JP2006347730A - Paper carrying device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To stably carry paper, by surely restraining jumping-up of the carried paper. <P>SOLUTION: In this paper carrying device 5, a feed roller 15 rotating for carrying the paper and a driven feed roller 16 making a pair with this feed roller 15, are arranged in a paper carrying passage 12. A central near part in the width direction of the paper is sandwiched and sent between the driven feed roller 16 and the feed roller 15. A pair of guides 21 for guiding an end part in the width direction of the carrier paper are rotatably supported by a pair of support shafts 19 of a pair of driven feed rollers 16. The guides 21 slidingly contact with the paper on a second guide surface 26 formed as an inclined face, and surely restrain the jumping-up of the end part of the carried paper. The pair of guides 21 and the pair of driven feed rollers 16 are juxtaposed at a predetermined interval in the axial direction S, and stably carry the paper, and restrain an inclination of the paper. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a paper conveying apparatus that is provided in a copying machine or the like and conveys paper.

In the paper transport device, for example, a transport path for transporting paper is partitioned between a pair of partition members, and a pair of rollers facing each other is provided to feed the paper along the transport path. When one roller is driven to rotate, the other roller rotates in conjunction with this. The paper is fed between the pair of rollers.
When the paper passes between the pair of rollers, the passed paper may jump and hit a partition member near the rollers. As a result, abnormal noise may occur.

Therefore, there is a paper transport device having a pressing member that presses the paper in order to suppress the occurrence of paper splash (see, for example, Patent Documents 1 and 2).
In Patent Document 1, the pressing member is a plurality of leaf springs that can contact the paper, and is disposed away from the roller at a position downstream of the roller in the paper conveyance direction, and in the paper width direction. Are arranged side by side.

In Patent Document 2, the pressing member is a leaf spring that can come into contact with the paper, and is disposed in the vicinity of the roller in the paper conveyance direction, and is disposed at a position corresponding to the central portion of the paper in the width direction of the paper. Has been.
Japanese Utility Model Publication No. 1-70746 Japanese Patent Laid-Open No. 10-232567

However, in Patent Document 1, since the pressing member is separated from the pair of rollers in the transport direction, it may not be possible to suppress the jumping of the paper.
In Patent Document 2, since the pressing member is in contact with the central portion in the width direction of the paper, the end in the width direction in which the paper is likely to jump cannot be pressed, and the jump may not be suppressed.
SUMMARY OF THE INVENTION An object of the present invention is to provide a paper transport device that can reliably suppress paper splashing.

  The paper transport device of the present invention is provided in a paper transport path, and is paired with a feed roller that rotates to transport the paper. The paper is sandwiched between the feed rollers and rotated in accordance with the rotation of the feed roller. A driven feed roller, and a guide for guiding the edge of the sheet to be conveyed, arranged at a predetermined interval from the driven feed roller along the axial direction of the driven feed roller, It has a guide surface formed on an inclined surface that protrudes obliquely to the paper conveyance path as it goes downstream in the conveyance direction.

  According to the present invention, the guide can come into contact with the end portion in the width direction (corresponding to a direction orthogonal to the transport direction) of the transported paper in the vicinity of the feed roller and the driven feed roller in the transport direction. Can be reliably suppressed. As a result, the occurrence of abnormal noise can be suppressed. In addition, it is possible to guide the edge in the width direction of the sheet with a guide, and to stably convey the central portion in the width direction of the sheet by the feed roller and the driven feed roller. Therefore, it is possible to suppress the occurrence of tilting of the paper and the folding of the edge of the paper.

In the present invention, the guide may be rotatably held on a support shaft for rotatably supporting the driven feed roller.
In this configuration, since the guide rotates, the impact when the paper contacts the guide can be reduced, so that the generation of abnormal noise can be further suppressed. Since the guide is rotatably held, the support shaft for the driven feed roller can also be used, so that the structure can be simplified.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
In the present embodiment, description will be made in accordance with a case where the sheet conveying apparatus is applied to a copying machine as an image forming apparatus. However, the image forming apparatus may be a printer, a facsimile, or the like.
FIG. 1 is a schematic configuration diagram showing a sheet conveying device of a copying machine, and other parts of the copying machine are schematically shown.

The image forming apparatus 1 includes an image reading unit 2 for reading a document image and obtaining image data, an image forming unit 3 for forming an image on a sheet based on the image data obtained by the image reading unit 2, and the image forming unit. 3 has a sheet conveying device 5 that conveys the sheet from the sheet supply unit 4.
The paper supply unit 4 stores paper in a stacked state. The sheets are fed one by one from the sheet supply unit 4 and sent to the image forming unit 3 in accordance with the timing of image formation in the image forming unit 3.

  In the image forming unit 3, the outer peripheral surface of the photosensitive drum 6 is uniformly charged by the main charger 7 while rotating the photosensitive drum 6 as an image carrier. At the same time, beam light corresponding to the image data is generated by the optical unit 8 to expose the photosensitive drum 6, and a desired image corresponding to the image data is formed on the outer peripheral surface of the photosensitive drum 6 to statically. An electrostatic latent image is formed. The electrostatic latent image is visualized into a toner image by the developing device 9. The toner image is transferred by the transfer unit 10 to a sheet as a transfer material sent from the sheet supply unit 4. The sheet on which the toner image is transferred is sent to the fixing unit 11 where the toner image is heated and fixed on the sheet. Thereafter, the paper is discharged out of the machine.

The paper transport device 5 sends the paper fed from the paper supply unit 4 to the image forming unit 3 in accordance with the timing of image formation. In FIG. 1, a sheet conveyance path is illustrated by a one-dot chain line.
The paper transport device 5 includes first and second partition members 13 and 14 that partition a paper transport path 12 for feeding paper from the paper supply unit 4 to the image forming unit 3, and along the paper transport path 12. A pair of registration rollers for feeding a sheet fed by these rollers 15 and 16 to the image forming unit 3 in accordance with the timing of image formation. It has rollers 17 and 18. The sheet is conveyed from the bottom to the top so as to be substantially along the vertical direction as the conveyance direction H. In the transport direction H, a pair of rollers 15 and 16 and first and second partition members 13 and 14 are arranged upstream of the pair of registration rollers 17 and 18.

The first and second partition members 13 and 14 are disposed to face each other. Between the first and second partition members 13 and 14, a gap is formed as the paper transport path 12. In the paper transport path 12, both sides of the paper face the corresponding first and second partition members 13 and 14, respectively.
The feed roller 15 is rotatable around its central axis 15a, is supported by the first partition member 13, and is drivably connected to an electric motor (not shown) as a drive source. The driving-side feed roller 15 is driven and rotated to convey the paper.

  The driven feed roller 16 is supported by the second partition member 14 via a support shaft 19 and is rotatable about a central axis 16 a of the driven feed roller 16 (corresponding to the central axis of the support shaft 19). It is. The driven feed roller 16 is supported so as to be displaceable with respect to the feed roller 15 in a direction in which the pair of rollers 15 and 16 face each other, and a biasing member (not shown) such as a spring toward the feed roller 15. Z)).

  The central axis 15a of the feed roller 15 and the central axis 16a of the driven feed roller 16 are arranged in parallel to each other. These central axes 15a and 16a are parallel to the direction perpendicular to the transport direction and extend in a direction along the surface of the transported paper. A direction in which the central axes 15a and 16a extend (also referred to as an axial direction S. The axial direction S is a direction perpendicular to the paper surface in FIG. 1) corresponds to the width direction of the conveyed paper.

The driven feed roller 16 and the drive-side feed roller 15 are in contact with each other at the nip portion. A nip portion of the pair of rollers 15 and 16 is disposed in the sheet conveyance path 12.
When the feed roller 15 on the driving side rotates and the driven feed roller 16 rotates in conjunction with the rotation, the paper is passed between the driven feed roller 16 and the feed roller 15 and the nip portion of the driven feed roller 16. It is sandwiched between the nip portion of the feed roller 15 and fed to the pair of registration rollers 17 and 18.

One registration roller 17 is rotatably supported by the first partition member 13 and is drivably connected to an electric motor (not shown) as a drive source. The other registration roller 18 is rotatably supported by the second partition member 14. The pair of registration rollers 17 and 18 extend in parallel to the axial direction S and are arranged to face each other.
The pair of registration rollers 17 and 18 starts to rotate in synchronization with the image formation timing. By the time rotation is started, the downstream end of the sheet in the conveyance direction is in contact with the pair of registration rollers 17 and 18. By rotating the pair of registration rollers 17 and 18, the sheet is sandwiched between them, and the sheet is sent out between the photosensitive drum 6 and the transfer unit 10.

In the present embodiment, the second partition member 14, the driven registration roller 18, and the driven feed roller 16 form a unit 20.
FIG. 2 is a perspective view of the unit 20. Please refer to FIG. 2 and FIG.
The unit 20 includes a single second partition member 14, single driven registration rollers 17 and 18, and two driven feed rollers 16.

In the present embodiment, the unit 20 has a pair of guides 21 that can guide the end portion P1 in the width direction of the paper P to be conveyed.
The guide 21 slidably contacts the corresponding end portion P1 in the width direction of the paper P to guide the end portion P1, thereby preventing the paper P from bouncing. Since the sheet 21 is likely to jump immediately after the sheet 21 is separated from the state where the sheet P is sandwiched between the nip portions of the feed roller 15 and the driven feed roller 16, the position corresponding to the nip portion of the driven feed roller 16 in the transport direction H. And it arrange | positions in the position close | similar to this position. Further, since the end portion P1 of the sheet P in the width direction tends to jump, the guide 21 is disposed at a position corresponding to the end portion P1 of the sheet P in the width direction.

  A pair of driven feed rollers 16 are disposed between the pair of guides 21. The pair of guides 21 and the pair of driven feed rollers 16 are arranged side by side along the axial direction S of the driven feed roller 16 and are arranged with a predetermined interval therebetween. The distance between the pair of driven feed rollers 16 is a value in a range from a half to a quarter of the distance between the pair of guides 21, for example, a value of one third.

  With respect to the width direction of the paper, one guide 21 is disposed at a position facing one end P1 in the width direction of the paper P being conveyed, and can be guided in contact with this end. The other guide 21 is disposed at a position facing the other end portion P1 in the width direction of the sheet P being conveyed, and can be guided by contacting the end portion P1. The pair of driven feed rollers 16 is disposed at a position facing a predetermined portion P2 near the center in the width direction of the paper P to be conveyed, and the predetermined portion P2 is located between both ends P1 in the width direction of the paper P. It is a part in. In the present embodiment, the predetermined portion P2 is a pair of portions adjacent to the central portion in the width direction of the paper P being conveyed. The pair of portions are portions on both sides of the center portion that avoid the center portion in the width direction of the sheet. The pair of driven feed rollers 16 can feed a predetermined portion P2 of the paper between the corresponding feed rollers 15.

  Further, the unit 20 is configured to be substantially symmetrical with respect to the width direction of the paper. That is, the axis of symmetry is a straight line that passes through the central position of the paper transport path 12 in the paper width direction and extends in the transport direction H. A pair of guides 21 are arranged so as to be symmetric with respect to the straight line. Further, a pair of driven feed rollers 16 are arranged so as to have the above-described line symmetry. Moreover, the 2nd division member 14 is formed in the shape which becomes the above-mentioned line symmetry.

The second partition member 14 has first, second, and third portions 22, 23, and 24 that are arranged in order from the upstream side to the downstream side in the transport direction H.
A recess is formed in the second portion 23. A pair of driven feed rollers 16 and a pair of guides 21 are disposed in the recess. The nip portions of the pair of driven feed rollers 16 and the guide surfaces of the pair of guides 21 are disposed so as to face the sheet conveyance path 12 from the recesses.

  The second portion 23 has a plurality of ribs 23a (only some are shown). Each rib 23 a is disposed at a position avoiding the pair of driven feed rollers 16 and the pair of guides 21, and extends along the conveyance direction H. The leading end portion of the rib 23 a continuously connects the planar first and third portions 22 and 24, and defines the sheet conveyance path 12 together with the first and third portions 22 and 24.

The pair of driven feed rollers 16 are rotatably attached to the pair of support shafts 19 so that they can rotate independently of each other. The pair of support shafts 19 are rotatably supported by the second partition member 14 so that they can be displaced independently of each other.
FIG. 3 is a perspective view of one guide 21, one driven feed roller 16, and one support shaft 19 illustrated on the upper side of FIG. 2. Please refer to FIG. 2 and FIG.

  One guide 21 is fitted and attached to one support shaft 19, and is rotatable with respect to the support shaft 19 around the central axis of the support shaft 19. Therefore, the one guide 21 and the one driven feed roller 16 are relatively rotatable around the central axis of the one support shaft 19. One guide 21 is connected to one driven feed roller 16 through one support shaft 19. One guide 21 follows the displacement of one driven feed roller 16 toward the sheet conveyance path 12 and can be displaced in the same manner as this displacement.

Similarly to the one guide 21, the one support shaft 19, and the one driven feed roller 16, the other guide 21, the other support shaft 19, and the other driven feed roller 16 are configured.
The pair of guides 21 can be displaced independently of each other and can be rotated independently of each other. The pair of guides 21 are formed in the same shape. Below, it demonstrates focusing on one guide 21. FIG.

The guide 21 is in contact with the end P1 of the sheet P in the width direction of the sheet at the portion facing the sheet transport path 12, and the first, second and third guide surfaces 25, which can guide the end P1. 26, 27. Each guide surface 25, 26, 27 is formed with a predetermined length in the width direction of the paper.
The first guide surface 25 is relatively upstream in the transport direction H, and is positioned upstream of the nip portion of the driven feed roller 16 with respect to the transport direction H when assembled in the unit 20. . The first guide surface 25 is formed in a convexly curved R surface having a circular arc cross section.

  The second guide surface 26 is disposed downstream of the first guide surface 25 in the transport direction H and is formed as a flat surface. The second guide surface 26 has a predetermined length straight in one direction from the position near the nip portion of the driven feed roller 16 toward the downstream side in the transport direction H in the state assembled to the unit 20. It extends in. The first and second guide surfaces 25 and 26 are connected continuously and smoothly.

Since the second guide surface 26 can guide and contact the sheet while the sheet is nipped at the nip portion and immediately after leaving the nip portion, the conveyance state of the sheet can be stabilized.
The second guide surface 26 is formed on an inclined surface that protrudes obliquely toward the paper conveyance path 12 as it goes downstream in the conveyance direction H. In the cross section perpendicular to the axial direction S, the distance between the second guide surface 26 and the central axis of the support shaft 19 is increased as the second guide surface 26 is located on the downstream side in the transport direction H. The second guide surface 26 includes a downstream portion 26a as described below. That is, in the cross section perpendicular to the axial direction S, the distance between the downstream portion 26a of the second guide surface 26 and the central axis of the support shaft 19 is compared with the second axis in the same position in the transport direction H. The distance between the surface of the partition member 14 and the central axis of the support shaft 19 is approximately equal to or longer than this distance.

The third guide surface 27 is disposed downstream of the second guide surface 26 in the transport direction H, and is formed on a convexly curved R surface having an arcuate cross section. The second and third guide surfaces 26 and 27 are connected continuously and smoothly.
FIG. 4 is a cross-sectional view of the main part of the sheet conveying device 5, mainly showing the guide 21. FIG. 5 is a cross-sectional view of another main part of the sheet conveying device 5, and mainly shows a feed roller 15 and a driven feed roller 16. Please refer to FIG. 4 and FIG.

  The guide 21 has first and second restricting portions 28 and 29 that restrict the rotation angle range around the support shaft 19. The first restricting portion 28 restricts one end of the rotation angle range of the guide 21 by abutting with the first abutting portion 30 provided in the concave portion of the second partition member 14, and the guide 21 Is restricted from rotating in one direction (clockwise in FIG. 4). The second restricting portion 29 restricts the other end of the rotation angle range of the guide 21 by abutting against the second abutting portion 31 provided in the concave portion of the second partition member 14, so that the guide 21 Is restricted from rotating in the other direction. By rotating the guide 21 in this way, the downstream portion 26a, which is the end portion of the second guide surface 26, can temporarily protrude into the paper transport path 12 from the tip of the rib 23a.

The first partition member 13 has a planar guide portion that faces the pair of guides 21. Further, the drive-side feed roller 15 is disposed at a position facing the driven feed roller 16 and is formed with substantially the same length in the width direction as the corresponding driven feed roller 16.
Referring to FIGS. 1 and 2, in the paper transport device 5 of the present embodiment, the paper transported one by one from the paper supply unit 4 through the paper transport path 12 is at the downstream end in the transport direction H. First, the first guide surface 25 of the guide 21 guides at both end portions P1 in the width direction. The sheet is sandwiched between the nip portion between the driving-side feed roller 15 and the driven-feed roller 16 at a predetermined center P2 in the width direction at the upstream end in the transport direction H. It is sent as the rollers 15 and 16 rotate.

  Next, referring to FIG. 4 and FIG. 5, a predetermined portion in the center in the width direction at the upstream end in the transport direction H is separated from the nip portions of the feed roller 15 and the driven feed roller 16, It is transported a predetermined distance. During this time, the sheet is fed while being guided by the second guide surface 26 of the guide 21 at the end in the width direction at the upstream end in the transport direction H. The guide 21 can stably guide the paper while attenuating the paper splash by rotating with the friction between the guide shaft 19 and following the movement (bounce) of the paper. .

As described above, according to the embodiment of the present invention, the guide 21 can contact the end portion P1 of the sheet P to be transported in the vicinity of the feed roller 15 and the driven feed roller 16 in the transport direction H. Can be reliably suppressed. As a result, the occurrence of abnormal noise can be suppressed.
Further, with respect to the width direction of the sheet, both ends of the sheet are guided by the pair of guides 21, and only a predetermined portion near the center of the sheet is sandwiched between the feed roller 15 and the driven feed roller 16. As a result, the paper can be stably conveyed. Therefore, the occurrence of problems such as the inclination of the sheet, the end of the sheet being folded, and the generation of wrinkles on the sheet during conveyance is suppressed.

  That is, when the end of the sheet in the width direction is sandwiched between the pair of rollers 15 and 16, the feeding force and frictional force of the rollers tend to act on the sheet as a large moment. As a result, the paper tends to be inclined or the paper tends to be wrinkled. On the other hand, when only a predetermined portion near the center in the width direction of the paper is sandwiched between the pair of rollers 15 and 16, the moment is sufficient, so that the paper is less likely to be inclined and wrinkles are less likely to occur. Further, when the pair of driven feed rollers 16 are arranged symmetrically with respect to the central portion in the width direction of the sheet, at least a part of the moment can be canceled.

Further, the guide 21 is rotatable and displaceable, and more preferably, the guide 21 is displaceable with friction, so that the sheet can be moved to the guide 21 as compared with an elastically displaceable guide (not shown). The impact at the time of contact can be alleviated and the generation of abnormal noise can be further suppressed.
Further, by attaching the guide 21 to the support shaft 19, the support shaft 19 for the driven feed roller 16 can be used in order to hold the guide 21 so as to be rotatable, so that the structure can be simplified.

Further, the second guide surface 26 of the guide 21 is formed on the above-described inclined surface, and the guide 21 is rotatably supported by the support shaft 19. Thereby, the guide 21 can be displaced in conjunction with the driven feed roller 16 via the support shaft 19.
Moreover, the following modifications can be considered about this embodiment. In the following description, differences from the above-described embodiment will be mainly described, and the same components are denoted by the same reference numerals and description thereof is omitted.

It is also conceivable that the driven feed roller 16 is provided with three or more or a single roller. In addition, the driven feed roller 16 may be fed with a corresponding central portion in the width direction of the sheet as the predetermined portion P2 of the sheet between the corresponding feed roller 15 and the sheet.
Three or more guides 21 may be provided. It is also conceivable that only a single guide 21 is provided and only one end in the width direction of the sheet is guided by this guide 21.

  The structure for supporting the guide 21 in a freely rotatable manner is not particularly limited. For example, the driven feed roller 16 may be attached to the support shaft 19 so as to be integrally rotatable, and the support shaft 19 may be rotatably supported by the second partition member 14. Further, the driven feed roller 16 may be rotatably fitted around a support shaft 19 fixed to the second partition member 14. Therefore, the guide 21 only needs to be rotatably held on the support shaft 19 for rotatably supporting the driven feed roller 16. Further, a dedicated support shaft (not shown) for rotatably supporting the guide 21 may be provided.

  Further, the second guide surface 26 may be formed on a curved inclined surface. In addition, the second guide surface 26 is formed on an inclined surface that can temporarily protrude into the paper conveyance path 12 toward the downstream side in the conveyance direction H. However, the present invention is not limited to this. It may be formed on an inclined surface that always protrudes to the paper conveyance path 12 toward the downstream side in the conveyance direction H regardless of the rotation position. In short, the guide 21 only needs to have a second guide surface 26 as a guide surface formed on an inclined surface that protrudes into the paper transport path 12 toward the downstream side in the transport direction.

  As the sheet conveying device 5, a plurality of types of sheets having different sizes may be conveyed. In this case, the central portion in the width direction of each size of paper may pass through the central position in the width direction of the paper transport path 12. Further, one end in the width direction of each size sheet may be conveyed along one end in the width direction of the sheet conveyance path 12. In addition, various design changes can be made within the scope of the matters described in the claims.

1 is a schematic configuration diagram of a copying machine including a sheet conveying device according to an embodiment of the present invention, and other parts of the copying machine are schematically illustrated. It is a perspective view of the unit shown in FIG. FIG. 3 is a perspective view of a guide, a driven feed roller and a support shaft shown in FIG. It is sectional drawing of the principal part of the paper conveying apparatus of FIG. 1, and mainly shows a guide. FIG. 6 is a cross-sectional view of another main part of the sheet conveying device of FIG. 1.

Explanation of symbols

DESCRIPTION OF SYMBOLS 5 ... Paper conveying apparatus 12 ... Paper conveying path 15 ... Feed roller 16 ... Driven feed roller 19 ... Support shaft 21 ... Guide 26 ... 2nd guide surface (guide surface)
H: Conveyance direction P: Paper P1: Paper edge S: Axial direction (driven roller)

Claims (2)

A driven feed roller that is provided in the paper transport path and that is paired with a feed roller that rotates to transport the paper, and that is driven by the rotation of the feed roller with the paper sandwiched between the feed roller;
Along the axial direction of the driven feed roller, the driven feed roller is arranged with a predetermined interval, and has a guide for guiding the end of the conveyed paper,
The paper transporting apparatus according to claim 1, wherein the guide has a guide surface formed on an inclined surface that protrudes obliquely into the paper transporting path toward the downstream side in the transporting direction. In the paper conveying apparatus according to claim 1,
The sheet conveying device according to claim 1, wherein the guide is rotatably held on a support shaft for rotatably supporting the driven feed roller.

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