JP6520794B2 - Sheet conveying apparatus and image processing apparatus - Google Patents

Description

  The present invention relates to a sheet conveying apparatus for conveying a sheet member, and in particular, a sheet conveying apparatus configured such that two rotating bodies separated in a sheet conveying direction contact the sheet member during sheet conveyance, and an image processing including the same It relates to the device.

  An image reading apparatus is mounted on an image forming apparatus such as a copying machine or a printer which forms an image on a sheet by electrophotography. As an image reading apparatus, one provided with a document cover integrally provided with an automatic document feeder (ADF: Auto Document Feeder) is known. Inside the automatic document feeder, a feeding roller for feeding a document sheet placed on a document tray to an inner conveyance path, and a conveyance roller for further feeding a document sheet conveyed by the feeding roller to an inner conveyance path Is provided.

  Also, as an example of a conventional automatic document feeder, the feeding roller is provided at the center in the width direction, and the conveyance rollers are provided at respective positions outside the feeding roller in the width direction. The configuration is known (see Patent Document 1).

JP 2008-280179 A

  However, in the conventional automatic document feeder, the sheet roller is pulled by the conveyance roller on the downstream side because the feed roller and the plurality of conveyance rollers contact and convey one document sheet. As a result, the document sheet may be bent. For example, when a document sheet is pulled in an oblique direction toward each of the transport rollers outside in the width direction from the feed roller, the document sheet is widthwise outer than a straight line connecting the feed roller and the transport roller outside in the width direction. Flex as the part hangs down. When the document sheet is conveyed by the plurality of conveyance rollers on the downstream side in the state where the document sheet is bent, the document sheet may be wrinkled.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a sheet conveying apparatus capable of preventing formation of wrinkles on a sheet member at the time of conveyance by reducing a deflection generated in the sheet member in the process of conveying a sheet member such as a document sheet. An object of the present invention is to provide an image processing apparatus.

  A sheet transport apparatus according to one aspect of the present invention includes a first transport unit, a second transport unit, a transport guide pair, and a plurality of guide ribs. The first conveyance unit includes a first rotating body that conveys the sheet member in a predetermined sheet conveyance direction. The second conveyance unit includes at least two second rotating bodies arranged in a width direction intersecting the sheet conveyance direction, and the sheet member conveyed from the first conveyance unit in the sheet conveyance direction Transport downstream. The conveyance guide pair is disposed to face each other to form a sheet conveyance path from the first conveyance unit to the second conveyance unit. The plurality of guide ribs are provided on the guide surface of at least one of the conveyance guides of the conveyance guide pair so as to be separated in the width direction, and extend along the sheet conveyance direction. Among the plurality of guide ribs, a first guide rib provided on the center side in the width direction with respect to each of the second rotating bodies and disposed at a position near the second rotating body is more than other second guide ribs. The protruding height with respect to the guide surface is high.

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

  According to the present invention, it is possible to prevent the formation of wrinkles on the sheet member at the time of conveyance by reducing the bending that occurs on the sheet member in the process of conveying the sheet member such as the original sheet.

FIG. 1 is a view showing the configuration of an image forming apparatus and an image reading apparatus according to an embodiment of the present invention. FIG. 2 is a diagram showing the configuration of the image reading apparatus. FIG. 3 is a view showing the configuration of a feeding mechanism provided in the automatic document feeder. FIG. 4 is a perspective view showing a configuration of a first lower conveyance guide provided in the automatic document feeder. FIG. 5A is a view showing the configuration of the first guide rib provided in the second lower conveyance guide, and FIG. 5B is a view showing the configuration of the second guide rib provided in the second lower conveyance guide. FIG. 6 is a view showing a relationship between the first guide rib and the second guide rib in the second lower conveyance guide.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings as appropriate. Note that the embodiment described below is only an example embodying the present invention, and the embodiment of the present invention can be appropriately modified without departing from the scope of the present invention.

  The configurations of an image forming apparatus 10 (an example of the image processing apparatus of the present invention) and an image reading apparatus 20 (an example of the image processing apparatus of the present invention) according to the embodiment of the present invention will be described with reference to FIGS. Do. In the following description, the vertical direction 6 is defined on the basis of the state where the image forming apparatus 10 is installed on a flat floor surface (the state shown in FIG. 1). Further, the front-rear direction 7 is defined with the surface on the near side with respect to the paper surface of FIG. 1 as the front (front) of the image forming apparatus 10. Further, when viewing the image forming apparatus 10 of FIG. 1 from the front side, the left and right direction 8 (direction perpendicular to the sheet of FIG. 1) is defined. Further, in the present specification, the downstream side in the sheet conveying direction and the downstream side in the original conveying direction are simply referred to as “downstream side”, and the upstream side in the sheet conveying direction and the upstream side in the original conveying direction are simply referred to. It may be called "upstream side".

  As shown in FIG. 1, the image forming apparatus 10 includes an image reading device 20, an image forming unit 30 (an example of an image processing unit according to the present invention), an operation display unit (not shown), a sheet feeding device 40, and a pair of conveying rollers. 46 and a control unit (not shown) for controlling them. The transport roller pair 46 is an example of the second transport unit of the present invention. Although the image reading apparatus 20 is illustrated as an embodiment of the present invention in the present embodiment, the present invention is not limited to this, and the present invention is realized as a printer, a facsimile apparatus, and a copying machine including the image reading apparatus 20. It may be

  The sheet feeding device 40 conveys a printing sheet (an example of a sheet member of the present invention) toward the image forming unit 30. The sheet feeding device 40 includes a tray-shaped sheet storage portion 41 and a sheet feeding mechanism 42. The feeding mechanism 42 is an example of the first transport unit of the present invention. Print sheets on which an image is formed by the image forming unit 30 are stacked in the sheet storage unit 41. The feeding mechanism 42 picks up and transports the print sheets stored in the sheet storage unit 41 one by one. The feeding mechanism 42 is provided on the upper side of the right end of the sheet storage unit 41. The feeding mechanism 42 is provided at the center of the housing 30A in the front-rear direction 7.

  The feeding mechanism 42 includes a pickup roller 43 and a sheet feeding roller pair 44 formed of a pair of rotating members (rotating rollers). The paper feed roller pair 44 includes a drive roller 44A (an example of a first rotating body of the present invention) which is rotationally driven in contact with a printing sheet, and a separation roller 44B which is pressed against and driven by the drive roller 44A. When an instruction (for example, a print execution instruction) for feeding a print sheet to the image forming apparatus 10 is input, a motor provided for conveyance is rotationally driven. Thereby, the pickup roller 43 and the sheet feeding roller pair 44 are rotated. Then, the print sheet is fed from the sheet storage unit 41 by the pickup roller 43, and the print sheet is conveyed by the sheet feed roller pair 44 in the sheet conveyance direction (sheet conveyance direction).

  The print sheet conveyed by the sheet feed roller pair 44 enters a sheet conveyance path 48 formed downstream of the drive roller 44A in the sheet conveyance direction. Thus, the print sheet is guided by the sheet conveyance path 48 in the sheet conveyance direction. A transport roller pair 46 composed of a pair of rotating bodies (rotating rollers) is provided downstream of the drive roller 44A in the sheet transport direction. The transport roller pair 46 has a drive roller 46A (an example of a second rotating body of the present invention) which is rotationally driven in contact with a printing sheet, and a rotation roller 46B which is pressed against and driven by the drive roller 46A. In the present embodiment, a plurality of conveyance roller pairs 46 are provided at predetermined intervals in the width direction orthogonal to the sheet conveyance direction. When the print execution instruction is input to the image forming apparatus 10, the conveyance roller pair 46 is rotated by the rotational driving force from the motor. Then, when the leading end of the print sheet reaches the nip portion of the transport roller pair 46, the print sheet is transported to the downstream side in the sheet transport direction while being nipped by the plurality of transport roller pairs 46.

  The image forming unit 30 forms an electrophotographic image (image processing) based on the image data read by the image reader 20 or a print job input from the information processing apparatus such as an external personal computer through communication. Run. Specifically, the image forming unit 30 performs an image forming process for forming an image on the printing sheet conveyed from the sheet storage unit 41 by the feeding mechanism 42. As shown in FIG. 1, the image forming unit 30 includes a photosensitive drum 31, a charging device 32, a developing device 33, a toner container 34, a transfer roller 35, a charge removing device 36, a fixing roller 37, a pressure roller 38, and laser scanning. A unit (LSU) 39, a housing 30A for containing them, and the like are provided. In the present embodiment, the electrophotographic image forming unit 30 is described as an example, but the image forming unit 30 is not limited to the electrophotographic type, and may be an inkjet recording type or other than that. The recording system or printing system may be used.

  The image reading apparatus 20 executes an image reading process of reading image data from a document. As shown in FIG. 1, the image reading device 20 is provided on the top of a housing 30 </ b> A of the image forming unit 30.

  As shown in FIG. 2, the image reading device 20 includes a contact glass 11, a reading unit 12 (an example of an image processing unit according to the present invention), mirrors 13 and 14, an optical lens 15, a CCD 16, and a housing for accommodating them. It has 20A and so on. The contact glass 11 is attached to the upper surface of the housing 20A, and the reading unit 12 and the like are provided inside the housing 20A. The image reading apparatus 20 further includes a document cover 22 attached to the housing 20A and an ADF (automatic document feeder) 21 provided on the document cover 22. The ADF 21 is an example of the sheet conveying apparatus of the present invention.

  The reading unit 12 includes an LED light source 121 and a mirror 122. The reading unit 12 is configured to be movable in the left-right direction 8 shown in FIG. 2 by a moving mechanism (not shown) using a motor such as a stepping motor. Then, when the reading unit 12 is moved in the left-right direction 8 by the motor, light emitted from the LED light source 121 toward the contact glass 11 is scanned in the left-right direction 8.

  When light is emitted from the LED light source 121, the mirror 122 reflects light reflected by the back surface (facing surface) of the document or document cover 22 toward the mirror 13 and reflects the light. The light reflected by the mirror 122 is guided to the optical lens 15 by the mirrors 13 and 14. The optical lens 15 condenses the incident light and causes the light to be incident on the CCD 16.

  The CCD 16 is a photoelectric conversion element that converts the received light into an electric signal (voltage) according to the amount of light (intensity of luminance) and outputs the electric signal to a control unit (not shown). The control unit generates image data of a document by image processing of the electric signal from the CCD 16. In the present embodiment, an example in which the CCD 16 is used as an imaging device will be described. However, instead of the reading mechanism using the CCD 16, a reading mechanism using a contact image sensor (CIS: Contact Image Sensor) can be applied. is there.

  As shown in FIG. 2, the ADF 21 is provided on the document cover 22. The ADF 21 conveys a document (an example of a sheet member of the present invention) to a predetermined reading position 12A described later. The ADF 21 includes a document tray 21A, a feeding mechanism 23, a pair of registration rollers 26, a pair of conveyance rollers 27, a document holder 28, a sheet discharge unit 21B, and the like. The feeding mechanism 23 is an example of the first transport unit of the present invention. The registration roller pair 26 is an example of the second conveyance unit of the present invention.

  The discharge unit 21B is provided on the top surface of the document cover 22, and the document tray 21A is disposed above the discharge unit 21B. The ADF 21 conveys a document along a curved document conveyance path 29 extending from the document tray 21A to the paper discharge unit 21B. The document conveyance passage 29 is a passage for conveying a document, and is a straight passage 29A extending generally horizontally from the document tray 21A to the left, a curved passage 29B bent downward from the straight passage 29A, and a curved passage And a discharge path 29C extending rightward from 29B to the paper discharge unit 21B. The straight path 29A is an example of the sheet conveyance path of the present invention.

  The feeding mechanism 23 is provided at the most upstream position in the document conveyance direction (sheet conveyance direction) in which the document is conveyed in the document conveyance path 29. The feeding mechanism 23 is provided at the center of the housing 20A in the width direction (front-rear direction 7) orthogonal to the document conveyance direction. On the other hand, a plurality of resist roller pairs 26 are provided to be aligned in the width direction.

  The feeding mechanism 23 has a feeding rotating body 24 (an example of a first rotating body of the present invention) and a separation roller 25 which is pressed against the feeding rotating body 24 and driven. The feed roller 24 includes a pickup roller 24A, a drive roller 24B, and a feed belt 24C. A drive roller 24B is provided downstream of the pickup roller 24A. The driving roller 24B is rotationally driven by receiving a rotational driving force from a motor. A feed belt 24C is provided to wind the drive roller 24B and the pickup roller 24A. Therefore, when the drive roller 24B is rotationally driven, the rotational drive force is transmitted to the feed belt 24C, and further, the rotational drive force is transmitted from the feed belt 24C to the pickup roller 24A, and the pickup roller 24A is rotated. Do.

  Pickup roller 24A conveys a document in the document conveyance direction by contacting and rotating the uppermost document among a plurality of documents placed on document tray 21A via feed belt 24C. The separation roller 25 is provided below the feed rotation body 24 and rotatably supported while being in pressure contact with the feed belt 24C. The feed belt 24C and the separation roller 25 separate the originals fed from the pickup roller 24A one by one, and further transport the originals in the original transport direction.

  On the downstream side of the drive roller 24B in the document conveyance path 29, a registration roller pair 26 including a pair of rotating bodies (rotating rollers) is provided. The registration roller pair 26 transports the document to the reading position 12A, and is brought into pressure contact with the driving roller 26A (an example of the second rotating body of the present invention) and the driving roller 26A which are rotationally driven in contact with the document. And a driven roller 26B to be driven. In the present embodiment, a plurality of resist roller pairs 26 are provided at predetermined intervals in the width direction orthogonal to the document conveyance direction.

  The driving roller 26A is rotationally driven by a motor (not shown), and is rotatably provided on the inner frame of the ADF 21 below the document conveyance path 29. The driven roller 26B is in pressure contact with the drive roller 26A. The driven roller 26B is rotatably provided above the drive roller 26A with the document conveyance path 29 interposed therebetween. When the drive roller 26A is rotationally driven, the driven roller 26B follows the rotation of the drive roller 26A.

  The registration roller pair 26 carries out skew correction (skew correction) on the document fed from the feeding mechanism 23, and then conveys the document further downstream. Specifically, skew correction is performed by pressing the front end of the document sent from the upstream side against the nip portion of the registration roller pair 26 while the rotation of the registration roller pair 26 is stopped. Then, when the time required for the skew correction elapses, the registration roller pair 26 is rotationally driven. As a result, the skew-corrected document is conveyed in the document conveyance direction. When a plurality of documents are sequentially and successively conveyed in ADF 21, skew correction for each document is performed by performing an intermittent drive operation in which registration roller pair 26 is repeatedly stopped and driven every time the documents are conveyed. It will be.

  A plurality of transport roller pairs 27 are appropriately disposed downstream of the registration roller pair 26. A plurality of documents set on the document tray 21A are sequentially conveyed one by one toward the reading position 12A on the contact glass 11 by the feeding mechanism 23 and the registration roller pair 26. Then, the document is transported by the transport roller pair 27 so as to pass through the reading position 12A, and is further transported to the paper discharge unit 21B.

  In the present embodiment, at the timing when the document is nipped and conveyed by the registration roller pair 26, the drive transmission path to the drive roller 24B of the feeding rotary member 24 is blocked. For example, an electromagnetic clutch is provided between the motor and the drive roller 24B, and the drive transmission path can be connected or disconnected by controlling the electromagnetic clutch. When the drive transmission path is shut off, the feed roller 24 can be idled. Even in the idleable state, sliding friction occurs between the rotation shaft of each of the pickup roller 24A, the drive roller 24B, and the separation roller 25 and the bearing. The sliding friction acts as a load in the rotational direction of the feed roller 24.

  The document conveyance path 29 has an opening exposed to the contact glass 11 side at the reading position 12A. A document holder 28 is disposed above the opening. The document passing through the reading position 12A is guided from the opening to the outside of the ADF 21 (upper surface of the contact glass 11) by the document holder 28 and slides on the contact glass 11 and passes the reading position 12A. It is again guided inside the ADF 21 from the opening. At this time, the image reading apparatus 20 causes the reading unit 12 to read the image on the surface of the document passing through the reading position 12A. Specifically, when the document is moved by the ADF 21, the reading unit 12 is disposed below the reading position 12A, and the image data of the document being moved is read by the reading unit 12 at the reading position 12A.

  As shown in FIG. 3, the straight path 29 A of the document conveyance path 29 is a conveyance path for guiding the document placed on the document tray 21 A to the nip portion of the registration roller pair 26. As described above, the straight path 29A is formed in a straight line extending generally horizontally in the left direction from the document tray 21A. The straight path 29A is a space (conveying space) formed by the plurality of conveyance guides 61 to 63 (the first lower conveyance guide 61, the second lower conveyance guide 62, and the upper conveyance guide 63).

  The upper conveyance guide 63 constitutes an upper guide surface of the straight path 29A, and is provided above the straight path 29A. The lower surface 63A of the upper conveyance guide 63 is an upper guide surface for guiding the document in the document conveyance direction in the upper conveyance guide 63. The driven roller 26B is rotatably supported by the upper conveyance guide 63. The first lower conveyance guide 61 and the second lower conveyance guide 62 constitute a lower guide surface of the straight path 29A, and are provided below the straight path 29A. The first lower conveyance guide 61 is integrally formed with a holder 51 rotatably supporting the separation roller 25, and extends from the holder 51 to the downstream side in the document conveyance direction. The upper conveyance guide 63 and the first lower conveyance guide 61 are disposed to face each other in the vertical direction 6 to form a conveyance space as an upstream portion (upstream straight line) of the straight line 29A. Be done.

  The second lower conveyance guide 62 (an example of the conveyance guide of the present invention and the lower conveyance guide) is separated from the end of the first lower conveyance guide 61 on the downstream side of the document conveyance direction with a gap therebetween. Is provided downstream of the The driving roller 26A is rotatably supported by the second lower conveyance guide 62. The second lower conveyance guide 62 has an inclined surface 62A and a flat surface 62B on its upper surface. The inclined surface 62A is continuous with the upstream end of the flat surface 62B in the document conveyance direction, and obliquely intersects the straight path 29A. The first lower conveyance guide 61 is provided so as to partially cover the inclined surface 62A. Therefore, a part of the inclined surface 62A and the flat surface 62B of the second lower conveyance guide 62 are exposed. A part of the inclined surface 62A and the flat surface 62B are lower guide surfaces for guiding the document to the downstream side in the document transport direction in the second lower transport guide 62. The upper conveyance guide 63 and the second lower conveyance guide 62 are disposed to face each other in the vertical direction 6 to form a conveyance space as a downstream portion (downstream straight line) of the straight line 29A. Be done. Here, the second lower conveyance guide 62 and the upper conveyance guide 63 are an example of a pair of conveyance guides of the present invention.

  As shown in FIG. 4, in the present embodiment, four drive rollers 26 </ b> A are rotatably supported by the second lower conveyance guide 62. Each driving roller 26A is attached to a rotating shaft 52 (see FIG. 3) extending in the width direction supported by the lower surface of the second lower conveyance guide 62. In the flat surface 62B of the second lower conveyance guide 62, four rectangular through openings 54 formed at predetermined intervals in the width direction are formed. The roller surface of the drive roller 26A is exposed to the flat surface 62B (guide surface of the straight path 29A) of the second lower conveyance guide 62 from each through opening 54. In other words, the drive roller 26A is provided on the second lower transport guide 62 so that the roller surface is exposed from the through opening 54 to the straight path 29A.

  By the way, like the ADF 21 described above, one feeding rotating body 24 is provided at the center in the width direction, and a plurality of resist roller pairs 26 are provided outside the feeding rotating body 24 in the width direction. In the configuration described above, the document is conveyed in a state in which the feed roller 24 and the plurality of registration roller pairs 26 are in contact with one document. In this case, for example, when a plurality of resist roller pairs 26 sandwich the downstream end of the document and the feed roller 24 contacts the center of the upstream end of the document, the conveyance force by the resist roller pair 26 The document is pulled in the document conveyance direction by the load due to the sliding friction applied to the feed roller 24. In this case, the document may be distorted. For example, when the document is pulled in an oblique direction from the feeding rotary body 24 toward each of the resist roller pairs 26 on the outer side in the width direction, a straight line connecting the feed rotary body 24 and the resist roller pair 26 on the outer side in the width direction. It bends so that the part of the outside of the cross direction hangs down more than the above. When the document is conveyed by the plurality of resist roller pairs 26 on the downstream side in the state where the document is bent, the document may be wrinkled.

  For this reason, in the present embodiment, the second lower side conveyance guide 62 is configured such that it is possible to prevent the formation of wrinkles on the document at the time of conveyance of the document by reducing the deflection generated on the document in the conveyance process of the document. The first guide rib 66 and the second guide rib 67 having different heights with respect to the flat surface 62B are provided.

  As shown in FIG. 4, each of the guide ribs 66 and 67 protrudes upward from the upper surface of the second lower conveyance guide 62, and is a narrow and long plate-like protrusion extending in the document conveyance direction. It is. In other words, the guide ribs 66 and 67 extend in the direction in which the document is guided by the second lower conveyance guide 62. The original is guided downstream by the guide ribs 66 and 67. The guide ribs 66 and 67 are integrally formed with the second lower conveyance guide 62.

  Specifically, the plurality of guide ribs 66 and 67 are provided on the upper surface of the second lower conveyance guide 62 so as to be separated in the width direction. The plurality of guide ribs 66 and 67 extend to the vicinity of the drive roller 26A along the document conveyance direction. In detail, the downstream edge portion 68A of the first guide rib 66 (an example of the first portion of the present invention) and the downstream edge portion 68B of the second guide rib 67 (an example of the second portion of the present invention) It extends downstream of the upstream edge 54A of the opening 54, but does not reach the center of the drive roller 26A. In the present embodiment, the guide ribs 66 and 67 extend downstream of the end edge 54A on the upstream side of the through opening 54 by a predetermined distance. Here, the edge portion 68A is a portion near the end portion on the downstream side in the first guide rib 66, and is a portion corresponding to the flat surface 62B in the first guide rib 66. In addition, the edge portion 68B is a portion near the end portion on the downstream side in the second guide rib 67, and is a portion corresponding to the flat surface 62B in the second guide rib 67. In the following, the edge portions 68A and 68B may be collectively referred to as an edge portion 68.

  Four first guide ribs 66 are formed on the upper surface of the second lower conveyance guide 62. Each first guide rib 66 is formed in the vicinity of the drive roller 26A1 located at the outermost side in the width direction among the four drive rollers 26A. The drive roller 26A1 is provided at a position spaced apart from the center in the width direction on the feed rotational body 24 in the width direction and at the outermost position in the width direction. The first guide rib 66 is formed at a position on the center side (inner side) in the width direction than the drive roller 26A1 in the width direction.

  The four first guide ribs 66 are roughly divided into two long ribs 66A and two short ribs 66B. One long rib 66A and one short rib 66B are provided as a set of guide ribs in the vicinity of each driving roller 26A1 on the flat surface 62B. Of the pair of guide ribs, the long rib 66A is formed along the inner edge 54B of the through opening 54 located on the outer side in the width direction. Further, the short ribs 66B are formed at a position spaced apart from the long ribs 66A by a predetermined distance on the center side (inside) in the width direction. The long rib 66A extends from the vicinity of the upstream edge 54A of the through opening 54 to the upstream side, extends the inclined surface 62A further to the upstream side, and reaches the upstream end of the inclined surface 62A. The short ribs 66B extend near the downstream end of the inclined surface 62A.

  In the present embodiment, the first guide rib 66 has an edge portion 68A on the downstream side (the drive roller 26A side) in a specific area A1 (an area surrounded by a broken line in FIG. 6) on the flat surface 62B shown in FIG. It is provided to be located. In other words, the edge portion 68A of the first guide rib 66 is provided on the center side (inner side) in the width direction than each of the drive rollers 26A1 and is disposed in the vicinity of the drive roller 26A1. The specific area A1 is an area including an intersection point P1 of two straight lines L1 and L2 and an edge line L3 in FIG. More specifically, the specific area A1 is a substantially rectangular area having straight lines L1 and L2 as diagonals, and is closer to the center in the width direction than the driving roller 26A1, and is more than the intermediate position P2 in FIG. It is an area defined on the side of the driving roller 26A1. Here, the intermediate position P2 is a position defined in the middle of the drive roller 26A1 and the drive roller 26A2 in the width direction. Further, straight lines L1 and L2 are straight lines connecting the axial center of the drive roller 24B of the feeding rotary member 24 and the axial center of the drive roller 26A1 positioned on the outermost side in the width direction (one-dot chain line in FIG. Is a straight line indicated by In addition, the edge line L3 is a straight line (straight line indicated by a dot-and-dash line in FIG. 6) extending in the width direction passing through the center of the edge portion 68 of the plurality of guide ribs 66 and 67 on the flat surface 62B. The central portion is a substantially central portion of the edge portion 68 in the document conveyance direction.

  Further, six second guide ribs 67 are formed on the flat surface 62B. The second guide rib 67 is formed in the vicinity of the drive roller 26A1 located at the outermost side in the width direction among the four drive rollers 26A. Specifically, the second guide rib 67 is formed on the outer side in the width direction than the drive roller 26A1, and more specifically, on the outer side in the width direction of the through opening 54 positioned on the outermost side in the width direction. It is formed at a position corresponding to the edge 54C. The second guide rib 67 is also formed in the vicinity of the two drive rollers 26A2 located inside in the width direction. Each of the six guide ribs 67 has the same shape and size, and extends upstream from a position corresponding to the edge portion 68A of the first guide rib 66 in the width direction, and reaches the upstream end of the inclined surface 62A.

  In addition to the guide ribs 66 and 67, a short rib 69 having a length in the document conveyance direction shorter than the guide ribs 66 and 67 is formed on the flat surface 62B. The short ribs 69 extend from the upstream edge 54A of each through opening 54 to the upstream side. Two short ribs 69 are formed on the flat surface 62B corresponding to each of the through openings 54, and a total of eight short ribs 69 are formed. The upstream ends of these short ribs 69 do not reach the inclined surface 62A.

  Further, as shown in FIG. 5, on the lower surface 63A of the upper conveyance guide 63, a plurality of guide ribs 70 extending in the document conveyance direction are formed. The plurality of guide ribs 70 are formed at positions opposed to the plurality of guide ribs 66 and 67. Each of the plurality of guide ribs 70 has the same shape and size, and the same projection length from the lower surface 63A. A plurality of guide ribs 70 guide the document downstream.

  In the present embodiment, as shown in FIGS. 5A and 5B, the first guide rib 66 is formed in a shape higher than the second guide rib 67 on the flat surface 62B. Here, FIG. 5A is a side view when the second guide rib 67 is viewed from the width direction. FIG. 5B is a side view when the first guide rib 66 is viewed from the width direction. More specifically, as shown in FIGS. 5A and 5B, the edge 68A of the first guide rib 66 has a height higher than the edge 68B of the second guide rib 67 with respect to the flat surface 62B. . Thus, a distance D10 (see FIG. 5B) vertically sandwiched by the edge portion 68A and the guide rib 70, and a gap D20 (see FIG. 5A) vertically sandwiched by the edge portion 68B and the guide rib 70. Of the former, the distance D10 is narrower. That is, the distance D10 formed by the edge portion 68A is narrower than the distance D20 formed by the edge portion 68B. Here, the interval D10 and the interval D20 are transport spaces in which the document is transported.

  Further, as shown in FIG. 5B, the edge portion 68A of the first guide rib 66 is spaced from the downstream end of the edge portion 68A to a predetermined position (upstream end of the edge portion 68A) spaced a predetermined distance upstream from the downstream end. It is formed in the shape which maintains D10 uniformly. Specifically, in the first guide rib 66, the edge 68A is formed to have substantially the same height (constant height) from the flat surface 62B up to the vicinity of the downstream end of the flat surface 62B. There is. As a result, the distance D10 from the edge portion 68A to the downstream end of the flat surface 62B becomes constant. In the present embodiment, the distance D10 is set to about 1.0 mm.

  On the other hand, as shown in FIG. 5A, the edge portion 68B of the second guide rib 67 is formed in such a shape as to gradually increase the distance D20 from the downstream end of the edge portion 68B toward the upstream side. Specifically, the second guide rib 67 is inclined downward toward the flat surface 62B from the edge portion 68B toward the upstream side, and is formed to be gradually lowered toward the upstream side. In other words, the edge portion 68B is formed to be inclined downward to the flat surface 62B so as to gradually widen the transport space of the straight path 29A formed by the edge portion 68B toward the upstream side. Thus, the distance D20 from the edge 68B to the downstream end of the flat surface 62B gradually increases. In the present embodiment, the distance D20 between the edge portion 68B and the guide rib 70 is set to about 3.0 mm, and the height D21 at the downstream end of the flat surface 62B is set to about 0.8 mm.

  As described above, in the present embodiment, the edge portion 68A of the first guide rib 66 is formed higher in height from the flat surface 62B than the edge portion 68B of the second guide rib 67. Therefore, in the flat surface 62B, the sizes in the vertical direction 6 of the intervals D10 and D20 formed by the guide ribs 66 and 67 are different. Specifically, the distance D10 is narrower than the distance D20. As a result, even if the above-described deflection occurs when the document is conveyed by the feed roller 24 and the registration roller pair 26, the portion where the deflection occurs passes through the narrow gap D10. When passing through the narrow portion, the bent portion is guided to the nip portion of the pair of resist rollers 26 without curling. As a result, when the sheet is nipped and conveyed by the registration roller pair 26, it is possible to prevent the formation of wrinkles on the document.

  In the above-described embodiment, the configuration in which the heights of the edge portions 68A and 68B of the guide ribs 66 and 67 are different in the second lower transport guide 62 is illustrated, but the present invention is not limited to this configuration. In the present invention, the heights of the guide ribs 66 and 67 formed on the second lower conveyance guide 62 are made uniform, and the protruding length of the guide rib 70 facing the guide rib 67 rather than the guide rib 70 facing the guide rib 66 The height of the guide 63 from the lower surface 63A may be increased. Even in this case, the distance D10 can be narrower than the distance D20. Further, by changing the height of each of the guide ribs 66, 67, 70, as a result, the distance D10 may be narrower than the distance D20.

  In the above-described embodiment, the ADF 21 is illustrated as an example of the present invention, but the present invention is not limited to this configuration. For example, according to the present invention, the image forming apparatus 10 is configured as a sheet conveying apparatus including the feeding mechanism 42 of the sheet feeding device 40, the conveyance roller pair 46, and the sheet conveying path 48 formed in the image forming apparatus 10. It may be In this case, the above-described guide ribs 66, 67, 70 are formed on a pair of conveyance guides arranged to sandwich the sheet conveyance path 48.

10: Image forming apparatus 20: Image reading apparatus 21: ADF
23: feeding mechanism 24: feeding rotating body 25: separation roller 61: first lower conveyance guide 62: second lower conveyance guide 63: upper conveyance guide 66: first guide rib 67: second guide rib 70: guide rib

Claims (6)

A first transport unit including a first rotating body configured to transport the sheet member in a predetermined sheet transport direction;
A second member that conveys the sheet member conveyed from the first conveyance section to the downstream side in the sheet conveyance direction, including at least two second rotating bodies arranged in a width direction intersecting the sheet conveyance direction; A transport unit,
A pair of conveyance guides that form sheet conveyance paths from the first conveyance unit to the second conveyance unit by being disposed to face each other;
A plurality of guide ribs provided in the width direction on the guide surface of at least one of the conveyance guides of the conveyance guide pair and extending along the sheet conveyance direction;
Among the plurality of guide ribs, a first guide rib provided on the center side in the width direction with respect to each of the second rotating bodies and disposed at a position near the second rotating body is more than other second guide ribs. projection height with respect to the guide surface rather high,
The guide surface of the one of the transport guides is a flat surface extending horizontally,
The one of the conveyance guides has an inclined surface which is continuous with the upstream end of the flat surface in the sheet conveyance direction and obliquely intersects the sheet conveyance path.
The plurality of guide ribs extend from the flat surface to the inclined surface,
The first portion corresponding to the flat surface in the first guide rib, the than the second portion corresponding to the flat surface at a second guide rib, protrusion height is high has a sheet conveying apparatus for said flat surface. The second rotating body is provided to the one conveyance guide such that an outer peripheral surface thereof is exposed to the sheet conveyance path from an opening formed in the one conveyance guide.
2. The sheet conveying apparatus according to claim 1 , wherein the first portion extends downstream of the edge on the upstream side of the sheet conveyance direction of the opening in the sheet conveyance direction. The first portion is formed at a constant height to a predetermined position spaced apart by a predetermined distance on the upstream side of the sheet conveyance direction.
The second site, wherein the conveying space in the sheet conveying path in the sheet conveyance direction according to claim 1 or 2 is formed on the inclined shape toward the flat surface so as to increase gradually toward the upstream side Sheet transport device. The sheet conveyance path extends horizontally from the first conveyance unit and reaches the second conveyance unit.
The conveyance guide pair has an upper conveyance guide having an upper guide surface of the sheet conveyance path, and a lower conveyance guide having a lower guide surface of the sheet conveyance path.
The sheet conveying apparatus according to any one of claims 1 to 3 , wherein the plurality of guide ribs are provided on the lower conveyance guide. The first rotating body is provided at a position corresponding to the center in the width direction in the sheet conveyance path,
The second rotating member is a position spaced outwardly from both ends of the width direction in the first rotating body, one of claims 1 is provided at a position outside the most the width direction 4 The sheet conveying device described in. A sheet conveying apparatus according to any one of claims 1 to 5 .
An image processing unit configured to perform image processing on a sheet member conveyed by the sheet conveyance device.

Images