JP2017217894A - Inkjet recording device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inkjet recording device that can stably impart a waveform shape to a sheet.SOLUTION: The inkjet recording device comprises: a conveyance roller pair 59 which is provided in a conveyance path 65 of a sheet 12, and holds the sheet 12 at a plurality of nip positions NP along a right and left direction 9; a recording head 38 which is arranged at a downstream side in a conveyance direction 15 of the nip positions NP, and discharges ink droplets from nozzles 39; a waveform-shape imparting mechanism 75 having a plurality of contact members 81 which come into contact with an upper surface of the sheet 12 between the nip positions NP and the nozzles 39 in the conveyance path 65 and are disposed at intervals in a right and left direction 9, and imparting a waveform-shape to the sheet 12; an arm 112 which can be moved to a first position protruding into the conveyance path 65 from a lower part and a second position protruding less than the first position, at an upstream position in a conveyance direction 15 of the nip position NP and is energized to the first position; and an optical sensor 113 that detects the arm 112. In the right and left direction 9, a position of one end part 112A of the arm 112 does not overlap with a position of an end part 81B at the downstream side of the contact member 81.SELECTED DRAWING: Figure 5

Description

  The present invention relates to an inkjet recording apparatus that records an image on a sheet by ejecting ink from nozzles.

  2. Description of the Related Art Conventionally, ink jet recording apparatuses that record an image on a sheet by discharging ink from nozzles provided in a recording head are known. In an ink jet recording apparatus, a sheet conveyed through a conveyance path formed inside the apparatus may be lifted from a platen that supports the sheet. If the lift of the sheet occurs at a position facing the recording head, the distance between the sheet and the recording head changes, which may affect the image quality of the image recorded on the sheet.

  In order to solve such a problem, Patent Document 1 discloses an ink jet recording apparatus configured to give a wave shape along a width direction orthogonal to the conveyance direction to a sheet conveyed in the conveyance direction. Is disclosed. The ink jet recording apparatus includes a plurality of contact portions in order to give a wave shape to the sheet. The plurality of abutting portions are arranged at intervals in the width direction downstream of the conveyance roller pair in the conveyance path in the conveyance direction of the sheet and upstream in the conveyance direction of the nozzle, and press the upper surface of the sheet.

  Further, the ink jet recording apparatus includes a registration sensor for detecting the sheet upstream of the conveyance roller pair in the conveyance path in the conveyance direction. The registration sensor protrudes into the conveyance path from below to above and is biased upward.

Japanese Patent Laying-Open No. 2015-24602

  In the ink jet recording apparatus disclosed in Patent Document 1, the sheet is urged upward by a registration sensor. As a result, the sheet is deformed upward at the portion urged by the registration sensor. For this reason, if the abutting portion comes into contact with the upper surface of the sheet downstream of the registration sensor in the transport direction, the corrugated shape may not be stably imparted to the sheet depending on the position of the abutting portion in the width direction. It was.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an ink jet recording apparatus that can stably give a wave shape to a sheet.

  (1) An ink jet recording apparatus according to the present invention is provided in a conveyance path through which a sheet passes, and the sheet is nipped at a plurality of nip positions spaced in the width direction perpendicular to the sheet conveyance direction. A transport unit that transports in the direction of travel, and is disposed downstream of the plurality of nip positions in the transport path in the transport direction, and is disposed in one of the transport direction in the transport path and an orthogonal direction that is orthogonal to the width direction. A recording head that ejects ink droplets from the nozzles toward the sheet that is conveyed along the conveyance path; and the recording head that is disposed opposite to the recording head and disposed on the other of the orthogonal directions in the conveyance path. Between the platen that supports the sheet and the plurality of nip positions and the nozzles in the conveyance path, facing the nozzles in the sheet. A wave shape imparting mechanism that has a plurality of first abutting portions that are in contact with one surface and are spaced apart in the width direction, and that imparts a wave shape along the width direction to the sheet, and the conveyance path At a position upstream of the plurality of nip positions in the conveyance direction, and having a protruding portion that protrudes into the conveyance path from the other of the orthogonal directions to the other, the first position, and the first position A moving member that can move to a second position where the protruding amount of the protruding portion into the conveyance path is small and is biased toward the first position, and the moving member at the first position or the second position. And a sensor for detecting. In the width direction, the position of the protrusion does not overlap with the position of the plurality of first contact portions.

  According to the said structure, the part which contact | abuts the protrusion part in a sheet | seat deform | transforms upwards. When a wave shape is given to the sheet, a portion of the sheet that is in contact with the first contact portion is deformed downward to become a wave-shaped recess. And according to the said structure, the position of the protrusion part does not overlap with the position of a some 1st contact part in the width direction. That is, in the width direction, the portion that deforms upward of the sheet is different from the portion that deforms downward of the sheet. As a result, it is possible to avoid a situation in which the corrugation cannot be stably applied to the sheet.

  (2) The wave shape imparting mechanism is located between the plurality of first contact portions adjacent in the width direction, and contacts the second surface on the back of the first surface of the sheet. It further has a second abutting portion that cooperates with the first abutting portion to give the sheet a wave shape along the width direction. In the width direction, the position of the protrusion overlaps with the position of the second contact portion.

  According to the said structure, the part which contact | abuts the protrusion part in a sheet | seat deform | transforms upwards. When a wave shape is given to the sheet, the portion of the sheet that is in contact with the second contact portion is deformed upward to become a wave-shaped convex portion. And according to the said structure, the position of the protrusion part overlaps with the position of a 2nd contact part in the width direction. That is, in the width direction, portions that are deformed upward of the sheet are substantially at the same position. Thereby, a waveform can be stably provided with respect to a sheet | seat.

  (3) In the width direction, the position of the protruding portion does not overlap with the plurality of nip positions.

  The sheet is in a state of being deformed upward in contact with the protruding portion upstream of the plurality of nip positions in the conveyance direction. According to the above configuration, since the position of the protruding portion does not overlap with the plurality of nip positions in the width direction, the sheet is conveyed downstream in the conveyance direction from the plurality of nip positions without breaking the state. can do.

  (4) Of the intervals between the plurality of adjacent nip positions, the interval corresponding to the protrusion in the width direction is the same as the protrusion in the width direction among the intervals between the adjacent nip positions. Greater than unsupported interval.

  According to the said structure, the space | interval corresponding to a protrusion part is large in the width direction among the space | intervals between adjacent nip positions. Therefore, the sheet can be transported from the upstream in the transport direction to the downstream of the plurality of nip positions from the upstream in the transport direction without losing the deformed state in contact with the protrusion.

  (5) The protrusion is disposed at the center of the conveyance path in the width direction. The plurality of first contact portions are arranged symmetrically with respect to an imaginary line that passes through the center of the conveyance path in the width direction and extends along the conveyance direction at a viewpoint along the orthogonal direction. Yes.

  According to the said structure, the some 1st contact part is arrange | positioned equally centering on the protrusion part in the width direction. Thereby, the wave shape along the width direction can be stably provided to the sheet.

  (6) For example, the transport unit includes a driving roller and a driven roller that is disposed to face the driving roller and is driven by the driving roller.

  (7) For example, the drive roller contacts the first surface of the sheet, and the driven roller contacts the second surface behind the first surface of the sheet.

  (8) For example, a plurality of the driven rollers are provided at intervals in the width direction.

  According to the present invention, a wave shape along the width direction can be stably imparted to the sheet.

FIG. 1 is a perspective view of a multifunction machine 10 as an example of an embodiment of the present invention. FIG. 2 is a longitudinal sectional view schematically showing the internal structure of the printer unit 11. FIG. 3 is a cross-sectional view taken along the line III-III in FIG. 2 and shows the conveying roller pair 59 and the detection unit 110. FIG. 4 is a cross-sectional view taken along the line IV-IV in FIG. 2 and shows the wave shape imparting mechanism 75 and the platen 42. FIG. 5 is a plan view schematically showing the wave shape imparting mechanism 75, the transport roller pair 59, the platen 42, and the detection unit 110. FIG. 6 is a plan view schematically showing the wave shape imparting mechanism 75, the conveyance roller pair 59, the platen 42, and the detection unit 110 in the modified example.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings as appropriate. The embodiment described below is merely an example of the present invention, and it is needless to say that the embodiment of the present invention can be changed as appropriate without departing from the gist of the present invention. In the following description, the vertical direction 7 is defined with reference to the state where the multifunction machine 10 is installed (the state shown in FIG. 1), and the front-rear direction 8 is defined with the surface on which the opening 13 is provided as the front surface 14. Then, the left-right direction 9 is defined when the multifunction machine 10 is viewed from the front. The up-down direction 7, the front-rear direction 8, and the left-right direction 9 are orthogonal to each other.

[Overall structure of MFP 10]
As shown in FIG. 1, the multifunction machine 10 (an example of an ink jet recording apparatus) is generally formed in a thin rectangular parallelepiped. A printer unit 11 is provided in the lower part of the multifunction machine 10. The multifunction machine 10 has various functions such as a facsimile function and a print function. The multifunction machine 10 has a function of recording an image on one side of a sheet 12 (see FIG. 2, an example of a sheet) by an inkjet method as a print function. Note that the multifunction machine 10 may record an image on one side and both sides of the paper 12.

[Feeding tray 20]
As shown in FIG. 1, an opening 13 is formed in the front of the printer unit 11. The feeding tray 20 can be inserted into and removed from the printer unit 11 through the opening 13 by moving in the front-rear direction 8. The feeding tray 20 is a box-shaped member that is open at the top. As shown in FIG. 2, the bottom plate 22 of the feeding tray 20 supports the sheets 12 in a stacked state. A discharge tray 21 is supported above the front portion of the feeding tray 20. The discharge tray 21 moves in the front-rear direction 8 together with the feeding tray 20. On the upper surface of the discharge tray 21, the paper 12 on which an image is recorded by the recording unit 24 is discharged. The discharge tray 21 may be supported by the printer unit 11.

[Feeding unit 16]
As shown in FIG. 2, the feeding unit 16 is disposed below the recording unit 24. The feeding unit 16 includes a feeding roller 25, a feeding arm 26, a drive transmission mechanism 27, and a shaft 28. The feed roller 25 is rotatably supported at the tip end portion of the feed arm 26. The feeding arm 26 rotates in the direction of an arrow 29 about a shaft 28 provided at the base end. As a result, the feed roller 25 can be brought into contact with and separated from the feed tray 20 or the paper 12 supported by the feed tray 20.

  The feeding roller 25 is rotated by a driving force of a feeding motor (not shown) transmitted by a drive transmission mechanism 27 in which a plurality of gears are engaged. As a result, among the sheets 12 supported by the bottom plate 22 of the feeding tray 20, the uppermost sheet 12 that is in contact with the feeding roller 25 is fed to the conveyance path 65. The drive transmission mechanism 27 is not limited to a form in which a plurality of gears are meshed, and may be a belt spanned between the shaft 28 and the shaft of the feeding roller 25, for example.

[Conveyance path 65]
As shown in FIG. 2, a conveyance path 65 extends from the rear end portion of the feeding tray 20. The conveyance path 65 is a path through which the paper 12 passes. The conveyance path 65 includes a curved portion 33 and a straight portion 34. The curved portion 33 extends so as to make a U-turn from the rear to the front while moving upward. The straight portion 34 extends substantially along the front-rear direction 8.

  The bending portion 33 is formed by an outer guide member 18 and an inner guide member 19 that face each other with a predetermined interval. The outer guide member 18 and the inner guide member 19 are extended in the left-right direction 9 (an example of the width direction) which is a direction orthogonal to the paper surface in FIG. The straight line portion 34 is formed by a conveying roller pair 59 described later, a recording portion 24 and a platen 42 facing each other with a predetermined interval, and a discharge roller pair 44 described later.

  The sheet 12 supported by the feeding tray 20 is conveyed by the feeding roller 25 through the curved portion 33 and reaches the conveying roller pair 59. The sheet 12 sandwiched between the conveyance roller pair 59 is conveyed forward with the straight line portion 34 directed toward the recording unit 24. An image is recorded by the recording unit 24 on the sheet 12 that has arrived immediately below the recording unit 24. The sheet 12 on which the image is recorded is conveyed forward through the linear portion 34 and discharged to the discharge tray 21. As described above, the sheet 12 is transported along the transport direction 15 indicated by the one-dot chain line arrow in FIG. The conveyance direction 15 is orthogonal to the left-right direction 9.

[Recording unit 24]
As shown in FIG. 2, the recording unit 24 is disposed above the linear part 34. A platen 42 is disposed below the straight line portion 34 and at a position facing the recording head 38 of the recording unit 24. That is, the platen 42 is disposed below the linear portion 34. As described above, the recording unit 24 is disposed in one of the up and down directions 7 (an example of the orthogonal direction) in the straight portion 34, and the platen 42 is disposed in the other of the up and down directions 7 in the straight portion 34.

  The platen 42 is a flat plate-like member in which the length in the front-rear direction 8 and the left-right direction 9 is longer than the length in the up-down direction 7. As shown in FIG. 5, the platen 42 includes a plurality of ribs 76 (an example of a second contact portion) on the upper surface 43 thereof. Each rib 76 extends in the front-rear direction 8. The ribs 76 are provided at intervals in the left-right direction 9. In the present embodiment, five ribs 76 are provided, but the number of ribs 76 is not limited to five.

  As shown in FIG. 4, the platen 42 supports the paper 12 that is transported in the transport direction 15 through the linear portion 34 of the transport path 65 by the upper ends of the ribs 76. That is, the rib 76 contacts the lower surface of the paper 12 (the back surface of the paper 12). The lower surface of the paper 12 is an example of the second surface. Note that the platen 42 may not have a flat plate shape as long as it can support the paper 12.

  As shown in FIG. 2, the recording unit 24 includes a carriage 40 and a recording head 38. The carriage 40 is supported so as to be movable along the left-right direction 9 by two guide rails 56, 57 arranged at intervals in the front-rear direction 8. The guide rail 56 is disposed upstream of the recording head 38 in the transport direction 15. The guide rail 57 is disposed downstream of the recording head 38 in the transport direction 15. The guide rails 56 and 57 are supported by a pair of side frames (not shown) arranged outside the straight portion 34 of the transport path 65 in the left-right direction 9. The carriage 40 moves when a driving force is applied from a carriage drive motor (not shown).

  The recording head 38 is mounted on the carriage 40. Ink is supplied to the recording head 38 from an ink cartridge (not shown). A plurality of nozzles 39 are formed on the lower surface of the recording head 38. When the carriage 40 moves in the left-right direction 9, the recording head 38 ejects ink droplets from the nozzles 39 toward the platen 42. As a result, the linear portion 34 is conveyed in the conveying direction 15 and an image is recorded on the paper 12 supported by the platen 42.

[Conveying roller pair 59 and discharging roller pair 44]
As shown in FIG. 2, a pair of conveyance rollers 59 (an example of a conveyance unit) is arranged upstream of the recording head 38 in the linear portion 34 in the conveyance direction 15. A discharge roller pair 44 is disposed downstream of the recording head 38 in the linear portion 34 in the transport direction 15.

  The conveyance roller pair 59 includes a conveyance roller 60 (an example of a driving roller) and a pinch roller 61 (an example of a driven roller) disposed below the conveyance roller 60 so as to face the conveyance roller 60.

  As shown in FIG. 3, the transport roller 60 is a columnar member that extends in the left-right direction 9. The transport roller 60 is supported by a pair of side frames (not shown) so as to be rotatable about an axis 66 along the left-right direction 9.

  A plurality of pinch rollers 61 are provided at intervals in the left-right direction 9. In the present embodiment, four pinch rollers 61 are provided, but the number of pinch rollers 61 is not limited to four. Each pinch roller 61 is supported by a roller holder (not shown) so as to be rotatable about an axis 67 along the left-right direction 9. Each pinch roller 61 is pressed against the conveyance roller 60 by an elastic member (not shown) such as a coil spring.

  The conveyance roller 60 contacts the upper surface of the paper 12 (the surface of the paper 12). The upper surface of the paper 12 is a surface facing the nozzle 39 of the recording unit 24 and is an example of a first surface. Each pinch roller 61 contacts the lower surface of the paper 12. Thereby, the conveyance roller pair 59 can hold the paper 12.

  As described above, the four pinch rollers 61 are provided at intervals in the left-right direction 9. Therefore, as shown in FIGS. 3 and 5, the transport roller 60 and the pinch roller 61 pinch the paper 12 at four nip positions NP spaced apart in the left-right direction 9. The nip position NP is an area where the conveyance roller 60 and the pinch roller 61 are in contact with each other when the sheet 12 is not sandwiched between the conveyance roller pair 59. As described above, the conveyance roller pair 59 is disposed upstream of the recording direction 38 in the linear portion 34 in the conveyance direction 15. Therefore, the nip position NP is arranged upstream of the recording direction 38 in the linear portion 34 in the transport direction 15.

  As shown in FIG. 3 and FIG. 5, among the three intervals I1, I2, and I3 between the plurality of adjacent nip positions NP, the interval I2 located at the center in the left-right direction 9 is outside both sides in the left-right direction 9. It is larger than the intervals I1 and I3 located in the direction. In other words, the length of the interval I2 in the left-right direction 9 is longer than the length of the intervals I1, I3 in the left-right direction 9. Note that the length of the interval I2 in the left-right direction 9 may be equal to or less than the length of the intervals I1, I3 in the left-right direction 9.

  As shown in FIG. 2, the discharge roller pair 44 includes a discharge roller 62 and a spur 63 disposed above the discharge roller 62 so as to face the discharge roller 62.

  The discharge roller 62 includes a shaft 64 extending in the left-right direction 9 and a roller portion 58 attached so as to cover the shaft 64 with a space in the left-right direction 9. The discharge roller 62 is rotatably supported by a pair of side frames (not shown).

  A plurality of spurs 63 are provided at intervals in the left-right direction 9. Each spur 63 is provided at a position facing the roller portion 58 of the discharge roller 62. The spur 63 is pressed against the roller portion 58 of the discharge roller 62 by an elastic member (not shown) such as a coil spring. The discharge roller pair 44 can sandwich the paper 12.

  The conveyance roller 60 and the discharge roller 62 are rotated by a driving force applied from the conveyance motor. When the transport roller 60 rotates while the paper 12 is sandwiched between the transport roller pair 59, the paper 12 is transported in the transport direction 15 by the transport roller pair 59 and transported onto the platen 42. When the discharge roller 62 rotates while the paper 12 is held between the discharge roller pair 44, the paper 12 is transferred in the transfer direction 15 by the discharge roller pair 44 and is transferred onto the discharge tray 21.

[Abutting member 81]
As shown in FIG. 2, an abutting member 81 is disposed upstream of the nozzle 39 in the linear portion 34 in the transport direction 15. The contact member 81 is formed of a synthetic resin (for example, polyacetal (POM)).

  As shown in FIG. 4, a plurality of contact members 81 are arranged at intervals in the left-right direction 9. In the present embodiment, the number of contact members 81 is six, but may be a number other than six. Each contact member 81 may be independent or connected to each other.

  As shown in FIG. 2, each contact member 81 is attached to the guide rail 56 by a known means such as fitting at the upstream end 81 </ b> A in the conveying direction 15. Each contact member 81 is curved downward and forward from the upstream end 81A. Thereby, each contact member 81 is extended to the upstream vicinity of the conveyance direction 15 of the nozzle 39 arranged most upstream among the plurality of nozzles 39. Each contact member 81 extends toward the platen 42 in the vertical direction 7. The downstream end portion 81 </ b> B (an example of the first contact portion) in the conveyance direction 15 of each contact member 81 can contact the upper surface of the paper 12 supported by the platen 42. The downstream end portion 81 </ b> B is located between the nip position NP and the nozzle 39 in the linear portion 34.

[Waveform imparting mechanism 75]
As shown in FIG. 4, the wave shape imparting mechanism 75 includes the plurality of ribs 76 and the plurality of contact members 81 described above. The wave shape imparting mechanism 75 imparts a wave shape along the left-right direction 9 to the paper 12.

  Each rib 76 is located between the downstream end portions 81 </ b> B of the contact members 81 adjacent in the left-right direction 9. The upper end of each rib 76 is located above the lower end of the downstream end portion 81 </ b> B of each contact member 81. In other words, the portion of each rib 76 that contacts the lower surface of the paper 12 is positioned above the portion of the downstream end 81 </ b> B of each contact member 81 that contacts the upper surface of the paper 12. As a result, the paper 12 supported by the ribs 76 and in contact with the downstream end portion 81 </ b> B of each contact member 81 has a wave shape continuous in the left-right direction 9. That is, the plurality of ribs 76 give a wave shape along the left-right direction 9 to the sheet 12 in cooperation with the plurality of contact members 81.

[Detection unit 110]
As shown in FIG. 2, a detection unit 110 is provided upstream of the nip position NP in the transport path 65 in the transport direction 15. As illustrated in FIGS. 2 and 3, the detection unit 110 includes a shaft 111, an arm 112 (an example of a moving member) that can rotate around the shaft 111, a light emitting element 117 that emits light, and a light emitting element 117. The optical sensor 113 (an example of a sensor) which has the light receiving element 118 which receives the light irradiated from 1 and the urging member 114 are provided.

  The arm 112 is rotatable to a first position indicated by a solid line in FIG. 2 and a second position indicated by a broken line in FIG.

  One end 112 </ b> A (an example of a protruding portion) of the arm 112 at the first position protrudes into the transport path 65 from the inner guide member 19 toward the outer guide member 18. The protruding tip of the one end 112 </ b> A of the arm 112 at the first position protrudes to the vicinity of the outer guide member 18.

  One end 112A of the arm 112 at the second position protrudes into the transport path 65 from the inner guide member 19 toward the outer guide member 18 as in the first position, but one end of the arm 112 at the second position. The protruding tip of 112A does not protrude to the vicinity of the outer guide member 18. That is, the amount of protrusion of the one end 112A of the arm 112 at the second position into the transport path 65 is smaller than the amount of protrusion of the arm 112 at the first position into the transport path 65. Note that the amount of protrusion of the one end 112A of the arm 112 at the second position into the transport path 65 may be zero. That is, the one end 112 </ b> A of the arm 112 at the second position may not protrude into the transport path 65.

  The optical sensor 113 detects the arm 112. The light emitting element 117 and the light receiving element 118 of the optical sensor 113 are arranged so as to sandwich the other end 112B of the arm 112 at the first position. The light emitting element 117 and the light receiving element 118 may be arranged so as to sandwich the other end 112B of the arm 112 at the second position. Further, the arm 112 is not limited to the optical sensor 113 but may be a mechanical sensor, for example.

  The biasing member 114 is a coil spring. One end of the urging member 114 is attached to the other end 112B of the arm 112. The other end of the urging member 114 is attached to the frame 115 of the printer unit 11. The urging member 114 is arranged to urge the arm 112 from the second position to the first position. In the present embodiment, the urging member 114 has a natural length when the arm 112 is in the first position, and is longer than the natural length when the arm 112 is in the second position. Accordingly, the biasing member 114 applies a biasing force to the first position with respect to the arm 112 at the second position. The urging member 114 is not limited to a coil spring as long as it urges the arm 112, and may be a leaf spring, for example. Further, the arm 112 may be urged toward the first position without depending on the urging member 114. For example, by setting the weights of the portion of the arm 112 closer to the shaft 111 and the portion of the arm 112 closer to the shaft 111 to different weights, the arm 112 is biased toward the first position by its own weight. You may make it do.

  When an external force is not applied to the one end 112A of the arm 112, the arm 112 is in the first position. The other end 112B of the arm 112 at the first position enters the optical path from the light emitting element 117 to the light receiving element 118 of the optical sensor 113 and blocks light passing through the optical path. At this time, a low level signal is output from the optical sensor 113 to a control unit (not shown). That is, the optical sensor 113 outputs a low level signal when detecting the arm 112 at the first position. Here, the control unit is configured by a CPU, a memory, and the like, and controls the operation of the multifunction machine 10 by the CPU executing a program stored in the memory.

  When the one end 112A of the arm 112 is pushed by the leading end of the sheet 12 to be conveyed, the arm 112 rotates from the first position to the second position in the direction of the arrow 116. When the arm 112 is rotated to the second position, the other end 112B of the arm 112 is removed from the optical path, and light passes through the optical path. At this time, a high level signal is output from the optical sensor 113 to the control unit. That is, the optical sensor 113 outputs a high level signal when detecting the arm 112 at the second position. Based on the signal from the optical sensor 113, the control unit detects the downstream end of the paper 12 in the transport direction 15 (the front end of the paper 12) and the upstream end of the paper 12 in the transport direction 15 (the rear end of the paper 12).

  When the rear end of the paper 12 is separated from the arm 112 by the paper 12 passing through the arm 112, the arm 112 is urged by the urging member 114 and rotates in the direction opposite to the arrow 116 to rotate the first. Return to position.

[Position of arm 112 in the left-right direction 9]
As shown in FIGS. 3 and 5, the position of the one end 112A of the arm 112 in the left-right direction 9 is included in the range of the interval I2. In other words, in the left-right direction 9, the interval I <b> 2 corresponds to the arm 112. Here, as described above, the interval I2 is an interval located at the center in the left-right direction 9 among the three intervals I1, I2, and I3 between the plurality of adjacent nip positions NP. That is, in the left-right direction 9, the position of the one end 112A of the arm 112 does not overlap with the plurality of nip positions NP. In the left-right direction 9, one end 112A of the arm 112 corresponds to the interval I1 that is longer in the left-right direction 9 than the intervals I2, I3.

  As shown in FIG. 5, in the left-right direction 9, the position of the one end portion 112 </ b> A of the arm 112 is between the downstream end portions 81 </ b> B of the adjacent contact members 81. That is, in the left-right direction 9, the position of the one end 112 </ b> A of the arm 112 does not overlap with the position of the downstream end 81 </ b> B of the contact member 81.

  As shown in FIG. 5, the position of the one end 112 </ b> A of the arm 112 overlaps the position of the rib 76 in the left-right direction 9.

  As shown in FIG. 5, one end 112 </ b> A of the arm 112 is disposed at the center of the straight line portion 34 in the left-right direction 9. In addition, the downstream end portions 81 </ b> B of the six contact members 81 are arranged symmetrically with respect to the virtual line 74 at the viewpoint along the vertical direction 7. The virtual line 74 is a line that passes through the center of the straight portion 34 in the left-right direction 9 and extends along the front-rear direction 8 (conveying direction 15).

  Of the five ribs 76, the rib 76 disposed at the center in the left-right direction 9 is located at the center of the straight line portion 34 in the left-right direction 9, that is, on the imaginary line 74. In addition, among the five ribs 76, the four ribs 76 arranged other than the center in the left-right direction 9 are arranged symmetrically with respect to the virtual line 74. The four pinch rollers 61 are arranged symmetrically with respect to the virtual line 74.

  Note that the one end portion 112 </ b> A of the arm 112 may be disposed at a position other than the center of the straight portion 34 in the left-right direction 9. Further, the downstream end 81 </ b> B of the contact member 81, the rib 76, and the pinch roller 61 may not be arranged symmetrically with respect to the virtual line 74.

[Effect of the embodiment]
According to the present embodiment, the portion of the paper 12 that contacts the one end 112A of the arm 112 is pushed by the one end 112A of the arm 112 biased by the biasing member 114 and deformed upward. When the corrugated shape is imparted to the paper 12, the portion of the paper 12 that is in contact with the downstream end 81B of the abutting member 81 is deformed downward to become a corrugated concave portion. According to the above embodiment, in the left-right direction 9, the position of the one end 112 </ b> A of the arm 112 does not overlap with the position of the downstream end 81 </ b> B of the plurality of contact members 81. That is, in the left-right direction 9, the portion that deforms upward of the paper 12 and the portion that deforms downward of the paper 12 are at different positions. As a result, it is possible to avoid a situation in which a waveform cannot be stably applied to the paper 12.

  Further, according to the present embodiment, the portion of the paper 12 that contacts the one end portion 112 </ b> A of the arm 112 is pushed by the one end portion 112 </ b> A of the arm 112 that is biased by the biasing member 114 and is deformed upward. When the corrugated shape is imparted to the paper 12, the portion of the paper 12 that is in contact with the rib 76 is deformed upward to become a corrugated convex portion. According to the above embodiment, the position of the one end 112 </ b> A of the arm 112 overlaps the position of the rib 76 in the left-right direction 9. That is, in the left-right direction 9, the portions that deform upward of the paper 12 are substantially at the same position. Thereby, a wave shape can be stably given to the paper 12.

  Further, according to the present embodiment, the sheet 12 is in a state of being deformed upward in contact with the one end 112A of the arm 112 upstream of the plurality of nip positions NP in the transport direction 15. According to the above-described embodiment, the position of the one end 112A of the arm 112 in the left-right direction 9 does not overlap with the plurality of nip positions NP. It can be transported downstream in the transport direction 15 from NP.

  Further, according to the present embodiment, the interval corresponding to the one end portion 112A of the arm 112 in the left-right direction 9 is large among the intervals between the plurality of adjacent nip positions NP. Therefore, the sheet 12 is moved in the conveyance direction 15 more than the plurality of nip positions NP from the upstream of the plurality of nip positions NP from the upstream of the plurality of nip positions NP without breaking the state deformed upward by contacting the one end 112A of the arm 112. It can be conveyed downstream.

[Modification]
In the above embodiment, in the left-right direction 9, the position of the one end 112 </ b> A of the arm 112 overlaps the position of the rib 76. However, as shown in FIG. 6, in the left-right direction 9, the position of the one end 112 </ b> A of the arm 112 may not overlap with the position of the rib 76.

  In the above embodiment, the position of the one end 112A of the arm 112 in the left-right direction 9 is included in the range of the interval I2, but the position of the one end 112A of the arm 112 is included in the range of the intervals I1 and I3. It may be.

  In the above embodiment, only one arm 112 is arranged, but a plurality of arms 112 may be arranged. For example, three arms 112 may be arranged, and each of the three arms 112 may be arranged at intervals I1, I2, and I3.

  In the above embodiment, the position of the one end 112A of the arm 112 in the left-right direction 9 may be included in the range of the nip position NP. That is, in the left-right direction 9, the position of the one end 112A of the arm 112 may not be included in the range of the intervals I1, I2, and I3.

  In the above embodiment, a plurality of pinch rollers 61 are provided at intervals in the left-right direction 9, but the number of pinch rollers 61 may not be plural. In this case, the pinch roller 61 includes a shaft extending in the left-right direction 9 and a roller portion attached so as to cover the shaft with a space in the left-right direction 9. Each of the roller portions comes into contact with the transport roller 60, so that the transport roller 60 and the pinch roller 61 sandwich the paper 12 at a plurality of nip positions spaced in the left-right direction 9.

  In the above-described embodiment, the wave shape imparting mechanism 75 includes the contact member 81 and the rib 76, and the contact member 81 and the rib 76 cooperate to impart a wave shape to the paper 12. However, it is not limited to the contact member 81 and the rib 76 that give the paper 12 a wave shape. For example, instead of the contact member 81, a spur roller may contact the upper surface of the paper 12. For example, instead of the ribs 76, a plurality of protrusions arranged at intervals in the left-right direction 9 may contact the lower surface of the paper 12.

  In the above embodiment, the arm 112 is moved to the first position and the second position by rotating, but the arm 112 may be moved by other than rotation. For example, the arm 112 may move by sliding along the vertical direction 7 of the arm 112.

  The arm 112 is not limited to the shape shown in FIGS. 2, 3, 5, and 6, and is a shape that can move in contact with the paper 12 and can detect a change in position due to the movement. If it is, it can take an arbitrary shape.

  In the above embodiment, the pinch roller 61 is disposed below the transport roller 60 so as to face the transport roller 60. However, the transport roller 60 and the pinch roller 61 may be disposed upside down. That is, the conveyance roller 60 may be disposed below the pinch roller 61 so as to face the pinch roller 61.

  In the above embodiment, the paper 12 is transported by the roller pair (the transport roller pair 59 and the discharge roller pair 44), but the paper 12 is not transported by the roller pair. For example, the paper 12 may be conveyed by a belt disposed in the conveyance path 65. That is, the transport unit is not limited to a roller pair, and may be a belt, for example.

7 ... Up and down direction (orthogonal direction)
9 ... Left-right direction (width direction)
10: Multifunction machine (inkjet recording device)
12 ... paper (sheet)
15 ... Conveying direction 38 ... Recording head 39 ... Nozzle 42 ... Platen 59 ... Conveying roller pair (conveying unit)
65 ... conveying path 75 ... wave shape imparting mechanism 81 ... contact member 81B ... downstream end (first contact portion)
112 ... arm 112A ... one end (protruding part)
113 ... Optical sensor (sensor)
NP ... nip position

Claims (8)

A conveyance unit that is provided in a conveyance path through which the sheet passes and conveys the sheet in the conveyance direction by holding the sheet at a plurality of nip positions spaced in the width direction orthogonal to the conveyance direction of the sheet;
It is provided downstream of the plurality of nip positions in the transport path in the transport direction, and is disposed in one of the transport direction and the orthogonal direction perpendicular to the width direction in the transport path. A recording head that ejects ink droplets from nozzles toward the conveyed sheet;
A platen that is provided opposite to the recording head, is disposed on the other side in the orthogonal direction in the conveyance path, and supports a sheet;
Between the plurality of nip positions and the nozzles in the conveyance path, there are a plurality of first contact portions that are in contact with the first surface of the sheet facing the nozzles and are spaced apart in the width direction. And a wave shape imparting mechanism for imparting a wave shape along the width direction to the sheet;
A first position that has a protruding portion that protrudes into the conveyance path from the other of the orthogonal directions toward the other upstream of the plurality of nip positions in the conveyance path; A movable member that is movable to the second position where the protruding amount of the protruding portion into the conveyance path is smaller than that, and is biased toward the first position;
A sensor for detecting the moving member at the first position or the second position,
The ink jet recording apparatus, wherein, in the width direction, the position of the protruding portion does not overlap with the positions of the plurality of first contact portions. The wave shape imparting mechanism is located between the plurality of first contact portions adjacent in the width direction, and contacts the second surface behind the first surface of the sheet, thereby causing the plurality of first contact points. A second abutting portion for providing a wave shape along the width direction to the sheet in cooperation with the contacting portion;
The inkjet recording apparatus according to claim 1, wherein the position of the protruding portion overlaps the position of the second contact portion in the width direction.   The ink jet recording apparatus according to claim 1, wherein, in the width direction, the position of the protruding portion does not overlap with the plurality of nip positions.   Of the intervals between the adjacent nip positions, the interval corresponding to the protrusion in the width direction corresponds to the protrusion in the width direction among the intervals between the adjacent nip positions. The inkjet recording apparatus according to claim 3, wherein the inkjet recording apparatus is larger than the non-interval. The protrusion is disposed at the center of the conveyance path in the width direction,
The plurality of first contact portions are arranged symmetrically with respect to an imaginary line that passes through the center of the conveyance path in the width direction and extends along the conveyance direction at a viewpoint along the orthogonal direction. The ink jet recording apparatus according to claim 1.   The inkjet recording apparatus according to claim 1, wherein the transport unit includes a driving roller and a driven roller that is disposed to face the driving roller and is driven by the driving roller. The drive roller contacts the first surface of the sheet,
The inkjet recording apparatus according to claim 6, wherein the driven roller is in contact with a second surface behind the first surface of the sheet.   The ink jet recording apparatus according to claim 6, wherein a plurality of the driven rollers are provided at intervals in the width direction.

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