JP2007021906A - Droplet delivery apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent a treatment liquid from adhering to the discharging surface of an ink delivery head. <P>SOLUTION: A space S1 where an ink droplet is discharged and a space S2 where the treatment liquid is discharged are divided with a dividing plate 44 provided between a treatment liquid delivery head 34L and the ink delivery head 34Y. Thereby, a mist of the treatment liquid does not reach the ink delivery head 34Y. Therefore, the treatment-liquid mist does not adhere to the discharging surface of the ink delivery head due to agglutination reaction with ink. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a droplet discharge device that discharges ink onto a transported recording medium.

  As a droplet discharge device that discharges ink to a transported recording medium, a droplet discharge device that further improves the image quality of an image formed by ink by discharging a treatment liquid is known.

  Treatment liquids improve the image quality of the image by causing reactions such as insolubilization and aggregation with the components in the ink, thereby improving the water resistance of the image and suppressing bleeding between different ink colors. is there. In addition, there is one that does not react with ink and improves the glossiness of the image to improve the image quality.

  In a droplet discharge device that discharges ink and processing liquid, when ink and processing liquid are discharged, the ink and processing are performed by satellites (micro droplets) that are formed accompanying the main droplets or bounce on the recording medium. The liquid becomes mist.

  When the mist of the processing liquid adheres to the ejection surface of the ink ejection head, it may cause an agglomeration reaction with the ink, or the processing liquid itself may adhere and block the nozzle, resulting in ejection failure.

  In order to solve this problem, Patent Document 1 discloses a configuration in which the distance between the conveyed recording medium and the treatment liquid ejection head is larger than the distance between the conveyed recording medium and the ink ejection head. .

With this configuration, the mist generated when the processing liquid is discharged is diffused into the space formed by increasing the distance between the processing liquid discharge head and the recording medium, and reaches the ink discharge head adjacent to the processing liquid discharge head. Hard to adhere. Further, since the distance between the processing liquid discharge head and the recording medium to be conveyed is large, it is possible to reduce the amount of bounce mist in which insolubilized substances adhering to the processing liquid discharge head are mixed.
JP 2002-154195 A

  However, in a device equipped with an ink discharge head and a treatment liquid discharge head having a length over the entire width of the recording area, a large amount of ink and treatment liquid mist is generated. Cannot be sufficiently prevented from adhering to the ejection surface of the ink ejection head.

  An object of the present invention is to prevent the processing liquid from adhering to the ejection surface of the ink ejection head in consideration of the above facts.

  The droplet discharge device according to claim 1 of the present invention includes an ink discharge head that discharges ink to a transported recording medium, a processing liquid discharge head that discharges a processing liquid to the recording medium, the ink discharge head, A partition member provided between the processing liquid discharge head and partitioning the space from which the ink is discharged and the space from which the processing liquid is discharged; and provided at a front end portion of the partition member and contacting the recording medium. And a roller.

  The treatment liquid refers to a liquid that improves the image quality of an image formed by ink, and includes both those that react with ink and those that do not react with ink.

  In addition, as a treatment liquid that reacts with ink, for example, by causing a reaction such as insolubilization and aggregation with components in the ink, the water resistance of the image is improved, or bleeding between different ink colors is suppressed, There are some which improve the image quality.

  Further, as the processing liquid that does not react with ink, for example, there is a liquid that improves the glossiness of the image and improves the image quality of the image.

  In the configuration of the first aspect, the partition member provided between the ink discharge head and the processing liquid discharge head partitions the space from which ink is discharged from the space from which the processing liquid is discharged.

  For this reason, the mist of the processing liquid generated when the processing liquid is discharged does not reach the ink discharge head. Accordingly, the mist of the processing liquid does not cause an agglomeration reaction with the ink and does not generate a fixed substance on the ejection surface of the ink ejection head. Further, the processing liquid itself does not adhere to the ejection surface of the ink ejection head.

  In addition, a roller that comes into contact with the recording medium to be conveyed is provided at the tip of the partition member, which follows the recording medium conveyance, so that it does not become a conveyance resistance of the recording medium.

  According to a second aspect of the present invention, there is provided a liquid droplet ejection apparatus according to the first aspect, further comprising a pressing unit that presses the roller against the recording medium.

  When the treatment liquid is water-soluble, it is considered that the recording medium floats due to moisture absorption by the recording medium. However, in the configuration of claim 2, the pressing means presses the roller against the recording medium. Further, it is possible to suppress the floating of the recording medium and prevent the recording medium from being jammed in the conveyance path.

  A droplet discharge device according to a third aspect of the present invention is characterized in that, in the configuration of the first or second aspect, a heating means for heating the roller is provided.

  In this configuration, since the heating unit heats the roller that contacts the recording medium, the drying of the ink or the treatment liquid impregnated in the recording medium can be accelerated.

  According to a fourth aspect of the present invention, there is provided the liquid droplet ejection apparatus according to any one of the first to third aspects, further comprising a peeling unit that peels off deposits attached to the surface of the roller. To do.

  In this configuration, the peeling means peels off the adhering matter such as paper dust that adheres to the surface of the roller after long-term use, so that the adhering matter becomes a conveyance resistance of the recording medium, and the conveyance bias of the recording medium can be prevented.

  According to a fifth aspect of the present invention, in the liquid droplet ejection device according to any one of the first to fourth aspects, the processing liquid ejection head is disposed upstream of the ink ejection head in the transport direction of the recording medium. It is characterized by being.

  A droplet discharge device according to a sixth aspect of the present invention is characterized in that, in the configuration of any one of the first to fourth aspects, the processing liquid does not have a color.

  Thereby, even if a roller contacts and presses the recording medium after application of the treatment liquid, the recording medium is not soiled.

  Since the present invention has the above-described configuration, the treatment liquid can be prevented from sticking to the ejection surface of the ink ejection head.

  Hereinafter, an example of an embodiment according to a droplet discharge device of the present invention will be described with reference to the drawings.

  First, an overall configuration of an ink jet printer as a droplet discharge device will be outlined with reference to FIG.

  As shown in FIG. 1, the ink jet printer 10 includes an apparatus housing 13, and a paper feed cassette 12 in which a sheet (recording medium) P is accommodated is provided below the apparatus housing 13. A pick-up roll 14 for taking out the paper P from the inside of the paper feed cassette 12 is arranged at the upper portion of the front end side (left end side in FIG. 1) of the paper feed cassette 12 in pressure contact with the front end side of the upper surface of the paper P.

  Further, a first conveyance path 18 is formed that extends from the leading end of the paper feed cassette 12 and reaches the conveyance belt 32 in the center of the apparatus. A plurality of first conveyance roll pairs 20 for nipping and conveying the paper P to the conveyance belt 32 are provided along the first conveyance path 18.

  The conveyance belt 32 is wound around a driven roller 28 arranged upstream in the paper conveyance direction and a driving roller 30 arranged downstream, and the rotation of the driving roller 30 causes an arrow A direction (clockwise) in FIG. Direction).

  The conveyance belt 32 is a conveyance unit that electrostatically attracts and conveys the paper P. A nip roller 38 disposed above the driven roller 28 presses the paper P against the conveyance belt 32 and conveys the paper P to the conveyance belt 32. Adhere to.

  Disposed above the transport belt 32 is a droplet discharge head 34 that discharges liquid droplets onto the paper P transported on the transport belt 32 to record an image.

  The droplet discharge head 34 includes four ink discharge heads 34Y, 34M, 34C, and 34K that discharge ink droplets of four colors of yellow (Y), magenta (M), cyan (C), and black (K), respectively. Is provided on the downstream side in the paper conveyance direction, and a full-color image can be recorded.

  On the upstream side of the ink ejection heads 34Y, 34M, 34C, and 34K in the paper conveyance direction, for example, a cohesive reaction with ink is performed to promote ink fixing and to improve the image density and water resistance. A treatment liquid discharge head 34L for discharging the liquid is disposed. The arrangement of the treatment liquid discharge head 34L has a sufficient image quality improvement effect even if it is upstream, downstream or even between the ink discharge heads 34Y, 34M, 34K, but the ink penetrates the paper P. Since it is desirable that it is applied to the paper P before printing, it is preferably located at the uppermost stream as shown in the figure.

  The droplet discharge head 34 faces the flat portion 32F of the transport belt 32, and the opposed region is a discharge region where ink droplets and processing liquid are discharged from the droplet discharge head 34. The paper P transported through the first transport path 18 is held by the transport belt 32, reaches this discharge region, and faces the liquid droplet discharge head 34, and ink corresponding to image information from the liquid droplet discharge head 34. Drops and processing liquid are deposited.

  Above the droplet discharge head 34, ink tanks 40Y, 40M, 40C, and 40K that supply ink to the respective ink discharge heads 34Y, 34M, 34C, and 34K, and a processing liquid tank that supplies processing liquid to the processing liquid discharge head 34L 40L is disposed.

  A second conveyance path 24 is formed that extends upward from the conveyance belt 32 and reaches the paper discharge tray 22 that stores the paper P on which an image is recorded. A plurality of second transport roll pairs 26 are provided along the second transport path 24 to sandwich and transport the paper P to the paper discharge tray 22. A reverse conveyance path 36 for duplex printing is connected from the second conveyance path 24 to the first conveyance path 18.

  With the above configuration, the paper P taken out from the paper feed cassette 12 by the pickup roll 14 is transported through the first transport path 18 by the plurality of transport roll pairs 20 and sent to the transport belt 32.

  The sheet P sent to the conveyance belt 32 is subjected to image recording by ejecting treatment liquid and ink droplets from the droplet ejection head 34 at the flat portion 32F, and the second conveyance is performed by the plurality of conveyance roll pairs 26. The paper is conveyed through the path 24 and discharged to the paper discharge tray 22.

  When performing double-sided recording, the paper on which single-sided recording has been performed is transported from the second transport path 24 via the reverse transport path 36 to the first transport path 18 and sent again to the transport belt 32, where image recording is performed. Done. As described above, a series of image recording is performed.

  Next, the configuration of the droplet discharge head 34 will be described.

  As shown in FIG. 2, the processing liquid discharge head 34L and the ink discharge heads 34Y, 34M, 34C, and 34K have an effective recording area that is long in the paper width of the paper P (the length in the direction perpendicular to the transport direction). Both end portions thereof are supported by the side plate 42 of the holder.

  The treatment liquid discharge head 34L and the ink discharge heads 34Y, 34M, 34C, and 34K are each composed of an elongated substrate 60 and a plurality of unit heads 62 that are divided along the longitudinal direction. . Further, the long substrate 60 is provided with an opening 64, and is connected to the treatment liquid tank 40L and the ink tanks 40Y, 40M, 40C, and 40K by tubes passed through the opening 64, respectively.

  A partition plate (partition member) 44 is provided between the processing liquid ejection head 34L and the ink ejection head 34Y to partition the space S1 from which ink droplets are ejected from the space S2 from which the processing liquid is ejected (FIG. 5). 4).

  The partition plate 44 is elongated in the paper width of the paper P in the same manner as the processing liquid discharge head 34L and the ink discharge heads 34Y, 34M, 34C, 34K.

  The partition plate 44 is supported by an L-shaped support member 50 fixed to the side plate 42 and a pin 46 attached to the support member 50 so as to be slidable in the vertical direction.

  That is, the shaft portion of the pin 46 is passed through the hole 50A of the support member 50, the tip end portion of the shaft portion is fixed to both end portions of the partition plate 44, and the pin 46 slides in the hole 50A. The plate 44 moves up and down integrally with the pin 46. When the pin 46 is lowered by a certain amount, the head portion of the pin 46 comes into contact with the edge of the hole 50A, and the downward movement is stopped.

  In the present embodiment, the partition plate 44 is supported by the side plate 42, but is not limited thereto, and may be configured to be supported by the apparatus housing 13, for example.

  A spring (pressing means) 48 that presses the partition plate 44 downward (paper P side) is attached to the shaft portion of the pin 46.

  As shown in FIG. 3, a roller 52 that is in contact with the sheet P and whose axial direction is the direction (longitudinal direction) orthogonal to the transport direction of the sheet P is pivotally supported at the leading end of the partition plate 44. Similarly to the partition plate 44, the roller 52 is also long in the width of the paper P.

  Since this roller 52 comes into contact with the paper P from which the processing liquid has been discharged, the processing liquid adheres to the surface of the roller 52 by long-term use, and the processing liquid or paper dust adheres to the surface of the roller 52. It is possible.

  Therefore, in this embodiment, a blade (peeling means) 54 that peels off the processing liquid attached to the surface of the roller 52 is provided on the side surface of the partition plate 44. The blade 54 abuts the tip portion on the surface of the roller 52 and scrapes off the processing liquid on the roller surface. A receiving portion (not shown) for receiving the processing liquid scraped by the blade 54 is provided.

  Further, a heater (heating means) 56 for heating the roller 52 is provided on, for example, a side surface of the partition plate 44. The heater 56 conducts heat to the axial center of the roller 52 and heats the surface of the roller 52.

  Next, the operation of the above embodiment will be described.

  As shown in FIG. 4, the processing liquid is discharged from the processing liquid discharge head 34 </ b> L on the upstream side in the transport direction of the paper P onto the paper P transported by the transport belt 32. Next, ink is ejected from the ink ejection head 34Y on the downstream side in the transport direction of the paper P.

  The mist of the processing liquid generated by the discharge of the processing liquid is caused to flow downstream in the transport direction by the air flow generated when the paper P is transported.

  However, in this embodiment, the partition plate 44 provided between the treatment liquid ejection head 34L and the ink ejection head 34Y partitions the space S1 from which ink droplets are ejected from the space S2 from which the treatment liquid is ejected. Therefore, the mist of the processing liquid does not reach the ink discharge head 34Y. For this reason, the mist of the treatment liquid does not cause an agglomeration reaction with the ink and does not adhere to the ejection surface of the ink ejection head.

  In the present embodiment, since the roller 52 that comes into contact with the paper P to be transported is provided at the tip of the partition plate 44, it does not serve as a transport resistance for the paper P, but is a space S1 in which ink droplets are ejected. The space S2 in which the processing liquid is discharged is surely partitioned, and the mist of the processing liquid does not reach the ink discharge head 34Y. Further, since the processing liquid has almost no color compared to other inks, the paper P is not soiled even when the roller 52 comes into contact therewith.

  In this embodiment, since the spring 48 presses the roller 52 against the paper P, the paper P that has absorbed moisture can be prevented from being lifted or warped, and the paper P can be prevented from being jammed.

  Further, in this embodiment, the heater 56 heats the roller 52 that contacts the paper P, so that drying of the treatment liquid impregnated with the paper P can be accelerated and the expansion of the paper P is suppressed. Therefore, it is possible to prevent a paper jam of the paper P that is likely to occur.

  In the present embodiment, the blade 54 peels off the processing liquid adhering to the surface of the roller 52, so that the processing liquid can be prevented from adhering and becoming a conveyance resistance of the paper P.

  Note that the inkjet printer 10 according to the present embodiment has a long shape in which the effective recording area is equal to or larger than the width of the recording paper (the length in the direction orthogonal to the transport direction), yellow (Y), magenta (M ), Cyan (S), and Black (K), which is a so-called Full Width Array (FWA) type in which full-color images are recorded by four inkjet recording heads corresponding to four colors.

  However, the droplet discharge device of the present invention is not limited to the Full Width Array (FWA) type. For example, by selectively discharging ink droplets from the nozzles while the ink discharge head moves in the main scanning direction, When a part of the image based on the image data is recorded in a predetermined band area and one movement in the main scanning direction is completed, the paper is conveyed by a predetermined pitch in the sub-scanning direction, and again the ink ejection head A so-called Partial Width Array (PWA) type in which a part of an image based on image data is recorded in the next band area while moving in the main scanning direction may be used.

  In the present embodiment, the spring 48 is used as the pressing means for pressing the roller 52 against the paper P. However, the pressing means of the present invention is not limited to this, and may be an elastic member such as rubber. Any member that presses the roller 52 against the paper P may be used.

  In the present embodiment, as the heating means for heating the roller 52, a configuration in which heat is conducted to the axis of the roller 52 by the heater 56 disposed on the side surface of the partition plate 44 is used. For example, a heater built in the roller 52 may be used as long as it is a member that heats the roller 52.

  Further, in the present embodiment, the blade 54 that scrapes off the deposit is used as the stripping unit that strips the deposit attached to the surface of the roller 52. However, the stripping unit of the present invention is not limited to this, for example, The structure which adsorb | sucks an adhering matter and peels may be sufficient and the member which peels the adhering matter adhering to the surface of the roller 52 should just be used.

FIG. 1 is a schematic diagram illustrating the overall configuration of an inkjet printer according to an embodiment of the present invention. FIG. 2 is a perspective view showing the droplet discharge head according to the present embodiment. FIG. 3 is a perspective view showing the partition plate according to the present embodiment. FIG. 4 is a front view showing the partition plate according to the present embodiment.

Explanation of symbols

10 Inkjet printer (droplet discharge device)
34Y Ink discharge head 34L Treatment liquid discharge head 44 Partition plate (partition member)
48 Spring (Pressing means)
52 Roller 54 Blade (peeling means)
56 Heater (heating means)
P paper (recording medium)
S1 space S2 space

Claims (6)

An ink ejection head for ejecting ink onto a recording medium to be conveyed;
A processing liquid discharge head for discharging the processing liquid to the recording medium;
A partition member provided between the ink discharge head and the processing liquid discharge head, and partitioning a space from which the ink is discharged and a space from which the processing liquid is discharged;
A roller provided at a tip of the partition member and contacting the recording medium;
A droplet discharge apparatus comprising:   The droplet discharge device according to claim 1, further comprising a pressing unit that presses the roller against the recording medium.   The droplet discharge device according to claim 1, further comprising a heating unit configured to heat the roller.   The liquid droplet ejection apparatus according to claim 1, further comprising a peeling unit that peels off deposits attached to the surface of the roller.   5. The liquid droplet ejection apparatus according to claim 1, wherein the processing liquid ejection head is disposed upstream of the ink ejection head in the transport direction of the recording medium.   The droplet discharge apparatus according to claim 1, wherein the processing liquid has no color.

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