JP2013220916A - Device and method of paper processing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a paper processing device and a paper processing method capable of performing proper center-folding processing corresponding to use.SOLUTION: A control part performs control so that a folding part 320 has two modes of a first folding mode of discharging paper together with a folding knife by rotating a plurality of rollers after sandwiching the paper in the plurality of rollers and a second folding mode of discharging the paper by rotating the plurality of rollers after extracting the folding knife sandwiched by the paper in a state of not rotating the plurality of rollers after sandwiching the paper in the plurality of rollers.

Description

  The present invention relates to a paper processing apparatus and a paper processing method for forming a crease on a paper on which an image is formed.

  By connecting various paper processing apparatuses in the image forming apparatus, various bookbinding processes can be performed and used as a printing apparatus.

  For example, as shown in FIG. 22, a sheet bundle is formed by forming a central fold (a1) of the sheet and the sheet is folded in the middle, and stapling is performed on the fold portion of the bundle (ST in FIG. 22). Is possible.

  Further, as shown in FIG. 23, a pressure is applied to the back portion of the saddle-stitched sheet bundle with a roller or the like, and a back cover portion is formed by folding the corners b1 and b2, so that the spine is similar to the perfect binding. Processing is possible.

  Note that such saddle stitching processing and square back processing are proposed in the following patent documents.

JP 2009-120398 A JP 2004-196523 A JP2011-116101A

  In the above-mentioned Patent Document 1, the center folding of the sheet is folded from both sides by rollers to perform center folding for saddle stitching, but the roller clamping pressure is set according to the presence or absence of square back processing. It is made to change, and it is made to perform a square back process favorably.

  Moreover, the above-mentioned patent document 2 proposes a mechanism that makes a fold stand out.

  And in the above-mentioned patent document 3, the proposal about the control at the time of performing an appropriate square back process according to the paper type is made.

  Since the square back process is executed after the above-described middle folding process and saddle stitching process, as shown in FIG. 24, the middle fold a1 ′ during the saddle stitching process remains on the spine cover portion, and the booklet quality is reduced. Turned out to be lower.

  In this case, it is considered possible to make the middle folds in the back cover inconspicuous by using a thick folding knife or a folding knife with a sharp tip.

  However, at the same time, the folds of all the sheets other than the spine cover are weakened, so that it becomes unpreferable as a middle fold. In other words, if an appropriate crease is not provided by the middle fold, the accuracy of the binding position can be maintained by conveying from the folded portion to the overlapping portion or the saddle stitching portion, positioning in the overlapping portion or the saddle stitching portion, or the like. A new problem occurs.

  That is, it has been impossible to achieve both the improvement of the booklet quality by erasing the middle fold of the spine and the appropriate folding of the entire paper other than the spine.

  SUMMARY An advantage of some aspects of the invention is that it provides a sheet processing apparatus and a sheet processing method capable of executing an appropriate half-folding process according to an application.

  That is, the present invention for solving the above-described problems is as follows.

  (1) In this invention, while pressing a folding knife against a portion that becomes a valley of a fold of the paper, the portion that becomes a ridge of the paper is sandwiched between a plurality of rollers including a first roller and a second roller, A fold is formed on the paper by a paper processing device comprising: a fold for forming a crease in the paper; and a controller for controlling rotation of the plurality of rollers, movement of the folding knife, and clamping pressure of the plurality of rollers. A first folding mode in which the paper is ejected together with the folding knife by rotating the plurality of rollers after the paper is sandwiched between the plurality of rollers, and the plurality of rollers after the paper is sandwiched between the plurality of rollers. A second folding mode in which the folding knife sandwiched between the sheets is pulled out without rotating, and then the sheets are discharged by rotating the plurality of rollers. It has to be switched between the two modes.

  (2) Further, in the above (1), the sheet processing apparatus includes a corner processing unit that performs a corner processing for flattening a back folding portion of a sheet bundle composed of a plurality of sheets formed with folds. When the square spine processing is performed, a fold is formed in the first folding mode for at least the outermost sheet of the sheet bundle.

  (3) In the above (1)-(2), a crease is formed in the second folding mode for paper other than the paper that is the outermost side of the paper bundle.

  (4) In the above (1) to (3), when forming a crease in the first folding mode, the roller is more than the clamping pressure when the paper is sandwiched between the plurality of rollers. The clamping pressure when discharging from the container is increased.

  (5) In the above (1) to (4), when the fold is formed in the second folding mode, the clamping pressure is kept at a predetermined value, and the plurality of rollers are kept rotatable. The folding knife sandwiched between the sheets in a state in which the sheet is sandwiched between the plurality of rollers, the clamping pressure is increased in a state where the sheet is sandwiched between the plurality of rollers together with the folding knife, and the plurality of rollers are not rotated. And the paper is discharged by rotating the plurality of rollers.

  (6) Further, in the above (1) to (5), the plurality of rollers are arranged in contact with one of the first roller group, one of the plurality of rollers, and the one of the one in contact with the third roller. A second roller group is configured by a roller, a second folding knife having a blade thickness smaller than that of the folding knife is provided, and the first fold is formed at a position other than the center of the paper so that the first fold is formed between the first roller groups. After the paper is sandwiched, the folding knife sandwiched between the paper is pulled out, and the first roller group and the second roller are ejected from the first roller group and sandwiched between the second roller group. While rotating the roller group, the sheet is sandwiched between the second roller group while pressing a second folding knife against the valley portion of the second fold so as to form a second fold on the sheet.

  According to the present invention, the following effects can be obtained.

  When forming a crease in a sheet by the sheet processing apparatus of the present invention, a first folding mode in which the sheet is sandwiched between the plurality of rollers, and then the sheet is discharged together with a folding knife by rotating the plurality of rollers. After pinching the paper, it is possible to switch between two modes: the second folding mode in which the paper is ejected by pulling out the folding knife sandwiched between the paper without rotating the rollers and then rotating the rollers. doing.

  Therefore, in the first folding mode, the sheet with the folding knife sandwiched is discharged from the plurality of rollers, so the fold is weakened. In the second folding mode, only the sheet without the folding knife sandwiched is ejected from the plurality of rollers, so the folding line is strong. Stick. In other words, it is possible to improve the quality of the booklet by erasing the middle crease and to make an appropriate crease, making it possible to execute an appropriate middle folding process according to the application. Become.

  In addition, when square spine processing is performed, a fold is formed in the first folding mode for at least the outermost paper in the bundle of sheets, thereby eliminating the middle fold of the spine cover during square spine processing. Thus, it is possible to improve the quality of the booklet, and it is possible to execute an appropriate folding process according to the application.

  In addition, by forming a crease in the second fold mode for the paper other than the paper that is the outermost of the paper bundle, it is possible to make an appropriate crease for the entire paper other than the back cover, depending on the application. It is possible to execute an appropriate folding process.

  Further, when forming a fold in the first folding mode, the paper and the folding knife are integrated as a result of increasing the clamping pressure when the paper is ejected from the roller, rather than the clamping pressure when the paper is sandwiched between the rollers. Since it is reliably discharged, it is possible to erase the middle fold and improve the quality of the booklet, and it is possible to execute an appropriate middle fold process according to the application.

  Further, when the fold is formed in the second folding mode, the clamping pressure is maintained at a predetermined value, the sheet is sandwiched between the plurality of rollers, and the clamping pressure is increased in a state where the sheet is sandwiched between the plurality of rollers together with the folding knife. Pulling out the folding knife sandwiched between the paper without rotating the roller and rotating the rollers to discharge the paper makes it possible to reliably pull out the folding knife while leaving the paper. Thus, it is possible to execute an appropriate folding process according to the application.

  Further, after the sheet is sandwiched between the first roller groups so that the first fold is formed at a position other than the center of the sheet, the folding knife sandwiched between the sheets is pulled out, and the sheet is discharged from the first roller group. In addition, the second fold knife is formed in the valley portion of the second fold so that the second fold is formed on the sheet while rotating the first roller group and the second roller group in the direction sandwiched between the second roller group. While pressing the sheet, the sheet is sandwiched between the second roller group, so that an appropriate crease can be given as a tri-fold, and an appropriate half-folding process according to the application can be executed.

1 is a block diagram illustrating a configuration of a sheet processing apparatus according to an embodiment of the present invention. It is a block diagram which shows the structure of the paper processing apparatus of embodiment of this invention. It is a block diagram which shows the structure of the paper processing apparatus of embodiment of this invention. 3 is a flowchart illustrating a basic operation of the sheet processing apparatus according to the embodiment of the present invention. It is explanatory drawing which shows the operation state of the reverse conveying apparatus of embodiment of this invention. 6 is a flowchart illustrating an operation of the sheet processing apparatus according to the embodiment of the present invention. It is explanatory drawing which shows the operation state of the reverse conveying apparatus of embodiment of this invention. It is explanatory drawing which shows the operation state of the reverse conveying apparatus of embodiment of this invention. It is explanatory drawing which shows the operation state of the reverse conveying apparatus of embodiment of this invention. It is explanatory drawing which shows the operation state of the reverse conveying apparatus of embodiment of this invention. 6 is a flowchart illustrating an operation of the sheet processing apparatus according to the embodiment of the present invention. It is explanatory drawing which shows the operation state of the reverse conveying apparatus of embodiment of this invention. It is explanatory drawing which shows the operation state of the reverse conveying apparatus of embodiment of this invention. It is explanatory drawing which shows the operation state of the reverse conveying apparatus of embodiment of this invention. It is explanatory drawing which shows the operation state of the reverse conveying apparatus of embodiment of this invention. It is explanatory drawing which shows the operation state of the reverse conveying apparatus of embodiment of this invention. 6 is a flowchart illustrating an operation of the sheet processing apparatus according to the embodiment of the present invention. It is explanatory drawing which shows the operation state of the reverse conveying apparatus of embodiment of this invention. It is explanatory drawing which shows the operation state of the reverse conveying apparatus of embodiment of this invention. It is explanatory drawing which shows the operation state of the reverse conveying apparatus of embodiment of this invention. It is explanatory drawing which shows the operation state of the reverse conveying apparatus of embodiment of this invention. It is explanatory drawing which shows the mode of saddle stitching. It is explanatory drawing which shows the mode of a square back process. It is explanatory drawing which shows the mode of a square back process.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention (hereinafter referred to as embodiments) will be described in detail with reference to the drawings.

[Configuration of image forming system]
With reference to FIG. 1 and FIG. 2, the configuration of an image forming system including a sheet processing apparatus according to the present embodiment will be described. As shown in FIGS. 1 and 2, the image forming system includes an image forming apparatus 100, a reverse conveyance apparatus 200, a paper processing apparatus 300, and a paper processing apparatus 400.

  The image forming apparatus 100 controls each unit in the image forming apparatus 100 and controls the entire system as a sheet processing apparatus, a communication unit 102 for communicating with other connected apparatuses, and an operator An operation display unit 103 for notifying the control unit 101 of an operation input signal corresponding to an operation input by the user and displaying the status of the image forming apparatus 100; storing a control program and various setting data; and using it as a work area for the control program Storage unit 104, sheet feeding unit 105 that feeds the stored paper, transport unit 110 that feeds the fed and image-formed paper at a predetermined speed, and scans the document to generate image data A document reading unit 120 that performs image formation, a storage unit 130 that stores image data and various types of data when forming an image, and various image processes necessary for image formation. The image processing unit 140 to be executed, an image forming unit 150 for performing image formation (printing) on the basis of the image formation instruction and the image data is configured to include a. Note that the paper on which the image is formed by the image forming apparatus 100 is carried out toward the reverse conveyance apparatus 200 at the subsequent stage.

  The reverse conveying apparatus 200 is connected to the subsequent stage of the image forming apparatus 100, and includes a control unit 201 that controls each unit in the reverse conveying apparatus 200 and a communication unit 202 for communicating with the image forming apparatus 100 and the sheet processing apparatus 300. A storage unit 204 that stores the control program and various setting data and is used as a work area for the control program, a conveyance unit 210 that conveys the sheet at a predetermined speed, and an inversion unit that inverts the sheet from the image forming apparatus 100 220 and an aligning unit 230 that aligns the reversed paper.

  The sheet processing apparatus 300 is connected to the subsequent stage of the reverse conveying apparatus 200, and includes a control unit 301 that controls each unit in the sheet processing apparatus 300 and a communication unit 302 that communicates with the image forming apparatus 100 and the reverse conveying apparatus 200. A storage unit 304 that stores a control program and various setting data and is used as a work area of the control program, a discharge path selection unit 305 that selects a discharge path for discharging a post-processed sheet bundle, and a predetermined sheet. Folded by the conveyance unit 310 that conveys at a speed, the folding unit 320 that folds the sheet in half or in three, the overlapping unit 330 that stacks the sheets for post-processing to form a bundle of sheets, and the folding unit 320 Square-back processing for performing a square-back process for flattening a saddle-stitched portion 340 for performing saddle-stitching as a post-processing on a sheet and a back-folded portion of a sheet bundle on which a folding line for saddle-stitching is formed 350, and includes a cutting unit 360 for cutting the fore edge portion of the saddle-stitched sheet bundle, a discharge unit 390 for discharging the saddle-stitching or the middle-folded sheet bundle, a.

  The sheet processing apparatus 400 is connected to the subsequent stage of the sheet processing apparatus 300, and includes a control unit 401 that controls each unit in the sheet processing apparatus 400 and a communication unit 402 that communicates with the image forming apparatus 100 and the sheet processing apparatus 300. A storage unit 404 that stores a control program and various setting data and is used as a work area of the control program, a discharge path selection unit 405 that selects a discharge path for discharging a post-processed sheet bundle, and a predetermined sheet. A transport unit 410 that transports at a speed, a staple unit 420 that staples a bundle of sheets, a main tray discharge unit 440 that discharges sheets with the main tray as a discharge destination, and a sub-tray discharge unit 450 that discharges sheets with the sub-tray as a discharge destination And comprising.

  Note that when the paper transported from the image forming apparatus 100 in the X direction in FIG. 2 is post-processed by the paper processing apparatus 400, the post-processing is performed while being transported in the X direction as it is, and is discharged. On the other hand, when the post-processing is executed in the sheet processing apparatus 300, as shown in FIG. 2, the folding unit 320 performs the middle folding with the Y direction as a ridgeline and conveys the Y direction, while superimposing the unit 330 and the saddle stitching unit 340. In addition, the saddle stitching is performed while being overlapped with each other, and further, the spine back processing unit 350 performs the square back processing to flatten the back cover portion with the roller 350R by the square back processing unit 350, thereby performing the post-processing execution efficiency. As a result, the productivity of the image forming system can be increased. Then, as shown in FIG. 3, the sheet bundle subjected to the square back processing is transported in the −X direction and the cutting portion 360 fore edge is cut, and then transported in the Z direction, so that the discharge roller 390r and the discharge belt It is discharged in the X direction by 390b.

  In addition, the connection of the image forming apparatus 100, the reverse conveying apparatus 200, the paper processing apparatus 300, and the paper processing apparatus 400 in FIGS. 1 to 3 is an example of an image forming system, and is not limited to such a connection. Absent.

〔basic action〕
Hereinafter, the basic operation of this embodiment will be described with reference to the flowcharts in FIG. Here, a paper processing apparatus 300 in the image forming system in the connected state shown in FIGS. 1 and 2 is taken as a specific example.

  When image formation is started, the control unit 301 of the sheet processing apparatus 300 requests the control unit 101 for information (post-processing mode information) related to the processing mode for post-processing (step S11 in FIG. 4). .

  Here, the sheet processing apparatus 300 requests post-processing mode information regarding the folding type (half-fold / three-fold), the presence / absence of saddle stitching, and the presence / absence of the corner back processing. In this embodiment, in addition to the post-processing mode information described above, the paper processing apparatus 300 requests information on whether or not the paper to be processed is a cover page.

  In response to the request for post-processing mode information from the control unit 301 described above, the control unit 101 notifies the control unit 301 of post-processing mode information related to the paper processing apparatus 300 from the job information. Note that settings relating to post-processing are made on the operation display unit 103 of the image forming apparatus 100 before the start of image formation or on the operation screen of an external PC (not shown). Therefore, the control unit 101 extracts necessary information based on such settings relating to post-processing, and notifies the control unit 301 of post-processing mode information.

  The control unit 301 that has received the post-processing mode information from the control unit 101 determines a folding type such as whether the folding type of the sheet processing for the image formation to be executed is “tri-fold” or “half-fold” (FIG. 4 in step S12).

  Here, if the folding type for the sheet processing to be executed is “tri-fold” (“tri-fold” in step S12 in FIG. 4), the control unit 301 instructs the folding unit 320 to perform tri-fold, and the folding is performed. The unit 320 executes tri-fold control to fold the paper in three (step S17 in FIG. 4). Note that the three-fold control is a known control in which the folding unit 320 folds the paper in a folding manner such as winding three-fold, but will be described in detail later.

  On the other hand, if the folding type of the sheet processing to be executed is “center folding” (“center folding” in step S12 in FIG. 4), the control unit 301 determines whether or not the corner back processing is selected (FIG. 4). 4 in step S13).

  Here, if it is a middle folding and there is no square back processing (NO in step S13 in FIG. 4), the control unit 301 instructs the folding unit 320 to perform the second folding mode control as a normal middle folding control. The folding unit 320 executes normal half-folding control to fold the sheet in half (step S15 in FIG. 4).

  If the sheet processing to be executed is half-folded and the corner processing is present (YES in step S13 in FIG. 4), it is determined whether or not the page to be processed is a cover page. Is determined (step S14 in FIG. 4).

  If it is half-folded and square-back processing is performed and the sheet is not a cover (NO in step S14 in FIG. 4), the control unit 301 performs the second folding as the normal middle-folding control for the folding unit 320. A mode control instruction is given, and the folding unit 320 executes normal half-folding control to fold the sheet in half (step S15 in FIG. 4).

  On the other hand, if it is half-folded, square-back processing is performed, and the sheet is a cover (YES in step S14 in FIG. 4), the control unit 301 sets the cover-folding control as the cover middle-folding control. An instruction for one-fold mode control is given, and the folding unit 320 executes half-folding control suitable for the cover sheet to fold the sheet into two (step S16 in FIG. 4).

  Here, the normal half-fold control is a half-fold control for creating a normal crease in which a fold mark remains in a streak shape, as will be described later. Further, the cover half-folding control is a process for making the folds of the middle fold weaker and less conspicuous than the normal half-folding control, as will be described later.

  Here, it is determined whether or not the cover is a cover, but it may be determined that the cover is one or two sheets close to the cover and the cover, or other sheets. This is because, in the case of thick paper, the case of a half-folded mark as shown in FIG. In this case, according to the sheet thickness, the first folding mode control may be performed only for the cover when the sheet is thin, or for the cover plus several sheets when the sheet is thick.

[Folder configuration]
Here, the configuration of the folding unit 320 in which the first folding mode control is executed will be described with reference to FIG.

  FIG. 5 is a cross-sectional configuration diagram illustrating the basic configuration of the folding unit 320 in the sheet processing apparatus 300 in the XZ plane. Here, the sheet conveyed from the image forming apparatus 100 or the reverse conveyance apparatus 200 to the folding unit 320 is conveyed at a predetermined speed in the folding unit 320 by the conveyance rollers 3211 and 3212 and the conveyance rollers 3221 and 3222.

  When folding is performed at the folding unit 320, the sheet is stopped in a state where the sheet is regulated at a predetermined position by the leading end stopper 3230. Thereafter, the folding knife 3250 with the Y direction as the longitudinal direction is extended in the Z direction between the folding rollers 3241 and 3242 by the folding knife driving unit 3251, whereby the sheet is sandwiched between the folding rollers 3241 and 3242, Is formed. At this time, the folding rollers 3241 and 3242 are rotatable. Then, the folding knife 3250 is raised after a predetermined time set by the timer and then stopped, and the sheet and the folding knife 3250 are driven in the returning direction by the rotation of the folding rollers 3241 and 3242. The folding unit 320 can execute not only the middle folding for folding the center of the sheet for saddle stitching but also the three folding for folding the two places on the sheet.

  In the above configuration, the folding rollers 3241 and 3242 are a plurality of rollers constituting the first roller group for forming the first fold at the time of middle folding and trifolding. Further, the folding rollers 3242 and 3243 are a plurality of rollers that constitute a second roller group for forming a second fold when tri-folding. The folding rollers 3241 and 3242 are drive rollers, and the folding roller 3243 is a driven roller.

  Further, in the above configuration, the folding rollers 3241 and 3242 are provided with a clamping pressure application unit (not shown) that makes the clamping pressure for the paper variable when the paper is sandwiched and conveyed in the middle.

  Further, in this embodiment, the folding knife 3250 is thicker than the conventional folding knife and is configured not to have a sharp tip so that the fold mark is not conspicuous in the middle folding of the spine cover. .

[First folding mode control]
Hereinafter, the first folding mode control as the normal middle folding control will be described with reference to the flowchart of FIG.

  Here, the first folding mode control refers to a normal folding knife that is thicker than the conventional folding knife and has a sharp tip when the square back process is performed on the cover sheet of the sheet bundle. This is a control of the process for making the fold of the middle fold weaker and less conspicuous than the middle fold control.

  First, when the normal folding control for normal use is started, in a state where the sheet conveyed from the image forming apparatus 100 is stopped at a predetermined position by the leading end stopper 3230 (FIG. 5), the control unit 301 performs the folding roller The clamping pressure between 3241 and 3242 is controlled to a low pressure (step S101 in FIG. 6), and as shown in FIG. The folding knife driving unit 3251 is controlled so that the paper and the folding knife 3250 are inserted into the sheet (step S102 in FIG. 6). Accordingly, the sheet and the folding knife 3250 are integrated, and the sheet is sandwiched between the folding rollers 3241 and 3242. At this time, the folding rollers 3241 and 3242 in a rotatable state rotate in the normal rotation direction (the direction in which the paper is inserted) by inserting the paper and the folding knife between the folding rollers 3241 and 3242. .

  After the control unit 301 detects that the folding knife 3250 is driven by the folding knife drive unit 3251 for a certain period of time or until it is detected by the sensor (step S103 in FIG. 6), the control unit 301 The clamping pressure between the folding rollers 3241 and 3242 is switched to a strong pressure (step S104 in FIG. 6, FIG. 8).

  After the control unit 301 detects that the clamping pressure has been switched (YES in step S105 in FIG. 6), the control unit 301 turns the folding rollers 3241 and 3242 in the reverse rotation direction (paper to the original position). And the folding knife driving unit 3251 drives the folding knife 3250 to return to the standby position (step S106 in FIG. 6), and the sheet and the folding knife 3250 are both placed between the folding rollers 3241 and 3242. (Step S107 in FIG. 6, FIG. 9).

  It is detected that the paper and the folding knife 3250 are completely discharged from between the folding rollers 3241 and 3242 (YES in step S108 in FIG. 6), and each step to be executed in the control of the first folding mode is as follows. When the completion is detected (YES in step S109 in FIG. 6), the control unit 301 stops the rotational driving of the folding rollers 3241 and 3242 (step S110 in FIG. 6), and between the folding rollers 3241 and 3242. Is switched to a low pressure (step S111 in FIG. 6, FIG. 10).

  For this reason, in the first folding mode, the sheet sandwiching the folding knife 3250 that is thicker than the conventional folding knife and has no sharp tip is discharged from the plurality of rollers. The crease according to the shape of the tip is weak. In other words, it is possible to improve the quality of the booklet by removing the middle crease during the corner back processing.

[Second folding mode control]
Hereinafter, the second folding mode control as the normal middle folding control will be described with reference to the flowchart of FIG.

  Here, the second folding mode control means that the conventional folding knife has a thickness that is thicker than that of the conventional folding knife and a folding portion that can weaken the crease with a folding knife that is not sharpened at the tip. It is control of the process which forms a crease | fold.

  First, when the normal folding control for normal use is started, in a state where the sheet conveyed from the image forming apparatus 100 is stopped at a predetermined position by the leading end stopper 3230 (FIG. 5), the control unit 301 performs the folding roller The clamping pressure between 3241 and 3242 is controlled to a low pressure (step S201 in FIG. 11), and as shown in FIG. 12, the folding rollers 3241 and 3242 are rotated in the normal rotation direction (the direction in which the paper is inserted). (Step S202 in FIG. 11), the folding knife driving unit 3251 is controlled so that the folding knife 3250 is applied to the portion that becomes the valley of the sheet fold, and the sheet and the folding knife 3250 are inserted between the folding rollers 3241 and 3242. (Step S203 in FIG. 11). Accordingly, the sheet and the folding knife 3250 are integrated, and the sheet is sandwiched between the folding rollers 3241 and 3242.

  In the state explanatory diagrams of FIGS. 12 to 16, only one sheet is shown for the sake of clarity, but actually, a plurality of sheets can be processed simultaneously.

  After the control unit 301 detects that the folding knife 3250 is driven by the folding knife drive unit 3251 for a certain period of time or until it is detected by the sensor (YES in step S204 in FIG. 11), the control unit 301 Switches the clamping pressure between the folding rollers 3241 and 3242 to a strong pressure (step S205 in FIG. 11, FIG. 13).

  After detecting that the clamping pressure has been switched, the control unit 301 stops the rotation of the folding rollers 3241 and 3242 (step S206 in FIG. 11), and further stops the folding rollers 3241 and 3242. (Step S207 in FIG. 11).

  Then, after the completion of the control for fixing the folding state of the folding rollers 3241 and 3242 is detected (YES in step S208 in FIG. 11), the control unit 301 drives the folding knife while keeping the folding rollers 3241 and 3242 in a fixed state. The unit 3251 drives the folding knife 3250 to return to the standby position and discharges only the folding knife 3250 from between the folding rollers 3241 and 3242 separately from the paper (steps S209 and FIG. 14 in FIG. 11). In this state, the folding rollers 3241 and 3242 in the fixed state press the sheet with a strong clamping pressure, so that the sheet does not move and only the folding knife 3250 is pulled out.

  When the completion of pulling out the folding knife 3250 is detected by a sensor or the like not shown (YES in step S210 in FIG. 11), the control unit 301 ejects the folding rollers 3241 and 3242 in the reverse direction (discharges the paper to the original position). (In step S211 in FIG. 6). At this time, since the crease portion of the paper is crushed between the folding rollers 3241 and 3242 having a strong clamping pressure without the folding knife 3250 being sandwiched (see FIG. 15), an appropriate and sharp crease similar to the conventional one is formed. Is done.

  When it is detected that the paper is completely discharged from the folding rollers 3241 and 3242, and it is detected that each step to be executed by the control of the second folding mode is completed (YES in step S212 in FIG. 11). ), The controller 301 stops the rotation of the folding rollers 3241 and 3242 (step S213 in FIG. 11), and switches the clamping pressure between the folding rollers 3241 and 3242 to a low pressure (step S214 in FIG. 11, FIG. 11). 16).

  For this reason, in the second folding mode, even when the folding knife 3250 that is thicker than the conventional folding knife and has a sharp tip is used, only the paper that does not sandwich the folding knife is removed from the plurality of rollers. Since it is discharged, the crease is strongly attached. That is, even when the folding knife 3250 for improving the booklet quality by erasing the middle fold is used, it is possible to apply a proper and sharp crease similar to the conventional one, and an appropriate one according to the application. It is possible to execute the middle folding process.

[Tri-fold mode control]
Hereinafter, the tri-fold mode control will be described with reference to the flowchart of FIG.

  Here, the folding rollers 3241 and 3242 are a plurality of rollers constituting the first roller group for forming the first fold at the time of three-folding. Further, the folding rollers 3242 and 3243 are a plurality of rollers that constitute a second roller group for forming a second fold when tri-folding.

  Here, the three-fold mode control will be described by taking a three-fold winding as a specific example. Further, as described above, the folding knife 3250 that is also used for the middle folding is a folding knife that is thicker than the conventional folding knife and has a sharp tip, and is referred to as a first folding knife 3250 here. On the other hand, the second folding knife 3252 for forming the second fold is a thin and sharp knife similar to the conventional one. In addition, about the folding knife drive part which drives the 2nd folding knife 3252, since the thing of the structure similar to the folding knife drive part 3251 can be used, illustration is abbreviate | omitted.

  First, when starting normal folding control, the control is performed in a state where the sheet conveyed from the image forming apparatus 100 is stopped at a predetermined position suitable for forming a first folded third fold. The unit 301 controls the clamping pressure between the folding rollers 3241 and 3242 to be a strong pressure (step S301 in FIG. 17), and as shown in FIG. 18, the folding rollers 3241 and 3242 are rotated in the forward direction (the direction in which the paper is inserted). ) (Step S302 in FIG. 17). After that, the first folding knife 3250 is applied to the first fold valley and the folding knife driving unit 3251 is controlled so that the sheet and the first folding knife 3250 are inserted between the folding rollers 3241 and 3242. (Step S303 in FIG. 17).

  As described above, the folding rollers 3241 and 3242 are driven in the forward rotation direction while applying a strong clamping pressure prior to the insertion of the first folding knife 3250, so that the thickness is thicker than the conventional folding knife and the tip is not sharp. Even when the first folding knife in the state is used, the sheet is sandwiched between the folding rollers 3241 and 3242 with a strong crease.

  In the state explanatory diagrams of FIGS. 18 to 21, only one sheet is shown for the sake of clarity, but actually, a plurality of sheets can be processed simultaneously.

  After the control unit 301 detects that the first folding knife 3250 is driven by the folding knife drive unit 3251 for a certain period of time or until the position detected by the sensor has reached the switching timing (step S304 in FIG. 17). In step S305 in FIG. 17 and FIG. 19, the control unit 301 switches the clamping pressure between the folding rollers 3241 and 3242 to a low pressure.

  Here, the control unit 301 stops and fixes the rotational driving of the folding rollers 3241 and 3242 (step S306 in FIG. 17), and can confirm whether the processing for the first fold is completed (step in FIG. 17). In S307, the folding rollers 3241 and 3242 are kept fixed, and the folding knife driving unit 3251 is driven to return the first folding knife 3250 to the standby position so that only the first folding knife 3250 is separated from the paper. The paper is discharged from between the folding rollers 3241 and 3242 (step S308 in FIG. 17).

  Thereafter, the control unit 301 controls the driving so that the second folding knife 3252 and the second fold of the paper are positioned at appropriate positions by rotational driving of the folding rollers 3241 and 3242 (steps S309 and FIG. 20 in FIG. 17). ). At this time, the portion where the sheets are not folded is sandwiched between the folding rollers 3241 and 3242 by tri-folding.

  Then, as shown in FIG. 21, the control unit 301 applies the second folding knife 3252 to the portion that becomes the second fold valley, and inserts the sheet and the second folding knife 3252 between the folding rollers 3242 and 3243. (Step S310 in FIG. 17), and the folding rollers 3241, 3242 and 3243 are rotated in the normal rotation direction (direction in which the paper is inserted) (Step S311 in FIG. 17). Here, the sheet is removed from the folding rollers 3241 and 3242 of the first roller group in the insertion direction, and the second fold portion of the sheet is inserted between the folding rollers 3242 and 3243 of the second roller group. Become. As a result, the second fold portion of the sheet and the second folding knife 3252 are integrated and are sandwiched between the folding rollers 3242 and 3243 which are the second roller group.

  When it is detected that each step to be executed for forming the second fold is completed by the above-described control in the three-fold mode (YES in step S312 in FIG. 17), the control unit 301 performs the folding rollers 3241, 3242, 3243. Is stopped (step S313 in FIG. 17). After this, the control unit 301 controls to discharge the folded paper in either direction.

  For this reason, even when the first folding knife 3250 having a thick thickness and a sharp tip is used, the first fold can be given an appropriate and sharp first fold as in the prior art. The second folding knife 3252 in a thin and sharp state similar to the conventional one can be used to make an appropriate and sharp second fold similar to the conventional one.

  Therefore, even when the first folding knife 3250 having a thickness larger than that of the conventional folding knife and having a sharp tip is used, it is possible to make an appropriate and sharp crease similar to the conventional one. Even when the folding knife 3250 is used to erase the middle folds and improve the booklet quality, it is possible to apply appropriate and sharp creases similar to the conventional ones when tri-folding, depending on the application. Appropriate middle folding processing and tri-folding processing can be executed.

[Other Embodiments]
In the above-described embodiment, in the image forming system that transports the paper on which the image is formed in the X direction, the folded or saddle stitched paper is transported in the Y direction. However, the present invention is not limited to this. A half-folded or saddle-stitched sheet may be conveyed in the X direction, or may be conveyed in an intermediate direction between X and Y.

  In the above embodiment, the case where the middle folding control and the three folding control are possible is shown as a specific example, but the folding unit 320 may have a function of performing another folding. For example, in order to perform Z-shaped tri-folding, a configuration having other folding rollers and other folding knives may be used.

DESCRIPTION OF SYMBOLS 100 Image forming apparatus 101 Control part 102 Communication part 103 Operation display part 104 Storage part 105 Paper feed part 130 Storage part 140 Image processing part 150 Image formation part 200 Reverse conveyance apparatus 300 Paper processing apparatus 301 Control part 302 Communication part 310 Conveyance part 320 Folding unit 330 Overlapping unit 340 Saddle stitching unit 350 Square spine processing unit 360 Cutting unit 390 Discharge unit 400 Saddle stitching device

Claims (12)

A crease is formed on the paper by pressing a folding knife against the fold valley of the paper and sandwiching the fold crest of the paper between a plurality of rollers including a first roller and a second roller. A sheet processing apparatus for forming a crease in the sheet, comprising: a folding unit; and a control unit that controls rotation of the plurality of rollers, movement of the folding knife, and clamping pressure of the plurality of rollers.
The controller is
A first folding mode for discharging the paper together with the folding knife by rotating the plurality of rollers after the paper is sandwiched between the plurality of rollers;
A second folding mode in which after the paper is sandwiched between the plurality of rollers, the folding knife sandwiched between the paper is pulled out without rotating the plurality of rollers, and then the paper is discharged by rotating the plurality of rollers. ,
The two modes are switchable,
A paper processing apparatus. The paper processing apparatus includes a square back processing unit that performs a square back processing to flatten a back folding portion of a sheet bundle composed of a plurality of sheets of creases formed,
The controller is
When the square spine processing is performed, control is performed so that a fold is formed in the first folding mode for the paper that is at least the outermost side of the paper bundle.
The sheet processing apparatus according to claim 1. The controller is
Control is performed so that a crease is formed in the second fold mode for paper other than the paper that is the outermost side of the paper bundle,
The sheet processing apparatus according to any one of claims 1-2. The controller is
When forming a crease in the first fold mode,
Control to increase the clamping pressure when the paper is discharged from the roller, rather than the clamping pressure when the paper is sandwiched between the plurality of rollers.
The sheet processing apparatus according to claim 1, wherein the sheet processing apparatus is a sheet processing apparatus. The controller is
When forming a fold by the second folding mode,
Maintaining the clamping pressure at a predetermined value, and sandwiching the paper between the plurality of rollers in a state in which the plurality of rollers are kept rotatable,
Increasing the clamping pressure in a state where the paper is sandwiched between the plurality of rollers together with the folding knife,
Pulling out the folding knife sandwiched between the sheets without rotating the plurality of rollers,
Discharging the paper by rotating the plurality of rollers;
The sheet processing apparatus according to claim 1, wherein the sheet processing apparatus is controlled as follows. The plurality of rollers constitutes a first roller group, a third roller arranged to contact one of the plurality of rollers, and the one roller in contact with the third roller constitutes a second roller group,
A second folding knife having a blade thickness smaller than that of the folding knife;
The controller is
After the paper is sandwiched between the first roller groups so as to form a first fold at a position other than the center of the paper, the folding knife sandwiched between the paper is pulled out,
A second fold is formed on the sheet while rotating the first roller group and the second roller group in a direction in which the sheet is discharged from the first roller group and sandwiched between the second roller group. In addition, the paper is sandwiched between the second roller group while pressing the second folding knife against the second fold valley.
The sheet processing apparatus according to claim 1, wherein the sheet processing apparatus is controlled as follows. A crease is formed on the paper by pressing a folding knife against the fold valley of the paper and sandwiching the fold crest of the paper between a plurality of rollers including a first roller and a second roller. A paper processing method for forming a crease in the paper by a paper processing device comprising: a folding part; and a control part for controlling rotation of the plurality of rollers, movement of the folding knife, and clamping pressure of the plurality of rollers,
A first folding mode for discharging the paper together with the folding knife by rotating the plurality of rollers after the paper is sandwiched between the plurality of rollers;
A second folding mode in which after the paper is sandwiched between the plurality of rollers, the folding knife sandwiched between the paper is pulled out without rotating the plurality of rollers, and then the paper is discharged by rotating the plurality of rollers. ,
A paper processing method characterized in that the two modes can be switched. The paper processing apparatus includes a square back processing unit that performs a square back processing to flatten a back folding portion of a sheet bundle composed of a plurality of sheets of creases formed,
When the square spine processing is performed, a crease is formed in the first folding mode for the paper that is at least the outermost side of the paper bundle.
The sheet processing method according to claim 7. A crease is formed in the second folding mode for paper other than the paper that is the outermost side of the paper bundle,
The sheet processing method according to any one of claims 7 to 8, wherein the sheet processing method is performed. When forming a crease in the first fold mode,
The clamping pressure at the time of discharging the paper from the roller is higher than the clamping pressure at the time of sandwiching the paper between the plurality of rollers.
The sheet processing method according to any one of claims 7 to 9, wherein the sheet processing method is performed. When forming a fold by the second folding mode,
Maintaining the clamping pressure at a predetermined value, and sandwiching the paper between the plurality of rollers in a state in which the plurality of rollers are kept rotatable,
Increasing the clamping pressure in a state where the paper is sandwiched between the plurality of rollers together with the folding knife,
Pulling out the folding knife sandwiched between the sheets without rotating the plurality of rollers,
Discharging the paper by rotating the plurality of rollers;
The sheet processing method according to any one of claims 7 to 10, wherein the sheet processing method is performed. The plurality of rollers constitutes a first roller group, a third roller arranged to contact one of the plurality of rollers, and the one roller in contact with the third roller constitutes a second roller group,
A second folding knife having a blade thickness smaller than that of the folding knife;
After the paper is sandwiched between the first roller groups so as to form a first fold at a position other than the center of the paper, the folding knife sandwiched between the paper is pulled out,
A second fold is formed on the sheet while rotating the first roller group and the second roller group in a direction in which the sheet is discharged from the first roller group and sandwiched between the second roller group. In addition, the paper is sandwiched between the second roller group while pressing the second folding knife against the second fold valley.
The sheet processing method according to any one of claims 7 to 11, wherein the sheet processing method is performed.

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