JP2017105594A - Sheet conveyance device and image processing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sheet conveyance device capable of suppressing an occurrence of wrinkles in a sheet member during discharging the sheet member from a sheet discharge port, and an image processing device provided with the sheet conveyance device.SOLUTION: A sheet conveyance device 60 includes four discharge roller pairs 25 arranged separately from each other. A discharge roller pair 25 includes a drive roller 25A and a driven roller 25B arranged so as to face each other. The driven roller 25B is energized to a drive roller 25A side by an elastic member 97. Driven rollers 25B1, 25B4 located outside with respect to a width direction of a vertical conveyance path 26 are energized to the drive roller 25A side by energization force smaller than in driven rollers 25B2, 25B3 located inside.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a sheet conveying apparatus, and more particularly to a sheet conveying apparatus that discharges a sheet member from a sheet discharge port to the outside, and an image processing apparatus including the sheet conveying apparatus.

  In general, an image processing apparatus such as a copying machine or a printer is provided with a seating member that seats and discharges printing paper (sheet member) on which an image is formed (see Patent Document 1). The waist of the printing paper indicates resistance when a force in the bending direction is applied to the printing paper, and is also referred to as “stiffness” or “rigidity”.

  When the printing paper is ejected while being sandwiched between the pair of ejection rollers, the seating member presses and curves the printing paper downward or above the nip portion of the ejection roller pair. This increases the strength of the printing paper.

JP 2010-143211 A

  However, when the printing paper is bent by the seating member, the end in the width direction of the printing paper is drawn inward, and thus there is a possibility that the printing paper is wrinkled.

  The present invention has been made in view of the circumstances described above, and an object of the present invention is to provide a sheet conveying device capable of suppressing the occurrence of wrinkles in the sheet member when the sheet member is discharged from the sheet discharge port, and An object of the present invention is to provide an image processing apparatus provided with this.

  A sheet conveying apparatus according to one aspect of the present invention includes three or more discharge roller pairs, a roller driving unit, an urging unit, and a seating member. The three or more discharge roller pairs have a driving roller and a driven roller arranged so as to face each other across a discharge path reaching a sheet discharge port, and sandwich the sheet member conveyed in the discharge path Discharge from the sheet discharge port to the outside. The three or more discharge roller pairs are spaced apart from each other in the width direction of the discharge path that intersects the discharge direction of the sheet. The roller driving unit rotationally drives the driving roller. The urging unit urges the driven roller toward the driving roller. The seating member seats the sheet member conveyed through the ejection path between two adjacent ejection roller pairs of the plurality of ejection roller pairs. The urging portion urges the driven roller positioned relatively outside in the width direction toward the driving roller with a urging force smaller than the driven roller positioned relatively inside.

  An image processing apparatus according to another aspect of the present invention includes an image forming unit that forms an image on a sheet member, and the sheet conveying apparatus.

  According to the present invention, it is possible to suppress wrinkling of the sheet member when the sheet member is discharged from the sheet discharge port.

FIG. 1 is a perspective view showing an image processing apparatus according to an embodiment of the present invention. FIG. 2 is a schematic diagram showing an internal configuration of the image processing apparatus of FIG. is there. FIG. 3 is a perspective view illustrating the sheet conveying apparatus. FIG. 4 is a perspective view showing a conveyance guide of the sheet conveying apparatus of FIG. FIG. 5 is a perspective view illustrating a conveyance guide of the sheet conveying apparatus in FIG. 3. FIG. 6 is a schematic diagram illustrating a configuration of a discharge roller pair included in the sheet conveying device of FIG. 3.

  Hereinafter, a sheet conveying apparatus 60 according to an embodiment of the present disclosure and an image processing apparatus 10 including the sheet conveying apparatus 60 will be described with reference to the drawings. For convenience of explanation, the vertical direction of the state where the image processing apparatus 10 is installed on a flat surface (the state shown in FIG. 1) is defined as the up and down direction 6. Further, the front-rear direction 7 is defined with the surface on which the operation display panel 17 is provided as the front surface (front surface). Further, a left-right direction 8 is defined with reference to the front of the image processing apparatus 10. In addition, embodiment described below is only an example which actualized this invention, and does not limit the technical scope of this invention.

  First, a schematic configuration of the image processing apparatus 10 will be described with reference to FIGS. 1 and 2. As shown in FIG. 1, the image processing apparatus 10 is a so-called in-body discharge type multifunction peripheral, and includes various functions such as a printer, a copier, a FAX apparatus, and a scanner. The image processing apparatus 10 forms an image of the input image on a printing paper P (an example of a sheet member of the present invention) using a printing material such as toner. Note that the image processing apparatus 10 is not limited to a multifunction machine, and the present invention can be applied to a dedicated machine such as a printer, a copying machine, a FAX apparatus, or a scanner having an ADF 13.

  The image processing apparatus 10 includes an image reading unit 12 and an image forming unit 14. The image reading unit 12 performs processing for reading an image of a document, and is provided on the upper portion of the image processing apparatus 10. The image forming unit 14 performs processing for forming an image based on the electrophotographic method, and is provided below the image reading unit 12. The image forming unit 14 includes two paper feeding devices 27 and 28 arranged in two upper and lower stages. The upper sheet feeder 27 is provided integrally with the housing 29 at the lowermost part of the image forming unit 14. The lower sheet feeding device 28 is of an extension type connected as an optional device to the bottom surface of the casing 29 of the image forming unit 14. The paper feeding device 28 is configured to be detachable from the bottom surface of the housing 29. A paper discharge unit 30 is provided on the right side of the image forming unit 14. The image forming unit 14 is not limited to an electrophotographic type, and may be an inkjet recording type, or may be a recording method or printing method other than that.

  A paper discharge space 21 for discharging the printing paper P is provided above the image forming unit 14. The paper discharge unit 30 is provided so as to connect the image forming unit 14 and the image reading unit 12 while forming a paper discharge space 21 between the image forming unit 14 and the image reading unit 12. As shown in FIG. 1, the front side and the left side of the paper discharge space 21 are open. Further, the rear side and the right side of the paper discharge space 21 are not opened, the rear side is closed, and a paper discharge unit 30 is provided on the right side. In the paper discharge space 21, a paper discharge tray 21A for holding the discharged printing paper P is provided.

  As shown in FIG. 1, the image reading unit 12 includes a document table 23. When the image processing apparatus 10 functions as a copying machine, a copy is instructed from the operation display panel 17 after a document is set on the document table 23 and the document cover 24 is closed. Thereby, the reading operation by the image reading unit 12 is started, and the image data of the document is read. Then, the read image data is sent to the image forming unit 14. In FIG. 1, the document cover 24 (see FIG. 2) of the image reading unit 12 is not shown.

  As shown in FIG. 2, the image reading unit 12 includes an ADF 13. The ADF 13 is an automatic document feeder, and transports the document set on the document tray 45 to the paper discharge unit 49 through the reading position 43 on the document table 23.

  The image forming unit 14 forms an image on a printing paper P having a predetermined size such as an A size or a B size based on image data read by the image reading unit 12 or image data input from the outside. In the present embodiment, the image forming unit 14 forms a single-sided printing process (single-sided image forming process) that forms an image on only one side of the printing paper P in accordance with a preset printing mode (single-sided printing mode or double-sided printing mode). Or a double-sided printing process (double-sided image forming process) for forming images on both sides of the printing paper P. When the single-sided printing process is performed, the image forming unit 14 discharges the printing paper P on which the image is formed on one side to the paper discharge tray 21 </ b> A of the paper discharge space 21. On the other hand, when the double-sided printing process is performed, the image forming unit 14 switches back the printing paper P on which the image is formed on one side and then sends it to the reverse conveyance path 39 to form the image on the back side of the printing paper P again. Thereafter, the printing paper P on which images are formed on both sides is discharged to the paper discharge tray 21 </ b> A of the paper discharge space 21.

  As shown in FIG. 2, the image forming unit 14 mainly controls the paper feeding devices 27 and 28, the electrophotographic image transfer unit 18, the fixing unit 19, the sheet conveying device 60, and the image forming unit 14. And a control unit (not shown). The image forming unit 14 includes a transport motor and a discharge motor (both not shown). The discharging motor is an example of the roller driving unit of the present invention.

  The paper feeding devices 27 and 28 convey the printing paper P toward the image transfer unit 18.

  As shown in FIG. 2, in the image forming unit 14, a vertical conveyance path 26 is formed upward from the paper feeding devices 27 and 28. A section from the exit of the fixing unit 19 to the sheet discharge port 37 (an example of the sheet discharge port of the present invention) in the vertical conveyance path 26 is an example of the discharge path of the present invention.

  The image transfer unit 18 performs an image transfer process on the printing paper P conveyed from the paper feeding devices 27 and 28. Specifically, the image transfer unit 18 transfers the toner image to the printing paper P using a printing material such as toner based on the input image data.

  The fixing unit 19 fixes the toner image transferred to the printing paper P onto the printing paper P by heat. The printing paper P that has been fixed is conveyed from the fixing unit 19 to the paper discharge port 37 along the vertical conveyance path 26.

  A sheet conveying device 60 is provided above the fixing unit 19. As shown in FIG. 3, the sheet conveying apparatus 60 includes a discharge roller pair 25 and a seating member 81.

  As shown in FIG. 2, a paper discharge port 37 through which the printing paper P is discharged is formed at the end of the vertical conveyance path 26. The sheet discharge port 37 is an opening that is long in the front-rear direction 7.

  The discharge roller pair 25 is provided in the vicinity of the paper discharge port 37. The discharge roller pair 25 is a pair of rollers configured by a drive roller 25A and a driven roller 25B that are in pressure contact with each other. The driving roller 25 </ b> A and the driven roller 25 </ b> B are arranged so as to face each other with the vertical conveyance path 26 interposed therebetween. The driving roller 25 </ b> A is rotatably supported by the conveyance guide 65. A gear 94 is fixed to the end of the rotation shaft 93 (see FIG. 6) of the driving roller 25A, and bidirectional rotational driving force from the discharging motor is transmitted to the driving roller 25A through the gear 94. . For this reason, the driving roller 25 </ b> A can rotate in the rotation direction according to the input rotational driving force. The driven roller 25B can rotate to the conveyance guide 64 while being movable in the contact / separation direction with respect to the driving roller 25A via a rotating shaft 98 (first to fourth rotating shafts 98A to 98D) that can swing in the vertical direction. Is pivotally supported. The driven roller 25B is urged toward the drive roller 25A via the rotating shaft 98 by an elastic member 97 (see FIG. 6) such as a coil spring. The elastic member 97 is an example of an urging portion of the present invention. Thereby, the driven roller 25B is always pressed against the surface of the driving roller 25A with an appropriate elastic biasing force. Therefore, when the driving roller 25A is rotationally driven, the driven roller 25B is also driven by contact friction.

  In the present embodiment, a plurality of discharge roller pairs 25 are provided at predetermined intervals along the front-rear direction 7 (corresponding to the width direction of the present invention). Specifically, as shown in FIGS. 3 to 5, the four discharge roller pairs 25 are based on the center in the width direction of the vertical conveyance path 26 (corresponding to the discharge path of the present invention) reaching the sheet discharge port 37. Are arranged symmetrically. Accordingly, four drive rollers 25A and four driven rollers 25B are provided. In FIG. 4, since the upper conveyance guide 65 is removed, the driving roller 25A is not shown in FIG. FIG. 5 is a perspective view showing the upper conveyance guide 65, and therefore the driven roller 25B is not shown in FIG.

  By controlling the rotation direction of the discharge motor, the four discharge roller pairs 25 sandwich the printing paper P at the nip portion that is a pressure contact between the driving roller 25A and the driven roller 25B and from the paper discharge port 37. The printing paper P is transported in either the discharge direction toward the paper discharge space 21 or the reverse direction toward the reverse transport path 39.

  When single-sided printing processing is performed in the image forming unit 14, the printing paper P on which the toner image is transferred on one side by the image transfer unit 18 passes through the fixing unit 19, and then passes through the vertical conveyance path 26 to four discharge rollers. Each of the pairs 25 is discharged from the paper discharge port 37 to the outside.

  On the other hand, when the double-sided printing process is performed in the image forming unit 14, the printing paper P on which an image is first formed on one side passes through the fixing unit 19, and then the leading end is exposed to the outside from the paper discharge port 37. In the state, the discharge roller pair 25 is stopped. At this time, the rear end of the printing paper P in the discharge direction is held in a state of being sandwiched by the discharge roller pair 25. Thereafter, the discharge roller pair 25 is rotated in the reverse rotation direction by the reverse rotation drive of the discharge motor. As a result, the printing paper P is reversely transported (switchback transport) along the vertical transport path 26 and enters the reverse transport path 39.

  As shown in FIG. 5, in the conveyance guide 65, a seating member 81 (that is, the seating members 81 </ b> A to 81 </ b> C) is provided between two adjacent drive rollers 25 </ b> A among the four drive rollers 25 </ b> A. ing. The waist member 81 seats the printing paper P by pressing the printing paper P in contact with the printing paper P conveyed through the vertical conveyance path 26. Specifically, in the front-rear direction 7, a seating member 81A is disposed between the first driving roller 25A from the front and the second driving roller 25A from the front, and the second driving roller 25A from the front A waisting member 81B is disposed between the third driving roller 25A from the front, and a waisting member 81C is disposed between the third driving roller 25A from the front and the fourth driving roller 25A from the front. Has been placed.

  When the waist members 81 </ b> A to 81 </ b> C impart waist to the printing paper P, the printing paper P is curved in a wave shape when viewed from the downstream side in the conveyance direction of the printing paper P (the front end side of the printing paper P).

  When the printing paper P on which the image is fixed by the fixing unit 19 is conveyed toward the paper discharge port 37 through the vertical conveyance path 26, the leading edge of the printing paper P is along the guide rib 78 and the nip of the discharge roller pair 25. Guided to the club. At this time, the leading edge of the printing paper P comes into contact with the waist member 81 on the upstream side in the transport direction from the nip portion. The leading edge of the printing paper P in contact with the waist member 81 advances to the nip portion of the discharge roller pair 25. Then, at the same time as the leading end is sandwiched between the discharge roller pair 25, the seating member 81 presses the printing paper P downward from the nip portion. As a result, the printing paper P is bent into a wave shape to give a strong waist.

  Note that, when the printing paper P is bent by the seating member 81, the end of the printing paper P in the width direction is drawn inward, and thus there is a possibility that the printing paper P is wrinkled. In the present embodiment, in order to suppress the generation of wrinkles, the elastic force of the elastic member 97 corresponding to the outer discharge roller pair 25 among the elastic members 97 corresponding to the four discharge roller pairs 25 is changed to the inner discharge roller. It is smaller than the elastic force of the elastic member 97 corresponding to the pair 25.

  Specifically, as shown in FIG. 6, in this embodiment, the driving roller 25A1, the driving roller 25A2, the driving roller 25A3, and the driving roller 25A4 are arranged at predetermined intervals, and are driven at positions facing them. A roller 25B1, a driven roller 25B2, a driven roller 25B3, and a driven roller 25B4 are arranged.

  The driven roller 25B1 is rotatably supported by the first rotating shaft 98A, the driven roller 25B2 is rotatably supported by the second rotating shaft 98B, and the driven roller 25B3 is rotated by the third rotating shaft 98C. The driven roller 25B4 is rotatably supported by the fourth rotating shaft 98D.

  The first rotation shaft 98A is supported by the conveyance guide 64 in a state in which the first rotation shaft 98A can move in the contact / separation direction with respect to the drive roller 25A1. The second rotating shaft 98B is supported by the roller mounting portion 64A of the transport guide 64 in a state in which the second rotating shaft 98B can move in the contact / separation direction with respect to the drive roller 25A2. The third rotation shaft 98C is supported by the conveyance guide 64 in a state in which the third rotation shaft 98C can move in the contact / separation direction with respect to the drive roller 25A3. The fourth rotation shaft 98D is supported by the conveyance guide 64 in a state in which the fourth rotation shaft 98D can move in the contact / separation direction with respect to the drive roller 25A4.

  An elastic member 97A is provided between the first rotating shaft 98A and the roller mounting portion 64A. The elastic member 97A biases the first rotating shaft 98A toward the drive roller 25A1. An elastic member 97B is provided between the second rotating shaft 98B and the roller mounting portion 64A. The elastic member 97B biases the second rotating shaft 98B toward the drive roller 25A2. An elastic member 97C is provided between the third rotating shaft 98C and the roller mounting portion 64A. The elastic member 97C biases the third rotating shaft 98C toward the driving roller 25A3. An elastic member 97D is provided between the fourth rotating shaft 98D and the roller mounting portion 64A. The elastic member 97D biases the fourth rotation shaft 98D toward the drive roller 25A4.

  In the present embodiment, among the four sets of elastic members 97A to 97D, the elastic force of the elastic member 97A and the elastic member 97D corresponding to the outer discharge roller pair 25 is the elastic member 97B corresponding to the inner discharge roller pair 25 and It is set smaller than the elastic force of the elastic member 97C. The elastic force of the elastic member 97A and the elastic force of the elastic member 97D are set to be the same, and the elastic force of the elastic member 97B and the elastic force of the elastic member 97C are set to be the same.

  As a result, among the four driven rollers 25B1 to 25B4, the driven roller 25B1 and the driven roller 25B4 positioned on the outer side are urged with a larger force than the driven roller 25B2 and the driven roller 25B3 positioned on the inner side. If it does so, the frictional force which arises in the nip part of the discharge roller pair 25 located outside among the four discharge roller pairs 25 will become weaker than the frictional force which arises in the nip part of the discharge roller pair 25 located inside.

  Here, as in the present embodiment, in the case where the printing paper P is seated by the seating member 81, when the undulation is formed on the printing paper P, both ends of the printing paper P are drawn toward the inside. As a result, the traveling direction of both ends of the printing paper P tends to be inward, and wrinkles are likely to occur. However, if the frictional force generated at the nip portion of the discharge roller pair 25 located on the outer side is made smaller than the frictional force generated at the nip portion of the discharge roller pair 25 positioned on the inner side as in this embodiment, printing is performed. Even if the traveling direction of both ends of the paper P is inward, the both ends of the printing paper P slide on the nip portion of the discharge roller pair 25 located outside before the printing paper P is wrinkled. Can be easily shifted outward. As a result, a large force that causes wrinkles does not act on the printing paper P, so that the generation of wrinkles can be suppressed. Such an effect is not limited to the case where the printing paper P is transported in the discharge direction, but can be obtained similarly when the printing paper P is transported in the reverse direction.

  As described above, according to the present embodiment, the occurrence of wrinkles can be suppressed both when the printing paper P is transported in the discharge direction and when it is transported in the reverse direction. In addition, according to the present embodiment, the elastic force of the elastic member 97A and the elastic member 97D located on the outside is reduced by a simple configuration in which the elastic force of the elastic member 97B and the elastic member 97C located on the inside is made smaller. Can be suppressed.

  Further, in the above-described embodiment, the four sheet discharge roller pairs 25 are provided in the sheet conveying device 60, but the present invention is not limited to this. When at least three or more discharge roller pairs 25 are provided, the driven roller positioned relatively outside is biased toward the driving roller with a biasing force smaller than the driven roller positioned relatively inside. Thus, the same operation and effect as the above-described embodiment can be obtained.

  In the above-described embodiment, the configuration capable of transporting in the reverse direction is illustrated, but the present invention is not limited to this, and the present invention can also be applied to configurations that cannot be transported in the reverse direction.

  In the above-described embodiment, the sheet conveying device 60 that discharges the printing paper P from the image forming unit 14 has been described. However, the present invention is not limited to this. For example, in the ADF 13, the present invention can be applied to a mechanism in which a document is discharged to the paper discharge unit 49 by the transport roller.

DESCRIPTION OF SYMBOLS 10 Image forming apparatus 25 Discharge roller pair 25A1-25A4 Drive roller 25B1-25B4 Follower roller 37 Paper discharge port 60 Sheet conveyance apparatus 64 Conveyance guide 65 Conveyance guide 81A-81C Seating member 97A-97D Elastic member

Claims (5)

A driving roller and a driven roller arranged so as to face each other across a discharge path leading to a sheet discharge port, and sandwiching a sheet member conveyed through the discharge path and discharging the sheet from the sheet discharge port to the outside; At least three or more discharge roller pairs disposed apart from each other in the width direction of the discharge path intersecting the discharge direction of the sheet;
A roller drive unit that rotationally drives the drive roller;
A biasing portion that biases the driven roller toward the drive roller;
A seating member that sits on a sheet member conveyed through the discharge path between two adjacent discharge roller pairs of the plurality of discharge roller pairs;
The urging unit is a sheet conveying device that urges the driven roller positioned relatively outside in the width direction to the drive roller side with a smaller urging force than the driven roller positioned relatively inside. The biasing portion includes a plurality of elastic members provided corresponding to each of the driven rollers,
The elastic force of the elastic member corresponding to the driven roller positioned relatively outside in the width direction is smaller than the elastic force of the elastic member corresponding to the driven roller positioned relatively inside. The sheet conveying apparatus according to 1.   The sheet conveying apparatus according to claim 1, wherein the discharge roller pair is disposed symmetrically with respect to a center in the width direction.   The sheet conveying device according to claim 1, wherein the roller driving unit is capable of driving the driving roller to rotate forward and reversely. An image forming unit for forming an image on a sheet member;
An image processing apparatus comprising: the sheet conveying apparatus according to claim 1.