JP4396532B2 - Paper conveying apparatus and image forming apparatus - Google Patents

Description

  The present invention relates to a sheet conveying apparatus that conveys a sheet and an image forming apparatus including the sheet conveying apparatus, and in particular, a sheet conveying apparatus that includes a driving roll that is rotationally driven and a driven roll that is driven in pressure contact with the driving roll. The present invention also relates to an image forming apparatus including the sheet conveying device.

2. Description of the Related Art A conventional image forming apparatus that includes a drive roll that is driven to rotate and a driven roll that is driven in pressure contact with the drive roll is known as a paper transport apparatus that transports a recording medium (paper) such as paper or OHP. It has been. As a driven roll, there is known a driven roll having a plurality of driven roll parts arranged in the axial direction and a connecting shaft for connecting the plurality of driven roll parts.
The following prior art (J01) is well known as a sheet conveying apparatus provided with such a driven roll.
(J01) Technology described in Patent Document 1 (Japanese Patent Application Laid-Open No. 2002-344163) Patent Document 1 includes a plurality of driven roll sections, a connecting shaft that connects the plurality of driven roll sections, and an outer driven roll section. A paper transport device having a driven shaft having an end shaft provided at an end portion, and pressing and pressing an end shaft support member (bearing) supporting the end shaft toward a driving roll by a spring. It describes, but the member which supports a connecting shaft is not described.

JP 2002-344163 A (FIGS. 5 and 6)

(Problems of conventional technology)
In the prior art (J01), since the member that supports the connecting shaft is not provided, the driven roll is deformed in a direction away from the driving roll when the paper is sandwiched and conveyed between the driving roll and the driven roll. There is a problem that there is a possibility that the paper cannot be accurately conveyed.
In order to solve this problem, it is conceivable to provide a bearing (bearing) so that the connecting shaft is rotatably supported and the position of the connecting shaft does not move during conveyance. However, since the orientation of the paper conveyed to the pressure contact area (nip) between the driving roll and the driven roll, the state of the wave of the paper, etc., differ from paper to paper, the paper conveyance direction and the paper are different even if such a bearing is used. The sheet may bend in a direction perpendicular to the width direction (a direction in which the driving roll and the driven roll face each other). When the paper is bent, the bent portion comes into contact with the driving roll and the driven roll, and noise is generated, the paper is transported obliquely, wrinkles are generated on the paper, and the image quality is deteriorated. was there.

In view of the above circumstances, the present invention has the following description (O01) as a technical problem.
(O01) Suppressing the bending of the paper during the conveyance of the paper.

(Invention)
Next, the present invention that has solved the above problems will be described. In order to facilitate the correspondence between the elements of the present invention and elements of specific examples (examples) of the embodiments described later, Add the code enclosed in parentheses. The reason why the present invention is described in correspondence with the reference numerals of the embodiments described later is to facilitate understanding of the present invention, and not to limit the scope of the present invention to the embodiments.

(First invention)
In order to solve the technical problem, the paper transport device of the first invention is:
A paper transporting member having a drive roll that is rotationally driven and a driven roll that is driven in pressure contact with the drive roll;
A pair of driven roll portions disposed apart from each other in the axial direction; an elastically deformable connecting shaft for connecting the pair of driven roll portions; and an end shaft provided at an outer end portion of the pair of driven roll portions; And said follower roll having
An end shaft support member that rotatably supports the end shaft;
A connecting shaft support member that supports the connecting shaft so as to be rotatable and movable in the paper conveying direction, and that holds the driven roll in pressure contact with the driving roll;
It is provided with.

(Operation of the first invention)
In the paper transport device according to the first aspect of the present invention having the above-described configuration requirements, a paper transport member having a drive roll that is rotationally driven and a driven roll that is driven in pressure contact with the drive roll transports the paper. The follower rolls are provided at a pair of follower roll portions disposed apart in the axial direction, an elastically deformable connecting shaft for connecting the pair of follower roll portions, and outer ends of the pair of follower roll portions. And an end shaft. The end shaft support member rotatably supports the end shaft. The connecting shaft support member supports the connecting shaft so as to be rotatable and movable in the paper transport direction, and holds the driven roll in pressure contact with the drive roll.

  Therefore, in the sheet conveying device of the first invention, the driven roll and the drive roll are held in pressure contact with each other by the connecting shaft support member that supports the connecting shaft, so that the connecting shaft is deformed in a direction away from the driving roll. It is possible to prevent the paper from being accurately fed. In the paper transport device of the first invention, the connecting shaft support member supports the connecting shaft so as to be movable in the paper transport direction, and the end shaft support member rotatably supports the end shaft. Therefore, there are cases where the connecting shaft portion is elastically deformed in the paper transport direction in accordance with the transport of the transported paper and the driving roll, and the driven roll portion transports the paper so as to spread the paper outward in the paper width direction. In this case, since the recording paper is expanded in the paper width direction, it is possible to suppress the paper from being bent, and it is possible to suppress the generation of noise, the paper being inclined, and the generation of wrinkles. It is done.

(First Embodiment 1)
The sheet conveying apparatus according to the first aspect of the present invention is the first invention, wherein
The connecting shaft support member configured by a leaf spring that presses the connecting shaft in the driving roll press-contact direction;
It is provided with.
(Operation of the first invention)
In the sheet conveying apparatus according to the first aspect of the present invention having the above-described structural requirements, the connecting shaft support member is configured by a leaf spring that presses the connecting shaft in the driving roll press-contact direction. Therefore, the configuration can be simplified, the number of parts can be reduced, and the cost can be suppressed.

(First Embodiment 2)
A sheet conveying apparatus according to a second aspect of the first invention is the sheet conveying apparatus according to the first aspect of the present invention or the first aspect of the first invention.
The driven roll integrally formed of a resin material;
It is provided with.
(Operation of the second aspect of the first invention)
In the paper conveying apparatus according to the second aspect of the first invention having the following constituent elements, the driven roll is integrally formed of a resin material. Therefore, the number of parts can be reduced and the cost can be suppressed.

(Second invention)
In order to solve the technical problem, an image forming apparatus according to a second aspect of the invention includes the sheet conveying apparatus according to any one of the first aspect and the first and second aspects of the invention.
(Operation of the second invention)
The image forming apparatus according to the second aspect of the invention having the above-described constituent features includes the sheet conveying device according to any one of the first aspect and the first and second aspects of the invention, so that the connecting shaft support member drives the connecting shaft. Since it is brought into pressure contact with the roll, it can be prevented that the connecting shaft is deformed in a direction away from the drive roll and the paper cannot be accurately fed. In the image forming apparatus according to the second aspect of the present invention, the paper conveying device supports the connecting shaft supporting member so that the connecting shaft can move in the paper conveying direction, and the end shaft supporting member rotatably supports the end shaft. ing. Therefore, the connecting shaft portion may be elastically deformed in the paper transport direction according to the transport of the transported paper or the drive roll, and the driven roll unit may transport the paper so as to spread the paper outward in the paper width direction. In this case, since the recording paper is expanded in the paper width direction, it is possible to suppress the paper from being bent, and to suppress the generation of noise, the paper being inclined, and the generation of wrinkles. be able to. Therefore, it is possible to suppress deterioration in image quality due to inclination or wrinkling of the paper.

The above-described present invention has the following effects (E01) to (E03).
(E01) It is possible to suppress the bending of the sheet during the sheet conveyance.
(E02) It is possible to suppress the generation of noise due to the bending of the sheet, the conveyance of the sheet at an inclination, and the generation of wrinkles.
(E03) It is possible to suppress deterioration in image quality due to the inclination or wrinkling of the paper.

Next, specific examples (examples) of the embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited to the following examples.
In order to facilitate understanding of the following description, in the drawings, the front-rear direction is the X-axis direction, the left-right direction is the Y-axis direction, the up-down direction is the Z-axis direction, and arrows X, -X, Y, -Y, The direction indicated by Z and -Z or the indicated side is defined as the front side, the rear side, the right side, the left side, the upper side, the lower side, or the front side, the rear side, the right side, the left side, the upper side, and the lower side, respectively.
In the figure, “•” in “○” means an arrow heading from the back of the page to the front, and “×” in “○” is the front of the page. It means an arrow pointing from the back to the back.

FIG. 1 is an overall perspective view of an image forming apparatus including a sheet conveying device according to a first exemplary embodiment of the present invention.
2 is a longitudinal sectional view of the image forming apparatus shown in FIG.
1 and 2, an image forming apparatus U including a fixing device according to the first embodiment includes a printer U0 as an image forming apparatus main body and an optional sheet reversing device U1 that is detachably attached to the printer U0. I have. A first paper discharge tray TRh is provided on the upper surface of the printer U0.
On the upper surface of the printer U0, a UI (user interface) for input operation by a user is provided, and a power switch and the like are provided on the UI.
A lower door cover D1 (see FIGS. 1 and 2) is provided on the left side wall of the printer U0. The lower door cover D1 is rotatable between a normal position indicated by a solid line and an open position (jam clear position) indicated by a virtual line (two-dot chain line).

Electrical signals such as image data and printer control commands transmitted from the host computer HC are input to the controller C of the printer U0. The controller C includes a microcomputer and a storage device. The controller C temporarily stores the input image data, and outputs the image data to the laser drive circuit DL as image data for forming a latent image at a predetermined timing.
The laser drive circuit DL outputs a laser drive signal to the ROS (latent image forming apparatus) according to the input image data. The operation of the UI (user interface), the laser drive circuit DL, the developing roll Ga, which will be described later, and the power supply circuit E for applying a bias voltage to the transfer roll TR as a transfer device, is controlled by the controller C.

The photosensitive member (image carrier) PR is rotated integrally with its axis PRa in the direction of the arrow (clockwise in FIG. 2), and its surface is uniformly charged by a charging roll (charging member) CR. Then, exposure scanning is performed with a laser beam L of the ROS (latent image forming apparatus) at the latent image writing position, and an electrostatic latent image is formed.
The surface of the photoconductor PR on which the electrostatic latent image is formed rotates and moves sequentially, a developing area (area facing the developing roll Ga) and a transfer area (area facing the transfer roll TR, that is, an image recording area) Q1. Pass through.
The developing device G includes a developing container V that rotatably supports the developing roll Ga and the developer stirring members Gb, Gc, and Gd and that stores the developer. The developing device G is on the photoconductor PR that passes through the developing region. The electrostatic latent image is developed into a toner image.
A toner image forming device (PR + CR + ROS + G) for forming a toner image (image) on the photoconductor PR is formed by the photoconductor PR, the charging roll CR, ROS (latent image forming device), and the developing device G.

A plurality of paper feed trays TR1 to TR4 (see FIGS. 1 and 2) contain recording sheets (paper sheets) S for image recording to be conveyed to the transfer area Q1, and each of the paper feed trays TR1. ... -TR4 can enter / exit into a tray accommodating space inside the printer U0 from a paper feed tray insertion port formed on the front surface of the printer U0.
In FIG. 2, rails (movingly supporting) both left and right ends of the paper feed trays TR <b> 1 to TR <b> 4 that are put in and out (inserted and withdrawn) from the paper feed tray insertion opening are provided inside the lower portion of the printer U <b> 0 (tray storage space). Tray support members) RL1 and RL1 are disposed, and the paper feed trays TR1 to TR4 are supported by a pair of left and right rails RL1 and RL1 so as to be movable in the front-rear direction.

In FIG. 2, a paper feeding device K having a pick-up roll Rp and a separating roll Rs having a feed roll and a retard roll is provided on the upper side of the paper feed trays TR1 to TR4.
The recording sheets S taken out by the pickup roll Rp of the paper feeding device K are separated one by one by the separating roll Rs and fed to the main body sheet conveyance path SH1 of the sheet conveyance device SH. The fed recording sheet S is arranged on a sheet conveyance path SH1, and includes a plurality of sheet conveyance rolls (a rubber roll (driving roll) 1 that is driven to rotate and a driven roll 2 that is driven to rotate while being pressed against the driving roll). (Sheet conveying member) Ra is conveyed. In FIG. 2, the driven roll of the transport roll Ra is supported by the lower door cover D1, and moves integrally with the lower door cover D1 when the lower door cover D1 is opened and closed.

The recording sheet S conveyed by the sheet conveying roll Ra is conveyed to the transfer area Q1 at a predetermined timing by a registration roll Rr (see FIG. 2).
The printer (image forming apparatus main body) U0 is provided with a manual feed tray sheet transport path SH2 and a reverse sheet transport path SH3 that join the main body sheet transport path SH1.

  In FIG. 2, a transfer roll TR to which a transfer bias is applied is disposed in the transfer region Q1. The transfer roll TR is in pressure contact with the photosensitive member PR in the transfer region Q1, and transfers the toner image on the photosensitive member PR to the recording sheet S passing through the transfer region Q1. Note that a transfer device that transfers (records) a toner image (image) formed on the photoconductor PR onto a recording sheet is formed on the photoconductor instead of being configured only by the transfer roll TR as in the first embodiment. The toner image is primarily transferred to the intermediate transfer member by the primary transfer member, and the toner image on the intermediate transfer member is secondarily transferred to the recording sheet by the secondary transfer member. Or a transfer member of the type.

An image (recording image S) is formed on the recording sheet S by the toner image forming device (PR + CR + ROS + G) including the photoconductor PR, the charging roll CR, ROS (latent image forming device) and the developing device G, and the transfer roll TR as a transfer device. An image recording member (PR + CR + ROS + G + TR) for recording a toner image is configured.
After the toner image on the surface of the photoconductor PR is transferred to the recording sheet S in the transfer region Q1, the residual toner attached to the surface of the photoconductor PR is collected by the cleaner CL1. The photoconductor PR from which the residual toner adhering to the surface is collected by the cleaner CL1 is charged by the charging roll CR.

  The recording sheet S on which the unfixed toner image is transferred in the transfer area Q1 is conveyed to the fixing device F with the toner image being unfixed. The fixing device F has a pair of fixing rolls Fh and Fp that rotate while being pressed against each other. The unfixed toner image on the recording sheet S is heat-fixed when passing through the fixing nip Q2 which is a pressure contact region between the pair of fixing rolls Fh and Fp. The recording sheet S on which the fixing toner image is formed is then guided by the sheet guide and conveyed to the paper discharge roll R1. The recording sheet S is discharged from the sheet discharge port Ha (see FIG. 2) to the discharge tray (first discharge tray) TRh by the discharge roll R1.

A main body sheet reversing path SH4 connected to the sheet discharge port Ha is provided inside the printer U0.
The optional sheet reversing device U1 has an option sheet reversing path SH5 therein, and the upstream end of the option sheet reversing path SH5 is connected to the downstream end of the main body sheet reversing path SH4. The recording sheet S conveyed to the optional sheet reversing path SH5 is sequentially conveyed to the reversing sheet conveying path SH3 and the main body sheet conveying path SH1, and further to the transfer area Q1 by a sheet conveying roll Ra, a registration roll Rr, and the like. Be transported.
The main body sheet reversing path SH4, the option sheet reversing path SH5, and the reversing sheet conveying path SH3 constitute a sheet reversing path (SH3 + SH4 + SH5).

A sheet reversing device U1 (optional device) that can be attached to and detached from the printer (image forming apparatus main body) U0 has a manual feed tray TR0 and a recording medium from the manual feed tray TR0 to the manual feed tray sheet transport path SH2. An optional manual sheet feeding path SH6 for conveying a sheet is provided. The sheet S fed from the manual feed tray TR0 is transported from the optional manual feed sheet transport path SH6 and the manual feed tray sheet transport path SH2 to the main body sheet transport path SH1, and then to the main body sheet transport path SH1. The sheet is conveyed to the transfer area Q1 by the sheet conveying roll Ra and the registration roll Rr arranged along the line.
The sheet reversing device U1 is provided with an optional sheet discharge tray (second sheet discharge tray) TRh1 connected to the option sheet reversing path SH5. An optional sheet discharge path SH7 is provided between the optional sheet discharge tray TRh1 and the option sheet reversing path SH5. The recording sheet conveyed through the option sheet discharge path SH7 is discharged from the sheet discharge port Hb to the option discharge tray TRh1.

(Description of driven roll)
FIG. 3 is an explanatory diagram of a lower door cover of the image forming apparatus according to the first exemplary embodiment.
In FIG. 3, hinge connecting portions 6 for hinge connection to the image forming apparatus main body U0 are formed at both ends of the lower portion of the inner wall of the lower door cover D1, and a projection 6a for connecting the front hinge has a hole. 6a 'is formed, and a pin 6b' is provided on the rear projection 6b. A pair of magnets 7 are supported on both ends of the upper portion of the inner wall of the lower door cover D1, and the lower door cover D1 is attached to the normal position by being attracted by a magnetic force (not shown) on the image forming apparatus main body U0 side. Hold the cover in the closed position. In addition, a grip portion 8 that is gripped when the user opens and closes the lower door cover D1 is provided on the upper front side of the lower door cover D1.

  A plurality of driven roll cases 11 in which the driven rolls 2 of the sheet conveying roll Ra are accommodated are supported on the inner wall of the lower door cover D1. In FIG. 3, between each driven roll case 11 inside the lower door cover D1, a guide member for guiding the recording sheet S conveyed in the main body sheet conveying path SH1 (see the one-dot chain line in FIG. 3). However, illustration is omitted for the description of the present invention.

4 is an explanatory view of a driven roll case of Example 1, FIG. 4A is a perspective view, FIG. 4B is a view seen from the direction of arrow IVB in FIG. 4A, FIG. 4C is a view seen from the direction of arrow IVC in FIG. 4D is a view seen from the direction of arrow IVD in FIG. 4C, FIG. 4E is a cross-sectional view taken along the line IVE-IVE in FIG. 4B, and FIG. 4F is a cross-sectional view taken along the line IVF-IVF in FIG.
In FIG. 4, the driven roll case 11 includes an upper plate 13 extending in the front-rear direction, a side wall 14 bent downward from the right end of the upper plate 13, and a lower plate bent leftward from the lower end of the side wall 14. 16. A plurality of upper spring mounting holes 13a (see FIG. 4A) are formed in the central portion of the upper plate 13. On the side wall 14 of the case body 12, roll protrusions 14a and 14a for the driven roll 2a of the driven roll 2 to protrude toward the drive roll 1 are formed. A plurality of lower spring mounting holes 16a (see FIG. 4C) are formed in the lower plate 16 of the case body 12 corresponding to the upper spring mounting port 13a. 4D, a pair of screwing portions 16b extending downward is integrally formed at the left end portion (−Y end portion) of the lower plate 16, and the screwing portions 16b each have a screw through hole 16c. And screw penetration long hole 16d is formed. Therefore, the driven roll case 11 is attached to the lower door cover D1 by the screw that passes through the screw through hole 16c and the screw through long hole 16d.

  In FIG. 4, the driven roll case 11 includes a driven roll 2, end shaft support members (end bearings) 21 and 21 that rotatably support both ends of the driven roll 2, and the driven roll. A connecting shaft support member (connecting shaft bearing) 22 that rotatably supports the central portion of 2 is accommodated. The shaft support members 21 and 22 are urged toward the drive roll 1 by urging springs 23 whose both ends are mounted in the spring mounting holes 13a and 16a. Therefore, when the lower door cover D1 is held in the normal position, the driving roll 1 and the driven roll 2 are pressed against each other with a predetermined pressure (nip pressure) by the biasing spring 23.

FIG. 5 is an explanatory diagram of the driven roll, FIG. 5A is a plan view, and FIG. 5B is a cross-sectional view taken along the line VB-VB in FIG. 5A.
4 and 5, the driven roll 2 is disposed in the paper width direction so as to be sandwiched between the drive roll 1 and the recording sheet S is sandwiched and conveyed downstream in the paper conveyance direction. And a connecting shaft 2b for connecting the pair of driven roll portions 2a, and end shafts 2c provided at both outer ends of the driven roll 2. In the driven roll 2 of the first embodiment, the driven roll portion 2a, the connecting shaft 2b, and the end shaft 2c are integrally formed of a resin material (plastic). Further, in the driven roll portion 2a of the first embodiment, the outer peripheral surface of the driven roll portion 2a is the edge of the roll protrusion 14a when the lower door cover D1 is moved to the open position (the state is not pressed against the drive roll 1). It is designed to be held in contact with the

6A and 6B are explanatory views of the end shaft support member, FIG. 6A is a perspective view, FIG. 6B is a view seen from the arrow VIB direction in FIG. 6A, FIG. 6C is a view seen from the arrow VIC direction in FIG. 6B is a view seen from the direction of the arrow VID in FIG. 6B, FIG. 6E is a view seen from the direction of the arrow VIE in FIG. 6B, and FIG. 6F is a sectional view taken along the line VIF-VIF in FIG.
In FIG. 6, the end shaft support member 21 has a cylindrical portion 21b in which an end shaft support hole 21a into which the end shaft 2c is fitted is formed, and the biasing force is applied to the outer peripheral surface of the cylindrical portion 21b. The spring 23 is engaged. A pair of locking portions 21c and 21c extending in the radial direction of the cylindrical portion 21b are formed on the outer peripheral surface of the cylindrical portion 21b. The locking portion 21 c is locked to the inner surface of the driven roll case 11 when the driven roll 2 is driven to rotate in a state where it is disposed in the driven roll case 11. Accordingly, the end shaft support member 21 does not rotate together with the driven roll 2 but supports the end shaft 2c of the driven roll 2 in a rotatable manner.

  A positioned portion 21d is formed in the cylindrical portion 21b opposite to the end shaft support hole 21a. In the positioned portion 21d, a rib guide groove 21e is formed along the left-right direction (the Y-axis direction, the direction facing the drive roll 1, the direction of mounting on the lower door cover D1), and the left end of the rib guide groove 21e ( On the lower door cover D1 side), a tapered portion 21f is formed so as to spread outward. Therefore, when the driven roll case 11 is mounted on the lower door cover D1, positioning ribs (not shown) formed on the lower door cover D1 are guided by the tapered portion 21f and engaged with the rib guide grooves 21e. Then, the end shaft support member 21 is positioned. The end shaft support member 21 is prevented from rotating by the rib guide groove 21e and the positioning rib. That is, in the end shaft support member 21 of the first embodiment, the locking portion 21c and the rib guide groove 21e constitute a rotation stop of the end shaft support member 21.

7 is an explanatory view of the connecting shaft support member, FIG. 7A is a side view, FIG. 7B is a view seen from the direction of arrow VIIB in FIG. 7A, and FIG. 7C is a sectional view taken along the line VIIC-VIIC in FIG.
In FIG. 7, the connecting shaft support member 22 is formed integrally with a semi-cylindrical portion 31 with which the urging spring 23 engages with an outer peripheral surface 31 a (see FIG. 7C), and both axial ends of the semi-cylindrical portion 31. Plate portion 32 formed. The connecting shaft support groove 31b that forms the inner peripheral surface of the semi-cylindrical portion 31 is long in the groove width direction (vertical direction, direction along the paper conveyance direction), and is in pressure contact with the groove depth direction (left and right direction, drive roll). Direction). Therefore, as shown in FIGS. 7B and 7C, the length of the connecting shaft support groove 31b in the groove width direction is longer than the diameter of the connecting shaft 2b (see the two-dot chain line in FIGS. 7B and 7C). The connecting shaft 2b is supported so as to be movable in the groove width direction (paper transport direction). On the other hand, as shown in FIGS. 7B and 7C, the depth of the connecting shaft support groove 31b in the groove depth direction is such that the connecting shaft support groove 31b is connected to the connecting shaft when the lower door cover D1 is held in the normal position. The driven roll 2 is formed in such a depth that it is held in contact with the drive roll 1 in contact with 2b.

Locking portions 32a are formed at the upper end portion and the lower end portion of the plate portion 32. Like the locking portion 21c, the plate portion 32 is connected to the driven roll case 11 while being rotated in the driven roll case 11. The shaft support member 22 is locked to the inner surface of the driven roll case 11 so as not to rotate. The interval between the plate portions 32 at both ends is formed to be substantially the same as the length of the connecting shaft 2b, and engages with the end surface of the driven roll portion 2a when the driven roll 2 is shaken in the axial direction. Therefore, it is possible to reduce the displacement of the driven roll 2 in the axial direction and to prevent the biasing spring 23 that engages with the outer peripheral surface 31a of the inner semi-cylindrical portion 31 from being detached.
The drive roll 1, the driven roll 2, the driven roll case 11, the end shaft support member 21, the connecting shaft support member 22, the urging spring 23, and the like constitute the paper transport device 41 of the first embodiment.

(Operation of Example 1)
In the image forming apparatus U having the sheet conveying device 41 according to the first embodiment having the above-described configuration, the end shaft 2c of the driven roll 2 is rotatably supported by the end shaft support member 21, and the connecting shaft 2b is supported by the connecting shaft. The member 22 is supported so as to be able to move in the paper conveyance direction and to hold the state where the driven roll 2 is pressed against the drive roll 1 (the state where the recording sheet S can be held). In the image forming apparatus U provided with the sheet conveying device 41 of the first embodiment, the recording sheet S can be accurately fed, and the skew and wrinkle of the sheet due to the bending of the recording sheet S do not occur. . About this effect, this inventor thinks as follows.

8A and 8B are diagrams for explaining the operation of the driven roll according to the first embodiment. FIG. 8A is a diagram for explaining a normal operation, and FIG.
In the paper transport device 41 according to the first exemplary embodiment, the driven roll 2 is held in pressure contact with the drive roll 1, so that the connecting shaft 2 b is deformed in a direction away from the drive roll 1 and the paper cannot be transported accurately. Can be prevented. In FIG. 8, the connecting shaft 2 b is supported by the connecting shaft support member 22 so as to be movable in the paper transport direction. Therefore, when the recording sheet S is transported, the recording sheet S transported and the drive roll 1 rotate. The portion of the connecting shaft 2b of the driven roll 2 that is driven to rotate is elastically deformed downstream in the paper transport direction. Accordingly, as shown in FIG. 8, the driven roll 2 is elastically deformed in a bow shape, and the pair of driven roll portions 2a conveys the recording sheet S so as to spread outward in the paper width direction. Therefore, in the paper conveying device 41 of the first embodiment, the recording sheet S is suppressed from being bent, noise is generated by the bent recording sheet S, the recording sheet S is conveyed in an inclined manner, The generation of wrinkles was suppressed.

  Moreover, in the paper conveying apparatus 41 of Example 1, since the driven roll 2 is integrally molded with the resin material, the number of parts can be reduced, and manufacturing costs, maintenance costs, and the like can be suppressed.

Next, a second embodiment of the present invention will be described. In the description of the second embodiment, components corresponding to those of the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted. To do. The second embodiment is different from the first embodiment in the following points, but is configured in the same manner as the first embodiment in other points.
9 is an explanatory view of the driven roll case of Example 2, FIG. 9A is a view seen from the left side corresponding to FIG. 4D of Example 1, FIG. 9B is a sectional view taken along line IXB-IXB of FIG. These are explanatory drawings of the example 1 of a change of Example 2 corresponding to FIG. 9B.

9A and 9B, in the sheet conveying device 41 ′ according to the second embodiment, the connecting shaft 2b is attached to the drive roll 1 side instead of the connecting shaft support member 22 and the urging spring 23 of the driven roll 2 according to the first embodiment. A leaf spring (connection shaft support member) 22 ′ that is urged and supported so as to be movable in the paper transport direction is fixedly supported by the driven roll case 11.
The drive roll 1, the driven roll 2, the end shaft support member 21, the leaf spring (connection shaft support member) 22 ′, and the like constitute a sheet transport device 41 ′ according to the second embodiment.

(Operation of Example 2)
In the sheet conveying apparatus 41 ′ according to the second embodiment having the above-described configuration, the leaf spring 22 ′ urges the connecting shaft 2b toward the drive roll 1 and supports it so as to be movable in the sheet conveying direction. The same effects as the transport device 41 are obtained. Furthermore, since the connecting shaft support member 22 'is configured by the leaf spring 22' in the sheet conveying device 41 'according to the second embodiment, the configuration becomes simple, the number of parts can be reduced, and the cost can be reduced.

(Modification 1 of Example 2)
In FIG. 9C, in the paper conveying device 41 ″ according to the first modification of the second embodiment, instead of the leaf spring 22 ′ according to the second embodiment, it is arranged so as to wind around the connection shaft 2b, and the connection shaft 2b is connected to the drive roll 1 side. A leaf spring (connecting shaft support member) 22 ″ is used which is urged to be supported and movably supported in the paper conveying direction.
The sheet conveying device 41 ″ of the second embodiment having the above configuration has the same effects as the sheet conveying device 41 ′ of the second embodiment.

(Example of change)
As mentioned above, although the Example of this invention was explained in full detail, this invention is not limited to the said Example, A various change is performed within the range of the summary of this invention described in the claim. It is possible. Modification examples (H01) to (H05) of the present invention are exemplified below.
(H01) The present invention is not limited to a printer, and can be applied to an image forming apparatus such as a copying machine, a FAX, or a multifunction machine. Further, the present invention is not limited to a monochrome image forming apparatus, and can be applied to a color image forming apparatus.

(H02) In the above embodiment, the driven roll 2 is integrally formed. However, the present invention is not limited to this. For example, the driven roll 2 may be constituted by a plurality of driven rolls and a single shaft penetrating the driven roll portion. In this case, the shaft may be a rotation shaft that is rotatably supported by the shaft support members 21 and 22, or may be a fixed shaft that is fixedly supported by the shaft support members 21 and 22. Is possible. Furthermore, the end shaft 2c and the connecting shaft 2b can be configured separately.
(H03) In the above embodiment, the driven roll 2 is made of a resin material. However, the invention is not limited to this, and the driven roll 2 can be made of an elastically deformable material. For example, it can be configured by a metal material, a hard rubber material, or the like.

(H04) In the above-described embodiment, the shaft support members 21 and 22 are configured to be urged toward the drive roll 1 by the urging spring 23. However, the present invention is not limited to this. For example, the urging spring 23 is omitted. Thus, the driving roll 1 can be biased toward the driven roll 2 side.
(H05) In the above embodiment, the paper transport device 41 that transports the paper S fed from the paper feed trays TR1 to TR4 has been described. However, the present invention is not limited to this, and other parts that transport the paper on the paper transport path It is also possible to apply to. Therefore, the present invention is not limited to the driven roll 2 that is disposed on the door cover D1 that can be opened and closed and that can be pressed against and separated from the driving roll 1, and is applied to a driven roll in which the driving roll and the driven roll are disposed so as not to be separated from each other. Is also possible.

FIG. 1 is an overall perspective view of an image forming apparatus including a sheet conveying device according to a first exemplary embodiment of the present invention. 2 is a longitudinal sectional view of the image forming apparatus shown in FIG. FIG. 3 is an explanatory diagram of a lower door cover of the image forming apparatus according to the first exemplary embodiment. 4 is an explanatory view of a driven roll case of Example 1, FIG. 4A is a perspective view, FIG. 4B is a view seen from the direction of arrow IVB in FIG. 4A, FIG. 4C is a view seen from the direction of arrow IVC in FIG. 4D is a view seen from the direction of arrow IVD in FIG. 4C, FIG. 4E is a cross-sectional view taken along the line IVE-IVE in FIG. 4B, and FIG. 4F is a cross-sectional view taken along the line IVF-IVF in FIG. FIG. 5 is an explanatory diagram of the driven roll, FIG. 5A is a plan view, and FIG. 5B is a cross-sectional view taken along the line VB-VB in FIG. 5A. 6A and 6B are explanatory views of the end shaft support member, FIG. 6A is a perspective view, FIG. 6B is a view seen from the arrow VIB direction in FIG. 6A, FIG. 6C is a view seen from the arrow VIC direction in FIG. 6B is a view seen from the direction of arrow VID in FIG. 6B, FIG. 6E is a view seen from the direction of arrow VIE in FIG. 6B, and FIG. 6F is a cross-sectional view taken along the line VIF-VIF in FIG. 7 is an explanatory view of the connecting shaft support member, FIG. 7A is a side view, FIG. 7B is a view seen from the direction of arrow VIIB in FIG. 7A, and FIG. 7C is a sectional view taken along the line VIIC-VIIC in FIG. 8A and 8B are diagrams for explaining the operation of the driven roll according to the first embodiment. FIG. 8A is a diagram for explaining a normal operation, and FIG. 9 is an explanatory view of the driven roll case of Example 2, FIG. 9A is a view seen from the left side corresponding to FIG. 4D of Example 1, FIG. 9B is a sectional view taken along line IXB-IXB of FIG. These are explanatory drawings of the example 1 of a change of Example 2 corresponding to FIG. 9B.

Explanation of symbols

1 ... Driving roll,
2 ... Follower roll,
2a ... driven roll part,
2b ... connecting shaft,
2c ... end shaft,
21 ... End shaft support member,
22, 22 ', 22 "... connecting shaft support member,
22 '... leaf spring,
41, 41 ′, 41 ″...
Ra: a sheet conveying member.

Claims (4)

A paper transporting member having a drive roll that is rotationally driven and a driven roll that is driven in pressure contact with the drive roll;
A pair of driven roll portions disposed apart from each other in the axial direction; an elastically deformable connecting shaft for connecting the pair of driven roll portions; and an end shaft provided at an outer end portion of the pair of driven roll portions; And said follower roll having
An end shaft support member that rotatably supports the end shaft;
A connecting shaft support member that supports the connecting shaft so as to be rotatable and movable in the paper conveying direction, and that holds the driven roll in pressure contact with the driving roll;
A sheet conveying apparatus comprising: The connecting shaft support member configured by a leaf spring that presses the connecting shaft in the driving roll press-contact direction;
The sheet conveying apparatus according to claim 1, further comprising: The driven roll integrally formed of a resin material;
The sheet conveying apparatus according to claim 1, further comprising: An image forming apparatus comprising the sheet conveying device according to claim 1.

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