JP6746900B2 - Paper humidifier and image forming system - Google Patents

Description

The present invention relates to a paper humidifier and an image forming system.

Conventionally, a paper humidifying device for humidifying a paper is known. This paper humidifier is provided with a pair of water vessels for storing water, a pair of water supply rollers for pumping water stored in the pair of water vessels, and a nip portion provided in contact with the pair of water supply rollers on the sheet conveyance path. And a pair of humidifying rollers to be formed. The pair of humidifying rollers are in a state where water is applied to the surface by the water from the pair of water supplying rollers, and the paper is humidified when passing through the nip portion formed by the pair of humidifying rollers (for example, Patent Document 1). reference).

Here, like a humidifying roller of a paper humidifying device, a pair of rollers that form a nip portion and through which the paper passes through the nip portion are the end portions in the paper width direction (hereinafter the paper end portion) due to the passage of a large number of paper sheets. The abutting part of is deteriorated.

Therefore, a fixing device has been proposed in which measures against deterioration of the abutting portion of the sheet edge are taken. This fixing device forms a nip portion by a fixing roller and a pressing roller, and stops printing when these rollers deteriorate. Further, in this fixing device, the entire fixing unit including the fixing roller and the pressing roller is swung in a direction (roller axis direction) orthogonal to the sheet conveying direction so that the sheet end passes through different positions between the rollers. (For example, see Patent Document 2). This makes it difficult for the roller to deteriorate and prolongs the life of the roller.

JP, 2014-202900, A JP, 2005-1572, A

Here, in the paper humidifying device described in Patent Document 1, if the pair of humidifying rollers deteriorate, the deteriorated portion will adhere more water than the other portions. When the end portion of the sheet passes through such a deteriorated portion, excessive humidification occurs at the end portion of the sheet, and waviness occurs at the end portion of the sheet. When such undulation occurs, there is no choice but to replace the pair of humidifying rollers.

Therefore, when the technique described in Patent Document 2 is applied to rock the pair of humidifying rollers, it is difficult for the pair of humidifying rollers to deteriorate, and therefore the period until the pair of humidifying rollers is replaced is lengthened. be able to. That is, the life can be extended.

However, when swinging the pair of humidifying rollers as described above, the number of movements of the humidifying rollers in the roller axis direction increases, and the control load thereof increases.

The present invention has been made to solve such a problem, and an object of the present invention is to provide a paper humidifying device and an image that can extend the life of a pair of humidifying rollers while suppressing the control load. To provide a forming system.

Further, the paper humidifying device according to the present invention is a paper humidifying device that humidifies a paper by passing the paper through a nip portion formed by a pair of humidifying rollers to which water is applied, When the cumulative amount indicating the cumulative total of the edges of the sheet that have passed through the same position on the pair of humidifying rollers is equal to or greater than a predetermined amount, a predetermined area in the width direction including the position is a degraded area. When the deterioration determining unit for determining and the deterioration determining unit determines that there is a newly deteriorated region, the pair of humidifying rollers are moved in the roller axis direction by a predetermined movement amount. A movement control means, a pair of water boats for storing water, and a pair of water supply rollers for drawing water stored in the pair of water boats and applying water in contact with the pair of humidifying rollers, A pair of humidification rollers, the pair of water ships, and the pair of water supply rollers constitute a humidification unit, the movement control means, by moving the humidification unit in the roller axial direction, the pair of The humidifying roller is moved in the roller axial direction.

According to the paper humidifying device of the present invention, when the cumulative amount indicating the cumulative total of the paper edges passing through the same position on the pair of humidifying rollers is equal to or more than a predetermined amount, a predetermined region in the width direction including the position. Is determined to be a deterioration area, and when it is determined that a new deterioration area exists, the pair of humidifying rollers are moved in the roller axis direction by a predetermined movement amount. For this reason, when a deteriorated region occurs in the pair of humidifying rollers, the pair of humidifying rollers can be moved so that the edge of the sheet does not pass through the deteriorated region. Further, the applicant of the present application has found that, with regard to the humidifying roller, undulation does not occur unless the edge of the paper passes through the deteriorated area. That is, it has been found that undulation does not occur in the central portion of the paper even when the central portion of the paper passes through the deteriorated area. Therefore, it is not necessary to move the pair of humidifying rollers in the roller axial direction before the specific area of the pair of humidifying rollers becomes the deteriorated area. You will not be forced to. Therefore, it is possible to extend the life of the pair of humidifying rollers while suppressing the control load. Further, the pair of humidifying rollers, the pair of water ships, and the pair of water supply rollers constitute a humidifying unit, and by moving the humidifying unit in the roller axial direction, the pair of humidifying rollers is moved in the roller axial direction. .. In this way, by moving the humidifying unit together, the positional relationship between the pair of humidifying rollers and the pair of water ships and the pair of water supplying rollers is not disturbed, and the situation where the humidifying amount becomes unstable can be prevented. You can

According to the present invention, it is possible to provide a sheet humidifying device and an image forming system capable of extending the life of a pair of humidifying rollers while suppressing the control load.

FIG. 1 is a schematic configuration diagram showing an image forming system including a sheet humidifying device according to an embodiment. FIG. 2 is a configuration diagram showing details of a paper humidifying section shown in FIG. 1. It is a schematic perspective view which shows a humidification unit. FIG. 2 is a functional block diagram showing a control unit of the post-processing device shown in FIG. 1. FIG. 5 is a conceptual diagram showing an example of operations of a cumulative distance calculation unit and a cumulative distance storage unit shown in FIG. 4. It is the schematic which shows an example of operation|movement of the paper humidifying device which concerns on this embodiment, (a) shows an initial position, (b) shows the position after the first movement, (c) shows the position after the second movement. Is shown. 6A and 6B are schematic diagrams showing the operation of the sheet humidifying device according to the present embodiment, where FIG. 9A shows an initial position, FIG. 8B shows an example in which the edge of the sheet after the initial movement corresponds to a deteriorated region, c) shows an example when avoiding all the deteriorated areas. It is a flow chart which shows operation of a paper humidification device concerning this embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited to the following embodiments.

FIG. 1 is a schematic configuration diagram showing an image forming system including a sheet humidifying device according to the present embodiment. The image forming system 1 illustrated in FIG. 1 includes an image forming apparatus A and a post-processing apparatus B that performs post-processing on a sheet P on which an image is formed by the image forming apparatus A.

The image forming apparatus A is a tandem color type that forms a full-color image on the paper P by arranging a plurality of photoconductors facing one intermediate transfer belt in a vertical direction. And an image reading device 2 including an automatic document feeder and a scanning exposure device, and an image forming unit 3 and a plurality of paper feed trays 4 at the bottom.

The image reading device 2 is a device that conveys a document placed on a document tray of an automatic document conveying device by a conveying unit, scans and exposes an image on one side or both sides of the document, and reads image information. The image reading device 2 is also configured to read image information of a document placed on the contact glass.

The image forming unit 3 receives paper P supplied from a plurality of paper feed trays 4, and is based on image information read by the image reading device 2 or image information transmitted from a PC (personal computer) or the like. Then, an image is formed on the paper P.

The image forming section 3 is composed of an image transfer section 3a and a fixing section 3b. The image transfer section 3a forms a toner image on the photoconductor by an electrophotographic process of charging, exposing and developing, and transfers the image onto the paper P. In the present embodiment, the image transfer portion 3a is of a type having an intermediate transfer belt. The toner images on the plurality of photoconductors are transferred to the intermediate transfer belt, and the toner images on the intermediate transfer belt are transferred to the paper P. It

The fixing unit 3b forms a nip portion for transporting the paper P with a heating roller and a pressure roller, heats and pressurizes the paper P while transporting the paper P to melt the toner, and transfers the toner to the paper P by the image transfer unit 3a. The fixed image is fixed on the paper P.

Furthermore, the image forming apparatus A includes a reversing path 5 that connects the downstream side of the fixing section 3b to the upstream side of the image transfer section 3a. The reversing path 5 is a path for reversing the front and back of the sheet P and then re-conveying the sheet P to the image transfer portion 3a. By means of this reversal path 5, it is possible to form images on the front and back sides of the paper P.

The post-processing device B is for cutting (including punching) the paper P, humidifying, folding, stapling, and the like. The post-processing apparatus B includes various paths R1 and R2, a paper discharge tray Tr, a paper humidifying section C, and a control section 90. The sheet humidifying unit C and the control unit 90 constitute a sheet humidifying device.

The first route R1 is a route for receiving the image-formed sheet P and transporting it to the sheet humidifying section C, and the second route R2 is a route for transporting the sheet P passing through the sheet humidifying section C to the discharge tray Tr. Is. Here, the paper P on which the image is formed by the image forming apparatus A is in a charged state, and the charged paper P causes various inconveniences. Therefore, the paper humidifying device humidifies the paper P on which an image is formed.

Although the second path R2 guides the paper P to the paper discharge tray Tr in the present embodiment, a folding mechanism, a stapling mechanism, or the like may be provided on the second path R2. Also, another mechanism such as a cutting mechanism may be provided in the first route R1.

FIG. 2 is a configuration diagram showing details of the paper humidifying section C shown in FIG. The paper humidifying section C shown in FIG. 2 humidifies the paper P as the paper P passes through a nip portion N formed by a pair of humidifying rollers 10 to which water is applied. Such a paper humidifying section C includes a pair of water rollers 20, a pair of water supply rollers 30, and a pair of draining rollers 40, in addition to the pair of humidifying rollers 10. The pair of components 10, 20, 30, 40 are arranged symmetrically with the transport path R interposed therebetween.

The pair of water ships 20 store water and are formed in an arcuate cross section along the outer periphery of the water supply roller 30. A part of the pair of water supply rollers 30 is immersed in the water stored in the pair of water ships 20, and the water of the water ship 20 is pumped up as the water rollers 20 rotate. Further, the pair of water supply rollers 30 are arranged so as to be in contact with the pair of humidification rollers 10. Therefore, the pair of humidifying rollers 10 are coated with water on their surfaces as the pair of water supply rollers 30 rotate.

The pair of draining rollers 40 are water amount limiting members that limit the amount of water held by the pair of water supplying rollers 30. The water draining roller 40 is rotatably supported and limits the amount of water retained on the surface of the water supplying roller 30 by coming into contact with the water supplying roller 30 or approaching the water supplying roller 30 with a gap. Therefore, the humidifying roller 10 is coated with a limited amount of water by the draining roller 40. The draining roller 40 is not limited to a rotatably supported roller-shaped member, but may be, for example, a plate-shaped member.

Further, as shown in FIG. 2, the paper humidifying section C includes a water supply roller pressing spring 50 and a cam mechanism 60, and is configured such that the pair of humidifying rollers 10 can come into contact with and separate from each other. The water supply roller pressing spring 50 is a spring member that biases the pair of humidifying rollers 10 in a direction in which they approach each other. The cam mechanism 60 is composed of two cam members 61 arranged coaxially with the rotation axis AX of the pair of humidifying rollers 10, and these two cam members 61 sandwich the conveyance path R of the paper P therebetween. They are arranged symmetrically. These cam members 61 are rotatably supported about the rotation axis AX, and are shaped like a sphere so that the lengths of the radii differ from the rotation axis AX. Therefore, when the cam members 61 rotate together and the long and long portions are positioned between the rotation axes AX, the direction in which the pair of humidifying rollers 10 are separated from each other against the biasing force of the water supply roller pressing spring 50. Apply force to. With such a cam mechanism 60, the nip pressure of the pair of humidifying rollers 10 can be changed.

In particular, when the longest part rl of the cam member 61 is located between the rotation axes AX, the pair of humidifying rollers 10 are separated from each other. Therefore, when the pair of humidifying rollers 10 are separated from each other, the sheet P is conveyed to the subsequent stage without being humidified by the sheet humidifying section C.

Needless to say, in the above, the pair of water supply rollers 30 and the water draining roller 40 are configured to operate following the contact and separation of the pair of humidifying rollers 10. The amount of humidification of the paper P can be controlled by adjusting the pressing force of the draining roller 40 against the water supply roller 30 or the amount of the gap, but if possible, the nip pressure using the cam mechanism 60 is adjusted. It may be controlled by doing.

Further, the sheet humidifying section C is unitized by housing the above-mentioned respective sections 10, 20, 30, 40, 50, 60 in a housing, and constitutes a humidifying unit E. FIG. 3 is a schematic perspective view showing the humidifying unit E. As shown in FIG. 3, the humidifying unit E is provided in the housing 70 with an opening for introducing the paper P and an opening for discharging the paper P after humidification.

Further, in the present embodiment, the paper humidifying section C includes a moving mechanism 80. The moving mechanism 80 is a mechanism for moving the humidifying unit E in the roller axial direction of the humidifying roller 10 and the like, and includes a motor 81, a gear 82, and a worm gear 83. The motor 81 is composed of, for example, a stepping motor, and rotates based on an instruction from the control unit 90. The gear 82 is fixed to the rotating shaft of the motor 81, and the groove portion of the peripheral surface thereof is adapted to mesh with the thread groove portion of the worm gear 83. One end of the worm gear 83 is fixed to the side surface of the housing 70 of the humidifying unit E.

When the motor 81 rotates, the humidifying unit E passes through a drive transmission system including a gear 82 and a worm gear 83, in a direction (arrow X direction and arrow X direction) orthogonal to the conveyance direction (arrow Y direction) of the paper P. The roller axis direction). As a result, the components 10, 20, 30, 40, 50, 60 inside the humidifying unit E also move in the arrow X direction together with the housing 70. Since the motor 81 can rotate in the forward and reverse directions, it is configured to be movable in one direction of the roller axis direction and in the other direction opposite to the one direction.

Although the humidifying unit E is unitized by being housed in the housing 70 in the present embodiment, the humidifying unit E is not limited to the housing 70 in particular, and may be unitized by being integrated by a frame member or the like. Good.

FIG. 4 is a functional block diagram showing the control unit 90 of the post-processing apparatus B shown in FIG. The control unit 90 shown in FIG. 4 controls the entire post-processing apparatus B. The control unit 90 is also configured to communicate with the control unit 6 of the image forming apparatus A, and acquires from the image forming apparatus A the information necessary for controlling the paper humidifying unit C. The information to be acquired is, for example, paper size information.

Such a control unit 90 includes a cumulative distance calculation unit 91, a cumulative distance storage unit 92, a deterioration determination unit (deterioration determination means) 93, a movement control unit (movement control means) 94, and a deterioration area storage unit (deterioration). Area storage means) 95 is provided as a component of the paper humidifier. The cumulative distance calculation unit 91 calculates, for each position on the pair of humidifying rollers 10, a cumulative amount indicating the cumulative total of the sheet edges of the sheet P. Here, the cumulative amount is a total distance obtained from the length and the number of sheets P that pass through the pair of humidifying rollers 10. The total distance storage unit 92 stores the total distance calculated by the total distance calculation unit 91.

FIG. 5 is a conceptual diagram showing an example of operations of the cumulative distance calculation unit 91 and the cumulative distance storage unit 92 shown in FIG. As shown in FIG. 5, for example, 100 sheets of paper P1 having a length L1 pass through the nip portion N of the pair of humidifying rollers 10. In this case, the cumulative distance calculation unit 91 calculates the total distance as 100×L1 for the two positions A1 corresponding to the edge of the sheet. Similarly, if, for example, 150 sheets of paper P2 having a paper width different from the paper P1 and a length L2 pass through, the cumulative distance calculation unit 91 sets the total distance to 150×L2 for the two positions A2 corresponding to the paper edges. And calculate. The total distance storage unit 92 stores the total distance calculated by the total distance calculation unit 91 as described above. Further, when there is a total distance stored in the past, the total distance storage unit 92 adds the total distance newly calculated by the total distance calculation unit 91 to the total distance stored in the past, and stores the total distance. Will be done.

Please refer to FIG. When the cumulative amount indicating the cumulative total of the sheet edges passing through the same position on the pair of humidifying rollers 10 is equal to or larger than a predetermined amount, the deterioration determining unit 93 determines that the predetermined region in the width direction including the position is the deterioration region. It is to judge that it has become. That is, the deterioration determination unit 93 determines whether or not the total distance at each position in the width direction of the pair of humidifying rollers 10 is equal to or greater than a predetermined unusable distance at which the humidifying roller 10 becomes unusable. Then, when the deterioration determining unit 93 determines that the distance becomes the unusable distance or more, the deterioration determining unit 93 determines that the predetermined area in the width direction including the position becomes the deterioration area. The unusable distance is set to a distance (that is, 89100 m) after passing 300,000 sheets of A4 paper (length 297 mm), for example.

When the deterioration determining unit 93 determines that there is a newly deteriorated region, the movement control unit 94 moves the pair of humidifying rollers 10 (humidifying unit E) by a predetermined moving amount in the roller axial direction. To move to.

Here, for example, when one direction of the roller axial direction is “−” and the other direction is “+”, the initial position (position of the center line of the paper P) of the pair of humidifying rollers 10 is +5 mm. It has become. In this case, the predetermined first movement amount is −10 mm, and the second movement amount is +5 mm. The amount of movement after the third time is also predetermined. When performing such a movement, the movement control unit 94 realizes the above movement by rotating the motor 81 shown in FIG. 3 forward or backward.

6A and 6B are schematic diagrams showing an example of the operation of the sheet humidifying device according to the present embodiment, where FIG. 6A shows the initial position, FIG. 6B shows the position after the initial movement, and FIG. 6C shows the second time. The position after movement is shown.

As shown in FIG. 6A, in the pair of humidifying rollers 10, the center position CP in the roller width direction is displaced from the center line CL of the paper P by 11 (for example, 5 mm) in the other direction. There is. In such a state, when it is determined that the deterioration area DA1 (see FIG. 6B) is newly generated, the movement control unit 94 moves the entire humidifying unit E to move the pair of humidifying rollers 10. The position shown in FIG.

As shown in FIG. 6B, the pair of humidifying rollers 10 is in a state where the center position CP in the roller width direction is displaced from the center line CL of the paper P by 12 (for example, 5 mm) in one direction. There is. That is, the pair of humidifying rollers 10 has been moved in the other direction by l1+l2 (for example, 10 mm). In such a state, when a large number of sheets P are passed and a new deterioration area DA2 (see FIG. 6C) is generated, the movement control unit 94 moves the entire humidification unit E to move the pair. The humidifying roller 10 is set to the position shown in FIG.

As shown in FIG. 6C, the pair of humidifying rollers 10 is in a state where the center position CP in the roller width direction is aligned with the center line CL of the paper P. That is, the pair of humidifying rollers 10 is moved by 12 (for example, 5 mm) in one direction. After that, similarly, each time the deterioration determining unit 93 determines that a new deterioration area DA has occurred, the movement control unit 94 moves the entire humidifying unit E to preset the pair of humidifying rollers 10. Move by the amount of movement.

Please refer to FIG. 4 again. The deterioration area storage unit 95 stores information about the deterioration area determined to be a deterioration area by the deterioration determination unit 93. Therefore, in the example shown in FIG. 6, when it is determined that the new deterioration areas DA1 and DA2 have occurred, the deterioration area storage unit 95 stores the information (particularly the position information) of the deterioration areas DA1 and DA2. Become.

7A and 7B are schematic diagrams showing another example of the operation of the sheet humidifying device according to the present embodiment, where FIG. 7A shows an initial position and FIG. 7B shows the edge of the sheet after the initial movement corresponds to the deteriorated area. An example in the case of doing is shown, and (c) shows an example when avoiding all the deterioration areas.

First, as illustrated in FIG. 7A, for example, it is assumed that the deterioration area DA exists at a plurality (four) widthwise positions of the pair of humidifying rollers 10. Then, as shown in FIG. 7B, it is assumed that a new deteriorated area DA3 is generated by humidifying a large number of sheets P. In this case, the movement control unit 94 attempts to move the pair of humidifying rollers 10 in the roller axis direction by moving the humidifying unit E by a predetermined moving amount.

However, as shown in FIG. 7C, when the humidifying unit E is moved by a predetermined movement amount, the paper edge of the next paper P is deteriorated in the past stored in the deterioration area storage unit 95. It will pass through the area DA.

In such a case, the movement control unit 94 determines whether there is an avoidance movement destination that avoids all the deterioration areas DA stored in the deterioration area storage unit 95. That is, it is determined whether or not there is an avoidance destination where the sheet edge of the next sheet P does not pass through all the deteriorated areas DA. Then, when there is the avoidance movement destination, for example, as illustrated in FIG. 7D, the movement control unit 94 moves the pair of humidifying rollers 10 to a position different from that in FIG. 7C.

That is, the movement control unit 94 moves the humidifying unit E from the state of FIG. 7B to the state of FIG. 7D. In this way, the sheet humidifying device prevents the sheet edge of the next sheet P from passing through the deterioration area DA when the pair of humidifying rollers 10 are moved by the predetermined movement amount. ..

FIG. 8 is a flowchart showing the operation of the paper humidifying device according to this embodiment. Note that the processing shown in FIG. 8 will be described as an example of being repeatedly executed every time a predetermined number of sheets of paper P are conveyed to the paper humidifying section C, but the processing is not limited to this, and may be executed at fixed timings. May be.

As shown in FIG. 8, the control unit 90 first determines whether or not the humidifying process is performed on the paper P supplied to the paper humidifying unit C (S1). For example, the control unit 90 determines not to perform the humidification process when it is determined that the surroundings are at a predetermined humidity or higher based on a signal from a humidity sensor (not shown). When it is determined that the humidifying process is not performed (S1: NO), the process shown in FIG. 8 ends. When it is determined that the humidifying process is not performed, the control unit 90 separates the pair of humidifying rollers 10.

When it is determined that the humidifying process is performed (S1: YES), the sheet P is humidified by the nip conveyance by the pair of humidifying rollers 10. Then, the cumulative distance calculation unit 91 calculates the total distance based on the information such as the paper size and the number of image formations acquired from the control unit 6 of the image forming apparatus A (S2), and the cumulative distance storage unit 92 determines in step S2. The total distance calculated in step S3 is added to the past amount and stored (S3).

Next, the deterioration determination unit 93 determines whether or not a new deterioration area DA has occurred, based on the total distance information stored in the cumulative distance storage unit 92 (S4). When it is determined that the new deterioration area DA has not been generated (S4: NO), the processing shown in FIG. 8 ends. On the other hand, when it is determined that a new deterioration area DA has occurred (S4: YES), the deterioration area storage unit 95 stores information on the new deterioration area DA (S5).

Next, when the moisturizing unit E is moved in the roller axis direction by a predetermined movement amount, the movement control unit 94 stores all the paper edge portions of the next paper P stored in the deterioration area storage unit 95. It is determined whether the normal area excluding the deteriorated area DA is passed (S6).

When it is determined that the humidifying unit E passes through the normal region (S6: YES), the movement control unit 94 moves the humidifying unit E in the roller axial direction by a predetermined moving amount (S7). Then, the process shown in FIG. 8 ends.

When it is determined that the vehicle does not pass through the normal area (S6: NO), the movement control unit 94 determines whether there is an avoidance movement destination (S8). In this process, the movement control unit 94 determines the avoidance movement destination based on the information of all the past deterioration areas DA stored in the deterioration area storage unit 95. At this time, the movement control unit 94 assumes that it has moved by a predetermined amount (5 mm) in one direction or the other direction, for example, determines whether the normal region is passed at that time, and if it is determined that the normal region is not passed. In addition, it is assumed that a predetermined amount (5 mm) is further moved, and at that time, it is determined whether or not the normal area is passed. Then, as a result of repeating this, when it is determined that the normal area cannot be passed, the movement control unit 94 determines that there is no avoidance movement destination (S8: NO), and the processing shown in FIG. 7 ends. In this case, the control unit 90 may, for example, separate the pair of humidifying rollers 10 to stop the humidifying function, or the humidifying rollers 10 may be completely deteriorated on the display unit of the post-processing apparatus B or the image forming apparatus A. It displays that it has gone down.

On the other hand, when the movement control unit 94 determines that there is an avoidance movement destination (S8: YES), the movement control unit 94 moves the humidification unit E to the avoidance movement destination determined in step S8 (S9). Then, the process shown in FIG. 8 ends.

In this way, according to the sheet humidifying apparatus and the image forming system 1 according to the present embodiment, the cumulative amount indicating the cumulative number of the sheet edges passing the same position on the pair of humidifying rollers 10 becomes equal to or larger than the predetermined amount. In this case, when it is determined that the predetermined area in the width direction including the position has become the deterioration area DA, and it is judged that there is a new area that has become the deterioration area DA, a pair of pairs of predetermined movement amounts are used. The humidifying roller 10 is moved in the roller axis direction. Therefore, when the deteriorated area DA is generated in the pair of humidifying rollers 10, the pair of humidifying rollers 10 can be moved so that the sheet edge does not pass through the deteriorated area. Further, the applicant of the present application has found that, regarding the humidifying roller 10, no waviness occurs unless the edge of the paper passes through the deterioration area DA. That is, it has been found that undulation does not occur in the central portion of the paper even when the central portion of the paper passes through the deterioration area DA. Therefore, it is not necessary to move the pair of humidifying rollers 10 in the roller axial direction before the specific area of the pair of humidifying rollers 10 becomes the deterioration area DA. The 10 is no longer frequently moved. Therefore, it is possible to extend the life of the pair of humidifying rollers 10 while suppressing the control load.

Further, when it is determined that the paper edge of the next paper P passes through the deterioration area DA when the pair of humidifying rollers 10 are moved in the roller axis direction, the paper edge of the next paper P is the entire deterioration area. The pair of humidifying rollers 10 is moved to a position where DA is avoided. For this reason, the number of deteriorated areas DA becomes large, and when the pair of humidifying rollers 10 are moved by a predetermined movement amount, it is possible to prevent the edge of the paper from passing through the deteriorated areas DA, and the paper can be appropriately used. It is possible to prevent undulations at the ends.

In addition, the cumulative amount is the total distance of the edges of the sheet of paper that is obtained from the length and number of sheets of paper P that passes through the pair of humidifying rollers 10, and the total distance is equal to or greater than a predetermined unusable distance at which the paper cannot be used. It is determined that the area that has become the deterioration area DA. Therefore, as compared with the case where the deterioration area DA is judged only from the number of sheets, the judgment accuracy of the deterioration area DA can be improved.

In addition, since the pair of humidifying rollers 10 is configured to be movable in one direction along the roller axis and in the other direction opposite to the one direction, the pair of humidifying rollers 10 can be moved in two directions, resulting in a longer life. Can contribute to realization.

Further, since the pair of humidifying rollers 10 are configured to be able to come into contact with and separate from each other, when humidification is not required, the pair of humidifying rollers 10 can be separated from each other to achieve a longer life of the humidifying rollers 10. You can

In addition, the pair of humidifying rollers 10, the pair of water ships 20, and the pair of water supply rollers 30 constitute a humidifying unit E, and by moving the humidifying unit E in the roller axial direction, the pair of humidifying rollers 10 is moved. Move in the roller axis direction. In this way, by moving the humidifying unit E together, the positional relationship between the pair of humidifying rollers 10 and the pair of water ships 20 and the pair of water supplying rollers 30 is not broken, and the humidifying amount becomes unstable. Can be prevented.

Although the sheet humidifying device and the image forming system 1 according to the present invention have been described above based on the embodiment, the present invention is not limited to this, and changes may be made without departing from the spirit of the present invention. Alternatively, if possible, the techniques described in the embodiments and the known techniques may be combined.

For example, in the process shown in FIG. 8, the humidifying unit E is moved every time the deterioration area DA is generated in the pair of humidifying rollers 10. However, the present invention is not limited to this, and the deterioration area DA is newly added to the pair of humidifying rollers 10. May occur, and when it is determined that the next sheet P passes through the newly generated deterioration area DA, the humidifying unit E may be moved. As a result, even if a new deterioration area DA is generated, when the paper P having a different paper size is to be humidified next, it is necessary to move the humidifying roller 10 without passing the paper P through the new deterioration area DA. Because there is no.

Further, although the movement control unit 94 moves the humidifying unit E in the above-described embodiment, the present invention is not limited to this, and only the pair of humidifying rollers 10 may be moved. In this case, the central axes of the pair of humidifying rollers 10 may be supported by thrust bearings.

Further, in the above-described embodiment, the sheet humidifier is built in the post-processing apparatus B connected to the subsequent stage of the image forming apparatus A, but the present invention is not limited to this, and the sheet humidifying apparatus is not connected to the image forming apparatus A and the sheet after image formation is formed. It may be applied to an offline finisher that performs post-treatment on P alone. In this case, the off-line finisher may be provided with means for acquiring the paper size and the number of paper sheets P.

1: Image forming system 2: Image reading device 3: Image forming unit 3a: Image transfer unit 3b: Fixing unit 4: Paper feed tray 5: Reverse path 6: Control unit 10: Humidifying roller 20: Water ship 30: Water supply roller 40 : Draining roller 50: Water supply roller pressing spring 60: Cam mechanism 61: Cam member 70: Housing 80: Moving mechanism 81: Motor 82: Gear 83: Worm gear 90: Control unit 91: Total distance calculation unit 92: Total distance storage unit 93: Deterioration judging section (deterioration judging means)
94: Movement control unit (movement control means)
95: Degraded area storage unit (degraded area storage means)
A: Image forming device AX: Rotation axis B: Post-processing device C: Paper humidifying part DA: Deteriorated area E: Humidifying unit N: Nip part P: Paper R: Conveying path R1: First path R2: Second path Tr: Output tray

Claims (1)

A sheet humidifying device for humidifying a sheet by passing the sheet through a nip formed by a pair of humidifying rollers to which water is applied,
When the cumulative amount indicating the cumulative total of the edges of the sheet, which are the edges in the width direction of the sheet, passing through the same position on the pair of humidifying rollers is equal to or more than a predetermined amount, the predetermined area in the width direction including the position is deteriorated. Deterioration determination means to determine that the area has become,
When it is determined by the deterioration determining unit that a region that has become the newly deteriorated region exists, a movement control unit that moves the pair of humidifying rollers in the roller axis direction by a predetermined movement amount,
A pair of water boats for storing water, and a pair of water supply rollers for drawing water stored in the pair of water boats and contacting the pair of humidifying rollers to apply water
The pair of humidification rollers, the pair of water ships, and the pair of water supply rollers constitute a humidification unit,
The sheet humidifying device, wherein the movement control means moves the pair of humidifying rollers in the roller axial direction by moving the humidifying unit in the roller axial direction.

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