An image forming apparatus includes a print engine, a sheet transportation unit, a line sensor, and a control unit. The print engine is configured to physically print an image to be printed on a print sheet. The sheet transportation unit is configured to transport the print sheet. The line sensor is arranged along a direction perpendicular to a transportation direction of the print sheet, and configured to detect positions of both end edges of the print sheet. The control unit is configured to (a) determine as a sheet center actual position a center position of the print sheet on the basis of the detected positions of both end edges of the print sheet, and (b) adjust a center position of the image to be printed so as to cause the center position of the image to be printed to agree with the sheet center actual position.

An image forming apparatus includes a print engine, a sheet transportation unit, a line sensor, and a control unit. The print engine is configured to physically print an image to be printed on a print sheet. The sheet transportation unit is configured to transport the print sheet. The line sensor is arranged along a direction perpendicular to a transportation direction of the print sheet, and configured to detect positions of both end edges of the print sheet. The control unit is configured to (a) determine as a sheet center actual position a center position of the print sheet on the basis of the detected positions of both end edges of the print sheet, and (b) adjust a center position of the image to be printed so as to cause the center position of the image to be printed to agree with the sheet center actual position.

In an image-forming apparatus, when a sheet length of a first sheet is shorter than or equal to a predetermined length, a controller supplies power to an electromagnetic clutch to convey the first sheet and a second sheet so that a sheet gap of the second sheet is equivalent to a first gap. When the sheet length of the first sheet is longer than the predetermined length, the controller supplies power to the electromagnetic clutch to successively convey a first number of sheets so that the sheet gap of each of the first number of sheets is equivalent to the first gap. After the first number of sheets has been conveyed, the controller supplies power to the electromagnetic clutch to convey at least one sheet so that the sheet gap of each of the at least one sheet is equivalent to a second gap greater than the first gap.

When an open hole is detected at the front end of a sheet at a conveyance start position, a registration operation to correct a tilt posture of the sheet is avoided, and the present velocity is retrained to convey the sheet without temporarily stopping the sheet having the tilt posture.

A recoding medium conveying device includes a conveyance belt, a first sensor, a second sensor, and circuitry. The conveyance belt has an endless loop shape and a length capable of conveying a plurality of recording media in one rotation. The first sensor is disposed upstream from the conveyance belt in a conveyance direction of a recording medium and is configured to detect the recording medium. The second sensor is configured to detect a home position of the conveyance belt. The circuitry is configured to adjust a rotation speed of the conveyance belt, while the conveyance belt makes one rotation, to eliminate an amount of deviation between a first detection timing of the recording medium detected by the first sensor and a second detection timing of the home position of the conveyance belt detected by the second sensor.

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.

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 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.

Provided are a medium conveyance apparatus, control method, and control program to enable determining whether multi-feed of a medium has occurred by a greater precision. A medium conveyance apparatus includes a storage device to store in advance region information of a predetermined region in a medium, a feed roller to feed the medium, a slant detection module to detect an amount of slant of the fed medium, an overlap detection module to detect region information of a region in which overlap has occurred in the fed medium, a correction module to correct the detected region information based on the amount of slant, and a multi-feed determination module to determine that multi-feed of the medium has occurred if the corrected region information does not correspond to the stored region information and determine that multi-feed of the medium has not occurred if the corrected region information corresponds to the stored region information.