JP2008265975A - Curl correction device and image forming system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a curl correction device in which curl correction force is stable and jam treatment is easy in the curl correction device capable of performing curl correction not depending on a curl direction of paper. <P>SOLUTION: A conveying passage 100 having a curl correction part N is constituted by a first belt unit and a second belt unit, and the curl correction part is arranged such that a curl correction direction is different relative to the adjacent curl correction part. A roller at a paper conveying out port side of the conveying passage 100 is made a drive roller, and a roller at a paper conveying-in port side is made a tension roller. The tension roller is made into a constitution that it can be displaced in a direction approximately parallel to a paper conveying direction at the paper conveying-in port of the conveying passage. Further, the conveying passage 100 can be released by rotating the second belt unit around an axis of the drive roller. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a curl correction apparatus that corrects paper curl and an image forming system including the curl correction apparatus.

  In recent years, electrophotographic image forming apparatuses have been used in the field of light printing such as POD (Print On Demand), and in response to demands for image quality and high speed, various post-processing can be performed with high accuracy. It is required that it can be processed.

  The sheet on which the image is formed by the electrophotographic image forming apparatus is fixed by heating the toner image on the surface thereof with a fixing device. The paper may be curled (also referred to as a curl) due to the difference between the heating at the time of fixing and the expansion and contraction of the front and back of the paper that occurs at the time of subsequent heat dissipation.

  In such a curled paper, there is a curling problem in the conveyance failure problem due to the curl of the paper being caught on the conveyance path during conveyance, or in the post-processing step of aligning the bundle of the paper. The sheet bundle becomes uneven, and there arises a problem that the post-processing cannot be performed with high accuracy.

  Therefore, there is a curl correction device as a device for correcting the curl of the paper. The curl correction device is a device that reduces the original curl amount by attaching curl in the direction opposite to the direction in which the paper curls. However, the curl direction and curl amount of paper may differ greatly depending on paper characteristics such as paper basis weight, eye direction, and unsealed surface, the amount of toner transferred to the paper, and image forming conditions of the fixing device. is there. In such a case, in the method of forcing the curl in one direction with a single curl correction device, when the curl direction of the paper is opposite to the target direction, the curl correction device is used to correct the curl. Since the direction is the same as the original curl direction, there is an adverse effect of increasing the curl amount.

  Patent Document 1 discloses a curl correction device that changes a curl correction force by winding a belt around a conveyance roller and changing the winding angle, and a curl correction that changes a curl correction force according to the type of paper or image density. An apparatus is disclosed.

Patent Document 2 discloses a curl removing device in which a plurality of rollers are continuously arranged in pressure contact with each other on a conveyance path, and paper is conveyed to a pressure contact region between the rollers to perform curl correction.
JP-A-5-341600 Japanese Utility Model Publication No. 61-80756

  However, the curl correction devices disclosed in Patent Document 1 all perform curl correction by predicting the amount of curl and varying the curl correction, and the prediction accuracy is not sufficient and the prediction is wrong. The curl correction will not work as expected. Further, since it has only one direction of curl correction function, it cannot cope with a sheet in which the curl in the other direction has occurred.

  The curl removal device disclosed in Patent Document 2 can cope with paper in which any direction of curl occurs, but in the curl removal device, a plurality of rollers are pressed against each other with a constant tension. The roller is driven by the above. In this case, when a paper jam occurs, such as a paper jam, the rollers must be separated from each other, resulting in a complicated structure and the difficulty of jamming to remove the jammed paper. Is done.

  SUMMARY OF THE INVENTION In view of the above problems, an object of the present invention is to provide a curl correction apparatus capable of correcting curl without depending on the curl direction of paper, and providing a curl correction apparatus with stable curl correction force and easy jam processing. Is.

  The above object is achieved by the invention described below.

(1) A curl correction apparatus that includes a conveyance path that conveys an image-formed sheet and includes a plurality of curl correction units that curl and deform the sheet to correct the curl. And
A first belt unit having a first endless belt stretched around three or more rollers;
A second belt unit having a second endless belt stretched around three or more rollers;
With
The conveyance path is formed by the first belt unit and the second belt unit,
The curl correction part is formed by winding one endless belt around a roller facing the endless belt together with the other endless belt,
The curl correction part is arranged so that the curl correction direction is different from the adjacent curl correction part,
The rollers of the first belt unit and the second belt unit on the paper carry-out side of the transport path are drive rollers driven by a drive motor,
The roller of the first belt unit and the roller of the second belt unit on the paper carry-in side of the conveyance path are tension rollers,
The curl correction apparatus according to claim 1, wherein the tension roller is displaceable in a direction substantially parallel to a paper transport direction at a paper transport inlet of the transport path.

  (2) The curl correction apparatus according to (1), wherein the conveyance path can be opened by rotating the second belt unit about an axis of the drive roller.

(3) Among the rollers of the first belt unit, the rollers other than both the driving roller and the tension roller are displacement rollers capable of displacing the roller position in a direction orthogonal to the sheet conveying direction.
The curl correction device according to (1) or (2), wherein the curl correction force in the curl correction unit formed by the displacement roller can be changed by displacing the displacement roller.

  (4) The conveyance direction on the paper carry-in side of the conveyance path and the conveyance direction on the paper carry-out side are on the same line, and the shape of the conveyance path can be changed to a straight shape by displacing the displacement roller in the retracting direction. (3) The curl correction apparatus according to (3).

  (5) The conveyance path has a curl correction portion having the highest curl correction force on the upstream side in the conveyance direction, and curl correction is performed so that the curl correction force gradually decreases from the curl correction portion toward the downstream side in the conveyance direction. The curl correction apparatus according to any one of (1) to (4), wherein a portion is disposed.

(6) an image forming unit that forms an image on a sheet;
The curl correction device according to any one of (1) to (5), wherein the curl correction is performed on the paper on which the image is formed by the image forming unit.
A post-processing device that performs post-processing on the paper that has been curled by the curl correcting device;
An image forming system comprising:

  According to the present invention, it is possible to obtain a curl correction apparatus that can correct curl without depending on the curl direction of the paper, and has a stable curl correction force and easy jam processing.

  Although the present invention will be described based on an embodiment, the present invention is not limited to the embodiment.

  FIG. 1 is an overall view of an image forming system according to an embodiment of the present invention. The image forming system includes an image forming apparatus A, a curl correction apparatus B1, and a sheet post-processing apparatus B2.

[Image forming apparatus A]
The image forming apparatus A has an automatic document feeder 1 and an image reading unit 2 in the upper part, and the lower part is composed of a printer unit.

  In the printer section, 3 is a paper storage section for storing the paper S. An image is formed on the sheet S in the printer engine 5 that forms a toner image on the photoconductor 4 by an electrophotographic process in which the photoconductor 4 is charged, exposed, and developed. Is fixed. The fixing device 6 forms a nip for transporting the paper S by the heating roller 6b and the pressure roller 6c. The heating roller 6b includes a heat source 6a, and controls the heating roller 6b to a constant temperature by controlling the amount of heat generated by the heat source by a temperature sensor (not shown). While the sheet S is conveyed to the nip of the fixing device 6, the toner is melted by heating and pressing to fix the toner image on the sheet S.

  The sheet S is fed from the sheet storage unit 3 by the first sheet feeding unit 3a, and after being temporarily stopped by the second sheet feeding unit 3b, the sheet is fed and image formation is performed. The paper is discharged from the paper discharge port by the roller 8.

  As the transport path of the paper S, a paper feed path 7 from the paper storage unit 3 to the printer engine 5, a transport path 9 a from the printer engine 5 through the fixing device 6 and the paper discharge roller 8 to the paper discharge port, and an image formed. A double-sided conveyance path 9 b is provided for reversing the cover sheet, switching back, and conveying the sheet to the sheet feeding path 7 again.

  Reference numeral tp denotes an operation display unit, which includes a touch panel in which a touch screen is arranged on a display unit constituted by a liquid crystal panel. Various modes in the image forming apparatus A and output modes using the sheet post-processing apparatus B2 can be set by operations on the operation display unit tp.

  The control means C1 disposed in the image forming apparatus A is connected to the control means C2 of the curl correction apparatus B1 and the control means C3 of the sheet post-processing apparatus B2 via the communication means C4.

  The sheet S discharged from the image forming apparatus A is conveyed to the sheet post-processing apparatus B2 through the curl correction apparatus B1.

[Curl straightening device B1]
The curl correction apparatus B1 has a main part 10. The main part 10 has a first belt unit 11 and a second belt unit 12, and a transport path 100 is formed by endless belts 11 </ b> B and 12 </ b> B of both belt units. By conveying the sheet to the conveying path 100, the sheet is decurled (curled). Details will be described later.

[Post-processing device B2]
The paper post-processing apparatus B2 performs various post-processing on the paper S discharged from the image forming apparatus A and conveyed through the curl correction apparatus B1, and is a punching machine, a folding machine, a flat stitching machine, or a middle folding machine. A binding machine, a gluing bookbinding machine, a cutting machine, etc. are generically named.

  In the paper post-processing device B2, a staple device will be described as a representative example of the paper post-processing device B2 that performs post-processing on the paper that has been curled by the curl straightening device B2.

  The sheet post-processing device B2 includes, from the top in the figure, an insertion sheet feeding means 40, a shift means 20, a processing tray 30, and a stapling means 50 that contain insertion sheets (used for front and back covers). They are arranged in a column in a substantially vertical direction.

  In the processing tray 30, a plurality of sheets S on which images are formed by the image forming apparatus A are temporarily placed to create a sheet bundle. The paper placed on the processing tray 30 is subjected to vertical alignment in the transport direction and width alignment perpendicular to the vertical direction, and then staple processing is performed by the stapling unit 50 on the paper bundle.

  The shift unit 20 performs a shift process for changing the paper discharge position in the paper width direction orthogonal to the paper transport direction for each predetermined number of sheets on the image-formed paper discharged from the image forming apparatus A.

  An inlet conveyance unit 70 is disposed on the upper right side of the sheet post-processing apparatus B2. In addition, on the left side of the sheet post-processing apparatus B2 in the figure, a movable sheet discharge tray 81 for discharging and stacking sheets on which images have been formed is disposed. The discharge tray 81 can accommodate up to about 3000 sheets (A4 size, B5 size) on which images are formed.

[Curl correction device]
FIG. 2 is a cross-sectional view of the main part 10 of the curl correction apparatus B1. The main portion 10 includes a first belt unit 11 and a second belt unit 12, and a conveyance path 100 having a curl correction portion is formed by both belt units, and the paper is conveyed to the conveyance path 100 to correct the curl of the paper. Alternatively, curl removal is performed.

  The first belt unit 11 includes rollers 111, 112, 113, and 114, and the second belt unit 12 includes rollers 121, 122, 123, and 124. The endless belt 11B and the second endless belt 12B are stretched. N1 to N5 are curl correction units, and each curl correction unit is a curl correction unit in which a conveyance path is curved by winding the endless belts 11B and 12B around rollers 122, 123, 124, 112, and 113 facing the endless belt. Is formed. The paper that passes through the main portion 10 is carried in from the paper carry-in port 100a of the curl correction unit N1 and carried out from the paper carry-out port 100b of the curl correction unit N5 in the conveyance path 100.

  In the present embodiment, the roller radius r, the winding angle, and the correction direction in each curl correction unit are set as shown in Table 1. “Up” in the correction direction is a correction direction that causes an upward curl on the processing tray 30 (or the discharge port of the image forming apparatus), and “down” is a correction that results in the downward curl. It is a direction.

  The conveyance unit 100 includes a curl correction unit N2 having the highest curl correction force on the upstream side in the conveyance direction, and the curl correction unit gradually decreases from the curl correction unit N2 toward the downstream side in the conveyance direction. Is placed. The curl correction force of each curl correction unit is set to have a different curl correction force by setting the roller diameter and the winding angle of the endless belt around the roller. In addition, the curl correction portions are arranged so that the curl correction directions are different from the curl correction portions adjacent to each other.

  By doing so, it is possible to obtain a curl correction device that can correct the curl without depending on the curl direction of the paper.

[Drive roller]
Both the roller 114 of the first belt unit and the roller 124 of the second belt unit in the vicinity of the paper exit 100b function as drive rollers. The drive rollers 114 and 124 are driven by drive motors M1 and M2 via drive gears (not shown), respectively.

  In this way, by using the downstream roller near the paper exit 100b as the driving roller, the endless belts 11B and 12B become the tension side in the curl correction unit N in the conveyance path 100, and the curl correction force is stabilized and increased. Can be maintained.

[Tension roller]
Both the roller 111 of the first belt unit and the roller 121 of the second belt unit near the paper carry-in port 100a function as tension rollers. The tension rollers 111 and 121 can be displaced in a direction substantially parallel to the paper conveyance direction at the paper carry-in entrance 100a (the direction of the arrow d1 in FIG. 2). As tension, a predetermined load, for example, 1 kgf is applied in the direction opposite to the conveyance direction.

  In this way, even if production variations in the belt lengths of the endless belts 11B and 12B or tension load fluctuations when the paper S passes through the conveyance path 100 occur, the position and winding angle of the curl correction unit can be set. Since it can maintain, the curl correction force in a curl correction part can be stabilized.

[Displacement roller]
FIG. 3 is an explanatory view showing the displacement of the displacement roller. In FIG. 3A, among the plurality of rollers of the first belt unit 11, rollers excluding the roller 114 used as a driving roller and the roller 111 used as a tension roller, that is, the roller 112 and the roller 113 are This is a displacement roller capable of displacing the roller position in a direction (arrow d2 direction in FIG. 3) perpendicular to the paper transport direction. Reference numerals 112c and 113c denote eccentric cams which can be rotated by a motor (not shown).

  The central axes of the displacement rollers 112 and 113 are supported by a long hole shaft (not shown), and the position can be displaced along the long hole shaft by rotating the eccentric cams 112c and 113c. Since the long hole shaft extends in a direction (d2 direction) orthogonal to the conveyance path 100 (paper conveyance direction), the curl correction portions N2, N4 and intermediate curls thereof are moved by moving the eccentric cams 112c, 113c, respectively. It is possible to change the winding angle of the endless belt around the roller at the correction portion N3. This makes it possible to vary the curl correction force at the curl correction units N2 to N4.

  FIG. 3B shows the state of the main portion 10 when the displacement rollers 112 and 113 are displaced away from the belt, that is, in the retracting direction, and there is almost no contact pressure between the displacement rollers 112 and 113 and the belt. Is shown.

  As shown in the figure, the conveyance path 100 can be changed to a straight shape by displacing the displacement rollers 112 and 113 in the retracting direction. This is because the rollers 111, 114, 121, 124 at both ends of the first belt unit 11 and the second belt unit 12 have the same outer diameter, and a line connecting the centers of the rollers 111 and 114, the rollers 121 and the rollers This is because the lines connecting the centers of 124 are arranged in parallel. As a result, the conveyance direction at the paper carry-in port 100a and the conveyance direction at the paper carry-out port 100b are on the same line, so that the shape of the conveyance path 100 is made straight by displacing the displacement rollers 112 and 113 to the retracted position. Can do.

  In the case of the straight shape shown in FIG. 3B, the curl correction force is substantially zero. It is used when the curl correction device B2 transports thick paper or paper that has not passed through the fixing device 6 or other paper that does not require curl correction.

  By doing so, there is an advantage that it is not necessary to separately provide a bypass conveyance path for conveying paper that does not need to be curled.

  The change of the curl correction force by the eccentric cams 112c and 113c is performed by the control unit C1 of the image forming apparatus A via the control unit C2 of the curl correction apparatus B1. In the control means C1, a desired curl correction force is calculated based on the user setting by the operation display unit tp or the information on the paper to be conveyed stored in association with the paper storage unit 3, and according to the calculated value, the eccentric cam 112c, The position of 113c is varied.

[Opening mechanism]
FIG. 4 is a diagram illustrating an opening mechanism of the main part 10. In FIG. 1, the curl correction apparatus B1 has a guide rail (not shown). Along the guide rail, the main portion 10 and the surrounding conveyance roller pairs can be pulled out to the near side (front direction in FIG. 1).

  When a paper jam occurs in the curl correction apparatus B1, the main part 10 is pulled out along the guide rail in a state where the image system is stopped, and is pulled out. The conveyance path 100 of the main part 10 is opened from the state shown in FIG. 4A to the state shown in FIG.

  The opening can be released by rotating in the clockwise direction (arrow d3) in the same figure around the axis of the driving roller 124 of the second belt unit. Each roller 121 to 124 of the second belt unit is supported at both ends by panels (not shown), and is opened as shown in FIG. 4B by rotating the panel around the axis of the driving roller 124. It has a possible configuration.

  The rollers 111 and 121 as tension rollers are supported at both ends by a panel, but can be displaced in a direction substantially parallel to the paper conveyance direction at the paper carry-in port 100a as described above. That is, in the present embodiment shown in FIG. 4, the tension rollers are displaced in the opposite direction (arrows d4 and d5) from the drive rollers 114 and 124 in accordance with the opening operation for releasing the second belt unit from the first belt unit. Therefore, the endless belt does not sag.

  As described above, the configuration that can be opened makes it possible to easily perform jam processing (return processing) when a paper jam occurs around the transport path 100. In addition, since the displacement direction of the tension roller 111 is substantially parallel to the sheet conveyance direction (arrow d5), the displacement of the roller due to the opening can be reduced, and it is easy to secure a space for the jam processing, so that the jam processing can be easily performed. It can be carried out.

  In the present embodiment, an example in which five curl correction portions N1 to N5 are provided in each of the first belt unit and the second belt unit by four rollers and an endless belt has been described, but the present invention is not limited to this. It is good also as a curl correction apparatus using a piece or five or more rollers.

1 is an overall view of an image forming system according to an embodiment of the present invention. It is sectional drawing of the principal part 10 of the curl correction apparatus B1. It is explanatory drawing which shows the displacement of a displacement roller. It is a figure explaining the opening mechanism of the principal part.

Explanation of symbols

A image forming apparatus B1 curl correction apparatus B2 post-processing apparatus 10 main part 100 transport path 100a paper carry-in port 100b paper carry-out port 11 first belt unit 11B endless belt 111, 112, 113, 114 roller 12 second belt unit 12B endless belt 121, 122, 123, 124 Roller M1, M2 Drive motor N1, N2, N3, N4, N5 Curl correction unit

Claims (6)

A curling correction apparatus for correcting a curl generated on a paper, which is a transport path for transporting an image-formed paper, includes a transport path having a plurality of curl correction sections that curl and deform the paper to correct the curl,
A first belt unit having a first endless belt stretched around three or more rollers;
A second belt unit having a second endless belt stretched around three or more rollers;
With
The conveyance path is formed by the first belt unit and the second belt unit,
The curl correction part is formed by winding one endless belt around a roller facing the endless belt together with the other endless belt,
The curl correction part is arranged so that the curl correction direction is different from the adjacent curl correction part,
The roller of the first belt unit and the roller of the second belt unit on the paper carry-out side of the conveyance path are drive rollers driven by a drive motor,
The roller of the first belt unit and the roller of the second belt unit on the paper carry-in side of the conveyance path are tension rollers,
The curl correction device according to claim 1, wherein the tension roller is displaceable in a direction substantially parallel to a paper transport direction at a paper transport inlet of the transport path. The curl correction apparatus according to claim 1, wherein the conveyance path can be opened by rotating the second belt unit about an axis of the driving roller. Among the rollers of the first belt unit, the rollers other than both the driving roller and the tension roller are displacement rollers capable of displacing the roller position in a direction perpendicular to the sheet conveying direction.
3. The curl correction apparatus according to claim 1, wherein the curl correction force in the curl correction unit formed by the displacement roller can be changed by displacing the displacement roller. The conveyance direction on the paper carry-in side of the conveyance path and the conveyance direction on the paper carry-out side are on the same line, and the shape of the conveyance path can be changed to a straight shape by displacing the displacement roller in the retracting direction. The curl correction apparatus according to claim 3. The conveyance path has a curl correction part having the highest curl correction force on the upstream side in the conveyance direction, and the curl correction part is arranged so that the curl correction force gradually decreases from the curl correction part toward the downstream side in the conveyance direction. The curl correction apparatus according to any one of claims 1 to 4, wherein the curl correction apparatus is provided. An image forming unit for forming an image on paper;
The curl correction apparatus according to any one of claims 1 to 5, wherein the curl correction is performed on the paper on which the image is formed by the image forming unit.
A post-processing device that performs post-processing on the paper that has been curled by the curl correcting device;
An image forming system comprising:

Images