JP2018008782A - Intermediate unit, post-processing device, and printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an intermediate unit suppressing a curl of a medium.SOLUTION: An intermediate unit 200 conveys a sheet P from an intermediate paper feeding port 201 through which the sheet P as a medium printed by a printing unit 11 is carried in to an intermediate paper discharge port 202 through which the sheet P is discharged to a post-processing unit 100 performing post-processing of the sheet P. The intermediate unit 200 comprises at least one bending section (first and second bending sections 249 and 259) bending the sheet P in a direction opposite to a direction of a curl generated in association with dryness of the sheet P. The bending section through which the sheet P passes is selected according to a difference in liquid amount ratios of liquid in a prescribed region R of the sheet P by the printing unit 11.SELECTED DRAWING: Figure 4

Description

  The present invention relates to an intermediate unit, a post-processing apparatus, and a printing apparatus.

  Conventionally, a printing unit that prints images and characters by ejecting ink onto a medium such as transported paper, and punch processing that punches holes in the printed paper and paper every predetermined number of sheets There has been known an intermediate unit that is disposed between a post-processing unit that performs post-processing such as stapling processing to bind sheets, and conveys paper from a printing unit to the post-processing unit. For example, Patent Document 1 receives paper discharged from a printing apparatus (printing unit), performs paper switchback, and sends the paper toward a post-processing apparatus (post-processing unit) that performs post-processing on the paper. A transport device (intermediate unit) is disclosed.

JP 2013-71833 A

  By the way, the paper as a medium has a basic structure of cellulose, which is a paper fiber, and a structure is formed by binding cellulose molecules by hydrogen bonds. When printing on this paper with water-based ink that can provide higher image quality than oil-based ink, the bonds between cellulose are broken, and the fibers are shrunk and curled due to the recombination of cellulose that occurs as the ink is subsequently dried. Occurs. In the intermediate unit described in Patent Document 1, the drying of the paper progresses in the middle of conveyance, and the conveyance path for conveying the curled paper from the printing unit to the post-processing unit is blocked or aligned with the stack portion of the post-processing unit. There was a problem that post-processing could not be performed without it.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or application examples.

  [Application Example 1] The intermediate unit according to this application example transfers the medium from the paper supply port into which the medium printed by the printing unit is carried to the paper discharge port to be discharged to the post-processing unit that performs post-processing of the medium. An intermediate unit for transporting, comprising at least one curved portion that curves the medium in a direction opposite to the direction of curling that occurs as the medium is dried, and is ejected to a predetermined area of the medium by the printing unit. The curved portion passing through the medium is selected in accordance with the liquid volume ratio difference of the liquid.

  According to this application example, the intermediate unit includes at least one bending portion that curves the medium in a direction opposite to the direction of curling that occurs as the medium dries. The direction of curl generated in the process of drying the medium can be estimated from the amount of liquid ejected onto the medium when the medium is printed. For example, when the amount of liquid ejected on the surface is larger than the amount of liquid ejected on the back surface of the rectangular medium, curling is performed such that the short side of the rectangle is warped on the front side. In the intermediate unit of this application example, a curved portion that passes through the medium is selected in accordance with the liquid volume ratio difference of the liquid ejected to a predetermined area of the medium. In other words, the intermediate unit conveys the medium via the curved portion having a shape opposite to the curl according to the curl shape estimated from the liquid amount ratio difference. Thereby, curling caused by drying of the medium is suppressed, so that the medium can be suitably transported to the post-processing unit. Therefore, it is possible to provide an intermediate unit that suppresses curling that occurs in the medium.

  Application Example 2 It is preferable that the intermediate unit described in the application example includes a switchback mechanism for reversing the front and back of the medium and a plurality of the bending portions.

  According to this application example, since the intermediate unit includes the switchback mechanism that reverses the front and back of the medium, the medium continuously printed by the printing unit is arranged in the printing order in the post-processing unit. In addition, since the intermediate unit includes a plurality of curved portions, the processing speed of the intermediate unit can be improved, or the curved portions can be provided in different shapes.

  Application Example 3 The intermediate unit described in the application example includes a plurality of the switchback mechanisms, and each switchback mechanism includes the bending portions having different shapes, and the bending portions that pass through the medium. Is preferably selected by a switchback path constituting the switchback mechanism.

  According to this application example, the intermediate unit has a plurality of switchback mechanisms including curved portions having different shapes. Since the bending portion is attached to the switchback mechanism, the bending portion through which the medium passes can be selected by selecting a switchback path that constitutes the switchback mechanism.

  Application Example 4 In the intermediate unit described in the application example, it is preferable that the medium is held in the curved portion.

  According to this application example, the intermediate unit holds the medium with the curved portion having a shape opposite to the curl generated when the medium is dried, and therefore, the curl generated in the medium can be further suppressed.

  Application Example 5 In the intermediate unit described in the application example described above, the switchback mechanism includes a plurality of bending portions having different shapes and branch portions that guide the medium to the bending portions. It is preferable.

  According to this application example, the switchback mechanism includes a plurality of curved portions having different shapes and a branch portion that guides the medium to each curved portion. Since one switchback mechanism includes a plurality of curved portions, the size of the intermediate unit can be reduced.

  Application Example 6 In the intermediate unit described in the application example, it is preferable that the bending portion overlaps the switchback path.

  According to this application example, since the bending portion forms a shape that bends the medium overlapping the switchback path, the size of the intermediate unit can be reduced.

  Application Example 7 In the intermediate unit described in the application example described above, it is preferable that the plurality of curved portions include at least two shapes of a C shape, an inverted C shape, an S shape, and an inverted S shape. .

  According to this application example, the plurality of curved portions include at least two shapes of the C shape, the reverse C shape, the S shape, and the reverse S shape, and therefore can correspond to media that curl into different shapes. it can.

  Application Example 8 The intermediate unit according to the application example includes the bending portion corresponding to the size of the medium, and the bending portion that passes through the medium according to the size and the liquid volume ratio difference is provided. It is preferred that it be selected.

  According to this application example, since the intermediate unit includes the curved portion corresponding to the size of the medium, it is possible to suitably curve the media having different sizes.

  Application Example 9 A post-processing apparatus according to this application example includes an intermediate unit according to any one of application examples 1 to 8, a post-processing unit that performs post-processing on a medium discharged from the intermediate unit, It is characterized by having.

  According to this application example, the post-processing apparatus includes an intermediate unit that suppresses curling generated in the medium and conveys the medium to the post-processing unit. Therefore, it is possible to provide a post-processing apparatus that suitably performs post-processing of the medium.

  Application Example 10 In the post-processing apparatus described in the application example, it is preferable that the intermediate unit and the post-processing unit are configured in the same casing.

  According to this application example, in the post-processing apparatus, the intermediate unit and the post-processing unit are configured in the same casing, and thus the post-processing apparatus can be downsized.

  Application Example 11 A printing apparatus according to this application example includes the post-processing apparatus according to Application Example 9 or Application Example 10, and a printing unit that performs printing on a medium and discharges the medium after printing to the post-processing apparatus. It is characterized by comprising.

  According to this application example, the printing apparatus includes the post-processing device that suitably post-processes the medium. Therefore, it is possible to provide a printing apparatus that suitably performs from the printing of the medium to the post-processing.

FIG. 2 is a perspective view illustrating the overall configuration of the printing apparatus according to the first embodiment. FIG. 3 is a schematic structural diagram showing an internal configuration of a printing unit. The schematic structure figure which shows the internal structure of a post-processing unit. The schematic structure figure which shows the internal structure of an intermediate unit. FIG. 3 is an electrical block diagram illustrating an electrical configuration of the printing apparatus. FIG. 9 is a flowchart for explaining the operation of the printing apparatus. FIG. 6 is a front view for explaining a predetermined area of a sheet and a print duty. FIG. 6 is a back view illustrating a predetermined area of a sheet and a print duty. The figure explaining the curved part provided in the 1st switchback mechanism. The figure explaining the curved part provided in the 2nd switchback mechanism. FIG. 6 is a schematic diagram illustrating an internal configuration of an intermediate unit according to a second embodiment. FIG. 3 is an electric block diagram illustrating an electrical configuration of a printing apparatus including an intermediate unit. FIG. 6 is a front view illustrating a predetermined area of a sheet. FIG. 6 is a back view illustrating a predetermined area of a sheet. The figure explaining the reverse C-shaped curved part provided in the 1st switchback mechanism. The figure explaining the C-shaped curved part provided in the 1st switchback mechanism. The figure explaining the reverse S-shaped curved part provided in the 1st switchback mechanism. The figure explaining the S-shaped curved part provided in the 1st switchback mechanism. The figure explaining the reverse C-shaped curved part provided in the 2nd switchback mechanism. The figure explaining the C-shaped curved part provided in the 2nd switchback mechanism. The figure explaining the reverse S-shaped curved part provided in the 2nd switchback mechanism. The figure explaining the S-shaped curved part provided in the 2nd switchback mechanism. The figure explaining the principal part of the intermediate unit which concerns on the modification 1. FIG. The figure explaining the principal part of the intermediate unit which concerns on the modification 2. FIG. The figure explaining the principal part of the intermediate unit which concerns on the modification 3. FIG. FIG. 6 is a front view illustrating a predetermined area of a sheet. FIG. 6 is a back view illustrating a predetermined area of a sheet. The figure explaining the principal part of the intermediate unit which concerns on the modification 4. FIG. The perspective view which expanded the branch path partially.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following drawings, the scale of each member or the like is shown differently from the actual scale so as to make each member or the like recognizable.
1 to 4, 8 to 10, 13 to 23, 25, and 26, for convenience of explanation, the X axis, the Y axis, and the Z axis are illustrated as three axes orthogonal to each other. The upper end side of the arrow indicating the axial direction is “+ side”, and the base end side is “− side”. A direction parallel to the Z axis is referred to as a “Z axis direction”, a direction parallel to the X axis is referred to as an “X axis direction”, and a direction parallel to the Y axis is referred to as a “Y axis direction”.

(Embodiment 1)
FIG. 1 is a perspective view illustrating the overall configuration of the printing apparatus according to the first embodiment. FIG. 2 is a schematic structural diagram showing the internal configuration of the printing unit. The configuration of the printing apparatus 10 and the printing unit 11 will be described with reference to FIG.

  As shown in FIGS. 1 and 2, the printing apparatus 10 includes a printing unit 11 and a post-processing device 18 disposed on the side of the printing unit 11 along the left-right direction (Y-axis direction) in FIG. 2. ing. Further, the post-processing device 18 includes an intermediate unit 200 and a post-processing unit 100. The printing unit 11 and the post-processing unit 100 are connected by an intermediate unit 200. In this embodiment, the horizontal direction in which the printing unit 11, the intermediate unit 200, and the post-processing unit 100 are arranged in this order is the Y axis, the vertical direction (vertical direction) is the Z axis, and the direction intersecting the Y axis and the Z axis (the width of the paper P). Direction) is the X axis.

<Configuration of printing unit>
The printing unit 11 is a so-called composite printing apparatus, and includes a printer unit 12 that performs printing on a sheet P as a medium, a scanner unit 13 disposed on the printer unit 12 (+ Z axis side), and a scanner unit 13. The automatic paper feeder 14 is provided. An operation unit 17 for performing various operations of the printing apparatus 10 is provided on the side surface on the −X axis side of the scanner unit 13 on the printer unit 12.

  As shown in FIG. 2, the printer unit 12 includes a medium transport path 20 through which the paper P is transported and a plurality of rollers (roller pairs) and transports the paper P along the medium transport path 20. A transport unit 21 is provided. Further, in the printer unit 12, a support base 22 that supports the paper P from the lower side in the vertical direction (−Z axis side), and a recording unit that prints (records) an image on the paper P supported by the support base 22. 23 are accommodated.

  The printer unit 12 conveys the paper P on the support table 22 and along the medium conveyance path 20 with the direction intersecting the width direction of the paper P as the conveyance direction. The recording unit 23 includes a line head as a liquid ejecting head capable of ejecting ink at the same time over substantially the entire width of the paper P at the bottom, and the ink from the + Z-axis side with respect to the paper P conveyed on the support base 22. An image, a character, etc. are printed by spraying (discharging) and attaching.

  The printed paper P is transported from the recording unit 23 to the medium transport path 20 by the paper discharge roller pair 24 and other plural transport roller pairs 25, and the medium discharge provided at the downstream end of the medium transport path 20 is performed. It is discharged from the outlet 26. The paper P discharged from the medium discharge port 26 falls and is placed in a stacked state as shown by a two-dot chain line in FIG. 2 on a placement table 27 disposed on the upper side (+ Z axis side) of the recording unit 23. Is done. That is, the mounting table 27 sequentially receives and supports the printed sheets P that are discharged from the medium discharge port 26 and dropped.

  As shown in FIGS. 1 and 2, the mounting table 27 has a substantially rectangular plate shape, and is inclined so that the height becomes higher in the discharge direction of the paper P (the white arrow direction shown in FIG. 2). doing. The upper surface of the mounting table 27 is an inclined mounting surface 28, and the paper P is mounted on the mounting surface 28. A convex portion 29 extending in the discharge direction is formed at the approximate center in the width direction X of the paper P on the placement surface 28.

  Then, the paper P placed on the placement surface 28 slides down in the direction opposite to the discharge direction along the inclination of the placement surface 28, and as shown by the two-dot chain line in FIG. The + Y-axis side end is positioned by abutting against a vertical side wall 30 provided below the medium discharge port 26 in the printer unit 12. Note that the discharge direction of the paper P is inclined more than the placement surface 28 with respect to the horizontal plane.

  As shown in FIG. 2, in the present embodiment, the medium conveyance path 20 includes a medium supply path that supplies the paper P to the recording unit 23, and a medium discharge path 34 that conveys the paper P from the recording unit 23 to the medium discharge port 26. And a branch conveyance path 44 branched from the medium discharge path 34. The medium supply path includes a first medium supply path 31, a second medium supply path 32, and a third medium supply path 33.

  The medium discharge path 34 includes a curved path 34A that is curved with the recording surface of the paper P printed by the recording unit 23 inside, while the paper P printed by the recording unit 23 is conveyed to the medium discharge port 26, and A straight path 34B through which the sheet P is conveyed in one direction from the curved path 34A toward the medium discharge port 26 is provided.

  The medium discharge path 34 is moved from the state in which the recording surface of the sheet P faces upward (+ Z axis side) in the vertical direction to the lower side (−Z axis) when the sheet P is conveyed along the curved path 34A and the straight path 34B. It functions as a curve reversal path for reversing the paper P in a state facing the side. Therefore, the sheet P passes through the medium discharge path 34 functioning as the curved inversion path, so that the recording surface faces the mounting surface 28 of the mounting table 27, and the recording unit 23 is discharged onto a mounting table 27 located above 23.

  In the medium discharge path 34 of the medium transport path 20, the transport direction of the paper P transported on the straight path 34B is one direction of the straight path 34B. In the present embodiment, this one direction is the medium discharge port 26. It is assumed to be a diagonal direction that rises toward the top. Therefore, the direction (one direction) of the inclined straight path 34B is the discharge direction of the paper P discharged from the medium discharge port 26.

  The first medium supply path 31 is a path for transporting the paper P inserted from the insertion port 36 exposed by opening the cover 35 provided on one side surface (−Y axis side) of the printer unit 12 to the recording unit 23. is there. In other words, the paper P inserted into the insertion slot 36 is pressed against the first drive roller 38a by the hopper 37, and is conveyed by the rotational drive of the first drive roller 38a, so that the first drive roller 38a and the first driven roller 38b are in contact with each other. After being sandwiched between them, the first drive roller 38a is driven to rotate from the first medium supply path 31 toward the recording unit 23.

  The second medium supply path 32 conveys the paper P placed on the paper cassette 39 that can be inserted into and removed from the bottom, which is the lower side (−Z axis side) of the printer unit 12, to the recording unit 23. It is a route. That is, the paper P placed in a stacked state on the paper cassette 39 is fed out by the pickup roller 40 and separated one by one by the separation roller pair 41, and then the second drive roller 42a. It is sandwiched between the second driven roller 42b and conveyed from the second medium supply path 32 toward the recording unit 23 by the rotational drive of the second drive roller 42a.

  The third medium supply path 33 records again the paper P on which one side of the sheet has been printed by the recording unit 23 when performing double-sided printing that prints on both sides of the sheet P (paper side). This is a route to be conveyed to the unit 23. That is, a branch conveyance path 44 that branches from the medium discharge path 34 by the operation of the branch mechanism 43 provided in the middle of the medium discharge path 34 is provided downstream of the recording unit 23 in the conveyance direction of the paper P. . The branch conveyance path 44 is provided with a branch conveyance path roller pair 45 capable of both normal rotation and reverse rotation on the downstream side of the branch mechanism 43.

  Then, the sheet P on which the sheet surface on one side is printed is transported by the pair of branch transport path rollers 45 that normally rotate to the branch transport path 44 from the recording unit 23 side toward the mounting table 27 side during double-sided printing. . At this time, the paper P transported to the branch transport path 44 does not come into contact with the paper P placed in a stacked state on the placement table 27 when a part Pe on the upper end side in the transport direction jumps out from the medium discharge port 26. The pop-out position is set as follows.

  Thereafter, the sheet P conveyed to the branch conveyance path 44 is reversely conveyed on the branch conveyance path 44 from the placement table 27 side to the recording unit 23 side by the reverse-conversion branch conveyance path roller pair 45. At this time, the reversely transported paper P is transported toward the recording unit 23 by the plurality of transport roller pairs 25 via the third medium supply path 33. By passing through the third medium supply path 33, the sheet P is reversed so that the non-printed sheet surface faces the recording unit 23, and is sandwiched between the third driving roller 46a and the third driven roller 46b. Then, it is conveyed toward the recording unit 23 by the rotational drive of the third drive roller 46a.

  The sheet P conveyed toward the recording unit 23 through each medium supply path is conveyed to the alignment roller pair 47 disposed on the upstream side in the conveyance direction of the recording unit 23, and then the alignment roller pair 47 whose rotation is stopped. The upper end of the butt. Then, the inclination of the sheet P with respect to the conveyance direction is corrected (skewed) according to the state where the sheet P hits the alignment roller pair 47. Then, the skewed paper P is conveyed to the recording unit 23 side by the subsequent rotational driving of the alignment roller pair 47.

  The sheet P conveyed to the recording unit 23 side by the alignment roller pair 47 is disposed on the upstream side in the conveyance direction of the sheet P with respect to the recording unit 23 or on the downstream side in the conveyance direction. The paper is conveyed while facing the recording unit 23 by the discharged paper roller pair 24 and the conveying roller pair 25. Printing is performed by ejecting (discharging) ink as a liquid from the recording unit 23 facing the transported paper P.

  As shown in FIG. 2, the printer unit 12 includes a liquid storage unit 50 that stores ink to be supplied to the recording unit 23. That is, the liquid storage unit 50 supplies the stored ink to the recording unit 23 through an ink supply path (not shown) configured by a tube or the like, and the recording unit 23 ejects the supplied ink to form an image on the paper P. Etc. In the present embodiment, the liquid storage unit 50 is arranged on the + side in the Z-axis direction with respect to the paper P placed on the placement table 27. Further, the liquid storage section 50 is disposed so as to cover at least a part of the medium discharge path 34 when viewed from the + Z-axis direction.

  That is, the upper side of the medium discharge path 34 that is the curved reversal path has an oblique shape that faces in one direction by the straight path 34B that continues from the curved path 34A. Therefore, in the printer unit 12, a space 12S is formed on the upper side from the upper part of the curved path 34A to the medium discharge port 26 of the linear path 34B having an oblique shape.

  In the present embodiment, the space 12S is formed in the printer unit 12 in the width direction X so as to cover the medium discharge path 34 when viewed from above. The liquid storage unit 50 is disposed in the space 12S so as to cover at least a part of the medium discharge path 34 when viewed from above. In the present embodiment, the liquid storage unit 50 is disposed so as to cover the entire medium discharge path 34 in the width direction X when viewed from above.

  In this space 12S, among the plurality of transport roller pairs 25 functioning as discharge rollers provided in the medium discharge path 34, the transport roller pair 25a located on the most downstream side in the transport direction of the paper P in the medium discharge path 34 is The liquid reservoir 50 is provided at a position overlapping the liquid reservoir 50 when viewed from the horizontal direction.

  Further, in this space 12 </ b> S, a sheet that is located in the space excluding the space occupied by the liquid storage unit 50, downstream of the medium discharge port 26 in the discharge direction of the paper P, and discharged from the medium discharge port 26. A blower 57 that blows air in a direction in which P is pressed against the placement surface 28 is provided. The blower 57 includes a rotary fan 58 and is provided at a position overlapping the liquid reservoir 50 when viewed in the horizontal direction.

  In the present embodiment, the air blowing part 57 is arranged so that the air blowing port faces both ends in the width direction X of the paper P around the convex part 29 (see FIG. 1) of the placement surface 28. A pair is provided in the width direction X of the paper P. Needless to say, the number of the air blowing units 57 may be one, and the air blowing port may be formed in a shape that continues in the width direction X of the paper P.

  The liquid reservoir 50 is mounted with ink cartridges 51, 52, 53, and 54 as liquid reservoirs that store a plurality of types of ink (here, four colors), and the ink cartridges 51, 52, 53, and 54, respectively. The frame body 55 is configured. Each of the ink cartridges 51, 52, 53, and 54 has a substantially rectangular parallelepiped shape having a longitudinal direction, and can be inserted into and removed from the box-like frame body 55 having an opening on one side with the longitudinal direction as an insertion / extraction direction. It is attached to.

  In the present embodiment, the insertion / extraction direction of each ink cartridge 51, 52, 53, 54 is a direction along the X-axis direction. For this reason, the printer unit 12 is provided with an opening (not shown) through which the opening of the frame 55 is exposed when viewed from the X-axis direction, and a storage unit cover 56 (see FIG. 1) capable of opening and closing the opening. ing. Then, for example, the user of the printing apparatus 10 opens the reservoir cover 56 (see FIG. 1) to expose an opening (not shown), and the ink cartridges 51, 52, 53,. 54 can be inserted into and removed from the frame 55 along the X-axis direction.

  In the present embodiment, each of the ink cartridges 51, 52, 53, 54 is mounted on the frame body 55, the short direction is the Z-axis direction, and the long direction is the X-axis direction. The thickness direction is the Y-axis direction along the discharge direction. The ink cartridges 51, 52, 53, and 54 have the same length in the short direction (Z-axis direction) and are mounted on the frame 55 in a state of being aligned in the thickness direction.

  Of the ink cartridges 51, 52, 53, 54, the ink cartridge 54 is an ink cartridge that stores ink of the color (for example, black) having the highest ejection frequency from the recording unit 23. On the other hand, it is arrange | positioned in the position most distant to the opposite side to the mounting base 27 side. The ink cartridge 54 is thicker than the other ink cartridges 51, 52, 53, and stores a larger amount of ink than the ink storage amount of the other ink cartridges 51, 52, 53. It is possible to do.

  As shown in FIG. 2, a part of the third medium supply path 33, which is an inversion path for reversing the paper P with the mounting table 27, is formed between the recording unit 23 and the mounting table 27 in the printer unit 12. A path forming member 61 having a rectangular plate shape is disposed. That is, the third medium supply path 33 is formed by the lower surface of the mounting table 27 and the upper surface of the path forming member 61. The path forming member 61 is inclined so that its height increases as it goes in the discharging direction.

  Further, in the printer unit 12, a communication path 62 that branches from the upstream end of the curved path 34 </ b> A in the medium discharge path 34 and extends to the intermediate unit 200 is provided. The communication path 62 is provided with a communication conveyance roller pair 63 that conveys the paper P in the communication path 62 toward the intermediate unit 200. At the branch portion between the medium discharge path 34 and the communication path 62, the sheet P conveyed through the medium discharge path 34 can be switched so as to be conveyed to one of the curved path 34A side and the communication path 62 side. A switching flap 64 is provided.

The switching flap 64 has a position for guiding the printed paper P printed by the recording unit 23 and conveyed along the medium discharge path 34 to the curved path 34A side (a position indicated by a solid line in FIG. 2) and the communication path 62 side. It is displaced between the position leading to (the position indicated by the two-dot chain line in FIG. 2).
The printing unit 11 includes a control unit 65 that controls the printing apparatus 10 as a whole.

<Ink composition>
Next, ink (ink composition) as a recording material for recording on the paper P will be described.
The ink is preferably a water-based ink composition in which the main solvent of the ink is water from the viewpoints of safety, handleability, and various performances (coloring property, suitability for breakthrough, ink reliability, etc.). The strikethrough aptitude refers to a property suitable for suppressing ink from penetrating excessively into the paper P and passing through.

It is preferable to use pure water or ultrapure water such as ion exchange water, ultrafiltration water, reverse osmosis water, or distilled water. In particular, it is preferable to use water sterilized by ultraviolet irradiation or addition of hydrogen peroxide in order to prevent the generation of mold and bacteria and enable long-term storage of the ink.
Further, water is preferably contained in the ink composition in an amount of 10% by mass to 75% by mass from the viewpoint of ensuring appropriate physical property values (such as viscosity) of the ink and ensuring the stability and reliability of the ink.

Inks include inks (for example, inks such as cyan, magenta, and yellow) corresponding to full-color recording (image formation and printing), black inks, white inks, and the like, each of which contains a color material.
The color material preferably contains at least one selected from pigments, dyes, metal oxides and the like in each color ink.
The pigment is not particularly limited, and there are inorganic pigments and organic pigments for black, and organic pigments of various colors such as yellow, magenta, and cyan.
As dyes, various dyes such as direct dyes, acid dyes, food dyes, basic dyes, reactive dyes, disperse dyes, vat dyes, soluble vat dyes, reactive disperse dyes as dyes of various colors such as yellow, magenta and cyan Etc. can be used.

In addition, the ink may contain a water-soluble organic solvent, polyhydric alcohols, betaines, sugars, ureas, surfactants, and the like in addition to the coloring material in order to obtain predetermined ink characteristics. Predetermined ink characteristics include wettability and penetrability of ink on the paper P, curl to the paper P, cockling suitability, suitability for back-through, clogging suitability for ink ejection, suitability for viscosity characteristics depending on ink temperature, and the like. .
Specifically, for example, 1,2-alkanediol, glycol ether, pyrrolidone derivatives, and polyhydric alcohols as water-soluble organic solvents, glycerin, 1,2,6-hexanetriol, diethylene glycol, triethylene glycol, tetra Ethylene glycol, dipropylene glycol and the like can be used. As the surfactant, known fluorine-based surfactants, acetylene glycol-based surfactants, silicon-based surfactants, and the like can be used.

  As another component, when a pigment is contained in the ink, a dispersant for dispersing the pigment may be added. Further, the ink may further contain a pH adjusting agent, a complexing agent, an antifoaming agent, an antioxidant, an ultraviolet absorber, an antiseptic / antifungal agent, etc., in order to further improve the properties of the ink.

<Configuration of post-processing unit>
FIG. 3 is a schematic structural diagram showing the internal configuration of the post-processing unit. Next, the configuration of the post-processing unit 100 will be described with reference to FIG.

  The post-processing unit 100 feeds the paper P discharged from the intermediate unit 200 into the post-processing unit 100 and the paper discharge for discharging the post-processed paper P. And a post-processing paper discharge port 123. The post-processing paper feed port 122 is provided on the −Y-axis side surface facing the intermediate unit 200, and the post-processing paper discharge port 123 is provided on the + Y-axis side surface opposite to the post-processing paper feed port 122. ing. A stacking tray 131 on which the sheets P discharged from the post-processing paper discharge port 123 are stacked is provided below the post-processing paper discharge port 123 so as to protrude upward on the + Y axis side.

  Inside the post-processing unit 100, a punch unit 124 that performs punch processing for punching holes in the paper along the transport path of the paper P from the post-processing paper supply port 122 to the post-processing paper discharge port 123, and the paper And a stapling unit 125 that performs stapling processing for binding a predetermined number of sheets. The staple unit 125 performs a staple process on the paper P placed on the processing tray 128. The post-processing unit 100 includes a transport roller 127 that transports the paper P along the transport path, a processing tray 128, and a paper discharge roller 129.

  The transport roller 127 is disposed on the downstream side of the post-processing paper feed port 122 and on the downstream side of the punch unit 124 in the transport path of the paper P, and is transported as it is from the post-processing paper feed port 122 (processed by the punch unit 124). Paper not processed) or the paper processed by the punch unit 124 is conveyed downstream.

  The processing tray 128 is disposed on the downstream side of the transport roller 127 in the transport path of the paper P, and temporarily places the paper to be stapled by the staple unit 125. One end of the processing tray 128 is disposed on the post-processing discharge port 123 side, the other end of the processing tray 128 is disposed on the staple unit 125 side, and the lower end of the paper P is applied to the other end of the processing tray 128. Thus, the lower end of the paper P is aligned.

  The paper discharge roller 129 is disposed on one end side of the processing tray 128, and is configured to discharge the paper P placed on the processing tray 128 for each sheet or for each bundle of a predetermined number. The paper discharge roller 129 includes a pair of rollers that sandwich the paper P placed on the processing tray 128 from above and below, and the paper P is discharged from the post-processing paper discharge port 123 by rotating the paper discharge roller 129. . Specifically, the paper discharge roller 129 is configured to be movable so that a pair of rollers are separated from or pressed against each other. The paper discharge roller 129 is separated when the paper P is placed on the processing tray 128, and the paper placed on the processing tray 128 is removed. When discharging, press contact is performed so that the sheet is sandwiched with an appropriate nip pressure corresponding to the number of sheets. As a result, the paper P that has been punched or stapled is stacked on the processing tray 128.

<Configuration of intermediate unit>
FIG. 4 is a schematic structural diagram showing the internal configuration of the intermediate unit. Next, the configuration of the intermediate unit 200 will be described with reference to FIG.

  As shown in FIG. 4, the intermediate unit 200 includes an intermediate paper feed port 201 serving as a paper feed port for feeding the paper P discharged from the communication path 62 of the printing unit 11 into the intermediate unit 200, and a post-processing unit. And an intermediate paper discharge port 202 as a paper discharge port for discharging the paper P. The intermediate paper feed port 201 is provided above the −Y-axis side surface facing the printing unit 11, and the intermediate paper discharge port 202 is located above the + Y-axis side surface facing the post-processing paper feed port 122. Is provided.

  The intermediate unit 200 discharges the paper P from the paper supply port (intermediate paper supply port 201) into which the paper P as a medium printed by the printing unit 11 is carried to the post-processing unit 100 that performs post-processing of the paper P. The sheet P is conveyed to the intermediate sheet discharge port 202). The intermediate unit 200 dries the ink discharged onto the paper P by the printing unit 11 while the paper P is transported from the intermediate paper supply port 201 to the intermediate paper discharge port 202, and reverses the front and back of the paper P. A device with a function.

  In the intermediate unit 200, an intermediate transport path 210 for transporting the paper P from the intermediate paper feed port 201 to the intermediate paper discharge port 202 is provided. The intermediate conveyance path 210 is formed so that the sheet P is conveyed along a long path while being curved with the direction intersecting the width direction (X-axis direction) of the sheet P being the conveyance direction. While the paper P is transported along this path, the ejected ink is dried.

  The intermediate conveyance path 210 is provided with a plurality of intermediate conveyance roller pairs 221 along the intermediate conveyance path 210. The pair of intermediate transport rollers 221 is rotationally driven in a state where the paper P is sandwiched from both the front and back sides, whereby the paper P is transported along the intermediate transport path 210.

  The intermediate unit 200 has an introduction path 211 for introducing the paper P fed from the intermediate paper feed port 201 into the intermediate unit 200. The downstream end of the introduction path 211 extends obliquely downward from the intermediate sheet feeding port 201 in the + Y axis direction. The upstream end of the introduction path 211 is connected to the communication path 62 of the printing unit 11 via the intermediate sheet feeding port 201. In addition, an introduction sensor 222 that detects the paper P conveyed through the introduction path 211 is provided upstream of the introduction path 211.

  A switchback mechanism for reversing the front and back of the paper P is provided at the downstream end of the introduction path 211 extending obliquely downward. The intermediate unit 200 according to the present embodiment has a plurality of switchback mechanisms including a first switchback mechanism 240 and a second switchback mechanism 250.

The first switchback mechanism 240 includes a first reversing path 242 and a first reversing roller pair 245 that reverse the transport direction of the paper P, a first inlet path 241 that serves as an inlet to the first reversing path 242, and a first reversing path 242. The 1st exit channel | path 243 used as the exit from is included. The first inlet path 241, the first reverse path 242, and the first outlet path 243 constitute a first switchback path 248.
The second switchback mechanism 250 also includes a second reversing path 252 and a second reversing roller pair 255 for reversing the transport direction of the paper P, a second inlet path 251 serving as an inlet to the second reversing path 252, and a second reversing path. A second exit path 253 that serves as an exit from the path 252 is included. The second inlet path 251, the second reversing path 252, and the second outlet path 253 constitute a second switchback path 258.

  The upstream end of the first inlet path 241 and the upstream end of the second inlet path 251 are connected to the downstream end of the introduction path 211. The first inlet path 241 branches from the downstream end of the introduction path 211 and extends along the + Y axis direction. The second inlet path 251 branches from the downstream end of the introduction path 211 and extends along the −Z axis direction. That is, the intermediate transport path 210 branches from the branch point A, which is the downstream end of the introduction path 211, to the first inlet path 241 and the second inlet path 251. Then, the sheet P conveyed on the introduction path 211 is guided to one of the first inlet path 241 and the second inlet path 251 by the operation of the guide flap 223 provided at the branch point A. The position of the guide flap 223 is switched between a position where the sheet P conveyed on the introduction path 211 is guided to the first entrance path 241 and a position where the sheet P is guided to the second entrance path 251.

  The configuration of the first switchback mechanism 240 will be described. The upstream end of the first inversion path 242 is connected to the downstream end of the first inlet path 241. The first inversion path 242 extends along the + Y axis direction, and then extends in the −Z axis direction while drawing an arc.

  The upstream end of the first outlet path 243 is connected to the upstream end of the first inversion path 242. That is, the first outlet path 243 branches from the first connection point B where the downstream end of the first inlet path 241 and the upstream end of the first inversion path 242 are connected, and extends from the −Y axis direction to the −Z axis direction. It extends in an arc shape. In addition, a first outlet sensor 246 that detects the paper P conveyed through the first outlet path 243 is provided at an intermediate portion of the first outlet path 243.

  In addition, the downstream end (first connection point B) of the first inlet path 241 allows the sheet P to move from the first inlet path 241 to the first inversion path 242, while the first inversion path 242 passes through the first inlet path 241. A first regulating flap 247 that regulates the movement of the sheet P to the inlet path 241 and guides it to the first outlet path 243 is provided. The first regulating flap 247 is biased so as to close the downstream end of the first inlet path 241 by a biasing force by a biasing member (not shown).

  That is, when the paper P is transported from the first inlet path 241 to the first reversing path 242, the upper end of the paper P comes into contact so that the first regulating flap 247 opens the downstream end of the first inlet path 241. Is displaced. On the other hand, when the paper P is reversely conveyed (switched back) from the first reversing path 242, it is restricted from being conveyed to the first inlet path 241 by the first regulating flap 247, and the paper P is in the first outlet path. Guide to 243.

  Two pairs of first reverse roller pairs 245 that can rotate in the forward rotation direction and the reverse rotation direction are provided upstream of the first reverse path 242. A first reversing sensor 244 that detects the paper P conveyed on the first reversing path 242 is provided on the downstream side of the first reversing roller pair 245. The two pairs of first reversing rollers 245 perform forward rotation driving or reverse rotation driving based on a signal transmitted when the first reversing sensor 244 detects the paper P. That is, the paper P transported from the first inlet path 241 to the first reverse path 242 is reversed in the transport direction of the paper P by the first reverse roller pair 245 and transported in the direction of the first outlet path 243 (switchback). Is done.

  The configuration of the second switchback mechanism 250 will be described. The upstream end of the second inversion path 252 is connected to the downstream end of the second inlet path 251. The second inversion path 252 extends along the −Z axis direction, and then extends in the + Y axis direction while drawing an arc.

  The upstream end of the second outlet path 253 is connected to the upstream end of the second inversion path 252. That is, the second outlet path 253 branches from the second connection point C where the downstream end of the second inlet path 251 and the upstream end of the second inversion path 252 are connected, and from the + Z-axis direction toward the + Y-axis direction. It extends in an arc shape. In addition, a second outlet sensor 256 that detects the paper P conveyed through the second outlet path 253 is provided in an intermediate portion of the second outlet path 253.

  Further, the second connection point C allows the movement of the paper P from the second inlet path 251 to the second reversing path 252, while allowing the paper P to move from the second reversing path 252 to the second inlet path 251. A second restriction flap 257 is provided that regulates and leads to the second outlet path 253. The second regulating flap 257 is biased so as to close the downstream end of the second inlet path 251 by a biasing force by a biasing member (not shown).

  That is, when the paper P is transported from the second inlet path 251 to the second reversing path 252, the upper end of the paper P comes into contact so that the second restriction flap 257 opens the downstream end of the second inlet path 251. Is displaced. On the other hand, when the paper P is reversely conveyed (switched back) from the second reversing path 252, it is restricted from being conveyed to the second inlet path 251 by the second regulating flap 257, and the paper P is in the second outlet path. Guided to H.253.

  Two pairs of second reverse roller pairs 255 that can rotate in the forward direction and the reverse direction are provided in the upstream portion of the second reverse path 252. Further, a second reversing sensor 254 that detects the paper P conveyed through the second reversing path 252 is provided on the downstream side of the second reversing roller pair 255. The two pairs of second reversing rollers 255 perform normal rotation driving or reverse rotation driving based on a signal transmitted when the second reversing sensor 254 detects the paper P. That is, the sheet P conveyed from the second inlet path 251 to the second reversing path 252 is reversed in the conveying direction of the sheet P by the second reversing roller pair 255 and is conveyed in the direction of the second outlet path 253 (switchback). Is done. The first and second switchback mechanisms 240 and 250 are reversed when the front and back sides of the paper P fed from the intermediate paper feed port 201 are discharged from the intermediate paper discharge port 202. As a result, the sheets continuously printed by the printing unit 11 are arranged in the printing order in the post-processing unit 100.

The downstream end of the first outlet path 243 and the downstream end of the second outlet path 253 are joined at a junction point D located between the first switchback mechanism 240 and the second switchback mechanism 250. The upstream end of the derivation path 218 is connected to the junction point D. The lead-out path 218 extends obliquely downward in the + Y-axis direction, bypasses the lower end of the first inversion path 242 and extends in the + Z-axis direction, on the upper portion of the side surface on the + Y-axis side. It extends to the provided intermediate paper discharge port 202. The downstream end of the lead-out path 218 is connected to the post-processing paper feed port 122 of the post-processing unit 100 via the intermediate paper discharge port 202.
Note that the first switchback mechanism 240 and the second switchback mechanism 250 of the present embodiment are substantially line symmetrical with respect to the direction in which the lead-out path 218 extends obliquely downward from the confluence point D toward the + Y axis direction. It is configured.

In the present embodiment, the post-processing device 18 in which the intermediate unit 200 and the post-processing unit 100 are configured separately is illustrated, but post-processing in which the intermediate unit and the post-processing unit are configured in the same casing. It may be a device. Thereby, size reduction of an apparatus can be achieved.
Further, in the present embodiment, the printing apparatus 10 in which the printing unit 11, the intermediate unit 200, and the post-processing unit 100 are configured separately is illustrated. However, the printing unit, the intermediate unit, and the post-processing unit are the same casing. The printing apparatus comprised by these may be sufficient. This can further reduce the size of the device.
Further, the printing unit and the intermediate unit may be configured by the same casing.

<Electrical configuration>
FIG. 5 is an electrical block diagram illustrating an electrical configuration of the printing apparatus. Next, the electrical configuration of the printing apparatus 10 will be described with reference to FIG.

  The printing apparatus 10 includes a control unit 65 that controls each unit of the printing unit 11, the intermediate unit 200, and the post-processing unit 100. The intermediate unit 200 and the post-processing unit 100 according to the present embodiment are controlled by a control unit 65 provided in the printing unit 11. The control unit 65 includes an interface unit (I / F) 72, a CPU 73, a storage unit 74, a unit control circuit 75, and the like. The interface unit 72 is for transmitting and receiving data to and from an input device 71 that handles input signals and images. Although the control unit 65 has been described as being provided in the printing unit 11, a configuration in which a control unit is provided in each of the printing unit, the intermediate unit, and the post-processing unit may be used. A configuration in which a control unit is provided in any of the intermediate unit and the post-processing unit may be employed.

  The input device 71 controls a print job that causes the printing unit 11 to perform printing, and a personal computer or the like can be used. The input device 71 includes general image processing application software that handles image data to be printed, and printer driver software that generates print data for causing the control unit 65 to execute printing. The input device 71 may be configured integrally with the printing device 10.

  The CPU 73 receives input signals from various detector groups 76 including the introduction sensor 222, the first inversion sensor 244, the first exit sensor 246, the second inversion sensor 254, and the second exit sensor 256 provided in the intermediate unit 200. It is an arithmetic processing unit for performing processing and overall control of the printing apparatus 10. For example, the CPU 73 calculates the amount of liquid (ink) discharged on the front and back in a predetermined area R (see FIGS. 7A and 7B) of the paper P from the print data input from the input device 71.

  The storage unit 74 is a storage medium for securing an area for storing a program of the CPU 73, a work area, and the like, and includes storage elements such as a RAM (Random Access Memory) and an EEPROM (Electrically Erasable Programmable Read Only Memory). Yes.

  The control unit 65 controls each unit of the printing unit 11 according to a control signal output from the unit control circuit 75 and executes printing on the paper P. Then, for example, the printed paper P is transported from the communication path 62 to the intermediate paper supply port 201 of the intermediate unit 200 according to the post-processing conditions input to the operation unit 17.

  The control unit 65 drives the guide flap 223, the first reverse roller pair 245, the second reverse roller pair 255, the intermediate transport roller pair 221 and the like provided in the intermediate unit 200 by a control signal output from the unit control circuit 75. Then, the paper P printed by the printing unit 11 is conveyed from the intermediate paper supply port 201 to the intermediate paper discharge port 202 for discharging it to the post-processing unit.

  The guide flap 223 moves in a direction in which the paper P is guided to either the first switchback path 248 or the second switchback path 258 by controlling a rotating solenoid (not shown) that drives the guide flap 223 by the control unit 65. To do.

  The first reversing roller pair 245 controls a motor and a clutch (not shown) that drive the first reversing roller pair 245 according to signals output from the first reversing sensor 244 and the first outlet sensor 246 by the control unit 65. Thus, the sheet P conveyed from the first inlet path 241 to the first reversing path 242 is reversed and conveyed to the first outlet path 243.

  The second reversing roller pair 255 controls a motor and a clutch (not shown) that drive the second reversing roller pair 255 according to signals output from the second reversing sensor 254 and the second outlet sensor 256 by the control unit 65. Thus, the sheet P conveyed from the second inlet path 251 to the second reverse path 252 is reversely conveyed to the second outlet path 253.

  The intermediate conveyance roller pair 221 controls a motor and a clutch (not shown) that drive the intermediate conveyance roller pair 221 of each unit according to signals output from the various detector groups 76 including the introduction sensor 222 by the control unit 65. As a result, the paper P is conveyed from the intermediate paper feed port 201 to the intermediate paper discharge port 202 via the first switchback mechanism 240 or the second switchback mechanism 250.

The control unit 65 controls each part of the post-processing unit 100 according to a control signal output from the unit control circuit 75 to perform post-processing on the paper P, and stacks the post-processed paper P on the stacking tray 131. For example, the control unit 65 performs post-processing such as punch processing for punching holes in the paper P and stapling processing for binding paper every predetermined number in accordance with the post-processing conditions input to the operation unit 17.
Further, the control unit 65 controls each device (not shown) provided in the printing apparatus 10.

<Operation of printing device>
FIG. 6 is a flowchart for explaining the operation of the printing apparatus. FIG. 7A is a front view for explaining a predetermined area of the paper and the print duty. FIG. 7B is a back view illustrating a predetermined area of the paper and the print duty. FIG. 8 is a diagram illustrating a bending portion provided in the first switchback mechanism. FIG. 9 is a diagram illustrating a bending portion provided in the second switchback mechanism. Next, the operation of the printing apparatus 10 will be described with reference to FIGS.

  Step S1 is a print job receiving process for receiving a print job. The control unit 65 receives a print job for recording an image on the paper P from the input device 71 and stores the print job in the storage unit 74.

  Step S2 is a printing process. The control unit 65 controls each unit of the printing unit 11 to execute printing on the paper P.

  In step S3, it is determined whether the front and back print duty difference is greater than or equal to a threshold value. The control unit 65 calculates the liquid amount ratio of ink as droplets ejected on the front and back in the predetermined area R of the paper P by the printing unit 11 from the print data of the print job received in step S1. Find the difference. In the following description, the liquid amount ratio is also referred to as “print duty”, and the liquid amount ratio difference is also referred to as “print duty difference”.

Here, the predetermined region R and the print duty will be described.
FIG. 7A shows the front surface PF of the paper P printed on both sides, and FIG. 7B shows the back surface PB of the paper P printed on both sides. In the double-side printed paper P, the first printed surface is a back surface PB, and the later printed surface is a front surface PF. As shown in FIGS. 7A and 7B, on the front surface PF and the back surface PB of the paper P, there is a print area PE on which ink is actually ejected for printing an image or characters, and ink along the outer periphery of the print area PE. A blank area PW having the same width as a non-printing area where no ink is discharged is provided. In the present embodiment, the entire print area PE is set as the predetermined area R. Note that when the width of the non-printing area is “0 mm”, so-called borderless printing is set, the entire surface of the sheet P becomes the predetermined area R.

  The print duty is the amount of ink ejected from the recording unit 23 in the predetermined area R of the paper P based on the ejection data included in the print data, and the maximum size dot is formed in the predetermined area R of the paper P. In this case, the ratio to the amount of ink ejected from the recording unit 23 is expressed in “%”. For example, as shown in FIGS. 7A and 7B, when the print duty of the predetermined region R on the front surface PF side of the paper P is 80% and the print duty of the predetermined region R on the back surface PB side of the paper P is 25%, The printing duty difference (liquid amount ratio difference) is 55%.

  When the front and back print duty difference in the predetermined region R is equal to or greater than the threshold (step S3: Yes), the process proceeds to step S4. If the front and back print duty difference in the predetermined region R is equal to or smaller than the threshold (step S3: No), the control unit 65 conveys the paper P to the intermediate paper discharge port 202 and proceeds to step S6. The threshold is determined by the surrounding environment, the size of the paper P, and the like. For example, when the size of the paper P is A4, the temperature is 25 ° C., and the humidity is 15%, the threshold for the print duty difference is set to 50%. The control unit 65 refers to the threshold setting table stored in the storage unit 74 and determines the threshold value for the print duty difference.

  In step S4, it is determined whether the front and back print Duty in the predetermined region R is larger on the front surface PF than the back surface PB (front> back). When the print duty of the front surface PF is larger than the print duty of the back surface PB (step S4: Yes), the process proceeds to step S5A. When the printing duty of the back surface PB is larger than the printing duty of the front surface PF (step S4: No), the process proceeds to step S5B.

Here, curl that occurs on the paper P due to the print duty difference will be described.
The paper P has a basic structure of cellulose, which is a paper fiber, and forms a structure by binding cellulose molecules by hydrogen bonds. When the solvent of the water-based ink penetrates into the paper P, the bonds between the cellulose molecules are cut and the fibers are elongated. For example, when the printing duty of the front surface PF of the paper P is significantly larger than the printing duty of the back surface PB, the fibers on the front surface PF side are stretched more than the fibers on the back surface PB side, and the front surface PF curls in a convex shape. This curl is called “primary curl”. The primary curl settles with ink penetration, but after the ink solvent begins to dry, the cellulose molecules recombine and the fibers on the side with the larger print duty shrink. For example, when the paper P that has been primarily curled in the above-described convex shape is dried, the surface PF curls in a concave shape in the direction opposite to the primary curl. This curl is called “secondary curl”. Secondary curl is also called permanent curl, and the act of suppressing this curl is called decal.

Subsequently, the configuration of the bending portion for decurling the secondary curl will be described.
As shown in FIGS. 8 and 9, the intermediate unit 200 serves as a plurality of bending portions that bend the sheet P in a direction opposite to the direction of curl (secondary curl) that occurs when the sheet P as a medium is dried. First and second bending portions 249 and 259 are provided. In the present embodiment, the switchback mechanisms 240 and 250 are provided with first and second bending portions 249 and 259 having different shapes. Further, the first bending portion 249 overlaps with the first switchback path 248 that constitutes the first switchback mechanism 240, and the second bending portion 259 and the second switchback path 258 that constitutes the second switchback mechanism 250. overlapping.

  Specifically, the first bending portion 249 is formed in the first switchback path 248. The first curved portion 249 corresponds to a range where the paper P shown in FIG. 8 is located. That is, the first bending portion 249 is formed in a region overlapping the first inversion path 242 included in the first switchback path 248 and the first outlet path 243. In FIG. 8, the first curved portion 249 has an “inverted C-shape” shape with the + Y axis direction facing upward, and the front side of the paper P (the surface on the + Z axis side in FIG. 8) is convex (+ Y axis). Curved in a reverse C shape with the direction up. Since the first bending portion 249 forms a shape that bends the paper P overlapping the first switchback path 248, the intermediate unit 200 can be reduced in size.

  The second bending portion 259 is formed in the second switchback path 258. The second bending portion 259 corresponds to the range where the paper P shown in FIG. 9 is located. That is, the second bending portion 259 is formed in a region overlapping the second reversing path 252 included in the second switchback path 258 and the second outlet path 253. In FIG. 9, the second curved portion 259 has a “C” shape with the −Z axis direction facing upward, and the front side of the paper P (the surface on the + Y axis side in FIG. 9) is concave (the −Z axis). Curved in a C shape with the direction facing up. Since the second bending portion 259 forms a shape that bends the paper P overlapping with the second switchback path 258, the intermediate unit 200 can be reduced in size.

  As described above, the first and second bending portions 249 and 259 provided in the present embodiment include at least one of “C shape”, “reverse C shape”, “S shape”, and “reverse S shape”. It includes two shapes (“C”, “Reverse C”). Accordingly, the paper P that is secondarily curled into different shapes (C-shaped and inverted C-shaped) can be decurled.

  Step S5A is a convex decurling process. The control unit 65 is configured to cause the curved portion (the first portion) to pass through the paper P in accordance with the liquid amount ratio difference (printing duty difference) of the liquid (ink) ejected on the front and back in the predetermined region R of the paper P in the printing unit 11. The curved portion 249 or the second curved portion 259) is selected. In the present embodiment, the first bending portion 249 is formed in the first switchback path 248, and the second bending portion 259 is formed in the second switchback path 258. Therefore, the bending portion (the first bending portion 249 or the second bending portion 259) that passes through the paper P is the switchback path (first switchback mechanism 240, second switchback mechanism 250) that constitutes the switchback mechanism (first switchback mechanism 250). 1 switchback path 248 and second switchback path 258).

  When a paper P having a printing duty on the front surface PF larger than the printing duty on the back surface PB is fed from the introduction path 211, the control unit 65 uses the guide flap 223 as a path for passing the paper P through the first bending section 249. One switchback path 248 is selected. As a result, the paper P is transported from the first inlet path 241 to the first reverse path 242, reverses the transport direction by the first reverse roller pair 245, and then travels toward the first outlet path 243. Then, the control unit 65 holds the paper P with the first bending unit 249. Specifically, when the paper P reaches the position where the first bending portion 249 is formed based on the signals from the first reverse sensor 244 and the first outlet sensor 246, the control unit 65 sets the first reverse roller pair 245. Stop driving. Thereby, as shown in FIG. 8, the surface PF (the surface on the + Z-axis side) of the paper P is held in a convex shape.

  The paper P having a printing duty of the front surface PF larger than the printing duty of the back surface PB causes a secondary curl having a concave surface PF. That is, since the paper P is decurled in a convex shape opposite to the concave secondary curl, the secondary curl that occurs as the paper P dries is suppressed. Further, since the paper P is held in a convex shape, the decurling effect is improved. The control unit 65 conveys the paper P decurled in a convex shape to the intermediate paper discharge port 202. In the present embodiment, the paper P is held on the first curved portion 249 and decurled. However, the conveyance speed of the paper P in the first curved portion 249 is decreased, or the first curved portion 249 is used. In this case, the conveyance direction of the paper P may be reversed a plurality of times, and the forward and backward movements of the paper P may be repeated.

Step S5B is a concave decurling process.
When the paper P having a larger print duty on the back surface PB than the print duty on the front surface PF is fed from the introduction path 211, the control unit 65 uses the guide flap 223 as a path through which the paper P passes through the second bending portion 259. Two switchback paths 258 are selected. As a result, the paper P is transported from the second inlet path 251 to the second reversing path 252, the transport direction is reversed by the second reversing roller pair 255, and then the paper P travels to the second outlet path 253. Then, the control unit 65 holds the sheet P with the second bending unit 259. Specifically, when the paper P reaches the position where the second bending portion 259 is formed based on the signals from the second reversing sensor 254 and the second outlet sensor 256, the control unit 65 sets the second reversing roller pair 255 to Stop driving. As a result, as shown in FIG. 9, the front surface PF (the surface on the + Y-axis side) of the paper P is held in a concave shape.

  The paper P having a larger print duty on the back surface PB than the print duty on the front surface PF produces a secondary curl having a convex surface PF. That is, since the paper P is decurled into a concave shape (reverse C shape) opposite to the convex secondary curl, the secondary curl that occurs as the paper P dries is suppressed. Further, since the paper P is held in a concave shape, the decurling effect is improved. The control unit 65 conveys the paper P decurled in a concave shape to the intermediate paper discharge port 202. In the present embodiment, the paper P is held by the second bending portion 259 and decurled. However, the conveyance speed of the paper P in the second bending portion 259 is decreased, or the second bending portion 259 is decreased. In this case, the conveyance direction of the paper P may be reversed a plurality of times, and the forward and backward movements of the paper P may be repeated.

  Step S6 is a post-processing step. The control unit 65 controls each unit of the post-processing unit 100 in accordance with the post-processing conditions input to the operation unit 17, and performs post processing such as punch processing for punching punch holes in the paper P and stapling processing for binding a predetermined number of sheets. Processing is performed, and the sheets P are stacked on the stacking tray 131.

  As described above, the intermediate unit 200 of the present embodiment includes the first switchback mechanism 240 including the first bending portion 249 and the second switch including the second bending portion 259 having a shape different from that of the first bending portion 249. And a back mechanism 250. Accordingly, by selecting one of the first switchback path 248 and the second switchback path 258 for transporting the paper P, the curved portions (the first curved portion 249 and the second curved portion 259) that pass through the paper P are selected. Can be selected.

In the present embodiment, the printing apparatus 10 including the printing unit 11, the intermediate unit 200, and the post-processing unit 100 has been described. However, the present invention is discharged from the intermediate unit 200, or the intermediate unit 200 and the intermediate unit 200. The post-processing device 18 including the post-processing unit 100 that performs post-processing on the sheet P is also effective.
Moreover, although the intermediate unit 200 of the present embodiment has been described as including two switchback mechanisms (first and second switchback mechanisms 240 and 250), a configuration including three or more switchback mechanisms It may be. As a result, it is possible to provide curved portions having different shapes and improve the processing speed for decurling.

As described above, according to the intermediate unit 200, the post-processing device 18, and the printing device 10 according to the first embodiment, the following effects can be obtained.
The intermediate unit 200 according to the present embodiment includes first and second curved portions 249 and 259 that bend the paper P in a shape opposite to the secondary curl that occurs as the paper P is dried. The intermediate unit 200 causes the paper P to pass through either the first curved portion 249 or the second curved portion 259 according to the print duty difference in the predetermined region R of the paper P. Since the paper P is bent in a shape opposite to the secondary curl at the first curved portion 249 or the second curved portion 259, the secondary curl generated as the paper P is dried is suppressed. Thereby, the paper P can be suitably conveyed to the post-processing unit 100. Therefore, it is possible to provide the intermediate unit 200 that suppresses the secondary curl generated on the paper P.

Since the intermediate unit 200 includes first and second switchback mechanisms 240 and 250 that reverse the front and back of the paper P, the post-processing unit 100 aligns the paper P continuously printed by the printing unit 11 in the printing order. Can do.
The intermediate unit 200 includes a first switchback path 248 in which the first bending portion 249 is formed, and a second switchback path 258 in which the second bending portion 259 is formed. As a result, the intermediate unit 200 selects either the first switchback path 248 or the second switchback path 258 for transporting the paper P according to the print duty difference, so that the paper P has a shape opposite to that of the secondary curl. Can be curved.

Since the intermediate unit 200 holds the paper P in a state of being bent in a shape opposite to the secondary curl at the first and second bending portions 249 and 259, the effect of decurling is improved.
The first bending portion 249 of the intermediate unit 200 forms a shape that curves the paper P overlapping with the first switchback path 248, and the second bending portion 259 overlaps with the second switchback path 258. Therefore, the intermediate unit 200 can be reduced in size.
Since the intermediate unit 200 includes curved portions having different shapes of the first curved portion 249 having an inverted C shape and the second curved portion 259 having a C shape, the intermediate unit 200 has different shapes (C shape or inverted C shape). The paper P that is secondarily curled into a letter shape can be decurled.

  The post-processing device 18 includes a post-processing unit 100 and an intermediate unit 200 that appropriately suppresses secondary curl that occurs as the paper P is dried and transports the paper P to the post-processing unit 100. Therefore, it is possible to provide the post-processing device 18 that suitably performs the post-processing of the paper P.

  The printing apparatus 10 includes a printing unit 11 and a post-processing device 18 that suitably performs post-processing of the paper P. Thereby, it is possible to provide the printing apparatus 10 that suitably performs post-processing of the paper P after printing.

(Embodiment 2)
FIG. 10 is a schematic diagram illustrating an internal configuration of the intermediate unit according to the second embodiment. FIG. 11 is an electrical block diagram showing an electrical configuration of the printing apparatus including the intermediate unit. The internal configuration of the intermediate unit 300 will be described with reference to FIGS. 10 and 11. In addition, about the component same as Embodiment 1, the same number is used and the overlapping description is abbreviate | omitted.

<Configuration of intermediate unit>
The intermediate unit 300 includes a first switchback mechanism 340 and a second switchback mechanism 350.

  The configuration of the first switchback mechanism 340 will be described. The first switchback mechanism 340 includes a first branch path 341 and a second branch path 342. The first branch path 341 branches from a first connection point B where the downstream end of the first inlet path 241, the upstream end of the first inversion path 242 and the upstream end of the first outlet path 243 are connected, and the −Y axis Extends in a circular arc shape from the direction toward the + Z-axis direction. In addition, a first branch sensor 346 that detects the paper P conveyed on the first branch path 341 is provided at the downstream end of the first branch path 341.

  The sheet P conveyed in the + Y-axis direction through the first inlet path 241 is guided to the first inversion path 242 by the guide flap 347 provided at the first connection point B. Further, the sheet P conveyed in the −Y-axis direction through the first reversing path 242 is guided to one of the first outlet path 243 and the first branch path 341 by the guide flap 347. The guide flap 347 guides the sheet P transported in the + Y-axis direction through the first inlet path 241 to the first reversing path 242 and the sheet P transported through the first reversing path 242 in the −Y-axis direction. The position is switched between a position for guiding to the first exit path 243 and a position for guiding to the first branch path 341.

The second branch path 342 branches from a branch point E where the first inversion path 242 extends in the + Y-axis direction and begins to bend in the −Z-axis direction, and extends in an arc shape from the + Y-axis direction toward the + Z-axis direction. doing. The sheet P conveyed in the + Y-axis direction on the first reversing path 242 is one of the direction of traveling in the first reversing path 242 and the direction of traveling on the second branch path 342 by the guide flap 349 provided at the branch point E. It is guided to either one. The guide flap 349 is located between a position for guiding the sheet P conveyed in the + Y-axis direction in the first reversing path 242 in a direction along the first reversing path 242 and a position for guiding the paper P to the second branch path 342. The position can be switched with.
The guide flaps 347 and 349 function as branch portions that guide the paper P to first to fourth curved portions 361, 362, 363, and 364, which will be described later.

  The configuration of the second switchback mechanism 350 will be described. The second switchback mechanism 350 includes a third branch path 351 and a fourth branch path 352. The third branch path 351 branches from the second connection point C where the downstream end of the second inlet path 251, the upstream end of the second inversion path 252, and the upstream end of the second outlet path 253 are connected, and the + Z axis direction Extends in a circular arc shape toward the -Y-axis direction. In addition, a third branch sensor 356 that detects the paper P conveyed on the third branch path 351 is provided at the downstream end of the third branch path 351.

  Then, the sheet P conveyed in the second entrance path 251 in the −Z-axis direction is guided to the second inversion path 252 by the guide flap 357 provided at the second connection point C. Further, the sheet P conveyed in the + Z-axis direction through the second reversing path 252 is guided to one of the second exit path 253 and the third branch path 351 by the guide flap 357. The guide flap 357 is a position for guiding the paper P conveyed from the second inlet path 251 to the second reversing path 252 and a position for guiding the paper P conveyed from the second reversing path 252 to the second outlet path 253. And the position for guiding to the third branch path 351.

The fourth branch path 352 branches from a branch point F where the second inversion path 252 extends in the −Z-axis direction and starts to bend in the + Y-axis direction, and has an arc shape from the −Z-axis direction to the −Y-axis direction. It is extended. Then, the sheet P conveyed in the −Z-axis direction on the second reversing path 252 has a direction of traveling in the second reversing path 252 and a direction of traveling in the fourth branch path 352 by the guide flap 359 provided at the branch point F. You will be guided to one of them. The guide flap 359 includes a position for guiding the sheet P conveyed in the −Z-axis direction in the second reversing path 252 in a direction along the second reversing path 252 and a position for guiding the paper P to the fourth branch path 352. The position can be switched between.
The guide flaps 357 and 359 function as branch portions that guide the paper P to fifth to eighth curved portions 371, 372, 373, and 374, which will be described later.

<Electrical configuration>
Next, the electrical configuration of the printing apparatus 10 including the intermediate unit 300 will be described with reference to FIG.
The printing apparatus 10 includes a control unit 65 that controls each unit of the printing unit 11, the intermediate unit 300, and the post-processing unit 100. The intermediate unit 300 and the post-processing unit 100 according to the present embodiment are controlled by the control unit 65 provided in the printing unit 11.

  The CPU 73 includes an introduction sensor 222, a first reversing sensor 244, a first outlet sensor 246, a second reversing sensor 254, a second outlet sensor 256, a first branch sensor 346, and a third branch sensor 356 provided in the intermediate unit 300. Is an arithmetic processing unit for processing input signals from various detector groups 76 including the above and controlling the entire printing apparatus 10.

  The guide flap 347 controls a rotating solenoid (not shown) that drives the guide flap 347 by the control unit 65, whereby the paper P is transferred from the first inlet path 241 to the first reverse path 242 and from the first reverse path 242 to the first outlet. It moves to the path | route 243 in the direction guided to either the 1st inversion path | route 242 to the 1st branch path | route 341.

  The guide flap 349 controls the rotary solenoid (not shown) that drives the guide flap 349 by the control unit 65, whereby the paper P is moved in the direction along the first inversion path 242 and from the first inversion path 242 to the second branch path 342. , Move in the direction of guiding to either.

  The guide flap 357 controls the rotating solenoid (not shown) that drives the guide flap 357 by the control unit 65, whereby the paper P is transferred from the second inlet path 251 to the second inversion path 252 and from the first inversion path 242 to the second outlet. It moves to the path 253 in the direction of guiding to any one of the second inversion path 252 to the third branch path 351.

  The guide flap 359 controls the rotating solenoid (not shown) that drives the guide flap 359 by the control unit 65, whereby the paper P is moved in the direction along the second inversion path 252 and from the second inversion path 252 to the fourth branch path 352. , Move in the direction of guiding to either.

Next, the predetermined area when obtaining the print duty in the second embodiment will be described.
FIG. 12A is a front view illustrating a predetermined area of a sheet. FIG. 12B is a back view illustrating a predetermined area of the sheet. In the double-side printed paper P, the first printed surface is a back surface PB, and the later printed surface is a front surface PF. As shown in FIGS. 12A and 12B, on the front surface PF and the back surface PB of the paper P, there is a print area PE on which ink is actually ejected in order to print an image or characters, and ink along the outer periphery of the print area PE. A blank area PW having the same width as a non-printing area where no ink is discharged is provided. In the present embodiment, the long side of the rectangular paper P is divided into three equal parts, and regions R1, R2, and R3 are formed from the upper end side. Each of the areas R1, R2, and R3 is a predetermined area for obtaining the print duty. Note that the numerical value (%) shown in the drawing indicates the print duty in the predetermined area.

<Curved part>
Next, the configuration of the bending portion for decurling the secondary curl will be described.
FIG. 13 is a diagram illustrating an inverted C-shaped curved portion provided in the first switchback mechanism. FIG. 14 is a diagram illustrating a C-shaped bending portion provided in the first switchback mechanism. FIG. 15 is a diagram illustrating an inverted S-shaped bending portion provided in the first switchback mechanism. FIG. 16 is a diagram for explaining an S-shaped bending portion provided in the first switchback mechanism.

  FIG. 17 is a diagram illustrating an inverted C-shaped curved portion provided in the second switchback mechanism. FIG. 18 is a diagram illustrating a C-shaped bending portion provided in the second switchback mechanism. FIG. 19 is a diagram illustrating an inverted S-shaped curved portion provided in the second switchback mechanism. FIG. 20 is a diagram illustrating the S-shaped bending portion provided in the second switchback mechanism.

  The intermediate unit 300 includes a curved portion corresponding to the size of the paper P.

  As shown in FIGS. 13 to 16, the first switchback mechanism 340 includes, for example, first to fourth bending portions 361, 362, 363, 364 as a plurality of bending portions having different shapes corresponding to the A4 size. I have. The first to fourth curved portions 361, 362, 363, and 364 include at least two shapes of “C shape”, “reverse C shape”, “S shape”, and “reverse S shape”. In the present embodiment, “C-shape”, “reverse C-shape”, “S-shape”, and “reverse S-shape” are provided.

  As shown in FIGS. 17 to 20, the second switchback mechanism 350 includes, for example, fifth to eighth curved portions 371, 372, 373 and 374 as a plurality of curved portions having different shapes corresponding to the A3 size. I have. The fifth to eighth curved portions 371, 372, 373, and 374 include at least two shapes of “C shape”, “reverse C shape”, “S shape”, and “reverse S shape”. In the present embodiment, “C-shape”, “reverse C-shape”, “S-shape”, and “reverse S-shape” are provided.

The first curved portion 361 is formed in a range where the paper P shown in FIG. 13 is located. That is, the first bending portion 361 is formed by the first inversion path 242 and the first outlet path 243. In FIG. 13, the first bending portion 361 has an “inverted C shape” with the + Y-axis direction facing upward.
For example, when a paper P is fed having a paper size: A4, a predetermined area R1: a front-back Duty difference is greater than or equal to a threshold and the front PF side is large, and a predetermined area R3: a front-back Duty difference is greater than or equal to the threshold and the front PF side is large. The operation of the intermediate unit 300 will be described. In FIG. 13, the paper P has a C-shaped secondary curl with the + Y-axis direction facing upward, with the upper end side and the lower end side being warped on the surface PF side.

  The control unit 65 controls the guide flap 223 as a conveyance path of the paper P, and first curved portions (first to fourth curved portions 361, 362, 363, 364) corresponding to the A4 size are formed. The first switchback path 248 constituting the switchback mechanism 340 is selected. Then, the control unit 65 controls the guide flaps 347 and 349 to guide the upper end of the paper P to the first reverse path 242. Further, the controller 65 drives the guide flap 347 and the first reverse roller pair 245 to guide the lower end of the paper P to the first outlet path 243, and holds the paper P in the first curved portion 361.

  Specifically, the control unit 65 reaches a position where the paper P reversely conveyed from the first reverse path 242 forms the first curved portion 361 based on signals from the first reverse sensor 244 and the first outlet sensor 246. When this occurs, the driving of the first reversing roller pair 245 is stopped. As a result, in FIG. 13, the paper P is held in an “inverted C shape” with the + Y-axis direction facing upward, so that C-shaped secondary curl that occurs as the paper P dries is suppressed. Then, the control unit 65 conveys the decurled paper P to the intermediate paper discharge port 202.

The second curved portion 362 is formed in a range where the paper P shown in FIG. 14 is located. That is, the second bending portion 362 is formed by the second branch path 342, the upstream side of the first inversion path 242, and the first branch path 341. In FIG. 14, the second bending portion 362 has a “C-shape” with the + Y-axis direction facing up.
For example, when a paper P is fed having a paper size: A4, a predetermined area R1: the front and back duty difference is greater than or equal to a threshold value and small on the front PF side, and a predetermined area R3: the front and back duty difference is greater than or equal to a threshold value and the front surface PF side is small. The operation of the intermediate unit 300 will be described. In FIG. 14, the paper P has an inverted C-shaped secondary curl with the + Y axis direction facing upward, with the upper end side and the lower end side being warped on the back surface PB side.

  The control unit 65 controls the guide flap 223 as a conveyance path of the paper P, and first curved portions (first to fourth curved portions 361, 362, 363, 364) corresponding to the A4 size are formed. The first switchback path 248 constituting the switchback mechanism 340 is selected. Then, the control unit 65 controls the guide flaps 347 and 349 to guide the upper end of the paper P from the first reverse path 242 to the second branch path 342. Further, the control unit 65 drives the guide flap 347 and the first reverse roller pair 245 to guide the lower end of the paper P to the first branch path 341, and holds the paper P in the second bending portion 362.

  Specifically, the control unit 65 reaches a position where the paper P reversed and conveyed from the first reversing path 242 forms the second bending portion 362 based on signals from the first reversing sensor 244 and the first branch sensor 346. When this occurs, the driving of the first reversing roller pair 245 is stopped. Accordingly, in FIG. 14, the paper P is held in a “C-shape” with the + Y-axis direction facing upward, and thus an inverted C-shaped secondary curl that occurs as the paper P is dried is suppressed. Then, the control unit 65 repeats the reverse conveyance of the paper P, and conveys the decurled paper P to the intermediate paper discharge port 202.

The third curved portion 363 is formed in a range where the paper P shown in FIG. 15 is located. That is, the third bending portion 363 is formed by the first inversion path 242 and the first branch path 341. In FIG. 15, the third bending portion 363 has an “inverted S shape” with the + Y-axis direction facing upward.
For example, when a paper P is fed having a paper size: A4, a predetermined area R1: front and back duty difference is greater than or equal to a threshold value and large on the front PF side, and a predetermined area R3: front and back duty difference is greater than or equal to a threshold value and the front surface PF side is small. The operation of the intermediate unit 300 will be described. In FIG. 15, the sheet P has an S-shaped secondary curl with the upper end side warped toward the front surface PF and the lower end side warped toward the back surface PB, with the + Y-axis direction being the top.

  The control unit 65 controls the guide flap 223 as a conveyance path of the paper P, and first curved portions (first to fourth curved portions 361, 362, 363, 364) corresponding to the A4 size are formed. The first switchback path 248 constituting the switchback mechanism 340 is selected. Then, the control unit 65 controls the guide flaps 347 and 349 to guide the upper end of the paper P to the first reverse path 242. Further, the control unit 65 drives the guide flap 347 and the first reverse roller pair 245 to guide the lower end of the paper P to the first branch path 341, and holds the paper P in the third bending portion 363.

  Specifically, the control unit 65 reaches a position where the paper P reversely conveyed from the first reverse path 242 forms the third curved portion 363 based on signals from the first reverse sensor 244 and the first branch sensor 346. When this occurs, the driving of the first reversing roller pair 245 is stopped. As a result, in FIG. 15, the paper P is held in an “inverted S shape” with the + Y-axis direction facing upward, so that S-shaped secondary curl that occurs as the paper P dries is suppressed. Then, the control unit 65 repeats the reverse conveyance of the paper P, and conveys the decurled paper P to the intermediate paper discharge port 202.

The fourth curved portion 364 is formed in a range where the paper P shown in FIG. 16 is located. That is, the fourth bending portion 364 is formed by the second branch path 342, the upstream side of the first inversion path 242, and the first outlet path 243. In FIG. 16, the fourth bending portion 364 has an “S-shape” with the + Y axis direction facing upward.
For example, when paper P having a paper size: A4, a predetermined area R1: front and back duty difference is greater than or equal to a threshold and the front PF side is small, and a predetermined area R3: front and back duty difference is greater than or equal to a threshold and the front PF side is large is fed. The operation of the intermediate unit 300 will be described. In FIG. 16, the paper P has an inverted S-shaped secondary curl with the + Y-axis direction facing upward, with the upper end side warped toward the back surface PB and the lower end side warped toward the front surface PF.

  The control unit 65 controls the guide flap 223 as a conveyance path of the paper P, and first curved portions (first to fourth curved portions 361, 362, 363, 364) corresponding to the A4 size are formed. The first switchback path 248 constituting the switchback mechanism 340 is selected. Then, the control unit 65 controls the guide flaps 347 and 349 to guide the upper end of the paper P from the first reverse path 242 to the second branch path 342. Further, the control unit 65 drives the guide flap 347 and the first reverse roller pair 245 to guide the lower end of the paper P to the first outlet path 243, and holds the paper P in the fourth bending portion 364.

  Specifically, the control unit 65 reaches a position where the paper P reversed and conveyed from the first reversing path 242 forms the fourth bending portion 364 based on signals from the first reversing sensor 244 and the first outlet sensor 246. When this occurs, the driving of the first reversing roller pair 245 is stopped. As a result, in FIG. 16, the paper P is held in an “S-shape” with the + Y-axis direction facing upward, so that the reverse S-shaped secondary curl that occurs as the paper P dries is suppressed. Then, the control unit 65 conveys the decurled paper P to the intermediate paper discharge port 202.

The fifth curved portion 371 is formed in a range where the paper P shown in FIG. 17 is located. That is, the fifth bending portion 371 is formed by the fourth branch path 352, the second inversion path 252 and the third branch path 351. In FIG. 17, the fifth bending portion 371 has an “inverted C-shape” shape with the −Z-axis direction facing upward.
For example, when a sheet P is fed having a paper size: A3, a predetermined area R1: the front and back Duty difference is greater than or equal to a threshold and the front PF side is large, and a predetermined area R3: the front and back Duty difference is greater than or equal to the threshold and the front PF side is large. The operation of the intermediate unit 300 will be described. In FIG. 17, the paper P has a C-shaped secondary curl with the −Z-axis direction facing upward, with the upper end side and the lower end side being warped on the surface PF side.

  The control unit 65 controls the guide flap 223 as the conveyance path of the paper P, and the second curved portion (the fifth to eighth curved portions 371, 372, 373, and 374) corresponding to the A3 size is formed. The second switchback path 258 constituting the switchback mechanism 350 is selected. Then, the control unit 65 controls the guide flaps 357 and 359 to guide the upper end of the paper P from the second reverse path 252 to the fourth branch path 352. Further, the control unit 65 drives the guide flap 357 and the second reverse roller pair 255 to guide the lower end of the paper P to the third branch path 351, and holds the paper P in the fifth curved portion 371.

  Specifically, the control unit 65 reaches the position where the paper P reversed and conveyed from the second reversing path 252 forms the fifth bending portion 371 based on the signals from the second reversing sensor 254 and the third branch sensor 356. Then, the driving of the second reversing roller pair 255 is stopped. As a result, in FIG. 17, the paper P is held in an “inverted C shape” with the −Z-axis direction facing upward, so that C-shaped secondary curl that occurs as the paper P dries is suppressed. Then, the control unit 65 repeats the reverse conveyance of the paper P, and conveys the decurled paper P to the intermediate paper discharge port 202.

The sixth curved portion 372 is formed in a range where the paper P shown in FIG. 18 is located. That is, the sixth bending portion 372 is formed by the second inversion path 252 and the second outlet path 253. In FIG. 18, the sixth bending portion 372 has a “C-shape” with the −Z-axis direction facing upward.
For example, when a paper P is fed having a paper size: A3, a predetermined area R1: front and back Duty difference is greater than or equal to a threshold and the front PF side is small, and a predetermined area R3: front and back Duty difference is greater than or equal to the threshold and the front PF side is small. The operation of the intermediate unit 300 will be described. In FIG. 18, the paper P has an inverted C-shaped secondary curl with the −Z-axis direction facing upward, with the upper end side and the lower end side warping on the back surface PB side.

  The control unit 65 controls the guide flap 223 as the conveyance path of the paper P, and the second curved portion (the fifth to eighth curved portions 371, 372, 373, and 374) corresponding to the A3 size is formed. The second switchback path 258 constituting the switchback mechanism 350 is selected. Then, the control unit 65 controls the guide flaps 357 and 359 to guide the upper end of the paper P along the second reverse path 252. Further, the controller 65 drives the guide flap 357 and the second reversing roller pair 255 to guide the lower end of the paper P to the second outlet path 253, and holds the paper P in the sixth curved portion 372.

  Specifically, the control unit 65 reaches a position where the sheet P reversed and conveyed from the second reversing path 252 forms the sixth bending portion 372 based on signals from the second reversing sensor 254 and the second exit sensor 256. Then, the driving of the second reversing roller pair 255 is stopped. Accordingly, in FIG. 18, the sheet P is held in a “C shape” with the −Z axis direction facing upward, and thus an inverted C-shaped secondary curl that occurs as the sheet P dries is suppressed. Then, the control unit 65 conveys the decurled paper P to the intermediate paper discharge port 202.

The seventh curved portion 373 is formed in a range where the paper P shown in FIG. 19 is located. That is, the seventh curved portion 373 is formed by the fourth branch path 352, the second inversion path 252, and the second exit path 253. In FIG. 19, the seventh curved portion 373 has an “inverted S-shape” with the −Z-axis direction facing upward.
For example, when a paper P is fed having a paper size: A3, a predetermined area R1: front and back duty difference is greater than or equal to a threshold value and large on the front PF side, and a predetermined area R3: front and back duty difference is greater than or equal to a threshold value and the front surface PF side is small. The operation of the intermediate unit 300 will be described. In FIG. 19, this paper P has an S-shaped secondary curl with the upper end side warped toward the front surface PF and the lower end side warped toward the back surface PB, with the −Z-axis direction being the top.

  The control unit 65 controls the guide flap 223 as the conveyance path of the paper P, and the second curved portion (the fifth to eighth curved portions 371, 372, 373, and 374) corresponding to the A3 size is formed. The second switchback path 258 constituting the switchback mechanism 350 is selected. Then, the control unit 65 controls the guide flaps 357 and 359 to guide the upper end of the paper P from the second reverse path 252 to the fourth branch path 352. Further, the controller 65 drives the guide flap 357 and the second reversing roller pair 255 to guide the lower end of the paper P to the second outlet path 253, and holds the paper P in the seventh curved portion 373.

  Specifically, the control unit 65 reaches a position where the sheet P reversely conveyed from the second reversing path 252 forms the seventh curved portion 373 based on signals from the second reversing sensor 254 and the second exit sensor 256. Then, the driving of the second reversing roller pair 255 is stopped. Accordingly, in FIG. 19, the paper P is held in an “inverted S-shape” with the −Z axis direction facing upward, and therefore, an S-shaped secondary curl that occurs as the paper P is dried is suppressed. Then, the control unit 65 conveys the decurled paper P to the intermediate paper discharge port 202.

The eighth curved portion 374 is formed in a range where the paper P shown in FIG. 20 is located. That is, the eighth bending portion 374 is formed by the second inversion path 252 and the third branch path 351. In FIG. 20, the eighth curved portion 374 has an “S-shape” with the −Z-axis direction facing upward.
For example, when paper P having a paper size: A3, a predetermined area R1: front and back duty difference is greater than or equal to a threshold and the front PF side is small, and a predetermined area R3: front and back duty difference is greater than or equal to a threshold and the front PF side is large is fed. The operation of the intermediate unit 300 will be described. In FIG. 20, the paper P has an inverted S-shaped secondary curl with the −Z axis direction facing upward, with the upper end side warped toward the back surface PB and the lower end side warped toward the front surface PF.

  The control unit 65 controls the guide flap 223 as the conveyance path of the paper P, and the second curved portion (the fifth to eighth curved portions 371, 372, 373, and 374) corresponding to the A3 size is formed. The second switchback path 258 constituting the switchback mechanism 350 is selected. Then, the control unit 65 controls the guide flaps 357 and 359 to guide the upper end of the paper P along the second reverse path 252. Further, the controller 65 drives the guide flap 357 and the second reversing roller pair 255 to guide the lower end of the paper P to the third branch path 351, and holds the paper P in the eighth curved portion 374.

  Specifically, the control unit 65 reaches the position where the paper P reversed and conveyed from the second reversing path 252 forms the eighth bending portion 374 based on the signals from the second reversing sensor 254 and the third branch sensor 356. Then, the driving of the second reversing roller pair 255 is stopped. Accordingly, in FIG. 20, the paper P is held in an “S-shape” with the −Z-axis direction facing upward, and thus, an inverted S-shaped secondary curl that occurs as the paper P is dried is suppressed. Then, the control unit 65 repeats the reverse conveyance of the paper P, and conveys the decurled paper P to the intermediate paper discharge port 202.

  As described above, the intermediate unit 300 includes a curved portion corresponding to the size of the paper P, and a curved portion that passes through the paper P is selected according to the size of the paper P and the print duty difference (liquid amount ratio difference). Is done. Thereby, the paper P of a different size can be curved appropriately. Also, the first switchback mechanism 340 of the present embodiment is provided with first to fourth bending portions 361, 362, 363, 364 having different shapes, and the second switchback mechanism 350 has fifth shapes having different shapes. Since the eighth bending portions 371, 372, 373, and 374 are provided, the intermediate unit 300 can be reduced in size.

In the present embodiment, the intermediate unit 300 has been described. However, the present invention can also be applied to a post-processing apparatus including the intermediate unit 300 or a post-processing apparatus including the intermediate unit 300 and a printing unit including a printing unit. There is an effect.
Moreover, although the intermediate unit 300 of the present embodiment has been described as corresponding to the A4 size and A3 size paper P, the present invention is not limited to this. It may be an intermediate unit capable of handling combinations of different sizes.
Moreover, although the intermediate unit 300 of the present embodiment has been described as including two switchback mechanisms (first and second switchback mechanisms 340 and 350), a configuration including three or more switchback mechanisms It may be. As a result, it is possible to handle three or more paper sizes, and to improve the processing speed for decurling.

As described above, according to the intermediate unit 300 according to the second embodiment, the following effects can be obtained.
The intermediate unit 300 includes first and second switchback mechanisms 340 and 350. The first switchback mechanism 340 corresponds to the A4 size paper P and bends the paper P in a shape opposite to that of the secondary curl. The first C-shaped curved portion 361 and the C-shaped second curved portion 362 are curved. , An inverted S-shaped third bending portion 363 and an S-shaped fourth bending portion 364 are provided. The second switchback mechanism 350 corresponds to the A3 size paper P and bends the paper P in a shape opposite to that of the secondary curl. The reverse C-shaped fifth curved portion 371 and the C-shaped sixth curved portion 372 are provided. , An inverted S-shaped seventh curved portion 373 and an S-shaped eighth curved portion 374 are provided. The intermediate unit 300 selects a curved portion that passes through the paper P in accordance with the size of the paper P and the print duty difference. Thereby, the paper P of a different size can be curved appropriately.
In addition, since the first and second switchback mechanisms 340 and 350 are formed with a plurality of curved portions having different shapes, the intermediate unit 300 can be reduced in size.

  Note that the present invention is not limited to the above-described embodiment, and various modifications and improvements can be added to the above-described embodiment. A modification will be described below.

(Modification 1)
FIG. 21 is a diagram illustrating a main part of the intermediate unit according to the first modification. The intermediate unit 400 of this modification has a different shape from the bending portion described in the first embodiment. The intermediate unit 400 of this modification will be described with reference to FIG. In addition, the curved part of this modification is demonstrated as what is provided in the 2nd switchback mechanism 250 in Embodiment 1. FIG. Moreover, about the same component as Embodiment 1, the same number is attached | subjected and the overlapping description is abbreviate | omitted.

  The second switchback mechanism 250 includes a first branch path 401 and a second branch path 402 that branch from a branch point H of the second reverse path 252 on the downstream side (−Z axis side) of the second reverse roller pair 255. ing. The second switchback mechanism 250 includes third and fourth branch paths 403 and 404 that branch from the branch point G of the second reverse path 252 on the upstream side (+ Z axis side) of the second reverse roller pair 255. ing.

  The first branch path 401 is a circular cylinder that branches from the branch point H to the −Y axis side and has a spiral shape in which the curvature gradually decreases counterclockwise in plan view from the −X axis direction. The second branch path 402 is a circular cylinder that branches from the branch point H to the + Y-axis side and has a spiral shape in which the curvature gradually decreases clockwise in a plan view from the −X-axis direction. The third branch path 403 is a circular cylinder that branches from the branch point G to the −Y axis side and has a spiral shape in which the curvature gradually decreases clockwise in plan view from the −X axis direction. The fourth branch path 404 is a circular cylinder that branches from the branch point G to the + Y-axis side and has a spiral shape in which the curvature gradually decreases counterclockwise in plan view from the −X-axis direction.

  A guide flap 411 is provided at the branch point H. The guide flap 411 includes a position where the paper P conveyed in the −Z-axis direction along the second reversing path 252 is guided to the first branch path 401, a position where the paper P is guided to the second branch path 402, and the second reversing path 252. The position is switched between the position that is guided in the direction along the direction. Further, the guide flap 411 guides the paper P conveyed in the + Z axis direction along the second reversing path 252 in the direction along the second reversing path 252.

  At the branch point G, a guide flap 412 is provided. The guide flap 412 guides the sheet P conveyed in the −Z axis direction along the second inversion path 252 in a direction along the second inversion path 252. In addition, the guide flap 412 has a position for guiding the paper P conveyed in the + Z-axis direction along the second reversing path 252 to the third branch path 403, a position for guiding the paper P to the fourth branch path 404, and a second reversing path 252. The position is switched between a position guided in the direction along the line.

Next, the form of the bending portion will be described.
The first form of the bending portion is formed by a first branch path 401, a third branch path 403, and a second inversion path 252 between the first branch path 401 and the third branch path 403. When the intermediate unit 400 holds the upper end side of the paper P in the first branch path 401 and the lower end side of the paper P in the third branch path 403 by the second reverse roller pair 255 and the guide flaps 411 and 412. In FIG. 21, the C-shaped secondary curl with the −Z-axis direction as the upper side occurring as the paper P is dried can be suppressed.

  The second form of the bending portion is formed by the second branch path 402, the fourth branch path 404, and the second inversion path 252 between the second branch path 402 and the fourth branch path 404. When the intermediate unit 400 holds the upper end side of the paper P in the second branch path 402 and the lower end side of the paper P in the fourth branch path 404 by the second reverse roller pair 255 and the guide flaps 411 and 412. In FIG. 21, it is possible to suppress the reverse C-shaped secondary curl with the −Z-axis direction facing upward as the paper P is dried.

  The third form of the bending portion is formed by a first branch path 401, a fourth branch path 404, and a second inversion path 252 between the first branch path 401 and the fourth branch path 404. When the intermediate unit 400 holds the upper end side of the paper P in the first branch path 401 and the lower end side of the paper P in the fourth branch path 404 by the second reverse roller pair 255 and the guide flaps 411 and 412. In FIG. 21, it is possible to suppress the S-shaped secondary curl with the −Z-axis direction as the upper side occurring as the paper P is dried.

  The fourth form of the bending portion is formed by the second branch path 402, the third branch path 403, and the second inversion path 252 between the second branch path 402 and the third branch path 403. When the intermediate unit 400 holds the upper end side of the paper P in the second branch path 402 and the lower end side of the paper P in the third branch path 403 by the second reverse roller pair 255 and the guide flaps 411 and 412. In FIG. 21, it is possible to suppress the reverse S-shaped secondary curl with the −Z-axis direction facing upward as the paper P is dried.

As described above, according to the intermediate unit 400 according to the present modification, the following effects can be obtained in addition to the effects of the first embodiment.
The intermediate unit 400 includes spiral first to fourth branch paths 401, 402, 403, and 404. Since the paper P is decurled by the curved portion including any of the spiral first to fourth branch paths 401, 402, 403, 404, the effect of suppressing the secondary curl generated on the paper P is improved. .

(Modification 2)
FIG. 22 is a diagram for explaining a main part of the intermediate unit according to the second modification. The intermediate unit 500 of this modification has a different shape from the bending portion described in the first embodiment. The intermediate unit 500 of this modification will be described with reference to FIG. In addition, the curved part of this modification is demonstrated as what is provided in the 2nd switchback mechanism 250 in Embodiment 1. FIG. Moreover, about the same component as Embodiment 1, the same number is attached | subjected and the overlapping description is abbreviate | omitted.

  The second reversal path 552 extends along the −Z axis direction from the second connection point C where the downstream end of the second inlet path 251 and the upstream end of the second outlet path 253 are connected, and then draws an arc. Extending in the + Y-axis direction. The second inversion path 552 includes an upstream inversion path 552a extending along the −Z axis direction, and a downstream inversion path 552b extending in the + Y axis direction while drawing an arc.

The downstream inversion path 552b includes a lifting device (not shown) that moves up and down in the Z-axis direction. Further, the upstream inversion path 552a is configured such that the length in the Z-axis direction expands and contracts as the downstream inversion path 552b moves up and down.
The second inversion path 552 forms a second switchback path 558 together with the second inlet path 251 and the second outlet path 253.

  The second bending portion 559 is included in the second switchback path 558 and is formed by the second inversion path 552 and the second outlet path 253. Since the intermediate unit 500 moves up and down the downstream inversion path 552b, the size of the second curved portion 559 changes, so that the paper P having a different paper size can be decurled. In addition, since the decurling position (the arc portion that bends from the −Z-axis direction to the + Y-axis direction) is arbitrarily determined, the decurling can be accurately performed at a place where decurling is necessary.

As described above, according to the intermediate unit 500 according to the present modification, the following effects can be obtained in addition to the effects of the first embodiment.
Since the intermediate unit 500 includes the extendable second bending portion 559, it is possible to decur the sheets P having different paper sizes with the same bending portion (second bending portion 559). Accordingly, it is not necessary to provide a curved portion for each paper size, so that the intermediate unit 500 can be reduced in size.

(Modification 3)
FIG. 23 is a diagram for explaining a main part of an intermediate unit according to Modification 3. The intermediate unit 600 of this modification has a different shape from the curved portion described in the first embodiment. An intermediate unit 600 of this modification will be described with reference to FIG. In addition, the curved part of this modification is demonstrated as what is provided in the 2nd switchback mechanism 250 in Embodiment 1. FIG. Moreover, about the same component as Embodiment 1, the same number is attached | subjected and the overlapping description is abbreviate | omitted.

The second reversing path 252 includes a reversing guide 252a that guides one side (side on the −X axis side) along the transport direction of the paper P, and a reversing guide 252b that guides the other side (side on the + X axis side). have.
The second switchback mechanism 250 includes a first branch guide 601a, a second branch guide 602a, and a reverse guide 252b that branch from the branch point Ha of the reverse guide 252a on the downstream side (−Z axis side) of the second reverse roller pair 255. The first branch guide 601b and the second branch guide 602b branch from the branch point Hb. Further, the second switchback mechanism 250 has a third branch guide 603a, a fourth branch guide 604a, and a reverse guide that branch from the branch point Ga of the reverse guide 252a on the upstream side (+ Z axis side) of the second reverse roller pair 255. A third branch guide 603b and a fourth branch guide 604b branch from the branch point Gb of 252b are included.

The first branch guide 601a branches off from the branch point Ha, and extends in an arc shape from the −Z axis direction to the −Y axis direction. The first branch guide 601b branches from the branch point Hb and extends in an arc shape from the −Z axis direction to the −Y axis direction.
The second branch guide 602a branches from the branch point Ha and extends in an arc shape from the −Z axis direction to the + Y axis direction. The second branch guide 602b branches from the branch point Hb and extends in an arc shape from the −Z axis direction to the + Y axis direction.

The third branch guide 603a branches from the branch point Ga and extends in an arc shape from the + Z-axis direction to the -Y-axis direction. The third branch guide 603b branches from the branch point Gb and extends in an arc shape from the + Z-axis direction to the -Y-axis direction.
The fourth branch guide 604a branches from the branch point Ga and extends in an arc shape from the + Z-axis direction toward the + Y-axis direction. The fourth branch guide 604b branches from the branch point Gb and extends in an arc shape from the + Z axis direction to the + Y axis direction.

  In addition, a flat plate 611 that covers the sheet P conveyed on the second inversion path 252 from the front and back sides is provided in a rectangular range having the vertices at the branch points Ha, Hb, Ga, and Gb.

  A guide flap (not shown) is provided at the branch point Ha. The guide flap guides one long side (long side in the + X axis direction) of the sheet P conveyed in the −Z axis direction to the first branch guide 601a through the second inversion path 252 and the second branch guide 602a. The position is switched between a position to be guided to the position and a position to be guided in a direction along the reversing guide 252a. Further, the guide flap guides one long side of the sheet P conveyed in the + Z-axis direction in the direction along the reversing guide 252a along the second reversing path 252.

  A guide flap (not shown) is provided at the branch point Hb. The guide flap guides the other long side (long side in the −X axis direction) of the sheet P conveyed in the −Z axis direction to the first branch guide 601b through the second inversion path 252 and the second branch guide. The position is switched between the position for guiding to 602b and the position for guiding in the direction along the reversing guide 252b. Further, the guide flap guides the other long side of the sheet P conveyed in the + Z-axis direction in the direction along the reversing guide 252b along the second reversing path 252.

  A guide flap (not shown) is provided at the branch point Ga. The guide flap guides one long side (long side in the + X-axis direction) of the sheet P conveyed in the −Z-axis direction in the direction along the reversal guide 252a through the second inversion path 252. Further, the guide flap reverses the position where one long side of the paper P conveyed in the + Z-axis direction along the second reversing path 252 is guided to the third branch guide 603a, the position where the long side is guided to the fourth branch guide 604a, The position is switched between a position that is guided in a direction along the guide 252a.

  A guide flap (not shown) is provided at the branch point Gb. The guide flap guides the other long side (long side in the −X axis direction) of the sheet P conveyed in the −Z axis direction along the second inversion path 252 in the direction along the reverse guide 252b. Further, the guide flap reverses the position where the other long side of the sheet P conveyed in the + Z-axis direction along the second reversing path 252 is guided to the third branch guide 603b, the position where the other long side is guided to the fourth branch guide 604b, The position is switched between a position that is guided in a direction along the guide 252b.

Next, the predetermined area when obtaining the print duty in Modification 3 will be described.
FIG. 24A is a front view illustrating a predetermined area of a sheet. FIG. 24B is a rear view illustrating a predetermined area of the sheet. In the double-side printed paper P, the first printed surface is a back surface PB, and the later printed surface is a front surface PF. As shown in FIGS. 24A and 24B, on the front surface PF and the back surface PB of the paper P, there is a print area PE on which ink is actually ejected in order to print an image or characters, and ink along the outer periphery of the print area PE. A blank area PW having the same width as a non-printing area where no ink is discharged is provided.

  In the present modification, the rectangular paper P has nine regions each having a long side and a short side divided into three equal parts. Each region is defined as regions R11 to R33 by a combination of a matrix of 1 to 3 rows from the upper end to the lower end and 1 to 3 columns from the left to the right on the front surface PF of the paper P shown in FIG. 24A. Each of the areas R11 to R33 is a predetermined area for obtaining the print duty. Note that the numerical value (%) shown in the drawing indicates the print duty in the predetermined area. Although the predetermined area has been described as corresponding to the areas R11 to R33, a plurality of areas in contact with each other may be set as the predetermined area.

Next, as an example, the form of a curved portion for decurling the paper P having the print duty shown in FIGS. 24A and 24B will be described.
The print duty on the front surface PF side of the paper P is a predetermined area R11: 80%, a predetermined area R13: 25%, a predetermined area R31: 25%, a predetermined area R33: 80%, and other predetermined areas: 50%.
The print duty on the back PB side of the paper P is a predetermined area R11: 25%, a predetermined area R13: 80%, a predetermined area R31: 80%, a predetermined area R33: 25%, and other predetermined areas: 50%.
Accordingly, the paper P has a secondary curl in which the predetermined region R11 and the predetermined region R33 are curled toward the front surface PF, and the predetermined region R13 and the predetermined region R31 are curled toward the back surface PB.

  The curved portion for decurling the paper P shown in FIGS. 24A and 24B includes a first branch guide 601b, a second branch guide 602a, a third branch guide 603a, a fourth branch guide 604b, and a first branch. A reversing guide 252b between the guide 601b and the fourth branch guide 604b and a reversing guide 252a between the second branch guide 602a and the third branch guide 603a are formed. The intermediate unit 600 can suppress the secondary curl caused by the drying of the paper P illustrated in FIGS. 24A and 24B, for example, by holding the paper P in the curved portion.

As described above, according to the intermediate unit 600 according to the present modification, the following effects can be obtained in addition to the effects of the first embodiment.
The intermediate unit 600 includes the first to fourth branch guides 601a, 601b, 602a, 602b, 603a, 603b, 604a, and 604b according to the print duty difference in each of the predetermined areas R11, R13, R31, and R33 of the paper P. The curved portion formed including at least one of the two is selected, and the secondary curl of the paper P is decurled. As a result, the intermediate unit 600 of this modification can individually decur secondary curls that occur at the four corners (predetermined regions R11, R13, R31, R33) of the paper P.

(Modification 4)
FIG. 25 is a diagram for explaining a main part of the intermediate unit according to the fourth modification. FIG. 26 is a partially enlarged perspective view of the branch path. The intermediate unit 700 of this modification has a different shape from the branch path described in Modification 3. An intermediate unit 700 according to this modification will be described with reference to FIGS. 25 and 26. FIG. In addition, about the component same as the modification 3, the same number is attached | subjected and the overlapping description is abbreviate | omitted.

  The second reversing path 252 is provided with an exposed portion 752 that exposes the paper P conveyed on the second reversing path 252 on the upstream side of the second reversing roller pair 255.

  The second switchback mechanism 250 includes a first branch guide 701a, a second branch guide 702a, and a reverse guide that branch from a branch point Ha of the reverse guide 252a on the downstream side (−Z axis side) of the second reverse roller pair 255. The first branch guide 701b and the second branch guide 702b branch from the branch point Hb of 252b are included. Further, the second switchback mechanism 250 includes a third branch guide 703a, a fourth branch guide 704a, and a reversal branching from a branch point Ga of the reversal guide 252a on the upstream side (+ Z axis side) of the second reversing roller pair 255. A third branch guide 703b and a fourth branch guide 704b branch from the branch point Gb of the guide 252b are included.

  FIG. 26 is a diagram illustrating the shapes of the first branch guide 701b and the second branch guide 702b. As shown in FIGS. 25 and 26, the first branch guide 701b is a spiral that branches from the branch point Hb in the −Y axis direction and gradually decreases in curvature counterclockwise in plan view from the −X axis direction. It is a circular cylinder. The second branch guide 702b is a cylindrical column that branches in the + Y-axis direction from the branch point Hb and has a spiral shape that gradually decreases in curvature in a plan view from the -X-axis direction. The first branch guide 701b and the second branch guide 702b are integrally formed, and are provided at a position overlapping the corner on the + X axis side at the upper end of the paper P (on the −Z axis side in FIG. 25). The cylinder axes of the first branch guide 701b and the second branch guide 702b are inclined by approximately 45 ° with respect to the long side and the short side forming the corner of the paper P.

  The first branch guide 701a is a cylindrical column that branches in the −Y-axis direction from the branch point Ha and has a spiral shape in which the curvature gradually decreases counterclockwise in plan view from the −X-axis direction. The second branch guide 702a is a spiral cylinder that branches from the branch point Ha in the + Y-axis direction and gradually decreases in curvature clockwise in a plan view from the −X-axis direction. The first branch guide 701a and the second branch guide 702a are integrally formed and provided at a position overlapping the corner on the −X axis side at the upper end of the paper P. The cylindrical axes of the first branch guide 701a and the second branch guide 702a are inclined by approximately 45 ° with respect to the long side and the short side forming the corner of the paper P.

The third branch guide 703a and the fourth branch guide 704a have a moving mechanism (not shown) that moves toward the reverse guide 252a in the exposed portion 752, and are detachably provided on the reverse guide 252a.
The third branch guide 703a is a spiral shape that branches in the −Y-axis direction from the branch point Ga when mounted on the reversing guide 252a and gradually decreases in curvature clockwise in plan view from the −X-axis direction. It is a cylinder that made. The fourth branch guide 704a is a spiral cylinder that branches in the + Y-axis direction from the branch point Ga and has a gradually decreasing curvature counterclockwise in plan view from the -X-axis direction. The third branch guide 703a and the fourth branch guide 704a are integrally formed, and are provided at a position overlapping the corner on the −X axis side at the lower end (+ Z axis side in FIG. 25) of the paper P. The cylindrical axes of the third branch guide 703a and the fourth branch guide 704a are inclined by approximately 45 ° with respect to the long side and the short side forming the corner of the paper P. The third branch guide 703a and the fourth branch guide 704a are attached to and detached from the reversing guide 252a by moving a plane formed by the X axis and the Z axis in a direction intersecting the cylinder axis.

The third branch guide 703b and the fourth branch guide 704b have a moving mechanism (not shown) that moves toward the reverse guide 252b in the exposed portion 752, and are detachably provided on the reverse guide 252b.
The third branch guide 703b is a spiral shape that branches in the −Y-axis direction from the branch point Gb when mounted on the reversing guide 252b and gradually decreases in curvature clockwise in plan view from the −X-axis direction. It is a cylinder that made. The fourth branch guide 704b is a spiral cylinder that branches from the branch point Gb in the + Y-axis direction and gradually decreases in curvature counterclockwise in plan view from the −X-axis direction. The third branch guide 703b and the fourth branch guide 704b are integrally formed and provided at a position overlapping the corner on the + X axis side at the lower end of the paper P. The cylinder axes of the third branch guide 703b and the fourth branch guide 704b are inclined by approximately 45 ° with respect to the long side and the short side forming the corner of the paper P. The third branch guide 703b and the fourth branch guide 704b are attached to and detached from the reversing guide 252b by moving a plane formed by the X axis and the Z axis in a direction intersecting the cylinder axis.

  A guide flap (not shown) is provided at the branch point Ha. The guide flaps guide the second X-axis side corner of the upper end of the sheet P conveyed in the -Z-axis direction along the second reversing path 252 to the first branch guide 701a and the position to guide the second branch guide 702a. And the position to be guided in the direction along the reversing guide 252a. The guide flaps guide the second reversing path 252 in the direction along the reversing guide 252a at the corner on the −X axis side at the upper end of the sheet P conveyed in the + Z-axis direction.

  A guide flap (not shown) is provided at the branch point Hb. The guide flaps guide the + X-axis side corner of the upper end of the sheet P conveyed in the −Z-axis direction through the second reversing path 252 to the first branch guide 701b and the position to guide the second branch guide 702b. And the position to be guided in the direction along the reversing guide 252b. Further, the guide flap guides the corner on the + X-axis side at the upper end of the sheet P conveyed in the + Z-axis direction in the direction along the reversing guide 252b through the second reversing path 252.

  A guide flap (not shown) is provided at the branch point Ga. In the paper P transported in the −Z-axis direction on the second reversing path 252, at least one of the two upper corners of the paper P is the first branch guide 701 a, 701 b and the second branch guide 702 a, 702 b. When the conveyance of the paper P is stopped by being guided by at least one of the above, the third and fourth branch guides 703a and 704a move toward the −X-axis side corner at the lower end of the paper P. At this time, the guide flap moves together with the third branch guide 703a and the fourth branch guide 704a, the position at which the −X-axis side corner at the lower end of the paper P is guided to the third branch guide 703a, and the fourth branch guide. The position is switched between a position for guiding to 704a and a position for guiding in the direction along the reversing guide 252a.

  A guide flap (not shown) is provided at the branch point Gb. In the paper P transported in the −Z-axis direction on the second reversing path 252, at least one of the two upper corners of the paper P is the first branch guide 701 a, 701 b and the second branch guide 702 a, 702 b. When the conveyance of the paper P is stopped by being guided by at least one of the above, the third and fourth branch guides 703b and 704b move toward the + X-axis side corner at the lower end of the paper P. At this time, the guide flap moves together with the third branch guide 703b and the fourth branch guide 704b, and guides the corner on the + X axis side at the lower end of the paper P to the third branch guide 703b and the fourth branch guide 704b. The position is switched between a position to be guided to and a position to be guided in a direction along the reversing guide 252b.

  For example, the curved portion for decurling the paper P shown in FIGS. 24A and 24B includes a first branch guide 701b, a second branch guide 702a, a third branch guide 703a, a fourth branch guide 704b, A reversing guide 252b between the first branching guide 701b and the fourth branching guide 704b and a reversing guide 252a between the second branching guide 702a and the third branching guide 703a are formed. The intermediate unit 700 can suppress, for example, secondary curl caused by the drying of the paper P illustrated in FIGS. 24A and 24B by holding the paper P in the curved portion.

As described above, according to the intermediate unit 700 according to the present modification, in addition to the effects of Modification 3, the following effects can be obtained.
The intermediate unit 700 includes the first to fourth branch guides 701a, 701b, 702a, 702b, 703a, 703b, 704a, and 704b according to the print duty differences in the predetermined areas R11, R13, R31, and R33 of the paper P. The curved portion formed including at least one of the two is selected, and the secondary curl of the paper P is decurled. As a result, the intermediate unit 700 of this modification can individually decur secondary curls that occur at the four corners (predetermined regions R11, R13, R31, R33) of the paper P.
The intermediate unit 700 decals the sheet P with a curved portion formed including at least one of the spiral first to fourth branch guides 701a, 701b, 702a, 702b, 703a, 703b, 704a, and 704b. Therefore, the effect of suppressing the secondary curl generated on the paper P is improved.

  DESCRIPTION OF SYMBOLS 10 ... Printing apparatus, 11 ... Printing unit, 12 ... Printer part, 13 ... Scanner part, 14 ... Automatic paper feeder, 17 ... Operation part, 18 ... Post-processing apparatus, 20 ... Medium conveyance path, 21 ... Conveyance part, 23 ... Recording unit, 62 ... Communication path, 63 ... Communication conveying roller pair, 64 ... Switching flap, 65 ... Control unit, 71 ... Input device, 72 ... Interface unit, 73 ... CPU, 74 ... Storage unit, 75 ... Unit control circuit 76 ... detector group, 100 ... post-processing unit, 122 ... post-processing paper feed port, 123 ... post-processing paper discharge port, 124 ... punching unit, 125 ... staple unit, 127 ... transport roller, 128 ... processing tray, 129 ... Discharge roller 131 ... Stacking tray 200,300,400,500,600,700 ... Intermediate unit 201 ... Intermediate paper feed port 202 ... Intermediate paper discharge port 210 ... Intermediate 211, introduction path, 218 ... lead-out path, 221 ... intermediate transport roller pair, 222 ... introduction sensor, 223, 347, 349, 357, 359, 411, 412 ... guide flap, 240, 340 ... first switchback Mechanism, 241 ... first inlet path, 242 ... first reverse path, 243 ... first outlet path, 244 ... first reverse sensor, 245 ... first reverse roller pair, 246 ... first outlet sensor, 247 ... first regulation Flap, 248 ... first switchback path, 249,361 ... first bending portion, 250,350 ... second switchback mechanism, 251 ... second inlet path, 252,552 ... second reversing path, 252a, 252b ... reversing Guide, 253 ... second outlet path, 254 ... second reversing sensor, 255 ... second reversing roller pair, 256 ... second outlet sensor, 2 7 ... 2nd regulation flap, 258, 558 ... 2nd switchback path, 259, 362, 559 ... 2nd bending part, 341, 401 ... 1st branch path, 342, 402 ... 2nd branch path, 346 ... 1st Branch sensor, 351, 403 ... third branch path, 352, 404 ... fourth branch path, 356 ... third branch sensor, 363 ... third curved part, 364 ... fourth curved part, 371 ... fifth curved part, 372 ... sixth bending part, 373 ... seventh bending part, 374 ... eighth bending part, 552a ... upstream inversion path, 552b ... downstream inversion path, 601a, 601b, 701a, 701b ... first branch guide, 602a, 602b , 702a, 702b ... second branch guide, 603a, 603b, 703a, 703b ... third branch guide, 604a, 604b, 704a, 704b ... fourth branch guide, P ... paper, PB ... back surface, PF ... front surface, R, R1, R3, R11, R13, R31, R33 ... predetermined areas.

Claims (11)

An intermediate unit for transporting the medium from a paper feed port into which a medium printed by the printing unit is carried to a paper discharge port to be discharged to a post-processing unit that performs post-processing of the medium;
Comprising at least one curved portion that curves the medium in a direction opposite to a direction of curling that occurs when the medium is dried;
The intermediate unit, wherein the bending unit that passes through the medium is selected in accordance with a liquid volume ratio difference in a predetermined region of the medium in the printing unit. A switchback mechanism for reversing the front and back of the medium;
A plurality of the curved portions;
The intermediate unit according to claim 1, comprising: A plurality of the switchback mechanisms;
Each switchback mechanism is provided with the curved portion having a different shape,
The intermediate unit according to claim 2, wherein the bending portion through which the medium passes is selected by a switchback path constituting the switchback mechanism.   The intermediate unit according to any one of claims 1 to 3, wherein the medium is held in the curved portion. The switchback mechanism includes a plurality of curved portions having different shapes,
The intermediate unit according to any one of claims 2 to 4, further comprising: a branch portion that guides the medium to each of the curved portions.   The intermediate unit according to any one of claims 2 to 5, wherein the curved portion overlaps the switchback path.   The plurality of curved portions include at least two shapes of a C shape, an inverted C shape, an S shape, and an inverted S shape, according to any one of claims 2 to 6. The intermediate unit described. The curved portion corresponding to the size of the medium;
The intermediate unit according to any one of claims 1 to 7, wherein the curved portion that passes through the medium is selected according to the size and the liquid amount ratio difference. The intermediate unit according to any one of claims 1 to 8,
A post-processing unit for performing post-processing on the medium discharged from the intermediate unit;
And a post-processing device.   The post-processing apparatus according to claim 9, wherein the intermediate unit and the post-processing unit are configured in the same casing. A post-processing device according to claim 9 or claim 10,
A printing unit for printing on a medium and discharging the medium after printing to the post-processing device;
A printing apparatus.

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