JP2007070036A - Sheet conveying device, sheet processing device, and image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reliably correct any skew without damaging a fore-end of a paper sheet. <P>SOLUTION: When a conveying path for connecting a conveying path T3 for guiding a paper sheet to a punching device P to a conveying path T1 on the upstream side thereof is constituted of a conveying path R2 having the curvature, a correction roller 9 is provided on the conveying path R2 having this curvature or immediately behind a point at which the curvature of the conveying path R2 is ended, and a space A for forming a deflected portion formed when a fore-end of a paper sheet is butted to the correction roller 9 during the skew correction is formed on the conveying path other than the conveying path R2 having the curvature, i.e., on the conveying path R1 in the present embodiment. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a conveying device that conveys a recording sheet, a sheet processing device that performs predetermined processing such as punching processing on a recording sheet conveyed by the conveying device, and a copier, printer, and facsimile including the sheet processing device The present invention relates to an image forming apparatus such as a digital multifunction peripheral.

  In this type of apparatus, it is necessary to surely correct the skew. If the skew is not reliably corrected, the punching position is shifted, or a plurality of punching positions are located on the end of the recording sheet (hereinafter referred to as paper). Tilting and lowering the drilling quality.

  Therefore, for example, in Patent Document 1, a registration sensor is provided in a conveyance path on the downstream side of the registration roller for the purpose of providing a sheet post-processing apparatus including a cover feeder that can correct skew. A bent portion inside the turn portion on the downstream side is formed in a flat shape by the guide plate, and a space is formed between the bent portion on the outside and a punch unit is provided in the immediate vicinity of the inlet roller downstream in the sheet conveying direction. If there is a punching instruction from the image forming apparatus side on the conveyed image-formed paper and the cover sheet sent from the cover feeder, the punching process is executed. A paper post-processing apparatus is described which is stopped at the nip and bent in the space portion so that skew correction is performed.

  Japanese Patent Application Laid-Open No. 2004-228688 punches a sheet from an image forming apparatus with a punch unit for the purpose of providing a sheet processing apparatus that has high quality and reliability and is advantageous in terms of cost by a simple mechanism. In the paper post-processing apparatus, the inlet roller pair positioned at the uppermost stream of the punch unit can be controlled on / off independently of the driving limit of other paper conveying means such as the first conveying roller pair by an inlet (drive) motor. Only the inlet (drive) motor that is used for punching processing is turned off so that the leading edge of the paper is brought into contact with the nip portion of the pair of inlet rollers, and the paper skew is caused by the paper conveying force from the remaining paper conveying means. A paper post-processing device that corrects the image is described.

In each of these conventional techniques, a space in which the sheet bends is provided on the upstream side of the roller that abuts the leading end of the sheet.
JP 2002-274699 A JP 2002-160848 A

  However, as shown in FIG. 6, the correction roller 9 is provided on the linear conveyance path R <b> 1 upstream of the punching device P in the processing path 22, and the front end of the sheet is positioned at the nip of the correction roller 9 at the time of skew correction upstream of the correction roller 9. 7A and 7B, even when a space for creating a bend that can be made when abutting against the paper is provided, the moment when the leading edge of the paper S abuts against the correction roller 9 as shown in FIGS. Therefore, the sheet S tries to bend excessively. In that case, a sound is generated from the sheet S at the moment when the sheet can be bent, and an excessive force is applied to the leading end of the sheet, so that the leading end of the sheet may be damaged depending on the shape of the correction roller 9.

  Further, as shown in FIG. 8, the correction roller 9 is provided on the linear conveyance path R3 that guides the paper to the punching device P, and a space that creates a deflection when the front end of the paper abuts against the nip of the correction roller 9 during skew correction. Is provided on a conveyance path R2 having a curvature (hereinafter also referred to as a curved portion) R2, depending on the direction of curl generated on the conveyed paper S, as shown in FIGS. 9 (a), 9 (b), and 9 (c). As shown, the sheet S may be conveyed while being swollen when passing through the curved conveyance path R2. If the sheet is conveyed while being swelled as described above, it is not possible to sufficiently produce the deflection generated at the time of skew correction, and the skew of the paper S cannot be completely corrected.

  Further, when the skew correction of the conveyed paper S is performed, the leading edge of the paper is abutted against the nip of the correction roller 9, but the curl is generated at the leading edge of the conveyed paper S as shown in FIG. If the curling direction is opposite to the turn direction of the conveying path R2 having the curvature in which the correction roller 9 is provided, the leading edge of the sheet enters the nip of the correction roller 9 as shown in FIG. Before the sheet enters, a portion other than the leading edge of the sheet S may come into contact with the correction roller 9 and the leading edge of the sheet cannot enter the nip of the correction roller 9 in some cases. In such a case, the skew of the paper S cannot be completely corrected.

  The present invention has been made in view of such a state of the prior art, and an object thereof is to make it possible to surely perform skew correction without damaging the front end of the paper.

  In order to achieve the above object, the first means is a sheet conveying apparatus that conveys a recording sheet along a sheet conveying path having a curved portion in part, wherein the skew correcting means for correcting the skew of the recording sheet is the curved portion. It is provided in the part.

  The second means is a sheet conveying apparatus for conveying a recording sheet along a sheet conveying path having a curved portion in part, and a skew correcting means for correcting a skew of the recording sheet is provided immediately after the curved portion forming portion. It is characterized by.

  The third means is that in the first or second means, the skew correction means is bent on the sheet conveyance path when the recording sheet is bent by a correction roller and a nip of the correction roller. The space is provided in a portion other than the curved portion on the upstream side in the recording sheet conveyance direction from the correction roller installation portion.

  The fourth means is characterized in that, in the third means, a portion other than the bending portion is a linear portion of the sheet conveying path.

  The fifth means is characterized in that, in the third means, the upstream side of the correction roller installation portion of the curved portion where the correction roller is installed is formed in a linear shape.

  The sixth means is characterized in that, in the fifth means, the gap dimension of the conveyance path formed in the linear shape is smaller than the gap dimension other than the conveyance path.

  The seventh means includes a sheet conveying apparatus according to any one of the first to sixth means, and a sheet processing means provided at a linear portion downstream or upstream in the recording sheet conveying direction of the skew correcting means. A processing apparatus is provided.

  An eighth means is the seventh means, wherein the sheet processing means is a punch hole punching device.

  A ninth means is characterized in that the image forming apparatus includes a sheet conveying apparatus according to any one of the first to sixth means.

  A tenth means is characterized in that the image forming apparatus includes a sheet processing apparatus according to the seventh or eighth means.

  In the embodiment described later, the recording sheet is on the sheet S, the skew correction unit is on the correction roller 9 and the deflection forming space A, the curved portion is on the conveyance paths R2 and R4, and the linear portion of the sheet conveyance path is the conveyance path. In R1, R3, the linear shape corresponds to SA, the punch hole punching device corresponds to punching device P, the sheet conveying device corresponds to reference numeral 15, the paper post-processing device corresponds to reference numeral 2, and the image forming apparatus corresponds to reference numeral 1.

  According to the present invention, it is possible to prevent the sheet from being bent in the bending forming space during the conveyance, regardless of the direction of the curl generated on the sheet being conveyed, thereby scratching the leading edge of the sheet. It is possible to reliably perform skew correction without any problem.

  Embodiments of the present invention will be described below with reference to the drawings.

<First Embodiment>
FIG. 1 is a diagram showing a system configuration of an image forming apparatus according to the first embodiment of the present invention. For example, as shown in FIG. 1, the sheet processing apparatus is used as one system that is connected to the subsequent stage of the image forming apparatus 1 such as a copying machine and integrated with the image forming apparatus. Since it is a sheet, it is also called a sheet post-processing apparatus. Hereinafter, the sheet post-processing apparatus will be described. In this example, the sheet post-processing apparatus 2 includes two conveyance paths, that is, a path 21 that leads to the subsequent stage without performing any processing, and a processing path 22 that performs predetermined processing, here punching processing (punch hole punching processing). A sheet conveying device 15 is provided. The sheet output from the image forming apparatus 1 is transported to the post-processing apparatus 2 and is transported downstream along the path 21 by transport rollers 3, 4, and 5 when punch hole punching is not performed. When punching holes, the sheet conveyed by the conveying roller 3 is deflected downward by the switching claw T and conveyed along the processing path 22 by the conveying rollers 6, 7, and 8. In the processing path 22, the front end of the sheet is abutted against the nip of the correction roller 9 and the skew is corrected, and then conveyed by the correction roller 9, and the punching device P performs the punching process. Then, after the punching process is completed, the sheet S is transported downstream along the processing path 22 by the transport rollers 10, 11, 12, 13, and 5.

  In this embodiment, when the conveyance path connecting the conveyance path R3 that guides the sheet to the punching device P and the conveyance path R1 upstream thereof is constituted by a conveyance path (curved portion) R2 having a curvature, it is shown in FIG. As described above, the correction roller 9 is provided on the conveyance path R2 having this curvature (on the curved portion) or immediately after the point at which the curvature of the conveyance path R2 ends (immediately after the curved portion), and the front end of the sheet is corrected when the skew is corrected. A space A that creates a bent portion when it is abutted against is provided on a conveyance path other than the conveyance path R2 having a curvature, in this embodiment, a linear conveyance path R1. With this arrangement, it is possible to prevent the sheet from being bent in the bending forming space A during the conveyance, regardless of the direction of the curl generated on the sheet being conveyed. Also, since the sheet always bends in the direction of the turn of the transport path R2 at the moment when the leading edge of the sheet hits the correction roller 9, an excessive butting force is not applied in the transport direction of the sheet S. It is also possible to prevent damage at the leading edge of the paper and sound generated when the paper S hits the correction roller 9.

<Second Embodiment>
FIG. 1 shows an example in which the skew correction of the paper S is performed on the upstream side of the punching device P, but the skew correction of the paper S can also be performed on the downstream side of the punching device P. This example is shown in FIG. 2 as a second embodiment.

  In the second embodiment, the conveyance roller 10 in the first embodiment functions as a correction roller. When the conveyance path that connects the linear conveyance path R3 that guides the sheet to the punching device P and the conveyance path R5 downstream of the linear conveyance path R3 is configured as a conveyance path R4 having a curvature (a conveyance path having a curved portion), a correction roller 10 is provided on the conveyance path R4 (FIG. 2) having this curvature or immediately after the point at which the curvature of the conveyance path R4 ends, and a bent portion formed when the leading edge of the sheet is abutted against the correction roller 10 during skew correction. The space A to be created is provided on a conveyance path other than the conveyance path R4 having a curvature, in this embodiment, on the conveyance path R3. The other parts are configured in the same way as in the first embodiment described above and function in the same way, so redundant description will be omitted.

  By configuring in this way, the same effect as in the first embodiment can be obtained.

<Third Embodiment>
This embodiment is a modified example of the conveyance path R2 having a curvature, and FIG. 3 is a diagram showing a main part of the conveyance path R2 of this embodiment.
When skew correction is performed on the sheet S being conveyed, the leading edge of the sheet abuts against the nip of the correction roller 9. In this modification, the shape of the conveyance path R <b> 2 has a curvature that guides the sheet S to the nip of the correction roller 9. Is a linear shape SA from the nip of the conveying roller 9 to the upstream portion as shown in FIG. When the linear shape SA is used in this manner, even when curl is generated in the paper S, the curl is extended and the curl is reduced, so that it is easy to enter the nip of the correction roller 9. As a result, even if the curl size of the conveyed paper S is large, the leading edge of the paper abuts against the nip of the correction roller 9, and the skew correction can be surely performed.

  Other parts that are not particularly described are configured in the same manner as the first embodiment described above and function in the same manner, and thus redundant description is omitted.

<Fourth Embodiment>
This embodiment is a further modification of the third embodiment, and FIG. 4 is a diagram showing a main part of the transport path R2 of this embodiment.
In the fourth embodiment, as shown in FIG. 4, the distance d1 between conveyances of the conveyance path having a linear shape SA upstream of the nip of the correction roller 9 is made narrower than the distance d2 between conveyances of other conveyance paths. is there. In this way, if the inter-conveyance distance d1 immediately before the correction roller 9 is reduced, the effect of further extending the curl at the front end of the paper is increased, and the shape is advantageous for skew correction.

  Other parts that are not particularly described are configured in the same manner as the first and third embodiments described above and function in the same manner, and thus redundant description is omitted.

  FIG. 5 is a flowchart showing an example of a processing procedure when the punching process is performed by the sheet post-processing apparatus 2 having the configuration shown in FIG. In this processing procedure, when punch hole punching processing is performed (step S1-YES), the branch claw T is rotated from the initial position when the leading edge of the sheet is detected by the entrance sensor s1 (step S2). The paper S is guided to the processing path 22 side by opening the side. In parallel with this, the transport rollers 6, 7, and 8 are rotated to transport the paper S along the processing path 22 (step S3). When the leading edge of the sheet S conveyed through the processing path 22 is detected by the sheet detection sensor s2 (step S4), the conveying roller 8 immediately before the correction roller 9 is rotated by a certain amount of rotation and then stopped to correct the leading edge of the sheet. Skew correction is performed by contacting the nip of the roller 9 and bending it by a certain amount (step S5). Next, the correction rollers 8 and 10 and the correction roller 9 are rotated (step S6), and when the paper detection sensor s2 detects the rear edge of the paper (step S7), the conveyance roller 10 is rotated by a certain amount and then stopped (step S8). ). A punching hole is punched at a predetermined position on the rear end side of the paper by the punching device P (step S9), and the paper S is transported by rotating the transport rollers 10, 11, 12, 13 and 5 (step S10). When the trailing edge of the sheet is detected by the sheet sensor s3 (step S11), the process is finished.

  When punching processing is not performed (step S1-NO), the conveying rollers 3, 4, and 5 are rotated (step S13) with the branch claw T held at the initial position (step S13), and the paper is discharged. When the sensor s3 detects the trailing edge of the sheet (step S14), the process ends.

  In the above-described embodiment, the correction roller 9 is provided in the paper post-processing apparatus 2. However, in the case where the paper conveyance path having such a configuration is provided integrally with the image forming apparatus 1 or in the same housing. The sheet conveying apparatus is installed in the image forming apparatus 1.

As described above, according to the above-described embodiment,
(1) By defining the position of the correction roller on the conveyance path having a curvature (curved portion of the conveyance path), it is possible to reasonably form the bending that occurs during skew correction regardless of the curl that has occurred on the paper. In addition, it is possible to prevent scratches at the front end of the paper.
(2) By providing a space in which the sheet bends in a conveyance path (straight conveyance path) other than the conveyance path having a curvature, the curl generated on the conveyed sheet is in any direction during the conveyance. It is possible to prevent the sheet from being bent in the bending forming space.
(3) Since the shape of the conveyance path 2 having a curvature for guiding the sheet to the nip of the correction roller is linear from the nip of the conveyance roller to the upstream portion, even if the sheet is curled, the curl is extended. Since the curl is reduced, it is possible to easily enter the nip of the correction roller. This makes it possible to perform skew correction by reliably abutting the leading edge of the sheet against the correction roller nip regardless of any curl generated on the sheet.
There are effects such as.

1 is a diagram illustrating a system configuration of an image forming apparatus according to a first embodiment of the present invention. FIG. 3 is a diagram illustrating a system configuration of an image forming apparatus according to a second embodiment of the present invention. It is a figure which shows the system configuration | structure of the image forming apparatus which concerns on the 3rd Embodiment of this invention. It is a figure which shows the system configuration | structure of the image forming apparatus which concerns on the 4th Embodiment of this invention. It is a flowchart which shows the process sequence of the paper post-processing apparatus in the 1st Embodiment of this invention. FIG. 10 is a diagram illustrating a schematic configuration of a part of a correction roller of a paper post-processing apparatus according to a conventional example. It is a figure which shows the relationship with the paper contact | abutted to the nip of the correction roller in FIG. It is a figure which shows the shape of a conveyance path when the bending space formation part in a prior art example is provided on the conveyance path with a curvature. It is a figure which shows the state of the bending of the paper conveyed by the conveyance path of FIG. It is a figure which shows the relationship between the paper front end in a prior art example, and the nip part of a correction roller.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 2 Paper post-processing apparatus 9 Correction roller 15 Sheet conveying apparatus A Deflection forming space P Punching apparatus S Paper SA Linear shape R1, R3 Linear conveying path R2, R4 Conveying path (curved part of conveying path) )

Claims (10)

In a sheet conveying apparatus that conveys a recording sheet along a sheet conveying path having a curved portion in part,
A sheet conveying apparatus, wherein a skew correcting means for correcting a skew of the recording sheet is provided in the bending portion. In a sheet conveying apparatus that conveys a recording sheet along a sheet conveying path having a curved portion in part,
A sheet conveying apparatus, wherein skew correcting means for correcting a skew of a recording sheet is provided immediately after the curved portion forming portion. The skew correction means comprises a correction roller and a space that creates the deflection on the sheet conveyance path when the recording sheet abuts on the nip of the correction roller and bends,
3. The sheet conveying apparatus according to claim 1, wherein the space is provided in a portion other than the curved portion on the upstream side in the recording sheet conveying direction from the correction roller installation portion.   The sheet conveying apparatus according to claim 3, wherein a portion other than the curved portion is a linear portion of the sheet conveying path.   4. The sheet conveying apparatus according to claim 3, wherein an upstream side of the correction roller installation portion of the curved portion where the correction roller is installed is formed in a linear shape.   6. The sheet conveying apparatus according to claim 5, wherein a gap dimension of the conveyance path formed in the linear shape is smaller than a gap dimension other than the conveyance path. A sheet conveying apparatus according to any one of claims 1 to 6,
A sheet processing means provided in a straight line portion downstream or upstream of the recording sheet conveyance direction of the skew correction means;
A sheet processing apparatus comprising:   8. The sheet processing apparatus according to claim 7, wherein the sheet processing means is a punch hole punching apparatus.   An image forming apparatus comprising the sheet conveying device according to claim 1. An image forming apparatus comprising the sheet processing apparatus according to claim 7.

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