JP2008230814A - Sheet processing device and image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sheet processing device and an image forming device capable of efficiently folding a sheet bundle with good appearance and performing bookbinding. <P>SOLUTION: While pressing a folding part Pc of a folded sheet bundle PA, fold reinforcement means 861 (861a, 861b) are moved along the folding part Pc, so as to reinforce a fold. Along with the movement of the fold reinforcement means 861, the downstream side in the movement direction of the fold reinforcement means 861 of the folding part Pc of the sheet bundle PA is humidified by a humidifying means 880. The portion of the folding part Pc of the sheet bundle PA humidified by the humidifying means 880 is heated via the fold reinforcement means 861 by heating means 881 (881a, 881b). <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a sheet processing apparatus and an image forming apparatus, and more particularly to a configuration for folding and binding a sheet bundle.

  2. Description of the Related Art Conventionally, in an image forming apparatus such as a copying machine or a laser beam printer, after an image is formed, a sheet to be discharged is taken in, and after that, the sheet is processed in the vicinity of the approximate center of the sheet, Some have a sheet processing apparatus that performs saddle stitching by performing processing.

  In such a sheet processing apparatus, when performing saddle stitch binding, a plurality of sheets conveyed one by one are aligned in the storage tray, and then the vicinity of the center is bound. Next, a center folding process is performed by inserting a plurality of sheets together into the nip of the pair of folding rollers. Thereafter, the sheet bundle that has been subjected to the folding process in this way is discharged from the discharge port on the discharge side of the pair of folding rollers toward the lower discharge tray with the folding portion at the top.

  By the way, in such a conventional sheet processing apparatus, folding may be insufficient due to swelling of the sheet bundle. For this reason, a fold reinforced roller pair that can move in a direction perpendicular to the sheet conveying direction (hereinafter referred to as the width direction) is provided, and the fold reinforced roller pair is caused to travel while pressing the fold portion, thereby performing the middle folding process. There is one in which the fold is strengthened (see Patent Document 1).

  However, if the crease is simply reinforced by the pair of crease strengthening rollers, the fold may return to the original state due to the elasticity of the sheet when the pressure is released. Causes the problem of an open and unsightly appearance.

  The opening of the fore edge appears prominently when the sheet constituting the middle folded bundle is a highly rigid sheet such as thick paper or when the number of sheets in the middle folded bundle is large. On the other hand, even if the sheet has low rigidity such as thin paper or the number of sheets is small, for example, when the amount of moisture contained in the sheet is small in a low humidity environment, or when the sheet is bent in a direction perpendicular to the sheet gap In some cases, the stiffness of the sheet with respect to the folding direction increases and an opening appears.

  This problem is different from the method of increasing the pressure of the pair of folding rollers, because even if the pressure applied to the sheet bundle is increased by the pair of folding rollers and the pair of crease-enhancing folding rollers that perform the middle folding process, the pressure is not improved to some extent. A solution is required. Therefore, conventionally, as an example of the means for solving the problem, there is known a method for easily forming a crease by a humidifying means and a heating means (see Patent Document 2).

  FIG. 9 is a diagram illustrating a schematic configuration of a sheet bundle bending portion of a sheet processing apparatus having such a conventional humidifying unit and heating unit.

  In FIG. 9, 21 is a humidification chamber, 22 and 23 are first and second humidification nozzles that constitute humidification means together with the humidification chamber 21, 24 is a heating roller pair that constitutes heating means, 26 is a folding roller pair, and 27 is exhaust. It is a paper roller.

  Here, the humidifying chamber 21 is for humidifying the sheet P being conveyed on the upstream side of the stack tray 25, and the first humidifying nozzle 22 is arranged on the upstream side of the pair of folding rollers 26 to be folded in the middle direction. This is for humidifying the part forming the fold.

  The heating roller pair 24 is for forming a crease in the middle fold bundle that has been conveyed in a state of being humidified by the first humidifying nozzle 22. The 2nd humidification nozzle 23 is for humidifying the part in which the crease | fold of a middle fold bundle is formed in the nip part of the heating roller pair 24. FIG.

  The sheet is humidified by the humidifying chamber 21, the first and second humidifying nozzles 22 and 23, and the sheet humidified by the heating roller pair 24 is heated, so that the rigidity of the sheet at the bent portion is increased by moisture and heat. Can be reduced. As a result, the folding effect of the folding roller pair 26 and the heating roller pair 24 is increased, so that it is possible to provide an intermediate folded bundle with less opening and good appearance.

JP 2003-182928 A JP-A-11-157247

  However, in the conventional sheet processing apparatus having such a humidifying means and a heating means, the humidifying chamber 21 is configured to humidify even a portion where the sheet P is not bent, so that unnecessary humidification is not performed. It was efficiency. Further, there is a possibility that the sheet will be stretched due to humidification after the humidification in the humidification chamber 21 until the fold is formed by the pair of folding rollers 26, and the sheet P may be wavy and the resulting wrinkles may be wrinkled. It was.

  Further, the humidifying chamber 21, the first and second humidifying nozzles 22 and 23, and the heating roller pair 24 are arranged in a conveyance path provided inside the sheet processing apparatus upstream from the discharge roller pair 27. For this reason, the moisture discharged from the humidification chamber 21 and the first and second humidification nozzles 22 and 23 and the moisture evaporated from the half-folded bundle by the heating roller pair 24 stay in the sheet processing apparatus.

  In particular, for example, in the case where the humidification is performed from the outer surface side of the middle folded bundle in a state where the first and second humidifying nozzles 22 and 23 are in a booklet, a large amount is required to allow sufficient moisture to penetrate into the inner folded bundle. Need moisture. When these moisture saturates in the sheet processing apparatus and adheres to the conveyance roller or the conveyance guide, the conveyance slip due to the decrease in the roller conveyance force, or paper breakage due to the sheet sticking to the guide member, conveyance failure, etc. There was a risk of causing problems.

  Accordingly, the present invention has been made in view of such a situation, and an object of the present invention is to provide a sheet processing apparatus and an image forming apparatus capable of folding and binding a sheet bundle efficiently and visually. To do.

  The present invention relates to a sheet processing apparatus for performing a bookbinding process by folding a sheet bundle, a humidifying means for humidifying a folded portion of the folded sheet bundle, and a crease while pressing the folded portion of the sheet bundle humidified by the humidifying means. And a heating unit that heats the folded portion of the sheet bundle that has been creased by the crease strengthening unit. It is.

  As in the present invention, the sheet bundle is efficiently obtained by humidifying the fold portion of the sheet bundle downstream in the moving direction of the crease strengthening means and heating the humidified portion via the crease strengthening means. It can be folded and bound.

  Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a diagram showing a schematic configuration of a digital copying machine as an example of an image forming apparatus provided with a sheet processing apparatus according to a first embodiment of the present invention.

  In FIG. 1, reference numeral 1000 denotes a digital copying machine. The digital copying machine 1000 includes a digital copying machine main body 1 and a scanner 102 disposed on an upper portion of the digital copying machine main body (hereinafter referred to as a copying machine main body) 1. ing.

  Here, the scanner 102 for reading a document includes a document feeder 101, a scanner unit 904, a lens 908, an image sensor 909, and the like. When the document D is read by the scanner 102, the document D is first set on the tray 900a of the document feeder 101. At this time, it is assumed that the document D is set with the face on which the image is formed on the tray 900a facing upward.

  Next, after the originals D set in this way are conveyed one by one from the top page in order to the left (in the direction of the arrow in the figure) by the original feeder 101, the original D is left on the platen glass 902 through a curved path. The paper is conveyed from the right direction to the right direction, and then discharged onto the paper discharge tray 912.

  At this time, when reading the original by so-called flow reading, the scanner unit 904 is held in a predetermined position, and the original D passes through the scanner unit 904 from left to right. The reading process is performed. In this reading process, when passing over the platen glass 902, the document D is irradiated with light from the lamp 903 of the scanner unit 904, and the reflected light is imaged through the mirrors 905, 906, 907 and the lens 908. Guide to 909. The document image data read by the image sensor 909 is subjected to predetermined image processing and sent to the exposure apparatus 910.

  On the other hand, when reading a document by so-called fixed reading, the document D transported by the document feeder 101 is temporarily stopped on the platen glass 902, and the scanner unit 904 is moved from left to right in this state, thereby moving the document. The reading process is performed. Further, when reading a document without using the document feeder 101, the user lifts the document feeder 101 and sets the document on the platen glass 902.

  Further, the copying machine main body 1 includes a sheet feeding unit 9002 that feeds sheets P stored in cassettes 914 and 915, and an image forming unit 103 that forms an image on the sheet fed by the sheet feeding unit 9002. Etc.

  Here, the image forming unit 103 includes a photosensitive drum 911, a developing unit 913, a transfer charger 916, and the like, and laser light from the exposure device 910 is irradiated onto the photosensitive drum during image formation. As a result, a latent image is formed on the photosensitive drum. Further, the latent image is visualized as a toner image by the developing device 913 thereafter. A fixing device 917, a discharge roller 104, and the like are disposed on the downstream side of the image forming unit 103. An operation unit 152 is provided on the upper surface of the copying machine main body 1.

  Next, an image forming operation of the copying machine main body 1 having such a configuration will be described.

  First, as described above, the image data of the document D read by the image sensor 909 in the flow reading or fixed reading in the scanner 102 is sent to the exposure device 910 after being subjected to predetermined image processing. . The exposure device 910 outputs a laser beam corresponding to this image signal.

  The laser beam is irradiated onto the photosensitive drum 911 while being scanned by the polygon mirror 910a, whereby an electrostatic latent image corresponding to the scanned laser beam is formed on the photosensitive drum 911. Next, the electrostatic latent image formed on the photosensitive drum 911 is developed by the developing unit 913 and visualized as a toner image.

  On the other hand, the sheet P is conveyed from any of the cassettes 914, 915, the manual sheet feeding unit 925, and the double-sided conveyance path 924 to a transfer unit constituted by the photosensitive drum 911 and the transfer charger 916, and is visualized in this transfer unit. The toner image on the photosensitive drum is transferred to the sheet P. The transferred sheet P is subjected to a fixing process by a fixing device 917.

  Next, the sheet P that has passed through the fixing device 917 is once guided to a path 922 by the flapper 921, and after the trailing edge of the sheet has passed through the flapper 921, the sheet P is switched back and conveyed to the discharge roller 104 by the flapper 921. Drain from 1. As a result, the sheet P can be discharged from the copying machine main body 1 with the surface on which the toner image is formed facing down (face down).

  In addition, when the sheet P is discharged face-down by such a so-called reverse sheet discharge to perform image forming processing sequentially from the first page, for example, when performing image forming processing using the document feeder 101. The page order can be aligned. Also, the page order can be aligned when image forming processing is performed on image data from a computer.

  When image forming processing is performed on a hard sheet P such as an OHP sheet conveyed from the manual sheet feeding unit 925, the surface on which the toner image is formed is directed upward without guiding the sheet P to the pass 922 ( The paper is discharged from the copying machine main body 1 by the discharge roller 104 at the face up.

  When forming images on both sides of the sheet, the sheet P is guided straight from the fixing device 917 toward the discharge roller 104, and the sheet P is switched back immediately after the trailing end of the sheet P passes through the flapper 921. To guide to the double-sided conveyance path 924.

  By the way, the copying machine main body 1 is provided with a finisher 2 that is a sheet processing apparatus that performs binding processing and bookbinding processing on an image-formed sheet discharged from the copying machine main body 1.

  Here, the finisher 2 fetches sheets from the copying machine main body 1, aligns a plurality of fetched sheets and bundles them as one sheet bundle, sort processing, and non-sort processing. Further, a staple process (binding process) for stapling the rear end side of the sheet bundle and a bookbinding process are performed. As shown in FIG. 2, the staple unit 600 for stapling the sheet and the sheet bundle are folded in two. A saddle stitch bookbinding unit 800 which is a bookbinding processing unit for bookbinding is provided.

  Here, as shown in FIG. 2, the finisher 2 includes a conveyance path 520 for taking a sheet from the copying machine main body 1 into the apparatus. The conveyance path 520 includes an entrance roller 501 and a conveyance roller 502. ˜508 are provided. A punch unit 530 is provided between the transport roller 502 and the transport roller 503, and the punch unit 530 operates as necessary to perform a punching process at the rear end of the transported sheet. .

  Further, a flapper 513 is provided at the end of the transport path 520, and the flapper 513 switches the path between an upper discharge path 521 and a lower discharge path 522 connected downstream. Here, the upper paper discharge path 521 is for discharging paper to the upper stack tray 701 by the upper paper discharge roller 509, and the lower paper discharge path 522 is provided with a pair of transport rollers 510 to 512. This is for discharging paper to the processing tray 550.

  Reference numeral 514 denotes a switching flapper that switches the conveyance path to a lower discharge path 522 or a saddle discharge path 523 described later. The sheet is discharged to the processing tray 550 by switching the switching flapper 514 to the solid line position. It has become.

  Then, after the sheets are discharged to the processing tray 550, the sheets are sequentially bundled while being aligned, and according to the setting by the operation unit 152 (see FIG. 1) provided in the copier body 1, Staple processing is performed. Thereafter, the sheet bundle is discharged to the stack trays 700 and 701 by the bundle discharge roller pair 551. Note that the stapling process is performed by the stapler 560, and the stapler 560 is movable in the width direction and can be stapled at an arbitrary position on the sheet.

  The stack trays 700 and 701 are configured to be movable in the vertical direction. The upper stack tray 701 is a sheet from the upper discharge path 521 and the processing tray 550, and the lower stack tray 700 is a processing tray. Sheets from 550 can be received. In this manner, a large number of sheets can be stacked on the stack trays 700 and 701, and the stacked sheets are regulated and aligned by the rear end guide 710 extending in the vertical direction at the rear end.

  On the other hand, when the sheet bundle is saddle-stitched, that is, in the saddle-stitch bookbinding mode, the sheet passes through the saddle discharge path 523 by switching the switching flapper 514 provided in the middle of the lower discharge path 522 to the broken line position. And sent to the saddle stitch bookbinding portion 800. In this case, the sheet is first delivered to the saddle entrance roller pair 801, selected according to the size by the flapper 802 operated by a solenoid, and carried into the storage guide 803 of the saddle stitch bookbinding unit 800.

  The sheet thus carried into the storage guide 803 is conveyed by the sliding roller 804 until the leading end contacts the sheet positioning member 805 that can move in the vertical direction. The saddle entrance roller pair 801 and the sliding roller 804 are driven by a motor M1.

  In addition, a stapler 820 including a driver 820a that protrudes a needle that is opposed to the storage guide 803 and an anvil 820b that bends the protruded needle is provided in the middle of the storage guide 803.

  Here, the sheet positioning member 805 stops at a position where the central portion in the sheet conveyance direction becomes the binding position of the stapler 820 when the sheet is loaded. The sheet positioning member 805 is movable in the vertical direction under the driving of the motor M2, and can change its position according to the sheet size.

  A pair of folding rollers 810a and 810b are provided on the downstream side of the stapler 820, and a protruding member 830 is provided at a position opposite to the pair of folding rollers 810a and 810b. The protruding member 830 has a position retracted from the storage guide 803 as a home position, and protrudes toward the stored sheet bundle by driving the motor M3.

  By projecting toward the sheet bundle in this way, the sheet bundle can be pushed into the nip between the pair of folding rollers 810a and 810b, and thereby the sheet bundle can be folded. The protruding member 830 returns to the home position again after the sheet bundle is pushed in.

  On the other hand, between the folding roller pair 810 (810a, 810b) into which the sheet bundle is pushed, a pressure sufficient to crease the sheet bundle is applied by a spring (not shown). As it passes, the sheet bundle is creased. The sheet bundle thus creased is then discharged to the folded bundle discharge tray 850 via the first folding and conveying roller pair 811a and 811b and the second folding and conveying roller pair 812a and 812b.

  A pressure sufficient to convey and stop the folded sheet bundle is also applied to the first folding conveyance roller pair and the second folding conveyance roller pair 811a, 811b, 812a, and 812b, which are the two conveyance units. It has been. The pair of folding rollers 810, the first pair of folding and conveying rollers 811a and 811b, and the pair of second folding and conveying rollers 812a and 812b are rotated at the same speed by the same motor M4.

  When the sheet bundle bound by the stapler 820 is folded, the sheet positioning member 805 is moved a predetermined distance from the position at the time of the stapling process so that the stapling position of the sheet bundle comes to the nip position of the folding roller pair 810 after the stapling process is completed. I try to lower it. Thereby, the sheet bundle can be folded around the position where the stapling process is performed.

  In FIG. 2, 813 is a conveyance guide that connects the folding roller pair 810 and the first folding conveyance roller pair 811 (811a, 811b), and 814 is a first folding conveyance roller pair 811 and a second folding conveyance roller pair 812 ( 812a and 812b).

  Reference numeral 815 denotes an alignment plate pair that has a surface that protrudes from the storage guide 803 around the outer peripheral surfaces of the pair of folding rollers 810a and 810b and aligns the sheets stored in the storage guide 803. The alignment plate pair 815 is positioned in the width direction of the sheet by being driven by the motor M5 and moving in the nipping direction with respect to the sheet.

  Meanwhile, a crease press unit 860 for reinforcing the folds of the sheet bundle is provided downstream of the second fold conveyance roller pair 812a and 812b so as to spatially overlap the fold bundle discharge tray 850. Here, the crease press unit 860 includes a press roller pair 861 that rotates along the crease while pressing a folded portion of the folded sheet bundle, and a press holder 862 that is a holding unit that supports the press roller pair 861. ing.

  The folds are strengthened by moving the press holder 862 along the creases while the press roller pair 861 constituting the crease strengthening means nips the folded portion of the sheet bundle. The press holder 862 can be moved in the front-rear direction of the finisher 2 as the motor M6 is driven.

  The home position of the press holder 862 is the back side of the finisher 2, and this position is detected by a home sensor (not shown). When the press holder 862 is at the home position, the second fold conveyance roller pair 812 can discharge the sheet bundle to the fold bundle discharge tray 850.

  That is, the crease press unit 860 rotates the motor M6 so that each roller constituting the press roller pair 861 integrally with the press holder 862 rotates at the same peripheral speed as the moving speed of the press holder 862 and in the opposite direction. Is configured to do. Further, by driving each roller of the press roller pair 861 in this way, the rideability on the half-folded bundle of the press roller pair 861 is improved.

  By the way, when the folded middle sheet bundle, which is a folded sheet bundle, is subjected to crease reinforcement processing by a press roller pair 861, as shown in FIG. The stopped state is held by two roller pairs across the center in the conveyance direction.

  That is, as shown in FIG. 5, in the middle folded bundle PA, the nip pressure of the second folding conveying roller pair 812 on the front end side, and the nip pressure of the first folding conveying roller pair 811 on the rear end side and the size of the middle folded bundle. Depending on (the length in the conveying direction), the nip pressure of the pair of folding rollers 810 is also applied. As a result, when the press roller pair 861 nips the folded folded bundle, the folded folded bundle can be efficiently suppressed even if a rotational moment occurs.

  FIG. 3 is a control block diagram of the digital copying machine 1000. The CPU circuit unit 150 is provided in the copying machine main body 1 and has a CPU (not shown). Then, according to the control program stored in the ROM 151 and the setting of the operation unit 152, the automatic document feed control unit 153, the image input control unit 154, the image signal control unit 155, the image output control unit 156, the finisher control unit 157, the external I / O F158 is controlled.

  Here, the automatic document feed controller 153 controls the document feeder 101, the image input controller 154 controls the scanner 102, and the image input controller 154 controls the exposure device 910. A finisher control unit 157 as a control unit is provided in the finisher 2 and controls operations of the staple unit 600 and the saddle stitch bookbinding unit 800 of the finisher 2.

  The operation unit 152 includes a plurality of keys for setting various functions relating to image formation, a display unit for displaying a setting state, and the like. Then, a key signal corresponding to each key operation by the user is output to the CPU circuit unit 150, and corresponding information is displayed on the display unit based on the signal from the CPU circuit unit 150.

  The RAM 159 is used as an area for temporarily storing control data and a work area for computations associated with control. An external I / F 158 is an interface between the digital copying machine 1000 and an external computer 160, develops print data from the computer 160 into a bitmap image, and outputs it as image data to the image signal control unit 155.

  Further, the image input control unit 154 outputs an image of the document read by the image sensor 909 to the image signal control unit 155, and the image output control unit 156 outputs the image data from the image signal control unit 155 to an exposure (not shown). Output to the device 910.

  Next, the saddle stitch bookbinding process performed by the saddle stitch bookbinding unit 800 according to the present embodiment will be described.

  When the saddle stitch bookbinding mode is set by the user, the sheets P on which images have been formed are discharged from the discharge roller 104 of the copying machine body 1 in sequence as appropriate. The sheet P is first delivered to the inlet roller pair 501 and then passes through the conveyance path 520 and enters the lower paper discharge path 522.

  Thereafter, the sheet P is guided to the saddle discharge path 523 by the switching flapper 514 provided in the lower discharge path 522. Then, the sheet is discharged to the storage guide 803 while being guided by the flapper 802 corresponding to the sheet size, and is also abutted against the sheet positioning member 805 stopped in advance at a position suitable for the sheet size while receiving the conveying force of the sliding roller 804. .

  As a result, positioning in the conveyance direction is performed, and thereafter, the alignment is performed by the alignment plate pair 815 that has been waiting at a position where there is no problem in discharging the sheet, and positioning in the width direction is also performed. The above-described sheet storage and alignment operations are performed each time the sheet P is discharged.

  Next, when the alignment of the final sheet is completed, the stapler 820 staples the central portion in the conveyance direction of the sheet bundle, and when the staple binding is completed, the sheet positioning member 805 is lowered. As the sheet positioning member 805 is lowered, the sheet bundle moves downward. Thereafter, the sheet positioning member 805 stops at the position where the central portion of the sheet bundle, that is, the staple binding portion, corresponds to the nip of the folding roller pair 810.

  Next, the protruding member 830 that has been waiting at the standby position is moved in the direction of the arrow, and the sheet bundle is folded by inserting the central portion of the sheet bundle into the nip of the folding roller pair 810 while expanding the folding roller pair 810. .

  At this time, the folding roller pair 810 is rotated by the motor M4 (see FIG. 2) together with the first and second folding conveying roller pairs 811 and 812, and the folded sheet bundle is a folded sheet bundle with the folding portion at the top. Then, it is conveyed through the conveyance guides 813 and 814. Then, as shown in FIG. 4, when the middle folded bundle PA is conveyed to a position where the folding portion nips the press roller pair 861 (861a, 861b), the motor M4 stops.

  At this time, as described above, the middle fold bundle PA has the second fold conveyance roller pair 812 at the front end and the first fold conveyance roller pair 811 and the size of the middle fold bundle at the rear end side with the center in the conveyance direction interposed therebetween. Depending on the (length in the transport direction), the folding roller pair 810 can reliably hold it. In addition, the protrusion member 830 moves to the retracted position again when the protrusion is completed.

  Here, prior to such conveyance of the middle folded bundle PA, the press holder 862 stands by at a standby position (back side) corresponding to the size (width direction) of the middle folded bundle PA. Then, as shown in FIG. 4, when the stop of the middle folded bundle PA is completed and the folding portion Pc of the middle folded bundle PA is inserted into the sheet guide 871, the motor M6 is driven to rotate the press roller pair 861. While moving to the near side.

  Thereafter, the rollers 861a and 861b of the press roller pair 861 first come into contact with the side surfaces of the half-fold bundle PA that is stopped and held. At this time, since each of the rollers 861a and 861b is rotating, each of the rollers can smoothly run up the side end of the middle folded bundle PA and nip the folded portion Pc. As a result, in synchronization with the movement of the press holder 862, the middle folded bundle PA can be nipped without a response delay. This operation does not change even if the thickness of the middle folded bundle PA increases.

  As described above, since the middle folded bundle PA can be nipped between the press roller pair 861 without delay in response in synchronization with the movement of the press holder 862, the middle folded bundle PA is wrinkled, torn, roller marks, etc. You can prevent damage.

  The standby position of the press roller pair 861 may be provided at two locations on the back side and the front side. That is, the configuration may be such that after the press roller pair 861 moves along the fold from the standby position on the back side, it moves as it is to the standby position on the front side to open the path in the conveyance direction of the middle folded bundle P. In this case, after moving along the crease, the time required to return to the back standby position can be shortened, which is effective in improving productivity.

  Incidentally, the crease press unit 860 is provided with a humidifying nozzle 880 and heat rods 881 (881a, 881b) provided inside the press roller pair 861 as shown in FIG.

  Here, the humidifying nozzle 880, which is a humidifying means for humidifying the folding portion, applies moisture in advance to the folding portion of the middle fold bundle PA where the crease press unit 860 moves on the downstream side of the press roller pair 861. It is. In this way, moisture is preliminarily applied to the downstream side of the press roller pair 861 to soften the rigidity of the sheet, increase the bending effect of the press roller pair 861, and obtain a middle folded bundle PA with a good appearance with little opening. be able to.

  Further, the humidifying nozzle 880 is configured to move along the fold line in synchronization with the movement of the press roller pair 861. This makes it possible to reinforce the fold of the fold immediately after humidification by the press roller pair 861, and to perform crease reinforcement in a good state in which almost no elongation of the sheet due to humidification occurs.

  Even when the sheet is stretched by humidification, the time from humidification to crease reinforcement by the press roller pair 861 can always be kept constant throughout the folded portion. Thereby, the stretch state of the sheet at the time of strengthening the crease can be kept uniform over the entire folding portion, and the occurrence of press wrinkles due to the difference in the stretch state of the sheet can be prevented.

  The configuration of the humidifying nozzle 880 is not limited to the configuration that moves integrally along the crease as shown in FIG. For example, the nozzles are arranged over the entire fold along the crease and the nozzles that sequentially apply moisture are switched in synchronization with the movement of the press roller pair 861 to humidify the downstream side of the press roller pair 861. It may be a configuration.

  Further, the humidification amount by the humidification nozzle 880 may be controlled according to the humidification condition for the folded portion. For example, the humidification amount for the folded portion is controlled for each middle folded bundle PA on the basis of the information related to the force to open the folded middle folded bundle PA, that is, the information related to the opening condition of the middle folded bundle PA. You may do it.

  In addition, as a condition for increasing the opening amount of the half-fold bundle P, when a highly rigid sheet is used, when the number of sheets is large, the amount of moisture contained in the sheet in the copier body or the sheet processing apparatus at low humidity When there is little, the case where it bends in the direction perpendicular | vertical to the space | interval of the sheet | seat is assumed.

  When controlling the amount of humidification, first, information such as sheet thickness information, number of folded sheets, humidity environment information, etc. is detected by a detection means provided in the copying machine main body or in the sheet processing apparatus. Alternatively, it may be recognized in advance by means such as a user input from the operation unit 152. Thereafter, the finisher control unit 157 serving as a humidification control unit controls the humidification amount of the humidification nozzle 880 based on the information related to the opening condition of the half-fold bundle.

  In addition, as the control of the humidification amount, for the middle folded bundle under the condition that the opening amount is not so large, the humidification amount is set to be small, and for the middle folded bundle under the condition that the opening amount is increased, Control to increase the amount of humidification. In addition, it is only necessary to make settings so that humidification is not performed for the middle folded bundle under the condition that there is no opening amount, and for each middle folded bundle, control for selectively switching between humidification and non-humidification for the middle folded bundle is performed. May be.

  And by such control, it becomes possible to apply an appropriate amount of humidification to the folded portion according to the opening condition of the middle fold bundle, and as a result, it is possible to efficiently provide a middle fold bundle with good appearance with little opening. it can.

  Further, the humidifying nozzle 880 may be controlled not only to control the humidification amount with respect to the folded portion but also to switch between humidification and non-humidification at the time of crease with respect to one middle folded bundle.

  For example, a location where the load received by the sheet is greater than other locations, such as the vicinity of the side surface of the center folded bundle where the press roller pair 861 first contacts, the vicinity of the needle hole where the needle binding is performed, and the strength of the sheet Set the amount of humidification to a weakened area or set it to non-humidified.

  That is, when humidifying the folded portion, control is performed so as to reduce the humidification amount with respect to the predetermined range of the folded portion, or control so as not to humidify. Accordingly, it is possible to efficiently provide a half-folded bundle having a small appearance and having no opening, which is free from turning and folding of the bundle side surface and tearing of the sheet starting from the needle hole.

  Note that the humidifying nozzle 880 has, for example, a form in which droplets are ejected by a piezo element used in a head of an ink jet printer, and a form in which droplets are ejected by bubbles generated by heating.

  Further, the humidifying means for humidifying the sheet bundle is not limited to the humidifying nozzle 880, and a similar effect can be obtained even in a configuration in which moisture is applied with a roller, brush, brush or the like. Needless to say.

  Further, the humidifying solution may be water, a volatile substance such as ethanol, a transparent ink for an ink jet printer, or the like, and the stiffness of the sheet can be temporarily softened at the time of crease formation. Anything that does not hinder the appearance of the center folded bundle may be used. Furthermore, the humidifying solution is not limited to room temperature, and may be, for example, heated steam. In this case, it is needless to say that the softening of the sheet is further promoted by heat and moisture, the folding effect by the press roller pair 861 is increased, and a good-looking middle folded bundle with less opening can be provided.

  On the other hand, the heat rod 881 provided inside the press roller pair 861 heats the entire press roller pair, and the heat rod 881 causes the folded portion of the middle folded bundle PA to pass through the press roller pair 861. The amount of heat is given. And the rigidity of the middle folded bundle PA can be increased by applying heat to the folded portion of the middle folded bundle PA by the heat rod 881 which is a heating means for heating the folded portion in this way.

  Thereby, the bending effect by the press roller pair 861 can be increased, and an intermediate folded bundle having a small appearance and a small opening can be obtained. Further, it is possible to efficiently release unnecessary moisture from the middle fold bundle after the crease is formed, and to apply heat to the fold portion of the middle fold bundle together with the pressure of the press roller pair 861. The folded folds of the intermediate fold bundle can be cured and fixed.

  Further, by providing the heat rod 881 integrally with the press roller pair 861, heat can be applied to the middle folded bundle in synchronization with the folding operation of the middle folded bundle by the press roller pair 861. Thereby, the amount of heat can be efficiently applied to the folded portion of the middle folded bundle in a timely manner.

  In addition, this heat rod 881 can also control the heating conditions with respect to a folding part. For example, the heating amount for the folded portion may be controlled for each middle folded bundle based on the information related to the opening condition of the middle folded bundle described above.

  In this case, the finisher control unit 157 serving as a heating control unit may control the heating amount of the heat rod 881 based on information related to the opening condition of the half-fold bundle. In addition, as the control of the heating amount, for the middle folded bundle under a condition where the opening amount is not so large, the heating amount is set to be small, and for the middle folded bundle under a condition where the opening amount is increased, Set a large amount of heating.

  In addition, for a half-folded bundle under the condition that there is no opening amount, it may be set so that heating is not performed, and heating and non-heating are selectively switched for each half-folded bundle (each sheet bundle). Control may be performed. And by such control, it becomes possible to apply an appropriate amount of heating to the folded portion according to the opening condition of the middle folded bundle, and it is possible to efficiently provide the middle folded bundle PA with a small appearance and good appearance. .

  In addition, the heat rod 881 may be controlled not only to control the heating amount for the folded portion, but also to switch between heating and non-heating at the time of folding a single folded bundle PA.

  For example, a location where the load received by the sheet is greater than other locations, such as the vicinity of the side surface of the center folded bundle where the press roller pair 861 first contacts, the vicinity of the needle hole where the needle binding is performed, and the strength of the sheet Set the heating amount to a weakened part or set it to non-heating.

  That is, when heating the folded portion, the heating is controlled so as to reduce the heating of the folded portion within a predetermined range or not. Accordingly, it is possible to efficiently provide a half-folded bundle having a small appearance and having no opening, which is free from turning and folding of the bundle side surface and tearing of the sheet starting from the needle hole.

  Heretofore, the heat rod 881 provided inside the press roller pair 861 has been described as the heating means, but the present embodiment is not limited to this. For example, external heating means that abuts on the outer periphery of the press roller pair 861 or means for causing the press roller pair 861 to generate heat by electromagnetic induction heating may be used. Further, when the heating temperature is about 100 ° C. or higher, it is possible to efficiently promote the moisture release of the middle folded bundle PA.

  As described above, in this embodiment, the fold part Pc of the middle folded bundle is humidified on the downstream side in the moving direction of the press roller pair 861, and the humidified portion is heated by the heat rod 881 via the press roller pair 861. Like to do.

  As a result, the rigidity of the sheet can be changed by moisture and heat without causing unnecessary humidification, and as a result, the sheet can be efficiently and without wavy and folded wrinkles, and without causing a conveyance failure. , You can get a nice looking middle fold.

  By the way, the humidifying nozzle 880 as the humidifying means and the heat rod 881 as the heating means described so far are both disposed on the outer peripheral portion of the main body 2a of the finisher 2 outside the main body of the sheet processing apparatus shown in FIG. The crease press unit 860 is provided.

  By providing the humidifying nozzle 880 and the heat rod 881 outside the finisher body in this manner, the moisture released from the humidifying nozzle 880 and the moisture heated by the heat rod 881 and evaporated from the middle folded bundle enter the finisher. Can be prevented. Thereby, it is possible to prevent the occurrence of conveyance failures such as conveyance slip and guide sticking due to moisture adhering to the conveyance roller or conveyance guide in the finisher 2.

  In the above description, the press roller pair 861 moves (scans) from the standby position on the back side to the front side, and at this time, the downstream side in the moving direction of the press roller pair 861 is humidified by the humidifying nozzle 880. However, the present embodiment is not limited to this.

  For example, when moving from the front side to the back side, similarly, a nozzle for humidifying the downstream side of the movement of the press roller pair 861 is separately provided, or relative to the press roller pair in conjunction with the movement of the press roller pair 861. You may comprise the humidification nozzle which moves, maintaining a position. And by comprising in this way, in the bidirectional | two-way movement of the press roller pair 861, effective humidification, heating, and pressurization with respect to a folding part can be performed.

  Furthermore, until now, although the humidification direction by the humidification nozzle 880 was demonstrated as a structure used as the direction which turns the back of the folding part Pc of the middle folding bundle PA, this invention is not limited to this. For example, as shown in FIG. 6, the structure which arrange | positions the humidification nozzle 882 (882a, 882b) which humidifies from the upper and lower sides on both sides of the folding part Pc of the middle folding bundle PA may be sufficient. Furthermore, the humidification direction and the number of the humidifying nozzles with respect to the folding portion are not limited to this as long as the configuration can perform appropriate humidification with respect to the folding portion.

  Further, in the present embodiment, the configuration in which the finisher 2 is provided with the finisher control unit 157 configuring the humidification control unit and the heating control unit has been described, but the present invention is not limited to this configuration. For example, the finisher control unit 157 may be integrated into the CPU circuit unit 150 serving as control means provided in the copying machine main body 1 so that the finisher 2 is directly controlled from the copying machine main body 1.

  Next, a second embodiment of the present invention will be described.

  FIG. 7 is a diagram showing a schematic configuration of a crease press unit provided in the sheet processing apparatus according to the present embodiment. In FIG. 7, the same reference numerals as those in FIG. 5 described above indicate the same or corresponding parts.

  In FIG. 7, 883a and 883b are dehumidifying roller pairs for dehumidifying the folded portion Pc of the middle folded bundle PA, and these dehumidifying roller pairs 883 (883a and 883b) are located upstream in the moving direction of the press roller pair 861. In addition, it is provided integrally with the press roller pair 861. In addition, as a material of the dehumidification roller pair 883 which is this dehumidification means, the material excellent in water absorption like a foam, a porous body, a fiber absorber etc. is used, for example.

  Here, by providing the dehumidifying roller pair 883 on the upstream side in the moving direction of the press roller pair 861 and integrally, after the crease is strengthened by pressurization while being heated by the press roller pair 861, it is removed from the middle fold bundle PA. Unnecessary moisture can be efficiently removed. Thus, by performing dehumidification by the dehumidifying roller pair 883a, 883b, it becomes possible to more efficiently remove unnecessary water from the middle fold bundle PA after the crease reinforcement is finished.

  In this embodiment, it is assumed that the press roller pair 861 moves to the front side from the standby position on the back side, and the dehumidifying roller pair 883 is provided on the back side of the press roller pair 861. Is not limited to this. For example, when moving from the front side to the back side, a dehumidifying roller pair may be separately arranged on the downstream side in the moving direction of the press roller pair 861.

  Further, the dehumidifying roller pair 883 may be configured to move to the downstream side in the moving direction of the press roller pair 861 in conjunction with the change in the moving direction of the press roller pair 861. According to this configuration, effective dehumidification of the folded portion can be performed in bidirectional movement.

  By the way, in the first and second embodiments described so far, the crease reinforcing means and the dehumidifying means are each constituted by a pair of rollers (press roller pair 861 and dehumidifying roller pair 883). May be configured by other than the roller pair.

  Next, a third embodiment of the present invention in which such a crease strengthening means and a dehumidifying means are configured by a unit other than a roller pair will be described.

  FIG. 8 is a schematic configuration diagram of a crease press unit provided in the sheet processing apparatus according to the present embodiment. In FIG. 8, the same reference numerals as those in FIG. 5 described above indicate the same or corresponding parts.

  In FIG. 8, 884 is a press plate provided facing the press roller 861a that moves with respect to the folding portion, and this press plate 884 is disposed across the entire folding portion of the middle folded bundle PA in the width direction. Yes. Then, the press roller 861a including the heat rod 881a moves along the press plate 884, and the fold portion of the middle fold bundle PA is sandwiched between the press plate 884 and the press roller 861a. Can be strengthened.

  Here, in the present embodiment, the crease reinforcement means is configured by a press roller 861a that moves along the crease. Further, in the present embodiment, the dehumidifying means can also be configured by the press plate 884 by configuring the surface in contact with the middle folded bundle PA of the press plate 884 with a material excellent in water absorption.

  And by comprising in this way, the unnecessary water | moisture content is removed more efficiently from the middle folded bundle PA after reinforcement | strengthening at the same time on the opposite side which is heating and pressurizing a folding part with the press roller 861a. can do.

1 is a diagram illustrating a schematic configuration of a digital copying machine as an example of an image forming apparatus including a sheet processing apparatus according to a first embodiment of the present invention. Sectional drawing of the finisher which is the said sheet processing apparatus. FIG. 3 is a control block diagram of the digital copying machine. The figure explaining bookbinding processing operation of the above-mentioned finisher. The figure which shows schematic structure of the crease press unit provided in the said finisher. The figure which shows the other structure of the crease press unit provided in the said finisher. The figure which shows schematic structure of the crease press unit provided in the sheet processing apparatus which concerns on the 2nd Embodiment of this invention. The figure which shows schematic structure of the crease press unit provided in the sheet processing apparatus which concerns on the 3rd Embodiment of this invention. The figure explaining schematic structure of the sheet bundle bending part of the conventional sheet processing apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Digital copying machine main body 2 Finisher 103 Image forming part 157 Finisher control part 800 Saddle stitch bookbinding part 860 Crease press unit 861 Press roller pair 880 Humidification nozzle 881 Heat rod 882 Humidification nozzle 883 Dehumidification roller pair 884 Press plate 1000 Digital copying machine PA Folded Pc Folding part of middle folded bundle

Claims (20)

In a sheet processing apparatus that performs a bookbinding process by bending a sheet bundle,
A humidifying means for humidifying the folded portion of the folded sheet bundle;
A crease reinforcing unit that moves along the fold while pressing a fold portion of the sheet bundle humidified by the humidifying unit and reinforces the fold of the sheet bundle;
Heating means for heating the folded portion of the sheet bundle whose creases are reinforced by the crease strengthening means;
A sheet processing apparatus comprising:   The sheet processing apparatus according to claim 1, wherein the crease strengthening unit, the humidifying unit, and the heating unit are disposed outside the main body of the sheet processing apparatus.   The sheet processing apparatus according to claim 1, wherein the heating unit heats the fold portion via the crease strengthening unit.   The sheet processing apparatus according to claim 1, wherein the humidifying unit humidifies the folded portion in synchronization with the movement of the crease reinforcing unit.   The sheet processing apparatus according to claim 4, wherein the humidifying unit moves integrally with the crease reinforcing unit.   The humidification control means for controlling the humidification amount of the humidification means with respect to the folded portion according to the force to open the sheet bundle once folded is provided. The sheet processing apparatus according to the description.   The sheet processing according to claim 6, wherein the humidification control unit performs control so as to switch a humidification amount for the folded portion for each sheet bundle in accordance with a force to open the sheet bundle once folded. apparatus.   The said humidification control means controls to switch humidification and non-humidification with respect to the said folding part for every sheet bundle according to the force which the sheet bundle once folded is opened. Sheet processing device.   The said humidification control means controls so that the humidification amount with respect to the predetermined range of the said folding part may be decreased when the said folding part is humidified by the said humidification means. Sheet processing equipment.   The said humidification control means controls so that humidification may not be performed with respect to the predetermined range of the said folding part, when the said folding part is humidified by the said humidification means. The sheet processing apparatus according to the description.   4. The heating control unit according to claim 1, further comprising a heating control unit configured to control a heating amount of the heating unit with respect to the folded portion in accordance with a force to open the sheet bundle once bent. 5. The sheet processing apparatus according to the description.   The sheet processing according to claim 11, wherein the heating control unit performs control so as to switch a heating amount for the folding portion for each sheet bundle in accordance with a force to open the once folded sheet bundle. apparatus.   12. The heating control unit according to claim 11, wherein the heating control unit performs control so as to switch between heating and non-heating of the folded portion for each sheet bundle in accordance with a force to open the once folded sheet bundle. Sheet processing device.   14. The heating control unit according to claim 11, wherein when the folding unit is heated by the heating unit, the heating control unit controls the heating amount with respect to a predetermined range of the folding unit to be reduced. Sheet processing equipment.   14. The heating control unit according to claim 11, wherein when the folding unit is heated by the heating unit, the heating control unit performs control so as not to heat a predetermined range of the folding unit. Sheet processing device.   The sheet processing apparatus according to any one of claims 1 to 15, further comprising a dehumidifying unit that dehumidifies a fold portion in which a fold is reinforced by the crease reinforcing unit.   The sheet processing apparatus according to claim 16, wherein the dehumidifying unit dehumidifies the folded portion on the upstream side in the moving direction of the crease reinforcing unit.   18. The sheet processing apparatus according to claim 16, wherein the dehumidifying unit is provided opposite to the crease reinforcing unit, and dehumidifies while sandwiching the fold portion together with the fold reinforcing unit.   An image forming unit that forms an image on a sheet, and the sheet processing apparatus according to any one of claims 1 to 18 that performs bookbinding processing on a sheet on which an image is formed by the image forming unit. An image forming apparatus. An image forming unit that forms an image on a sheet;
A sheet processing apparatus that performs a bookbinding process by folding a sheet on which an image is formed by the image forming unit;
Control means for controlling the sheet processing apparatus,
The sheet processing apparatus includes:
A humidifying means for humidifying the folded portion of the folded sheet bundle;
A crease reinforcing unit that moves along the fold while pressing a fold portion of the sheet bundle humidified by the humidifying unit and reinforces the fold of the sheet bundle;
Heating means for heating the folded portion of the sheet bundle that has been creased by the crease strengthening means,
The image forming apparatus, wherein the control unit controls a humidification amount of the humidifying unit with respect to the folding unit and a heating amount of the heating unit with respect to the folding unit.

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