JP2012224049A - Apparatus and method for jetting droplet - Google Patents

Abstract

An amount of wetting and spreading of ultraviolet curable ink ejected onto an ejected object can be adjusted.
An ultraviolet ray irradiating unit for adjusting an ultraviolet ray irradiation state applied to an ultraviolet ray curable ink jetted to a jetted part includes an ultraviolet ray irradiation state, the ultraviolet ray irradiation time for the ultraviolet ray curable ink, and the ultraviolet ray. The irradiation adjustment unit is a lifting unit 82 that adjusts the distance from the light emitting unit 81 to the injection target, a tilting unit that adjusts the ultraviolet emission direction of the light emitting unit, a control unit that adjusts the output of the light emitting unit, It is a control part which adjusts the moving speed with respect to the to-be-injected object of a light emission part.
[Selection] Figure 5

Description

  The present invention relates to a droplet ejecting apparatus and a droplet ejecting method.

  The droplet ejecting apparatus includes an ejecting head in which nozzles for ejecting ink are formed. By relatively moving the ejecting head and the ejected object, the ink is ejected and arranged in a wide range of the ejected object.

  As such a liquid droplet ejecting apparatus, an apparatus including a light emitting unit that ejects ultraviolet curable ink as ink and emits ultraviolet rays irradiated to the ultraviolet curable ink ejected onto an ejected object is known. (For example, refer to Patent Document 1).

Japanese Patent Laying-Open No. 2005-313445

By the way, since the ultraviolet curable ink is an ink that is cured by being irradiated with ultraviolet rays, the viscosity is low and spreads until the ultraviolet rays are irradiated. Therefore, in order to realize higher-definition drawing, a droplet ejecting apparatus that ejects ultraviolet curable ink is configured to irradiate ultraviolet curable ink with ultraviolet rays in a short time.
For this reason, in general, in a droplet ejecting apparatus, a light emitting unit is fixed in the vicinity of the ejecting head, and a configuration in which ultraviolet rays are immediately irradiated to the ultraviolet curable ink ejected from the ejecting head is conceivable. ing.

  However, high-definition drawing is not always required depending on the pattern to be drawn by the droplet ejecting apparatus. For example, when a pattern such as a gradation is included, rough drawing may be suitable.

In the conventional droplet ejecting device, the irradiation time and amount of the ultraviolet light emitted by the light emitting unit cannot be adjusted, and the UV curable ink ejected from the ejecting head is always in the same amount of wetting and spreading. Will be cured.
For this reason, the wet spread amount of the ultraviolet curable ink cannot be adjusted according to the pattern to be drawn.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a droplet ejecting apparatus and a droplet ejecting method capable of adjusting the amount of wetting and spreading of ultraviolet curable ink ejected onto an ejected object. And

  As means for solving the above problems, the present invention adopts the following configuration.

  According to a first aspect of the present invention, there is provided a liquid droplet ejecting apparatus comprising: an ejection head that ejects ultraviolet curable ink onto an ejected object; and a light emitting unit that emits ultraviolet light that irradiates the ultraviolet curable ink ejected onto the ejected object. And the structure of having an irradiation control part which adjusts the irradiation state of the said ultraviolet-ray irradiated to the said ultraviolet curable ink sprayed on the said to-be-jetted part is employ | adopted.

The ultraviolet curable ink is cured as the cumulative amount of the irradiated ultraviolet light increases.
Here, the integrated light amount is a value proportional to the illuminance of ultraviolet rays and the irradiation time, with the illuminance of ultraviolet rays and the irradiation time as parameters.
For this reason, in curing the ultraviolet curable ink, it is necessary to lengthen the irradiation time when the illuminance of the ultraviolet light is low, and it is necessary to increase the illuminance of the ultraviolet light in order to shorten the ultraviolet irradiation time.
The ultraviolet curable ink spreads wet until the cumulative amount of ultraviolet light exceeds a certain threshold. In other words, if it is possible to adjust the irradiation state of the ultraviolet rays radiated to the ultraviolet curable ink, it is possible to adjust the time until the cumulative amount of ultraviolet light exceeds a certain threshold, and the amount of wet spread of the ultraviolet curable ink Can be adjusted.
According to the present invention, the irradiation state is adjusted by the irradiation adjusting unit.
Therefore, according to the present invention, it is possible to adjust the amount of wetting and spreading of the ultraviolet curable ink ejected to the ejected object, and it is possible to draw various patterns.

  According to a second invention, in the first invention, the irradiation state of the ultraviolet rays is such that the illuminance of the ultraviolet rays with respect to the ultraviolet curable ink, the irradiation time of the ultraviolet rays with respect to the ultraviolet curable ink, and the ultraviolet rays with respect to the ultraviolet curable ink. A configuration in which one or a plurality of irradiation start timings is employed is adopted.

  According to the present invention employing such a configuration, one or more of the illuminance of ultraviolet rays to the ultraviolet curable ink, the irradiation time of ultraviolet rays to the ultraviolet curable ink, and the irradiation start timing of ultraviolet rays to the ultraviolet curable ink are adjusted. This makes it possible to easily adjust the amount of wetting and spreading of the ultraviolet curable ink ejected onto the ejected object.

  According to a third aspect of the present invention, in the first or second aspect of the invention, the irradiation adjustment unit is a lifting unit that adjusts a distance from the light emitting unit to the ejected object by moving the light emitting unit up and down. Is adopted.

  According to the present invention employing such a configuration, it is possible to easily adjust the irradiation state of the ultraviolet rays by adjusting the distance from the light emitting unit to the injection target by the elevating unit.

  According to a fourth invention, in the first or second invention, the irradiation adjusting unit is a tilting unit that adjusts an ultraviolet emission direction of the light emitting unit by tilting the light emitting unit.

  According to the present invention employing such a configuration, the irradiation state of ultraviolet rays can be easily adjusted by adjusting the ultraviolet emission direction of the light emitting unit by the tilting unit.

  According to a fifth aspect of the present invention, in the first or second aspect of the invention, the irradiation adjustment unit is a control unit that adjusts the output of the light emitting unit.

  According to the present invention employing such a configuration, the irradiation state of ultraviolet rays can be easily adjusted by adjusting the output of the light emitting unit by the control unit.

  According to a sixth aspect of the present invention, in the first or second aspect of the invention, the irradiation adjustment unit is a control unit that adjusts a moving speed of the light emitting unit with respect to the injection target.

  According to the present invention, the irradiation state of the ultraviolet light can be easily adjusted by adjusting the moving speed of the light emitting unit with respect to the injection target by the control unit.

  A seventh invention adopts a configuration in which, in the sixth invention, the ejection head and the light emitting unit are movable independently.

  According to the present invention employing such a configuration, the moving speed of the ejection head and the moving speed of the light emitting unit can be made different, so that the ultraviolet irradiation state can be adjusted more flexibly.

  An eighth invention is a droplet jetting method in which an ultraviolet curable ink is jetted onto an ejected object, and the ultraviolet curable ink ejected onto the ejected object is irradiated with ultraviolet rays, and is ejected onto the ejected portion. A configuration is adopted in which the irradiation state of the ultraviolet rays irradiated to the ultraviolet curable ink is adjusted.

  According to the present invention employing such a configuration, it is possible to adjust the amount of wetting and spreading of the ultraviolet curable ink ejected to the ejected object, and it is possible to draw various patterns.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram illustrating a schematic configuration of a droplet ejecting apparatus according to an embodiment of the present invention, where (a) is a plan view of the droplet ejecting apparatus and (b) is a side view of the droplet ejecting apparatus. (A)-(c) is a figure which shows schematic structure of an ejection head. It is a top view which shows the ejection surface (lower surface) of an ejection head. It is a bottom view which shows schematic structure of a head unit. It is a side surface schematic diagram containing the light emission part with which the droplet ejecting apparatus in one Embodiment of this invention is provided. It is a side surface schematic diagram containing the light emission part with which the modification of the droplet ejecting apparatus in one Embodiment of this invention is provided. It is a side surface schematic diagram containing the light emission part with which the modification of the droplet ejecting apparatus in one Embodiment of this invention is provided.

  DESCRIPTION OF EMBODIMENTS Hereinafter, an embodiment of a droplet ejecting apparatus and a droplet ejecting method according to the present invention will be described with reference to the drawings. In the following drawings, the scale of each member is appropriately changed in order to make each member a recognizable size.

1A and 1B are schematic views showing a schematic configuration of a first embodiment of a droplet ejecting apparatus according to the present invention, wherein FIG. 1A is a plan view of the droplet ejecting apparatus, and FIG. FIG. 3 is a side view of the droplet ejecting apparatus. FIGS. 1A and 1B show a case where the droplet ejecting apparatus of the present invention is applied to a printing apparatus that performs printing on a continuous long recording medium 10 (conveyed medium). ing. In FIGS. 1A and 1B, reference numeral 1 denotes a droplet ejecting apparatus. The droplet ejecting apparatus 1 includes an ejecting head 20 that ejects droplets of ultraviolet curable ink as ink, and an ejecting head 20. An irradiation device 80 (see FIG. 4) for irradiating the ejected ultraviolet curable ink S (see FIG. 6 and the like) with ultraviolet rays is provided.
The droplet ejecting apparatus 1 according to the present embodiment includes a head mechanism unit 2 having an ejecting head 20, a supply / discharge mechanism unit 3, an ink supply unit (not shown), a maintenance unit 5, and a control unit 60. , And is configured.

  The ejection head 20 is an inkjet ejection head, and includes an ink containing an ultraviolet curable component, that is, an ultraviolet curable ink S as droplets, and a recording portion of a continuous long band-shaped recording medium 10. It is sprayed toward the surface. Here, as the recording medium 10, a medium capable of recording with the ultraviolet curable ink S is used in this embodiment, and specifically, polyethylene terephthalate (PET), polyethylene (PE), polycarbonate (PC), and polypropylene are used. A flexible film such as (PP) is used.

  The supply / discharge mechanism unit 3 supplies (conveys) the recording medium 10 to a recording position by the ejection head 20 and discharges (conveys) the recording medium 10 from the recording position. The ink supply unit supplies ink stored in a storage tank (not shown) to the ejection head 20. The maintenance unit 5 performs maintenance of the ejection head 20. In this embodiment, the maintenance unit 5 recovers the nozzle ejection state by cleaning the ejection head 20.

The supply / discharge mechanism unit 3 includes a supply reel 31, a take-up reel 32, a suction unit 33, an idler roller 37, an idler roller 38, and a Y-axis scanning mechanism 42.
The Y-axis scanning mechanism 42 includes two sets of Y-axis guide rails 42a and Y-axis sliders 42b. The suction unit 33 includes a suction table 33a, a table base 43, a table lifting mechanism 44, a supply roller 34, a driven roller 34a, a medium feeding roller 36, and a driven roller 36a. Each reel and each roller are rotatable around a rotation axis, and the respective rotation axes are substantially parallel to each other.
The direction in which the recording medium 10 is fed is a direction substantially orthogonal to the rotation axes of the reels and rollers that are substantially parallel to each other. A direction parallel to the axial direction of the rotation axis of each reel and each roller is expressed as an X-axis direction, and a feeding direction of the recording medium 10 is expressed as a Y-axis direction.

  One Y-axis guide rail 42a of the Y-axis scanning mechanism 42 is disposed on each side in the X-axis direction with the suction table 33a interposed therebetween, and extends in the Y-axis direction. The Y-axis slider 42b is provided on the bottom surface of the table base 43 and is disposed on the Y-axis guide rail 42a in that state. The Y-axis slider 42b is moved on the Y-axis guide rail 42a by a Y-axis drive motor (not shown). It is configured to slide in the extending direction.

  The suction table 33 a of the suction unit 33 is fixed to a table lifting mechanism 44 fixed on the table base 43. The suction table 33a is configured to hold the recording medium 10 on the upper surface thereof, and therefore, the upper surface is a surface on the side that holds the recording medium 10, that is, a holding surface. Under such a configuration, the ultraviolet curable ink S is ejected from the ejection head 20 in a state where the recording medium 10 is held on the holding surface, and droplets of the ink land on the recording medium 10. It is like that.

The suction table 33a is provided with a suction recess (not shown) consisting of a suction hole or suction groove connected to a negative pressure source (not shown), and the suction recess opens on the holding surface. .
As a result, the recording medium 10 is held and fixed on the holding surface by being sucked and sucked by the suction recess connected to the negative pressure source in a state where the predetermined portion is positioned on the holding surface. It has become.

  The table raising / lowering mechanism 44 raises and lowers the suction table 33a in the Z-axis direction. The holding position (suction surface) of the suction table 33a becomes a predetermined position in the Z-axis direction, and the table base from the suction position. It is moved up and down between the retreat positions close to 43 and is held and fixed at each position. The position of the holding surface of the suction table 33a when in the suction position substantially coincides with the positions of the upper ends of the outer periphery of the supply roller 34 and the outer periphery of the medium feed roller 36, which will be described later. Here, the Z-axis direction refers to the normal direction on the holding surface of the suction table 33a.

  On both sides of the suction table 33a in the Y-axis direction, a supply roller 34 and a driven roller 34a, and a medium feeding roller 36 and a driven roller 36a are disposed. The supply roller 34 and the driven roller 34a, and the medium feeding roller 36 and the driven roller 36a are fixed to the table base 43 via a support member (not shown), and in that state, the suction table 33a is sandwiched on both sides thereof. It is arranged. The supply roller 34 and the driven roller 34a are disposed on the upstream side of the suction table 33a, that is, on the supply reel 31 side, and the medium feed roller 36 and the driven roller 36a are on the downstream side of the suction table 33a, that is, the take-up reel 32. It is arranged on the side.

  The table base 43 can be moved in the Y-axis direction by the Y-axis scanning mechanism 42 and can be held at an arbitrary position in the Y-axis direction. The suction table 33a, the supply roller 34 and the driven roller 34a, the medium feeding roller 36 and the driven roller 36a arranged on the table base 43 are also movable in the Y-axis direction by the Y-axis scanning mechanism 42. And it can hold | maintain in the arbitrary positions in a Y-axis direction.

  The supply reel 31, the idler roller 37, the suction unit 33, the idler roller 38, and the take-up reel 32 included in the supply / discharge mechanism unit 3 are arranged in this order in the Y-axis direction, which is the supply direction of the recording medium 10. The supply reel 31 side is the upstream side in the supply direction of the recording medium 10, and the take-up reel 32 side is the downstream side.

  In the suction unit 33, the supply roller 34 and the driven roller 34a, the suction table 33a, the medium feeding roller 36, and the driven roller 36a are arranged in this order in the Y-axis direction. Therefore, in the supply / discharge mechanism 3, the supply reel 31, the idler roller 37, the supply roller 34 and the driven roller 34a, the suction table 33a, the medium feeding roller 36 and the driven roller 36a, the idler roller 38, and the winding roller The reels 32 are arranged in this order in the Y-axis direction.

  A belt-shaped recording medium 10 is wound around the supply reel 31, and the recording medium 10 is fed out by rotating the supply reel 31 by a supply motor (not shown). The outer periphery of the driven roller 34a is disposed in contact with the outer periphery of the supply roller 34 and is pressed against the supply roller 34 by an urging device (not shown). The supply roller 34 is rotated by a supply motor (not shown), and the driven roller 34 a that is in direct or indirect contact with the supply roller 34 is rotated by the rotation of the supply roller 34. It has become. Under such a configuration, the recording medium 10 sandwiched between the supply roller 34 and the driven roller 34 a is fed by the rotation of the supply roller 34.

  The idler roller 37 has a rotating shaft that can swing in the Z-axis direction and is biased to one of the swing directions (downward in the present embodiment). The idler roller 37 is brought into contact with the portion of the recording medium 10 between the supply reel 31, the supply roller 34, and the driven roller 34a by the urging force. Under such a configuration, the recording medium 10 is urged by the idler roller 37, so that it is between the supply reel 31 and the idler roller 37, and between the idler roller 37, the supply roller 34, and the driven roller 34a. The part of is stretched without slack.

  Therefore, the state when the recording medium 10 is supplied and sandwiched between the supply roller 34 and the driven roller 34a is easily maintained substantially flat. Note that the amount of slack in the portion between the supply reel 31, the supply roller 34, and the driven roller 34a varies depending on the difference between the supply speed of the recording medium 10 in the supply roller 34 and the feeding speed of the recording medium 10 in the supply reel 31. To do. However, by changing the position of the idler roller 37 following the fluctuation of the slack amount, the tensioned state is maintained without slack. Similarly, the fluctuation of the slack amount of the recording medium 10 between the supply reel 31, the supply roller 34, and the driven roller 34a due to the movement of the suction unit 33 is also maintained in a tensioned state without any slack. It has become.

  The outer periphery of the driven roller 36a is disposed in contact with the outer periphery of the supply roller 36, and is pressed against the medium feeding roller 36 by an urging device (not shown). The medium feed roller 36 is rotated by a medium feed motor (not shown), and a driven roller 36a that directly or indirectly contacts the medium feed roller 36 is driven by the rotation of the medium feed roller 36. To rotate. Under such a configuration, the recording medium 10 sandwiched between the medium feeding roller 36 and the driven roller 36 a is fed by the rotation of the medium feeding roller 36.

  Here, the feed amount by the medium feed roller 36 is set to be larger than the feed amount by the supply roller 34. Further, a torque control mechanism (not shown) is incorporated in the power transmission mechanism from the medium feed motor to the medium feed roller 36. Under such a configuration, the recording medium 10 that is fed faster than the supply roller 34 by the medium feed roller 36 has a torque controlled by the torque control mechanism at a portion between the supply roller 34 and the medium feed roller 36. It is designed to be tensioned according to the tension.

  The holding surface of the suction table 33a faces the stretched portion. That is, a portion of the recording medium 10 located on the holding surface of the suction table 33a is stretched with a tension according to the torque controlled by the torque control mechanism. Here, the position of the holding surface of the suction table 33 a located at the above-described suction position substantially coincides with the position of the surface formed by the outer peripheral upper end of the medium feeding roller 36 and the outer peripheral upper end of the supply roller 34. Therefore, the holding surface of the suction table 33a located at the suction position is in contact with and holds the recording medium 10 stretched between the supply roller 34 and the medium feed roller 36.

  The suction table 33a is configured to hold the recording medium 10 on its holding surface. The holding surface is a flat surface. Therefore, the surface to be held in the recording medium 10, that is, the surface opposite to the surface to be recorded is held flat by the holding surface. Although not shown, the holding surface is provided with a suction concave portion including a suction hole or a suction groove. The suction surface is used to suck the holding surface of the recording medium 10, and the suction table 33a. It is adsorbed and held on the holding surface. That is, a negative pressure source (not shown) such as a suction pump is connected to the suction concave portion via a pipe or the like, so that the suction concave portion sucks the recording medium 10 located on the opening. ing.

The take-up reel 32 is rotated by a take-up motor (not shown), so that the recording medium 10 fed from the medium feed roller 36 is taken up by the take-up reel 32. It has become.
The idler roller 38 has a rotating shaft that can swing in the Z-axis direction and is biased in one of the swing directions. The idler roller 38 is brought into contact with the portion of the recording medium 10 between the medium feeding roller 36 and the driven roller 36 a and the take-up reel 31 by the urging force. Under such a configuration, the recording medium 10 is urged by the idler roller 38, so that the medium feeding roller 36, the driven roller 36 a and the take-up reel 31, and the idler roller 38 and the take-up reel 32. The part between is stretched without slack.

  Therefore, the recording medium 10 is easily maintained in a substantially flat state when being wound on the take-up reel 32. The amount of slack in the portion between the medium feed roller 36 and the take-up reel 32 depends on the difference between the feed speed of the recording medium 10 at the medium feed roller 36 and the take-up speed of the recording medium 10 at the take-up reel 32. fluctuate. However, by changing the position of the idler roller 38 following the fluctuation of the slack amount, the tensioned state is maintained without slack. Similarly, the fluctuation of the slack amount of the recording medium 10 between the medium feeding roller 36 and the take-up reel 32 due to the movement of the suction unit 33 is also maintained in a tensioned state without slack. ing.

  Under such a state, the recording medium 10 is sent from the supply reel 31 to the take-up reel 32, and recorded (printed) on a portion held on the holding surface of the suction table (medium holding portion) 33a in the middle. Has been made.

The head mechanism unit 2 includes a head carriage 22 and an X-axis scanning mechanism 11.
The X-axis scanning mechanism 11 includes two sets of an X-axis guide rail 11a, an X-axis slider 11b, and a support base 11d, and four guide rail support columns 11c. The support base 11d is disposed on each side of the suction table 33a in the X-axis direction with the suction table 33a interposed therebetween, and is located between the pair of Y-axis guide rails 42a and 42a. It is arranged. A maintenance unit 5 is disposed between one Y-axis guide rail 42a and the support base 11d.

  On each of the two support bases 11d and 11d, two guide rail support pillars 11c are erected on each end in the Y-axis direction, one in total. One of the two X-axis guide rails 11a is bridged between the guide rail support pillars 11c erected at the end of the support base 11d on the supply reel 31 side, and above the suction table 33a. It is arranged in a state extending in the X-axis direction. The other of the pair of X-axis guide rails 11a is bridged between the guide rail support columns 11c erected at the end of the support base 11d on the take-up reel 32 side, and the suction table 33a It is arranged in a state extending upward in the X-axis direction.

  The X-axis slider 11b is disposed on the X-axis guide rail 11a, and is configured to slide on the X-axis guide rail 11a in the extending direction by an X-axis drive motor (not shown). Is. Both ends of the bridge plate 27 of the head carriage 22 are fixed to the X-axis slider 11b supported on each of the two X-axis guide rails 11a. The bridge plate 27 having both ends fixed to the X-axis slider 11b is suspended between the two X-axis guide rails 11a while being supported by the X-axis slider 11b. Based on such a configuration, the bridge plate 27 is slid in the extending direction on the X-axis guide rail 11a by the X-axis drive motor, and at an arbitrary position in the X-axis direction. It is supposed to be retained.

  The head carriage 22 includes a bridge plate 27, a sub-carriage 28, and a head unit 21. The sub-carriage 28 is provided at substantially the center of the lower surface of the bridge plate 27, and the head unit 21 is fixed to the lower surface side of the sub-carriage 28. An ejection head 20 is provided on the lower surface side of the head unit 21, and a nozzle substrate 25 on which nozzles 24 are formed is disposed on the bottom side of the ejection head 20 as shown in FIG. . Under such a configuration, the ejection head 20 is positioned on the holding surface of the suction table 33a. At this time, the nozzle substrate 25 is opposed to the holding surface.

Here, the suction unit 33 can be moved in the Y-axis direction by the Y-axis scanning mechanism 42, and thus the holding surface of the suction table 33a can be moved in the Y-axis direction. That is, it is possible to scan the portion of the recording medium 10 held by suction on the holding surface of the suction table 33a in the Y-axis direction.
On the other hand, the ejection head 20 of the head unit 21 fixed to the sub-carriage 28 is scanned in the X-axis direction when the bridge plate 27 provided with the sub-carriage 28 is moved in the X-axis direction by the X-axis scanning mechanism 11. It is supposed to be made.

  Under such a configuration, the X-axis scanning mechanism 11 causes the ejection head 20 of the head unit 21 to scan in the X-axis direction, and the Y-axis scanning mechanism 42 suctions and holds the suction head 33 on the holding surface of the suction table 33a. Can be scanned in the Y-axis direction. That is, the nozzle 24 of the ejection head 20 can be made to face almost the entire surface of the recording medium 10 held by the holding surface of the suction table 33a.

Therefore, the recording target portion of the recording medium 10 sucked and held on the holding surface of the suction table 33a is moved to the ejection position in the Y axis direction and stopped, and synchronized with the movement of the head unit 21 in the X axis direction. By ejecting the ultraviolet curable ink S as droplets from the ejection head 20, the droplets (dots) of the ultraviolet curable ink S can be arranged at desired positions on the recording medium 10.
Therefore, main scanning for moving the head unit 21 in the X-axis direction (first direction) and sub-scanning (for moving the recording medium 10 sucked and held on the holding surface of the suction table 33a in the Y-axis direction (second direction)). (Line feed) is controlled by the control unit 60 as will be described later, the ejection head 20 of the head unit 21 is made to face an arbitrary position on the recording medium 10 held on the holding surface of the suction table 33a, and the state The ultraviolet curable ink S can be ejected as droplets. As a result, a desired image can be formed (recorded) on the recording medium 10. That is, in the present embodiment, the ultraviolet curable ink S is ejected onto the recording medium 10 while the ejecting head 20 is repeatedly reciprocated in the first direction (X direction), and the ejecting head 20 is moved one way (forward movement). Each time the recording medium 10 is moved backward, the recording medium 10 is turned in the second direction, whereby a desired image is formed on the recording medium 10.

  Next, the ejection head 20 will be described with reference to FIGS. 2 (a) to 2 (c) and FIG. 2A to 2C are diagrams illustrating a schematic configuration of the ejection head 20, FIG. 2A is an external perspective view illustrating a schematic configuration of the ejection head 20, and FIG. 2B is an internal structure of the ejection head 20. FIG. 4C is a main part perspective view illustrating the nozzle part of the ejection head 20. FIG. 3 is a plan view showing an ejection surface (lower surface) of the ejection head 20, and is a diagram for explaining a schematic configuration of the nozzle row. 2A and 3, the X axis, the Y axis, and the Z axis indicate the state in which the ejection head 20 is incorporated in the droplet ejection apparatus 1. Are coincident with the X axis, the Y axis, and the (Z axis).

  As shown in FIG. 2A, the ejection head 20 is formed with a nozzle substrate 25, and a large number of nozzles 24 are linearly arranged on the nozzle substrate 25 along the Y-axis direction. A plurality of nozzle rows 70 are formed in the X-axis direction. In the present embodiment, eight nozzle rows 70 are formed as shown in FIG. In the present embodiment, these nozzle rows 70 are an image forming ink having a color material, that is, a first nozzle row 71 in which nozzles for ejecting color ink are arranged, and an undercoat or overcoat ink, that is, a color. And a second nozzle row 72 in which nozzles for ejecting clear ink, white ink, or the like without material are arranged.

  Specifically, in order from the left side in FIG. 3, as the first nozzle row 71, the first nozzle row 71C that ejects C (cyan) as a color ink, the first nozzle row that ejects M (magenta). 71M, the first nozzle row 71Y that ejects Y (yellow), and the first nozzle row 71K that ejects black (K) are arranged one by one. Furthermore, as the second nozzle row 72, two second nozzle rows 72CR for ejecting clear ink for undercoat and two second nozzle rows 72W for ejecting white ink for overcoat are arranged. Yes. That is, in the present embodiment, the number of the second nozzle rows 72CR and 72W is larger than the number of the first nozzle rows 71C, 71M, 71Y, and 71K that eject the color ink.

Here, in FIG. 3, odd-numbered nozzle rows from the left side, that is, the first first nozzle row 71C, the third first nozzle row 71Y, the fifth second nozzle row 72CR, and the seventh first nozzle row 71CR. In the second nozzle row 72W, the positions of the corresponding nozzles 24 in the Y-axis direction are the same between the nozzle rows, and the intervals between the nozzles 24 along the Y-axis direction are all the same. . Accordingly, the nozzles 24 in each nozzle row are arranged at an equal pitch.
Similarly, in FIG. 3, the even-numbered nozzle rows from the left side, that is, the second first nozzle row 71M, the fourth first nozzle row 71K, the sixth second nozzle row 72CR, and the eighth eighth nozzle row. In the second nozzle row 72W, the positions of the corresponding nozzles 24 in the Y-axis direction are the same between the nozzle rows, and the intervals between the nozzles 24 along the Y-axis direction are all formed and arranged the same. Accordingly, the nozzles 24 in each nozzle row are arranged at an equal pitch.

However, two nozzle rows adjacent in the X-axis direction, for example, between the first nozzle row 71C and the first nozzle row 71M, between the first nozzle row 71Y and the first nozzle row 71K, Between the second nozzle rows 72CR and between the two second nozzle rows 72W, the positions of the nozzles 24 are staggered with a half-pitch shift in the Y-axis direction.
Note that each of the nozzle rows 71 and 72 is formed by arranging 180 nozzles 24 in this embodiment.
Then, the ultraviolet curable ink S is ejected as droplets from the nozzle 24 and landed on the surface of the opposing recording medium 10, so that the ejection head 20 is placed at a desired position on the recording medium 10. S can be arranged.

  As shown in FIGS. 2B and 2C, the ejection head 20 is obtained by laminating a pressure chamber plate 51 on a nozzle substrate 25 and further laminating a diaphragm 52 on the pressure chamber plate 51. The pressure chamber plate 51 is formed with a liquid pool 55 that is always filled with the ultraviolet curable ink S supplied to the ejection head 20. The liquid pool 55 includes the vibration plate 52, the nozzle substrate 25, and a wall ( (Not shown). The ultraviolet curable ink S is supplied to the liquid pool 55 via the liquid supply hole 53 of the vibration plate 52. The pressure chamber plate 51 is formed with a pressure chamber 58 partitioned by a plurality of head partition walls 57.

  The pressure chambers 58 are provided corresponding to the respective nozzles 24, and the number of the pressure chambers 58 and the number of the nozzles 24 are the same. A functional liquid is supplied to the pressure chamber 58 from a liquid pool 55 through a supply port 56 positioned between the two head partition walls 57. A set of the pressure chamber 58, the nozzle 24, and the supply port 56 of the head partition wall 57 is arranged in a line along the liquid pool 55, and the nozzles 24 arranged in a line form a nozzle line 24A. Although not shown in FIG. 2B, another nozzle row 24 </ b> A is formed on the side of the nozzle row 24 </ b> A including the nozzles 24.

  As shown in FIG. 2C, piezoelectric elements 59 are arranged on the diaphragm 52 corresponding to the respective pressure chambers 58, that is, corresponding to the individual nozzles 24. The piezoelectric element 59 has a piezoelectric layer sandwiched between a lower electrode and an upper electrode. When a driving waveform (driving voltage) is applied between the electrodes, the ultraviolet curable ink S is ejected from the corresponding nozzle 24. It is supposed to let you. Here, the piezoelectric element 59 is controlled by the control unit 60 shown in FIGS. 1 (a) and 1 (b).

Next, a schematic configuration of the head unit 21 provided in the head mechanism unit 2 will be described with reference to FIG. FIG. 4 is a bottom view showing a schematic configuration of the head unit 21. Note that the X axis and Y axis shown in FIG. 4 coincide with the X axis and Y axis shown in FIG.
As shown in FIG. 4, the head unit 21 has a unit plate 23 attached to the lower surface of the sub-carriage 28, and nine ejection heads 20 mounted on the lower surface side of the unit plate 23. Irradiation devices 80 for irradiating ultraviolet rays are respectively disposed on both sides of the ejection head 20 in the X-axis direction. In FIG. 4, nine ejection heads 20 are arranged. However, the number of ejection heads 20 is not limited to this, and for example, 15 may be arranged.

  The ejection head 20 is fixed to the unit plate 23 by a holding member (not shown) with the nozzle substrate 25 facing downward. The nine ejection heads 20 are divided in the Y-axis direction to form three head groups 20A each including three ejection heads 20 each. The nozzle row 24A of each ejection head 20 is arranged along the Y-axis direction with the head unit 21 attached to the droplet ejection device 1.

  The three ejection heads 20 constituting one head set 20A are arranged so that the ejection heads 20 of the other ejection head 20 are in the Y axis direction with respect to the nozzles 24 of the ejection heads 20 adjacent to each other. The nozzles 24 at the end are arranged with a shift of one nozzle pitch. In the three jet heads 20 included in the head set 20A under such a configuration, all the nozzles 24 are arranged at an equal pitch in the Y-axis direction when the positions of all the nozzles 24 in the X-axis direction are the same. become. In other words, at the same position in the X-axis direction, the droplets ejected from the nozzles 24 constituting the respective nozzle rows 24A of the respective ejection heads 20 are arranged in a straight line at equal intervals in the Y-axis direction by design. To land.

  Further, in the three head sets 20A included in the head unit 21, all the nozzles 24 are arranged at an equal pitch in the Y-axis direction when the positions of all the nozzles 24 in the X-axis direction are the same. In other words, at the same position in the X-axis direction, the droplets ejected from the nozzles 24 constituting the respective nozzle rows 24A of the respective ejection heads 20 are arranged in a straight line at equal intervals in the Y-axis direction by design. It has come to land. Therefore, the 18 nozzle rows 24A included in the nine ejection heads 20 in the three head sets 20A included in the head unit 21 can be handled as one nozzle row.

  The irradiation device 80 is disposed on each side of the ejection head 20 in the X-axis direction. As a result, immediately after the ultraviolet curable ink S is ejected from the ejection head 20 toward the recording medium 10, the recording medium is provided. The ultraviolet curable ink S that has landed on the surface 10 can be irradiated with ultraviolet rays. That is, the ejection head 20 ejects the ultraviolet curable ink S while being scanned (main scanning) in the X-axis direction. Therefore, when the unit plate 23 is scanned in the X-axis direction, the irradiation is performed on the recording medium 10 by irradiating the recording medium 10 with ultraviolet rays from the irradiation device 80 located on the rear side in the moving direction. The ultraviolet curable ink S can be irradiated with ultraviolet rays.

  In the liquid droplet ejecting apparatus 1 of the present embodiment, the irradiation device 80 includes a light emitting unit 81 and an elevating unit 82 (irradiation adjusting unit) as shown in FIG.

The light emitting unit 81 emits ultraviolet light that irradiates the ultraviolet curable ink S ejected from the recording medium 10, and a plurality of light emitting units 81 are provided for the irradiation device 80.
Here, as the light emitting unit 81, a metal halide lamp, a xenon lamp, a carbon arc lamp, a chemical lamp, a low pressure mercury lamp, a high pressure mercury lamp, or the like can be used. An LED that emits light in the ultraviolet band can also be used.

The elevating unit 82 is fixed to the sub-carriage 28 or the unit plate 23, and adjusts the distance from the light emitting unit 81 to the recording medium 10 by elevating the light emitting unit 81.
The lifting / lowering unit 82 adjusts the distance from the light emitting unit 81 to the recording medium 10, thereby adjusting the irradiation state of the ultraviolet curable ink that is sprayed onto the recording medium 10, specifically the illuminance of the ultraviolet light. To do.

In addition, the ultraviolet curable ink S is cured as the integrated light quantity of the irradiated ultraviolet rays increases.
Here, the integrated light amount is a value proportional to the illuminance of ultraviolet rays and the irradiation time, with the illuminance of ultraviolet rays and the irradiation time as parameters.
That is, by adjusting the distance from the light emitting unit 81 to the recording medium 10 and adjusting the illuminance of ultraviolet rays by the elevating unit 82, it is possible to adjust the time until the ultraviolet curable ink S is cured, and recording is performed. The amount of wetting and spreading of the ultraviolet curable ink S sprayed on the medium 10 can be adjusted.

  Examples of the ultraviolet curable ink S that is cured by ultraviolet rays include those prepared by adding adjuvants such as an antifoaming agent and a polymerization inhibitor to a mixture of a vehicle, a photopolymerization initiator, and a pigment. The vehicle is prepared by adjusting the viscosity of an oligomer, monomer or the like having photopolymerization curability with a reactive diluent. Therefore, the solvent is not volatilized for the purpose of curing the ink.

  As the vehicle, monofunctional or polyfunctional polymerizable compounds can be used. More specifically, oligomers (prepolymers) such as polyester acrylate, epoxy acrylate, and urethane acrylate can be exemplified, and these materials can also be used as a reactive diluent for adjusting the viscosity as an ink.

  As the photopolymerization initiator, benzophenone series, benzoin series, acetophenone series, and thioxanthone series are widely used. More specifically, 4-benzoyl-N, N, N-trimethyl benzene methanenannium chloride, 2-hydroxy 3- (4-benzoyl-phenoxy) -N, N, N-trimethyl 1-propylene, -N, N-dimethyl N- [2- (1-oxo-2-propenyloxy) ethyl] A quaternary ammonium salt type water-soluble organic substance such as benzene methanol bromide can be used. This type of photopolymerization initiator has different ultraviolet absorption characteristics, reaction initiation efficiency, yellowing, and the like depending on its composition, so that it is properly used depending on the color of the ink.

  As the polymerization inhibitor, any compound that has radical scavenging ability and inhibits radical polymerization can be used. However, in consideration of jetting suitability in the ink jet recording apparatus, at least one compound selected from hydroquinones, catechols, hindered amines, phenols, phenothiazines, and condensed aromatic ring quinones is preferable.

  Examples of hydroquinones include hydroquinone, hydroquinone monomethyl ether, 1-o-2,3,5-trimethylhydroquinone, 2-tert-butylhydroquinone and the like. Examples of catechols include catechol, 4-methylcatechol, 4-tert-butylcatechol and the like. Examples of hindered amines include compounds having a tetramethylpiperidinyl group.

Examples of phenols include phenol, butylhydroxytoluene, butylhydroxyanisole, pyrogallol, gallic acid, gallic acid alkyl ester, and the like.
Examples of phenothiazines include phenothiazine. Examples of the condensed aromatic ring quinones include naphthoquinone and the like.

  Furthermore, the polymerization inhibitor may be carbon black or inorganic / organic fine particles having a polymerization-inhibiting functional group introduced on the surface. Examples of the polymerization-preventing functional group include a hydroxyphenyl group, a dihydroxyphenyl group, a tetramethylpiperidinyl group, and a condensed aromatic ring.

  Examples of the ultraviolet curable ink S include color inks containing color materials (color components) such as pigments and dyes, and clear inks for undercoat and overcoat. In addition, a white ink and a black ink that are used for overcoating, although containing a color material, can also be used.

  The control unit 60 controls the entire operation of the liquid droplet ejecting apparatus 1 of the present embodiment. For example, the control unit 60 controls the X-axis scanning mechanism 11 to perform main scanning in the X-axis direction, and controls the Y-axis scanning mechanism 42 to perform sub-scanning in the Y-axis direction. ing. Further, in addition to the scanning control by the control of the X-axis scanning mechanism 11 and the Y-axis scanning mechanism 42, the ejection control from the nozzles 24 (nozzle row 70) at the time of each scanning is performed. That is, it also has a function as an injection control unit that controls the injection corresponding to each scan.

  Then, in the droplet ejecting apparatus 1 of the present embodiment, the control unit 60 controls the irradiation device 80 according to the pattern printed on the recording medium 10. Specifically, the light emitting unit 81 is moved up and down by the lifting unit 82 of the irradiation device 80 according to the pattern printed on the recording medium 10 to adjust the distance from the light emitting unit 81 to the recording medium 10.

  For example, when the pattern to be printed requires high-definition drawing, it is preferable that the ultraviolet curable ink S does not wet and spread. For this reason, the control unit 60 causes the elevating unit 82 to set the height of the light emitting unit 81 so that the distance from the light emitting unit 81 to the recording medium 10 is shortened, and thereby the ultraviolet curable ink S is irradiated. Increase the illuminance of ultraviolet rays. Thereby, the ultraviolet curable ink S is cured in a short time and does not spread out, so that high-definition drawing can be performed.

  In addition, when the pattern to be printed is required to have a rough drawing, it is preferable that the ultraviolet curable ink S is spread. For this reason, the control unit 60 causes the elevating unit 82 to set the height of the light emitting unit 81 so that the distance from the light emitting unit 81 to the recording medium 10 is increased, and thereby the ultraviolet curable ink S is irradiated. Reduce the illuminance of ultraviolet rays. As a result, the ultraviolet curable ink S is cured over a long time and spreads wet, so that rough drawing can be performed.

  In order to eject ink onto the recording medium 10 by the droplet ejecting apparatus 1 having such a configuration and print a desired image, first, the control unit 60 causes the X-axis drive motor and the Y-axis in the X-axis scanning mechanism 11 to be printed. The Y-axis drive motor in the scanning mechanism 42 is driven to sequentially change the relative position between the ejection head 20 and the recording medium 10 on the suction table 33a. In parallel with such scanning control, a drive waveform (drive voltage) is applied to the piezoelectric element 59 of the ejection head 20 to drive it, and the ultraviolet curable ink S is ejected from each nozzle row 70 of the ejection head 20. Inject toward 10 and land.

The droplet ejecting apparatus 1 (droplet ejecting method) according to the present embodiment as described above includes the elevating unit 82 that adjusts the irradiation state of the ultraviolet ray radiated to the ultraviolet curable ink S ejected onto the recording medium 10. ing.
For this reason, the wet spread amount of the ultraviolet curable ink S sprayed onto the recording medium 10 can be adjusted, and various patterns can be drawn.

Further, in the liquid droplet ejecting apparatus 1 of the present embodiment, the amount of wetting and spreading of the ultraviolet curable ink S is adjusted by adjusting the illuminance of the ultraviolet light with respect to the ultraviolet curable ink S by moving the light emitting unit 81 up and down by the lifting unit 82. Adjust.
Since the illuminance of the ultraviolet rays with respect to the ultraviolet curable ink S can be adjusted only by raising and lowering the light emitting part 81 by the elevating part 82 as described above, the droplet ejecting apparatus 1 of the present embodiment makes it easy to make ultraviolet rays. It becomes possible to adjust the wet spread amount of the curable ink S.

In addition, as shown in FIG. 6, it can replace with the raising / lowering part 82, and the tilting part 83 can also be installed as an irradiation adjustment part of this invention.
The tilting part 83 adjusts the ultraviolet emission direction of the light emitting part 81 by tilting the light emitting part 81.
In such a case, when the light emitting unit 81 is directed directly below, the illuminance of ultraviolet rays irradiated to the ultraviolet curable ink S with the shortest distance from the light emitting unit 81 to the ultraviolet curable ink S Is the maximum. On the other hand, when the light emitting unit 81 is tilted, the distance from the light emitting unit 81 to the ultraviolet curable ink S is increased, and the illuminance of ultraviolet rays applied to the ultraviolet curable ink S is decreased.
In other words, when such a configuration is adopted, the illuminance of ultraviolet rays applied to the ultraviolet curable ink S is easily adjusted by the tilt angle (the tilt angle of the optical axis) of the light emitting unit 81 by the tilt unit 83. can do.

Further, it is possible to cause the control unit 60 to function as the irradiation adjusting unit of the present invention instead of the elevating unit 82.
Specifically, the control unit 60 controls the output of the light emitting unit 81. In such a case, the illuminance of the ultraviolet rays applied to the ultraviolet curable ink S is adjusted by adjusting the output of the light emitting unit 81. As a method for controlling the output of the light emitting unit 81, it is conceivable to reduce the amount of light emitted from the light emitting unit 81 or to intermittently drive the light emitting unit 81.
Even in such a case, since the irradiation state of the ultraviolet rays can be adjusted only by the control of the control unit 60, the wet spread amount of the ultraviolet curable ink S can be easily adjusted.

Further, as a configuration for causing the control unit 60 to function as the irradiation adjusting unit of the present invention, a configuration for adjusting the moving speed of the light emitting unit 81 with respect to the recording medium 10 can be considered.
In such a case, the ultraviolet irradiation time and the irradiation start timing for the ultraviolet curable ink S are adjusted by the moving speed of the light emitting unit 81 with respect to the recording medium 10, thereby adjusting the ultraviolet irradiation state.
Even in such a case, since the irradiation state of the ultraviolet rays can be adjusted only by the control of the control unit 60, the wet spread amount of the ultraviolet curable ink S can be easily adjusted.

In addition, when adjusting the moving speed of the light emission part 81 with respect to the recording medium 10, as shown in FIG. 7, it is also considered that the ejection head 20 and the light emission part 81 can be moved independently.
By adopting such a configuration, the moving speed of the ejection head 20 relative to the recording medium 10 and the moving speed of the light emitting unit 81 relative to the recording medium 10 can be made different, so that the ultraviolet irradiation state can be adjusted more flexibly. Is possible.

  As mentioned above, although preferred embodiment of this invention was described referring an accompanying drawing, it cannot be overemphasized that this invention is not limited to the said embodiment. Various shapes, combinations, and the like of the constituent members shown in the above-described embodiments are examples, and various modifications can be made based on design requirements and the like without departing from the spirit of the present invention.

  For example, in the above embodiment, the liquid droplet ejecting apparatus of the present invention is applied to a printing apparatus that performs printing on a continuous long recording medium. However, the present invention is not limited thereto, The object to be ejected is not long but can be a rectangular substrate. Moreover, as such a board | substrate, a glass substrate can also be made into object besides resin mentioned above.

In the above embodiment, the irradiation device 80 is applied to a serial type printing device that is fixed to the sub-carriage 28 or the unit plate 23 and scans the head unit 21 in the X-axis direction by the X-axis scanning mechanism 11. The invention is not limited to this, and a head carriage in which the length of the head carriage is equal to or greater than the length in the width direction of the printing area of the recording medium 10, a so-called line head, may be employed. Further, an irradiation device having a length equal to or greater than the length in the width direction of the printing area of the recording medium 10, a so-called line irradiation device may be employed.
Moreover, in the said embodiment, although the irradiation apparatus 80 showed the example which adjusts the distance from the light emission part 81 to the recording medium 10 by raising / lowering the light emission part 81 separately by the raising / lowering part 82, it is not restricted to this, You may employ | adopt the structure which adjusts the distance from the light emission part 81 to the recording medium 10 by raising / lowering the irradiation apparatus 80 with the unit plate 23. FIG. In this case, the irradiation device 80 may be configured to be movable up and down for each unit plate 23 disposed on both sides of the ejection head 20 in the X-axis direction, or configured so that the unit plates 23 on both sides move up and down together. May be.
In the above embodiment, the irradiation apparatus 80 has shown an example in which the tilting unit 83 individually adjusts the tilt angle of the light emitting unit 81 to adjust the distance from the light emitting unit 81 to the recording medium 10. Not limited to this, a configuration may be adopted in which the distance from the light emitting unit 81 to the recording medium 10 is adjusted by tilting the irradiation device 80 together with the unit plate 23. In this case, the irradiation device 80 may be configured to be tiltable for each of the unit plates 23 disposed on both sides of the ejection head 20 in the X-axis direction, or may be configured to tilt the unit plates 23 on both sides together. May be.

  DESCRIPTION OF SYMBOLS 1 ... Droplet ejecting apparatus, 10 ... Recording medium (subject to be ejected), 20 ... Ejecting head, 21 ... Head unit, 24 ... Nozzle, 60 ... Control unit, 80 ... Irradiating apparatus, 81 ... ... light emitting part, 82 ... lifting part (irradiation adjusting part), 83 ...... tilting part (irradiation adjusting part), S ... UV curable ink

Claims (8)

A liquid droplet ejecting apparatus comprising: an ejection head that ejects ultraviolet curable ink onto an object to be ejected; and a light emitting unit that emits ultraviolet light that irradiates the ultraviolet curable ink ejected onto the object to be ejected.
A liquid droplet ejecting apparatus comprising: an irradiation adjusting unit that adjusts an irradiation state of the ultraviolet ray irradiated to the ultraviolet curable ink ejected to the ejected part.   The ultraviolet irradiation state is one or a plurality of ultraviolet illuminance to the ultraviolet curable ink, ultraviolet irradiation time to the ultraviolet curable ink, and ultraviolet irradiation start timing to the ultraviolet curable ink. The droplet ejecting apparatus according to claim 1.   3. The droplet ejecting apparatus according to claim 1, wherein the irradiation adjusting unit is an elevating unit that adjusts a distance from the light emitting unit to the ejected object by moving the light emitting unit up and down.   3. The droplet ejecting apparatus according to claim 1, wherein the irradiation adjusting unit is a tilting unit that tilts the light emitting unit to adjust an ultraviolet emission direction of the light emitting unit.   The liquid droplet ejecting apparatus according to claim 1, wherein the irradiation adjusting unit is a control unit that adjusts an output of the light emitting unit.   The liquid droplet ejecting apparatus according to claim 1, wherein the irradiation adjusting unit is a control unit that adjusts a moving speed of the light emitting unit with respect to the ejected object.   The droplet ejecting apparatus according to claim 6, wherein the ejecting head and the light emitting unit are independently movable. A droplet jetting method in which an ultraviolet curable ink is jetted onto an ejected object, and the ultraviolet curable ink ejected onto the ejected object is irradiated with ultraviolet rays,
A droplet ejecting method, comprising: adjusting an irradiation state of the ultraviolet ray irradiated to the ultraviolet curable ink ejected to the ejected portion.

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