JP2018002485A - Sheet conveyance device and image formation apparatus with the same - Google Patents

Abstract

CONSTITUTION: A sheet conveyance device 10 includes an external conveyance guide 74 and an internal conveyance guide 76 which form a sheet conveyance path S in an image formation apparatus 100. The external conveyance guide 74 has a first conveyance part 78 arranged in a curved area C of the sheet conveyance path S and a second conveyance part 80 arranged in a non-curved area L. Then the external conveyance guide 74 is so formed as to have larger area of contact with a sheet, conveyed in the sheet conveyance path S, per unit length in a sheet conveying direction at the first conveyance part 78 than at the second conveyance part 80.EFFECT: Since pressure of contact between a sheet and a conveyance guide in a curved area of a sheet conveyance path can be reduced, damage that the conveyance guide gives to the sheet can be reduced, and a defect in transfer and a defect in fixation of toner to the sheet can be prevented.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a paper transport device and an image forming apparatus including the same, and more particularly to a paper transport device including a transport guide that forms a paper transport path including a curved region and a non-curved region, and an image forming device including the same.

  2. Description of the Related Art Conventionally, a pair of conveyance guides that guide a sheet so as to sandwich the front and back surfaces of the sheet are provided in the sheet conveyance path of the image forming apparatus. The transport guide is provided with ribs suitable for each paper size in order to reduce the contact area with the paper and reduce the transport resistance acting on the paper. However, in the area where the paper conveyance path is curved (curved area), the paper is strongly pressed against the conveyance guide by the stiffness (rigidity or elasticity) of the paper. For this reason, damage to the paper due to the ribs increases, and rib-like streaks (rib marks) may be formed on the paper. There is a risk that toner transfer failure and fixing failure may occur in the paper portion damaged by the ribs.

  Therefore, in the technique of Patent Document 1, a part of the conveyance guide is a movable rib, and the movable rib is arranged on the same floating shaft as the guide roller, thereby reducing the damage the conveyance guide (rib) gives to the paper, Rib marks are prevented from being formed on the paper.

JP 2004-345746 A [B65H 5/06]

  However, when a moving mechanism is provided for the conveyance guide as in the movable rib of Patent Document 1, the configuration becomes complicated, which causes a problem in reducing the size or thickness of the paper conveyance device. Further, the movement of the movable rib makes it easy for the leading edge of the paper to be caught in the area connected to the movable rib, and the paper jam and the leading edge of the paper are likely to be broken. Thus, there are many obstacles in adopting a moving mechanism for a conveyance guide.

  SUMMARY OF THE INVENTION Therefore, a main object of the present invention is to provide a novel sheet conveying device and an image forming apparatus including the same.

  Another object of the present invention is to provide a sheet conveying apparatus and an image forming apparatus provided with the sheet conveying apparatus that can reduce damage to the sheet with a simple configuration and prevent toner transfer failure and fixing failure.

  The invention according to claim 1 is a paper transport device including a transport guide that forms a paper transport path. The transport guide includes a first transport unit and a second transport unit, and each of the first transport unit and the second transport unit. Has a plurality of ribs provided at predetermined intervals in a direction perpendicular to the paper transport direction and extending along the paper transport direction, and is formed in the second transport unit between the ribs formed in the first transport unit. According to another aspect of the present invention, there is provided a sheet conveying device characterized in that a shallow groove portion that is shallower than a groove portion between ribs is formed.

  According to a second aspect of the present invention, in the sheet conveying apparatus including a conveying guide that forms a sheet conveying path, the conveying guide includes a first conveying unit and a second conveying unit, and the second conveying unit is orthogonal to the sheet conveying direction. A plurality of ribs that are provided at predetermined intervals in the direction of the sheet and extend along the sheet conveyance direction, and the entire sheet guide surface of the first conveyance unit is a flat surface without ribs. It is a transport device.

  According to a third aspect of the present invention, there is provided a sheet conveying apparatus including a conveying guide that forms a sheet conveying path, wherein the conveying guide includes a first conveying unit and a second conveying unit, and each of the first conveying unit and the second conveying unit. Has a plurality of ribs provided at predetermined intervals in a direction perpendicular to the paper conveyance direction and extending along the paper conveyance direction, and ribs formed in the first conveyance unit in the direction perpendicular to the paper conveyance direction. The number of ribs formed in the second transport unit is larger than the number of ribs formed in the second transport unit.

  According to the invention of any one of claims 1 to 3, since the contact pressure between the sheet and the first transport unit can be reduced, damage to the sheet by the transport guide in the first transport unit can be reduced, and toner on the sheet can be reduced. Transfer failure and fixing failure can be prevented. In addition, since the contact area between the first conveyance unit of the conveyance guide and the sheet is larger than that of the second conveyance unit, the apparatus can be prevented from becoming large, and the conveyance failure of the sheet hardly occurs.

  According to a fourth aspect of the present invention, there is provided a paper conveyance device according to any one of the first to third aspects, wherein the first conveyance unit and the second conveyance unit are integrally formed.

  The invention of claim 5 is dependent on any one of the inventions of claims 1 to 4, and at least one of both end portions of the first transport unit in the paper transport direction has an inclined portion that is inclined with respect to the paper transport direction. A sheet conveying device is formed.

  According to the fifth aspect of the present invention, at least one of the both ends of the first transport unit in the paper transport direction has a top portion as it goes to the front end side (second transport unit side) of the first transport unit in the paper transport direction. Since an inclined portion that is inclined with respect to the paper conveyance direction is formed so as to be away from the paper, it is possible to prevent the front edge of the paper from being caught by the end of the first conveyance section, and to prevent the paper jam or the paper front edge. Breaking is prevented.

  The invention according to claim 6 is dependent on any one of claims 1 to 5, wherein the sheet guide surface of the first transport unit and the sheet guide surface of the second transport unit are formed flush with each other. It is a guidance device.

  According to the sixth aspect of the present invention, the outer conveyance guide is formed so that the sheet conveyance surface of the first conveyance unit and the sheet conveyance surface of the second conveyance unit are flush with each other. It can be transported smoothly.

  The invention of claim 7 is a paper guide device according to any one of the inventions of claims 1 to 5, wherein the paper guide surface of the first transport unit is recessed from the paper guide surface of the second transport unit. .

  According to the seventh aspect of the present invention, since the outer conveyance guide is formed so that the sheet guide surface of the first conveyance unit is recessed from the sheet guide surface of the second conveyance unit, the sheet is conveyed by turning around this portion. It becomes like this. Therefore, the contact pressure between the outer conveyance guide and the sheet can be reduced, and damage to the sheet by the outer conveyance guide can be reduced.

  An eighth aspect of the present invention is an image forming apparatus including the paper conveying device according to any one of the first to seventh aspects.

  According to the eighth aspect of the present invention, the contact pressure between the sheet and the first conveyance unit can be reduced, so that the damage of the conveyance guide to the sheet in the first conveyance unit can be reduced, and the transfer of the toner to the sheet and the fixing failure are not performed. Can be prevented. Further, since the contact area between the first conveyance unit of the outer conveyance guide and the sheet is larger than that of the second conveyance unit, it is possible to prevent the apparatus from being enlarged and to prevent the conveyance failure of the sheet. .

  According to the present invention, since the contact pressure between the sheet and the first transport unit can be reduced, damage to the sheet by the transport guide in the first transport unit can be reduced, and defective transfer and fixing failure of toner on the sheet can be prevented. . In addition, since the contact area between the first conveyance unit of the conveyance guide and the sheet is larger than that of the second conveyance unit, the apparatus can be prevented from becoming large, and the conveyance failure of the sheet hardly occurs.

  The above object, other objects, features, and advantages of the present invention will become more apparent from the following detailed description of embodiments with reference to the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an illustrative view schematically showing a cross section of an image forming apparatus including a paper conveying apparatus according to a first embodiment of the invention. FIG. 2 is an illustrative view showing an enlarged sheet conveyance path of the image forming apparatus of FIG. 1. FIG. 2 is an illustrative view schematically showing a state in which an outer conveyance guide provided in the sheet conveyance device of FIG. 1 is viewed from a sheet guide surface side. 4A and 4B are cross-sectional views showing the outer conveyance guide of FIG. 3, wherein FIG. 3A shows a cross section taken along line IVa-IVa in FIG. 3, FIG. 3B shows a cross section taken along line IVb-IVb in FIG. 3 shows a cross section taken along line IVc-IVc. FIG. 9 is an illustrative view schematically showing a state where an outer conveyance guide provided in a sheet conveying apparatus according to a second embodiment of the present invention is viewed from the sheet guide surface side. 6 is a cross-sectional view showing the outer conveyance guide of FIG. 5, where (a) shows a cross section taken along line VIa-VIa in FIG. 5, (b) shows a cross section taken along line VIb-VIb in FIG. 5 shows a cross section taken along line VIc-VIc. FIG. 10 is an illustrative view schematically showing a state in which an outer conveyance guide provided in a sheet conveying apparatus according to a third embodiment of the present invention is viewed from the sheet guide surface side. FIG. 8 is a cross-sectional view showing the outer conveyance guide of FIG. 7, (a) showing a cross section taken along line VIIIa-VIIIa in FIG. 7, (b) showing a cross section taken along line VIIIb-VIIIb in FIG. 7 shows a cross section taken along line VIIIc-VIIIc. It is an illustration figure which shows a mode that the outer side conveyance guide with which the paper conveying apparatus which is 4th Example of this invention is provided was seen from the paper guide surface side. FIG. 10 is a cross-sectional view showing the outer conveyance guide of FIG. 9, (a) showing a cross section taken along line Xa-Xa in FIG. 9, (b) showing a cross section taken along line Xb-Xb in FIG. 9 shows a cross section taken along line Xc-Xc.

[First embodiment]
Hereinafter, a sheet conveying apparatus 10 according to a first embodiment of the present invention will be described with reference to the drawings as appropriate. FIG. 1 is an illustrative view schematically showing a cross section of an image forming apparatus 100 including a paper transport apparatus 10. FIG. 2 is an illustrative view showing a paper conveyance path S of the image forming apparatus 100 in an enlarged manner.

  Referring to FIGS. 1 and 2, a sheet conveying apparatus 10 is used in an image forming apparatus 100 such as a copying machine, a facsimile machine, a printer, and a complex machine thereof. As will be described in detail later, in the first embodiment, the sheet conveying apparatus 10 includes a pair of conveying guides G (an outer conveying guide 74 and an inner conveying guide 76) that form the sheet conveying path S, and the image forming apparatus 100. In the sheet transport path S, the sheet on which the toner image is fixed is disposed in an area for guiding the sheet to the sheet discharge tray 52.

  First, the configuration of the image forming apparatus 100 will be schematically described. In this embodiment, the image forming apparatus 100 is a multifunction peripheral (MFP) having a copying function, a printer function, a scanner function, a facsimile function, and the like. As shown in FIG. 1, the image forming apparatus 100 includes an apparatus main body 12 and an image reading device 14 disposed above the apparatus main body 12. The image forming apparatus 100 converts image data read by the image reading device 14 or image data transmitted from an external computer. Based on this, a multicolor or monochromatic image is formed on a predetermined paper (recording paper).

  The image reading device 14 includes a document placing table 16 formed of a transparent material, and a document pressing cover 18 is attached above the document placing table 16 through a hinge or the like so as to be freely opened and closed. The document pressing cover 18 is provided with an ADF (automatic document feeder) 24 that automatically feeds the documents placed on the document placing tray 20 one by one to the image reading position 22. An operation unit (not shown) such as a touch panel and operation buttons for receiving an input operation by the user is provided on the front side of the document table 18.

  The image reading device 14 includes an image reading unit 26 including a light source, a plurality of mirrors, an imaging lens, a line sensor, and the like. The image reading unit 26 exposes the document surface with a light source, and guides the reflected light reflected from the document surface to the imaging lens by a plurality of mirrors. Then, the reflected light is imaged on the light receiving element of the line sensor by the imaging lens. The line sensor detects the luminance and chromaticity of the reflected light imaged on the light receiving element, and generates image data based on the image on the document surface. As the line sensor, a CCD (Charge Coupled Device), a CIS (Contact Image Sensor), or the like may be used.

  Note that the image reading unit 26 sets the position facing the image reading position 22 as the home position, and when reading an image of a document placed on the document placement tray 20, a document conveyed by the ADF is read by the image. When passing through the position 22, the image on the surface of the original is read and the image data is acquired. When reading the image of the document placed on the document table 16, the light source, the mirror, and the like appropriately move below the document table 16 to read the image on the surface of the document, and the image data is read. get.

  The apparatus main body 12 of the image forming apparatus 100 includes a control unit 28 and an image forming unit 30. The control unit 28 includes a CPU, a memory, and the like, and transmits a control signal to each part of the image forming apparatus 100 in accordance with an input operation to an operation unit such as a touch panel, and executes various operations on the image forming apparatus 100. Let

  The image forming unit 30 includes an exposure unit 32, a developing device 34, a photosensitive drum 36, a cleaner unit 38, a charger 40, an intermediate transfer belt unit 42, a transfer roller (secondary transfer roller) 44, a fixing unit 46, and the like. An image is formed on a sheet (recording sheet) conveyed from the sheet feeding cassette 48 or the manual sheet feeding cassette 50, and the image-formed sheet is discharged to a discharge tray 52. As image data for forming an image on a sheet, as described above, image data read by the image reading unit 26, image data transmitted from an external computer, or the like is used.

  Note that image data handled in the image forming apparatus 100 corresponds to four color images of black (K), cyan (C), magenta (M), and yellow (Y). For this reason, each of the developing device 34, the photosensitive drum 36, the cleaner unit 38, and the charging device 40 is provided so as to form four types of latent images corresponding to the respective colors, thereby providing four image stations. Composed.

  The photosensitive drum 36 is an electrostatic latent image carrier having a photosensitive layer formed on the surface of a cylindrical substrate having conductivity. The charger 40 charges the surface of the photosensitive drum 36 to a predetermined potential. It is something to be made. Further, the exposure unit 32 is configured as a laser scanning unit (LSU) including a laser emitting portion and a reflection mirror, and exposes the surface of the charged photosensitive drum 36 so that an electrostatic latent image corresponding to image data is obtained. An image is formed on the surface of the photosensitive drum 36. The developing device 34 visualizes the electrostatic latent image formed on the surface of the photosensitive drum 36 with toner of four colors (YMCK). The cleaner unit 38 removes and collects the toner remaining on the surface of the photosensitive drum 36 after development and image transfer.

  The intermediate transfer belt unit 42 includes an intermediate transfer belt 54, a drive roller 56, a driven roller 58, four intermediate transfer rollers 60, and the like, and is disposed above the photosensitive drum 36. The intermediate transfer belt 54 is provided so as to be in contact with each photosensitive drum 36, and the toner images of the respective colors formed on the respective photosensitive drums 36 are sequentially superimposed on the intermediate transfer belt 54 using the intermediate transfer roller 60. As a result, a multicolor toner image is formed on the intermediate transfer belt 54. Further, a transfer roller 44 is disposed in the vicinity of the driving roller 56, and the toner formed on the intermediate transfer belt 54 by passing the sheet through the nip area between the intermediate transfer belt 54 and the transfer roller 44. The image is transferred to the paper.

  The fixing unit 46 includes a heat roller 62 and a pressure roller 64 and is disposed above the transfer roller 44. The heat roller 62 is set to have a predetermined fixing temperature. When the paper passes through the nip area between the heat roller 62 and the pressure roller 64, the toner image transferred to the paper is melted. The toner image is heat-fixed on the sheet by mixing and pressing. The fixing unit 46 performs the toner smoothing process by passing the paper through the nip area between the heat roller 62 and the pressure roller 64 in addition to the toner image fixing process as described above. It can also be done.

  As can be clearly understood from FIG. 2, in the apparatus main body 12, the paper placed on the paper feed cassette 48 or the manual paper feed cassette 50 is discharged through the transfer roller 44 and the fixing unit 46 to the paper discharge tray 52. A first sheet transport path S1 is provided for feeding to the printer. In addition, when performing duplex printing on a sheet, the sheet after the one-side printing is completed and passed through the fixing unit 46 is returned to the first sheet conveyance path S1 on the upstream side of the transfer roller 44 in the sheet conveyance direction. The second paper transport path S2 is provided. For convenience of explanation, when it is not necessary to distinguish the first paper transport path S1 and the second paper transport path S2, the first paper transport path S1 and the second paper transport path S2 are collectively transported. It will be called a road S. Similarly, the names of other components may be collectively referred to.

  The first paper transport path S1 is provided with a plurality of transport rollers 66a and 66b, a registration roller 68, a transfer roller 44, a fixing unit 46, and the like that function as a transport mechanism that applies a driving force to the paper. The second paper transport path S2 is provided with a plurality of transport rollers 66c, 66d, and 66e that function as a transport mechanism that applies a driving force to the paper. Further, at the downstream side of the fixing unit 46 in the sheet conveyance direction, the portion where the second sheet conveyance path S2 branches from the first sheet conveyance path S1 (the merging portion between the first sheet conveyance path S1 and the second sheet conveyance path S2). Is provided with a guide gate 70 for switching the paper transport direction.

  In addition to the above-described transport mechanism, the paper transport path S is provided with a plurality of transport guides G for guiding the paper so as to sandwich the front and back surfaces of the paper so as to be continuously arranged along the paper transport path S. The conveyance guide G is formed by an outer conveyance guide Go and an inner conveyance guide Gi that are arranged to face each other at a predetermined interval (for example, a guide width of about 2 mm). The outer conveyance guide Go is a conveyance guide G that forms the outer peripheral side (curved outer side) of the portion where the paper conveyance path S is curved, and the inner conveyance guide Gi is the inner peripheral side (curved portion) of the portion where the paper conveyance path S is curved. This is a conveyance guide G that forms the inner side. Each of the outer conveyance guide Go and the inner conveyance guide Gi is formed of an appropriate material such as synthetic resin or metal. In FIG. 2, the outer conveyance guide Go and the inner conveyance guide Gi are simplified and shown in a thin plate shape, but an appropriate shape is adopted as a specific shape of each conveyance guide G. Further, as will be described later, the transport guide G provided in the paper transport apparatus 10 of this embodiment constitutes a part of the paper transport path S, and therefore, a transport guide that forms another area of the paper transport path S. In order to distinguish from G, a special reference numeral (74, 76) is added.

  The outer peripheral side (outer side) and the inner peripheral side (inner side) in the transport guide G can also be referred to as the outer side and the inner side with respect to the bending direction of the paper transport path S. That is, depending on the bending direction of the paper transport path S, the transport guide G that forms the upper side of the paper transport path S becomes the outer transport guide Go, and the transport guide G that forms the lower side of the paper transport path S becomes the inner transport guide Gi. In some cases, the conveyance guide G that forms the lower side of the sheet conveyance path S may be the outer conveyance guide Go, and the conveyance guide G that forms the upper side of the sheet conveyance path S may be the inner conveyance guide Gi. Similarly, the conveyance guide G that forms the right side of the sheet conveyance path S may be the outer conveyance guide Go, and the conveyance guide G that forms the left side of the sheet conveyance path S may be the inner conveyance guide Gi. In some cases, the conveyance guide G that forms the left side of the sheet becomes the outer conveyance guide Go, and the conveyance guide G that forms the right side of the sheet conveyance path S becomes the inner conveyance guide Gi. In the paper conveyance path S that is curved in an S shape, the outer conveyance guide Go and the inner conveyance guide Gi are continuous.

  In the apparatus main body 12 of such an image forming apparatus 100, when performing single-sided printing, the sheets placed on the sheet feeding cassette 48 or the manual sheet feeding cassette 50 are first printed one by one by the pickup rollers 72a and 72b. It is guided to the sheet conveyance path S1 and conveyed to the registration roller 68 by the conveyance roller 66a. Then, the registration roller 68 conveys the sheet to the transfer roller 44 at a timing when the leading edge of the sheet and the leading edge of the image information on the intermediate transfer belt 54 are aligned, and the toner image is transferred onto the sheet. Thereafter, by passing through the fixing unit 46, the unfixed toner on the paper is melted and fixed by heat, and the paper is discharged onto the paper discharge tray 52 through the transport roller 66b.

  On the other hand, when performing double-sided printing, when the trailing edge of the paper that has passed through the fixing unit 46 after completion of single-sided printing reaches the conveyance roller 66b, the conveyance roller 66b is rotated backward and the guide gate 70 is moved downward. By switching to, the sheet runs backward and is guided to the second sheet conveyance path S2. The paper guided to the second paper transport path S2 is transported through the second paper transport path S2 by the transport rollers 66c, 66d, 66e, and enters the first paper transport path S1 on the upstream side of the registration roller 68 in the paper transport direction. Led. Thereafter, the sheet is conveyed to the transfer roller 44 by the registration roller 68 at a predetermined timing, but the front and back of the sheet are reversed at the stage where the second sheet conveying path S2 joins the first sheet conveying path S1, so that the transfer is performed. The roller 44 performs printing on the back side of the paper. Thereafter, by passing through the fixing unit 46, the unfixed toner on the back side of the sheet is melted and fixed by heat, and the sheet is discharged onto the sheet discharge tray 52 through the transport roller 66b.

  Here, the sheet conveyance path S is formed by combining a plurality of curved areas C (C1, C2, C3, C4, C5) and a non-curved area L that is an area other than these areas (see FIG. 1). ) In the curved region C of the paper transport path S, the paper is strongly pressed against the outer transport guide Go by the waist (rigidity or elasticity) of the paper. For this reason, if ribs are formed over the entire length of the outer conveyance guide Go on the sheet guide surface side, rib-shaped streaks (rib marks) may be formed on the sheet. In particular, the curvature of the first paper transport path S1 is large in a curved region C2 that is a junction of the first paper transport path S1 and the second paper transport path S2 on the downstream side of the fixing unit 46 in the paper transport direction. Thus, the sheet is strongly pressed against the outer conveyance guide 74 (Go) when passing through the curved region C2.

  Therefore, in this embodiment, the paper transport device 10 is arranged in the paper transport path S in an area for guiding the paper on which the toner image is fixed to the paper discharge tray 52. Then, the contact area per unit length in the sheet conveyance direction between the outer conveyance guide 74 and the sheet in the curved area C2 that is a joining portion of the first sheet conveyance path S1 and the second sheet conveyance path S2 is expressed as a non-curved area L. Larger than the contact area at. As a result, the contact pressure between the outer conveyance guide 74 and the sheet in the curved region C2 is reduced, and damage to the sheet by the outer conveyance guide 74 is reduced.

  However, as another embodiment of the present invention, the sheet conveying device 10 can be arranged in an area including any one of the other curved areas C1, C3, C4, and C5 of the sheet conveying path S. In addition, the sheet conveying apparatus 10 can be configured to include a plurality of curved regions C, or the sheet conveying apparatus 10 can be configured to include the entire sheet conveying path S.

  The curved area C in the present invention is an area where the sheet conveyance path S is curved with a curvature of a predetermined value or more (for example, 1/100 [1 / mm] or more), that is, the sheet is pressed against the outer conveyance guide Go. This indicates an area where a large pressure is applied to the paper. In addition, the non-curved region L indicates a linear region or a region that is gently curved with a curvature less than a predetermined value (for example, less than 1/100 [1 / mm]) but can be regarded as a linear region. That is, in the non-curved region L, there is a slight curvature that does not deviate from the spirit of the present invention, that is, a slight curvature that does not easily cause strong rubbing (pressing) between the outer conveyance guide Go and the paper. There may be.

  Hereinafter, the configuration of the sheet conveying apparatus 10 will be specifically described. With reference to FIG. 2, the sheet transport apparatus 10 includes an outer transport guide 74 and an inner transport guide 76. The outer conveyance guide 74 and the inner conveyance guide 76 are disposed so as to face each other, and form a sheet conveyance path S including a curved area C2 and a non-curved area L between the fixing unit 46 and the conveyance roller 66b. Further, a transport mechanism (fixing unit 46) that applies a driving force to the paper is provided on the downstream side of the outer transport guide 74 and the inner transport guide 76 in the paper transport direction. The sheet is transported toward the sheet discharge tray 52 through a sheet transport path S formed between the outer transport guide 74 and the inner transport guide 76 by receiving a driving force from the transport mechanism.

  The inner conveyance guide 76 is formed in a curved plate shape and is provided so as to extend from above the fixing unit 46 to the conveyance roller 66b. Although not shown, a plurality of ribs that protrude toward the paper side (curved outside) are formed on the paper guide surface side of the inner conveyance guide 76. These ribs are provided at a predetermined interval (for example, an interval of 10 to 30 mm) in a direction orthogonal to the sheet conveyance direction, and extend along the sheet conveyance direction. Note that the entire inner conveyance guide 76 may be integrally formed, or may be formed by a plurality of members.

  The outer conveyance guide 74 is provided so as to extend linearly in a substantially horizontal direction from above the guide gate 70 to the conveyance roller 66b. Hereinafter, the configuration of the outer conveyance guide 74 will be specifically described with reference to FIGS. 3 and 4. FIG. 3 is an illustrative view schematically showing a state in which the outer conveyance guide 74 is viewed from the paper guide surface side. 4 is a cross-sectional view showing the outer conveyance guide 74, (a) showing a cross section taken along line IVa-IVa in FIG. 3, (b) showing a cross section taken along line IVb-IVb in FIG. c) shows a section taken along line IVc-IVc in FIG.

  As shown in FIGS. 3 and 4, the outer conveyance guide 74 is integrally formed by integral molding, and the first conveyance unit 78 disposed in the curved region C <b> 2 and the second conveyance disposed in the non-curved region L. The base part 82 formed in the rectangular flat plate shape including the part 80 and covering the whole 1st conveyance part 78 and the 2nd conveyance part 80 is provided.

  A plurality of ribs 84 having a substantially semicircular cross section that protrudes from the base portion 82 toward the paper side (inner side of the curve) are formed on the paper guide surface side of the second transport unit 80. These ribs 84 are provided at a predetermined interval (for example, an interval of 10 to 30 mm) in a direction orthogonal to the sheet conveyance direction, and extend along the sheet conveyance direction. In the second transport unit 80, the top portions (tip portions) of the plurality of ribs 84 serve as a sheet guide surface. The protruding height of the rib 84 from the base portion 82 is, for example, 1 to 2 mm, and the width of the base end portion (the length in the direction orthogonal to the paper transport direction) is, for example, 2 mm. 3 and 4 show four ribs 84 extending in the paper conveyance direction for simplification of the drawing, the number of ribs 84 is arbitrary. For example, the second conveyance unit 80 includes About 10-20 ribs 84 extending in the paper transport direction are provided at predetermined intervals in a direction perpendicular to the paper transport direction.

  On the other hand, on the paper guide surface side of the first transport unit 78, a flat portion 86 having a rectangular flat plate shape protruding from the base portion 82 toward the paper side is formed. The flat portion 86 is formed on the entire sheet guide surface side of the first conveying portion 78, and the top portion of the flat portion 86 is a flat surface without unevenness. That is, the top (paper guide surface) of the first transport unit 78 is a flat surface without ribs. Further, the flat portion 86 and the plurality of ribs 84 described above have the same protruding height from the base portion 82, and the top portion of the flat portion 86 and the top portion of each rib 84, that is, the sheet transport of the first transport portion 78. The surface and the paper transport surface of the second transport unit 80 are continuous with each other.

  Furthermore, inclined portions 86a that are inclined with respect to the paper conveyance direction are formed at both ends (except for portions that are flush with the ribs 84) in the paper conveyance direction of the flat portion 86 (first conveyance unit 78). Is done. The inclined portion 86a is inclined so that the top portion thereof is separated from the paper as it goes toward the leading end side (second conveying portion 80 side) of the first conveying portion 78 in the paper conveying direction. However, the inclined portion 86a may be inclined not only in a straight line as shown in FIG. 4C but also in an arc shape so as to swell toward the paper side. Further, the inclined portion 86a may be formed only at the tops of both ends of the flat portion 86.

  As described above, the plurality of ribs 84 are formed in the second transport unit 80, whereas the paper guide surface of the first transport unit 78 is a flat surface without ribs so that the paper transport path S is transported. The contact area per unit length in the sheet conveyance direction with the sheet is larger in the first conveyance unit 78 than in the second conveyance unit 80. As a result, the contact pressure between the sheet and the outer conveyance guide 74 in the curved area C2 of the sheet conveyance path S is reduced. That is, the force with which the sheet is pressed against the outer conveyance guide 74 is dispersed and becomes smaller. For this reason, the damage that the outer conveyance guide 74 gives to the sheet in the curved region C2 is reduced.

  Further, by forming the sheet conveying surface of the first conveying unit 78 and the sheet conveying surface of the second conveying unit 80 to be flush with each other (that is, at the same height), the sheet has a region where the outer conveying guide 74 is provided. It is transported smoothly.

  Further, by forming the inclined portion 86 a in the first transport unit 78, it is possible to prevent the leading edge of the paper from being caught on the end of the first transport unit 78, and it is possible to prevent the paper jam and the leading edge bending of the paper. The inclined portions 86a are not necessarily formed at both ends of the first transport unit 78 in the paper transport direction, and at least at one end (upstream end) of the first transport unit 78 in the paper transport direction. What is necessary is just to be provided. In the first embodiment, when the sheet is moved backward to be guided to the second sheet conveying path S2 in order to perform double-sided printing, the conveying roller 66b side (the left side in FIGS. 2 and 3) of the first conveying unit 78 is used. Since the end portion is the upstream end portion in the sheet conveying direction, the inclined portion 86a can be formed only at the end portion of the first conveying portion 78 on the conveying roller 66b side.

  According to the first embodiment, since the contact pressure between the sheet and the outer conveyance guide 74 in the curved area C1 of the sheet conveyance path S can be reduced, damage to the sheet by the outer conveyance guide 74 can be reduced, and toner on the sheet can be reduced. Transfer failure and fixing failure can be prevented.

  Further, according to the first embodiment, the sheet guide surface of the first transport unit 78 is a flat surface without ribs, so that the contact area of the outer transport guide 74 with the sheet in the first transport unit 78 is reduced to the second. Since the size of the apparatus is simpler than that of the conveying unit 80, the apparatus can be prevented from being enlarged, and poor conveyance of the sheet hardly occurs.

  In the first embodiment, the flat portion 86 is formed on the entire sheet guide surface side of the first conveying portion 78 (that is, the entire curved region C2). However, the flat portion 86 is not necessarily the first conveying portion. It is not necessary to form the entire portion 78. In short, the outer conveyance guide 74 is such that the contact area per unit length in the sheet conveyance direction with the sheet conveyed through the sheet conveyance path S is larger in the first conveyance unit 78 than in the second conveyance unit 80. Should just be formed. For example, when the length of the first transport unit 78 in the paper transport direction is long, the flat portion 86 may be intermittently formed so as to be arranged at a predetermined interval in the paper transport direction. Further, the flat portion 86 is not formed over the entire length in the direction orthogonal to the paper conveyance direction of the first conveyance unit 78, but is formed in a part in the direction orthogonal to the paper conveyance direction. The flat part 86 can also be formed in the part except the both ends in the direction orthogonal to the transport direction. Further, for example, the flat portion 86 can be formed so as to gradually widen from the end portion of the first transport portion 78 in the paper transport direction toward the center portion (or a portion having a large curvature). In addition, it is good to form the rib which protrudes from the base part 82 suitably in the part which does not provide the flat part 86 of the 1st conveyance part 78. FIG. That is, the first transport unit 78 may have a portion where a rib is formed.

[Second Embodiment]
Next, with reference to FIG. 5 and FIG. 6, a sheet conveying apparatus 10 according to a second embodiment of the present invention will be described. In the second embodiment, in order to increase the contact area with the sheet in the first transport section 78 of the outer transport guide 74, the wide rib 88 is formed in the first transport section 78. And different. Since the configuration of the other parts is the same, parts common to the first embodiment described above are given the same reference numerals, and redundant explanations are omitted or simplified. Only the configuration of the outer conveyance guide 74 provided in the sheet conveying apparatus 10 of the embodiment will be described. FIG. 5 is an illustrative view schematically showing a state in which the outer conveyance guide 74 is viewed from the paper guide surface side. 6 is a cross-sectional view showing the outer conveyance guide 74, (a) showing a cross section taken along line VIa-VIa in FIG. 5, (b) showing a cross section taken along line VIb-VIb in FIG. c) shows a section taken along line VIc-VIc in FIG.

  As shown in FIGS. 5 and 6, the outer transport guide 74 includes a first transport unit 78 disposed in the curved region C2 and a second transport unit 80 disposed in the non-curved region L, and includes a first transport unit. 78 and the base part 82 formed in the rectangular flat plate shape covering the whole 2nd conveyance part 80 is provided.

  A plurality of ribs 84 having a substantially semicircular cross-section projecting from the base portion 82 toward the paper side are formed on the paper guide surface side of the second transport unit 80. The ribs 84 are provided at predetermined intervals in a direction orthogonal to the paper transport direction and extend along the paper transport direction. The width of the base end portion of the rib 84 (the length in the direction orthogonal to the paper transport direction) is, for example, 2 mm.

  On the other hand, on the paper guide surface side of the first transport unit 78, a plurality of ribs 88 having a substantially rounded rectangular cross section protruding from the base part 82 toward the paper side are formed. Each of the ribs 88 is formed so as to be continuous with each of the plurality of ribs 84 formed in the second transport unit 80 in the paper transport direction. That is, the plurality of ribs 88 are provided at predetermined intervals in a direction orthogonal to the paper transport direction and extend along the paper transport direction. The plurality of ribs 88 formed on the first transport unit 78 and the plurality of ribs 84 formed on the second transport unit 80 have the same protruding height from the base portion 82, and The top and the top of each rib 84, that is, the paper transport surface of the first transport unit 78 and the paper transport surface of the second transport unit 80 are continuous with each other.

  The ribs 88 formed on the first transport unit 78 are formed wider than the ribs 84 formed on the second transport unit 80 in a direction perpendicular to the paper transport direction. The width of each rib 88 (the length in the direction orthogonal to the sheet conveying direction) is, for example, 2 to 5 times the width of each rib 84 (that is, 4 to 10 mm). A flat surface having a width of 2 to 8 mm is formed. As a result, the contact area per unit length in the sheet conveyance direction with the sheet conveyed on the sheet conveyance path S is larger in the first conveyance unit 78 than in the second conveyance unit 80, and the sheet conveyance path S The contact pressure between the sheet and the outer conveyance guide 74 in the curved area C2 is reduced. It should be noted that the curvature of the side portion of each rib 88 (both ends in the direction orthogonal to the paper transport direction) is preferably set to be the same as the curvature of the side portion of each rib 84.

  In addition, at both ends of the rib 88 (first transport unit 78) in the paper transport direction, inclined portions 88a that are inclined with respect to the paper transport direction at portions protruding from the rib 84 in a direction perpendicular to the paper transport direction. Is formed. The inclined portion 88a is inclined so that the top portion thereof is separated from the paper as it goes to the second conveying portion 80 side. However, the inclined portion 88a may be inclined not only in an arc shape so as to swell toward the paper side as shown in FIG. 6C, but also in a linear shape.

  Also in the second embodiment, the contact pressure between the sheet and the outer conveyance guide 74 in the curved region C1 of the sheet conveyance path S can be reduced as in the first embodiment, so that the outer conveyance guide 74 applies to the sheet. Damage can be reduced and toner transfer failure and fixing failure to paper can be prevented.

  Further, by forming the rib 88 of the first conveyance unit 78 wider than the rib 84 of the second conveyance unit 80, the contact area of the outer conveyance guide 74 with the paper in the first conveyance unit 78 is set to the second conveyance unit 80. Therefore, the size of the apparatus can be prevented from being increased, and paper conveyance failure is unlikely to occur.

  In the second embodiment, each rib 88 is formed to be wide over the entire length in the paper conveyance direction. However, it is not necessary to form all the ribs 88 wide and the total length in the paper conveyance direction. It is not necessary to widen the rib 88 over the entire area. For example, when the length of the first transport unit 78 in the paper transport direction is long, the ribs 88 may be formed with intermittently wide portions so as to be arranged at predetermined intervals in the paper transport direction. Further, for example, every other rib 88 arranged in a direction orthogonal to the sheet conveying direction can be formed wider. Further, for example, the ribs 88 are not widened uniformly over the entire length in the paper transport direction, but are gradually widened from the end of the first transport unit 78 in the paper transport direction toward the center. It can also be formed. Of course, each rib 88 can be formed to have a different width.

[Third embodiment]
Next, with reference to FIG. 7 and FIG. 8, a sheet conveying apparatus 10 according to a third embodiment of the present invention will be described. In the third embodiment, in order to increase the contact area with the sheet in the first conveying portion 78 of the outer conveying guide 74, the first and second portions described above are formed by forming the shallow groove portion 90 in the first conveying portion 78. Different from the embodiment. Since the configuration of the other parts is the same, the same reference numerals are assigned to the parts common to the first and second embodiments described above, and the overlapping description is omitted or simplified. Only the configuration of the outer conveyance guide 74 provided in the sheet conveying apparatus 10 of the third embodiment will be described. FIG. 7 is an illustrative view schematically showing a state in which the outer conveyance guide 74 is viewed from the paper guide surface side. 8 is a cross-sectional view showing the outer conveyance guide 74, (a) showing a cross section taken along line VIIIa-VIIIa in FIG. 7, (b) showing a cross section taken along line VIIIb-VIIIb in FIG. c) shows a cross section taken along line VIIIc-VIIIc in FIG.

  As shown in FIGS. 7 and 8, the outer transport guide 74 includes a first transport unit 78 disposed in the curved region C2 and a second transport unit 80 disposed in the non-curved region L, and includes a first transport unit. 78 and the base part 82 formed in the rectangular flat plate shape covering the whole 2nd conveyance part 80 is provided. In addition, a plurality of ribs 84 having a substantially semicircular cross section are formed on the paper guide surface side of the base portion 82 and project from the base portion 82 toward the paper side. These ribs 84 are provided at predetermined intervals in a direction orthogonal to the paper transport direction, and the tops of the first transport unit 78 and the second transport unit 80 are flush with each other over the entire length of the first transport unit 78 and the second transport unit 80. Extending along. That is, the paper transport surface of the first transport unit 78 and the paper transport surface of the second transport unit 80 are continuous with each other.

  In the first transport unit 78, shallow grooves 90 that are shallower than the grooves formed between the ribs 84 of the second transport unit 80 are formed by filling the grooves formed between the ribs 84. . The depth of the shallow groove 90, that is, the height difference between the top of the rib 84 and the top of the shallow groove 90 is, for example, 0.1 to 0.3 mm. On the other hand, the depth of the groove between the ribs 84 in the second transport unit 80, that is, the protruding height of the ribs 84 from the base portion 82 is, for example, 1 to 2 mm. The sheet is slightly pressed in a direction perpendicular to the sheet conveyance direction by being pressed against the outer conveyance guide 74 at the time of conveyance, so that the sheet contacts the top of the shallow groove portion 90 together with the top of the rib 84. That is, the sheet can be received even at the top of the shallow groove portion 90. As described above, even when the shallow groove portion 90 is formed between the ribs 84 of the first transport unit 78, the contact area per unit length in the paper transport direction with the paper transported through the paper transport path S is the second. The first conveyance unit 78 is larger than the conveyance unit 80, and the contact pressure between the sheet and the outer conveyance guide 74 in the curved region C2 of the sheet conveyance path S is reduced.

  In addition, inclined portions 90a that are inclined with respect to the paper transport direction are formed at both ends of the shallow groove portion 90 (first transport unit 78) in the paper transport direction. The inclined portion 90a is inclined so that the top portion thereof is separated from the sheet as it goes toward the second conveying portion 80 side.

  Also in the third embodiment, the contact pressure between the sheet and the outer conveyance guide 74 in the curved region C1 of the sheet conveyance path S can be reduced as in the first embodiment, so that the outer conveyance guide 74 applies to the sheet. Damage can be reduced and toner transfer failure and fixing failure to paper can be prevented.

  Further, by forming the shallow groove portion 90 between the ribs 84 of the first transport unit 78, the contact area of the outer transport guide 74 with the sheet in the first transport unit 78 is made larger than that of the second transport unit 80. Since it is a structure, the enlargement of the apparatus can be prevented, and the conveyance failure of the sheet hardly occurs.

  In the third embodiment, the shallow groove portion 90 is formed over the entire length in the paper conveyance direction between all the ribs 84 formed in the first conveyance portion 78. However, the shallow groove portion 90 is formed in the first conveyance portion 78. It is not necessary to form the shallow groove portion 90 between all the ribs 84 to be formed, and it is not necessary to form the shallow groove portion 90 over the entire length of the first conveying portion 78 in the sheet conveying direction.

[Fourth embodiment]
Next, with reference to FIG. 9 and FIG. 10, a sheet conveying apparatus 10 according to a fourth embodiment of the present invention will be described. In the fourth embodiment, the number of ribs formed on the first transport unit 78 is set to the number of ribs of the second transport unit 80 in order to increase the contact area with the paper in the first transport unit 78 of the outer transport guide 74. This is different from the first to third embodiments described above. Since the configuration of the other parts is the same, the same reference numerals are assigned to the parts common to the above-described first to third embodiments, and the overlapping description is omitted or simplified. Only the configuration of the outer conveyance guide 74 provided in the sheet conveying apparatus 10 of the fourth embodiment will be described. FIG. 9 is an illustrative view schematically showing a state in which the outer conveyance guide 74 is viewed from the sheet guide surface side. 10 is a cross-sectional view showing the outer conveyance guide 74, (a) showing a cross section taken along line Xa-Xa in FIG. 9, (b) showing a cross section taken along line Xb-Xb in FIG. c) shows a cross section taken along line Xc-Xc in FIG.

  As shown in FIGS. 9 and 10, the outer conveyance guide 74 includes a first conveyance unit 78 disposed in the curved region C2 and a second conveyance unit 80 disposed in the non-curved region L, and includes a first conveyance unit. 78 and the base part 82 formed in the rectangular flat plate shape covering the whole 2nd conveyance part 80 is provided. In addition, a plurality of ribs 84 having a substantially semicircular cross section are formed on the paper guide surface side of the base portion 82 and project from the base portion 82 toward the paper side. These ribs 84 are provided at predetermined intervals in a direction orthogonal to the paper transport direction, and the tops of the first transport unit 78 and the second transport unit 80 are flush with each other over the entire length of the first transport unit 78 and the second transport unit 80. Extending along. That is, the paper transport surface of the first transport unit 78 and the paper transport surface of the second transport unit 80 are continuous with each other.

  In the first transport unit 78, a plurality of ribs 92 having a substantially semicircular cross section are formed in addition to the plurality of ribs 84. The ribs 92 are formed between the ribs 84 and extend along the paper conveyance direction over the entire length of the first conveyance unit 78. That is, more ribs 84 and 92 are formed in the first transport unit 78 than in the second transport unit 76. As a result, the contact area per unit length in the sheet conveyance direction with the sheet conveyed on the sheet conveyance path S is larger in the first conveyance unit 78 than in the second conveyance unit 80, and the sheet conveyance path S The contact pressure between the sheet and the outer conveyance guide 74 in the curved area C2 is reduced.

  In addition, inclined portions 92a that are inclined with respect to the paper transport direction are formed at both ends of each rib 92 (first transport unit 78) in the paper transport direction. The inclined portion 92a is inclined so that the top portion thereof is separated from the sheet as it goes toward the second conveying portion 80 side.

  Also in the fourth embodiment, the contact pressure between the sheet and the outer conveyance guide 74 in the curved region C1 of the sheet conveyance path S can be reduced as in the first embodiment, so that the outer conveyance guide 74 applies to the sheet. Damage can be reduced and toner transfer failure and fixing failure to paper can be prevented.

  Further, by increasing the number of ribs 84 and 92 formed in the first transport unit 78 as compared with the second transport unit 80, the contact area of the outer transport guide 74 with the paper in the first transport unit 78 is reduced to the second transport unit. Since it is a simple configuration that is larger than 80, it is possible to prevent an increase in the size of the apparatus, and it is difficult to cause paper conveyance failure.

  In the fourth embodiment, the other ribs 92 are formed over the entire length in the sheet conveyance direction between all the ribs 84 formed in the first conveyance unit 78. It is not necessary to form other ribs 92 between all the formed ribs 84, and it is not necessary to form other ribs 92 over the entire length of the first conveying unit 78 in the sheet conveying direction.

  In each of the first to fourth embodiments described above, the sheet conveyance surface of the first conveyance unit 78 and the sheet conveyance surface of the second conveyance unit 80 are continuous (ie, at the same height). Although the outer side conveyance guide 74 (Go) was formed, it is not limited to this. As another example, the outer conveyance guide 74 is formed so that the sheet guide surface of the first conveyance unit 78 is recessed (that is, the height is lowered) to the outer peripheral side than the sheet guide surface of the second conveyance unit 80. You can also. In this case, it is preferable that the first transport unit 78 and the second transport unit 80 are smoothly and continuously formed by forming an inclined portion at a connection portion between the first transport unit 78 and the second transport unit 80. .

  As described above, the outer conveyance guide 74 is formed so that the sheet guide surface of the first conveyance unit 78 is recessed from the sheet guide surface of the second conveyance unit 80, so that the sheet is conveyed with a large turn around this portion. That is, since the curvature of the curved region C2 can be reduced, the contact pressure between the outer conveyance guide 74 and the sheet can be decreased, and damage to the sheet by the outer conveyance guide 74 can be reduced.

  In each of the first to fourth embodiments described above, the outer conveyance guide 74 is formed so as to extend linearly in the sheet conveyance direction, but is not limited thereto. For example, when the paper transport device 10 is disposed in an area including other curved areas C1, C3, C4, and C5 of the paper transport path S, the outer transport guide 74 is curved so as to be curved along the paper transport path S. It can also be formed.

  Further, in each of the first to fourth embodiments described above, the shape of the base portion 82 is a rectangular flat plate shape, but the shape of the base portion 82 can be changed as appropriate and is not particularly limited. For example, a meat stealing part can be formed in the base part 82, or the base part 82 can be formed in a hollow shape. Further, for example, the base portion 82 can be formed in a frame shape provided at the peripheral edge portion of the outer conveyance guide 74.

  Furthermore, in each of the first to fourth embodiments described above, the first transport unit 78 and the second transport unit 80 are integrally formed. However, the first transport unit 78 and the second transport unit 80 Are not necessarily formed integrally, and the first conveyance unit 78 and the second conveyance unit 80 may be formed by combining different members that can be separated.

  Further, the outer conveyance guide 74 can be appropriately formed with a vent hole (not shown). For example, in the case of forming a vent hole in the first transport unit 78, in the first embodiment described above, a vent hole penetrating in the thickness direction through the flat portion 86 and the base portion 82 on the back side thereof may be formed. In the second to fourth embodiments described above, a vent hole penetrating the base portion 82 (and the shallow groove portion 90) between the ribs 84 and 88 in the thickness direction may be formed. Moreover, when forming a vent hole in the second transport unit 80, a vent hole penetrating the base portion 82 between the ribs 84 in the thickness direction may be formed.

  Furthermore, in each of the first to fourth embodiments described above, the paper transport device 10 is arranged in the paper transport path S that transports the paper (recording paper) on which an image is printed. However, the present invention is not limited to this. For example, the sheet conveying device 10 can be arranged on a sheet conveying path in an ADF (automatic document feeder) that conveys a sheet for reading an image.

  It should be noted that the specific numerical values such as the dimensions mentioned above are merely examples, and can be appropriately changed according to the needs of product specifications and the like.

DESCRIPTION OF SYMBOLS 10 ... Paper conveying apparatus 12 ... Apparatus main body 14 ... Image reading apparatus 24 ... ADF (automatic document feeder)
DESCRIPTION OF SYMBOLS 28 ... Control part 44 ... Transfer roller 46 ... Fixing unit 48 ... Paper feed cassette 52 ... Paper discharge tray 66 (66a-66e) ... Conveyance roller 68 ... Registration roller 74, Go ... Outer conveyance guide 76, Gi ... Inner conveyance guide 78 ... 1st conveyance part 80 ... 2nd conveyance part 82 ... Base part 84 ... Rib 86 ... Flat part 88 ... Wide rib 90 ... Shallow groove part 100 ... Image forming apparatus (multifunction machine)
S (S1, S2) ... paper transport path C (C1 to C5) ... curved area L ... non-curved area

Claims (8)

In a paper transport device comprising a transport guide that forms a paper transport path,
The transport guide includes a first transport unit and a second transport unit,
Each of the first transport unit and the second transport unit includes a plurality of ribs provided at predetermined intervals in a direction orthogonal to the paper transport direction and extending along the paper transport direction.
A sheet conveying apparatus, wherein a shallow groove portion shallower than a groove portion between ribs formed in the second conveying portion is formed between ribs formed in the first conveying portion. In a paper transport device comprising a transport guide that forms a paper transport path,
The transport guide includes a first transport unit and a second transport unit,
The second transport unit includes a plurality of ribs provided at predetermined intervals in a direction orthogonal to the paper transport direction and extending along the paper transport direction.
A sheet conveying apparatus, wherein the entire sheet guide surface of the first conveying unit is a flat surface without ribs. In a paper transport device comprising a transport guide that forms a paper transport path,
The transport guide includes a first transport unit and a second transport unit,
Each of the first transport unit and the second transport unit includes a plurality of ribs provided at predetermined intervals in a direction orthogonal to the paper transport direction and extending along the paper transport direction.
The sheet conveying apparatus according to claim 1, wherein the number of ribs formed in the first conveying unit is larger than the number of ribs formed in the second conveying unit in a direction orthogonal to the sheet conveying direction.   The sheet conveying apparatus according to any one of claims 1 to 3, wherein the first conveying unit and the second conveying unit are integrally formed.   The paper according to any one of claims 1 to 4, wherein an inclined portion that is inclined with respect to the paper conveyance direction is formed on at least one of both ends of the first conveyance unit in the paper conveyance direction. Conveying device.   6. The paper transport apparatus according to claim 1, wherein a paper guide surface of the first transport unit and a paper guide surface of the second transport unit are formed flush with each other.   6. The paper transport device according to claim 1, wherein a paper guide surface of the first transport unit is recessed from a paper guide surface of the second transport unit. 7.   An image forming apparatus comprising the sheet conveying device according to claim 1.

Images