The present invention is to provide a sheet bundle binding device capable of easily removing some sheets from a sheet bundle that has been subjected to staple-free binding. A corner Sc of a first sheet bundle which is accumulated on a processing tray is subjected to proper binding using a staple needle by a staple binding unit. Then, a corner of a second sheet bundle obtained by accumulating additional sheets on the first sheet bundle is pressed and deformed between crimping toothed parts of a staple-free binding unit to temporarily bind the second sheet bundle. Thus, the additional sheets can easily be removed from the second sheet bundle.

To provide a sheet bundle binding device capable of easily removing some sheets from a sheet bundle that has been subjected to staple-free binding. A corner Sc of a first sheet bundle Sb1 accumulated on a processing tray 24 is pressed and deformed between crimping toothed parts 54 and 55 of a staple-free binding unit 51 to bind the first sheet bundle Sb1 with a first binding force. Then, a corner of a second sheet bundle Sb2 obtained by accumulating additional sheets Sh2 on the first sheet bundle Sb1 is pressed and deformed between the crimping toothed parts 54 and 55 of the staple-free binding unit 51 to bind the second sheet bundle Sb2 with a second binding force smaller than the first binding force. Thus, the additional sheets can easily be removed from the second sheet bundle Sb2.

An image forming system superposes a plurality of recording sheets on top of another by a predetermined number of sheets and discharges the recording sheets. The image forming system includes a recording sheet conveyor, a recording sheet superposition unit, and a controller. The recording sheet conveyor conveys the recording sheets. The recording sheet superposition unit superposes a preceding recording sheet and a succeeding recording sheet sent from the recording sheet conveyor. The controller controls the recording sheet superposition unit not to superpose the preceding recording sheet and the succeeding recording sheet when the controller refers to recording sheet information of the preceding recording sheet and determines that the preceding recording sheet is a recording sheet of a specified kind.

An image forming system superposes a plurality of recording sheets on top of another by a predetermined number of sheets and discharges the recording sheets. The image forming system includes a recording sheet conveyor, a recording sheet superposition unit, and a controller. The recording sheet conveyor conveys the recording sheets. The recording sheet superposition unit superposes a preceding recording sheet and a succeeding recording sheet sent from the recording sheet conveyor. The controller controls the recording sheet superposition unit not to superpose the preceding recording sheet and the succeeding recording sheet when the controller refers to recording sheet information of the preceding recording sheet and determines that the preceding recording sheet is a recording sheet of a specified kind.

A notebook including a group of a preset number of consecutive unit forms which are printed on both faces thereof and spreadably zigzag-folded is produced through a process that includes: printing on both surfaces of a continuous web by two printers each equipped with an endless belt-shaped printing plate, with intermediate inversion of the two surfaces of the web, followed by zig-zag folding and cutting and separating the printed web for each of the preset number of forms. The obtained notebook is capable of preventing falsification and missing pages by inclusion of a horizontal ruled line provided in a main data region and formed of a succession of micro characters.

A notebook including a group of a preset number of consecutive unit forms which are printed on both faces thereof and spreadably zigzag-folded is produced through a process that includes: printing on both surfaces of a continuous web by two printers each equipped with an endless belt-shaped printing plate, with intermediate inversion of the two surfaces of the web, followed by zig-zag folding and cutting and separating the printed web for each of the preset number of forms. The obtained notebook is capable of preventing falsification and missing pages by inclusion of a horizontal ruled line provided in a main data region and formed of a succession of micro characters.

A post-processing apparatus comprises a first processing tray on which fed paper is placed; a paper binding section configured to bind a plurality of sheets of paper stacked on the first processing tray into one bundle; a second processing tray which a plurality of paper bundles bound on the first processing tray are sequentially conveyed to and placed on; a paper bundle gluing section configured to coat glue at a given position of the top surface of a first paper bundle placed on the second processing tray before a second paper bundle is placed on the first paper bundle; a pressing section configured to press and bind the first paper bundle with the second paper bundle between which glue is coated; and a control section configured to control the timing for conveying the second paper bundle onto the first paper bundle after the glue is coated.

A post-processing apparatus comprises a first processing tray on which fed paper is placed; a paper binding section configured to bind a plurality of sheets of paper stacked on the first processing tray into one bundle; a second processing tray which a plurality of paper bundles bound on the first processing tray are sequentially conveyed to and placed on; a paper bundle gluing section configured to coat glue at a given position of the top surface of a first paper bundle placed on the second processing tray before a second paper bundle is placed on the first paper bundle; a pressing section configured to press and bind the first paper bundle with the second paper bundle between which glue is coated; and a control section configured to control the timing for conveying the second paper bundle onto the first paper bundle after the glue is coated.

A device and a method for separating sheet material is provided. The separation of sheet material is not effected statically, but a suitable pick-up position and/or a suitable pick-up mechanism is selected for each sheet material piece, for example in dependence on the quality of a surface of the sheet material piece to be picked up, in order to pick up the sheet material piece from the sheet material stack and remove it from the same.

A control portion of an image forming apparatus creates an image list for performing the perfect-binding imposition of the images of the pages on the sheets so that the scores formed on the sheets are on the external surface of the center-folded sheets, for the sheets each having a size twice the size specified as each of the sheets on which the images of the book body are to be formed, when a book-body stacking portion accommodates the sheets center-folded by a folding portion along scores formed for every sheet from a predetermined direction by a scoring portion for each of the sheets having the images formed thereon by the image forming portion, and a bookbinding portion uses a glue-on cover to perform case binding of a bundle of the sheets glued to the side of the spine.