JP2019162849A - Device for discharging liquid - Google Patents

Abstract

To provide a liquid discharge device capable of improving the drying efficiency of a medium.SOLUTION: A liquid discharge device according to the present invention comprises a transport path for transporting a medium, a liquid discharge head for discharging a liquid onto the medium transported on the transport path, a discharge tray for discharging the medium, and a drying device for drying the medium. The transport path includes a first bending portion for bending the medium in a state where a surface of the medium onto which the liquid is discharged faces inward. The discharge tray has a second bending portion for bending the medium in a state where the surface of the medium onto which the liquid is discharged faces inward. The curvature of the medium bent by the first bending portion is larger than the curvature of the medium bent by the second bending portion. The drying device dries the medium transported on the first bending portion.SELECTED DRAWING: Figure 3

Description

  The present invention relates to an apparatus for discharging a liquid.

  In a device for ejecting liquid, a configuration is disclosed in which a drying device is provided on a conveyance path of a medium in order to dry the liquid attached to the medium (for example, Patent Document 1). In addition, a configuration is disclosed in which a medium is bent by providing unevenness on a paper discharge tray to suppress curling (for example, Patent Document 3).

  However, in the above-described prior art, it has been difficult to sufficiently suppress curling.

  In order to solve the above-described problems and achieve the object, the present invention includes a transport path through which a medium is transported, a liquid discharge head that discharges liquid onto the medium transported on the transport path, and the medium. An apparatus for discharging a liquid comprising a discharge tray to be discharged and a drying device for drying the medium, wherein the transport path bends the medium with the liquid discharge surface of the medium inside. The discharge tray includes a second bending portion that bends the medium with the liquid discharge surface of the medium facing inward, and the curvature of the medium bent by the first bending portion is the second bending portion. It is larger than the curvature of the medium bent by the bending part, The said drying apparatus is an apparatus which discharges the liquid characterized by drying the said medium conveyed on a said 1st bending part.

  According to the present invention, curling of a medium can be more efficiently reduced.

FIG. 1 is an overall schematic diagram of an apparatus (image forming apparatus) that discharges liquid. FIG. 2 is an internal schematic diagram of an apparatus (image forming apparatus) that discharges liquid. FIG. 3 is a detailed explanatory diagram of the transport path and its peripheral configuration in the first embodiment. FIG. 4 is a detailed explanatory diagram of the transport path and its peripheral configuration in the first embodiment. FIG. 5 is a perspective view of the paper discharge tray in the first embodiment. FIG. 6 is a front view of the paper discharge tray in the first embodiment. FIG. 7 is a relationship diagram of elapsed time, curl amount, and curl direction. FIG. 8 is a detailed explanatory diagram of the transport path and its peripheral configuration in the first embodiment. FIG. 9 is a front view of the paper discharge tray in the first embodiment. FIG. 10 is a detailed explanatory diagram regarding the sheet bending direction in the first embodiment. FIG. 11 is a detailed explanatory diagram of a transport path and its peripheral configuration in the second embodiment. FIG. 12 is a detailed explanatory diagram of the transport path and its peripheral configuration in the third embodiment. FIG. 13 is a detailed explanatory diagram of a transport path and its peripheral configuration in the third embodiment. FIG. 14 is a detailed explanatory diagram of a transport path and its peripheral configuration in the fourth embodiment. FIG. 15 is a detailed explanatory diagram of a conveyance path and its peripheral configuration in the fifth embodiment. FIG. 16 is a detailed explanatory diagram of a transport path and its peripheral configuration in the sixth embodiment. FIG. 17 is a plan view of a conveyance path in the seventh embodiment.

(First embodiment)
An outline of an apparatus (image forming apparatus) 1000 that ejects liquid will be described with reference to FIGS. 1 and 2. The apparatus 1000 that ejects liquid includes an apparatus main body 1001, a paper feed tray 2, a paper discharge tray 10, an operation unit 900, an ADF 901, a cartridge holder 910, a cartridge 912, and a post-processing device 14.

  The paper feed tray 2 stores paper P (medium). The paper discharge tray 10 is a discharge destination of the paper P on which an image or the like is formed by a liquid discharge head described later. On the paper discharge tray 10, a protrusion 101 (second bent portion) not shown in FIG. 2 is provided. Details of the protrusion 101 will be described later with reference to FIGS. The operation unit 900 includes a touch panel, physical buttons, and the like, and the user can instruct a print command or the like to the apparatus main body via the operation unit 900. The ADF 901 is a so-called scanner device.

  The cartridge 912 is a liquid storage container that stores liquid (ink or the like) discharged from the liquid discharge head, and is mounted on the cartridge holder 910. The liquid in the cartridge 912 is sent to the liquid discharge head via a tube or the like. The post-processing device 14 is a device that collects paper with a stapler and bends the paper.

  FIG. 2 is a diagram illustrating an internal configuration of the apparatus main body 1001. The apparatus main body 1001 includes a transport roller 4, a transport path 60, a drying device 20, a liquid discharge head 7, a discharge port 8, and a switching unit 12.

  The transport roller 4 is a roller for transporting the paper P on the paper feed tray 2 or the transport path 60 in the transport direction. The conveyance roller 4 is a combination of a plurality of rollers that can be rotationally driven by a driving source such as a motor and a roller that is only fitted in a bearing without a driving force (not distinguished in this embodiment).

  The transport path 60 is a path for transporting the paper P on the paper feed tray 2, and is configured such that the paper P is discharged from the discharge port 8 after the paper P passes below the liquid ejection head 7. Has been. The drying device 20 is a device that dries the paper P transported on the transport path 60, and specifically includes a blower. Details of the conveyance path 60 and the drying device 20 will be described later with reference to FIGS. 3 and 4.

  The liquid discharge head 7 is a portion that discharges liquid onto the paper P on the transport path 60, and a piezo ink jet head using a piezoelectric element, a thermal ink jet head using heat, or the like can be used. . In the present embodiment, a so-called line type ink jet head (or a one-pass type ink jet head) in which a plurality of liquid discharge heads are arranged in a direction intersecting the transport direction of the paper P is used.

  The switching unit 12 is a claw for switching the transport direction of the paper P, and guides the paper P on which the liquid has been ejected to the post-processing device 14, guides it to the discharge port 8, or a switchback path to be described later. Guide to 61.

  Next, the conveyance path 60 and the paper drying method of the present embodiment will be described in more detail with reference to FIGS.

  3 and 4 are enlarged views of the conveyance path 60 and its periphery in FIG. The conveyance path 60 includes a switchback path 61 (first bent portion), a discharge path 62 (first bent portion), a head upward path 64, and a discharge path 63. The switchback path 61 included in the transport path 60 is a path for bending the sheet P on which the liquid has been discharged with the liquid discharge surface of the sheet P inside, and for switching back and front of the sheet P.

  When reversing the paper P, the switching unit 12 located downstream of the liquid ejection head 7 in the conveyance direction of the paper P is operated to guide the paper P on which the liquid has been ejected to the switchback path 61. After the paper P reaches the vicinity of the end of the switchback path 61 (near the discharge port 8), the paper P is transported to the upstream side by reversing the driving of the transport roller 4 or the like. When the paper P reaches the vicinity of the end of the switchback path 61 (in the vicinity of the discharge port 8), the paper P is bent along the switchback path 61 as shown in FIG.

  Thereafter, the paper P is transported to the ejection path 63 via the head upper path 64 above the liquid ejection head 7. As described above, the transport direction and the front and back of the paper P can be reversed.

  After the liquid ejection onto one or both sides of the paper P is completed, the paper P is guided to the discharge path 62 (FIG. 4). The discharge path 62 is a path connecting the liquid discharge head 7 and the discharge port 8, and the paper P is discharged from the discharge port 8 to the discharge tray 10.

  In this embodiment, since the discharge tray 10 is arranged above the liquid discharge head 7 in the vertical direction, the discharge path 62 is separated from the liquid discharge head 7 from the downstream of the liquid discharge head 7 to the discharge port 8. Thus, it is curved (warped). Further, the switchback path 61 is arranged so as to be adjacent (along) the discharge path 62.

  Thereby, the switchback path 61 and the discharge path 62 can be stored in a small space.

  Further, in the vicinity of the conveyance path 60, the above-described drying device 20 (drying means) is disposed. Specifically, the drying device 20 is disposed at a position facing the switchback path 61 and the discharge path 62. The drying device 20 is a device for drying the liquid adhering to the paper P, such as a device that rotates a fan or the like to send air to dry, or a device that heats and drys the paper P by a heating unit such as a heater. Is mentioned. Of course, a combination thereof may be used. Further, the drying means includes curing means for curing the liquid using a UV lamp or the like. In the present embodiment, the drying device 20 is a blower that sends air by rotating a fan.

  Here, the drying device 20 dries the paper P on the switchback path 61 and the paper P on the discharge path 62. In other words, the drying device 20 is arranged so that the paper P on the switchback path 61 and the paper P on the discharge path 62 can be dried. More specifically, the switchback path 61 and the discharge on the air blowing direction by the drying device 20 (or the heating energy irradiation direction by the heating unit, collectively referred to herein as the drying energy supply direction F). The path 62 is arranged.

  As a result, the drying energy from the drying device 20 is supplied to both the paper P located in the switchback path 61 and the paper P located in the discharge path 62, so that the paper P can receive the drying energy in the transport path 60. The range can be expanded and the drying efficiency can be improved.

  In this embodiment, the switchback path 61 is arranged closer to the drying apparatus 20 than the discharge path 62 in the drying energy supply direction F by the drying apparatus 20. In other words, the drying device 20 is disposed so as to face the discharge path 62 with the switchback path 61 interposed therebetween. Thereby, the paper P conveyed to the switchback path 61 at the time of duplex printing can be dried immediately, and more efficient drying can be performed.

  The liquid that has landed on the paper P penetrates into the paper P, and in the process, the liquid P is mainly swollen so that the liquid discharge surface side is convex, and the paper P is curled. I know I will (warp).

  Therefore, in the present embodiment, as shown in FIG. 3 and the like, the switchback path 61 and the discharge path 62 protrude toward the drying energy supply direction F by the drying device 20 (downstream of the drying energy supply direction F). A configuration is adopted in which the sheet is bent and the liquid discharge surface side of the sheet P is bent inwardly so that the side is convex. That is, the switchback path 61 conveys the paper P such that the liquid discharge surface of the paper P faces the drying device 20 side. Similarly, the discharge path 62 conveys the paper P such that the liquid discharge surface of the paper P faces the drying device 20 side. Thus, the drying energy from the drying device 20 is supplied to the liquid discharge surface side of the paper P.

  Accordingly, the switchback path 61 can bend the paper P with the liquid discharge surface of the paper P facing inward. In other words, the switchback path 61 bends (warps) the paper P to be curled with the liquid discharge surface side convex. Thereby, the curl of the paper P is corrected. Then, while performing the correction, the curling is further corrected by supplying the drying energy to the liquid discharge surface side. “Curl” is almost synonymous with “warp”, and the meaning includes “wrinkle”, “yore”, and the like. That is, the curl of the paper P means a state in which the paper P is curved, and the liquid discharge surface side rises (becomes convex).

  Here, the curvature of the paper when the switchback path 61 (first bending portion) bends the paper P is represented as 1 / R1 (R1 is the radius of the curved portion). Of the curvatures given to the paper P, the maximum curvature is 1 / R1. In this embodiment, the curvature of the switchback path 61 and the curvature of the paper discharge path 62 are substantially equal, but may be different.

  Next, details of the protrusion 101 (second bent portion) of the present embodiment will be described with reference to FIGS. 5 and 6.

  FIG. 5 is a perspective view of the apparatus main body 1001. The apparatus main body 1001 includes a protrusion 101 in addition to the discharge port 8 and the discharge tray 10 described above. The protruding portion 101 is a member that protrudes upward from the surface of the paper discharge tray 10 and bends the paper P. Further, the protruding portion 101 is provided in a long direction along the paper discharge direction of the paper P near the center of the paper discharge tray 10 in the width direction of the paper P (direction orthogonal to the paper discharge direction).

  FIG. 6 is a diagram of the configuration in the vicinity of the protrusion 101 when viewed from the conveyance direction of the paper P. The paper P discharged from the paper discharge port 8 is stacked so that the vicinity of the center in the width direction of the paper P is in contact with the upper end portion of the protrusion 101. Thereby, the paper P can be bent (warped) with the liquid discharge surface of the paper P inside as shown in FIG. At this time, the curvature of the paper P when the protrusion 101 (second bending portion) bends the paper P is represented by 1 / R2 (R2 is the radius of the curved portion). Here, among the curvatures given to the paper P, the curvature near the center in the width direction of the paper P is 1 / R2.

  Further, since the discharge path 62 is configured to go to the paper discharge tray 10 while switching back the paper P on which the liquid is discharged, the paper discharged to the paper discharge tray 10 has a surface to be discharged. The paper is discharged downward (so-called face-down paper discharge). Therefore, the bending of the sheet P by the protrusion 101 (second bending portion) is the bending direction with the discharge target surface on the inside, similarly to the bending direction by the switchback path 61 (first bending portion).

  Here, in the present embodiment, the curvature of the paper P bent by the switchback path 61 (first bent portion) and the paper discharge path 62 (first bent portion) is bent by the protrusion 101 (second bent portion). The curvature of the paper P is larger. That is, the curvature of the paper P bent from the switchback path 61 (first bent portion) and the paper discharge path 62 (first bent portion) is set to 1 / R1, and is bent by the protrusion 101 (second bent portion). When the curvature of the paper P is 1 / R2, (1 / R1)> (1 / R2) is set. In other words, the bending by the first bending portion is more powerful than the second bending portion. Thereby, more efficient curl suppression can be achieved. The reason will be described below.

  As described above, the liquid that has landed on the paper P penetrates into the paper P, and in the process, the liquid discharge surface side of the paper P is mainly swollen so that the liquid discharge surface side becomes convex. It is known that P curls. This curl is referred to herein as a back curl.

  On the other hand, if the sheet P that has absorbed the liquid is left for a certain period of time (several hours), it may curl in the direction opposite to the back curl (that is, curl with the liquid discharge surface side concave). know. This curl is referred to herein as a face curl.

  In particular, the paper P discharged onto the paper discharge tray 10 is likely to be left for a long time during continuous printing or when left by the user, and in that case, face curl is particularly likely to occur. In addition, during single-sided printing, the amount of adhesion of the liquid is biased between the front and back of the paper P, so the curl amount tends to increase. Even if the face curl does not occur, the back curl immediately after printing gradually decreases with time.

  FIG. 7 is a graph illustrating the relationship between the curl direction and the curl direction of the paper P on which the liquid is discharged and the passage of time. The vertical axis represents the curl direction and the curl direction. The upper side means back curl, and the lower side means face curl. In addition, although the content described hereafter is described based on an inventor's knowledge and consideration, it does not limit the generating principle of an effect. Depending on the paper material, thickness, ink components, and the like, the magnitude and transition of the curl may change.

  A line A indicated by a solid line shows an example when no correction or drying is performed after the liquid is discharged onto the paper P. As described above, since the back curl greatly occurs immediately after discharge, the user takes out the curled paper. Also, it is not practical to leave a sheet on the sheet discharge tray for several hours until the curl amount decreases.

  A line B indicated by an alternate long and short dash line indicates an example when the sheet P is corrected by only the second bent portion (projection portion 101) after the liquid is discharged onto the sheet P and discharged onto the sheet discharge tray. In this case, the curl (back curl) suppression effect immediately after discharge can be sufficiently obtained, but face curl occurs with time, and the correction direction of the paper P by the second bent portion is the direction that promotes face curl. In some cases, the curl amount of the paper P increases instead. In other words, the timing at which the curl is reduced is slightly shifted as compared with the case indicated by the line A, and the curl becomes larger than the case indicated by the line A if the time for the user to collect the paper is late. . Of course, curl is large even when paper is collected too early. As described above with respect to the line A and the line B, there is a possibility that a malfunction may occur even if the sheet correction force is too small or too large.

  Compared with the case of the line B, a line C indicated by a broken line indicates a curl amount when the sheet is further corrected by curling while drying by blowing air to the sheet at the first bending portion. At this time, the curvature of the first bent portion and the curvature of the second bent portion are the same. In this example, it is possible to obtain a large curl correction force by correcting the paper while drying it at the first bending portion, and the curl amount immediately after the paper is discharged is smaller than the case described above. However, since the curvature of the second bent portion is the same as that of the first bent portion (relatively large), the back curl is promoted thereafter. Therefore, there is a high possibility that the paper is greatly curled soon after the paper is discharged.

  A line D indicated by a bold line indicates a curl amount when the present embodiment is used. In the present embodiment, by setting (1 / R1)> (1 / R2), the correction amount of the paper P by the second bending portion is relatively smaller than the correction amount by the first bending portion. Thereby, for example, the face curl is generated in the paper P discharged to the paper discharge tray 10 with time, and the correction force is also applied when the correction direction of the paper P by the second bending portion becomes the direction for promoting the face curl. The curl is difficult to be promoted due to the small size. That is, the curl amount in both cases can be reduced immediately after paper discharge and after a long time after paper discharge.

  Further, even if face curl does not occur, the back curl amount gradually decreases, so that the correction amount of the paper P by the second bending portion is relatively smaller than the correction amount by the first bending portion. The correction amount is more appropriate for the curl amount, and curling can be efficiently suppressed.

  Further, since the correction amount of the paper P by the first bending portion is relatively larger than the correction amount by the second bending portion, the paper P mainly including back curl can be corrected more strongly.

  Further, in the present embodiment, in order to further correct the back curl having a relatively large curl amount, the drying device 20 is disposed so as to dry the paper P conveyed on the switchback path 61 (or the discharge path 62). ing. With these configurations, for a back curl with a relatively large curl amount that is likely to occur immediately after printing, a large curvature by satisfying (1 / R1)> (1 / R2) and drying by the drying device 20 are combined. For the face curl with a relatively small curl amount after that, correct it with a small curvature by satisfying (1 / R1)> (1 / R2). , Curling can be efficiently suppressed.

  Even if the face curl does not occur, the back curl amount gradually decreases with time. Therefore, the correction amount of the paper P by the second bending portion is larger than the correction amount by the first bending portion (and the drying device 20). Is relatively small, it becomes a more appropriate correction amount with respect to the reduced curl amount, and curling can be efficiently suppressed.

  Further, it is desirable that the protrusion 101 is configured to be movable in the vertical direction, and is moved downward with time so that the curvature applied to the paper P is reduced. Thereby, the correction force can be reduced in accordance with the face curl that occurs with time and the back curl that decreases with time, and a more efficient curl suppressing effect can be obtained.

  In the present embodiment, the bending strength of the paper P has been described by the curvature given to the paper P. However, each part of the apparatus main body 1001 provided with the bending strength of the paper P using FIGS. 8 and 9. The configuration will be described.

  FIG. 8 is a diagram illustrating the configuration of the switchback path 61 as the first bent portion (a part of the configuration described above is omitted). The switchback path 61 is a path connecting the start point 61a and the end point 61b. Here, the starting point 61a is a position where the transport direction of the paper P changes from the horizontal direction to the upward direction. The end point 61b is the position of the end of the sheet P in the conveyance direction when the sheet P is reversed (more specifically, when the conveyance speed of the sheet P is 0).

  Then, in the perpendicular direction of the line segment connecting the start point 61a and the end point 62b, the distance to a part of the switchback path 61 farthest from the line segment is a1, and the start point 61a and the end point 62b of the first bending portion 61 are When the distance is b1, a1 / b1 corresponds to the bending strength of the first bending portion.

  Here, the switchback path 61 is used as the first bent portion. However, when the first bent portion is the discharge path 62, the starting point is a position where the transport direction of the paper P changes from the horizontal direction to the upward direction. The end point can be the position of the discharge port 8 (for example, the position where the switching unit 12 is provided).

  9 is a view of the configuration in the vicinity of the protruding portion 101 when viewed from the conveyance direction of the paper P, as in FIG. The distance from the surface 101b of the paper discharge tray 10 (the base of the protrusion 101) to the outermost end 101a of the protrusion 101 in the protrusion direction of the protrusion 101 is a2, and the paper P on the protrusion 101 in the paper width direction is a2. When the distance from one end to the other end of the paper P is b2, a2 / b2 corresponds to the bending strength of the second bending portion.

  Then, by configuring each part so that (a1 / b1)> (a2 / b2), the curl suppressing effect described above can be obtained. Furthermore, when the start point and end point of the discharge path 62 are a1 and b1, respectively, and the start point and end point of the switchback path 61 are a0 and b0, respectively, (a0 / b0)> (a1 / b1)> (a2 / b2) By doing so, the curl correction force becomes more gradual, and curling can be suppressed more efficiently.

  Further, it is desirable that the protrusion 101 is configured to be movable in the vertical direction, and is moved downward with time so that the curvature applied to the paper P is reduced. That is, it is desirable to configure so that a2 becomes smaller as time passes. Thereby, the correction force can be reduced in accordance with the face curl that occurs with time and the back curl that decreases with time, and a more efficient curl suppressing effect can be obtained.

  In addition, it is known that the amount of curling of the paper described above increases as the amount of water contained in the liquid (ink) increases. On the other hand, ink with a low water content (for example, an ink with a water content of about 20% by mass) has a small curl in the first place. Therefore, when this embodiment is combined, a curl in the opposite direction is formed depending on conditions. (It is not meant to exclude the possibility of combination). In particular, when the curvature of the switchback path is small, the influence of reverse curl is significant.

  Therefore, in this embodiment, it is particularly preferable to use an ink having a water content of 50% by mass or more. By combining an ink having a water content of 50% by mass or more with this embodiment, it is possible to achieve both ejection of ink having a high water content and curling suppression. An ink having a water content of 50% by mass or more has advantages such as low viscosity and stable liquid ejection by the liquid ejection head 7 (for example, ejection at a high frequency is possible).

  Further, as shown in FIG. 3 and the like, not only the switchback path 61 but also the discharge path 61 are arranged so as to protrude toward the supply direction of the drying energy by the drying device 20. Thereby, the reverse direction curl mentioned above also in the discharge path 61 can be reduced.

  Next, the bending direction of the paper P will be described with reference to FIG. FIG. 10 is a plan view of the paper P to be transported. The paper P is transported in the transport direction indicated by the arrow X. FIG. The switchback path 61 or the paper discharge path 62 at this time bends the sheet P around the direction intersecting the transport direction of the sheet P, and the axis (first axis) can be represented by C1. This is because, as described above, the switchback path 61 and the paper discharge path 62 are configured to lift the paper P transported along the transport direction X in the vertical direction.

  Further, the protruding portion 101 (second bending portion) bends the paper P around the direction parallel to the conveyance direction X of the paper P, and the axis (second axis) can be represented by C2. That is, C2 (second axis) intersects with C1 (first axis), and the protrusion 101 has the direction intersecting the bending axis C1 of the paper P as the switchback path 61 (first bending part) as an axis. Bend. This is because, as described above, the protruding portion 101 is provided along the transport direction X in the vicinity of the central portion in the direction orthogonal to the transport direction X.

  As a result, the paper P can be bent (warped) by two axes, and the correction direction of the paper becomes multifaceted compared to when the paper P is warped by one axis, and curl suppression can be performed more efficiently. Note that “bending around C1 as an axis” can be rephrased as “bending so as to be convex when viewed from a direction perpendicular to the paper conveyance direction”. Further, “bending with C2 as an axis” can be rephrased as “bending so as to be convex as seen from the paper transport direction (or paper discharge direction)”.

(Second Embodiment)
Next, a second embodiment will be described with reference to FIG. FIG. 11 is a schematic diagram of the apparatus main body when a plurality of sheets are printed.

  For example, when the user instructs the apparatus main body to print a plurality of sheets, it is recalled that a plurality of sheets P are simultaneously positioned on the conveyance path 60. At this time, when the paper P is located in the discharge path 62 in a range where the drying energy is supplied by the drying device 20 (referred to as a supplied range Af), the paper P positioned in the switchback path 61 is supplied. If the range Af is covered (in other words, the paper P overlaps the drying energy supply line), the paper P in the discharge path 62 cannot be efficiently dried.

  Therefore, in the present embodiment, when the paper P (first medium) is located in the supply range Af of the discharge path 62, the paper P (second medium) conveyed through the switchback path 61 is dried. In view of the apparatus 20, the entire supply range Af is not covered. Note that “not covering all” means that the sheet P (second medium) conveyed through the switchback path 61 covers a part of the supplied range Af as viewed from the drying device 20 as shown in FIG. And a form in which the paper P (second medium) conveyed through the switchback path 61 does not cover the supplied range Af at all when viewed from the drying device 20.

  Specifically, the above transport method can be performed by adjusting the drive amount of the transport roller 4 or adjusting the transport amount of the paper by adjusting the distance between the switchback path 61 and the discharge path 62.

  As a result, it is possible to reduce drying energy from being blocked by the paper P in the switchback path 61 and reaching the paper P in the discharge path 62, so that more efficient drying can be performed. In order to further improve the drying efficiency, when the paper P (first medium) is positioned in the supply range Af of the discharge path 62, the paper P (second paper) conveyed in the switchback path 61 is used. The medium is preferably not overlapped with the supply range Af as seen from the drying device 20. However, when transporting the sheets so as not to overlap at all, it may take a long time to transport, so that the paper P in the switchback path 61 covers a part of the supplied range Af as seen from the drying device 20 as shown in FIG. You may enjoy some of the supplied energy. In this way, it is possible to reduce both the printing time and the paper drying efficiency.

  Further, when a blower is used as the drying device 20, the movement of air is less likely to wrap around the paper P than the movement of heat or the like, and thus the effect of increasing the drying efficiency by the present embodiment is great.

  The “supplied range” is “a blowed range” and “a wind receiving range” when the drying device 20 is a blower, and “an irradiated range” and “a heated range” when the drying device 20 is heated. When the drying device 20 is a curing line irradiation device such as a UV lamp, it can be restated as “irradiated range” or the like, and the configuration is not limited.

(Third embodiment)
Next, a third embodiment will be described with reference to FIGS.

  In this embodiment, arrangement | positioning of the drying apparatus 20 differs compared with each embodiment mentioned above. Specifically, the drying device 20 is disposed on the side facing the switchback path 61 across the discharge path 62, and the energy supplied toward the side opposite to the liquid discharge surface side of the paper P (that is, the back surface). To supply.

  When the amount of liquid adhering to the paper P is large, if a strong wind is applied in a state where the liquid immediately after printing is not completely dried, the liquid may move and the print quality may be impaired. In such a case, this modification is effective, and the movement of the liquid can be prevented by drying from the back surface.

(Fourth embodiment)
Next, a fourth embodiment will be described with reference to FIG.

  In this embodiment, the drying device 20 in each of the above-described embodiments is a heating device 21. The heating device 21 is configured by, for example, a heat transfer heater. Since most of the drying energy by the heating device 21 becomes heat energy, heat can be transferred through the parts (for example, plastic) constituting the switchback path 61. Accordingly, as compared with a blower using a fan, the drying energy can easily reach the back side of the switchback path 61 (that is, the discharge path 62 side), and more efficient drying can be performed.

(Fifth embodiment)
Next, a fifth embodiment will be described with reference to FIG.

  In the present embodiment, a shielding unit 30 is added to the configuration of the first embodiment described above. The shielding unit 30 is provided in a long length along the width direction of the paper P on the downstream side of the liquid ejection head 7 in the transport direction of the paper P. As a result, it is possible to reduce the influence of the drying energy (for example, air blowing) of the drying device 20 that is reflected and reaches the vicinity of the liquid discharge head 7 and affects liquid discharge.

(Sixth embodiment)
Next, a sixth embodiment will be described with reference to FIG.

  In the present embodiment, a heating device 22 is provided as a drying means as compared with the above-described embodiments. The heating device 22 is disposed adjacent to both the switchback path 61 and the discharge path 62 (disposed between the switchback path 61 and the discharge path 62). Thereby, the drying energy by the heating device 22 can be given not only to the switchback path 61 but also to the discharge path 62, so that more efficient drying can be performed.

(Seventh embodiment)
Next, a seventh embodiment will be described with reference to FIG.

  FIG. 17 is a plan view of the switchback path 61 (viewed from a direction orthogonal to the paper surface of the paper P) (shown without considering the curvature of the switchback path 61).

  The switchback path 61 includes the transport roller 4 and the hole 42 described above. The hole 42 is a space for holding the transport roller 4, and the shaft 41 extending from the transport roller 4 is held at the inner peripheral portion of the hole 42, so that the inner wall of the hole 42 and the transport roller 4 are A gap 43 is formed between them. Thereby, the drying energy by the drying device 20 can pass through the hole portion 42 (in other words, the gap 43 that is the gap between the transport roller 4 and the hole portion 42), and the drying energy reaches the discharge path 62 more efficiently. be able to.

  Further, the same effect can be obtained even if a hole 44 is separately provided in a portion not related to the holding of the conveying roller 4. This configuration can be applied not only to the switchback path 61 but also to other transport paths including the discharge path 62.

  As mentioned above, although each embodiment concerning the present invention was described, the present invention is not limited to each above-mentioned embodiment as it is, and in the implementation stage, it modifies and constitutes a component in the range which does not deviate from the gist. it can. Various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the above-described embodiments. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, constituent elements over different embodiments may be appropriately combined.

  In the present application, the liquid to be ejected is not particularly limited as long as it has a viscosity and surface tension that can be ejected from the head. However, the viscosity is 30 mPa · s or less at room temperature, normal pressure, or by heating and cooling. It is preferable that More specifically, solvents such as water and organic solvents, colorants such as dyes and pigments, functional materials such as polymerizable compounds, resins, and surfactants, and biocompatible materials such as DNA, amino acids, proteins, and calcium. , Edible materials such as natural pigments, solutions, suspensions, emulsions, and the like. These include, for example, inkjet inks, surface treatment liquids, components of electronic devices and light emitting devices, and formation of electronic circuit resist patterns. It can be used in applications such as liquids for use, three-dimensional modeling material liquids, and the like.

  As energy generation sources for discharging liquid, piezoelectric actuators (laminated piezoelectric elements and thin film piezoelectric elements), thermal actuators using electrothermal transducers such as heating resistors, electrostatic actuators consisting of a diaphragm and counter electrode are used. To be included.

  The “apparatus for ejecting liquid” includes an apparatus that includes a liquid ejection head or a liquid ejection unit and that ejects liquid by driving the liquid ejection head. The apparatus for ejecting liquid includes not only an apparatus capable of ejecting liquid to an object to which liquid can adhere, but also an apparatus for ejecting liquid toward the air or liquid.

  This “apparatus for discharging liquid” may include means for feeding, transporting, and discharging a liquid to which liquid can adhere, as well as a pre-processing apparatus and a post-processing apparatus.

  For example, as a “liquid ejecting device”, an image forming device that forms an image on paper by ejecting ink, a powder is formed in layers to form a three-dimensional model (three-dimensional model) There is a three-dimensional modeling apparatus (three-dimensional modeling apparatus) that discharges a modeling liquid onto the powder layer.

  Further, the “apparatus for ejecting liquid” is not limited to an apparatus in which significant images such as characters and figures are visualized by the ejected liquid. For example, what forms a pattern etc. which does not have a meaning in itself, and what forms a three-dimensional image are also included.

  The above-mentioned “material (medium) to which a liquid can adhere” means a liquid to which the liquid can be at least temporarily attached, which adheres and adheres, and which adheres and permeates. Specific examples include recording media such as paper, recording paper, recording paper, film, and cloth, electronic parts such as electronic substrates and piezoelectric elements, powder layers (powder layers), organ models, and test cells. Yes, unless specifically limited, includes everything that the liquid adheres to.

  The material of the “material (medium) to which the liquid can adhere” is not limited as long as the liquid such as paper, thread, fiber, fabric, leather, metal, plastic, glass, wood, ceramics can be adhered even temporarily.

  In addition, the “device for ejecting liquid” includes a device in which the liquid ejection head and the device to which the liquid can adhere move relatively, but is not limited thereto. Specific examples include a serial type apparatus that moves the liquid discharge head, a line type apparatus that does not move the liquid discharge head, and the like.

  In addition, as the “device for ejecting liquid”, other than the above, a treatment liquid coating apparatus that ejects a treatment liquid onto a sheet in order to apply the treatment liquid to the surface of the sheet for the purpose of modifying the surface of the sheet, There is an injection granulation apparatus that granulates raw material fine particles by spraying a composition liquid in which raw materials are dispersed in a solution through a nozzle.

  Note that the terms “image formation”, “recording”, “printing”, “printing”, “printing”, “modeling” and the like in the terms of the present application are all synonymous.

4 Transport roller 7 Liquid discharge head 8 Discharge port 10 Discharge tray 20 Drying device (blower device)
DESCRIPTION OF SYMBOLS 21 Heating device 22 Heating device 41 Shaft 42 Hole part 43 Crevice 60 Conveyance path 61 Switchback path (1st bending part)
62 Discharge path (first bend)
101 Protrusion (second bending part)
1001 Apparatus main body (apparatus for discharging liquid, image forming apparatus)

JP 2011-068485 A JP 2011-194888 A JP 2013-144375 A

Claims (7)

A transport path through which the medium is transported;
A liquid ejection head for ejecting liquid onto the medium transported on the transport path;
A discharge tray from which the medium is discharged;
A device for discharging a liquid comprising a drying device for drying the medium,
The transport path includes a first bending portion that bends the medium with a liquid discharge surface of the medium facing inward,
The discharge tray has a second bending portion that bends the medium with the liquid discharge surface of the medium facing inward,
The curvature of the medium bent by the first bending portion is larger than the curvature of the medium bent by the second bending portion,
The said drying apparatus dries the said medium conveyed on the said 1st bending part. The apparatus which discharges the liquid characterized by the above-mentioned. A transport path through which the medium is transported;
A liquid ejection head for ejecting liquid onto the medium transported on the transport path;
A discharge tray from which the medium is discharged;
A device for discharging a liquid comprising a drying device for drying the medium,
The transport path includes a first bending portion that transports the medium between a start point and an end point while bending the medium with a liquid discharge surface of the medium being inward.
The discharge tray has a second bent portion that protrudes from the surface of the discharge tray and bends the medium with the liquid discharge surface of the medium inside.
A1 to a distance from a first segment that is farthest from the line segment in a direction perpendicular to the line segment connecting the start point and the end point,
The distance between the start point and the end point of the first bending part is b1,
The distance from the surface of the discharge tray to the outermost end of the second bent portion in the protruding direction of the second bent portion is a2,
When the distance from one end to the other end of the medium in the paper width direction of the medium on the second bent portion is b2,
(A1 / b1)> (a2 / b2),
The said drying apparatus dries the said medium conveyed on the said 1st bending part. The apparatus which discharges the liquid characterized by the above-mentioned. The apparatus for discharging a liquid according to claim 2, wherein the second bending portion is movable in the projecting direction, and moves in a direction in which the a2 becomes smaller as time elapses. (A0 / b0)> (a1 / b1)> (a2 / b2) where a0 and b0 are the start point and end point of the switchback path 61 for switching back the transport direction of the medium, respectively. The apparatus which discharges the liquid of Claim 2 or 3. The apparatus for discharging a liquid according to any one of claims 1 to 4, wherein the liquid contains 50% by mass or more of moisture. The first bending section bends the medium about a first axis that intersects the conveyance direction of the medium,
6. The apparatus for ejecting liquid according to claim 1, wherein the second bending portion is bent with a second axis intersecting the first axis as an axis. 6. The apparatus for discharging a liquid according to any one of claims 1 to 6, wherein the first bending portion includes a switchback path for switching back the transport direction of the medium.

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