JP2010069708A - Droplet delivering device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To shift to following processing after surely suppressing warpage of a medium. <P>SOLUTION: The humidity of image receiving paper P is adjusted by a humidistat 26 in order to suppress curling caused on the image receiving paper P by recording an image on one surface. Since the image receiving paper P is brought into tight-contact with a belt 50 by suction of a suction fan 24 when the curling of the image receiving paper P is eliminated, it is detected by a pressure sensor. When the tight-contact of the image receiving paper P with the belt 50 by an amount equivalent to size of the image receiving paper P is detected by the pressure sensor, the image receiving paper P is conveyed to a stage in which the following processing is performed. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a droplet discharge device, and more particularly, to a droplet discharge device that forms an image by discharging droplets such as ink.

  As a droplet discharge device, for example, an ink jet printer that forms an image by discharging ink onto a medium such as image receiving paper is widely used.

  For example, the technology described in Patent Document 1 includes a printing unit that performs printing by discharging ink onto a medium, and a front / back reversing unit that reverses the front and back of the medium printed by the printing unit. In a printing apparatus in which the standby time for drying the ink ejected to the medium is set before the medium is reversed by the reversing unit, the amount of ink ejected by the printing unit and the ink ejected by the printing unit It has been proposed that double-sided printing is performed while setting the standby time according to the elapsed time of the ink and shortening the ink dry standby time and improving the printing speed.

  However, when double-sided printing is performed as described above, there is a problem in that when one side is printed, ink is ejected and dried, causing the medium to warp and clog the transport unit. .

On the other hand, as a technique for suppressing the warp of the medium, a technique described in Patent Document 2 has been proposed. Specifically, it has been proposed to suppress the warping of the medium by conditioning the medium.
JP 2004-314505 A Japanese Patent Laid-Open No. 06-198868

  By the way, in the case where the next processing is performed on the image receiving paper in which the medium is warped as in the technique described in Patent Document 1, in order to prevent the image receiving paper from being clogged when transported to the next processing. As in the technique described in Patent Document 2, it is conceivable to shift to the next process after suppressing the warp of the medium.

  However, in the technique described in Patent Document 2, since the medium is simply conditioned, the process proceeds to the next process even if the warp of the medium is not eliminated, and the warp of the medium is not eliminated. It is conceivable that the medium will be clogged.

  The present invention has been made in consideration of the above facts, and an object of the present invention is to shift to the next process after reliably suppressing the warp of the medium.

  In order to achieve the above object, the invention described in claim 1 is characterized in that the humidity control means for adjusting the humidity of the dried medium after the droplets are discharged by the droplet discharge means for discharging the droplets, and the humidity control Detecting means for detecting that the warpage of the medium has been eliminated by the means, and a medium conveyed from the first conveying path for conveying the medium from the droplet discharge means to the humidity control means. A transport unit having an endless belt that transports the medium to a second transport path that reverses the transport direction and transports the medium from the humidity control unit to the droplet discharge unit by reversing the front and back; and the detection unit When it is detected that the warp of the medium has been eliminated, the transport unit is controlled to transport the medium transported from the first transport path and humidity-controlled by the humidity control unit to the second transport path. And control means It is.

  According to the first aspect of the present invention, the warp generated in the medium after the droplets are discharged onto the medium by the droplet discharge unit that discharges the droplets is caused by the humidity adjustment unit. It is solved by adjusting.

  In addition, the transport unit reverses the transport direction of the medium transported from the first transport path for transporting the medium from the droplet discharge unit to the humidity control unit, and the droplet discharge unit from the humidity control unit. The belt has an endless belt that conveys the medium to the second conveyance path for conveying the medium with the front and back reversed. That is, the transport direction of the medium is reversed by the endless belt and transported to the second transport path, so that liquid droplets can be ejected by the liquid droplet ejecting means to the back side of the medium. At this time, since the conveyance direction of the medium is reversed by the belt, when the conveyance direction of the medium is reversed using the roller pair, the roller pair and the medium slip when the conveyance direction is reversed, and slip traces or the like are generated. Although scratches are formed, scratches such as slip marks when the transport direction is reversed can be prevented.

  The detecting means detects that the medium warp has been eliminated by the humidity adjusting means, and the control means detects that the medium processing has been eliminated by the detecting means. The conveying means is controlled to convey the medium conditioned by the humidity adjusting means to the second conveying path. That is, the humidity adjustment by the humidity control unit is performed until the warp of the medium is eliminated by the detection unit, and the process proceeds to the next processing by controlling the transport unit after the warp of the medium is eliminated. It is possible to shift to the next process after reliably suppressing.

  The detection means detects pressure of each through hole generated by the suction means for sucking the medium from a plurality of through holes provided in the endless belt as in the invention described in claim 2. And means for determining whether or not the warping of the medium has been eliminated based on the detection result of the pressure detection means. That is, when the pressure of the plurality of through holes corresponding to the size of the medium (for example, the length of the medium) corresponds to the pressure when the medium is sucked to the belt by the suction means, the warp of the medium is eliminated. It can be detected that the warp of the medium has been eliminated by determining that the medium has been warped.

  Further, as in the invention according to claim 3, the detection means includes a light emitting element that emits light and a light receiving element that receives light from the light emitting element, and when the medium is warped, The light emitting element and the light receiving element may be arranged so that the medium on the belt blocks the optical path from the light emitting element to the light receiving element. Accordingly, it is possible to detect that the warp of the medium has been eliminated by detecting that the optical path from the light emitting element to the light receiving element is not blocked.

  As described above, according to the present invention, since it is detected that the warp of the medium has been eliminated by the humidity adjustment by the humidity control means, the process proceeds to the next process. There is an effect that it can be transferred to.

  Hereinafter, an example of an embodiment of the present invention will be described in detail with reference to the drawings. In the present embodiment, the present invention is applied to an inkjet printer.

  FIG. 1 is a diagram showing a schematic configuration of an ink jet printer according to an embodiment of the present invention.

  As shown in FIG. 1, the inkjet printer 10 according to the embodiment of the present invention includes a plurality of roller pairs 32 and rollers, and the image receiving paper P is conveyed by these roller pairs. The image receiving paper P is conveyed from a paper supply unit (not shown) that supplies the image receiving paper P to the ink jet printer 10 to a discharge unit 34 that discharges the image receiving paper P. In the present embodiment, the image receiving paper P is conveyed intermittently.

  In the conveyance path of the image receiving paper P, an image recording unit 14 that ejects ink and records an image on the image receiving paper P is provided.

  The image recording unit 14 includes a recording head that ejects ink according to image data. The image recording unit 14 performs recording in the main scanning direction by moving the recording head in a direction crossing the conveyance direction of the image receiving paper P. Movement in the sub-scanning direction is performed by intermittent conveyance.

  A drying unit 20 for drying the image receiving paper P on which an image is recorded is provided on the downstream side of the image recording unit 14 in the conveying direction of the image receiving paper P. The drying unit 20 includes a drying heat source 36, a drying fan 38, and a fan 37. By these, the image receiving paper P on which an image is recorded with ink is dried. In the present embodiment, the drying heat source 36, the drying fan 38, and the fan 37 are provided to dry the image receiving paper P. However, the present invention is not limited to this, and a waiting time for drying is set. Then, the image receiving paper P may be dried.

  Further, on the downstream side of the drying unit 20 in the conveyance direction of the image receiving paper P, a first reverse conveyance for conveying the image receiving paper P to the front / back reversing unit 40 for reversing in order to record an image on the back side of the image receiving paper P. A branch between a path 42 and a discharge path 44 for discharging the image receiving paper P is provided. That is, when recording an image on the back side of the image receiving paper P, the image receiving paper P is conveyed to the front / back reversing unit 40 via the first reverse conveying path 42 (downward in FIG. 1), and the image receiving paper P is discharged. In this case, the sheet is conveyed to the discharge unit 34 via the discharge path 44 (left direction in FIG. 1).

  By the way, when images are recorded on both sides of the image receiving paper P, the image is recorded by ejecting ink on one side and dried by the drying unit 20, thereby warping the image receiving paper P (hereinafter referred to as curl). ) Occurs. Therefore, in the present embodiment, the humidity controller 26 for adjusting the humidity of the image receiving paper P is provided in the front / back reversing unit 40 for reversing the front and back of the image receiving paper P.

  The ink jet printer 10 according to the present embodiment conveys the image receiving paper P to the front / back reversing unit 40 via the first reversing conveyance path 42 when recording images on both sides. Then, the humidity of the image receiving paper P is adjusted by adjusting the humidity inside the front / back reversing unit 40 with respect to the image receiving paper P conveyed to the front / back reversing unit 40, and curling of the image receiving paper P is suppressed. The image receiving paper P is discharged from. Further, the image receiving paper P discharged from the front / back reversing unit 40 is conveyed again to the image recording unit 14 through the second reversing conveyance path 46 for reversing and conveying the image receiving paper P to the image recording unit 14, and the image receiving paper. An image is recorded on the back side of P. Thereafter, the image receiving paper P recorded on both sides is conveyed to the discharge unit 34 through the discharge path 44. The pair of rollers sharing the first reverse conveyance path 42 and the second reverse conveyance path 46 is configured to convey the image receiving paper P to the front / back reversing unit 40 and to discharge the image receiving paper P from the front / back reversing unit 40. The rotation direction is reversed.

  Here, a detailed configuration of the front / back reversing unit 40 will be described. 2 is a diagram illustrating a detailed configuration of the front / back reversing unit 40, FIG. 3 is a diagram illustrating an outline of the front / back reversing conveyance unit of the front / back reversing unit 40, and FIG. 4 is a part of the front / back reversing conveyance unit. FIG.

  The front and back reversing unit 40 is provided with a humidity controller 26 and a humidity sensor 28. By adjusting the humidity in the front and back reversing unit 40 to a predetermined humidity, the image receiving paper P is humidified and curled. .

  The front / back reversing unit 40 includes a front / back reversing conveyance unit 48 for conveying the image receiving paper P conveyed by the roller pair 32 to a predetermined position (predetermined stop position) of the front / back reversing unit 40. The front / back reversing conveyance unit 48 is configured to convey the image receiving paper P at the same speed as the roller pair 32, and the speed difference between the conveyance of the image receiving paper P by the roller pair 32 and the conveyance of the image receiving paper P by the front / back reversing conveyance unit 48. This prevents the image receiving paper P from being damaged such as slip marks.

  The front / back reversing conveyance unit 48 includes an endless belt 50 and rollers 52 and 54 for rotating the belt 50 forward and backward. One roller 52 (or roller 54) is a driving roller and drives the driving roller to rotate the belt 50 and convey the image receiving paper P conveyed to a predetermined position of the front / back reversing unit 40. After the humidity control described later is performed, the drive roller is reversed and the image receiving paper P is discharged from the front / back reversing unit 40.

  As shown in FIGS. 3 and 4, the belt 50 is configured by connecting a plurality of plate-like members 50 </ b> A in a caterpillar shape. Each plate-like member 50 </ b> A is provided with a plurality of suction through holes 50 </ b> B for bringing the image receiving paper P into close contact with the belt 50 along the width direction of the image receiving paper P. A chamber portion 56 for sucking air from the through hole 50B is provided on the opposite side of the plate-like member 50A from the image receiving paper P. In addition, the chamber part 56 may be provided for every through-hole 50B, and may be provided for every plate-shaped member 50A.

  As shown in FIG. 4, each chamber portion 56 is connected to a tube 58, and each tube 58 is connected to a suction chamber belt 60 that rotates together with the belt 50, and the tube 58 is placed in the suction chamber belt 60. A suction fan 24 for sucking air from is provided. That is, while the suction chamber belt 60 rotates together with the tube 58 and the plate-like member 50 </ b> A, the suction fan 24 sucks air from the through-hole 50 </ b> B so that the image receiving paper P adheres to the belt 50.

  Each chamber 56 is provided with a pressure sensor 30 to detect whether the image receiving paper P is in close contact with the belt 50.

  Next, the configuration of the control system of the ink jet printer 10 according to the embodiment of the present invention will be described. FIG. 5 is a block diagram showing the configuration of the control system of the inkjet printer 10 according to the embodiment of the present invention.

  The operation of the inkjet printer 10 is comprehensively controlled by the control unit 12. As shown in FIG. 5, the control unit 12 includes an image recording unit 14, a main transport driving unit 16, a drying position driving unit 18, a drying unit 20, a front / back reversing transport driving unit 22, a suction fan 24, a humidity controller 26, A humidity sensor 28 and a pressure sensor 30 are connected. Note that only representative parts of the components connected to the control unit 12 are described.

  The image recording unit 14 includes a recording head and a motor for moving the recording head in the sub-scanning direction, and the control unit 12 controls image recording on the image receiving paper P by controlling the recording head and the motor. To do.

  The main conveyance driving unit 16 conveys the image receiving paper P by driving the roller pair 32 and the like described above. That is, the control unit 12 controls the main conveyance driving unit 16 to feed the image receiving paper P to the image recording unit 14, convey it to the discharge unit 34, and receive the image from the front / back reversing unit 40 to the image recording unit 14. The conveyance of the paper P is controlled.

  The drying position driving unit 18 includes a belt-shaped conveyance unit, and conveys the image receiving paper P in the drying unit 20. The configuration for conveying the image receiving paper P in the drying unit 20 can be the same as that of the front / back reversing unit 40.

  The drying unit 20 sucks the drying heat source 36 for drying the image receiving paper P, the drying fan 38 for blowing the heat of the drying heat source 36 to the image receiving paper P, and the conveying unit of the drying position driving unit 18. And the like, and the drive is controlled by the control of the control unit 12, respectively.

  As described above, the front / reverse reverse conveyance driving unit 22 drives the front / reverse reverse conveyance unit 28 by rotating the belt 50 forward / reversely by driving the roller 52 (or the roller 54) in the normal rotation and reverse rotation directions to reverse the front / back. The image receiving paper P in the unit 40 is conveyed.

  The suction fan 24 performs suction to bring the image receiving paper P into close contact with the belt 50, the humidity controller 26 is provided to adjust the humidity in the front / back reversing unit 40, and the control unit 12 is provided in the front / back reversing unit 40. The humidity controller 26 is controlled so that the humidity is adjusted to a predetermined humidity range while being monitored by the humidity sensor 28.

  The pressure sensor 30 detects a pressure for detecting whether or not the image receiving paper P is sucked by the suction fan 24 and adheres to the belt 50, and the control unit 12 is based on the detection result of the pressure sensor 30. The curl of the image receiving paper P is judged to be eliminated.

  Next, a process for recording both sides of the image receiving paper P in the ink jet printer 10 according to the embodiment of the present invention configured as described above will be described. FIG. 6 is a flowchart showing a flow of processing performed by the control unit 12 when recording both sides of the image receiving paper P in the inkjet printer 10 according to the embodiment of the present invention. 6 will be described as a process from when an image is recorded on one side of the image receiving paper P and drying by the drying unit 20 to when the front and back sides are reversed.

  When the drying of the image receiving paper P by the drying unit 20 is completed, in step 100, the driving of the humidity controller 26 is started and the process proceeds to step 102. The driving start of the humidity controller 26 may be started together with an instruction to start image recording.

  In step 102, it is determined whether or not the humidity of the front / back reversing unit 40 is within a predetermined range. For this determination, it is determined whether or not the humidity detected by the humidity sensor 28 is within, for example, 50% ± 10%. If the determination is negative, the process waits until the determination is affirmed and proceeds to step 104. To do.

  In step 104, the image receiving paper P is transported by controlling the driving of the main transport driving unit 16. That is, the image receiving paper P is conveyed from the drying unit 20 to the front / back reversing unit 40 by each roller pair 32 or the like.

  In step 106, driving of the front / back reversing conveyance driving unit 22 and the suction fan 24 is started, and the process proceeds to step 108.

  In step 108, it is determined whether or not the image receiving paper P is at the stop position of the front / back reversing unit 40. In this determination, the image receiving paper P is transported to the front / back reversing unit 40 by each roller pair 32 of the main transport driving unit 16 and transported to a predetermined stop position of the front / back reversing unit 40 by the belt 50 of the front / back reversing transport driving unit 22. However, it may be determined from the detection result of the sensor, or a time necessary for transporting the image receiving paper P from the drying unit 20 to the stop position has elapsed. It may be determined whether or not. If the determination in step 108 is negative, the process waits until the determination is affirmative and proceeds to step 110.

  In step 110, the driving of the front / back reversing conveyance driving unit 22 is stopped and the process proceeds to step 112.

  In step 112, it is determined whether or not the image receiving paper P has been curled. In this determination, it is determined whether or not the pressure sensor 30 detects that curling is suppressed by the humidity control of the humidity controller 26 and that the ends (for example, both ends in the transport direction) of the image receiving paper P are in close contact with the belt 50. To do. That is, it is determined whether or not the pressure sensor 30 corresponding to the length to the both ends of the image receiving paper P (or the size of the image receiving paper P) has detected the pressure when the image receiving paper P and the belt 50 are in close contact with each other. If the determination is negative, the process waits until the determination is affirmative and proceeds to step 114.

  In step 114, the front / back reversal conveyance driving unit 22 starts reversal driving, and the main conveyance driving unit 16 is driven so that the image receiving paper P is conveyed through the second reversal conveyance path 46, and the process proceeds to step 116.

  In step 116, it is determined whether or not the image receiving paper P is discharged from the front / back reversing unit 40. This determination is made, for example, by determining whether or not the discharge of the image receiving paper P from the front / back reversing unit 40 is detected by the sensor, or after the reversal driving of the front / back reversing conveyance driving unit 22 is started, the image receiving paper P is discharged. It is determined whether or not a necessary time has elapsed until the determination is made, and the process waits until the determination is affirmed, and the process proceeds to step 118.

  In step 118, the front / back reversing conveyance driving unit 22 is stopped, and the series of processes is ended. Note that when the processing up to reversing the front and back of the image receiving paper P is completed, image recording on the surface opposite to the surface on which the image is recorded is performed.

  Thus, in the inkjet printer 10 according to the present embodiment, when an image is recorded on one side, the image receiving paper P is conveyed to the front / back reversing unit 40. At this time, as shown in FIG. 7A, the image receiving paper P is curled by recording an image on one surface. However, when the humidity is adjusted by the humidity controller 26, FIG. As shown in FIG. 4, curling of the image receiving paper P is suppressed. Further, when the curl of the image receiving paper P is eliminated, the image receiving paper P comes into close contact with the belt 50 by the suction of the suction fan 24, and the pressure sensor 30 provided in the chamber unit 56 causes the image receiving paper P to adhere to the belt 50. Detected. The curling of the image receiving paper P is eliminated by detecting the close contact of the size of the image receiving paper P (which may be the length of the image receiving paper P) with the belt 50 by the pressure sensor 30 provided in each chamber portion 56. Therefore, it is possible to reliably detect the curl removal and then eject the image from the front / back reversing unit 40 and perform image recording on the other side as shown in FIG. When the other side of the image is recorded, it is possible to prevent the image receiving paper P from being jammed in the conveyance path or the image recording unit 14.

  That is, since it is detected that the curl generated by the image recording has been eliminated by the humidity control of the humidity controller 26, the process proceeds to the next process. Therefore, the curl of the image receiving paper P is surely eliminated and then the process proceeds to the next process. Can do.

  Further, in the present embodiment, the image receiving paper P is conveyed by each roller pair 32 up to the front / back reversing unit 40, and the image receiving paper P is conveyed by the belt 50 of the front / back reversing conveying unit 48 in the front / back reversing unit 40. Therefore, when the rollers are conveyed to the front / back reversing unit 40 by each roller pair 32 and the conveying direction is reversed by the front / back reversing unit 40, scratches such as slip marks generated on the image receiving paper P due to slippage of the roller pair 32 and the like are prevented. be able to.

  In the above embodiment, the determination as to whether or not the curl of the image receiving paper P has been eliminated is made based on the detection result of the pressure sensor 30, but the present invention is not limited to this. For example, FIG. As shown, when the image receiving paper P placed on the belt 50 of the front / back reversing conveyance unit 48 is curled, the light emitting element that emits light so as to block the optical path from the light emitting element 62 to the light receiving element 64 62 and a light receiving element 64 that receives light from the light emitting element 62 may be arranged to determine whether or not the image receiving paper P has been curled. In FIG. 8, the light emitting element 62 and the light receiving element 64 are arranged on one diagonal line of the image receiving paper, but the light emitting element 62 and the light receiving element 64 may be arranged on two diagonal lines. Moreover, you may make it arrange | position the light emitting element 62 and the light receiving element 64 in another site | part instead of a diagonal line. Further, in FIG. 8, the light emitting element 62 and the light receiving element 64 are arranged in the example in which the through hole 60B of the above embodiment is provided and sucked by the suction fan 24. However, the present invention is not limited to this. The hole 50B and the suction fan 24 may be omitted, and the light-emitting element 62 and the light-receiving element 64 may be provided in a manner that eliminates curling of the image receiving paper P only by humidity adjustment by the humidity controller 26.

  In the above-described embodiment, the inkjet printer 10 that records an image on the image receiving paper P is described as an example of a droplet discharge device. However, the present invention is not limited to this, and a chemical or the like may be applied to a medium such as a flexible printed circuit board. The present invention may be applied to a droplet discharge apparatus that performs etching by discharging the droplets.

1 is a diagram illustrating a schematic configuration of an ink jet printer according to an embodiment of the present invention. It is a figure which shows the detailed structure of a front-back inversion part. It is a figure which shows the outline of the front-back inversion conveyance part of a front-back inversion part. It is an enlarged view which shows a part of front-back inversion conveyance part. 1 is a block diagram illustrating a configuration of a control system of an ink jet printer according to an embodiment of the present invention. 4 is a flowchart showing a flow of processing performed by a control unit when recording both sides of image receiving paper in the ink jet printer according to the embodiment of the present invention. It is a figure for demonstrating the flow of operation | movement of the front-and-back inversion part of the inkjet printer concerning embodiment of this invention. It is a figure which shows the example which detects the curl of image receiving paper with a light emitting element and a light receiving element.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Inkjet printer 12 Control part 14 Image recording part 22 Front and back inversion conveyance drive part 26 Humidifier 30 Pressure sensor 42 1st inversion conveyance path 46 2nd inversion conveyance path 50 Belt 50B Through-hole 62 Light emitting element 64 Light receiving element P Image receiving paper

Claims (3)

Humidity control means for adjusting the humidity of the dried medium after the droplets are discharged by the droplet discharge means for discharging the droplets;
Detecting means for detecting that the warp of the medium has been eliminated by the humidity adjusting means;
The transport direction of the medium transported from the first transport path for transporting the medium from the droplet discharge means to the humidity control means is reversed to the droplet discharge means from the humidity control means to the droplet discharge means. Conveying means having an endless belt for conveying the medium to a second conveying path for conveying the medium upside down;
When the detection unit detects that the warp of the medium is eliminated, the transport is performed so that the medium transported from the first transport path and humidity-controlled by the humidity control unit is transported to the second transport path. Control means for controlling the means;
A droplet discharge device comprising:   The detection means is based on a pressure detection means for detecting a pressure of each through hole generated by a suction means for sucking a medium from a plurality of through holes provided in the belt, and a detection result of the pressure detection means. The liquid droplet ejection apparatus according to claim 1, further comprising: a determination unit that determines whether or not the warp of the medium has been eliminated.   The detection means includes a light emitting element that emits light and a light receiving element that receives light from the light emitting element. When the medium is warped, an optical path from the light emitting element to the light receiving element is provided on the belt. The droplet discharge device according to claim 1, wherein the light emitting element and the light receiving element are arranged so as to block the medium.

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