Drying method using a drying apparatus, drying apparatus, and recording apparatus

Abstract

The present invention provides a drying method, drying apparatus, and recording apparatus that can improve the drying efficiency of a medium. [Solution] The drying apparatus has a heating section for heating a medium from which a liquid has been discharged, and a first contact section that can come into contact with the medium between the heating section and the medium. The heating section has a first electrode, a second electrode arranged 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 the first electrode to a transmission line capable of transmitting a high-frequency voltage, and a second conductor electrically connecting the transmission line to the second electrode. The drying method using the drying apparatus includes a drying step of drying an image area of ​​a medium on which an image has been recorded, and a preheating step of heating the first contact section before the drying step.

Description

Technical Field

[0001] The present invention relates to a drying method using a drying device, a drying device, and a recording device.

Background Art

[0002] For example, as disclosed in Patent Document 1, there is disclosed a liquid ejection device including a drying device that dries a medium in a state where the medium abuts on a support portion, which is an example of an abutting portion. In order to improve the drying efficiency, such a drying device includes an alternating current electric field generation unit that dries the medium by generating an electromagnetic wave with respect to the medium on which the liquid has been ejected. Such an alternating current electric field generation unit is an example of a heating unit, and generates an electromagnetic wave with respect to the medium by supplying a high-frequency voltage between a first electrode and a second electrode. Thereby, the medium on which the liquid has been ejected can be dried.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in such a drying device, although the medium is dried by heating the liquid ejected onto the medium, when the temperature of the abutting portion where the medium abuts is lower than the temperature of the medium, the amount of heat transferred to the abutting portion from the medium becomes likely. As a result, there is a risk that the drying efficiency of the medium may decrease.

Means for Solving the Problems

[0005] A drying method using a drying apparatus that solves the above problems is a drying method using a drying apparatus having a heating unit for heating a medium from which a liquid has been discharged, and a first contact unit that can come into contact with the medium between the heating unit and the medium, wherein the heating unit has a first electrode, a second electrode arranged 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 the first electrode to a transmission line capable of transmitting a high-frequency voltage, and a second conductor electrically connecting the transmission line to the second electrode, and the method includes a drying step of drying an image area of ​​a medium on which an image has been recorded, and a preheating step of heating the first contact unit before the drying step.

[0006] A drying apparatus for solving the above problems comprises a heating section for heating a medium from which a liquid has been discharged, and a first contact section that is in contact with the medium between the heating section and the medium, wherein the heating section comprises a first electrode, a second electrode arranged 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 the first electrode to a transmission line capable of transmitting a high-frequency voltage, and a second conductor electrically connecting the transmission line to the second electrode, and the first contact section is made of a material having electromagnetic heating properties.

[0007] A recording device that solves the above problems comprises a recording unit that records an image on a medium by discharging a liquid onto the medium, a heating unit that heats the medium from which the liquid has been discharged by the recording unit, and a first contact unit that is in contact with the medium between the heating unit and the medium, wherein the heating unit comprises a first electrode, a second electrode 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 having a coil and capable of transmitting a high-frequency voltage, and a second conductor that electrically connects the transmission line to the second electrode, and the first contact unit is made of a material having electromagnetic heating properties. [Brief explanation of the drawing]

[0008] [Figure 1]Figure 1 is a schematic diagram showing a recording system according to the first embodiment. [Figure 2] Figure 2 is a schematic diagram showing the drying unit of the first embodiment. [Figure 3] Figure 3 is a perspective view showing the heating section of the first embodiment. [Figure 4] Figure 4 is a schematic diagram showing the drying unit in the preheating and drying processes of the first embodiment. [Figure 5] Figure 5 is a flowchart showing the temperature monitoring process of the first embodiment. [Figure 6] Figure 6 is a schematic diagram showing the drying unit in the preheating and drying processes of the third embodiment. [Figure 7] Figure 7 is a perspective view showing the drying unit of the fourth embodiment. [Modes for carrying out the invention]

[0009] [First Embodiment] The following describes a drying method using a drying apparatus, and an embodiment of a recording system including the drying apparatus and recording device. In the following description, the direction intersecting the vertical direction Z is referred to as the width direction X, and the direction intersecting the vertical direction Z and the width direction X is referred to as the intersection direction Y. One direction along the width direction X is referred to as the first width direction X1, and the other direction along the width direction X is referred to as the second width direction X2. One direction along the intersection direction Y is referred to as the first intersection direction Y1, and the other direction along the intersection direction Y is referred to as the second intersection direction Y2. The upper part of the vertical direction Z is referred to as the upper Z1, and the lower part of the vertical direction Z is referred to as the lower Z2. The upper Z1 corresponds to an example of the first direction. A plan view from the upper Z1 is simply referred to as a plan view.

[0010] <Configuration of recording system 10> As shown in Figure 1, the recording system 10 is a system that records data onto a medium 90. In particular, the recording system 10 is a system that records data onto the medium 90 by dispensing a liquid onto the medium 90. The recording system 10 is a system that dries the medium 90 after dispensing the liquid and recording data. The medium 90 is a cloth, but it may also be paper or the like.

[0011] 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 records by ejecting ink, which is an example of a liquid, onto the medium 90.

[0012] The liquid may be a pigment ink. The pigment ink contains a pigment, water, and a solvent. The solvent may include, for example, glycerin. Glycerin is a solvent that prevents clogging of the nozzle that dispenses the liquid. The vaporization of glycerin improves the abrasion resistance of the medium 90 from which the pigment ink is dispensed. The pigment ink may be colored or colorless.

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

[0014] The recording system 10 includes a feeding unit 13. The feeding unit 13 feeds the medium 90 to the recording device 11 before recording. The feeding unit 13 includes a feeding roller 13A. The feeding roller 13A extends along the width direction X. In the width direction X, the width of the feeding roller 13A is longer than the width of the medium 90. The feeding roller 13A is configured to rotatably hold a first roll body 91. The first roll body 91 is a wound-up medium 90 before recording. The medium 90 may be long. In this way, the feeding 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 recorded by the recording device 11. In particular, the winding unit 14 winds up the recorded medium 90 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 the second roll body 92. The second roll body 92 is the wound-up recorded medium 90. Thus, the winding roller 14A winds up the medium 90 recorded by the recording device 11 and dried by the drying device 12.

[0016] <Configuration of the recording device 11> The recording device 11 includes a recording unit 20, a recording support unit 21, and a recording conveyance unit 22. The recording unit 20 is configured to record an image on the medium 90 by discharging a liquid onto the medium 90. The area where the recording unit 20 records an image corresponds to an example of an image area. The recording unit 20 discharges a liquid onto the 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 conveyed by the recording conveyance unit 22.

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

[0018] The head 23 includes a nozzle surface 24 in which a plurality of nozzles (not shown) are open. The nozzle surface 24 is a surface facing downward Z2. The nozzle surface 24 is a surface facing the surface 90A of the medium 90 conveyed by the recording conveyance unit 22. Each of the plurality of nozzles is configured to open downward Z2. Each of the plurality of nozzles is configured to discharge a liquid.

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

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

[0021] The recording conveyance portion 22 is configured to convey the medium 90 in the conveyance direction D. The conveyance direction D is a direction along the crossing direction Y. The recording conveyance portion 22 may include a plurality of rollers. The recording conveyance portion 22 conveys the medium 90 in the conveyance direction D using a plurality of rollers, or may convey the medium 90 in the conveyance direction D using a conveyance belt driven by a plurality of rollers. The recording conveyance portion 22 may perform intermittent conveyance that repeats the conveyance and stop of the medium 90.

[0022] <Configuration of the drying device 12> 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 uses the medium 90 recorded by the recording unit 20 as an object to be dried.

[0023] The drying unit 30 is configured to dry the medium 90 after recording by generating electromagnetic waves. The drying unit 30 is located above Z1 and below Z2 of the medium 90, and may be located above Z1 of the medium 90 or below Z2 of the medium 90.

[0024] [[ID=The drying apparatus 12 includes a high-frequency voltage generating unit 31. The drying apparatus 12 may include a plurality of high-frequency voltage generating units 31. The high-frequency voltage generating unit 31 is configured to generate a high-frequency voltage. The high-frequency voltage generating unit 31 supplies a high-frequency voltage to the drying unit 30 via a transmission line 32.

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

[0027] The drying apparatus 12 includes a drying conveying section 33. The drying conveying section 33 is configured to convey the medium 90 in the conveying direction D. The drying conveying section 33 is an example of a conveying section. The conveying direction D is the direction along the intersecting direction Y. The drying conveying section 33 may convey the medium 90 in the conveying direction D using a plurality of rollers. The drying conveying section 33 may perform continuous conveying to continuously convey the medium 90. Slack in the medium 90 may occur between the recording conveying section 22 and the drying conveying section 33.

[0028] The drying apparatus 12 includes a control unit 50. The control unit 50 controls the drying apparatus 12. More specifically, the control unit 50 controls the drying unit 30. The control unit 50 controls the high-frequency voltage generation unit 31. The control unit 50 controls the drying transport unit 33.

[0029] The control unit 50 may consist of one or more processors that perform various processes according to a computer program. The control unit 50 may consist of one or more dedicated hardware circuits. The control unit 50 may consist of an application-specific integrated circuit that performs at least some of the various processes. The control unit 50 may consist of a circuit that includes a combination of processors and hardware circuits. The processor includes a CPU and memory such as RAM and ROM. The memory stores program code or instructions configured to cause the CPU to perform processes. Memory, i.e., computer-readable media, includes any readable media that can be accessed by a general-purpose or dedicated computer.

[0030] The drying unit 30 includes a heating unit 40. The heating unit 40 heats the medium 90 from which the liquid has been discharged by the recording unit 20. The heating unit 40 is configured to generate electromagnetic waves in response to the application of a high-frequency voltage. The heating unit 40 is an example of an electromagnetic wave generator. The heating unit 40 is located above Z1 of the medium 90, but is not limited to this position.

[0031] The heating unit 40 dries the medium 90 by heating it from its surface 90A. More specifically, the heating unit 40 heats the liquid discharged onto the medium 90 from its surface 90A. The heating unit 40 dries the medium 90 by vaporizing the liquid discharged onto the medium 90. In other words, the heating unit 40 dries the medium 90 regardless of whether or not the medium 90 is saturated with water vapor. Therefore, the heating unit 40 does not need to blow dry gas that is not saturated with water vapor around the medium 90.

[0032] The heating unit 40 generates an alternating electric field by generating electromagnetic waves. The electromagnetic waves generated by the heating unit 40 are mainly composed of an electric field. Compared to a heating unit that generates ordinary electromagnetic waves, the heating unit 40 can significantly reduce the induction of a magnetic field caused by the generated electric field.

[0033] To give a specific example, the heating unit 40 generates electromagnetic waves at 2.4 GHz, but is not limited to this. The heating unit 40 may, for example, generate electromagnetic waves in the range of 3 MHz to 300 MHz. The heating unit 40 may, for example, generate electromagnetic waves in the range of 300 MHz to 30 GHz, and within that range, it may generate electromagnetic waves in the range of 10 MHz to 20 GHz.

[0034] The drying unit 30 includes a first contact portion 51 and a second contact portion 52. In other words, the drying apparatus 12 includes a first contact portion 51 and a second contact portion 52. The first contact portion 51 is positioned to face the surface 90A of the medium 90. The first contact portion 51 is provided between the heating portion 40 and the medium 90. The first contact portion 51 may be flat. The first contact portion 51 is capable of contacting the medium 90 between the heating portion 40 and the medium 90. The first contact portion 51 protects the first electrode 41 and the second electrode 42, which will be described later.

[0035] The second contact portion 52 is positioned to face the back surface 90B of the medium 90. The second contact portion 52 may be flat. The second contact portion 52 is capable of contacting the medium 90. The second contact portion 52 is capable of supporting the medium 90. The second contact portion 52 is configured to sandwich the medium 90 between itself and the first contact portion 51. In this way, the first contact portion 51 and the second contact portion 52 are provided to sandwich the medium 90.

[0036] The first contact portion 51 and the second contact portion 52 are made of a material that transmits electromagnetic waves generated by the heating portion 40. The first contact portion 51 and the second contact portion 52 are made of an insulating material. The first contact portion 51 and the second contact portion 52 may be glass plates. The first contact portion 51 and the second contact portion 52 may be ceramic with high transparency. The first contact portion 51 and the second contact portion 52 may be made of resin with low dielectric loss tangent. The first contact portion 51 and the second contact portion 52 may be made of polypropylene. The first contact portion 51 and the second contact portion 52 may be made of polyethylene.

[0037] The drying unit 30 includes a temperature detection unit 53. The temperature detection unit 53 is configured to detect the temperature of at least the first contact portion 51. The temperature detection unit 53 may also detect the temperatures of the first contact portion 51 and the second contact portion 52.

[0038] <Arrangement of multiple heating units 40> As shown in Figure 2, the drying unit 30 may include a plurality of heating units 40. The plurality of heating units 40 are arranged side by side in the intersecting direction Y. The plurality of heating units 40 may be integrally configured to share a second electrode 42, which will be described later. The second electrode 42 in the plurality of heating units 40 may be shared at adjacent positions in the intersecting direction Y.

[0039] Multiple heating units 40 may comprise upstream heating units 40A and downstream heating units 40B. Multiple heating units 40 may comprise multiple upstream heating units 40A and multiple downstream heating units 40B. The number of upstream heating units 40A may be greater than the number of downstream heating units 40B, but may be less than the number of downstream heating units 40B, or may be the same number as the number of downstream heating units 40B.

[0040] The upstream heating section 40A and the downstream heating section 40B may be controlled by the control unit 50 to have different heating amounts. When drying the medium 90, the upstream heating section 40A may be controlled to have a higher heating amount than the downstream heating section 40B.

[0041] The upstream heating section 40A and the downstream heating section 40B may each be connected to a plurality of different high-frequency voltage generating units 31. The control unit 50 may control the heating amount from the upstream heating section 40A and the heating amount from the downstream heating section 40B to be different by making the high-frequency voltages output from the plurality of high-frequency voltage generating units 31 to the upstream heating section 40A and the downstream heating section 40B, respectively.

[0042] As a specific example, let's describe the drying of a medium 90 from which pigment ink has been ejected as a liquid. When drying the medium 90 from which pigment ink has been ejected, preliminary drying and final drying are performed. Preliminary drying involves vaporizing 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.

[0043] This drying process is performed after the preliminary drying. This drying process vaporizes the solvent contained in the pigment ink at approximately 270°C to 300°C. It is desirable to maintain the pigment ink temperature without excessively raising it during this drying process to ensure reliable vaporization of glycerin without causing thermal denaturation of the medium 90. This drying process should ideally be performed for a longer duration than the preliminary drying process.

[0044] For these reasons, the upstream heating unit 40A is located upstream in the conveying direction D to perform preliminary drying. The downstream heating unit 40B is located downstream in the conveying direction D to perform main drying. The upstream heating unit 40A generates stronger electromagnetic waves than the downstream heating unit 40B. During preliminary drying, the upstream heating unit 40A generates stronger electromagnetic waves than the downstream heating unit 40B, allowing for a rapid increase in temperature. Subsequently, during main drying, the downstream heating unit 40B can maintain the temperature without excessively increasing it.

[0045] <Configuration of the heating section 40> Here, the configuration of the heating section 40 will be explained in detail with reference to Figure 3. From here on, one heating section 40 will be described as representative.

[0046] As shown in Figure 3, the heating unit 40 comprises a first electrode 41, a second electrode 42, a first conductor 43, and a second conductor 44. Figure 3 shows the first electrode 41 and the second electrode 42 positioned on the upper Z1 side of the medium 90.

[0047] The first electrode 41 is flat, but may also be rod-shaped. In a plan view, the first electrode 41 has its length in the width direction X. That is, the first electrode 41 extends in the width direction X in a plan view. The first electrode 41 may also be rectangular in a plan view.

[0048] The first electrode 41 has a first electrode surface 41A. The first electrode surface 41A is the surface facing downward Z2. That is, the first electrode surface 41A is the surface facing the surface 90A of the medium 90. The first electrode 41 may be positioned such that the first electrode surface 41A is in contact with the first contact portion 51.

[0049] The first electrode 41 comprises a central portion 41B and two end portions 41C. The central portion 41B is the part located in the center in the width direction X. The two end portions 41C are the parts located at both ends in the width direction X. The central portion 41B and the two end portions 41C are integrally formed.

[0050] The central portion 41B constitutes the first electrode surface 41A. The central portion 41B is positioned so as to overlap with the second electrode 42 in the vertical direction Z. In other words, at least a portion of the first electrode 41 is positioned so as to overlap with the second electrode 42 in the vertical direction Z.

[0051] Both ends 41C are configured to slope upward with respect to the outside in the width direction X. Both ends 41C are positioned away from the first contact portion 51. That is, both ends 41C extend upward Z1 away from the medium 90 in the vertical direction Z. Both ends 41C may be curved away from the first contact portion 51.

[0052] The second electrode 42 is flat. The second electrode 42 has a second electrode surface 42A. The second electrode surface 42A is the surface facing downward Z2. That is, the second electrode surface 42A is the surface facing the surface 90A of the medium 90. The second electrode 42 may be positioned such that the second electrode surface 42A is in contact with the first contact portion 51.

[0053] The second electrode 42 has an opening 42B. The opening 42B is rectangular in plan view, but may be a rounded rectangle. The first electrode 41 is located at the opening 42B in plan view. The opening 42B surrounds the first electrode 41 in plan view. In other words, the second electrode 42 is positioned to surround the first electrode 41 in plan view.

[0054] 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 a conductor 43B. The conductor 43B is connected to the transmission line 32.

[0055] 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 column 44A. The second conductor 44 may include a plurality of support columns 44A. The support columns 44A are electrically connected to the second electrode 42. The support columns 44A extend upward Z1 from the second electrode 42. The support columns 44A are made of metal.

[0056] The second conductor 44 may be equipped with a top plate 44B. The top plate 44B is electrically connected to the support column 44A. The top plate 44B is provided at the upper end of the support column 44A. The top plate 44B may be integrated with the support column 44A. The top plate 44B is made of metal.

[0057] With the heating section 40 configured in this way, when a high-frequency voltage is applied, 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.

[0058] Such a heating unit 40 can transfer a large amount of thermal energy to the medium 90 by generating electromagnetic waves. The heating unit 40 uses an electromagnetic wave method rather than a heat conduction method, and does not require components such as heating wires. This makes it possible to miniaturize the heating unit 40.

[0059] Furthermore, the minimum separation distance between the first electrode 41 and the second electrode 42 is less than or equal to 1 / 10 of the wavelength of the electromagnetic waves output from the heating unit 40. 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. As a result, the intensity of the electromagnetic waves that reach far distances from the first electrode 41 and the second electrode 42 can be reduced. In other words, the electromagnetic waves generated from the heating unit 40 are very strong in the vicinity of the first electrode 41 and the second electrode 42, and very weak at a distance.

[0060] Such a heating unit 40 can concentrate an alternating electric field near the first electrode 41 and the second electrode 42 by appropriately controlling the frequency band of the electromagnetic waves it generates. In other words, it is possible to suppress the impact on the surroundings caused by the generation of electromagnetic waves 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, for example, 3 mm to 3 cm.

[0061] <Method for drying medium 90> Next, the drying method for the medium 90 using the drying apparatus 12 will be described with reference to Figure 4. As shown in Figure 4, the drying process is performed after the preheating process. In other words, the preheating process is performed before the drying process. The preheating process is a process of heating the first contact portion 51 and the second contact portion 52 before the drying process.

[0062] In the preheating process, a preheating medium 99 is transported between the first contact portion 51 and the second contact portion 52. The preheating medium 99 is composed separately from the medium 90 to be dried, but it may be continuously connected to the medium 90 to be dried.

[0063] The preheating medium 99 is coated with a liquid. The preheating medium 99 has the liquid coated on its surface 99A, but the liquid may also be coated on its back surface 99B, or on both the surface 99A and the back surface 99B. The preheating medium 99 has the liquid coated on its surface 99A in a predetermined pattern. Thus, the preheating medium 99 includes a preheating region to which the liquid is coated.

[0064] The preheating medium 99 comprises an upstream region 99C and a downstream region 99D. The upstream region 99C is the region located upstream in the transport direction D. The upstream region 99C is positioned between the first upstream region 51A of the first contact portion 51 and the second upstream region 52A of the second contact portion 52.

[0065] The downstream region 99D is the region located downstream in the transport direction D. The downstream region 99D is located further downstream in the transport direction D than the upstream region 99C. The downstream region 99D is positioned between the first downstream region 51B of the first contact portion 51 and the second downstream region 52B of the second contact portion 52.

[0066] The downstream region 99D is coated with more liquid than the upstream region 99C. The downstream region 99D may be coated with liquid in a solid pattern. The upstream region 99C may be coated with liquid at predetermined intervals, unlike a solid pattern, but it may be a smaller solid pattern than the downstream region 99D.

[0067] The first upstream region 51A is the region located upstream in the transport direction D of the first contact portion 51. The first downstream region 51B is the region located downstream in the transport direction D of the first contact portion 51. The first upstream region 51A is the region facing the upstream heating portion 40A. The first downstream region 51B is the region facing the downstream heating portion 40B.

[0068] The second upstream region 52A is the region located upstream of the transport direction D in the second contact portion 52. The second downstream region 52B is the region located downstream of the transport direction D in the second contact portion 52. The second upstream region 52A is the region facing the upstream heating portion 40A. The second downstream region 52B is the region facing the downstream heating portion 40B.

[0069] In the preheating process, the heating unit 40 heats the liquid of the preheating medium 99 in response to the application of a high-frequency voltage. As a result, the liquid applied to the preheating medium 99 vaporizes, heating the preheating medium 99, the first contact portion 51, and the second contact portion 52.

[0070] Thus, in the preheating process, the heating unit 40 heats the first contact portion 51 and the second contact portion 52 while they are in contact with the preheating medium 99 to which the liquid has been applied.

[0071] In particular, more liquid is applied to the downstream region 99D than to the upstream region 99C. As a result, the amount of heat transferred is greater to the first downstream region 51B and the second downstream region 52B, which are opposite the downstream region 99D, than to the first upstream region 51A and the second upstream region 52A, which are opposite the upstream region 99C.

[0072] Thus, in the preheating process, the heating unit 40 heats the first contact portion 51 such that the first downstream region 51B is hotter than the first upstream region 51A. The heating unit 40 heats the second contact portion 52 such that the second downstream region 52B is hotter than the second upstream region 52A.

[0073] In the preheating process, the downstream heating section 40B may be controlled to heat a higher amount than the upstream heating section 40A. This reduces the difference between the time it takes for the liquid applied to the upstream region 99C to vaporize and the time it takes for the liquid applied to the downstream region 99D to vaporize.

[0074] When the preheating treatment is complete, the preheating medium 99 is discharged from between the first contact portion 51 and the second contact portion 52. The preheating treatment may be completed when a predetermined time has elapsed since the heating of the preheating medium 99 began. The preheating treatment may also be completed when the first contact portion 51 and the second contact portion 52 reach a predetermined temperature based on a detection signal from the temperature detection unit 53.

[0075] The drying process, which takes place after the preheating process, is a process of drying the image area of ​​the medium 90 on which the image is recorded. In the drying process, the medium 90 to be dried is transported between the first contact part 51 and the second contact part 52.

[0076] In the drying process, the heating unit 40 dries the medium 90 by vaporizing the liquid discharged onto it in response to the application of a high-frequency voltage. In this case, the first contact portion 51 and the second contact portion 52 are at a temperature that has risen during the preheating process. Therefore, it becomes difficult for the heat transferred to the liquid discharged onto the medium 90 to be transmitted to the first contact portion 51 and the second contact portion 52.

[0077] In particular, during the drying process, the upstream heating section 40A may be controlled to provide a higher amount of heat than the downstream heating section 40B. This allows the medium 90 to be transported in the transport direction D, enabling both pre-drying and final drying to be performed at an appropriate temperature.

[0078] <Temperature monitoring process> Next, the temperature monitoring process will be described with reference to Figure 5. The temperature monitoring process is performed by the control unit 50 during the drying process.

[0079] As shown in Figure 5, in step S10, the control unit 50 determines whether the temperatures of the first contact portion 51 and the second contact portion 52 are below a threshold based on the detection signal from the temperature detection unit 53. The threshold is a value such that the amount of heat transferred from the medium 90 to the first contact portion 51 and the second contact portion 52 becomes large.

[0080] If the control unit 50 determines that the temperatures of the first contact portion 51 and the second contact portion 52 are not below a threshold, it proceeds to step S11. If the control unit 50 determines that the temperatures of the first contact portion 51 and the second contact portion 52 are below a threshold, it proceeds to step S13.

[0081] In step S11, the control unit 50 performs normal transport control processing. In this processing, the control unit 50 reads the first transport speed from memory. The control unit 50 controls the drying transport unit 33 to transport the medium 90 at the first transport speed. The first transport speed is the speed at which the medium 90 is transported under normal circumstances.

[0082] In step S12, the control unit 50 performs normal heating control processing. In this processing, the control unit 50 reads a first high-frequency voltage from memory. The control unit 50 controls the high-frequency voltage generator 31 to apply the first high-frequency voltage to the heating unit 40. The first high-frequency voltage is the high-frequency voltage that is normally applied to the heating unit 40.

[0083] In step S13, the control unit 50 executes high-speed transport control processing. In this processing, the control unit 50 reads the second transport speed from memory. The second transport speed is the speed at which the medium 90 is transported when the temperature of the first contact section 51 and the second contact section 52 decreases. The second transport speed is faster than the first transport speed. The control unit 50 controls the drying transport section 33 to transport the medium 90 at the second transport speed.

[0084] In step S14, the control unit 50 performs a high-temperature control process. In this process, the control unit 50 reads a second high-frequency voltage from memory. The second high-frequency voltage is the high-frequency voltage applied to the heating unit 40 when the temperature of the first contact portion 51 and the second contact portion 52 decreases. The second high-frequency voltage is higher than the first high-frequency voltage. The control unit 50 controls the high-frequency voltage generator 31 to apply the second high-frequency voltage to the heating unit 40.

[0085] Thus, in the drying process, the control unit 50 increases the amount of heating by the heating unit 40 and increases the transport speed of the medium 90 by the drying transport unit 33 when the temperatures of the first contact portion 51 and the second contact portion 52 fall below a threshold. In other words, the heating unit 40 increases the amount of heating when the temperatures of the first contact portion 51 and the second contact portion 52 fall below a threshold. The drying transport unit 33 increases the transport speed of the medium 90 when the temperatures of the first contact portion 51 and the second contact portion 52 fall below a threshold.

[0086] <Operation and Effects of the First Embodiment> The operation and effects of the first embodiment will now be described. (1-1) The drying method by the drying apparatus 12 includes a drying step of drying the image area of ​​the medium 90 on which the image is recorded, and a preheating step of heating the first contact portion 51 before the drying step. With this configuration, even if the temperature of the first contact portion 51 is low, the temperature of the first contact portion 51 can be raised in advance by performing the preheating step of heating the first contact portion 51 before the drying step. For example, when the drying step is started, the temperature of the first contact portion 51 has not risen, but by performing the preheating step, the temperature of the first contact portion 51 can be raised in advance. This reduces the temperature difference between the first contact portion 51 and the temperature of the medium 90. Therefore, it is possible to make it difficult to transfer the amount of heat to the medium 90 from the first contact portion 51 during the drying step. Consequently, the drying efficiency of the medium 90 can be improved.

[0087] (1-2) The preheating step may include a step of heating the first contact portion 51 with the heating portion 40 while the first contact portion 51 is in contact with the preheating medium 99. With this configuration, the temperature of the first contact portion 51 that comes into contact with the preheating medium 99 can be raised in advance by heating the liquid applied to the preheating medium 99. This makes it difficult for heat to be transferred to the first contact portion 51 for the medium 90 during the drying step. Therefore, the drying efficiency of the medium 90 can be improved.

[0088] (1-3) The liquid is a pigment ink containing a pigment, water, and a solvent. The preheating step is a step of heating the first contact portion 51 with the heating portion 40 such that the first downstream region 51B is hotter than the first upstream region 51A. With this configuration, the water contained in the pigment ink can be vaporized by heating it in the first upstream region 51A, and the solvent contained in the pigment ink can be vaporized by heating it in the first downstream region 51B, which is hotter than the first upstream region 51A. Therefore, the drying efficiency of the medium 90 can be improved.

[0089] (1-4) In the drying process, when drying a medium 90 from which a large amount of liquid is discharged, a large amount of liquid vaporizes from the medium 90. Therefore, the temperature of the first contact portion 51 does not easily decrease. On the other hand, when drying a medium 90 from which a large amount of liquid is not discharged in the drying process, the amount of liquid vaporized from the medium 90 is small. Therefore, the temperature of the first contact portion 51 tends to decrease. Thus, conventionally, even after the drying process has started, in areas where no liquid is discharged to the medium 90 and in areas where the amount of liquid discharged to the medium 90 is small, the amount of liquid vaporized from the medium 90 is small, and there is a risk that the temperature of the first contact portion 51 will decrease.

[0090] Therefore, in this embodiment, the drying process involves increasing the amount of heating by the heating unit 40 and increasing the transport speed of the medium 90 when the temperature of the first contact portion 51 falls below a threshold. With this configuration, even if the temperature of the first contact portion 51 falls below a threshold during the drying process, the drying efficiency of the medium 90 can be improved by increasing the amount of heating by the heating unit 40. In addition, damage to the medium 90 can be reduced by increasing the transport speed of the medium 90.

[0091] (1-5) The drying apparatus 12 includes a second contact portion 52 that sandwiches the medium 90 between it and the first contact portion 51. With this configuration, when the solvent contained in the pigment ink is vaporized, the water contained in the pigment ink is vaporized and the resulting moisture remains near the medium 90. This makes it possible to reduce the difference in the amount of heat generated by the pigment ink depending on the type of medium 90 and the type of liquid. In addition, by improving the airtightness between the first contact portion 51 and the second contact portion 52 and the medium 90, the medium 90 can be dried in an environment in which the pigment ink is less likely to oxidize. An imbalance in the distance between the medium 90 and the heating portion 40 can be suppressed. The shrinkage of the medium 90 that occurs when the medium 90 is heated can be suppressed. Therefore, the occurrence of thermal denaturation of the medium 90 can be suppressed. Thus, the medium 90 can be dried while maintaining the quality of the medium 90.

[0092] (1-6) The preheating step is a step of heating the first contact portion 51 and the second contact portion 52 before the drying step. With this configuration, even if the temperature of the second contact portion 52 is low, the preheating step of heating the second contact portion 52 before the drying step can raise the temperature of the second contact portion 52 in advance. This reduces the temperature difference between the second contact portion 52 and the temperature of the medium 90. Therefore, it is possible to make it more difficult for heat to be transferred to the second contact portion 52 for the medium 90 during the drying step. Consequently, the drying efficiency of the medium 90 can be improved.

[0093] (1-7) The preheating step may include a step of heating the second contact portion 52 with the heating portion 40 while the second contact portion 52 is in contact with the preheating medium 99. With this configuration, the temperature of the second contact portion 52 that comes into contact with the preheating medium 99 can be raised in advance by heating the liquid applied to the preheating medium 99. This makes it difficult for heat to be transferred to the second contact portion 52 during the drying step. Therefore, the drying efficiency of the medium 90 can be improved.

[0094] (1-8) The preheating step is a step of heating the second contact portion 52 with the heating unit 40 such that the second downstream region 52B is hotter than the second upstream region 52A. With this configuration, the water contained in the pigment ink can be vaporized by heating it in the second upstream region 52A, and the solvent contained in the pigment ink can be vaporized by heating it in the second downstream region 52B, which is hotter than the second upstream region 52A. Therefore, the drying efficiency of the medium 90 can be improved.

[0095] (1-9) The drying process involves increasing the amount of heating by the heating unit 40 and increasing the transport speed of the medium 90 when the temperature of the second contact portion 52 falls below a threshold. With this configuration, even if the temperature of the second contact portion 52 falls below a threshold during the drying process, the drying efficiency of the medium 90 can be improved by increasing the amount of heating by the heating unit 40. In addition, damage to the medium 90 can be reduced by increasing the transport speed of the medium 90.

[0096] [Second Embodiment] Next, a second embodiment will be described. In the following description, redundant explanations of the same configuration as in the previously described embodiment will be omitted or simplified, and configurations that differ from those in the previously described embodiment will be described.

[0097] As shown in Figure 4, in the second embodiment, an electromagnetically heated sheet material may be used as the preheating medium 99 in the preheating step. The electromagnetically heated sheet material is a sheet material that has electromagnetic heating properties. The electromagnetically heated sheet material may be made of a material such as rubber. The preheating medium 99 does not need to be coated with liquid.

[0098] Thus, in the preheating process, the first contact portion 51 and the second contact portion 52 are heated by the heating portion 40 while in contact with the electromagnetic heating sheet material 99 used as the preheating medium.

[0099] In particular, the electromagnetic heating sheet material, like the preheating medium 99, contains more electromagnetically heating material in the downstream region 99D than in the upstream region 99C. Thus, in the preheating process, the first contact portion 51 is heated by the heating unit 40 such that the first downstream region 51B is hotter than the first upstream region 51A. In the preheating process, the second contact portion 52 is heated by the heating unit 40 such that the second downstream region 52B is hotter than the second upstream region 52A.

[0100] <Operation and Effects of the Second Embodiment> The operation and effects of the second embodiment will now be described. (2-1) The preheating step is a step in which the first contact portion 51 is brought into contact with the preheating medium 99 having electromagnetic heating properties, and the first contact portion 51 is heated by the heating portion 40. With this configuration, by heating the preheating medium 99 having electromagnetic heating properties, the temperature of the first contact portion 51 that comes into contact with the preheating medium 99 can be raised in advance. This makes it difficult for the amount of heat to be transferred to the medium 90 from the first contact portion 51 during the drying step. Therefore, the drying efficiency of the medium 90 can be improved.

[0101] (2-2) The preheating step is a step in which the second contact portion 52 is in contact with the preheating medium 99 having electromagnetic heating properties, and the second contact portion 52 is heated by the heating portion 40. With this configuration, by heating the preheating medium 99 having electromagnetic heating properties, the temperature of the second contact portion 52 that is in contact with the preheating medium 99 can be raised in advance. This makes it difficult for the amount of heat to be transferred to the medium 90 from the second contact portion 52 during the drying step. Therefore, the drying efficiency of the medium 90 can be improved.

[0102] [Third Embodiment] Next, a third embodiment will be described. As shown in Figure 6, in the third embodiment, the first contact portion 51 and the second contact portion 52 may be made of a material that has electromagnetic heating properties. As a result, the first contact portion 51 and the second contact portion 52 are heated by the heating portion 40 during the preheating process. In such a case, the preheating process may be performed without using the preheating medium 99.

[0103] The material having electromagnetic heating properties may be, for example, carbon. The first contact portion 51 and the second contact portion 52 may be made of materials such as graphite or ceramic instead of glass plates.

[0104] In particular, the first contact portion 51 may be configured such that the first downstream region 51B contains more electromagnetically heating material than the first upstream region 51A. The second contact portion 52 may be configured such that the second downstream region 52B contains more electromagnetically heating material than the second upstream region 52A.

[0105] Thus, in the preheating process, the heating unit 40 heats the first contact portion 51 such that the first downstream region 51B is hotter than the first upstream region 51A. The heating unit 40 heats the second contact portion 52 such that the second downstream region 52B is hotter than the second upstream region 52A.

[0106] <Operation and Effects of the Third Embodiment> The operation and effects of the third embodiment will now be described. (3-1) The first contact portion 51 is made up of a material that has electromagnetic heating properties. With this configuration, the temperature of the first contact portion 51 can be raised in advance by heating the first contact portion 51 which contains the electromagnetic heating property material. This makes it difficult for heat to be transferred to the first contact portion 51 for the medium 90 during the drying process. Therefore, the drying efficiency of the medium 90 can be improved.

[0107] (3-2) The first contact portion 51 is configured such that the first downstream region 51B contains more electromagnetically heat-generating material than the first upstream region 51A. With this configuration, the first contact portion 51 is heated by the heating unit 40 so that the first downstream region 51B is hotter than the first upstream region 51A. As a result, the water contained in the pigment ink can be vaporized by heating in the first upstream region 51A, and the solvent contained in the pigment ink can be vaporized by heating in the first downstream region 51B, which is hotter than the first upstream region 51A. Therefore, the drying efficiency of the medium 90 can be improved.

[0108] (3-3) The second contact portion 52 is made up of a material that has electromagnetic heating properties. With this configuration, the temperature of the second contact portion 52 can be raised in advance by heating the second contact portion 52 which contains the electromagnetic heating property material. This makes it difficult for heat to be transferred to the second contact portion 52 for the medium 90 during the drying process. Therefore, the drying efficiency of the medium 90 can be improved.

[0109] (3-4) The second contact portion 52 is configured such that the second downstream region 52B contains more electromagnetically heating material than the second upstream region 52A. With this configuration, the second contact portion 52 is heated by the heating portion 40 such that the second downstream region 52B is hotter than the second upstream region 52A. As a result, the water contained in the pigment ink can be vaporized by heating in the second upstream region 52A, and the solvent contained in the pigment ink can be vaporized by heating in the second downstream region 52B, which is hotter than the second upstream region 52A. Therefore, the drying efficiency of the medium 90 can be improved.

[0110] [Fourth Embodiment] Next, a fourth embodiment will be described. As shown in Figure 7, in the fourth embodiment, the drying unit 30 may include a conductor housing 80. In Figure 7, the conductor housing 80 is shown by a dashed line.

[0111] The conductive housing 80 may be provided inside the housing of the drying apparatus 12. The conductive housing 80 is electrically conductive. The conductive housing 80 is configured to house the heating unit 40. The conductive housing 80 may be configured to house a plurality of heating units 40. The conductive housing 80 is cylindrical in shape along the transport path of the medium 90. The conductive housing 80 may be provided so that the transport direction D is its longitudinal side.

[0112] The conductor housing 80 is provided with an outlet 80A. The outlet 80A is located in a first intersecting direction Y1 of the conductor housing 80. The outlet 80A is provided for discharging the medium 90 from the inside to the outside of the conductor housing 80. The conductor housing 80 is provided with an inlet 80B. The inlet 80B is located in a second intersecting direction Y2 of the conductor housing 80. The inlet 80B is provided for transporting the medium 90 from the outside to the inside of the conductor housing 80.

[0113] The conductive housing 80 may be electrically connected to the second electrode 42. The conductive housing 80 may be grounded. In this way, the conductive housing 80 functions in the same way as the second electrode 42. Thus, the heating unit 40 may generate electromagnetic waves through the first electrode 41, the second electrode 42, and the conductive housing 80.

[0114] [Example of changes] This embodiment can be implemented with the following modifications. This embodiment and the following modifications can be combined with each other to the extent that they do not contradict each other technically.

[0115] In the fourth embodiment, the second electrode 42 may be provided integrally with the conductor housing 80. The drying apparatus 12 does not need to have the second electrode 42 if the conductor housing 80 is grounded, and the conductor housing 80 may function as the second electrode 42.

[0116] In the first and second embodiments, the amount of liquid applied to the upstream region 99C and the downstream region 99D may be the same, or more liquid may be applied to the upstream region 99C than to the downstream region 99D.

[0117] In the third embodiment, the first contact portion 51 may be configured to contain the same amount of electromagnetically heating material in the first upstream region 51A and the first downstream region 51B. The first contact portion 51 may be configured such that the first upstream region 51A contains more electromagnetically heating material than the first downstream region 51B.

[0118] In the third embodiment, the second contact portion 52 may be configured such that the same amount of electromagnetically heating material is included in the second upstream region 52A and the second downstream region 52B. The second contact portion 52 may be configured such that the second upstream region 52A contains more electromagnetically heating material than the second downstream region 52B.

[0119] In the third embodiment, the preheating process may be performed while the preheating medium 99 is being transported between the first contact portion 51 and the second contact portion 52. The upstream heating unit 40A and the downstream heating unit 40B may each adjust the intensity of the electromagnetic waves they output, even when the same high-frequency voltage is supplied from the high-frequency voltage generation unit 31. The control unit 50 may directly control the amount of heating from the upstream heating unit 40A and the amount of heating from the downstream heating unit 40B without going through the high-frequency voltage generation unit 31.

[0120] The upstream heating unit 40A and the downstream heating unit 40B may have the same intensity of electromagnetic waves output when the same high-frequency voltage is supplied from the high-frequency voltage generation unit 31. Multiple heating units 40 may have the same intensity of electromagnetic waves output when the same high-frequency voltage is supplied from the high-frequency voltage generation unit 31.

[0121] The drying apparatus 12 may include a plurality of temperature detection units 53. The drying apparatus 12 may include a temperature detection unit 53 that detects the temperature of the first contact portion 51 and a temperature detection unit 53 that detects the temperature of the second contact portion 52. The control unit 50 may perform control based on the temperature of the first contact portion 51 and the temperature of the second contact portion 52. In this way, the temperature detection unit 53 may detect the temperature of at least one of the first contact portion 51 and the second contact portion 52. The drying apparatus 12 does not have to include a temperature detection unit 53.

[0122] • In the preheating process, the amount of heating in the downstream heating section 40B may be greater than that in the upstream heating section 40A. This allows the temperature of the first downstream region 51B and the second downstream region 52B to rise more than that of the first upstream region 51A and the second upstream region 52A.

[0123] The multiple heating units 40 may be arranged so that their longitudinal direction is in the intersecting direction Y. In this case, the first electrode 41 may be arranged so as to extend along the intersecting direction Y. The multiple heating units 40 may be arranged so as to be inclined with respect to the width direction X and the intersecting direction Y.

[0124] • Multiple heating units 40 are integrally configured by sharing a second electrode 42, but they do not necessarily have to share the second electrode 42. Multiple heating units 40 may each be configured as separate units. The drying unit 30 may have multiple heating units 40 arranged in one or more rows in the width direction X. The drying unit 30 may have multiple heating units 40 arranged in one or more rows in the intersecting direction Y.

[0125] The heating unit 40 may heat the medium 90 from the back surface 90B side. The heating unit 40 may heat the medium 90 from both the front surface 90A side and the back surface 90B side. The heating unit 40 may be scannable in the width direction X.

[0126] The drying unit 30 does not need to have a second contact portion 52, as long as it has at least a first contact portion 51. The heating portion 40 may be located below Z2 of the medium 90. In this case, the first contact portion 51 is located below Z2 of the medium 90.

[0127] The first electrode 41 is not limited to a flat plate shape, but may be, for example, a nearly flat plate shape. A nearly flat plate shape may include, for example, a shape that curves in the thickness direction which is along the vertical direction Z, or a rectangular shape with an extremely large aspect ratio, and may also include a linear shape.

[0128] The second electrode 42 is not limited to a flat plate shape, and may, for example, be a nearly flat plate shape. A nearly flat plate shape may include, for example, a shape that curves in the thickness direction which is along the vertical direction Z, or a rectangular shape with an extremely large aspect ratio, and may also include a linear shape.

[0129] At least one of the first electrode surface 41A and the second electrode surface 42A is not limited to a planar shape, but may be a general planar shape. The general planar shape may include, for example, a shape that curves in the thickness direction which is along the vertical direction Z, or a rectangular shape with an extremely large aspect ratio, and may also include linear shapes.

[0130] The heating unit 40 may not be provided in the drying apparatus 12, but in the recording device 11. In other words, the recording device 11 may include the heating unit 40. In this case, the heating unit 40 should be provided on the downstream side of the recording unit 20 in the transport direction D. Thus, the heating unit 40 may be applied to the recording device 11 instead of the drying apparatus 12.

[0131] A lateral printer may be used as the recording device 11. A lateral printer is a printer in which the carriage 25 is movable in two directions: the main scanning direction and the sub-scanning direction.

[0132] The medium 90 is not limited to a roll. The medium 90 may be paper, resin films or sheets, resin-metal composite films, laminate films, textiles, nonwoven fabrics, metal foils, metal films, ceramic sheets, and clothing, etc.

[0133] The liquid can be any liquid that can adhere to the medium 90 and allow for recording on the medium 90. The liquid may be a dye ink, such as a disperse dye ink or a reactive dye ink. For example, the ink may include a mixture of functional material particles, such as pigments or metal particles, dissolved, dispersed, or mixed in a solvent, and shall encompass various compositions such as water-based inks, oil-based inks, gel inks, and hot-melt inks.

[0134] As used herein, the expression "at least one of" means one or more of the desired options. For example, as used herein, if there are two options, the expression "at least one of" means either one option or both of the two options. As another example, as used herein, if there are three or more options, the expression "at least one of" means either one option or any combination of two or more options.

[0135] [Note] The following describes the technical concepts and their effects as understood from the embodiments and modifications described above. These technical concepts and their effects can be combined with each other to the extent that they do not contradict each other.

[0136] [1] A drying method using a drying apparatus, comprising a heating section for heating a medium from which a liquid has been discharged, and a first contact section that can contact the medium between the heating section and the medium, wherein the heating section comprises a first electrode, a second electrode arranged 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 the first electrode to a transmission line capable of transmitting a high-frequency voltage, and a second conductor electrically connecting the transmission line to the second electrode, and comprising a drying step for drying an image area of ​​a medium on which an image has been recorded, and a preheating step for heating the first contact section before the drying step.

[0137] With this configuration, even if the temperature of the first contact point is low, a preheating step is performed to heat the first contact point before the drying process, thereby raising the temperature of the first contact point in advance. This reduces the temperature difference between the first contact point and the temperature of the medium. As a result, it becomes more difficult to transfer heat to the first contact point during the drying process. Consequently, the drying efficiency of the medium can be improved.

[0138] [2] A drying method using the above-described drying apparatus, wherein the preheating step may include a step of heating the first contact portion with the heating portion while the first contact portion is in contact with a preheating medium coated with liquid.

[0139] With this configuration, the temperature of the first contact area that comes into contact with the preheating medium can be raised in advance by heating the liquid applied to the preheating medium. This makes it more difficult for heat to be transferred to the first contact area during the drying process. Therefore, the drying efficiency of the medium can be improved.

[0140] [3] A drying method using the above-described drying apparatus, wherein the preheating step may include a step of heating the first contact portion with the heating portion while the first contact portion is in contact with a preheating medium having electromagnetic heating properties.

[0141] With this configuration, the temperature of the first contact area that comes into contact with the preheating medium can be raised in advance by heating the preheating medium, which has electromagnetic heating properties. This makes it difficult for heat to be transferred to the first contact area during the drying process. Therefore, the drying efficiency of the medium can be improved.

[0142] [4] A drying method using the above-described drying apparatus, wherein the liquid is a pigment ink containing a pigment, water, and a solvent, and the preheating step may include a step of heating the first contact portion with the heating portion such that the temperature of the first downstream region located downstream in the transport direction is higher than the temperature of the first upstream region located upstream in the transport direction in which the medium is transported.

[0143] In this configuration, the liquid is a pigment ink containing pigment, water, and solvent. The first contact area is heated by a heating unit such that the temperature in the first downstream region, located downstream in the transport direction, is higher than that in the first upstream region, located upstream in the transport direction in which the medium is transported. Therefore, the water contained in the pigment ink can be vaporized by heating it in the first upstream region, and the solvent contained in the pigment ink can be vaporized by heating it in the first downstream region, which is hotter than the first upstream region. Thus, the drying efficiency of the medium can be improved.

[0144] [5] A drying method using the above-described drying apparatus, wherein the first contact portion may be configured to include a material having electromagnetic heating properties. With this configuration, the temperature of the first contact area, which contains a material with electromagnetic heating properties, can be raised in advance by heating the first contact area. This makes it difficult for heat to be transferred to the first contact area during the drying process. Therefore, the drying efficiency of the medium can be improved.

[0145] [6] A drying method using the above-described drying apparatus, wherein the liquid is a pigment ink containing a pigment, water and a solvent, and the first contact portion may be configured such that the first downstream region, located downstream in the transport direction, contains more electromagnetically heating material than the first upstream region, located upstream in the transport direction in which the medium is transported.

[0146] In this configuration, the liquid is a pigment ink containing pigment, water, and solvent. The first contact area contains more electromagnetically heating material in the first downstream region located downstream in the transport direction than in the first upstream region located upstream in the transport direction. As a result, the first contact area is heated by the heating unit so that the temperature in the first downstream region located downstream in the transport direction is higher than that in the first upstream region located upstream in the transport direction where the medium is transported. Therefore, the water contained in the pigment ink can be vaporized by heating it in the first upstream region, and the solvent contained in the pigment ink can be vaporized by heating it in the first downstream region, which is hotter than the first upstream region. Thus, the drying efficiency of the medium can be improved.

[0147] [7] A drying method using the above-described drying apparatus, wherein the drying apparatus includes a temperature detection unit for detecting the temperature of the first contact portion, and the drying step may include a step of increasing the amount of heating by the heating unit and increasing the transport speed of the medium when the temperature of the first contact portion falls below a threshold.

[0148] In this configuration, when the temperature of the first contact area falls below a threshold, the amount of heating by the heating unit is increased, and the transport speed of the medium is also increased. Therefore, even if the temperature of the first contact area falls below a threshold during the drying process, the drying efficiency of the medium can be improved by increasing the amount of heating by the heating unit. In addition, damage to the medium can be reduced by increasing the transport speed of the medium.

[0149] [8] A drying method using the above-described drying apparatus, wherein the drying apparatus comprises a second contact portion that sandwiches a medium between itself and the first contact portion, the liquid is a pigment ink containing a pigment, water and a solvent, and the preheating step may include a step of heating the first contact portion and the second contact portion before the drying step.

[0150] In this configuration, the liquid is a pigment ink containing pigment, water, and solvent. Before the drying process, the second contact point, which sandwiches the medium between the first contact point and the second contact point, is heated in addition to the first contact point. As a result, when the solvent contained in the pigment ink is vaporized, the water contained in the pigment ink vaporizes and remains near the medium. This reduces the difference in the amount of heat generated by the pigment ink depending on the type of medium and the type of liquid. In addition, by improving the airtightness between the first and second contact points and the medium, the medium can be dried in an environment where the pigment ink is less likely to oxidize. Imbalances in the distance between the medium and the heating point can be suppressed. Shrinkage of the medium due to heating can be suppressed. As a result, the occurrence of thermal denaturation of the medium can be suppressed. Therefore, the medium can be dried while maintaining its quality.

[0151] In addition, even if the temperature of the second contact area is low, a preheating step is performed to heat the second contact area before the drying process, thereby raising its temperature in advance. This reduces the temperature difference between the second contact area and the medium. As a result, it becomes more difficult to transfer heat to the second contact area during the drying process. Consequently, the drying efficiency of the medium can be improved.

[0152] [9] The drying apparatus comprises a heating section for heating a medium from which a liquid has been discharged, and a first contact section that is in contact with the medium between the heating section and the medium, wherein the heating section comprises a first electrode, a second electrode arranged 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 the first electrode to a transmission line capable of transmitting a high-frequency voltage, and a second conductor electrically connecting the transmission line to the second electrode, and the first contact section is made of a material having electromagnetic heating properties. With this configuration, the same effects as in [5] can be achieved.

[0153]

[10] In the above-described drying apparatus, the liquid is a pigment ink containing a pigment, water and a solvent, and the first contact portion may be configured such that the first downstream region, located downstream in the transport direction, contains more electromagnetically heating material than the first upstream region, located upstream in the transport direction in which the medium is transported. This configuration can produce effects similar to those of [6].

[0154]

[11] The drying apparatus includes a transport unit for transporting a medium and a temperature detection unit for detecting the temperature of the first contact portion. The heating unit may increase the amount of heating when the temperature of the first contact portion falls below a threshold, and the transport unit may increase the transport speed of the medium when the temperature of the first contact portion falls below a threshold. This configuration can achieve the same effects as in [7].

[0155]

[12] The drying apparatus includes a second contact portion that sandwiches a medium between itself and the first contact portion, the liquid being a pigment ink containing a pigment, water, and a solvent, and the heating portion may heat the first contact portion and the second contact portion. This configuration can produce the same effects as in [8].

[0156]

[13] The recording device comprises a recording unit that records an image on a medium by discharging a liquid onto the medium, a heating unit that heats the medium from which the liquid has been discharged by the recording unit, and a first contact unit that is in contact with the medium between the heating unit and the medium, wherein the heating unit comprises a first electrode, a second electrode 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 having a coil and capable of transmitting a high-frequency voltage, and a second conductor that electrically connects the transmission line to the second electrode, and the first contact unit is made of a material having electromagnetic heating properties. With this configuration, the same effects as in [5] can be achieved. [Explanation of Symbols]

[0157] 10...Recording system, 11...Recording device, 12...Drying device, 13...Feeding unit, 13A...Feeding roller, 14...Winding unit, 14A...Winding roller, 20...Recording unit, 21...Recording support unit, 22...Recording transport unit, 23...Head, 24...Nozzle surface, 25...Carriage, 26...Carriage support unit, 30...Drying unit, 31...High-frequency voltage generation unit, 32...Transmission line, 33...Drying transport unit, 40...Heating unit, 40A...Upstream heating unit, 40B...Downstream heating unit, 41...First electrode, 41A...First electrode surface, 41B...Center part, 41C...Both ends, 42...Second electrode, 42A...Second electrode surface, 42B...Opening, 43...First conductor, 43A...Coil, 43B...Conducting wire, 44...Second conductor Body, 44A…Support column, 44B…Top plate, 50…Control unit, 51…First contact part, 51A…First upstream area, 51B…First downstream area, 52…Second contact part, 52A…Second upstream area, 52B…Second downstream area, 53…Temperature detection unit, 80…Conductor housing, 80A…Discharge port, 80B…Inlet, 90…Media, 90A…Front surface, 90B…Back surface, 91…First roll body, 92…Second roll body, 99…Media for preheating, 99A…Front surface, 99B…Back surface, 99C…Upstream area, 99D…Downstream area, D…Conveying direction, X…Width direction, X1…First width direction, X2…Second width direction, Y…Intersection direction, Y1…First intersection direction, Y2…Second intersection direction, Z…Vertical direction, Z1…Upward, Z2…Downward.

Claims

1. A drying method using a drying apparatus having a heating unit for heating a medium from which a liquid is discharged, and a first contact unit that can come into contact with the medium between the heating unit and the medium, The aforementioned heating section is First electrode and A second electrode is arranged to surround the first electrode in a plan view from a first direction toward the medium, A first conductor electrically connects a transmission line having a coil and capable of transmitting a high-frequency voltage to the first electrode, A second conductor electrically connects the transmission line and the second electrode, It has, A drying process to dry the image area of ​​the medium on which the image is recorded, The process includes a preheating step of heating the first contact portion before the drying step, A drying method using a drying apparatus characterized by the following features.

2. A drying method using the drying apparatus described in claim 1, The preheating step includes a step of heating the first contact portion with the heating portion while the first contact portion is in contact with a preheating medium coated with liquid, A drying method using a drying apparatus characterized by the following features.

3. A drying method using the drying apparatus described in claim 1, The preheating step includes a step of heating the first contact portion with the heating portion while the first contact portion is in contact with a preheating medium having electromagnetic heating properties. A drying method using a drying apparatus characterized by the following features.

4. A drying method using a drying apparatus according to any one of claims 1 to 3, The liquid is a pigment ink containing a pigment, water, and a solvent. The preheating step includes heating the first contact portion with the heating unit such that the temperature of the first downstream region, located downstream in the conveying direction, is higher than the temperature of the first upstream region, located upstream in the conveying direction, in which the medium is conveyed. A drying method using a drying apparatus characterized by the following features.

5. A drying method using a drying apparatus according to any one of claims 1 to 3, The first contact portion is composed of a material having electromagnetic heating properties. A drying method using a drying apparatus characterized by the following features.

6. A drying method using the drying apparatus described in claim 5, The liquid is a pigment ink containing a pigment, water, and a solvent. The first contact portion is configured such that the first downstream region, located downstream in the transport direction, contains more electromagnetically heating material than the first upstream region, located upstream in the transport direction in which the medium is transported. A drying method using a drying apparatus characterized by the following features.

7. A drying method using a drying apparatus according to any one of claims 1 to 3, The drying apparatus includes a temperature detection unit for detecting the temperature of the first contact portion, The drying process includes increasing the amount of heating by the heating unit and increasing the conveying speed of the medium when the temperature of the first contact portion falls below a threshold. A drying method using a drying apparatus characterized by the following features.

8. A drying method using a drying apparatus according to any one of claims 1 to 3, The drying apparatus includes a second contact portion that sandwiches the medium between the first contact portion and the second contact portion. The liquid is a pigment ink containing a pigment, water, and a solvent. The preheating step includes heating the first contact portion and the second contact portion before the drying step. A drying method using a drying apparatus characterized by the following features.

9. A heating unit that heats the medium from which the liquid is discharged, Between the heating element and the medium, there is a first contact element that can come into contact with the medium, Equipped with, The aforementioned heating section is First electrode and A second electrode is arranged to surround the first electrode in a plan view from a first direction toward the medium, A first conductor electrically connects a transmission line having a coil and capable of transmitting a high-frequency voltage to the first electrode, A second conductor electrically connects the transmission line and the second electrode, It has, The first contact portion is composed of a material having electromagnetic heating properties. A drying apparatus characterized by the following features.

10. A drying apparatus according to claim 9, The liquid is a pigment ink containing a pigment, water, and a solvent. The first contact portion is configured such that the first downstream region, located downstream in the transport direction, contains more electromagnetically heating material than the first upstream region, located upstream in the transport direction in which the medium is transported. A drying apparatus characterized by the following features.

11. A drying apparatus according to claim 9, A transport unit that transports the media, A temperature detection unit for detecting the temperature of the first contact portion, Equipped with, The heating unit increases the amount of heating when the temperature of the first contact portion falls below a threshold. The transport unit increases the transport speed of the medium when the temperature of the first contact portion falls below a threshold. A drying apparatus characterized by the following features.

12. A drying apparatus according to any one of claims 9 to 11, It is further provided with a second contact portion that sandwiches a medium between the first contact portion and the second contact portion, The liquid is a pigment ink containing a pigment, water, and a solvent. The heating unit heats the first contact portion and the second contact portion. A drying apparatus characterized by the following features.

13. A recording unit that records an image onto a medium by discharging a liquid onto the medium, A heating unit that heats the medium from which the liquid has been discharged by the recording unit, Between the heating element and the medium, there is a first contact element that can come into contact with the medium, Equipped with, The aforementioned heating section is First electrode and A second electrode is arranged to surround the first electrode in a plan view from a first direction toward the medium, A first conductor electrically connects a transmission line having a coil and capable of transmitting a high-frequency voltage to the first electrode, A second conductor electrically connects the transmission line and the second electrode, It has, The first contact portion is composed of a material having electromagnetic heating properties. A recording device characterized by the following features.

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