JP6897197B2 - 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 processing apparatus having a plurality of paper transport paths inside, which is compatible with various paper processing functions for image-formed paper, has become widespread. In the paper processing device, from the viewpoint of preventing the size of the device from becoming large and reducing costs, a humidifying section for applying water to the paper to humidify the paper is provided at the inlet of the device before the paper transport path is branched into a plurality of branches. is there. The humidifying portion has, for example, a humidifying roller pair capable of holding water on the outer peripheral surface, and has a configuration in which water is applied to the paper when the paper is sandwiched and conveyed by the humidifying roller pair (see, for example, Patent Document 1). ).

In such a paper processing device, when humidifying thin paper, in order to prevent the tip of the paper from wrapping around the humidifying roller, the paper is accepted with the humidifying roller pair separated, and the tip of the paper is the humidifying roller pair. After passing through the nip portion of the above, the humidifying roller pair is crimped.
When crimping a pair of humidifying rollers, if the crimping speed becomes too high, the impact load at the moment of crimping becomes too large, which causes motor step-out. Therefore, the crimping speed is set so that the crimping speed is equal to or less than the predetermined value at which such a problem does not occur. Therefore, the time from the start of crimping to the end of crimping is simply the time obtained by dividing the separation distance between the humidifying roller pairs by the crimping speed. It takes.

Japanese Unexamined Patent Publication No. 2014-091605

By the way, in such an apparatus, in order to improve productivity, it has been studied to control the transfer speed of the paper after the rear end of the paper has passed through the fixing portion of the image forming apparatus.
Here, in the case of paper whose length in the transport direction is longer than the distance from the fixing portion to the humidifying portion, the humidifying roller pair has already crimped the paper when the rear end of the paper has passed through the fixing portion. A sufficient humidified area can be secured.
However, in the case of paper whose length in the transport direction is shorter than the distance from the fixing portion to the humidifying portion, as shown in FIG. 8, when the transport speed is increased when the rear end of the paper P passes through the fixing portion 81, the transport speed is increased. Since the paper P reaches the humidifying portion 82 in a state where the transport speed is increased, the distance through which the paper P is transported during the crimping operation becomes long, the non-humidified region of the paper P becomes large, and the effect of sufficient humidification is obtained. (Dehumidification performance, etc.) may not be obtained.
Further, in such a device, it is conceivable to reduce the paper transport speed after passing through the humidifying section, such as when an image inspection device or the like is provided on the downstream side of the humidifying section in the paper transport direction. Even in such a case, for paper whose length in the transport direction is shorter than the distance from the fixing portion to the humidifying portion, the transport speed is increased when the rear end of the paper passes through the fixing portion, as in the case of long paper. If it is lowered, the effect of humidification can be obtained, but the transport speed is lowered more quickly than necessary, resulting in a decrease in productivity.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a paper humidifying device and an image forming system capable of increasing productivity while ensuring a stable humidifying effect.

In order to solve the above problems, according to the present invention, in a paper humidifier,
A pair of humidifying rollers that add water to the paper to humidify it,
A humidifying roller driving unit that presses the humidifying roller pair to form a nip and separates the humidifying roller pair from each other.
A transport drive unit that accelerates or decelerates the paper transport speed, and
After the paper passes through the nip position with the humidifying roller pair separated, the humidifying roller driving unit is controlled to crimp the humidifying roller pair to form the nip portion, and the paper is passing through the nip portion. In addition, a control unit that controls the transfer drive unit to change the paper transfer speed,
It is characterized by having.

Further, according to the present invention, in an image forming system,
An image forming device that forms an image on paper,
The paper humidifier connected to the image forming apparatus and humidifying the paper on which the image is formed by the image forming apparatus, and the paper humidifying apparatus.
It is characterized by being equipped with.

According to the present invention, productivity can be increased while ensuring a stable humidifying effect.

It is a figure which shows the schematic structure of the image formation system. It is a block diagram which shows the main functional composition of an image forming apparatus and a paper humidifying apparatus. It is a schematic diagram which shows the structure of a humidifying part. It is a flowchart which shows the operation of a humidifying part. It is a figure for demonstrating operation of a humidifying part. It is a figure for demonstrating operation of a humidifying part. It is a figure which shows the modification of the image formation system. It is a figure for demonstrating a conventional problem.

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 examples.

First, the configuration of the paper humidifier and the image forming system in the present embodiment will be described.

FIG. 1 is a diagram showing a schematic configuration of an image forming system 1.
As shown in FIG. 1, the image forming system 1 includes an image forming device 3, a paper humidifying device 5, and a paper processing device 7.

The image forming apparatus 3 is an apparatus for forming an image on paper by an electrophotographic method. The image forming apparatus 3 conveys the paper on which the image is formed to the paper humidifying apparatus 5.
The paper humidifying device 5 is a device that performs a humidifying treatment of applying water to the paper conveyed from the image forming device 3. The paper humidifying device 5 conveys the humidified paper to the paper processing device 7. The paper humidifying device 5 can also convey the paper to the paper processing device 7 without performing the humidifying treatment.
The paper processing device 7 is a device that performs a predetermined paper processing on the paper conveyed from the paper humidifying device 5 and discharges the paper. Examples of the paper processing include decal processing, stapling processing, punching hole processing, folding processing, bookbinding processing, and the like.
The image forming device 3, the paper humidifying device 5, and the paper processing device 7 are configured to be detachable from adjacent devices.

FIG. 2 is a block diagram showing a main functional configuration of the image forming apparatus 3 and the paper humidifying apparatus 5.

The image forming apparatus 3 includes a control unit 30 having 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. The external communication unit 34, the interface 35, the scanner 36, the image processing unit 37, the image forming unit 38, and the conveying unit 39 are provided.
The control unit 30 is connected to the storage unit 31, the operation unit 32, the display unit 33, the external communication unit 34, the interface 35, the scanner 36, the image processing unit 37, the image forming unit 38, and the conveying unit 39 via the bus 3b. ing.

The CPU 301 reads and executes a 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 various control programs, setting data, and the like executed by the CPU 301. Instead of the ROM 303, a rewritable non-volatile memory such as an EEPROM (Electrically Erasable Programmable Read Only Memory) or a flash memory may be used.

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

The storage unit 31 is composed of 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 external communication unit 34, and the like. Note that these image data and the like may be stored in the RAM 302.

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

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

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

The interface 35 is a means for transmitting and receiving data to and from the paper humidifying device 5, and is composed of, for example, any of various serial interfaces.

The scanner 36 reads the image formed on the paper, generates image data including monochromatic image data for each color component of R (red), G (green), and B (blue), 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 data stored in the storage unit 31 is subjected to various image processing and stored 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 the network into raster-format image data such as a bitmap. The image data converted and generated by the rasterization processing unit includes monochromatic image data for each color component of C (cyan), M (magenta), Y (yellow), and K (black).
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 lookup table, and monochromatic image data of each color of C, M, Y, and K. Generate image data including. In addition, the color conversion unit performs a predetermined color correction process on the image data.
The gradation correction unit sets the gradation value of the image data by referring to a look-up table in which the correction value corresponding to each gradation value is defined so that the gradation characteristic of the image related to the image data becomes a predetermined characteristic. 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.
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 partially or wholly realized by the control unit 30, or the image forming apparatus 3 may be used. The configuration may be realized by another image processing device provided externally.

The image forming unit 38 forms an image on paper based on the image data stored in the storage unit 31. The image forming unit 38 includes four sets of exposure units 381, photoconductors 382, and developing units 383 corresponding to the color components of C, M, Y, and K, respectively. Further, the image forming unit 38 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 the charged photoconductor 382 with a laser beam, and exposes the photoconductor 382 to form an electrostatic latent image on the photoconductor 382. The developing unit 383 supplies toner (coloring material) of a predetermined color (any of C, M, Y, and K) on the exposed photoconductor 382 by a developing roller charged on the exposed photoconductor 382. The formed electrostatic latent image is developed.
An image (monochromatic image) formed of the toners of C, M, Y, and K on each of the four photoconductors 382 corresponding to C, M, Y, and K is formed from each photoconductor 382 onto the transfer body 384. They are sequentially stacked and transferred. 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 transfer rollers, and rotates according to the rotation of each transfer body transfer roller.

The secondary transfer roller 385 transfers the color image on the transfer body 384 onto the paper fed from the paper feed tray 3a. Specifically, when a predetermined transfer voltage is applied to the secondary transfer roller 385 that sandwiches the paper and the transfer body 384, the toner forming the color image on the transfer body 384 is attracted to the paper side and becomes the paper. Transcribed.

The fixing unit 386 heats and pressurizes the paper on which the toner is transferred to perform a fixing process for fixing the toner on the paper. The fixing portion 386 includes a heating roller 386a and a pressure roller 386b for sandwiching the paper.
The heating roller 386a is heated to a predetermined target temperature (for example, a temperature within the range of 180 ° C. or higher and 200 ° C. or lower) by a heater as a heating source. The pressure roller 386b is urged toward the heating roller by an elastic member (not shown).
When the paper on which the image formed by the toner is transferred by the secondary transfer roller 385 passes through the nip portion N1 (see FIG. 3 and the like) of the rollers 386a and 386b, the image formed by the toner is fixed on the paper. Toner.
Further, a sensor PS1 is provided downstream of the fixing portion 386 in the paper transport direction.
The sensor PS1 is, for example, an optical sensor and detects paper passing through the nip portion N1.

The transport unit 39 includes a plurality of paper transport rollers for transporting the paper by rotating while sandwiching the paper, and transports the paper along a predetermined transport path. The transport unit 39 includes a resist roller 391 arranged on the upstream side of the secondary transfer roller 385 in the transport direction. The resist roller 391 temporarily stops the feeding of the fed paper, and adjusts the timing of feeding the paper to the secondary transfer roller 385. Further, the transport unit 39 includes a reversing mechanism 392 that reverses the front and back sides of the paper that has been fixed by the fixing unit 386 and transports the paper to the secondary transfer roller 385. In the image forming apparatus 3, when the image is formed on both sides of the paper, the front and back sides of the paper are reversed by the reversing mechanism 392, and when the image is formed on only one side of the paper, the front and back sides of the paper are reversed by the reversing mechanism 392. The paper is conveyed to the paper humidifier 5 without being inverted.

The paper humidifying device 5 includes a control unit 50 having a CPU 501, a RAM 502, and a ROM 503, an interface 51, a transport unit 52, a humidifying unit 53, and a paper processing unit 54.
The control unit 50 is connected to the interface 51, the transport unit 52, the humidification unit 53, and the paper processing unit 54 via the bus 5b.

The CPU 501 reads and executes a control program stored in the ROM 503, and performs various arithmetic processes.

The RAM 502 provides the CPU 501 with a working memory space and stores temporary data. This temporary data includes, for example, various setting information related to the humidification process.

The ROM 503 stores various control programs, setting data, and the like executed by the CPU 501. A rewritable non-volatile memory such as an EEPROM or a flash memory may be used instead of the ROM 503.

The control unit 50 including the CPU 501, the RAM 502, and the ROM 503 collectively controls each part of the paper humidifying device 5 according to the above-mentioned various control programs. For example, the control unit 50 causes the humidifying unit 53 to humidify the paper under the conditions indicated by the setting information stored in the RAM 502.

The interface 51 is a means for transmitting and receiving data to and from the image forming apparatus 3, and is composed of, for example, any of various serial interfaces.

The transport unit 52 includes a guide member that guides the paper, a paper transport roller that transports the paper by rotating while sandwiching the paper, and the like, and transports the paper along the transport path 52a.

The humidifying unit 53 is a mechanism for performing a humidifying treatment in which water is applied to the paper to humidify the paper.
For example, by performing a humidifying treatment on the paper charged by the application of the transfer voltage or static electricity generated during transportation by the humidifying unit 53, it is possible to prevent the occurrence of phenomena such as floating and sticking of the paper.
The humidifying portion 53 of the present embodiment includes a pair of humidifying rollers arranged so as to be arranged in the vertical direction, and has a configuration in which water is applied to the paper when the paper to be conveyed in the horizontal direction is sandwiched and conveyed. The details of the humidifying section 53 will be described later.

The paper processing unit 54 is a mechanism for performing another paper processing on the paper that has passed through the humidifying unit 53. In the present embodiment, the paper processing unit 54 handles the paper that has been curled by transportation, fixing and heating, or the like. The decaler unit 541 to be corrected, the paper reversing unit 542 that appropriately reverses the front and back of the paper when ejected from the paper humidifying device 5, and the purging unit that stores the paper ejected from the paper humidifying device when a malfunction occurs. It is equipped with 543.

Next, the detailed configuration of the humidifying section 53 will be described.
FIG. 3 is a schematic view showing the configuration of the humidifying portion 53.

The humidifying section 53 includes an upper humidifying roller 531a, a lower humidifying roller 531b, an upper water supply roller 532a, a lower water supply roller 532b, a first pumping roller 533, a second pumping roller 534, an upper water storage section 535, a lower water storage section 536, and an upstream. It has a side sensor PS2 and a downstream side sensor PS3, and is configured to humidify the conveyed paper from above and below the paper surface.
A guide member (not shown) is provided before and after the humidifying rollers 531a and 531b to vertically sandwich the transport path 52a, and the paper is guided by the guide member to reach the nip portion N2 of the humidifying rollers 531a and 531b.

The humidifying rollers 531a and 531b, the water supply rollers 532a and 532b, the first pumping roller 533, and the second pumping roller 534 are all cylindrical members, and each has a rotation axis set parallel to the horizontal direction. Rotate to the center.
Further, all of these rollers have a structure capable of supporting water on the peripheral surface. Examples of the material of the outer peripheral surface capable of supporting water include a hydrophilic resin such as polypropylene.

The humidifying rollers 531a and 531b are arranged so as to be in contact with each other to form a nip portion N2.
The humidifying rollers 531a and 531b are provided with humidifying roller driving units 531a and 531b1, respectively, and the humidifying rollers 531a and 531b can be moved in a direction of contacting or separating from each other by driving the driving units.

The upper water supply roller 532a comes into contact with the upper humidifying roller 531a and supplies water carried on the surface to the outer peripheral surface of the upper humidifying roller 531a. The lower water supply roller 532b abuts on the lower humidifying roller 531b and supplies the water carried on the surface to the outer peripheral surface of the lower humidifying roller 531b.

The first pumping roller 533 and the second pumping roller 534 play a role of pumping the water stored in the upper water storage unit 535 and supplying it to the upper water supply roller 532a.
The first pumping roller 533 is arranged so as to be in contact with the upper water supply roller 532a, and the second pumping roller 534 is in contact with the first pumping roller 533 and in contact with the water stored in the upper water storage unit 535. Arranged like this.
In the present embodiment, the pumping roller is arranged only in the configuration on the upper side of the humidifying section 53, and the upper water supply roller 532a does not come into direct contact with the water stored in the upper water storage section 535, but is the first pumping roller. Water is supplied via 533 and a second pumping roller 534.
On the other hand, the lower water supply roller 532b is arranged so as to be in contact with the water stored in the lower water storage unit 536, and is configured to receive water directly from the lower water storage unit 536.
However, the present invention is not limited to this embodiment, and a pumping roller that comes into contact with the lower water supply roller 532b may be provided.

The upper water storage unit 535 and the lower water storage unit 536 play a role of storing water for humidifying the paper.
In the present embodiment, the upper water storage unit 535 is arranged so as to supply water to the upper water supply roller 532a via the first pumping roller 533 and the second pumping roller 534.
Further, the lower water storage unit 536 is arranged so as to supply water to the lower water supply roller 532b.
Further, the water stored in the upper water storage unit 535 and the lower water storage unit 536 may contain an additive such as a surfactant within a range that does not hinder the image. When the water contains an additive, the amount of water retained on the surfaces of the humidifying rollers 531a and 531b increases.

The upstream sensor PS2 is provided on the upstream side of the humidifying rollers 531a and 531b with respect to the transport path 52a, and the downstream sensor PS3 is provided on the downstream side of the humidifying rollers 531a and 531b with respect to the transport path 52a. There is.
The upstream sensor PS2 and the downstream sensor PS3 are, for example, optical sensors and detect paper passing through the transport path 52a.

Although not shown, the configuration may include a drain roller that regulates the amount of water held on the surfaces of the upper water supply roller 532a and the lower water supply roller 532b and absorbs water.
Further, the configuration of the humidifying portion 53 is not limited to the above-mentioned one as long as it is provided with humidifying rollers 531a and 531b and can carry out humidification by sandwiching and transporting the paper.

The upper humidifying roller 531a and the lower humidifying roller 531b are rotated by the rotation driving unit (conveying driving unit) M to form a nip and convey the paper, so that they rotate in opposite directions (with direction).
The upper water supply roller 532a rotates in the with direction in conjunction with the rotation of the upper humidifying roller 531a, and the lower water supply roller 532b rotates in the with direction in conjunction with the rotation of the lower humidifying roller 531b. Further, the first pumping roller 533 rotates in the with direction in conjunction with the rotation of the upper water supply roller 532a, and the second pumping roller 534 interlocks with the rotation of the first pumping roller 533 in the with direction. Rotate to.

In the present embodiment, the water supply rollers 532a, 532b, the first pumping roller 533, and the second pumping roller 534 are rotating in conjunction with (following) the rotation direction of the humidifying rollers 531a and 531b. As an embodiment of the above, a mode in which a drive unit is provided on each humidifying roller, each water supply roller, and each pumping roller and is rotated is also conceivable.

Next, the operation of the humidifying unit 53 performed in the paper humidifying device 5 of the image forming system 1 having the above configuration will be described.

The paper humidifying device 5 of the present embodiment executes control that makes it possible to improve productivity while securing a humidifying region of the paper in the humidifying treatment.

FIG. 4 is a flowchart showing the humidification treatment of the present embodiment.
The operation of the humidifying unit 53 is executed under the control of the control unit 50 of the paper humidifying device 5.
Further, such an operation is performed on thin paper, and the humidifying rollers 531a and 531b receive the paper in a separated state.

First, the control unit 50 determines whether or not the length of the paper in the transport direction is shorter than a predetermined value (for example, whether or not it is shorter than plain paper) (step S101), and when it is determined that the length is equal to or greater than the predetermined value (step). S101: NO), the process proceeds to step S107 described later.

On the other hand, when it is determined that the value is shorter than the predetermined value (step S101: YES), the control unit 50 determines whether or not the tip of the paper has passed the nip position corresponding to the nip portion N2 of the humidifying rollers 531a and 531b (step S101: YES). In step S102), if the process has not passed (step S102: NO), the process of step S102 is repeated.

On the other hand, when the tip of the paper passes through the nip position (step S102: YES), the control unit 50 crimps the humidifying rollers 531a and 531b (step S103) to increase the paper transport speed (step S104).

Next, the control unit 50 determines whether or not the rear end of the paper has passed through the nip portion N2 (step S105), and if not (step S105: NO), repeats the process of step S105.

On the other hand, when the rear end of the paper passes through the nip portion N2 (step S105: YES), the control unit 50 separates the humidifying rollers 531a and 531b (step S106), and ends this process.

Further, in step S101, when it is determined that the length of the paper in the transport direction is equal to or greater than a predetermined value (step S101: NO), the control unit 50 asks whether the tip of the paper has passed the nip positions of the humidifying rollers 531a and 531b. Whether or not it is determined (step S107), and if it has not passed (step S107: NO), the process of step S107 is repeated.

On the other hand, when the tip of the paper passes through the nip position (step S107: YES), the control unit 50 crimps the humidifying rollers 531a and 531b (step S108).

Next, the control unit 50 determines whether or not the rear end of the paper has passed through the nip portion N1 of the rollers 386a and 386b of the fixing portion 386 (step S109), and if not (step S109: NO). , The process of step S109 is repeated.

On the other hand, when the rear end of the paper passes through the nip portion N1 (step S109: YES), the control unit 50 shifts to the step S104 described above.

FIG. 5 is a diagram for explaining the operation of the humidifying section 53 when humidifying paper having a short length in the transport direction, and corresponds to steps S101 to S106.
As shown in FIG. 5, in the case of paper P1 having a short length in the transport direction, when the front end of the paper passes through the nip positions of the humidifying rollers 531a and 531b, the rear end of the paper P1 surely presses the nip portion N1. It's missing.
Therefore, when it is confirmed that the tip of the paper P1 has passed through the nip positions of the humidifying rollers 531a and 531b (step S102: YES), the humidifying rollers 531a and 531b are crimped to immediately increase the paper transport speed. Therefore, the area of the non-humidified region R1 due to the crimping operation can be suppressed, the humidified region R2 on the paper P1 can be secured, and the productivity can be maximized.

FIG. 6 is a diagram for explaining the operation of the humidifying section 53 when humidifying paper having a long length in the transport direction, and corresponds to the steps S101, S107 to S109, and steps S104 to S106.
As shown in FIG. 6, in the case of the paper P2 having a long length in the transport direction, when the tip of the paper P2 passes through the nip positions of the humidifying rollers 531a and 531b, the rear end of the paper P2 passes through the nip portion N1. It may not be cut.
Therefore, after confirming that the tip of the paper P2 has passed the nip positions of the humidifying rollers 531a and 531b (step S107: YES) and confirming that the rear end of the paper P2 has passed the nip portion N1 (step S107: YES). S109: YES), the humidifying rollers 531a and 531b are crimped, and then the paper transport speed is increased, so that the productivity can be maximized while securing the humidifying region in the paper P2.

Here, the transport speed of the paper after acceleration may be a preset speed, but the paper transport in the non-humidified region R1 of the paper depends on the separation distance of the nip portions N2 of the humidifying rollers 531a and 531b and the crimping speed. It is preferable to determine the length L (mm) in the direction to be an arbitrary predetermined value.
The time t (s) required for crimping can be expressed by the following formula (1) when the separation distance is I (mm) and the crimping speed is v (mm / s).
t = I / v ... (1)
Further, the length L (mm) of the non-humidified region R1 of the paper can be expressed by the following formula (2) when the paper transport speed is V (mm / s).
L = V × I / v ... (2)
Assuming that the length L (mm) of the non-humidifying region R1 of the paper is an arbitrary predetermined value, the paper transport speed V (mm / s) can be calculated by the following formula (3).
V = L × v / I ... (3)
By determining the paper transport speed in this way, the length L (mm) of the non-humidifying region R1 of the paper can be set to an arbitrary length, so that a stable humidifying effect can be ensured.

As described above, according to the present embodiment, the humidifying rollers 531a and 531b, which moisturize the paper by applying water, and the humidifying rollers 531a, 531b are crimped to form the nip portion N2, and the humidifying rollers 531a, Humidifying roller drive units 531a1 and 531b1 that separate 531b, rotary drive unit M that accelerates and decelerates the paper transport speed, and humidifying roller drive after the paper passes through the nip position with the humidifying rollers 531a and 531b separated. Controls 531a1 and 531b1 are controlled to crimp the humidifying rollers 531a and 531b to form a nip portion N2, and while the paper is passing through the nip portion N2, the rotation drive portion M is controlled to change the paper transport speed. A unit 50 and the like are provided.
Therefore, since the paper transport speed can be increased after the humidification of the paper starts, the paper is excessively transported during the crimping operation of the humidifying rollers 531a and 531b, and the humidifying region R2 of the paper becomes short for humidification. It is possible to prevent the occurrence of a situation in which the effect cannot be obtained.
Therefore, productivity can be increased while ensuring a stable humidifying effect.

Further, according to the present embodiment, the humidifying rollers 531a and 531b transfer the paper conveyed from the fixing unit 386 on the upstream side of the humidifying rollers 531a and 531b in the paper conveying direction to fix the image on the paper. The receiving and controlling unit 50 changes the paper transport speed after the humidifying rollers 531a and 531b form the nip portion N2 and the rear end of the paper passes through the fixing portion 386.
Therefore, the transport speed of the paper can be changed in a state where the humidification of the paper has started and the rear end of the paper has passed through the fixing portion 386.

Further, according to the present embodiment, in the control unit 50, the distance of the paper conveyed during the crimping operation of the humidifying rollers 531a and 531b is a predetermined distance according to the separation distance and the crimping speed of the humidifying rollers 531a and 531b. The paper transport speed at the time of reaching the humidifying rollers 531a and 531b is determined so as to be.
Therefore, the non-humidifying region R1 of the paper can be set to an arbitrary length, and a desired humidifying effect can be obtained.

In the above embodiment, the configuration for accelerating the transport speed of the paper during humidification has been described as an example, but it is also possible to execute the control for decelerating the transport speed of the paper during humidification.
For example, when an image inspection device or the like is provided on the downstream side of the humidifying section 53 in the paper transport direction, control for lowering the transport speed is executed during the humidification of the paper.
In this regard, for example, if the transport speed is lowered when the rear end of the paper passes through the fixing portion 386, the speed of the paper is slowed down more than necessary in front of the image inspection device, which causes a decrease in productivity. By lowering the transport speed during humidification, the range in which the transport speed is lowered can be minimized, so that it is possible to prevent the productivity from dropping more than necessary.

Further, the present invention is not limited to the above-described embodiment, and it goes without saying that the specific configuration can be appropriately changed.

For example, when the length of the paper along the paper transport direction is shorter than the distance from the nip portion N1 to the nip portion N2, the paper transport speed is changed when the humidifying rollers 531a and 531b form the nip portion N2. Even in a configuration in which the mode 1 and the second mode for changing the paper transport speed when the rear end of the paper passes through the nip portion N1 can be selected by a user operation on the operation unit 32. good.
The control unit 50 executes the first mode or the second mode according to the user operation on the operation unit 32.
The first mode is a mode for increasing productivity while ensuring the effect of humidification, and the second mode is a mode for increasing productivity most.
With this configuration, it is possible to execute processing according to the user's intention.

Further, when the distance from the fixing portion 386 to the nip position of the humidifying rollers 531a and 531b is longer than a predetermined reference value longer than the length along the paper conveying direction of the paper, the rear end of the paper passes through the fixing portion 386. At that time, the paper transport speed may be increased, and the paper transport speed may be slowed down before the front edge of the paper reaches the nip position.
Specifically, for example, as shown in FIG. 7, an image forming system 1A having a paper processing device 9 between the image forming device 3 and the paper humidifying device 5 can be considered.
In such a configuration, the paper transport speed while passing through the paper processing device 9 is preferably as fast as possible from the viewpoint of increasing productivity, and the paper transport speed is set when the rear end of the paper passes through the nip portion N1. It is controlled to be as fast as possible. The paper transport speed is slowed down before the front edge of the paper reaches the nip position of the humidifying rollers 531a and 531b. The slowed speed may be the original speed before the speed was increased, or may be slower or faster than the original speed. Further, as described above, even if the speed is determined so that the distance of the paper conveyed during the crimping operation of the humidifying rollers 531a and 531b (the length along the conveying direction of the non-humidifying region R1) becomes a predetermined distance. good. Then, after the paper is started to be humidified, the paper transport speed may be increased again.
With such a configuration, productivity can be increased while ensuring a humidifying effect regardless of the device configuration.

Further, although the configuration in which the humidifying section 53 is provided in the transport path in which the paper is transported in the horizontal direction is illustrated, the configuration in which the humidifying section 53 is provided in the transport path in which the paper is transported in the vertical direction is also possible. it can. That is, the humidifying unit 53 that humidifies the paper transported in the vertical direction may be configured to control the transfer speed of the paper during humidification.

1, 1A Image forming system 3 Image forming device 5 Paper humidifying device 7, 9 Paper processing device 30 Control unit 32 Operation unit 38 Image forming unit 386 Fixing unit PS1 Sensor N2 Nip unit 50 Control unit 53 Humidifying unit 531a Upper humidifying roller 531b Lower Humidifying rollers 531a1, 531b1 Humidifying roller drive unit M Rotation drive unit (conveyance drive unit)
N2 Nip PS2 Upstream sensor PS3 Downstream sensor P1, P2 Paper R1 Non-humidifying area R2 Humidifying area

Claims (6)

A pair of humidifying rollers that add water to the paper to humidify it,
A humidifying roller driving unit that presses the humidifying roller pair to form a nip and separates the humidifying roller pair from each other.
A transport drive unit that accelerates or decelerates the paper transport speed, and
After the paper passes through the nip position with the humidifying roller pair separated, the humidifying roller driving unit is controlled to crimp the humidifying roller pair to form the nip portion, and the paper is passing through the nip portion. Also provided with a control unit that controls the transfer drive unit to change the paper transfer speed .
The humidifying roller pair receives the paper transported from the fixing portion on the upstream side in the paper transport direction with respect to the humidifying roller pair to fix the image on the paper.
The control unit changes the paper transfer speed after the humidifying roller pair forms the nip portion and the rear end of the paper passes through the fixing portion.
Further, when the length of the paper along the paper transport direction is shorter than the distance from the fixing portion to the nip position, the first method of changing the paper transport speed when the humidifying roller pair forms the nip portion. It is provided with an operation unit that accepts a user operation for selecting a mode and a second mode for changing the paper transport speed when the rear end of the paper passes through the fixing unit.
The paper humidifying device is characterized in that the control unit executes the first mode or the second mode in response to a user operation on the operation unit. The control unit
When the distance from the fixing portion to the nip position is longer than a predetermined reference value longer than the length along the paper conveying direction of the paper, the paper conveying speed is increased when the rear end of the paper passes through the fixing portion. The paper humidifying device according to claim 1 , wherein the paper conveying speed is reduced before the front edge of the paper reaches the nip position. A pair of humidifying rollers that add water to the paper to humidify it,
A humidifying roller driving unit that presses the humidifying roller pair to form a nip and separates the humidifying roller pair from each other.
A transport drive unit that accelerates or decelerates the paper transport speed, and
After the paper passes through the nip position with the humidifying roller pair separated, the humidifying roller driving unit is controlled to crimp the humidifying roller pair to form the nip portion, and the paper is passing through the nip portion. Also provided with a control unit that controls the transfer drive unit to change the paper transfer speed .
The humidifying roller pair receives the paper transported from the fixing portion on the upstream side in the paper transport direction with respect to the humidifying roller pair to fix the image on the paper.
The control unit changes the paper transfer speed after the humidifying roller pair forms the nip portion and the rear end of the paper passes through the fixing portion.
When the distance from the fixing portion to the nip position is equal to or greater than a predetermined reference value longer than the length along the paper conveying direction of the paper, the control unit receives the paper when the rear end of the paper passes through the fixing portion. A paper humidifying device characterized by increasing the transport speed of the paper and slowing down the transport speed of the paper before the front edge of the paper reaches the nip position. When the control unit reaches the nip position so that the distance of the paper conveyed during the crimping operation of the humidifying roller pair becomes a predetermined distance according to the separation distance of the humidifying roller pair and the crimping speed. The paper humidifying device according to any one of claims 1 to 3 , wherein the paper transport speed of the paper is determined. A pair of humidifying rollers that add water to the paper to humidify it,
A humidifying roller driving unit that presses the humidifying roller pair to form a nip and separates the humidifying roller pair from each other.
A transport drive unit that accelerates or decelerates the paper transport speed, and
After the paper passes through the nip position with the humidifying roller pair separated, the humidifying roller driving unit is controlled to crimp the humidifying roller pair to form the nip portion, and the paper is passing through the nip portion. Also provided with a control unit that controls the transfer drive unit to change the paper transfer speed.
When the control unit reaches the nip position so that the distance of the paper conveyed during the crimping operation of the humidifying roller pair becomes a predetermined distance according to the separation distance of the humidifying roller pair and the crimping speed. for paper humidifier it characterized by determining the transport speed of the paper. An image forming device that forms an image on paper,
The paper humidifier according to any one of claims 1 to 5, which is connected to the image forming apparatus and humidifies the paper on which the image is formed by the image forming apparatus.
An image forming system characterized by being equipped with.

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