JP2018122561A - Image recorder, drying device and image recording method - Google Patents

Abstract

The present invention provides a technique capable of suppressing a decrease in drying efficiency in an ink drying process using electromagnetic waves. An image recording apparatus includes a drying unit that irradiates ink attached to a surface of a base material with electromagnetic waves and heats the ink. The drying unit 5 is provided with an introduction opening 542 for introducing the base material 2 into the inside and a lead-out opening 541 for leading the base material 2 from the inside, and is a material that transmits electromagnetic waves through the cylindrical waveguide portion 53. And is disposed at a position between the inlet opening 542 and the outlet opening 541 inside the waveguide portion 53 and faces the surface 2S to which the ink in the substrate 2 introduced into the waveguide portion 53 is adhered. And an opposing member 10. [Selection] Figure 5

Description

  The present invention relates to a technique for recording an image on the surface of a substrate by ejecting ink droplets toward the substrate such as paper by an inkjet method, and more particularly, a technique for drying ink attached to the surface of the substrate. About.

  A conventional ink jet type image recording apparatus has, for example, ink droplets from a plurality of ejection openings provided in a head toward the surface of a long belt-like (web-like) base material that moves in the longitudinal direction with respect to the head. By discharging the ink, ink is adhered to the surface of the substrate. Thereafter, the substrate to which the ink is attached is dried to dry the ink, and the image is fixed on the surface of the substrate.

  In this drying process, for example, it is known to irradiate the ink attached to the surface of the substrate with electromagnetic waves. For example, Patent Document 1 discloses that ink is irradiated with a microwave supplied from a magnetron and reflected by a propeller member. Further, it is disclosed that drying of ink is promoted by sending warm air from a fan into a waveguide.

  When the ink is irradiated with microwaves, the molecules of the ink solvent (water in the case of water-based ink) are heated and vaporized by vibration. As described above, since the drying method using microwaves can selectively heat the solvent of the ink, another drying method, for example, a method of heating the ink by blowing hot air onto the substrate, or a method of heating the substrate The ink can be dried more efficiently than the method in which the ink is heated by contacting the drum.

  The waveguide forms a highly occlusive space in order to prevent leakage of microwaves from the outside. For this reason, when a base material is introduced into the inside of the waveguide and a drying process is performed, the solvent vapor evaporated from the ink attached to the base material stays inside the waveguide. Therefore, if the drying process is continued, the solvent vapor amount inside the waveguide gradually increases, which may reduce the drying efficiency. Further, when the amount of the solvent vapor inside the waveguide increases, the solvent vapor may condense and become droplets and adhere to the substrate, which may cause a reduction in image quality.

  In Patent Document 1, a solution to “a problem that the solvent vapor generated by the evaporation of the ink solvent stays in the waveguide, so that the drying speed of the ink discharged to the medium by the solvent vapor cannot be sufficiently obtained” is solved. As a countermeasure, ventilation means (fans) for ventilating the waveguide are provided at the start and end portions of the waveguide.

JP 2010-125781 A

  However, even with the above technique, it is difficult to sufficiently remove the solvent vapor and paper dust from the inside of the waveguide, and the increase in the amount of solvent vapor and paper dust inside the waveguide causes a decrease in the drying efficiency of the ink. There was a fear.

  An object of this invention is to provide the technique which can suppress the fall of drying efficiency in the drying process of the ink using electromagnetic waves.

  In order to solve the above-described problem, a first aspect is an image recording apparatus, a head unit that ejects ink droplets toward a base material based on image data, and a head unit that discharges ink droplets. A drying unit that irradiates the ink attached to the surface of the material with electromagnetic waves and heats the ink, and the drying unit introduces the base into the inside and leads out the base from the inside And a waveguide formed in a cylindrical shape, an electromagnetic wave supply unit that supplies the electromagnetic wave to the inside of the waveguide, and a material that transmits the electromagnetic wave. And an opposing member that is disposed at a position between the introduction opening and the lead-out opening and faces the surface of the base material introduced into the waveguide to which the ink is attached.

  A 2nd aspect is an image recording device of the 1st aspect, Comprising: The said opposing member is formed wider than the said base material.

  A 3rd aspect is an image recording device of the 2nd aspect, Comprising: The said opposing member has a pair of opposing part arrange | positioned facing both surfaces of the said base material, respectively.

  A fourth aspect is the image recording apparatus according to the second aspect or the third aspect, wherein the facing member is formed in a cylindrical shape surrounding the periphery of the base material.

  A fifth aspect is the image recording apparatus according to any one of the first to fourth aspects, wherein the electromagnetic wave includes a microwave having a wavelength of 110 mm or more and 340 mm or less, and the opposing member has a relative dielectric constant. It is made of a material whose value obtained by multiplying the dielectric loss angle is 0.0012 or less.

  A sixth aspect is the image recording apparatus according to the fifth aspect, wherein the heat resistant temperature of the material of the facing member is 200 ° C. or higher.

  A seventh aspect is the image recording apparatus according to the fifth aspect or the sixth aspect, wherein the material of the facing member is quartz glass.

  An eighth aspect is the image recording apparatus according to any one of the first to seventh aspects, wherein the opposing member and the base material introduced into the waveguide through the introduction opening are provided. An airflow forming unit that forms an airflow toward the introduction opening or the outlet opening is further provided in between.

  A ninth aspect is the image recording apparatus according to the eighth aspect, wherein the airflow forming unit forms an airflow from the introduction opening toward the outlet opening.

  A tenth aspect is the image recording apparatus according to the eighth aspect or the ninth aspect, wherein the airflow forming unit is configured to transmit the base material and the inside of the waveguide from one of the introduction opening and the discharge opening. A gas supply unit that supplies gas toward the opposing member, and a gas between the base member and the opposing member inside the waveguide from the other of the introduction opening and the extraction opening. A gas suction unit for suction.

  An eleventh aspect is a drying apparatus that irradiates an ink attached to the surface of a base material with electromagnetic waves and heats the ink, and includes an introduction opening for introducing the base material into the inside and a derivation for deriving the base material from the inside. And a waveguide formed in a cylindrical shape, an electromagnetic wave supply unit that supplies the electromagnetic wave to the inside of the waveguide, and a material that transmits the electromagnetic wave. And an opposing member that is disposed at a position between the introduction opening and the lead-out opening and faces the surface of the base material introduced into the waveguide to which the ink is attached.

  A twelfth aspect is the drying apparatus according to the eleventh aspect, wherein an air flow toward the introduction opening or the lead-out opening is formed between the facing member and the base material introduced into the waveguide. An airflow forming unit;

  A thirteenth aspect is an image recording method, an ejection step of ejecting ink droplets from a head portion based on image data toward a substrate, and the ejected from the head portion and adhered to the surface of the substrate. A drying step of irradiating the ink with electromagnetic waves and heating the ink, wherein the drying step is formed in a cylindrical shape, and an introduction opening for introducing the substrate into the interior and a derivation for deriving the substrate from the interior An electromagnetic wave supplying step of supplying the electromagnetic wave into a waveguide provided with an opening, an introducing step of introducing the base material through the introducing opening, and a material that transmits the electromagnetic wave, the waveguide A facing step in which a facing member disposed at a position between the introduction opening and the lead-out opening in the inside is opposed to the surface of the base material introduced into the waveguide to which the ink is attached; Guidance Through the outlet opening formed in the tube, and a deriving step of deriving the base of the interior of the waveguide to the outside.

  A fourteenth aspect is the image recording method according to the thirteenth aspect, wherein the introduction opening or the lead-out opening is provided between the facing member and the base material introduced into the waveguide in the introduction step. An air flow forming step for forming an air flow toward

  According to the image recording apparatus of the first aspect, since the solvent vapor and paper dust generated from the ink adhering to the surface of the base material can be blocked by the opposing member, the solvent vapor diffuses inside the waveguide. Can be reduced. Accordingly, an increase in the amount of solvent vapor inside the waveguide can be suppressed, and a decrease in ink drying efficiency can be suppressed.

  According to the image recording apparatus of the second aspect, since the base material is covered with the facing member wider than the base material, the solvent vapor that diffuses while spreading in the width direction of the base material can be blocked by the facing member. This effectively reduces the diffusion of the solvent vapor into the waveguide.

  According to the image recording apparatus of the third aspect, since the opposing member faces both sides of the base material, the base material can be shielded from both sides, so that the solvent vapor can be effectively reduced from diffusing inside the waveguide. it can.

  According to the image recording apparatus of the fourth aspect, by surrounding the periphery of the base material, the diffusion of the solvent vapor into the waveguide can be effectively reduced.

  According to the image recording apparatus of the fifth aspect, the microwave absorption of the counter member can be kept low by forming the counter member with a material whose relative dielectric constant multiplied by the dielectric loss angle is 0.0012 or less. Therefore, the ink can be efficiently dried.

  According to the image recording apparatus of the sixth aspect, by forming the facing member with a material having a heat-resistant temperature of 200 ° C. or higher, it is possible to reduce thermal deformation of the facing member due to high-temperature solvent vapor or the like.

  According to the image recording apparatus of the seventh aspect, the opposing member having high heat resistance can be obtained by forming the opposing member with quartz glass. In addition, since the counter member in which the ink solvent hardly permeates can be obtained, the cleaning operation of the counter member can be facilitated.

  According to the image recording apparatus of the eighth aspect, an air flow toward the introduction opening or the lead-out opening is formed between the facing member and the base material introduced into the inside of the waveguide. The generated solvent vapor is discharged outside the waveguide. Thereby, since it can suppress that solvent vapor | steam settles between an opposing member and a base material, the fall of the drying efficiency of an ink can be suppressed.

  According to the image recording apparatus of the ninth aspect, since the air flow is formed in the same direction as the conveyance direction of the substrate, the solvent vapor can be discharged without hindering the movement of the substrate.

  According to the image recording apparatus of the tenth aspect, an air flow from one of the introduction opening and the discharge opening to the other can be formed between the base material and the opposing member inside the waveguide.

  According to the drying apparatus of the eleventh aspect, since the solvent vapor generated from the ink adhering to the surface of the substrate can be blocked by the opposing member, it is possible to reduce the diffusion of the solvent vapor into the waveguide. Accordingly, an increase in the amount of solvent vapor inside the waveguide can be suppressed, and a decrease in ink drying efficiency can be suppressed.

  According to the drying apparatus of the twelfth aspect, an air flow directed toward the introduction opening or the lead-out opening is formed between the opposing member and the base material introduced into the waveguide, thereby generating from the surface of the base material. The solvent vapor and paper powder thus discharged are discharged to the outside of the waveguide. Thereby, since it can suppress that solvent vapor | steam settles between an opposing member and a base material, the fall of the drying efficiency of an ink can be suppressed.

  According to the image recording method of the thirteenth aspect, since the solvent vapor or paper powder generated from the ink adhering to the surface of the substrate can be blocked by the opposing member, the solvent vapor diffuses inside the waveguide. Can be reduced. Accordingly, an increase in the amount of solvent vapor inside the waveguide can be suppressed, and a decrease in ink drying efficiency can be suppressed.

  According to the image recording method of the fourteenth aspect, an air flow toward the introduction opening or the lead-out opening is formed between the facing member and the base material introduced into the inside of the waveguide. The generated solvent vapor and paper dust are discharged outside the waveguide. Thereby, since it can suppress that solvent vapor | steam settles between an opposing member and a base material, the fall of the drying efficiency of an ink can be suppressed.

1 is a schematic side view showing an image recording apparatus 1 of an embodiment. It is a schematic perspective view which shows the whole drying part 5 of embodiment. It is a schematic plan view which shows the cross section of the drying part 5 of embodiment. It is a front view which shows the cross section of the drying part 5 in the A1-A1 line shown in FIG. It is a side view which shows the cross section of the drying part 5 in the A2-A2 line shown in FIG. It is a schematic perspective view which decomposes | disassembles and shows the waveguide part 53 of embodiment. 3 is a flowchart showing the operation of the image recording apparatus 1 of the embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In addition, the component described in this embodiment is an illustration to the last, and is not a thing of the meaning which limits the scope of the present invention only to them. In the drawings, the size and number of each part may be exaggerated or simplified as needed for easy understanding.

  Further, in each figure, in order to clarify the directional relationship, a coordinate system in which the Z-axis direction is the vertical direction and the XY plane is the horizontal plane is appropriately attached. In this coordinate system, the direction in which the tip of the arrow faces is the + (plus) direction, and the opposite direction is the-(minus) direction.

<1. Embodiment>
FIG. 1 is a schematic side view illustrating an image recording apparatus 1 according to an embodiment. The image recording apparatus 1 records an image on the surface 2S of the substrate 2 by ejecting ink droplets toward the substrate 2 by an inkjet method. Here, the base material 2 is a sheet formed in a long belt shape (web shape), but the form of the base material 2 is not limited to this.

  The image recording apparatus 1 includes a housing 100 that accommodates each element. The image recording apparatus 1 includes a delivery unit 3, a head unit 4, a drying unit 5 (drying device), a gas supply unit 61, a gas suction unit 65, a winding unit 7, and a control unit 8. The delivery unit 3, the head unit 4, the drying unit 5, the winding unit 7, and the control unit 8 are disposed inside the housing 100. The gas supply unit 61 and the gas suction unit 65 are disposed inside and outside the housing 100. It is arrange | positioned over both. However, some or all of the sending unit 3, the head unit 4, the drying unit 5, the winding unit 7, and the control unit 8 may be disposed outside the housing 100.

  The web-shaped substrate 2 is fed from the delivery unit 3 arranged in a roll state by the conveyance drive unit 90, and then horizontally transported in the longitudinal direction (Y direction), and is wound into a roll by the winding unit 7. Taken. Here, the horizontal conveyance means that the surface 2S which is the main surface (the surface having the largest area) of the substrate 2 is conveyed in a state parallel to the horizontal plane (XY plane). For example, the transport driving unit 90 rotationally drives a drive motor provided in the winding unit 7 and detects the transport speed, position information, and the like of the base material 2 with a rotary encoder or the like. The conveyance driving unit 90, the sending unit 3, and the winding unit 7 are examples of moving units that move the base material 2.

  The head unit 4 and the drying unit 5 are disposed so as to face the surface 2S (XY plane) of the substrate 2 in a section where the substrate 2 is horizontally conveyed. The head unit 4 includes a first head 41, a second head 42, a third head 43, and a fourth head 44 that are arranged on the upper side (+ Z side) of the substrate 2 that is horizontally conveyed and are sequentially arranged in the Y direction. .

  Each of the first head 41 to the fourth head 44 ejects ink droplets of a specific color toward the surface 2S (the main surface on the + Z side (the surface having the largest area)) of the substrate 2. For example, the first head 41 ejects cyan (C) ink droplets, the second head 42 ejects magenta (M) ink droplets, and the third head 43 ejects yellow (Y) ink droplets. The droplets are ejected, and the fourth head 44 may eject droplets of black (K) ink. Each of the first head 41 to the fourth head 44 may be configured to be able to eject ink droplets of three different sizes (large size, medium size, and small size).

  The first head 41 is provided with a plurality of discharge ports (not shown) arranged in the X direction on the bottom surface facing the surface 2S of the substrate 2, and a specific color (independently from each of the plurality of discharge ports). For example, ink droplets of cyan) are ejected. The plurality of ejection openings are provided over a width that is equal to or larger than the size of the region in which an image is to be recorded in the width direction (X direction) of the substrate 2. Similar to the first head 41, the second head 42 to the fourth head 44 are also provided with a plurality of ejection openings, respectively.

  The drying unit 5 is disposed on the downstream side (+ Y side) in the transport direction of the base material 2 relative to the head unit 4. The drying unit 5 performs a drying process in which the ink discharged from the head unit 4 is irradiated with electromagnetic waves on the portion of the base material 2 where the surface 2S adheres to dry the ink.

  As an electromagnetic wave with which the substrate 2 is irradiated in the drying unit 5, a microwave having a wavelength of 110 mm or more and 340 mm or less is preferable, but the wavelength of the electromagnetic wave can be appropriately determined according to the type of the solvent of the ink. When the ink is aqueous, an electromagnetic wave to which the absorption wavelength of the solvent component (water) contained in the ink belongs, specifically, a microwave having a frequency of 2.45 GHz (gigahertz) can be used.

  FIG. 2 is a schematic perspective view showing the entire drying unit 5 of the embodiment. FIG. 3 is a schematic plan view showing a cross section of the drying unit 5 of the embodiment. FIG. 4 is a front view showing a cross section of the drying unit 5 along the line A1-A1 shown in FIG. FIG. 5 is a side view showing a cross section of the drying section 5 along the line A2-A2 shown in FIG.

  The drying unit 5 includes an electromagnetic wave generation unit 51, an amplifier unit 52, a waveguide unit 53, a reflection unit 55, and a short circuit unit 57. The electromagnetic wave generator 51 includes a magnetron that generates an electromagnetic wave such as a microwave. The amplifier unit 52 emits the electromagnetic wave generated by the electromagnetic wave generation unit 51 toward the waveguide unit 53. The reflection unit 55 reflects the electromagnetic wave emitted from the amplifier unit 52 and passed through the waveguide unit 53. Inside the waveguide portion 53, a standing wave is generated by an electromagnetic wave emitted from the amplifier portion 52 and reflected by the reflecting portion 55. The short-circuit portion 57 terminates the electromagnetic waves that are not reflected by the reflection portion 55.

  The waveguide portion 53 is a member formed in a cylindrical shape extending in the X direction. Specifically, the waveguide section 53 includes a + Y side wall 531, a −Y side side wall 532 facing the side wall 531, a + Z side side wall 534, and a −Z side side wall 535 facing the side wall 534. It is a member formed in the shape of a square tube having.

  The waveguide portion 53 is provided with a substrate passage portion 54 for allowing the substrate 2 to pass through the inside of the waveguide portion 53. The base material passage portion 54 forms a lead-out opening 541 in the side wall 531 on the + Y side of the waveguide portion 53. In addition, the base material passage portion 54 forms an introduction opening 542 in the side wall 532 on the −Y side of the waveguide portion 53. The lead-out opening 541 and the introduction opening 542 are slit-like openings larger than the length in the width direction (X direction) of the substrate 2.

  The base material 2 was introduced into the waveguide portion 53 from the introduction opening 542 provided on the −Y side of the waveguide portion 53 and then provided on the + Y side through the waveguide portion 53. Derived from the outlet opening 541. Here, the lead-out opening 541 and the introduction opening 542 are provided on the same XY plane, and the base material 2 passes through them linearly. However, it is not essential to provide the outlet opening 541 and the inlet opening 542 on the same plane.

  A pair of projecting portions 544 and 544 projecting toward the + Y side are provided on the outer surface (+ Y side surface) of the side wall 531. The pair of overhang portions 544 and 544 are formed in a long shape extending in the X direction longer than the outlet opening 541 and are disposed on the + Z side and the −Z side of the outlet opening 541. The pair of overhang portions 544 and 544 reduce electromagnetic wave leakage from the lead-out opening 541 to the external space by reflecting the electromagnetic wave emitted from the lead-out opening 541 to the inside of the waveguide portion 53. As shown in FIG. 5, the base material 2 passes between the pair of overhang portions 544 and 544 after passing through the introduction opening 542.

  A pair of projecting portions 545 and 545 projecting toward the −Y side is also provided on the outer surface (−Y side surface) of the side wall 532. The pair of overhang portions 545 and 545 are formed in a long shape extending longer in the X direction than the introduction opening 542, and are disposed on the + Z side and the −Z side of the introduction opening 542. The pair of overhang portions 545 and 545 reflects electromagnetic waves emitted from the introduction opening 542 to the inside of the waveguide portion 53, thereby reducing leakage of electromagnetic waves from the introduction opening 542 to the external space. As shown in FIG. 5, the base material 2 passes between the pair of projecting portions 545 and 545, passes through the inside of the waveguide portion 53, and passes through the introduction opening 542.

<Amplifier 52>
The amplifier unit 52 may be made of a low dielectric constant material, for example, a resin material such as high density polyethylene (UHMW) polytetrafluoroethylene. Note that high-density polyethylene may be used as the amplifier unit 52 from the viewpoint of ease of processing and cost. When the electromagnetic wave generation unit 51 generates an electromagnetic wave, the length between the amplifier unit 52 and the reflection unit 55 in the waveguide unit 53 becomes a multiple of ½ wavelength of the electromagnetic wave, so that a standing wave is generated. In addition, since drying efficiency is good, the heating chamber by generation | occurrence | production of a standing wave is illustrated, but this is not essential and drying is possible even in the state of irregular electromagnetic waves in the waveguide part 53. .

<Reflecting part 55>
The reflection unit 55 is disposed on the + X side of the waveguide unit 53 and reflects the electromagnetic wave emitted from the amplifier unit 52. The reflection surface (−X side surface) facing the inside of the waveguide portion 53 of the reflection portion 55 can be formed of a material that reflects electromagnetic waves, for example, a metal such as aluminum. The reflection unit 55 is disposed such that a node of a standing wave generated between the reflection surface and the output surface of the amplifier unit 52 is located on the reflection surface.

<Opposing member 10>
As shown in FIG. 5, the facing member 10 is disposed inside the waveguide portion 53. The facing member 10 is a member facing the surface 2S to which the ink in the substrate 2 introduced into the waveguide portion 53 is attached at a position between the introduction opening 542 and the outlet opening 541.

  Here, the facing member 10 has a shielding frame (see FIG. 6) formed in a cylindrical shape (here, a rectangular cylindrical shape) surrounding the periphery of the substrate 2. More specifically, the facing member 10 includes a pair of facing portions 101 and 102 facing in the Z direction, and a pair of facing portions 103 and 104 that connect the + X end and the −X end of the pair of facing portions 101 and 102, respectively. With. The opposing portions 101 to 104 surround the periphery of the base material 2 that passes through the inside of the waveguide portion 53, thereby blocking the solvent vapor generated from the ink attached to the base material 2, so that the solvent vapor is guided to the waveguide. The diffusion to the inside of the portion 53 is suppressed.

  The facing portions 101 and 102 are plate-like portions parallel to the XY plane. The facing portion 101 is disposed on the + Z side of the base material 2 that passes through the inside of the waveguide portion 53. The −Z side surface of the facing portion 101 is a smooth surface parallel to the XY plane and faces the surface 2S on the + Z side of the substrate 2. The facing portion 102 is disposed on the −Z side of the base material 2 that passes through the inside of the waveguide portion 53. The + Z side surface of the facing portion 102 is a smooth surface parallel to the XY plane and faces the −Z side surface of the substrate 2. That is, the facing portions 101 and 102 are an example of a pair of facing portions that are disposed to face both surfaces of the substrate 2.

  The facing portions 103 and 104 are plate-like portions parallel to the YZ plane. The facing portion 103 is disposed on the + X side of the base material 2 that passes through the inside of the waveguide portion 53. The −X side surface of the facing portion 103 is a smooth surface parallel to the YZ plane and faces the side end portion on the + X side of the substrate 2. The facing portion 104 is disposed on the −X side of the base material 2 that passes through the inside of the waveguide portion 53. The + X side surface of the facing portion 104 is a smooth surface parallel to the YZ plane and faces the −X side end portion of the substrate 2.

  As shown in FIG. 5, the length in the Y direction of the facing member 10 of this example is longer than the length from the outlet opening 541 to the inlet opening 542 and longer than the + Y side surface of the side wall 531 to the −Y side surface of the side wall 532. It has become. The + Y side end portions of the facing portions 101 and 102 extend to positions outside the lead-out opening 541 of the waveguide portion 53 and overlap with the pair of projecting portions 544 and 544 in the Z direction. Further, the −Y side end portions of the facing portions 101 and 102 extend to positions outside the introduction opening 542 of the waveguide portion 53 and overlap with the pair of projecting portions 545 and 545 in the Z direction. Yes.

  The length of the facing member 10 in the Z direction is substantially the same as the length of the lead-out opening 541 and the introduction opening 542 in the Z direction. The opposing portion 102 on the −Z side is formed on the edge forming the outlet opening 541 of the side wall 531, the protruding portion 544 on the −Z side, the edge forming the introduction opening 542 on the side wall 532, and the protruding portion 545 on the −Z side. The opposing member 10 is supported by contacting. The + Z side surface of the facing portion 101 is in contact with the + Z side surface of the edge portion forming the lead-out opening 541 in the side wall 531 and is in contact with the + Z side surface of the edge portion forming the introduction opening 542 in the side wall 532.

  By causing the opposing portions 101 and 102 to make overall contact with the edge of the outlet opening 541 and the edge of the introducing opening 542 in the X direction, a gap between the opposing portions 101 and 102 and the side walls 531 and 532 is formed. Can be eliminated. Thereby, it is possible to reduce the solvent vapor generated from the substrate 2 from entering the inside of the waveguide portion 53.

  The length of the opposing member 10 in the X direction is substantially the same as the length of the lead-out opening 541 and the introduction opening 542 in the X direction. The + X side surface of the facing portion 103 is in contact with the + X side surface of the edge that forms the lead-out opening 541 and the introduction opening 542 of the side walls 531 and 532. Further, the −X side surface of the facing portion 104 is in contact with the −X side surface of the edge portion that forms the lead-out opening 541 and the introduction opening 542 of the side walls 531 and 532.

  By causing the opposing portions 103 and 104 to contact the edge of the outlet opening 541 and the edge of the introduction opening 542 in the entire Z direction, the gap between the opposing portions 103 and 104 and the side walls 531 and 532 is eliminated. be able to. Thereby, it is possible to reduce the solvent vapor generated from the substrate 2 from entering the inside of the waveguide portion 53.

  It is not essential that the facing portions 101 to 104 of the facing member 10 are brought into contact with the edges of the outlet opening 541 and the inlet opening 542 in the side walls 531 and 532. For example, part or all of the facing portions 101 to 104 may be supported in a non-contact state with the edge portions of the lead-out opening 541 and the introduction opening 542.

  Here, a mounting example of the facing member 10 with respect to the inside of the waveguide portion 53 will be described. FIG. 6 is a schematic perspective view showing the waveguide portion 53 of the embodiment in an exploded manner. As shown in FIG. 6, the waveguide portion 53 can be configured, for example, by stacking two components 53 a and 53 b formed in a U-shaped cross section in the Z direction. The component 53 a is a member corresponding to the −Z side portion of the waveguide portion 53, and the component 53 b is a member corresponding to the + Z side portion of the waveguide portion 53. Concave parts 581 and 582 that are recessed in the X direction are provided in the middle part of the end faces of the part 53a facing the + Y side and the + Y side of the −Y side. In addition, concave portions 583 and 584 that are recessed in the X direction are provided in the middle portion of the end faces of the component 53b facing the + Y side and the −Y side −Z side. In a state where the parts 53a and 53b are combined, the recesses 581 and 583 form the lead-out opening 541, and the recesses 582 and 584 form the introduction opening 542.

  In a state where the two parts 53a and 53b are disassembled, the opposing member 10 is fitted into the recesses 581 to 584, whereby the opposing member 10 is located between the lead-out opening 541 and the introduction opening 542 inside the waveguide portion 53. It is in a state of being mounted across.

  Note that the mounting example shown in FIG. 6 is an example, and the opposing member 10 may be mounted inside the waveguide portion 53 by other methods. For example, the facing member 10 may be inserted into the waveguide portion 53 through the lead-out opening 541 or the introduction opening 542 of the waveguide portion 53.

  Although not shown, the + Y side portion and the −Y side portion of the facing member 10 are not added to the side walls 531 and 532 of the waveguide portion 53, the pair of overhang portions 544 and 544, or the pair of overhang portions 545 and 545. You may provide the mechanism which latches.

  The facing member 10 is made of a material that transmits electromagnetic waves. The electromagnetic wave (stationary wave) generated in the waveguide portion 53 passes through the facing member 10 and is absorbed by the ink attached to the substrate 2. When the electromagnetic wave is a microwave, the material of the facing member 10 is a nonpolar substance such as quartz glass, high density polyethylene, fluororesin (PTFE), borosilicate glass, soda glass (dipole moment is zero or substantially zero). Substance).

  Here, a material suitable as the material of the facing member 10 will be described. The microwave power P absorbed by the dielectric is theoretically defined by the following equation (1).

P = K · ε · tan δ · f · E ² Equation (1)

  In equation (1), “K” is a constant (0.556 × 10 −10), “ε” is the dielectric constant of the dielectric, “tan δ” is the dielectric loss angle of the dielectric, and “f” is Frequency (Hz) and “E” indicate electric field strength (V / m), respectively.

  As shown in Formula (1), the heat generation amount of the dielectric is proportional to the relative dielectric constant (ε) and the dielectric loss angle (tan δ). Therefore, the smaller the value (= ε · tan δ) obtained by multiplying the dielectric body (ε) by the dielectric loss angle (tan θ), the smaller the microwave absorption.

  Table 1 shows the relative dielectric constant, dielectric loss angle, and heat-resistant temperature of each material. Ε · tan θ of each material obtained from Table 1 is 0.00037 for quartz glass, 0.00115 to 0.001175 for high-density polyethylene, 0.00042 for fluororesin, 0.01702 for borosilicate glass, and soda glass. 0.145. In order to efficiently dry the ink adhering to the base material 2, it is desirable that the counter member 10 absorbs less microwaves. Specifically, quartz glass, high-density polyethylene, and fluororesin are desirable, and the value of ε · tan δ is desirably 0.0012 or less (Requirement 1).

  Moreover, since the opposing member 10 is exposed to the high-temperature solvent vapor | steam generated from the ink of the base material 2, it is desirable for heat-resistant temperature (melting | fusing point) to be high. For example, it is desirable that the heat resistant temperature of the material of the facing member 10 is 200 ° C. or higher (Requirement 2). Among the materials listed in Table 1, materials that satisfy this requirement are quartz glass, fluororesin, and borosilicate glass.

  Furthermore, there is a possibility that solvent vapor, ink, dust, etc. may adhere to the inside of the facing member 10. For this reason, when considering the ease of maintenance of the facing member 10 (specifically, the cleaning operation), it is desirable that the surface of the facing member 10 is hard and that absorption (penetration) of ink, dirt, etc. does not occur easily. (Requirement 3). Among the materials listed in Table 1, materials that satisfy the requirement 3 are quartz glass, borosilicate glass, and soda glass.

  Among the materials listed in Table 1, a material suitable as the facing member 10 is quartz glass that satisfies the requirements 1 to 3. Quartz glass has a relatively low microwave absorption and a relatively high heat resistance temperature. Furthermore, since quartz glass is relatively high in hardness, it is relatively easy to process to improve the smoothness of the surface of the facing member 10. Therefore, by adopting quartz glass as the material of the opposing member 10, maintenance of the opposing member 10 is facilitated.

<Gas supply unit 61>
The gas supply unit 61 is a unit that supplies gas to the drying unit 5. As shown in FIG. 1, the gas supply unit 61 includes a blower drive unit 611 that applies pressure to the gas, a cylindrical supply duct 612 that guides the gas pumped from the blower drive unit 611 to the drying unit 5, and an external And an air intake duct 613 for guiding the gas taken in from the air to the air blowing drive unit 611.

  A known blower having a fan can be used as the blower driving unit 611. The blower driving unit 611 can be configured to be able to blow warm air by providing a heater (electric heater or the like) at the front stage or the rear stage of the fan. Further, the blower driving unit 611 is provided with a known dehumidifier before or after the fan, thereby dehumidifying a low dew point gas (for example, air having a dew point lower than normal temperature such as a dew point of 0 ° C., or a humidity of 30 to 45). % Air).

<Gas suction part 65>
The gas suction unit 65 is a unit that sucks gas from the drying unit 5. The gas suction unit 65 includes a suction drive unit 651 that applies pressure to the gas, a cylindrical suction duct 652 that guides the gas in the drying unit 5 to the suction drive unit 651, and a gas pumped from the suction drive unit 651. An exhaust duct 653 for discharging to the outside.

  As shown in FIGS. 1 and 5, the leading end of the supply duct 612 includes a gas supply port portion 6121 that discharges gas on the + Z side of the substrate 2 and a gas supply that discharges gas on the −Z side of the substrate 2. It is divided into a mouth portion 6122. Although not shown, the gas supply port portions 6121 and 6122 form gas supply ports that extend in the X direction and whose front ends face the introduction opening 542, and the width direction (X Gas) at a substantially uniform flow rate over the direction). More specifically, the gas supply port portion 6121 discharges gas between the base member 2 and the facing portion 101 of the facing member 10 inside the waveguide portion 53. The gas supply port portion 6122 discharges gas between the base member 2 and the facing portion 102 of the facing member 10 inside the waveguide portion 53.

  Further, as shown in FIGS. 1 and 5, the distal end portion of the suction duct 652 sucks the gas on the + Z side of the base material 2 and the gas suction port portion 6521 for sucking the gas on the −Z side of the base material 2. It is divided into a gas suction port 6522. Although not shown, the gas suction ports 6521 and 6522 form a gas suction port extending in the X direction and having a tip directed toward the lead-out opening 541, and the width direction (X Aspirate the gas over the direction). More specifically, the gas suction port portion 6521 sucks the gas between the base member 2 and the facing portion 101 of the facing member 10 inside the waveguide portion 53. The gas suction port 6522 sucks the gas between the base member 2 and the facing portion 102 of the facing member 10 inside the waveguide portion 53.

  As shown in FIG. 5, the gas discharged from the gas supply port portion 6121 passes between the base material 2 and the facing portion 101 and is sucked into the gas suction port portion 6521. Thus, by forming an air flow from the inlet opening 542 toward the outlet opening 541, the solvent vapor generated from the ink is discharged to the outside of the waveguide portion 53. Thereby, it is possible to suppress the solvent vapor from standing between the facing member 10 and the base material 2. Further, by forming an air flow in the same direction as the transport direction (+ Y direction) of the base material 2, the solvent vapor can be discharged without hindering the movement of the base material.

  Furthermore, in this embodiment, the gas discharged from the gas supply port 6122 on the −Z side from the base material 2 passes between the base material 2 and the facing portion 102 and is sucked into the gas suction port 6522. . As a result, an air flow can be formed between the main surfaces on both sides of the base material 2 and the facing portions 101 and 102, and therefore, the base material 2 is less fluttered than when the air flow is formed only on one side. it can. Thereby, it can reduce that the base material 2 contacts other members (for example, the opposing member 10, the overhang | projection parts 544,545, etc.). In particular, it is possible to reduce the contact of the surface 2S, to which the ink is adhered, with other members, thereby suppressing the deterioration of the image quality of the image formed on the substrate 2.

  Note that it is not essential to form an airflow on both sides of the base material 2 in the Z direction. For example, the airflow may be formed only on the surface 2S side. In addition, it is not essential to form an airflow in the direction from the outlet opening 541 toward the introduction opening 542 (that is, the same direction as the transport direction (+ Y direction) of the base material 2), and even if an airflow in the opposite direction is formed. Good. In this case, since the relative speed of the airflow with respect to the base material 2 can be increased, the drying efficiency of the base material 2 can be improved.

  It is not essential to supply the gas from the outside of the introduction opening 542 (or the outside of the outlet opening 541) of the waveguide portion 53. For example, inside the waveguide portion 53, gas is supplied between the base material 2 and the facing portion 101 (or the facing portion 102), and the airflow is discharged to the outlet opening 541 or the inlet opening 542. Good.

<Control unit 8>
The control unit 8 controls the operation of each element by issuing an operation command to each element of the image recording apparatus 1. The configuration of the control unit 8 as hardware is the same as that of a general computer. That is, the control unit 8 stores a CPU that performs various arithmetic processes, a ROM that is a read-only memory that stores basic programs, a RAM that is a readable and writable memory that stores various information, and a control application or data. A storage unit is provided.

<Operation>
FIG. 7 is a flowchart showing the operation of the image recording apparatus 1 of the embodiment. When the image recording apparatus 1 starts operation based on an input from the user, the control unit 8 issues an operation command to each element of the image recording apparatus 1, and operations (image recording operations) described below are sequentially executed. The

  In addition, as described below, here, the discharge step S10, the electromagnetic wave supply step S20, the introduction step S30, the facing step S40, the airflow formation step S50, and the derivation step S60 are performed. The execution order can be arbitrarily changed. It can also be assumed that a plurality of steps are executed in parallel.

  When the discharge step S <b> 10 is started, the control unit 8 issues an operation command to the conveyance driving unit 90, and the base material 2 is continuously conveyed from the sending unit 3 to the winding unit 7. Subsequently, the control unit 8 issues an operation command to 4, and the head unit 4 executes ejection of ink droplets to the substrate 2 based on the image data (ejection control signal) transmitted from the control unit 8. As a result, a plurality of CMYK ink droplets adhere to the surface 2S of the substrate 2 based on the halftone dot image corresponding to the original image.

  Then, electromagnetic wave supply process S20 is performed. In the electromagnetic wave supply step S <b> 20, the control unit 8 issues an operation command to the electromagnetic wave generation unit 51 of the drying unit 5, and the electromagnetic wave is supplied into the waveguide unit 53. As a result, an electromagnetic wave standing wave is formed between the amplifier unit 52 and the reflection unit 55 inside the waveguide unit 53.

  Then, introduction process S30 is performed. In the introduction step S <b> 30, the portion of the base material 2 to which the ink has adhered is introduced into the inside of the waveguide portion 53 through the lead-out opening 541 by the continuous transport of the base material 2 by the transport driving unit 90.

  Subsequently, the facing step S40 is performed. In the facing step S <b> 40, the portion of the base material 2 to which the ink has adhered is opposed to the facing member 10 by continuous transport of the base material by the transport driving unit 90. More specifically, the surface 2S of the base material 2 faces the facing portion 101 of the facing member 10, and the back surface opposite to the surface 2S of the base material 2 faces the facing portion 102 of the facing member 10.

  Subsequently, an airflow forming step S50 is performed. In the airflow forming step S50, an airflow from the introduction opening 542 toward the outlet opening 541 is formed between the facing member 10 and the portion of the base material 2 where the ink is adhered. In addition, in the air flow formation, the control unit 8 gives an operation command to the gas supply unit 61 and the gas suction unit 65, and the gas discharge from the gas supply port units 6121 and 6122 and the gas in the gas suction port units 6521 and 6522 are performed. This is realized by performing suction. The air flow formation itself may be started after (or before) the continuous conveyance of the base material 2 is started in the discharge step S10.

  Subsequently, a derivation step S60 is performed. In the derivation step S <b> 60, the portion of the base material 2 that has been dried and fixed by the continuous conveyance of the base material 2 by the transport driving unit 90 is led out of the waveguide section 53 through the introduction opening 542. Is done.

<Effects>
According to the image recording apparatus 1 of the present embodiment, the solvent vapor generated from the ink adhering to the surface 2S of the base material 2 by the electromagnetic wave irradiation inside the waveguide portion 53 is caused to flow to the opposing member 10 (particularly, the opposing portion 101). Can be blocked. This can reduce the diffusion of the solvent vapor into the waveguide portion 53. Therefore, an increase in the amount of solvent vapor inside the waveguide portion 53 can be suppressed, and a decrease in ink drying efficiency can be suppressed.

  Further, an air flow is formed between the base member 2 and the opposing member 10 inside the waveguide portion 53, whereby an air flow from the introduction opening 542 toward the outlet opening 541 is formed. Solvent vapor generated from the surface of the substrate is discharged outside the waveguide. Thereby, it can suppress that solvent vapor | steam settles between an opposing member and a base material, and can suppress the fall of drying efficiency.

<2. Modification>
Although the embodiment has been described above, the present invention is not limited to the above, and various modifications are possible.

  For example, in the above embodiment, the facing member 10 includes the facing portions 101 to 104 so as to surround the entire periphery of the portion of the base material 2 that passes through the waveguide portion 53. However, it is not essential that the facing member 10 includes all of the facing portions 101 to 104. For example, it is also conceivable that the facing member 10 is only the facing portion 101. In this case, the opposing portion 101 faces only the surface 2S of the substrate 2 inside the waveguide portion 53, but the surface 2S is a surface to which ink is attached and the substrate 2 Is the main surface with the largest area. For this reason, even if the facing member 10 is configured only by the facing portion 101, it is possible to effectively reduce diffusion into the waveguide portion 53 by directly receiving the catalyst vapor generated from the surface 2 </ b> S at the facing portion 101. It is also conceivable that the opposing member 10 is only a pair of opposing portions 101 and 102. In this case, the diffusion of the catalyst vapor into the waveguide portion 53 can be suppressed more than when only the facing portion 101 is used.

  Further, the length of the facing member 10 in the Y direction may be shorter than the length between the side walls 531 and 532 of the waveguide portion 53. In this case, a gap is formed between the facing member 10 and the side wall 531 or the side wall 532, but the solvent vapor can be blocked by the facing member 10 (particularly, the facing portion 101), so that the facing member 10 is not provided. The diffusion of the solvent vapor into the waveguide can be reduced.

  Here, the temperature of the ink adhering to the substrate 2 rises as it travels inside the waveguide portion 53. Accordingly, the solvent in the ink evaporates on the + Y side (closer to the downstream side in the transport direction of the base material 2) than the position on the −Y side (closer to the upstream side in the transport direction of the base material 2) in the waveguide section 53. It's easy to do. That is, the amount of solvent vapor generated on the + Y side (that is, the side wall 531 side) in the waveguide portion 53 can be increased. Therefore, in order to suppress the penetration of the solvent vapor into the waveguide portion 53, it is desirable that the facing member 10 is in contact with the edge portion of the outlet opening 541 in the side wall 531 without any gap. Further, the + Y side end of the facing member 10 is positioned outside the edge of the lead-out opening 541 (a position overlapping with the pair of projecting portions 544 and 544 in the Z direction or a pair of projecting portions 544 and 544). It is desirable to extend to the position on the + Y side.

  Although the present invention has been described in detail, the above description is illustrative in all aspects, and the present invention is not limited thereto. It is understood that countless variations that are not illustrated can be envisaged without departing from the scope of the present invention. The configurations described in the above embodiments and modifications can be appropriately combined or omitted as long as they do not contradict each other.

DESCRIPTION OF SYMBOLS 1 Image recording apparatus 2 Base material 2S Surface 4 Head part 5 Drying part 10 Opposing member 101,102,103,104 Opposing part 51 Electromagnetic wave generating part 52 Amplifier part 53 Waveguide part 531 532, 533, 534 Side wall 54 Base material Through part 541 Lead-out opening 542 Introduction opening 55 Reflection part 57 Short-circuit part 61 Gas supply part 6121,6122 Gas supply port part 65 Gas suction part 6521,6522 Gas suction port part

Claims (14)

A head unit that ejects ink droplets based on image data toward the substrate;
A drying unit that heats the ink by irradiating the ink discharged from the head unit and adhering to the surface of the substrate with electromagnetic waves;
With
The drying unit
A waveguide formed in a cylindrical shape, provided with an introduction opening for introducing the substrate into the interior and a lead-out opening for deriving the substrate from the inside;
An electromagnetic wave supply unit for supplying the electromagnetic wave into the waveguide;
It is formed of a material that transmits the electromagnetic wave, and is disposed at a position between the introduction opening and the lead-out opening inside the waveguide, and the ink on the base material introduced into the waveguide adheres thereto. A facing member facing the surface;
An image recording apparatus comprising: The image recording apparatus according to claim 1,
The image recording apparatus, wherein the facing member is formed wider than the base material. The image recording apparatus according to claim 2,
The said opposing member is an image recording device which has a pair of opposing part arrange | positioned facing each of both surfaces of the said base material. The image recording apparatus according to claim 2 or claim 3, wherein
The counter member is an image recording apparatus formed in a cylindrical shape surrounding the periphery of the substrate. The image recording apparatus according to any one of claims 1 to 4, wherein:
The electromagnetic wave includes a microwave having a wavelength of 110 mm to 340 mm,
The image recording apparatus, wherein the facing member is made of a material having a value obtained by multiplying a relative dielectric constant by a dielectric loss angle is 0.0012 or less. The image recording apparatus according to claim 5, wherein
An image recording apparatus in which a heat resistant temperature of a material of the facing member is 200 ° C. or higher. The image recording apparatus according to claim 5 or 6, wherein
An image recording apparatus, wherein the material of the facing member is quartz glass. The image recording apparatus according to any one of claims 1 to 7,
An airflow forming portion that forms an airflow toward the introduction opening or the outlet opening between the opposing member and the base material introduced into the waveguide through the introduction opening;
An image recording apparatus further comprising: The image recording apparatus according to claim 8, wherein
The image recording apparatus, wherein the air flow forming unit forms an air flow from the introduction opening toward the outlet opening. The image recording apparatus according to claim 8 or 9, wherein
The airflow forming part is
From one of the introduction opening and the lead-out opening, a gas supply unit that supplies gas toward the gap between the base member and the opposing member inside the waveguide;
From the other of the introduction opening and the lead-out opening, a gas suction part that sucks a gas between the base member and the facing member inside the waveguide;
An image recording apparatus. A drying device that heats the ink by irradiating the ink attached to the surface of the substrate with electromagnetic waves,
A waveguide formed in a cylindrical shape, provided with an introduction opening for introducing the substrate into the interior and a lead-out opening for deriving the substrate from the inside;
An electromagnetic wave supply unit for supplying the electromagnetic wave into the waveguide;
It is formed of a material that transmits the electromagnetic wave, and is disposed at a position between the introduction opening and the lead-out opening inside the waveguide, and the ink on the base material introduced into the waveguide adheres thereto. A facing member facing the surface;
A drying apparatus comprising: 12. The drying device of claim 11, wherein
An airflow forming unit that forms an airflow toward the introduction opening or the outlet opening between the facing member and the base material introduced into the waveguide;
The drying device further comprising: An ejection process for ejecting ink droplets from the head part based on the image data toward the substrate;
A drying step of heating the ink by irradiating the ink discharged from the head part and adhering to the surface of the substrate with electromagnetic waves;
Including
The drying step
An electromagnetic wave supplying step of supplying the electromagnetic wave to the inside of a waveguide formed in a cylindrical shape and provided with an introduction opening for introducing the base material into the interior and a lead-out opening for deriving the base material from the inside;
Introducing the base material through the introduction opening;
An opposing member formed of a material that transmits the electromagnetic wave and disposed at a position between the introduction opening and the lead-out opening in the waveguide, and the substrate in the substrate introduced into the waveguide A facing step to face the surface to which the ink has adhered;
A derivation step of deriving the substrate inside the waveguide to the outside through the derivation opening formed in the waveguide;
An image recording method comprising: The image recording method according to claim 13, comprising:
An air flow forming step of forming an air flow toward the introduction opening or the outlet opening between the facing member and the base material introduced into the waveguide in the introduction step;
An image recording method comprising:

Images