JP2017132040A - Image recording device and ink curing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image recording device configured to accelerate curing of ink while suppressing supplied amounts of inert gas.SOLUTION: Ink whose curing is accelerated by being irradiated with light of a specific wavelength band is imparted to a base material 9. An enclosure 41 has a first opening 413 provided at a first site 411 positioned closer to a downstream side of a conveyance passage than an image recording portion and opposed to the conveyance passage, and a second opening 414 provided at a second site 412 different form the first site 411. A light source provided inside the enclosure 41 applies light of a specific wavelength band toward the first site 411. A gas supply portion 44 supplies inert gas to inside of the enclosure 41 through at least one second opening 414. By action of light transmitting through the first site 411 of the enclosure 41 and inert gas which blows out through the first opening 413 provided in the first site 411 of the enclosure 41, curing of the ink is accelerated while suppressing supplied amounts of the inert gas.SELECTED DRAWING: Figure 3

Description

  The present invention relates to an image recording apparatus and an ink curing apparatus that record an image using ink whose curing is accelerated by irradiation with light in a specific wavelength range.

  As an ink whose curing is accelerated by irradiation with light in a specific wavelength region, for example, there is an ultraviolet curable ink. UV curable ink is an ink that starts a polymerization reaction that has been suppressed by a polymerization inhibitor when irradiated with ultraviolet light, and cures very slowly until irradiated with ultraviolet light, and cures when irradiated with ultraviolet light. Is promoted.

  Patent Document 1 discloses a technique in an inkjet image recording apparatus that forms an image by ejecting ultraviolet curable ink onto the surface of a substrate to be conveyed, and then cures the ink by irradiating the surface with ultraviolet light. Is disclosed.

  However, it is known that even if the ultraviolet curable ink is irradiated with ultraviolet rays, if the surrounding atmosphere of the ultraviolet curable ink contains a large amount of oxygen, the curing of the ink is inhibited. This is because radicals generated at the beginning of the polymerization reaction are combined with oxygen in the surrounding atmosphere.

JP2015-58675A JP 2008-221651A JP2015-54434A

  Therefore, Patent Document 2 and Patent Document 3 disclose a technique of covering the periphery of a substrate irradiated with ultraviolet rays with a cover and supplying an inert gas (for example, nitrogen) into the cover. In this technique, the amount of oxygen in the atmosphere in the cover can be reduced while suppressing the amount of inert gas supplied.

  However, even if this technique is used, it is difficult to sufficiently reduce the amount of oxygen in the ambient atmosphere of the ultraviolet curable ink. This is because the ambient atmosphere of the ultraviolet curable ink is an atmosphere corresponding to the boundary layer of the substrate to be transported, and in this atmosphere, the purge action by the inert gas supplied into the cover is difficult. As a result, there is a possibility that the curing of the ink is inhibited as described above.

  Such a problem is not limited to ultraviolet curable inks, but is common to inks whose curing is accelerated by irradiation with light in other wavelength ranges.

  SUMMARY An advantage of some aspects of the invention is that it provides a technique for promoting ink curing while suppressing the amount of inert gas supplied.

  In order to solve the above-described problem, an image recording apparatus according to a first aspect includes a transport unit that transports a base material along a transport path, and a surface of the base material that is transported by the transport unit in a specific wavelength range. An image recording unit that applies ink that is accelerated by being irradiated with light, and light in the specific wavelength region while supplying an inert gas to the surface of the base material that is transported by the transport unit. An ink curing unit that irradiates, wherein the ink curing unit is located on the downstream side of the conveyance path with respect to the image recording unit, and is provided in at least one first portion facing the conveyance path. A housing having an opening and at least one second opening provided in a second portion different from the first portion; and the specific wavelength provided in the housing and toward the first portion. A light source for irradiating light in the region; Both have a gas supply unit for supplying the internal inert gas in the casing from one of the second opening, at least part of said first portion is transmitted through the light of the specific wavelength band.

  An image recording apparatus according to a second aspect is the image recording apparatus according to the first aspect, wherein when the first part of the housing faces the surface of the base material, Among these, there is an overlapping region between an irradiation region irradiated with light of the specific wavelength region by the light source and a purge region where the surrounding atmosphere of the surface is purged by the inert gas supplied from the gas supply unit. To do.

  An image recording apparatus according to a third aspect is the image recording apparatus according to the first aspect, wherein when the first part of the housing faces the surface of the substrate, the at least one At least one virtual axis in each of the first openings passes through an irradiation region of the surface irradiated with light in the specific wavelength region by the light source.

  An image recording apparatus according to a fourth aspect is the image recording apparatus according to the third aspect, wherein the at least one virtual axis is between the housing and the base material in the transport path. It passes through the upstream part of the region.

  An image recording apparatus according to a fifth aspect is the image recording apparatus according to any one of the first to fourth aspects, wherein the at least one first opening is the specific wavelength of the first part. It is formed outside the transmission region through which the light of the region is transmitted.

  An image recording apparatus according to a sixth aspect is the image recording apparatus according to any one of the first to fourth aspects, wherein the at least one first opening is the specific wavelength of the first part. It is formed inside a transmissive region where light of the region is transmitted.

  An image recording apparatus according to a seventh aspect is the image recording apparatus according to any one of the first to sixth aspects, wherein the transport path is between the housing and the base material, At least one first opening is inclined toward the upstream side from the inside to the outside of the housing in the first portion.

  An image recording apparatus according to an eighth aspect is the image recording apparatus according to any one of the first to seventh aspects, wherein the region in which the at least one first opening is formed intersects a conveyance path. The length of the region is smaller than the length of the casing with respect to the direction along the transport path between the casing and the base material.

  An image recording apparatus according to a ninth aspect is the image recording apparatus according to any one of the first to eighth aspects, wherein the light in the specific wavelength region is ultraviolet light.

  In the ink curing device according to the tenth aspect, the substrate to which the ink that is cured by being irradiated with light in a specific wavelength region is applied is conveyed along the conveyance path. An ink curing device that irradiates light in the specific wavelength range while supplying an inert gas to a surface, wherein the first portion is provided in at least one first portion facing the transport path, and the first portion A housing having at least one second opening provided in a second portion different from the first light source, and a light source that is provided inside the housing and irradiates light in the specific wavelength region toward the first portion And a gas supply part that supplies an inert gas into the housing from the at least one second opening, and at least a part of the first part transmits light in the specific wavelength region.

  According to any of the image recording apparatus according to any one of the first to ninth aspects or the ink curing apparatus according to the tenth aspect, the light transmitted through the first part of the housing and the first part provided in the first part of the housing By the action of the inert gas ejected from one opening, the curing of the ink can be promoted while suppressing the supply amount of the inert gas.

1 is a diagram illustrating a configuration of an image recording apparatus 1. FIG. It is a bottom view of the head unit 24 and the thickening light irradiation unit 30. 3 is an XZ side view schematically showing a fixing light irradiation unit 40 and a base material 9. FIG. 3 is a conceptual diagram showing a positional relationship between an irradiation region 70 and a purge region 71 on the surface of a substrate 9. FIG. It is a flowchart which shows the flow of a process. FIG. 10 is an XZ side view schematically showing a fixing light irradiation unit 40A and a base material 9 according to a modification. FIG. 9 is an XZ side view schematically showing a fixing light irradiation unit 40B and a base material 9 according to a modification. In the modification, it is a conceptual diagram which shows the positional relationship of the irradiation area | region 70 and the purge area | region 71C on the surface of the base material 9. FIG.

  Hereinafter, embodiments will be described with reference to the drawings. In the drawings, parts having similar configurations and functions are denoted by the same reference numerals, and redundant description is omitted. In addition, the following embodiment is an example which actualized this invention, and is not an example which limits the technical scope of this invention. In the drawings, the size and number of each part may be exaggerated or simplified. In the drawings, XYZ orthogonal coordinate axes may be attached to explain directions. The + Z direction on the coordinate axis is a vertically upward direction, and the XY plane is a horizontal plane.

<1 embodiment>
<1.1 Configuration of Image Recording Apparatus 1>
FIG. 1 is a diagram illustrating a configuration of an image recording apparatus 1 according to the embodiment.

  The image recording apparatus 1 discharges ink from the plurality of head units 21 to 24 to the base material 9 (for example, printing paper) while transporting the base material 9 which is a belt-like base material, whereby An inkjet printing apparatus for recording an image. As shown in FIG. 1, the image recording apparatus 1 includes a conveyance unit 10, an image recording unit 20, a thickening light irradiation unit 30, a fixing light irradiation unit 40, and a control unit 50.

  The transport unit 10 is a mechanism that transports the base material 9 in the longitudinal direction along the transport path. The conveyance unit 10 includes an unwinding unit 11, a plurality of conveyance rollers 12, and a winding unit 13. The plurality of transport rollers 12 include a first switching roller 61, a second switching roller 62, and a nip roller 63 which will be described later. The base material 9 is unwound from the unwinding unit 11 and is transported along a transport path constituted by a plurality of transport rollers 12. Each transport roller 12 guides the base material 9 to the downstream side of the transport path by rotating about the horizontal axis (Y axis). In addition, the substrate 9 after the conveyance is collected to the winding unit 13.

  As shown in FIG. 1, the base material 9 moves substantially horizontally below the image recording unit 20 along the arrangement direction of the plurality of head units 21 to 24. At this time, the surface of the base material 9 (that is, the surface of the printing paper) is directed to the head units 21 to 24 located above. The transport unit 10 includes a first switching roller 61, a second switching roller 62, and a nip roller 63 on the downstream side of the transport path from the image recording unit 20.

  The nip roller 63 is actively rotated at a constant speed while being in contact with both surfaces of the substrate 9 and sandwiching the substrate 9. When the substrate 9 is conveyed, the control unit 50 adjusts the rotation speed of the unwinding unit 11 with respect to the rotation speed of the nip roller 63. Thereby, tension is given to the substrate 9. As a result, slack and wrinkles of the base material 9 during conveyance are suppressed.

  The image recording unit 20 is a mechanism that ejects ink whose curing is accelerated by irradiating the surface of the substrate 9 conveyed by the conveying unit 10 with light in a specific wavelength region. In this embodiment, an ultraviolet curable ink that is cured by being irradiated with ultraviolet rays is used as such an ink. For example, the image recording unit 20 includes four head units 21 to 24. Each head unit 21 to 24 applies droplets of ultraviolet curable ink of each color of C (Cyan), M (Magenta), Y (Yellow), and K (Black), which are color components of a color image, to the surface of the substrate 9. To discharge each. Each head unit 21 to 24 is fixedly arranged with respect to the frame of the image recording apparatus 1.

  FIG. 2 is a bottom view of the head unit 24 and the thickening light irradiation unit 30. As shown in FIG. 2, the head unit 24 of this embodiment has two recording heads 201. Further, as shown in an enlarged manner in FIG. 2, a plurality of nozzles 202 are regularly arranged on the lower surface of the recording head 201. Similarly, the other three head units 21 to 23 have two recording heads 201 each having a plurality of nozzles 202. At the time of printing, droplets of ultraviolet curable ink of each color are ejected from the plurality of nozzles 202 of each head unit 21 to 24 toward the surface of the substrate 9. As a result, a color image is recorded on the surface of the substrate 9.

  The thickening light irradiation unit 30 is a mechanism that irradiates the substrate 9 with the first irradiation light on the downstream side of the conveyance path from the image recording unit 20. As shown in FIG. 2, a plurality of LED (Light Emitting Diode) light sources 31 are regularly arranged on the lower surface of the thickening light irradiation unit 30. In the example of FIG. 2, a plurality of LED light source 31 columns extending in the Y-axis direction (horizontal direction orthogonal to the conveyance path) are arranged in two rows at intervals along the conveyance path. There may be a mode in which only one row of the plurality of LED light sources 31 extending in the direction is arranged.

  The 1st irradiation light irradiated from each LED light source 31 contains the ultraviolet-ray which is the light of a specific wavelength range. For this reason, when 1st irradiation light is irradiated to the ink on the base material 9, the viscosity of an ink will increase. However, the amount of the first irradiation light irradiated from the thickening light irradiation unit 30 is smaller than the amount of the second irradiation light irradiated from the fixing light irradiation unit 40. For this reason, the ink on the substrate 9 is not completely cured. That is, by the first irradiation light, the inks of the respective colors on the base material 9 are in a semi-cured state with reduced fluidity.

  When the ink is semi-cured, spreading of the ink on the substrate 9 is suppressed. Therefore, in the transport path downstream from the thickening light irradiating unit 30, the print quality is less likely to deteriorate due to ink spreading.

  In the present embodiment, among the plurality of head units 21 to 24 of the image recording unit 20, the head unit 24 that discharges black ink is disposed on the most downstream side of the transport path. Then, immediately after the black ink is ejected from the head unit 24, the first irradiation light is irradiated from the thickening light irradiation unit 30. For this reason, on the surface of the base material 9, it is possible to effectively suppress the spread of black ink that has a particularly large influence on the print quality.

  In the present embodiment, the thickening light irradiation unit 30 is disposed close to the head unit 24. However, since the light amount of the first irradiation light emitted from the thickening light irradiation unit 30 is small, the head Even if the first irradiation light leaks to the unit 24 side, the head unit 24 is hardly affected. Therefore, problems such as the ink in the head unit 24 being cured by the leakage light from the thickening light irradiation unit 30 and the nozzle 202 being clogged are unlikely to occur. In particular, in this embodiment, the LED light source 31 is used as the light source of the thickening light irradiation unit 30. The LED light source 31 has a narrower wavelength band of irradiation light and less heat generation due to light irradiation than the metal halide lamp 42 used in the fixing light irradiation unit 40. For this reason, the influence with respect to the head unit 24 which adjoins can be suppressed more.

  As described above, the thickening light irradiation unit 30 can be disposed close to the head unit 24. For this reason, it is possible to suppress an increase in the footprint (device floor area) of the image recording apparatus 1 due to the mounting of the thickening light irradiation unit 30.

  A first switching roller 61 as a first switching unit is disposed between the thickening light irradiation unit 30 and the fixing light irradiation unit 40. The first switching roller 61 rotates while contacting the back surface of the substrate 9. Thereby, the conveyance direction of the base material 9 is changed from the + X direction to the −Z direction.

  Here, in the 1st switching roller 61, when the direction of conveyance of the base material 9 is changed, the base material 9 curves greatly. For this reason, if the ink adhering to the base material 9 remains uncured, the print quality may be deteriorated due to spreading of the ink. However, in the image recording apparatus 1 according to the present embodiment, the ink on the base material 9 is in a semi-cured state when it passes through the first switching roller 61. Thereby, the spreading of ink in the first switching roller 61 is suppressed.

  Further, the first switching roller 61 of the present embodiment is in contact with the back surface of the base material 9 instead of the front surface of the base material 9. For this reason, the surface of the first switching roller 61 does not contact the semi-cured ink. Therefore, a decrease in print quality at the first switching roller 61 is further suppressed.

  FIG. 3 is an XZ side view schematically showing the fixing light irradiation unit 40 and the substrate 9. FIG. 4 is a conceptual diagram showing the positional relationship between the irradiation region 70 and the purge region 71 on the surface of the substrate 9. In FIG. 3, seven light beams are represented by dotted arrows among the many light beams (second irradiation light) irradiated by the fixing light irradiation unit 40.

  The fixing light irradiation unit 40 functions as an ink curing unit (also referred to as an ink curing device) that irradiates the surface of the substrate 9 conveyed by the conveyance unit 10 with the second irradiation light while supplying an inert gas. . The fixing light irradiating unit 40 includes a housing 41 located on the downstream side of the conveyance path from the image recording unit 20, a metal halide lamp 42 provided in the housing 41, a reflector 43, and a housing 41. A gas supply unit 44 for supplying an inert gas (for example, nitrogen).

  The housing 41 has a first opening 413 provided in the first part 411 facing the conveyance path, and a second opening 414 provided in a second part 412 different from the first part 411.

  The region where the first opening 413 is formed is a region whose longitudinal direction is the direction intersecting the transport direction, and specifically, a slit-shaped region whose longitudinal direction is the Y-axis direction orthogonal to the transport direction. . In addition, the length of the region is smaller than the length of the casing 41 in the direction along the conveyance path (Z-axis direction) between the casing 41 and the base material 9. Therefore, when the gas supply unit 44 supplies an inert gas from the second opening 414 to the inside of the housing 41, the inert gas passes through the inside of the housing 41 having a relatively large inner diameter at a low speed, In particular, the first opening 413 having a narrow inner diameter is supplied toward the surface of the substrate 9 at a high speed.

  As described above, in this embodiment, the inert gas is supplied at a flow rate faster than the aspect in which the inert gas is supplied into the cover that covers the periphery of the substrate (for example, the aspects described in Patent Document 2 and Patent Document 3). The purge action by the inert gas can be sufficiently performed in the atmosphere corresponding to the boundary layer of the base material 9 that can be supplied to the base material 9 while suppressing the supply amount of the inert gas. As a result, a purge region 71 in which the ambient atmosphere around the surface 9 is purged by the inert gas supplied from the gas supply unit 44 is formed on the surface of the base material 9.

  In FIG. 3, among the atmospheres around the surface of the base material 9, the atmosphere AT1 containing a large amount of oxygen is shown by shading, and the atmosphere AT2 purged with an inert gas and containing little oxygen is shown by a white background. As shown in FIG. 3, an atmosphere AT1 containing a large amount of oxygen is formed in the region on the ± Z side of the purge region 71, and an atmosphere AT2 containing little oxygen is formed in the purge region 71.

  The metal halide lamp 42 is a tubular light source that extends in the Y-axis direction of the substrate 9. The reflector 43 is a parallel light type reflector that is provided so that its reflection surface covers the + X side of the metal halide lamp 42. For this reason, the second irradiation light emitted from the metal halide lamp 42 is directly or indirectly reflected toward the first portion 411 by being reflected by the reflector 43. Further, at least a part of the first portion 411 is made of a material (for example, glass) that transmits light in a specific wavelength range. For this reason, the 2nd irradiation light radiate | emitted from the metal halide lamp 42 permeate | transmits the 1st site | part 411, and is irradiated to the irradiation area | region 70 among the surfaces of the base material 9 conveyed.

  The 2nd irradiation light irradiated from the metal halide lamp 42 contains the ultraviolet-ray which is light of a specific wavelength range. Further, the second irradiation light emitted from the metal halide lamp 42 has a sufficient amount of light to completely cure the ink. For this reason, when the second irradiation light is applied to the ink on the substrate 9, the ink is cured and the ink is fixed on the surface of the substrate 9.

  As shown in FIGS. 3 and 4, the virtual axis 90 in the first opening 413 passes through the irradiation region 70 with the first portion 411 of the housing 41 facing the surface of the base material 9. Here, the virtual axis 90 refers to the center position of the region of the first opening 413 formed on the inner surface of the housing 41 and the center position of the region of the first opening 413 formed on the outer surface of the housing 41. It is a virtually connected straight line. Further, as shown in FIG. 4, there is an overlapping region between the irradiation region 70 and the purge region 71. As described above, since the purge action by the inert gas sufficiently works in the purge area 71, in this overlapping area, the ink is efficiently inhibited while inhibiting the inhibition of ink curing due to the presence of a large amount of oxygen in the atmosphere. Curing can be accelerated.

  As shown in FIG. 3, the first opening 413 is formed inside a transmission region through which the second irradiation light (light in a specific wavelength region) is transmitted in the first portion 411. Since the inert gas is supplied toward the surface of the base material 9 from the first opening 413, in this aspect, an overlapping region between the irradiation region 70 and the purge region 71 can be formed more reliably.

  The inert gas supplied to the surface of the base material 9 along the virtual axis 90 is pulled downstream (−Z side) along the transport path due to the viscosity of the transported base material 9. For this reason, as shown in FIGS. 3 and 4, in a mode in which the virtual axis 90 passes through the upstream (+ Z side) portion of the irradiation region 70 with respect to the space between the casing 41 and the base material 9 in the transport path. The overlapping region of the irradiation region 70 and the purge region 71 can be formed over a wide range in the Z-axis direction. As a result, ink curing can be efficiently promoted while inhibiting inhibition of ink curing over a wide range in the Z-axis direction.

  In addition, the fixing light irradiation unit 40 includes two plate-like members 45 provided on the upper and lower sides of the casing 41 so as to be flush with the first portion 411 of the casing 41 on the −X side. For this reason, in the aspect of this embodiment, compared with the case where the + X side of the base material 9 is opened, the atmosphere around the surface of the base material 9 is easily maintained, and the purge region 71 is maintained in a wide range.

  The fixing light irradiation unit 40 irradiates the second irradiation light toward the base material 9 conveyed in the −Z direction between the first switching roller 61 and the second switching roller 62. If the direction of conveyance of the substrate 9 is not changed between the image recording unit 20 and the fixing light irradiation unit 40, a part of the second irradiation light irradiated from the fixing light irradiation unit 40 is This tends to affect the image recording unit 20. In this case, it is necessary to dispose the fixing light irradiation unit 40 far away from the image recording unit 20. However, in this image recording apparatus 1, the transport direction of the base material 9 is switched from the + X direction to the −Z direction between the image recording unit 20 and the fixing light irradiation unit 40. For this reason, leakage light from the fixing light irradiation unit 40 does not easily reach the image recording unit 20. Therefore, problems such as the ink in each of the head units 21 to 24 being cured and the nozzle 202 being clogged can be suppressed. In this way, it is not necessary to largely separate the fixing light irradiation unit 40 from the image recording unit 20, and the footprint of the image recording apparatus 1 can be reduced.

  In particular, in the image recording apparatus 1, the base material 9 is transported so as to cross an imaginary line segment connecting the head unit 24 arranged on the most downstream side and the fixing light irradiation unit 40. More specifically, the base material is arranged so as to cross a line segment connecting an arbitrary point on the lower surface which is the ejection surface of the head unit 24 and an arbitrary point on the metal halide lamp 42 or the reflector 43 of the fixing light irradiation unit 40. 9 is conveyed. For this reason, the second irradiation light emitted from the metal halide lamp 42 or the second irradiation light reflected by the reflector 43 is blocked by the base material 9 and does not reach any of the head units 21 to 24. Therefore, unnecessary curing of ink in the head units 21 to 24 can be suppressed.

  A second switching roller 62 as a second switching unit is disposed downstream of the fixing light irradiation unit 40 in the conveyance path. The second switching roller 62 rotates while contacting the surface of the substrate 9. Thereby, the conveyance direction of the base material 9 is changed so as to approach the + X direction. The base material 9 that has passed through the second switching roller 62 is collected by the winding unit 13 through the nip roller 63 and the plurality of transport rollers 12.

  The control unit 50 is means for controlling the operation of each unit in the image recording apparatus 1. The control unit 50 of the present embodiment is configured by a computer having an arithmetic processing unit 51 such as a CPU, a memory 52 such as a RAM, and a storage unit 53 such as a hard disk drive. As indicated by a broken line in FIG. 1, the control unit 50 includes the unwinding unit 11, the winding unit 13, the four head units 21 to 24, the thickening light irradiation unit 30, and the fixing light irradiation unit 40. And the nip roller 63 are electrically connected to each other. The control unit 50 temporarily reads the computer program P stored in the storage unit 53 into the memory 52, and the arithmetic processing unit 51 performs arithmetic processing based on the computer program P, thereby controlling the operation of each unit described above. To do. Thereby, the printing process in the image recording apparatus 1 proceeds.

  The control unit 50 is electrically connected to the server 2 installed outside the image recording apparatus 1. The server 2 stores image data D to be printed. During the printing process, the substrate 9 is transported by the transport unit 10, and the control unit 50 reads the designated image data D from the server 2, and based on the image data D, the respective colors from the head units 21 to 24. Of ink. As a result, an image corresponding to the image data D is recorded on the surface of the substrate 9.

<1.2 About print processing>
Next, the printing process in the image recording apparatus 1 will be described. When printing processing is performed in the image recording apparatus 1, the base material 9 is continuously conveyed from the unwinding unit 11 toward the winding unit 13. Then, various processes such as ink ejection and light irradiation are sequentially performed on each part of the base material 9 in the longitudinal direction. FIG. 5 is a flowchart showing a flow of processing sequentially received by a part (hereinafter referred to as “target part”) when paying attention to a part of the base material 9 in the longitudinal direction.

  First, the target portion of the base material 9 is unwound from the unwinding unit 11 and is conveyed below the image recording unit 20 while being guided by the plurality of conveying rollers 12 (step S1). When the target portion reaches below the image recording unit 20, the image recording unit 20 ejects ink droplets of each color from the plurality of nozzles 202 of the head units 21 to 24 toward the surface of the target portion ( Step S2). As a result, a color image is formed on the surface of the target portion. As described above, the ink ejected in step S2 is an ultraviolet curable ink.

  When the target portion of the base material 9 passes through the image recording unit 20, the thickening light irradiation unit 30 then irradiates the first irradiation light toward the surface of the target portion (step S3). Here, the target portion of the base material 9 passes below the plurality of LED light sources 31 that are continuously lit. Thereby, the viscosity of the ink adhering to the surface of the target portion increases, and the ink is in a semi-cured state.

  Subsequently, the target portion of the base material 9 passes through the first switching roller 61. As a result, the conveyance direction of the target portion is changed from the + X direction to the −Z direction (step S4). At this time, the target portion of the base material 9 is curved, but since the ink attached to the target portion is in a semi-cured state, the print quality is hardly deteriorated due to spreading of the ink.

  Next, the fixing light irradiation unit 40 irradiates the second irradiation light while supplying an inert gas toward the surface of the target portion (step S5). Here, the target portion of the base material 9 passes through the front of the metal halide lamp 42 that is continuously lit. As a result, the ink attached to the surface of the target portion is cured, and the ink is fixed on the surface.

  Subsequently, the target portion of the base material 9 passes through the second switching roller 62. Thereby, the direction of conveyance of the target portion is changed so as to approach the + Z direction from the −Z direction. At this time, the surface of the target portion comes into contact with the surface of the second switching roller 62. However, since the ink attached to the target portion is completely cured, printing by contact with the second switching roller 62 is performed. Degradation is unlikely to occur. Thereafter, the target portion of the base material 9 is conveyed while being guided by the nip roller 63 and the plurality of conveying rollers 12, and is collected to the winding unit 13 (step S6). Thus, the printing process for the target portion of the base material 9 is completed.

<2 Modification>
While the embodiments of the present invention have been described above, the present invention can be modified in various ways other than those described above without departing from the spirit of the present invention.

  FIG. 6 is an XZ side view schematically showing the fixing light irradiation unit 40A and the base material 9 according to a modification. In FIG. 6, seven light beams are represented by dotted arrows as representatives among the many light beams (second irradiation light) irradiated by the fixing light irradiation unit 40 </ b> A.

  As shown in FIG. 6, in the fixing light irradiation unit 40A, the first opening 413A is located outside the housing 41A from the inside of the housing 41A in the first portion 411A with respect to the space between the housing 41A and the base material 9 in the transport path. Inclined toward the upstream side (+ Z side). In other words, in the fixing light irradiation unit 40A, with respect to the space between the housing 41A and the base material 9 in the conveyance path, the virtual axis 90A is upstream from the inside of the housing 41A to the outside of the first portion 411A (+ Z side) ). For this reason, the inert gas supplied to the surface of the base material 9 along the virtual axis 90 </ b> A collides with the boundary layer (layer containing a lot of oxygen) of the base material 9, and around the surface of the base material 9. The atmosphere can be efficiently purged with an inert gas. The first opening may be inclined with respect to the base material 9 in addition to the case where the first opening is perpendicular to the base material 9 as in the above embodiment.

  FIG. 7 is an XZ side view schematically showing the fixing light irradiation unit 40B and the base material 9 according to a modification. In FIG. 7, seven light rays are represented by dotted arrows as a representative of a number of light rays (second irradiation light) irradiated by the fixing light irradiation unit 40B.

  As shown in FIG. 7, in the fixing light irradiation unit 40B, the first opening 413B is formed outside the transmission region of the first portion 411B through which the second irradiation light is transmitted. For this reason, when the second irradiation light passes through the transmission region of the first part 411B, the optical path is disturbed due to the presence of the first opening 413B (for example, the location where the first opening is provided and the first opening are The optical path is not disturbed due to the difference in refractive index between the portions not provided. Moreover, the inert gas supplied to the surface of the base material 9 along the virtual axis 90 </ b> B is pulled downstream (−Z side) along the transport path due to the viscosity of the transported base material 9. For this reason, as shown in FIG. 7, in the aspect in which the virtual axis 90B passes the upstream (+ Z side) portion of the irradiation region, even if the first opening 413B is formed outside the transmission region, the irradiation is performed. An overlapping region between the region and the purge region can be formed. In addition to the case where the first opening is provided in the transmission region of the first part as in the above embodiment, the first opening may be provided outside the transmission region of the first part as in the modification.

  FIG. 8 is a conceptual diagram showing the positional relationship between the irradiation region 70 and the purge region 71C on the surface of the base material 9 in a modified example.

  As shown in FIG. 8, a plurality of circular first openings 413C are provided at equal intervals in the Y-axis direction in the first part of the housing according to this modification. Also in this modified example, as in the above-described embodiment, the region where the plurality of first openings 413C are formed is a region whose longitudinal direction is a direction intersecting the transport direction (specifically, the Y-axis direction). Accordingly, the inert gas is supplied toward the surface of the base material 9 that is transported from the regions of the plurality of first openings 413C that intersect the transport path, so that the atmosphere around the surface is purged with the inert gas. A purge region 71C is formed on the surface. The number of first openings may be one as in the above embodiment, or may be plural as in this modification. Further, the shape of the first opening may be a slit shape as in the above embodiment, may be a circular shape as in the present modification, or may be another shape. Also, the number and shape of the second openings can be changed.

  Moreover, although the image recording apparatus 1 demonstrated the aspect which inkjet-prints on the printing paper as the base material 9 in the said embodiment, it is not restricted to this. For example, as the base material 9, a belt-like body (for example, a resin film or the like) other than general paper may be used. Also, the printing method is not limited to inkjet printing, and offset printing or the like may be used.

  Moreover, although the said embodiment demonstrated the aspect in which a series of base material 9 was conveyed along the conveyance path | route extended in the longitudinal direction, the aspect by which the several base material 9 is conveyed along a conveyance path | route sequentially. It doesn't matter.

  Moreover, although the said embodiment demonstrated the aspect which the light of a specific wavelength range is an ultraviolet-ray, the light (for example, visible light) other than an ultraviolet-ray may be sufficient as the light of a specific wavelength range. In this case, instead of the metal halide lamp 42, a light source that emits light in a specific wavelength region is used.

  Moreover, although the said embodiment demonstrated the aspect in which the reflector 43 was a parallel light type reflecting plate, the reflector 43 may be a condensing type reflecting plate.

  Moreover, although the said 1st site | part 411 demonstrated the aspect comprised that the light of a specific wavelength range permeate | transmits in the said embodiment, what is necessary is just for at least one part of the 1st site | part 411 to transmit the light of a specific wavelength range. .

  Moreover, in the said embodiment, although the area | region in which the 1st opening 413 was formed was an area | region which makes a Y-axis direction a longitudinal direction, it is not restricted to this. The region in which the first opening is formed is another mode in which the direction intersecting the transport path is the longitudinal direction (for example, the mode including both the Y-axis direction and the Z-axis direction is the longitudinal direction). May be.

  Moreover, in the said embodiment, the image recording part 20 had the four head units 21-24. However, the number of head units included in the image recording unit 20 may be 1 to 3, or 5 or more. For example, in addition to C, M, Y, and K colors, a head unit that discharges special color inks may be provided.

  The image recording apparatus and the ink curing apparatus according to the embodiment and the modifications thereof have been described above. However, these are examples of the preferred embodiment of the present invention, and do not limit the scope of the present invention. Within the scope of the invention, the present invention can be freely combined with each embodiment, modified with any component in each embodiment, or increased or decreased with any component in each embodiment.

DESCRIPTION OF SYMBOLS 1 Image recording apparatus 2 Server 9 Base material 10 Conveyance part 20 Image recording part 21-24 Head unit 30 Light irradiation part for thickening 31 LED light source 40, 40A, 40B Light irradiation part for fixing 41, 41A, 41B Case 42 Metal halide Lamp 43 Reflector 44 Gas supply unit 50 Control unit 70 Irradiation region 71, 71C Purge region 90, 90A-90C Virtual axis 411, 411A, 411B First part 412 Second part 413, 413A-413C First opening 414 Second opening AT1 , AT2 atmosphere

Claims (10)

A transport unit for transporting the substrate along the transport path;
An image recording unit that applies ink whose curing is accelerated by irradiating light of a specific wavelength range on the surface of the base material transported by the transport unit;
An ink curing unit that irradiates light of the specific wavelength range while supplying an inert gas to the surface of the base material transported by the transport unit;
With
The ink curing unit is
At least one first opening provided in a first part that is located downstream of the image recording unit and opposed to the conveyance path, and provided in a second part that is different from the first part. A housing having at least one second opening;
A light source that is provided inside the housing and irradiates light in the specific wavelength region toward the first part;
A gas supply unit for supplying an inert gas into the housing from the at least one second opening;
Have
The image recording apparatus, wherein at least a part of the first part transmits light in the specific wavelength range. The image recording apparatus according to claim 1,
When the first part of the housing faces the surface of the base material, an irradiation region of the surface irradiated with light of the specific wavelength region by the light source, and an ambient atmosphere of the surface An image recording apparatus in which there is an overlapping area with a purge area purged by the inert gas supplied from the gas supply unit. The image recording apparatus according to claim 1,
When the first part of the housing faces the surface of the base material, at least one virtual axis in the at least one first opening is in the specific wavelength range by the light source of the surface. An image recording apparatus that passes through an irradiation area irradiated with light. The image recording apparatus according to claim 3,
The image recording apparatus, wherein the at least one virtual axis passes through an upstream portion of the irradiation region with respect to the conveyance path between the casing and the base material. An image recording apparatus according to any one of claims 1 to 4, wherein
The image recording apparatus, wherein the at least one first opening is formed outside a transmission region through which light in the specific wavelength region is transmitted in the first portion. An image recording apparatus according to any one of claims 1 to 4, wherein
The image recording apparatus, wherein the at least one first opening is formed in a transmission region through which light in the specific wavelength region is transmitted in the first portion. An image recording apparatus according to any one of claims 1 to 6, wherein
The at least one first opening is inclined toward the upstream side from the inside of the housing to the outside of the first portion with respect to the space between the housing and the base material in the transport path. apparatus. An image recording apparatus according to any one of claims 1 to 7,
The region in which the at least one first opening is formed is a region having a longitudinal direction in a direction intersecting the transport path,
The image recording apparatus, wherein a length of the region is smaller than a length of the casing in a direction along the conveyance path between the casing and the base material. An image recording apparatus according to any one of claims 1 to 8, wherein
The image recording apparatus, wherein the light in the specific wavelength region is ultraviolet light. The substrate is supplied with an inert gas to the surface of the substrate when the substrate to which ink that is accelerated by being irradiated with light in a specific wavelength region is applied is conveyed along the conveyance path. An ink curing device that irradiates light in a wavelength range,
A housing having at least one first opening provided in a first part facing the transport path and at least one second opening provided in a second part different from the first part;
A light source that is provided inside the housing and irradiates light in the specific wavelength region toward the first part;
A gas supply unit for supplying an inert gas into the housing from the at least one second opening;
With
An ink curing device, wherein at least a part of the first part transmits light in the specific wavelength region.

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