JP2018008781A - Intermediate conveyance device, post-processing device, and printer - Google Patents

Abstract

An intermediate conveyance device that suppresses curling of a medium and can be smoothly conveyed is provided. An intermediate transport device includes a transport path, a transport unit that transports a medium along the transport path, and a convex part, and presses the convex part against the medium that transports the transport path. And a section. [Selection] Figure 12A

Description

  The present invention relates to an intermediate conveyance device, a post-processing device, and a printing device.

  2. Description of the Related Art Conventionally, there has been known a sheet conveying apparatus including a correcting unit that corrects curl of a sheet on which an image is formed by an electrophotographic image forming apparatus (see, for example, Patent Document 1).

JP 2002-321860 A

  However, the sheet conveying apparatus has a problem that the curl of the sheet on which the image is formed by the ink jet printer cannot be corrected. That is, when an image is formed using an inkjet printer, the sheet on which the image is formed curls (primary curl) when ink (moisture) is absorbed, and then the absorbed ink is dried. A curl different from the primary curl (secondary curl) occurs. Accordingly, the curling behavior of the sheet on which the image is formed by the ink jet printer is completely different from the case where the image is formed by the electrophotographic image forming apparatus. It cannot be suppressed.

  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 An intermediate transport apparatus according to this application example includes a transport path, a transport unit that transports a medium along the transport path, and a convex portion, and the medium transports the transport path. And a pressing portion that presses the convex portion.

For example, when a medium on which an image is formed is transported using an ink jet printer, the medium may curl as ink (moisture) is absorbed or the ink is dried, and the medium may be jammed (jammed) in the transport path or the like. is there.
So, according to the said structure, it presses with a convex part with respect to the medium conveyed. If it does so, for example, when a convex part is pressed against one side of the medium, the interval between the celluloses constituting the medium on the one side is reduced. On the other hand, the interval of the cellulose on the other surface side where the convex portion is not pressed is extended (widened). The one side pressed by the convex part is in a state where the interval between the celluloses is reduced, so that the bonding between the celluloses is accelerated compared to the other side, and the interval between the celluloses is extended and the state is maintained on the other side. While cellulose is bonded.
Therefore, by pressing the medium with the convex part, it becomes possible to make the bonding state of the cellulose different on one side and the other side of the medium, and curling (particularly secondary curling) can be suppressed.

  Application Example 2 In the intermediate transfer device according to the application example, the pressing unit includes a plurality of the convex portions, and the distance from a common reference to the top of each convex portion is equal. .

  According to this configuration, the convex portion can be uniformly pressed against the medium.

  Application Example 3 In the intermediate conveyance device according to the application example described above, when the difference between the print duty on one side of the medium and the print duty on the other side is equal to or greater than a predetermined value, The convex portion is pressed against the surface with the lower print duty.

When the difference between the print duty on one side of the medium and the print duty on the other side is equal to or greater than a predetermined value, curl (especially secondary curl) tends to occur. Specifically, when the surface with the higher print duty is placed on the opposite side in the direction of gravity, the primary curl has a surface with the higher print duty appearing concave in the direction of gravity. Thereafter, as the ink in the medium dries, secondary curl appears. In the secondary curl, the surface with the higher print duty is convex with respect to the direction of gravity (the direction opposite to the direction of the primary curl).
Therefore, the convex portion is pressed against the surface with the lower print duty (the surface opposite to the surface with the higher print duty). If it does so, the space | interval of the cellulose of the surface side with a lower printing duty will be in the state shrunk | reduced, the coupling | bonding between cellulose will be accelerated | stimulated, and the surface with the lower printing duty will be kept flat. On the other hand, the interval between the celluloses on the surface side with the higher printing duty is in a uniformly extended state, and the bonding between the celluloses starts while maintaining a constant interval. That is, on the side of the surface with the higher print duty, free bonds between celluloses are restricted. Accordingly, curling (particularly secondary curling) can be easily suppressed.
Note that “duty” is duty (%) = number of actual recording dots / (vertical resolution × horizontal resolution) × 100 (where “actual recording dot number” is the actual number of recording dots per unit area. "Vertical resolution" and "Horizontal resolution" are resolutions per unit area, respectively).

  Application Example 4 The pressing portion of the intermediate conveyance device according to the application example includes a roller, and the convex portion is formed on the surface of the roller.

  According to this structure, a convex part can be easily pressed with respect to a medium by rotating a roller.

  Application Example 5 The pressing unit of the intermediate conveyance device according to the application example includes a first roller and a second roller having a hardness higher than that of the first roller, and the convex surface is provided on the surface of the second roller. A portion is provided, and the medium is sandwiched between the first roller and the second roller.

  According to this configuration, when the medium is sandwiched between the first roller and the second roller, the convex portion provided on the second roller is pushed into the first roller side. Therefore, the convex portion can be easily pressed against the medium.

  Application Example 6 In the intermediate conveyance device according to the application example, the convex portion has a curved surface.

  According to this configuration, the medium can be prevented from being damaged when the convex portion is pressed against the medium.

  Application Example 7 In the intermediate conveyance device according to the application example, two pairs of the pressing portions are provided, and one of the two pairs of pressing portions is pressed along the conveyance direction of the medium in the conveyance path. In the portion, the one surface of the medium and the second roller face each other, and in the other pressing portion, the other surface opposite to the one surface of the medium and the second roller face each other. It is characterized by that.

  According to this configuration, the two pairs of pressing portions (roller pairs) are arranged in a state of being offset from each other in the transport direction. Therefore, it is possible to efficiently press the one surface or the other surface of the medium with the convex portion against the medium that is transported along the transport path.

  Application Example 8 In the intermediate transfer device according to the application example, the first roller and the second roller can be separated from each other.

  According to this configuration, for example, the convex portion can be pressed only on one side of the medium, or the convex portion can be pressed only on the other side of the medium. Furthermore, the convex portion can be not pressed against the medium. That is, whether or not the convex portion is pressed can be selected in accordance with the curling state of the medium.

  Application Example 9 The transport path of the intermediate transport device according to the application example includes an introduction path in which the medium is introduced and a transport direction in which the medium introduced from the introduction path is transported. A first branch path and a second branch path that branch in different directions from a branch point that becomes a downstream end, a first inversion path in which the medium is inverted from the downstream end of the first branch path, and the second branch path A second reversing path in which the medium is reversed from the downstream end of the medium, a first merging path in which the medium reversed by the first reversing path is conveyed, and the medium reversed by the second reversing path is conveyed. A second merging path, a derivation path extending from a merging point where the downstream end of the first merging path and the downstream end of the second merging path merge, and the two pairs of pressing portions are the derivation Characterized by being placed in the route To.

  According to this configuration, the two pairs of pressing portions are arranged in a region where the medium is conveyed in common. That is, since it is not necessary to provide two pairs of pressing portions in each branch path, it is possible to save space and simplify the configuration of the intermediate transfer device.

  Application Example 10 The pressing portion of the intermediate conveyance device according to the application example includes a first roller and a second roller, and the convex portion is provided on each surface of the first roller and the second roller. Provided, wherein the medium is sandwiched between the first roller and the second roller.

  According to this configuration, by sandwiching the medium between the first roller and the second roller, both surfaces of the medium are pressed by the convex portions. Thereby, even when curling from both sides of the medium, that is, when the medium curls while twisting, curling can be effectively suppressed.

  Application Example 11 The post-processing apparatus according to this application example includes a transport path, a transport unit that transports a medium along the transport path, and a convex portion, and the medium that transports the transport path. A pressing unit that presses the convex part, a stacker that temporarily places the medium transported from the transport path, and a post-process that is performed on the medium that is placed on the stacker. And a processing unit.

  According to this configuration, by pressing the medium with the convex portion, the interval between the cellulose is uniformly extended and the cellulose is bonded while maintaining the state, thereby suppressing the bonding between the free cellulose and curling (particularly Secondary curl) can be suppressed. Then, the medium is placed on a stacker, and post-processing such as stapling is performed. Here, since the medium is placed on the stacker in a state where curling is suppressed, the medium can be aligned and post-processing can be reliably performed without causing a conveyance failure due to catching of the medium or the like.

  Application Example 12 A printing apparatus according to this application example includes an image forming apparatus that forms an image on a medium, a conveyance path, a conveyance unit that conveys the medium along the conveyance path, and a convex part. An intermediate conveyance device having a pressing portion that presses the convex portion against the medium that conveys the conveyance path, a stacker that temporarily places the medium conveyed from the conveyance path, and And a post-processing device that includes a post-processing unit that performs post-processing on the medium placed on the stacker.

  According to this configuration, the medium on which the image is formed by the image forming apparatus is transported to the post-processing apparatus via the intermediate transport apparatus. Here, in the intermediate conveyance device, by pressing the medium with the convex portion, the interval between the cellulose is uniformly extended and the cellulose is bonded while maintaining the state, so that the bonding between the free cellulose is suppressed and the curl is curled. (Especially secondary curl) can be suppressed. Then, the medium is placed on a stacker, and post-processing such as stapling is performed. When the medium is placed on the stacker, since the medium is in a curled state, the medium can be aligned and reliably post-processed without causing a conveyance failure due to the medium being caught. .

1 is a schematic diagram illustrating a configuration of a printing apparatus according to a first embodiment. 1 is a partial configuration diagram illustrating a configuration of an image forming apparatus according to a first embodiment. FIG. 3 is a configuration diagram illustrating a configuration of a cartridge mounting unit according to the first embodiment. FIG. 3 is a configuration diagram illustrating a configuration of a cartridge according to the first embodiment. Explanatory drawing which shows the state with which the cartridge was mounted | worn with respect to the cartridge mounting part concerning 1st Embodiment. 1 is a configuration diagram showing a configuration of an image forming apparatus according to a first embodiment. The block diagram which shows the structure of the intermediate conveyance apparatus concerning 1st Embodiment. FIG. 3 is a schematic diagram illustrating an operation method of the printing apparatus according to the first embodiment. FIG. 3 is a schematic diagram illustrating an operation method of the printing apparatus according to the first embodiment. FIG. 3 is a schematic diagram illustrating an operation method of the printing apparatus according to the first embodiment. FIG. 3 is a schematic diagram illustrating an operation method of the printing apparatus according to the first embodiment. Schematic which shows the structure of the pressing part concerning 1st Embodiment. Schematic which shows the structure of the pressing part concerning 1st Embodiment. Schematic which shows the structure of the pressing part concerning 1st Embodiment. FIG. 2 is a block diagram illustrating a partial configuration of a control unit of the printing apparatus according to the first embodiment. 3 is a flowchart illustrating a control method of the printing apparatus according to the first embodiment. The schematic diagram which shows the operation | movement method of the pressing part concerning 1st Embodiment. The schematic diagram which shows the operation | movement method of the pressing part concerning 1st Embodiment. The schematic diagram which shows the operation | movement method of the pressing part concerning 1st Embodiment. Schematic which shows the structure of the pressing part concerning 2nd Embodiment. Explanatory drawing which shows the arrangement | positioning method of the pressing part concerning 2nd Embodiment. Explanatory drawing which shows the arrangement | positioning method of the pressing part concerning 2nd Embodiment. Schematic which shows the structure of the pressing part concerning the modification 1. FIG. Schematic which shows the structure of the pressing part concerning the modification 1. FIG. An example of other forms of a pressing part concerning modification 2. An example of other forms of a pressing part concerning modification 2. An example of other forms of a pressing part concerning modification 2. An example of other forms of a pressing part concerning modification 2.

  Hereinafter, first and second 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.

(First embodiment)
First, the configuration of the printing apparatus will be described. FIG. 1 is a schematic diagram illustrating a configuration of a printing apparatus. As illustrated in FIG. 1, the printing apparatus 1 according to the present embodiment includes an image forming apparatus 100, an intermediate conveyance device 200, and a post-processing device 300. In addition, a control unit 10 (see FIG. 10) that comprehensively controls driving of each mechanism in the printing apparatus 1 is provided. The image forming apparatus 100 is an apparatus that forms an image on a sheet M as a medium, for example. The post-processing apparatus 300 is an apparatus that performs post-processing such as a stapler process that binds a plurality of sheets M on which images are formed with staples (needles). The intermediate conveyance device 200 is a device that reverses the sheet M on which the image is formed by the image forming apparatus 100 and conveys the sheet M to the post-processing apparatus 300. The intermediate conveyance device 200 is disposed between the image forming apparatus 100 and the post-processing device 300.

  In the printing apparatus 1 of the present embodiment, the third discharge path 153 serving as the upstream conveyance path of the image forming apparatus 100 is connected to the intermediate conveyance path 218 (conveyance path) of the intermediate conveyance apparatus 200, and the intermediate conveyance path 218 is connected to the rear. It is connected to the downstream conveyance path 319 of the processing apparatus 300. Then, the post-processing device from the image forming apparatus 100 on the upstream side in the conveyance direction of the sheet M via the intermediate conveyance device 200 by the upstream conveyance route 153, the intermediate conveyance route 218, and the downstream conveyance route 319. A conveyance path (two-dot chain line in FIG. 1) extending to 300 is configured.

  As shown in FIG. 1, the image forming apparatus 100 is an ink jet printer that records images such as characters, figures, and photographs by attaching ink as an example of liquid to a sheet M as an example of a medium. The recording apparatus side housing 101 has a substantially rectangular parallelepiped shape. An operation unit 102 for performing various operations of the image forming apparatus 100 is attached to the upper part of the recording apparatus side housing 101.

  A rectangular opening / closing cover 105 is provided below the operation unit 102. The opening / closing cover 105 is provided so as to be rotatable with the long side of the lower end of the opening / closing cover 105 as a base end, and an open position where the tip side opposite to the base end is separated from the image forming apparatus 100 and a recording apparatus side housing. It is configured to be rotatable between two positions including a closed position that constitutes a part of the body 101.

2 is a partial configuration diagram illustrating the configuration of the image forming apparatus, FIG. 3 is a configuration diagram illustrating the configuration of the cartridge mounting unit, FIG. 4 is a configuration diagram illustrating the configuration of the cartridge, and FIG. It is explanatory drawing which shows the state in which the cartridge was mounted | worn with respect to the part. FIG. 6 is a configuration diagram showing the configuration of the image forming apparatus.
As shown in FIGS. 1 and 2, a cartridge mounting unit 1006 is disposed at the back (Y-axis direction) of the opening / closing cover 105 on the image forming apparatus 100 side. The cartridge 1004 is individually detachably mounted on the cartridge mounting portion 1006.

  A plurality of cartridges 1004 are detachably mounted on the cartridge mounting portion 1006. In the present embodiment, four types of cartridges 1004 (1004A (black), 1004B (black), 1004C (yellow), 1004D (magenta)), 1004E (corresponding to four colors (black, yellow, magenta, cyan)) are used. Cyan)) is mounted on the cartridge mounting portion 1006. In this embodiment, two cartridges 1004A and 1004B corresponding to black are mounted. Therefore, in this embodiment, a total of five cartridges 1004 are mounted on the cartridge mounting portion 1006 (see FIG. 5).

  Then, by opening the opening / closing cover 105, an opening of the cartridge mounting portion 1006 appears, and the cartridge 1004 can be attached and detached. In this embodiment, since the amount of black ink used is large, the cartridge 1004 containing black ink is made thicker (thickness in the X-axis direction) than the cartridge 1004 containing ink of other colors. Increased capacity. In the following description, the cartridges 1004A, 1004B, 1004C, 1004D, and 1004E are referred to as cartridges 1004A, 1004D, and 1004E, respectively.

  When the cartridge 1004 is mounted on the cartridge mounting portion 1006, ink can be supplied to the recording head 111 (see FIG. 6) via a tube (not shown). In the present embodiment, ink is supplied by sucking ink in the cartridge 1004 by a pump mechanism (not shown) of the image forming apparatus 100. An ink suction tube is provided for each type of ink. Here, a state where the cartridge 1004 is mounted on the cartridge mounting unit 1006 is also referred to as a “mounted state”.

  Next, a detailed configuration of the cartridge mounting unit 1006 will be described. As shown in FIG. 3, the cartridge mounting portion 1006 includes an attachment mechanism portion 1008 and a plate 1602, and is an assembly product in which both members are covered with a cover member 1604. In a state where the cartridge mounting unit 1006 is incorporated in the image forming apparatus 100, the mounting mechanism unit 1008 is positioned on the back side in the Y-axis direction of the recording apparatus-side housing 101, and the plate 1602 is located in front of the mounting mechanism unit 1008 in the Y-axis direction. Side (opening / closing cover 105 side). The plate 1602 and the cover member 1604 define a cartridge housing chamber 1061. The cartridge storage chamber 1061 has a rectangular shape, and a cartridge mounting opening 1068 into which the cartridge 1004 can be inserted and discharged is provided on the side facing the mounting mechanism 1008.

  The plate 1602 has slots 1061A to 1061E for mounting the respective cartridges 1004. The slots 1061A to 1061E extend from the mounting mechanism unit 1008 side to the cartridge mounting port 1068 and guide the mounted cartridge 1004 from the cartridge mounting port 1068 side to the mounting mechanism unit 1008 side.

  The mounting mechanism unit 1008 includes an air inlet 1069, a mounting engagement ratchet 1075, a contact mechanism 1080, a first mounting bar 1082, a second mounting bar 1084, a distribution unit 1640, and an ink introduction pipe 1643. It is provided for each of the slots 1061A to 1061E, and the air first sub inlet 1070 and the air second sub inlet 1071 are provided only for the slots 1061A and 1061B. When an air injection tube 1957 (see FIG. 4) of the cartridge 1004 is inserted, the air injection port 1069 injects air into the cartridge 1004 through the air injection tube 1957. The mounting engagement ratchet 1075 engages with the cartridge 1004 at the end of mounting of the cartridge 1004, and prevents the cartridge 1004 from being inadvertently detached when the mounting is completed. The contact mechanism 1080 includes a contact terminal group, contacts the contact mechanism 1050 (see FIG. 4) on the cartridge 1004 side, and transmits various data such as ink color and remaining amount to the control unit 10.

  The first mounting bar 1082 and the second mounting bar 1084 are engaged with the cartridge 1004 at the end of the mounting of the cartridge 1004 to position the cartridge 1004 in the mounting completed state. The distribution unit 1640 is configured to surround an ink introduction tube 1643 for introducing ink into the image forming apparatus 100. The distribution unit 1640 receives the force applied from the cartridge 1004 at the end of the mounting of the cartridge 1004, and receives the ink supply port 1414 ( Assists the insertion of the ink introduction tube 1643 into (see FIG. 4). The air first sub-injection port 1070 and the air second sub-injection port 1071 are inserted into the air 100 sub-injection tube 1958 and the air second sub-injection tube 1959 of the cartridge 1004 to be described later. Air is injected or sucked into two air injection bags (not shown) in the cartridge 1004 through the sub injection pipes 1958 and 1959. Air injection / suction by the air injection port 1069, the air first sub-injection port 1070, and the air second sub-injection port 1071 is performed by an air pump (not shown) provided in the image forming apparatus 100.

  Next, the detailed configuration of the cartridge 1004 will be described. The image forming apparatus 100 according to the present embodiment uses the cartridge 1004 for each ink color, accommodates a large amount of black ink in the large-capacity cartridges 1004A and 1004B, and inks of other colors compared to the cartridges 1004A and 1004B. The cartridges 1004C to 1004E having a small capacity are accommodated. Hereinafter, the cartridge 1004A will be described as an example regarding the detailed configuration of the cartridge.

  As shown in FIG. 4, the cartridge 1004 </ b> A has a long shape extending from the mounting end mounted on the cartridge mounting unit 1006 of the image forming apparatus 100 along the mounting direction, that is, the Y-axis direction. The cartridge 1004A is configured by assembling the second case 1402 to the first case 1401, and the first case 1401 has a long shape extending along the mounting direction CS and has one end surface opened in the longitudinal direction. The inside of the opening is used as an ink containing portion (not shown). Even the second case 1402 has a long shape extending along the mounting direction CS, and is assembled to the first case 1401 so as to cover the opening of the first case 1401. Thereby, the ink storage part (not shown) inside the opening is sealed. In the cartridge 1004A, one end when both cases are assembled is a first wall 1042 that is a mounting end, a first wall 1042 that is forward of the mounting direction CS, and a second wall 1043 that extends on the upper surface of the cartridge toward the other end. A third wall 1044 extending on the lower surface of the cartridge toward the other end, a fourth wall 1045 that is a long surface of the second case 1402, a fifth wall 1046 that is a long surface of the first case 1401, and the other The sixth wall 1047 at the end surrounds the ink containing portion (not shown).

  The upper corner portion of the first wall 1042 is a concave portion 1041, and the cartridge 1004 A has a contact mechanism 1050, a first bar insertion hole 1422, an ink supply port 1414, and a first wall 1042 from the concave portion 1041 side. A bottomed first recess 1445, a bottomed second recess 1090, a second bar insertion hole 1424, and a ratchet engagement portion 1049 are provided. The contact mechanism 1050 includes a contact terminal group, contacts the contact mechanism 1080 (see FIG. 3) in the mounting mechanism unit 1008 of the cartridge mounting unit 1006, and transmits various data such as ink color and remaining amount to the control unit 10. . The first bar insertion hole 1422 and the second bar insertion hole 1424 enter the first mounting bar 1082 and the second mounting bar 1084 of the mounting mechanism unit 1008 at the end of mounting of the cartridge 1004A, and position the cartridge 1004A in the mounting completed state. Do. The ink supply port 1414 opens toward the front in the mounting direction CS, and the ink introduction pipe 1643 of the mounting mechanism unit 1008 is inserted at the end of mounting of the cartridge 1004A, and air is injected into the cartridge 1004 through the air injection pipe 1957. To supply ink.

  The bottomed first concave portion 1445 is formed to surround the ink supply port 1414, and receives the distribution unit 1640 (see FIG. 3) of the cartridge mounting portion 1006 at the end of mounting of the cartridge 1004A. The bottomed second recess 1090 surrounds the air injection tube 1957, the air first sub injection tube 1958, and the air second sub injection tube 1959. The air injection tube 1957 enters the air injection port 1069 of the mounting mechanism unit 1008 at the end of mounting of the cartridge 1004A, and injects air into the internal space of the cartridge 1004. The air first sub-injection tube 1958 and the air second sub-injection tube 1959 enter the air first sub-injection port 1070 and the air second sub-injection port 1071 of the mounting mechanism 1008 at the end of the mounting of the cartridge 1004A, and the air enters the cartridge 1004A. It injects and sucks into two air injection bags (not shown). Air injection / suction by the air injection tube 1957, the air first sub-injection tube 1958, and the air second sub-injection tube 1959 is performed by an air pump (not shown) provided in the image forming apparatus 100. The ratchet engaging portion 1049 is formed on the lower surface of the cartridge 1004A on the first wall 1042 side, and the mounting engagement ratchet 1075 of the mounting mechanism portion 1008 is engaged at the end of mounting of the cartridge 1004A, and the cartridge 1004 in the mounting completed state. Prevent inadvertent omission.

  Further, as shown in FIG. 5, the cartridge 1004 </ b> A is in an attitude in which the arrow mark M indicating the mounting direction CS is placed on the upper surfaces of the first case 1401 and the second case 1402, that is, the cartridge 1004 </ b> A is mounted on the image forming apparatus 100. It is provided on the upper surface in the vertical direction. The arrow mark M is formed so that the arrow outline rises in a convex shape, and is formed closer to the ink supply port 1414 than the center in the longitudinal direction of the cartridge 1004A. In this embodiment, the arrow mark M is the cartridge 1004A. Is formed on the mounting end side on the first wall 1042 side. The arrow mark M is formed in half in each of the first case 1401 and the second case 1402, and forms one mark (arrow) in the assembled state of the first case 1401 and the second case 1402. The user visually recognizes that the pointing direction is the mounting direction CS of the cartridge 1004A.

  As described above, the cartridge 1004 of the present embodiment is formed in an elongated shape, and can hold a large amount of ink while suppressing the height dimension. Thereby, the enlargement of the image forming apparatus 100 can be suppressed. Further, the cartridges 1004 can be smoothly mounted on the cartridge mounting portion 1006 by the slots 1061A to 1061E and the like provided in the cartridge mounting portion 1006.

  As shown in FIG. 1, the image forming apparatus 100 is provided with a sheet cassette 103 in the vertical direction Z from the center to the lower part of the image forming apparatus 100. In the present embodiment, four paper cassettes 103 are arranged in the vertical direction Z. Each sheet cassette 103 stores sheets M on which recording is performed by the image forming apparatus 100 in a stacked state. Each paper cassette 103 is formed with a grip portion 103a that can be gripped by the user. The paper cassette 103 is configured to be detachable from the recording apparatus side housing 101. Note that the sheets M stored in each sheet cassette 103 may be of different types or of the same type.

  A rectangular front plate cover 104 is provided above the uppermost sheet cassette 103 in the vertical direction Z. The front plate cover 104 is rotatably provided with a long side adjacent to the paper cassette 103 as a base end, and an open position where a front end side opposite to the base end is separated from the image forming apparatus 100 and a recording apparatus side housing. It is configured to be rotatable between two positions including a closed position that constitutes a part of the body 101.

  Further, as shown in FIG. 6, a discharge port 108 through which the sheet M is discharged is formed in a part of the recording apparatus side housing 101 on the intermediate transport apparatus 200 side. Further, below the discharge port 108, a discharge tray 109 extending from the recording apparatus side housing 101 to the intermediate transport apparatus 200 is provided so as to be attachable as necessary. That is, the sheet M discharged through the discharge port 108 is placed on the discharge tray 109. The paper discharge tray 109 is configured to be detachable from the recording apparatus side housing 101, and moves from the proximal end connected to the recording apparatus side housing 101 to the distal end opposite to the proximal end. It has an upward gradient (upward to the left in FIG. 6) inclined upward.

  As shown in FIG. 6, in a recording apparatus side housing 101 included in the image forming apparatus 100, a recording unit 110 that performs recording from the upper side in the vertical direction Z with respect to the sheet M, and an in-apparatus conveyance path 120. And a transport unit 130 for transporting along. The in-device transport path 120 is formed so that the paper M is transported with the direction intersecting the width direction as the transport direction when the direction along the front-rear direction Y is the width direction of the paper M.

  The recording unit 110 includes a line head type recording head 111 that can simultaneously eject ink over substantially the entire width direction of the paper M. The recording unit 110 forms an image on the paper M by causing ink ejected from the recording head 111 to adhere to a recording surface (surface on which an image is printed) facing the recording head 111 on the paper M.

  The conveyance unit 130 is disposed along the conveyance path 120 in the apparatus, and includes a plurality of conveyance roller pairs 131 that are driven by a conveyance drive motor (not shown), and a belt conveyance unit 132 that is provided directly below the recording unit 110. doing. That is, ink is ejected from the recording head 111 to the sheet M being conveyed by the belt conveying unit 132, and recording is performed.

  The belt conveyance unit 132 includes a driving roller 133 disposed upstream of the recording head 111 in the conveyance direction, a driven roller 134 disposed downstream of the recording head 111 in the conveyance direction, and each of these rollers 133. And an endless belt 135 hung on 134. When the driving roller 133 is driven and rotated, the belt 135 circulates, and the paper M is conveyed to the downstream side by the circulating belt 135. That is, the outer peripheral surface of the belt 135 functions as a support surface that supports the paper M on which recording is performed.

  The in-apparatus transport path 120 is branched into a supply path 140 through which the paper M is transported toward the recording unit 110, a discharge path 150 through which the paper M recorded and recorded by the recording unit 110 is transported. And a branch path 160 branched by the mechanism 147.

  The supply path 140 includes a first supply path 141, a second supply path 142, and a third supply path 143. In the first supply path 141, the sheet M inserted from the insertion port 141 b exposed by opening the cover 141 a provided on the right side surface of the recording apparatus side housing 101 is conveyed to the recording unit 110. That is, the paper M inserted from the insertion port 141 b is conveyed linearly toward the recording unit 110 by the rotational drive of the first drive roller pair 144.

  In the second supply path 142, in the vertical direction Z, the sheets M respectively accommodated in the sheet cassette 103 provided at the lower portion of the recording apparatus side housing 101 are conveyed to the recording unit 110. That is, the sheets M stored in the sheet cassette 103 in a stacked state are reversed in posture in the vertical direction Z after the uppermost sheet M is fed out by the pickup roller 142a and separated one by one by the separation roller pair 145. However, it is conveyed toward the recording unit 110 by the rotational drive of the second drive roller pair 146.

  In the third supply path 143, when performing double-sided printing in which images are recorded on both sides of the paper M, the paper M on which one side has been recorded by the recording unit 110 is conveyed again to the recording unit 110. That is, a branch path 160 that branches from the discharge path 150 is provided downstream of the recording unit 110 in the transport direction. That is, when performing duplex printing, the sheet M is conveyed to the branch path 160 by the operation of the branch mechanism 147 provided in the middle of the discharge path 150. Further, the branch path 160 is provided with a branch path roller pair 161 capable of both normal rotation and reverse rotation on the downstream side of the branch mechanism 147.

  At the time of duplex printing, the paper M on which one side is printed is once guided to the branch path 160 by the branch mechanism 147 and conveyed downstream in the branch path 160 by the branch path roller pair 161 rotating in the forward direction. Thereafter, the sheet M conveyed to the branch path 160 is reversely conveyed from the downstream side to the upstream side in the branch path 160 by the branch path roller pair 161 that rotates in the reverse direction. That is, the conveyance direction of the sheet M conveyed on the branch path 160 is reversed.

  The sheet M reversely conveyed from the branch path 160 is conveyed to the third supply path 143 and is conveyed toward the recording unit 110 by a plurality of conveyance roller pairs 131. By being conveyed through the third supply path 143, the sheet M is reversed so that the other side not printed faces the recording unit 110, and is conveyed toward the recording unit 110 by the rotational drive of the third drive roller pair 148. Is done. In other words, the third supply path 143 functions as a reverse transport path for transporting the paper M while reversing the posture of the paper M in the vertical direction Z.

  Among the supply paths 141, 142, and 143, the second supply path 142 and the third supply path 143 convey the sheet M toward the recording unit 110 while the posture of the sheet M is curved in the vertical direction Z. On the other hand, compared to the second supply path 142 and the third supply path 143, the first supply path 141 transports the sheet M toward the recording unit 110 without significantly curving the posture of the sheet M. .

  The sheet M conveyed through the supply paths 141, 142, and 143 is conveyed to the alignment roller pair 149 disposed upstream of the recording unit 110 in the conveyance direction, and then is transferred to the alignment roller pair 149 that has stopped rotating. Its tip hits. Then, the inclination of the sheet M with respect to the transport direction is corrected (skewed) according to the state in which the sheet M abuts against the alignment roller pair 149. Then, the sheet M whose inclination is corrected is aligned and conveyed to the recording unit 110 by the subsequent rotational driving of the alignment roller pair 149.

  The recording unit 110 performs recording on one side or both sides, and the paper M on which recording has been completed is transported by a transport roller pair 131 along a discharge path 150 that forms a downstream portion of the in-device transport path 120. The discharge path 150 is branched into a first discharge path 151, a second discharge path 152, and a third discharge path 153 at a position downstream of the position branched from the branch path 160. That is, the sheet M on which recording has been completed is transported through a common discharge path (upstream discharge path) 154 that constitutes an upstream portion of the discharge path 150, and then guided by a guide mechanism (switching) provided at the downstream end of the common discharge path 154. The guide part) 180 guides to any one of the first to third discharge paths 151, 152, and 153 constituting the downstream part of the discharge path 150.

  The first discharge path (upper discharge path) 151 is provided so as to extend upward of the recording apparatus side housing 101 and bend along the branch path 160. The sheet M conveyed through the first discharge path 151 is discharged from a discharge port 155 that opens at a part of the recording apparatus side housing 101 so as to be the end of the first discharge path 151. Then, the paper M discharged from the discharge port 155 falls downward in the vertical direction Z, and is discharged onto the mounting table 156 in a stacked state as indicated by a two-dot chain line in FIG. Note that the paper M is discharged from the discharge port 155 to the mounting table 156 in a posture in which the recording surface in single-sided printing faces downward in the vertical direction Z by the conveyance roller pairs 131 arranged at a plurality of locations in the discharge path 150. The

  The mounting table 156 has an upwardly inclined shape that rises upward in the vertical direction Z as it goes to the right in the left-right direction X, and the sheets M are mounted on the mounting table 156 in a stacked state. At this time, each sheet M placed on the placement table 156 moves to the left along the inclination of the placement table 156, and the vertical side wall 157 provided below the discharge port 155 of the recording apparatus side housing 101. Placed close to.

  The first discharge path 151 has a curved inversion path 151 a that reverses the front and back of the sheet M while the sheet M recorded by the recording unit 110 is conveyed to the discharge port 155. That is, the curve reversal path 151a is curved with the recording surface of the paper M recorded by the recording unit 110 facing inward, and from the state in which the recording surface of the paper M faces upward in the vertical direction Z in the vertical direction Z. The paper M is reversed so that it faces downward. Therefore, in the discharge path 150, the sheet M passes through the curved inversion path 151a and is discharged from the discharge port 155 in a state where the recording surface at the time of single-sided printing faces the mounting table 156.

  The second discharge path 152 branches below the first discharge path 151 in the vertical direction Z and extends linearly (horizontally) from the recording unit 110 toward the intermediate conveyance device 200. Therefore, the sheet M transported through the second discharge path 152 is not transported in a curved posture as in the first discharge path 151, and the posture is kept constant as when passing through the recording unit 110. It is conveyed linearly and discharged from the discharge port 108 toward the discharge tray 109. That is, the second discharge path 152 functions as a non-reverse discharge path for transporting the paper M toward the paper discharge tray 109 without reversing the posture of the paper M.

  The third discharge path 153 branches to the lower side in the vertical direction Z than the second discharge path 152 and extends obliquely downward in the vertical direction Z so as to go below the recording apparatus side housing 101. And the downstream end is connected to the intermediate conveyance path 218 which the intermediate conveyance apparatus 200 has. That is, the sheet M transported through the third discharge path 153 is discharged to the intermediate transport device 200.

  A part of the discharge path 150 and a part of the branch path 160 are attached to a drawer unit 170 provided in the recording apparatus side housing 101. The drawer unit 170 is configured to be detachable from the recording apparatus side housing 101.

  Here, the paper M that can be applied to the printing apparatus 1 is preferably one having hygroscopicity and flexibility. For example, plain paper such as electrophotographic copying paper, silica, alumina, polyvinyl alcohol (PVA), polyvinyl pyrrolidone ( Inkjet paper provided with a water-soluble ink absorbing layer containing PVP) or the like. Further, art paper, coated paper, cast paper, and the like used for general offset printing can be given as a type of absorbent recording medium having a relatively low penetration rate of water-soluble ink.

In the present embodiment, “paper M” generally refers to paper that is made of pulp (main component is cellulose) and is used for a printer or the like, and is defined by JIS-P-0001 No. 6139. Specific examples include high-quality paper, PPC copy paper, and non-coated printing paper. The paper M can also use what is marketed from each company, for example, various things, such as Xerox 4200 (made by Xerox), GeoCycle (made by Gerogia-Pacific), can be used. Moreover, it is preferable that the paper M has a basis weight of 60 to 120 g / m ² .

  Next, the ink composition used in the printing apparatus 1 (image forming apparatus 100) of the present embodiment will be described.

  The ink composition according to this embodiment preferably contains at least one compound selected from the group consisting of (A), (B), and (C) described later. In addition, the ink composition is preferably an aqueous ink composition in which the main solvent of the ink is water from the viewpoints of safety, handleability, and various performances (coloring property, back-through ability, ink reliability), 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 to enable long-term storage of the ink. From the viewpoint of ensuring appropriate physical properties (such as viscosity) of the ink and ensuring the stability and reliability of the ink, water is preferably contained in the ink composition in an amount of 60% by mass to 10% by mass.

  By defining the content of water contained in the ink composition within the above range, the amount of water absorbed by the cellulose in the paper M is less than that of the conventional ink composition, resulting in cockling and curling. The thought swelling of cellulose can be suppressed. Hereinafter, properties suitable for suppressing cockling or curling are also referred to as “cockling suitability” and “curl suitability”, respectively.

  When the water content is less than 10% by mass, the fixability to the recording medium (paper M) may be lowered. On the other hand, when the water content exceeds 60% by mass, like a conventional aqueous ink composition, when printing on a recording medium having an absorption layer of a paper support with poor ink absorbability, Curling is likely to occur.

  The viscosity of the ink in the temperature range of 10 ° C. to 40 ° C. is affected by the temperature characteristics of the colorant, humectant, solvent, etc. contained in the ink. Among these, the influence of the humectant is particularly great, and the viscosity at 10 ° C. is likely to increase and the viscosity at 40 ° C. is likely to decrease depending on the type, addition amount, and content ratio of the humectant. In the present specification, the fact that the difference in viscosity at 10 ° C. to 40 ° C. is smaller is described as being excellent in the viscosity characteristics depending on the temperature of the ink.

  The ink composition according to the present embodiment has the following (A), (B), and (B) from the viewpoint of maintaining an appropriate balance of curling, cockling suitability, back-through suitability, clogging suitability, and viscosity characteristics depending on ink temperature. It is preferable to include at least one compound selected from the group consisting of C). These compounds also act as humectants. Here, the compound (A) is at least one compound selected from the group consisting of glycerin, 1,2,6-hexanetriol, diethylene glycol, triethylene glycol, tetraethylene glycol, and dipropylene glycol, and (B) The compound of (C) is at least one compound selected from the group consisting of trimethylolpropane and trimethylolethane, and the compound of (C) is selected from the group consisting of betaines, sugars and ureas, and has a molecular weight of 100. At least one compound in the range of ~ 200.

The compound (A) is particularly effective for suppressing clogging and also has an effect for suppressing curling and cockling. However, the material is inferior in penetrability due to its excellent permeability to a recording medium. From the viewpoint of more effectively and reliably achieving the above effects, glycerin and triethylene glycol are preferred as the compound (A).
The compound (B) is particularly effective for suppressing clogging, and also has a penetration-inhibiting effect, and thus is a substance excellent in the back-through suitability. From the viewpoint of more effectively and reliably achieving these effects, trimethylolpropane is preferred as the compound (B).
Since the compounds (A) and (B) have a large viscosity difference at 10 ° C. to 40 ° C., the viscosity characteristics due to temperature are greatly affected as the content in the ink composition increases. The ink composition also has a large viscosity difference at 10 ° C to 40 ° C.

  The compound (C) is a substance particularly excellent in curling and cockling suitability. Further, this compound is a substance having excellent viscosity characteristics depending on temperature. Specific examples of the compound (C) include glycine betaine (molecular weight 117, also referred to as “trimethylglycine”), γ-butyrobetaine (145), homarin (137), trigonelline (137), carnitine (same 161), homoserine betaine (161), valine betaine (159), lysine betaine (188), ornithine betaine (176), alanine betaine (117), stachydrin (185) and glutamate betaine (189) Betaines that are N-trialkyl substitutes of amino acids such as glucose (180), mannose (180), fructose (180), ribose (150), xylose (150), arabinose (150) Galactose (180) and sorbitol (182) Sugars such as allyl urea (100), N, N-dimethylolurea (120), malonyl urea (128), carbamylurea (103), 1,1-diethylurea (116), n-butyl Examples include ureas (116), creatinine (113), and benzylurea (150). Moreover, the tendency for the viscosity difference in 10 to 40 degreeC to become large that the molecular weight is less than 100 becomes strong. On the other hand, when the molecular weight is 200 or more, the viscosity of the ink composition tends to increase with respect to the amount of the compound added to the ink composition. Therefore, the molecular weight of the compound (C) is preferably in the range of 100 to 200. In these, since the effect which suppresses curl is especially high, betaines and saccharides are preferable and betaines are more preferable. From the same viewpoint, as the betaines, glycine betaine is more preferable, and as the saccharide, sorbitol is more preferable. Among these, glycine betaine is particularly preferable. As the glycine betaine, for example, a commercially available product such as amino coat (manufactured by Asahi Kasei Chemicals Corporation) can be used.

These compounds are contained in the ink composition in a total amount of (A), (B) and (C) in an amount of 10% by mass to 40% by mass from the viewpoint of curling aptitude, cockling aptitude, back-through aptitude, and clogging aptitude. It is preferable that
Moreover, about those compounds, mass ratio of content is (A) :( B) :( C) = (1.0) :( 0.1) from a viewpoint of exhibiting the said effect by those compounds with sufficient balance. -1.0): (1.0-3.5) is preferable. When the mass ratio of the compound (B) to the compound selected from the group (A) (referred to as “compound of (A)” hereinafter the same) is larger than the above, curl suitability and cockling suitability are reduced. However, if it is decreased, the suitability for see-through is reduced. When the mass ratio of the compound (C) to the compound (A) is larger than the above, clogging suitability is lowered, and when it is reduced, curl suitability and cockling suitability are lowered.

  In addition, the ink composition according to the present embodiment is used for the purpose of preventing clogging in the vicinity of the nozzle of the inkjet head, appropriately controlling the permeability and bleeding of the ink to the recording medium, and imparting the drying property of the ink. It is preferable to contain a water-soluble organic solvent. From the above viewpoint, the water-soluble organic solvent preferably contains 1,2-alkanediol and / or glycol ether. Specific examples of 1,2-alkanediol include 1,2-octanediol, 1,2-hexanediol, 1,2-pentanediol, and 4-methyl-1,2-pentanediol. Specific examples of the glycol ether include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, ethylene glycol monomethyl ether acetate, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol mono-n-propyl ether. Ethylene glycol mono-iso-propyl ether, diethylene glycol mono-iso-propyl ether, ethylene glycol mono-n-butyl ether, ethylene glycol mono-t-butyl ether, diethylene glycol mono-t-butyl ether, triethylene glycol mono-n-butyl ether, 1-methyl-1-methoxybutanol, propylene Recall monomethyl ether, propylene glycol monoethyl ether, propylene glycol mono-t-butyl ether, propylene glycol mono-n-propyl ether, propylene glycol mono-iso-propyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, di Examples include propylene glycol mono-n-propyl ether and dipropylene glycol mono-iso-propyl ether. In addition to the above, 2-pyrrolidone, N-methyl-2-pyrrolidone and the like can also be used as the water-soluble organic solvent. These water-soluble organic solvents can be used singly or in combination of two or more, and 1 mass in the ink composition from the viewpoint of ensuring appropriate physical properties (such as viscosity) of the ink, ensuring print quality, and reliability. % To 50% by mass is preferable.

  Furthermore, the ink composition preferably contains a surface tension adjusting agent in order to control the wettability of the ink to the recording medium and to obtain the permeability to the recording medium and the printing stability in the ink jet recording method. As the surface tension adjusting agent, acetylene glycol surfactants and polyether-modified siloxanes are preferable. Examples of acetylene glycol-based surfactants include Surfynol 420, 440, 465, 485, 104, STG (above, Air Products, product name), Olfine PD-001, SPC, E1004, E1010 (above, day). Shinken Chemical Co., Ltd., product name), acetylenol E00, E40, E100, LH (above, Kawaken Fine Chemicals Co., Ltd., product name). Examples of the polyether-modified siloxanes include BYK-346, 347, 348, and UV3530 (Bic Chemie product). These may be used alone or in combination of two or more in the ink composition, and are included so that the surface tension of the ink composition is preferably adjusted to 20 mN / m to 40 mN / m, preferably 0 in the ink composition. .1% by mass to 3.0% by mass.

  If necessary, a pH adjuster, a complexing agent, an antifoaming agent, an antioxidant, an ultraviolet absorber, an antiseptic / antifungal agent, and the like can be added to the ink composition. As the pH adjuster, for example, alkali hydroxides such as lithium hydroxide, potassium hydroxide, sodium hydroxide and / or alkanolamines such as ammonia, triethanolamine, tripropanolamine, diethanolamine, monoethanolamine are used. it can. In particular, it is preferably adjusted to pH 6 to 10 including at least one pH adjusting agent selected from alkali metal hydroxide, ammonia, triethanolamine, and tripropanolamine. If the pH is out of this range, the material constituting the ink jet printer is adversely affected, and the clogging recovery property tends to deteriorate.

  The ink composition according to this embodiment preferably contains a pigment for the purpose of image formation and printing. As the pigment used in the ink composition according to this embodiment, any of known inorganic pigments and organic pigments can be used. Examples of such pigments include pigment yellow, pigment red, pigment violet, pigment blue, and pigment black described in the Color Index, as well as phthalocyanine, azo, anthraquinone, azomethine, and condensed rings. Examples thereof include pigments of the type. Further, organic pigments such as yellow No. 4, No. 5, 205, 401; orange No. 228, 405; blue No. 1, 404, carbon black, titanium oxide, zinc oxide, zirconium oxide, iron oxide, ultramarine , Inorganic pigments such as bitumen and chrome oxide. Examples of the color index of the pigment include C.I. I. Pigment Yellow 1, 3, 12, 13, 14, 17, 24, 34, 35, 37, 42, 53, 55, 74, 81, 83, 95, 97, 98, 100, 101, 104, 108, 109, 110, 117, 120, 128, 138, 150, 153, 155, 174, 180, 198, C.I. I. Pigment Red 1,3,5,8,9,16,17,19,22,38,57: 1,90,112,122,123,127,146,184,202, C.I. I. Pigment Bio Red 1,3,5: 1, 16, 19, 23, 38, C.I. I. Pigment Blue 1, 2, 15, 15: 1, 15: 2, 15: 3, 15: 4, 16, C.I. I. Pigment Black 1 and 7 may be mentioned, and one or more pigments may be included in the ink composition.

  The pigment used in the present embodiment may be a resin dispersion type. The pigment of such an embodiment is a pigment dispersion liquid dispersed in an aqueous medium using a ball mill, a roll mill, a bead mill, a high-pressure homogenizer, a high-speed stirring disperser, and the like, together with a dispersant such as a polymer dispersant and a surfactant. Alternatively, a dispersibility-imparting group (hydrophilic functional group and / or salt thereof) is directly or indirectly bonded to the pigment surface via an alkyl group, an alkyl ether group, an aryl group, etc., and an aqueous medium without a dispersant The pigment composition is preferably blended in the ink composition as a pigment dispersion which is processed as a self-dispersing pigment dispersed and / or dissolved therein and dispersed in an aqueous medium.

  Examples of dispersants include polymer dispersants such as natural polymer compounds such as glue, gelatin and saponin, polyvinyl alcohols, polypyrrolidones, acrylic resins (polyacrylic acid, acrylic acid-acrylonitrile copolymer, Vinyl acetate-acrylic acid copolymer, vinyl acetate-acrylic acid ester copolymer, etc.), styrene-acrylic acid resins (styrene-acrylic acid copolymer, styrene-methacrylic acid copolymer, styrene-methacrylic acid- Acrylic acid alkyl ester copolymer, styrene-α-methylstyrene-acrylic acid copolymer, styrene-α-methylstyrene-acrylic acid-alkyl acrylate copolymer, styrene-vinyl acetate-acrylic acid copolymer, etc. ), Styrene-maleic acid resins, vinyl acetate-fatty acid vinyl-ethylene Synthetic polymer compounds such as resins of tyrene copolymer and their salts, and the like, and the constitution of the copolymer may be any of random type, block type and graft type.

  Examples of surfactants used as dispersants include anionic surfactants such as fatty acid salts, higher alkyl dicarboxylates, higher alcohol sulfate esters, higher alkyl sulfonates, fatty acid amine salts, and fatty acid ammonium salts. Nonionic surfactants such as cationic surfactants, polyoxyalkyl ethers, polyoxyalkyl esters, sorbitan alkyl esters and the like can be mentioned.

  Of these dispersants, water-insoluble resins are particularly preferable. Specifically, the water-insoluble resin is composed of a block copolymer resin of a monomer having a hydrophobic group and a monomer having a hydrophilic group, and contains at least a monomer having a salt-forming group. A resin having a solubility in 100 g of water at 25 ° C. of less than 1 g later is preferred. Examples of the monomer having a hydrophobic group include methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-amyl methacrylate, isoamyl methacrylate, n-hexyl methacrylate, 2-ethylhexyl methacrylate, octyl methacrylate, decyl. Methacrylic acid esters such as methacrylate, dodecyl methacrylate, octadecyl methacrylate, cyclohexyl methacrylate, phenyl methacrylate, benzyl methacrylate, glycidyl methacrylate, vinyl esters such as vinyl acetate, vinylcyan compounds such as acrylonitrile and methacrylonitrile, styrene, α- Methylstyrene, vinyltoluene, 4-t-butylstyrene Emissions, chlorostyrene, vinyl anisole, aromatic vinyl monomers such as vinyl naphthalene. These can be used individually by 1 type or in mixture of 2 or more types. Examples of the monomer having a hydrophilic group include polyethylene glycol monomethacrylate, polypropylene glycol monomethacrylate, and ethylene glycol / propylene glycol monomethacrylate. These may be used alone or in combination of two or more. be able to. Examples of the monomer having a salt-forming group include acrylic acid, methacrylic acid, styrene carboxylic acid, and maleic acid, and these can be used alone or in combination of two or more. Furthermore, a macromonomer such as a styrene macromonomer or a silicone macromonomer having a polymerizable functional group at one end, or other monomers can be used in combination.

  This water-insoluble resin is preferably used as a salt neutralized with a tertiary amine such as ethylamine or trimethylamine, or an alkali neutralizer such as lithium hydroxide, sodium hydroxide, potassium hydroxide or ammonia, and has a weight average molecular weight of 10,000. About ˜150,000 is preferable from the viewpoint of stably dispersing the pigment.

  A self-dispersing pigment that can be dispersed and / or dissolved in water without a dispersant is, for example, an active species having a dispersibility-imparting group or a dispersibility-imparting group by applying a physical treatment or a chemical treatment to the pigment. It is produced by bonding (grafting) to the surface of the pigment. Examples of the physical treatment include vacuum plasma treatment. Examples of the chemical treatment include a wet oxidation method in which the pigment surface is oxidized with an oxidizing agent in water, and a method in which a carboxyl group is bonded via a phenyl group by bonding p-aminobenzoic acid to the pigment surface. it can. Since the ink composition containing the self-dispersing pigment does not need to contain the above-mentioned dispersant to be contained for dispersing a normal pigment, there is almost no foaming due to the reduction of the defoaming property caused by the dispersant. It is easy to prepare an ink having excellent ejection stability. In addition, since a significant increase in viscosity due to the dispersant can be suppressed, a larger amount of pigment can be contained, the printing density can be sufficiently increased, or handling becomes easy. Because of these advantages, the self-dispersing pigment is particularly effective for black ink compositions that require a high concentration, and the black ink composition used as the ink composition of the present embodiment has no dispersant. It is preferable that at least a self-dispersing pigment that can be dispersed and / or dissolved in water is contained.

  In the present embodiment, a self-dispersing pigment that is surface-treated by oxidation treatment with hypohalous acid and / or hypohalite or ozone is preferable from the viewpoint of high color development. Commercially available products can also be used as self-dispersing pigments. Examples of such commercially available products include Microjet CW-1 (trade name; manufactured by Orient Chemical Industry Co., Ltd.), CAB-O-JET200, CAB. -O-JET300 (the above-mentioned brand name; Cabot company make) can be illustrated.

  These pigments preferably have a volume average particle diameter in the range of 50 nm to 200 nm from the viewpoint of storage stability of the ink and prevention of nozzle clogging. These volume average particle diameters can be obtained by particle diameter measurement using a Microtrac UPA150 (manufactured by Microtrac) or a particle size distribution analyzer LPA3100 (manufactured by Otsuka Electronics Co., Ltd.).

  These pigments are preferably contained in the ink composition in a range of 6% by mass or more. If the content is less than 6% by mass, the print density (color developability) may be insufficient. Moreover, the upper limit of the content is not specifically limited, For example, content may be 25 mass% or less. When the content is larger than 25% by mass, there may be a problem in reliability such as nozzle clogging or unstable discharge.

The ink composition according to the present embodiment preferably contains a resin emulsion from the viewpoint of improving fixability to a recording medium. The resin emulsion preferably contains resin particles having a minimum film forming temperature of less than 20 ° C. By using a resin emulsion containing resin particles having a minimum film forming temperature of less than 20 ° C., the resin particles are formed into a film at an ambient temperature under a use environment that is usually 20 ° C. or higher. Improves fixing properties and abrasion resistance on recording media.
Here, the minimum film-forming temperature is measured as follows. First, a resin emulsion is applied to a thickness of 0.3 mm on a stainless steel plate of a temperature gradient test apparatus. Immediately after application, the basket containing silica gel is placed on a plate and covered with a transparent plastic lid. After the coating film has dried, the temperature at the boundary between the uniform continuous film portion and the cloudy portion is read to obtain the minimum film forming temperature.

  These resin emulsions contain one or more resin particles selected from the group consisting of acrylic resins, methacrylic resins, vinyl acetate resins, vinyl chloride resins, and styrene-acrylic resins. Is preferred. These resins may be used as a homopolymer or may be used as a copolymer, and any of a single-phase structure and a multiphase structure (core-shell type) can be used.

Furthermore, at least one of the resin emulsions contained in the ink composition used in the present embodiment is blended in the ink composition in the form of an emulsion of resin particles obtained by emulsion polymerization of unsaturated monomers. It is preferable. Even if the resin particles are added alone to the ink composition, the dispersion of the resin particles may be insufficient. Therefore, the emulsion form is preferable for the production of the ink composition. The emulsion is preferably an emulsion of acrylic resin particles, that is, an acrylic emulsion, from the viewpoint of the storage stability of the ink composition.
An emulsion of resin particles (such as an acrylic emulsion) can be obtained by a known emulsion polymerization method. For example, an unsaturated monomer (such as an unsaturated vinyl monomer) can be obtained by emulsion polymerization in water in which a polymerization initiator and a surfactant are present.

  Examples of unsaturated monomers include acrylic acid ester monomers, methacrylic acid ester monomers, aromatic vinyl monomers, vinyl ester monomers, vinyl cyanide monomer monomers that are generally used in emulsion polymerization. , Halogenated monomers, olefin monomers, and diene monomers.

  More specifically, as an unsaturated monomer, methyl acrylate, ethyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, n-amyl acrylate, isoamyl acrylate, n-hexyl acrylate, 2-ethylhexyl acrylate Acrylates such as octyl acrylate, decyl acrylate, dodecyl acrylate, octadecyl acrylate, cyclohexyl acrylate, phenyl acrylate, benzyl acrylate, glycidyl acrylate; methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n -Amyl methacrylate, isoamyl methacrylate, n-hexyl methacrylate , Methacrylates such as 2-ethylhexyl methacrylate, octyl methacrylate, decyl methacrylate, dodecyl methacrylate, octadecyl methacrylate, cyclohexyl methacrylate, phenyl methacrylate, benzyl methacrylate, glycidyl methacrylate; vinyl esters such as vinyl acetate; vinyl such as acrylonitrile, methacrylonitrile Cyanide compounds; halogenated monomers such as vinylidene chloride and vinyl chloride; aromatic vinyl monomers such as styrene, α-til styrene, vinyl toluene, 4-t-butyl styrene, chlorostyrene, vinyl anisole, vinyl naphthalene; ethylene Olefins such as propylene; dienes such as butadiene and chloroprene; vinyls such as vinyl ether, vinyl ketone and vinyl pyrrolidone. Nyl monomer; unsaturated carboxylic acid such as acrylic acid, methacrylic acid, itaconic acid, fumaric acid and maleic acid; acrylamides such as acrylamide, methacrylamide and N, N′-dimethylacrylamide; 2-hydroxyethyl acrylate, 2 -Hydroxypropyl acrylate, 2-hydroxyethyl methacrylate, hydroxyl group-containing monomers such as 2-hydroxypropyl methacrylate. These may be used alone or in combination of two or more.

  A crosslinkable monomer having two or more polymerizable double bonds can also be used as the unsaturated monomer. Examples of the crosslinkable monomer having two or more polymerizable double bonds include polyethylene glycol diacrylate, triethylene glycol diacrylate, 1,3-butylene glycol diacrylate, 1,4-butylene glycol diacrylate, 1,6-hexanediol diacrylate, neopentyl glycol diacrylate, 1,9-nonanediol diacrylate, polypropylene glycol diacrylate, 2,2′-bis (4-acryloxypropyloxyphenyl) propane, 2,2 ′ -Diacrylate compounds such as bis (4-acryloxydiethoxyphenyl) propane; Triacrylate compounds such as trimethylolpropane triacrylate, trimethylolethane triacrylate, tetramethylolmethane triacrylate Tetraacrylate compounds such as ditrimethylol tetraacrylate, tetramethylol methane tetraacrylate, pentaerythritol tetraacrylate; hexaacrylate compounds such as dipentaerythritol hexaacrylate; ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, polyethylene glycol di Methacrylate, 1,3-butylene glycol dimethacrylate, 1,4 butylene glycol dimethacrylate, 1,6-hexanediol dimethacrylate, neopentyl glycol dimethacrylate, dipropylene glycol dimethacrylate, polypropylene glycol dimethacrylate, polybutylene glycol dimethacrylate , 2, 2 Dimethacrylate compounds such as' -bis (4-methacryloxydiethoxyphenyl) propane; trimethacrylate compounds such as trimethylolpropane trimethacrylate and trimethylolethane trimethacrylate; methylenebisacrylamide; divinylbenzene. These may be used alone or in combination of two or more.

  In addition to the polymerization initiator and surfactant used in emulsion polymerization, a chain transfer agent, further a neutralizing agent, and the like may be used according to a conventional method. In particular, the neutralizing agent is preferably ammonia or an inorganic alkali hydroxide such as sodium hydroxide or potassium hydroxide.

  In the present embodiment, the resin emulsion contains 1 resin particle in the ink composition from the viewpoint of more effectively obtaining the ink-appropriate properties of the ink composition, reliability (clogging, ejection stability, etc.), fixability, and the like. It is preferable to contain so that it may become the range of 10 mass%-10 mass%.

  The volume average particle diameter of the resin emulsion contained in the ink composition is preferably 5 nm to 400 nm, and preferably 50 nm to 200 nm, from the viewpoints of dispersion stability and fixability of the resin particles in the ink composition. Is more preferable. The volume average particle diameter is measured using, for example, a Coulter counter N4 (trade name, manufactured by Coulter Inc.).

  Next, the intermediate transfer device 200 will be described. As shown in FIG. 1, the intermediate transport apparatus 200 includes an intermediate transport unit 252 as a transport unit that transports the paper M along the intermediate transport path 218. The intermediate transport unit 252 includes at least one reversing unit (two first reversing units 241 and 242 in the present embodiment) that reverses the transported paper M. The first reversing unit 241 and the second reversing unit 242 are located downstream of the recording unit 110 in the transport direction in the transport path, and reverse the paper M on which an image is formed (printed). The intermediate transport apparatus 200 has a drying function for drying the paper M on which an image has been formed in the image forming apparatus 100 while transporting the paper M along the intermediate transport path 218, and an inversion function for inverting the paper M transported from the image forming apparatus 100. And.

  The intermediate conveyance path 218 of the intermediate conveyance apparatus 200 is connected to the third discharge path 153 of the image forming apparatus 100. The intermediate conveyance path 218 includes an introduction path 243 whose upstream end is connected to the third discharge path 153, and a first branch path 244 and a second branch path 245 that branch at a branch point A that is a downstream end of the introduction path 243. And have. That is, to the branch point A, the downstream end of the introduction path 243, the upstream end of the first branch path 244, and the upstream end of the second branch path 245 are connected. The path lengths of the first branch path 244 and the second branch path 245 in the transport direction are substantially the same.

  Further, the intermediate transport path 218 is connected to the first junction path 246 connected to the first connection point B that is the downstream end of the first branch path 244 and the second connection point C that is the downstream end of the second branch path 245. And a second merging path 247 connected thereto. The path lengths in the transport direction of the first merge path 246 and the second merge path 247 are substantially the same length.

  The first inversion path 248 included in the first inversion unit 241 is connected to the first connection point B. The second inversion path 249 of the second inversion unit 242 is connected to the second connection point C. That is, to the first connection point B, the downstream end of the first branch path 244, the upstream end of the first merge path 246, and one end of the first inversion path 248 are connected. The second connection point C is connected to the downstream end of the second branch path 245, the upstream end of the second junction path 247, and one end of the second inversion path 249. Note that the path lengths of the first inversion path 248 and the second inversion path 249 are configured to be equal to or longer than the length of the sheet M on which image formation (printing) can be performed by the image forming apparatus 100 in the transport direction.

  Furthermore, the intermediate conveyance path 218 has a junction point D where the first junction path 246 and the second junction path 247 meet, and has a lead-out path 250 connected to the junction point D. In other words, the downstream end of the first joining path 246, the downstream end of the second joining path 247, and the upstream end of the outlet path 250 are connected to the joining point D. The derivation path 250 extends downward between the first inversion path 248 and the second inversion path 249 toward the post-processing device 300, and then extends upward by turning around the first inversion path 248. . The downstream end of the lead-out path 250 is connected to the downstream transport path 319 of the post-processing device 300.

  In the present embodiment, the introduction path 243, the first branch path 244, and the second branch path 245 constitute the pre-reversal path 218a, and the first merge path 246, the second merge path 247, and the derivation path 250 Thus, a reverse path 218b is configured. The pre-reversing path 218a is located upstream of the first reversing unit 241 or the second reversing unit 242 in the transport direction in the transport direction. Further, the post-reversal path 218b is located downstream of the first reversing unit 241 or the second reversing unit 242 in the transport direction in the transport direction. In other words, the intermediate transport path 218 has a pre-reversal path 218a located on the upstream side in the transport direction with respect to the first reversing section 241 and the second reversing section 242 and a post-reversal path 218b located on the downstream side in the transport direction. doing.

  As shown in FIG. 7, the intermediate transport apparatus 200 includes an intermediate transport unit 252 that can transport the paper M along the intermediate transport path 218. The first reversing unit 241 and the second reversing unit 242 in the intermediate conveyance unit 252 are configured to be able to reverse the conveyed paper M.

  On the introduction path 243, the first branch path 244, and the second branch path 245, a first transport roller pair 254 that is driven by a drive motor (not shown) is disposed. Further, a second transport roller pair 256 driven by a drive motor (not shown) is disposed on the first joining path 246, the second joining path 247, and the outlet path 250. In addition, the number of the 1st conveyance roller pair 254 and the 2nd conveyance roller pair 256 can be arbitrarily set by the form of each conveyance path | route, etc. Then, with each roller pair of the intermediate transport unit 252 sandwiching and supporting the paper M from both the front and back sides, one of the roller pairs is rotationally driven to transport the paper M along the transport path.

  The introduction path 243 is provided with an introduction detection unit 258 that detects the paper M. The introduction detection unit 258 is, for example, a light transmission type or light reflection type photo interrupter, and includes a light emitting unit that emits light and a light receiving unit that receives light emitted from the light emitting unit. As the light emitting element of the light emitting unit, for example, an LED (Light Emitting Diode) light emitting element, a laser light emitting element, or the like is applied. In addition, the light receiving unit includes a phototransistor, a photo IC, and the like. The presence / absence of the sheet M (ON / OFF of light reception in the light receiving unit) can be detected by the light emitting unit and the light receiving unit. A guide flap 259 is provided at a branch point A on the downstream side in the transport direction from the introduction detection unit 258. The guide flap 259 is driven by a solenoid or the like, and switches to which of the first branch path 244 and the second branch path 245 the sheet M conveyed through the introduction path 243 is guided.

  Further, at the downstream end of the first branch path 244, the movement of the sheet M from the first branch path 244 to the first inversion path 248 is allowed, while the sheet M from the first inversion path 248 to the first branch path 244 is allowed. The 1st control flap 261 which controls the movement of is provided. Further, at the downstream end of the second branch path 245, the sheet M is allowed to move from the second branch path 245 to the second inversion path 249, while the sheet M from the second inversion path 249 to the second branch path 245 is allowed. A second restriction flap 262 is provided to restrict the movement of the second movement. The first restriction flap 261 and the second restriction flap 262 are biased so as to block the downstream end of the first branch path 244 or the second branch path 245 by a biasing force by a biasing member (not shown). . The first restriction flap 261 and the second restriction flap 262 may be configured to be driven by a solenoid or the like.

  The first reversing unit 241 includes a first reversal detecting unit 264 that detects the sheet M fed into the first reversing path 248 and a first reversing roller pair 265 provided on the first reversing path 248 (this embodiment). 2 pairs) are arranged. The first reversing roller pair 265 is driven forward or reversely by a first reversing motor (not shown) based on a signal transmitted when the first reversal detection unit 264 detects the paper M.

  The second reversing unit 242 includes a second reversal detecting unit 267 that detects the paper M sent to the second reversing path 249, and a second reversing roller pair 268 provided on the second reversing path 249. In the embodiment, 5 pairs) are arranged. The second reverse roller pair 268 is driven to rotate forward or reversely by a second reverse motor (not shown) based on a signal transmitted when the second reverse detection unit 267 detects the paper M. The first and second inversion detection units 264 and 267 are, for example, photo interrupters, and the specific configuration is the same as that of the introduction detection unit 258.

  A pressing unit 280 is disposed on the intermediate conveyance path 218. The configuration of the pressing unit 280 will be described later.

  Next, the configuration of the post-processing apparatus will be described. As shown in FIG. 1, the post-processing apparatus 300 includes a substantially box-shaped frame 320. The frame 320 includes a post-processing paper feed port 322 and a post-processing paper discharge port 323. The post-processing paper feed port 322 and the post-processing paper discharge port 323 are each formed with an opening, and the post-processing paper feed port 322 is disposed corresponding to the downstream end of the intermediate transport path 218 of the intermediate transport device 200. The intermediate transport path 218 and the downstream transport path 319 are connected. The downstream transport path 319 is arranged from the post-processing paper feed port 322 to the post-processing paper discharge port 323, and the paper M transported from the intermediate transport device 200 is supplied from the post-processing paper feed port 322, and the paper M After being subjected to post-processing and the like, it is discharged from the post-processing discharge port 323.

  A stacker 328, a post-processing unit 325, and the like are disposed inside the frame 320. The stacker 328 temporarily places the paper M, and is formed in a direction substantially perpendicular to the placement surface 328a having a substantially flat surface on which the paper M can be placed, and the end of the placement surface 328a. Wall surface 328b.

  The post-processing unit 325 performs punch processing for punching punch holes in the paper M, stapling processing for binding the paper M every predetermined number of times, and the width of the paper M in the width direction of the paper M. Post-processing such as shift processing for adjusting the position by shifting in the width direction for each sheet or for each bundle is performed by an appropriate mechanism. The post-processing unit 325 can perform a paper folding unit that performs the folding process of the paper M, a cutting process that cuts the paper M, a signature process that folds the paper M, a bookbinding process that collates the paper M, a collation process, and the like. A mechanism may be provided.

  In addition, a downstream transport unit 335 is disposed along the downstream transport path 319 inside the frame 320. The downstream transport unit 335 includes a transport roller pair 327 driven by a driving roller (not shown). A pair of paper discharge rollers 329 is disposed in the vicinity of the post-processing paper discharge port 323 in the downstream conveyance path 319. The transport roller pair 327 is arranged on the upstream side of the stacker 328 and the post-processing unit 325 in the downstream transport path 319, and transports the paper M fed from the post-processing paper feed port 322 to the stacker 328.

  In addition, a guide portion 330 that guides the paper M that is transported along the downstream transport path 319 is provided inside the frame body 320. The guide part 330 has a protrusion shape. The guide portion 330 includes a guide surface 330a having a substantially flat surface, and the guide surface 330a is disposed so as to face the downstream conveyance path 319 (stacker 328). The dimension width of the guide surface 330a of the present embodiment that is approximately perpendicular to the conveyance direction of the sheet M has a dimension that is substantially equivalent to the dimension width of the sheet M that is approximately orthogonal to the conveyance direction. Thereby, the paper M can be easily guided. The guide unit 330 is disposed on the downstream side of the transport roller pair 327 in the downstream side transport path 319 and on the upstream side of the paper discharge roller pair 329. Accordingly, the sheet M conveyed from the conveyance roller pair 327 is conveyed to the stacker 328 via the guide unit 330.

  The stacker 328 of the present embodiment is disposed on the downstream side of the conveyance roller pair 327 in the downstream conveyance path 319 and temporarily places the paper M to be processed by the post-processing unit 325. The stacking surface 328a of the stacker 328 is arranged in an oblique direction so that at least one end side of the plurality of sheets M mounted on the stacker 328 is aligned. In the present embodiment, one end of the stacker 328 is disposed on the post-processing discharge port 323 side, and the other end (wall surface 328b) of the stacker 328 is disposed on the post-processing unit 325 side. The post-processing paper discharge port 323 is disposed above the post-processing unit 325, and the stacker 328 is disposed obliquely so as to be downward toward the post-processing unit 325. As a result, one end side of the sheet M placed on the stacker 328 comes into contact with the wall surface 328b of the stacker 328, so that one end side of the sheet M is aligned.

  The pair of paper discharge rollers 329 is disposed on one end side of the stacker 328 and is configured to discharge the paper M placed on the stacker 328 one by one or one bundle of a predetermined number. The paper discharge roller pair 329 includes a first paper discharge roller 329a and a second paper discharge roller 329b. The first paper discharge roller 329a and the second paper discharge roller 329b are arranged in the vertical direction Z, and the first paper discharge roller 329a is disposed above the second paper discharge roller 329b. The first paper discharge roller 329a and the second paper discharge roller 329b are configured to be separated and press-contacted. In the present embodiment, the first paper discharge roller 329a is configured to be movable with respect to the second paper discharge roller 329b by a drive motor.

When the paper M transported from the transport roller pair 327 is placed on the stacker 328, the paper discharge roller pair 329 is separated. In this state, after a part of the paper M passes between the first paper discharge roller 329a and the second paper discharge roller 329b, the paper M is fed by the first paper discharge roller 329a and the second paper discharge roller 329b. The paper is pressed (nip) so as to be pinched, and the pair of paper discharge rollers 329 (first paper discharge roller 329a and second paper discharge roller 329b) is rotated in the direction of returning to the stacker 328 side. As a result, the sheet M is placed on the stacker 328. Then, until the predetermined number of sheets M are placed on the stacker 328, the separation and press-rotating operation by the first discharge roller 329a and the second discharge roller 329b is repeated.
Note that one end of the paper M placed on the stacker 328 is positioned between the first paper discharge roller 329a and the second paper discharge roller 329b.

  Further, when the paper M that has been post-processed by the post-processing unit 325 is discharged to the discharge tray 331 side, a predetermined number of sheets M are nipped by the discharge roller pair 329, and the discharge roller pair 329 (the first discharge roller pair 329) The paper discharge roller 329a and the second paper discharge roller 329b) are rotated in a direction to be conveyed to the side opposite to the stacker 328 side. Thereby, the paper M can be discharged to the paper discharge tray 331 side.

  The paper discharge tray 331 is provided outside the frame body 320 and stacks the paper M discharged from the post-processing paper discharge port 323. The paper discharge tray 331 has a placement surface 331 a on which the paper M is loaded (placed), and is provided to protrude toward the outside of the frame 320.

  Next, a basic operation method of the printing apparatus will be described. 8 to 11 are schematic diagrams illustrating an operation method of the printing apparatus. In the following description, a conveyance mode of the sheet M conveyed from the image forming apparatus 100 to the post-processing apparatus 300 via the intermediate conveyance apparatus 200 will be described. Note that the sheet M supplied to the recording head 111 of the image forming apparatus 100 and conveyed is the first sheet Ma, the second sheet Mb, and the third sheet Mc in order from the first sheet, and the fourth sheet M is the fourth sheet M. This will be described as paper Md.

  First, when a printing process (image forming process) is executed, the control unit 10 drives each drive motor. Accordingly, the pickup roller 142a, the transport roller pair 131, the drive roller 133, the first transport roller pair 254, the second transport roller pair 256, the first reverse roller pair 265, and the second reverse roller pair 268 connected to each drive motor. The transport roller pair 327 and the like are driven.

  Then, the recording unit 110 forms an image (prints) on the paper M by ejecting ink from the recording head 111. In this case, the printing process may be single-sided printing or double-sided printing.

  As shown in FIG. 8, the first paper Ma conveyed through the third discharge path 153 at the speed before reversal is delivered to the introduction path 243 at substantially the same speed. When the introduction detection unit 258 detects the leading edge of the first sheet Ma, the control unit 10 drives the solenoid to position the guide flap 259 at the first position P1. That is, the guide flap 259 guides the first paper Ma to the first branch path 244. Then, the first sheet Ma conveyed to the first connection point B moves the first restriction flap 261 against the urging force of the urging member when the leading end contacts the first restriction flap 261. That is, the first restriction flap 261 moves so as to open the downstream end of the first branch path 244. Therefore, the first sheet Ma is sent to the first reversing path 248 at the speed before reversal by the first reversing roller pair 265 that is normally rotated. When the first sheet Ma passes through the first restriction flap 261, the first restriction flap 261 moves from a position where the downstream end of the first branch path 244 is opened to a position where it is closed.

  As illustrated in FIG. 9, when the first reverse detection unit 264 detects the trailing edge of the first sheet Ma, the control unit 10 switches the first reverse roller pair 265 that has been normally driven to reverse drive. Then, the first reversing unit 241 sends the first paper Ma from the first reversing path 248 to the first connection point B side at the post-reversing speed. At this time, the first restriction flap 261 guides the first sheet Ma to the first merge path 246. That is, the first reversing unit 241 reverses the direction of the first paper Ma by sending the first paper Ma sent from the first branch path 244 to the first joining path 246.

  When the introduction detection unit 258 detects the leading edge of the second sheet Mb, the control unit 10 drives the solenoid to change the position of the guide flap 259. That is, the control unit 10 moves the guide flap 259 located at the first position P1 to the second position P2. Then, the guide flap 259 guides the second sheet Mb to the second branch path 245.

  As shown in FIG. 10, the first paper Ma reversed by the first reversing unit 241 is conveyed at a post-reversal speed on the post-reversal path 218 b. Then, when the first sheet Ma passes through the first connection point B, the control unit 10 rotates the first reversing roller pair 265 in the normal direction. Further, when the second reverse detection unit 267 detects the trailing edge of the second sheet Mb, the control unit 10 rotates the second reverse roller pair 268 in the reverse direction. That is, the second reversing unit 242 reverses the second sheet Mb and sends it to the second joining path 247 at the post-reversing speed in the same manner as the first reversing unit 241.

  Further, when the introduction detection unit 258 detects the leading edge of the third sheet Mc, the control unit 10 drives the solenoid to change the position of the guide flap 259. Specifically, the control unit 10 moves the guide flap 259 located at the second position P2 to the first position P1. That is, the guide flap 259 guides the conveyed paper M alternately to the first branch path 244 and the second branch path 245.

  As shown in FIG. 11, the second sheet Mb that has been reversed by the second reversing unit 242 and sent to the second merge path 247 is conveyed through the derivation path 250 via the merge point D. At this time, the intermediate transport unit 252 transports the first paper Ma and the second paper Mb at a speed after reversal that is slower than the speed before reversal. Therefore, the interval in the transport direction between the first paper Ma and the second paper Mb is narrower than that when the pre-reverse path 218a is transported at the pre-reverse speed.

  When the first reverse detection unit 264 detects the trailing edge of the third paper Mc, the control unit 10 rotates the first reverse roller pair 265 in the reverse direction and sends the third paper Mc to the first joining path 246. When the introduction detection unit 258 detects the leading edge of the fourth sheet Md, the control unit 10 drives the solenoid to change the position of the guide flap 259 to the second position P2.

  Then, the intermediate conveyance device 200 sequentially sends the first paper Ma introduced first to the post-processing device 300. That is, the sheet M is sent to the post-processing apparatus 300 with the surface of the sheet M reversed in the intermediate conveyance device 200. Further, since the downstream transport unit 335 transports the paper M at a processing speed faster than the post-inversion speed, the interval between the papers M increases. The sheets M are sequentially conveyed to the stacker 328, and when a predetermined number of sheets M are placed on the stacker 328, the post-processing unit 325 performs processing such as stapling, and the sheet discharge roller pair 329 drives the sheet discharge tray. It is discharged to 331.

  Next, the problem concerning the printing apparatus 1 (post-processing apparatus 300) of this embodiment is demonstrated. As described above, when the image forming apparatus 100 is an inkjet printer including the recording head 111 that discharges ink as droplets, the sheet M on which the image is formed by the image forming apparatus 100 absorbs ink (moisture). As the ink dries, it may curl (the paper is curved or the paper is rounded). For this reason, when the paper M on which an image is formed by the image forming apparatus 100 (inkjet printer) is sequentially placed on the stacker 328, when the degree of curling of the paper M placed first increases, There is a possibility that the sheet M conveyed from the contact with the curled portion of the sheet M previously placed may cause a conveyance defect.

Further, the mechanism of occurrence of curling of the paper M will be described in detail. The paper M of the present embodiment is composed mainly of cellulose, and the celluloses are formed by hydrogen bonding. For this reason, for example, when ink is applied to one side of the paper M by the image forming apparatus 100, hydrogen bonds between celluloses are broken by absorption of the ink. Then, the space between the cellulose is widened, and the one side of the paper M on which the ink is applied becomes easier to extend than the other side (the surface on which the ink is not applied) opposite to the one side of the paper M. . For this reason, when one side of the sheet M is placed in the direction of gravity (downward), the sheet M curls in a convex shape in the direction of gravity (primary curl).
Further, after the primary curl is generated, when the ink absorbed on the paper M is dried, the celluloses are freely connected by hydrogen bonding, and the interval between the celluloses is narrowed. Then, one side of the sheet M on which ink is applied shrinks more than the other side. For this reason, when one side of the paper M is placed in the direction of gravity, the paper M is concave in the direction of gravity (convex in the direction opposite to the direction of gravity) as opposed to the primary curl. ) (Secondary curl).

  Here, in the post-processing apparatus 300 of this embodiment, curling of the paper M (particularly secondary curling) becomes a problem. Specifically, the sheet M on which an image is formed by the image forming apparatus 100 is conveyed to the post-processing apparatus 300 via the intermediate conveying apparatus 200. In this process, the secondary curl increases as the ink applied to the paper M progresses over time, so that the paper M transported later is already placed on the stacker 328. It will be caught by the curled part of M and a conveyance defect will generate | occur | produce.

  Further, the occurrence of curling of the paper M occurs not only in single-sided printing but also in double-sided printing. That is, when the print duty on one side of the paper M is different from the print duty on the other side, the paper M may be curled. In particular, when the difference between the print duty on one side of the paper M and the print duty on the other side is a predetermined value or more (for example, about 50% or more), the occurrence of curling of the paper M becomes significant.

  Therefore, in the present embodiment, the intermediate conveyance device 200 includes a pressing portion 280 that has a convex portion and presses the convex portion against the sheet M that is conveyed on the intermediate conveyance path 218. The pressing part 280 of this embodiment has a roller, and a convex part is formed on the surface of the roller. Hereinafter, the configuration of the pressing unit 280 will be described.

  12A, 12B, and 13 are schematic views showing the configuration of the pressing portion. As illustrated in FIG. 12A, the pressing unit 280 includes a first roller 281 and a second roller 291 having a higher hardness than the first roller 281. A convex portion 290 is provided on the surface of the second roller 291. The convex portion 290 can be pressed against the paper M by sandwiching the paper M between the first roller 281 and the second roller 291. The hardness of the first and second rollers 281 and 291 can be measured using various hardness measuring instruments.

  The first roller 281 of the present embodiment is configured by a core metal 283 disposed at the center of rotation and a soft body 284 disposed so as to surround the periphery of the core metal 283. The core metal 283 is made of a metal such as aluminum, iron, or stainless steel, and is hollow. The soft body 284 is made of, for example, silicon rubber, urethane rubber, fluorine rubber, nitrile rubber, butyl rubber, acrylic rubber, or the like. The soft body 284 may be a rubber foam. The first roller 281 may be entirely composed of the soft body 284 without including the cored bar 283 as long as the mechanical strength can be maintained.

  As for the 2nd roller 291, the core metal 293 is arrange | positioned in the rotation center part. The core metal 293 is made of a metal such as aluminum, iron, or stainless steel. Further, the core metal 293 is hollow. A convex portion 290 is provided on the surface of the second roller 291. The core metal 293 and the convex part 290 are integrated. That is, the convex portion 290 is also made of the same metal as the core metal 293. That is, the second roller 291 having a higher hardness than the first roller 281 is configured. And the 1st roller 281 and the 2nd roller 291 are connected to a drive motor, and the 1st roller 281 and the 2nd roller 291 rotate by the drive of a drive motor. By driving and rotating the first roller 281 and the second roller 291, the paper M can be smoothly conveyed while pressing the convex portion 290 against the paper M.

A plurality of convex portions 290 are formed on the surface of the second roller 291. A concave portion 290a is formed between the convex portion 290 and the convex portion 290, and the convex portion 290 and the concave portion 290a are continuously formed on the surface of the second roller 291. As shown to FIG. 12A, the convex part 290 of this embodiment has a curved surface. That is, the top of the convex part 290 has a gently curved surface. Accordingly, it is possible to prevent the paper M from being damaged when the convex portion 290 is pressed against the paper M.
Further, as shown in FIG. 12B, the distance t from the rotation axis center R (a common reference) of the second roller 291 to the top of each convex portion 290 in the cross-sectional view is equal. Accordingly, the convex portion 290 can be uniformly pressed against the paper M.

  Moreover, as shown in FIG. 13, the 1st roller 281 and the 2nd roller 291 are comprised so that separation | spacing is possible. That is, the first roller 281 and the second roller 291 are configured to be capable of being pressed and separated (nip). In the present embodiment, the second roller 291 is configured to be movable with respect to the first roller 281 by a drive motor that is driven at the time of separation. Specifically, when the second roller 291 is moved to the first position Ps1, the first roller 281 and the second roller 291 are pressed against each other (nip), and the second roller 291 is moved to the second position Ps2. In this case, the first roller 281 and the second roller 291 are separated. Thereby, it is possible to select whether or not to press the convex portion 290 against the paper M.

  Moreover, in this embodiment, as shown in FIG. 7, two pairs of pressing parts 280 (the 1st pressing part 280a and the 2nd pressing part 280b) are provided. Then, along the conveyance direction of the sheet M on the intermediate conveyance path 218, one surface of the sheet M and the second roller 291 face each other in the first pressing unit 280a, and one surface of the sheet M in the second pressing unit 280b. It arrange | positions so that the 2nd roller 291 and the other side opposite to may oppose. That is, the two pairs of pressing portions 280 are arranged in a state of being offset from each other in the transport direction. As a result, the one surface or the other surface of the paper M can be efficiently pressed against the paper M transporting the intermediate transport path 218 by the convex portion 290. In the present embodiment, the first pressing portion 280a is disposed on the upstream side in the transport direction with respect to the second pressing portion 280b.

  Further, the two pairs of pressing portions 280 are arranged in the lead-out path 250. That is, by arranging the two pairs of pressing portions 280 in the area where the paper M is conveyed in common, the intermediate conveying device 200 can be downsized and the configuration of the intermediate conveying device 200 can be simplified. Further, the two pairs of pressing portions 280 are disposed on the upstream side of the lead-out path 250. As a result, the convex portion 290 can be pressed before the conveyed paper M is completely dried, and curling of the paper M can be suppressed. Further, the two pairs of pressing portions 280 are arranged in a region where the lead-out path 250 extends substantially linearly. Thereby, generation | occurrence | production of jam can be suppressed.

  Next, the configuration of the control unit of the printing apparatus will be described. FIG. 14 is a block diagram illustrating a partial configuration of the control unit of the printing apparatus. In FIG. 14, the configuration related to the control of the pressing unit 280 is mainly shown.

  As illustrated in FIG. 14, the printing apparatus 1 includes a control unit 10. The control unit 10 includes a CPU, a ROM, a RAM as storage means, and an input / output interface, and the CPU processes various signals input via the input / output interface based on the data of the ROM and RAM. And a control signal is output to each drive unit. For example, the CPU performs various controls based on a control program stored in the ROM. In addition, the control unit 10 is configured to calculate the print duty corresponding to each side of the paper M based on the print data transmitted from the external device or the like, and to compare the print duty of each side of the paper M. ing.

  Each control unit (introduction detection unit 258, first and second inversion detection units 264, 267) is connected to the control unit 10, and detection data is transmitted from each detection unit. Further, each drive motor (drive motor, first and second reversing motor) is connected to the control unit 10, and a drive control signal generated based on the detection data is transmitted from the control unit 10 to each drive motor. Each drive motor is driven and controlled. As the drive motors are driven, members such as rollers and roller pairs connected to the drive motors (first and second transport roller pairs 254 and 256, first and second reverse roller pairs 265 and 268, first 1 roller 281 and 2nd roller 291) drive.

  Next, a method for controlling the printing apparatus will be described. In detail, the control method of a pressing part is demonstrated. FIG. 15 is a flowchart illustrating a control method of the printing apparatus. FIGS. 16 to 18 are schematic diagrams illustrating the operation method of the pressing unit. In the present embodiment, when the difference between the print duty on one side of the paper M and the print duty on the other side is equal to or greater than a predetermined value, the convex side of the one side and the other side has a lower print duty. Press part 290. Details will be described below.

As shown in FIG. 15, in step S101, it is determined whether or not the difference between the print duty on one side of the paper M and the print duty on the other side is greater than or equal to a predetermined value. Specifically, the control unit 10 calculates the print duty of the one side Ma and the other side Mb of the paper M based on, for example, print data transmitted from an external device or the like. Then, the calculated print duty of the one surface Ma and the print duty of the other surface Mb are compared. Then, it is determined whether or not the comparison value is equal to or greater than a predetermined value. If it is equal to or greater than the predetermined value (YES), the process proceeds to step S102, and if it is less than the predetermined value (NO), the process proceeds to step S105.
The predetermined value can be arbitrarily set. In general, the larger the difference between the print duty of the one side Ma and the print duty of the other side Mb, the easier the secondary curl occurs. For this reason, for example, the predetermined value can be set to 30% or 50% based on the results of experiments and evaluations related to secondary curl.

  When the process proceeds to step S105, the two pairs of pressing portions 280 (first pressing portion 280a and second pressing portion 280b) are separated. Specifically, as shown in FIG. 16, the second rollers 291 of the first and second pressing portions 280a and 280b are moved to the second position Ps2. As a result, the first roller 281 and the second roller 291 of the first and second pressing portions 280a and 280b are separated from each other, and convex portions are formed on both surfaces (one surface Ma, the other surface Mb) of the conveyed paper M. The sheet M is conveyed in a state where the 290 is not pressed.

  When the process proceeds to step S102, it is determined whether the print duty of the one side Ma is higher than the print duty of the other side Mb. Specifically, the printing duty of the one surface Ma and the printing duty of the other surface Mb in the control unit 10 are determined based on the comparison calculation result. If it is determined that the print duty of the one side Ma is higher than the print duty of the other side Mb (YES), the process proceeds to step S103, where the print duty of the one side Ma is the print duty of the other side Mb. If determined to be lower than (NO), the process proceeds to step S104.

  And when it transfers to step S103, the convex part 290 is pressed with respect to the other surface Mb. Specifically, as shown in FIG. 17, the second roller 291 corresponding to the other surface Mb of the second pressing portion 280b is moved to the first position Ps1. As a result, the first roller 281 and the second roller 291 of the second pressing portion 280b are in pressure contact (nip). Moreover, the 1st roller 281 and the 2nd roller 291 of the 2nd pressing part 280b are rotationally driven. Note that the second roller 291 of the first pressing portion 280a is positioned at the second position Ps2. Accordingly, the sheet M is conveyed while the convex portions 290 of the second roller 291 of the second pressing portion 280b are uniformly pressed only on the other surface Mb.

  Thus, when the convex portion 290 is pressed against the other side Mb of the paper M, the interval between the celluloses constituting the paper M on the other side Mb is reduced. On the other hand, the distance between the cellulose on the one surface Ma side where the convex portion 290 is not pressed is extended (expanded). Then, the other surface Mb side pressed by the convex portion 290 is in a state where the interval between the celluloses is reduced. Therefore, as the paper M is dried, the bonding between the cellulose is accelerated as compared with the one surface Ma side, and the one surface Ma. On the side, the distance between the cellulose is extended and the cellulose is bonded while maintaining the state. As a result, the cellulose is bonded to each other while the interval between the cellulose is uniformly extended on the one surface Ma side and the state is maintained, so that free bonding between the cellulose is suppressed and secondary curl is suppressed.

  When the process proceeds to step S104, the convex portion 290 is pressed against the one surface Ma. Specifically, as shown in FIG. 18, the second roller 291 corresponding to the one surface Ma of the first pressing portion 280a is moved to the first position Ps1. As a result, the first roller 281 and the second roller 291 of the first pressing portion 280a are in pressure contact (nip). Moreover, the 1st roller 281 and the 2nd roller 291 of the 1st pressing part 280a are rotationally driven. Note that the second roller 291 of the second pressing portion 280b is positioned at the second position Ps2. As a result, the sheet M is conveyed while the convex portions 290 of the second roller 291 of the first pressing portion 280a are uniformly pressed only on the one surface Ma.

  Accordingly, when the convex portion 290 is pressed against the one side Ma of the paper M, the interval between the celluloses constituting the paper M on the one side Ma side is reduced. On the other hand, the distance between the cellulose on the other surface Mb side where the convex portion 290 is not pressed is extended (expanded). Then, the one surface Ma side pressed by the convex portion 290 is in a state where the interval between the cellulose is reduced, and as the paper M is dried, the bonding between the cellulose is accelerated as compared with the other surface Mb side, and the other surface Mb. On the side, the distance between the cellulose is extended and the cellulose is bonded while maintaining the state. As a result, the gap between the cellulose is uniformly stretched on the other surface Mb side, and the cellulose is bonded while maintaining the state, whereby the bonding between the free cellulose is suppressed and the secondary curl is suppressed.

  As described above, according to the present embodiment, the following effects can be obtained.

  In the paper M on which an image is formed by the image forming apparatus 100 (inkjet printer), when the difference between the printing duty of the one side Ma and the printing duty of the other side Mb of the paper M is a predetermined value or more, the printing duty is low. The convex portion 290 is pressed against the other side (one side Ma or the other side Mb of the paper M). Thereby, secondary curl is suppressed. Further, since the sheet M in which the secondary curl is suppressed is conveyed to the post-processing apparatus 300, occurrence of a defect such as a jam is suppressed, and the post-processing can be performed reliably.

(Second Embodiment)
Next, a second embodiment will be described. Note that the basic configuration of the printing apparatus (image forming apparatus, intermediate conveyance apparatus, and post-processing apparatus) is the same as that of the first embodiment, so that the description thereof is omitted, and the configuration different from that of the first embodiment, that is, the pressing unit The configuration will be described.

  FIG. 19 is a schematic diagram illustrating the configuration of the pressing unit according to the present embodiment. As shown in FIG. 19, the pressing unit 480 of this embodiment includes a first roller 481 and a second roller 491. And the convex part 490 is provided in each surface of the 1st and 2nd roller 481,491. By sandwiching the paper M between the first roller 481 and the second roller 491, the convex portion 290 can be pressed against both surfaces of the paper M.

  As for the 1st roller 481 and the 2nd roller 491 of this embodiment, the metal core 493 is arrange | positioned in the rotation center part. The core metal 493 is made of a metal such as aluminum, iron, or stainless steel. Further, the cored bar 493 is hollow. In addition, convex portions 490 are provided on the surfaces of the first roller 481 and the first roller 491. The core metal 493 and the convex portion 490 are integrated. That is, the convex portion 490 is also made of the same metal as the core metal 493. And the 1st roller 481 and the 2nd roller 491 are connected to a drive motor, and the 1st roller 481 and the 2nd roller 491 rotate by the drive of a drive motor. By driving and rotating the first roller 481 and the second roller 491, the paper M can be smoothly conveyed while pressing the convex portions 490 against both sides of the paper M.

A plurality of convex portions 490 are formed on the surfaces of the first roller 481 and the second roller 491. A concave portion 490a is formed between the convex portion 490 and the convex portion 490, and the convex portion 290 and the concave portion 290a are continuously formed on the surfaces of the first roller 481 and the second roller 491. Moreover, the convex part 490 has a curved surface. Accordingly, it is possible to prevent the paper M from being damaged when the convex portion 490 is pressed against the paper M.
Further, the distance from the rotation axis center R (common reference) of the first roller 481 to the top of each convex portion 490 in the cross-sectional view is configured to be equal. Similarly, the distance from the rotation axis center R (a common reference) of the second roller 491 in a cross-sectional view to the top of each convex portion 490 is configured to be equal. Accordingly, the convex portion 490 can be uniformly pressed against the paper M.

  In the present embodiment, when the paper M is sandwiched between the first roller 481 and the second roller 491, the convex portion 490 of the first roller 481 and the convex portion 490 of the second roller 491 are shifted. It is arranged to be pressed. That is, when the paper M is sandwiched between the first roller 481 and the second roller 491, the convex portion 490 of the first roller 481 and the concave portion 490a of the second roller 491 correspond to each other, and the concave portion 490a of the first roller 481 The convex part 490 of the 2nd roller 491 is arrange | positioned so that it may mutually correspond. 20 and 21 are explanatory views showing a method for arranging the pressing portions. Specifically, the arrangement method of the convex portions 490 of the first roller 481 and the convex portions 490 of the second roller 491 when the paper M is sandwiched between the first roller 481 and the second roller 491 is shown. As shown in FIGS. 20 and 21, the convex portion 490 of the second roller 491 is positioned between the convex portions 490 of the first roller 481 in the Y-axis direction, and the convex portion 490 of the second roller 491 in the Y-axis direction. It arrange | positions so that the convex part 490 of the 1st roller 481 may be located in between. Thus, when the paper M is sandwiched between the first roller 481 and the second roller 491, the convex portion 490 of the first roller 481 and the convex portion 490 of the second roller 491 are staggered (for example, staggered). ). Therefore, when the paper M is sandwiched between the first roller 481 and the second roller 491, the convex portions 490 of the first roller 481 and the convex portions 490 of the second roller 491 do not interfere with each other, and both surfaces of the paper M are efficiently provided. The convex portion 490 can be pressed against the surface.

  The pressing unit 480 is configured such that the first roller 481 and the second roller 491 can be separated from each other. That is, the 1st roller 481 and the 2nd roller 491 are comprised so that press contact (nip) and separation | spacing are possible. Thereby, for example, pressure contact (nip) or separation can be selected in accordance with the difference between the print duty on one side of the paper M and the print duty on the other side. The pressing unit 480 is disposed in the derivation path 250, for example.

  As described above, according to the present embodiment, in addition to the effects of the first embodiment, the following effects can be obtained.

  The sheet M is formed in the image forming apparatus 100 (inkjet printer) and is conveyed into the intermediate conveying apparatus 200 in a state where it is not completely dried. When the paper M absorbs ink, a primary curl occurs, and then a secondary curl that curls to the opposite side of the primary curl occurs. In the intermediate conveyance device 200, the secondary curl generated when the ink applied to the paper M dries becomes a problem. Then, secondary curling may occur while the sheet M is twisted. This is presumably because the print duty is different between one side and the other side of a certain area of the paper M. Therefore, the paper M is sandwiched between the first roller 481 and the second roller 491 provided with the convex portion 490, and the convex portion 490 is pressed against one side and the other side of the paper M. Thereby, since the cellulose recombines in a state where the interval between the cellulose on one side of the sheet M and the interval between the cellulose on the other side are uniformly extended, secondary curl can be suppressed.

  In addition, this invention is not limited to embodiment mentioned above, A various change, improvement, etc. can be added to embodiment mentioned above. A modification will be described below.

(Modification 1) In the pressing portion 280 of the first embodiment, the convex portion 290 is provided on the rotatable second roller 291, but the configuration is not limited thereto. For example, a convex portion may be provided on the surface of a flat plate or the like. 22 and 23 are schematic views showing the configuration of the pressing portion according to this modification. As shown in FIG. 22, the pressing portion 580 according to this modification includes a plate portion 581 having a flat surface and a plurality of convex portions 590 provided on the flat surface 581 a of the plate portion 581. The plate portion 581 and the convex portion 590 are made of a metal such as aluminum or stainless steel.
Further, the distance (height) from the flat surface 581a (a common reference) to the top of each convex portion 590 is configured to be equal. Therefore, the convex portion 590 can be uniformly pressed against the paper M.

Then, as shown in FIG. 23, the convex portion 590 can be pressed against the paper M. Specifically, the convex portion 590 of the pressing unit 580 is disposed so as to face the surface of the sheet M, and the pressing unit 580 is configured such that the distance from the sheet M can be changed by a drive motor or the like. Specifically, the convex portion 590 can be varied between a position where the convex portion 590 can be pressed against (pressed against) the paper M placed on the support surface T and a position where the convex portion 590 and the paper M are not in contact with each other. Is done.
For example, the pressing unit 580 is disposed at a relatively flat place on the downstream side of the second inversion path 249 (see FIG. 1). Then, a support surface T that supports the paper M may be provided on the second inversion path 249 corresponding to the pressing unit 580. Even if it does in this way, the same effect as the above can be acquired.

(Modification 2) The convex portions 290 and 490 of the pressing portions 280 and 480 of the first and second embodiments have a gently curved surface, but are not limited thereto. Hereinafter, other embodiments of the convex portion will be described. 24 to 27 are examples of other forms of the pressing portion according to this modification. First, as illustrated in FIG. 24, the pressing portion 690 includes a roller 695, and a plurality of convex portions 691 are formed on the surface of the roller 695. The convex portion 691 has a quadrangular prism shape. Even in this case, the convex portion 691 can be pressed against the paper M. The shape of the convex portion 691 is not limited to a quadrangular prism but may be a polygonal prism.
As shown in FIG. 25, the pressing portion 790 includes a roller 795, and a plurality of convex portions 791 are formed on the surface of the roller 795. The convex portion 791 has a columnar shape having a substantially X shape in plan view. Even in this manner, the convex portion 791 can be pressed against the paper M.
In addition, as illustrated in FIG. 26, the pressing unit 890 includes a roller 895, and a plurality of convex portions 891 are formed on the surface of the roller 895. The convex portion 891 has a cylindrical shape. Even in this way, the convex portion 891 can be pressed against the paper M. Note that the shape of the convex portion 891 is not limited to a cylindrical shape, and may be a columnar shape.
As shown in FIG. 27, the pressing portion 990 includes a roller 995, and a plurality of convex portions 991 are formed on the surface of the roller 995. The convex portion 991 has a spherical shape. Even in this way, the convex portion 991 can be pressed against the paper M.
In addition, it is comprised so that the distance from the rotating shaft center R (common reference) of the rollers 695,795,895,995 to the top part of each convex part 691,791,891,991 in sectional view may become equal. Accordingly, the convex portions 691, 791, 891, 991 can be uniformly pressed against the paper M.

  (Modification 3) In the first and second embodiments, the pressing portions 280 and 480 are arranged in the lead-out path 250, but the present invention is not limited to this. For example, the pressing portions 280 and 480 may be disposed in the first inversion path 248 and the second inversion path 249, respectively. According to this configuration, since the pressing portions 280 and 480 are arranged on the upstream side in the transport direction of the paper M from the lead-out path 250, the convex portions 290 and 490 are formed on the paper M before the paper M is further dried. It can be pressed and curling can be further suppressed.

  (Modification 4) In the first embodiment, the pressing unit 280 is driven based on the difference between the printing duty of the entire one surface Ma of the paper M and the printing duty of the entire other surface Mb. However, the present invention is not limited to this. Not. For example, a print duty in a partial area on one side Ma of the paper M (for example, an edge portion of the paper M) and a partial area on the other side Mb corresponding to a partial area on the one side Ma of the paper M. The pressing unit 280 may be driven based on the difference from the printing duty. Then, the difference between the print duty in a partial area on one side Ma of the paper M and the print duty in a partial area on the other side Mb corresponding to the partial area on the one side Ma of the paper M is greater than or equal to a predetermined value. In this case, the convex portion 290 is pressed against only a partial area of the paper M. That is, in the area of the sheet M that presses the convex portion 290, the sheet M is pressed by the first roller 281 and the second roller 291 and the first roller 281 and the second roller 291 are separated in other areas. In this way, the occurrence of curling can be suppressed more efficiently.

  (Modification 5) In the above embodiment, the intermediate transfer device 200 and the post-processing device 300 are configured separately, but the present invention is not limited to this configuration. For example, the post-processing device 300 may include the intermediate transfer device 200. That is, the post-processing apparatus 300 includes an intermediate conveyance path 218 as a conveyance path, a conveyance unit 252 that conveys the paper M along the intermediate conveyance path 218, and a convex portion 290, and a sheet that conveys the intermediate conveyance path 218. A pressing unit 280 that presses the convex portion 290 against M, a stacker 328 that temporarily places the paper M conveyed from the intermediate conveyance path 218, and the paper M that is placed on the stacker 328, An apparatus provided with a post-processing unit 325 that executes post-processing may be used. Even in this case, since the paper M is placed on the stacker 328 in a state where curling is suppressed, the paper M can be aligned and the post-processing can be reliably performed without a conveyance defect.

  (Modification 6) In the above-described embodiment, the recording unit 110 in the image forming apparatus 100 has been described by taking the line head type recording head 111 capable of simultaneously discharging ink over substantially the entire width direction of the paper M as an example. The configuration is not limited to this. For example, a serial head printer may be used. Further, the image forming apparatus 100 may be configured to include a conveyance path dedicated to single-sided printing. Even if it does in this way, the same effect as the above can be acquired.

DESCRIPTION OF SYMBOLS 1 ... Printing apparatus, 10 ... Control part, 100 ... Image forming apparatus, 110 ... Recording part, 111 ... Recording head, 153 ... 3rd discharge path, 200 ... Intermediate conveyance apparatus, 218 ... Intermediate conveyance path (conveyance path), 241 ... 1st inversion part, 242 ... 2nd inversion part, 243 ... introduction path, 244 ... 1st branch path, 245 ... 2nd branch path, 246 ... 1st merge path, 247 ... 2nd merge path, 248 ... 1st Reversing path, 249 ... second reversing path, 250 ... leading path, 252 ... intermediate transport section (transport section), 280 ... pressing section, 280a ... first pressing section, 280b ... second pressing section, 281 ... first roller, 284 ... soft body, 290 ... convex part, 290a ... concave part, 291 ... second roller, 300 ... post-processing device, 325 ... post-processing part, 328 ... stacker, 480 ... pressing part, 481 ... first roller, 490 ... convex Part, 49 a ... concave portion, 491 ... second roller, 580 ... pressing portion, 581 ... plate portion, 581a ... flat surface, 590 ... convex portion, 690 ... pressing portion, 691 ... convex portion, 695 ... roller, 790 ... pressing portion, 791 ... convex part, 795 ... roller, 890 ... pressing part, 891 ... convex part, 895 ... roller, 990 ... pressing part, 991 ... convex part, 995 ... roller, 1004 (1004A, 1004B, 1004C, 1004D, 1004E) ... cartridge , 1006. Cartridge mounting portion.

Claims (12)

A transport route;
A transport unit that transports the medium along the transport path;
An intermediate conveying apparatus comprising: a pressing portion that has a convex portion and presses the convex portion against the medium that conveys the conveyance path. In the intermediate conveyance apparatus according to claim 1,
The pressing portion has a plurality of the convex portions,
The intermediate conveying apparatus characterized in that the distance from a common reference to the top of each convex portion is equal. In the intermediate conveyance apparatus according to claim 1 or 2,
When the difference between the print duty on one side of the medium and the print duty on the other side is equal to or greater than a predetermined value, the convex portion with respect to the lower side of the one side and the other side with the lower print duty An intermediate transfer device characterized by pressing the In the intermediate conveyance device according to any one of claims 1 to 3,
The said pressing part has a roller, The said convex part is formed in the surface of the said roller, The intermediate conveyance apparatus characterized by the above-mentioned. In the intermediate conveyance device according to any one of claims 1 to 4,
The pressing portion is
A first roller;
A second roller having a higher hardness than the first roller,
The convex portion is provided on the surface of the second roller,
An intermediate transporting apparatus, wherein the medium is sandwiched between the first roller and the second roller. In the intermediate conveyance apparatus according to claim 5,
The intermediate conveying apparatus, wherein the convex part has a curved surface. In the intermediate conveyance apparatus according to claim 5 or 6,
Two pairs of the pressing parts are provided,
Along the conveyance direction of the medium in the conveyance path, in one of the two pressing portions, the one surface of the medium and the second roller face each other, and the other pressing portion. Then, it arrange | positions so that the other surface opposite to the said one surface of the said medium and the said 2nd roller may oppose, The intermediate conveyance apparatus characterized by the above-mentioned. In the intermediate conveyance device according to any one of claims 5 to 7,
The intermediate conveying apparatus, wherein the first roller and the second roller are separable. In the intermediate transfer device according to claim 7 or 8,
The transport path is
An introduction path through which the medium is introduced;
A first branch path and a second branch path that branch in different directions from a branch point that is a downstream end of the introduction path in a conveyance direction in which the medium introduced from the introduction path is conveyed;
A first inversion path through which the medium is inverted from the downstream end of the first branch path;
A second inversion path through which the medium is inverted from the downstream end of the second branch path;
A first merging path through which the medium reversed by the first reversing path is conveyed;
A second merging path through which the medium reversed by the second reversing path is conveyed;
A derivation path extending from a merging point where the downstream end of the first merging path and the downstream end of the second merging path merge,
The intermediate conveying apparatus, wherein the two pairs of pressing portions are arranged in the lead-out path. In the intermediate conveyance device according to any one of claims 1 to 4,
The pressing portion is
A first roller;
A second roller,
The protrusions are provided on the surfaces of the first roller and the second roller,
An intermediate transporting apparatus, wherein the medium is sandwiched between the first roller and the second roller. A transport route;
A transport unit that transports the medium along the transport path;
A pressing part that has a convex part and presses the convex part against the medium transporting the transport path;
A stacker for temporarily placing the medium conveyed from the conveyance path;
A post-processing apparatus, comprising: a post-processing unit that performs post-processing on the medium placed on the stacker. An image forming apparatus for forming an image on a medium;
An intermediate transport apparatus having a transport path, a transport section that transports the medium along the transport path, and a pressing section that has a convex section and presses the convex section against the medium that transports the transport path. When,
A post-processing apparatus comprising: a stacker for temporarily placing the medium transported from the transport path; and a post-processing unit for performing post-processing on the medium placed on the stacker. A printing apparatus comprising:

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