JP2021031195A - Recording medium conveyance device and image formation apparatus - Google Patents

Abstract

To provide a recording medium conveyance device and an image formation apparatus which can suppress the abnormal sound that is generated due to the conveyance of a recording medium by a stop roll in comparison to a case where the movement in the axial direction of a first conveyance roll and a second conveyance roll on the upstream side in the conveyance direction of the recording medium is always restrained with respect to the stop roll.SOLUTION: A first conveyance roll forms a loop in a stopped recording medium by bringing the tip of the recording medium into contact with a stop roll, and is movable in the axial direction by receiving the force in the axial direction that is generated in the conveyed recording medium. A second conveyance roll rotates, holds and conveys the recording medium to deliver the recording medium to the first conveyance roll, and is movable in the axial direction by receiving the force in the axial direction that is generated in the conveyed recording medium.SELECTED DRAWING: Figure 1

Description

The present invention relates to a recording medium transport device and an image forming device.

The paper transport device described in Patent Document 1 is a first method for correcting skew by abutting a pair of handling rollers that separate and convey paper one by one and a tip of paper conveyed by the pair of handling rollers. A pair of resist rollers and a pair of second resist rollers for abutting the tip of the paper conveyed by the first pair of resist rollers to correct skewing are provided.

Japanese Unexamined Patent Publication No. 2013-237506

In the conventional recording medium transfer device, the tip of the recording medium conveyed by the transfer roll is abutted against the stop roll, and the stop roll stops the tip of the recording medium. As a result, a loop is formed in the recording medium, and the skew of the conveyed recording medium is corrected.

When the degree of skew of the conveyed recording medium is large, the difference between the height of the loop at one end and the height of the loop at the other end becomes large in the width direction of the recording medium. The difference in loop height is maintained when the axial movement of the first first transport roll and the second second transport roll on the upstream side is restricted with respect to the stop roll in the transport direction of the recording medium. In this state, the stop roll conveys the recording medium. As a result, abnormal noise may be generated.

An object of the present invention is that the first transport roll on the upstream side in the transport direction of the recording medium can move in the axial direction with respect to the stop roll, and the axial movement of the second transport roll is always restricted. Then, the abnormal noise generated by the stop roll carrying the recording medium is suppressed.

The recording medium transfer device according to the first aspect of the present invention has a stop roll that stops the tip of the transferred recording medium in a state where the rotation is stopped, and a stop roll that rotates to sandwich and convey the recording medium to the stop roll. A first transport roll capable of forming a loop in a recording medium that has stopped by abutting the tip of the recording medium and being movable in the axial direction by receiving an axial force generated in the transporting recording medium. The recording medium is rotated and conveyed with the recording medium sandwiched between them, and the recording medium is delivered to the first transfer roll. The recording medium is sandwiched and conveyed with the tip of the recording medium abutted against the stop roll. It is characterized by including a second transport roll that is movable in the axial direction by receiving an axial force generated in the recording medium.

In the recording medium transfer device according to the second aspect of the present invention, in the recording medium transfer device according to the first aspect, the first transfer roll is arranged in the central portion of the moving region of the first transfer roll in the axial direction. It is characterized by including a first arrangement mechanism for arranging the second transfer roll in the axial direction and a second arrangement mechanism for arranging the second transfer roll in a central portion of a moving region of the second transfer roll.

The recording medium transfer device according to the third aspect of the present invention is the recording medium transfer device according to the second aspect, wherein the first arrangement mechanism is provided on both ends of the first transfer roll, respectively, and the first transfer is performed. It is characterized in that, in a state where the roll is arranged in the central portion of the moving region, one side is provided with a pair of first urging members for urging the first transport roll on the other side.

The recording medium transfer device according to the fourth aspect of the present invention is the recording medium transfer device according to the second or third aspect, wherein the second arrangement mechanism is provided on both ends of the second transfer roll, respectively. It is characterized in that, in a state where the second transport roll is arranged in the central portion of the moving region, one side is provided with a pair of second urging members for urging the second transport roll on the other side.

The recording medium transfer device according to the fifth aspect of the present invention is the recording medium transfer device according to the fourth aspect which cites the third aspect, and the urging force of the second urging member is the urging force of the first urging member. It is characterized by being weak compared to the urging force.

The recording medium transfer device according to the sixth aspect of the present invention restrains or allows the axial movement of the second transfer roll in the recording medium transfer device according to any one of the first to fifth aspects. It is characterized by being provided with a restraint mechanism.

The recording medium transfer device according to the seventh aspect of the present invention includes the recording medium transfer device according to the sixth aspect, which includes another restraint mechanism that restrains or allows the axial movement of the first transfer roll. It is a feature.

The recording medium transfer device according to the eighth aspect of the present invention controls the restraint mechanism in the recording medium transfer device according to the seventh aspect, and the first transfer until the transferred recording medium hits the stop roll. It is characterized by including a control unit that restrains the axial movement of the roll and the second transport roll and allows the axial movement when the stop roll rotates.

The image forming apparatus according to the ninth aspect of the present invention includes an image on the recording medium conveying device according to any one of the first to eighth aspects for conveying the recording medium and the recording medium conveyed by the recording medium conveying device. It is characterized by including an image forming portion for forming the above.

In the recording medium transfer device according to the first aspect of the present invention, the first transfer roll on the upstream side in the transfer direction of the recording medium can move in the axial direction with respect to the stop roll, and the movement of the second transfer roll in the axial direction is possible. Compared with the case where the stop roll is always restrained, it is possible to suppress the abnormal noise generated by the stop roll carrying the recording medium.

In the recording medium transport device according to the second aspect of the present invention, the first transport roll and the second transport roll are in a state of transporting the recording medium as compared with the case where the first transport roll and the second transport roll are arranged at any position in the moving region. It is possible to suppress variations in the positions where the first transport roll and the second transport roll are arranged.

In the recording medium transport device according to the third aspect of the present invention, the position where the first transport roll is arranged varies as compared with the case where the urging member is provided on only one side of the first transport roll. It can be suppressed.

In the recording medium transport device according to the fourth aspect of the present invention, the position where the second transport roll is arranged varies as compared with the case where the urging member is provided on only one side of the second transport roll. It can be suppressed.

In the recording medium transport device according to the fifth aspect of the present invention, the stop roll transports the recording medium as compared with the case where the urging force of the first urging member and the urging force of the second urging member are the same. The generated abnormal noise can be suppressed.

In the recording medium transfer device according to the sixth aspect of the present invention, the axial movement of the second transfer roll can be switched between a restraint state and an allowable state.

In the recording medium transfer device according to the seventh aspect of the present invention, the axial movement of the first transfer roll can be switched between a restraint state and an allowable state.

In the recording medium transport device according to the eighth aspect of the present invention, as compared with the case where the restrained first transport roll and the second transport roll are allowed to move in the axial direction before the recording medium hits the stop roll. After the tip of the recording medium is abutted against the stop roll over the width direction of the recording medium, abnormal noise generated by the stop roll carrying the recording medium can be suppressed.

In the image forming apparatus according to the ninth aspect of the present invention, the movement of the first transport roll and the second transport roll on the upstream side in the transport direction of the recording medium with respect to the stop roll is always restricted in the axial direction. Compared with the case where the device is provided, it is possible to suppress the generation of abnormal noise generated by transporting the recording medium.

It is a developed view which showed the main part of the recording medium transporting apparatus which concerns on embodiment of this invention. It is a main part of the recording medium transporting apparatus which concerns on embodiment of this invention, and is the development view which showed the transporting state of a recording medium. It is a main part of the recording medium transporting apparatus which concerns on embodiment of this invention, and is the development view which showed the transporting state of a recording medium. It is a main part of the recording medium transporting apparatus which concerns on embodiment of this invention, and is the development view which showed the transporting state of a recording medium. (A) (B) It is a development side view which looked at the main part of the recording medium transporting apparatus which concerns on embodiment of this invention from the axial direction. (A) (B) It is a development side view which looked at the main part of the recording medium transporting apparatus which concerns on embodiment of this invention from the axial direction. (A) (B) It is a development side view which looked at the main part of the recording medium transporting apparatus which concerns on embodiment of this invention from the axial direction. (A) (B) It is a development side view which looked at the main part of the recording medium transporting apparatus which concerns on embodiment of this invention from the axial direction. It is a perspective view which showed the restraint mechanism of the recording medium transporting apparatus which concerns on embodiment of this invention. It is a perspective view which showed the restraint mechanism of the recording medium transporting apparatus which concerns on embodiment of this invention. It is a block diagram which showed the image holder and the like of the image forming apparatus which concerns on embodiment of this invention. It is a schematic block diagram which showed the image forming apparatus which concerns on embodiment of this invention. It is a developed view which showed the main part of the recording medium transporting apparatus which concerns on the comparative embodiment with respect to embodiment of this invention. It is a main part of the recording medium transporting apparatus which concerns on the comparative embodiment with respect to the embodiment of this invention, and is the development | development | drawing which showed the transporting state of the recording medium. It is a main part of the recording medium transporting apparatus which concerns on the comparative embodiment with respect to the embodiment of this invention, and is the development | development | drawing which showed the transporting state of the recording medium.

An example of the recording medium transport device and the image forming device according to the embodiment of the present invention will be described with reference to FIGS. 1 to 15. The arrow H shown in each figure is the vertical direction and indicates the vertical direction of the device, the arrow W is the horizontal direction and indicates the width direction of the device, and the arrow D is the horizontal direction and indicates the depth direction of the device.

(Overall configuration of image forming apparatus)
As shown in FIG. 12, the image forming apparatus 10 includes an image forming unit 12 for forming a toner image by an electrophotographic method, an accommodating unit 18 accommodating a recording medium P, and a control unit 28 for controlling each unit. ing. Further, the image forming apparatus 10 conveys the recording medium P accommodated in the accommodating unit 18 toward the image forming unit 12 along the conveying path 16, and reverses the recording medium P conveyed along the conveying path 16. It is provided with a transport unit 14 that transports the recording medium P along the line 26 by inverting the front and back surfaces and transports the recording medium P toward the image forming unit 12 again. The image forming method is not limited to the electrophotographic method, and may be, for example, an inkjet method.

In this configuration, in the image forming apparatus 10, the toner image formed by the image forming unit 12 is formed on the surface of the recording medium P which is conveyed along the conveying path 16. Further, the recording medium P on which the toner image is formed is discharged to the outside of the apparatus main body 10a.

On the other hand, when a toner image is formed on the back surface of the recording medium P, the recording medium P on which the toner image is formed on the front surface is conveyed along the inversion path 26, and the toner image formed again by the image forming unit 12 is displayed. It is formed on the back surface of the recording medium P. Then, the recording medium P is discharged to the outside of the apparatus main body 10a.

[Image forming unit 12]
As shown in FIG. 12, the image forming unit 12 transfers a plurality of toner image forming units 30 that form toner images of each color, and a transfer that transfers the toner image formed by the toner image forming unit 30 to the recording medium P. It is provided with a unit 32. Further, the image forming unit 12 includes a fixing device 34 for fixing the toner image transferred to the recording medium P by the transfer unit 32 to the recording medium P.

-Toner image forming unit 30-
A plurality of toner image forming units 30 are provided so as to form a toner image for each color. In the present embodiment, the toner image forming unit 30 of a total of four colors of yellow (Y), magenta (M), cyan (C), and black (K) is provided. In the following description, when it is not necessary to distinguish between yellow (Y), magenta (M), cyan (C), and black (K), Y, M, C, and K attached to the reference numerals are omitted. To do.

The toner image forming unit 30 of each color is basically configured in the same manner except for the toner to be used, and as shown in FIG. 11, the rotating cylindrical image holder 40 and the charge for charging the image holder 40 are charged. It is equipped with a vessel 42. Further, the toner image forming unit 30 uses an exposure device 44 for irradiating the charged image holder 40 with exposure light to form an electrostatic latent image and a developer G containing toner to convert the electrostatic latent image into a toner image. It is provided with a developing device 46 for developing. As a result, the toner image forming unit 30 of each color forms a toner image of each color using the toner of each color.

Further, as shown in FIG. 12, the image holder 40 of each color is in contact with the orbiting transfer belt 50 (details will be described later). Then, in the circumferential direction of the transfer belt 50 (see the arrow in the figure), the toner image forming portions 30 of yellow (Y), magenta (M), cyan (C), and black (K) are arranged in this order from the upstream side. They are arranged side by side in the horizontal direction.

-Transfer unit 32-
As shown in FIG. 12. It is provided with a primary transfer roll 52, which is arranged on the opposite side and transfers the toner image formed on the image holder 40 of each color to the transfer belt 50.

Further, the transfer unit 32 is arranged on the opposite side of the winding roll 56 around which the transfer belt 50 is wound and the winding roll 56 with the transfer belt 50 interposed therebetween, and records the toner image transferred on the transfer belt 50. It includes a secondary transfer roll 54 that transfers to the medium P. A transfer nip NT for transferring the toner image to the recording medium P is formed between the secondary transfer roll 54 and the transfer belt 50.

In this configuration, the toner image is primarily transferred by the primary transfer roll 52 onto the transfer belt 50 in the order of yellow (Y), magenta (M), cyan (C), and black (K). On the other hand, the toner image is transferred from the transfer belt 50 to the recording medium P which is sandwiched between the transfer belt 50 and the secondary transfer roll 54 and conveyed. Further, the recording medium P on which the toner image is transferred is delivered to the fixing device 34.

-Fixing device 34-
As shown in FIG. 12, the fixing device 34 is arranged on the downstream side of the transfer nip NT in the transport direction of the recording medium P. The fixing device 34 heats and pressurizes the toner image transferred to the recording medium P while conveying the recording medium P, and fixes the toner image on the recording medium P.

[Accommodation unit 18]
As shown in FIG. 12, the accommodating unit 18 includes an accommodating member 20 capable of accommodating the recording medium P, and a delivery roll 22 for sending the highest-level recording medium P loaded on the accommodating member 20 to the transport path 16. I have.

[Transporting unit 14]
As shown in FIG. 12, the transport unit 14 is arranged on one side (left side in the drawing) in the device width direction with respect to the accommodating unit 18, and the recording medium P sent out from the accommodating member 20 is conveyed. The recording medium P is conveyed along the transfer path 16. Further, when forming a toner image on the back surface of the recording medium P, the transport unit 14 reverses the front and back of the recording medium P by reversing the transport direction (by switchback transport) 26. The recording medium P is conveyed along the above. The details of the transport unit 14 will be described later.

(Action of the whole composition)
In the image forming apparatus 10, an image is formed as follows.

First, the charger 42 of each color shown in FIG. 11 uniformly negatively charges the surface of the image holder 40 of each color at a predetermined potential. Subsequently, the exposure apparatus 44 irradiates the surface of the charged image holder 40 of each color with exposure light to form an electrostatic latent image. Further, the developing device 46 for each color develops the electrostatic latent image and visualizes it as a toner image. Further, the toner images formed on the surface of the image holder 40 of each color are sequentially transferred to the transfer belt 50 by the primary transfer roll 52.

Therefore, the recording medium P sent out from the accommodating member 20 shown in FIG. 12 to the transfer path 16 by the delivery roll 22 is sent out to the transfer nip NT in which the transfer belt 50 and the secondary transfer roll 54 are in contact with each other. In the transfer nip NT, the toner image of the transfer belt 50 is transferred to the surface of the recording medium P by transporting the recording medium P between the transfer belt 50 and the secondary transfer roll 54.

Further, the toner image transferred to the surface of the recording medium P is fixed to the recording medium P by the fixing device 34. Then, the recording medium P on which the toner image is fixed is discharged to the outside of the apparatus main body 10a.

On the other hand, when a toner image is also formed on the back surface of the recording medium P, the recording medium P on which the toner image is formed on the front surface is conveyed along the inversion path 26, so that the front and back surfaces are inverted and transferred again. It is transported to the nip NT. Then, the toner image formed through the same steps as described above is transferred to the back surface of the recording medium P. Further, the toner image transferred to the back surface of the recording medium P is fixed to the recording medium P by the fixing device 34. Further, the recording medium P on which the toner image is fixed is discharged to the outside of the apparatus main body 10a.

(Main part composition)
Next, the transport unit 14 will be described. The transport unit 14 is an example of a recording medium transport device.

As shown in FIG. 12, the transport unit 14 has a first transport roll 60 and a second transport roll 60 that transport the recording medium P along the transport path 16 in which the recording medium P sent out from the accommodating member 20 is transported. It has 64 and. Further, the transport unit 14 includes a stop roll 68 for transporting the recording medium P along the transport path 16 and a discharge roll 70.

The second transport roll 64, the first transport roll 60, the stop roll 68, and the discharge roll 70 are arranged in this order from the upstream side to the downstream side in the transport direction of the recording medium P (hereinafter, “media transport direction”). .. The secondary transfer roll 54 and the fixing device 34 are arranged between the stop roll 68 and the discharge roll 70.

Further, the transport unit 14 is arranged on the upstream side of the stop roll 68 in the medium transport direction, and includes a detection sensor 96 (see FIG. 1) that detects the tip of the transport recording medium P.

Further, the transport unit 14 transfers the recording medium P to the conversion roll 36, the transport roll 38, and the transport path 16 along the reversing path 26 that reverses the front and back by reversing the transport direction of the recording medium P. It is provided with a switching member 58 that guides the recording medium P conveyed along the line to the reversing path 26.

Further, the first transport roll 60 is movable in the axial direction, and the transport unit 14 arranges the first transport roll 60 in the central portion of the moving region of the first transport roll 60 in the axial direction. The arrangement mechanism 94 is provided. Further, the second transport roll 64 is movable in the axial direction, and the transport unit 14 arranges the second transport roll 64 in the central portion of the moving region of the second transport roll 64 in the axial direction. The mechanism 114 is provided. Further, the transport unit 14 is provided with a restraint mechanism 120 (see FIG. 9) for restraining the axial movement of the second transport roll 64 and the axial movement of the first transport roll 60, respectively.

[Transportation of recording medium P in inversion path 26]
First, the transport of the recording medium P in the inversion path 26 will be described.
As shown in FIG. 12, the inversion path 26 extends from the branch path 26a branching from the downstream portion of the transport path 16 in the medium transport direction and the branch path 26a, and the recording medium P switches back. It has a turning path 26b. Further, the reversing path 26 extends from the end of the turning path 26b in a direction different from that of the branch path 26a, has a J shape when viewed from the depth direction of the device, and guides the recording medium P toward the stop roll 68. It has a character path 26c.

Then, the transport unit 14 stops the two conversion rolls 36 that switch back the recording medium P that has entered the conversion path 26b from the branch path 26a and the recording medium P that has switched back and entered the J-shaped path 26c. It is provided with three transport rolls 38 for transporting toward.

In this configuration, the switching member 58 guides the recording medium P on which the toner image is formed on the surface to the branch path 26a. The two conversion rolls 36 receive the recording medium P that has entered the conversion path 26b from the branch path 26a, and by switching back, the front and back sides of the recording medium P are inverted and conveyed toward the J-shaped path 26c. The three transport rolls 38 receive the recording medium P that has entered the J-shaped road 26c from the conversion path 26b, transport the recording medium P toward the stop roll 68, and abut the tip of the recording medium P against the stop roll 68.

The stop roll 68 whose rotation has stopped temporarily stops the tip of the recording medium P to correct the skew of the recording medium P, and then rotates to convey the recording medium P to the transfer nip NT.

[Transport of recording medium P in transport path 16]
Next, the transport of the recording medium P in the transport path 16 will be described.
As shown in FIG. 12, the transport path 16 includes a curved path 16a extending in one direction in the device width direction from the delivery roll 22 of the accommodating portion 18 and extending upward in a curved shape, and upward from the end of the curved path 16a. It has an extending upper road 16b. The branch path 26a described above branches from a portion of the upper path 16b on the downstream side in the medium transport direction. Further, the upper road 16b is arranged on the image forming portion 12 side with respect to the J-shaped road 26c described above.

The second transport roll 64, the first transport roll 60, and the stop roll 68 are arranged so as to transport the recording medium P sent out from the accommodating portion 18 along the curved path 16a. The stop roll 68 is arranged at the end of the curved road 16a, and the upper road 16b extends upward from the stop roll 68.

Hereinafter, the stop roll 68, the first transfer roll 60, the first arrangement mechanism 94, the second transfer roll 64, the second arrangement mechanism 114, and the restraint mechanism 120 will be described. In FIGS. 1 to 8, each portion is shown by making the curved curved path 16a linear.

-Stop roll 68-
The stop roll 68 includes a pair of stop rolls 72a and 72b, as shown in FIGS. 1 and 5 (A).

The stop roll bodies 72a and 72b have the same configuration, and include shaft portions 74a and 74b extending in the depth direction of the device and cylindrical roll portions 76a and 76b through which the shaft portions 74a and 74b penetrate. It includes a pair of bearings 78a and 78b. The shaft portions 74a and 74b are made of a metal material, and the roll portions 76a and 76b are made of a rubber material. If there is no particular distinction between the stop roll body 72a and the stop roll body 72b, the alphabet at the end is omitted.

Further, three roll portions 76 are arranged on one side and three on the other side with respect to the reference line CL of the transport path 16. Further, the three roll portions 76 on one side are arranged so as to come into contact with one side portion in the width direction of the recording medium P to be conveyed, and the three roll portions 76 on the other side are the recording to be conveyed. It is arranged so as to be in contact with the other side portion of the medium P in the width direction. The distance from the roll portion 76 on one side to the roll portion 76 on the other side (L01 in the figure) is longer than the distance from the roll portion 76 on one side to the roll portion 76 (P01 in the figure). .. Further, the shaft portion 74 is integrally with the roll portion 76, and the movement in the axial direction is restrained by a restraining member (not shown).

In this configuration, the stop roll 68 rotates by transmitting a rotational force from a drive source (not shown) of one of the stop rolls 72. The control of the rotation of the stop roll 68 by the control unit 28 will be described together with the operation described later.

− First transport roll 60−
As shown in FIGS. 1 and 5A, the first transport roll 60 includes a pair of transport roll bodies 82a and 82b.

The transport roll bodies 82a and 82b have the same configuration, and include shaft portions 84a and 84b extending in the depth direction of the device and cylindrical roll portions 86a and 86b through which the shaft portions 84a and 84b penetrate. It includes a pair of bearings 88a and 88b. The shaft portions 84a and 84b are made of a metal material, and the roll portions 86a and 86b are made of a rubber material. If there is no particular distinction between the transport roll body 82a and the transport roll body 82b, the alphabet at the end is omitted.

Further, one roll portion 86 is arranged on one side and one on the other side with respect to the reference line CL. The portion outside the roll portion 86 in the axial direction (the side far from the reference line CL) and the portion inside the roll portion 76 arranged on the most reference line CL side in the axial direction (the side closer to the reference line CL) are It overlaps in the axial direction.

In this configuration, the first transport roll 60 is configured to rotate by transmitting a rotational force from a drive source (not shown) of one of the transport roll bodies 82. Then, the first transfer roll 60 conveys the recording medium P, abuts the tip of the recording medium P against the stop roll 68 in the state where the rotation is stopped, and temporarily stops the recording medium P. The control of the rotation of the first transport roll 60 by the control unit 28 will be described together with the operation described later.

Further, the shaft portion 84 is supported by a support member (not shown) so as to be integrally movable with the roll portion 86 so as to be movable in the axial direction. In the present embodiment, with the first transport roll 60 arranged in the central portion of the moving region of the first transport roll 60, the shaft portion 84 is integrated with the roll portion 86 and is 1.5 [mm] on one side. It is said to be movable. 1.5 [mm] is an example, and may be further increased or decreased as required.

− First placement mechanism 94−
As shown in FIG. 1, the first arrangement mechanism 94 includes a disk-shaped collar member 90 attached to the inside in the axial direction with respect to the bearing 88 at both ends of the shaft portion 84, and the collar member 90. A compression coil spring 92 (hereinafter referred to as “compression spring 92”) arranged in a compressed state is provided between the bearing 88 and the bearing 88. Here, the urging force of the compression spring 92 is determined so as to be movable in the axial direction by receiving the axial force generated in the recording medium P conveyed by the first conveying roll 60. The compression spring 92 is an example of the first urging member.

In this configuration, one compression spring 92 urges the transport roll body 82 to the other compression spring 92 side, and the other compression spring 92 urges the transport roll body 82 to one compression spring 92 side. As a result, the first arrangement mechanism 94 arranges the first transfer roll 60 in the central portion of the moving region of the first transfer roll 60 in the axial direction. As described above, the first arrangement mechanism 94 functions as a variation suppressing means for suppressing the positional variation of the first transport roll 60 in the axial direction.

-Second transport roll 64-
As shown in FIGS. 1 and 5A, the second transport roll 64 is arranged at a position where the recording medium P is sandwiched in a state where the tip of the transport recording medium P is abutted against the stop roll 68. ing. The second transport roll 64 includes a pair of transport roll bodies 102a and 102b.

The transport roll bodies 102a and 102b have the same configuration, and include shaft portions 104a and 104b extending in the depth direction of the device and cylindrical roll portions 106a and 106b through which the shaft portions 104a and 104b penetrate. It includes a pair of bearings 108a and 108b. The shaft portions 104a and 104b are made of a metal material, and the roll portions 106a and 106b are made of a rubber material. If there is no particular distinction between the transport roll body 102a and the transport roll body 102b, the alphabet at the end is omitted.

Further, one roll portion 106 is arranged on one side and one on the other side with respect to the reference line CL. The axially outer portion of the roll portion 106 and the axially inner portion of the roll portion 76 arranged closest to the reference line CL side overlap in the axial direction.

In this configuration, the second transport roll 64 rotates by transmitting a rotational force from a drive source (not shown) to one of the transport roll bodies 102. The control of the rotation of the second transport roll 64 by the control unit 28 will be described together with the operation described later.

Further, the shaft portion 104 is supported by a support member (not shown) so as to be integrally movable with the roll portion 106 in the axial direction. In the present embodiment, with the second transport roll 64 arranged in the central portion of the moving region of the second transport roll 64, the shaft portion 104 is integrated with the roll portion 106 and is 2.5 [mm] on one side. It is said to be movable. As described above, the moving region of the second transport roll 64 is wider than the moving region of the first transport roll 60. 2.5 [mm] is an example, and may be further increased or decreased depending on the moving region of the first transport roll 60. Further, the difference from the moving region of the first transport roll 60 is not limited to 1 [mm], and may be further increased or decreased as necessary.

-Second placement mechanism 114-
As shown in FIG. 1, the second arrangement mechanism 114 includes a disk-shaped collar member 110 attached to the inside in the axial direction with respect to the bearing 108 at both ends of the shaft portion 104, and the collar member 110. A compression coil spring 112 (hereinafter referred to as “compression spring 112”) arranged in a compressed state is provided between the bearing 108 and the bearing 108. Here, the urging force of the compression spring 112 is determined so as to be movable in the axial direction by receiving the axial force generated in the recording medium P conveyed by the second transfer roll 64. The compression spring 112 is an example of a second urging member.

Further, the urging force of the compression spring 112 is weaker than the urging force of the compression spring 92. In other words, the force required to move the second transport roll 64 in the axial direction by a unit distance is weaker than the force required to move the first transport roll 60 by a unit distance in the axial direction.

In this configuration, one compression spring 112 urges the transport roll 102 to the other compression spring 112 side, and the other compression spring 112 urges the transport roll 102 to one compression spring 112 side. As a result, the second arrangement mechanism 114 arranges the second transfer roll 64 in the central portion of the moving region of the second transfer roll 64 in the axial direction.

-Restriction mechanism 120-
The restraint mechanism 120 is arranged on one side of the first transport roll 60 and the second transport roll 64 in the axial direction, respectively. Hereinafter, the restraint mechanism 120 arranged on one side in the axial direction of the first transport roll 60 will be described.

As shown in FIG. 9, the restraint mechanism 120 has a notch plate 122 in which a U-shaped notch 122a into which a part of the flange member 90 attached to the shaft portion 84a of the transport roll body 82a is inserted is formed. The moving portion 124, which is a solenoid for moving the notch plate 122 in the plate thickness direction, is provided. The solenoid is an example, and may be another drive source having a function of moving the notch plate.

In this configuration, the moving portion 124 has a insertion position (see FIG. 9) in which a part of the collar member 90 is inserted into the notch 122a, and the notch 122a and the collar member 90 are separated from each other in the radial direction of the shaft portion 84a. The notch plate 122 is moved to the open position (see FIG. 10). With the notch plate 122 arranged at the insertion position, the restraint mechanism 120 restrains the axial movement of the first transport roll 60. On the other hand, with the notch plate 122 arranged in the open position, the restraint mechanism 120 allows the first transport roll 60 to move in the axial direction. The control of the restraint mechanism 120 by the control unit 28 will be described together with the operation described later. As described above, the restraint mechanism 120 functions as a restraint permitting means for restraining or allowing the axial direction of the first transport roll 60. In the restraint mechanism 120, the arrangement of the notch plate 122 and the flange member 90 may be reversed. That is, the first transport roll 60 may be provided with a groove so as to be fitted with the convex portion of the notch plate 120.

[Detection sensor 96]
As shown in FIG. 1, the detection sensor 96 that detects the tip of the recording medium P to be conveyed is on the stop roll 68 side between the first transfer roll 60 and the stop roll 68 in the medium transfer direction, and is conveyed. It is arranged on the reference line CL when viewed from the thickness direction of the recording medium P to be recorded.

(Action of main part composition)
Next, the operation of the main part configuration will be described while comparing with the transport part 514 according to the comparative form. First, the configuration of the transport unit 514 will be mainly described as being different from the transport unit 14.

[Structure of transport unit 514]
As shown in FIG. 13, the transport unit 514 includes a first transport roll 560 for transporting the recording medium P, a second transport roll 564, and a stop roll 68. In the medium transport direction, the second transport roll 564, the first transport roll 560, and the stop roll 68 are arranged in this order. Further, the transport unit 514 does not include the first arrangement mechanism 94, the second arrangement mechanism 114, and the restraint mechanism 120.

The first transport roll 560 includes a pair of transport roll bodies 582a and 582b.

The transport roll bodies 582a and 582b have the same configuration, and include shaft portions 84a and 84b extending in the depth direction of the device, and cylindrical roll portions 86a and 86b through which the shaft portions 84a and 84b penetrate. It includes a pair of bearings 88a and 88b. Further, the shaft portions 84a and 84b are integrally restrained with the roll portions 86a and 86b in the axial movement by a restraining member (not shown). In this configuration, the first transport roll 560 rotates by transmitting a rotational force from a drive source (not shown) to one of the transport roll bodies 582.

The second transport roll 564 includes a pair of transport roll bodies 602a and 602b.

The transport roll bodies 602a and 602b have the same configuration, and include shaft portions 104a and 104b extending in the depth direction of the device and cylindrical roll portions 106a and 106b through which the shaft portions 104a and 104b penetrate. It includes a pair of bearings 108a and 108b. Further, the shaft portions 104a and 104b are integrally restrained with the roll portions 106a and 106b in the axial movement by a restraining member (not shown). In this configuration, the second transport roll 564 rotates by transmitting a rotational force from a drive source (not shown) to one of the transport roll bodies 602.

[Action of transport units 14, 514]
Regarding the actions of the transport units 14 and 514, the recording medium P sent out from the accommodating member 20 and transported is along the medium transport direction, and the recording medium P is skewed with respect to the medium transport direction. The case and the case will be described. Each member is controlled and operated by the control unit 28.

-When the recording medium P to be transported is along the medium transport direction-
In the state before the recording medium P is sent from the accommodating member 20 to the transport path 16, the rotations of the second transport roll 64, 564, the first transport roll 60, 560, and the stop roll 68 are stopped. Further, in the transport unit 14, the restraint mechanism 120 restrains the axial movement of the first transport roll 60 and the second transport roll 64, 564.

When the recording medium P is sent out from the accommodating member 20 to the transport path 16, the second transport rolls 64, 564 and the first transport rolls 60, 560 shown in FIGS. 1 and 13 rotate and are sent out to the transport path 16. The recording medium P is transported to the downstream side in the medium transport direction.

The rotating second transport rolls 64, 564 and the rotating first transport rolls 60, 560 abutt the tip of the recording medium P against the nip portion N of the stop roll 68, as shown in FIG. 5 (A). The stop roll 68 whose rotation has stopped temporarily stops the tip of the recording medium P.

Further, the rotating second transport roll 64, 564 and the rotating first transport rolls 60, 560 transport the recording medium P whose tip has been temporarily stopped and stop. In the present embodiment, the rotating second transport roll 64, 564 and the rotating first transport roll 60, 560 transport the recording medium P whose tip has been temporarily stopped by 5 [mm] as an example.

The rotating second transport rolls 64, 564 and the rotating first transport rolls 60, 560 are stopped after a certain period of time has elapsed after the detection sensor 96 detects the tip of the recording medium P. As a result, as described above, the rotating second transport rolls 64, 564 and the rotating first transport rolls 60, 560 transport the recording medium P and stop.

By transporting the recording medium P whose tip is temporarily stopped, the tip of the recording medium P is abutted against the nip portion N of the stop roll 68 over the width direction of the recording medium P, and the tip of the recording medium P is stopped. Along the axial direction of 68.

As a result, as shown in FIG. 5B, a loop is formed on the recording medium P in the portion between the stop roll 68 and the first transport rolls 60 and 560. The “loop” is a shape that bulges in the thickness direction of the recording medium P with respect to the transport path 16. The shape of the loop shown in each figure is exaggerated.

Further, as shown in FIGS. 6A and 6B, after the stop roll 68 is rotated, the second transfer roll 64, 564 and the first transfer roll 60, 560 are rotated, so that the recording medium P is rotated. Is transported to the downstream side in the medium transport direction.

Further, when the stop roll 68 rotates, the control unit 28 controls the restraint mechanism 120 to allow the first transfer roll 60 and the second transfer roll 64 to move in the axial direction. In other words, the control unit 28 controls the restraint mechanism 120 to restrain the axial movement of the first transport roll 60 and the second transport roll 64 while the rotation of the stop roll 68 is stopped. ..

Here, "when the stop roll 68 rotates, the first transfer roll 60 and the second transfer roll 64 are allowed to move in the axial direction" means that the stop roll 68 rotates and then the stop roll 68 rotates twice. It is said that the first transfer roll 60 and the second transfer roll 64 are allowed to move in the axial direction in the meantime.

-When the recording medium P to be transported is skewed with respect to the medium transport direction-
In the transport unit 14, when the recording medium P is sent from the accommodating member 20 to the transport path 16, the second transport roll 64 and the first transport roll 60 rotate and transport as shown in FIGS. 2 and 3. The recording medium P sent out to the path 16 is conveyed to the downstream side in the medium conveying direction. The degree of skew of the recording medium shown in each figure and the amount of movement of the first transport roll 60 and the second transport roll 64 in the axial direction are exaggerated.

Further, in the transport unit 514, when the recording medium P is sent from the accommodating member 20 to the transport path 16, the second transport roll 564 and the first transport roll 560 rotate as shown in FIGS. 14 and 15. The recording medium P sent out to the transport path 16 is transported to the downstream side in the medium transport direction.

The rotating second transport rolls 64, 564 and the rotating first transport rolls 60, 560 abutt the tip of the recording medium P against the nip portion N of the stop roll 68, as shown in FIG. 7 (A). The stop roll 68 whose rotation has stopped temporarily stops the tip of the recording medium P.

Further, the rotating second transport roll 64, 564 and the rotating first transport rolls 60, 560 transport the recording medium P whose tip has been temporarily stopped and stop. In the present embodiment, the rotating second transport roll 64, 564 and the rotating first transport roll 60, 560 transport the recording medium P whose tip has been temporarily stopped by 5 [mm] as an example.

The rotating second transport rolls 64, 564 and the rotating first transport rolls 60, 560 are stopped after a certain period of time has elapsed after the detection sensor 96 detects the tip of the recording medium P. As a result, the rotating second transport roll 64, 564 and the rotating first transport roll 60, 560 transport the recording medium P whose tip has been temporarily stopped and stop.

By transporting the recording medium P whose tip is temporarily stopped, the tip of the recording medium P is abutted against the nip portion N of the stop roll 68 over the width direction of the recording medium P, and the tip of the recording medium P is stopped. Along the axial direction of 68. As a result, the skew of the recording medium P is corrected, and as shown in FIG. 7B, a loop is formed in the recording medium P in the portion between the stop roll 68 and the first transport rolls 60 and 560. Will be done.

Here, the tip of the recording medium P that is oblique with respect to the medium transport direction is along the axial direction of the stop roll 68. Therefore, the height of the loop at one end in the width direction of the recording medium P that first reaches the nip portion N of the stop roll 68 (H01 in FIG. 7B) and later reaches the nip portion N of the stop roll 68. There is a difference from the height of the loop at the other end in the width direction of the recording medium P (H02 in FIG. 7B). Here, the "loop height" is the maximum amount of deformation in the thickness direction when the recording medium is deformed in the thickness direction of the recording medium P.

Therefore, in the transport unit 514, as shown in FIGS. 8A and 8B, after the stop roll 68 is rotated, the second transport roll 564 and the rotating first transport roll 560 are rotated. , The recording medium P is transported to the downstream side in the medium transport direction.

However, as described above, there is a difference between the height H01 of the loop at one end in the width direction of the recording medium P and the height H02 of the loop at the other end in the width direction of the recording medium P. In the transport unit 514, the stop roll 68 transports the recording medium P while the difference in the heights of the loops is maintained. As a result, abnormal noise may be generated. In other words, the height of one of the loops is higher than the height of the loop when the recording medium P to be transported is along the medium transport direction, so that an abnormal noise is generated. It may end up.

On the other hand, in the transport unit 14, as shown in FIGS. 8A and 8B, after the stop roll 68 is rotated, the second transport roll 64 and the rotating first transport roll 60 are rotated. , The recording medium P is transported to the downstream side in the medium transport direction.

Here, when the stop roll 68 rotates, the control unit 28 controls the restraint mechanism 120 to allow the first transfer roll 60 and the second transfer roll 64 to move in the axial direction. Therefore, as shown in FIGS. 3 and 4, the first transfer roll 60 and the second transfer roll 64 move in the axial direction by receiving the axial force generated in the recording medium P being conveyed, and record. The difference between the height of the loop at one end in the width direction of the medium P and the height of the loop at the other end in the width direction of the recording medium P is smaller than that of the transport unit 514. In the transport unit 14, the stop roll 68 transports the recording medium P in this state.

Specifically, when the tip of the recording medium P is abutted against the nip portion N of the stop roll 68, the tip of the recording medium P oblique to the medium transport direction is along the axial direction of the stop roll 68. .. As a result, the recording medium P is subjected to a force that tends to move in the axial direction. More specifically, since the recording medium P generates a force to move in the axial direction with the tip as the base point, the force to move in the axial direction becomes stronger as the distance from the tip is increased.

Therefore, the amount of movement of the second transport roll 64 in the axial direction is larger than the amount of movement of the first transport roll 60 in the axial direction. By moving the second transport roll 64 and the first transport roll 60 in the axial direction in this way, the height of the loop at one end in the width direction of the recording medium P and the loop at the other end in the width direction of the recording medium P The difference from the height is smaller than that of the transport unit 514. In the transport unit 14, the stop roll 68 transports the recording medium P in this state.

(Summary)
As described above, in the transport unit 14, the difference between the height of the loop at one end in the width direction of the recording medium P and the height of the loop at the other end in the width direction of the recording medium P is larger than that of the transport unit 514. In the smaller state, the stop roll 68 conveys the recording medium P. Therefore, in the transport unit 14, the abnormal noise generated by the stop roll 68 transporting the recording medium P is suppressed as compared with the transport unit 514.

Further, in the transport unit 14, when the first transport roll 60 on the upstream side in the medium transport direction can move in the axial direction with respect to the stop roll 68, and the axial movement of the second transport roll 64 is always restrained. In comparison with the above, the abnormal noise generated by the stop roll 68 carrying the recording medium P is suppressed. If the movement of the second transport roll 64 is constantly restrained, the sliding of the first transport roll 60 becomes insufficient, and the height of the loop at one end in the width direction of the recording medium P and the other than the width direction of the recording medium P This is because the difference from the height of the loop at the end is not reduced.

Further, in the transport unit 14, the first placement mechanism 94 arranges the first transport roll 60 in the central portion of the moving region of the first transport roll 60. Further, the second arrangement mechanism 114 arranges the second transfer roll 64 in the central portion of the moving region of the second transfer roll 64. As a result, the variation in the positions where the first transfer roll 60 and the second transfer roll 64 are arranged is suppressed as compared with the case where the first transfer roll and the second transfer roll are arranged at any position in the moving region. To.

Further, in the transport unit 14, compression springs 92 are provided on both ends of the first transport roll 60, respectively. Therefore, as compared with the case where the compression spring 92 is provided only on one side of the first transport roll 60, the variation in the position where the first transport roll 60 is arranged is suppressed.

Further, in the transport unit 14, compression springs 112 are provided on both ends of the second transport roll 64, respectively. Therefore, as compared with the case where the compression spring 112 is provided only on one side of the second transport roll 64, the variation in the position where the second transport roll 64 is arranged is suppressed.

Further, in the transport unit 14, the urging force of the compression spring 112 is weakened as the urging force of the compression spring 92. Therefore, the second transfer roll 64 easily moves in the axial direction with respect to the first transfer roll 60 as compared with the case where the urging force of the compression spring 112 and the urging force of the compression spring 92 are the same. Therefore, as compared with the case where the urging force of the compression spring 112 and the urging force of the compression spring 92 are the same, the height of the loop at one end in the width direction of the recording medium P and the loop at the other end in the width direction of the recording medium P The difference from the height becomes smaller.

Further, the transport unit 14 is provided with a restraint mechanism 120 for restraining the axial movement of the first transport roll 60 and the second transport roll 64. Therefore, the axial movement of the first transport roll 60 and the axial movement of the second transport roll 64 are switched between the restraint state and the allowable state.

Further, the transport unit 14 is provided with a restraint mechanism 120 for restraining the axial movement of the first transport roll 60 and the second transport roll 64. Therefore, the tip of the recording medium P records as compared with the case where the restrained first transport roll 60 and the second transport roll 64 are allowed to move in the axial direction before the recording medium P hits the stop roll 68. It is abutted against the nip portion N of the stop roll 68 over the width direction of the medium P.

Further, in the transport unit 14, while the rotation of the stop roll 68 is stopped, the movement of the first transport roll 60 and the second transport roll 64 in the axial direction is restrained, and when the stop roll 68 rotates, the first transport is performed. Allows axial movement of the roll 60 and the second transport roll 64. Therefore, while the rotation of the stop roll 68 is stopped, the first transfer roll 60 and the second transfer roll 64 are allowed to move in the axial direction, and when the stop roll 68 rotates, the first transfer roll 60 and the second transfer roll 60 and the second transfer roll 68 are allowed to move. (Ii) Compared to the case where the movement of the transport roll 64 in the axial direction is restrained, the tip of the recording medium P is abutted against the stop roll 68 over the width direction of the recording medium P, and then the stop roll 68 is the recording medium P. The abnormal noise generated by transporting the is suppressed.

Further, in the image forming apparatus 10, the abnormal noise generated by conveying the recording medium P is suppressed as compared with the case where the recording medium conveying device having the conveying unit 514 is provided.

Although the present invention has been described in detail with respect to specific embodiments, the present invention is not limited to such embodiments, and various other embodiments can be taken within the scope of the present invention. That is clear to those skilled in the art. For example, in the above embodiment, an example in which a recording medium transfer device is adopted as an image forming device has been described, but the device is not limited to the image forming device, and for example, a device that conveys a recording medium (sheet member) such as a ticket vending machine or an automatic ticket gate. It may be adopted.

Further, in the above embodiment, the correction of the skew of the recording medium P transported along the transport path 16 in order to form the toner image on the surface of the recording medium P has been described as an example. (Ii) The transport roll 64 is made movable in the axial direction, but in the case of correcting the skew of the recording medium P transported along the reverse path 26, the stop roll 68 is in the medium transport direction of the stop roll 68 in the reverse path 26. The first and second transfer rolls 38 on the upstream side may have the same structure as the first transfer roll 60 and the second transfer roll 64.

Further, although not particularly described in the above embodiment, when the axial movement of the first transport roll 60 and the second transport roll 64 is switched from restraint to permissible, the transport recording medium P is changed to the stop roll 68. It suffices as long as it is between the abutment and the rotation of the stop roll 68. Here, "after the recording medium P hits the stop roll 68" is after the central portion of the recording medium P in the width direction reaches the nip portion of the stop roll 68.

Further, in the above embodiment, the first arrangement mechanism 94 for arranging the first transfer roll 60 in the central portion of the moving region and the second arrangement mechanism 114 for arranging the second transfer roll 64 in the central portion of the moving region are provided. , It is not necessary to have these. However, in this case, the action produced by providing these is not produced.

Further, in the above embodiment, the compression springs 94 and 114 are provided on both end portions of the first transport roll 60 and the second transport roll 64, but they may be tension springs, or only one side portion. There may be. In this case, the action of providing the compression springs on both ends does not work.

Further, in the above embodiment, the restraint mechanism for restraining the movement of the first transport roll 60 and the second transport roll 64 is provided, but for example, the roll portion of the first transport roll and the roll portion of the second transport roll can be moved. You may restrain it.

Further, in the above embodiment, the restraint mechanism for restraining the movement of the first transport roll 60 and the second transport roll 64 is provided, but the restraint mechanism may not be provided. However, in this case, the action of providing the restraint mechanism does not play.

10 Image forming device 12 Image forming unit 14 Conveying unit (example of medium transporting device)
28 Control unit 60 First transfer roll 64 Second transfer roll 68 Stop roll 92 Compression spring (an example of the first urging member)
94 First arrangement mechanism 112 Compression spring (example of second urging member)
114 Second Arrangement Mechanism 120 Restraint Mechanism (Example of Restraint Mechanism and Other Restraint Mechanisms)

Claims (9)

A stop roll that stops the tip of the recording medium being conveyed while the rotation is stopped,
The recording medium is rotated and conveyed across the recording medium, and the tip of the recording medium is abutted against the stop roll to form a loop in the stopped recording medium, and the axial force generated in the conveyed recording medium is received. The first transport roll, which is movable in the axial direction,
The recording medium is rotated and conveyed with the recording medium sandwiched between them, and the recording medium is delivered to the first transfer roll. The recording medium is sandwiched and conveyed with the tip of the recording medium abutting against the stop roll. A second transport roll that can move in the axial direction by receiving the axial force generated in the recording medium,
A recording medium transport device comprising. A first arrangement mechanism for arranging the first transfer roll in the central portion of the moving region of the first transfer roll in the axial direction.
A second arrangement mechanism for arranging the second transfer roll in the central portion of the moving region of the second transfer roll in the axial direction.
The recording medium transport device according to claim 1. The first arrangement mechanism is provided on both ends of the first transfer roll, and one of the first transfer rolls is attached to the other side in a state where the first transfer roll is arranged in the central portion of the moving region. The recording medium transport device according to claim 2, further comprising a pair of urged first urging members. The second arrangement mechanism is provided on both ends of the second transfer roll, and one of the second transfer rolls is attached to the other side in a state where the second transfer roll is arranged in the central portion of the moving region. The recording medium transport device according to claim 2 or 3, further comprising a pair of urging second urging members. The recording medium transport device according to claim 4, wherein the urging force of the second urging member is weaker than the urging force of the first urging member. The recording medium transport device according to any one of claims 1 to 5, further comprising a restraint mechanism for restraining or allowing the axial movement of the second transport roll. The recording medium transport device according to claim 6, further comprising a restraint mechanism that restrains or allows the axial movement of the first transport roll. The restraint mechanism is controlled to restrain the axial movement of the first transport roll and the second transport roll until the conveyed recording medium hits the stop roll, and when the stop roll rotates, the axial direction The recording medium transport device according to claim 7, further comprising a control unit that allows the movement of the media. The recording medium transport device according to any one of claims 1 to 8, which transports the recording medium.
An image forming unit that forms an image on a recording medium conveyed by the recording medium conveying device, and an image forming unit.
An image forming apparatus comprising.