JP2012166412A - Ink jet recording device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink jet recording device capable of maintaining good printing quality even when a recording medium is heated for ink curing.SOLUTION: The ink jet recording device includes: a drawing part discharging ultraviolet curable ink from an ink jet head 9 to the recording medium W while relatively displacing the ink jet head 9 mounted to a carriage for drawing on the recording medium W; a light irradiation part 34 mounted to the carriage and curing the ultraviolet curable ink on the recording medium W by application of ultraviolet rays; and a preheating part 33 facing the recording medium W prior to the relatively displaced ink jet head 9 and preheating the recording medium W to reduce a temperature difference with the recording medium W of which temperature is increased by application of the ultraviolet rays.

Description

  The present invention relates to an ink jet recording apparatus that performs drawing on a recording medium by discharging an active energy ray curable ink.

Conventionally, as this type of inkjet recording apparatus, a printing medium (recording medium) that scans in the sub-scanning direction and an inkjet recording head that scans in the main scanning direction and discharges ultraviolet curable ink (active energy ray-curable ink) to the recording medium (Inkjet head) and an ultraviolet irradiation device provided on both sides of the inkjet recording head in the main scanning direction are known (see Patent Document 1).
This ultraviolet irradiation device extends on the downstream side in the print medium feeding direction (sub-scanning direction) longer than the ink jet recording head. When the ink jet recording head is main-scanned, printing and ultraviolet light are applied to the print medium. Irradiation takes place. That is, ultraviolet curing of the ultraviolet curable ink landed immediately after printing is performed. In parallel with this operation, the printed region after the line feed (main scan) is also irradiated with ultraviolet rays. As a result, the ultraviolet curable ink is reliably cured.

JP 2004-1326 A

Incidentally, a UV lamp such as a metal halide lamp or a light emitting diode (UVLED) is used for the irradiation of ultraviolet rays. Regardless of which is used, the recording medium (printing medium) is heated by heat generation.
For this reason, in the above-described conventional inkjet recording apparatus, after drawing (printing), the ultraviolet curable ink can be reliably cured by irradiating ultraviolet rays, but the recording medium is simultaneously heated. At the time of drawing, since drawing and ultraviolet irradiation are performed almost simultaneously, drawing is performed while the recording medium is heated and expanded by the ultraviolet rays. For this reason, there has been a problem that the printing quality is deteriorated, for example, the landing position of the ultraviolet curable ink is shifted.

  An object of the present invention is to provide an ink jet recording apparatus that can maintain good print quality even when a recording medium is heated for ink curing.

  An inkjet recording apparatus of the present invention includes a drawing unit that performs drawing on a recording medium by ejecting active energy ray-curable ink from the inkjet head while moving the inkjet head mounted on the carriage relative to the recording medium, Mounted on the carriage, irradiates the active energy ray to irradiate the active energy ray-cured ink on the recording medium, and faces the recording medium prior to the relatively moving inkjet head, and preheats the recording medium And a preheating unit for performing the above operation.

According to this configuration, the recording medium is heated before drawing by the preheating unit prior to drawing and irradiation of the active energy ray performed simultaneously with drawing. For example, the preheating is preferably performed so that the temperature difference from the recording medium heated by irradiation with active energy rays is reduced. For this reason, since the temperature conditions before drawing and at the time of drawing become substantially equal, the recording medium hardly expands at the time of drawing, and stable drawing can be performed. Therefore, even if the recording medium is heated for ink curing, good print quality can be maintained.
This is particularly effective when the recording medium expands due to heating or when the elongation of the recording medium reaches equilibrium in one scan.

  In this case, it is preferable that the preheating unit preheats the recording medium by irradiating active energy rays.

  According to this configuration, since the preliminary heating can be performed under the same heating conditions as the heating by the light irradiation unit at the time of drawing, the structure and control can be simplified.

  In this case, it is preferable that the drawing unit relatively moves the inkjet head in the main scanning direction and the sub-scanning direction, and the preheating unit preheats the recording medium by at least the line feed distance in the subscanning direction.

  According to this configuration, the drawing area drawn in one scan and the preheating area to be preheated can be matched, and the recording medium can be preheated efficiently.

  In this case, it is preferable that the unit drawing area where drawing is performed by one main scanning and the unit heating area where preheating is performed by one main scanning are adjacent to each other on the recording medium.

  According to this configuration, since the drawing operation can be performed immediately after the preheating, the recording medium can be prevented from being cooled, and the recording medium can be efficiently preheated.

  In this case, the preheating unit is preferably mounted on the carriage.

  According to this configuration, since it is not necessary to provide a dedicated axis (moving mechanism) for scanning the preheating unit, the configuration of the apparatus can be simplified.

  In this case, it is preferable that the light irradiation part and the preheating part are integrally formed.

  According to this configuration, since the preheating of the recording medium and the curing of the active energy ray curable ink can be performed with one apparatus, the apparatus configuration can be simplified and the cost can be reduced.

  In this case, the light irradiation unit and the preheating unit are configured by a single light irradiation lamp extending in the sub-scanning direction, and the effective irradiation width in the sub-scanning direction by the light irradiation unit is equal to the nozzle row length of the inkjet head. Correspondingly, it is preferable that the effective irradiation width in the sub-scanning direction by the preheating unit corresponds to at least the line feed distance.

  According to this configuration, the drawing area to be drawn in one scan can be appropriately preheated in advance.

  In this case, the light irradiation lamp further includes an auxiliary irradiation unit that extends in the sub-scanning direction so as to sandwich the light irradiation unit between the preheating unit and cures the active energy ray-curable ink on the recording medium. It is preferable.

  According to this configuration, the active energy ray-curable ink in the drawing area after drawing can be reliably cured. In particular, it is useful when using various active energy ray curable inks (including different colors) having different curing characteristics.

  In this case, the active energy rays are preferably ultraviolet rays having a predetermined center wavelength.

(A) of the drawing apparatus which concerns on 1st Embodiment is a top view, (b) is a side view. It is explanatory drawing which showed typically the drawing operation which concerns on 1st Embodiment. (A) of the drawing apparatus which concerns on 2nd Embodiment is a top view, (b) is a side view. It is explanatory drawing which showed typically the drawing operation which concerns on 2nd Embodiment.

  Hereinafter, an ink jet recording apparatus of the present invention will be described with reference to the accompanying drawings. This ink jet recording apparatus discharges an ultraviolet curable ink (active energy ray curable ink) to a thin film-like recording medium to be discharged in a so-called reel-to-reel format by an ink jet head. It prints images and the like. In the following description, the recording medium conveyance direction is defined as the X-axis direction, and the direction orthogonal to the X-axis direction is defined as the Y-axis direction.

  As shown in FIG. 1, an inkjet recording apparatus 1 includes a machine base 2, a feeding device 3 that feeds out a long recording medium W wound in a roll shape, and a winding device that winds up a printed recording medium W. 4 and a work stage 5 disposed on the machine base 2 for sucking and setting the supplied recording medium W, and extending in the X-axis direction, and passing the recording medium W in the X-axis direction via the work stage 5 The X-axis table 6 that is intermittently fed, the Y-axis table 7 spanned in the Y-axis direction so as to straddle the X-axis table 6, the carriage 8 that is movably mounted on the Y-axis table 7, and the carriage 8 The inkjet head 9 for drawing on the recording medium W by discharging ultraviolet curable ink and the carriage 8 are mounted on the carriage 8 so as to face the recording medium W before the inkjet head 9 and preheat the recording medium W. Recording media By irradiating ultraviolet rays comprises the ultraviolet irradiation device 10 to cure the ultraviolet curable ink, to. The drawing unit described in the claims includes an X-axis table 6, a Y-axis table 7, a carriage 8, and an inkjet head 9.

  The ink jet recording apparatus 1 includes an ink supply device (not shown) for supplying ultraviolet curable ink to the ink jet head 9, a maintenance device (not shown) for maintaining and recovering the functions of the ink jet head 9, and the ink jet recording device 1. And a control device 11 for overall control.

  In the ink jet recording apparatus 1, the recording medium W fed out by the feeding apparatus 3 is sucked and set by the work stage 5, and then the recording medium W is intermittently fed in the X-axis direction via the work stage 5 by the X-axis table 6 (sub-direction). Scanning), and drawing is performed by ejecting ultraviolet curable ink from the inkjet head 9 while reciprocating (main scanning) the carriage 8 with respect to the drawable area of the recording medium W set by suction. In addition, the ultraviolet irradiation device 10 mounted on the carriage 8 preheats a certain area before drawing in parallel with the drawing operation and irradiates ultraviolet rays immediately after drawing to cure the ultraviolet curable ink. Yes.

  Corresponding to the movement of the ultraviolet irradiation device 10 mounted on the carriage 8, the recording medium W is drawn by a unit heating area in which preheating is performed before drawing by one main scanning and by one main scanning. A unit drawing area is set. The unit heating area and the unit drawing area are adjacent to each other so that the drawing operation can be started immediately after the preliminary heating. That is, the unit heating area becomes a unit drawing area where drawing is performed by the inkjet head 9 by the subsequent sub-scanning after the preliminary heating. The recording medium W is not limited to a roll that can be continuously supplied, and a single-sheet recording medium W may be used.

  The feeding device 3 and the winding device 4 are respectively arranged on the upstream side and the downstream side in the X-axis direction so as to sandwich the machine base 2 and the work stage 5. The recording medium W is fed out from the feeding device 3 in a state where a light tension is applied, and is taken up by the winding device 4.

  The work stage 5 sucks and sets the recording medium W sent from the feeding device 3 through a plurality of holes (not shown) formed on the surface thereof. A feed roller 12 and a feed roller 13 are respectively attached to the upstream end and the downstream end of the work stage 5 in the conveyance (X-axis) direction. In addition, although detailed description is abbreviate | omitted, the some hole formed in the work stage 5 is each connected with the vacuum suction equipment and compressed air supply equipment which are not shown in figure.

  The feed roller 12 and the feed roller 13 are free-rotating nip rollers provided so as to be movable up and down, arranged side by side in the X-axis direction, sandwiching the recording medium W, and placed on the upper surface of the work stage 5 Let W come. The work stage 5 is intermittently fed in the X-axis direction (from the upstream side to the downstream side) by the X-axis table 6 with the recording medium W being sucked and set.

  The X-axis table 6 is disposed on the machine base 2 and has a pair of X-axis guide rails 14 extending in the X-axis direction, and an X-axis for slidably moving the work stage 5 along the X-axis guide rails 14. And a moving mechanism 15. The X-axis table 6 moves the recording medium W in the X-axis direction (sub-scanning) by the drawing width (line feed distance) until the carriage 8 stopped during the forward movement (or backward movement) until the next backward movement (or forward movement). Send to the downstream side (direction feed).

  The Y-axis table 7 includes a Y-axis guide rail 16 that spans the machine base 2 so as to straddle the Y-axis direction, and a Y-axis movement mechanism 17 that slidably moves the carriage 8 along the Y-axis guide rail 16. ,have. The Y-axis table 7 reciprocates the inkjet head 9 and the ultraviolet irradiation device 10 in the Y-axis direction (main scanning direction) via the carriage 8.

  The carriage 8 carries the inkjet head 9 and the ultraviolet irradiation device 10 and is slidably engaged with the Y-axis guide rail 16 on the upstream side in the X-axis direction. As will be described in detail later, the ultraviolet irradiation device 10 has a pair of light irradiation lamps 31, 31, and the pair of light irradiation lamps 31, 31 are arranged on both sides in the Y-axis direction of the inkjet head 9. Are mounted on the carriage 8.

  The inkjet head 9 has a nozzle surface 22 in which a plurality of discharge nozzles 21 are opened, and a plurality of nozzle rows 23 each having a plurality of discharge nozzles 21 arranged at equal intervals are mutually connected to the nozzle surface 22. They are arranged in parallel. In the inkjet head 9, different types (colors) of ultraviolet curable ink are ejected for each nozzle row 23.

  In this embodiment, so-called ultraviolet curable ink is used, and the nozzle surface 22 has a plurality of clear (CL), yellow (Y), cyan (C), magenta (M), and black (K). The nozzle rows 23 are sequentially arranged in the main scanning direction (Y-axis direction). The color, the number of colors, and the arrangement of each color of the ultraviolet curable ink may be arbitrarily set depending on the application. Further, the ink is not limited to the ultraviolet curable ink, and may be an infrared curable ink or a visible light curable ink.

  The ultraviolet irradiation device 10 has a pair of light irradiation lamps 31 and 31 mounted on the carriage 8 with the inkjet head 9 interposed therebetween. Each light irradiation lamp 31 is configured by an LED array in which a plurality of light emitting diodes (LEDs) 32 are arranged at equal intervals in the X-axis direction, and the irradiation surface is disposed at a position higher than the nozzle surface 22 of the inkjet head 9. ing. Each light irradiation lamp 31 faces the recording medium W prior to the inkjet head 9 and irradiates ultraviolet rays having a predetermined center wavelength to preheat the recording medium W, and the recording medium W immediately after drawing. And a light irradiating unit 34 for irradiating ultraviolet rays to cure the ultraviolet curable ink, and the X-axis direction (in the sub-scanning direction). In the present embodiment, each ultraviolet irradiation device 10 includes a plurality of light emitting diodes 32 having a predetermined center wavelength, but a mercury lamp, a metal halide lamp, or the like may be used. Further, when printing is performed only in the forward path or only in the backward path in the movement of the inkjet head 9 in the main scanning direction, the ultraviolet irradiation device 10 may be configured by only the light irradiation lamp 31 on one side.

  The preheating unit 33 is disposed on both sides of the inkjet head 9 in the Y-axis direction and on the upstream side in the transport direction of the recording medium W from the inkjet head 9 (substantially, the nozzle row 23). The effective irradiation width in the sub-scanning direction by the preheating unit 33 is designed to correspond to at least the intermittent feed (for the line feed distance) of the recording medium W by the X-axis table 6. That is, the preheating unit 33 irradiates the unit heating area for one main scan with ultraviolet rays, and after the subsequent line feed, the unit heating area faces the inkjet head 9 and the light irradiation unit 34 as a unit drawing area. It is like that.

  The preheating unit 33 scans the recording medium W before drawing along with the main scanning (forward or backward movement) of the carriage 8, and the recording medium W is heated by the irradiation of ultraviolet rays from the light irradiation unit 34. The recording medium W is heated so as to reduce the temperature difference. That is, the preheating unit 33 preheats the unit heating area (for the line feed distance in the sub-scanning direction) of the one main scan before drawing so as to be the same temperature as the unit drawing area at the time of drawing. As a result, the temperature of the unit drawing area before drawing is substantially equal to that at the time of drawing, so that the recording medium W is hardly expanded during drawing and drawing is performed. Note that the preheating unit 33 may be formed to be sufficiently long in the Y-axis direction, and the number of light emitting diodes 32 to be lit may be adjusted according to the amount of line feed.

  The light irradiation unit 34 is provided on both sides of the inkjet head 9 in the Y-axis direction, and is formed integrally with the preheating unit 33. The effective irradiation width in the sub-scanning direction by the light irradiation unit 34 is designed to correspond to the length of the nozzle row 23 of the inkjet head 9. In this case, the light irradiation unit 34 performs main scanning (forward movement or backward movement) together with the ink jet head 9 to face the recording medium W immediately after the ultraviolet curable ink is discharged, and is a unit in which drawing is performed in one main scanning. The drawing area is irradiated with ultraviolet rays to cure the ultraviolet curable ink discharged onto the recording medium W. That is, in the embodiment, ink curing is performed with the pair of light irradiation units 34 always turned on, and a light amount (integrated light amount) necessary for ink curing can be obtained by a plurality of main scans. .

  Next, a series of drawing operations will be described with reference to FIG. First, the carriage 8 at the home position is moved forward in the main scanning direction by the Y-axis table 7 with the light emitting diode 32 turned on by driving the ultraviolet irradiation device 10 and preheating the unit heating area. Perform (FIGS. 2A and 2B). That is, in the first pass, only preheating is performed, and drawing operation is not performed (empty scan).

  Then, the recording medium W is sub-scanned by the line feed distance in the X-axis direction by the X-axis table 6 (FIG. 2C). Next, the carriage 8 is moved backward by the Y-axis table 7 (second pass). At this time, the unit heating area becomes the unit drawing area, and the ultraviolet irradiation is performed by the light irradiation unit 34 immediately after the ultraviolet curable ink is discharged in the unit drawing area. In parallel with this operation, preheating is performed in the new unit heating region by the preheating unit 33 (FIG. 2D). Then, the X-axis table 6 again scans the recording medium W in the X-axis direction by the line feed distance. Drawing is performed on the recording medium W by repeating the above steps.

  According to the above configuration, since the recording medium W is heated before drawing by the preheating unit 33, the temperature conditions before drawing and at the time of drawing become substantially equal, so that the recording medium W may expand almost at the time of drawing. And stable drawing can be performed.

  Next, an inkjet recording apparatus 1 according to the second embodiment of the present invention will be described with reference to FIG. In addition, in order to avoid the duplicate description, a different part from 1st Embodiment is mainly demonstrated. In the ultraviolet irradiation device 10 of the inkjet recording apparatus 1, each of the light irradiation lamps 31 is arranged so that the light irradiation unit 34, the preheating unit 33, and the light irradiation unit 34 are sandwiched between the preheating unit 33. And an auxiliary irradiation unit 35 that extends in the scanning direction and cures the ultraviolet curable ink on the recording medium W. Also in this case, the light irradiation lamp 31 is composed of a series of LED arrays.

  The auxiliary irradiating sections 35 are disposed on both sides of the inkjet head 9 in the Y-axis direction and on the downstream side in the transport direction of the recording medium W from the inkjet head 9 (substantially, the nozzle row 23). Further, the effective irradiation width in the sub-scanning direction by the auxiliary irradiation unit 35 is designed to correspond to at least the intermittent feed (for the line feed distance) of the recording medium W by the X-axis table 6. The auxiliary irradiating unit 35 scans the recording medium W after drawing by main scanning (forward or backward movement) of the carriage 8, thereby reliably curing the ultraviolet curable ink ejected on the recording medium W. In this case, the auxiliary irradiating unit 35 is for complementing the light irradiating unit 34, and when the ultraviolet curable ink is reliably cured by the light irradiating unit 34, the auxiliary irradiating unit 35 may be main-scanned in the off state. Good.

  Next, a series of drawing operations will be described with reference to FIG. First, the carriage 8 at the home position moves forward in the main scanning direction by the Y-axis table 7 and performs preheating on the unit heating region (FIGS. 4A and 4B). That is, in the first pass, only preheating is performed, and drawing operation is not performed (empty scan).

  Then, the recording medium W is sub-scanned by the line feed distance in the X-axis direction by the X-axis table 6 (FIG. 4C). Next, the carriage 8 is moved backward by the Y-axis table 7 (second pass). At this time, the unit heating area becomes the unit drawing area, and the ultraviolet irradiation is performed by the light irradiation unit 34 immediately after the ultraviolet curable ink is discharged in the unit drawing area. In parallel with this operation, preheating is performed in the new unit heating region by the preheating unit 33 (FIG. 4D).

Then, when moving the carriage 8 forward (or backward), the above process is repeated until the first preheated region passes through the inkjet head 9. In the scanning after the first preheated region has passed through the inkjet head 9, the unit heating region becomes the unit drawing region, and in the unit drawing region, immediately after the ultraviolet curable ink is discharged, the light irradiating unit 34 emits ultraviolet rays. Irradiation takes place. In parallel with this operation, preheating is performed by the preheating unit 33 in a new unit heating region. Further, the drawing region after drawing is irradiated with ultraviolet rays by the auxiliary irradiation unit 35, and complementary curing of the ultraviolet curable ink is performed (FIGS. 4E and 4F). Drawing is performed on the recording medium W by repeating the above steps.
Finally, the carriage 8 moves back and forth in the main scanning direction by the Y-axis table 7 and irradiates the drawing area after drawing with ultraviolet rays. That is, the n-th pass, which is the final pass, is only subjected to complementary curing, and no drawing operation is performed (empty scan).

According to the above configuration, since the recording medium W is irradiated with ultraviolet rays by the auxiliary irradiation unit 35 after drawing, the ultraviolet curable ink can be reliably cured.
In particular, the auxiliary irradiating unit 35 functions effectively when ultraviolet curable inks having different curing characteristics are used, or when the light irradiating unit 34 is insufficient in light quantity due to contamination.

  In addition, although this embodiment demonstrated the case where the light irradiation part 34 and the preheating part 33 were formed integrally, the light irradiation part 34 and the preheating part 33 may be formed separately. Further, although the case where the preheating unit 33 is mounted on the carriage 8 common to the inkjet head 8 and the light irradiation unit 34 has been described, it may be mounted on another carriage 8. In such a case, a preheating unit moving mechanism that freely moves the preheating unit 33 along the Y-axis guide rail 16 is provided (not shown).

  DESCRIPTION OF SYMBOLS 1 ... Inkjet recording apparatus 6 ... X-axis table 7 ... Y-axis table 8 ... Carriage 9 ... Inkjet head 33 ... Preheating part 34 ... Light irradiation part 35 ... Auxiliary irradiation part W ... Recording medium

Claims (9)

A drawing unit that draws on the recording medium by discharging active energy ray-curable ink from the inkjet head while moving the inkjet head mounted on the carriage relative to the recording medium;
A light irradiation unit mounted on the carriage and irradiating active energy rays to cure the active energy ray curable ink on the recording medium;
An ink jet recording apparatus comprising: a preheating unit that faces the recording medium prior to the relatively moving ink jet head and preheats the recording medium.   The inkjet recording apparatus according to claim 1, wherein the preheating unit preheats the recording medium by irradiating the active energy ray. The drawing unit moves the inkjet head relatively in the main scanning direction and the sub-scanning direction,
3. The ink jet recording apparatus according to claim 2, wherein the preheating unit preheats the recording medium for at least the line feed distance of the ink jet head in the sub-scanning direction.   4. The unit drawing area in which the drawing is performed by one main scanning and the unit heating area in which the preliminary heating is performed by the one main scanning are adjacent to each other on the recording medium. 2. An ink jet recording apparatus according to 1.   The inkjet recording apparatus according to claim 2, wherein the preheating unit is mounted on the carriage.   The inkjet recording apparatus according to claim 5, wherein the light irradiation unit and the preheating unit are integrally formed. The light irradiation part and the preheating part are composed of a single light irradiation lamp extending in the sub-scanning direction,
The effective irradiation width in the sub-scanning direction by the light irradiation unit corresponds to the nozzle row length of the inkjet head, and the effective irradiation width in the sub-scanning direction by the preheating unit corresponds to at least the line feed distance. 6. An ink jet recording apparatus according to claim 5, wherein   The light irradiation lamp further includes an auxiliary irradiation unit that extends in the sub-scanning direction so as to sandwich the light irradiation unit between the preliminary heating unit and cures the active energy ray-curable ink on the recording medium. The ink jet recording apparatus according to claim 7, wherein the ink jet recording apparatus is provided.   9. The ink jet recording apparatus according to claim 1, wherein the active energy ray is an ultraviolet ray having a predetermined center wavelength.

Images