JP2017065100A - Inkjet printing device - Google Patents

Abstract

[Problem] To prevent the edge of a sheet from lifting up during printing. [Solution] In order to fix the lifted portion of the edge of a sheet P caused by folding or warping, which cannot be completely sucked by the suction conveyor belt 22c of the belt conveyor section 22, to the belt conveyor surface, a non-suction area E2 on the belt conveyor surface of the suction conveyor belt 22c is used as an adhesive application area E3, and an adhesive application roller 101 of an adhesive application section 100 applies a predetermined amount of weakly viscous adhesive to the application area E3. Then, during printing, a pressing roller 34 arranged upstream of the inkjet head 32 presses the sheet P against the belt conveyor surface of the suction conveyor belt 22c on which the adhesive has been applied. [Selected Figure] Figure 3

Description

  The present invention relates to an ink jet printing apparatus that performs printing by ejecting ink onto a sheet as a print medium from an ink jet head.

  2. Description of the Related Art As an image forming apparatus that forms a desired image on a sheet serving as a printing medium, an inkjet printing apparatus that forms an image by ejecting ink droplets from a nozzle of an inkjet head and landing on the sheet is widely used.

  In this type of inkjet printing apparatus, a sheet as a printing medium is conveyed during a printing process. If the end of the sheet is lifted, the lifted part may come into contact with the inkjet head during conveyance. When the raised portion of the paper comes into contact with the ink jet head, the head surface may be damaged, dirt due to ink adhering to the head surface or the periphery of the ink jet head may adhere, or paper jam may occur.

  It is possible to solve this problem by increasing the gap between the head between the inkjet head and the belt conveyance surface as a countermeasure against the paper floating during the conveyance, but if the gap between the heads is large, As an adverse effect, there is a problem that the ink mist discharged from the head increases and the paper and the vicinity of the inkjet head become dirty.

  In view of this, as disclosed in the following patent document, measures have been taken as a method for suppressing sheet lift without widening the gap between the heads.

  In Patent Document 1 below, an inkjet head composed of a plurality of head modules arranged in a staggered manner along the main scanning direction orthogonal to the sub-scanning direction, which is the paper transport direction, has a predetermined interval along the sub-scanning direction. And a line-type inkjet printing apparatus arranged in parallel. In this apparatus, a stepped guide roller urged downward (vertical direction) is arranged on the upstream side in the sub-scanning direction of each head, and before the leading edge of the conveyed paper reaches each head, the stepped guide roller is arranged. The attached guide roller presses the sheet against the belt conveyance surface of the suction conveyance belt, and assists the suction by the suction conveyance belt to suppress the floating of the sheet.

JP 2012-176513 A

  However, in the apparatus of Patent Document 1, when the paper is conveyed in a folded state, the belt can be temporarily pressed against the belt conveyance surface of the suction conveyance belt by the stepped guide roller. There is a risk that it will begin to fold again against this suction force and come into contact with the head surface during conveyance.

  In addition, since the action of the suction force by the suction conveyance belt varies depending on the type of paper to be sucked (material, thickness, size, shape, etc.), in the specification where the type of paper used by the print job can be changed, There is a possibility that the lifting of the edge of the sheet cannot be suppressed.

  Furthermore, in the apparatus of Patent Document 1, it is conceivable to increase the suction force by the suction means (suction fan) according to the type of paper. However, increasing the suction force changes the air flow, which is a problem in the past. There is a possibility that the ink mist that has not been scattered will be scattered in an unfavorable direction and the inside of the apparatus and the paper may be stained.

  Therefore, the present invention has been made in view of the above problems, and an ink jet that can prevent the paper surface from being lifted during printing to prevent damage to the head surface, and can prevent adhesion and damage to the paper. An object of the present invention is to provide a printing apparatus.

In order to achieve the above object, a first aspect according to the present invention includes an endless suction conveyance belt provided with a plurality of suction ports, and sucks air from the back side of the belt through the suction ports. Sucking and conveying means having suction means for sucking and holding paper on the belt surface;
A printing unit in which a line-like inkjet head that discharges ink from nozzles onto the paper conveyed by the suction conveyance unit is provided above the suction conveyance unit;
A pressing unit that is disposed above the suction conveyance unit and upstream of the printing unit and that presses the sheet against a conveyance surface of the suction conveyance belt;
An adhesive application means for applying a low-viscosity adhesive for adhesively fixing the paper to an area excluding at least the suction port of the suction conveyance belt;
An ink jet printing apparatus comprising:

According to a second aspect of the present invention, in the inkjet printing apparatus according to the first aspect, the suction conveyance belt includes a suction region in which the plurality of suction ports are formed and parallel to the paper conveyance direction, and the suction port includes Non-suction areas that are not formed and are parallel to the paper conveyance direction are alternately provided in the width direction of the belt,
The suction conveyance belt is provided alternately with the suction area and the non-suction area parallel to the paper conveyance direction in the width direction of the belt,
The pressure-sensitive adhesive applying means arranges a disk-shaped application plate having a coating surface with a circumferential surface having the same width as the non-suction area of the suction conveyance belt on the roller shaft at the same interval as the non-suction area. An ink jet printing apparatus comprising: an adhesive application roller that applies the adhesive with the application surface in contact with the non-suction area.

  According to a third aspect of the present invention, in the inkjet printing apparatus according to the first or second aspect, the solvent for dissolving the adhesive is applied to the adhesive application region of the suction conveyance belt, and the suction conveyance belt An ink jet printing apparatus comprising: an adhesive removing means for collecting a belt surface adhering material containing the adhesive dissolved by the solvent applied to the substrate.

  According to the ink jet printing apparatus according to the first aspect, the pressing roller disposed on the upstream side of the ink jet head is used to press the paper on the belt conveying surface of the suction conveying belt to which the weakly viscous adhesive that adheres and fixes the paper is applied. By pressing the entire paper surface, the entire paper surface can be fixed to the belt conveyance surface by the suction force by the suction conveyance belt and the adhesion force by the adhesive. This prevents the edge of the paper from being lifted, so that the head surface of the inkjet head is not damaged by the raised part of the paper, and it is possible to prevent the occurrence of paper stains and paper jams due to head contact. it can.

  In addition, since the end of the paper can be securely fixed to the belt conveyance surface of the suction conveyance belt, the head gap between the suction conveyance belt and the inkjet head can be narrower than that of the conventional apparatus, and ink discharge It is possible to solve problems such as ink scattering.

  According to the ink jet printing apparatus according to the second aspect, the adhesive application roller has a configuration in which an application plate having a peripheral surface having the same width as that of the non-suction region is disposed on the roller shaft at the same interval as the non-suction region. Therefore, the adhesive can be accurately applied to the non-suction area without aligning the non-suction area of the suction conveyance belt and the peripheral surface of the coating plate during the adhesive application process.

  According to the ink jet printing apparatus according to the third aspect, the adhesive is dissolved by applying a solvent to the applied adhesive according to the number of printed sheets and the elapsed time after application of the adhesive, and includes the dissolved adhesive. Since it has an adhesive removal unit that collects belt surface deposits, it removes the old adhesive at a time when the raised part of the paper edge is not fixed due to a decrease in the adhesive strength of the adhesive. It can be used in such a state that a certain adhesive force is always kept by applying the agent.

It is the schematic which showed the structure of the inkjet printing apparatus which concerns on this invention. FIG. 4A is a side cross-sectional view schematically showing a printing unit and a belt conveyance unit of the apparatus, and FIG. 4B is a plan view schematically showing the printing unit and the belt conveyance part of the apparatus. It is the figure which showed typically the adhesive application part and adhesive removal part of the apparatus. (A) is the figure which showed an example of the adhesive application roller and the application quantity adjustment roller, (b) is the figure which showed an example of the solvent application roller and the application quantity adjustment roller. (A) is the figure which showed the state in which the adhesive was apply | coated to the application area | region at the time of an adhesive application | coating process, (b) was the figure which showed the state in which the solvent was apply | coated to the application | coating area | region at the time of an adhesive removal process. is there. It is a figure which shows the other form example of an adhesive application part.

  Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the accompanying drawings. The present invention is not limited by this embodiment, and other forms, examples, operational techniques, and the like that can be considered by those skilled in the art based on this form are all included in the scope of the present invention. To do.

  In the present specification, in the following description with reference to the accompanying drawings, when the words “up”, “down”, “left”, and “right” are used to indicate directions and positions, this is shown in FIG. Matches top, bottom, left, and right.

In each drawing, the width direction of the belt conveyance unit 22 of the conveyance unit 20 is defined as a “main scanning direction”, and a direction orthogonal to the main scanning direction (that is, the conveyance direction of the paper P) is defined as a “sub-scanning direction”. To do. Thus, for example, in FIG. 1, the horizontal direction of the paper surface is the sub-scanning direction, and the depth direction of the paper surface is the main scanning direction.

[About device configuration]
As shown in FIG. 1 or FIG. 2, an inkjet printing apparatus 1 according to the present embodiment is an image forming apparatus that prints a predetermined image on a sheet P that is a printing medium. 20, a printing unit 30, a paper discharge unit 40, a reversing unit 50, a storage unit 60, a control unit 70, a setting display unit 80, and an image reading unit 90.

  The print job executed by the inkjet printing apparatus 1 of the present invention includes various printing conditions (number of prints, print data (characters, images), single-sided / double-sided printing, color settings (single color, multicolor), output magnification, etc. ) Is set information.

  This print job includes information received through various communication networks such as the Internet (Internet) and Ethernet (registered trademark), for example, on which print conditions are set by an external terminal such as a PC (personal computer) or a server, Information in which printing conditions are appropriately set by the setting display unit 80 is used for document data obtained by reading a document as a medium by the image reading unit 90.

  As shown in FIG. 1, a circulation path R <b> 1 is set in the casing of the inkjet printing apparatus 1 as a transport path for paper P that is a print medium. This circulation path R1 is for returning to the normal path R2 after switching the normal path R2 for transporting the image-formed paper P to the paper discharge unit 40 and the front and back in the transport direction of the paper P with the image formed on the front surface. This is a closed-loop circulation path composed of the reverse path R3. The sheet P is image-formed while being conveyed in the counterclockwise direction in the figure along the circulation path R1, and is switched back through the reverse path R3 as necessary. In addition, a paper feed route R4 that connects the paper feed unit 10 is connected to the upstream side of the printing unit 30 in the circulation route R1.

―Paper Feeder―
The paper feeding unit 10 is disposed on the most upstream side of the transport path, and feeds the paper P to the printing unit 30. The paper feed unit 10 picks up an external paper feed tray 11 that is partly exposed outside the housing and the paper P loaded on the external paper feed tray 11 one by one and supplies it to the printing unit 30. An external paper feed roller 12 to be sent, a plurality of internal paper feed trays 13 arranged in the apparatus casing on which different sizes of paper P are stacked for each size, and a specification among the paper P stacked on the internal paper feed tray 13 A plurality of internal paper feed rollers 14 for picking up the fed paper P one by one and feeding it to the printing unit 30 are provided.
The external paper feed roller 12 and the internal paper feed roller 14 are each driven by a motor (not shown).

―Transport section―
The transport unit 20 transports the paper P in a predetermined direction in the circulation path R1. The transport unit 20 is arranged near the junction of the paper feed path R4 and the reversing path R3, temporarily stops the paper P transported from the paper feed unit 10 or the reversing unit 50, and then enters the printing unit 30 at a predetermined timing. A registration roller 21 is provided to convey the toner.

  Further, the transport unit 20 has an endless suction transport belt 22c formed with a plurality of suction holes 22e spanned between the driving roller 22a and the driven roller 22b, and a sheet P from the back side of the suction transport belt 22c on the belt. And a suction means 22d for generating a negative pressure for air suction, and the sheet P, which is disposed below the printing unit 30 and conveyed from the registration roller 21, is sucked and held on the suction conveyance belt 22c and conveyed. A belt conveyance unit 22 (corresponding to “suction conveyance means” in claims).

  Further, the moving speed of the belt conveyance unit 22 (that is, the conveyance speed of the paper P) is output to an encoder (not shown) provided in the driven roller 22b, for example, so as to be a conveyance speed suitable for the contents of the print job. Based on this, the controller 70 controls the number of rotations of a drive motor (not shown) connected to the drive roller 22a.

  The suction holes 22e formed in the suction conveyance belt 22c are arranged at predetermined intervals in parallel with the moving direction (sub-scanning direction) of the suction conveyance belt 22c, and the rows of the suction holes 22e extend along the main scanning direction. Several are arranged. Then, as shown in FIG. 2B, on the belt conveyance surface of the suction conveyance belt 22c, a “suction region E1” that is a region for sucking the paper P and a region that does not suck the paper P are “non-suction”. Two areas of “suction area E2” are alternately set along the main scanning direction.

More specifically, the suction region E1 is a band-like region including a through region of the suction hole 22e and a non-penetrated region between the suction holes 22e in the sub-scanning direction, and is used for sucking the paper P to the belt conveyance surface. It is an area.
The non-suction region E2 is a belt-like region where the suction hole 22e is not formed between the adjacent suction regions E1, and is a region where the negative pressure by the suction means 22d does not act and the sheet P is not sucked.

  The transport unit 20 is composed of a plurality of pairs of transport rollers, and transports the paper P transported by the belt transport unit 22 so as to make a U-turn from the right to the left along the normal path R2. 23.

  The registration roller 21 and the upper surface transport roller 23 are each driven by a motor (not shown).

  On the downstream side of the belt conveyance unit 22, an adhesive application unit that applies a low-viscosity adhesive for adhering and fixing the paper P to a predetermined range on the belt conveyance surface of the suction conveyance belt 22c (“adhesive application unit” in the claims) And an adhesive removing section (corresponding to “adhesive removing means” in claims) 110 for removing the adhesive applied to the belt conveying surface.

-Adhesive application part-
As shown in FIG. 3, the adhesive application unit 100 includes an adhesive application roller 101, an application amount adjustment roller 102, a squeeze receiving roller 103, and an adhesive supply container 104 as a unit, and a suction conveyance belt 22c. It is provided so as to be able to approach / separate. Therefore, the adhesive application unit 100 waits at a standby position separated from the belt conveyance unit 22 when the adhesive is not applied as in the printing process, and when performing the adhesive application process, the belt of the suction conveyance belt 22c. It moves to a position where the conveying surface and the application surface of the adhesive application roller 101 come into contact with each other.
The adhesive supply container 104 has a shape in which the liquid supply portion protrudes in the main scanning direction (not shown), and approaches the position where the adhesive application roller 101 comes into contact with the belt conveyance surface of the suction conveyance belt 22c. At this time, the adhesive supply container 104 does not interfere with the normal path R <b> 2 and the upper surface transport roller 23.

As shown in FIG. 4A, the adhesive application roller 101 prevents the adhesive from being applied to the suction area E1 set on the suction conveyance belt 22c when applying the adhesive. The disc-shaped coating plate 101a having a circumferential surface with the same width as the coating surface and the spacer member 101b with the same width as the suction region E1 are alternately arranged with respect to the roller shaft 101c. Further, since the adhesive is applied to the non-suction area E2 set on the suction conveyance belt 22c, the length between the coating plates 101a at both ends in the longitudinal direction (axial direction) is the suction area E1 in the width direction of the suction conveyance belt 22c. The length is approximately the same as the width. Furthermore, the coating plate 101a only needs to have chemical resistance to the adhesive, and is formed of, for example, a metal such as stainless steel or aluminum or plastic (regardless of thermosetting or thermoplastic). .
Note that the adhesive application roller 101 shown in FIG. 4A is an example in which eight non-suction areas E2 are set on the belt surface of the suction conveyance belt 22c. If the adhesive application roller 101 shown in FIG. 4 (a) is used in the belt conveyance unit 22 shown in FIG. 2 (b), the number of application plates 101a in FIG. 4 (a) may be six.

Thus, the adhesive application roller 101 has a configuration in which the application plates 101a and the spacer members 101b are alternately arranged with respect to the roller shaft 101c. Therefore, during the adhesive application process, the alignment between the non-suction area E2 of the suction conveyance belt 22c and the peripheral surface of the application plate 101a and the alignment of the suction area E1 and the spacer member 101b are not necessary. As shown to 5 (a), an adhesive can be apply | coated to the non-attraction | suction area | region E2. That is, during the adhesive application process, the non-suction area E2 functions as an “application area E3” where the adhesive is applied.
FIG. 5 (a) shows the mode of application of the adhesive for convenience, and shows the case where five non-suction areas E2 are set, but the adhesive shown in FIG. 4 (a). If the application roller 101 is used in the belt conveyance unit shown in FIG. 5A, the number of application plates 101a in FIG. 4A may be five.

  Further, the application range of the adhesive to the suction conveyance belt 22c is not required to apply the adhesive to the application region E3 on the entire belt conveyance surface, and is at least the size of the sheet P to be conveyed (long side and short side length). What is necessary is just to apply | coat to the corresponding application | coating area | region E3.

  The application amount adjusting roller 102 stores a predetermined amount of the adhesive supplied from the adhesive supply container 104 with the squeeze receiving roller 103, and applies an amount of adhesive corresponding to the application amount of the adhesive application roller 101 to the application plate. It supplies to the application surface (circumferential surface) of 101a. When adjusting the supply amount of the adhesive by the application amount adjustment roller 102, the supply amount or the rotation amount of the application amount adjustment roller 102 is adjusted by adjusting the interval between the application amount adjustment roller 102 and the aperture receiving roller 103 or the rotation amount of the application amount adjustment roller 102. The application area can be adjusted.

  The adhesive application roller 101 and the application amount adjustment roller 102 are structured to be interlocked and connected by a gear mechanism (not shown), and the other roller is driven by driving one of the rollers by a drive motor 105. It has become. In FIG. 3, the application amount adjustment roller 102 is driven by the drive motor 105.

  The pressure-sensitive adhesive stored in the pressure-sensitive adhesive supply container 104 is expressed as “adhesion condition” on the belt conveyance surface by using the belt conveyance surface as a result of warping or folding of the edge of the paper P that cannot be absorbed by the suction force of the conveyance by the belt conveyance unit 22. “It has a weakly viscous adhesive force to fix”, “After application, the adhesiveness to the paper P is maintained for a plurality of times, and at the separation position of the paper P after being sucked and conveyed by the belt conveying unit 22. It is necessary to have two characteristics, “the paper P has a re-peelability that naturally peels from the belt conveyance surface with the movement of the suction conveyance belt 22c”. And as an adhesive which has such weak viscosity and removability, the acrylic adhesive for weak removability corresponds, for example.

  In addition, since the adhesive force may be too strong immediately after the adhesive is applied, it is necessary to start the printing process after the application is dried for a predetermined time and can be removed again. The drying time of the pressure-sensitive adhesive is appropriately determined depending on the composition of the pressure-sensitive adhesive and the amount applied, but is approximately several minutes.

  In addition, the pressure-sensitive adhesive having the above-mentioned pressure-sensitive adhesive conditions may be selected as long as it has an optimal pressure-sensitive adhesive force depending on the paper quality (material and thickness) of the paper P used during printing and the transport speed of the paper P. .

-Adhesive removal part-
As shown in FIG. 3, the adhesive removing unit 110 includes a solvent application roller 111, an application amount adjusting roller 112, and a solvent container 113 as a unit for removing the adhesive applied to the suction conveyance belt 22c. It is provided so as to be close to / separated from the suction conveyance belt 22c. Therefore, the adhesive removing unit 110 stands by at a standby position separated from the belt conveying unit 22 when the adhesive is not removed as in the printing process, and when performing the adhesive removing process, the belt of the suction conveying belt 22c. The conveying surface moves to a position where the application surface of the solvent application roller 111 comes into contact.

The solvent application roller 111 has the same shape as the adhesive application roller 101 as shown in FIG. 4B in order to apply a solvent that dissolves the adhesive to the adhesive application region E3 applied to the suction conveyance belt 22c. doing. That is, the solvent application roller 111 includes a disk-shaped application plate 111a having a coating surface with a circumferential surface having the same width as the non-suction region E2 serving as the coating region E3, and a spacer member 111b having the same width as the suction region E1. Alternatingly arranged with respect to 111c. Further, since the solvent is applied to the non-suction area E2 set on the suction conveyance belt 22c, the length between the coating plates 111a at both ends in the longitudinal direction (axial direction) is substantially the same as the width direction of the suction conveyance belt 22c. It has become. Furthermore, the coating plate 111a only needs to have chemical resistance to the solvent, and is formed of, for example, a metal such as stainless steel or aluminum or plastic (regardless of thermosetting or thermoplastic).
Note that the solvent application roller 111 shown in FIG. 4B is an example in the case where eight non-suction areas E2 serving as application areas E3 are set on the belt surface of the suction conveyance belt 22c. If the solvent application roller 111 shown in FIG. 4B is used in the belt conveyance unit shown in FIG. 2B, the number of the application plates 111a shown in FIG.

  Thus, the solvent application roller 111 has a configuration in which the application plates 111a and the spacer members 111b are alternately arranged with respect to the roller shaft 111c so as to have the same shape as the adhesive application roller 101. For this reason, during the adhesive removal process, the alignment between the non-suction area E2 of the suction conveyance belt 22c and the peripheral surface of the coating plate 111a and the alignment of the suction area E1 and the spacer member 111b are not necessary. As shown in 5 (b), a solvent is applied to the application region E3 where the adhesive is applied, and the applied adhesive dissolved by the solvent, paper dust adhering to the belt conveying surface, belt surface deposits such as dust, etc. Can be recovered.

  In addition, by applying the solvent to the belt conveyance surface of the suction conveyance belt 22c by applying the solvent to the belt conveyance surface of the suction conveyance belt 22c by forming the application plate 111a in a sponge shape such as polyurethane or forming many fine irregularities on the application surface, The belt surface deposits can be recovered while scraping efficiently.

  The solvent application roller 111 and the application amount adjustment roller 112 are structured to be interlocked and connected by a gear mechanism (not shown), and the other roller is driven by driving one of the rollers by the drive motor 114. It has become. In FIG. 3, the application amount adjusting roller 112 is driven by the drive motor 114.

  The solvent storage container 113 is provided with a filtering means (not shown) for filtering out impurities such as adhesive and paper powder contained in the contained solvent, and the impurities contained in the contained solvent are periodically removed. It has been removed. In addition, an opening / closing lid 113a that is driven and controlled so as to open at the time of adhesive removal processing and to close at other times is provided on the upper portion of the solvent storage container 113 so that the stored solvent does not volatilize. . Further, the solvent storage container 113 is provided with a solvent supply means (not shown) for detecting the amount of the solvent stored so that a constant amount of the solvent is always stored.

  The solvent stored in the solvent container 113 only needs to have a function of dissolving only the adhesive applied to the suction conveyance belt 22c. For example, when an acrylic adhesive for re-peeling, which is a weakly viscous adhesive, is used as the adhesive, depending on the composition of the adhesive, for example, methyl acetate, ethyl acetate, acetone, toluene, methylene chloride, ethylene dichloride, Solvents such as trichlene and perchlen can be used.

  In addition, since it is necessary to volatilize the component of a solvent after apply | coating a solvent, it is necessary to start a printing process, after making it dry for a predetermined time after application | coating. Although the drying time of a solvent is prescribed | regulated by the composition of a solvent, it will be about several minutes in general.

―Printing Department―
The printing unit 30 includes a head unit 31 that ejects ink, and prints by ejecting ink on the paper P conveyed from the paper feeding unit 10.

  As shown in FIG. 2A, the head unit 31 corresponds to a plurality of color inks having a plurality of head blocks arranged in a staggered manner along the main scanning direction orthogonal to the sub-scanning direction that is the conveyance direction of the paper P. The line-type inkjet head 32 (also simply referred to as “head 32”) is provided. Further, the head 32 is parallel to the main scanning direction side in the order of the cyan head 32C, the black head 32K, the magenta head 32M, and the yellow head 32Y from the upstream side to the downstream side in the paper conveyance direction. The head holder 33 holds the inkjet heads 32C to 32Y.

  Each head block of each of the ink jet heads 32C to 32Y is provided with a plurality of ink jet nozzles (not shown) for ejecting ink toward the paper P in the main scanning direction, and a voltage is applied to the piezoelectric element of each nozzle. As a result, the element is vibrated to discharge a uniform droplet from the nozzle. Various colors are formed by ejecting ink on the surface of the paper P conveyed by the belt conveyance unit 22 at a predetermined timing in line units and superimposing a predetermined amount of ink on the same pixel. In addition, the head block which comprises each inkjet head 32 is arrange | positioned so that some nozzles may overlap between the blocks which adjoin in the conveyance direction.

  Further, as shown in FIGS. 2A and 2B, on the upstream side in the transport direction of each of the inkjet heads 32C to 32Y, the paper P is pressed against the belt transport surface of the suction transport belt before reaching each head. A pressing roller 34 (corresponding to “pressing means” in the claims) 34 is disposed. The pressing roller 34 has a configuration in which a large-diameter portion having a large diameter and a small-diameter portion having a smaller diameter than the large-diameter portion are alternately connected on the same rotation shaft (see FIG. 2B). . In addition, each roller 34 has a large-diameter portion staggered so that the large-diameter portion covers each head block of each inkjet head 32C-32Y from the upstream side at a position facing each inkjet head 32C-32Y. Is provided.

  The pressing roller 34 is vertically movable along a guide groove 34 a formed on the side surface of the head holder 33 in the vertical direction. Further, the presser roller 34 presses the conveyed paper P (particularly, the end of the paper) against the belt transport surface of the belt transport unit 22, so that the presser roller 34 moves downward (by a biasing force that does not hinder the transport of the paper P ( The roller surface is disposed in contact with the belt conveyance surface by a form biased in the belt conveyance surface direction or by its own weight.

  Since the peripheral surface of the large diameter portion of the pressing roller 34 needs to press the entire sheet P against the suction conveyance belt 22c, the large diameter portion of each pressing roller 34 ends in the axial direction when viewed from the sheet conveyance direction. The length of the overlapping portion of the large-diameter portion is at least the length in the width direction (main scanning direction) of the conveyed paper P.

―Output unit―
The paper discharge unit 40 is connected to the downstream end of the normal path R2 and discharges the printed paper P. The paper discharge unit 40 includes a paper discharge table 41 on which the discharged paper P is stacked, and a paper discharge roller 42 that conveys the paper P conveyed by the upper surface conveyance roller 23 and discharges it to the paper discharge table 41. I have.

―Reversing part―
The reversing unit 50 is provided in the reversing path R3, and after reversing the front and back of the single-side printed paper P conveyed from the normal path R2, the direction reversing process is performed in which the front and rear in the conveying direction are switched while conveying the reversing path R3. Then, it is conveyed to the registration roller 21.

The reversing unit 50 temporarily transports the paper P, which has been transported by the upper surface transporting roller 23, to the switchback unit 52, and then transports the paper P to the refeed roller 53. The reversing unit 51 temporarily A switchback unit 52, which is a space for carrying in, a re-feed roller 53 for transporting the paper P transported by the reversing roller 51 to the registration roller 21, and a paper P transported from the upper transport roller 23 And a switching gate 54 for guiding the paper P carried out from the switchback portion 52 by the reverse roller 51 to the refeed roller 53.
The reversing roller 51 and the refeed roller 53 are each driven by a motor (not shown).

―Storage unit―
The storage unit 60 is configured by, for example, a flash memory, an HDD (Hard Disk Drive), or the like, and stores various information (computer program, application software, etc.) necessary for driving each unit of the inkjet printing apparatus 1.

  Further, the storage unit 60 stores an application execution time when the adhesive application unit 100 performs the adhesive application process and a removal execution time when the adhesive removal unit 110 executes the adhesive removal process. These implementation periods are periods defined based on a period during which the viscosity of the adhesive functions effectively, and are defined by, for example, a predetermined number of printed sheets or an elapsed time after application of the adhesive.

  Furthermore, the storage unit 60 includes an application process control program for driving and controlling the adhesive application unit 100 during the adhesive application process, and a removal process control program for driving and controlling the adhesive removal unit 110 during the adhesive removal process. I remember it.

―Control part―
The control unit 70 is configured by a processor such as a CPU (Central Processing Unit), for example, and reads a computer program and various application software stored in the storage unit 60 to perform program processing, in addition to print processing based on a print job, Arithmetic processing necessary for control processing and various processing of the entire inkjet printing apparatus 1 is executed.

  Note that the control unit 70 has a built-in interface unit (not shown), receives a print job from an external terminal (not shown) via a communication network, and stores the received print job in the storage unit 60.

  Further, the control unit 70 drives and controls each part of the adhesive application unit 100 at the time of application of the adhesive according to the application processing control program stored in the storage unit 60, and performs predetermined control on the belt conveyance surface of the suction conveyance belt 22c. After the adhesive is applied to the application area E3 (non-suction area E2), the adhesive application process is terminated after a predetermined drying time.

  When performing the adhesive application process, it is necessary to rotate the suction conveyance belt 22c in accordance with the rotation of the adhesive application roller 101. However, the adhesive is accurately applied to the application region E3 of the suction conveyance belt 22c. As described above, both are rotated in the same direction, and the movement amount per unit time of the application surface of the adhesive application roller 101 and the movement amount per unit time of the belt conveyance surface of the suction conveyance belt 22c are synchronized. The drive motor 105 and the drive roller 22a are preferably driven and controlled. Thereby, an adhesive can be more reliably apply | coated, without interfering with mutual rotation.

  Further, the control unit 70 drives and controls each part of the adhesive removing unit 110 at a time when the adhesive is removed according to the removal processing control program stored in the storage unit 60, and performs predetermined control on the belt conveyance surface of the suction conveyance belt 22c. After applying a solvent to the adhesive applied to the application area E3 (non-suction area E2) and recovering the belt surface deposit containing the adhesive dissolved in the solvent, the adhesive is removed after a predetermined drying time. finish.

  When carrying out the adhesive removing process, it is necessary to rotate the suction conveyance belt 22c in accordance with the rotation of the solvent application roller 111. However, the solvent is applied to the application region E3 of the suction conveyance belt 22c, and the belt surface Both are rotated in the same direction so that the deposits can be collected accurately, and further, the amount of movement of the application surface of the solvent application roller 111 per unit time and the movement of the belt conveyance surface of the suction conveyance belt 22c per unit time. It is preferable to drive and control the drive motor 114 and the drive roller 22a so that the amount is synchronized. Thereby, the application | coating process of a solvent and collection | recovery of a belt surface deposit can be performed more reliably, without interfering with mutual rotation.

―Setting display section―
The setting display unit 80 is an input device including, for example, operation keys, a display / input panel, and the like, and is provided on the outside of the housing. The setting display unit 80 outputs an operation signal to the control unit 70 when a predetermined operation is performed when setting various setting information necessary for the inkjet printing apparatus 1 in addition to the setting of the print job by the user.

―Image reading part―
The image reading unit 90 includes a light source that emits light for irradiating a document, a CCD image sensor that receives reflected light from the document and performs photoelectric conversion, and optically reads an image of the document to generate image data. . The image reading unit 90 reads a document when using the copy function and the scanner function.

[About processing operations]
Next, an operation example during the adhesive application process and an operation example during the adhesive removal process in the inkjet printing apparatus 1 described above will be described. In addition, since the printing process in the inkjet printing apparatus 1 is the same as the conventional processing operation, the description thereof is omitted.

-Adhesive application treatment-
In the adhesive application process, when the adhesive application timing is reached, the adhesive application unit 100 is first brought close to the belt conveyance unit 22 before the printing process starts, and the application surface of the adhesive application roller is conveyed by the belt of the suction conveyance belt 22c. The surface is brought into contact with the non-suction area E2.

  Next, the drive motor 105 is driven to rotate the application amount adjusting roller 102 and the adhesive application roller 101 at a predetermined movement speed, and the drive roller 22a is driven to rotate the suction conveyance belt 22c at a predetermined movement speed. The adhesive is applied to the application area E3 (non-suction area E2) of the suction conveyance belt 22c.

  Thereafter, the pressure-sensitive adhesive is dried after a predetermined drying time, and the processing is terminated.

-Adhesive removal treatment-
In the pressure-sensitive adhesive removing process, when the time for removing the pressure-sensitive adhesive is reached, first, the pressure-sensitive adhesive removing unit 110 is brought close to the belt conveying unit 22 before the printing process is started, and the solvent application roller 111 is applied with the opening / closing lid 113a opened. The surface is brought into contact with the non-suction area E2 on the belt conveyance surface of the suction conveyance belt 22c.

  Next, the drive motor 114 is driven to rotate the application amount adjusting roller 112 and the solvent application roller 111 at a predetermined movement speed, while driving the drive roller 22a to rotate the suction conveyance belt 22c at a predetermined movement speed. A solvent is applied to the application region E3 (non-suction region E2) of the suction conveyance belt 22c. Further, the solvent application roller 111 collects the belt surface adhering material including the adhesive dissolved in the solvent simultaneously with the application of the solvent. Further, after the solvent application process, the open / close lid 113a is closed so that the solvent does not volatilize.

  Thereafter, the solvent is dried after a predetermined drying time, and the processing is terminated. Further, the filtering means is appropriately operated according to the number of times of application of the solvent to remove impurities contained in the solvent. Needless to say, after removing the old pressure-sensitive adhesive in the pressure-sensitive adhesive removing process, a new pressure-sensitive adhesive coating process is performed to apply a new weakly viscous pressure-sensitive adhesive to the suction conveyance belt.

  As described above, the inkjet printing apparatus 1 described above fixes the lifted part due to the folding or warping of the end of the paper P that cannot be sucked by the suction conveyance belt 22c of the belt conveyance unit 22 to the belt conveyance surface. The non-suction area E2 on the belt conveyance surface of the suction conveyance belt 22c is used as the application area E3 of the low-viscosity adhesive, and a predetermined amount of low-viscosity adhesive is applied to the application area E3 by the adhesive application roller 101 of the adhesive application unit 100. Apply. Then, during the printing process, the sheet P is pressed against the belt conveyance surface of the suction conveyance belt 22c to which the weakly viscous adhesive is applied by the pressing roller 34 disposed on the upstream side of the inkjet head 32.

  As a result, the paper P is securely fixed to the belt conveyance surface of the suction conveyance belt 22c, so that the end of the paper P is lifted (particularly, the suction force of the belt conveyance unit 22 such as paper folding that occurs at the end of the paper) It is possible to prevent a lift that cannot be completely sucked). Therefore, the head surface of the ink jet head 32 due to the raised portion of the paper P is not damaged, and the ink stain on the paper P and the paper jam due to the head contact can be prevented.

  Further, since the end portion of the paper P can be securely fixed to the belt conveyance surface of the suction conveyance belt 22c, the head gap between the suction conveyance belt 22c and the inkjet head 32 can be narrower than that of the conventional apparatus. In addition, problems such as ink scattering during ink ejection can be solved.

  Furthermore, the adhesive application roller 101 has a configuration in which a coating plate 101a having a coating surface with a circumferential surface having the same width as the non-suction region E2 serving as the coating region E3 is disposed on the roller shaft 101c at the same interval as the non-suction region E2. Therefore, the adhesive can be accurately applied to the non-suction region E2 without aligning the non-suction region E2 of the suction conveyance belt 22c with the peripheral surface of the application plate 101a during the adhesive application process. it can.

  Also, an adhesive removing unit that applies a solvent to the applied adhesive according to the number of printed sheets and the elapsed time after application of the adhesive, dissolves the adhesive, and collects belt surface deposits containing the dissolved adhesive 110, the old adhesive is removed in accordance with the time when the lifted portion of the paper edge is not fixed due to a decrease in the adhesive strength of the adhesive, and a new adhesive is applied to always maintain a constant adhesive strength. Can be used in a state of holding.

[Other embodiments]
In addition, this invention is not limited to embodiment mentioned above, For example, as shown below, according to a use environment etc., it can also change suitably and can implement. Further, the following modifications can be implemented in any combination within a range not departing from the gist of the present invention.

-Modification 1-
In the above-described embodiment, the adhesive application unit 100 has been described with the configuration in which the low-viscosity adhesive is applied using the adhesive application roller 101 as the application area E3 in the non-suction area E2 of the suction conveyance belt 22c. It is not limited to.

The adhesive application part 100 of this invention should just be the structure which can apply | coat an adhesive so that an adhesive may not be apply | coated to the suction hole 22e penetrated at least to the belt conveyance surface of the suction conveyance belt 22c.
Therefore, as shown in FIG. 6, the adhesive application roller 101 in the adhesive application unit 100 is moved in the main scanning direction and the sub direction with respect to the belt conveyance surface of the suction conveyance belt 22 cd like an inkjet head in a serial type inkjet printing apparatus. The pressure sensitive adhesive discharge head 106 may be relatively movable in the scanning direction. In such a configuration, after the adhesive discharge head 106 is moved to a predetermined position in the sub-scanning direction, the application region is moved back and forth in the width direction (main scanning direction) of the belt conveyance surface of the suction conveyance belt 22c. The adhesive can be applied by applying an adhesive to E3, moving the suction conveyance belt 22c in the sub-scanning direction by a predetermined distance after the reciprocating operation, and repeating these operations alternately.

  Note that when the adhesive discharge head 106 is employed as the configuration of the adhesive application unit 100, the discharge amount and discharge range of the adhesive can be arbitrarily set, and therefore set on the belt conveyance surface of the suction conveyance belt 22c. The applied region E3 (non-suction region E2) can be a region other than the suction holes 22e penetrating the belt conveyance surface. Therefore, since the adhesive can be applied also between the suction holes 22e in the suction area E1 parallel to the conveyance direction set on the belt conveyance surface of the suction conveyance belt 22c, the application area of the adhesive increases, and the paper P Can be securely fixed to the belt conveying surface.

-Modification 2-
Furthermore, in the above-described embodiment, as the timing for performing the pressure-sensitive adhesive removal processing, the implementation time defined in advance based on the number of printed sheets and the elapsed time from the time of applying the pressure-sensitive adhesive is stored in the storage unit 60. It is not limited to.

  For example, the sheet P from the belt conveyance surface of the suction conveyance belt 22c is detected by a method for detecting the presence or absence of a floating portion by a light emitting / receiving sensor or a method for detecting the presence or absence of a floating portion from an image captured by an imaging unit such as a CCD camera. The degree of lifting may be detected, and the adhesive removal process and the adhesive coating process may be performed when it is determined that there is lifting of the edge of the sheet due to a decrease in adhesive strength.

-Modification 3-
Furthermore, in the above-described embodiment, the mode of performing the pressure-sensitive adhesive removing process after the pressure-sensitive adhesive coating process and performing the pressure-sensitive adhesive coating process again is shown, but the present invention is not limited to such a mode. For example, it is possible to perform control such that a predetermined number of prints are performed after the adhesive coating process, and then the adhesive coating process is performed again, so that the adhesive strength is periodically recovered. In addition, the adhesive removing process can be performed after printing a predetermined number of sheets or after a predetermined printing time has elapsed, and the user visually confirms a decrease in the adhesive strength of the adhesive or contamination of the adhesive. In some cases, it may be performed manually.

DESCRIPTION OF SYMBOLS 1 ... Inkjet printing apparatus 10 ... Paper feed part 20 ... Conveyance part 22 ... Belt conveyance part (suction conveyance means)
22c ... Suction conveyance belt 22d ... Suction means 22e ... Suction hole 30 ... Printing section (printing means)
34 ... Pressing means (34a ... Guide groove)
DESCRIPTION OF SYMBOLS 40 ... Paper discharge part 50 ... Inversion part 60 ... Memory | storage part 70 ... Control part 80 ... Setting display part 90 ... Image reading part 100 ... Adhesive application part (adhesive application means)
101 ... Adhesive application roller (101a ... application plate, 101b ... spacer member, 101c ... roller shaft)
DESCRIPTION OF SYMBOLS 102 ... Coating amount adjustment roller 103 ... Diaphragm receiving roller 104 ... Adhesive container 105 ... Drive motor 110 ... Adhesive removal part (adhesive removal means)
111 ... Solvent application roller (111a ... application plate, 111b ... spacer member, 111c ... roller shaft)
112 ... Application amount adjusting roller 113 ... Solvent container (113a ... Opening / closing lid)
114: Drive motor P: Paper as a printing medium E1: Suction area E2: Non-suction area E3: Application area

Claims (3)

Suction conveyance means having an endless suction conveyance belt provided with a plurality of suction openings, and a suction means for sucking air from the back surface side of the belt through the suction openings and sucking and holding paper on the belt surface When,
A printing unit in which a line-like inkjet head that discharges ink from nozzles onto the paper conveyed by the suction conveyance unit is provided above the suction conveyance unit;
A pressing unit that is disposed above the suction conveyance unit and upstream of the printing unit and that presses the sheet against a conveyance surface of the suction conveyance belt;
An adhesive application means for applying a low-viscosity adhesive for adhesively fixing the paper to an area excluding at least the suction port of the suction conveyance belt;
An ink jet printing apparatus comprising: The suction conveyance belt includes a suction region in which the plurality of suction ports are formed and parallel to the paper conveyance direction, and a non-suction region in which the suction port is not formed and is parallel to the paper conveyance direction. Provided alternately in the direction,
The suction conveyance belt is provided alternately with the suction area and the non-suction area parallel to the paper conveyance direction in the width direction of the belt,
The pressure-sensitive adhesive applying means arranges a disk-shaped application plate having a coating surface with a circumferential surface having the same width as the non-suction area of the suction conveyance belt on the roller shaft at the same interval as the non-suction area. The inkjet printing apparatus according to claim 1, further comprising: an adhesive application roller that applies the adhesive with the application surface of the adhesive in contact with the non-suction area.   A pressure-sensitive adhesive removing unit that applies a solvent that dissolves the pressure-sensitive adhesive to a pressure-sensitive adhesive application region of the suction conveyance belt and collects belt surface deposits including the pressure-sensitive adhesive dissolved by the solvent applied to the suction conveyance belt. The inkjet printing apparatus according to claim 1, further comprising:

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