JPH0710311A - Paper sheet transfer device - Google Patents

Abstract

PURPOSE:To suppress the transfer skew of a paper sheet and prevent the warp such as floating on both the sides of a paper sheet, as a paper sheet transfer device for transfer-supplying the paper sheet to a memory device for printing, etc. CONSTITUTION:A pressing roller 21 which is shorter than a paper feeding roller 1 is arranged so as to be turnable in a pressed state for the center part in the main scan direction of the paper feeding roller 1 which is revolved by a prescribed driving force, and pressing rollers 22 and 23 which are made of the softer material than the pressing roller 21 are arranged at both the side parts in the coaxial form of the pressing roller 21, and the pressing roller 21 nip-transfers the center of a paper sheet 40, and the transfer skew is exceedingly suppressed. At the same time, the pressing rollers 22 and 23 maintain the pressed states of both the sides of the paper sheet 40 without applying a transfer force, and the warp such as floating generated on both the siies of the paper sheet 40 is prenveted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet conveying apparatus for conveying a sheet, and more particularly to a sheet conveying apparatus for conveying a sheet to a recording apparatus such as a printing apparatus.

[0002]

2. Description of the Related Art Conventionally, FIG.
There was something shown in. FIG. 3 is a schematic perspective view of a conventional sheet conveying device. In the figure, a conventional sheet conveying device includes a drive roller 101 in which a center support shaft 102 is driven in a predetermined rotation direction by a motor 103, and a drive roller 1
01 and a pressure roller 105, which is disposed to face 01 in a pressed state and is axially supported in a freely rotating state, and the drive roller 101.
And a photosensitive material cassette 104 that supplies the paper 106 between the pressure rollers 105.

A conventional sheet conveying device based on the above structure is
The entire lateral area of the paper 106 is nipped by the pressing force generated between the drive roller 101 and the pressure roller 105, and the paper 106 is rotated in the direction of the arrow by the rotation of the drive roller 101.
To transport.

FIG. 4 is a perspective view showing a schematic structure of a paper transporting device integrated with a conventional printing device. In the paper transporting device shown in FIG. 4, a central support shaft 112 is rotated by a motor 113 via a belt 119. Drive roller 111
And a plurality of split rollers 115, 1 arranged on the center support shaft 117 so as to face the drive roller 111 in a pressed state.
16 between the pressure roller 120 that supports 16 and the drive roller 111 and the split rollers 115 and 116.
22, a photosensitive material cassette 114 for supplying 22, an optical system 118 for scanning and projecting light corresponding to the print content on the supplied paper 122, and reacting it with the photosensitive material of the paper 122 for printing; Roller 111 and split roller 11
It is configured to include a winding unit 123 that winds and collects the paper 122 discharged between the spaces 5, 5 and 116.

The printing device of the paper transporting device based on the above construction draws out the paper 122 sandwiched by the driving roller 111 and the dividing rollers 125 and 126 from the photosensitive material cassette 114, and then, with respect to the printing portion 121 of the drawn paper 122. The optical system 118 optically scans. By this optical scanning, the photosensitive material of the paper 122 at the printing position 121 changes color to perform printing.

The entire area of the front side of the sheet 122 in contact with the driving roller 111 is brought into contact with the driving roller 111, and the partial areas on both sides of the rear side are nipped by the split rollers 115 and 116 and conveyed.

[0007]

Since the conventional sheet conveying apparatus is constructed as described above, in the apparatus shown in FIG. 3, the driving roller 101 is provided on the entire lateral surface of the sheet 106.
Since it is transported by the pressure roller 106 and the pressure roller 106,
There is a problem that the pressure distribution between the driving roller 101 and the pressure roller 105 may be biased, and the bias of the pressure distribution causes a disturbance in the transport direction of the paper 106 (transport skew).

Further, the paper transporting device in the printing device shown in FIG. 4 is supported by a center support shaft 117.
Since the sheet 122 is pressed and sandwiched by the two split rollers 115 and 116, the two split rollers 115 and 11
There is a problem in that the pressure balance of No. 6 is lost, the two sides of the sheet 122 cannot be symmetrically conveyed, and a conveyance skew occurs.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a sheet conveying apparatus which has no sheet conveyance skew and can prevent warping such as floating on both sides of the sheet. .

[0010]

SUMMARY OF THE INVENTION A sheet conveying apparatus according to the present invention has a center support shaft pivotally supported by a fixed support portion and a drive roller which is rotated by a predetermined drive force, and a main scanning direction of the drive roller. A sheet having a pressure roller shorter than the drive roller and rotatably arranged in a pressed state with respect to a central portion, and a sheet which conveys a sheet in a predetermined direction by a pressing drive force of the drive roller and the pressure roller. The transporting device has pressing rollers formed on the coaxially opposite side portions of the pressure roller, the pressure roller being made of a member softer than the pressure roller.

Further, in the sheet conveying apparatus according to the present invention, the pressure roller is formed of an elastic member having a circular cross section, if necessary.
The drive roller may be formed of a non-elastic member having a circular cross section.

[0012]

According to the present invention, a pressure roller shorter than the drive roller is rotatably arranged in a pressed state and rotatably with respect to the central portion in the main scanning direction of the drive roller rotated by a predetermined driving force. By disposing the pressing roller made of a material that is more flexible than the pressure roller on both sides of the roller on the same axis, the main pressure roller nips and conveys the center of the paper, and the conveyance skew is suppressed as much as possible and the pressing roller is pressed. The rollers maintain the pressed state on both sides of the sheet with almost no conveyance force, and prevent warping such as floating on both sides of the sheet.

Further, the drive roller is formed of an inelastic member,
Since the main pressure roller arranged to be pressed against this is formed of an elastic member, the contact pressure force of the elastic member of the main pressure roller to the sheet is improved, so that the conveying speed can be made more accurate and the conveying skew can be improved. Prevent the occurrence of.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A sheet conveying apparatus according to an embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view of a printing apparatus using a sheet conveying apparatus according to an embodiment of the present invention.

Referring to FIG. 1, the sheet conveying apparatus according to the present embodiment has a sheet feeding roller 1 which is rotated by a driving force of a motor 12 via a coupling 11 and a free rotation which is opposed to the sheet feeding roller 1. A main pressure roller 21 at the center of the support shaft 24 in the longitudinal direction, and an auxiliary roller 2 formed by disposing two pressing rollers 22 and 23 on both sides of the main pressure roller 21. The paper 40 which is wound in a roll shape is stored and the paper feed roller 1 and the auxiliary roller 2
The photosensitive material cassette 4 that supplies the paper 40 to the space between them and the take-up unit 7 that winds and stores the paper 40 discharged from the paper feed roller 1 are provided as basic configurations.

The paper feed roller 1 is formed of a metal cylinder and has an outer shape without distortion to accurately transmit the peripheral speed of its rotation as the conveying speed of the paper 40. The pressure roller 21 is formed of an elastic cylindrical member such as synthetic resin or rubber, and the pressing force reliably nips the paper 40 with the paper feed roller 1 and transfers the paper 40.

The pressing rollers 22 and 23 are made of a softer member than the pressure roller 21, for example, a cylindrical member such as a sponge or a radial flocking brush having a weak repulsive force. Paper 4 with sliding contact maintained
Prevents warping such as 0 floating.

In addition to the above structure, a back tension mechanism 3 is arranged between the paper feed roller 1 and the auxiliary roller 2 and the photosensitive material cassette 4. This back tension mechanism 3
Is provided in a back tension roller 31 that rotates via the belt 34 by the driving force of the motor 33, and is arranged in a state of freely rotating by pressing so as to face the back tension roller 31, and the center of the support shaft 324 in the main scanning direction. Pressure roller 3
21 and an auxiliary roller 32 formed by disposing two pressing rollers 322 and 323 on both sides of the pressure roller 321.
And a configuration including.

The back tension roller 31 is formed of a metal cylinder like the paper feed roller 1, and the auxiliary roller 32 is formed of the same rough material as the auxiliary roller 2.

An optical system 5 of the printing apparatus is arranged between the paper feed roller 1 and the auxiliary roller 2 and the back tension mechanism section 3. The optical system 5 includes a polygon mirror 51 that sequentially scans writing light in the main scanning direction of the paper 40, and an Fθ lens 52 that forms an image of the writing light reflected and emitted from the polygon mirror 51 at a printing position 6 on the paper 40. It is the structure provided with.

The paper feed roller 1 and the auxiliary roller 2,
A cutter 8 is disposed between the winding unit 7 and the winding unit 7. The cutter 8 is configured to cut the sheet 40 in the main scanning direction by moving the circular knife 82 laterally on the guide 81.

Next, the paper feeding operation of the paper feeding apparatus of this embodiment based on the above construction will be described.

First, the paper 40 is passed from the photosensitive material cassette 4 to the winding section 7 via the back tension mechanism 3, the paper feed roller 1 and the auxiliary roller 2. When the paper feed roller 1 is rotated by the motor 12 in such a state, the paper 40 is conveyed to the take-up unit 7 side (the direction of arrow A in the figure) by this rotational force and the pressing force of the pressure roller 21.

When the sheet 40 is conveyed, the back tension mechanism 3 applies a force to the sheet 40 so as to convey the sheet 40 in the direction of arrow B, which is opposite to the conveying direction of the sheet 40 (direction of arrow A). That is, the back tension mechanism 3 rotates the motor 33 in the direction of arrow C and the back tension roller 31 in the direction of arrow D. The rotational force in the direction of arrow D and the pressing force of the pressure roller 321 apply a force to the paper 40 in the direction of arrow B. The force in the arrow B direction is extremely smaller than the force for conveying the sheet 40 in the arrow A direction. As described above, the paper feed roller 1 and the auxiliary roller 2 and the back tension mechanism 3 apply a force in opposite directions to the paper 4
Since it is added to 0, it is possible to transfer the sheet 40 in a flat state without bending at the printing position 6 where printing is performed by the optical system 5.

Further, both sides of the sheet 40 are brought into sliding contact with the sheet feeding roller 1 by the two pressing rollers 22 and 23, and the sheet 40 is transported by being brought into sliding contact with the back tension roller 3 by the two auxiliary rollers 322 and 323. Since this is performed, warpage such as floating at the side edge of the sheet 40 is prevented.

In this way, the optical system 5 projects the light corresponding to the printing on the sheet 40 conveyed in the flat state and without the warp, and the printing is performed on the photosensitive surface of the sheet 40. The printed sheet 40 is transported and cut at a predetermined portion by the cutter 8.

Next, the pressure roller 21 of the auxiliary roller 2
The reason why the pressure roller 321 of the auxiliary roller 32 is formed in a part of the central portion in the main scanning direction will be described with reference to FIG. 2 and (Table 1). FIG. 2 is an explanatory diagram of the skew amount in the sheet conveyance.

In the figure, the paper feed roller 1 contacts the entire area of the paper 40 in the main scanning direction, the pressure roller 21 contacts a part of the central portion of the paper 40, and the paper 40 moves in the direction of arrow A.
To transport. In this way, when the sheet 40 is brought into contact with and pinched by the paper feed roller 1 and the pressure roller 21 and is conveyed to cause skew (or meandering) in the conveying direction, the length of the main pressure roller 21 causes skew. The quantity 3σ changes. Experimental data of this change are shown in (Table 1).

[0029]

[Table 1]

In this (Table 1), if the pressure roller 21 and the pressure roller 321 are short, the skew amount 3σ
Is clearly reduced. If the pressure roller 21 (and the pressure roller 321) is shortened in this manner, the paper 40
The warp such as floating becomes large at both end portions of the. The warp such as floating can be prevented by the two pressing rollers 23 and 24 (and the pressing rollers 322 and 323).

Although the back tension mechanism 3 is provided in the above embodiment, the paper feed roller 1 and the auxiliary roller 2 are not provided with the back tension mechanism 3.
The sheet 40 can be conveyed and pressed only by the above.

Further, in the above-described embodiment, the printer is combined with the printer. However, the printer may be combined with a facsimile, a copying machine, various readers, or the like.

[0033]

As described above, according to the present invention, a pressure roller shorter than the driving roller is rotatably pressed and rotatable with respect to the central portion in the main scanning direction of the driving roller rotated by a predetermined driving force. In addition, by disposing the pressing roller formed of a member that is more flexible than the pressure roller on both sides of the pressure roller on the same axis, the main pressure roller nips and conveys the center of the sheet, and the conveyance skew is minimized. Restrain and
The pressing roller maintains the pressed state on both sides of the sheet with almost no conveyance force, and thus has an effect of preventing warpage such as floating on both sides of the sheet.

Further, the drive roller is formed of an inelastic member,
Since the pressure roller arranged to be pressed against this is formed of an elastic member, the contact pressure of the pressure roller on the sheet by the elastic member is improved, which improves the conveyance accuracy and further reduces the occurrence of conveyance skew. Has the effect of preventing.

[Brief description of drawings]

FIG. 1 is a perspective view of a printing apparatus using a sheet conveying apparatus according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram of a skew amount during sheet conveyance in the same embodiment.

FIG. 3 is a schematic perspective view of a conventional sheet conveying device.

FIG. 4 is a perspective view of a schematic configuration of a paper conveyance device integrated with a conventional printing device.

[Explanation of symbols]

 1 Paper Feed Roller 2 Auxiliary Roller 3 Back Tension Mechanism 4 Sensitive Material Cassette 5 Optical System 6 Printing Section 7 Winding Section 12 Motor 21 Pressure Roller 22,23 Pressing Roller 321 Pressing Roller 322, 323 Pressing Roller

Claims (2)

[Claims] 1. A center support shaft is rotatably supported by a fixed support portion, and a drive roller that rotates by a predetermined drive force and a rotatable state while being pressed against a central portion of the drive roller in the main scanning direction. A paper transporting device, comprising: a pressure roller shorter than the drive roller disposed, and transporting a paper in a predetermined direction by a pressing drive force of the drive roller and the pressure roller, which is coaxial with the pressure roller. A sheet conveying device, characterized in that it has a pressing roller formed on a side portion of the pressing roller with a softer member than a pressure roller. 2. The sheet conveying apparatus according to claim 1, wherein the pressure roller is formed of an elastic member having a circular cross section, and the driving roller is formed of an inelastic member having a circular cross section.