JP2007191294A - Sheet conveying device and image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sheet conveying device and an image forming device capable of certainly conveying the sheet to an image formation part again and keeping good image quality. <P>SOLUTION: A guide means 24 abutted on an image formation surface side of the sheet S is movably provided between sheet conveying means 11, 12, 13 and a sheet inversion conveying means 15, and the guide means 24 is retreated when it reaches the sheet inversion means 15 and is pressed by the sheet S conveyed by the sheet inversion conveying means 15 and the sheet conveying means 11, 12, 13. Further, when the sheet S is passed through the sheet conveying means 11, 12, 13, it is moved to a guide position for guiding the sheet S conveyed toward a re-conveying passage R by inversion of the sheet inversion conveying means 15. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a sheet conveying apparatus and an image forming apparatus, and more particularly to an apparatus that reverses a sheet on which an image is formed on a first surface and conveys the sheet again to an image forming unit.

  Conventionally, as an example of an image forming apparatus such as a printer, a facsimile machine, and a copying machine, there is an image forming apparatus that can form images on both sides of a sheet. In such an image forming apparatus, in order to form an image on the second surface opposite to the sheet on which the image is formed on the first surface, the sheet after the image is formed on the first surface is reversed. And a sheet conveying device constituting a re-conveying unit for conveying the image again to the image forming unit.

  Here, in such a conventional sheet conveying apparatus, normally, a sheet on which an image is formed on the first surface is reversely provided with a roller pair or the like that can rotate forward and reverse, and the sheet is switched back by this roller pair and conveyed. This is done by switchback means that reverse the direction.

  FIG. 7 is a diagram showing a schematic configuration of a laser beam printer which is an example of an image forming apparatus provided with such a conventional sheet conveying apparatus. The laser beam printer 111 is capable of forming images on both sides of the sheet S, and includes a sheet re-conveying unit 1113 configured by an image forming unit 119 that performs image formation and a sheet conveying device that inverts the sheet S. ing.

  In such a laser beam printer 111, when images are formed on both sides of the sheet S, first, an image is formed on one side by the image forming unit 119, and then the sheet S on which the image is fixed by the fixing unit 120. Is conveyed to a switchback roller 1115 that can rotate forward and backward.

  Thereafter, when the trailing edge of the sheet S passes through the first nip N1 between the fixing discharge roller pair 1112 and the first roller 1111, the switchback roller pair 1115 temporarily stops and then reversely rotates. Accordingly, the sheet S is continuously sent to the sheet re-conveying unit 1113 in a state where the leading end and the trailing end are reversed. The sheet re-conveying unit 1113 includes a fixing discharge roller pair 1112 from the upstream, a second roller 1114 that forms a second nip N2 together with the fixing discharge roller pair 1112, an inner guide 1117 and an outer guide 1116, and a re-feed roller pair. 1118 is mainly configured.

  Here, when the sheet passes through the first nip N1 of the fixing discharge roller pair 1112, the rear end of the sheet S on which an image is formed is released from the restraint by the fixing discharge roller pair 1112 and the first roller 1111. . Thereafter, when the switchback roller pair 1115 is temporarily stopped, the sheet S is temporarily stopped along the outer guide 1116 according to the nip angle of the switchback roller pair 1115.

  As a result, when the switchback roller pair 1115 rotates in the reverse direction thereafter, the sheet S is switched back along the outer guide 1116 and smoothly into the second nip N2 formed by the fixing discharge roller pair 1112 and the second roller 1114. It will be sent.

  Thereafter, the sheet S is fed again to the image forming unit 119 by the refeed roller pair 1118 to form an image on the second surface, and then provided from the sheet discharge unit 1119 to the upper surface of the printer main body 111A. The paper is discharged to a paper discharge unit 1126.

  As means for switching the transport path by these switchback transport or the like, a configuration in which an actuator and a guide supported by rotation are installed is disclosed. (For example, refer to Patent Document 1).

JP 2000-118829 A

  However, in such a conventional sheet conveying apparatus and image forming apparatus, in general, the sheet S is often curled by the heat applied by the fixing unit 120 when passing through the fixing unit 120.

  For example, if the trailing edge of the sheet S is curled toward the printing surface, the trailing edge of the sheet S heading toward the second nip N2 due to the reverse rotation of the switchback roller pair 1115 cannot enter the second nip N2 well, and the first There is a case of heading to the nip N1. Here, since the first nip N1 rotates in the direction in which the sheet S is discharged, a jam may occur when the rear end faces the first nip N1 in this way.

  On the other hand, the sheet conveying speed of the switchback roller pair 1115 and the fixing discharge roller pair 1112 is substantially the same, but the sheet conveying speed of the switchback roller pair 1115 may be faster than the sheet conveying speed of the fixing discharge roller pair 1112. In such a case, the sheet S immediately after passing through the fixing unit 120 is pulled by such a difference in sheet conveyance speed between the two roller pairs, and is conveyed while being in contact with the guide member 1117.

  Here, since the sheet S immediately after passing through the fixing unit 120 has poor toner adhesion, when the sheet S is conveyed while being in contact with the guide member 1117 as described above, the toner image on the sheet is peeled off, and the image quality is improved. There was a decline.

  Therefore, the present invention has been made in view of such a current situation, and a sheet conveying apparatus and an image forming apparatus that can reliably convey a sheet again to the image forming unit and can maintain good image quality. The object is to provide an apparatus.

  The present invention provides a sheet conveying apparatus that reverses a sheet so as to form an image on a second surface opposite to the sheet on which an image is formed on the first surface by an image forming unit, and conveys the image again to the image forming unit. A sheet conveying unit that conveys a sheet on which an image is formed, a reconveying path for conveying the sheet on which the image is formed on the first surface to the image forming unit again, and the sheet conveying unit Reversible sheet reversing and conveying means for reversing and conveying the sheet to the reconveying path, and image formation of the sheet conveyed by the sheet conveying means provided between the sheet conveying means and the sheet reversing and conveying means A guide means that contacts the surface side, and the guide means reaches the sheet reverse conveying means and is conveyed by the sheet reverse conveying means and the sheet conveying means. The sheet retracts when pressed by a sheet, and moves to a guide position for guiding the sheet conveyed toward the re-conveyance path by reversing the sheet reversing conveyance unit when the sheet passes through the sheet conveying unit. It is what.

  As in the present invention, when the guide means is pressed by the sheet reversing and conveying means and the sheet conveyed by the sheet conveying means, the guide means prevents the toner image from being peeled off by being retracted. And good image quality can be maintained. Further, when the sheet passes through the sheet conveying unit, the guide unit moves to a guide position for guiding the sheet conveyed toward the re-conveying path by the reverse rotation of the sheet reverse conveying unit, thereby reliably image the sheet. It can be conveyed again to the forming part.

  The best mode for carrying out the present invention will be described below in detail with reference to the drawings.

  FIG. 1 is a diagram showing a schematic configuration of a laser beam printer which is an example of an image forming apparatus provided with a sheet conveying apparatus according to a first embodiment of the present invention.

  In FIG. 1, reference numeral 1 denotes a laser beam printer capable of forming images on both sides of a sheet. The laser beam printer 1 includes a laser beam printer main body 1A and an image forming unit 1B for forming an image. Further, after an image is formed on the first surface, a refeed conveyance unit 1C configured by a sheet conveyance device that again supplies the sheet S to the image forming unit 1B in order to form an image on the second surface (back surface). And a feeding unit 1D for separating and feeding the sheets S one by one to the image forming unit 1B.

  Here, the image forming unit 1B includes a process cartridge 6, a transfer roller 9, and the like, and the feeding unit 1D receives the sheet S stored in the sheet feeding cassette 2 and the sheet feeding cassette 2 that is a sheet storing unit that stores the sheet S. A feeding roller 30 for feeding is provided. The process cartridge 6 is integrally provided with a photosensitive drum 7 and process means (charging means, developing means, cleaning means) acting on the photosensitive drum 7, and is detachable from a laser beam printer main body (hereinafter referred to as printer main body) 1A. It has become.

  In addition, the refeed conveyance unit 1C is configured around the discharge path R1 and the reconveyance path R starting from the discharge roller pair 16 and reaching the junction 19 with the conveyance path from the sheet feed cassette 2. is there. In the present embodiment, a sheet discharge section 14 including a discharge roller pair 16 capable of forward and reverse rotation, an intermediate discharge roller pair 15 serving as a sheet reverse conveying means, and a fixing discharge roller 11 is disposed in the discharge passage R1. . Further, in the re-conveying path R located downstream of the discharge path R1 in the sheet conveying direction, a curve reversing unit 17, a lateral registration correcting unit 18, a refeed roller 20 and the like are arranged.

  The fixing discharge roller 11 also serves as a switchback roller. The fixing discharge roller 11 holds the sheet S together with the fixing discharge roller 11 and conveys the sheet S to the intermediate discharge roller pair 15. Are to come into pressure contact. Further, a second roller 13 that presses the sheet S together with the fixing discharge roller 11 to switch back the sheet S and moves toward the re-conveying path R is pressed against the fixing discharge roller 11. Note that a sheet conveying unit that conveys a sheet on which an image is formed includes the fixing discharge roller 11, the first roller 12, and the second roller 13. A passage between the fixing discharge roller 11 and the intermediate discharge roller pair 15 in the discharge passage R1 is a curved conveyance path.

  The curve reversing unit 17 is for changing the conveyance direction of the sheet from the vertical direction to the horizontal direction, and the curve reversing unit 17 is located inside and outside the curvature of the conveyance path, respectively. It consists of an inner guide 17a and an outer guide 17b.

  In FIG. 1, 8 is a laser scanner unit, 10 is a fixing unit as a fixing unit, and 25 is a sheet discharge stacking base. Reference numeral 31 denotes a controller board that controls the operation of the laser beam printer 1 and has a function of performing image formation processing on an image signal of a computer (not shown) connected thereto.

  Reference numeral 21 denotes a refeed path unit. The refeed path unit 21 is provided with a drive means (not shown) that drives the intermediate discharge roller pair 15 and the discharge roller pair 16 in the forward and reverse directions. Reference numerals 22 and 23 denote curved inner guide members and outer guide members which are provided between the fixing discharge roller 11 and the intermediate discharge roller pair 15 and guide the printing surface side and the non-printing surface side of the sheet S. The inner guide member 22 has a rotation guide member 24 that is a guide means biased to a predetermined position by a spring (not shown) at a position facing the outer guide member 23 so as to be rotatable. It is supported. In other words, the passage between the fixing discharge roller 11 and the intermediate discharge roller pair 15 in the discharge passage R1 is a curved conveyance path, and the rotation guide member 24 is provided inside the curved conveyance path. .

  In the present embodiment, the rotation guide member 24 is disposed above with a predetermined clearance with respect to the escape angle of the sheet S of the first nip N1. Thereby, when passing through the first nip N1, the sheet S is conveyed without being caught by the rotation guide member 24 as described later.

  In the present embodiment, the conveying speeds of the sheets S conveyed by the relay roller pair 4, the registration roller pair 5, the transfer roller 9, the fixing unit 10, the fixing discharge roller 11 and the intermediate discharge roller pair 15 are substantially equal to each other. It is set to be equal. Further, the conveyance path from the discharge roller pair 16 and the intermediate discharge roller pair 15 provided in the discharge passage R1 for discharging the sheet S to the outside of the printer main body to the nip N2 between the fixing discharge roller 11 and the second roller 13 is the first. The same transport path as that of the discharge path R1 on the first surface is used.

  Next, an image forming operation of the laser beam printer 1 configured as described above will be described.

  When image information is sent from a personal computer (not shown) and the controller board 31 that has image-processed the image information issues a print command, the sheet S stacked on the paper feed cassette 2 that is detachably attached to the printer main body 1A. Is fed by a feed roller 30. Thereafter, the sheets S are separated one by one by the separation roller pair 3 and then conveyed to the registration roller pair 5 through the relay roller 4 to correct skewing. Further, after the skew feeding is corrected by the registration roller pair 5 in this way, it is sent to a transfer portion constituted by a nip between the photosensitive drum 7 and the transfer roller 9 in the process cartridge.

  On the other hand, laser light L having image information converted into a bit image is irradiated on the photosensitive drum based on the image information together with the print command, and a latent image is formed on the surface of the photosensitive drum 7 according to the bit image. . Further, by developing this latent image, a toner image is formed on the photosensitive drum.

  The toner image formed on the photosensitive drum in this way is transferred to the sheet S sent to the transfer portion by the registration roller pair 5. Further, the sheet S to which the toner image has been transferred is thereafter sent to the fixing unit 10 and is heated and pressurized by the fixing unit 10 so that the toner image is semi-permanently fixed.

  The sheet S that has passed through the fixing unit 10 is sent to the first nip N1 between the fixing discharge roller 11 and the first roller 12. Here, when an image is formed only on the first surface of the sheet S, an intermediate discharge roller pair that is rotated forward by being guided by the inner and outer guide members 22 and 23 and the rotation guide member 24 thereafter. 15 is sent. Thereafter, the sheet is sent to the discharge roller pair 16 by the intermediate discharge roller pair 15 and discharged to the sheet discharge stacking table 25 by the discharge roller pair 16.

  On the other hand, when images are formed on both sides of the sheet S, the sheet S first passes through the first nip N1 of the fixing discharge roller 11, and then is rotated by the intermediate discharge roller pair 15 and the discharge roller pair 16 that are rotating forward. It is conveyed toward the discharge stacking table 25.

  Thereafter, when the trailing end of the sheet passes through the first nip N1, the intermediate discharge roller pair 15 and the discharge roller pair 16 are temporarily stopped and then reversely rotated. As a result, the sheet S enters the second nip N2 formed by the fixing discharge roller 11 and the second roller 13 with the rear end of the leading edge reversed, and is nipped and conveyed by the fixing discharge roller 11 and the second roller 13 to be reversed. It enters the re-conveying path R through the curved portion 17.

  Next, the sheet S is skew-corrected by a lateral registration correction unit 18 provided in the re-conveyance path R, and is conveyed by the re-feed roller 20 to a junction 19 with the conveyance path from the sheet cassette 2. . After that, the toner image formed on the photosensitive drum is transferred to the transfer section through the relay roller 4 and the registration roller pair 5.

  Next, the sheet S passes through the fixing unit 10, the first nip N <b> 1 between the fixing discharge roller 11 and the first roller 12, and then is guided by the inner and outer guide members 22 and 23 and the rotation guide member 24. It is sent to the intermediate discharge roller pair 15 that is rotating. Thereafter, the sheet is discharged onto the sheet discharge stack 25 by the discharge roller pair 16.

  Next, the state of the sheet discharge unit 14 during automatic double-sided printing in which images are formed on both sides of the sheet S will be described.

  In the case of automatic duplex printing, after an image is formed on the first surface, the sheet S passes through the first nip N1 of the fixing discharge roller 11 as shown in FIG. Here, in the present embodiment, as described above, the rotation guide member 24 pivotally supported by the inner guide member 22 and urged to a predetermined position by a spring (not shown) is the first nip N1. With respect to the escape angle of the sheet S, the sheet S is disposed above with a predetermined clearance C. As a result, the sheet S is conveyed without the leading end being caught by the rotation guide member 24.

  Next, the sheet S reaches the intermediate discharge roller pair 15 that is rotating forward, and is conveyed by the intermediate discharge roller pair 15, the fixing discharge roller 11, and the first roller 12. At this time, depending on the mode of the apparatus, the conveyance speed of the intermediate discharge roller pair 15 may be set faster than the conveyance speed of the fixing discharge roller 11. In this case, the sheet S is stretched substantially linearly at the nip N3 of the intermediate discharge roller pair 15 and the first nip N1 of the fixing discharge roller 11 as shown in FIG.

  Here, when the sheet S is in such a state, the rotation guide member 24 is pressed by the tensioned sheet S and rotates in the direction of arrow A, and the nip of the intermediate discharge roller pair 15 is rotated. Retreat to a straight line connecting N3 and the first nip N1 of the fixing discharge roller 11.

  When the rotation guide member 24 rotates in this way, the sheet S can be conveyed without applying an excessive load to the sheet S. As a result, even when there is a difference in sheet conveyance speed between the two roller pairs, the toner immediately after being heated and permanently fixed by the fixing unit 10 by the rotation guide member 24 in contact with the image forming surface side of the sheet S. The sheet S can be conveyed without the image being peeled off.

  Next, when the trailing edge of the sheet S passes through the first nip N1 of the fixing discharge roller 11 and reaches a predetermined position, the intermediate discharge roller pair 15 rotates reversely so as to guide the sheet S to the refeed conveyance path. Begin.

  Here, when the sheet passes through the first nip N1, the rear end portion of the sheet S is released from the restraint by the first nip N1, and thus the sheet S is not stretched substantially in a straight line. As a result, as shown in FIG. 3A, the rotation guide member 24 is rotated in the direction of arrow B by a spring (not shown) and guides the sheet S conveyed by the reverse rotation of the intermediate discharge roller pair 15. Move to position. As a result, the sheet S is urged toward the outer guide member 23 side.

  Further, when the rotation guide member 24 moves to the guide position in this way, the first nip N1 of the fixing discharge roller 11 is blocked by the outer guide member 23, and the movement of the sheet S to the fixing discharge roller side is performed. Be regulated. Therefore, as the intermediate discharge roller pair 15 is reversed, the sheet S is reliably and smoothly conveyed to the second nip N2 between the fixing discharge roller 11 and the second roller 13 as shown in FIG. .

  As described above, when the rotation guide member 24 is pressed by the sheet S conveyed by the fixing discharge roller 11 and the intermediate discharge roller pair 15, the toner image on the sheet is peeled off by being retracted. Can be prevented and good image quality can be maintained. Further, when the sheet S passes through the fixing discharge roller 11, the rotation guide member 24 moves to the guide position, so that good switchback conveyance can be realized regardless of the curl factor, and the sheet is reliably imaged. It can be conveyed again to the forming unit 1B.

  Next, a second embodiment of the present invention will be described.

  FIG. 4 is a diagram showing a schematic configuration of a laser beam printer which is an example of the image forming apparatus according to the embodiment of the present invention. In FIG. 4, the same reference numerals as those in FIG. 1 denote the same or corresponding parts.

  In FIG. 4, a third roller 26 is a roller that contacts the sheet S, and the third roller 26 is rotatably provided at the rotation end of the rotation guide member 24 that contacts the sheet S.

  Next, a description will be given of a state in automatic duplex printing in which images are formed on both sides of the sheet of the sheet discharge unit 14 including the rotation guide member 24 having the third roller 26 provided at the rotation end in this way. .

  In the case of automatic duplex printing, after an image is formed on the first surface, the sheet S passes through the first nip N1 of the fixing discharge roller 11 as shown in FIG. Here, the rotation guide member 24 is disposed above with a predetermined clearance C with respect to the escape angle of the sheet S in the first nip N1. As a result, the sheet S is conveyed without the leading end being caught by the third roller 26 of the rotation guide member 24.

  Next, the sheet S is conveyed by the intermediate discharge roller pair 15 rotating in the forward direction. At this time, the conveyance speed of the intermediate discharge roller pair 15 may be faster than the conveyance speed of the fixing discharge roller 11. In this case, the sheet S is stretched substantially linearly at the nip N3 of the intermediate discharge roller pair 15 and the first nip N1 of the fixing discharge roller 11 as shown in FIG.

  Here, when the sheet S is in such a state, the rotation guide member 24 is pressed by the tensioned sheet S and rotates in the direction of arrow A, and the nip of the intermediate discharge roller pair 15 is rotated. Retreat to a straight line connecting N3 and the first nip N1 of the fixing discharge roller 11.

  When the rotation guide member 24 rotates in this way, the sheet S can be conveyed without applying an excessive load to the sheet S. At this time, the third roller 26 is brought into contact with the sheet S, and the third roller 26 is driven in accordance with the conveyance of the sheet S. Therefore, the third roller 26 can be conveyed without being rubbed on the printing surface.

  As a result, even when there is a difference in sheet conveyance speed between the two roller pairs, the toner immediately after being heated and permanently fixed by the fixing unit 10 by the rotation guide member 24 in contact with the image forming surface side of the sheet S. The sheet S can be conveyed without the image being peeled off.

  Next, when the trailing edge of the sheet S passes through the first nip N1 of the fixing discharge roller 11 and reaches a predetermined position, the intermediate discharge roller pair 15 rotates reversely so as to guide the sheet S to the refeed conveyance path. Begin.

  Here, when the sheet passes through the first nip N1, the rear end portion of the sheet S is released from the restraint by the first nip N1, and thus the sheet S is not stretched substantially in a straight line. As a result, as shown in FIG. 6A, the rotation guide member 24 and the third roller 26 are rotated in the direction of arrow B by a spring (not shown), and are conveyed by the reverse rotation of the intermediate discharge roller pair 15. Move S to the guide position. As a result, the sheet S is urged toward the outer guide member 23 side.

  Further, when the rotation guide member 24 moves to the guide position in this way, the first nip N1 of the fixing discharge roller 11 is blocked by the outer guide member 23, and the movement of the sheet S to the fixing discharge roller side is performed. Be regulated. Therefore, the sheet S is reliably and smoothly conveyed to the second nip N2 between the fixing discharge roller 11 and the second roller 13 as shown in FIG. .

  As described above, the third roller 26 is provided at the rotation end of the rotation guide member 24, and the third roller 26 is driven according to the conveyance of the sheet S, so that the rotation guide member 24 is not rubbed on the printing surface. The sheet S can be conveyed. Thus, the sheet S can be conveyed without peeling off the toner image immediately after being heated and permanently fixed by the fixing unit 10.

  In the description so far, the laser beam printer has been exemplified as the image forming apparatus provided with the sheet conveying apparatus according to the present invention, but the present invention is not limited to this. For example, the present invention can be applied to any image forming apparatus in which a sheet conveying apparatus such as a monochrome copying machine, a printer, a facsimile machine, a full color copying machine or the like can be installed.

1 is a diagram illustrating a schematic configuration of a laser beam printer which is an example of an image forming apparatus including a sheet conveying device according to a first embodiment of the present invention. FIG. 3 is a first diagram illustrating a state of the sheet conveying apparatus during automatic double-sided printing. FIG. 6 is a second diagram illustrating a state of the sheet conveying apparatus during automatic double-sided printing. FIG. 5 is a diagram illustrating a schematic configuration of a laser beam printer which is an example of an image forming apparatus including a sheet conveying device according to a second embodiment of the invention. FIG. 3 is a first diagram illustrating a state of the sheet conveying apparatus during automatic double-sided printing. FIG. 6 is a second diagram illustrating a state of the sheet conveying apparatus during automatic double-sided printing. FIG. 3 is a diagram illustrating a schematic configuration of a laser beam printer which is an example of an image forming apparatus including a conventional sheet conveying device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Laser beam printer 1B Image formation part 1C Refeed conveyance part 10 Fixing unit 11 Fixation discharge roller 12 1st roller 13 2nd roller 14 Sheet discharge part 15 Intermediate discharge roller pair 16 Discharge roller pair 22 Inner guide member 23 Outer guide member 24 Rotating guide member 26 Third roller R Re-conveying passage S Sheet

Claims (6)

In the sheet conveying apparatus that inverts the sheet so as to form an image on the second surface opposite to the sheet on which the image is formed on the first surface by the image forming unit, and conveys the image again to the image forming unit.
Sheet conveying means for conveying the sheet on which the image is formed;
A re-conveying passage for conveying the sheet on which the image is formed on the first surface to the image forming unit again;
A sheet reversing and conveying means capable of reversing forward and reverse to convey the sheet conveyed by the sheet conveying means to the re-conveying path;
A guide unit provided between the sheet conveying unit and the sheet reverse conveying unit, and abutting on an image forming surface side of the sheet conveyed by the sheet conveying unit,
The guide means retracts when it reaches the sheet reverse conveying means and is pressed by the sheet reverse conveying means and the sheet conveyed by the sheet conveying means, and when the sheet passes through the sheet conveying means, the sheet reverse conveying A sheet conveying apparatus, wherein the sheet conveying apparatus moves to a guide position for guiding the sheet conveyed toward the re-conveying path by reversing the means.   2. The sheet conveying apparatus according to claim 1, wherein the guide means moved to the guide position regulates movement of the sheet toward the re-conveying path toward the sheet conveying means by reversing the sheet reversing and conveying means. .   3. The sheet conveying apparatus according to claim 1, wherein a roller is provided at a contact portion of the guide means with the sheet.   The sheet conveying means is on the downstream side in the sheet conveying direction of the fixing unit for fixing the image formed on the sheet, the sheet reverse conveying means is above the sheet conveying means, and the guide means is the sheet conveying means and the sheet. The sheet conveying apparatus according to any one of claims 1 to 3, wherein the sheet conveying apparatus is provided at a position facing a curved guide member disposed between the reverse conveying means.   The sheet conveying means includes a roller that rotates in a sheet conveying direction, a first roller that contacts the roller and holds the sheet from the fixing unit together with the roller toward the sheet reverse conveying means, and the first roller And a second roller for holding and conveying the sheet conveyed by the reverse rotation of the sheet reversing and conveying means together with the roller toward the re-conveying path. Item 5. The sheet conveying apparatus according to any one of Items 1 to 4. An image forming apparatus comprising: an image forming unit; and the sheet conveying device according to claim 1 that conveys a sheet to the image forming unit.

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