JP2019196257A - Sheet processing device - Google Patents

Abstract

To reduce that displacement of a processing position is caused even when a plurality of times of processing are performed on the same sheet.SOLUTION: A puncher 200 is provided with a one-way rotating clutch C which allows that one rotational body pair of a register auxiliary roller pair 211 and a register roller pair 250 rotates in a direction pulled by a sheet by sheet processing of a striping unit 300. After striping is performed with respect to a first position of the sheet by the striping unit 300, when the sheet is conveyed to perform striping with respect to a second position nearer to upstream side of a conveyance direction than the first position of the sheet, the register auxiliary roller pair 211 starts rotation after the register roller pair 250, so that, even when performing a plurality of times of stripings on the same sheet, displacement of the position of a stripe is reduced, and striping can be performed at a desired position.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a sheet processing apparatus that processes sheets.

  Conventionally, a sheet processing apparatus needs to accurately process a desired position on a sheet. As an example of the sheet process, there is a process of adding a line to the sheet. Patent Document 1 discloses a sheet processing apparatus for adding a streak. In this sheet processing apparatus, a line is attached to a sheet whose conveyance is stopped across the upstream rotating body pair and the downstream rotating body pair. The upstream rotating body pair and the downstream rotating body pair are arranged in order from the upstream side to the downstream side of the sheet conveyance path, and convey and stop common sheets. The upstream rotating body pair is configured to rotate following the sheet that is pulled when adding a line. As described above, the conventional sheet processing apparatus can accurately apply the streak to a predetermined position of the sheet as the upstream rotating body pair rotates following the sheet.

JP 2013-133189 A

  However, in the conventional sheet processing apparatus, when a plurality of processes are performed on the same sheet, a shift occurs in the processing position every time a processing operation is performed, and the shift is accumulated. There was a case where a large deviation occurred.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a sheet processing apparatus with little processing position deviation even when the same sheet is processed a plurality of times.

  The present invention solves the above-described problems by an upstream rotating body pair and a downstream rotating body pair that are arranged in order from the upstream side in the sheet conveying direction and convey a sheet, the upstream rotating body pair, and the downstream rotating body pair. A processing means for processing a portion of the sheet that is nipped between the upstream rotating body pair and the downstream rotating body pair, and the upstream rotating body pair and the downstream rotating Rotation allowing means for allowing one of the pair of rotating bodies to rotate in a direction pulled by the sheet by the sheet processing of the processing means, and the upstream rotating body pair is provided by the processing means. After carrying out the processing on the first position of the sheet, when transporting the sheet to perform the processing on the second position upstream of the first position of the sheet in the transport direction, Starts rotation after the downstream rotor pair It was solved by the sheet processing apparatus according to claim.

  The present invention solves the above-described problems by an upstream rotating body pair and a downstream rotating body pair that are arranged in order from the upstream side in the sheet conveying direction and convey a sheet, the upstream rotating body pair, and the downstream rotating body pair. Processing means for processing a portion of the sheet sandwiched between the upstream rotating body pair and the downstream rotating body pair, and the upstream rotating body pair and the downstream rotating body. A rotation permitting means for allowing one of the pair of rotating bodies to rotate in a direction pulled by the sheet by the sheet processing of the processing means, and the upstream rotating body pair is a sheet by the processing means. When the sheet is conveyed so as to be subjected to the second position upstream of the first position of the sheet in the conveying direction after the process is performed on the first position, The sheet conveyance speed is slower than the pair of downstream rotating bodies. Substantially start rotating simultaneously with said downstream rotator pair so was resolved by the sheet processing apparatus characterized by.

  The present invention has an effect that even if the same sheet is processed a plurality of times, there is little shift in processing position.

1 is a schematic cross-sectional view along the sheet conveyance direction of an image forming system including a puncher as a sheet processing apparatus according to an embodiment of the present invention. FIG. 2 is a block diagram illustrating a configuration of a control unit that controls the image forming system. It is a cross-sectional schematic diagram along the sheet conveying direction of the puncher. FIG. 3 is a schematic view of the puncher creasing unit of FIG. 1 as viewed from the upstream side in the sheet conveyance direction to the downstream side. It is a control flowchart of the puncher of FIG. It is a figure for operation | movement explanation of a creasing unit. It is a control block diagram of a puncher control unit.

  Hereinafter, a puncher as a sheet processing apparatus according to an embodiment of the present invention and an image forming system including the puncher will be described with reference to the drawings. FIG. 1 is a schematic cross-sectional view along the sheet conveying direction of an image forming system 1 including a puncher 200 as a sheet processing apparatus according to an embodiment of the present invention.

(Image forming system 1)
In FIG. 1, an image forming system 1 is formed by an image forming apparatus 600 that forms a monochrome or color image on a sheet, a puncher 200 connected thereto, a finisher 100 connected thereto, and the like. The sheet P discharged from the main body 600A of the image forming apparatus 600 is processed by the puncher 200 and the finisher 100 connected online to the main body 600A.

  The image forming apparatus 600 includes a main body 600A, an operation unit 601, an image reading device 650, and the like. The main body 600A of the image forming apparatus 600 forms an image on a sheet based on reading information from the image reading apparatus 650 or image information transmitted from an external personal computer PC 620 (FIG. 2). The operation unit 601 is provided on the upper part of the main body 600 </ b> A of the image forming apparatus 600, and is a part where a user inputs information necessary for image formation and sheet processing to the image forming system 1. The image reading device 650 is provided on the upper part of the main body 600A of the image forming apparatus, reads a document, and transmits read information of the read document to the main body 600A. The image forming apparatus 600 can be used alone without being connected to the finisher 100. Further, the puncher 200 and the finisher 100 may be integrated into the main body 600A of the image forming apparatus 600 as a sheet discharging apparatus.

  The puncher 200 and the finisher 100 are connected in series to the side portion of the image forming apparatus 600. Inside the main body 600A of the image forming apparatus 600, sheet cassettes 909a and 909b that store sheets P are provided. The sheet P is sent out from the sheet cassettes 909a and 909b, and toner images of four colors of yellow, magenta, cyan, and black are transferred by the photosensitive drums 914a to 914d. Each of the photosensitive drums 914a to 914d constitutes an image forming unit that forms a toner image on the sheet P. After that, the sheet is conveyed to the fixing device 904 to fix the toner image, and in the single-sided image forming mode, the sheet is sent as it is from the discharge roller 907 to the puncher 200 through the discharge port 9.

  In the double-sided image forming mode, the sheet P is transferred from the fixing device 904 to the pair of reverse rollers 905. Then, when the rear end of the transport direction passes through the reverse flapper 3, the sheet P is transported back by the reverse rotation of the reverse roller pair 905 and is transported to the duplex transport roller pairs 906a to 906f. The sheet is turned upside down during the switchback conveyance.

  The four-color toner images are transferred to the sheet P by the yellow, magenta, cyan, and black photosensitive drums 914a to 914d on the back side. The sheet P on which the toner images are transferred on both sides is conveyed again to the fixing device 904 and the toner image is fixed, and then sent to the puncher 200 from the discharge port 9 by the discharge roller 907.

(Control part)
FIG. 2 is a block diagram showing the configuration of the control unit 4 that controls the image forming system 1 (FIG. 1). 2, a CPU (Central Processing Unit) circuit unit 630 includes a CPU 629, a ROM (Read Only Memory) 631, and a RAM (Random Access Memory) 655.

  The CPU circuit unit 630 is connected to an image reading device control unit 632, an image reader control unit 633, an image signal control unit 634, a printer control unit 635, a finisher control unit 636, a puncher control unit 638, an operation unit 601, an external interface 637, and the like. These are exchanged with signals, and are controlled in accordance with the program stored in the ROM 631 and the setting of the operation unit 601. The RAM 655 is used as an area for temporarily storing control data and a work area for calculations associated with control.

  The image reading device controller 632 controls the image reading device 650 (FIG. 1). The image reader control unit 633 controls the image reader 5 (FIG. 1). The printer control unit 635 controls the image forming apparatus 600.

  An image read by the image reader 5 is output from the image reader control unit 633 to the image signal control unit 634. The image output from the image signal control unit 634 to the printer control unit 635 is input to an exposure control unit (not shown) that controls the laser scanner 10.

  The puncher control unit 638 is mounted on the puncher 200, and exchanges information with the CPU circuit unit 630 of the image forming system 1 to control driving of the entire puncher 200. FIG. 7 is a control block diagram of the puncher control unit 638. In FIG. 7, an inlet sensor S1, an upstream sheet detection sensor S2, a discharge sheet detection sensor S3, a protruding plate motor M1, an upstream motor M2, a registration auxiliary motor M3, a registration motor M4, a downstream motor M5, and the like are connected to the puncher control unit 638. Has been. The puncher control unit 638 includes a CPU 638A, a ROM 638B, and a RAM 638C. The CPU 638A is connected to the CPU circuit unit 630, exchanges signals therewith, and controls the program stored in the ROM 638B, that is, the puncher 200. The RAM 638C is used as an area for temporarily storing control data and a work area for operations associated with control.

  A finisher control unit 636 (FIGS. 1 and 2) is mounted on the finisher 100 and performs drive control of the entire finisher 100 by exchanging information with the CPU circuit unit 630 of the image forming system 1.

  The puncher control unit 638 and the finisher control unit 636 may be provided in the image forming apparatus 600 integrally with the CPU circuit unit 630 so as to control the puncher 200 and the finisher 100 from the image forming apparatus 600 side.

  The external interface 637 is an interface from a personal computer (PC) 620, and develops print data into an image and outputs the image to the image signal control unit 634.

(Pancha 200)
FIG. 3 is a schematic cross-sectional view of the puncher 200 along the sheet conveyance direction. The puncher 200 takes in the sheets P discharged from the discharge port 9 (FIG. 1) of the image forming apparatus 600 in order, and lines the sheet P by the creasing portion 8.

(Description of schematic operation of the puncher 200)
The puncher 200 performs a creasing operation on the sheet in accordance with a user setting by the operation unit 601 provided in the image forming apparatus 600. The sheet P discharged from the discharge port 9 of the image forming apparatus 600 is delivered to the conveyance roller pair 202 provided at the inlet 12 of the puncher 200. At this time, the delivery timing of the sheet P is simultaneously detected by the entrance sensor S1.

  The sheet P is conveyed to the creasing portion 8 by the conveyance roller pairs 208, 209, and 210 and the registration auxiliary roller pair 211. The conveyance roller pair 208, 209, 210 is rotated by the upstream motor M2. The registration auxiliary roller pair 211 is rotated by a registration auxiliary motor M3. Then, the registration roller pair 250 temporarily receives the leading edge of the sheet in a rotation stopped state and corrects the skew posture of the sheet P to be straight, and then rotates by the registration motor M4 to convey the sheet. Then, when the registration roller pair 250 stops the sheet P at a predetermined position in the sheet conveyance direction, the creasing unit 300 for scoring the sheet P is activated, and the sheet P is streaked. The sheet P that has been scored by the scoring unit 300 is again nipped and conveyed by the registration roller pair 250, conveyed by the registration roller pair 250, the conveyance roller pairs 214, 215, 216, and 206, and is sent to the downstream finisher 100. Delivered. The delivery of the sheet is detected by the discharged sheet detection sensor S3. The conveyance roller pairs 214, 215, 216, 206 are rotated by a downstream motor M5.

(Screase unit (crease unit) 300)
The scoring unit 300 is arranged in order from the upstream side of the sheet conveyance path 6 and serves as a registration auxiliary roller pair 211 as an upstream rotation body pair capable of conveying and stopping conveyance of a common sheet P, and a downstream rotation body pair. Between the pair of registration rollers 250. The registration auxiliary roller pair 211 is formed by a driving roller 211a and a driven roller 211b. The registration roller pair 250 is also formed by a driving roller 250a and a driven roller 250b.

  The sheet conveyance path 6 is formed by upper and lower guide walls (not shown). A portion between the registration auxiliary roller pair 211 on the upstream side of the guide wall and the registration roller pair 250 on the downstream side is interrupted so that a creasing blade 304 described later can cross. In the downstream portion of the interrupted portion of the sheet conveyance path 6, a space AR is formed so that a loop of the sheet P for skew correction can be formed.

  Near the registration auxiliary roller pair 211, an upstream sheet detection sensor S2 for detecting the leading edge of the sheet and controlling the rotation of the registration roller pair 250 and the registration auxiliary roller pair 211 is provided. The upstream sheet detection sensor S2 is shielded by a shielding piece of a flag (not shown) that is pushed by the leading end of the sheet P and rotates. Alternatively, it may be a sensor that detects blocking when the sheet P passes.

  The creasing unit 300 serving as a processing unit is provided at a portion of the sheet sandwiched between the registration auxiliary roller pair 211 and the registration roller pair 250 and stopped between the registration auxiliary roller pair 211 and the registration roller pair 250. A sheet processing for adding a line is performed.

  As shown in FIG. 6, the creasing unit 300 is capable of adding a streak to the sheet P a plurality of times by repeating a scoring job at one location or a scoring job. The sheet P with the streaks can be accurately bent based on the streaks regardless of the thickness of the sheet P.

  A one-way rotation clutch (one-way clutch) C is provided between the driving roller 211a of the registration auxiliary roller pair 211 and the registration auxiliary motor M3 that is a driving source of the registration auxiliary roller pair 211. The one-way rotation clutch C as the rotation permitting means allows the drive roller 211a to rotate counterclockwise in the direction (leftward in FIG. 3) that is pulled by the sheet by the creasing sheet processing of the creasing unit 300. Yes.

  FIG. 4 is a schematic view of the creasing unit 300 of the puncher 200 of FIG. 1 as viewed from the upstream side in the sheet conveyance direction. 3 and 4, the creasing unit 300 is arranged across the sheet conveyance path 6 and in a direction perpendicular to the sheet conveyance direction. The creasing unit 300 includes a creasing blade 304, a die plate 305, a cam 282, a pinion 281 and a protruding plate motor M1.

  The die plate 305 is formed with a creasing groove 306. Shaft guides 307 a and 307 b are provided upright on the die plate 305. A movable plate 301 and a blade plate 303 are provided on the shaft guides 307a and 307b so as to be movable up and down. The scoring blade 304 is provided downward on the lower portion 303a of the blade plate 303, and a sheet is sandwiched between the scoring grooves 306 so that the sheet P is streaked. The scoring blade 304 forms a gap G between the scoring groove 306 and allows the sheet P to pass except when the sheet is streaked.

  The pressing springs 302a, 302b, and 302c are provided between the movable plate 301 and the blade plate 303. The movable plate 301 moves up and down with shaft guides 307a and 307b as guides.

  The release springs 308a and 308b are springs that push back the pushed blade plate 303 up. The top dead center of the blade plate 303 is a position where it is received by stoppers 309a and 309b provided at intermediate portions of the shaft guides 307a and 307b. The top dead center of the movable plate 301 is a position in contact with stoppers 310a and 310b provided at the upper ends of the shaft guides 307a and 307b.

  The cam 282 (FIG. 3) is rotated by the rotation of the protruding plate motor M1 that is rotated by the control of the puncher control unit 638 (FIG. 2). When the cam 282 rotates, as shown in FIG. 6D, which will be described later, the movable plate 301 is pushed down, and the blade plate 303 is moved through the pressing springs 302a, 302b, 302c and against the release springs 308a, 308b. Press down. The scoring blade 304 scores the sheet P with the scoring groove 306 sandwiching the sheet P therebetween.

  FIG. 5 is a control flowchart of the puncher 200 of FIG. This control flowchart is assumed to be stored in advance in the ROM 638B of FIG. FIG. 6 is a diagram for explaining the operation of the scoring unit 300.

  The user inputs the basis weight of the sheet to the operation unit 601 (S101). When the user presses a start button (not shown) of the operation unit 601, the CPU circuit unit 630 starts the image forming system 1 (S102). The image forming apparatus 600 starts conveying the sheet and forms an image on the sheet (S103). The sheet on which the image is formed is detected by the entrance sensor S1 of the puncher 200 (S104). Then, the puncher control unit 638 determines the sheet conveyance distance necessary to form a loop on the sheet by abutting the leading edge of the sheet against the registration roller pair 250 according to the basis weight of the sheet input in step S101. Calculate (S105). Then, when the upstream sheet detection sensor S2 detects the leading edge of the sheet, the puncher control unit 638 conveys the sheet conveyance distance necessary for forming a loop on the sheet (FIG. 6A). At this time, the registration motor M4 stops rotating. For this reason, the registration roller pair 250 stops rotating.

  The sheet P continues to be conveyed by the registration auxiliary roller pair 211 that continues to rotate, and is pressed against the nip of the registration roller pair 250 that has stopped rotating, thereby skewing the sheet P by bending the sheet. If so, it is corrected straight. (S106, S107, FIG. 6B)

  At this time, according to the basis weight of the sheet P input in advance, the distance to which the sheet is sent by being abutted against the registration roller pair 250 is determined. That is, the soft sheet with a small thickness is pressed against the registration roller pair 250 by increasing the feeding amount so that the skew is corrected. On the other hand, if the thick and hard sheet is fed in the same way as the thin sheet P, the registration auxiliary roller pair 211 slips and scratches the sheet P, or the sheet is received at the nip of the registration roller pair 250. Since it is lost, the feed amount is reduced and it is corrected. That is, the rotation stop time of the registration roller pair 250 is set longer as the sheet thickness is thinner.

  Thereafter, the sheet P is started to be conveyed by the registration roller pair 250 (S108). When conveyance of the sheet is started by the registration roller pair 250, the puncher control unit 638 stops the rotation of the registration auxiliary motor M3 (S109). The registration auxiliary roller pair 211 is connected between a registration auxiliary motor M3 and a one-way rotation clutch (one-way clutch) C so that the registration auxiliary roller pair 211 can rotate in the transport direction without receiving the rotational force of the registration auxiliary motor M3. . For this reason, the registration auxiliary roller pair 211 is pulled by the sheet conveyed by the registration roller pair 250 and rotates following the sheet. At this time, the above-described bending for skew correction disappears, and the sheet P is conveyed in a stretched state between the registration roller pair 250 and the registration auxiliary roller pair 211 (S110, FIG. 6C). .

  When the sheet P reaches the creasing position, the puncher control unit 638 stops the rotation of the registration motor M4 and stops the rotation of the registration roller pair 250. Accordingly, the rotation of the registration auxiliary roller pair 211 is also stopped, and the conveyance of the sheet P is stopped (S111). The puncher control unit 638 starts the projecting plate motor M1, rotates the cam 282 as shown in FIG. 6D, presses the scoring blade 304 against the sheet surface, and the scoring blade 304 and the scoring groove 306 A streak is made at the first creasing position of the sheet P (S112).

  As the sheet is scored, it is pulled by the scoring blade 304. Therefore, the registration auxiliary roller pair 211 receives a tensile force in the sheet conveying direction from the sheet, and the registration roller pair 250 receives a tensile force in the direction opposite to the sheet conveying direction from the sheet. However, since the one-way rotation clutch is provided in the registration auxiliary roller pair 211, the registration auxiliary roller pair 211 receives the tensile force of the sheet, rotates following the sheet, and rotates in the sheet conveyance direction. For this reason, the registration roller pair 250 does not rotate. As a result, a streak can be accurately applied to the position of the distance conveyed by the registration roller pair 250.

  Note that when the creasing to the sheet P is performed a plurality of times, the sheet P contracts by the first creasing. Due to the contraction of the sheet P, the second and subsequent creasing may not be formed at a predetermined position on the sheet. Therefore, it will be described next that the puncher 200 of the present embodiment is configured such that even if the creasing to the sheet P is performed a plurality of times, the creasing position is hardly distorted.

  The puncher control unit 638 sends the sheet as shown in FIG. 6E, and determines whether or not to add another streak to the sheet P (S113). When the puncher control unit 638 adds another line to the sheet P (YES in S113), the puncher control unit 638 uses the registration roller pair 250 to start the second registration roller pair 250 from the start (S108) to the second position. Transport (S114, S115). Then, the registration auxiliary roller pair 211 is also rotated by the registration auxiliary motor M3 and conveys a common sheet together with the registration roller pair 250.

  At this time, in order to prevent the sheet from bending and an error in the second scoring position, the puncher control unit 638 sets the rotation start timing of the registration auxiliary roller pair 211 from the start of rotation of the registration roller pair 250. Slightly delayed so that the sheet is properly tensioned. Note that even if the rotation start timing of the registration auxiliary roller pair 211 is slightly delayed and the sheet is pulled by the registration roller pair 250 and excessively tensioned, the one-way rotation clutch C provided on the registration auxiliary roller pair 211 is provided. As a result, the registration auxiliary roller pair 211 rotates following the pulling of the sheet, so that the excessive tension of the sheet is immediately eliminated.

  Thereafter, the registration roller pair 250 is again stopped by the information from the puncher control unit 638 (S116), and the sheet P is scored by the creasing blade 304 as shown in FIG. 6F (S117).

  Furthermore, when adding a line (YES in S118), the puncher control unit 638 again proceeds to the process S114. If no streak is made (NO in S113), the puncher control unit 638 rotates the registration auxiliary roller pair 211 and the registration roller pair 250 to convey the sheet (S119), and the scoring position is a scoring position. The section 8 is passed (S120), and the creasing is finished (S121). Thereafter, the puncher control unit 638 determines whether there is a next job (S122). If there is a next job (NO in S122), the process returns to step S102. If there is no next job (YES in S122), the puncher control unit 638 stops the registration auxiliary motor M3 to stop the registration auxiliary roller pair 211, and stops the registration motor M4 to stop the registration roller pair 250 ( S123). This completes the scoring job for a series of sheets.

  In the processes S114 and S115 described above, the puncher control unit 638 prevents the sheet from being bent and an error occurs in the second scoring position. The sheet is provided with an appropriate tension slightly after the start of rotation of the registration roller pair 250. However, the rotation start timing of the registration auxiliary roller pair 211 may be substantially the same as the rotation start timing of the registration roller pair 250. In this case, the puncher control unit 638 controls the registration auxiliary motor M3 so that the sheet conveyance speed of the registration auxiliary roller pair 211 is slower than the sheet conveyance speed of the registration roller pair 250 so that the sheet has an appropriate tension. To. Even in this case, even if the sheet is pulled too much by the registration roller pair 250, the registration auxiliary roller pair 211 is pulled by the one-way rotation clutch C provided in the registration auxiliary roller pair 211. Since it rotates following, the excessive tension of the sheet is immediately eliminated.

  In the above description, the streak is set on the basis of the front end of the sheet, but the streak may be set on the basis of the rear end of the sheet.

  Further, in the puncher 200, the sheet is creased by the creasing unit 300. However, instead of the creasing unit 300, a punching unit may be provided so as to perforate the sheet. Even in this case, a plurality of holes can be accurately formed in the sheet.

  As described above, the puncher (sheet processing apparatus) 200 performs sheet processing on the first position of the sheet by the creasing unit (processing means) 300 and then transports the sheet in the conveyance direction more than the first position of the sheet. When conveying a sheet to perform sheet processing on the second upstream position, the registration auxiliary roller pair (upstream rotating body pair) 211 rotates after the registration roller pair (downstream rotating body pair) 250. Therefore, even if sheet processing is performed multiple times on the same sheet, sheet processing position deviation is reduced and sheet processing is performed. It can be performed at a desired position.

  In addition, the puncher 200 performs the creasing process on the first position of the sheet by the creasing unit 300, and then performs the sheet process on the second position upstream in the transport direction from the first position of the sheet. When conveying the sheet to be applied, the registration auxiliary roller pair 211 may start rotating substantially simultaneously with the registration roller pair 250 so that the sheet conveyance speed is slower than the registration roller pair 250. In addition, the sheet can be provided with an appropriate tension, and even when the same sheet is processed a plurality of times, the sheet processing position can be reduced and the sheet processing can be formed at a desired position. .

  Further, since the rotation stop time of the registration roller pair 250 is set longer as the sheet thickness is thinner, the puncher 200 can perform sheet processing corresponding to the sheet thickness.

  P: sheet, C: one-way rotation clutch (rotation permitting means), S1: inlet sensor, S2: upstream sheet detection sensor, S3: discharged sheet detection sensor, M1: thrust plate motor, M2: upstream motor, M3: registration auxiliary motor , M4: registration motor, M5: downstream motor, 1: image forming system, 8: creasing section, 100: finisher, 200: puncher (sheet processing device), 211: registration auxiliary roller pair (upstream rotating body pair), 250: registration roller pair (upstream rotating body pair), 282: cam, 300: creasing unit (processing means), 304: creasing blade, 600: image forming apparatus, 650: image reading apparatus, 638: puncher control section .

Claims (4)

An upstream rotating body pair and a downstream rotating body pair that are arranged in order from the upstream side in the sheet conveying direction and convey the sheet;
Processing for processing a portion of the sheet sandwiched between the upstream rotating body pair and the downstream rotating body pair and stopped to be conveyed between the upstream rotating body pair and the downstream rotating body pair. Means,
Rotation allowing means for allowing one of the upstream rotating body pair and the downstream rotating body pair to rotate in a direction pulled by the sheet by the sheet processing of the processing means, and
The upstream rotating body pair performs the processing on the first position of the sheet by the processing means, and then performs the processing on the second position upstream in the transport direction from the first position of the sheet. When conveying the sheet to be processed, rotation is started after the downstream rotating body pair,
A sheet processing apparatus. An upstream rotating body pair and a downstream rotating body pair that are arranged in order from the upstream side in the sheet conveying direction and convey the sheet;
Processing means for processing a portion of the sheet sandwiched between the upstream rotating body pair and the downstream rotating body pair and stopped to be conveyed between the upstream rotating body pair and the downstream rotating body pair. When,
Rotation allowing means for allowing one of the upstream rotating body pair and the downstream rotating body pair to rotate in a direction pulled by the sheet by the sheet processing of the processing means, and
The upstream rotating body pair performs the processing on the first position of the sheet by the processing means, and then performs the processing on the second position upstream in the transport direction from the first position of the sheet. When conveying the sheet to be processed, rotation is started substantially simultaneously with the downstream rotating body pair so that the sheet conveying speed is slower than the downstream rotating body pair.
A sheet processing apparatus. The one rotating body pair is the upstream rotating body pair, and the rotation permitting means is a one-way clutch.
The sheet processing apparatus according to claim 1, wherein the sheet processing apparatus is a sheet processing apparatus. The downstream rotating body pair is a registration roller that receives the leading edge of the sheet conveyed by the upstream rotating body pair once in a rotation stopped state and corrects the skew of the sheet, and then rotates to convey the sheet. Is a pair,
The rotation stop time of the registration roller pair is longer as the sheet thickness is thinner.
The sheet processing apparatus according to claim 1, wherein the sheet processing apparatus is a sheet processing apparatus.

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