JP2010163219A - Paper folder, paper postprocessing device and image forming system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem that there is a case that a carrying failure occurs when paper is stopped by a paper pressing member depending on paper quality and the curl state of the paper though using the paper pressing member for assisting the bend of the paper, in a paper folder for forming a fold line in the paper by nipping and carrying a bend part by a folding means by bending the paper by carrying the paper in a state of fastening the paper tip. <P>SOLUTION: The paper pressing means has a base supported by a fixing part and having a free end, and a tip connected to the free end of the base and changing an angle with respect to the base by being pushed by the paper. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a paper folding device that performs paper folding processing, a paper post-processing device having a paper folding device, and an image forming system. The paper post-processing apparatus is connected to the image forming apparatus and performs post-processing such as folding processing on the paper on which the image is formed.

  A paper folding apparatus that performs a folding process such as bi-folding or tri-folding on a paper is disclosed in, for example, Japanese Patent Application Laid-Open No. 2003-122826.

  The paper folding device of Patent Document 1 feeds a folding means formed by a pair of rollers with a portion to be creased at the head, and nips and conveys the paper by a pair of rollers while conveying the paper. Fold it.

  Further, in Patent Document 1, when forming the first fold in the folding process of folding the paper in three, the paper is fed to the folding means using a folding plate and the second fold is formed. The paper is bent by conveying the paper with the front end of the paper stopped, and the bent portion is sent to the folding means.

  In the conveyance process of bending the paper for forming the second crease, the bending direction of the paper is regulated by the shape of the conveyance path.

JP 2004-99199 A

  In the folding process that restricts the bending of the paper depending on the shape of the transport path, the bending is not sufficiently restricted only by the shape of the transport path, and depending on the paper quality and curl state of the paper, the crease may not be correctly formed, and the corner may be bent. There is a problem such as. In addition, if the bending regulation by the conveyance path is strengthened, there may be a problem that the conveyance performance is reduced and a jam occurs.

  The present invention solves such a problem in the sheet folding apparatus, and can reliably fold a wide range of paper-quality sheets, a sheet post-processing apparatus including the sheet folding apparatus, and the sheet post-processing. An object of the present invention is to provide an image forming system including the apparatus.

  The object is achieved by the following invention.

1. Transport means for transporting paper by nip,
A leading edge stopping means for stopping the leading edge of the sheet conveyed by the conveying means;
A regulation unit that regulates the bending direction of the sheet that is bent between the conveyance unit and the leading end stop unit when the sheet is conveyed by the conveyance unit in a state where the leading end of the sheet is stopped by the leading end stop unit;
In a paper folding apparatus having a folding means that nips and conveys a bent paper between the conveying means and the leading edge stopping means and forms a crease in the paper,
Paper holding means for assisting bending of the paper by the regulating means,
The paper pressing means includes a base portion supported by a fixed portion and having a free end, and a front end portion that is connected to the free end of the base portion and changes an angle with respect to the base portion when pressed by the paper. apparatus.

  2. A sheet post-processing apparatus comprising the sheet folding apparatus according to 1 above.

  3. An image forming system comprising: an image forming apparatus that forms an image on a sheet; and the sheet post-processing apparatus according to 2 that performs post-processing on a sheet on which an image is formed by the image forming apparatus.

  In the present invention, the sheet pressing means formed by the base portion and the tip end portion connected to the free end of the base portion assists the regulating action of bending the paper and introduces the paper into the folding means.

  As a result, it is possible to fold a wide range of paper quality from thin paper to thick paper, and create a folded paper with uniform quality.

  In particular, even with a curled sheet, it is possible to perform a folding process by forming a correct crease.

1 is an overall view of an image forming system having an image forming apparatus A and a sheet post-processing apparatus FS according to an embodiment of the present invention. 3 is a front view of a folding unit 50. FIG. It is a figure explaining a trifold process. 6 is a diagram illustrating a first example of a sheet pressing member 59. FIG. FIG. 6 is a diagram illustrating an arrangement in a width direction of a sheet pressing member 59. It is a figure which shows the 2nd example of a paper pressing member. It is a figure which shows the 3rd example of a paper pressing member.

  Although the present invention will be described based on the illustrated embodiment, the present invention is not limited to the embodiment.

[Image forming system]
FIG. 1 is an overall view of an image forming system having an image forming apparatus A and a sheet post-processing apparatus FS according to an embodiment of the present invention.

<Image forming apparatus A>
The illustrated image forming apparatus A includes an image reading unit 1, an image processing unit 2, an image writing unit 3, an image forming unit 4, a paper feed cassette 5, a paper feed unit 6, a fixing device 7, a paper discharge unit 8, and automatic duplexing. A copy feeding unit (ADU) 9 is provided.

  An automatic document feeder DF is mounted on the upper part of the image forming apparatus A. A sheet post-processing device FS is connected to the left side of the image forming apparatus A in the drawing on the paper discharge unit 8 side.

  The document placed on the document table of the automatic document feeder DF is conveyed in the direction of the arrow, and an image on one or both sides of the document is read by the optical system of the image reading unit 1, and is read by the CCD image sensor 1A.

  The analog signal photoelectrically converted by the CCD image sensor 1A is subjected to analog processing, A / D conversion, shading correction, image compression processing, and the like in the image processing unit 2, and then sent to the image writing unit 3.

  At the time of image formation, output light is emitted from the semiconductor laser of the image writing unit 3, and the photosensitive drum 4A of the image forming unit 4 is irradiated to form a latent image. In the image forming unit 4, processes such as charging, exposure, development, transfer, separation, and cleaning are performed, and a toner image is formed on the photosensitive drum 4A. The recording paper S1 fed from the paper feeding cassette 5 by the paper feeding means 6 contacts the photosensitive drum 4A, and the toner image is transferred to the recording paper S1 by the transfer means 4B. The recording paper S1 carrying the toner image is fixed by the fixing device 7 and sent from the paper discharge unit 8 to the paper post-processing device FS. In the case of double-sided copying, the recording paper S1 that has undergone single-sided image processing is sent to the automatic double-sided copy paper feeding unit 9 by the conveyance path switching plate 8A, and after the toner image is transferred and fixed on the back side in the image forming unit 4 The paper is discharged from the paper discharge unit 8.

[Paper post-processing device FS]
The paper post-processing device FS includes a paper carry-in unit 20, insertion paper feeding units 30a and 30b, and a plurality of post-processing units. The post-processing unit includes a punching processing unit 40, a folding unit 50 as a paper folding device according to the embodiment of the present invention, an overlay processing unit 60, binding processing units 71 and 72, and a paper discharge unit 80.

  The insertion sheet feeding unit 30a is loaded with the insertion sheet S2, and the insertion sheet feeding unit 30b is loaded with another insertion sheet S3.

  The insertion sheets S2 and S3 are insertion sheets such as a cover sheet and an insert sheet inserted between the plurality of recording sheets S1 discharged from the image forming apparatus A. Like the recording sheet S1, the insertion sheets S2 and S3 are punched and folded. Processing can be performed.

  The insertion sheets S2 and S3 sent out from the insertion sheet feeding sections 30a and 30b are conveyed to the sheet carry-in section 20 through a downward conveyance path (without reference numerals).

  The punching processing unit 40 is disposed in the paper carry-in unit 20.

  In the following description, the recording sheet S1 and the insertion sheets S2 and S3 are collectively referred to as a sheet S.

  The folding unit 50 is disposed on a conveyance path H1 branched downward from the paper carry-in unit 20.

  The superposition processing unit 60 is disposed on the downstream side of the transport path H2 branched upward from the paper carry-in section 20, and includes transport paths H3, H4, and H5.

  In the binding processing unit 71 located on the downstream side, the superposition processing unit 60 transfers the succeeding paper S to the transport path H3 and the transport paths H4 and H5 in order to secure time for binding the preceding paper S. Wait.

  The conveyance path located on the downstream side of the conveyance path H2 is branched into a doubly curved conveyance path, and is divided into an inner conveyance path H4 and outer conveyance paths H3 and H5.

  A conveyance roller 21 is provided at the discharge port of the conveyance path H4 that forms an inner conveyance path that is branched and curved from the conveyance path H2, and rotates when the first sheet S of sheets S to be bound is conveyed. In a state in which the paper is stopped, the front end of the paper is received and kept in contact with the conveying roller 21.

  As described above, the sheet S conveyed on the conveyance path H2 waits in a state where the leading end abuts against the conveyance roller 21, but the subsequent sheet S enters the conveyance path H3 from the conveyance path H2 and is conveyed to the conveyance roller. 21 is reached.

  From the transport roller 21, the preceding sheet S and the succeeding sheet S are transported together and transported to the stacking unit 70 in a state where they overlap each other.

  The conveyance path H3 is continuous with the conveyance path H2 downstream of the conveyance path H2, and the conveyance path H5 is continuous with the conveyance path H3.

  The conveyance path H3 is branched into a conveyance path H5 and a conveyance path H6.

  The transport path H6 forms a paper discharge path for discharging the paper S to the fixed paper discharge tray 81.

  The fixed paper discharge tray 81 is disposed at a position protruding from the sheet post-processing device FS outside the conveyance path H6 on the conveyance roller 24 on the conveyance path H3, on the downstream side of the conveyance path H6 branched from the stacking processing unit 60. .

  As described above, the fixed paper discharge tray 81 is conveyed through the conveyance paths H2, H3, and H6 and accumulates the discharged paper S.

  The paper discharge unit 80 includes a paper discharge roller 22 and an alignment mechanism, and discharges the paper S to the lift paper discharge tray 82. Although not shown, the alignment mechanism is constituted by a known mechanism that reciprocates in the horizontal direction perpendicular to the transport discharge direction to align the sheets.

  The paper discharge roller 22 is composed of a pair of rollers. When the paper is not discharged, the pair of rollers are separated from each other.

  The sheet S transported by the transport roller 21 constitutes a paper discharge roller 22, travels leftward between a pair of spaced rollers, and reaches the stacking unit 70 when the rear end is separated from the transport roller 21. The accumulated portion 70 that has fallen and slanted is slid down, received by a stopper (not shown), and stopped on the accumulated portion 70.

  When the set number of sheets S are stacked on the stacking unit 70, the binding processing unit 71 operates to bind the sheets S.

  The bound sheet S is pushed up by the stopper and moves to the upper left on the stacking unit 70.

  At this time, a pair of rollers constituting the paper discharge roller 22 come into contact with each other to nip the paper S, convey it, and discharge it to the lift paper discharge tray 82.

  In the folding mode, the sheet S is conveyed downward along the conveyance path H <b> 1 from the sheet carry-in unit 20, is subjected to middle folding or tri-fold processing in the folding unit 50, and is discharged to the lower sheet discharge unit 83.

  In the saddle stitching mode, the paper S is transported from the paper carry-in unit 20 through the transport path H1, is subjected to saddle stitching processing in the binding processing unit 72, and is subjected to center folding processing in the folding unit 50, and then is sent to the lower paper discharge unit 83. Discharged.

There are the following four paths for discharging the paper S.
1) Paper carry-in section 20 → conveyance path H2 → conveyance path H3 → conveyance path H6 → fixed discharge tray 81
2) Paper carry-in section 20 → conveyance path H2 → conveyance paths H3, H4, H5 → stacking section 70 → discharge section 80 → lifting / discharging tray 82
3) Paper carry-in section 20 → conveyance path H2 → H4 → paper discharge section 80 → lifting / discharging tray 82
4) Paper carry-in part 20 → conveying path H1 → folding part 50 → lower sheet delivery part 83
The routes 1), 2) and 4) are as described above.

  The path 3) is selected when a large amount of image is formed without performing a binding process or a folding process.

  The paper S is discharged to the lifting / lowering tray 82 without post-processing, and the lifting / lowering tray 82 is indicated by a chain line in the figure so that the top surface of the discharged paper S is always at a constant height. Move down to.

  Therefore, it is possible to stack thousands of sheets on the lifting / discharging tray 82.

  FIG. 2 is a front view of a folding unit 50 as a paper folding device according to the embodiment of the present invention.

  The conveyance path H1 in FIG. 1 includes a guide member 51 including a guide plate 51A that guides the paper S at the upstream portion of the folding portion 50 and a guide plate 51B that guides the paper S at the downstream portion.

  A restriction member 51 </ b> C for restricting the position of the sheet S is provided on the transport path H <b> 1 on the downstream side of the folding unit 50. The regulating member 51C regulates the lower end of the paper S to a predetermined position, and can be displaced according to the paper size.

  The folding unit 50 includes a folding plate 52, a folding upper roller (hereinafter referred to as an upper roller) 53, a folding lower roller (hereinafter referred to as a lower roller) 54, a folding roller 55, a conveyance path switching member 57 as a switching guide means, A guide member 58 and a leading end stop member 581 constituting a folding introducing means are provided, and the sheet S is folded in half or in half.

  The upper roller 53 and the lower roller 54, which constitute folding means in the two-folding process and form the first folding means for forming the first fold in the three-folding process, are also the lower roller 54 and the folding roller 55 in the three-folding process. Between the two, a conveying means for bending and inserting the sheet S by conveyance is configured.

  The lower roller 54 and the folding roller 55 constitute a folding means for forming a second fold on the paper S by nipping and feeding the bent paper S.

  The lower roller 54 is shared by the conveying unit and the folding unit. However, the conveying unit and the folding unit may be configured by a pair of rollers, and a sheet folding device may be configured by four rollers. .

  The upper roller 53 and the lower roller 54 are supported by a pair of left and right pressing means that are substantially symmetrical. One pressing means supports the upper roller 53 in a rotatable manner, is supported by a support plate 532 that can swing around a support shaft 531, and one end of the support plate 532, and holds the upper roller 53 in the clamping position direction. And an urging spring 533. The other pressing means includes a support plate 542 that can swing around a support shaft 541 and a spring 543 that is locked to one end of the support plate 542 and biases the lower roller 54 toward the clamping position. The upper roller 53 and the lower roller 54 are driven and rotated by a folding roller drive motor (not shown). The outer peripheral surfaces of the upper roller 53 and the lower roller 54 are formed of a high friction resistance material.

  The conveyance path switching member 57 is driven by a solenoid SD and can swing, and is set at a position indicated by a solid line and guides the paper S to the conveyance path formed by the guide member 58 during the tri-fold process.

  The conveyance path switching member 57 is set to the position of the dotted line for bi-folding, that is, half-folding, saddle stitching and half-folding, and guides the paper S to the discharge port E1.

  58 is a guide member for guiding the paper S between the transport means and the front end stop member 581 as the front end stop means, and forms a guide surface such that the central portion of the paper S is bent downward as will be described later. It functions as a restricting means for restricting the bending direction of the paper S.

  Reference numeral 59 denotes a sheet pressing member as sheet pressing means for pressing the sheet S. In the example of the embodiment shown in FIG. 2, the sheet pressing member 59 is made of an elastic sheet member such as a PET (polyethylene terephthalate) film.

  The leading edge stopping member 581 bends the sheet S toward the second folding means by stopping the leading edge of the sheet S conveyed by the conveying means, that is, the upper roller 53 and the lower roller 54.

The folding operation of the folding unit 50 having the above configuration will be described.
1) Folding process (half-folding, saddle stitching, center folding)
The middle folding process is a mode in which folding processing is performed at the center in the transport direction of the paper S, and the middle folding and saddle stitching processing is a mode in which the central part of the paper S is bound and the middle folding process is performed at the central part. It is.

  In the half-folding process, a set number of sheets S are received and accumulated by the regulating member 51C. At the stage where the set number of sheets S are accumulated and regulated by the regulating member 51C, the folding plate 52 is driven by driving means (not shown) and the fold of the sheet S is inserted between the upper roller 53 and the lower roller 54. To do.

  In the half-folding and saddle stitching process, a set number of sheets S are received by the regulating member 51C and accumulated. When the set number of sheets S are collected and regulated by the regulating member 51C, the binding processing unit 72 operates to perform a binding process in which a binding needle is driven into the center of the sheet S.

  At the stage where the binding process is completed, the regulating member 51C moves and lowers the central portion of the paper S to the position of the folding plate 52.

  The upper roller 53 and the lower roller 54 rotate as indicated by the arrows simultaneously with the operation of the folding plate 52 at the set number of sheets accumulation stage in the middle folding process and the binding process end stage in the middle folding and saddle stitching process to fold the sheet S. Transport while processing.

  When the sheet S is nipped between the upper roller 53 and the lower roller 54, the folding plate 52 moves and retracts in the direction opposite to the transport direction of the sheet S.

  The sheet S that has been folded by the upper roller 53 and the lower roller 54 is transported with the crease at the head, passes under the guide by the transport path switching member 57 set at the dotted line position, and is ejected from the ejection port E1. The

In the half-folding mode and the saddle stitching and middle-folding mode, the sheet pressing member 59 is pushed by the sheet S and retracts, so that the sheet S is smoothly conveyed.
2) Tri-fold process In the tri-fold process, the transport path switching member 57 is set at a position indicated by a solid line.

  The sheet S is transported through the transport path H1, and the leading end of the sheet S abuts against the regulating member 51C and stops.

  At the stage where the set number of sheets S is regulated and accumulated by the regulating member 51C, the folding plate 52 is driven by a driving means (not shown) and moves along the conveyance path indicated by the chain line W1, and the fold of the sheet S is raised. Insert between the roller 53 and the lower roller 54.

  Simultaneously with the operation of the folding plate 52, the upper roller 53, the lower roller 54, and the folding roller 55 rotate as indicated by arrows, and the sheet S is conveyed while being folded.

  When the sheet S is nipped between the upper roller 53 and the lower roller 54, the folding plate 52 moves and retracts in the direction opposite to the transport direction of the sheet S.

  The sheet S folded by the upper roller 53 and the lower roller 54 is guided by the transport path switching member 57 and proceeds to the transport path formed by the guide member 58 with the fold as the head. The crease of the sheet S abuts on a leading edge stopping member 581 as a leading edge stopping means and stops.

  The upper roller 53, the lower roller 54, and the folding roller 55 continue to rotate even after the fold line of the sheet S hits the leading end stop member 581.

  As the upper roller 53 and the lower roller 54 continue to rotate, the sheet S bends and curves between the nip between the upper roller 53 and the lower roller 54 and the leading end stop member 581.

  As will be described below, the guide member 58 regulates the direction in which the sheet S bends due to the relationship between the upper roller 53 and the lower roller 54 serving as conveying means. As shown in FIG. 2B, the direction W2 of the paper guide surface of the guide member 58 intersects the conveyance path W1 formed by the upper roller 53 and the lower roller 54, and the angle θ formed by W1 and W2 is the same. The guide member 58 is formed to be smaller than 180 degrees on the side opposite to the folding means formed by the lower roller 54 and the folding roller 55. With such a shape of the conveyance path, the sheet S whose leading end is stopped by the leading end stopping member 581 is bent toward the folding unit constituted by the lower roller 54 and the folding roller 55.

  The curved sheet S enters the nip between the lower roller 54 and the folding roller 55, and a second fold is formed by the lower roller 54 and the folding roller 55.

  Due to the continued rotation of the lower roller 54 and the folding roller 55, the sheet S folded at two positions, that is, the sheet S that has been tri-folded, passes through the sheet discharge outlet E2 and is discharged from the folding unit 50 to be discharged from the lower section. It is discharged to the part 83 (see FIG. 1).

  The three-fold process will be described in detail with reference to FIGS. FIG. 3 is a diagram for explaining the three-fold process, and FIG. 4 is a diagram showing a first example of the sheet pressing member 59.

  As shown in FIG. 4, the upper end of the sheet pressing member 59 is fixed to the support member 61, and is formed by a base portion 59A and a distal end portion 59B. The sheet pressing member 59 is formed by adhering two elastic films. The base 59A includes a thin PET film 59C and a thick PET film 59D, and is fixed to the support member 61 at the upper end. It consists of a thin PET film 59C and is connected to the lower end, which is the free end of the base 59A. FIG. 4B shows the portions of the PET films 59C and 59D that are fixed to the support member 61 in (61).

  The PET film 59C has a thickness of 0.075 mm, and the PET film 59D has a thickness of 0.188 mm.

  59C has a length LG1 = 24 mm and a width HB1 = 8 mm. 59D has a length LG2 = 11 mm and a width HB2 = 8 mm.

  The sheet pressing member 59 is elastically deformed as a whole, but the lower end portion 59B is more easily deformed than the base portion 59A. That is, the base portion 59A has higher rigidity than the distal end portion 59B.

  The sheet pressing member 59 is disposed so that the substantially central portion of the leading end portion 59B intersects the conveyance path W1.

  Accordingly, the sheet S conveyed by the upper roller 53 and the lower roller 54 comes into contact with the substantially central portion of the leading end 59B, and the sheet pressing member 59 is elastically deformed.

  The sheet pressing member 59 assists the regulating action of the guide member 58 and reliably bends the sheet S downward at the center. When such an action of the paper pressing member 59 is strengthened, the leading edge of the loaded paper S may abut against the paper pressing member 59 and the paper conveyance to the guide member 5 may be hindered. In particular, when the paper S is a thin paper with weak stiffness, the leading edge of the paper may be bent.

  According to the present invention, such a problem can be prevented well. Next, the sheet pressing means used in the present invention will be described.

  3A and 4A show an initial state in which the paper S is not introduced into the folding unit 50. FIG. 3A and 4A, the sheet pressing member 59 has a flat plate shape.

  The sheet pressing member 59 is deformed as shown in FIGS. 3B and 4C. In this deformation, the tip portion 59B is greatly deformed. Thus, since the leading end 59B is greatly deformed, even if the leading edge of the sheet S collides with the sheet pressing member 59 at a high speed, the conveyance of the sheet S is not hindered and the sheet is smoothly conveyed.

  The sheet S passes between the sheet pressing member 59 and the conveyance path switching member 57, and the crease hits the leading end stop member 581 and stops. However, the sheet S is continuously conveyed by the upper roller 53 and the lower roller 54. Is done. As a result, the sheet S is bent downward between the lower roller 54 and the folding roller 55. The sheet pressing member 59 pushes the sheet S downward by its restoring force, and reliably curves the sheet S downward. The sheet S is greatly bent downward by further conveyance of the upper and lower rollers 53, 54, and the bent leading end portion is introduced into a folding means, that is, a nip between the lower roller 54 and the folding roller 55.

  When the sheet S is introduced into the folding means, the base 59A introduces the sheet S accurately and smoothly into the nip between the lower roller 54 and the folding roller 55 by its strong restoring force.

  In the state shown in FIG. 3C, that is, when the second fold of the paper S and the folding SA of the paper S enter the nip between the lower roller 54 and the folding roller 55, In some cases, the end of the SA in the width direction (direction perpendicular to the transport direction) is not smoothly introduced into the nip. As a result, the sheet may be bent or jammed.

  By providing the sheet pressing member 59, the lifting of the end in the width direction of the folded SA of the sheet S is suppressed, and the sheet S is sufficiently prevented from being bent or jammed.

  As shown in FIG. 5, one sheet pressing member 59 (591, 594) is provided at both ends in the width direction perpendicular to the sheet conveying direction W3, and two sheet pressing members 592, 593 are provided at the center. Is provided. FIG. 5 is a view showing the arrangement of the sheet pressing members 59 in the width direction.

  The sheet S having curl tends to be lifted at the end in the width direction. Therefore, the sheet pressing members 591 and 594 at the ends in the width direction are particularly important.

  In FIG. 5, SED1 is an A4S edge, that is, a side edge of A4 size paper conveyed with the paper conveyance direction W3 as a long side, and SED2 is an 8.5 × 11S edge, ie, a paper conveyance direction W3 as a long side. The side edge of 8.5 * 11 inch size paper conveyed is shown. It is particularly important to press the side edges SED1 and SED2 of the paper S by the paper pressing member 59. Even if the sheet pressing position of the sheet pressing member 59 is slightly shifted inward from the side edges SED1 and SED2, the lifting of the sheet S is sufficiently suppressed within the range of several mm.

  6 and 7 show second and third examples of the sheet pressing member 59. As shown in these drawings, the sheet pressing member 59 includes a base portion 59A and a tip portion 59B, and the base portion 59A is the same as that shown in FIG.

  In the second example of FIG. 6, the tip portion 59B is made of a thin PET film, and a loop is formed at the tip by folding. When the sheet S is transported, as described above, the sheet pressing member 59 is elastically deformed as a whole, and the leading end 59B is largely elastically deformed as shown in FIG. 6B. The sheet S is smoothly conveyed by such elastic deformation of the sheet pressing member 59.

  In the transporting process shown in FIG. 3C, the sheet pressing member 59 returns from the bent state in FIG. 3B to the flat plate-like initial state. ) Slides back on the sheet S. As shown in FIG. 6, by forming the leading end in a loop, the leading end smoothly slides on the sheet S, and the sheet pressing member 59 reliably returns to the state shown in FIG.

  The sheet pressing member 59 of the third example shown in FIG. 7 is composed of two rigid plate-like members. The base portion 59A is rotatably supported by the shaft 59E, and the base portion 59A and the tip end portion 59B are rotatably connected to each other by a connector 59F formed at the free end of the base portion 59A.

  In the initial state in which the sheet S is not introduced, as shown in FIG. 7A, the base portion 59A and the leading end portion 59B hang down in a vertical state due to their own weight.

  When the sheet S enters, as shown in FIG. 7B, the base 59A rotates about the shaft 59E, and the leading end 59B rotates about the connector 59F with respect to the base 59A. By such an operation of the sheet pressing member 59, the sheet S is smoothly conveyed as shown in FIG. The tip is stopped by the tip stop member 581. At the stage where the sheet S is bent and the crease is introduced into the folding means, the sheet pressing member 59 returns to the initial state of FIG.

  In the example shown in FIG. 7, the paper pressing performance of the paper pressing member 59 can be adjusted by making the mass of the base portion 59A and the mass of the tip end portion 59B different from each other. The member 59 can be made highly durable.

A Image forming apparatus FS Post-processing apparatus 50 Folding part 53 Upper roller 54 Lower roller 55 Folding roller 57 Conveyance path switching member 58 Guide member 581 Tip stop member 59, 591 to 594 Paper pressing means 59A Base part 59B Tip part

Claims (8)

Transport means for transporting paper by nip,
A leading edge stopping means for stopping the leading edge of the sheet conveyed by the conveying means;
A regulation unit that regulates the bending direction of the sheet that is bent between the conveyance unit and the leading end stop unit when the sheet is conveyed by the conveyance unit in a state where the leading end of the sheet is stopped by the leading end stop unit;
In a paper folding apparatus having a folding means that nips and conveys a bent paper between the conveying means and the leading edge stopping means and forms a crease in the paper,
Paper holding means for assisting bending of the paper by the regulating means,
The paper pressing means includes a base portion supported by a fixed portion and having a free end, and a front end portion that is connected to the free end of the base portion and changes an angle with respect to the base portion when pressed by the paper. apparatus.   The sheet folding apparatus according to claim 1, wherein the conveying unit constitutes a pre-folding unit configured to fold the sheet.   The sheet folding apparatus according to claim 1, wherein the base portion and the tip portion are made of a sheet-like member having elasticity, and the base portion has higher rigidity than the tip portion.   The paper folding apparatus according to claim 3, wherein the leading end portion is formed of a loop-shaped member.   The base portion and the tip portion are made of a rigid body, the tip portion is rotatably connected to the base portion, and the base portion and the tip portion hold the paper by their own weights. Item 3. The sheet folding device according to Item 2.   The sheet folding device according to claim 1, wherein the sheet pressing unit is disposed at a position that presses at least a sheet end in the width direction perpendicular to the transport direction.   A sheet post-processing apparatus comprising the sheet folding apparatus according to claim 1.   An image forming system comprising: an image forming apparatus that forms an image on a sheet; and the sheet post-processing apparatus according to claim 7 that performs post-processing on the sheet on which an image is formed by the image forming apparatus. .

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