Drying apparatus and recording apparatus

Abstract

To provide a drying apparatus and a recording apparatus, capable of suppressing unevenness in a degree of drying of a medium.SOLUTION: A drying apparatus includes a drying part for drying a medium on which a liquid has been discharged, by generating electromagnetic waves in response to application of a high-frequency voltage. The drying part includes: a first electrode; a second electrode arranged 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 first electrode extends in a second direction intersecting the first direction. The second electrode has an opening surrounding the first electrode, and the opening has the second direction as a long side and a third direction intersecting the first direction and the second direction as a short side. A first distance between the first electrode and the short side of the opening in the second direction is longer than a second distance between the first electrode and the long side of the opening in the third direction.SELECTED DRAWING: Figure 2

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 toward the medium onto which liquid has been ejected. This drying device generates electromagnetic waves toward the medium by supplying a high-frequency voltage between a first electrode and a second electrode. This allows the medium onto which liquid has been ejected to be dried. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-155811 Summary of the Invention [Problem to be solved by the invention]

[0004] However, such a drying device may result in uneven drying of the medium, and therefore it is desirable to make the drying of the medium uniform. [Means for solving the problem]

[0005] A drying device that solves the above problem includes a drying unit that dries a medium onto which a liquid has been 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, the first electrode extending in a second direction intersecting the first direction, the second electrode having an opening that surrounds the first electrode, the opening having a long side in the second direction and a short side in a third direction intersecting the first direction and the second direction, and a first distance between the first electrode and the short side of the opening in the second direction is longer than a second distance between the first electrode and the long side of the opening in the third direction.

[0006] A recording device that solves the above problem includes a recording unit that performs recording by ejecting liquid onto a medium, and a drying unit that dries the medium onto which liquid 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, wherein the first electrode extends in a second direction that intersects with the first direction, and the second electrode has an opening that surrounds the first electrode, the opening having a long side in the second direction and a short side in a third direction that intersects with the first and second directions, and a first distance between the first electrode and the short side of the opening in the second direction is longer than a second distance between the first electrode and the long side of the opening in the third direction. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a schematic diagram showing a recording system according to the first embodiment. [Figure 2] FIG. 2 is a perspective view showing the drying unit of the first embodiment. [Figure 3] FIG. 3 is a schematic diagram showing the drying unit of the first embodiment. [Figure 4] FIG. 4 is a schematic diagram showing the drying unit of the first embodiment. [Figure 5] FIG. 5 is a perspective view showing a drying unit of the second embodiment. [Figure 6] FIG. 6 is a schematic diagram showing a drying unit of a modified example. DETAILED DESCRIPTION OF THE INVENTION

[0008] [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. The width direction X corresponds to an example of a second direction. The depth direction Y corresponds to an example of a third direction.

[0009] <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.

[0010] 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 ink, which is an example of a 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, for example, paper.

[0011] 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.

[0012] 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.

[0013] 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.

[0014] <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.

[0015] 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.

[0016] 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.

[0017] 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).

[0018] 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.

[0019] 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.

[0020] <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.

[0021] 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.

[0022] 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.

[0023] 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.

[0024] 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.

[0025] The drying device 12 includes a dry conveying section 33. The dry conveying section 33 is configured to convey the medium 90 in a conveying direction D. The dry conveying section 33 functions as an example of a moving section that moves the medium 90 relative to the drying section 36, which will be described later. The conveying direction D is a direction along the depth direction Y. The conveying direction D corresponds to an example of a relative movement direction.

[0026] Drying and conveying section 33 may use multiple rollers to convey medium 90 in conveying direction D. Drying and conveying section 33 may perform continuous conveyance, which continuously conveys medium 90. Slack in medium 90 may occur between recording and conveying section 22 and dry and conveying section 33.

[0027] 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.

[0028] 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.

[0029] 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.

[0030] 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.

[0031] 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.

[0032] 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.

[0033] 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.

[0034] 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.

[0035] <Configuration of Drying Unit 36> 2, 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 in which the first electrode 41 and the second electrode 42 are arranged on the downward Z2 side.

[0036] The first electrode 41 has a flat plate shape, but may have a rod 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.

[0037] 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.

[0038] The first electrode 41 has a central portion 41B and both end portions 41C. The central portion 41B is a portion located in the center in the width direction X. The both end portions 41C are portions located on both ends in the width direction X. The central portion 41B and the both end portions 41C are provided integrally.

[0039] The central portion 41B constitutes the first electrode surface 41A. The central portion 41B is provided at a position overlapping with the second electrode 42 in the vertical direction Z. That is, at least a portion of the first electrode 41 is provided at a position overlapping with the second electrode 42 in the vertical direction Z.

[0040] Both end portions 41C are configured to slope upward toward the outside in the width direction X. Both end portions 41C are positioned away from the facing portion 45. In other words, both end portions 41C extend upward Z1 away from the medium 90 in the vertical direction Z. Both end portions 41C may be curved away from the facing portion 45.

[0041] 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.

[0042] The second electrode 42 has an opening 42B. The opening 42B has a rectangular shape in a plan view, but may have a rounded rectangular shape. The first electrode 41 is located in the opening 42B in a plan view. The opening 42B surrounds the first electrode 41 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.

[0043] 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.

[0044] 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.

[0045] The second conductor 44 may include a top plate 44B. The top plate 44B is electrically connected to the support columns 44A. The top plate 44B is provided on the upper ends of the support columns 44A. The top plate 44B connects the multiple support columns 44A. The top plate 44B may be integral with the support columns 44A. The top plate 44B 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] <Configuration of First Electrode 41 and Second Electrode 42> 3, the first electrode 41 is provided to have a length of a distance D11 in the width direction X. The second electrode 42 is provided to have a length of a distance D12 in the width direction X and a length of a distance D22 in the depth direction Y. The distance D12 is longer than the distance D22.

[0052] The opening 42B is provided so that it has a length of distance D13 in the width direction X and a length of distance D23 in the depth direction Y. Distance D13 is longer than distance D23. In this way, the opening 42B is provided so that the long side 42C is in the width direction X and the short side 42D is in the depth direction Y. The opening 42B may be provided so that the distance D23, which is the length of the short side 42D, is one-third or less of the distance D13, which is the length of the long side 42C. The distance D23 may be one-third or less of the distance D11.

[0053] The distance between the first electrode 41 and the short side 42D in the width direction X is a first distance D1. The distance between the first electrode 41 and the long side 42C in the depth direction Y is a second distance D2. The first distance D1 is longer than the second distance D2. By configuring the first electrode 41 and the second electrode 42 in this manner, it is possible to weaken the electric field generated between the end portions 41C of the first electrode 41 and the short sides 42D. Specifically, by slanting the end portions 41C of the first electrode 41 upward Z1, it is possible to weaken the electromagnetic waves with respect to the medium 90. By making the first distance D1 longer than the second distance D2, it is possible to weaken the electromagnetic waves with respect to the medium 90. This prevents a strong electric field region from concentrating at the end portions 41C of the first electrode 41, and it is possible to prevent uneven drying of the medium 90.

[0054] <Arrangement of drying unit 36> 4, when the drying unit 30 includes multiple drying sections 36, the multiple drying sections 36 may be arranged in the width direction X and the 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. In this way, the multiple drying sections 36 are arranged so as to be aligned in the width direction X. The multiple drying sections 36 are arranged so as to be aligned in the depth direction Y.

[0055] The multiple drying sections 36 include a first drying section 36A and a second drying section 36B. The first drying section 36A and the second drying section 36B may generate electromagnetic waves of different intensities. The first drying section 36A may generate stronger electromagnetic waves than the second drying section 36B, but may also generate weaker electromagnetic waves than the second drying section 36B.

[0056] In detail, 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 and the resonant frequency of the second drying section 36B can be made different.

[0057] In this way, the first drying section 36A and the second drying section 36B have different resonance frequencies. As a specific example, the plurality of first drying sections 36A in the first row C1 and the plurality of second drying sections 36B in the second row C2 have different resonance frequencies.

[0058] The first drying section 36A is disposed in the first region R1. The second drying section 36B is disposed in the second region R2. The first region R1 is a region located on the upstream side of the conveying direction D. The second region R2 is a region located on the downstream side of the conveying direction D. In other words, the second region R2 is a region located downstream of the first region R1 in the conveying direction D.

[0059] The first region R1 has the same number of rows of drying units 36 arranged in the depth direction Y as the second region R2. The first region R1 may have a smaller number of rows of drying units 36 arranged in the depth direction Y than the second region R2. The first region R1 may have a larger number of rows of drying units 36 arranged in the depth direction Y than the second region R2.

[0060] The plurality of drying sections 36 are arranged in each row so as to be aligned in the width direction X. As a specific example, the plurality of drying sections 36 are arranged in the first row C1 so as to be aligned in the width direction X. The plurality of drying sections 36 are arranged in the second row C2 so as to be aligned in the width direction X. The first row C1 and the second row C2 may be adjacent rows in the depth direction Y.

[0061] In this way, the multiple drying sections 36 in the first row C1 and the multiple drying sections 36 in the second row C2 are arranged to be aligned in the depth direction Y. The multiple drying sections 36 in the first row C1 and the multiple drying sections 36 in the second row C2 are arranged to be at different positions in the width direction X.

[0062] As a specific example, a case will be described in which a medium 90 onto which pigment ink has been ejected as a liquid is dried. The pigment ink contains 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 has been ejected.

[0063] When drying the medium 90 onto which the pigment ink has been ejected, preliminary drying and main drying are performed. Preliminary drying involves evaporating the water contained in the pigment ink at approximately 100°C. In such cases, it is desirable to rapidly increase the temperature of the pigment ink.

[0064] Main drying is performed after preliminary drying. Main drying vaporizes the solvent contained in the pigment ink at approximately 300°C. During main drying, it is desirable to maintain the temperature of the pigment ink without excessively increasing it, in order to increase the reliability of vaporization of the glycerin without causing thermal denaturation of the medium 90. Main drying is desirably performed for a longer period of time than preliminary drying.

[0065] For this reason, the first drying section 36A generates stronger electromagnetic waves than the second drying section 36B. The first region R1 has fewer rows of drying sections 36 arranged in the depth direction Y than the second region R2.

[0066] In the preliminary drying, the first drying section 36A generates stronger electromagnetic waves than the second drying section 36B, and can rapidly increase the temperature. Then, in the main drying, the second drying section 36B can maintain the temperature without excessively increasing it.

[0067] The medium 90 is transported at a constant speed in the transport direction D. Therefore, when the first region R1 has fewer rows of drying units 36 than the second region R2, the drying time by the second drying unit 36B arranged in the second region R2 can be longer than the drying time by the first drying unit 36A arranged in the first region R1.

[0068] For example, as the medium 90 dries, the water contained in the medium 90 decreases. In this way, when the water content of water with a high dielectric constant contained in the medium 90 decreases, the dielectric constant decreases. For this reason, it is desirable to vary the resonance frequency stepwise with respect to the conveying direction D.

[0069] <Actions and Effects of the First Embodiment> The operation and effects of the first embodiment will be described. (1-1) In the past, the first electrode was extended in the width direction X, and strong electric field regions tended to concentrate in the areas near both ends of the first electrode, for example, due to the same principle as corona discharge. As a result, the amount of heat generated in the areas near both ends of the first electrode was large, while the amount of heat generated in other areas was small. This resulted in uneven heating depending on the area, which resulted in uneven drying of the medium 90.

[0070] Therefore, the first distance D1 between the first electrode 41 and the short side 42D of the opening 42B in the width direction X is longer than the second distance D2 between the first electrode 41 and the long side 42C of the opening 42B in the depth direction Y. This configuration makes it possible to avoid concentration of electromagnetic waves at both end portions 41C of the first electrode 41. This makes it possible to equalize the generated electromagnetic waves. Therefore, it is possible to suppress unevenness in the degree of dryness of the medium 90.

[0071] (1-2) The plurality of drying sections 36 are arranged side by side in the depth direction Y. According to this configuration, by arranging the plurality of drying sections 36 side by side in the depth direction Y, it is possible to suppress a decrease in the drying efficiency of the medium 90.

[0072] (1-3) The plurality of drying sections 36 are arranged side by side in the width direction X. According to this configuration, by arranging the plurality of drying sections 36 side by side in the width direction X, it is possible to suppress a decrease in the drying efficiency of the medium 90.

[0073] (1-4) A plurality of drying sections 36 are arranged in the first row C1 so as to be aligned in the width direction X, and a plurality of drying sections 36 are arranged in the second row C2 adjacent to the first row C1 in the depth direction Y so as to be aligned in the width direction X. The plurality of drying sections 36 in the first row C1 and the plurality of drying sections 36 in the second row C2 are arranged so as to be positioned differently in the width direction X. According to this configuration, by arranging the plurality of drying sections 36 so as to be aligned in both the width direction X and the depth direction Y, it is possible to suppress a decrease in the drying efficiency of the medium 90. In addition, by arranging the plurality of drying sections 36 in the first row C1 and the plurality of drying sections 36 in the second row C2 at different positions in the width direction X, it is possible to suppress unevenness in the degree of drying of the medium 90.

[0074] (1-5) A portion of the first electrode 41 is provided at a position that overlaps with the second electrode 42 in the vertical direction Z. With this configuration, the distance from the medium 90 to both the portion of the first electrode 41 and the second electrode 42 in the vertical direction Z can be made the same. Therefore, a decrease in the drying efficiency of the medium 90 can be suppressed.

[0075] (1-6) The first electrode 41 has a central portion 41B in the width direction X and both end portions 41C in the width direction X. The both end portions 41C extend upward Z1 away from the medium 90 in the vertical direction Z. This configuration makes it possible to prevent the concentration of electromagnetic waves at the both end portions 41C of the first electrode 41. This makes it possible to equalize the generated electromagnetic waves. Therefore, it is possible to suppress unevenness in the degree of dryness of the medium 90.

[0076] (1-7) The center portion 41B and both end portions 41C are integrally formed. This configuration allows the center portion 41B and both end portions 41C to be integrally formed, thereby efficiently transmitting high-frequency voltage. This prevents a decrease in the drying efficiency of the medium 90.

[0077] (1-8) The drying conveying unit 33 moves the medium 90 relative to the drying unit 36 ​​in the depth direction Y. With this configuration, the medium 90 can be moved relative to the drying unit 36 ​​along the depth direction Y, which intersects with the width direction X, which is the longitudinal direction of the first electrode 41 and the opening 42B. This allows the drying region to be expanded in the width direction X, which is independent of moving the medium 90 relative to the drying unit 36. Therefore, unevenness in the degree of dryness of the medium 90 can be suppressed.

[0078] (1-9) A plurality of first drying sections 36A are arranged in the first row C1 so as to be aligned in the width direction X. A plurality of second drying sections 36B are arranged in the second row C2 so as to be aligned in the width direction X. The plurality of first drying sections 36A in the first row C1 and the plurality of second drying sections 36B in the second row C2 have different resonance frequencies. With this configuration, the plurality of first drying sections 36A in the first row C1 and the plurality of second drying sections 36B in the second row C2, which are aligned in the depth direction Y in which the medium 90 moves relative to the drying section 36, can have different resonance frequencies. Therefore, the degree of dryness of the medium 90 can be adjusted.

[0079] [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.

[0080] 5, in the second embodiment, the second electrode 42 has a plurality of openings 42B. In the width direction X, the second electrode 42 may be longer than the width of the medium 90. In the width direction X, the long side 42C of the openings 42B may be longer than the width of the medium 90.

[0081] The drying unit 36 ​​includes a plurality of first electrodes 41 and a first conductor 43. The plurality of first electrodes 41 are arranged so as to be surrounded by a plurality of openings 42B. In the width direction X, each of the plurality of first electrodes 41 may be longer than the width of the medium 90. The distance between the first electrode 41 and the short side 42D in the width direction X is longer than the distance between the first electrode 41 and the long side 42C in the depth direction Y.

[0082] The drying conveying section 33 moves the medium 90 relative to the drying section 36 in the depth direction Y. The direction of relative movement is along the depth direction Y. In other words, the width direction X intersecting with the conveying direction D is the longitudinal direction of the drying section 36.

[0083] In this way, the drying section 36 in the second embodiment is configured to include the plurality of drying sections 36 in the first embodiment. More specifically, the drying section 36 in the second embodiment is configured so that the first electrode 41 and the second electrode 42 are elongated in the width direction X. The drying section 36 in the second embodiment is configured so that the plurality of second electrodes 42 aligned in the depth direction Y in the first embodiment are integrated together.

[0084] <Actions and Effects of the Second Embodiment> The operation and effects of the second embodiment will be described. (2-1) In the width direction X, the long side 42C of the opening 42B is longer than the width of the medium 90, and the first electrode 41 is also longer than the width of the medium 90. With this configuration, the medium 90 can be moved relative to the drying unit 36 ​​along the depth direction Y, which intersects with the width direction X, which is the longitudinal direction of the first electrode 41 and the opening 42B. This allows the drying region to be expanded in the width direction X, which is independent of moving the medium 90 relative to the drying unit 36. Therefore, unevenness in the degree of drying of the medium 90 can be suppressed.

[0085] [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.

[0086] In the second embodiment, the drying conveying section 33 may move the medium 90 relative to the drying section 36 in the width direction X. The direction of relative movement is along the width direction X. In other words, the width direction X, which is along the conveying direction D, is the longitudinal direction of the drying section 36.

[0087] 6, when the drying conveying section 33 moves the medium 90 along the depth direction Y relative to the drying section 36, the longitudinal direction of the drying section 36 may be inclined with respect to the width direction X and the depth direction Y. The direction of relative movement is inclined with respect to the width direction X and the depth direction Y.

[0088] In this way, the direction of relative movement of the medium 90 relative to the drying unit 36 ​​is a direction that is inclined with respect to the width direction X. With this configuration, even when the medium 90 is moved relative to the drying unit 36 ​​in a relative movement direction that is inclined with respect to the width direction X, the medium 90 can be continuously dried. Therefore, unevenness in the degree of dryness of the medium 90 can be suppressed.

[0089] The drying device 12 may include a moving unit that moves the drying section 36. The drying device 12 may include a moving unit that moves both the drying section 36 and the medium 90. In this manner, the moving unit may be configured to move the medium 90 relative to the drying section 36.

[0090] In the first embodiment, the multiple first drying sections 36A in the first row C1 and the multiple second drying sections 36B in the second row C2 do not have to be adjacent to each other in the depth direction Y. In other words, a drying section 36 in another row may be disposed between the multiple first drying sections 36A in the first row C1 and the multiple second drying sections 36B in the second row C2 in the depth direction Y.

[0091] The first electrode 41 may have both end portions 41C inclined upward Z1 so as to branch off. The first electrode 41 does not have to have both end portions 41C inclined upward Z1. In other words, the both end portions 41C may be provided at the same position as the central portion 41B in the vertical direction Z. In this way, the first electrode 41 is provided at a position overlapping with the second electrode 42 in the vertical direction Z.

[0092] The drying unit 36 ​​may be disposed so that the depth direction Y is its longitudinal direction. In other words, the depth direction Y may be an example of the second direction. The width direction X may be an example of the third direction. The drying unit 36 ​​may be disposed so that it is inclined with respect to the width direction X and the depth direction Y. The direction inclined with respect to the width direction X and the depth direction Y may be an example of the second direction.

[0093] The drying unit 30 may include one or more drying sections 36. The multiple drying sections 36 may be arranged in multiple rows in the width direction X. The multiple drying sections 36 may be arranged in multiple rows in the depth direction Y.

[0094] 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.

[0095] 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.

[0096] The first electrode 41 is not limited to a flat plate shape and may be, for example, a substantially flat plate shape. The substantially 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.

[0097] 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.

[0098] 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.

[0099] 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.

[0100] 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.

[0101] 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.

[0102] The liquid can be any liquid that can be applied to the medium 90 to record on the medium 90. For example, ink includes particles of functional materials made of solids such as pigments or metal particles dissolved, dispersed, or mixed in a solvent, and includes various compositions such as water-based ink, oil-based ink, gel ink, and hot-melt ink.

[0103] 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.

[0104] [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.

[0105] (A) A drying device includes a drying section that dries a medium onto which a liquid has been ejected by generating electromagnetic waves in response to the application of a high-frequency voltage, the drying section 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, the first electrode extending in a second direction intersecting the first direction, the second electrode having an opening that surrounds the first electrode, the opening having a long side in the second direction and a short side in a third direction intersecting the first direction and the second direction, and a first distance between the first electrode and the short side of the opening in the second direction is longer than a second distance between the first electrode and the long side of the opening in the third direction.

[0106] According to this configuration, the first electrode extends in the second direction, and the first distance between the first electrode and the short side of the opening in the second direction is longer than the second distance between the first electrode and the long side of the opening in the third direction. This prevents the electromagnetic waves from concentrating at both ends of the first electrode. This allows the generated electromagnetic waves to be uniformly distributed. This prevents uneven drying of the medium.

[0107] (B) In the drying device, a plurality of the drying sections may be arranged in the third direction. According to this configuration, by arranging the plurality of drying units so as to be aligned in the third direction, it is possible to suppress a decrease in the efficiency of drying the medium.

[0108] (C) In the drying device, a plurality of the drying sections may be arranged in the second direction. According to this configuration, by arranging the plurality of drying units so as to be aligned in the second direction, it is possible to suppress a decrease in the efficiency of drying the medium.

[0109] (D) In ​​the above drying device, a plurality of the drying sections may be arranged in a first row so as to line up in the second direction, and a plurality of the drying sections may be arranged in a second row adjacent to the first row in the third direction so as to line up in the second direction, and the plurality of the drying sections in the first row and the plurality of the drying sections in the second row may be arranged so as to be at different positions in the second direction.

[0110] According to this configuration, by arranging the multiple drying sections so that they are aligned in both the second direction and the third direction, it is possible to prevent a decrease in the drying efficiency of the medium. In addition, by arranging the multiple drying sections in the first row and the multiple drying sections in the second row at different positions in the second direction, it is possible to prevent unevenness in the degree of drying of the medium.

[0111] (E) In the drying device, the opening may be provided so that the length of the short side is one-third or less of the length of the long side. This configuration can achieve the same effect as (A).

[0112] (F) In the drying device, the first electrode may be provided at a position overlapping the second electrode in the first direction. With this configuration, the distance between the first electrode and the medium in the first direction can be made the same for both the first electrode and the second electrode, thereby preventing a decrease in the efficiency of drying the medium.

[0113] (G) In the drying device, the first electrode may have a central portion in the second direction and both end portions in the second direction, and the both end portions may extend in a direction away from the medium in the first direction.

[0114] This configuration makes it possible to prevent the electromagnetic waves from concentrating at both ends of the first electrode, thereby making it possible to equalize the generated electromagnetic waves and thus suppress unevenness in the degree of drying of the medium.

[0115] (H) In the drying device, the central portion and the both end portions may be integrally formed. According to this configuration, the central portion and both end portions are integrally formed, which allows for efficient transmission of high frequency voltage, thereby preventing a decrease in the efficiency of drying the medium.

[0116] (I) The drying device may include a moving unit that moves the medium relative to the drying unit along the third direction. This configuration allows the medium to be moved relative to the drying unit along a third direction that intersects with the second direction, which is the longitudinal direction of the first electrode and the opening. This allows the drying area to be expanded in the second direction, which is independent of the movement of the medium relative to the drying unit. This prevents unevenness in the degree of drying of the medium.

[0117] (J) In the drying device, a plurality of the drying sections may be arranged in a first row so as to line up in the second direction, and a plurality of the drying sections may be arranged in a second row so as to line up in the second direction, and the plurality of the drying sections in the first row and the plurality of the drying sections in the second row may have different resonant frequencies.

[0118] With this configuration, the resonant frequencies of the first row of drying sections and the second row of drying sections aligned in the third direction in which the medium moves relative to the drying sections can be made different, thereby adjusting the degree of dryness of the medium.

[0119] (K) The drying device may include a moving unit that moves the medium relative to the drying unit along a relative movement direction, and the relative movement direction may be a direction that is inclined with respect to the second direction.

[0120] With this configuration, even when the medium is moved in the relative movement direction, the medium can be dried continuously, thereby preventing unevenness in the degree of dryness of the medium.

[0121] (L) A recording device includes a recording unit that performs recording by discharging a liquid onto a medium, and a drying unit that dries the medium onto which the liquid has been discharged by the recording unit 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 plan view from a first direction toward the medium, a first conductor that electrically connects the first electrode to a transmission line that has a coil and is capable of transmitting a high-frequency voltage, and a second conductor that electrically connects the transmission line to the second electrode, the first electrode extending in a second direction intersecting the first direction, the second electrode having an opening that surrounds the first electrode, the opening having a long side in the second direction and a short side in a third direction intersecting the first and second directions, a first distance between the first electrode and the short side of the opening in the second direction being longer than a second distance between the first electrode and the long side of the opening in the third direction. This configuration can achieve the same effect as (A). [Explanation of symbols]

[0122] C1...first row, C2...second row, D...conveyance direction, D1...first distance, D11...distance, D12...distance, D13...distance, D2...second distance, D22...distance, D23...distance, R1...first area, R2...second area, 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 transport section, 23...head, 24...nozzle surface, 25...ki carriage, 26...carriage support section, 30...drying unit, 31...high frequency voltage generating section, 32...transmission line, 33...drying conveying section, 34...drying support section, 35...control section, 36...drying section, 36A...first drying section, 36B...second drying section, 41...first electrode, 41A...first electrode surface, 41B...center section, 41C...both ends, 42...second electrode, 42A...second electrode surface, 42B...opening, 42C...long side, 42D...short side, 43...first conductor, 43A...coil, 43B...conductor, 44...second conductor, 44A...support, 44B...top plate, 45...opposing section, 90...medium, 90A...surface, 90B...back side, 91...first roll body, 92...second roll body.

Claims

1. a drying unit that dries the medium onto which the liquid 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 first electrode extends in a second direction intersecting the first direction, the second electrode has an opening surrounding the first electrode; the opening has a long side in the second direction and a short side in a third direction intersecting the first direction and the second direction, a first distance between the first electrode and a short side of the opening in the second direction is longer than a second distance between the first electrode and a long side of the opening in the third direction; A drying device characterized by:

2. The drying device according to claim 1, A plurality of the drying units are arranged so as to be aligned in the third direction. A drying device characterized by:

3. The drying device according to claim 1, A plurality of the drying units are arranged so as to be aligned in the second direction. A drying device characterized by:

4. The drying device according to claim 1, a plurality of the drying units are arranged in a first row so as to be aligned in the second direction; a plurality of the drying units are arranged in a second row adjacent to the first row in the third direction so as to be aligned in the second direction; the plurality of drying units in the first row and the plurality of drying units in the second row are arranged so as to be at different positions in the second direction; A drying device characterized by:

5. The drying device according to any one of claims 1 to 4, The opening is provided so that the length of the short side is one-third or less of the length of the long side. A drying device characterized by:

6. The drying device according to any one of claims 1 to 4, The first electrode is provided at a position overlapping the second electrode in the first direction. A drying device characterized by:

7. The drying device according to any one of claims 1 to 4, the first electrode has a central portion in the second direction and both end portions in the second direction, The two end portions extend in a direction away from the medium in the first direction. A drying device characterized by:

8. The drying device according to claim 7, The central portion and the both end portions are integrally formed. A drying device characterized by:

9. The drying device according to any one of claims 1 to 4, a moving unit that moves the medium relative to the drying unit along the third direction, A drying device characterized by:

10. 10. The drying device according to claim 9, a plurality of the drying units are arranged in a first row so as to be aligned in the second direction; a plurality of the drying units are arranged in a second row so as to be aligned in the second direction; the first row of the plurality of drying sections and the second row of the plurality of drying sections have different resonance frequencies; A drying device characterized by:

11. The drying device according to any one of claims 1 to 4, a moving unit that moves the medium relative to the drying unit along a relative movement direction, the relative movement direction is a direction inclined with respect to the second direction, A drying device characterized by:

12. a recording unit that performs recording by ejecting liquid onto a medium; a drying unit that dries the medium onto which the liquid has been ejected by the recording unit by generating an electromagnetic wave 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 first electrode extends in a second direction intersecting the first direction, the second electrode has an opening surrounding the first electrode; the opening has a long side in the second direction and a short side in a third direction intersecting the first direction and the second direction, a first distance between the first electrode and a short side of the opening in the second direction is longer than a second distance between the first electrode and a long side of the opening in the third direction; A recording device characterized by:

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