Dryer and recording device

Abstract

To provide a dryer capable of drying a medium for a short time while maintaining the quality of the medium, and a recording device.SOLUTION: A dryer includes a drying section that dries a medium to which pigment ink containing pigment, water and a solvent is discharged by generating electromagnetic waves in accordance with application of high-frequency voltage. The drying section includes: a first electrode; a second electrode disposed to surround the first electrode in plan view from a first direction toward the medium; a first conductor having a coil and electrically connecting a transmission line capable of transmitting the high-frequency voltage and the first electrode; and a second conductor electrically connecting the transmission line and the second electrode. The drying section generates electromagnetic waves so that irradiation intensity of the electromagnetic waves in the medium to which the pigment ink is discharged forms a pulse shape on a time-series basis.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a drying device and a recording device. [Background technology]

[0002] For example, Patent Document 1 discloses a drying device that dries a medium by generating electromagnetic waves on the medium onto which a liquid has been ejected. The liquid may be a pigment ink. The pigment ink contains a pigment, water, and a solvent, and the solvent may contain, for example, glycerin.

[0003] This type of drying device generates high-intensity electromagnetic waves in the medium by supplying a high-frequency voltage between the first and second electrodes, thereby boiling the liquid ejected onto the medium and drying the medium in a short time, regardless of whether the water vapor around the medium is saturated or not. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-16742 Summary of the Invention [Problem to be solved by the invention]

[0005] However, such drying devices generate high-intensity electromagnetic waves, which can cause thermal degradation of the media. Therefore, it is desirable to dry the media in a short time while maintaining the quality of the media. [Means for solving the problem]

[0006] A drying device that solves the above problem includes a drying unit that dries a medium onto which a pigment ink containing pigment, water, and a solvent has been ejected by generating electromagnetic waves in response to the application of a high-frequency voltage, the drying unit having a first electrode, a second electrode that is arranged to surround the first electrode in a planar view from a first direction toward the medium, a first conductor that has a coil and electrically connects the first electrode to a transmission line capable of transmitting a high-frequency voltage, and a second conductor that electrically connects the transmission line to the second electrode, and the drying unit generates electromagnetic waves so that the irradiation intensity of the electromagnetic waves on the medium onto which the pigment ink has been ejected is pulsed in a time series.

[0007] A recording device that solves the above problem comprises a recording unit that performs recording by ejecting a pigment ink containing pigment, water, and a solvent onto a medium, and a drying unit that dries the medium onto which the pigment ink has been ejected by the recording unit by generating electromagnetic waves in response to the application of a high-frequency voltage, wherein the drying unit has a first electrode, a second electrode that is arranged to surround the first electrode in a planar view from a first direction toward the medium, a first conductor that has a coil and electrically connects the first electrode to a transmission line capable of transmitting a high-frequency voltage, and a second conductor that electrically connects the transmission line to the second electrode, and the drying unit generates electromagnetic waves so that the irradiation intensity of the electromagnetic waves on the medium onto which the pigment ink has been ejected is pulsed in a time series. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic diagram showing a recording system according to the first embodiment. [Figure 2] FIG. 2 is a top view showing the drying unit of the first embodiment. [Figure 3] FIG. 3 is a perspective view showing the drying unit of the first embodiment. [Figure 4] FIG. 4 is a flowchart showing the drying control process of the first embodiment. [Figure 5] FIG. 5 is an explanatory diagram showing the intensity of the electromagnetic wave in the medium and the temperature in the medium in the first embodiment. [Figure 6]FIG. 6 is a top view showing the drying unit of the second embodiment. [Figure 7] FIG. 7 is an explanatory diagram showing the intensity of the electromagnetic wave in the medium of the second embodiment. [Figure 8] FIG. 8 is a top view showing the drying unit of the third embodiment. [Figure 9] FIG. 9 is an explanatory diagram showing the intensity of an electromagnetic wave in a medium according to the third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] [First embodiment] An embodiment of a recording system including a drying device and a recording device will be described below. In the following description, the direction intersecting the vertical direction Z will be referred to as the width direction X, and the direction intersecting the vertical direction Z and the width direction X will be referred to as the depth direction Y. One direction along the width direction X will be referred to as the first width direction X1, and the other direction along the width direction X will be referred to as the second width direction X2. One direction along the depth direction Y will be referred to as the first depth direction Y1, and the other direction along the depth direction Y will be referred to as the second depth direction Y2. The upper side of the vertical direction Z will be referred to as the upper direction Z1, and the lower side of the vertical direction Z will be referred to as the lower direction Z2. The vertical direction Z corresponds to an example of a first direction.

[0010] <Configuration of recording system 10> 1, the recording system 10 is a system that performs recording on a medium 90. In particular, the recording system 10 is a system that performs recording on the medium 90 by ejecting a liquid onto the medium 90. The recording system 10 is a system that dries the medium 90 after recording by ejecting the liquid.

[0011] The liquid is a pigment ink. The pigment ink contains a pigment, water, and a solvent. The solvent may contain, for example, glycerin. The glycerin is a solvent that prevents clogging of the nozzles that eject the liquid. Vaporization of the glycerin improves the abrasion resistance of the medium 90 onto which the pigment ink is ejected.

[0012] The recording system 10 includes a recording device 11. The recording device 11 is configured to record on a medium 90. In particular, the recording device 11 records on the medium 90 by ejecting a liquid onto the medium 90. The recording device 11 may be an inkjet printer that performs recording by ejecting a pigment ink as the liquid onto the medium 90. The medium 90 includes a front surface 90A and a back surface 90B. The medium 90 is fabric, but may also be paper, for example.

[0013] The recording system 10 includes a drying device 12. The drying device 12 is configured to dry the medium 90 after recording onto which the recording device 11 ejects the liquid. In particular, the drying device 12 dries the medium 90 after recording by generating electromagnetic waves.

[0014] The recording system 10 includes a feed unit 13. The feed unit 13 feeds a pre-recorded medium 90 to the recording device 11. The feed unit 13 includes a feed roller 13A. The feed roller 13A extends along the width direction X. In the width direction X, the width of the feed roller 13A is longer than the width of the medium 90. The feed roller 13A is configured to rotatably hold a first roll body 91. The first roll body 91 is a wound pre-recorded medium 90. The medium 90 may be long. In this manner, the feed roller 13A holds the medium 90 to be fed to the recording device 11.

[0015] The recording system 10 includes a winding unit 14. The winding unit 14 winds up the recorded medium 90 that has been recorded by the recording device 11. In particular, the winding unit 14 winds up the recorded medium 90 that has been dried by the drying device 12. The winding unit 14 includes a winding roller 14A. The winding roller 14A extends along the width direction X. In the width direction X, the width of the winding roller 14A is longer than the width of the medium 90. The winding roller 14A is configured to rotatably hold a second roll body 92. The second roll body 92 is the recorded medium 90 that has been wound up. In this way, the winding roller 14A winds up the medium 90 that has been recorded by the recording device 11 and dried by the drying device 12.

[0016] <Configuration of Recording Device 11> Here, the configuration of the recording device 11 will be described in detail. The recording device 11 includes a recording unit 20, a recording support unit 21, and a recording transport unit 22. The recording unit 20 is configured to perform recording on the medium 90 by ejecting a liquid onto the medium 90. The recording unit 20 is configured to perform recording on the medium 90 by ejecting a liquid onto a surface 90A of the medium 90. The recording unit 20 performs recording on the medium 90 supported by the recording support unit 21. The recording unit 20 performs recording on the medium 90 transported by the recording transport unit 22.

[0017] The recording unit 20 includes a head 23. The head 23 may be a serial head or a line head. A serial head is a head that scans the width direction X of the medium 90. A line head is a head that records simultaneously across the width direction X of the medium 90.

[0018] The head 23 has a nozzle surface 24 in which a plurality of nozzles (not shown) open. The nozzle surface 24 faces downward Z2. The nozzle surface 24 faces the surface 90A of the medium 90 transported by the recording transport unit 22. Each of the plurality of nozzles is configured to open downward Z2. Each of the plurality of nozzles is configured to eject liquid.

[0019] The recording unit 20 may include a carriage 25 and a carriage support unit 26. The carriage 25 is configured to support the head 23. The carriage support unit 26 extends along the width direction X. The carriage support unit 26 supports the carriage 25 so that it can move along the width direction X. The carriage 25 can move in the width direction X along the carriage support unit 26 by a driving force from a driving source (not shown).

[0020] The recording support unit 21 is configured to support the medium 90 transported by the recording transport unit 22. The recording support unit 21 is located below the recording unit 20 in the Z2 direction. The recording support unit 21 supports the back surface 90B of the medium 90 transported by the recording transport unit 22. The recording support unit 21 is located below the head 23 in the Z2 direction.

[0021] The recording transport unit 22 is configured to transport the medium 90 in a transport direction D. The transport direction D is a direction along the depth direction Y. The recording transport unit 22 may include multiple rollers. The recording transport unit 22 transports the medium 90 in the transport direction D using multiple rollers, but may also transport the medium 90 in the transport direction D using a transport belt driven by multiple rollers. The recording transport unit 22 may perform intermittent transport by repeatedly transporting and stopping the medium 90.

[0022] <Configuration of Drying Device 12> Next, the configuration of the drying device 12 will be described in detail. The drying device 12 includes a drying unit 30. The drying unit 30 is configured to dry the medium 90 after recording. That is, the drying device 12 dries the medium 90 that has been recorded by the recording section 20.

[0023] The drying unit 30 is configured to dry the recorded medium 90 by generating electromagnetic waves. The drying unit 30 is located above the medium 90 at Z1, but may also be located below the medium 90 at Z2, or may be located both above and below the medium 90 at Z1 and Z2. Thus, the vertical direction Z is the direction toward the medium 90.

[0024] The drying device 12 includes a high-frequency voltage generating section 31. The high-frequency voltage generating section 31 is configured to generate a high-frequency voltage. The high-frequency voltage generating section 31 supplies the high-frequency voltage to the drying unit 30 via a transmission line 32.

[0025] The transmission line 32 is a line that connects the drying unit 30 and the high-frequency voltage generating unit 31. The transmission line 32 is capable of transmitting the high-frequency voltage from the high-frequency voltage generating unit 31 to the drying unit 30. In other words, the transmission line 32 is capable of transmitting the high-frequency voltage.

[0026] The transmission line 32 may be a coaxial cable, but is not limited to a coaxial cable. The transmission line 32 may include a first line and a second line. The first line may be the core wire of the transmission line 32. The second line may be an electromagnetic shield that covers the first line.

[0027] The drying device 12 includes a dry conveying section 33. The dry conveying section 33 is configured to convey the medium 90 in the conveying direction D. The dry conveying section 33 may use multiple rollers to convey the medium 90 in the conveying direction D. The dry conveying section 33 conveys the medium 90 at a predetermined speed in the conveying direction D. The dry conveying section 33 performs intermittent conveyance by repeatedly conveying and stopping the medium 90. Slack in the medium 90 may occur between the recording conveying section 22 and the dry conveying section 33.

[0028] The drying device 12 includes a drying support section 34. The drying support section 34 is configured to support the medium 90 transported by the drying conveying section 33. The drying support section 34 is located in the Z2 below the drying unit 30. The drying support section 34 supports the back surface 90B of the medium 90 transported by the drying conveying section 33. The drying support section 34 is located in the Z2 below the drying section 36, which will be described later.

[0029] The drying device 12 includes a control unit 35. The control unit 35 controls the drying device 12. More specifically, the control unit 35 controls the drying unit 30. The control unit 35 controls the high-frequency voltage generating unit 31. The control unit 35 controls the drying conveying unit 33.

[0030] The control unit 35 may be configured with one or more processors that execute various processes according to a computer program. The control unit 35 may be configured with one or more dedicated hardware circuits. The control unit 35 may be configured with an application specific integrated circuit that executes at least some of the various processes. The control unit 35 may be configured with a circuit that includes a combination of a processor and a hardware circuit. The processor includes a CPU and memory such as RAM and ROM. The memory stores program code or instructions that are configured to cause the CPU to execute processes. The memory, i.e., computer-readable medium, includes any readable medium that can be accessed by a general-purpose or special-purpose computer.

[0031] The drying unit 30 includes a drying section 36. That is, the drying device 12 includes a drying section 36. The drying unit 30 may include multiple drying sections 36. The drying section 36 may be rectangular in plan view from the vertical direction Z. The drying section 36 may be arranged so that the width direction X is the longitudinal direction. Hereinafter, the plan view from the vertical direction Z will be simply referred to as plan view.

[0032] The drying unit 36 ​​is configured to generate electromagnetic waves in response to application of a high-frequency voltage. The drying unit 36 ​​generates electromagnetic waves in response to application of a high-frequency voltage. In this way, the drying unit 36 ​​is configured to dry the medium 90 onto which the liquid has been ejected by the recording unit 20. The drying unit 36 ​​is an electromagnetic wave generating unit.

[0033] The drying unit 36 ​​generates an AC electric field by generating electromagnetic waves. The electromagnetic waves generated by the drying unit 36 ​​are mainly composed of electric fields. Compared to electromagnetic wave generating units that generate normal electromagnetic waves, the drying unit 36 ​​can significantly reduce the induction of a magnetic field due to the generated electric field.

[0034] As a specific example, the drying unit 36 ​​generates electromagnetic waves of 2.4 GHz, but is not limited to this. The drying unit 36 ​​may generate electromagnetic waves of, for example, 3 MHz to 300 MHz. The drying unit 36 ​​may generate electromagnetic waves of, for example, 300 MHz to 30 GHz, and particularly, may generate electromagnetic waves of 10 MHz to 20 GHz.

[0035] The drying unit 36 ​​dries the medium 90 by heating the medium 90 from the surface 90A. Specifically, the drying unit 36 ​​heats the liquid ejected onto the medium 90 from the surface 90A. The drying unit 36 ​​dries the medium 90 by vaporizing the liquid ejected onto the medium 90. In other words, the drying unit 36 ​​dries the medium 90 regardless of whether the water vapor is saturated around the medium 90. Therefore, the drying unit 36 ​​does not need to blow dry gas that is not saturated with water vapor around the medium 90.

[0036] <Arrangement of drying unit 36> 2, when the drying unit 30 includes multiple drying sections 36, the multiple drying sections 36 may be arranged in the width direction X, and multiple drying sections 36 may be arranged in the depth direction Y. In this case, the multiple drying sections 36 may be arranged across the entire width of the medium 90 in the width direction X. The multiple drying sections 36 may also be arranged across a distance d10 in the depth direction Y. In this way, the region of the medium 90 facing the multiple drying sections 36 corresponds to the drying region.

[0037] <Configuration of Drying Unit 36> 3, the drying unit 36 ​​includes a first electrode 41, a second electrode 42, a first conductor 43, and a second conductor 44. The drying unit 36 ​​may also include a facing unit 45. Fig. 2 is a diagram showing the first electrode 41 and the second electrode 42 arranged on the downward Z2 side.

[0038] The first electrode 41 has a flat plate shape. The first electrode 41 has a longitudinal direction in the width direction X in a plan view. That is, the first electrode 41 extends in the width direction X in a plan view. The first electrode 41 may have a rectangular shape in a plan view.

[0039] The first electrode 41 has a first electrode surface 41A. The first electrode surface 41A faces downward Z2. In other words, the first electrode surface 41A faces the surface 90A of the medium 90. The first electrode 41 is disposed so that the first electrode surface 41A abuts against the facing portion 45.

[0040] The second electrode 42 has a flat plate shape. The second electrode 42 has a second electrode surface 42A. The second electrode surface 42A faces downward Z2. In other words, the second electrode surface 42A faces the surface 90A of the medium 90. The second electrode 42 is disposed so that the second electrode surface 42A abuts against the facing portion 45.

[0041] The second electrode 42 has an opening 42B. The opening 42B has a rounded rectangular shape in a plan view, but may have a rectangular shape. The first electrode 41 is located in the opening 42B in a plan view. In other words, the second electrode 42 is disposed so as to surround the first electrode 41 in a plan view.

[0042] The first conductor 43 is configured to electrically connect the transmission line 32 and the first electrode 41. The first conductor 43 includes a coil 43A. The coil 43A extends in the vertical direction Z. One end of the coil 43A is connected to the first electrode 41. The other end of the coil 43A is connected to the conducting wire 43B.

[0043] The second conductor 44 is configured to electrically connect the transmission line 32 and the second electrode 42. The second conductor 44 may include a support pillar 44A. The second conductor 44 may include a plurality of support pillars 44A. The support pillars 44A are electrically connected to the second electrode 42. The support pillars 44A extend upward Z1 from the second electrode 42. The support pillars 44A are made of metal.

[0044] The second conductor 44 may include a connecting portion 44B. The connecting portion 44B is electrically connected to the support pillar 44A. The connecting portion 44B is provided on the upper end of the support pillar 44A. The connecting portion 44B connects multiple support pillars 44A together. The connecting portion 44B may be integral with the support pillar 44A. The connecting portion 44B may be H-shaped in a plan view. The connecting portion 44B is made of metal.

[0045] The second conductor 44 may include a top plate 44C. The top plate 44C is located above Z1 the connecting portion 44B. The top plate 44C is electrically connected to the connecting portion 44B. The top plate 44C may be integral with the connecting portion 44B. The top plate 44C is made of metal.

[0046] The facing portion 45 is located between the first electrode 41 and the second electrode 42 and the medium 90. The facing portion 45 may be flat. The facing portion 45 is made of a material that transmits the electromagnetic waves generated by the drying unit 36. The facing portion 45 is arranged to face the surface 90A of the medium 90. The facing portion 45 may or may not be in contact with the medium 90. The facing portion 45 protects the first electrode 41 and the second electrode 42. The facing portion 45 is made of an insulating member. The facing portion 45 may be a glass plate. The facing portion 45 may be a ceramic with high transparency. The facing portion 45 may be made of a resin with a low dielectric tangent. The facing portion 45 may be made of polypropylene. The facing portion 45 may be made of polyethylene.

[0047] By configuring the drying unit 36 ​​in this manner, when a high-frequency voltage is applied to the first electrode 41 and the second electrode 42, the first electrode 41 and the second electrode 42 generate electromagnetic waves in response to the application of the high-frequency voltage, thereby heating the medium 90.

[0048] The drying unit 36 ​​can transfer large amounts of heat energy to the medium 90 by generating electromagnetic waves. The drying unit 36 ​​uses electromagnetic waves instead of heat conduction, and does not need to include components such as heating wires. This allows the drying unit 36 ​​to be made smaller.

[0049] Furthermore, the minimum separation distance between the first electrode 41 and the second electrode 42 is 1 / 10 or less of the wavelength of the electromagnetic waves output from the drying unit 36. This allows the electromagnetic waves generated when a high-frequency voltage is applied to be attenuated in the vicinity of the first electrode 41 and the second electrode 42. This allows the intensity of the electromagnetic waves reaching distant locations from the first electrode 41 and the second electrode 42 to be reduced. In other words, the electromagnetic waves generated from the drying unit 36 ​​are very strong in the vicinity of the first electrode 41 and the second electrode 42 and very weak in the distant locations.

[0050] By appropriately controlling the frequency band of the generated electromagnetic waves, such drying unit 36 ​​can generate an AC electric field intensively near the first electrode 41 and the second electrode 42. In other words, it is possible to suppress the influence of the generated electromagnetic waves on the surroundings beyond the vicinity of the first electrode 41 and the second electrode 42. The vicinity of the first electrode 41 and the second electrode 42 may correspond to a range of 3 mm to 3 cm, for example.

[0051] <Drying control treatment> The drying control process will now be described with reference to Fig. 4. The drying control process is a process executed by the control unit 35 when a drying instruction is received from the user.

[0052] 4, in step S10, the control unit 35 executes a conveyance control process. In this process, the control unit 35 controls the dry conveyance unit 33 to convey the medium 90 in the conveyance direction D. In particular, the control unit 35 performs intermittent conveyance in which the conveyance of the medium 90 is stopped for a predetermined time after the medium 90 has been conveyed in the conveyance direction D by a distance d10.

[0053] Distance d10 is the distance at which the drying unit 36 ​​is disposed in the transport direction D. In other words, distance d10 is the distance corresponding to the drying area for drying the medium 90. The predetermined time is a time corresponding to the control pattern of the drying unit 36. The control pattern is a pattern for controlling the drying unit 36. The control pattern is a pattern in which the drying unit 36 ​​generates electromagnetic waves.

[0054] In step S11, the control unit 35 executes a drying process. In this process, the control unit 35 controls the high-frequency voltage generating unit 31 to supply a high-frequency voltage to the drying unit 36. As a result, the control unit 35 controls the high-frequency voltage generating unit 31 to drive the drying unit 36.

[0055] In particular, the control unit 35 controls the high-frequency voltage generating unit 31 to drive the drying unit 36 ​​based on the control pattern, so that the drying unit 36 ​​generates electromagnetic waves based on the control pattern while the transport of the medium 90 is stopped.

[0056] In step S12, the control unit 35 determines whether the drying process based on the control pattern has ended. If the control unit 35 determines that the drying process based on the control pattern has not ended, the control unit 35 proceeds to step S11. If the control unit 35 determines that the drying process based on the control pattern has ended, the control unit 35 proceeds to step S13.

[0057] In step S13, the control unit 35 determines whether a drying end condition is met. The drying end condition may be met when a drying end command is received from the user. The drying end condition may also be met when a predetermined time has elapsed.

[0058] If the control unit 35 determines that the drying termination condition is not met, the process proceeds to step S10. If the control unit 35 determines that the drying termination condition is met, the control unit 35 controls the drying conveyance unit 33 to stop conveying the medium 90, and controls the high-frequency voltage generation unit 31 to stop supplying high-frequency voltage to the drying unit 36. Thereafter, the control unit 35 ends the drying control process.

[0059] In this way, the control unit 35 repeatedly performs a transport control process to transport the medium 90 in the transport direction D by a distance d10 until the drying end condition is met, and then performs a drying process based on the control pattern on the drying area while the transport of the medium 90 is stopped.

[0060] <Control pattern> Next, a control pattern for controlling the drying unit 36 ​​will be described with reference to FIG. 5, the control pattern is a pattern in which the intensity of the electromagnetic waves generated from the drying unit 36 ​​is intensity S from the timing indicated by reference symbol T0 to the timing indicated by reference symbol T1. The time t1 from the timing indicated by reference symbol T0 to the timing indicated by reference symbol T1 may be, for example, 3 seconds. In this way, the control pattern is a pattern in which the electromagnetic waves are generated over a first pulse width from the timing indicated by reference symbol T0 to the time t1. The timing indicated by reference symbol T0 corresponds to an example of a first start timing.

[0061] The control pattern is a pattern in which no electromagnetic waves are generated from the drying unit 36 ​​from the timing indicated by reference symbol T1 to the timing indicated by reference symbol T2. The time t0 from the timing indicated by reference symbol T1 to the timing indicated by reference symbol T2 may be, for example, 1 second. The time t0 is shorter than the time t1.

[0062] The control pattern is a pattern in which the intensity of the electromagnetic waves generated from the drying unit 36 ​​is intensity S from the timing indicated by symbol T2 to the timing indicated by symbol T3. The time t2 from the timing indicated by symbol T2 to the timing indicated by symbol T3 may be, for example, 0.5 seconds. Time t2 is shorter than time t0 and time t1. In this way, the control pattern is a pattern in which electromagnetic waves are generated over a second pulse width from the timing indicated by symbol T2 to time t2. The timing indicated by symbol T2 corresponds to an example of a second start timing.

[0063] The control pattern is a pattern in which electromagnetic waves are not generated from the drying unit 36 ​​from the timing indicated by reference symbol T3 to the timing indicated by reference symbol T4 and from the timing indicated by reference symbol T5 to the timing indicated by reference symbol T6. The time t0 from the timing indicated by reference symbol T3 to the timing indicated by reference symbol T4 and the time t0 from the timing indicated by reference symbol T5 to the timing indicated by reference symbol T6 may be the same as the time t0 from the timing indicated by reference symbol T1 to the timing indicated by reference symbol T2.

[0064] The control pattern is a pattern in which the intensity of the electromagnetic waves generated from the drying unit 36 ​​is intensity S from the timing T4 to the timing T5 and from the timing T6 to the timing T7. The time t2 from the timing T4 to the timing T5 and the time t2 from the timing T6 to the timing T7 may be the same as the time t2 from the timing T2 to the timing T3. In this way, the control pattern is a pattern in which electromagnetic waves are generated over the second pulse width from the timings T4 and T6.

[0065] The control pattern is a pattern in which electromagnetic waves are generated for a time t1, then no electromagnetic waves are generated for a time t0, and then electromagnetic waves are generated for a time t2, and this is repeated three times.

[0066] In this way, the drying unit 36 ​​generates electromagnetic waves for the medium 90 so that the intensity of the generated electromagnetic waves is pulsed in a time series. Furthermore, when the transport of the medium 90 is stopped, the intensity of the electromagnetic waves generated by the drying unit 36 ​​corresponds to the irradiation intensity of the electromagnetic waves on the medium 90. In other words, the drying unit 36 ​​generates electromagnetic waves so that the irradiation intensity of the electromagnetic waves on the medium 90 is pulsed in a time series.

[0067] <Drying principle of Media 90> Pigment ink as a liquid is ejected onto the medium 90 by the recording device 11. Unlike dye ink, which soaks into the medium 90, the pigment ink is fixed to the surface 90A of the medium 90 to record.

[0068] Pigment ink contains water in addition to pigment. Pigment ink also contains glycerin as a solvent. When the temperature of pigment ink reaches approximately 100°C, the water contained in the pigment ink evaporates. When the temperature of pigment ink reaches approximately 290°C, the glycerin contained in the pigment ink evaporates.

[0069] The pigment ink ejected onto the surface 90A of the medium 90 is heated by electromagnetic waves generated by the drying unit 36. This causes the water and solvent contained in the pigment ink to evaporate, drying the medium 90. In particular, the evaporation of glycerin contained in the pigment ink can improve the abrasion resistance of the medium 90.

[0070] The electromagnetic waves generated by the drying unit 36 ​​do not heat the gas surrounding the medium 90. Therefore, the electromagnetic waves do not directly heat the medium 90 itself, but heat the pigment ink. In this way, the generation of electromagnetic waves itself is not a direct cause of thermal degradation of the medium 90. On the other hand, when the pigment ink is heated by the generation of electromagnetic waves, the heat of the pigment ink is transferred to the medium 90. This can cause thermal degradation of the medium 90.

[0071] For example, if the medium 90 is made of cotton cloth, thermal degradation of the medium 90 occurs if the temperature of the medium 90 remains at approximately 270°C for 1 second. Thermal degradation of the medium 90 includes the property of the medium 90 turning yellow. In addition, if the temperature of the medium 90 exceeds 400°C, there is a risk of the medium 90 catching fire, so it is necessary to prevent the temperature of the medium 90 from exceeding approximately 350°C.

[0072] Thus, when drying the medium 90 onto which the pigment ink has been ejected, it is necessary to raise the temperature of the pigment ink to 290°C or higher. On the other hand, it is necessary to dry the medium 90 so that the temperature of the medium 90 does not exceed approximately 350°C, and the temperature of the medium 90 does not exceed approximately 270°C continuously for 1 second.

[0073] 5, when the drying unit 36 ​​generates electromagnetic waves based on the control pattern, the temperature of the medium 90 rises from the timing indicated by the symbol T0 to approximately 100°C. In this way, by rapidly raising the temperature of the medium 90 from the timing indicated by the symbol T0, water contained in the pigment ink is evaporated, thereby performing pre-drying. The temperature then reaches approximately 310°C at the timing indicated by the symbol T2.

[0074] From the timing indicated by reference symbol T2, the drying unit 36 ​​stops generating electromagnetic waves. As a result, the temperature of the medium 90 drops and reaches approximately 250°C at the timing indicated by reference symbol T3. At this time, the temperature of the medium 90 exceeds approximately 290°C for a period of time t3.

[0075] From the timing indicated by reference symbol T3, the drying unit 36 ​​generates electromagnetic waves, causing the temperature of the medium 90 to rise and reach approximately 310°C at the timing indicated by reference symbol T4. Thereafter, from the timing indicated by reference symbol T4, the drying unit 36 ​​stops generating electromagnetic waves. As a result, the temperature of the medium 90 drops and reaches approximately 250°C at the timing indicated by reference symbol T5.

[0076] At this time, the temperature of the medium 90 exceeds approximately 290° C. for a period of time t3. Furthermore, the temperature of the medium 90 exceeds approximately 270° C. for a period of time t4. For example, the period of time t3 may be 0.4 seconds, and the period of time t4 may be 0.6 seconds.

[0077] In this way, the temperature of the medium 90 is rapidly increased from time T0 to time T2, and then does not exceed approximately 350°C, exceeds 290°C for time t3, and then exceeds 270°C for time t4, repeatedly. Then, at time T7, drying based on the control pattern is completed.

[0078] This allows for main drying to vaporize the solvent contained in the pigment ink without causing thermal denaturation of the medium 90. In particular, for main drying, electromagnetic waves are generated over three cycles to ensure that the glycerin is vaporized. The time from the timing indicated by reference symbol T0 to the timing indicated by reference symbol T7 may be, for example, 7.5 seconds.

[0079] <Actions and Effects of the First Embodiment> The operation and effects of the first embodiment will be described. (1-1) Conventionally, main drying has been performed by blowing high-temperature hot air or irradiating infrared rays, but this requires drying at a moderate temperature for a long period of time, such as 120 seconds, which reduces the drying efficiency and also leads to an increase in the size of the system.

[0080] Therefore, the drying unit 36 ​​generates electromagnetic waves so that the irradiation intensity of the electromagnetic waves on the medium 90 onto which the pigment ink has been ejected is pulsed in a time series. With this configuration, the medium 90 can be dried in a short time by generating electromagnetic waves in response to the application of a high-frequency voltage.

[0081] In addition, even if the electromagnetic wave intensity is strong, the irradiation intensity of the electromagnetic wave on the medium 90 can be pulsed in a time series. This makes it possible to suppress thermal degradation of the medium 90 onto which the pigment ink has been ejected. Therefore, the medium 90 can be dried in a short time while maintaining the quality of the medium 90.

[0082] (1-2) The drying unit 36 ​​generates electromagnetic waves based on a control pattern. The control pattern is a pulsed pattern in which electromagnetic waves are generated from the timing indicated by the reference symbol T0 over a first pulse width, and then from the timing indicated by the reference symbol T2 over a second pulse width that is shorter than the first pulse width. This configuration allows the timing of generating electromagnetic waves to be controlled based on the control pattern. This improves the accuracy of controlling the temperature of the pigment ink.

[0083] In particular, by generating electromagnetic waves over a first pulse width from the timing indicated by reference symbol T0, it is possible to increase the rate at which the temperature of the pigment ink ejected onto the medium 90 is raised. Then, by generating electromagnetic waves over a second pulse width that is shorter than the first pulse width from the timing indicated by reference symbol T2, it is possible to prevent the temperature of the pigment ink ejected onto the medium 90 from being raised excessively. This makes it possible to prevent thermal degradation of the medium 90 onto which the pigment ink has been ejected. Therefore, it is possible to dry the medium 90 in a short time while maintaining the quality of the medium 90.

[0084] (1-3) The drying unit 36 ​​generates electromagnetic waves based on the control pattern while the transport of the medium 90 is stopped. With this configuration, electromagnetic waves can be generated based on the control pattern while the transport of the medium 90 is stopped. This increases the accuracy of controlling the temperature of the pigment ink. This reduces the occurrence of thermal degradation of the medium 90 onto which the pigment ink has been ejected. This allows the medium 90 to be dried in a short time while maintaining the quality of the medium 90.

[0085] (1-4) The drying unit 36 ​​is provided on the surface 90A side of the medium 90. Therefore, the medium 90 can be dried by heating the liquid from the surface 90A side of the medium 90 onto which the liquid has been ejected.

[0086] [Second embodiment] Next, a second embodiment will be described. In the following description, the same configuration as in the already described embodiment will be omitted or simplified, and only the configuration different from the already described embodiment will be described.

[0087] 6, in the second embodiment, the drying section 36 in the drying device 12 may include a first drying section 36A and a second drying section 36B. The drying section 36 may include a plurality of first drying sections 36A and a plurality of second drying sections 36B. In other words, the drying device 12 may include the first drying section 36A and the second drying section 36B.

[0088] The first drying section 36A generates electromagnetic waves to pre-dry the medium 90. The first drying section 36A is provided in the upstream region R11. The upstream region R11 is located upstream in the transport direction D of a downstream region R12, which will be described later.

[0089] The second drying section 36B performs main drying of the medium 90 by generating electromagnetic waves. The second drying section 36B is provided in the downstream region R12. As such, the second drying section 36B is provided downstream of the first drying section 36A in the conveying direction D. Between the upstream region R11 and the downstream region R12 in the conveying direction D, an intermediate region R13 where electromagnetic waves are not generated is provided.

[0090] The first drying section 36A generates electromagnetic waves with a higher intensity than the second drying section 36B. Specifically, by configuring the inductance of the coil 43A of the first drying section 36A and the inductance of the coil 43A of the second drying section 36B to be different, the resonant frequency of the first drying section 36A can be made different from the resonant frequency of the second drying section 36B. In this way, by making the resonant frequency of the first drying section 36A higher than the resonant frequency of the second drying section 36B, the intensity of the electromagnetic waves generated from the first drying section 36A can be made higher than the intensity of the electromagnetic waves generated from the second drying section 36B.

[0091] The high-frequency voltage generating unit 31 may include a first high-frequency voltage generating unit 31A and a second high-frequency voltage generating unit 31B. The first high-frequency voltage generating unit 31A supplies a high-frequency voltage to the first drying unit 36A. The second high-frequency voltage generating unit 31B supplies a high-frequency voltage to the second drying unit 36B.

[0092] The control unit 35 causes the drying and conveying unit 33 to perform continuous conveyance, which continuously conveys the medium 90. The control unit 35 controls the first high-frequency voltage generating unit 31A to cause the first drying unit 36A to generate electromagnetic waves based on the first control pattern while the medium 90 is being continuously conveyed at a predetermined speed. As a result, the first drying unit 36A generates electromagnetic waves based on the first control pattern while the medium 90 is being continuously conveyed at the predetermined speed.

[0093] The control unit 35 controls the second high-frequency voltage generating unit 31B to cause the second drying unit 36B to generate electromagnetic waves based on the second control pattern while the medium 90 is being continuously transported at a predetermined speed. As a result, the second drying unit 36B generates electromagnetic waves based on the second control pattern while the medium 90 is being continuously transported at a predetermined speed.

[0094] As shown in FIG. 7, the first control pattern is a pattern in which electromagnetic waves of a predetermined intensity are continuously generated. The first control pattern is a pattern for controlling the first drying unit 36A. Therefore, the first control pattern is a pattern in which electromagnetic waves of a first intensity S1 are continuously generated from the first drying unit 36A. As a result, the first drying unit 36A continuously generates electromagnetic waves of a predetermined intensity based on the first control pattern while the medium 90 is continuously transported at a predetermined speed.

[0095] The second control pattern is a pulsed pattern that generates electromagnetic waves over a predetermined pulse width. The second control pattern is a pattern for controlling the second drying unit 36B. Therefore, the second control pattern causes the second drying unit 36B to generate pulsed electromagnetic waves of a second intensity S2 that is smaller than the first intensity S1. The predetermined pulse width may be the same as the second pulse width at time t2, or may be shorter or longer than the second pulse width. As a result, the second drying unit 36B generates pulsed electromagnetic waves over a predetermined pulse width based on the second control pattern while the medium 90 is continuously transported at a predetermined speed.

[0096] In this manner, as the medium 90 is continuously transported at a predetermined speed along the transport direction D, the first drying unit 36A generates electromagnetic waves at a first intensity S1 for a predetermined time period, targeting the dried region of the medium 90 disposed in the upstream region R11. The predetermined time period may be time t1. As a result, the electromagnetic waves from the first drying unit 36A are continuously irradiated onto the dried region of the medium 90 in the upstream region R11.

[0097] The medium 90 is then transported so that the dry region of the medium 90 moves from the upstream region R11 to the intermediate region R13. The dry region of the medium 90 placed in the intermediate region R13 is not irradiated with electromagnetic waves for a predetermined time. The predetermined time may be time t0.

[0098] Next, the medium 90 is transported so that the dried region of the medium 90 moves from the intermediate region R13 to the downstream region R12. The second drying unit 36B generates electromagnetic waves at a predetermined speed and a second intensity S2 for a time corresponding to a predetermined pulse width, targeting the dried region of the medium 90 arranged in the downstream region R12, over three cycles. As a result, the pulsed electromagnetic waves from the second drying unit 36B are irradiated onto the dried region of the medium 90 in the downstream region R12.

[0099] Thus, in the second embodiment, as in the first embodiment, the drying section 36 including the first drying section 36A and the second drying section 36B generates electromagnetic waves so that the irradiation intensity of the electromagnetic waves on the medium 90 is pulsed in a time series.

[0100] <Actions and Effects of the Second Embodiment> The operation and effects of the second embodiment will be described. (2-1) The first drying unit 36A generates electromagnetic waves based on a first control pattern while the medium 90 is continuously transported at a predetermined speed. The first control pattern is a pattern that continuously generates electromagnetic waves of a predetermined intensity. The second drying unit 36B is provided downstream of the first drying unit 36A in the transport direction D. The second drying unit 36B generates electromagnetic waves based on a second control pattern while the medium 90 is continuously transported at a predetermined speed. The second control pattern is a pulsed pattern that generates electromagnetic waves over a predetermined pulse width. With this configuration, the medium 90 onto which the pigment ink has been ejected can be dried without stopping the transport of the medium 90. This increases the speed at which the medium 90 onto which the pigment ink has been ejected can be dried.

[0101] In addition, the generation of electromagnetic waves from the first drying unit 36A can increase the speed at which the temperature of the pigment ink ejected onto the medium 90 is raised. The generation of electromagnetic waves from the second drying unit 36B can prevent the temperature of the pigment ink ejected onto the medium 90 from rising excessively. This can prevent thermal degradation of the medium 90 onto which the pigment ink has been ejected. Therefore, the medium 90 can be dried in a short time while maintaining the quality of the medium 90.

[0102] (2-2) The resonant frequency of the first drying section 36A is different from that of the second drying section 36B, and the first drying section 36A generates electromagnetic waves with a higher intensity than the second drying section 36B. According to this configuration, by differentiating the resonant frequency of the first drying section 36A from that of the second drying section 36B, the first drying section 36A can generate electromagnetic waves with a higher intensity than the second drying section 36B. Therefore, the generation of electromagnetic waves from the first drying section 36A can further increase the rate at which the temperature of the pigment ink ejected onto the medium 90 is increased. Furthermore, the generation of electromagnetic waves from the second drying section 36B can further prevent the temperature of the pigment ink ejected onto the medium 90 from being excessively increased. This can prevent thermal degradation of the medium 90 onto which the pigment ink has been ejected. Therefore, the medium 90 can be dried in a short time while maintaining the quality of the medium 90. Furthermore, the control load for controlling the intensity of the electromagnetic waves generated by the first drying section 36A and the intensity of the electromagnetic waves generated by the second drying section 36B can be reduced.

[0103] [Third embodiment] Next, a third embodiment will be described. 8, in the third embodiment, the first drying section 36A is provided in the first region R21. The second drying section 36B is provided in the second region R22. The second region R22 is a region provided downstream of the first region R21 in the conveying direction D. In this way, the second drying section 36B is provided downstream of the first drying section 36A in the conveying direction D. The second region R22 may be provided at three locations downstream of the first region R21 in the conveying direction D.

[0104] A third region R23 is provided between the first region R21 and the second region R22 in the conveying direction D. The third region R23 is a region where electromagnetic waves are not generated. In other words, the second region R22 is a region where the third region R23 is provided between the first region R21. The third region R23 is also provided between the second regions R22 in the conveying direction D. In other words, the second region R22 is a region where the third region R23 is provided between the second regions R22.

[0105] The first region R21 is provided over a first distance d11 in the conveying direction D. That is, the first distance d11 is the distance of the first region R21 in the conveying direction D. The second region R22 is provided over a second distance d12 in the conveying direction D. That is, the second distance d12 is the distance of the second region R22 in the conveying direction D. The third region R23 is provided over a third distance d13 in the conveying direction D. That is, the third distance d13 is the distance of the third region R23 in the conveying direction D.

[0106] The first distance d11 is longer than the second distance d12. The ratio of the first distance d11 to the second distance d12 to the third distance d13 may be the same as the ratio of the time t1 to the time t2 to the time t0. As a specific example, the ratio of the first distance d11 to the second distance d12 to the third distance d13 may be 6:1:2.

[0107] The first distance d11 may be equal to the product of a predetermined speed at which the medium 90 is transported and time t1. The second distance d12 may be equal to the product of a predetermined speed at which the medium 90 is transported and time t2. The third distance d13 may be equal to the product of a predetermined speed at which the medium 90 is transported and time t3.

[0108] The first drying section 36A and the second drying section 36B may be supplied with the same high-frequency voltage from the high-frequency voltage generating section 31. The control section 35 controls the high-frequency voltage generating section 31 based on the control pattern so as to cause the first drying section 36A and the second drying section 36B to generate electromagnetic waves.

[0109] The control unit 35 causes the drying and conveying unit 33 to perform continuous conveyance, which continuously conveys the medium 90. The control unit 35 controls the high-frequency voltage generating unit 31 to cause the first drying unit 36A and the second drying unit 36B to generate electromagnetic waves based on the control pattern while the medium 90 is being continuously conveyed at a predetermined speed. In other words, the first drying unit 36A and the second drying unit 36B generate electromagnetic waves based on the control pattern while the medium 90 is being continuously conveyed at a predetermined speed.

[0110] As shown in FIG. 9, the control pattern is a pattern in which electromagnetic waves are continuously generated at a predetermined intensity. The control pattern is a pattern for controlling the first drying unit 36A and the second drying unit 36B. Therefore, the control pattern is a pattern in which the first drying unit 36A continuously generates electromagnetic waves at a first intensity S1. The control pattern is a pattern in which the second drying unit 36B continuously generates electromagnetic waves at a second intensity S2. As a result, the first drying unit 36A and the second drying unit 36B continuously generate electromagnetic waves at a predetermined intensity based on the control pattern while the medium 90 is continuously transported at a predetermined speed.

[0111] In this manner, as the medium 90 is continuously transported at a predetermined speed along the transport direction D, the first drying unit 36A generates electromagnetic waves at a first intensity S1 for a time t1, targeting the dried region of the medium 90 placed in the first region R21. As a result, the electromagnetic waves from the first drying unit 36A are continuously irradiated onto the dried region of the medium 90 in the first region R21.

[0112] Thereafter, the medium 90 is transported so that the dry region of the medium 90 moves from the first region R21 to the third region R23. The dry region of the medium 90 placed in the third region R23 is not irradiated with electromagnetic waves for a period of time t0.

[0113] Next, the medium 90 is transported so that the dried region of the medium 90 moves from the third region R23 to the second region R22. The second drying unit 36B generates electromagnetic waves at the second intensity S2 for the time t2, targeting the dried region of the medium 90 placed in the second region R22, over three cycles. As a result, the pulsed electromagnetic waves from the second drying unit 36B are irradiated onto the dried region of the medium 90 in the second region R22.

[0114] Thus, in the third embodiment, as in the first and second embodiments, the drying section 36 including the first drying section 36A and the second drying section 36B generates electromagnetic waves so that the irradiation intensity of the electromagnetic waves on the medium 90 is pulsed in a time series.

[0115] <Actions and Effects of the Third Embodiment> The operation and effects of the third embodiment will be described. (3-1) The first drying unit 36A is provided in the first region R21. The second drying unit 36B is provided in the second region R22. The second region R22 is provided downstream of the first region R21 in the transport direction D. The second region R22 is provided with a third region R23 between the first region R21 in the transport direction D and the third region R23, where no electromagnetic waves are generated. The first distance d11 in the transport direction D from the first region R21 is longer than the second distance d12 in the transport direction D from the second region R22. The first drying unit 36A and the second drying unit 36B generate electromagnetic waves based on a control pattern while the medium 90 is continuously transported at a predetermined speed. The control pattern is a pattern that continuously generates electromagnetic waves of a predetermined intensity. This configuration allows the medium 90 onto which pigment ink has been ejected to be dried without stopping the transport of the medium 90. This increases the speed at which the medium 90 onto which pigment ink has been ejected is dried.

[0116] In addition, the generation of electromagnetic waves from the first drying unit 36A can increase the speed at which the temperature of the pigment ink ejected onto the medium 90 is raised. The generation of electromagnetic waves from the second drying unit 36B can prevent the temperature of the pigment ink ejected onto the medium 90 from rising excessively. This can prevent thermal degradation of the medium 90 onto which the pigment ink has been ejected. Therefore, the medium 90 can be dried in a short time while maintaining the quality of the medium 90.

[0117] Furthermore, by providing the first drying section 36A in the first region R21 and the second drying section 36B in the second region R22, the control load for controlling the first drying section 36A and the second drying section 36B can be reduced.

[0118] [Example of change] This embodiment can be modified as follows: This embodiment and the following modifications can be combined and implemented within the scope of technical compatibility.

[0119] In the second embodiment, one or more first drying sections 36A may be arranged in the depth direction Y in the upstream region R11. One or more first drying sections 36A may be arranged in the width direction X in the upstream region R11. One or more second drying sections 36B may be arranged in the depth direction Y in each downstream region R12. One or more second drying sections 36B may be arranged in the width direction X in each downstream region R12.

[0120] In the second embodiment, the number of first drying sections 36A arranged in the depth direction Y in the upstream region R11 may differ from the number of second drying sections 36B arranged in the depth direction Y in each downstream region R12. The number of first drying sections 36A arranged in the depth direction Y in the upstream region R11 may be greater than or less than the number of second drying sections 36B arranged in the depth direction Y in each downstream region R12. The number of second drying sections 36B arranged in the depth direction Y in each downstream region R12 may differ.

[0121] In the third embodiment, one or more first drying sections 36A may be arranged in the depth direction Y in the first region R21. One or more first drying sections 36A may be arranged in the width direction X in the first region R21. One or more second drying sections 36B may be arranged in the depth direction Y in each of the second regions R22. One or more second drying sections 36B may be arranged in the width direction X in each of the second regions R22.

[0122] In the third embodiment, the number of first drying sections 36A arranged in the depth direction Y in the first region R21 may differ from the number of second drying sections 36B arranged in the depth direction Y in each of the second regions R22. The number of first drying sections 36A arranged in the depth direction Y in the first region R21 may be greater than or less than the number of second drying sections 36B arranged in the depth direction Y in each of the second regions R22. The number of second drying sections 36B arranged in the depth direction Y in each of the second regions R22 may differ.

[0123] In the first embodiment, the control unit 35 may continuously transport the medium 90. In the second and third embodiments, the control unit 35 may intermittently transport the medium 90. In the first embodiment, the drying unit 36 ​​may generate electromagnetic waves such that the intensity of the electromagnetic waves in the preliminary drying is higher than the intensity of the electromagnetic waves in the main drying. The drying unit 36 ​​may generate electromagnetic waves such that the intensity of the electromagnetic waves in the preliminary drying is lower than the intensity of the electromagnetic waves in the main drying.

[0124] In the second and third embodiments, the drying unit 36 ​​may generate electromagnetic waves so that the intensity of the electromagnetic waves during pre-drying is the same as the intensity of the electromagnetic waves during main drying. In the second and third embodiments, the drying unit 36 ​​may generate electromagnetic waves so that the intensity of the electromagnetic waves during pre-drying is lower than the intensity of the electromagnetic waves during main drying. In these cases, the drying unit 36 ​​may dry the medium 90 onto which the pigment ink has been ejected by extending the time for which the electromagnetic waves are generated as pre-drying.

[0125] The drying device 12 may perform main drying without pre-drying. In particular, in the first embodiment, the control pattern may be a pattern that generates electromagnetic waves in multiple pulses over a predetermined pulse width. Furthermore, in the second and third embodiments, the drying device 12 may not include the first drying unit 36A if the irradiation intensity of the electromagnetic waves on the medium 90 onto which the pigment ink has been ejected is pulsed in a time series. In other words, the drying device 12 may include at least the second drying units 36B arranged in multiple rows in the transport direction D if the irradiation intensity of the electromagnetic waves on the medium 90 onto which the pigment ink has been ejected is pulsed in a time series.

[0126] In the third embodiment, the third region R23 was a region where the drying unit 36 ​​was not arranged, but it may also be a region where the drying unit 36 ​​is arranged but where electromagnetic waves are not generated from the drying unit 36.

[0127] In the main drying, the electromagnetic waves may be generated so that the irradiation intensity of the electromagnetic waves on the medium 90 is pulsed two or four or more times in a time series. In other words, two or four or more cycles may be repeated in the main drying. It is sufficient that the electromagnetic waves are generated so that the irradiation intensity of the electromagnetic waves on the medium 90 is pulsed in a time series at least in the preliminary drying and the main drying. In this case, in the main drying, the electromagnetic waves may be generated so that the irradiation intensity of the electromagnetic waves on the medium 90 is pulsed only once in a time series.

[0128] The control unit 35 may control the high-frequency voltage supplied from the high-frequency voltage generation unit 31 to the drying unit 36 ​​by the drying unit 36 ​​itself, rather than by the high-frequency voltage generation unit 31. Specifically, if the drying unit 36 ​​can generate electromagnetic waves based on a control pattern, it may receive a high-frequency voltage based on the control pattern from the high-frequency voltage generation unit 31. If the drying unit 36 ​​can generate electromagnetic waves based on a control pattern, it may receive a high-frequency voltage from the high-frequency voltage generation unit 31 and generate electromagnetic waves as an envelope based on the control pattern.

[0129] The relationship between the high-frequency voltage generating unit 31 and the drying unit 36 ​​may be one-to-many or one-to-one. In particular, in the second embodiment, the relationship between the first high-frequency voltage generating unit 31A and the first drying unit 36A may be one-to-many or one-to-one. In the second embodiment, the relationship between the second high-frequency voltage generating unit 31B and the second drying unit 36B may be one-to-many or one-to-one.

[0130] The drying unit 36 ​​may be disposed so that its longitudinal direction is the depth direction Y. The drying unit 36 ​​may be disposed so that it is inclined with respect to the width direction X and the depth direction Y. When the drying unit 30 includes multiple drying sections 36, the multiple drying sections 36 may be arranged in multiple rows in the width direction X. When the drying unit 30 includes multiple drying sections 36, the multiple drying sections 36 may be arranged in multiple rows in the depth direction Y.

[0131] The drying unit 36 ​​may be provided on the back surface 90B side of the medium 90. The drying unit 36 ​​may be provided on both the front surface 90A side and the back surface 90B side of the medium 90. The drying unit 36 ​​may be scannable in the width direction X.

[0132] The drying unit 36 ​​may be provided separately from the facing unit 45. In other words, the drying unit 36 ​​does not have to include the facing unit 45. In this case, it is preferable that the facing unit 45 be provided between the first electrode 41 and the second electrode and the medium 90.

[0133] The first electrode 41 is not limited to a flat plate shape and may be, for example, a generally flat plate shape. The generally flat plate shape may include, for example, a shape curved in the thickness direction, which is the direction along the vertical direction Z, or a linear shape with an extremely large aspect ratio of a rectangular shape. The first electrode 41 may have a shape that has a thickness in the vertical direction Z, or multiple electrode members may be connected in the vertical direction Z.

[0134] The second electrode 42 is not limited to a flat plate shape and may be, for example, a generally flat plate shape. The generally flat plate shape may include, for example, a shape curved in the thickness direction, which is the direction along the vertical direction Z, or a linear shape with an extremely large aspect ratio of a rectangular shape.

[0135] At least one of the first electrode surface 41A and the second electrode surface 42A is not limited to a planar shape and may be a substantially planar shape. The substantially planar shape may include, for example, a shape curved in the thickness direction, which is the direction along the vertical direction Z, or a linear shape with an extremely large aspect ratio of a rectangular shape.

[0136] The drying unit 36 ​​may be provided in the recording device 11, rather than in the drying device 12. That is, the recording device 11 may include the drying unit 36. In this case, the drying unit 36 ​​may be provided downstream of the recording device 20 in the transport direction D. In this way, the drying unit 36 ​​may be applied to the recording device 11, rather than the drying device 12.

[0137] A lateral printer may be used as the recording device 11. A lateral printer is a printer in which a carriage 25 can move in two directions, the main scanning direction and the sub-scanning direction.

[0138] The medium 90 is not limited to a roll, and may be paper, a resin film or sheet, a resin-metal composite film, a laminate film, a woven fabric, a nonwoven fabric, a metal foil, a metal film, a ceramic sheet, clothing, or the like.

[0139] The liquid can be any pigment ink that adheres to the medium 90 and records on the medium 90. The pigment ink may contain a solvent other than glycerin. In such cases, the intensity of the electromagnetic waves irradiated onto the medium may be varied depending on the boiling point and solvent ratio of the solvent contained in the pigment ink. Specifically, the intensity of the electromagnetic waves irradiated onto the medium can be adjusted by adjusting at least one of the first pulse width, the second pulse width, the number of times the electromagnetic waves are generated at the second pulse width, the intensity at which the electromagnetic waves are generated, and the number and arrangement of the drying units 36.

[0140] The phrase "at least any" used herein means one or more of the desired options. As an example, when the number of options is two, the phrase "at least any" used herein means only one option or both options. As another example, when the number of options is three or more, the phrase "at least any" used herein means only one option or any combination of two or more options.

[0141] [Note] The technical concepts and their effects that can be understood from the above-described embodiments and modifications will be described below. The technical concepts and their effects can be combined with each other to the extent that they are not technically inconsistent.

[0142] (A) The drying device includes a drying unit that dries a medium onto which a pigment ink containing pigment, water, and a solvent is ejected by generating electromagnetic waves in response to the application of a high-frequency voltage, the drying unit including a first electrode, a second electrode that is arranged to surround the first electrode in a planar view from a first direction toward the medium, a first conductor that has a coil and electrically connects the first electrode to a transmission line capable of transmitting a high-frequency voltage, and a second conductor that electrically connects the transmission line to the second electrode, and the drying unit generates electromagnetic waves so that the irradiation intensity of the electromagnetic waves on the medium onto which the pigment ink is ejected is pulsed in a time series.

[0143] According to this configuration, by generating electromagnetic waves in response to the application of high-frequency voltage, the medium can be dried in a short time. In addition, even if the intensity of the electromagnetic waves is high, the irradiation intensity of the electromagnetic waves on the medium can be pulsed in a time series. This makes it possible to suppress the occurrence of thermal degradation of the medium onto which the pigment ink has been ejected. Therefore, the medium can be dried in a short time while maintaining its quality.

[0144] (B) In the drying device, the drying section generates electromagnetic waves based on a control pattern, and the control pattern may be a pulsed pattern that generates electromagnetic waves from a first start timing over a first pulse width, and generates electromagnetic waves from a second start timing that is later than the first start timing over a second pulse width that is shorter than the first pulse width.

[0145] According to this configuration, the timing of generating the electromagnetic waves can be controlled based on the control pattern, thereby improving the accuracy of controlling the temperature of the pigment ink. In particular, by generating electromagnetic waves over a first pulse width from the first start timing, the speed at which the temperature of the pigment ink ejected onto the medium is increased can be increased. Then, by generating electromagnetic waves over a second pulse width, which is shorter than the first pulse width, from the second start timing, which is after the first start timing, it is possible to prevent the temperature of the pigment ink ejected onto the medium from being excessively increased. This makes it possible to prevent thermal degradation of the medium onto which the pigment ink has been ejected. Therefore, the medium can be dried in a short time while maintaining the quality of the medium.

[0146] (C) The drying device may include a drying conveying unit that conveys the medium along a conveying direction, the drying conveying unit intermittently conveying the medium along the conveying direction, and the drying unit may generate electromagnetic waves based on the control pattern while the conveying of the medium by the drying conveying unit is stopped.

[0147] This configuration allows electromagnetic waves to be generated based on the control pattern while the medium is stopped. This improves the accuracy of controlling the temperature of the pigment ink. This reduces thermal degradation of the medium onto which the pigment ink has been ejected. This allows the medium to be dried in a short time while maintaining its quality.

[0148] (D) The drying device includes a drying and conveying section that conveys a medium along a conveying direction, the drying section having a first drying section and a second drying section that is located downstream of the first drying section in the conveying direction, the first drying section generating electromagnetic waves based on a first control pattern while the medium is being continuously conveyed by the drying and conveying section at a predetermined speed, and the second drying section generating electromagnetic waves based on a second control pattern while the medium is being continuously conveyed by the drying and conveying section at a predetermined speed, the first control pattern being a pattern that continuously generates electromagnetic waves of a predetermined intensity, and the second control pattern being a pulsed pattern that generates electromagnetic waves over a predetermined pulse width.

[0149] According to this configuration, the medium onto which the pigment ink has been ejected can be dried without stopping the transport of the medium, thereby increasing the speed at which the medium onto which the pigment ink has been ejected can be dried.

[0150] In addition, the generation of electromagnetic waves from the first drying unit can increase the speed at which the temperature of the pigment ink ejected onto the medium is raised. Furthermore, the generation of electromagnetic waves from the second drying unit, which is located downstream of the first drying unit in the transport direction, can prevent the temperature of the pigment ink ejected onto the medium from rising excessively. This can prevent thermal degradation of the medium onto which the pigment ink is ejected. Therefore, the medium can be dried in a short time while maintaining the quality of the medium.

[0151] (E) The drying device includes a drying and conveying section that conveys the medium along the conveying direction, the drying section having a first drying section and a second drying section that is located downstream of the first drying section in the conveying direction, the first drying section being located in a first region, the second drying section being located in a second region, the second region being located downstream of the first region in the conveying direction and having a third region between the first region and the first region in the conveying direction in which electromagnetic waves are not generated, a first distance in the conveying direction of the first region being longer than a second distance in the conveying direction of the second region, the first drying section and the second drying section generating electromagnetic waves based on a control pattern while the medium is continuously conveyed by the drying and conveying section at a predetermined speed, and the control pattern may be a pattern that continuously generates electromagnetic waves of a predetermined intensity.

[0152] According to this configuration, the medium onto which the pigment ink has been ejected can be dried without stopping the transport of the medium, thereby increasing the speed at which the medium onto which the pigment ink has been ejected can be dried.

[0153] In addition, the generation of electromagnetic waves from the first drying unit can increase the rate at which the temperature of the pigment ink ejected onto the medium is raised. Furthermore, the generation of electromagnetic waves from the second drying unit, which is located downstream of the first drying unit in the transport direction, can prevent the temperature of the pigment ink ejected onto the medium from being excessively raised. This can prevent thermal degradation of the medium onto which the pigment ink is ejected. Therefore, the medium can be dried in a short time while maintaining the quality of the medium. Furthermore, by providing the first drying unit in the first region and the second drying unit in the second region, the control load for controlling the first drying unit and the second drying unit can be reduced.

[0154] (F) In the drying device, the first drying section may have a resonant frequency different from that of the second drying section, and the first drying section may generate electromagnetic waves with a higher intensity than the second drying section.

[0155] According to this configuration, by differentiating the resonant frequency of the first drying unit from the resonant frequency of the second drying unit, the first drying unit can generate electromagnetic waves with a higher intensity than the second drying unit. Therefore, the generation of electromagnetic waves from the first drying unit can further increase the rate at which the temperature of the pigment ink ejected onto the medium is increased. Furthermore, the generation of electromagnetic waves from the second drying unit can further prevent the temperature of the pigment ink ejected onto the medium from being excessively increased. This can prevent thermal degradation of the medium onto which the pigment ink is ejected. Therefore, the medium can be dried in a short time while maintaining the quality of the medium. Furthermore, the control load for controlling the intensity of the electromagnetic waves generated by the first drying unit and the intensity of the electromagnetic waves generated by the second drying unit can be reduced.

[0156] (G) A printing device includes a recording unit that performs recording by ejecting a pigment ink containing pigment, water, and a solvent onto a medium, and a drying unit that dries the medium onto which the pigment ink has been ejected by the recording unit by generating electromagnetic waves in response to the application of a high-frequency voltage, wherein the drying unit has a first electrode, a second electrode that is arranged to surround the first electrode in a plan view from a first direction toward the medium, a first conductor that has a coil and electrically connects the first electrode to a transmission line capable of transmitting a high-frequency voltage, and a second conductor that electrically connects the transmission line to the second electrode, and the drying unit generates electromagnetic waves so that the irradiation intensity of the electromagnetic waves on the medium onto which the pigment ink has been ejected is pulsed in a time series. This configuration achieves the same effect as (A). [Explanation of symbols]

[0157] D...conveyance direction, d10...distance, d11...first distance, d12...second distance, d13...third distance, R11...upstream region, R12...downstream region, R13...intermediate region, R21...first region, R22...second region, R23...third region, S...strength, S1...first strength, S2...second strength, X...width direction, X1...first width direction, X2...second width direction, Y...depth direction, Y1...first depth direction, Y2...second depth direction, Z...vertical direction, Z1...upper, Z2...lower, 10...recording system, 11...recording device, 12...drying device, 13...feed section, 13A...feed roller, 14...winding section, 14A...winding roller, 20...recording section, 21...recording support section, 22...recording conveying section, 23...head, 24 ...nozzle surface, 25...carriage, 26...carriage support portion, 30...drying unit, 31...high frequency voltage generating portion, 31A...first high frequency voltage generating portion, 31B...second high frequency voltage generating portion, 32...transmission line, 33...drying conveying portion, 34...drying support portion, 35...control portion, 36...drying portion, 36A...first drying portion, 36B...second drying portion, 41...first electrode, 41A...first electrode surface, 42...second electrode, 42A...second electrode surface, 42B...opening, 43...first conductor, 43A...coil, 43B...conductor, 44...second conductor, 44A...support, 44B...connecting portion, 44C...top plate, 45...opposing portion, 90...medium, 90A...surface, 90B...back surface, 91...first roll body, 92...second roll body.

Claims

1. a drying unit that dries a medium onto which a pigment ink containing a pigment, water, and a solvent has been ejected by generating electromagnetic waves in response to application of a high-frequency voltage; The drying section A first electrode; a second electrode disposed to surround the first electrode in a plan view from a first direction toward the medium; a first conductor having a coil and electrically connecting a transmission line capable of transmitting a high frequency voltage to the first electrode; a second conductor electrically connecting the transmission line and the second electrode; and the drying unit generates electromagnetic waves so that the irradiation intensity of the electromagnetic waves on the medium onto which the pigment ink has been ejected is pulsed in a time series manner; A drying device characterized by:

2. The drying device according to claim 1, the drying unit generates electromagnetic waves based on a control pattern; the control pattern is a pulsed pattern in which an electromagnetic wave is generated from a first start timing over a first pulse width, and an electromagnetic wave is generated from a second start timing that is later than the first start timing over a second pulse width that is shorter than the first pulse width. drying equipment.

3. The drying device according to claim 2, a dry conveying unit that conveys the medium along a conveying direction; the dry conveying unit intermittently conveys the medium along the conveying direction; the drying unit generates electromagnetic waves based on the control pattern while the drying and conveying unit stops conveying the medium. drying equipment.

4. The drying device according to claim 1, a dry conveying unit that conveys the medium along a conveying direction; the drying unit includes a first drying unit and a second drying unit provided downstream of the first drying unit in the transport direction, the first drying unit generates electromagnetic waves based on a first control pattern while the medium is continuously transported by the drying transport unit at a predetermined speed; the second drying unit generates electromagnetic waves based on a second control pattern while the medium is continuously transported by the drying transport unit at a predetermined speed; the first control pattern is a pattern in which an electromagnetic wave of a predetermined intensity is continuously generated, The second control pattern is a pulsed pattern that generates an electromagnetic wave over a predetermined pulse width. drying equipment.

5. The drying device according to claim 1, a dry conveying unit that conveys the medium along a conveying direction; the drying unit includes a first drying unit and a second drying unit provided downstream of the first drying unit in the transport direction, The first drying section is provided in a first region, The second drying section is provided in a second region, the second region is a region that is provided downstream of the first region in the transport direction, and a third region in which no electromagnetic waves are generated is provided between the second region and the first region in the transport direction, a first distance in the transport direction of the first region is longer than a second distance in the transport direction of the second region; the first drying unit and the second drying unit generate electromagnetic waves based on a control pattern while the medium is continuously transported at a predetermined speed by the drying transport unit; The control pattern is a pattern in which an electromagnetic wave of a predetermined intensity is continuously generated. drying equipment.

6. The drying device according to claim 4 or claim 5, a resonance frequency of the first drying section is different from a resonance frequency of the second drying section, The first drying section generates electromagnetic waves having a higher intensity than the second drying section. drying equipment.

7. a recording unit that performs recording by ejecting a pigment ink containing a pigment, water, and a solvent onto a medium; a drying unit that dries the medium onto which the pigment ink has been ejected by the recording unit by generating electromagnetic waves in response to application of a high-frequency voltage; The drying section A first electrode; a second electrode disposed to surround the first electrode in a plan view from a first direction toward the medium; a first conductor having a coil and electrically connecting a transmission line capable of transmitting a high frequency voltage to the first electrode; a second conductor electrically connecting the transmission line and the second electrode; and the drying unit generates electromagnetic waves so that the irradiation intensity of the electromagnetic waves on the medium onto which the pigment ink has been ejected is pulsed in a time series manner; A recording device characterized by:

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