A sheet conveying device, which is included in an image forming apparatus, includes a pair of rollers configured to convey a sheet in a sheet conveyance passage, a detector configured to optically detect an attitude of the sheet, one of a rotation device to rotate the pair of rollers in a direction parallel to a plane of the sheet and a moving device to move the pair of rollers in a width direction, and a controller configured to correct the attitude of the pair of rollers at a time interval, based on a detection result obtained by the detector. The controller performs the correcting operation by setting, according to reflectance of the sheet, at least one of a light emission time of the detector, the time interval of the correcting operation, light emission intensity of the detector and a conveying speed of the sheet.

A medium conveying apparatus includes a plurality of feed rollers, each feed roller rotating independently at a respective speed to feed a medium, a first sensor located on a downstream side of the plurality of feed rollers in a medium conveying direction and also in a central part in a direction perpendicular to the medium conveying direction, to detect the medium, a second sensor and a third sensor located on both sides of the first sensor in the direction perpendicular to the medium conveying direction, to respectively detect the medium, and a processor to change the speed of one of the plurality of feed rollers at least until the first sensor detects the medium when any of the second sensor or the third sensor detects the medium and the first sensor does not detect the medium within a predetermined time.

A medium transport device includes a first transporter configured to transport a medium by nipping the medium along with rotation, a second transporter configured to transport the medium and disposed on an upstream side of the first transporter in a transport direction of the medium, a first adjuster configured to adjust a position of the medium in a width direction by moving the first transporter and the second transporter in the width direction of the medium with the medium nipped by the first transporter and the second transporter, and a second adjuster configured to adjust a contact pressure of the first transporter for the medium and a contact pressure of the second transporter for the medium based on resistance caused when the medium is moved in the width direction.

A sheet transporting device includes: a skew correcting component configured to correct any skew of a sheet by executing speed-gap driving in which first and second transporting components that are arranged at respective positions in a direction intersecting a direction of sheet transport are driven for a predetermined time period with a speed gap between the first and second transporting components; and a changing component configured to change, with reference to a characteristic relevant to sheet transport, a state of the speed-gap driving of the skew correcting component.

An apparatus comprising a conveyance roller configured to convey a print medium, a print unit configured to execute printing on the print medium, a platen arranged to face the print unit and configured to support the print medium, a sensor configured to emit light to the platen and detect light from the platen, and a control unit configured to execute first control of acquiring, as a first value, a detected value before the print medium reaches a light irradiation region of the sensor, and acquiring, as a second value, a detected value after the print medium is conveyed to include the light irradiation region, wherein the control unit further execute second control of correcting a conveyance amount of the print medium by the conveyance roller based on the first value and the second value.

An image processing apparatus includes a registration roller, a first conveying roller, and a second conveying roller. The registration roller is disposed on a conveying path of a sheet to be subjected to image processing, and corrects the skew of the sheet by allowing the leading end of the sheet abut thereon in a stopped state. The first conveying roller is disposed upstream of the registration roller on the conveying path at a position where a first loop space for deflecting the sheet is interposed between the first conveying roller and the registration roller. The second conveying roller is disposed upstream of the first conveying roller at a position where a second loop space is interposed between the two conveying rollers. The second conveying roller conveys the sheet at a conveying speed that is equal to or higher than the conveying speed of the first conveying roller.

A relay transport device configured to relay and transport a medium fed from the feeding device to the recording device includes a first restriction section having a first restriction surface configured to position one first edge of the medium in a width direction of the medium fed from the feeding device; a transport section configured to transport the medium toward the first restriction surface; a first auxiliary guide disposed downstream of the first restriction section in the transport direction and having a first auxiliary guide surface configured to restrict a position of the first edge of the medium; and a second auxiliary guide disposed on an opposite side from the first auxiliary guide with the medium interposed therebetween and having a second auxiliary guide surface configured to restrict a position of a second edge of the medium on the opposite side from the first edge.

Provided are a sheet position detection apparatus, a sheet conveyance apparatus, and an image formation apparatus. The sheet position detection apparatus has a first and a second conveyance roller which are arranged to oppose across a sheet to be conveyed and to nip the sheet, and a detector configured to detect an end position of the sheet, the detector has a light emitter and a light receptor arranged on the first conveyance roller side, the light emitter and the light receptor are arranged such that a light emitted from the light emitter is reflected on a reflective face of the second conveyance roller and enters the light receptor, and the detector detects passage of an end of the sheet based on a change in the amount of light entering the light receptor when the sheet shields a light emitted from the light emitter.

A printing apparatus comprises a conveyance control unit which controls conveyance of printing sheets so that a trailing edge of a preceding sheet as a printing sheet precedingly fed from the stacking unit and a leading edge of a succeeding sheet as a printing sheet succeedingly fed from the stacking unit overlap each other; and a skew correction unit which performs skew correction of the succeeding sheet while the succeeding sheet overlaps the preceding sheet by the conveyance control unit. The skew correction unit makes the leading edge of the succeeding sheet abut against the conveyance roller during a time from an end of a last line feed operation by the conveyance roller for printing on the preceding sheet by the printing unit to start of a next conveyance operation.

A sheet transfer device for transferring a sheet between two sheet processing devices comprising a switch for directing sheets from a first transport path coming from the first sheet processing device onto a two-way transport path or for directing sheets from the two-way transport path onto a second transport path for feeding sheets to the second sheet processing device. A transport pinch is provided along the two way transport path for reversing a sheet on the two-way transport path. When in use, the two-way transport path extends downward in a vertically extending free-hanging chamber wherein the sheet engaged by the transport pinch is allowed to hang freely under the influence of gravity. Thereby, a compact device is formed which is able to adjust the sheet to a suitable orientation for the second processing device. The device further prevents forces from the first processing device to disrupt the sheet's orientation in the second processing device.