JP6206609B2 - Droplet discharge device - Google Patents

Description

  The present invention relates to a droplet discharge device.

  A black image formed on a recording medium by irradiating an infrared laser to an image such as a character formed by ejecting water-soluble black ink droplets onto the recording medium, and evaporating moisture in the image. An image forming apparatus that suppresses bleeding is conventionally known (see, for example, Patent Document 1).

JP 2014-184687 A

  In the present invention, only a movable infrared irradiation device for evaporating moisture in an image formed by droplets ejected onto a recording medium by infrared rays is disposed downstream of the droplet ejection head in the conveyance direction of the recording medium. It is an object of the present invention to provide a droplet discharge device that can efficiently remove water vapor present around a recording medium as compared with the configuration.

  In order to achieve the above object, according to a first aspect of the present invention, there is provided a droplet discharge device according to the first aspect of the present invention, wherein the width direction of the recording medium is the longitudinal direction and the droplet is applied to the recording medium conveyed along the conveyance path. A liquid droplet ejection head for forming an image by ejecting the liquid, and a liquid ejection device disposed so as to be movable downstream of the liquid droplet ejection head in the transport direction of the recording medium, and evaporates moisture in the image formed on the recording medium Three or more movable infrared irradiation devices to be moved, and the downstream side in the transport direction of the recording medium from the droplet discharge head, and the upstream side in the transport direction of the recording medium from the three or more movable infrared irradiation devices A fixed infrared irradiating device that is provided in a housing fixed to the recording medium and evaporates moisture in an image formed on the recording medium; and the casing on the upstream side in the transport direction of the recording medium from the fixed infrared irradiating device. Formed in the body The air flow path for sending air to the recording medium and the casing formed downstream of the fixed infrared irradiation device in the transport direction of the recording medium and sucking water vapor present around the recording medium A suction flow path.

  Further, the droplet discharge device according to claim 2 is the droplet discharge device according to claim 1, wherein the three or more movable infrared irradiation devices are in a direction orthogonal to a conveyance direction of the recording medium. When viewed from the side, it is arranged along the transport path so as to irradiate infrared rays from the normal direction of the recording medium.

  According to the first aspect of the present invention, the movable infrared irradiation for evaporating the moisture in the image formed by the droplets ejected onto the recording medium by infrared rays on the downstream side in the transport direction of the recording medium from the droplet ejection head. Compared with a configuration in which only the apparatus is arranged, water vapor present around the recording medium can be efficiently removed.

  According to the second aspect of the present invention, the movable infrared irradiation device irradiates infrared rays from an oblique direction with respect to the normal direction of the recording medium in a side view as viewed from a direction orthogonal to the conveyance direction of the recording medium. Compared to the above, it is possible to promote the evaporation of moisture in the image formed by the droplets discharged to the recording medium.

1 is a schematic side view illustrating a configuration of an ink jet recording apparatus according to a first embodiment. It is a graph which shows the relationship between the irradiation timing by the movable laser apparatus which concerns on 1st Embodiment, and the temperature of the water | moisture content in the image formed with the ink droplet discharged on the continuous paper. It is a schematic side view which shows the structure of the inkjet recording device which concerns on 2nd Embodiment. It is a schematic side view which shows the structure of the inkjet recording device which concerns on 3rd Embodiment. It is a schematic sectional side view which shows the structure of the periphery of the fixed laser apparatus which concerns on 3rd Embodiment.

  Hereinafter, embodiments according to the present invention will be described in detail with reference to the drawings. For convenience of explanation, an arrow UP appropriately shown in each drawing is an upward direction of the ink jet recording apparatus 10 as an example of a droplet discharge apparatus, and a front side of the paper is a front direction of the ink jet recording apparatus 10. In the following, the transport direction of the continuous paper P as an example of the recording medium is simply referred to as “transport direction”, and the upstream side in the transport direction and the downstream side in the transport direction are simply referred to as “upstream side” and “downstream side”, respectively. May say. Further, in this specification, the first embodiment and the second embodiment are read as “first reference example” and “second reference example”, respectively, and the third embodiment is read as “this embodiment”. .

<First Embodiment>
First, the ink jet recording apparatus 10 according to the first embodiment will be described. As shown in FIG. 1, the ink jet recording apparatus 10 ejects ink droplets (droplets) from the ink jet recording head 20 provided in the apparatus main body 12 onto the continuous paper P, whereby the continuous paper P An image is formed on the top.

  The continuous paper P includes a plurality of conveyance rolls 14 that support the continuous paper P while rotating in the axial direction from the lower side, and the continuous paper P from the upper side. A plurality of tension rolls 16 that are pressed while rotating are transported through a transport path 18 constituted by the tension rolls 16. The ink jet recording head 20 is disposed at a position facing the continuous paper P conveyed in the image forming area 18A in the conveyance path 18 in the vertical direction.

  In the inkjet recording head 20, the width direction of the continuous paper P transported along the transport path 18 is the longitudinal direction, and has a length equal to or greater than the paper width of the continuous paper P. The inkjet recording head 20 is arranged in the order of black (K), cyan (C), magenta (M), and yellow (Y) from the upstream side in the transport direction of the continuous paper P, and each inkjet recording head 20K, 20C, 20M, and 20Y are configured to eject ink droplets of each color sequentially from the top to the continuous paper P.

  In addition, a movable infrared irradiation device that irradiates infrared rays toward the continuous paper P conveyed through the conveyance path 18 between the black (K) inkjet recording head 20K and the cyan (C) inkjet recording head 20C. (Hereinafter referred to as “movable laser device”) 22 is arranged.

  Then, downstream of the most downstream yellow (Y) inkjet recording head 20 </ b> Y and upstream of the outlet 12 </ b> A of the continuous paper P in the apparatus main body 12, the continuous paper P transported through the transport path 18. A plurality of (for example, three) movable infrared irradiation devices (hereinafter referred to as “movable laser devices”) 24, 26, and 28 for irradiating infrared rays are arranged.

  Each movable laser device 22, 24, 26, 28 is configured to be movable individually (independently) along the transport path 18 by a known moving mechanism (not shown). The devices 24, 26, and 28 can be arranged so that the distance between them is different. The movable laser devices 22, 24, 26, and 28 are vertical cavity surface emitting lasers, and can evaporate moisture in an image formed by ink droplets ejected onto the continuous paper P. It has become.

  More specifically, the movable laser device 22 disposed between the black (K) inkjet recording head 20K and the cyan (C) inkjet recording head 20C has a black (K) ejected from the inkjet recording head 20K. ) Is irradiated with infrared rays on the image (mainly characters) formed by the ink droplets to evaporate water in the image.

  Then, the movable laser devices 24, 26, and 28 arranged on the downstream side of the most downstream yellow (Y) inkjet recording head 20Y are cyan (C) ejected from the inkjet recording heads 20C, 20M, and 20Y, respectively. ), Infrared rays are sequentially applied to an image formed by magenta (M) and yellow (Y) ink droplets to evaporate moisture in the image.

  As the above-mentioned known moving mechanism, for example, a guide rail that movably supports each movable laser device 22, 24, 26, and 28, and each movable laser device 22, 24, 26, and 28 is moved individually. A rack and a pinion to be driven and an electric motor that rotationally drives each pinion are exemplified, but the moving mechanism in the present embodiment is not particularly limited.

  The positions of the movable laser devices 24, 26, and 28 arranged on the downstream side of the most downstream yellow (Y) inkjet recording head 20Y are determined according to the transport speed of the continuous paper P, the type of ink (for each color). The difference in the infrared absorption rate) and the paper type (thickness (heat capacity) and ink penetration rate) are set as appropriate. In the first embodiment, as an example, the positions of the movable laser devices 24, 26, and 28 are set based on the conveyance speed of the continuous paper P.

  Further, each movable laser device 22, 24, 26, 28 is infrared rays from the normal direction of the continuous paper P in the side view shown in FIG. It is arranged along the conveyance path 18 so as to irradiate. That is, the movable laser devices 22, 24, 26, 28 are arranged so that their optical axes coincide with the normal direction of the continuous paper P.

  Next, the operation of the inkjet recording apparatus 10 according to the first embodiment configured as described above will be described.

  First, each movable laser device 24, 26, 28 is arranged at an appropriate position based on the conveyance speed of the continuous paper P. That is, each movable laser device 24, 26, 28 can sequentially irradiate infrared rays at an appropriate irradiation timing (in the image formed on the continuous paper P, the optical density exceeding the target threshold value). As can be obtained) and are individually moved by known movement mechanisms.

  The movable laser device 22 is disposed as close as possible to the black (K) inkjet recording head 20K. As a result, the temperature of the water in the black (K) image formed on the continuous paper P is quickly raised to the boiling temperature, so that bleeding due to the penetration of the water into the continuous paper P is reduced. , The reduction of the optical density of the image (mainly characters) is suppressed or prevented.

  When the positions of the movable laser devices 22, 24, 26, and 28 are determined, the print job can be executed. Then, when the print job is executed, each inkjet recording head 20K, 20C, Ink droplets are ejected from 20M and 20Y, respectively. As a result, images are sequentially formed on the continuous paper P.

  Here, when ink droplets are ejected from the black (K) ink jet recording head 20 </ b> K onto the continuous paper P to form an image (mainly characters), infrared rays are emitted from the movable laser device 22. As a result, the water in the black (K) image formed on the continuous paper P is quickly heated to the boiling temperature (100 ° C.) and evaporated.

  Further, when ink droplets are ejected from the cyan (C), magenta (M), and yellow (Y) ink jet recording heads 20C, 20M, and 20Y onto the continuous paper P, a movable laser device is formed. Infrared rays are sequentially emitted from 24, 26, and 28. As a result, the water in the cyan (C), magenta (M), and yellow (Y) images formed on the continuous paper P is heated to the boiling temperature (100 ° C.) and evaporated.

  More specifically, as indicated by the solid line in FIG. 2, first, infrared rays are emitted from the movable laser device 24, so that after T1 seconds, cyan (C), magenta (M), and yellow (Y). The temperature of the moisture in the image is raised to the boiling temperature. At this time, it is desirable that the movable laser device 24 is also arranged as close as possible to the yellow (Y) inkjet recording head 20Y (the most downstream inkjet recording head 20).

  Next, when the continuous paper P is transported, the transport time (heat radiation to the atmosphere) and a part of the water in the image evaporate, so that the temperature of the water in the image is slightly lowered. By irradiating infrared rays from the laser device 26, the temperature of moisture in the image of cyan (C), magenta (M), and yellow (Y) is raised again to the boiling temperature after T2 seconds.

  Further, when the continuous paper P is transported, the transport time (heat radiation to the atmosphere) and a part of the water in the image evaporate, so that the temperature of the water in the image is slightly lowered again. By irradiating infrared rays from the movable laser device 28, the temperature of water in the image of cyan (C), magenta (M), and yellow (Y) is raised to the boiling temperature again after T3 seconds.

  As described above, in the inkjet recording apparatus 10 according to the first embodiment, each movable laser device 24, 26, 28 is an image formed on the continuous paper P by transporting the continuous paper P (dissipating heat to the atmosphere) and the continuous paper P. As the water content in the image partially evaporates, the remaining water temperature in the image is returned to the boiling temperature again at an appropriate irradiation timing before the temperature of the remaining water in the image falls to a predetermined temperature. It is possible to raise the temperature.

  Therefore, compared to a configuration (not shown) in which one or a plurality of infrared irradiation devices are fixed and arranged on the downstream side of the most downstream inkjet recording head 20Y, that is, a configuration in which an appropriate irradiation timing cannot be selected, The image formed on the continuous paper P is efficiently dried, and the optical density of the image formed on the continuous paper P is reduced or reduced.

  In other words, bleeding due to the penetration of moisture into the continuous paper P is reduced, the optical density of the image formed on the continuous paper P is improved, and the continuous paper P is a slowly permeable paper. Even in this case, the occurrence of spots due to the flow of ink droplets is suppressed. In addition, when the conveyance speed of the continuous paper P is changed, the positions of the movable laser devices 24, 26, and 28 are appropriately changed according to the change.

  In the same manner as described above, infrared rays are irradiated at an appropriate irradiation timing. For example, when the conveyance speed of the continuous paper P is set to a half speed, as indicated by the broken line in FIG. The temperature of moisture in the image of (C), magenta (M), and yellow (Y) is raised to the boiling temperature.

  Next, when the continuous paper P is transported, the transport time (heat radiation to the atmosphere) and a part of the water in the image evaporate, so that the temperature of the water in the image is slightly lowered. By irradiating infrared rays from the laser device 26, the temperature of moisture in the image of cyan (C), magenta (M), and yellow (Y) is raised to the boiling temperature again after T5 seconds.

  Further, when the continuous paper P is transported, the transport time (heat radiation to the atmosphere) and a part of the water in the image evaporate, so that the temperature of the water in the image is slightly lowered again. By irradiating infrared rays from the movable laser device 28, the temperature of water in the image of cyan (C), magenta (M), and yellow (Y) is again raised to near the boiling temperature after T6 seconds. .

  As described above, the timing of changing the position (interval) of each movable laser device 24, 26, 28 is the execution of a print job after changing the transport speed (or ink type or paper type) of the continuous paper P. Before. In addition, when changing the conveyance speed of the continuous paper P and obtaining an appropriate irradiation timing, the movable laser devices 24 and 26 divided into three or more on the downstream side of the ink jet recording head 20Y on the most downstream side. , 28 is particularly effective.

  Further, each movable laser device 22, 24, 26, 28 emits infrared rays from the normal direction of the continuous paper P in a side view as viewed from the direction orthogonal to the conveyance direction of the continuous paper P. Arranged along the transport path 18. Therefore, each movable laser device 22, 24, 26, 28 in the image formed on the continuous paper P as compared with the configuration in which infrared rays are irradiated from an oblique direction with respect to the normal direction of the continuous paper P Moisture evaporation is promoted.

  The two movable laser devices 26 and 28 arranged on the downstream side of the movable laser device 24 are heated to the boiling temperature by the movable laser device 24, and then transport the continuous paper P ( Heat is released to the atmosphere) and the remaining moisture in the image that has become a little lower with the evaporation of some of the moisture in the image formed on the continuous paper P is irradiated with infrared rays and boiled again Since the temperature is raised to the temperature, the output is smaller than that of the movable laser device 24.

  For example, in a configuration (not shown) in which one infrared irradiation device long in the transport direction is fixed and arranged on the downstream side of the ink jet recording head 20Y on the most downstream side, the density decreases when the heating rate is slow. The infrared output cannot be reduced (to suppress the optical density reduction). However, in the movable laser devices 24, 26, and 28 according to the first embodiment, the output of infrared rays can be individually set, so that the output can be reduced in total. Therefore, the power consumption of the inkjet recording apparatus 10 is reduced.

  In the first embodiment, the three movable laser devices 24, 26, and 28 are arranged on the downstream side of the most downstream ink jet recording head 20Y. However, the present invention is not limited to this. It is sufficient that at least two movable laser devices 24 and 26 are arranged in addition to the movable laser device 22. Alternatively, the movable laser devices 22, 24, 26, and 28 may be arranged on the downstream side of the ink jet recording heads 20K, 20C, 20M, and 20Y for the respective colors.

  That is, the movable laser device 22 is disposed between the inkjet recording head 20K and the inkjet recording head 20C, and the movable laser device 24 is disposed between the inkjet recording head 20C and the inkjet recording head 20M. The movable laser device 26 may be disposed between the inkjet recording head 20Y and the movable laser device 28 on the downstream side of the inkjet recording head 20Y. In this case, intercolor bleeding and color mixing are more effectively suppressed or prevented.

Second Embodiment
Next, the ink jet recording apparatus 10 according to the second embodiment will be described. In addition, the same code | symbol is attached | subjected to the site | part equivalent to the said 1st Embodiment, and detailed description (a common effect | action is also included) is abbreviate | omitted suitably.

  As shown in FIG. 3, in the inkjet recording apparatus 10 according to the second embodiment, a movable laser apparatus 22 is interposed between a black (K) inkjet recording head 20K and a cyan (C) inkjet recording head 20C. Are disposed, and the movable laser devices 22, 24, 26, and 28 are disposed only on the downstream side of the most downstream yellow (Y) inkjet recording head 20Y.

  Therefore, in the inkjet recording apparatus 10 according to the second embodiment, infrared rays are emitted more than in the first embodiment in response to a change in the conveyance speed (or ink type or paper type) of the continuous paper P. The degree of freedom in selecting the irradiation timing is high. Therefore, compared with the first embodiment or more, the image formed on the continuous paper P is efficiently dried, and the optical density of the image formed on the continuous paper P is suppressed or reduced. Is prevented.

<Third Embodiment>
Next, an inkjet recording apparatus 10 according to the third embodiment will be described. In addition, the same code | symbol is attached | subjected to the site | part equivalent to the said 1st Embodiment and 2nd Embodiment, and detailed description is abbreviate | omitted suitably.

  As shown in FIG. 4, in the inkjet recording apparatus 10 according to the third embodiment, the black (K) inkjet recording head 20K and the cyan (C) inkjet recording head 20C, as in the second embodiment. The movable laser device 22 is not disposed between them, and the movable laser devices 22, 24, 26, and 28 are disposed only on the downstream side of the most downstream yellow (Y) inkjet recording head 20Y. Yes.

  In the ink jet recording apparatus 10 according to the third embodiment, the most downstream ink jet recording head 20Y (the most downstream ink jet recording head) is disposed between the most downstream yellow (Y) ink jet recording head 20Y and the most upstream movable laser apparatus 22. A fixed infrared irradiation device (hereinafter ““ 30) (referred to as “fixed laser device”).

  As shown in FIG. 5, the fixed laser device 30 has an irradiation surface 31 facing the continuous paper P (conveying path 18) at a lower portion of a casing 32 fixed to the apparatus main body 12 of the inkjet recording apparatus 10. Attached. An air flow path 34 for blowing air to the continuous paper P is formed on the upstream side of the housing 32, and the continuous paper P and the fixed laser device are provided on the downstream side of the housing 32. A suction flow path 36 is formed for sucking water vapor J existing between 30 and 30.

  The most downstream yellow (Y) ink jet recording head 20Y also has a nozzle surface 21 at the bottom of the casing 40 fixed to the apparatus body 12 of the ink jet recording apparatus 10, and the continuous paper P (conveyance path 18). It is attached toward. A suction flow path 42 for sucking the ink mist S floating between the continuous paper P and the ink jet recording head 20Y is formed on the downstream side of the housing 40.

  Moreover, the housing | casing 40 and the housing | casing 32 are mutually joined by the conveyance direction. That is, the downstream side surface of the housing 40 and the upstream side surface of the housing 32 are joined to each other. Thus, the position in the transport direction between the yellow (Y) inkjet recording head 20Y and the fixed laser device 30 is ensured to be constant. Note that the irradiation surface 31 of the fixed laser device 30 is covered with a protective glass 38.

  Then, the fixed laser device 30 also irradiates infrared rays from the normal direction of the continuous paper P in the side view shown in FIG. 4 as viewed from the direction orthogonal to the conveyance direction of the continuous paper P. Arranged along the transport path 18. That is, the fixed laser device 30 is also arranged so that its optical axis coincides with the normal direction of the continuous paper P.

  Next, the operation of the inkjet recording apparatus 10 according to the third embodiment configured as described above will be described. In addition, since the effect | action by movable laser apparatus 22, 24, 26, 28 is common to the said 1st Embodiment and 2nd Embodiment, here, the effect | action by having provided the fixed laser apparatus 30 is demonstrated. .

  On the upstream side of the fixed laser device 30, the air is blown from the air flow path 34 toward the continuous paper P. That is, an air flow for removing the ink mist S floating around the continuous paper P (between the continuous paper P and the ink jet recording head 20Y) by the suction flow path 42 is formed. Therefore, the protective glass 38 covering the irradiation surface 31 of the fixed laser device 30 is prevented from being contaminated with the ink mist S as compared with the configuration in which the airflow is not formed.

  Further, since air is blown from the air flow path 34 toward the continuous paper P on the upstream side of the fixed laser device 30, the area around the continuous paper P (the continuous paper P and the fixed laser device 30) An air flow for removing the water vapor J existing between the suction flow paths 36 is also formed. Therefore, it is possible to suppress the occurrence of condensation on the protective glass 38 that covers the irradiation surface 31 of the fixed laser device 30 as compared with the configuration in which the airflow is not formed.

  As described above, in the inkjet recording apparatus 10 according to the third embodiment, since the fixed laser device 30 is provided at a constant position with respect to the inkjet recording head 20Y on the most downstream side, the inkjet recording on the most downstream side is provided. Compared with a configuration in which only a plurality of (for example, five) movable laser devices are arranged on the downstream side of the head 20Y, the water vapor J existing around the continuous paper P and the floating ink mist S are efficiently removed. Is done.

  The inkjet recording apparatus 10 according to the present embodiment has been described with reference to the drawings. However, the inkjet recording apparatus 10 according to the present embodiment is not limited to the illustrated one and does not depart from the gist of the present invention. The design can be changed as appropriate within the range. For example, the recording medium is not limited to the continuous paper P, but may be cut paper (plain paper).

  Further, the movable infrared irradiation device and the fixed infrared irradiation device are not limited to lasers as long as they have a structure capable of emitting infrared rays. For example, the movable infrared irradiation device and the fixed infrared irradiation device may be configured by a light emitting diode (LED) capable of emitting infrared rays, an infrared heater, or the like.

  In FIG. 1, a fixed laser device 30 may be disposed between the yellow (Y) inkjet recording head 20 </ b> Y and the movable laser device 24, and the movable laser device 22 may be used as the fixed laser device 30. . Furthermore, the fixed laser device 30 is arranged on the downstream side of the ink jet recording heads 20K, 20C, 20M, and 20Y for each color, and only the movable laser device 22 is arranged on the downstream side of the fixed laser device 30 on the most downstream side. You may make it the structure to carry out.

10 Inkjet recording device (an example of a droplet discharge device)
18 Transport path 20 Inkjet recording head (an example of a droplet discharge head)
22 Movable laser device (an example of movable infrared irradiation device)
24 Movable laser device (example of movable infrared irradiation device)
26 Movable laser device (an example of movable infrared irradiation device)
28 Movable laser device (example of movable infrared irradiation device)
30 Fixed laser device (an example of a fixed infrared irradiation device)
32 Housing 34 Blower channel 36 Suction channel P Continuous paper (an example of a recording medium)

Claims (2)

A liquid droplet ejection head that forms an image by ejecting liquid droplets onto the recording medium transported along a transport path, the width direction of the recording medium being a longitudinal direction;
Three or more movable infrared irradiation devices that are arranged so as to be movable downstream from the droplet discharge head in the conveyance direction of the recording medium, and evaporate moisture in the image formed on the recording medium;
Provided in a casing fixed downstream of the droplet discharge head in the transport direction of the recording medium and upstream of the three or more movable infrared irradiation devices in the transport direction of the recording medium; A fixed infrared irradiation device for evaporating moisture in the image formed on the medium;
An air flow path formed in the casing on the upstream side in the conveyance direction of the recording medium than the fixed infrared irradiation device, and for blowing air to the recording medium;
A suction channel formed in the casing on the downstream side in the conveyance direction of the recording medium from the fixed infrared irradiation device, and for sucking water vapor existing around the recording medium;
A droplet discharge device comprising:   The three or more movable infrared irradiation devices are arranged along the conveyance path so as to irradiate infrared rays from the normal direction of the recording medium in a side view as viewed from a direction orthogonal to the conveyance direction of the recording medium. The droplet discharge device according to claim 1, wherein the droplet discharge device is disposed.