Printing device and control method of printing device

Abstract

To provide a printing device that can convey a medium accurately, while preventing poor conveyance caused by increase of conveyance loads.SOLUTION: A printing device 1 comprises a control part 100 that conveys a printing medium S at first acceleration V1, when conveying the printing medium S, after a stop time during which conveyance of the printing medium S is stopped exceeds a predetermined time, and conveys the printing medium S at second acceleration V2 larger than the first acceleration V1, when conveying the printing medium S before the stop time exceeds the predetermined time.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a printing device and a method for controlling a printing device. [Background technology]

[0002] Conventionally, printing devices equipped with a mechanism for drying an image printed on the printing surface of a medium have been known. For example, Patent Document 1 discloses a printing device having a drying oven with a back heater that contacts the back surface of the print medium to heat the print medium, and an air blower that is positioned opposite the back heater and blows hot air onto the surface of the print medium. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2023-133808 Summary of the Invention [Problem to be solved by the invention]

[0004] However, if the medium remains in the drying oven for a predetermined time or longer, the medium may stick to the back heater, which increases the transport load on the medium and can cause transport problems. [Means for solving the problem]

[0005] The present disclosure provides a printing apparatus including a conveying unit that performs intermittent conveyance that repeats an operation of conveying a medium a predetermined distance in a conveyance direction and an operation of stopping the conveyance of the medium, a printing unit that ejects a liquid onto the medium while the conveyance of the medium is stopped during the intermittent conveyance, a drying unit that dries the liquid ejected by the printing unit onto the medium, and a control unit, wherein the drying unit has a contact heating unit and an air flow ejection unit that is disposed at a position opposite the contact heating unit and ejects an air flow from an air flow ejection port, and the contact heating unit is configured to eject the liquid onto the medium from the printing unit. the control unit conveys the medium at a first acceleration when conveying the medium after a stop time during which conveyance of the medium by the conveying unit has stopped has elapsed for a predetermined time or more, and conveys the medium at a second acceleration greater than the first acceleration when conveyance of the medium is carried out before the stop time has elapsed for the predetermined time, and the stop time of the medium during the intermittent conveyance is less than the predetermined time.

[0006] The present disclosure provides a printing apparatus including a transport unit that performs intermittent transport, repeating an operation of transporting a medium a predetermined distance in a transport direction and an operation of stopping transport of the medium, a printing unit that ejects a liquid onto the medium while transport of the medium is stopped during the intermittent transport, and a drying unit that dries the liquid ejected onto the medium by the printing unit, wherein the drying unit has a contact heating unit and an air flow ejection unit that is disposed at a position opposite the contact heating unit and ejects an air flow from an air flow ejection port, and the contact heating unit has a printing surface that is the surface of the medium onto which the printing unit ejects the liquid, is provided with a contact heating surface that contacts the opposite back surface, and the air flow injection port faces the contact heating surface. A control method for a printing device, wherein when the medium is transported after a stop time during which the transport unit has stopped transporting the medium has elapsed for a predetermined time or more, the medium is transported at a first acceleration, and when the medium is transported before the stop time has elapsed for the predetermined time, the medium is transported at a second acceleration that is greater than the first acceleration, and the stop time of the medium during the intermittent transport is less than the predetermined time. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a diagram showing the configuration of a printing apparatus. [Figure 2] FIG. [Figure 3] FIG. 2 is a perspective view of the periphery of the drying unit of the printing apparatus as viewed from the rear side. [Figure 4] FIG. 3 is a cross-sectional view of the drying unit and its surroundings of the printing apparatus as viewed from the rear side. [Figure 5] FIG. 2 is a block diagram showing a control system of the printing apparatus. [Figure 6] A diagram showing one frame of a print medium. [Figure 7] FIG. 3 is a diagram showing values ​​of a plurality of control items controlled by a control unit. [Figure 8] 4 is a timing chart showing the operation of the printing device. [Figure 9] 4 is a flowchart showing the operation of the printing device. [Figure 10] FIG. 10 is a diagram showing the values ​​of a plurality of control items controlled by a control unit according to the first modification. [Figure 11] FIG. 10 is a diagram showing a change in the first acceleration in the second modification. DETAILED DESCRIPTION OF THE INVENTION

[0008] [1. Overall configuration of the printing device of the first embodiment] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. 1 is a schematic diagram showing the general configuration of a printing device 1 according to a first embodiment. In FIG. 1 and the figures described below, XYZ Cartesian coordinates are shown to explain the directions in the installed state of the printing device 1. The Z axis indicates the vertical direction in the installed state of the printing device 1, and can be called the height direction. The upward vertical direction is defined as the +Z direction, and the downward vertical direction is defined as the -Z direction. The X axis indicates the left-right direction of the printing device 1. The right direction as viewed from the drawing is defined as the +X direction, and the left direction as viewed from the drawing is defined as the -X direction. The Y axis is perpendicular to the X axis and can be called the front-to-back direction. The direction from the back to the front as viewed in the drawing is defined as the +Y direction, and the direction from the front to the back as viewed in the drawing is defined as the -Y direction.

[0009] The printing device 1 prints on the print medium S using the printing unit 5. Various types of sheets can be used as the print medium S used in the printing device 1. In the following explanation, a configuration is shown in which the print medium S is label paper, in which labels with adhesive on the back are arranged on release paper and wound into a roll. There are no restrictions on the printing method of the printing device 1, but in this embodiment, an inkjet printer in which ink is ejected onto the print medium S by the printing unit 5 is shown as an example of the printing device 1.

[0010] The printing device 1 has a configuration in which a medium supply unit 3, a printing unit 5, a drying unit 7, a medium collection unit 8, and a control unit 100 are arranged in a housing 2. The housing 2 is attached to a frame (not shown) of the printing device 1, and houses the above-mentioned units.

[0011] The printing medium S is transported along a transport path 10 between the medium supply unit 3 and the medium recovery unit 8. A plurality of transport rollers 301-343 that come into contact with the printing medium S are arranged along the transport path 10. The printing medium S supplied from the medium supply unit 3 is transported along the transport path 10 in a transport direction T indicated by an arrow in the figure. Along the transport path 10, the transport rollers 301-321 are located upstream of the printing unit 5. In contrast, the transport rollers 322-343 are located downstream of the printing unit 5.

[0012] The printing device 1 is equipped with motors M1 to M6, which generate the driving force to transport the printing medium S. The motors M1 to M6 correspond to an example of a transport unit. The feed motor M1, which is motor M1, drives the supply shaft 31 of the medium supply unit 3, the feed nip motor M2, which is motor M2, drives the transport roller 305, and the supply nip motor M3, which is motor M3, drives the transport roller 318. These motors M1, M2, and M3 are the supply-side power sources that supply the printing medium S from the medium supply unit 3 to the printing unit 5. Meanwhile, the discharge nip motor M4, which is motor M4, drives the transport roller 334, the take-up nip motor M5, which is motor M5, drives the transport roller 342, and the take-up motor M6, which is motor M6, drives the take-up shaft 81 of the medium collection unit 8. These motors M4, M5, and M6 are power sources on the recovery side that recover the print medium S printed by the printing unit 5 into the medium recovery unit 8.

[0013] The medium supply unit 3 includes a cylindrical or columnar supply shaft 31. A roll 32 of printing medium S wound in a roll can be attached to the supply shaft 31, and the medium supply unit 3 supports the roll 32 via the supply shaft 31. The supply shaft 31 is rotated by the power of a payout motor M1, thereby paying out the printing medium S from the roll 32 toward the printing unit 5.

[0014] The printing unit 5 prints an image on the print medium S transported on the platen 54 while the transport of the print medium S is stopped. The printing unit 5 prints characters and images on the label of the print medium S by ejecting ink toward the print medium S. These characters and images are collectively referred to as an image. The printing unit 5 includes a platen 54, multiple ejection heads 51 that eject ink, and a carriage 53 that holds the ejection heads 51. An image is formed on the printing surface of the print medium S by the ink ejected by the ejection heads 51 onto the print medium S. The platen 54 has a rectangular surface that is arranged parallel to the XY plane. The platen 54 is, for example, a rectangular flat surface that is parallel to the XY plane when the printing device 1 is installed. The platen 54 supports the print medium S from below. The platen 54 may be formed with suction holes or the like that apply suction force to the print medium S to hold the print medium S on the platen 54. The platen 54 corresponds to an example of a support unit.

[0015] A carriage 53 is disposed above the platen 54 so as to face the platen 54. The carriage 53 is capable of reciprocating in the X-axis direction, which is the main scanning direction, along a first guide rail 25 installed in the printing device 1 along the X-axis direction. The carriage 53 is also capable of reciprocating in the Y-axis direction, which is the sub-scanning direction, along a second guide rail (not shown) installed along the Y-axis direction. The printing device 1 includes a first carriage motor M7 that moves the carriage 53 along the first guide rail 25, and a second carriage motor M8 that moves the carriage 53 along the second guide rail. The printing device 1 moves the ejection head 51 in the X-axis direction and the Y-axis direction using the power of these motors M7 and M8. With this configuration, the ejection head 51 can move in the X-axis direction and the Y-axis direction over the printing medium S supported by the platen 54 and eject ink all over the medium.

[0016] When printing on the print medium S, the printing device 1 performs intermittent transport of the print medium S. That is, the printing device 1 transports the print medium S to the platen 54 and stops transporting the print medium S when the print medium S is positioned in a predetermined area of ​​the platen 54. Then, the printing unit 5 ejects ink while moving the ejection head 51 in the X-axis and Y-axis directions, thereby printing on the print medium S. After printing, the printing device 1 transports the print medium S until the printed portion of the print medium S moves downstream of the platen 54 in the transport direction T. Then, the printing device 1 stops transporting the print medium S and performs printing using the printing unit 5.

[0017] In the conveying path 10, a feed-out buffer unit 60 and a meandering correction unit 70 that corrects meandering of the printing medium S are arranged between the medium supply unit 3 and the printing unit 5. The configuration of the feed-out buffer unit 60 will be described later.

[0018] The meandering correction unit 70 includes transport rollers 312 and 313 and corrects meandering of the printing medium S between the transport rollers 312 and 313. Meandering of the printing medium S is a phenomenon in which the transport direction T of the printing medium S tilts from the transport path 10 toward the Y-axis. An ideal transport state is one in which the printing medium S is transported from the medium supply unit 3 to the platen 54 without moving along the Y-axis. In this state, the printing medium S fed from the medium supply unit 3 moves along the X-axis without moving along the Y-axis and reaches the platen 54. However, due to factors such as the tilt of the transport rollers 303 to 311, the printing medium S may tilt relative to the X-axis. This tilted state is called meandering. The meandering correction unit 70 corrects the movement direction of the printing medium S when it tilts relative to the X-axis. The printing medium S transported from the meandering correction unit 70 toward the platen 54 is in a state in which meandering is almost eliminated.

[0019] Between the meandering correction unit 70 and the platen 54, there is provided a meandering accuracy maintaining area 75 that maintains the meandering accuracy of the printing medium S. Meandering accuracy refers to the degree of meandering of the printing medium S, i.e., the degree of movement in a direction intersecting the X-axis, and may also be called transport accuracy. Transport rollers 313, 314, 315, 316, 317, 318, 319, 320, and 321 are arranged in the meandering accuracy maintaining area 75.

[0020] The transport rollers 313 and 314 are attached directly or indirectly to the frame of the printing apparatus 1. The transport rollers 313 and 314 are supported so as to be freely rotatable. A vertical plate 71 fixed directly or indirectly to the frame of the printing device 1 is disposed in the meandering accuracy maintaining area 75. A transport roller 315 is rotatably supported at the lower end of the vertical plate 71. Six transport rollers 316, 317, 318, 319, 320, and 321 are disposed in the center and upper portions of the vertical plate 71. These transport rollers 316 to 321 are each rotatably supported by the vertical plate 71. Tension is applied to the transported printing medium S in the meandering accuracy maintaining area 75. This tension prevents the printing medium S from wrinkling or sagging. The printing medium S is transported to the platen 54 via the meandering accuracy maintaining area 75. The configuration including the transport rollers 313 to 321 and the vertical plate 71 disposed in the meandering accuracy maintaining area 75 is referred to as the transport roller unit 4.

[0021] The transport rollers 316 to 321 arranged in the meandering accuracy maintaining area 75 transport the print medium S while maintaining the meandering accuracy corrected by the meandering correction unit 70.

[0022] The supply nip motor M3 and the transport rollers 318 and 319 constitute a transport nip unit that transports the printing medium S. The control unit 100 controls the speed of the supply nip motor M3. The rotation of the supply nip motor M3 is transmitted to the transport roller 318. For example, the control unit 100 controls the rotation speed of the supply nip motor M3 so that the transport amount of the printing medium S transported to the printing unit 5 is constant. By controlling the speed of the supply nip motor M3, the rotation speed of the transport roller 318 is controlled.

[0023] In the transport path 10, the drying unit 7 is disposed downstream of the printing unit 5. The drying unit 7 dries the ink ejected onto the printing medium S by the printing unit 5. Transport rollers 322, 323, 324, and 325 are disposed in the drying unit 7. The transport roller 323 is disposed between the platen 54 and the drying unit 7, and applies a driving force to the printing medium S when transporting the printing medium S. The transport roller 323 corresponds to an example of a first drive roller. The drying unit 7 is equipped with a heater that heats at least one of the printing surface and the back side of the printing surface of the printing medium S, and dries the ink ejected by the printing unit 5.

[0024] A tension roller 326 is provided downstream of the drying unit 7. The tension roller 326 detects the tension of the print medium S in the printing unit 5. In addition, a post-drying discharge nip section 350 is arranged downstream of the transport roller 330 on the transport path 10. The post-drying discharge nip section 350 includes transport rollers 351, 352, and 353, and a transport nip motor M9 that drives the transport roller 352. The transport roller 352 applies a driving force to the print medium S when transporting the print medium S downstream of the drying unit 7 in the transport direction T of the print medium S. The transport roller 352 corresponds to an example of a second drive roller.

[0025] The control unit 100 controls the torque of the transport nip motor M9 based on the tension of the printing medium S detected by the tension roller 326, and controls the transport roller 352. The control unit 100 controls the torque of the transport nip motor M9 so that the tension of the printing medium S detected by the tension roller 326 becomes a predetermined tension.

[0026] In the transport path 10, transport rollers 327, 328, 329, and 330 are arranged downstream of the drying unit 7. The print medium S is transported to the take-up buffer unit 61 by these transport rollers 327-330.

[0027] [2. Structure of the feeding buffer section] The feed-side buffer unit 60 includes a feed-side fixed plate 65 that is fixed directly or indirectly to the frame of the printing device 1, and a feed-side movable plate 67 that is movable up and down. Seven transport rollers 303, 304, 305, 306, 307, 309, and 311 are rotatably supported on the feed-side fixed plate 65. Two transport rollers 308 and 310 are rotatably supported on the feed-side movable plate 67.

[0028] In the feed-side buffer section 60, the printing medium S is wound around each of the transport rollers 303 to 311. The transport rollers 303, 304, 305, 306, 307, 309, and 311 are supported by a feed-side fixed plate 65 so as not to move in the transport path 10. Meanwhile, the transport rollers 308 and 310 are movable up and down together with the feed-side movable plate 67. The transport rollers 308 and 310 and the feed-side movable plate 67 are suspended from the feed-side fixed plate 65 by the printing medium S.

[0029] The feed-side buffer unit 60 applies tension to the print medium S in the direction of gravity by the weight of the feed-side movable plate 67 and the transport rollers 308 and 310 attached to the feed-side movable plate 67 .

[0030] If slack occurs in the printing medium S between the medium supply unit 3 and the platen 54, the feed-side movable plate 67 moves down by an amount equal to the slack in the printing medium S, thereby absorbing the slack in the printing medium S. Furthermore, if strong tension is applied to the printing medium S in the transport direction T between the medium supply unit 3 and the platen 54, this tension causes the feed-side movable plate 67 to move up, thereby causing the printing medium S to be fed out of the feed-side buffer unit 60. In this way, the feed-side buffer unit 60 absorbs or relieves excess tension caused by excess printing medium S and a shortage of printing medium S between the medium supply unit 3 and the platen 54.

[0031] [3. Configuration of the winding buffer section] The take-up side buffer unit 61 includes a take-up side fixed plate 68 that is directly or indirectly fixed to the frame of the printing device 1, and a take-up side movable plate 69 that is vertically movable. Transport rollers 336 and 338 are rotatably supported on the take-up side fixed plate 68. A transport roller 337 is rotatably supported on the take-up side movable plate 69.

[0032] In the take-up side buffer section 61, the printing medium S is wound around each of the transport rollers 336, 337, and 338. The transport rollers 336 and 338 are supported by a take-up side fixed plate 68 so as not to move in the transport path 10. Meanwhile, the transport roller 337 is movable up and down together with the take-up side movable plate 69. The transport roller 337 and the take-up side movable plate 69 are suspended from the take-up side fixed plate 68 by the printing medium S.

[0033] The take-up side buffer unit 61 applies tension to the print medium S in the direction of gravity by the weight of the take-up side movable plate 69 and the transport roller 337 attached to the take-up side movable plate 69 .

[0034] If slack occurs in the printing medium S between the platen 54 and the medium collection unit 8, the take-up side movable plate 69 moves down by an amount equal to the slack in the printing medium S, thereby absorbing the slack in the printing medium S. Furthermore, if strong tension is applied to the printing medium S in the transport direction T between the platen 54 and the medium collection unit 8, this tension causes the take-up side movable plate 69 to move up, thereby unwinding the printing medium S from the take-up side buffer unit 61. In this way, the take-up side buffer unit 61 absorbs or relieves excess tension caused by excess printing medium S between the platen 54 and the medium collection unit 8 and by a shortage of printing medium S.

[0035] [4. Drying section configuration] FIG. 2 is a diagram showing the configuration of the drying unit 7. The drying section 7 includes a first drying section 710 and a second drying section 720.

[0036] The first drying section 710 is provided inside the housing 700. The first drying section 710 dries the print medium S that is transported from the supply port 701 after printing.

[0037] The second drying section 720 is provided inside the housing 700. The second drying section 720 dries the print medium S that is transported from the second communication port 703 after printing.

[0038] The first drying section 710 is located upstream of the second drying section 720 in the transport direction T. The first drying section 710 and the second drying section 720 have different transport directions T. In the first drying section 710, the transport direction T is the direction toward the −X direction, and in the second drying section 720, the transport direction T is the direction toward the +X direction.

[0039] The first drying section 710 includes a first contact heating section 711. The first contact heating section 711 is provided inside the housing 700. The first contact heating section 711 is provided in a position facing the back surface of the print medium S after printing. The back surface of the print medium S is the surface behind the printing surface of the print medium S on which an image is printed. The first contact heating section 711 dries the print medium S after printing by coming into contact with the back surface of the print medium S after printing.

[0040] The first contact heating section 711 has a first contact heating surface 713. The first contact heating surface 713 is the surface of the first contact heating section 711 that faces the back surface of the print medium S after printing. The first contact heating surface 713 is configured to come into contact with the back surface of the print medium S after printing. The first contact heating surface 713 is positioned so as to face the second contact heating surface 723, which will be described later, in the opposite direction.

[0041] The first contact heating surface 713 is curved in a downward convex shape in the -Z direction in the vertical direction Z. The first contact heating surface 713 may be a surface formed of a metal plate, for example, a surface formed of an aluminum plate. In particular, the first contact heating surface 713 may be configured to curve along a support member (not shown). Furthermore, the first contact heating surface 713 may have a curvature radius that increases the degree of contact with the print medium S after printing while preventing the drying unit 7 from becoming larger in the Z direction.

[0042] The first contact heating unit 711 includes a first heater 715. The first heater 715 may be a rubber heater provided on the rear surface of the first contact heating surface 713. This allows the first contact heating unit 711 to dry the print medium S that comes into contact with the first contact heating surface 713 after printing. The first drying section 710 includes a first airflow ejection section 719. The first airflow ejection section 719 is disposed in a position facing the first contact heating surface 713 of the first contact heating section 711, and heats the printing surface of the print medium S. The first airflow ejection section 719 is provided with a plurality of airflow ejection ports. The airflow ejection ports are not shown in the figure. In this way, the first airflow ejection section 719 dries the print medium S that comes into contact with the first contact heating surface 713 after printing.

[0043] The second drying section 720 includes a second contact heating section 721. The second contact heating section 721 is provided inside the housing 700. The second contact heating section 721 is provided in a position facing the back surface of the print medium S after printing. The second contact heating section 721 dries the print medium S after printing by coming into contact with the back surface of the print medium S after printing.

[0044] The second contact heating section 721 has a second contact heating surface 723. The second contact heating surface 723 is the surface of the second contact heating section 721 that faces the back surface of the print medium S after printing. The second contact heating surface 723 is configured to come into contact with the back surface of the print medium S after printing. The second contact heating surface 723 is positioned to face the first contact heating surface 713 in the opposite direction.

[0045] The second contact heating surface 723 is curved so as to protrude upward in the vertical direction Z toward the +Z direction. The second contact heating surface 723 may be a surface formed from a metal plate, for example, a surface formed from an aluminum plate. In particular, the second contact heating surface 723 may be configured to curve along a support member (not shown). Furthermore, the second contact heating surface 723 may have a curvature radius that increases the degree of contact with the print medium S after printing while preventing the drying unit 7 from becoming larger in the vertical direction Z.

[0046] The second contact heating unit 721 includes a second heater 725. The second heater 725 may be a rubber heater provided on the rear surface of the second contact heating surface 723. This allows the second contact heating unit 721 to dry the print medium S that comes into contact with the second contact heating surface 723 after printing. The second drying section 720 includes a second airflow ejection section 729. The second airflow ejection section 729 is disposed in a position facing the second contact heating surface 723 of the second contact heating section 721, and heats the printing surface of the print medium S. The second airflow ejection section 729 is provided with a plurality of airflow ejection ports. The airflow ejection ports are not shown in the figure. In this way, the second airflow ejection section 729 dries the print medium S that comes into contact with the second contact heating surface 723 after printing.

[0047] [5. Configuration of the rear side of the drying unit] Fig. 3 is a perspective view of the periphery of the drying unit of the printing apparatus 1 as seen from the rear side, and Fig. 4 is a cross-sectional view of the periphery of the drying unit 7 of the printing apparatus 1 as seen from the rear side. Arrow F in Fig. 4 indicates the flow of air current. On the rear side of the drying section 7, an intake section 810, a circulating mixer 813, a pressure chamber 801, a first airflow ejection section 719, a second airflow ejection section 729, a fan forming section 735, an exhaust passage 815, an exhaust duct 817, and an air blower 820 are provided.

[0048] The intake unit 810 includes an intake fan 811, which draws in outside air. The circulating mixer 813 includes a first valve 804A and a second valve 804B as valves 804, and the airflow F drawn in by the intake fan 811 of the intake unit 810 flows into the circulating mixer 813. The circulating mixer 813 mixes the airflow F drawn in by the intake fan 811 with the heated airflow F. The heated airflow F will be described later. Furthermore, the circulating mixer 813 is connected to the first pressure chamber 801A and the second pressure chamber 801B, which are the two pressure chambers 801. The airflow F mixed in the circulating mixer 813 flows into the first pressure chamber 801A and the second pressure chamber 801B.

[0049] The first pressure chamber 801A and the second pressure chamber 801B are units for uniformly applying the airflow F to the first nozzle box 717 and the second nozzle box 727. The first pressure chamber 801A is connected to a first airflow ejection section 719, and the second pressure chamber 801B is connected to a second airflow ejection section 729.

[0050] The first airflow ejection unit 719 includes a first nozzle box 717. The airflow F flowing into the first airflow ejection unit 719 flows into the first nozzle box 717. On the other hand, the second airflow ejection unit 729 includes a second nozzle box 727. The airflow F flowing into the second airflow ejection unit 729 flows into the second nozzle box 727. The first nozzle box 717 and the second nozzle box 727 are units for blowing the heated airflow F onto the printing medium S.

[0051] The first nozzle box 717 faces the first contact heating surface 713 and outputs the heated airflow F to a fan forming section 735 provided with a fan 730. The second nozzle box 727 faces the second contact heating surface 723 and outputs the heated airflow F to a fan forming section 735 provided with a fan 730. The fan 730 is a DC fan and exhausts the heated airflow F from the drying section 7.

[0052] The fan forming unit 735 is connected to an exhaust passage 815 which is connected to an exhaust duct 817, and the airflow F is sent from the fan forming unit 735 to the exhaust duct 817 via the exhaust passage 815. In other words, the airflow F circulated within the drying unit 7 is discharged from the exhaust duct 817 to the outside of the printing apparatus 1.

[0053] The fan forming unit 735 is also connected to the circulating mixer 813 via an exhaust passage 815, and collects the heated airflow F and mixes it with outside air. A first air blower 820A serving as the air blower 820 mixes the heated airflow F with outside air and sends it to the first pressure chamber 801A. A second air blower 820B serving as the air blower 820 mixes the heated airflow F with outside air and sends it to the second pressure chamber 801B. The first air blower 820A and the second air blower 820B, together with the intake fan 811 and the fan 730, facilitate the flow of the airflow F inside the drying unit 7. The first air blower 820A and the second air blower 820B correspond to an example of an airflow supply unit that supplies the airflow F to the printing surface of the printing medium S. The first blower 820A and the second blower 820B are collectively referred to as blower 820.

[0054] [6. Control system configuration] FIG. 5 is a block diagram showing the control system of the printing device 1. Next, the control system of the printing device 1 will be described with reference to FIG. The printing device 1 includes an operation unit 17, a display unit 18, a drive circuit 14, and a control unit 100.

[0055] The operation unit 17 is a device into which the operator operating the printing device 1 inputs printing conditions and the like, and is, for example, an operation panel equipped with switches. The operation unit 17 may be an input device such as a keyboard or a mouse, or may be a tablet computer or a portable terminal separate from the printing device 1. The operation unit 17 outputs the information input by the operator to the control unit 100.

[0056] The display unit 18 includes a display panel such as a liquid crystal display panel, and displays various information under the control of the control unit 100. The operation unit 17 and the display unit 18 can also be configured as an integrated touch panel.

[0057] The drive circuit 14 is connected to the first air blower 820A, the second air blower 820B, the payout motor M1, the payout nip motor M2, the supply nip motor M3, the discharge nip motor M4, the take-up nip motor M5, and the take-up motor M6. The drive circuit 14 is also connected to the first carriage motor M7, the second carriage motor M8, and the transport nip motor M9. The drive circuit 14 drives the first air blower 820A and the second air blower 820B under the control of the control unit 100. The drive circuit 14 also drives each of the motors M1 to M6 under the control of the control unit 100 to transport the printing medium S. The drive circuit 14 also drives the first carriage motor M7 and the second carriage motor M8 under the control of the control unit 100 to move the carriage 53 back and forth in the Y-axis direction. Furthermore, the drive circuit 14 drives the transport nip motor M9 under the control of the control unit 100 so that the tension of the print medium S detected by the tension roller 326 becomes a predetermined tension.

[0058] The drive circuit 14 is also connected to the ejection head 51 and the drying unit 7. The drive circuit 14 outputs control signals under the control of the control unit 100 to operate the ejection head 51 and form an image on the print medium S. The drive circuit 14 also operates the heater of the drying unit 7 under the control of the control unit 100 to dry the print medium S.

[0059] The control unit 100 is a computer device that includes a memory unit 110 and a processor 130 .

[0060] The storage unit 110 includes memories such as RAM (Random Access Memory) and ROM (Read Only Memory). The RAM is used for temporary storage of various data, and the ROM stores control programs for controlling the operation of the printing device 1, various setting information, and the like.

[0061] The processor 130 is an arithmetic processing device configured from a Central Processing Unit (CSU) and a Micro Processing Unit (MPU). The processor 130 executes a control program to control each part of the printing device 1. The processor 130 may be configured from a single processor or multiple processors. The processor 130 may also be configured as an SoC integrated with part or all of the storage unit 110 or other circuits. The processor 130 may also be configured as a combination of a CPU that executes programs and a DSP that executes predetermined arithmetic processing. Furthermore, all of the functions of the processor 130 may be implemented in hardware, or may be configured using a programmable device.

[0062] The control unit 100 executes the printing process. The control unit 100 controls the driving of the motors M1 to M6 to execute intermittent transport that repeats a transport operation that transports the print medium S a predetermined distance in the transport direction T and a stopping operation that stops the transport of the print medium S.

[0063] The control unit 100 transports the print medium S to a predetermined area on the platen 54 by this intermittent transport, and causes the printing unit 5 to print an image on the print medium S transported to the predetermined area on the platen 54. Furthermore, if the printing process is stopped midway, the control unit 100 measures the time during which the printing process is stopped. For example, there are cases where the printing process is stopped for a predetermined time or longer when an instruction to stop printing is received from the operation unit 17, or when cleaning of the ejection head 51 is required.

[0064] FIG. 6 is a diagram showing one frame of the print medium S. One frame refers to an image printed on the print medium S in one intermittent transport. That is, the print medium S is transported to a predetermined area of ​​the platen 54 by a transport operation included in the intermittent transport, and an image is printed on the stopped print medium S by a stopping operation included in the intermittent transport. The image printed on the print medium S by this one intermittent transport corresponds to one frame.

[0065] [7. Control operation of the control unit] When the control unit 100 transports the print medium S after stopping the transport of the print medium S for a predetermined period of time or longer, it controls the medium supply unit 3 so that the print medium S is transported at a first acceleration V1. Hereinafter, the image that is first printed on the print medium S after the start of a printing operation or the restart of a printing operation is referred to as the first frame. After printing of the first frame on the print medium S is completed, the print medium S is transported downstream in the transport direction T, and at this time the control unit 100 controls the medium supply unit 3 so that the acceleration of the transported print medium S becomes the first acceleration V1.

[0066] Furthermore, when the control unit 100 starts transporting the printing medium S before the stop time of transporting the printing medium S reaches a predetermined time, it controls the medium supply unit 3 so that the printing medium S is transported at the second acceleration V2. The first acceleration V1 is an acceleration smaller than the second acceleration V2. The second acceleration V2 is an acceleration during normal intermittent transport. The stop time during intermittent transport is less than the predetermined time. Therefore, when the control unit 100 forms an image on the printing medium S whose transport has been stopped and transports the printing medium S on which the image has been formed, it transports the printing medium S at the second acceleration V2.

[0067] The time during which the transport of the print medium S is stopped for a predetermined time or longer includes, for example, when the printing is on standby and when printing is temporarily stopped. The printing standby state refers to a state in which a print job has not been received from an external device such as a personal computer and a printing operation has not yet started. Printing is temporarily suspended when the printing device 1 receives a print job from an external device and starts printing, but printing on the print medium S is temporarily stopped due to user operation, head cleaning, or the like.

[0068] When the transport of the printing medium S is stopped for a predetermined time or longer, the control unit 100 controls the supply nip motor M3, the pay-out nip motor M2, and the discharge nip motor M4 so that the acceleration at which the printing medium S is transported becomes a first acceleration V1. Furthermore, when the transport of the printing medium S is stopped for less than the predetermined time, the control unit 100 controls the supply nip motor M3, the pay-out nip motor M2, and the discharge nip motor M4 so that the acceleration at which the printing medium S is transported becomes a second acceleration V2.

[0069] When the transport of the printing medium S is stopped for a predetermined time or longer, the printing medium S is transported at a first acceleration V1 that is smaller than the second acceleration V2, which is the transport acceleration during intermittent transport, thereby reducing the load on the printing medium S when transporting the printing medium S and reducing transport failures.

[0070] Furthermore, when the control unit 100 prints the first frame image on the print medium S, transports the print medium S at a first acceleration V1, and then transports the print medium S on which the second and subsequent frame images are printed, the control unit 100 controls the medium supply unit 3 so that the acceleration of the print medium S becomes the second acceleration V2. Because the print medium S is transported after the first frame image is printed, the sticking of the print medium S in the drying unit 7 is eliminated. Therefore, when the print medium S is transported after the second and subsequent frame images are printed on the print medium S, the control unit 100 controls the medium supply unit 3 so that the acceleration at which the print medium S is transported becomes the second acceleration V2.

[0071] Furthermore, the control unit 100 reduces the platen post tension during print standby and when printing is paused to a level lower than the platen post tension during printing. Similarly, the control unit 100 reduces the post-drying tension during print standby and when printing is paused to a level lower than the post-drying tension during printing.

[0072] The post-platen tension is the tension applied to the print medium S after it has passed the platen 54. The post-platen tension is the tension applied to the print medium S located between the platen 54 and the drying unit 7. The control unit 100 controls the rotation of the transport roller 323 to reduce the platen post tension applied to the print medium S during print standby and when printing is paused to be lower than the platen post tension applied to the print medium S during printing. The platen post tension applied to the print medium S during printing is referred to as the first platen post tension. Furthermore, the platen post tension applied to the print medium S during print standby and when printing is paused is referred to as the second platen post tension.

[0073] The post-drying tension is the tension applied to the print medium S that has passed through the drying unit 7. The post-drying tension is the tension applied to the print medium S that is positioned between the drying unit 7 and the transport roller 352. The control unit 100 controls the transport roller 352 by controlling the torque of the transport nip motor M9, and reduces the post-drying tension applied to the print medium S during print standby and when printing is paused to be lower than the post-drying tension applied to the print medium S during printing. The post-drying tension applied to the print medium S during printing is referred to as the first post-drying tension. Furthermore, the post-drying tension applied to the print medium S during print standby and when printing is paused is referred to as the second post-drying tension.

[0074] By lowering the platen post tension and post drying tension when printing is in standby and when printing is paused to be lower than the platen post tension and post drying tension when printing is in operation, it is possible to reduce the sticking of the printing medium S to the first contact heating surface 713 and the second contact heating surface 723.

[0075] Furthermore, the control unit 100 controls the air volume of the air blower 820 so that the air volume of the air blower 820 during printing standby and when printing is paused is less than the air volume of the air blower 820 during printing. Specifically, the control unit 100 controls the inverter provided in the drive circuit 14 to lower the drive frequency that drives the motor provided in the air blower 820 below the drive frequency during printing. This makes it possible to reduce sticking of the printing medium S to the first contact heating surface 713 and the second contact heating surface 723. The drive frequency of the air blower 820 during printing is referred to as the first drive frequency, and the drive frequency of the air blower 820 during printing standby and when printing is paused is referred to as the second drive frequency.

[0076] 7 shows the control items for label paper, where the print medium S is a strip of release paper and multiple labels, when the release paper is film, paper, or polyethylene-laminated. Label paper with a film release paper is referred to as back film, label paper with a paper release paper is referred to as back paper, and label paper with a polyethylene-laminated release paper is referred to as back PE laminate. The control items controlled by the control unit 100 include the first acceleration V1 and the second acceleration V2, the first drive frequency and the second drive frequency, the first platen post tension and the second platen post tension, and the first drying post tension and the second drying post tension.

[0077] The first acceleration V1 is 116 mm / s in all cases where the release paper is a film, the release paper is paper, or the release paper is a polyethylene laminate. 2 ]. The second acceleration V2 is 1470.998 [mm / s] when the film is used, when the release paper is used, or when the release paper is a polyethylene laminate. 2 ].

[0078] The first driving frequency, which is the driving frequency of the air blower 820 during printing operation, is 60 Hz when the release paper is a film or when the release paper is paper, and is 29 Hz when the release paper is a polyethylene laminate. The driving frequency of the air blower 820 during printing operation is denoted as H1. The second drive frequency, which is the drive frequency of the air blower 820 when printing is on standby or when printing is temporarily stopped, is 29 Hz when the release paper is film, paper, or polyethylene laminate. The drive frequency of the air blower 820 when printing is on standby or when printing is temporarily stopped is denoted as H2.

[0079] The first platen post tension, which is the platen post tension during printing, is 90 [N] in all cases where the release paper is film, paper, or polyethylene laminate. The platen post tension during printing is denoted as Tp1. The second platen post tension, which is the platen post tension when printing has stopped or is temporarily stopped, is 20 [N] when the release paper is film, paper, or polyethylene laminate. The platen post tension when printing has stopped or is temporarily stopped is denoted as Tp2.

[0080] The first post-drying tension, which is the post-drying tension during printing, is 100 [N] when the release paper is film, and 130 [N] when the release paper is paper or when the release paper is polyethylene laminate. The post-drying tension during printing is denoted as Td1. The second post-drying tension, which is the tension after drying when printing has stopped or is temporarily stopped, is 30 [N] whether the release paper is film, paper, or polyethylene laminate. The post-drying tension when printing has stopped or is temporarily stopped is denoted as Td2.

[0081] FIG. 8 is a timing chart showing the operation of the printing device 1. The operation of the printing device 1 will be described with reference to the timing chart shown in FIG. Assume that the printing operation of the printing device 1 is temporarily stopped at time t1 shown in Figure 8. For example, upon receiving a user operation, the control unit 100 causes the printing unit 5 to stop the printing operation. When the control unit 100 stops the printing operation of the printing unit 5, it controls the inverter provided in the drive circuit 14 to reduce the drive frequency that drives the motor provided in the blower 820 below the drive frequency during the printing operation, thereby reducing the air volume of the blower 820.

[0082] Next, the control unit 100 reduces the air volume of the air blower 820, and at time t2, reduces the platen post tension from Tp1 to Tp2. The control unit 100 controls the rotation of the transport roller 323 to reduce the tension applied to the print medium S to be lower than that during the printing operation.

[0083] Next, the control unit 100 reduces the post-platen tension, and then reduces the post-drying tension at time t3. After reducing the post-platen tension to Tp2, the control unit 100 controls the torque of the transport nip motor M9 to control the rotation of the transport roller 352, reducing the post-drying tension from Td1 to Td2, and waits until printing resumes.

[0084] Assume that at time t4, control unit 100 receives an instruction to start printing or resume printing. When control unit 100 receives the instruction to start printing or resume printing, at time t4, control unit 100 increases the drive frequency that drives the motor provided in blower 820. Control unit 100 changes the drive frequency from H2 to H1 to increase the airflow rate. By increasing the airflow rate, the temperature of the hot air output from blower 820 temporarily drops, but control unit 100 controls the temperature of the hot air output from blower 820 using PID control, so that the hot air output from blower 820 maintains a predetermined temperature.

[0085] For example, assume that the temperature of the hot air output from the air blower 820 reaches a predetermined temperature at time t5. When the temperature of the hot air output from the air blower 820 reaches the predetermined temperature, the control unit 100 increases the post-drying tension at time t5. The control unit 100 controls the torque of the transport nip motor M9 to control the rotation of the transport roller 352, thereby increasing the post-drying tension from Td2 to Td1.

[0086] When the post-drying tension increases to Td1, the control unit 100 increases the post-platen tension at time t6. The control unit 100 controls the rotation of the transport roller 323 to increase the tension applied to the print medium S from Tp2 to Tp1.

[0087] When the platen post tension increases to Tp1 at time t7, the control unit 100 starts flushing. Flushing is a maintenance operation in which an actuator (not shown) is driven to eject ink droplets unrelated to printing from the nozzles of the ejection head in order to prevent or clear clogging of the nozzles.

[0088] When flushing is completed at time t8, the control unit 100 moves the carriage 53 in the main scanning direction to move the printing unit 5 to the print start position. At this time, the main scanning direction in which the carriage 53 is moved is referred to as the first direction. The control unit 100 moves the carriage 53 back and forth in the main scanning direction. On the outbound path in which the carriage 53 is moved, printing is not performed on the printing medium S, but on the return path in which the carriage 53 is moved, printing is performed on the printing medium S. On the return path in which the carriage 53 is moved, the main scanning direction in which the carriage 53 is moved is referred to as the second direction.

[0089] At time t9, the control unit 100 moves the carriage 53 to the print start position, and causes the printing unit 5 to print on the return path of the reciprocating movement. The printing unit 5 prints the first frame on the printing medium S at time t10.

[0090] Next, at time t11 when printing of the first frame on the printing medium S by the printing unit 5 is completed, the control unit 100 starts transporting the printing medium S, and transports the printing medium S downstream in the transport direction T. At this time, the control unit 100 controls the supply nip motor M3, the payout nip motor M2, and the discharge nip motor M4 so that the acceleration at which the printing medium S is transported becomes a first acceleration V1. Furthermore, as shown in FIG. 8, when the transport speed of the printing medium S is increased, the control unit 100 accelerates the printing medium S at the first acceleration V1, and when the transport speed of the printing medium S is decreased and stopped, the control unit 100 decelerates the printing medium S at a deceleration value equal to the first acceleration V1.

[0091] Furthermore, the control unit 100 moves the carriage 53 in the first direction to the print start position at time t12 while moving the printing medium S downstream in the transport direction T. When the movement of the printing medium S is completed at time t13 and the movement of the carriage 53 in the first direction is completed at time t14, the control unit 100 moves the carriage 53 in the second direction at time t15 to print a second frame on the printing medium S.

[0092] When printing of the second frame on the printing medium S is completed at time t16, the control unit 100 starts transporting the printing medium S, transporting the printing medium S downstream in the transport direction T. At this time, the control unit 100 controls the supply nip motor M3, the payout nip motor M2, and the discharge nip motor M4 so that the acceleration at which the printing medium S is transported becomes a second acceleration V2. This second acceleration V2 is an acceleration with a value greater than the first acceleration V1. At this time, as shown in FIG. 8, when the transport speed of the printing medium S is increased, the control unit 100 accelerates the printing medium S at the second acceleration V2, and when the transport speed of the printing medium S is decreased and stopped, the control unit 100 decelerates the printing medium S at a deceleration value equal to the second acceleration V2.

[0093] FIG. 9 is a flowchart showing the operation of the control unit 100. The operation of the control unit 100 will be described with reference to the flowchart shown in FIG. First, the control unit 100 determines whether an event that requires the printing operation to be stopped has occurred (step S1). Events that require the printing operation to be stopped include, for example, when a print job is executed and the printing operation is completed, or when printing on the print medium S is temporarily stopped due to a user operation, head cleaning, or the like.

[0094] If an event that would cause the printing operation to be stopped has not occurred (step S1 / NO), the control unit 100 determines again whether an event that would cause the printing operation to be stopped has occurred. If an event occurs that requires the printing operation to be stopped (step S1 / YES), the control unit 100 reduces the drive frequency of the blower 820 from H1 to H2 (step S2).

[0095] Next, the control unit 100 controls the rotation of the transport roller 323 to reduce the post-platen tension from Tp1 to Tp2 (step S3). Furthermore, the control unit 100 controls the torque of the transport nip motor M9 to reduce the post-drying tension from Td1 to Td2 (step S4).

[0096] Next, the control unit 100 determines whether to start or resume the printing operation (step S5). The control unit 100 determines to start or resume the printing operation when a print job is received from an external device, when a user operation instructs the restart of printing, or when head cleaning is completed.

[0097] If the control unit 100 does not start or resume the printing operation (step S5 / NO), it waits until the printing operation is started or resumed. If the control unit 100 starts or resumes the printing operation (step S5 / YES), it increases the drive frequency of the blower 820 from H2 to H1 (step S6). After that, when the hot air temperature rises above a predetermined value, the control unit 100 controls the torque of the transport nip motor M9 to increase the post-drying tension from Td2 to Td1 (step S7). Furthermore, the control unit 100 controls the rotation of the transport roller 323 to increase the post-platen tension from Tp2 to Tp1 (step S8).

[0098] Next, the control unit 100 causes the printing unit 5 to perform pre-printing flushing (step S9). Thereafter, the control unit 100 moves the carriage 53 in a first main scanning direction (step S10) to move the carriage 53 to a print start position. Then, the control unit 100 prints an image that is a first frame on the printing medium S while moving the carriage 53 in a second main scanning direction (step S11).

[0099] Next, the control unit 100 determines whether printing of the first frame image onto the printing medium S is completed (step S12). If printing of the first frame image onto the printing medium S is not completed (step S12 / NO), the control unit 100 waits until printing of the first frame image is completed.

[0100] When printing of the first frame image on the printing medium S is completed (step S12 / YES), the control unit 100 controls the supply nip motor M3, the payout nip motor M2, and the discharge nip motor M4 to transport the printing medium S downstream in the transport direction T. At this time, the control unit 100 controls the supply nip motor M3, the payout nip motor M2, and the discharge nip motor M4 so that the acceleration of the printing medium S becomes a first acceleration V1 (step S13).

[0101] Furthermore, the control unit 100 transports the print medium S downstream in the transport direction T, and also moves the carriage 53, which has moved in the second direction, in the first direction to move the carriage 53 to the print start position (step S14).

[0102] Next, the control unit 100 determines whether or not the transport of the print medium S and the movement of the carriage 53 have finished (step S15). If the transport of the print medium S or the movement of the carriage 53 has not finished (step S15 / NO), the control unit 100 waits until the transport of the print medium S and the movement of the carriage 53 have finished.

[0103] When the control unit 100 has completed transporting the printing medium S and moving the carriage 53 (step S15 / YES), the control unit 100 prints a second frame on the printing medium S while moving the carriage 53 in the second direction of the main scanning direction (step S16).

[0104] Next, the control unit 100 determines whether printing of the second frame onto the printing medium S is completed (step S17). If printing of the second frame onto the printing medium S is not completed (step S17 / NO), the control unit 100 waits until printing of the second frame onto the printing medium S is completed.

[0105] When printing of the second frame image is completed, the control unit 100 controls the supply nip motor M3, the payout nip motor M2, and the discharge nip motor M4 to transport the printing medium S downstream in the transport direction T. At this time, the control unit 100 controls the supply nip motor M3, the payout nip motor M2, and the discharge nip motor M4 so that the acceleration of the printing medium S becomes the second acceleration V2 (step S18).

[0106] Next, the control unit 100 determines whether or not there is a next image to be printed on the print medium S (step S19). If there is a next image (step S19 / YES), the control unit 100 returns to step S14 and repeats the processes from step S14 onwards.

[0107] Furthermore, if there is no next image (step S19 / NO), that is, if the image data included in the print job received from the external device has been printed the number of times specified by the print job, the control unit 100 executes a termination process (step S20). This termination process includes a process of moving the carriage 53 in the first main scanning direction to the print start position, and a process of reducing the drive frequency of the air blower 820 from H1 to H2. The termination process also includes a process of reducing the post-platen tension from Tp1 to Tp2, and a process of reducing the post-drying tension from Td1 to Td2.

[0108] [8. Variation 1] Fig. 10 shows the control items for the modified label paper when the release paper is film, when the release paper is paper, and when the release paper is laminated with polyethylene. The control items are the same as those for the embodiment shown in Fig. 9.

[0109] In this modified example, if the back surface of the print medium S is made of a material that does not stick to the first contact heating surface 713 and the second contact heating surface 723, the medium supply unit 3 is controlled so that the acceleration when transporting the print medium S on which the image of the first frame is printed is the second acceleration V2. In other words, when transporting the print medium S on which the image of the first frame is printed, the print medium S is transported at the second acceleration V2, which is the acceleration during intermittent transport. An example of a material for the back surface of the print medium S that does not stick to the contact heating surface is film. The user operates the operation unit 17 to input the type of print medium S. The control unit 100 changes the acceleration when transporting the print medium S based on the type of print medium S received by the operation unit 17.

[0110] As shown in FIG. 10, when the material of the rear surface of the printing medium S is a film, the control unit 100 sets the first acceleration V1 and the second acceleration V2 to the same value, 1470.998 [mm / s 2 The supply nip motor M3, the delivery nip motor M2, and the discharge nip motor M4 are controlled so that:

[0111] Furthermore, when the material of the rear surface of the print medium S is a film, the control unit 100 controls the air blower 820 so that the first drive frequency and the second drive frequency have the same value, 29 [Hz].

[0112] Furthermore, when the material of the rear surface of the print medium S is a film, the control unit 100 controls the rotation of the transport roller 323 so that the first platen post tension and the second platen post tension have the same value, 20 [N].

[0113] Furthermore, when the material of the back surface of the print medium S is a film, the control unit 100 controls the torque of the transport nip motor M9 so that the first post-drying tension and the second post-drying tension have the same value, 30 [N].

[0114] [9. Variation 2] In the above-described embodiment, the control unit 100 controlled the slope of the first acceleration V1 that increases the transport speed of the printing medium S and the slope of the deceleration when the transport speed of the printing medium S is reduced to stop the printing medium S so that they have the same value. In this modification 2, the control unit 100 controls the supply nip motor M3, the payout nip motor M2, and the discharge nip motor M4 so that the absolute value of the slope of the first acceleration V1 and the absolute value of the slope of the deceleration are different. For example, the control unit 100 controls the supply nip motor M3, the delivery nip motor M2, and the discharge nip motor M4 so that the absolute value of the gradient of the deceleration is greater than the absolute value of the gradient of the first acceleration V1.

[0115] FIG. 11 is a diagram showing the first acceleration V1 and the second acceleration V2 of the second modification. 11A shows a case where the gradient of the first acceleration V1 shown in the above-described embodiment is the same as the gradient of the deceleration. The gradient of the first acceleration V1 shown in FIG. 11A is assumed to be "a," and the gradient of the deceleration is assumed to be "-a." Figure 11(B) shows a case where the slope of the first acceleration V1 is the same as in Figure 11(A), "a," but the deceleration slope is doubled to "-2a." The deceleration with a slope of "-2a" is referred to as the first deceleration. In the example shown in Figure 11(B), the printing start timing and transport start timing of the second frame of the image on the printing medium S can be advanced by the amount of the shortened time it takes to complete transport of the printing medium S.

[0116] Furthermore, the transport distance when the printing medium S is transported at a first acceleration V1 with a slope of "a", then decelerated at a first deceleration with a slope of "-2a" and stopped is defined as R1. The transport distance when the printing medium S is transported at a second acceleration V2, which is the acceleration used to transport the printing medium S from the second frame onwards, then decelerated at a second deceleration with the same slope as the slope of the second acceleration V2 and stopped is defined as R2. At this time, the slope of the first deceleration is adjusted so that the transport distance R1 and the transport distance R2 are the same.

[0117] Figure 11(C) shows a case where the slope of the first acceleration V1 is set to "2 / 3a," which is smaller than that in Figure 11(A), and the slope of the deceleration is set to "-2a," which is twice as large as that in Figure 11(A). Figure 11(C) also shows a case where the transport start timing and transport end timing of the print medium S for the first frame are matched to the transport start timing and transport end timing of the print medium S for the first frame shown in Figure 11(A). In this case, because the slope of the first acceleration V1 is small, the transport time of the print medium S for the first frame does not change. However, by increasing the first acceleration V1 over a longer period than in the case shown in Figure 11(A), the transport force can be increased and sticking of the print medium S to the first contact heating surface 713 and the second contact heating surface 723 can be further reduced.

[0118] 10. Other Embodiments The above-described embodiment and each of the modifications are preferred embodiments of the present invention, but the present invention is not limited to these and various modifications are possible within the scope of the gist of the present invention. For example, the processing units in the flowchart shown in Figure 9 are divided according to the main processing content to make the processing of the printing device 1 easier to understand. The present invention is not limited by the way in which the processing units shown in the flowchart of Figure 9 are divided or the names of the processing units. Furthermore, the processing of the printing device 1 can be divided into even more processing units depending on the processing content, or one processing unit can be divided so that it includes even more processes. Furthermore, the processing order of the above flowchart is not limited to the example shown in the figure.

[0119] 1 to 5 show functional configurations realized by the cooperation of hardware and software, and the specific implementation form is not particularly limited. Therefore, it is not necessary to implement hardware corresponding to each functional unit individually, and it is of course possible to implement a configuration in which a single processor executes a program to realize the functions of multiple functional units. Furthermore, some of the functions realized by software in the above embodiments may be realized by hardware, or some of the functions realized by hardware may be realized by software.

[0120] 11. Summary of the Disclosure A summary of this disclosure is provided below.

[0121] (Appendix 1) a conveying unit that performs intermittent conveyance by repeating an operation of conveying a medium by a predetermined distance in a conveyance direction and an operation of stopping the conveyance of the medium; a printing unit that ejects a liquid onto the medium while the conveyance of the medium is stopped in the intermittent conveyance, a drying unit that dries the liquid ejected by the printing unit onto the medium, and a control unit, wherein the drying unit has a contact heating unit and an air flow ejection unit that is disposed at a position opposite the contact heating unit and ejects an air flow from an air flow ejection port, and the contact heating unit is configured to perform intermittent conveyance by repeating an operation of conveying a medium by a predetermined distance in a conveyance direction and stopping the conveyance of the medium; a contact heating surface that contacts the back surface opposite the printing surface, the airflow injection port facing the contact heating surface, the control unit transporting the medium at a first acceleration if the medium is to be transported after a stop time during which the transport unit has stopped transporting the medium has elapsed for a predetermined time or more, and transporting the medium at a second acceleration that is greater than the first acceleration if the medium is to be transported before the stop time has elapsed for the predetermined time, and the stop time of the medium during the intermittent transport is less than the predetermined time.

[0122] According to this configuration, when the medium is transported after a predetermined time or more has elapsed during which the transport unit has stopped transporting the medium, the medium is transported at a first acceleration. When the medium is transported before the predetermined time has elapsed, the medium is transported at a second acceleration greater than the first acceleration. If the medium remains in the drying unit for a predetermined time or more, adhesion occurs between the medium and the contact heating surface. This adhesion can increase the transport load on the medium and cause transport problems. Therefore, if the stop time exceeds the predetermined time and the medium sticks to the contact heating surface, the medium is transported at a first acceleration smaller than the second acceleration, which increases the transport force of the medium and makes it easier to remove the medium from the contact heating surface. This prevents transport problems due to increased transport load and allows the medium to be transported accurately.

[0123] (Appendix 2) The control unit of the printing device described in Appendix 1 transports the medium at the first acceleration during the first intermittent transport if the stop time during which the transport of the medium was stopped before the intermittent transport is performed has elapsed for more than the predetermined time when the transport unit performs the intermittent transport, and transports the medium at the second acceleration during the second or subsequent intermittent transports.

[0124] According to this configuration, the medium is transported at a first acceleration during the first intermittent transport, and at the second acceleration during the second and subsequent intermittent transports. Therefore, if the medium is stuck to the contact heating surface, transporting the medium at the first acceleration, which is smaller than the second acceleration, increases the transport force of the medium and makes it easier to remove the stuck medium from the contact heating surface. Furthermore, since the medium is not stuck to the contact heating surface during the second and subsequent intermittent transports, transport failures due to increased transport load do not occur. Therefore, transporting the medium at the second acceleration, which is larger than the first acceleration, allows for efficient media transport.

[0125] (Appendix 3) A printing device as described in Appendix 1 or 2, wherein when the control unit starts transporting the medium after the stop time during which the transport of the medium by the transport unit has been stopped has elapsed for more than the predetermined time, the control unit starts transporting the medium at the first acceleration, and then decelerates the medium at a first deceleration to stop it, and the absolute value of the slope of the first deceleration is greater than the absolute value of the slope of the first acceleration.

[0126] According to this configuration, when the medium is transported after the predetermined stop time has elapsed, the medium starts to be transported at a first acceleration, and then the medium is decelerated at a first deceleration and stopped. Furthermore, the absolute value of the slope of the first deceleration is greater than the absolute value of the slope of the first acceleration. This reduces the time required to complete medium transport and shortens the time required to complete printing.

[0127] (Appendix 4) The printing device described in Appendix 3, wherein, when the control unit carries out transport of the medium before the stop time during which the transport of the medium by the transport unit is stopped reaches the specified time, the control unit starts transporting the medium at the second acceleration, then decelerates the medium at the second deceleration and stops the medium, and the transport distance of the medium when the medium is transported by accelerating at the first acceleration and then decelerating at the first deceleration is equal to the transport distance of the medium when the medium is transported by accelerating at the second acceleration and then decelerating at the second deceleration.

[0128] According to this configuration, when medium transport is performed before the stop time reaches the predetermined time, the medium starts to be transported at the second acceleration, and then the medium is decelerated at the second deceleration to stop. Furthermore, the transport distance of the medium when the medium is transported by accelerating at the first acceleration and then decelerating at the first deceleration is equal to the transport distance of the medium when the medium is transported by accelerating at the second acceleration and then decelerating at the second deceleration. Therefore, the transport distance can be made the same when the medium is transported at the first acceleration and decelerated at the first deceleration to stop, and when the medium is transported at the second acceleration and then decelerated at the second deceleration to stop.

[0129] (Appendix 5) The printing device further includes a support unit that supports the medium at a position facing the printing unit with the medium sandwiched between it, a first drive roller that applies a driving force to the medium when transporting the medium between the support unit and the drying unit in the medium transport direction, and a second drive roller that applies a driving force to the medium when transporting the medium downstream of the drying unit in the medium transport direction, wherein the control unit, when the time during which the medium is not transported is equal to or longer than the predetermined time, controls the first drive roller so that the tension applied to the medium located between the support unit and the drying unit is smaller than the tension applied to the medium located between the support unit and the drying unit while the medium is being transported, and controls the second drive roller so that the tension applied to the medium located between the drying unit and the second drive roller is smaller than the tension applied to the medium located between the drying unit and the second drive roller while the medium is being transported.

[0130] With this configuration, the first drive roller is controlled so that the tension applied to the medium positioned between the support unit and the drying unit is smaller than the tension applied to the medium positioned between the support unit and the drying unit during transport, thereby reducing sticking of the medium to the contact heating surface.

[0131] (Appendix 6) A printing device described in any one of Appendixes 1 to 5, wherein the drying unit includes an air flow supply unit that supplies an air flow to be sprayed from the air flow outlet onto the printing surface of the medium, and the control unit controls the air flow supply unit so that the amount of air flow supplied by the air flow supply unit is less than the amount of air flow supplied by the air flow supply unit while the medium is being transported when the time during which the medium is not transported is equal to or longer than the predetermined time.

[0132] According to this configuration, when the time during which the medium is not being transported exceeds a predetermined time, the airflow supply unit is controlled so that the amount of airflow supplied by the airflow supply unit is less than the amount of airflow supplied by the airflow supply unit during medium transport, thereby reducing the sticking of the medium to the contact heating surface that occurs during the time when the medium transport is stopped.

[0133] (Appendix 7) The printing apparatus includes a transport unit that performs intermittent transport, which repeats an operation of transporting a medium a predetermined distance in a transport direction and an operation of stopping transport of the medium, a printing unit that ejects liquid onto the medium while transport of the medium is stopped during the intermittent transport, and a drying unit that dries the liquid ejected onto the medium by the printing unit, wherein the drying unit has a contact heating unit and an air flow ejection unit that is disposed at a position opposite the contact heating unit and ejects an air flow from an air flow ejection port, and the contact heating unit is configured to dry a surface of the medium onto which the liquid is ejected by the printing unit. A control method for a printing device that has a contact heating surface that contacts the opposite back surface, and the air flow injection port faces the contact heating surface, wherein when the medium is transported after a stop time during which the transport unit has stopped transporting the medium has elapsed for a predetermined time or more, the medium is transported at a first acceleration, and when the medium is transported before the stop time has elapsed for the predetermined time, the medium is transported at a second acceleration that is greater than the first acceleration, and the stop time of the medium during the intermittent transport is less than the predetermined time.

[0134] According to this configuration, when the medium is transported after a predetermined time or more has elapsed during which the transport unit has stopped transporting the medium, the medium is transported at a first acceleration. When the medium is transported before the predetermined time has elapsed, the medium is transported at a second acceleration greater than the first acceleration. If the medium remains in the drying unit for a predetermined time or more, adhesion occurs between the medium and the contact heating surface. This adhesion can increase the transport load on the medium and cause transport problems. Therefore, if the stop time exceeds the predetermined time and the medium sticks to the contact heating surface, the medium is transported at a first acceleration smaller than the second acceleration, which increases the transport force of the medium and makes it easier to remove the medium from the contact heating surface. This prevents transport problems due to increased transport load and allows the medium to be transported accurately. [Explanation of symbols]

[0135] 1...printing device, 2, 700...housing, 3...medium supply unit, 4...transport roller unit, 5...printing unit, 7...drying unit, 8...medium recovery unit, 10...transport path, 14...drive circuit, 17...operation unit, 25...first guide rail, 31...supply shaft unit, 32...roll body, 51...discharge head, 53...carriage, 54...platen, 60...feed-out side buffer unit, 61...wind-up side buffer unit, 65...feed-out side fixed plate, 67...feed-out side movable plate, 68...wind-up side fixed Fixed plate, 69...winding side movable plate, 70...meandering correction unit, 71...vertical plate, 75...meandering accuracy maintaining area, 81...winding shaft, 100...control unit, 110...memory unit, 130...processor, 147B...second nozzle, 301, 303, 304, 305, 306, 307, 308, 309, 310, 311, 312, 314, 315, 316, 317, 318, 319, 320, 321, 322, 323, 324, 325, 327, 328 , 329, 330, 334, 336, 337, 338, 342, 343, 351, 352...conveyance roller, 326...tension roller, 350...post-drying discharge nip section, 700...casing, 701...supply port, 703...second communication port, 710...first drying section, 711...first contact heating section, 713...first contact heating surface, 715...first heater, 717...first nozzle box, 719...first air flow jet section, 720...second drying section, 721...second contact heating section, 723...second contact heating surface, 725...second heater, 727...second nozzle box, 729...second airflow injection section, 730...fan, 735...fan forming section, 801...pressure chamber, 801A...first pressure chamber, 801B...second pressure chamber, 804...valve, 804A...first valve, 804B...second valve, 810...intake section, 811...intake fan, 813...circulation mixing section, 815...exhaust passage, 817...exhaust duct, 820A...first air blower, 820B...second air blower.

Claims

1. a transport unit that performs intermittent transport by repeating an operation of transporting the medium a predetermined distance in a transport direction and an operation of stopping the transport of the medium; a printing unit that ejects a liquid onto the medium to print while the transport of the medium is stopped during the intermittent transport; a drying unit that dries the liquid ejected onto the medium by the printing unit; A control unit; Equipped with The drying section A contact heating section; an airflow injection unit that is disposed at a position opposite to the contact heating unit and that injects an airflow from an airflow injection port; and The contact heating unit is the printing unit includes a contact heating surface that contacts a back surface of the medium opposite to a printing surface that is a surface of the medium onto which the liquid is ejected, The airflow jetting port faces the contact heating surface, The control unit When the medium is to be conveyed after a predetermined time or more has elapsed during which the conveyance unit has stopped conveying the medium, the medium is conveyed at a first acceleration; If the medium is to be conveyed before the stop time has elapsed for the predetermined time, the medium is conveyed at a second acceleration that is greater than the first acceleration; a stop time of the medium during the intermittent transport is less than the predetermined time; Printing device.

2. The control unit When the transport unit performs the intermittent transport, if the stop time during which transport of the medium is stopped before the intermittent transport is performed has elapsed for more than the predetermined time, In a first transport of the medium during the intermittent transport, the medium is transported at the first acceleration; In the second or subsequent intermittent transport of the medium, the medium is transported at the second acceleration. The printing device according to claim 1 .

3. The control unit When the transport of the medium is performed after the stop time during which the transport unit has stopped transporting the medium has elapsed for the predetermined time or more, After starting to transport the medium at the first acceleration, the medium is decelerated at a first deceleration and stopped; an absolute value of a slope of the first deceleration is greater than an absolute value of a slope of the first acceleration; 3. The printing device according to claim 1.

4. The control unit When the medium is to be conveyed before the stop time during which the conveyance unit has stopped conveying the medium reaches the predetermined time, conveyance of the medium is started at the second acceleration, and then the medium is decelerated at a second deceleration and stopped; a transport distance of the medium when the medium is transported by accelerating at the first acceleration and then decelerating at the first deceleration is equal to a transport distance of the medium when the medium is transported by accelerating at the second acceleration and then decelerating at the second deceleration; The printing device according to claim 3 .

5. The printing device a support unit that supports the medium and is located opposite the printing unit with the medium sandwiched between them; a first drive roller, located between the support unit and the drying unit in a transport direction of the medium, that applies a driving force to the medium when transporting the medium; a second driving roller that applies a driving force to the medium when the medium is transported downstream of the drying unit in the transport direction of the medium; Furthermore, When the time during which the medium is not transported is equal to or longer than the predetermined time, the control unit controlling the first drive roller so that tension applied to the medium positioned between the support unit and the drying unit is smaller than tension applied to the medium positioned between the support unit and the drying unit during transport of the medium; The second drive roller is controlled so that tension applied to the medium positioned between the drying unit and the second drive roller is smaller than tension applied to the medium positioned between the drying unit and the second drive roller while the medium is being transported.

3. The printing device according to claim 1 or 2.

6. the drying unit includes an airflow supply unit that supplies an airflow to be sprayed from the airflow nozzle onto the printing surface of the medium, the control unit controls the airflow supply unit so that the amount of airflow supplied by the airflow supply unit is less than the amount of airflow supplied by the airflow supply unit while the medium is being transported, when the time during which the medium is not being transported is equal to or longer than the predetermined time.

3. The printing device according to claim 1.

7. a transport unit that performs intermittent transport by repeating an operation of transporting a medium a predetermined distance in a transport direction and an operation of stopping transport of the medium; a printing unit that ejects liquid onto the medium while transport of the medium is stopped during the intermittent transport, and a drying unit that dries the liquid ejected onto the medium by the printing unit; a control method for a printing device, the method comprising: the drying unit having a contact heating unit and an air flow jetting unit disposed at a position opposite the contact heating unit and jetting an air flow from an air flow jetting port; the contact heating unit having a contact heating surface that contacts a back surface of the medium opposite to a printing surface that is a surface of the medium onto which the printing unit ejects the liquid; and the air flow jetting port facing the contact heating surface, When the medium is to be conveyed after a predetermined time or more has elapsed during which the conveyance unit has stopped conveying the medium, the medium is conveyed at a first acceleration; If the medium is to be conveyed before the stop time has elapsed for the predetermined time, the medium is conveyed at a second acceleration that is greater than the first acceleration; a stop time of the medium during the intermittent transport is less than the predetermined time; A method for controlling a printing device.

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