Drying device for inkjet printing, recording system, recording device, and printing method

Abstract

A drying device for inkjet printing, wherein an irradiation unit that emits ultraviolet light faces a path along which a recording medium is conveyed and is positioned on a path leading from a first blowing unit for blowing warm air to a first suction unit for suctioning gas.

Description

Drying device for inkjet printing, recording system, recording device, and printing method

[0001] The present disclosure relates to a drying device that dries ink that has been deposited on a recording medium by inkjet printing, a recording system and recording device that include the drying device, and a printing method that uses the drying device.

[0002] In inkjet printing, in which printing is performed by propelling ink toward a recording medium (e.g., paper), various techniques have been proposed for drying ink that has landed on the recording medium (for example, see Patent Document 1 below). In Patent Document 1, a drying device and a melting device are arranged in sequence along a path along which the recording medium is transported. The drying device promotes evaporation of the ink medium by heating the recording medium. The melting device irradiates the ink with ultraviolet light (hereinafter sometimes abbreviated as "UV"), thereby raising the temperature of the polymer in the ink and melting the polymer. The polymer then solidifies and adheres to the recording medium. Patent Document 1 discloses an example of a drying device that blows warm air.

[0003] International Publication No. 2022 / 004486

[0004] A drying device for inkjet printing according to one aspect of the present disclosure includes a first irradiation unit for emitting ultraviolet rays to a recording medium, a first blower for blowing warm air, and a first suction unit for sucking gas, wherein the first irradiation unit is disposed between the first blower and the first suction unit.

[0005] A recording system according to one aspect of the present disclosure includes the drying device for inkjet printing described above and a head that ejects ink onto the recording medium.

[0006] A recording apparatus according to an aspect of the present disclosure includes the recording system described above and a transport unit configured to transport the recording medium along a path in a transport direction, wherein the head is disposed on the path upstream of the drying device in the transport direction and facing the path.

[0007] A printing method according to one aspect of the present disclosure is a printing method using the drying device for inkjet printing described above, and includes a step of adhering ink that contains an ultraviolet absorber and does not polymerize when exposed to ultraviolet light to the recording medium at a position upstream of the first air blowing section in the transport direction of the recording medium.

[0008] 1. A schematic perspective view of a recording apparatus according to a first embodiment. A schematic cross-sectional view taken along line II-II in FIG. 1. A schematic cross-sectional view of a recording apparatus according to a second embodiment. A schematic cross-sectional view of a recording apparatus according to a third embodiment. A schematic cross-sectional view of a recording apparatus according to a fourth embodiment. A schematic cross-sectional view of a recording apparatus according to a fifth embodiment. A schematic cross-sectional view of a recording apparatus according to a sixth embodiment.

[0009] For aspects that are described relatively later among the multiple aspects, only differences from the previously described aspects will be described. Matters not specifically mentioned may be considered to be the same as or inferred from the previously described aspects. Furthermore, for the sake of convenience, the same reference numerals may be used to refer to corresponding configurations in multiple aspects, even if there are differences.

[0010] The drawings used in the following description are schematic. Therefore, for example, certain shapes and / or dimensions may be exaggerated or details may be omitted. Furthermore, the dimensional proportions of the same components in the drawings do not necessarily match. However, this does not deny that shape and / or dimensional features may be extracted from the drawings.

[0011] For convenience, the drawings are illustrated with a Cartesian coordinate system D1D2D3, and terms such as D1 direction, D2 direction, and D3 direction are used. The recording device according to the embodiment may be used in any orientation. However, for convenience, terms that assume the +D3 side is upward are used.

[0012] Unless a contradiction arises, the term "D1 direction" may be replaced with terms such as "the transport direction of the recording medium" and "the direction along the path along which the recording medium is transported." The positive direction of the "D1 direction" is the direction toward the upstream side of the "transport direction of the recording medium," and may be referred to as the "first direction" in relation to the first to fifth embodiments (FIGS. 1 to 6). The negative direction of the "D1 direction" is the direction toward the downstream side of the "transport direction of the recording medium." The term "D2 direction" may be replaced with terms such as "a direction intersecting (e.g., perpendicular to) the path and along the surface of the path (the surface of the recording medium)" and "the width direction of the path." The term "D3 direction" may be replaced with terms such as "a direction intersecting (e.g., normal direction) to the surface of the path (recording medium)."

[0013] 1 is a schematic perspective view of a printer 1 (an example of a recording device) according to a first embodiment. The printer 1 is configured as an inkjet printer that performs color printing on a medium 101 (an example of a recording medium) such as paper. The medium 101 is transported generally from the +D1 side to the -D1 side.

[0014] Figure 2 is a schematic cross-sectional view taken along line II-II in Figure 1. The cross-section shown in Figure 2 spans the entire width of the medium 101 in the direction D2, for example. The printer 1 has the following components, for example, along the path 103 along which the medium 101 is transported. At least one head 3 (four in the illustrated example): Ejects ink toward the medium 101 (more specifically, its upper surface). First air blowing unit 5A: Blows warm air. First irradiation unit 7A: Irradiates UV light onto the medium 101 (more specifically, its upper surface, or the surface on which the ejected ink lands). First suction unit 9A: Suctions gas.

[0015] For convenience in explaining an embodiment having multiple blowers (see, for example, FIG. 6 ), the multiple blowers may be referred to as "first blower 5A" and "second blower 5B" to distinguish them from one another, or may be referred to without distinction as "blower 5." Even in an embodiment having a single blower, the blower may be referred to as "first blower 5A" to simply show the correspondence with other embodiments. The same applies to the suction unit and the irradiation unit.

[0016] The first air blowing unit 5A, the first irradiation unit 7A, and the first suction unit 9A are located, for example, downstream of the head 3 in the transport direction of the medium 101. The first irradiation unit 7A is located between the first air blowing unit 5A and the first suction unit 9A. Either the first air blowing unit 5A or the first suction unit 9A may be located relatively upstream, and in the example of FIG. 2, the first air blowing unit 5A is located upstream.

[0017] The ink temperature rises and the ink dries when UV light is irradiated onto the ink by the first irradiation unit 7A. Heating the ink with UV light can raise the ink temperature more quickly than heating with hot air, for example.

[0018] When the ink dries, the medium (e.g., water) contained in the ink evaporates. This increases the humidity in the space between the first irradiation unit 7A and the medium 101. The moisture in the space can be removed by sucking the gas using the first suction unit 9A. As a result, for example, the likelihood of the evaporated medium condensing at the first irradiation unit 7A is reduced, and ultimately the likelihood of the condensed medium reattaching to the medium 101 is reduced. This allows for stable printing with high image quality. Furthermore, for example, the evaporation rate of the medium increases as the humidity of the surrounding atmosphere decreases, so the evaporation rate of the medium can be increased.

[0019] The temperature of the gas surrounding the medium 101 rises as heat from the ink heated by UV is transferred to the gas. This temperature rise is beneficial to the evaporation of the medium. However, when gas is sucked from around the medium 101, the effect of the UV-induced temperature rise of the gas is reduced. The supply of warm air by the first air blowing unit 5A compensates for at least a portion of the reduction in the effect of the temperature rise. Because warm air is supplied to the first irradiation unit 7A on the side opposite the first suction unit 9A, the suction by the first suction unit 9A makes it easier for the warm air to enter between the first irradiation unit 7A and the medium 101, improving the compensation effect provided by the warm air.

[0020] In this way, in the printer 1, by adopting a configuration in which warm air is supplied either upstream or downstream of the irradiation area where UV irradiation is performed, and gas is sucked in either upstream or downstream of the irradiation area, for example, drying by UV can be made more efficient. As a result, for example, the distance along the path 103 required for drying the ink can be shortened, thereby making it possible to reduce the size of the printer 1. From another perspective, the time required for drying the ink can be shortened, and the transport speed of the media 101 (in other words, the printing speed) can be increased.

[0021] The above is an overview of the printer 1 according to the embodiment. The following will be described in the following general order. First, first to sixth embodiments will be described, in which the arrangement of the air blowing section and suction section differs from one another. Then, the configuration of each section will be described in detail. 1. Variations in the arrangement of the air blowing section and suction section 1.1. First embodiment (FIG. 2) 1.2. Second embodiment (FIG. 3) 1.3. Third embodiment (FIG. 4) 1.4. Fourth embodiment (FIG. 5) 1.5. Fifth embodiment (FIG. 6) 1.6. Sixth embodiment (FIG. 7) 1.7. Other examples 2. Printer in general 3. Ink 4. Drying device 4.1. Drying device in general 4.2. Irradiation section 4.3. Air blowing system including air blowing section 4.3.1. Variations in the air blowing system 4.3.2. Configuration of each section of the air blowing system 4.3.3. Utilization of exhaust heat from the irradiation section 4.4. Suction system including suction section 4.5. Storage box 4.6. Positional relationship with head 4.7. Specific examples of wind direction and volume 4.8. Various conditions 5. Summary of embodiments

[0022] (1. Variations in the arrangement of the air blowing unit and suction unit) (1.1. First embodiment) As already described, the printer 1 according to the first embodiment shown in FIG. 2 has a first air blowing unit 5A located upstream of the path 103 from the first irradiation unit 7A, and a first suction unit 9A located downstream of the path 103 from the first irradiation unit 7A. More specifically, the first air blowing unit 5A is located on the upper side of the path 103 and blows warm air toward the path 103. The first suction unit 9A is located on the upper side of the path 103 and sucks gas from the path 103 side. As a result, for example, a flow of warm air from upstream to downstream of the path 103 is generated between the first irradiation unit 7A and the medium 101 (path 103).

[0023] 1.2. Second Embodiment FIG. 3 is a schematic cross-sectional view of a printer 201 according to a second embodiment, corresponding to FIG. 2. The printer 201, in short, is configured by adding a second air blowing unit 5B to the printer 1 according to the first embodiment. The second air blowing unit 5B is located, for example, downstream of the path 103 from the first suction unit 9A and on the upper surface side of the path 103, and blows warm air toward the path 103. As a result, compared to the first embodiment, a flow from the second air blowing unit 5B toward the first suction unit 9A on the upper surface side of the medium 101 (a flow from downstream to upstream of the path 103) is added.

[0024] (1.3. Third embodiment) Fig. 4 is a schematic cross-sectional view of a printer 301 according to a third embodiment, and corresponds to Fig. 2. In short, the configuration of the printer 301 is similar to that of the printer 201 according to the second embodiment, except that a second suction unit 9B, a third air blowing unit 5C, and a fourth air blowing unit 5D are added.

[0025] The second suction unit 9B is located, for example, downstream of the path 103 from the second blower 5B and on the upper surface side of the path 103, and sucks gas from the path 103 side. As a result, for example, compared to the second embodiment, a flow from the second blower 5B toward the second suction unit 9B on the upper surface side of the medium 101 (a flow from upstream to downstream on the path 103) is added.

[0026] The third and fourth blower units 5C and 5D are located on the underside of the path 103 and blow warm air toward the path 103. This heats the medium 101 from below. Furthermore, depending on the configuration of the transport unit 13 (described later), vertical gas flow is permitted on the sides of the medium 101 (on both sides in the direction D2). Therefore, the third and fourth blower units 5C and 5D can cooperate with at least one suction unit 9 to achieve the functions described in the overview of the embodiment.

[0027] More specifically, the third air blowing unit 5C faces at least one of the first air blowing unit 5A and the first irradiation unit 7A (only the former in this embodiment) across the path 103. As a result, for example, compared to the second embodiment, a flow from the third air blowing unit 5C toward the first suction unit 9A (a flow from upstream to downstream on the path 103) is added. This flow, for example, extends from the bottom side of the medium 101, passing along the side of the medium 101, to the top side of the medium 101.

[0028] The fourth blower 5D faces the second blower 5B across the path 103. As a result, for example, compared to the second embodiment, a flow from the fourth blower 5D toward the first suction unit 9A (a flow from downstream to upstream on the path 103) and a flow from the fourth blower 5D toward the second suction unit 9B (a flow from upstream to downstream on the path 103) are added. This flow, for example, runs from the bottom side of the medium 101, passes along the side of the medium 101, and reaches the top side of the medium 101.

[0029] (1.4. Fourth embodiment) Fig. 5 is a schematic cross-sectional view of a printer 401 according to a fourth embodiment, and corresponds to Fig. 2. In short, the configuration of the printer 401 is the same as that of the printer 301 according to the third embodiment, except that a third suction unit 9C and a fourth suction unit 9D are added.

[0030] The third suction unit 9C and the fourth suction unit 9D are located on the lower surface side of the path 103 and suck gas from the side of the path 103. This makes it possible to control, for example, the flow of hot air on the lower surface side of the medium 101.

[0031] More specifically, the third suction unit 9C faces at least one of the first irradiation unit 7A and the first suction unit 9A (only the latter in this embodiment) across the path 103. From another perspective, the third suction unit 9C is located between the third blower unit 5C and the fourth blower unit 5D. As a result, for example, compared to the third embodiment, a flow from the third blower unit 5C toward the third suction unit 9C and a flow from the fourth blower unit 5D toward the third suction unit 9C are added. From another perspective, the flow of hot air from the third blower unit 5C downstream along the path 103 and the flow of hot air from the fourth blower unit 5D upstream along the path 103 have a larger proportion of the air volume on the lower side of the medium 101 compared to the air volume on the upper and lower sides of the medium 101 in the third embodiment.

[0032] Furthermore, the fourth suction unit 9D faces the second suction unit 9B across the path 103. From another perspective, the fourth suction unit 9D is located downstream of the fourth blower unit 5D on the path 103. As a result, for example, compared to the third embodiment, a flow from the fourth blower unit 5D toward the fourth suction unit 9D is added. From another perspective, the flow of warm air from the fourth blower unit 5D downstream on the path 103 has a larger proportion of the air volume on the lower side of the medium 101 compared to the air volume on the upper and lower sides of the medium 101.

[0033] 1.5. Fifth Embodiment Fig. 6 is a schematic cross-sectional view of a printer 501 according to a fifth embodiment, corresponding to Fig. 2. In short, the configuration of the printer 501 is the same as that of the printer 401 according to the fourth embodiment, except that the position of the third air blowing unit 5C is shifted downstream of the path 103. The third air blowing unit 5C is located, for example, below at least a portion (in the illustrated example, the entirety) of the first air blowing unit 5A and faces the first irradiation unit 7A. As a result, for example, compared to the fourth embodiment, the likelihood that the hot air from the third air blowing unit 5C will reach the head 3 is reduced.

[0034] 1.6. Sixth Embodiment FIG. 7 is a schematic cross-sectional view of a printer 601 according to a sixth embodiment. The printer 601 includes a first suction unit 9A, a first irradiation unit 7A, and a first air blower 5A, arranged in the aforementioned order along the path 103 in the negative direction of the D1 axis (the conveyance direction). The printer 601 may not include the air blower 5, the irradiation unit 7, and the suction unit 9. The printer 601 may include a second suction unit 9B, and the first air blower 5A and the first irradiation unit 7A may be disposed between the first suction unit 9A and the second suction unit 9B. In this case, the printer 601 includes the first suction unit 9A, the first irradiation unit 7A, the first air blower 5A, and the second suction unit 9B, arranged in the aforementioned order along the path 103 in the conveyance direction. The printer 601 may include a second irradiation unit 7B, which may be disposed between the first blower unit 5A and the second suction unit 9B. In this case, the printer 601 includes the first suction unit 9A, the first irradiation unit 7A, the first blower unit 5A, the second irradiation unit 7B, and the second suction unit 9B, which are arranged in the aforementioned order in the conveyance direction along the path 103. The printer 601 may also be configured without including any blower unit 5, irradiation unit 7, or suction unit 9 other than the first blower unit 5A, the first irradiation unit 7A, the second irradiation unit 7B, the first suction unit 9A, and the second suction unit 9B. The drying device 619 of such a printer 601 may have the blower unit 5, irradiation unit 7, and suction unit 9 disposed on only one side (top surface) of the media 101, like the drying device 19 and the drying device 219.

[0035] The configuration of the printer 601 may include a third air blowing unit 5C located on the opposite side of the path 103 from the first air blowing unit 5A. The third air blowing unit 5C may be located between the first irradiation unit 7A and the second suction unit 9B. The third air blowing unit 5C may be located between the first irradiation unit 7A and the second irradiation unit 7B. At least a portion of the first air blowing unit 5A and the third air blowing unit 5C may face each other.

[0036] The printer 601 may include a third suction unit 9C located on the opposite side of the path 103 from the first suction unit 9A. The printer 601 may include a fourth suction unit 9D located on the opposite side of the path 103 from the second suction unit 9B. The third suction unit 9C, the first irradiation unit 7A, the first air blower 5A, and the fourth suction unit 9D may be arranged in the aforementioned order along the path 103. Furthermore, in the printer 601, the third suction unit 9C, the first irradiation unit 7A, the first air blower 5A, the second irradiation unit 7B, and the fourth suction unit 9D may be arranged in the aforementioned order along the path 103. The first suction unit 9A and the third suction unit 9C may at least partially face each other. The second suction unit 9B and the fourth suction unit 9D may at least partially face each other.

[0037] (1.7. Other Examples) Although not particularly shown, other examples regarding variations in the arrangement of the blower unit 5 and the suction unit 9 will be given.

[0038] Any number of blowing units 5 and suction units 9 may be arranged alternately along the path 103. In addition, either the blowing unit 5 or the suction unit 9 may be positioned most downstream.

[0039] For example, in the second embodiment (a configuration in which the blower 5 and suction unit 9 are arranged only on the upper surface side of the path 103), the second suction unit 9B may be arranged downstream of the second blower 5B, as in the third embodiment. Furthermore, any number of blower units 5 and suction units 9 may be arranged alternately downstream of the second suction unit 9B. Naturally, in the third to fifth embodiments, any number of blower units 5 and suction units 9 may be arranged alternately downstream of the second suction unit 9B. In the fourth and fifth embodiments, any number of blower units 5 and suction units 9 may be arranged alternately downstream of the fourth suction unit 9D.

[0040] Furthermore, for example, conversely to the above, in the third to sixth embodiments (configurations in which blower units 5 are arranged on both the upper and lower sides of path 103), the number of alternately arranged blower units 5 and suction units 9 may be reduced. For example, in the third embodiment, the second suction unit 9B may be eliminated, and further, the second blower unit 5B and the fourth blower unit 5D may be eliminated. Furthermore, for example, in the fourth and fifth embodiments, the second suction unit 9B and the fourth suction unit 9D may be eliminated, and further, the second blower unit 5B and the fourth blower unit 5D may be eliminated.

[0041] When blowers 5 are provided on both the upper and lower sides of the path 103, the number of blowers 5 on the upper and lower sides may be the same or different. In the latter case, the number on either side may be relatively greater. From another perspective, the airflow rates of the blowers 5 on the upper and lower sides of the path 103 may be the same or different. The number and airflow rates of the blowers 5 have been described above, but the same applies to the number and suction rate of the suction units 9.

[0042] Although the multiple blower units 5 do not necessarily have the same airflow volume, for convenience, the explanation regarding the number of blower units 5 in the embodiment may be applied to the airflow volume of the blower units 5 (or may not be applied) unless a contradiction arises. The same applies to the number and suction volume of the suction units 9.

[0043] Regarding the difference in the number of blowers on the upper and lower surfaces, examples different from those in the embodiments will be given below. For example, in the third to fifth embodiments, one of the third blower 5C and the fourth blower 5D may be eliminated, or conversely, a blower 5 may be added between and / or downstream of these blowers. Also, for example, in the fourth and fifth embodiments, one of the third suction unit 9C and the fourth suction unit 9D may be eliminated, or conversely, a suction unit 9 may be added between and / or downstream of these blowers.

[0044] In the first to sixth embodiments, the blower 5 on the lower surface side (-D3 side) basically faces the blower 5 on the upper surface side (+D3 side). Also, the suction unit 9 on the lower surface side faces the suction unit 9 on the upper surface side. In other words, components of the same type face each other across the path 103. However, components of different types may face each other (see the first irradiator 7A and the third blower 5C in the fifth embodiment).

[0045] Regarding the above, examples other than the fifth embodiment will be given. For example, in the fourth embodiment, the third suction unit 9C may be shifted below the first irradiation unit 7A and face only the first irradiation unit 7A, or may be extended below the first irradiation unit 7A and face both the first irradiation unit 7A and the first suction unit 9A. Also, for example, unlike the above, in the fourth embodiment, the third blower unit 5C may be extended below the first irradiation unit 7A and face both the first blower unit 5A and the first irradiation unit 7A. Although not particularly shown, the blower unit 5 and the suction unit 9 may face each other (at least partially).

[0046] In the third embodiment, only one or more blower units 5 are provided on the lower surface side (-D3 side). Contrary to the third embodiment, only one or more suction units 9 may be located on the lower surface side.

[0047] In the first to sixth embodiments, at least one blower 5 and at least one suction unit 9 are provided on the upper surface side of the path 103. However, only one or more blowers 5, only one or more suction units 9, or only one of them may be provided on the upper surface side.

[0048] As can be understood from the explanation so far, the flow from the upper surface side (+D3 side) of path 103 to the lower surface side (-D3 side), and the flow to the opposite side, may or may not be actively utilized.

[0049] In the first to sixth embodiments, the path 103 (medium 101) is linear in side view (planar in three-dimensional view) at least in the range where the blower 5, the irradiation unit 7, and the suction unit 9 are arranged. However, the path 103 may be curved in a convex and / or concave shape in the above range (and / or its vicinity). In this case, depending on the specific aspect, it is possible to reduce the likelihood that the hot air will flow to the head 3.

[0050] As can be understood from the above, the surface of the path 103 (medium 101) that the blower 5, the irradiation unit 7, and the suction unit 9 face is not limited to the top or bottom surface. The "top surface" and "bottom surface" of the path 103 (medium 101) in the description of the embodiment may be replaced with the terms "first surface" and "surface opposite to the first surface (second surface)" unless a contradiction arises. Note that the blower 5 and the suction unit 9 may face the path 103 from the side of the path 103.

[0051] (2. Printers in General (Including Description of Ink)) In the following description, for convenience, the first embodiment (FIGS. 1 and 2) may be used as an example to represent multiple embodiments. Also, the reference numerals of the first embodiment may be followed in parentheses by the reference numerals of other embodiments (FIGS. 3 to 6). Unless a contradiction or the like arises, the description of the first embodiment may be applied to the other embodiments.

[0052] The printer 1 (201, 301, 401, 501, 601) has, for example, a recording system 11 (211, 311, 411, 511, 611) that ejects and dries ink, a transport unit 13 that transports the medium 101, and a controller 15 that controls these. The recording system 11 has a head unit 17 that includes one or more heads 3 (four in the example of FIG. 2 ), and a drying device 19 (219, 319, 419, 519, 619) that dries the ink. The drying device 19 has an air blowing unit 5, an irradiation unit 7, and a suction unit 9.

[0053] In the above, the controller 15 has been described as a part of the printer 1, and from another perspective, as a device separate from the drying device 19, the head unit 17, and the conveying section 13. However, when focusing on each device included in the printer 1, the controller 15 may be regarded as a controller for that device. For example, the controller 15 may be regarded as a part of the drying device 19, or as a part of the recording system 11.

[0054] It should be noted that a controller may be provided for each device included in the printer 1. For example, a separate hardware controller may be provided for each of the drying device 19, the head unit 17, and the conveying unit 13. The entire system including all of these controllers may be the controller 15. The controller 15 may also be provided in such a manner that it is indistinguishable from the hardware perspective. In any case, when focusing on each device, the controller 15 (all or part of it) may be considered as part of that device, as described above.

[0055] The printer 1 may be distributed in any manner. For example, the drying device 19 may be distributed separately from the head unit 17 and the transport unit 13. The recording system 11 may be distributed separately from the transport unit 13. The entire printer 1 may also be distributed.

[0056] In a configuration in which only the drying device 19 is distributed, it may be difficult to determine the transport direction of the media 101 (particularly its upstream and downstream directions) from the drying device 19 alone. In such a case, for example, with respect to the first to fifth embodiments, the direction from the first irradiation unit 7A to the first blower unit 5A may be identified as the "first direction." Then, assuming that the "first direction" is the upstream direction of the transport direction, it may be determined whether the wind direction, wind volume, wind speed, and positional relationships of various components described in the description of the embodiments are valid.

[0057] More specifically, the "first direction" may be defined as the first blower unit 5A, for example, by specifying the blower unit 5 that is aligned with the first irradiator 7A without the suction unit 9 interposed therebetween in a direction intersecting (e.g., perpendicular to) the irradiation direction (e.g., the direction of the optical axis) of the first irradiator 7A. If necessary, it may also be considered whether the blower unit 5 is located on the same side as the first irradiator 7A in the irradiation direction (e.g., direction D3). (Unlike the description of the embodiment, the third blower unit 5C in FIGS. 4 and 5 may be specified as the first blower unit 5A.) The direction from the first irradiator 7A to the first blower unit 5A along the intersecting direction may then be specified as the "first direction."

[0058] The printer 1 does not have any other drying devices that heat the medium 101, for example, upstream of the drying device 19 on the path 103. This reduces the likelihood that heat will affect the ejection characteristics of the head 3, for example. Note that the above-mentioned other drying devices refer to devices that actively heat the medium 101 for the purpose of drying the ink. In other words, even if the medium 101 is heated by exhaust heat from a device whose primary purpose is not to dry the ink (for example, heat generated by the driver of the head 3), the device that generates that exhaust heat is not included in the above-mentioned other heating devices.

[0059] The head unit 17 is configured for use in a so-called line printer. That is, the head unit 17 spans substantially the entire width (direction D2) of the medium 101. Then, as the medium 101 is transported, printing is performed in a band-shaped area extending in the direction D2, thereby forming a two-dimensional image. However, the head unit 17 may also be configured for use in a serial printer. In this case, the operation of printing while moving the head unit 17 in the direction D2 and the transport of the medium 101 are performed alternately. For convenience, in the description of the embodiments, a line printer will sometimes be used as an example unless otherwise specified.

[0060] In the head unit 17, each head 3, for example, spans almost the entire width of the medium 101. Each head 3 may be a single head or a collection of multiple heads. In the latter case, for example, multiple heads whose length in the D2 direction is smaller than the width of the medium 101 may be arranged in a staggered pattern when viewed in the D3 direction and across almost the entire width of the medium 101.

[0061] The head unit 17 has, for example, a total of four heads 3. The four heads 3 are arranged, for example, in the transport direction of the medium 101. The four heads 3 correspond to inks of different colors (four color inks). The four color inks are, for example, magenta (M), yellow (Y), cyan (C), and black (K). This allows the printer 1 to function as a color printer.

[0062] Unlike the above description, the head unit 17 may print in a single color, or conversely, may print in more than four colors. In other words, the number of colors is arbitrary. Also, two or more heads 3 may correspond to one color. Conversely, one head 3 may correspond to two or more colors. The number of heads 3 included in one head unit 17 (or, from another perspective, the printer 1) is arbitrary, and may be one.

[0063] The head 3 ejects ink droplets from, for example, nozzles (not shown) facing the medium 101. The configuration of the head 3 is arbitrary as long as it is capable of ejecting ink. For example, the type of actuator (not shown) that applies pressure to the ink for ejection may be a piezoelectric type that applies pressure to the ink by deforming a piezoelectric element, or a thermal type that applies pressure to the ink by heating the ink to generate bubbles.

[0064] The printer 1 prints on, for example, roll paper as the medium 101. However, the medium 101 may also be sheet paper. The size of the medium 101 is also arbitrary. For example, the size of the medium 101 may be small, like a receipt, a size commonly used in offices, or large, like a poster.

[0065] The transport unit 13 may have any configuration. 1 and 2 illustrate a configuration in which a roller in contact with the medium 101 is rotated. Other configurations include, for example, a configuration in which a belt that adsorbs the medium 101 is transported, and a configuration in which a drum around which the medium 101 is wound is rotated.

[0066] The controller 15 includes, for example, a computer, and controls the recording system 11 and the transport unit 13 based on print data including image data (which is a broad concept that includes text).

[0067] (3. Ink) The ink may be any ink, as long as it contains a medium that evaporates when heated and its temperature increases when irradiated with UV light. The "medium" may be, for example, a "solvent" (or "dispersion medium") that dissolves other substances (solutes), or a "dispersion medium" that disperses other substances (dispersoids). The fact that the temperature increases when irradiated with UV light means, in other words, that the ink contains a component that absorbs UV light (sometimes referred to as a "UV absorber").

[0068] Specifically, for example, the medium may be water or an organic solvent. In the description of the embodiments, water may be used as an example unless otherwise specified. Furthermore, for example, the UV absorber may be a colorant or may be a substance separate from the colorant. The colorant may be a pigment or a dye. For example, various known pigments and dyes may be used. Note that, for example, a component (transparent) that imparts gloss to the medium 101 may also be considered as a type of colorant.

[0069] The UV absorber other than the colorant may be added to the ink solely for the purpose of absorbing UV rays, or may be used for some other purpose. Examples of the latter use include protection of colorants or polymers (described below). Examples of UV absorbers other than colorants include dihydroxybenzophenone-based compounds, benzotriazole-based compounds, hydroxyphenyltriazine-based compounds, and cyanoacrylate-based compounds. These UV absorbers absorb UV rays, become excited from their ground state, and release a portion of the energy as heat when returning to the ground state. If the UV absorber not only absorbs UV rays and generates heat, but can do so repeatedly, heat generation by UV irradiation can be continued. Although ultraviolet polymerization initiators absorb UV rays, they generally decompose after absorption and therefore cannot repeatedly generate heat.

[0070] The colorant may be fixed to the medium 101 in any manner. For example, the fixation may be due to the colorant permeating the medium 101, due to the colorant accumulating on the medium 101 as the medium dries, due to a predetermined polymer melting and solidifying to fix to the medium 101 together with the colorant, or a combination of these.

[0071] Contrary to the above explanation, the ink does not contain a medium that evaporates when heated. For example, the ink is not one that polymerizes and hardens when exposed to UV light, thereby fixing the colorant to the medium 101 (i.e., UV-curable ink). However, the ink may contain a component that hardens when exposed to UV light, but in an amount that does not qualify it as UV-curable.

[0072] (4. Drying Device) (4.1. Drying Device in General) As described above, the drying device 19 has the air blowing unit 5, the irradiation unit 7, and the suction unit 9. The drying device 19 may also have the following components, for example. Air blowing system 21 (221, 321, 421, 521, 621): Includes the air blowing unit 5. Suction system 23 (223, 323, 423, 523, 623): Includes the suction unit 9. Storage box 25: Has a space 25s where ink is dried.

[0073] The air blowing system 21 refers to the entire configuration for generating and sending out hot air. For example, the air blowing system 21 includes a blower 27 and a heater 29, as will be described in detail later. The air blowing unit 5 refers to a portion of the air blowing system 21 that sends hot air directly toward the path 103 (at least a part of the air blowing system 21). For example, the air blowing unit 5 has at least an outlet (reference numeral omitted) from which the hot air is blown out.

[0074] The suction system 23 refers to the entire configuration for sucking gas. For example, the suction system 23 includes an aspirator 31, as will be described in detail later. The suction unit 9 refers to a portion of the suction system 23 that directly sucks gas from the path 103 side (at least a part of the suction system 23). For example, the suction unit 9 has at least a suction port (reference number omitted) that sucks in gas.

[0075] The medium 101 passes through the space 25s in the storage box 25. The irradiation unit 7 irradiates UV light onto the medium 101 passing through the space 25s. Warm air is supplied to the space 25s by the air blower 5. Gas is sucked from the space 25s by the suction unit 9. In this way, the ink is dried in the space 25s.

[0076] The storage box 25 stores, for example, the blower 5, the irradiation unit 7, and the suction unit 9. In the description of the embodiment, for convenience, the part of the air blowing system 21 that is stored in the storage box 25 may be regarded as the blower 5 unless otherwise specified. The same applies to the irradiation unit 7 and the suction unit 9. Note that the storage box 25 does not necessarily have to be provided.

[0077] In describing the positional relationship between the blower unit 5, the irradiation unit 7, and the suction unit 9, the position of the blower unit 5 may refer to, for example, the position of a part directly involved in blowing air (e.g., the air outlet and its surrounding area). Similarly, for the irradiation unit 7, the position of a part directly involved in UV irradiation (e.g., the opposing surface 7b or opening 7c described below) may refer to. For the suction unit 9, the position of a part directly involved in suction (e.g., the air inlet and its surrounding area) may refer to. In other words, the positional relationship of parts not directly involved in blowing air, irradiation, and suction (e.g., the flow path that sends warm air to the air outlet of the blower unit 5) may differ from that described in the embodiment.

[0078] In the above description, the drying device 19 has been described as including the air blowing system 21, the suction system 23, and the storage box 25. However, it is also possible to regard only the air blowing unit 5, the irradiation unit 7, and the suction unit 9 as the drying device 19, or to regard only the storage box 25 and the portion stored in the storage box 25 as the drying device 19.

[0079] One blower unit 5 may be configured by arranging two or more blowers along the path 103. The same applies to the irradiation unit 7 and the suction unit 9. From another perspective, in the description of the embodiment, the number of blowers 5 is counted not based on the configuration of the blower unit 5, but based on the arrangement of the blowers 5 with other components (for example, the irradiation unit 7 and the suction unit 9). The same applies to the irradiation unit 7 and the suction unit 9.

[0080] For example, in the fourth embodiment ( FIG. 5 ), it is assumed that a suction unit is added at a position facing the first irradiation unit 7A across the path 103. In this case, it is assumed that one third suction unit 9C is located between the third blower unit 5C and the fourth blower unit 5D, rather than two suction units 9.

[0081] Also, for example, in the fourth embodiment ( FIG. 5 ), it is assumed that the second blower 5B is configured by arranging two blowers along the path 103. In this case, it is not considered that the first suction unit 9A, blower, blower, and second suction unit 9B are sequentially arranged downstream of the first irradiation unit 7A. In other words, it is not considered that the suction unit 9 and the blower unit 5 are alternately arranged.

[0082] The boundaries between the blower 5, the irradiation unit 7, and the suction unit 9 may or may not be clear. For example, an example of the former is a configuration in which these components have separate housings. Examples of the latter are a configuration in which two or more adjacent components share a single housing, and a configuration in which the housing box 25 functions as a housing and the parts that make up these components (e.g., the light source 7a described below) are directly fixed to the housing box 25.

[0083] The pressure outside the storage box 25 may be, for example, atmospheric pressure. However, the pressure outside the storage box 25 may be different from atmospheric pressure. For example, the printer 1 may be placed and used in a chamber having a pressure different from atmospheric pressure.

[0084] The pressure inside the storage box 25 may be the same as, higher than, or lower than atmospheric pressure (or, from another perspective, the pressure outside the storage box 25). From another perspective, the relative relationship between the amount of gas sent by the blowing system 21 and the amount of gas sucked by the suction system 23 is arbitrary. When the pressure inside the storage box 25 is lower than the pressure outside the storage box 25, for example, the likelihood that the gas inside the storage box 25 will flow toward the head 3 is reduced.

[0085] The gas outside the storage box 25 may be air. The gas sent by the blower 5 may also be air. Of course, each of these may be a gas other than air.

[0086] The length of the path 103 along which drying is performed in the drying device 19 (or, from another perspective, the length of the storage box 25 in the D1 direction) is arbitrary. For example, when the transport speed of the media 101 is 100 m / min, the length along which drying is performed may be approximately 1.5 m.

[0087] (4.2. Irradiation Unit) The irradiation units 7 (first irradiation unit 7A and second irradiation unit 7B) are located above the path 103 and irradiate UV light onto ink located on the top surface of the medium 101. However, if the material of the medium 101 is a material that transmits UV light (for example, a translucent resin film), then, unlike the illustrated example, the irradiation units 7 may irradiate UV light onto ink located below the path 103 and on the top surface of the medium 101. However, the following description will be based on the illustrated example unless otherwise specified.

[0088] The irradiation unit 7 can, for example, irradiate the entire width of the medium 101 with UV. The irradiation unit 7 can also, for example, irradiate the medium 101 with UV almost uniformly in the width direction. The shape of the area of ​​the medium 101 that is irradiated with UV is, for example, a rectangle with sides parallel to the D1 direction and the D2 direction. The specific size and aspect ratio of the area are arbitrary. The distance (size of the gap) between the irradiation unit 7 and the medium 101 is also arbitrary.

[0089] The specific configuration of the irradiation unit 7 may be any appropriate configuration. For example, an irradiation unit that irradiates UV rays onto ink that polymerizes when irradiated with UV rays may be used as the irradiation unit 7. Of course, an irradiation unit 7 having a new configuration different from such an irradiation unit may also be used.

[0090] Furthermore, if the UV-irradiated area is continuous in the D1 direction, the efficiency of drying or the efficiency of increasing the temperature can be improved. However, as mentioned above, the irradiation unit 7 may be configured by arranging multiple irradiation units along the D1 direction. Such a configuration is used, for example, when it is difficult to arrange the irradiation units continuously due to structural limitations of the irradiation units. In such a configuration, the temperature increase may stagnate or the temperature may decrease due to the heat of vaporization between the multiple irradiation units. In such a case, efficient drying can be continued between the irradiation units by blowing warm air from the first blower unit 5A.

[0091] The irradiation unit 7 has, for example, at least a light source 7a (only the reference numeral in FIG. 2) that generates UV light. In addition, although not specifically shown, the irradiation unit 7 may have a reflecting mirror that reflects UV light leaking from the light source 7a to the side opposite the medium 101, a diaphragm having an opening that adjusts the cross-sectional shape of the UV light from the light source 7a, and / or a lens that focuses the UV light.

[0092] The light source 7a may be configured with appropriate elements, such as an LED (light emitting diode), an incandescent lamp, a fluorescent lamp, or a mercury lamp. The light source 7a may have only one of the above elements, or may have multiple elements. In FIG. 2 and other figures, an LED is shown schematically. The multiple LEDs are, for example, arranged across the entire width of the medium 101. The number of rows is arbitrary, and may be, for example, one row, or two or more rows.

[0093] As indicated by the reference numerals in Fig. 2, the irradiation unit 7 has an opposing surface 7b facing the path 103. The opposing surface 7b has an opening 7c that allows UV from the light source 7a to pass through to the path 103. The opening 7c may or may not be blocked by a light-transmitting member. When the opening 7c is not blocked, air may be blown or suctioned from the opening 7c. When blowing air, warm air may be blown.

[0094] The area of ​​the facing surface 7b around the opening 7c may (or may not) have, for example, a mirror surface (in the embodiment, this is the entire area, so the reference numeral is omitted). The mirror surface contributes to increasing the efficiency of UV irradiation of the ink by, for example, reflecting UV reflected by the medium 101 back toward the medium 101.

[0095] The specific configuration of the mirror surface is arbitrary. For example, the facing surface 7b may be one of the outer surfaces (the bottom surface) of the housing housing the light source 7a. However, the facing surface 7b may be the surface of a plate-like member that spans not only the irradiation unit 7 but also the adjacent blower unit and / or suction unit 9. The shapes of the facing surface 7b and the opening 7c are arbitrary, and may be, for example, rectangular, each with a long side spanning the width of the medium 101. The area of ​​the opening 7c is arbitrary, and may be, for example, 10% or more, 30% or more, or 50% or more of the area of ​​the facing surface 7b (including the area of ​​the opening 7c), or 80% or less, 50% or less, or 30% or less. The above lower and upper limits may be combined arbitrarily as long as no contradiction occurs.

[0096] Furthermore, for example, the mirror surface may be realized by a plate-shaped portion (e.g., a part of the housing of the irradiation unit 7) having the facing surface 7b being made of a predetermined metal material, or by the facing surface 7b being made of a metal film. In these cases, the specific metal material is arbitrary. The reflectance of the mirror surface is arbitrary and may be, for example, 50% or more or 80% or more. The reflectance may refer to the value at the peak frequency in the spectrum of UV generated by the light source 7a. The mirror surface may occupy, for example, 50% or more, 80% or more, or 95% or more of the area of ​​the facing surface 7b excluding the opening 7c. The area of ​​the mirror surface may be, for example, 0.2 times or more, 0.5 times or more, 1 time or more, 2 times or more, or 3 times or more the area of ​​the opening 7c.

[0097] Furthermore, the mirror surface may be formed by polishing or metallizing the outer surface of the irradiation unit 7. Alternatively, the mirror surface may be formed by attaching a plate-like object having a mirror surface to the outer surface of the irradiation unit 7.

[0098] The mirror surface mentioned here is one that focuses on the reflecting function, and does not take into account surface roughness. Therefore, for example, the mirror surface may have irregularities that cause diffuse reflection of UV light.

[0099] As is well known, UV light has a shorter wavelength than visible light, and its wavelength is, for example, 10 nm or more and 400 nm or less. The UV light emitted by the irradiation unit 7 may be near ultraviolet light or far ultraviolet light. Near ultraviolet light may be any of so-called UV-A, UV-B, and UV-C light. In other words, the wavelength of the UV light emitted by the irradiation unit 7 may be set appropriately. The UV light emitted by the irradiation unit 7 may have a narrow wavelength range in which the energy is distributed, like laser light, or may have a wide wavelength range.

[0100] The irradiance (intensity) of the UV light is arbitrary. For example, the irradiance may be set so that the ink can be heated to about its boiling point (e.g., 100°C) in a relatively short time (e.g., about 0.3 seconds). Furthermore, for example, the irradiance may be set so that the ink reaches its boiling point when it reaches the downstream end of the UV irradiation area. Such a setting may be set taking into consideration the temperature and volume of the hot air from the blower 5, the ease with which the ink absorbs UV light, the transport speed of the media 101, and the like. The same applies to the integrated light amount.

[0101] For example, the UV irradiance is 4000 mW / cm ２ The value may be, for example, per area of ​​the opening 7c, or may be per area of ​​the medium 101 if the UV emitted from the opening 7c is close to parallel light.

[0102] (4.3. Air Supply System Including Air Supply Unit) (4.3.1. Variations of Air Supply System) Figures 2 to 6 also show variations in the configuration of air supply system 21. Any variations in the arrangement of air supply unit 5 and suction unit 9 and any variations in the configuration of air supply system 21 may be combined together as long as no contradictions arise. In other words, the combinations shown in each figure are merely examples.

[0103] 2, a blower 27 and a heater 29 are provided outside the blower unit 5 (or, from another perspective, outside the accommodation box 25). The heater 29 is located, for example, in a flow path from the blower 27 to the blower unit 5.

[0104] 3 , the air blowing system 221 includes a plurality of air blowing units 5 (two in the illustrated example), and accordingly, the flow paths (reference numerals omitted) leading from the air blower 27 and the heater 29 to the air blowing units 5 are branched. In other words, the air blower 27 and the heater 29 are shared by the plurality of air blowing units 5.

[0105] 3 utilizes the exhaust heat of the first irradiation unit 7A. For example, the air blowing system 221 has a flow path 33 that supplies gas that has absorbed the heat generated inside the first irradiation unit 7A to the air blowing unit 5.

[0106] In the air blowing system 321 illustrated in Fig. 4, a plurality of (two) air blowers 27 are provided corresponding to a plurality of (four) air blowing units 5. However, the two air blowing units 5 on the upper surface side (+D3 side) of the path 103 share one air blower 27, as in the example of Fig. 3. Similarly, the two air blowing units 5 on the lower surface side (-D3 side) of the path 103 share one air blower 27.

[0107] 4, a heater 29 is provided for each blower 5. In other words, the heater 29 is not shared by multiple blowers 5. Specifically, a flow path extending from one blower 27 branches into multiple (two) tributaries along the way, and each tributary reaches one blower 5. A heater 29 is provided for each tributary.

[0108] In the air blowing system 421 illustrated in Fig. 5, a heater 29 is provided for each air blowing unit 5, similar to the example in Fig. 4. However, unlike the example in Fig. 4, the heater 29 is provided inside the air blowing unit 5 (from another perspective, inside the storage box 25).

[0109] 6, not only the heater 29 but also the fan 27 is provided inside the fan unit 5 (inside the storage box 25 from another perspective). From another perspective, the fan 27 is provided for each fan unit 5 (it is not shared by multiple fan units 5).

[0110] As described above, the blower unit 5 may or may not have the heater 29 and / or the blower 27. The heater 29 and / or the blower 27 may or may not be shared by two or more blower units 5.

[0111] An example other than the illustrated example will be given.

[0112] 2 to 6, the heater 29 is located on the side of the blower 27 closer to the blower unit 5 (downstream in the gas flow). However, the heater 29 may be located upstream in the gas flow relative to the blower 27. In this case, contrary to the examples of FIGS. 4 and 5, the number of blowers 27 may be less than the number of heaters 29. Furthermore, for example, a blower 27 may be provided for each blower unit 5, while the heater 29 may be shared by multiple blower units 5.

[0113] Both a heater 29 shared by multiple blower units 5 and a heater 29 for each blower unit 5 may be provided. In an embodiment in which blower units 5 are provided on both the upper and lower sides of the path 103 (e.g., FIG. 4 ), one blower 27 may be shared by all blower units 5, or one heater 29 may be shared by all blower units 5. Furthermore, in an embodiment in which two or more blower units 5 are provided and blowers 27 are provided outside the blower units 5 (e.g., FIG. 4 ), a blower 27 may be provided for each blower unit 5. Multiple heaters 29 and / or multiple blowers 27 may be provided for one blower unit 5.

[0114] The heater 29 may not be located inside the flow path through which the gas flows, but may be located outside (for example, on the outer peripheral surface) of a member that constitutes the flow path, or may be located inside (between the inner and outer peripheral surfaces) of a member that constitutes the flow path. The heater 29 and / or the blower 27 may be provided outside the blower unit 5 and inside the storage box 25. In this case, it is optional whether the heater 29 and / or the blower 27 are shared or not.

[0115] (4.3.2. Configuration of each part of the air blowing system) As described above, the air blowing unit 5 has at least an air outlet (reference numeral omitted) facing the path 103. The air blowing unit 5 sends gas toward the path 103, for example, across the entire width of the medium 101. The number, shape, direction, dimensions, etc. of the air outlets are arbitrary.

[0116] For example, a slit-shaped air outlet extending in the D2 direction across the width of the medium 101 may be provided, or multiple air outlets arranged in the D2 direction may be provided. In the former case, the number of slits may be one or two or more. Similarly, in the latter case, the air outlets may be arranged in one row or two or more rows. The distance from the air outlet to the path 103 may be the same as, or may be shorter or longer than, the distance from the opposing surface 7b of the irradiation unit 7 to the path 103.

[0117] Furthermore, for example, the orientation of the air outlet (in other words, the airflow direction at the position of the air outlet) may be parallel to the D3 direction or may be inclined relative to the D3 direction. The inclination angle may be less than 45° or may be 45° or greater. In an embodiment in which two or more slit-shaped air outlets (or an arrangement of two or more rows of air outlets) are provided, the orientations may be the same as or different from each other. For example, the orientations of the two air outlets may intersect with each other on the side of the path 103. Furthermore, the orientation of the air outlet may be parallel to the D1 direction (for example, on the -D1 side in the case of the first blower unit 5A).

[0118] 2 and the like are schematic diagrams, and are therefore depicted as if the entire blower unit 5 were a flow path. From another perspective, the cross-sectional area of ​​the flow path within the blower unit 5 is depicted as being larger than the opening area of ​​the outlet. The flow path of the blower unit 5 may actually be configured in this way, or may be configured to extend with a cross-sectional area equivalent to the opening area of ​​the outlet. Furthermore, the flow path of the blower unit 5 may be linear or curved as appropriate.

[0119] The blower 27 may include, for example, a fan and a motor for rotating the fan. The specific configuration is also arbitrary. For example, the blower 27 may perform suction in either the axial direction or the radial direction, or may perform air blowing in either the axial direction or the radial direction. Although there are standards that define a blower as one whose energy per unit mass imparted to gas satisfies a predetermined requirement, such a definition is not used in the present disclosure. In other words, the capacity of the blower 27 is arbitrary.

[0120] The heater 29 may be, for example, a heater using an electric heating wire, an induction coil, and / or a heat medium (fluid). The electric heating wire may be located within the airflow passage, inside a passage member constituting the passage (between the inner circumferential surface and the outer circumferential surface), and / or outside the passage member (e.g., on the outer circumferential surface), and may generate heat when supplied with power. The induction coil may generate an induced current in a metal located within the airflow passage, in a metal located within the passage member (which may be the passage member itself), and / or in a metal located outside the passage member. A heater using a heat medium may have a passage through which a heat medium (e.g., oil or water) flows adjacent to the airflow passage, and may heat the heat medium.

[0121] The multiple air blowing units 5 may have the same configuration as each other or different configurations from each other. The same applies to the multiple air blowers 27 and the multiple heaters 29. The hot air blown by the multiple air blowing units 5 may have different air volumes and / or temperatures from each other or may be the same from each other.

[0122] The temperature of the hot air at the air outlet is arbitrary. For example, if the medium 101 is paper, the temperature may be about 130° C. If the medium 101 is a resin film, the temperature may be 80° C. or higher and 90° C. or lower.

[0123] In addition to the above-described components (fan 27, heater 29, and blower unit 5), air blowing system 21 may (or may not) include, for example, sensors for detecting various physical quantities. Examples of sensors include sensors for detecting wind speed and / or wind direction, and temperature sensors. These sensors may be provided at appropriate positions and used for feedback control of air blowing system 21 by controller 15. Air blowing system 21 may also include, at appropriate positions, valves (for example, flow control valves). The valves may be manually operated or controlled by controller 15.

[0124] (4.3.3. Utilization of Exhaust Heat from Irradiation Unit) In the example shown in FIG. 3 , as described above, exhaust heat from the irradiation unit 7 is utilized to generate warm air. For example, in the irradiation unit 7, heat is generated when the light source 7a converts electricity into UV light. Also, a circuit board (not shown) that supplies electricity to the light source 7a generates heat. This heat may be utilized.

[0125] More specifically, for example, the irradiation unit 7 has a flow path and a fan (reference numeral omitted) for air-cooling the light source 7a and / or a circuit board (not shown). At least a part or all of the gas (e.g., air) flowing through the flow path may be supplied to the blower unit 5 via the flow path 33. Note that while Fig. 3 only illustrates the flow path 33 for discharging the gas after being used for air-cooling to the outside of the irradiation unit 7, it goes without saying that a flow path (which may include a simple opening) for sucking the gas into the irradiation unit 7 before being used for air-cooling may be provided. The flow path for suction opens to the outside of the storage box 25, for example.

[0126] 3, the hot air discharged from the irradiation unit 7 is supplied to multiple (or from another perspective, all) air blowers 5, but it may be supplied to only some or only one of the air blowers 5. Also, the air blower 27 and heater 29 may be omitted, and hot air may be generated solely by utilizing exhaust heat.

[0127] (4.4. Suction system including suction unit) The description of the air supply system 21 may be applied to the suction system 23 as long as no contradictions arise, except that the gas is not heated and that suction is performed instead of air supply. However, for example, in the description of the air supply system 21, the description of the heater 29 and the use of exhaust heat is omitted. Also, for example, the term air supply system 21 is replaced with the term suction system 23, the term blower 27 is replaced with the term suction machine 31, the term "air supply" is replaced with the term "suction," and the term "air outlet" is replaced with the term "suction port." Just to be sure, an overview of the air supply system 21 will be provided below.

[0128] The suction unit 9 may not include (e.g., FIGS. 2 to 5) or may include (e.g., FIG. 6) the suction device 31. In the former case, the suction device 31 may be located outside the storage box 25 (e.g., FIGS. 2 to 5), or may be located outside the suction unit 9 and inside the storage box 25 (not shown).

[0129] In an embodiment in which a plurality of suction units 9 are provided, one suction device 31 may be shared by two or more suction units 9 (e.g., Figures 4 and 5), or may not be shared in this manner (e.g., Figure 6). Also, in an embodiment in which a plurality of suction units 9 are provided, for example, all suction units 9 may share the same suction device 31 (not shown), some suction units 9 may share the same suction device 31 (e.g., Figures 4 and 5), or all suction units 9 may use different suction devices 31 (e.g., Figure 6).

[0130] The suction unit 9 has at least an intake port (reference numeral omitted) facing the path 103. The number, shape, orientation, and dimensions of the intake ports are arbitrary. For example, one or more slit-shaped intake ports extending across the entire width of the medium 101 may be provided, or one or more rows of intake ports arranged across the entire width of the medium 101 may be provided. The distance from the intake port to the path 103 may be the same as, or may be shorter or longer than, the distance from the opposing surface 7b of the irradiation unit 7 (or the outlet of the blower unit 5) to the path 103.

[0131] The suction device 31 is, for example, the opposite of the blower 27, in that its suction port is connected to the suction unit 9 (or constitutes the suction port of the suction unit 9) and its outlet is open to the outside (for example, the outside of the storage box 25). Otherwise, the description of the blower 27 can be used. The configurations of the suction device 31 and the blower 27 may be the same or different from each other.

[0132] The plurality of suction units 9 may have the same configuration as each other or different configurations from each other. The same applies to the plurality of suction machines 31. Furthermore, the plurality of suction units 9 may have different gas suction amounts (per unit time) from each other or may have the same gas suction amounts from each other.

[0133] In addition to the above-mentioned components (the aspirator 31 and the suction unit 9), the suction system 23 may (or may not) have, for example, sensors for detecting various physical quantities, and may (or may not) have valves (for example, flow control valves) at appropriate positions. A heat exchange unit may be provided between the suction system 23 and the air supply system 21, and the heat of the sucked hot air may be used to heat the air supply system 21.

[0134] (4.5. Storage Box) The storage box 25 has the aforementioned space 25s, an entrance 25a to the space 25s of the medium 101, and an exit 25b from the space 25s of the medium 101. Note that the space 25s refers to the space within the internal space of the storage box 25 that is in contact with the surfaces of the blower 5, the irradiation unit 7, and the suction unit 9 on the path 103 side (this does not include the space occupied by the blower 5, etc.).

[0135] The shapes and dimensions of the interior (inner surface), exterior (outer surface), space 25s, inlet 25a, and outlet 25b of the storage box 25 are arbitrary. For example, the space 25s has a thin shape extending along the path 103 with a substantially constant thickness (in the D3 direction) and a constant width (in the D2 direction). From another perspective, the length of the space 25s in the D3 direction is sufficiently shorter than the lengths in the D1 and D2 directions. When the path 103 is curved around an axis parallel to the D2 direction, the space 25s may or may not be curved along the path 103. The inlet 25a and the outlet 25b are, for example, slit-shaped and long in the D2 direction. The width of the slit (in the D3 direction) may be the same as, smaller than, or larger than the thickness (in the D3 direction) of the space 25s. The same applies to the dimension in the D2 direction.

[0136] The storage box 25 may be made of any suitable material. For example, the storage box 25 may be primarily made of metal, with a layer of insulating material (e.g., ceramic) on the inner surface. Furthermore, the wall surrounding the space 25s may be made of, for example, the inner surface of the storage box 25, components (e.g., the blower 5, the irradiation unit 7, and the suction unit 9) disposed within the storage box 25, and / or a suitable partition plate (reference numeral omitted) disposed within the storage box 25. These materials may also be arbitrary. The space 25s may be sealed, for example, except for the inlet 25a, the outlet 25b, and the openings for the blower 5 and the suction unit 9. The degree of sealing is arbitrary. Furthermore, the entire interior space of the storage box 25 (including the space outside the space 25s) may or may not be sealed, except for the inlet 25a and the outlet 25b. The space 25s may be a space sealed by the storage box 25 alone. Furthermore, a sealed space 25s may be formed by storing the blower 5, the irradiation unit 7, the suction unit 9, etc. in the storage box 25. Furthermore, the storage box 25 may be installed in the printer 1 to form the sealed space 25s. For example, the storage box 25 may have an open shape on one surface such as the bottom, and may be installed to cover the surface of the printer 1 to form the space 25s.

[0137] (4.6. Positional Relationship with Head) The positional relationship (e.g., distance) between the drying device 19 and the head 3 is arbitrary. For example, the distance along the path 103 from the first irradiation unit 7A, which is the irradiation unit 7 closest to the head 3, to the head 3 farthest from the irradiation unit 7 (the head 3 closest to the +D1 side) may be 0.5 m or more and 2.0 m or less. With respect to the distance, the reference position of the irradiation unit 7 may be the position closest to the head 3 in the portion contributing to irradiation (e.g., the edge of the opening 7c on the +D1 side). Furthermore, the reference position of the head 3 may be the position farthest from the irradiation unit 7 in the portion contributing to ejection (e.g., the position of the nozzle closest to the +D1 side). The distance between the two positions along the path 103 may be determined by identifying the positions obtained by projecting each of the two reference positions onto the upper surface of the path 103 in the normal direction of the upper surface.

[0138] (4.7. Specific Examples of Wind Direction and Air Volume) The outline of the wind direction around the medium 101 has already been described for each embodiment. Here, an example of the wind direction near the first blower 5A will be described in detail.

[0139] As described above, in the first to fifth embodiments, gas is sucked by the first suction unit 9A downstream of the first blower unit 5A on the path 103. Therefore, the warm air from the first blower unit 5A tends to flow downstream on the path 103. However, depending on the air volume of the first blower unit 5A (and / or other blower units 5), the suction volume of the first suction unit 9A (and / or other suction units 9), the shape of the space 25s, and the like, some warm air may flow upstream on the path 103 from the first blower unit 5A. In this case, the air volume and speed upstream are arbitrary.

[0140] For example, the volume of gas flowing from first blower 5A upstream along path 103 may be set to 0.2 times or less the volume of gas from first blower 5A. To achieve such a volume of gas, for example, the suction volume of first suction unit 9A may be increased, or the shape of space 25s may be adopted such that resistance to the flow upstream along path 103 is increased.

[0141] In a configuration in which the presence or absence of the media 101 affects the gas flow (for example, in a configuration in which roll paper is suspended between rolls as in the illustrated example), it may be determined whether the above-mentioned air volume is satisfied when the media 101 has the intended maximum dimension (for example, width) (the same applies to the air speed described below). The maximum dimension of the media 101 can be estimated, for example, from the opening 7c of the irradiation unit 7.

[0142] Furthermore, the air volume of the first blower unit 5A may be measured appropriately with the accuracy required to determine whether the above air volume is satisfied. For example, the product of the air velocity at the outlet of the first blower unit 5A and the opening area of ​​the outlet may be calculated. The air velocity at this time may be the air velocity at the center of the outlet (the velocity gradient may be ignored). If measurement with higher accuracy is required, the average value of the velocities measured at multiple positions may be used for the product of the cross-sectional area. Alternatively, integration may be performed based on the velocity distribution. If there are two or more outlets, the air volumes at each outlet may be summed.

[0143] Furthermore, the air volume from the first blower 5A to the upstream side of the path 103 may be the volume of gas passing upstream through a reference area set upstream of the first blower 5A. The reference area may be, for example, the area between the upstream edge of the path 103 on the opposing surface of the first blower 5A facing the path 103 and the path 103 (medium 101). The width of the reference area in the D2 direction may be the larger of the width of the arrangement range of one or more air outlets of the first blower 5A in the D2 direction or the width of the largest medium 101 described above. The air volume may be measured with the required accuracy as in the case of the air volume of the first blower 5A. The description in the previous paragraph may be applied to the air volume to the upstream side, with the air outlet replaced with the reference area.

[0144] When the upstream air volume is 0.2 times or less as described above, the upstream air volume of path 103 is roughly 2 / 8 or less (0.25 times or less) of the downstream air volume of path 103. If the downstream cross-sectional area of ​​path 103 and the upstream cross-sectional area of ​​path 103 are the same, the upstream wind speed is 0.25 times or less (0.3 times rounded to one decimal place) the downstream wind speed. Therefore, the upstream wind speed may be 0.3 times or less or 0.2 times or less the downstream wind speed.

[0145] The wind speed at a representative position may be used to determine whether the wind speed upstream of the path 103 is 0.3 times or less (or 0.2 times or less) the wind speed downstream of the path 103, for example (the speed distribution may be ignored). The representative position for the wind speed upstream of the path 103 may be the center of the reference area described above. The representative position for the wind speed downstream of the path 103 may be the center of the reference area obtained by replacing the word "upstream" with the word "downstream" in the description of the reference area described above.

[0146] (4.8. Various Conditions) Various conditions such as the illuminance of the irradiation unit 7, the accumulated amount of light for the same position on the media 101, the temperature and volume of the hot air in each blower unit 5, the suction volume of each suction unit 9, and the components of the ink (e.g., the amount of UV absorber) may be set appropriately according to the intended effect.

[0147] For example, the temperature of the ink may reach the boiling point or a temperature slightly lower than the boiling point at the downstream end in the transport direction of the UV-irradiated region. Furthermore, in the first to fifth embodiments, the hot air from the first air blowing section 5A may basically flow downstream of the path 103 to prevent condensation from forming on the head 3 side. Furthermore, the ink may be dried by the hot air downstream in the transport direction of the UV-irradiated region. To achieve these effects, the UV irradiance, the temperature and volume of the hot air, and the suction volume may be set according to the ink characteristics and the printing volume.

[0148] The ink may be completely dried at the downstream end of the drying device 19 in the conveying direction. However, if the ink dries too quickly, the appearance may be deteriorated and energy may be wasted. The conditions for UV, hot air, and suction may be set taking these points into consideration.

[0149] (5. Summary of the embodiment) As described above, the drying device 19 for inkjet printing according to the embodiment has a first irradiation unit 7A, a first air blowing unit 5A, and a first suction unit 9A. The first irradiation unit 7A emits ultraviolet (UV) rays toward the recording medium (media 101) (irradiates the media 101 with UV rays). The first air blowing unit 5A blows warm air. The first suction unit 9A sucks in gas. The first irradiation unit 7A is disposed between the first air blowing unit 5A and the first suction unit 9A.

[0150] From another perspective, the recording system 11 according to the embodiment includes the drying device 19 according to the embodiment and the head 3 that ejects ink and faces the path 103 .

[0151] From another perspective, the recording apparatus (printer 1 ) according to the embodiment includes a recording system 11 according to the embodiment, and a transport unit 13 that transports a medium 101 along a path 103 .

[0152] From another perspective, the printing method according to the embodiment is a printing method using the drying device 19 according to the embodiment, and includes a step of adhering ink that contains an ultraviolet absorber and does not polymerize in UV to the media 101 at a position upstream of the first air blowing section 5A on the path 103.

[0153] Therefore, for example, as explained in the overview of the embodiment, the efficiency of UV drying is improved. As a result, for example, the distance along the path 103 required for drying the ink can be shortened, thereby enabling the printer 1 to be made more compact. From another perspective, the time required for drying the ink can be shortened, and the transport speed of the media 101 (in other words, the printing speed) can be increased.

[0154] The drying device 219 (or 319, 419 or 519) may include a second blower 5B that blows hot air and is located downstream of the first suction unit 9A along the path 103.

[0155] In this case, for example, moisture is removed by the first suction unit 9A upstream of the second blower 5B, so that humid gas is less likely to flow between the second blower 5B and the media 101. As a result, for example, drying by the warm air of the second blower 5B is efficiently performed.

[0156] On the path 103, between the second blower 5B and the first suction unit 9A, the airflow direction may be from the second blower 5B to the first suction unit 9A (upstream of the path 103). In other words, the airflow volume of the first blower 5A, the suction volume of the first suction unit 9A, the airflow volume of the second blower 5B, etc. may be adjusted to achieve such an airflow direction (for example, if the airflow volume of the first blower 5A is relatively too high, the airflow direction may be opposite to that described above).

[0157] In this case, for example, the effect of making it more difficult for the humid gas to flow between the second blower section 5B and the medium 101 is improved, and the drying efficiency is also improved.

[0158] Note that the wind direction referred to here may, for example, refer to the general flow near the top surface of the medium 101. In other words, the wind direction in the unique region (partial region) near the side edge of the medium 101 does not necessarily have to be in the direction described above. Also, the wind direction referred to here may, for example, be the wind direction from the perspective of whether the wind volume is greater upstream or downstream of the path 103. Therefore, for example, the wind direction does not have to be parallel to the path 103. Also, for example, the magnitude relationship between the velocity component to the side and the velocity component to the upstream or downstream side is arbitrary. The same applies to the wind direction etc. described below.

[0159] On the path 103, between the first irradiation unit 7A and the first suction unit 9A, the airflow direction may be from the first irradiation unit 7A to the first suction unit 9A. For example, in the drying device 219 (or 319, 419, or 519), the airflow volume of the first blower unit 5A, the suction volume of the first suction unit 9A, the airflow volume of the second blower unit 5B, etc. may be adjusted to achieve such an airflow direction (for example, if the airflow volume of the second blower unit 5B is relatively too high, the airflow direction may be opposite to that described above).

[0160] In this case, for example, the probability that a highly humid gas will flow between the irradiation unit 7 and the medium 101 is reduced. As a result, for example, the efficiency of drying by UV irradiation is improved.

[0161] The drying device 319 (or 419 or 519) may include a second suction section 9B that is located downstream of the second blower section 5B along the path 103 and that sucks in gas.

[0162] Here, because suction is performed by the first suction unit 9A upstream of the second blower unit 5B, the warm air from the second blower unit 5B tends to flow upstream along the path 103. Conversely, there is a high probability that high-humidity gas will stagnate directly below and downstream of the second blower unit 5B. However, by performing suction by the second suction unit 9B downstream of the second blower unit 5B, the probability of such stagnation can be reduced. As a result, the efficiency of drying by the warm air directly below the second blower unit 5B can be improved.

[0163] The air volume of the gas flowing from the first blower 5A to the upstream of the path 103 may be 0.2 times or less relative to the air volume of the first blower 5A. And / or the air velocity of the gas flowing from the first blower 5A to the upstream of the path 103 may be 0.3 times or less relative to the air velocity of the gas flowing from the first blower 5A to the downstream of the path 103.

[0164] In this case, for example, there is a reduced likelihood that the hot air from the first air blowing section 5A will affect the temperature of the head 3 and / or the medium 101. In addition, there is a reduced likelihood that humid gas will condense on the head 3 and / or the medium 101. As a result, for example, image quality improves.

[0165] The ultraviolet illuminance of the irradiation unit 7 is 4000 mW / cm ２ It may be the following:

[0166] In this case, for example, the likelihood of an increase in heat generated when converting electricity to UV light can be reduced. Consequently, the likelihood of an increase in energy consumption can be reduced. When UV light is irradiated onto ink containing an ultraviolet absorber for heating, the ink temperature can be raised more rapidly than when heated with hot air. For example, when raising the temperature from room temperature to 100°C, it takes about 2.5 seconds with hot air, but this can be reduced to about 0.3 seconds with UV light. On the other hand, the conversion efficiency from electricity to UV light is relatively low, which tends to increase energy consumption. With the above-mentioned illuminance, it is easy to balance shortening the drying time with reducing energy consumption.

[0167] The irradiation unit 7 may include an opposing surface 7b facing the path 103. The opposing surface 7b may have an opening 7c that transmits UV light heading toward the path 103. The area of ​​the opposing surface 7b around the opening 7c may include a mirror surface.

[0168] In this case, for example, UV reflected from the medium 101 can be reflected by a mirror surface and irradiated again onto the medium 101. As a result, for example, it is possible to widen the range irradiated with UV or increase the intensity of UV irradiated onto the medium 101. Consequently, it is possible to shorten the distance and / or time required for drying.

[0169] The drying device 19 may have a storage box 25. The storage box 25 may have an inlet 25a and an outlet 25b for the medium 101. The storage box 25 may also house the irradiation unit 7, the first blower unit 5A, and the first suction unit 9A.

[0170] In this case, for example, it becomes easy to integrate the irradiation unit 7, the air blowing unit 5, and the suction unit 9, which facilitates downsizing of the drying device 19. Furthermore, since the irradiation unit 7, the air blowing unit 5, and the suction unit 9 are all integrated via the storage box 25, distribution of the drying device 19 becomes easier, and application to the existing conveying unit 13 becomes easier.

[0171] The drying device 19 may include a flow path 33 that supplies gas that has absorbed heat generated inside the irradiation unit 7 to the first blower unit 5A. In other words, the exhaust heat of the irradiation unit 7 may be used to generate warm air.

[0172] In this case, for example, the energy consumption of the drying device 19 can be reduced. As mentioned above, the use of UV rays is likely to increase energy consumption in exchange for shortening the drying time. However, by utilizing the exhaust heat, this disadvantage can be at least partially compensated for. From another perspective, the UV irradiance can be increased to shorten the drying time while reducing the likelihood of increasing energy consumption.

[0173] The drying device 319 (or 419, 519, or 619) may include a third blower 5C that blows hot air and faces at least one of the first irradiating unit 7A and the first blower 5A across the path 103.

[0174] In this case, for example, the temperature of the media 101 increased by the first irradiation unit 7A and the first blower unit 5A is more likely to be maintained. As a result, the drying time can be shortened. Also, depending on the configuration of the transport unit 13, the moisture on the lower surface side can be removed by the first suction unit 9A by utilizing the gas flow from the lower surface side to the upper surface side. This can reduce the likelihood of condensation on the lower surface side, for example.

[0175] The third blower 5C may be located downstream of at least a portion of the first blower 5A along the path 103 (FIG. 6).

[0176] In this case, for example, the hot air from the third blower section 5C is less likely to flow toward the head 3. As a result, the likelihood of the inconvenience (as described above) caused by the hot air flowing toward the head 3 is reduced.

[0177] The drying device 319 (or 419, 519, or 619) may include a third blower 5C and a fourth blower 5D that blow warm air. The third blower 5C may be opposed to at least one of the first irradiating unit 7A and the first blower 5A across the path 103. The fourth blower 5D may be opposed to the second blower 5B across the path 103.

[0178] In this case, for example, two air blowers 5 blow warm air from the bottom side, which improves the effectiveness of maintaining the temperature of the media 101. Also, for example, the pressure applied to the media 101 by the second air blower 5B and the pressure applied to the media 101 by the fourth air blower 5D at least partially cancel each other out. As a result, for example, the media 101 can be transported stably.

[0179] The drying device 419 (or 519) may include a third suction unit 9C located between the third air blower 5C and the fourth air blower 5D, and a fourth suction unit 9D located downstream of the fourth air blower 5D along the path 103. The first air blower 5A, the first suction unit 9A, the second air blower 5B, and the second suction unit 9B may be located on the side of the path 103 that is closer to the first irradiation unit 7A (the +D3 side). The third air blower 5C, the third suction unit 9C, the fourth air blower 5D, and the fourth suction unit 9D may be located on the opposite side of the path 103 from the first irradiation unit 7A (the -D3 side).

[0180] In this case, for example, first, the gas with high humidity on the upper surface of the medium 101 can be discharged from the upper surface. Even if the gas with high humidity flows to the lower surface, the gas can also be discharged on the lower surface, reducing the likelihood of the gas stagnation. Also, for example, the flow from the upper surface to the lower surface can be actively utilized to rapidly remove moisture from the upper surface of the medium 101.

[0181] In the drying device 619, the first irradiation unit 7A is disposed between the first blower unit 5A and the first suction unit 9A. Hot air flows in the direction D1 (the direction opposite to the conveying direction) through the path 103 at the position of the first irradiation unit 7A.

[0182] Here, we consider the relationship between the content of the medium in the gas and the ease with which the medium dries. As with the humidity (relative humidity) when the medium is water, even if the temperature and wind speed conditions are the same, if the content of the medium in the gas is high, the medium will dry slower from the ink, and if the content of the medium in the gas is low, the medium will dry faster. Here, we will use the term humidity to explain cases where the medium is not water. As with the humidity (relative humidity) of water, the humidity of a medium is the ratio of the actual mass of the medium to the maximum mass of the medium in a gaseous state that the gas can contain. Note that terms such as moisture and vapor pressure are also used for media other than water, just like humidity.

[0183] In addition, when the ink contains multiple media, the following description may be considered to be about the media with the highest mass content among the media, or may be considered to be about media with the highest mass content among the media, with the total mass content being 60 mass % or more, 70 mass % or more, or even 80 mass % or more.

[0184] The ink medium evaporated from the ink printed on the media 101 is contained in the gas in the path 103. When the humidity is high and the proportion of the medium in the ink decreases as the drying progresses, vapor pressure from the gas toward the ink exists, which may prevent the ink from drying or may cause the ink to dry slower than expected given the temperature and wind speed. By flowing warm air in the opposite direction to the transport direction at any point during drying, the amount of moisture in the gas can be reduced downstream from the point on the path 103 where drying is most active. This allows drying to progress even in the latter half of the drying process, even when the proportion of the medium in the ink has decreased. This allows the proportion of the medium in the ink to be reduced after drying by the warm air and irradiation is completed. The portion where the warm air flows in the opposite direction to the transport direction is preferably located upstream within the path 103. Specifically, the portion where the warm air flows in the opposite direction to the transport direction is preferably located within the upstream two-thirds of the path 103, or within the upstream half of the path 103.

[0185] Near the first irradiation unit 7A, moisture is rapidly generated by irradiation by the first irradiation unit 7A. If the warm air is directed downstream in the conveyance direction at the position of the first irradiation unit 7A, drying becomes relatively difficult in areas downstream in the conveyance direction from the first irradiation unit 7A where humidity is high. By directing the warm air from the position of the first irradiation unit 7A upstream in the conveyance direction, the humidity downstream in the conveyance direction from the first irradiation unit 7A can be reduced, allowing drying to be faster. The moisture that flows upstream in the conveyance direction from the first irradiation unit 7A is sucked in by the first suction unit 9A.

[0186] As described above, drying can be performed using warm air directed upstream in the transport direction along path 103, but the following point should be considered. At the downstream end of path 103 in the transport direction, there is an opening for outlet 25b for transporting media 101 out of drying device 619. Because warm air leaks out of drying device 619, it is difficult to flow warm air directed upstream in the transport direction along the entire path 103. Therefore, air is blown by first air blower 5A along path 103, generating warm air directed upstream in the transport direction from first air blower 5A and warm air directed downstream in the transport direction. Then, first irradiation unit 7A, located midway along the warm air directed upstream in the transport direction from first air blower 5A, irradiates UV light on media 101 to promote drying.

[0187] Moisture generated by irradiation by the first irradiation unit 7A or moisture generated by the hot air near the first irradiation unit 7A flows upstream in the transport direction and is sucked by the first suction unit 9A. The humidity of the hot air flowing upstream in the transport direction from the first irradiation unit 7A increases, but the ink has not yet dried at that position, and the high vapor pressure from the ink to gas may cause drying to progress. Furthermore, even if the ink itself does not dry at this position, the temperature of the ink and media 101 can be increased, which can accelerate drying downstream in the transport direction.

[0188] By setting the speed of the hot air at the position of the first irradiation unit 7A to 3 m / s or more, preferably 5 m / s or more, and particularly 7 m / s or more, moisture can be removed quickly and the humidity of the gas can be reduced, thereby speeding up drying, thereby increasing the drying rate of the ink when it reaches the first blower unit 5A.

[0189] Furthermore, the medium 101 that has passed through the first air blowing section 5A is dried by the warm air flowing downstream in the transport direction from the first air blowing section 5A. Before reaching the first air blowing section 5A, 60% by mass or more, preferably 70% by mass or more, and particularly 80% by mass or more of the medium in the ink may be dried. In this way, since drying has progressed by the time the ink reaches the first air blowing section 5A, the humidity downstream in the transport direction from the first air blowing section 5A can be reduced, allowing the ink with a reduced medium content to be dried. By setting the humidity of the gas from the first air blowing section 5A to the second suction section to 95% or less, preferably 90% or less, and particularly 80% or less, the ink with a reduced medium content due to drying can be dried. By setting the humidity from the first air blowing section 5A to the first suction section 9A to be higher than the humidity from the first air blowing section 5A to the second suction section 9B, the drying process from the first air blowing section 5A to the second suction section 9B can be accelerated. The humidity from the first blower 5A to the second suction unit 9B may be considered to be the humidity at the position of the first irradiation unit 7A. The humidity at the position of the first irradiation unit 7A may be, for example, 80% or more, further 90% or more, particularly 95% or more.

[0190] If the wind speed of the gas flowing from the first air blower 5A in the direction of the first suction unit 9A is faster than the wind speed of the gas flowing from the first air blower 5A in the direction of the second suction unit 9B, the drying progresses faster on the upstream side of the path 103 in the transport direction, and the humidity can be lowered on the downstream side of the first air blower 5A in the transport direction, allowing the ink whose medium content has been reduced by drying to dry more quickly. The wind speed can be compared between a position on the upstream side of the first air blower 5A in the transport direction that is adjacent to that position and where there are not yet any other air blowers 5, irradiation units 7, or suction units 9, and a position on the downstream side of the first air blower 5A in the transport direction that is adjacent to that position and where there are not yet any other air blowers 5, irradiation units 7, or suction units 9. In addition, when the third blower section 5C is positioned opposite the first blower section 5A, the wind speed of the gas flowing upstream in the conveying direction and the wind speed of the gas flowing downstream in the conveying direction may be compared for the warm air blown by the first blower section 5A and the third blower section 5C.

[0191] The wind speed of the gas flowing upstream and downstream in the conveying direction may be adjusted, for example, as follows: The suction volume of the first suction unit 9A may be increased relative to the suction volume of the second suction unit 9B. When other suction units 9 are present, the total suction volume of the suction units 9 located upstream in the conveying direction (e.g., the first suction unit 9A and the third suction unit 9C) may be increased relative to the total suction volume of the suction units 9 located downstream in the conveying direction (e.g., the second suction unit 9B and the fourth suction unit 9D). The distance along the path 103 from the first blower 5A to the first suction unit 9A may be shortened relative to the distance along the path 103 from the first blower 5A to the second suction unit 9B. The average cross-sectional area of ​​the path 103 from the first blower 5A to the first suction unit 9A may be narrowed relative to the average cross-sectional area of ​​the path 103 from the first blower 5A to the first suction unit 9A. The flow path resistance from the first blower 5A to the first suction unit 9A may be adjusted to be lower than the flow path resistance from the first blower 5A to the second suction unit 9B. Note that the flow path resistance may be evaluated assuming a case where no gas flows through the blower 5 and the suction unit 9 (they are closed). For example, if there are other blower units 5 and suction units 9 between the first blower 5A and the first suction unit 9A, the flow path resistance may be evaluated based on the case where no gas flows through those units (they are closed).

[0192] If the volume of gas flowing from the first blower 5A toward the first suction unit 9A is greater than the volume of gas flowing from the first blower 5A toward the second suction unit 9B, moisture is expelled more quickly, reducing humidity, accelerating the drying process upstream of the vapor path 103 in the transport direction. This reduces humidity downstream of the first blower 5A in the transport direction, allowing the ink whose medium content has been reduced by drying to dry more quickly. The air volume may be adjusted in the same manner as for the air speed, with respect to the suction volume and flow path resistance. Regarding the cross-sectional area, the air volume may be adjusted by making the average cross-sectional area of ​​the path 103 from the first blower 5A to the first suction unit 9A larger than the average cross-sectional area of ​​the path 103 from the first blower 5A to the second suction unit 9B.

[0193] If the second blower 5B is positioned so that at least a portion faces the first blower 5A, it can combine with the warm air blown from the first blower 5A to form warm air flowing upstream and downstream in the conveyance direction. If the second blower 5B and the first blower 5A are positioned substantially the same in the conveyance direction, the two blower airs can combine to efficiently form warm air flowing upstream and downstream in the conveyance direction. Furthermore, this configuration can approximate the ratio of the warm air flowing upstream and downstream in the conveyance direction from the first blower 5A to the ratio of the warm air flowing upstream and downstream in the conveyance direction from the second blower 5B. This configuration can reduce the difference in the ratio of the pressure applied by the gas to the top surface of the media 101 and the pressure applied to the bottom surface between the upstream and downstream sides of the positions where the first blower 5A and the second blower 5B are provided. This increases the vertical positional stability of the media 101 at the positions where the first air blower 5A and the second air blower 5B are provided, reducing the possibility of contact with the wall surface of the path 103. When the second air blower 5B is provided, the possibility of contact can be further reduced by providing the third suction unit 9C and the fourth suction unit 9D. Even when the first air blower 5A and the second air blower 5B are not opposed to each other, hot air can be configured to flow upstream and downstream in the conveying direction as long as the suction unit 9 is not disposed between the first air blower 5A and the second air blower 5B.

[0194] As described above, in the printer 601, warm air is blown upstream in the transport direction from the first air blower 5A, and irradiation is performed from the first irradiation unit 7A through this warm air. This causes drying to occur near the first irradiation unit 7A, and moisture generated by the warm air and irradiation flows upstream in the transport direction and is sucked by the first suction unit 9A, without substantially flowing downstream in the transport direction. The ink on the medium 101 that has passed through the first air blower 5A is exposed to relatively low-humidity warm air that flows downstream in the transport direction from the first air blower 5A. This allows the ink, which has already dried to a certain extent and has a low medium content, to be further dried (reduced medium content) on the medium 101 as it is transported from the drying device 619. The drying rate, defined as the ratio of the medium that has dried from the ink on the medium 101 by the time it is discharged from the drying device 619 to the medium contained in the ink to be printed, can be 95% or more, even 97% or more, and particularly 99% or more.

[0195] By reducing the air volume at the inlet 25a to between -25% and 25% (the direction outward from the inlet 25a is considered the positive direction) relative to the air volume flowing from the first blower 5A to the first suction unit 9A, it is possible to reduce the effects of the wind, temperature, and humidity on the head 3. By setting the air volume at the inlet 25a to between -10% and 10%, it is possible to further reduce the effects on the head 3. By directing the air at the inlet 25a in the direction entering the drying device 619 from the outside, it is possible to reduce the effects of the temperature and humidity on the head 3.

[0196] Furthermore, when suction is performed by the second suction unit 9B, the flow of warm air flowing upstream and downstream in the conveyance direction can be stabilized. The warm air sucked by the second suction unit 9B can be used to heat the warm air used in the blower unit 5 via the heat exchanger. Furthermore, by adjusting at least one of the dimensions and shape of the path 103 and the ratio of the suction amounts of the first suction unit 9A and the second suction unit 9B (including the case where a pre-adjusted value is designed), the flow of warm air can be made to be stable.

[0197] Drying downstream in the transport direction from the first air blower 5A is performed by the warm air blown by the first air blower 5A, but a second irradiation unit 7B may also be provided to further promote drying. Because the humidity is relatively low at the position of the second irradiation unit 7B, irradiation can accelerate drying even for ink whose medium content has decreased due to drying. By making the humidity at the position of the first irradiation unit 7A higher than the humidity at the position of the second irradiation unit 7B, the drying process caused by irradiation by the second irradiation unit 7B can be accelerated.

[0198] By increasing the irradiation amount of the first irradiation unit 7A compared to the irradiation amount of the second irradiation unit 7B (while keeping the total irradiation amount the same, but changing the ratio), drying can be further accelerated in the warm air blown upstream in the transport direction from the first air blowing unit 5A, reducing humidity at the position of the second irradiation unit 7B and ultimately reducing the medium content in the ink. The energy input to the first irradiation unit 7A may be greater than the energy input to the second irradiation unit 7B. The number of light sources 7a included in the first irradiation unit 7A may be greater than the number of light sources 7a included in the second irradiation unit 7B. The size of the arrangement range of the light sources 7a included in the first irradiation unit 7A along the transport direction may be greater than the size of the arrangement range of the light sources 7a included in the second irradiation unit 7B along the transport direction. The arrangement density of the light sources 7a included in the first irradiation unit 7A may be greater than the arrangement density of the light sources 7a included in the second irradiation unit 7B.

[0199] The distance along the path 103 from the irradiation unit 7 to the head 3 that is furthest from the irradiation unit 7 along the path 103 may be 0.5 m or more and 2.0 m or less.

[0200] In this case, for example, by setting the distance to 2.0 m or less, UV irradiation can be started after the ink lands on the medium 101, before there is much ink bleeding or surface spreading. As a result, bleeding or surface spreading can be stopped or slowed down. Furthermore, by setting the distance to 0.5 m or more, the likelihood of heat from UV irradiation reaching the position of the head 3 is reduced.

[0201] The technology according to the present disclosure is not limited to the above-described embodiments and may be implemented in various forms.

[0202] For example, the drying device may have components that contribute to drying other than the irradiation unit, the air blowing unit, and the suction unit. For example, a heating roller that contacts the underside of the recording medium may be disposed at a position opposite to the irradiation unit, the air blowing unit, and / or the suction unit located on the upper side (the side to be printed) of the recording medium, with the recording medium sandwiched therebetween.

[0203] Also, for example, the media is not limited to paper or film, but may be, for example, cut cloth, wood, or tiles transported by a transport unit including a belt conveyor.

[0204] An invention that does not require a suction unit may be extracted from this disclosure. For example, an invention that requires a blower unit that blows warm air by utilizing the exhaust heat of the irradiation unit may be extracted.

[0205] 1...printer (recording device), 3...head, 5...blowing section, 5A...first blowing section, 7...irradiation section, 9...suction section, 9A...first suction section, 11...recording system, 19...drying device, 101...media (recording medium), 103...path.

Claims

1. An inkjet printing drying device including a first irradiation unit for emitting ultraviolet rays to a recording medium, a first air blowing unit for sending warm air, and a first suction unit for sucking gas, wherein the first irradiation unit is disposed between the first air blowing unit and the first suction unit.

2. The inkjet printing drying device according to claim 1, further including a second air blowing unit for sending warm air, wherein the first suction unit is disposed between the first irradiation unit and the second air blowing unit.

3. The inkjet printing drying device according to claim 2, wherein the first irradiation unit, the first air blowing unit, and the second air blowing unit are disposed facing a path along which the recording medium is conveyed, and on the path, between the second air blowing unit and the first suction unit, the air flow direction is from the second air blowing unit toward the first suction unit.

4. The inkjet printing drying device according to claim 3, wherein on the path, between the first irradiation unit and the first suction unit, the air flow direction is from the first irradiation unit toward the first suction unit.

5. The inkjet printing drying device according to any one of claims 2 to 4, further including a second suction unit for sucking gas, wherein the second air blowing unit is disposed between the first irradiation unit and the second suction unit.

6. The inkjet printing drying device according to any one of claims 1 to 5, wherein the first irradiation unit and the first air blowing unit are disposed facing a path along which the recording medium is conveyed, and when a direction from the first irradiation unit toward the first air blowing unit along the path is defined as a first direction, in the path, the air volume of the gas flowing in the first direction from the first air blowing unit is 0.2 times or less of the air volume of the first air blowing unit.

7. The inkjet printing drying device according to any one of claims 1 to 6, wherein the first irradiation unit and the first air blowing unit are disposed facing a path along which the recording medium is conveyed, and when a direction from the first irradiation unit toward the first air blowing unit along the path is defined as a first direction, in the path, the air speed of the gas flowing in the first direction from the first air blowing unit is 0.3 times or less of the air speed of the gas flowing in the reverse direction of the first direction from the first air blowing unit.

8. The first irradiation unit and the first air blowing unit are arranged facing the path along which the recording medium is conveyed, and include a third air blowing unit that blows warm air and faces at least one of the first irradiation unit and the first air blowing unit with the path therebetween, the drying device for inkjet printing according to any one of claims 1 to 7.

9. When the direction from the first irradiation unit toward the first air blowing unit along the path is defined as the first direction, the third air blowing unit is located on the opposite side of the first direction in the path with respect to at least a part of the first air blowing unit, the drying device for inkjet printing according to claim 8.

10. The first irradiation unit and the first air blowing unit are arranged facing the path along which the recording medium is conveyed. When the direction from the first irradiation unit toward the first air blowing unit along the path is defined as the first direction, the drying device for inkjet printing according to claim 5 includes a third air blowing unit that blows warm air and faces at least one of the first irradiation unit and the first air blowing unit with the path therebetween, and a fourth air blowing unit that blows warm air and faces the second air blowing unit with the path therebetween.

11. It includes a third suction unit located between the third air blowing unit and the fourth air blowing unit, and a fourth suction unit located in the direction opposite to the first direction in the path with respect to the fourth air blowing unit. The first air blowing unit, the first suction unit, the second air blowing unit, and the second suction unit are located on the side of the first irradiation unit with respect to the path, and the third air blowing unit, the third suction unit, the fourth air blowing unit, and the fourth suction unit are located on the side opposite to the first irradiation unit with respect to the path, the drying device for inkjet printing according to claim 10.

12. It includes a second suction unit for sucking gas, and the first air blowing unit and the first irradiation unit are arranged between the first suction unit and the second suction unit, the drying device for inkjet printing according to claim 1.

13. It includes a second irradiation unit for emitting ultraviolet rays to the recording medium, and the second irradiation unit is arranged between the first air blowing unit and the second suction unit, the drying device for inkjet printing according to claim 12.

14. The first irradiation unit, the second irradiation unit, the first air blowing unit, the first suction unit, and the second suction unit are arranged facing the path along which the recording medium is conveyed, and include a third suction unit and a fourth suction unit for sucking gas. The third suction unit and the fourth suction unit are located on the side opposite to the first suction unit and the second suction unit with respect to the path. The first irradiation unit, the second irradiation unit, the first air blowing unit, the third suction unit, and the fourth suction unit are arranged in the order of the third suction unit, the first irradiation unit, the first air blowing unit, the second irradiation unit, and the fourth suction unit along the path. The drying device for inkjet printing according to claim 13.

15. The first air blowing unit, the first suction unit, and the second suction unit are arranged facing the path along which the recording medium is conveyed. In the path, the wind speed of the gas flowing from the first air blowing unit in the direction of the first suction unit is faster than the wind speed of the gas flowing from the first air blowing unit in the direction of the second suction unit. The drying device for inkjet printing according to any one of claims 12 to 14.

16. The first irradiation unit, the first air blowing unit, the first suction unit, and the second suction unit are arranged facing the path along which the recording medium is conveyed, and include a third air blowing unit for sending warm air. The third air blowing unit is located on the side opposite to the first air blowing unit with respect to the path. The third air blowing unit is located between the first irradiation unit and the second suction unit. The drying device for inkjet printing according to any one of claims 12 to 15.

17. The first irradiation unit, the first air blowing unit, the first suction unit, and the second suction unit are arranged facing the path along which the recording medium is conveyed, and include a third suction unit and a fourth suction unit for sucking gas. The third suction unit is located on the side opposite to the first suction unit with respect to the path. The fourth suction unit is located on the side opposite to the second suction unit with respect to the path. The first irradiation unit, the first air blowing unit, the third suction unit, and the fourth suction unit are arranged in the order of the third suction unit, the first irradiation unit, the first air blowing unit, and the fourth suction unit along the path. The drying device for inkjet printing according to any one of claims 12 to 16.

18. The first irradiation unit, the first air supply unit, the first suction unit, and the second suction unit are arranged facing the path along which the recording medium is conveyed. A third suction unit for sucking gas, which faces the first suction unit with the path therebetween. A fourth suction unit for sucking gas, which faces the second suction unit with the path therebetween. The drying device for inkjet printing according to any one of claims 12 to 17, which includes these.

19. The ultraviolet illuminance of the first irradiation unit is 4000 mW / cm ２ or less. The drying device for inkjet printing according to any one of claims 1 to 18.

20. The first irradiation unit and the first air supply unit are arranged facing the path along which the recording medium is conveyed. The first irradiation unit includes an opposing surface facing the path. The opposing surface has an opening that transmits ultraviolet rays toward the path. The region around the opening in the opposing surface includes a mirror surface. The drying device for inkjet printing according to any one of claims 1 to 19, which has these.

21. The drying device for inkjet printing according to any one of claims 1 to 20, which includes a housing box that has an inlet and an outlet of the recording medium and houses the first irradiation unit, the first air supply unit, and the first suction unit.

22. The drying device for inkjet printing according to any one of claims 1 to 21, which includes a flow path that supplies gas that has absorbed heat generated inside the first irradiation unit to the first air supply unit.

23. A recording system that includes the drying device for inkjet printing according to any one of claims 1 to 22, and a head that discharges ink onto the recording medium.

24. The recording system according to claim 23, and a conveyance unit that conveys the recording medium in the conveyance direction along a path. The first irradiation unit and the first air supply unit face the path and are arranged in the order of the first air supply unit and the first irradiation unit along the conveyance direction. The head is arranged facing the path upstream of the drying device in the conveyance direction in the path. A recording device.

25. A recording apparatus including: a drying device for inkjet printing according to claim 12; a head for discharging ink onto the recording medium; and a conveying unit for conveying the recording medium in a conveying direction along a path, wherein the first irradiation unit, the first blowing unit, the first suction unit, and the second suction unit face the path and are arranged in this order along the conveying direction: the first suction unit, the first irradiation unit, the first blowing unit, and the second suction unit, and the head is arranged to face the path upstream of the drying device in the conveying direction in the path.

26. A recording apparatus including: a drying device for inkjet printing according to claim 13; a head for discharging ink onto the recording medium; and a conveying unit for conveying the recording medium in a conveying direction along a path, wherein the first irradiation unit, the second irradiation unit, the first blowing unit, the first suction unit, and the second suction unit face the path and are arranged in this order along the conveying direction: the first suction unit, the first irradiation unit, the first blowing unit, the second irradiation unit, and the second suction unit, and the head is arranged to face the path upstream of the drying device in the conveying direction in the path.

27. The recording apparatus according to any one of claims 24 to 26, wherein the distance along the path from the first irradiation unit to the head that is farthest from the first irradiation unit along the path is 0.5 m or more and 2.0 m or less.

28. A printing method using the drying device for inkjet printing according to claim 1, the method including the step of attaching ink containing an ultraviolet absorber and not polymerized by ultraviolet rays to the recording medium at a position upstream of the first blowing unit in the conveying direction of the recording medium.

29. A printing method using the drying device for inkjet printing according to claim 25 or 26, the method drying 60% by mass or more of the medium contained in the ink on the recording medium before reaching the first blowing unit.

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