JP2002003050A - Sheet curl eliminating device and image forming device having it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To alleviate or eliminate a curl by simultaneously stiffening a curled sheet at plural parts. SOLUTION: This sheet curl eliminating device is provided with plural curl eliminating rotor pairs 5A, 5B jigzag arranged on both surface sides of a sheet in a direction perpendicular to the conveying direction for the sheet, and the rotor pairs 5A, 5B are provided so as to adjust their positions in the direction to adjust the jigzag amount. When a sheet is detected, a fan 6 is started, and the front surface temperature of the sheet is lowered.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet curl removing device for removing a sheet curl, and a copying machine, a printer, a facsimile equipped with the sheet curl removing device in a main body, and an image forming apparatus such as a composite device thereof. And about.

[0002]

2. Description of the Related Art A copying machine, which is an example of an image forming apparatus, includes:
To make it easier for the user to handle the sheets on which images have been formed, a large number of sheets are stacked, the sheets are arbitrarily sorted and discharged to a plurality of trays, and the sheets are turned upside down and discharged and stacked for stacking in the image forming order. Some types have the function of performing In addition, there are copiers having various post-processing functions. In such a copying machine, a toner image is formed on a sheet by an image forming unit, and the sheet is heated and pressed by a fixing device to fix the toner image on the sheet.

[0003] For this reason, the sheet curls in a curved shape due to the heating and pressurizing of the fixing device, and it may not be possible to smoothly receive the subsequent processing such as loading, discharging and reversing.

That is, when a sheet in a curled state is sent to a mechanism or an apparatus for carrying, sorting, reversing, stacking, and the like as post-processing, the sheet is caught or broken by a rib, a flapper, or the like on the conveyance path. Alternatively, it may be jammed and jammed.

Further, in the switchback means of the reversing mechanism, when a preceding sheet and a succeeding sheet pass each other, the curling of the sheet causes the succeeding sheet to be taken up by the preceding sheet and become entangled and jammed. May be.

Furthermore, curled sheets cause a significant reduction in stacking and alignment properties due to the effects of curling in a mechanism for simply stacking sheets.

Therefore, in order to reduce or eliminate the curl amount generated in the sheet, two rollers 102, 102 are pressed against one roller 101 shown in FIG.
One of a pair of rollers 103 and a pair of rollers 106 each having a sponge roller 104 and a roller 105 pushed into the sponge roller 104 shown in FIG. In the direction
He had curls.

[0008]

However, the roller pair 103 shown in FIG. 8 and the roller pair 106 shown in FIG.
In the configuration corresponding to the upper curl sheet whose front and rear ends are upward as shown in FIG. 7A, only the upper curl sheet has the lower curl whose front and rear ends are downward as shown in FIG. 7B. With the configuration corresponding to the sheet, only the lower curl sheet could reduce the curl amount of the sheet. Further, as shown in FIG. 7 (c), the curl amount of the curled sheet having a downward-facing or curving sheet having both sides facing downward and the curling sheet having both sides facing upward cannot be reduced.

(Object) In order to solve the above-mentioned problems, the present invention provides a sheet curling apparatus for simultaneously curling a curled sheet at a plurality of places to reduce or remove curl, and a sheet curling apparatus. It is an object of the present invention to provide an image forming apparatus provided with a sheet curl removing device in a main body.

[0010]

In order to achieve the above-mentioned object, a sheet curl removing apparatus according to the present invention is arranged on both sides of a sheet in a direction intersecting the sheet conveying direction, and is intertwined with each other. A decurling rotary body pair is provided.

In the sheet decurling apparatus of the present invention,
The rotating body of the pair of curl removing rotating bodies is provided so as to be position-adjustable in a direction for adjusting the intricate amount.

In the sheet decurling apparatus of the present invention,
The rotating body of the curl removing rotating body pair is a roller.

In the sheet decurling apparatus of the present invention,
The rotating body of the curl removing rotating body pair is an endless belt.

In order to achieve the above object, a sheet decurling apparatus according to the present invention comprises a sheet conveying means for conveying a sheet, and both sides of the sheet conveyed by the sheet conveying means intersecting the conveying direction of the sheet. And a pair of projecting ridges arranged in a direction.

In the sheet decurling apparatus of the present invention,
The ridges of the pair of ridges are provided so as to be position-adjustable in a direction for adjusting the amount of intrusion.

In order to achieve the above object, an image forming apparatus according to the present invention comprises an image forming means for forming a toner image on a sheet, and a fixing means for fixing the toner image formed by the image forming means on the sheet. And any one of the sheet curl removing devices for removing curl of the sheet on which the toner image is fixed.

To achieve the above object, an image forming apparatus according to the present invention comprises an image forming unit for forming a toner image on a sheet, and a fixing unit for fixing the toner image formed by the image forming unit on the sheet. And the sheet curl removing device according to any one of claims 1 to 6, wherein the curl is removed by the sheet curl removing device. And a cooling air supply device for sending air to the sheet.

To achieve the above object, an image forming apparatus according to the present invention comprises an image forming unit for forming a toner image on a sheet, and a fixing unit for fixing the toner image formed by the image forming unit on the sheet. 7. The sheet curl removing device according to claim 1, wherein the curl is removed from the sheet on which the toner image is fixed, and the sheet curled by the sheet curl removing device. And a post-processing device for performing processing.

To achieve the above object, an image forming apparatus according to the present invention comprises an image forming unit for forming a toner image on a sheet, and a fixing unit for fixing the toner image formed by the image forming unit on the sheet. And the sheet curl removing device according to any one of claims 1 to 6, wherein the curl is removed by the sheet curl removing device. The apparatus includes a cooling air supply device that sends air to the sheet, and a post-processing device that performs post-processing on the sheet from which the curl has been removed by the sheet curl removing device.

(Operation) The curl removing rotary member of the sheet curl removing device of the present invention rotates to convey the sheet. Since the curl removing rotary body pair is intricate with each other, the sheet is formed in a wave shape, and the sheet is stiffened to reduce or remove the curl of the sheet.

The sheet conveying means of the sheet decurling apparatus of the present invention feeds a sheet and passes the sheet between the pair of protrusions. Since the pair of ridges are intertwined with each other, the sheet is formed in a wave shape, the sheet is crimped, and the curl of the sheet is reduced or eliminated.

In the image forming apparatus of the present invention, the toner image formed by the image forming means for forming the toner image on the sheet is fixed on the sheet by the fixing means. At this time, the sheet is curled (curved) by the heating and pressing of the fixing unit. However, a sheet curl removing device forms the sheet in a wave shape, stiffens the sheet, and reduces or removes the curl of the sheet.

In the image forming apparatus of the present invention, the toner image formed by the image forming means for forming the toner image on the sheet is fixed on the sheet by the fixing means. At this time, the sheet is curled (curved) by the heating and pressing of the fixing unit. However, a sheet curl removing device forms the sheet in a wave shape, stiffens the sheet, and reduces or removes the curl of the sheet. Further, when the curl removing device is stiffening the sheet, the cooling air supply device cools the sheet heated by the fixing unit, lowers the surface temperature of the sheet, thereby promoting the curl removing ability, To ensure that the curl is reduced or eliminated.

In the image forming apparatus of the present invention, the toner image formed by the image forming means for forming a toner image on a sheet is fixed on the sheet by the fixing means. At this time, the sheet is curled (curved) by the heating and pressing of the fixing unit. However, the sheet curl removing device forms the sheet in a wavy shape, stiffens the sheet, and reduces the curl,
Or remove it. Further, when the curl removing device is stiffening the sheet, the cooling air supply device cools the sheet heated by the fixing unit and promotes the curl removing ability by lowering the surface temperature of the sheet S, Ensure that sheet curl is mitigated or eliminated.

In the image forming apparatus of the present invention, the toner image formed by the image forming means for forming the toner image on the sheet is fixed on the sheet by the fixing means. At this time, the sheet is curled (curved) by the heating and pressing of the fixing unit. However, the sheet curl removing device forms the sheet in a wavy shape, stiffens the sheet, and reduces the curl,
Or remove it. Further, when the curl removing device is stiffening the sheet, the cooling air supply device cools the sheet heated by the fixing unit and promotes the curl removing ability by lowering the surface temperature of the sheet S, Ensure that sheet curl is mitigated or eliminated. Then, the post-processing device performs post-processing on the sheet whose curl has been alleviated or removed.

[0026]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A copying machine 50 which is an example of an image forming apparatus having a sheet curl removing device 1 according to a first embodiment of the present invention in a main body 51 will be described below with reference to FIG. A sheet curl removing device 1 according to a first embodiment of the present invention will be described with reference to FIGS. 2 to 4, and a sheet curl removing device 2 according to a second embodiment of the present invention will be described with reference to FIG.
Finally, a sheet curl removing device 3 according to a third embodiment of the present invention will be described with reference to FIG. The copying machine 50 includes
Instead of the sheet curl removing device 1 of the first embodiment, the sheet curl removing devices 2 and 3 of the second and third embodiments can be incorporated. Further, the sheet curl removing devices 1, 2, and 3 of each embodiment can be incorporated not only in a copying machine but also in a main body of an image forming apparatus such as a printer, a facsimile, and a composite device thereof. I have.

(Copier) An automatic document feeder 52 for automatically circulating a document is provided above the main body 51 of the copier 50, and a sheet curl removing device 1 is provided downstream (left side in the figure). A post-processing device 53 is installed downstream of the sheet curl removing device 1.

The copying machine 50 employs a well-known electrophotographic system, and an image of a document positioned on a platen glass 54 is subjected to a photosensitive drum (image forming means) by an optical system 55.
A latent image is formed on the photosensitive drum 56, and the latent image is visualized (toner image) by a developing device 57 provided around the photosensitive drum 56. At the same time as this, the sheet cassette 5
8, the sheets are fed one by one, and fed to the photosensitive drum 56 by the sheet supply roller pair 59 and the like. And
The toner image on the photosensitive drum 56 is transferred to a sheet by a transfer unit 60 and is permanently fixed to the sheet by a fixing unit (fixing unit) 61.

The sheet on which the image forming process has been completed in this manner is heated and pressed by the fixing device 16 and is curled. The sheet is sent to the sheet curling device 1 by the discharge roller pair 62, and the curl is removed. Alleviated or eliminated. When forming an image on both sides of the sheet, the sheet is fed to the reversing path 63 and an image is formed on the other side.

The sheet whose curl has been alleviated or removed by the sheet curl removing device is sent to a post-processing device 53 and then discharged to a tray 64 for stacking or a binding device 65. The sheet is bound and discharged to the tray 64 or further bound and folded by the folding device 66 and discharged to the tray 67.

(Sheet curling device of the first embodiment)
The sheet curl removing device 1 is located on both sides of the conveyed sheet S, and has rotating shafts 4A and 4B parallel to each other that intersect with the sheet conveying direction, and a plurality of curls provided on the rotating shafts 4A and 4B. Removal Roller (Curl Removal Rotator Pair) 5
A, 5B and a fan (cooling air supply device) disposed on both sides of the conveyed sheet S to cool the sheet S
6, 6; gears 7A, 7B for rotatingly rotating the rotating shafts 4A, 4B; and a pinion 8 meshed with one of the gears 7B.
A motor 9 provided with a pinion 8, an entrance guide 10 for receiving the sheet S, an entrance sensor 11 for detecting a sheet entering the entrance guide 10, a discharge guide 12 for guiding the discharge of the sheet S, and the like. ing. The curl removing rollers 5A and 5B are connected to a rotating shaft 4 as shown in FIG.
A and 4B are arranged on both sides of the sheet in a direction intersecting the sheet conveying direction, and are intertwined with each other.

The sheet S discharged from the discharge roller pair 62
Is slightly heated by the fixing device 61. Sheet S
4A is curled upward as shown in FIG. 4A, the sheet S is guided by the entrance guide 10 and detected by the entrance sensor 11. Then, the motor 9 starts, one of the rotating shafts 4B is driven and rotated, and the other rotating shaft 4A is rotated.
Is driven to rotate. Thereby, the curl removing roller 5
A and 5B rotate so as to convey the sheet S toward the discharge guide 12. As shown in FIG.
Since A and 5B are intertwined with each other and overlap by the distance L1, a plurality of small stiffenings are simultaneously performed on the sheet S.

As shown in FIG. 3, the sheet S is bent in a direction parallel to the conveying direction and a thickness direction of the sheet S at a plurality of locations, alternately up and down, with a force in the opposite direction to form a wave. . As a result, the curl of the upper curled sheet is reduced or removed. On the other hand, when the sheet is detected by the entrance sensor 11, the fans 6, 6 are also started. The fan 6 cools the sheet S by applying air to the sheet S being conveyed by the curl removing rollers 5A and 5B, as shown in FIG. As a result, the surface temperature of the sheet S is reduced, the curl removing ability is promoted, and the curl of the upper curled sheet is reliably alleviated or removed. When the rear end of the sheet S passes through the entrance sensor 11 and exits the curl removing rollers 5A and 5B, the rotation of the motor 9 and the fan 6 is stopped.

The entrance guide 10 and the discharge guide 1
2 are arranged so as to avoid the curl removing rollers 5A and 5B for performing waisting, respectively, as shown in FIG.
The air blown to the sheet S is a curl removing roller 5A,
Only by being blocked by the shaft 5A and the shafts 4A and 4B, almost all of them can be fed into the sheet S, and a greater cooling effect can be obtained.

The curl of the other lower curl sheet, the semi-curl-shaped curl sheet, and the gutter-shaped curl sheet are alleviated or eliminated in the same manner.

As described above, the sheet curl removing device 1
By alleviating or removing the curl of the sheet S, the copying machine 52 causes the binding device 65, the folding device 66, or the like, which is the post-processing device 53, to catch, fold, or jam the sheet S. Various processes such as stacking, discharging, and reversing of sheets S can be smoothly performed by preventing improper stacking, poor alignment, and the like.

(Sheet curling device of second embodiment)
The sheet curl removing device 2 according to the second embodiment includes the curl removing rollers 5A and 5A of the sheet curl removing device 1 according to the first embodiment.
Instead of 5B, as shown in FIG. 5, a plurality of endless curl removing belts (curl removing rotating body pairs) 21 and 22 circulating in the sheet conveying direction are used to perforate the sheet S. ing. The curl removing belts 21 and 22
2 are the same as those of the sheet decurling apparatus 1 of the first embodiment,
And the description is omitted.

The curl removing belt 21 includes rotating shafts 23, 2
4 around a plurality of pulleys 25 and 26. The curl removing belt 22 is wound around a plurality of pulleys 29 and 30 provided on the rotating shafts 27 and 28. The rotation shafts 23, 24, 27, 28 are arranged in a direction intersecting the sheet conveying direction. Also, pulley 2
5, 26 and pulleys 29, 30 are intricate with each other.

Therefore, the curl removing belts 21 and 22
Are intricately overlapped by a distance L2, rotated in the sheet conveying direction, and while the sheet S is being conveyed, a plurality of small stiffenings are simultaneously performed on the sheet S to alleviate or remove the curl of the sheet. I do. Note that the sheet curl removing device 2 of the second embodiment also cools the sheet S by applying air to the sheet S being conveyed by the curl removing belts 21 and 22 with a fan.
The surface temperature is reduced to enhance the curl removing ability.

Thus, the sheet curl removing device 2
By reducing or removing the curl of the sheet S, the copying machine 50 can smoothly perform various processes such as stacking, discharging, and reversing the sheet S.

(Sheet Curling Device of Third Embodiment)
The sheet curl removing device 3 of the third embodiment includes the curl removing rollers 5A and 5A of the sheet curl removing device 1 of the first embodiment.
Instead of 5B, as shown in FIG. 6, a plurality of curl removing ribs (a pair of ridges) 3 provided along the sheet conveying direction.
The seat S is attached to the seat S by using the seats 1 and 32. Note that portions other than the portions related to the curl removing ribs 31 and 32 are the same as those of the sheet curl removing device 1 of the first embodiment, and the illustration and description of those portions are omitted.

The curl removing ribs 31 and 32 have a tip 31
The sheets a and 32a face each other and are arranged alternately in a direction intersecting with the sheet conveying direction, are intertwined with each other, and overlap by a distance L3. Decurling rib 3
Guide inclined surfaces 31b and 32b for guiding the sheet S are formed between the leading ends 31a and 32a of the curl removing ribs 31 and 32 on the upstream end sides of the curl removing ribs 31 and 32, respectively.

The sheet S fed to the curl removing ribs 31 and 32 by the discharge roller pair (sheet conveying means) 62 is guided by the guide inclined surfaces 31b and 32b, and the leading ends 31a and 32a of the curl removing ribs 31 and 32. The sheet S is passed between the leading ends 31a and 32a, and a plurality of seats are simultaneously attached to the sheet S during the passage to reduce or eliminate the curl of the sheet. Note that the sheet curl removing device 3 of the third embodiment also includes curl removing ribs 31,
Air is blown by a fan onto the sheet S passing between the leading ends 31a and 32a of the sheet 32 to cool the sheet S,
The surface temperature is reduced to enhance the curl removing ability.

As described above, the sheet curl removing device 3
By reducing or removing the curl of the sheet S, the copying machine 50 can smoothly perform various processes such as stacking, discharging, and reversing the sheet S.

The curl removing rollers 5A, 5A of the sheet curling devices 1, 2, 3 of the first, second, and third embodiments.
B overlap amount L1, curl removal belts 21 and
2 overlap amount L2, curl removing ribs 31, 32
May be variable according to the type and thickness of the sheet S or the amount of curl. In this case, the curl of the sheet S can be reliably alleviated or removed according to the type and thickness of the sheet S or the amount of curl.

[0046]

According to the sheet curl removing apparatus of the present invention, the sheet is formed in a wave shape by the pair of curl removing rotating members which are intertwined with each other, and the sheet is stiffened. Even if it does, it can be reliably mitigated or eliminated.

In the sheet decurling apparatus of the present invention,
If the rotating body of the curl removing rotating body pair is adjustable in position in the direction of adjusting the intricate amount, it is possible to reliably reduce the curl of the sheet according to the type and thickness of the sheet or the amount of curl, Alternatively, it can be removed.

In the sheet curl removing apparatus of the present invention, the sheet is formed in a wavy shape by the indented pair of ridges so that the sheet is stiffened. Can be reliably mitigated or eliminated.

In the sheet decurling apparatus of the present invention,
If the pair of ridges can be adjusted in the direction of adjusting the amount of intrusion, the curl of the sheet can be reliably reduced or removed according to the type, thickness, or amount of curl of the sheet. Can be.

In the image forming apparatus of the present invention, the sheet curled by heating and pressurizing by the fixing means is relaxed or removed by the sheet curl removing device, so that the sheet is caught, folded, jammed, and stacked. Sheet loading, discharging,
Various processes such as inversion can be performed smoothly.

[Brief description of the drawings]

FIG. 1 is a schematic longitudinal sectional view of a copying machine which is an image forming apparatus including a sheet curl removing device according to a first embodiment.

FIG. 2 is a schematic longitudinal sectional view of the sheet curl removing device of the first embodiment.

FIG. 3 is a view of the sheet curl removing device of FIG. 2 as viewed from the left side, and is a view as viewed from a downstream side in a sheet conveying direction.

FIG. 4 is an operation explanatory view of the sheet curl removing device of FIG. 2; FIG. 5A is a diagram illustrating a state in which a sheet is curled upward. FIG. 4B is a diagram illustrating a state in which the curl amount of the sheet is reduced.

FIG. 5 is a diagram illustrating a sheet curl removing device according to a second embodiment. FIG. 6A is a diagram illustrating the sheet curl removing device according to the second embodiment as viewed from a downstream side in a sheet conveying direction. (B) It is the figure which looked at (a) from the right side.

FIG. 6 is a diagram illustrating a sheet curl removing device according to a third embodiment. FIG. 7A is a diagram of the sheet curl removing device according to the third embodiment as viewed from a downstream side in a sheet conveying direction. (B) It is the figure which looked at (a) from the right side.

FIG. 7 is a perspective view of a curled sheet. (A) It is a perspective view of the sheet curled above. (B) It is a perspective view of the sheet which curled below. (C) It is a perspective view of the sheet curled in a semi-cylindrical shape. (D) is a perspective view of the sheet curled in a gutter shape.

FIG. 8 is a main partial view of a conventional sheet decurling apparatus.

FIG. 9 is a main partial view of another conventional sheet decurling apparatus.

[Explanation of symbols]

S Sheet 1, 2, 3, 3 Sheet curl removing device 4A shaft 4B shaft 5A, 5B Roller (curl removing rotating body, curl removing rotating body pair) 6 Fan (cooling air supply device) 21, 22 Curling removing belt (curling removing rotating body) 23, 24 Rotary shaft 25, 26 Pulley 27, 28 Rotary shaft 29, 30 Pulley 31, 32 Curl removing rib (projection, pair of projections) 31a, 32a Tip 31b of curl removing rib , 32b Guide inclined surface of curl removing rib 50 Copy machine (image forming apparatus) 51 Main body 53 Post-processing device 56 Photosensitive drum (Image forming means) 61 Fixing device (Fixing means) 62 Discharge roller pair (Sheet conveying means) 65 Binding device (Post-processing device) 66 Folding device (Post-processing device) 67 Tray

Claims (10)

[Claims] 1. A sheet decurling apparatus comprising a plurality of curl removing rotary members which are arranged on both sides of a sheet in a direction intersecting the sheet conveying direction and are intertwined with each other. 2. The sheet decurling apparatus according to claim 1, wherein the rotating body of the pair of curl removing rotary bodies is provided so as to be position-adjustable in a direction for adjusting the intricate amount. 3. The sheet decurling apparatus according to claim 1, wherein the rotary member of the pair of curl removing rotary members is a roller. 4. The sheet decurling apparatus according to claim 1, wherein the rotating member of the pair of curl removing rotary members is an endless belt. 5. A sheet conveying means for conveying a sheet, and arranged on both sides of the sheet conveyed by the sheet conveying means in a direction intersecting a conveying direction of the sheet,
A sheet curl removing device comprising: a pair of projecting ridges; 6. The sheet decurling apparatus according to claim 5, wherein the ridges of the pair of ridges are provided so as to be position-adjustable in a direction for adjusting the amount of the tangling. 7. An image forming unit for forming a toner image on a sheet, a fixing unit for fixing the toner image formed by the image forming unit on the sheet, and a curl of the sheet on which the toner image is fixed is removed. An image forming apparatus, comprising: the sheet curl removing device according to any one of claims 1 to 6. 8. An image forming unit for forming a toner image on a sheet, a fixing unit for fixing the toner image formed by the image forming unit on the sheet, and a curl removal of the sheet on which the toner image is fixed. The sheet curl removing device according to any one of claims 1 to 6, and a cooling air supply device that sends air to the sheet when the curl is removed by the sheet curl removing device. An image forming apparatus comprising: 9. An image forming unit for forming a toner image on a sheet, a fixing unit for fixing the toner image formed by the image forming unit on the sheet, and removing a curl of the sheet on which the toner image is fixed. The sheet curl removing device according to any one of claims 1 to 6, and a post-processing device that performs post-processing on a sheet whose curl has been removed by the sheet curl removing device. Image forming apparatus. 10. An image forming unit for forming a toner image on a sheet, a fixing unit for fixing the toner image formed by the image forming unit to the sheet, and a curl of the sheet on which the toner image is fixed is removed. The sheet curl removing device according to any one of claims 1 to 6, a cooling air supply device that sends air to a sheet when curl is removed by the sheet curl removing device, and the sheet curl. An image forming apparatus, comprising: a post-processing device that performs post-processing on a sheet from which a curl has been removed by a removing device.