JP2004284740A - Sheet handling device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress damage in a tip part of a paper to suppress disturbance in bookbinding such as crushing and folding and non-alignment of papers and to ensure productivity of recording. <P>SOLUTION: This sheet handling device is provided with a compile tray 31 receiving a sheet from an image formation device 1, a delivery roll 21 conveying and loading a sheet for the compile tray 31, and a control part 7 recognizing type of sheet loaded on the compile tray 31. The delivery roll 21 is constituted in such a way that sheet conveyance speed is reduced in a rear end part of sheet and conveyance speed in the rear end part of sheet can be changed based on the result of recognition by the control part 7. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a sheet processing apparatus for processing sheets (sheets) discharged from an image forming apparatus such as a printer and a copying machine, and more particularly, to a sheet processing apparatus having a sheet (sheet) bookbinding mechanism.
[0002]
[Prior art]
2. Description of the Related Art Sheet processing apparatuses that receive recorded paper (sheets) discharged from an image forming apparatus such as a printer or a copying machine and perform predetermined post-processing have been widely used in recent years. This is because, with the online use of the image forming apparatus, high productivity of recording by the image forming apparatus has been promoted, and stapling (staple) binding, punching (round hole punching), paper folding, and the like have been performed on the paper after image formation. This is because image forming apparatuses that ensure high productivity while equipped with processing means have become popular.
[0003]
Above all, many proposals have been made for a sheet post-processing apparatus that binds and takes out recorded sheets (sheets) discharged from an image forming apparatus. For example, a paper post-processing apparatus has been proposed in which a stack of sheets discharged from an image forming apparatus is bound at a central portion, the sheet is saddle-stitched at the binding position, folded into two, and the sheet is taken out as a bookbinding. I have.
[0004]
As these sheet post-processing devices, for example, each time a recording medium is stacked, the two alignment plates are driven to press the side surfaces of the recording medium with a predetermined pressing force to adjust the width direction of the recording medium, and the final When the recording media are stacked, by driving the two alignment plates and binding the recording media while pressing the side surfaces of the recording media with a predetermined pressing force, after the final recording media are stacked on the stacking means, There is a technique for shortening the processing time by making it unnecessary to perform the alignment with a predetermined pressing force again (for example, see Patent Document 1).
[0005]
[Patent Document 1]
JP-A-2002-160864 (page 3-5, FIG. 1)
[0006]
[Problems to be solved by the invention]
By the way, in the case where the recorded paper (sheet) discharged from the image forming apparatus is saddle-stitched and folded into two for bookbinding, a predetermined number of papers are accumulated and placed on a compile tray as a paper stacking means. However, the compile tray usually holds the paper in a vertical position because of the convenience of folding the book into two sheets with saddle stitching and the convenience of stacking the bound paper. It is installed to face a direction slightly inclined from the direction. Therefore, when the recorded paper discharged from the image forming apparatus is placed on the compile tray, the paper is loaded so as to drop toward the compile tray from above in the vertical direction.
[0007]
However, when the paper is dropped from above in the vertical direction toward the compile tray, if the paper size is the same but the paper quality is different, the difference in the drop speed occurs due to the difference in the weight of the paper. Is large, so the falling speed increases. When the falling speed of the paper increases, the leading edge of the paper when the falling paper hits a positioning stopper provided to move along the compile tray to determine the saddle stitching position and the folding position of the paper. There is a problem that the bookbinding may be disturbed due to damage such as crushing or breaking of the sheet, or the paper may be irregularly bounced off from the positioning stopper of the paper to cause paper misalignment in the paper transport direction. .
On the other hand, if the falling speed of the paper placed on the compile tray is uniformly reduced to reduce the collision damage of the leading end of the paper, the productivity of recording by the image forming apparatus is reduced. There was a problem that it would.
[0008]
The present invention has been made to solve such a technical problem, and an object of the present invention is to suppress the damage to the leading end portion of a sheet and to prevent the bookbinding from being broken or broken, and to prevent the sheet from being damaged. The purpose is to suppress the alignment and secure the productivity of the record.
[0009]
[Means for Solving the Problems]
With this object in mind, a sheet processing apparatus according to the present invention includes a sheet receiving unit that receives a sheet from an image forming apparatus, a sheet conveying unit that conveys and places a sheet on the sheet receiving unit, and a sheet receiving unit that places the sheet on the sheet receiving unit. Sheet type recognizing means for recognizing the type of sheet to be performed, and with respect to the sheet conveying means, the sheet conveying speed is reduced at the rear end of the sheet, and the sheet is recognized based on the recognition result by the sheet type recognizing means. The transport speed at the rear end is variable. Further, the sheet type recognizing means may be characterized in that the sheet type is recognized as a sheet type. In particular, the sheet conveying means may be characterized in that when the sheet type recognizing means recognizes the sheet as thick paper, the conveying speed at the rear end of the sheet is lower than that of plain paper. Further, the sheet type recognizing means may uniformly recognize that the sheet is a thick sheet when the sheet is fed from a predetermined sheet feeding means.
[0010]
Here, the sheet type recognizing means may recognize the type of the sheet based on information from the image forming apparatus. Further, the sheet conveying means may be characterized in that a plurality of conveying speeds at the rear end of the sheet are set, and one conveying speed is selected from the plurality of conveying speeds based on the recognition result of the sheet type recognizing means. it can.
[0011]
From other viewpoints, the sheet processing apparatus of the present invention provides a sheet receiving unit that receives a sheet from the image forming apparatus and a sheet receiving unit that receives the sheet from the first transport speed that is lower than the first transport speed. And a sheet conveying means for conveying the sheet while switching to the second conveying speed, wherein the second conveying speed is variable with respect to the sheet conveying means. Further, the apparatus further comprises a sheet type recognizing means for recognizing a type of the sheet conveyed to the sheet receiving means, wherein the sheet conveying means sets the second conveying speed based on a recognition result by the sheet type recognizing means. can do. Further, the sheet type recognizing means may be characterized in that the sheet type is recognized as a sheet type.
[0012]
Here, the sheet conveying means may set the second conveying speed based on information from the image forming apparatus. Further, the sheet conveying means may be characterized in that the second conveying speed is set at the rear end of the sheet.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
FIG. 1 is a diagram showing an overall configuration of a sheet processing apparatus to which the present embodiment is applied. The sheet processing apparatus (sheet processing apparatus) 2 is connected to the image forming apparatus 1 such as a printer or a copying machine that forms a color image by an electrophotographic method, and is used as a post-processing apparatus. The sheet processing apparatus 2 includes a transport unit 3 connected to the image forming apparatus 1, a folding unit 4 for performing a folding process on a sheet (paper) taken in by the transport unit 3, and a folding unit 4. The apparatus includes a finisher 5 that performs a predetermined final process on the passed sheet, an interposer 6 that supplies an interleaf such as a booklet cover, and a control unit 7 that controls each mechanism of the sheet processing apparatus 2. The control unit 7 is provided in the housing of the finisher 5 in the sheet processing apparatus 2 in FIG. 1, but may be provided in the housing of another unit. Further, all the control functions can be integrated in the main body of the image forming apparatus 1.
[0014]
When the sheet processing apparatus 2 composed of these units is divided by function, the sheet processing apparatus 2 is provided in the finisher 5, and is provided in the staple function unit 10 that generates a sheet bundle and executes stapling (staple) binding, and the finisher 5, A saddle stitch bookbinding function unit 30 that saddle stitches a sheet bundle and performs bookbinding, a folding function unit 50 that is provided in the folding unit 4 and that performs inner trifold (C-fold) and outer trifold (Z-fold) on a sheet, for example, A punch function unit 70 provided in the finisher 5 for punching two or four holes, an interposer 6, and the like are provided to supply a slip sheet such as a thick sheet or a window-open sheet used as a cover of a sheet bundle. It has a slip sheet function unit 80.
[0015]
Next, the saddle stitching function unit 30 provided in the finisher 5, which is a characteristic configuration of the present embodiment, will be described in detail.
FIG. 2 is a diagram illustrating the configuration of the saddle stitching function unit 30. As shown in FIG. 2, the saddle stitching function unit 30 includes a compile tray 31 as an example of a sheet receiving unit that accumulates a required number of sheets (sheets) after image formation when a booklet is created. A discharge roll 21 as an example of a sheet conveying means for discharging the sheet 31; an end guide 32 having a positioning stopper protruding above the compile tray 31 and moving along the compile tray 31 to determine a saddle stitching position and a folding position; In order to align the sheets stacked on the compile tray 31 toward the end guide 32, a sheet aligning member 33 composed of a rotating paddle, and in order to align the sheets stacked on the compile tray 31 in the width direction, Sheet as an example of a sheet aligning unit constituted by an aligning plate which is a pair of aligning members that slide Arranging member 34, a stapler 35 as an example of a sheet stapling means for saddle stitching a sheet which is integrated in the compile tray 31.
[0016]
Further, in order to fold from the saddle stitching position, the folding knife 36 that moves so as to protrude upward from below the compile tray 31 with respect to the bundle of sheets stapled by the stapler 35, the folding is started by the folding knife 36. A first folding roll 37 as a pair of rolls, a second folding roll 38 as a pair of rolls for further strengthening the folding of the sheet bundle conveyed by the first folding roll 37, and a second A transport roll 39 transports the bundle of sheets sandwiched by the folding rolls 38 to the discharge port, and a booklet tray 43 for stacking the bound bundle of sheets.
[0017]
Next, the operation of the saddle stitching function unit 30 will be described.
As shown in FIG. 2, in the finisher 5, printed (printed) paper output via the discharge roll 9 of the folding unit 4 is received at a paper entrance 71, and is provided near the paper entrance 71. After passing through the entrance roll 11, which is a pair of rolls for receiving sheets, a punching process is performed in the punch function unit 70 as necessary. The paper that has passed through the punch function unit 70 is sorted by the first gate 12 to the saddle stitching function unit 30 or the top tray 41 or the staple function unit 10.
[0018]
In the mere sheet discharge or creation of the edge-bound booklet, the sheet is turned upward at the first gate 12 based on an instruction from the control unit 7 and is further conveyed by the conveying rolls 13 to the top tray 41 or the staple function. It is sent to the unit 10. On the other hand, when a booklet with saddle stitching is created, the sheet is turned downward at the first gate 12 based on an instruction from the control unit 7, and is sent to the discharge roll 21 via the transport roll 14.
The discharge roll 21 sequentially places the conveyed sheets so that the sheets are stacked on the compile tray 31. For example, the number of sheets set by the control unit (not shown) of the image forming apparatus 1, such as 5, 10, 15, or the like, is accumulated on the compile tray 31. At this time, the end guide 32 has been moved and stopped, for example, so that the central portion of the sheet is located at the stapling position by the stapler 35. Further, at this time, the sheet aligning member 33 rotates toward the end guide 32 and presses the stacked sheets against the end guide 32 to assist the sheet alignment. Further, the paper width aligning member 34 slides in the width direction of the paper stacked on the compile tray 31 and aligns the stacked paper from the width direction.
[0019]
After a predetermined number of sheets are stacked on the compile tray 31, the stapler 35 performs saddle stitching on a predetermined portion (for example, a central portion) of the sheet. Next, the sheet bundle having undergone the saddle stitching is moved by the upward movement of the end guide 32 so that the folded portion (for example, the central portion of the sheet) is positioned at the tip end of the folding knife 36. Note that the folding knife 36 has its tip retracted below the compile tray 31 at the stage of accumulating sheets on the compile tray 31, the stage of saddle stitching by the stapler 35, and the stage of sheet transport after saddle stitching. It is configured not to appear on the surface of the tray 31.
[0020]
After the folding position of the sheet bundle has moved to the tip position of the folding knife 36, the folding knife 36 is pushed upward from below. That is, the folding knife 36 is directed upward in a direction perpendicular to the housing surface of the compile tray 31, and the leading end of the folding knife 36 contacts the sheet bundle. Further, the leading end is pushed upward, and the sheet bundle is lifted and sandwiched by the first folding roll 37. The folding knife 36 is configured to move to a position where the sheet bundle sufficiently digs into the first folding roll 37. In this way, the sheet bundle that has been subjected to the first-stage folding by the first folding roll 37 is conveyed to the second folding roll 38, and sufficient folding is performed by the load from the second folding roll 38. You. Thus, the fold is completed by passing through the second folding roll 38. After that, the bookbinding that is transported by the transport rolls 39 and generated is stacked on the booklet tray 43.
[0021]
Next, the operation of the end guide 32 will be described first. FIG. 3 is a diagram for explaining an operation mechanism of the saddle stitching bookbinding function unit 30 including the end guide 32 and the like. As an operation mechanism of the end guide 32, an end guide tray 322 provided with a positioning stopper 321 projecting from the bottom and supporting a sheet is connected to the end guide tray 322, and the end guide tray 322 is rotated by itself. 323, a drive roll 324 for driving the belt 323, an end guide motor 325 composed of a stepping motor that repeats normal rotation and reversal as a drive source of the drive roll 324, and a home position of the end guide tray 322 are detected. And a home position sensor 326 including a photo sensor.
Further, a paper alignment member 33 is disposed near the end guide 32. The sheet aligning member 33 includes a paddle 331 that rotates to align the sheets stacked on the compile tray 31 toward the positioning stopper 321 of the end guide tray 322, and a paddle motor 332 that includes a DC motor that drives the paddle 331. It has.
[0022]
From the state where the home position sensor 326 is positioned, the end guide motor 325 rotates under the control of the control unit 7 shown in FIG. 324 rotates clockwise and counterclockwise. The rotation of the drive roll 324 causes the belt 323 to rotate in one direction and the opposite direction, and the rotation of the belt 323 causes the end guide tray 322 to reciprocate in parallel with the compile tray 31. The end guide tray 322 stops at, for example, a predetermined position set in advance as a home position. In this state, based on an instruction from the control unit 7, the sheet is aligned with the center stapling position by the stapler 35 according to the size of the sheet carried into the compile tray 31. At this time, the paddle 331 of the sheet aligning member 33 is rotated by the paddle motor 332, and aligns the sheet carried into the compile tray 31 toward the positioning stopper 321 of the end guide tray 322.
Thereafter, the end guide motor 325 rotates to move the end guide tray 322 so that the center of the sheet bundle saddle stitched by the stapler 35 and the saddle stitch portion are aligned with the folding position by the folding knife 36, and the end guide tray 322 is moved by a predetermined distance. Stop after With these operations, positioning of the sheets stacked on the compile tray 31 to the saddle stitching position and positioning to the folding position are performed.
[0023]
Next, the operation of the paper width alignment member 34 will be described with reference to FIG. As shown in FIG. 3, as an operation mechanism of the paper width aligning member 34, a front tamper 341 and a rear tamper 342 as alignment plates for aligning paper in the paper width direction are fixed to the front tamper 341 in the paper width direction. The front rack gear 343 provided, the rear rack gear 344 fixed to the rear tamper 342 in the width direction of the paper, the front pinion gear 345 connected to the front rack gear 343, the rear pinion gear 346 connected to the rear rack gear 344, the front A front tamper motor 347 composed of a stepping motor that repeats normal rotation and reversal as a drive source of the tamper 341, a rear tamper motor 348 composed of a stepping motor that repeats normal rotation and reversal as a drive source of the rear tamper 342, and the front tamper 34 Front home sensor 349 for detecting the home position, and a rear home sensor 350 for detecting the home position of Riatanpa 342.
[0024]
The front tamper 341 and the rear tamper 342 are adjusted to the size of the sheet to be conveyed based on the instruction from the control unit 7 shown in FIG. 1 from the state where the positioning is performed by the front home sensor 349 and the rear home sensor 350, respectively. The home position is set for each sheet. Then, the sheet is conveyed and placed on the compile tray 31, and the front tamper motor 347 and the rear tamper motor 348 repeat normal rotation and reversal until the next sheet is conveyed to the compile tray 31. The driving of the front tamper motor 347 and the rear tamper motor 348 is transmitted from the front pinion gear 345 and the rear pinion gear 346 to the front tamper 341 and the rear tamper 342 via the front rack gear 343 and the rear rack gear 344, respectively. And the rear tamper 342 are slid. The paper placed on the compile tray 31 is tamped by the front tamper 341 and the rear tamper 342 from both sides in the paper width direction.
[0025]
After the front tamper 341 and the rear tamper 342 move once so as to sandwich the paper, they return to the home position for each paper size. Then, first, the rear tamper 342 moves in the direction away from the sheet, and the front tamper 341 moves in the direction away from the sheet slightly after the movement operation of the rear tamper 342. Thereafter, the front tamper 341 and the rear tamper 342 again Perform the operation of returning to the home position.
Such a series of operations is performed each time a sheet is placed on the compile tray 31, and the sheets are aligned in the sheet width direction.
[0026]
Further, when a predetermined number of sheets have been stacked on the compile tray 31, the front tamper 341 and the rear tamper 342 repeat the operation of sandwiching the sheets and the operation of separating from the sheets a plurality of times to adjust the alignment of the entire stacked sheet bundle. I'm trying to be perfect.
After that, when the end guide 32 finishes aligning the paper conveyed into the compile tray 31 with the saddle stitching position by the stapler 35, tamping is performed again with a weak pressing force to further prepare the paper bundle. Saddle stapling is performed by the stapler 35.
[0027]
Next, the operation of the booklet tray 43 will be described. FIG. 4 is a diagram for explaining the operation mechanism of the booklet tray 43. The operation mechanism of the booklet tray 43 includes a drive mechanism for driving the tray belt 432 while stretching one of the two belt belts 432 and one of the tray belts 432 for transporting the bound sheet bundle to the sheet removal tray 431 of the booklet tray 43. A roll 433, a support roll 434 that stretches the other of the tray belt 432, a drive transmission belt 435 that transmits drive to the drive roll 433, and a tray belt drive motor 436 that drives the tray belt 432 as a drive source of the tray belt 432. I have.
[0028]
The sheet bundle bound and saddle stitched and bound is discharged to the booklet tray 43 by the transport roll 39. Since the booklet tray 43 is installed at a position lower than the transport roll 39, the sheet bundle discharged from the transport roll 39 is placed so as to fall on the booklet tray 43. In synchronization with the sheet bundle being placed on the booklet tray 43, the tray belt drive motor 436 starts rotating under the control of the control unit 7 shown in FIG. Is transported to the paper take-out tray 431 from the printer. Then, the sheet bundle is conveyed to the sheet take-out tray 431 by the tray belt 432. When a plurality of sheet bundles are created, these sheet bundles are stacked on the sheet take-out tray 431.
[0029]
Next, an operation of the discharge roll 21 when a sheet is placed on the compile tray 31 from the discharge roll 21, which is a feature of the present embodiment, will be described.
FIG. 5 is a diagram illustrating an operation mechanism of the discharge roll 21. As shown in FIG. 5, the operation mechanism of the discharge roll 21 includes a shaft 22 that is rotatably supported by both side plates 25 a and 25 b of the saddle stitch bookbinding function unit 30 and has four discharge rolls 21 fixed thereto. An idle roll 23 that is disposed opposite the discharge roll 21 and pinches and transports the paper; a paddle 24 that is fixed to the shaft 22 and presses the paper against the compile tray 31; and is installed on a side plate 25a, and drives the shaft 22 to rotate. , A drive motor 26 composed of a plurality of gears and transmitting a driving force from the drive motor 26, and a sheet for detecting that the sheet has been conveyed to the saddle stitching function section 30 A detection sensor 28 is provided.
[0030]
When the image forming apparatus 1 starts an image forming operation, the drive motor 26 starts rotating based on an instruction from the control unit 7. The drive from the drive motor 26 is transmitted to the shaft 22 via the drive transmission unit 27, and the discharge roll 21 rotates with the peripheral speed on the outer peripheral surface of the roll set to the first transport speed of 800 mm / sec. When the printed sheet is conveyed, the sheet is conveyed to the compile tray 31 while being sandwiched between the discharge roll 21 and the idle roll 23. At this time, the paddle 24 rotates coaxially with the discharge roll 21, and works so as to press the rear end of the sheet conveyed to the compile tray 31 against the compile tray 31. As a result, the sheet is always kept in close contact with the compile tray 31, and when the sheet is placed on the compile tray 31, it is prevented that the sheet is turned back and forth in page order.
[0031]
On the other hand, the paper detection sensor 28 is configured by a photosensor that irradiates light to the paper and detects the presence or absence of the paper based on the reflected light. Are arranged at a predetermined interval. Then, it is detected whether or not the paper has been conveyed to the area where the paper detection sensor 28 is located, and whether or not the paper has passed through the paper detection sensor 28.
[0032]
When the paper detection sensor 28 detects that the paper has passed through the paper detection sensor 28, the control unit 7 controls the driving of the drive motor 26 to reduce the peripheral speed of the discharge roll 21 on the outer peripheral surface of the roll. The speed is reduced to the second transport speed of 250 mm / sec. That is, in a state where the rear end of the sheet has passed through the sheet detection sensor 28 and the rear end of the sheet is sandwiched between the discharge rollers 21, the peripheral speed of the discharge roller 21 is reduced to the first transport speed of 800 mm / sec. To reduce the second transport speed to 250 mm / sec, thereby reducing the transport speed of the paper at the final stage in which the paper is placed on the compile tray 31.
[0033]
After the sheet passes through the discharge roll 21, the sheet freely falls along the compile tray 31 to the end guide 32, and the rear end of the sheet is nipped between the discharge roll 21 and the idle roll 23 in this manner. The paper is decelerated during the period in which the paper is being conveyed, and the conveyance speed of the paper at the final stage when the paper is placed on the compile tray 31 is reduced. Can be relieved. As a result, it is possible to prevent the leading end of the paper from being damaged such as being crushed or broken, and to prevent the paper from rebounding from the end guide 32 when the paper abuts against the end guide 32. The occurrence of misalignment can also be suppressed. Further, since the discharge roll 21 is decelerated only during the period in which the rear end of the sheet is nipped and conveyed by the discharge roll 21 and the idle roll 23, the recording productivity in the image forming apparatus is not reduced.
After the paper has passed through the discharge roll 21, the peripheral speed of the discharge roll 21 is increased again to the first transport speed of 800 mm / sec, and the next paper is transported.
[0034]
Further, in the present embodiment, the second transport speed when the peripheral speed of the discharge roll 21 is reduced can be changed according to the type of the paper transported to the saddle stitching bookbinding function unit 30. It is configured. That is, when the sheet conveyed to the saddle stitching function unit 30 is, for example, thick paper, the sheet detection sensor 28 detects that the sheet has passed through the sheet detection sensor 28, Is reduced so that the second transport speed is 50 mm / sec, and the second transport speed at the rear end of the paper is further reduced than that of normal paper (plain paper). ing. Here, the thick paper generally refers to paper whose weighing is 129 gsm or more, but also includes resin sheets such as OHP, synthetic paper, and the like.
[0035]
This is because, in the case of heavy paper types such as thick paper, if the speed at which the paper starts free-fall along the compile tray 31 to the end guide 32 after passing the discharge roll 21 is high, the end guide 32 Since the impact due to the collision of the sheet becomes large in relation to the collision speed and the weight, the damage at the leading end of the sheet becomes extremely large. For this reason, the leading end of the sheet is more likely to be crushed or broken than a normal sheet, and the amount of rebound in the sheet conveyance direction is also increased.
On the other hand, when the thick paper is conveyed to the saddle stitching function unit 30, the peripheral speed of the discharge roll 21 at the rear end of the paper is further reduced as compared with the normal paper, so that the paper is added to the leading end of the paper. Damage can be reduced, and crushing or breaking of the leading end of the sheet can be suppressed in the same manner as a normal sheet, and rebound in the sheet conveyance direction can also be suppressed.
In the present embodiment, the second transport speed when the discharge roll 21 is decelerated is set to 50 mm / sec. However, the present invention is not limited to this.
[0036]
In the present embodiment, the control unit 7 having a function as a sheet type recognizing unit determines the type of the sheet conveyed to the saddle stitching function unit 30, but the sheet is supplied from the interposer 6 or a manual feed tray (not shown). In this case, the control unit 7 uniformly determines that the interleaving mode such as thick paper used for the front cover of the sheet bundle or open window paper is conveyed to the saddle stitching function unit 30, and the paper detection sensor 28 However, when it is detected that the paper has passed the paper detection sensor 28, the second transport speed of the discharge roll 21 is automatically reduced to 50 mm / sec.
[0037]
Here, control of the transport speed of the discharge roll 21 performed by the control unit 7 will be described. FIG. 6 is a flowchart illustrating a flow of a process performed by the control unit 7 regarding a change in the transport speed of the discharge roll 21 according to the type of sheet. In FIG. 6, when the image forming apparatus 1 starts the image forming operation, the discharge roll 21 rotates with the peripheral speed set to the first transport speed of 800 mm / sec (S101). Then, it is determined whether the conveyed paper is supplied from the interposer 6 or a manual tray (not shown) (S102). When the paper is not supplied from the interposer 6 or the manual feed tray (not shown), it is determined that the plain paper is conveyed to the saddle stitching bookbinding function unit 30, and whether or not the paper has passed the paper detection sensor 28 is determined. A determination is made (S103). Then, when the sheet has passed the sheet detection sensor 28, the peripheral speed of the discharge roll 21 is set to 250 mm / sec as the second transport speed (S104). Thereafter, it is determined whether there is a sheet to be conveyed next (S105). If there is a sheet to be conveyed next, the peripheral speed of the discharge roll 21 is again set to 800 mm / sec as the first conveyance speed. Is set (S101). On the other hand, when there is no sheet to be conveyed next, the discharge roll 21 is stopped (S109).
[0038]
In step S102, when it is determined that the conveyed paper is supplied from the interposer 6 or a manual feed tray (not shown), it is uniformly determined that the thick paper is conveyed to the saddle stitch bookbinding function unit 30, and the paper is detected. It is determined whether the passage through the sensor 28 has been completed (S106). Then, when the sheet has passed through the sheet detection sensor 28, the peripheral speed of the discharge roll 21 is set to 50 mm / sec as the second transport speed (S107). Thereafter, it is determined whether there is a sheet to be conveyed next (S108). If there is a sheet to be conveyed next, the peripheral speed of the discharge roll 21 is again set to 800 mm / sec as the first conveyance speed. Is set (S101). On the other hand, when there is no sheet to be conveyed next, the discharge roll 21 is stopped (S109).
[0039]
As described above, in the present embodiment, when thick paper is conveyed to the saddle stitching bookbinding function unit 30, the peripheral speed of the discharge roll 21 at the trailing end of the paper is further reduced as compared with that of plain paper, so that paper In this manner, it is possible to reduce the damage to the leading end of the sheet, suppress crushing or breaking of the leading end of the sheet in the same manner as a normal sheet, and also suppress the rebound in the sheet conveying direction. In addition, since the discharge roll 21 is decelerated only during a period in which the rear end of the sheet is being conveyed by the discharge roll 21, the productivity of recording in the image forming apparatus 1 does not decrease.
[0040]
It is to be noted that a determination of the type of paper conveyed to the saddle stitching function unit 30 is made by arranging a paper thickness sensor in a paper conveyance path before the paper is conveyed to the saddle stitching function unit 30. It is also possible to judge by a sensor. That is, according to the detection result of the paper thickness sensor, the second transport speed of the discharge roll 21 that has been reduced when the paper has passed through the paper detection sensor 28 may be configured to be variable. As the paper thickness sensor in this case, for example, a sensor that detects light transmittance in a non-image area of the paper or a sensor that includes a pair of rolls and detects a displacement amount of the roll when the paper passes through the roll And the like.
[0041]
Further, based on an input from an operation panel installed in the image forming apparatus 1 and a detection result from the above-described paper thickness sensor, the control unit 7 causes the paper type to be plain paper (64 to 128 gsm) or thick paper 1 (129). 162 gsm) and thick paper 2 (163 to 220 gsm). For example, the second transport speed when the discharge roll 21 is decelerated is set to 250 mm / sec for plain paper, whereas for thick paper 1, A plurality of speeds of 50 mm / sec and 20 mm / sec for the thick paper 2 may be set.
[0042]
【The invention's effect】
As described above, according to the present invention, it is possible to suppress the damage to the leading end portion of the paper to prevent the disorder of bookbinding such as crushing or folding and the misalignment of the paper, and to secure the recording productivity. Become.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating an overall configuration of a sheet processing apparatus to which an exemplary embodiment is applied;
FIG. 2 is a diagram illustrating a configuration of a saddle stitching function unit.
FIG. 3 is a diagram illustrating an operation mechanism of a saddle stitching function unit.
FIG. 4 is a diagram for explaining an operation mechanism of a booklet tray.
FIG. 5 is a diagram illustrating an operation mechanism of a discharge roll.
FIG. 6 is a flowchart illustrating a flow of a process related to a change in a transport speed of a discharge roll according to a type of paper.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Image forming apparatus, 2 ... Sheet processing apparatus, 5 ... Finisher, 6 ... Interposer, 7 ... Control part, 21 ... Discharge roll, 22 ... Shaft, 23 ... Idle roll, 24 ... Paddle, 25a, 25b ... Side plate, 26 , A drive motor, 27 a drive transmission unit, 28 a sheet detection sensor, 30 a saddle stitch bookbinding function unit, 31 a compile tray, 32 an end guide, 33 a paper alignment member, 34 a paper width alignment member, 35 a stapler , 43 ... Booklet tray

Claims (11)

A sheet processing apparatus for processing a sheet after an image is formed by the image forming apparatus,
Sheet receiving means for receiving a sheet from the image forming apparatus;
Sheet conveying means for conveying and placing the sheet on the sheet receiving means,
Sheet type recognition means for recognizing the type of the sheet placed on the sheet receiving means,
The sheet conveying means reduces the conveying speed of the sheet at the rear end of the sheet, and varies the conveying speed at the rear end of the sheet based on the recognition result by the sheet type recognizing means. Sheet processing device. 2. The sheet processing apparatus according to claim 1, wherein the sheet type recognition unit recognizes a sheet thickness as the type of the sheet. 3. The sheet conveying device according to claim 2, wherein when the sheet type recognizing device recognizes the sheet as thick paper, the conveying speed at the rear end of the sheet is lower than that of plain paper. A sheet processing apparatus as described in the above. 3. The sheet processing apparatus according to claim 2, wherein the sheet type recognizing unit uniformly recognizes that the sheet is a thick sheet when the sheet is fed from a predetermined sheet feeding unit. 2. The sheet processing apparatus according to claim 1, wherein the sheet type recognition unit recognizes the type of the sheet based on information from the image forming apparatus. In the sheet conveying means, a plurality of conveying speeds at the rear end of the sheet are set, and one conveying speed is selected from the plurality of conveying speeds based on a recognition result of the sheet type recognizing means. The sheet processing apparatus according to claim 1. A sheet processing apparatus for processing a sheet after an image is formed by the image forming apparatus,
Sheet receiving means for receiving a sheet from the image forming apparatus;
A sheet conveying unit configured to switch the first conveying speed to a second conveying speed lower than the first conveying speed and convey the sheet with respect to the sheet receiving unit;
2. The sheet processing apparatus according to claim 1, wherein the sheet conveying unit is configured to change the second conveying speed. The apparatus further includes a sheet type recognizing unit that recognizes a type of the sheet conveyed to the sheet receiving unit, wherein the sheet conveying unit sets the second conveying speed based on a recognition result by the sheet type recognizing unit. The sheet processing apparatus according to claim 7, wherein: 9. The sheet processing apparatus according to claim 8, wherein the sheet type recognition unit recognizes a sheet thickness as the type of the sheet. 8. The sheet processing apparatus according to claim 7, wherein the sheet conveying unit sets the second conveying speed based on information from the image forming apparatus. The sheet processing apparatus according to claim 7, wherein the sheet conveying unit sets the second conveying speed at a rear end of the sheet.

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