In steady control, a shaft control unit (922) adjusts rotation speed of a first support shaft (31) to cause a first roll (R1) to have peripheral speed equal to predetermined conveyance speed by maintaining a sheet storage amount in a storage mechanism (5) in a first storage amount as a reference. In storage amount adjustment control, the shaft control unit (922) accelerates the rotation speed of the first support shaft (31) to increase the peripheral speed of the first roll (R1) higher than the conveyance speed, until the sheet storage amount in the storage mechanism (5) reaches a predetermined second storage amount that is larger than the first storage amount. A calculation unit (911) calculates an outer diameter of the first roll (R1) based on the conveyance speed when the steady control is performed, and calculates the outer diameter of the first roll (R1) based on the sheet thickness calculated from a decrease amount of the outer diameter of the first roll (R1) in the steady control when the storage amount adjustment control is performed.

Personnel saving of a process from a printer to a sheet processing machine is achieved. A general printing management device is connected to be communicable with a conveyance management device that manages a plurality of automatic guided vehicles each conveying a stacker in which paper ejected from a printer is stackable. The general printing management device generates conveyance instruction information for conveying a stacker in which paper ejected from the printer is stacked from a sheet receiving position of the printer to a sheet supply position of a next processing machine, based on job information in which a manufacturing process procedure for manufacturing a printed product is registered, and transmits the conveyance instruction information to the conveyance management device.

Provided is a stacker including a stacking shelf on which printed paper from a printer is received and stacked, a lifting and lowering mechanism that lifts and lowers the stacking shelf, and a stacker control unit that controls the lifting and lowering mechanism. The stacker control unit controls the lifting and lowering mechanism to lift and lower the stacking shelf to a first predetermined height corresponding to the printer at a receiving position for receiving the paper from the printer, and to lift and lower the stacking shelf to a second predetermined height corresponding to a sheet processing machine at a paper supply position for supplying paper to the sheet processing machine, the paper supply position being different from the receiving position.

A sheet conveying device includes a corrector configured to correct a position of a sheet, and at least three detectors disposed in a sheet conveyance direction. Each of the at least three detectors is configured to detect a lateral end of the sheet according to a length of the sheet to be conveyed in the sheet conveyance direction. The corrector is configured to correct the position of the sheet based on detection results of each of the at least three detectors.

A reading apparatus to convey a document set on a document tray and to read an image of the conveyed document includes a control unit and a determining unit. The control unit performs lifting control for lifting the document tray in a case where a first condition is satisfied and performs lowering control for lowering the document tray in a case where a second condition is satisfied. The determining unit determines whether a predetermined period elapses after the lifting control of previous time is started. The control unit does not perform the lowering control even if the second condition is satisfied in a case where the determining unit determines that the predetermined period does not elapse.

A document reading apparatus having a display unit and a placement section on which plural documents is to be placed includes a conveyance unit and a reading unit. The conveyance unit conveys a document placed on the placement section. The reading unit reads a document conveyed by the conveyance unit and generates image data. Based on at least a reading mode being set on the document reading apparatus of reading a plurality of documents of a plurality of different sizes in a single job by the reading unit, first prompting information that prompts placement of the plurality of documents at a center of the placement section in a direction perpendicular to a document conveyance direction in which the conveyance unit conveys the plurality of documents is displayed on the display unit.

A sheet feeder apparatus includes a width detector for a sheet placed on a sheet placement portion, a conveyor for conveying sheets while separating the sheets one by one, a first detector for detecting a sheet having a first width at a plurality of first positions, a second detector for detecting a sheet having a second width that is not detected by the first sheet detector at a plurality of second positions, and a controller for determining skewing of a sheet based on a result of the detection of the sheet performed by the first detector if the width of the sheet is the first width, and determining skewing of a sheet based on a result of the detection performed by the second detector if the width of the sheet is the second width.

A sheet feeder apparatus includes a width detector for a sheet placed on a sheet placement portion, a conveyor for conveying sheets while separating the sheets one by one, a first detector for detecting a sheet having a first width at a plurality of first positions, a second detector for detecting a sheet having a second width that is not detected by the first sheet detector at a plurality of second positions, and a controller for determining skewing of a sheet based on a result of the detection of the sheet performed by the first detector if the width of the sheet is the first width, and determining skewing of a sheet based on a result of the detection performed by the second detector if the width of the sheet is the second width.

An image forming apparatus includes a sheet separation device, a first sheet feeder, a second sheet feeder, an image forming device, and circuitry. The sheet separation device is configured to separate a non-bonding portion of a two-ply sheet in which two sheets are overlapped and bonded together at a bonding portion of the two-ply sheet. The first sheet feeder is configured to feed the two-ply sheet. The second sheet feeder is configured to feed an inner sheet to be inserted between the two sheets. The image forming device is configured to form an image on a surface of the inner sheet. The circuitry is configured to cause the first sheet feeder to feed the two-ply sheet, perform a sheet separating operation on the two-ply sheet and cause the second sheet feeder to start feeding the inner sheet before completion of the sheet separating operation on the two-ply sheet.

The detection unit includes a first contact member, which comes into contact with a first surface of a recording material and a second contact member, which comes into contact with a second surface of the recording material, the first contact member and the second contact member being disposed so as to oppose each other thus being capable of nipping the recording material, and the first contact member and the second contact member are movable in a direction in which the first contact member and the second contact member nip the recording material, and is rotatable about an axis line extending in a predetermined direction, the predetermined direction being orthogonal to the direction in which the first contact member and the second contact member are movable and being orthogonal to a conveyance direction of the recording material.