rotates to convey the sheet in a predetermined conveyance direction. The feed roller is disposed on a downstream side of the pickup roller in the conveyance direction. The retard roller contacts the feed roller at a second contact point and conveys the sheet while separating the sheet. The conveyance rollers pair contacts each other at a third contact point and conveys the sheet passing through the second contact point to a conveyance path. The first contact point, the second contact point and the third contact point are disposed on a linear line in the conveyance direction, when viewed from axial directions of the rollers.

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 feeding apparatus includes a rotary member unit having a feeding rotary member to feed a recording material and a separating rotary member which forms a nip portion with the feeding rotary member, an output unit, and a control unit. Where a single recording material is fed to the nip portion, the separating rotary member is rotated in a predetermined direction by the single recording material and, where recording materials are overlapped with one another and fed to the nip portion, the separating rotary member rotation is stopped or rotated in a direction opposite to the predetermined direction to separate the overlapped recording materials. The output unit outputs a state signal in accordance with a separating rotary member rotation state. The control unit obtains a rotation speed of the separating rotary member from the state signal output and determines that the rotary member unit is replaced with a new product.