JP6701918B2 - Paper processing apparatus and image forming system - Google Patents

Description

  The present invention relates to a sheet processing device and an image forming system.

In the image forming apparatus, the stacked sheets are stuck to each other or the sheets are repulsed to each other and float due to the sheets being charged due to the application of a transfer voltage or the static electricity generated during conveyance. It is known that a phenomenon occurs, and as one of measures against it, it is considered to provide a mechanism for applying water to a sheet.
As a mechanism for applying water to the paper, for example, a humidifying roller pair capable of holding water on the outer peripheral surface and a water supply roller for supplying water to each of the humidifying roller pairs are provided, and the paper is sandwiched and conveyed by the humidifying roller pair. A configuration is known in which water is applied to the paper when doing (see, for example, Patent Document 1).

JP 2012-24953 A

In such an image forming apparatus, there is a demand for applying a desired amount of water to each surface of the paper in accordance with the type of paper and the image formed on the paper.
For example, when an image is formed only on one side of a sheet or when an image with high coverage is formed only on one side of a sheet, it is preferable to apply water only on one side of the sheet, and each side of the sheet is different. When a coverage image is formed, it is preferable to apply different amounts of water corresponding to the images on the respective surfaces.
However, in Patent Document 1, since the moisturizing roller pair is in a nipped state for a long time, the water applied to one surface is transferred to the other surface, and as a result, a desired amount of water is applied to each surface of the paper. There were things that weren't done.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a sheet processing apparatus and an image forming system capable of applying a desired amount of water to each surface of a sheet.

In order to solve the above problems, according to the present invention, a sheet processing apparatus,
A pair of humidifying rollers that press each other to form a nip portion, and add moisture to the paper when the paper is nipped and conveyed,
A drive unit for separating or pressing the humidifying roller pairs from each other,
A control unit for controlling the drive unit,
A water supply roller for supplying moisture to the outer peripheral surface of the pair of humidifying rollers,
A second drive unit that separates or abuts the water supply roller with respect to the humidification roller pair ,
The control unit controls the drive unit to separate the humidifying roller pair from each other to wait for the sheet, and presses the humidifying roller pair after the time when the leading edge of the sheet reaches the position corresponding to the nip portion, and The humidifying roller pair is separated before the rear end reaches the nip portion ,
The control unit is
When the nth (natural number) sheet is humidified and the (n+1)th sheet is not humidified, the second drive unit is controlled so that the distance from the rear end of the nth sheet to the nip portion is the water supply roller before shorter than the length of the circumference of the dampening roller and said Rukoto is separated from the humidifying roller pair.

According to the invention, the image forming system is
An image forming apparatus that forms an image on a sheet,
A sheet processing device which is connected to the image forming apparatus and humidifies a sheet on which an image is formed by the image forming apparatus;
It is characterized by having.

  According to the present invention, a desired amount of water can be applied to each side of the paper.

FIG. 1 is a diagram showing a schematic configuration of an image forming system. FIG. 3 is a block diagram showing main functional configurations of an image forming apparatus and a first sheet processing apparatus. It is a schematic diagram which shows the structure of a humidification part. It is a flow chart which shows the flow of humidification processing. It is a schematic diagram for demonstrating operation|movement of a humidification roller and a water supply roller in humidification processing. It is a schematic diagram for demonstrating operation|movement of a humidification roller and a water supply roller in humidification processing. It is a schematic diagram for demonstrating operation|movement of a humidification roller and a water supply roller in humidification processing. It is a schematic diagram which shows the modification of a structure of a humidification part.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the scope of the invention is not limited to the illustrated example.

FIG. 1 is a diagram showing a schematic configuration of an image forming system 1 which is an embodiment of the present invention.
The image forming system 1 includes a paper feeding device 2, an image forming device 3, a first paper processing device 4, and a second paper processing device 5.

The sheet feeding device 2 includes a plurality of large-capacity sheet accumulating units that accumulate a large number of sheets (sheets), and conveys the sheets from the sheet accumulating unit designated by the image forming apparatus 3 to the image forming apparatus 3. is there.
The image forming apparatus 3 is an apparatus that forms an image on a sheet by an electrophotographic method. The image forming apparatus 3 conveys the sheet on which the image is formed to the first sheet processing apparatus 4.
The first sheet processing device 4 is a device that performs a humidification process described later on the sheet delivered from the image forming device 3. The first sheet processing apparatus 4 conveys the sheet subjected to this processing to the second sheet processing apparatus 5.
The second sheet processing device 5 is a device that performs predetermined sheet processing on the sheet delivered from the first sheet processing device 4 and discharges the sheet. Examples of paper processing include decal processing, stapling processing, punching processing, folding processing, bookbinding processing, and the like.
The paper feeding device 2, the image forming device 3, the first paper processing device 4, and the second paper processing device 5 are configured to be attachable to and detachable from adjacent devices.

  FIG. 2 is a block diagram showing main functional configurations of the image forming apparatus 3 and the first sheet processing apparatus 4.

The image forming apparatus 3 includes a control unit 30 including a CPU (Central Processing Unit) 301, a RAM (Random Access Memory) 302, and a ROM (Read Only Memory) 303, a storage unit 31, an operation unit 32, and a display unit 33. A communication unit 34, an interface 35, a scanner 36, an image processing unit 37, an image forming unit 38, and a conveying unit 39.
The control unit 30 is connected to the storage unit 31, the operation unit 32, the display unit 33, the communication unit 34, the interface 35, the scanner 36, the image processing unit 37, the image forming unit 38, and the transport unit 39 via the bus 3b. There is.

  The CPU 301 reads out and executes the control program stored in the ROM 303 or the storage unit 31 to perform various arithmetic processes.

  The RAM 302 provides the CPU 301 with a working memory space and stores temporary data.

  The ROM 303 stores programs for various controls executed by the CPU 301, setting data, and the like. A rewritable nonvolatile memory such as an EEPROM (Electrically Erasable Programmable Read Only Memory) or a flash memory may be used instead of the ROM 303.

  The control unit 30 including the CPU 301, the RAM 302, and the ROM 303 integrally controls each unit of the image forming apparatus 3 according to the above-described various control programs. For example, the control unit 30 causes the image processing unit 37 to perform a predetermined image processing on the image data and stores the image data in the storage unit 31. Further, the control unit 30 causes the conveyance unit 39 to convey the sheet, and causes the image forming unit 38 to form an image on the sheet based on the image data stored in the storage unit 31.

  The storage unit 31 is configured by a DRAM (Dynamic Random Access Memory) or the like, and stores image data acquired by the scanner 36, image data input from the outside via the communication unit 34, and the like. The image data and the like may be stored in the RAM 302.

  The operation unit 32 includes operation keys and input devices such as a touch panel arranged so as to be superimposed on the screen of the display unit 33, and converts input operations on these input devices into operation signals and outputs the operation signals to the control unit 30.

  The display unit 33 includes a display device such as an LCD (Liquid crystal display), and displays the state of the image forming system 1 and an operation screen showing the contents of the input operation on the touch panel.

  The communication unit 34 communicates with a computer on the network or another image forming apparatus according to a control signal from the control unit 30 to send and receive image data and the like.

  The interface 35 is means for transmitting and receiving data to and from the first sheet processing device 4, and is configured by, for example, any of various serial interfaces.

  The scanner 36 reads an image formed on a sheet, generates image data including monochromatic image data for each of the R (red), G (green), and B (blue) color components, and stores the image data in the storage unit 31. ..

The image processing unit 37 includes a rasterization processing unit, a color conversion unit, a gradation correction unit, and a halftone processing unit. The image processing unit 37 performs various image processing on the image data stored in the storage unit 31 and stores the image data in the storage unit 31. ..
The rasterization processing unit converts vector format image data described in a predetermined page description language (PDL) input from a computer or the like on a network into raster format image data such as a bitmap. The image data converted and generated by the rasterization processing unit includes single color image data for each of C (cyan), M (magenta), Y (yellow), and K (black) color components.
The color conversion unit performs color conversion processing on the image data of each color of R, G, and B output from the scanner 36 with reference to a predetermined look-up table, and outputs single-color image data of each of C, M, Y, and K colors. Generate image data including. The color conversion unit also performs a predetermined color correction process on the image data.
The gradation correction unit refers to a look-up table in which a correction value corresponding to each gradation value is determined so that the gradation characteristic of the image related to the image data becomes a predetermined characteristic, and the gradation value of the image data is calculated. to correct.
The halftone processing unit performs halftone processing such as screen processing using a dither matrix and error diffusion processing on the image data.
A part or all of the rasterization processing unit, the color conversion unit, the gradation correction unit, and the halftone processing unit included in the image processing unit 37 may be realized by the control unit 30 or the image forming apparatus 3 may be configured to be realized. It may be configured to be realized by another image processing device provided outside.

  The image forming unit 38 forms an image on a sheet based on the image data stored in the storage unit 31. The image forming unit 38 includes four sets of an exposing unit 381, a photoconductor 382, and a developing unit 383 corresponding to the C, M, Y, and K color components, respectively. The image forming unit 38 also includes a transfer body 384, a secondary transfer roller 385, and a fixing unit 386.

The exposure unit 381 includes an LD (Laser Diode) as a light emitting element. The exposure unit 381 drives the LD based on the image data, irradiates and exposes the charged photoconductor 382 with laser light to form an electrostatic latent image on the photoconductor 382. The developing unit 383 supplies toner (color material) of a predetermined color (any one of C, M, Y, and K) by the developing roller that charges the exposed photoconductor 382, and the toner is applied onto the photoconductor 382. The formed electrostatic latent image is developed.
The images (monochromatic images) formed by the toners of C, M, Y, and K on the four photoconductors 382 corresponding to C, M, Y, and K, respectively, are transferred from the photoconductors 382 to the transfer body 384. Transferred one after another. As a result, a color image having C, M, Y, and K as color components is formed on the transfer body 384. The transfer body 384 is an endless belt wound around a plurality of transfer body transport rollers, and rotates according to the rotation of each transfer body transport roller.
The secondary transfer roller 385 transfers the color image on the transfer body 384 onto the sheet fed from the sheet feeding device 2 or the sheet feeding tray 3a. Specifically, when a predetermined transfer voltage is applied to the secondary transfer roller 385 that holds the sheet and the transfer body 384, the toner forming the color image on the transfer body 384 is attracted to the side of the sheet and is transferred to the sheet. Transcribed.

  The fixing unit 386 performs a fixing process of fixing the toner on the paper by heating and pressing the paper on which the toner is transferred. The fixing unit 386 includes a pair of rollers including a heating roller and a pressure roller that sandwich the sheet. The heating roller is heated to a predetermined target temperature (for example, a temperature within a range of 180° C. or higher and 200° C. or lower) by a heater as a heating source. The pressure roller is urged toward the heating roller by an elastic member (not shown). The sheet on which the image formed by the toner is transferred by the secondary transfer roller 385 passes through the nip portion between the heating roller and the pressure roller, so that the image formed by the toner is fixed on the sheet.

  The transport unit 39 includes a plurality of sheet transport rollers that transport the sheet by rotating the sheet while sandwiching the sheet, and transports the sheet along a predetermined transport path. The transport unit 39 includes a registration roller 391 arranged upstream of the secondary transfer roller 385 in the transport direction. The registration roller 391 temporarily stops the conveyance of the fed sheet and adjusts the timing of sending the sheet to the secondary transfer roller 385. Further, the transport unit 39 includes a reversing mechanism 392 that reverses the front and back of the sheet on which the fixing process has been performed by the fixing unit 386 and transports the sheet to the secondary transfer roller 385. In the image forming apparatus 3, when the images are formed on both sides of the sheet, the reversing mechanism 392 reverses the front and back of the sheet. The sheet is conveyed to the first sheet processing device 4 without being reversed.

  The first sheet processing device 4 includes a control unit 40 having a CPU 401, a RAM 402, and a ROM 403, an interface 41, a conveyance unit 42, and a humidification unit 43. The control unit 40 is connected to the interface 41, the transport unit 42, and the humidifying unit 43 via the bus 4b.

  The CPU 401 reads out and executes the control program stored in the ROM 403 to perform various arithmetic processes.

  The RAM 402 provides the CPU 401 with a working memory space and stores temporary data. The temporary data includes, for example, a set value related to a humidification process described later.

  The ROM 403 stores programs for various controls executed by the CPU 401, setting data, and the like. A rewritable non-volatile memory such as an EEPROM or a flash memory may be used instead of the ROM 403. The setting data includes, for example, a look-up table for determining the amount of water supplied to the paper in the humidifying process described later.

  The control unit 40 including the CPU 401, the RAM 402, and the ROM 403 collectively controls each unit of the first sheet processing apparatus 4 according to the various control programs described above. For example, the control unit 40 causes the humidifying unit 43 to humidify the paper under the condition indicated by the set value stored in the RAM 402.

  The interface 41 is means for transmitting and receiving data to and from the image forming apparatus 3, and is configured by any of various serial interfaces, for example.

  FIG. 3 is a schematic diagram showing the configurations of the transport unit 42 and the humidifying unit 43.

  The transport unit 42 includes guide members 421, 422, and 423 that guide the sheet M, sheet transport rollers 424 and 425 that transport the sheet by rotating the sheet M while sandwiching the sheet M, and along the transport path 42d. Transport the paper. Note that, in FIG. 3, the direction of the transport path 42d (transport direction) is the Y direction.

  The humidifying section 43 includes two first water supply rollers 431 provided to sandwich the transport path 42d vertically, and two second water supply rollers 432 that respectively contact outer peripheral surfaces of the two first water supply rollers 431. Two adjusting rollers 433 provided in the vicinity of the outer peripheral surfaces of the two second water supply rollers 432, and a pair of humidifiers that contact the outer peripheral surfaces of the two second water supply rollers 432 and sandwich the paper M, respectively. The roller 434 and the two water storage parts 435 for respectively supplying water to the two first water supply rollers 431 are provided.

  The first water supply roller 431, the second water supply roller 432, and the humidification roller 434 are cylindrical members that rotate on a rotation axis extending in the X direction, and have the same width in the X direction on the outer peripheral surface. ..

  Moreover, the 1st water supply roller 431, the 2nd water supply roller 432, and the humidification roller 434 are comprised by the outer peripheral surface so that water can be hold|maintained. Examples of the material of the outer peripheral surface capable of retaining water include a resin having hydrophilicity (for example, NBR).

  The 1st water supply roller 431 is arrange|positioned in the state which a part of outer peripheral surface was immersed in the water stored in the water storage part 435. The outer peripheral surface of the first water supply roller 431 is in contact with the outer peripheral surface of the second water supply roller 432. The first water supply roller 431 rotates around the rotation axis to draw up the water stored in the water storage section 435 to the outer peripheral surface and holds the water, and supplies the water to the outer peripheral surface of the second water supply roller 432.

The outer peripheral surface of the second water supply roller 432 is in contact with the outer peripheral surface of the first water supply roller 431 and the outer peripheral surface of the moisturizing roller 434, and the second water supply roller 432 rotates together with the rotation of the moisturizing roller 434. The water supplied from the outer peripheral surface of the water supply roller 431 is supplied to the outer peripheral surface of the humidifying roller 434.
The second water supply roller 432 is provided with a water supply roller drive unit 432a, and the second water supply roller 432 can be separated from or brought into contact with the humidification roller 434 by driving the water supply roller drive unit 432a. That is, the distance between the outer peripheral surface of the humidifying roller 434 and the outer peripheral surface of the second water supply roller 432 can be changed.
The water supply roller drive unit 432a is provided in each of the second water supply rollers 432.

The adjusting roller 433 is arranged in the vicinity of the second water supply roller 432 such that the outer peripheral surface thereof has a gap of a predetermined distance from the outer peripheral surface of the second water supply roller 432.
The adjustment roller 433 is a columnar member that rotates on a rotation shaft extending in the X direction, like the second water supply roller 432, and the width of the outer peripheral surface in the X direction is the same as or different from that of the second water supply roller 432. It is formed larger than the second water supply roller 432.

The adjustment roller 433 wipes excess water retained on the outer peripheral surface of the second water supply roller 432 by moving the outer peripheral surface of the adjustment roller 433 relative to the outer peripheral surface of the second water supply roller 432 (rotating in the opposite direction). is there. At this time, the water held in the second water supply roller 432 is changed by changing the distance between the outer peripheral surface of the adjustment roller 433 and the outer peripheral surface of the second water supply roller 432 by driving a drive unit (not shown). The amount can be adjusted. The drive unit is provided in each of the two adjusting rollers 433, and the two adjusting rollers 433 are independently controlled.
Note that the adjustment roller 433 may be one that can wipe the water of the second water supply roller 432, and thus may have a configuration that rotates in the opposite direction to the second water supply roller 432 or a configuration that does not rotate. Further, as long as the water of the second water supply roller 432 can be wiped, it is not limited to the roller-shaped member (adjustment roller 433), and for example, a plate-shaped member extending along the width direction (X direction) of the paper. And so on.

The water supply mechanism composed of the water storage section 435, the first water supply roller 431, the second water supply roller 432, and the adjusting roller 433 has one set each on the +Z direction side and the −Z direction side of the transport path 42d in FIG. Are arranged one by one.
Then, of the pair of humidifying rollers 434, the humidifying roller 434 arranged on the +Z side is supplied with water from the water supply mechanism on the +Z direction side, and the humidifying roller 434 arranged on the −Z side is supplied with water on the −Z direction side. Water is supplied from each.

The humidifying roller 434 is configured such that the width of the outer peripheral surface in the X direction is larger than the width of the paper M in the X direction. The pair of humidifying rollers 434 press each other to form a nip portion, sandwich the sheet M guided by the guide member 422, and rotate the sheet M while sandwiching the sheet M to convey the sheet M. Then, the pair of humidifying rollers 434 carry out the humidifying process of applying the water held on the outer peripheral surface to the paper M to humidify the paper M by conveying the paper M. Details of this humidifying treatment will be described later.
The humidifying roller 434 arranged on the −Z side is provided with a humidifying roller driving unit 434a, and the humidifying roller 434 arranged on the −Z side is arranged on the +Z side by the driving of the humidifying roller driving unit 434a. The moisturizing roller 434 can be separated or pressed. That is, the distance between the outer peripheral surface of the humidifying roller 434 arranged on the +Z side and the outer peripheral surface of the humidifying roller 434 arranged on the −Z side can be changed.

Next, the humidification process performed in the first sheet processing device 4 of the image forming system 1 having the above configuration will be described.
FIG. 4 is a flowchart showing the flow of humidification processing in this embodiment.
5 to 7 are schematic diagrams for explaining the movements of the humidifying roller 434 and the water supply roller 432 in the humidifying process of FIG.

The humidifying process is executed, for example, when an image is formed on the sheet M by the image forming apparatus 3 and the sheet M is delivered to the first sheet processing apparatus 4.
The humidifying process is performed under the control of the control unit 40 of the first sheet processing device 4.
Further, here, a case where the humidifying process of applying water only to the upper surface of the paper M is performed will be exemplified.

  First, the control unit 40 determines whether or not the job is to perform the humidifying process (step S1), and when the humidifying process is not performed (step S1: NO), the process ends.

  On the other hand, when performing the humidifying process (step S1: YES), the control unit 40 determines whether the job is for two or more sheets (step S2), and if the job is not for two or more sheets (step S2). S2: NO), and this process ends.

On the other hand, if the job is for two or more sheets, the control unit 40 determines whether the basis weight of the sheets is equal to or less than a predetermined value (for example, 60 g/m ² ) (that is, the sheets are thin paper). It is determined whether or not there is (step S3).
The reference value (predetermined value) of the basis weight of the paper is predetermined and stored in the storage unit 31. Further, this predetermined value can be appropriately set and changed by a user operation.

When the paper is not thin paper (step S3: NO), the control unit 40 causes the water supply roller 432 to contact the humidification roller 434 at a predetermined timing before the leading end of the paper reaches the position corresponding to the nip portion (FIG. 5(a)) (step S4).
Since the humidifying process of applying water only to the upper surface of the paper M is described here as an example, only the upper water supply roller 432 is brought into contact with the humidifying roller 434 in FIG. 5A. .

Next, the control unit 40 determines whether or not the timing at which the leading edge of the paper reaches the position corresponding to the nip portion has been reached (step S5), and the timing at which the leading edge of the paper reaches the position corresponding to the nip portion is reached. If not reached (step S5: NO), the process of step S5 is repeated.
On the other hand, when the timing at which the leading end of the sheet reaches the position corresponding to the nip portion is reached (step S5: YES), the control unit 40 presses the upper and lower humidifying rollers 434 at that timing (see FIG. 5B). ) (Step S6), the process proceeds to step S9 described later.

If the paper is thin paper in step S3 (step S3: YES), the control unit 40 determines whether the leading end of the paper has passed the position corresponding to the nip portion (step S7), When the tip portion has not passed the position corresponding to the nip portion (step S7: NO), the water supply roller 432 is separated from the humidifying roller 434, and the upper and lower humidifying rollers 434 are kept separated ( 6A), the processing of step S7 is repeated.
On the other hand, when the leading edge of the sheet has passed the position corresponding to the nip portion (step S7: YES), the control unit 40 brings the water supply roller 432 into contact with the humidifying roller 434 and, at the same time, causes the upper and lower humidifying rollers 434 to move. It is crimped (see FIG. 6B) (step S8), and the process proceeds to step S9 described later.

  Next, the control unit 40 determines whether or not the humidifying process is performed on the next sheet (step S9), and when the humidifying process is performed on the next sheet (step S9: YES), the below-described step S11. Move to.

  On the other hand, when the humidifying process is not performed on the next sheet (step S9: NO), the control unit 40 determines that the distance (L1) from the trailing edge of the sheet to the nip portion is the circumference of the second water supply roller 432. The second water supply roller 432 is separated from the humidifying roller 434 at a predetermined timing before it becomes shorter than the length (L2) of the above (see FIG. 7A) (step S10).

Next, the control unit 40 separates the upper and lower humidifying rollers 434 from each other at a predetermined timing before the time when the trailing edge of the paper reaches the nip portion (see FIG. 7B) (step S11).
Although illustration is omitted here, when the above step S9 is YES, the upper and lower humidifying rollers 434 are separated with the upper humidifying roller 434 and the second water supply roller 432 in contact with each other. It

Next, the control unit 40 determines whether or not there is the next sheet in the job (step S12), and if there is the next sheet (step S12: YES), returns to step S3 and repeats the subsequent processing.
On the other hand, if there is no next sheet (step S12: NO), this process ends.

  In the above example, the case where the humidifying process of applying water only to the upper surface of the sheet M is described, but the case of performing the humidifying process of applying water to only the lower surface of the sheet M or both sides of the sheet M is described. In addition, it goes without saying that the water is supplied from the lower water supply roller 432 to the lower humidification roller 434.

As described above, according to the present embodiment, the pair of humidifying rollers 434 and the pair of humidifying rollers 434, which form a nip portion by being pressed against each other and apply moisture to the sheet M when it is nipped and conveyed. A humidifying roller drive unit 434a for separating or pressing the two, and a control unit 40 for controlling the humidification roller drive unit 434a. The control unit 40 controls the humidification roller drive unit 434a to separate the pair of humidification rollers 434 from each other. And waits for the sheet M to press the pair of moisturizing rollers 434 after the time when the leading edge of the sheet reaches the position corresponding to the nip portion, and before the time when the trailing edge of the sheet reaches the nip portion. The rollers 434 are separated.
For this reason, the pair of humidifying rollers 434 are pressed against each other after the time when the leading edge of the paper reaches the position corresponding to the nip portion, and the pair of humidifying rollers 434 are separated before the time when the trailing edge of the paper reaches the nip portion. By doing so, it is possible to prevent the time during which the nip portion is pressure-bonded is too long and excessive water is applied to the paper M and the water applied to one surface is transferred to the other surface. Therefore, a desired amount of water can be applied to each surface of the paper M. That is, whether water is applied to only one surface of the paper M or water is applied to both surfaces of the paper M, a desired amount of water can be applied to each surface.

Further, according to the present embodiment, the second water supply roller 432 that supplies moisture to the outer peripheral surfaces of the pair of humidification rollers 434 and the second water supply roller 432 are separated from or abut on the pair of humidification rollers 434. And a water supply roller drive unit 432a for controlling the water supply roller drive unit 432a when the nth (natural number) sheet M is humidified and the (n+1)th sheet M is not humidified. The second water supply roller 432 is separated from the pair of humidification rollers 434 before the distance from the rear end of the n-th sheet to the nip portion becomes shorter than the length of the circumference of the second water supply roller 432.
Therefore, when the n-th sheet M is humidified and the n+1-th sheet M is not humidified, almost all the water supplied to the pair of humidifying rollers 434 is applied to the n-th sheet M, so that n+1. It is possible to prevent water from being applied to the first sheet M.

Further, according to the present embodiment, the pair of humidifying rollers 434 is formed by vertically arranging the two humidifying rollers 434 and 434.
Therefore, water is easily transmitted from the upper humidifying roller 434 to the lower humidifying roller 434. For example, when only the upper surface of the paper M is desired to be humidified, water is easily applied to the lower surface of the paper M. However, the pair of humidifying rollers 434 are separated from each other to wait for the sheet M, the pair of humidifying rollers 434 are pressure-bonded after the time when the leading edge of the sheet reaches the position corresponding to the nip portion, and the trailing edge of the sheet reaches the nip portion. By performing control to separate the pair of humidifying rollers 434 before the point of time, it is possible to prevent excessive water from being applied to the paper M.

Further, according to the present embodiment, the control unit 40 controls the humidifying roller driving unit 434a so that when the basis weight of the paper M is equal to or less than a predetermined value, the leading end of the paper corresponds to the nip portion. After reaching the position, the pair of humidifying rollers 434 are pressure-bonded, and when the basis weight of the sheet M is larger than a predetermined value, the pair of humidifying rollers 434 are pressure-bonded at the same time when the leading edge of the sheet reaches the position corresponding to the nip portion.
Therefore, when the paper M is a thin paper, it is possible to prevent the leading end of the paper from being wound around the humidifying roller 434.

Further, according to the present embodiment, the second water supply roller 432 that supplies moisture to the outer peripheral surfaces of the pair of humidification rollers 434 and the second water supply roller 432 are separated from or abut on the pair of humidification rollers 434. When the basis weight of the paper M is equal to or less than a predetermined value, the control unit 40 controls the water supply roller drive unit 432a. When the second water supply roller 432 is brought into contact with the pair of humidifying rollers 434 after reaching the corresponding positions, and the basis weight of the paper M is larger than a predetermined value, the pair of humidifiers before the leading edge of the paper reaches the nip portion. The second water supply roller 432 is brought into contact with the roller 434.
For this reason, when the paper M is a thin paper having a predetermined value or less, the start of water supply to the humidifying roller 434 is delayed, so that the amount of water supplied is reduced, and when the paper M is a thin paper, the water applied to one surface is It is possible to more effectively prevent the transfer to the other surface. Further, when the sheet M is a thin sheet, it is possible to more effectively prevent the leading end of the sheet from being wound around the humidifying roller 434.

  It should be noted that specific details such as the configurations and control procedures shown in the above-described embodiments can be appropriately changed without departing from the spirit of the present invention.

For example, as shown in FIG. 8, a configuration is provided in which the blade rollers 436 are provided near the pair of humidifying rollers 434 and serve as a water draining unit that wipes moisture on the outer peripheral surfaces of the pair of humidifying rollers 434 when the sheet M is not humidified. It is also preferable to
The blade roller 436 is, for example, a columnar member that rotates on a rotating shaft extending in the X direction, and the width of the outer peripheral surface in the X direction is the same as that of the humidifying roller 434 or larger than that of the humidifying roller 434.
The blade roller 436 wipes excess water retained on the outer peripheral surface of the humidifying roller 434 by moving its outer peripheral surface relative to the outer peripheral surface of the humidifying roller 434 (rotating in the opposite direction).
Note that the blade roller 436 may be one that can wipe the water of the humidifying roller 434, and thus may have a configuration that rotates in the opposite direction to the humidifying roller 434 or a configuration that does not rotate.
Further, as long as it can wipe the water of the humidifying roller 434, it is not limited to the roller-shaped member (blade roller 436), and it may be, for example, a plate-shaped member extending along the width direction (X direction) of the paper. May be.
With this configuration, when the next sheet is not humidified, the blade roller 436 may wipe the moisture of the humidifying roller 434 instead of the process of step S4 or in combination with the process of step S4. it can. Therefore, the amount of water of the pair of humidifying rollers 434 can be set to an appropriate amount, and excessive water can be prevented from being applied to the paper M from the pair of humidifying rollers 434.

  Further, in the above embodiment, the humidifying roller 434 arranged on the −Z side is provided with the humidifying roller driving unit 434a, and the humidifying roller arranged on the −Z side with respect to the humidifying roller 434 arranged on the +Z side. Although the configuration in which the 434 moves is described as an example, the humidifying roller 434 arranged on the +Z side may be provided with a driving unit, or the two humidifying rollers 434 may be provided with a driving unit. Is also good.

  In addition, in the above-described embodiment, the configuration including the first water supply roller 431 and the second water supply roller 432 has been described as an example, but the water supply roller may have a single configuration.

  Further, in the above-described embodiment, the configuration in which the humidifying unit 43 is provided in the transport path for transporting the paper in the Y direction has been described as an example, but the humidifying unit 43 is provided in the transport path for transporting the paper in the Z direction. It is also possible to have a configuration provided.

DESCRIPTION OF SYMBOLS 1 Image forming system 3 Image forming apparatus 30 Control section 38 Image forming section 4 First sheet processing apparatus 40 Control section 43 Humidifying section 431 First water supply roller 432 Second water supply roller 432a Water supply roller drive section (second drive section) )
433 Adjustment roller 434 Humidification roller 434a Drive unit 435 Water storage unit 436 Blade roller (drainage unit)
M paper

Claims (6)

A pair of humidifying rollers that press each other to form a nip portion, and add moisture to the paper when the paper is nipped and conveyed,
A drive unit for separating or pressing the humidifying roller pairs from each other,
A control unit for controlling the drive unit,
A water supply roller for supplying moisture to the outer peripheral surface of the pair of humidifying rollers,
A second drive unit that separates or abuts the water supply roller with respect to the humidification roller pair ,
The control unit controls the drive unit to separate the humidifying roller pair from each other to wait for the sheet, and presses the humidifying roller pair after the time when the leading edge of the sheet reaches the position corresponding to the nip portion, and The humidifying roller pair is separated before the rear end reaches the nip portion ,
The control unit is
When the nth (natural number) sheet is humidified and the (n+1)th sheet is not humidified, the second drive unit is controlled so that the distance from the rear end of the nth sheet to the nip portion is sheet processing apparatus according to claim Rukoto the dampening roller is separated from the humidifying roller pair before shorter than the length of the circumference of the dampening roller. A pair of humidifying rollers that press each other to form a nip portion, and add moisture to the paper when the paper is nipped and conveyed,
A drive unit for separating or pressing the humidifying roller pairs from each other,
A control unit for controlling the drive unit,
The control unit controls the drive unit to separate the humidifying roller pair from each other to wait for the sheet, and presses the humidifying roller pair after the time when the leading edge of the sheet reaches the position corresponding to the nip portion, and The humidifying roller pair is separated before the rear end reaches the nip portion,
The control unit is
When the grammage of the paper is below a predetermined value by controlling the drive unit, the humidifying roller pair is pressure-bonded after the leading edge of the paper reaches the position corresponding to the nip portion, If the amount is larger than the predetermined value , the sheet processing apparatus presses the humidifying roller pair at the same time when the leading edge of the sheet reaches a position corresponding to the nip portion . A pair of humidifying rollers that press each other to form a nip portion and add moisture to the paper when the paper is nipped and conveyed,
A drive unit for separating or pressing the humidifying roller pairs from each other,
A control unit for controlling the drive unit,
A water supply roller for supplying moisture to the outer peripheral surface of the pair of humidifying rollers,
A second drive unit that separates or abuts the water supply roller with respect to the humidification roller pair,
The control unit controls the drive unit to separate the humidifying roller pair from each other to wait for the sheet, and presses the humidifying roller pair after the time when the leading end of the sheet reaches the position corresponding to the nip portion. The humidifying roller pair is separated before the rear end reaches the nip portion,
The control unit is
When the basis weight of the paper is equal to or less than a predetermined value by controlling the second drive unit, the water supply roller is attached to the humidification roller pair after the leading end of the paper reaches the position corresponding to the nip portion. The sheet processing apparatus , wherein the water supply roller is brought into contact with the humidifying roller pair before the leading edge of the sheet reaches the nip portion when the basis weight of the sheet is larger than the predetermined value . The sheet processing apparatus according to any one of claims 1 to 3, wherein the humidifying roller pair includes two humidifying rollers arranged one above the other. The sheet according to any one of claims 1 to 4 , further comprising a water draining portion that is disposed in the vicinity of the humidifying roller pair and wipes moisture on an outer peripheral surface of the humidifying roller pair when the sheet is not humidified. Processing equipment. An image forming apparatus that forms an image on a sheet,
The sheet processing apparatus according to any one of claims 1 to 5, which is connected to the image forming apparatus and humidifies a sheet on which an image is formed by the image forming apparatus.
An image forming system comprising:

Images