JP6573305B2 - Inkjet printing system - Google Patents

Description

  The present invention relates to an inkjet printing system that performs printing on both sides of a medium.

  Conventionally, as an inkjet printing system that performs printing on both sides of a medium, a first inkjet head that performs printing on one side of the medium, and printing on the other side of the medium that has been printed by the first inkjet head And a second ink-jet head that executes the above-mentioned (for example, see Patent Document 1).

JP 2010-053497 A

  However, the conventional ink jet printing system has a problem that images printed on both sides of the medium are displaced.

  SUMMARY An advantage of some aspects of the invention is that it provides an inkjet printing system that can reduce the deviation of images printed on both sides of a medium.

  The inkjet printing system of the present invention includes a first inkjet head that performs printing on one side of a medium, and a second that executes printing on the other side of the medium on which printing has been performed by the first inkjet head. An inkjet head, first print control means for printing an image including a first image for adjustment of printing control by the first inkjet head, and a second image for adjustment of printing control Including a second print control unit that prints an image including the second inkjet head, and a shift correction unit that corrects a shift of images printed on both sides of the medium. At least one of the printing control by the first printing control means and the printing control by the second printing control means is the first image and the printing control. And correcting the deviation of the image to be printed on both sides of the medium by adjusting according to the amount of displacement of the second image.

  With this configuration, the inkjet printing system of the present invention controls printing according to the amount of deviation between the first image printed on one side of the medium and the second image printed on the other side of the medium. By adjusting, the shift of the image printed on both sides of the medium is corrected, so that the shift of the image printed on both sides of the medium can be reduced.

  In addition, the inkjet printing system of the present invention includes a double-sided image detection unit that detects the first image and the second image from the medium, and the first image and the first image based on a detection result by the double-sided image detection unit. A displacement amount calculating means for calculating a displacement amount of the second image may be provided.

  With this configuration, the inkjet printing system of the present invention automatically calculates the amount of shift between the first image and the second image, so that the user can determine the amount of shift between the first image and the second image. Convenience can be improved as compared with the configuration determined from the medium.

  In the inkjet printing system of the present invention, the double-sided image detection unit may detect the first image and the second image from one side of the medium.

  With this configuration, the inkjet printing system of the present invention simultaneously detects the first image printed on one side of the medium and the second image printed on the other side of the medium from one side of the medium. Compared to a configuration in which the first image printed on one side of the medium and the second image printed on the other side of the medium are detected from one side of the medium and the other side of the medium, respectively. The amount of shift between the first image and the second image can be detected with high accuracy. Therefore, the inkjet printing system of the present invention can correct the deviation of the image printed on both sides of the medium with high accuracy, and as a result, the deviation of the image printed on both sides of the medium can be further reduced. it can.

  In the inkjet printing system of the present invention, the deviation correction unit may print on both sides of the medium according to the amount of deviation between the first image and the second image calculated by the deviation amount calculation unit. It is also possible to correct image shift.

  With this configuration, the inkjet printing system of the present invention automatically corrects the shift of the image printed on both sides of the medium according to the automatically calculated shift amount of the first image and the second image. Therefore, it is compared with a configuration in which an appropriate instruction for correcting the shift of the image printed on both sides of the medium is manually input by the user based on the shift amount of the first image and the second image. Thus, convenience can be improved.

  In the inkjet printing system of the present invention, the first print control unit and the second print control unit may be configured such that the double-sided image detection unit displays the first image and the second image on one side of the medium. The first image and the second image may be printed in a state where the first image and the second image can be detected.

  With this configuration, the inkjet printing system of the present invention can simultaneously detect the first image printed on one side of the medium and the second image printed on the other side of the medium from one side of the medium. Therefore, the first image printed on one side of the medium and the second image printed on the other side of the medium are compared with the configuration of detecting from the one side of the medium and the other side of the medium, respectively. Thus, the amount of shift between the first image and the second image can be detected with high accuracy. Therefore, the inkjet printing system of the present invention can correct the deviation of the image printed on both sides of the medium with high accuracy, and as a result, the deviation of the image printed on both sides of the medium can be further reduced. it can.

  In the inkjet printing system according to the aspect of the invention, the deviation amount calculating unit may be configured to calculate the first image based on an average of a plurality of detection results of the first image and the second image by the double-sided image detection unit. The amount of shift of the second image may be calculated.

  With this configuration, the inkjet printing system of the present invention is configured so that the amount of shift between the first image and the second image varies every time the first image and the second image are detected by the double-sided image detection unit. It is possible to improve the accuracy of correcting the deviation of images printed on both sides of the medium. Therefore, the inkjet printing system of the present invention can further reduce the deviation of images printed on both sides of the medium.

  In addition, the inkjet printing system of the present invention includes a single-sided image detection unit that detects the first image from the medium before printing is performed by the second inkjet head, and the deviation correction unit includes: The shift of the image printed on both sides of the medium may be corrected by adjusting the printing control by the second printing control unit according to the detection result by the single-sided image detecting unit.

  With this configuration, the inkjet printing system of the present invention corrects the second image to be printed on the other side of the medium so that it does not deviate from the first image printed on the one side of the medium. After printing is performed on the first side of the image, the deviation of the image printed on both sides of the medium is further corrected according to the amount of deviation between the first image and the second image. The deviation can be further reduced.

  The ink jet printing system of the present invention can reduce the deviation of images printed on both sides of a medium.

1 is a plan view of an ink jet printing system according to an embodiment of the present invention. It is the schematic block diagram which observed the inkjet printing system shown in FIG. 1 from the front side. It is the schematic block diagram which observed the inkjet printing system shown in FIG. 1 from the right side surface side. It is a block diagram of the inkjet printing system shown in FIG. It is a figure which shows an example of the image which the surface printing control means shown in FIG. 4 makes a surface printer print. It is a figure at the time of observing the image shown in FIG. 5 from the back surface side of a medium. It is a flowchart of operation | movement of the inkjet printing system shown in FIG. 1 according to the detection result by a surface image position detection apparatus. FIG. 5 is a diagram illustrating an example of an image to be printed by a back surface printer by the back surface printing control unit illustrated in FIG. 4. It is a figure at the time of observing the image shown in FIG. 5, and the image shown in FIG. 8 from the back surface side of a medium. It is a flowchart of operation | movement of the inkjet printing system shown in FIG. 1 according to the detection result by the front and back image position detection apparatus. (A) It is a figure which shows an example different from the example shown in FIG. 9 of the front position mark and back position mark when it has not shifted | deviated. FIG. 12B is a diagram showing the front position mark and the back position mark shown in FIG.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

  First, the configuration of the ink jet printing system according to the present embodiment will be described.

  FIG. 1 is a plan view of an inkjet printing system 10 according to the present embodiment. FIG. 2 is a schematic configuration diagram of the inkjet printing system 10 observed from the front side. FIG. 3 is a schematic configuration diagram of the inkjet printing system 10 observed from the right side. In FIGS. 2 and 3, a part of the surface printers 20 and 30 are shown in cross section to show the internal configuration.

  As shown in FIGS. 1 to 3, the inkjet printing system 10 is a system that executes printing on one side of a medium 80 such as cloth and then executes printing on the other side of the medium 80. Hereinafter, one surface of the medium 80 is referred to as a front surface 80a, and the other surface of the medium 80 is referred to as a back surface 80b. The medium 80 may be other than cloth as long as it is a sheet.

  The ink jet printing system 10 is a front surface printer 20 that is an ink jet printer that performs printing on the front surface 80 a of the medium 80, and an ink jet printer that performs printing on the back surface 80 b of the medium 80 that has been printed on the front surface 80 a by the front surface printer 20. A back printer 30 is provided. The surface printers 20 and 30 are installed on the floor 90. In addition, the medium 80 is supplied to the surface printer 20 from a roller (not shown) around which the medium 80 is wound. Further, the medium 80 printed by the back surface printer 30 is taken up by a roller (not shown).

  The inkjet printing system 10 includes a reversing roller 41 that reverses the front and back of the medium 80 that has been printed on the front surface 80a by the front surface printer 20, and a direction change that changes the conveyance direction of the medium 80 whose front and back are reversed by the reversing roller 41. A constant tension is applied to the roller 42, the direction changing roller 43 that changes the conveying direction of the medium 80 whose conveying direction has been changed by the direction changing roller 42, and the medium 80 whose conveying direction has been changed by the direction changing roller 43. And a tension applying member 44. The reversing roller 41, the direction changing roller 42, the direction changing roller 43, and the tension applying member 44 are arranged side by side in the direction indicated by the arrow 10b orthogonal to the vertical direction indicated by the arrow 10a. The reversing roller 41, the direction changing roller 42, the direction changing roller 43, and the tension applying member 44 extend in a direction indicated by an arrow 10c orthogonal to both the direction indicated by the arrow 10a and the direction indicated by the arrow 10b. The reversing roller 41, the direction changing roller 42, and the direction changing roller 43 are in a state in which the position of the central axis extending in the direction indicated by the arrow 10c is fixed, and in a state in which the rotating is possible around the central axis. It is supported by a support mechanism (not shown). The tension applying member 44 is a member that applies a constant tension to the medium 80 by downward gravity in the vertical direction indicated by the arrow 10a. The inkjet printing system 10 includes the tension applying member 44 that applies a constant tension to the medium 80, thereby allowing the length of the medium 80 between the front surface printer 20 and the rear surface printer 30 to change. Therefore, it is possible to allow the conveyance speed of the medium 80 in the front printer 20 and the conveyance speed of the medium 80 in the back printer 30 to be different. As a result, the printing by the front printer 20 and the back printer 30 can be permitted. It is possible to control the printing by the printer to some extent independently.

  The ink jet printing system 10 is a medium after a front position mark as a first image for adjustment of printing control is printed on the front surface 80a by the front surface printer 20 and before printing is performed by the back surface printer 30. A front image position detection device 51 as a single-sided image detection unit for detecting a front position mark from 80 and a back position mark as a second image for adjustment of printing control are printed on the back surface 80b by the back surface printer 30. A front / back image position detection device 52 is provided as a double-sided image detection unit that detects a front position mark and a back position mark from the medium 80. The front image position detection device 51 is arranged on the conveyance path of the medium 80 between the front surface printer 20 and the rear surface printer 30. The front / back image position detection device 52 is disposed on the downstream side of the back printer 30 in the conveyance direction of the medium 80.

  The surface printer 20 includes a surface head 21 as a first ink jet head supported by a support mechanism (not shown) so as to be movable in a direction indicated by an arrow 10b, and a medium with respect to the surface head 21 in a direction indicated by an arrow 10c. Uniform printing conditions by the surface head 21, the conveyance roller 22 that conveys 80, the pressing roller 23 that is disposed at a position facing the conveyance roller 22 through the medium 80, and presses the medium 80 against the conveyance roller 22. In order to achieve this, the pre-heater 24 that warms the medium 80 before the ink is deposited by the surface head 21, the landing accuracy of the ink droplets that are ejected by the surface head 21 and land on the medium 80, and the ink bleeding after the landing Medium 80 when ink is deposited by the surface head 21 to prevent A print heater 25 for warming, and a after-heater 26 to warm the medium 80 after the ink has been deposited by the surface head 21 to facilitate drying of the ink that has been deposited on the medium 80 by surface head 21.

  Similarly, the back printer 30 has a back head 31 as a second inkjet head supported by a support mechanism (not shown) that is movable in the direction indicated by the arrow 10c, and the back head 31 in the direction indicated by the arrow 10b. A printing roller 32 that conveys the medium 80, a pressing roller 33 that is disposed at a position facing the conveyance roller 32 via the medium 80 and presses the medium 80 against the conveyance roller 32, and printing conditions by the back head 31. Preheater 34 for warming the medium 80 before ink is adhered by the back head 31 to equalize the ink, and the landing accuracy of the ink droplets ejected by the back head 31 and landing on the medium 80, and after landing In order to prevent the ink from bleeding, the ink is attached by the back head 31. A print heater 35 that warms the body 80, and an after heater 36 that warms the medium 80 after the ink is adhered by the back head 31 to promote drying of the ink adhered to the medium 80 by the back head 31. ing.

  FIG. 4 is a block diagram of the inkjet printing system 10.

  As shown in FIG. 4, an inkjet printing system 10 includes an operation unit 11 that is an input device such as a mouse and a keyboard to which various operations are input, and a display device such as an LCD (Liquid Crystal Display) that displays various information. A display unit 12, a communication unit 13 that is a communication device that communicates with an external device, an EEPROM (Electrically Erasable Programmable Read Only Memory) that stores various data, a HDD (Hard Disk Drive), and the like A storage unit 14 that is a device and a control unit 15 that controls the entire inkjet printing system 10 are provided.

  The control unit 15 includes, for example, a CPU (Central Processing Unit), a ROM (Read Only Memory) that stores programs and various data in advance, and a RAM (Random Access Memory) that is used as a work area of the CPU. ing. The CPU is configured to execute a program stored in the ROM or the storage unit 14.

  The control unit 15 executes a program stored in the ROM or the storage unit 14, thereby serving as a first print control unit that prints an image using the front head 21 (see FIGS. 2 and 3) of the front printer 20. The front surface printing control means 15a, the back surface printing control means 15b as the second printing control means for printing an image by the back surface head 31 (see FIGS. 2 and 3) of the back surface printer 30, and the front and back image position detecting device 52 (FIG. 1) and a displacement amount calculation means 15c for calculating the displacement amount of the front position mark and the back position mark, and the displacement of the image printed on both surfaces of the medium 80 (see FIG. 1). It functions as a deviation correcting means 15d for correcting.

  Next, the operation of the inkjet printing system 10 will be described.

  When print data is transmitted from a computer (not shown) such as a PC (Personal Computer), the front surface print control unit 15a displays an image based on the transmitted print data (hereinafter referred to as “target image”). Printing is performed on the medium 80 by the surface printer 20. Specifically, the front surface print control unit 15a performs ink movement on the medium 80 by the front head 21 while moving the front head 21 relative to the medium 80 in the main scanning direction indicated by the arrow 10b and the sub scanning direction indicated by the arrow 10c. To discharge. Here, when changing the relative position of the surface head 21 in the main scanning direction with respect to the medium 80, the surface printing control unit 15a moves the surface head 21 in the main scanning direction. Further, when changing the relative position of the surface head 21 in the sub-scanning direction with respect to the medium 80, the front surface printing control unit 15 a moves the medium 80 in the sub-scanning direction by the transport roller 22.

  When the target image is printed on the medium 80 by the surface printer 20, the front surface printing control unit 15 a also prints the surface position mark on the medium 80 together with the target image. That is, the image that the front surface printing control unit 15a prints on the front surface printer 20 includes the target image and the front position mark.

  FIG. 5 is a diagram illustrating an example of an image 60 that the front surface printing control unit 15a causes the front surface printer 20 to print.

  As shown in FIG. 5, the image 60 includes a target image 61 and a table position mark 62.

  The table position mark 62 includes a table reference position mark 62 a for determining the reference position of the target image 61. For example, the table reference position mark 62 a is preferably arranged on the downstream side of the target image 61 in the transport direction indicated by the arrow 10 c of the medium 80. Further, the table reference position mark 62a is preferably arranged at one end, the other end or the center of the medium 80 in the direction indicated by the arrow 10b, for example.

  The table position mark 62 includes at least one table relative position mark 62b for determining a relative position with respect to the table reference position mark 62a. For example, the front relative position mark 62b is formed on one end side of the target image 61 in the direction indicated by the arrow 10b of the medium 80, on the other end side of the target image 61 in the direction indicated by the arrow 10b of the medium 80, and on the target image 61. In contrast, the medium 80 is preferably disposed on one end side in the direction indicated by the arrow 10 c and on the other end side in the direction indicated by the arrow 10 c of the medium 80 with respect to the target image 61. In addition, the front relative position mark 62b is preferably arranged at at least one of the one end, the other end, and the center in the direction indicated by the arrow 10b of the medium 80, for example.

  The back surface printing control unit 15b causes the medium 80 to be conveyed in the sub-scanning direction indicated by the arrow 10b by the conveyance roller 32 of the back surface printer 30 as the front surface printing control unit 15a prints the front surface 80a.

  FIG. 6 is a diagram when the image 60 is observed from the back surface 80 b side of the medium 80.

  The front reference position mark 62a and the front relative position mark 62b printed on the front surface 80a of the medium 80 by the front surface printer 20 are printed on the thin medium 80, or even inside the medium 80 even if the medium 80 is a thick cloth. When the ink is printed with a large amount of ink so as to penetrate, it is transmitted to the back surface 80b of the medium 80 as shown in FIG. Therefore, when the medium 80 is transported in the sub-scanning direction indicated by the arrow 10b by the transport roller 32 of the back surface printer 30, the front reference position mark 62a and the front relative position mark 62b are transferred to the back surface of the medium 80 by the front image position detecting device 51. It is detected from the 80b side.

  FIG. 7 is a flowchart of the operation of the inkjet printing system 10 according to the detection result by the front image position detection device 51.

  The control unit 15 performs the operation shown in FIG. 7 every time the table position mark 62 is detected by the table image position detection device 51.

  As shown in FIG. 7, the deviation amount calculation unit 15 c includes a target image 61 in the data of the target image 61 actually printed on the front surface 80 a of the medium 80 by the front surface printer 20 and the image 60 generated by the front surface printing control unit 15 a. An amount of deviation from 61 is calculated (S101).

  Specifically, the deviation amount calculation unit 15c is configured to detect the position of the table reference position mark 62a in the detection result by the table image position detection device 51 and the table reference position mark 62a in the data of the image 60 generated by the front surface printing control unit 15a. Between the target image 61 actually printed on the front surface 80a of the medium 80 by the surface printer 20 and the target image 61 in the data of the image 60 generated by the front surface print control means 15a. The amount of deviation of the reference position in the direction indicated by 10b and the direction indicated by the arrow 10c can be calculated.

  Further, the deviation amount calculation means 15c is configured to detect the relative position of the table relative position mark 62b with respect to the table reference position mark 62a in the detection result by the table image position detection device 51, and the table in the data of the image 60 generated by the surface printing control means 15a. Based on the relative position of the front relative position mark 62b with respect to the reference position mark 62a, the target image 61 actually printed on the front surface 80a of the medium 80 by the front surface printer 20 and the image 60 generated by the front surface printing control means 15a. The amount of deviation in size in the direction of the table relative position mark 62b relative to the table reference position mark 62a and the amount of deviation in angle in the direction of the table relative position mark 62b relative to the table reference position mark 62a with respect to the target image 61 in the data. And can be calculated.

  After the processing of S101, the deviation correction unit 15d determines whether or not the amount of deviation calculated in S101 exceeds a specific allowable amount (S102).

  If the deviation correction unit 15d determines in S102 that the allowable amount is exceeded, the reference position, size, and angle of the image printed on the surface 80a of the medium 80 by the front printer 20 so that the amount of deviation falls within the allowable amount. Is instructed to the front surface printing control means 15a (S103). Accordingly, with respect to the target image 61 newly printed on the front surface 80a by the front surface printing control unit 15a, the deviation from the target image 61 in the data of the image 60 generated by the front surface printing control unit 15a is corrected.

  When the deviation correction unit 15d determines that the allowable amount is not exceeded in S102 or ends the processing in S103, the deviation printer 15d uses the target image 61 actually printed on the front surface 80a of the medium 80 by the front surface printer 20 and the back surface printer 30. At least one change in the reference position, size, and angle of the image printed on the back surface 80b of the medium 80 by the back surface printer 30 so that the image printed on the back surface 80b of the medium 80 overlaps without shifting through the medium 80. Is instructed to the back side printing control means 15b (S104). That is, the misalignment correcting unit 15d corrects misalignment of images printed on both sides of the medium 80 by adjusting the printing control by the back surface printing control unit 15b according to the detection result by the front image position detecting device 51.

  The deviation correcting unit 15d ends the operation illustrated in FIG.

  When the front reference position mark 62a is detected by the front image position detection device 51, the back surface printing control unit 15b detects a front reference position mark 62a by the front image position detection device 51 and then detects a specific amount by the transport roller 32. At the time of conveyance, printing by the back printer 30 is started. Specifically, the back surface printing control unit 15 b prints the mirrored target image obtained by mirroring the target image printed by the front surface printer 20 on the medium 80 by the back surface printer 30. Specifically, the back surface printing control unit 15b performs ink movement on the medium 80 by the back surface head 31 while relatively moving the back surface head 31 in the main scanning direction indicated by the arrow 10c and the sub scanning direction indicated by the arrow 10b. To discharge. Here, when changing the relative position of the back surface head 31 in the main scanning direction with respect to the medium 80, the back surface printing control unit 15b moves the back surface head 31 in the main scanning direction. Further, when changing the relative position of the back head 31 in the sub-scanning direction with respect to the medium 80, the back surface printing control unit 15b moves the medium 80 in the sub-scanning direction by the transport roller 32.

  Note that when the mirror image to be mirrored is printed on the medium 80 by the back printer 30, the back surface printing control unit 15b prints the back position mark on the medium 80 by the back printer 30 together with the mirror image to be mirrored. That is, the image that the back surface printing control unit 15b prints on the back surface printer 30 includes the mirror image and the back position mark.

  FIG. 8 is a diagram illustrating an example of an image 70 that the back surface printing control unit 15b causes the back surface printer 30 to print. In FIG. 8, in order to facilitate understanding of the image 70, the image 60 (see FIG. 6) that is printed on the front surface 80 a of the medium 80 and is transmitted through the back surface 80 b of the medium 80 is not drawn.

  As shown in FIG. 8, the image 70 includes a mirroring target image 71 and a back position mark 72.

  The back position mark 72 includes a back reference position mark 72 a for determining the reference position of the mirrored image 71. The back position mark 72 includes at least one back relative position mark 72b for determining a relative position with respect to the back reference position mark 72a.

  As shown in FIGS. 5 and 8, the image 70 printed on the back surface 80 b by the back surface printer 30 is a mirror image of the image 60 printed on the front surface 80 a by the front surface printer 20.

  FIG. 9 is a diagram when the image 60 and the image 70 are observed from the back surface 80 b side of the medium 80.

  The front reference position mark 62a and the front relative position mark 62b printed on the front surface 80a of the medium 80 by the front surface printer 20 are printed on the thin medium 80, or even inside the medium 80 even if the medium 80 is a thick cloth. When the ink is printed with a large amount of ink so as to penetrate, it is transmitted to the back surface 80b of the medium 80 as shown in FIG. Therefore, when the medium 80 is transported in the sub-scanning direction indicated by the arrow 10b by the transport roller 32 of the back surface printer 30, the front reference position mark 62a and the front relative position mark 62b are detected by the front / back image position detecting device 52. It is detected from the 80b side. Further, the back reference position mark 72 a and the back relative position mark 72 b printed on the back surface 80 b of the medium 80 by the back surface printer 30 are also detected from the back surface 80 b side of the medium 80 by the front and back image position detection device 52.

  FIG. 10 is a flowchart of the operation of the inkjet printing system 10 according to the detection result by the front and back image position detection device 52.

  The control unit 15 performs the operation shown in FIG. 10 every time the front / rear image position detection device 52 detects the front / rear position mark 62 and the back / front position mark 72.

  As shown in FIG. 10, the deviation amount calculation unit 15 c uses the data of the mirror image to be mirrored 71 actually printed on the back surface 80 b of the medium 80 by the back surface printer 30 and the data of the image 70 generated by the back surface printing control unit 15 b. The amount of deviation from the mirrored image 71 is calculated (S111).

  Specifically, the deviation amount calculation unit 15c is configured to detect the position of the back reference position mark 72a in the detection result by the front and back image position detection device 52, and the back reference position mark 72a in the data of the image 70 generated by the back surface printing control unit 15b. Between the mirrored image 71 actually printed on the back surface 80b of the medium 80 by the back surface printer 30 and the mirrored image 71 in the data of the image 70 generated by the back surface print control means 15b. The amount of deviation of the reference position in the direction indicated by the arrow 10b and the direction indicated by the arrow 10c can be calculated.

  Further, the deviation amount calculation unit 15c is configured to detect the relative position of the back relative position mark 72b with respect to the back reference position mark 72a in the detection result of the front and back image position detection device 52, and the back side in the data of the image 70 generated by the back side print control unit 15b. Based on the relative position of the back relative position mark 72b with respect to the reference position mark 72a, the mirroring target image 71 actually printed on the back surface 80b of the medium 80 by the back surface printer 30, and the image generated by the back surface printing control means 15b. The amount of size shift in the direction of the back relative position mark 72b with respect to the back reference position mark 72a and the angle of the direction of the back relative position mark 72b with respect to the back reference position mark 72a with respect to the mirrored image 71 in the data 70. The amount of deviation can be calculated.

  After the process of S111, the deviation correction unit 15d determines whether or not the amount of deviation calculated in S111 exceeds a specific allowable amount (S112).

  When the deviation correction unit 15d determines in S112 that the allowable amount is exceeded, the reference position, size, and angle of the image printed on the back surface 80b of the medium 80 by the back surface printer 30 so that the amount of deviation falls within the allowable amount. Is instructed to the back surface printing control means 15b (S113). Therefore, regarding the mirroring target image 71 newly printed on the back surface 80b by the back surface printing control unit 15b, the deviation from the mirroring target image 71 in the data of the image 70 generated by the back surface printing control unit 15b is corrected. .

  The deviation correcting unit 15d ends the operation illustrated in FIG. 10 when the process of S113 ends.

  When it is determined in S112 that the deviation amount calculation unit 15c does not exceed the allowable amount, the target image 61 actually printed on the front surface 80a of the medium 80 by the front surface printer 20 and the rear surface 80b of the medium 80 by the rear surface printer 30. The amount of deviation from the mirrored image 71 actually printed is calculated (S114).

  Specifically, the deviation amount calculation means 15c determines the position of the front reference position mark 62a in the detection result by the front and back image position detection device 52 and the position of the back reference position mark 72a in the detection result by the front and back image position detection device 52. Based on the arrow 10b between the target image 61 actually printed on the front surface 80a of the medium 80 by the front surface printer 20 and the mirrored target image 71 actually printed on the back surface 80b of the medium 80 by the back surface printer 30. And the amount of deviation of the reference position in the direction indicated by the arrow 10c can be calculated.

  Further, the deviation amount calculation means 15c is configured to detect the relative position of the front relative position mark 62b with respect to the front reference position mark 62a in the detection result by the front / back image position detection device 52, and the back reference position mark 72a in the detection result by the front / back image position detection device 52. The target image 61 actually printed on the front surface 80a of the medium 80 by the front surface printer 20 based on the relative position of the back relative position mark 72b with respect to the image, and the mirror image actually printed on the back surface 80b of the medium 80 by the back surface printer 30. It is possible to calculate the amount of deviation in size in the direction of the relative position mark relative to the reference position mark and the amount of deviation in angle in the direction of the relative position mark relative to the reference position mark with respect to the conversion target image 71.

  After the process of S114, the deviation correction unit 15d determines whether or not the amount of deviation calculated in S114 exceeds a specific allowable amount (S115).

  If the deviation correction unit 15d determines in S115 that the allowable amount is exceeded, the reference position, size, and angle of the image printed on the back surface 80b of the medium 80 by the back surface printer 30 so that the amount of deviation falls within the allowable amount. Is instructed to the back surface printing control means 15b (S116). That is, the misalignment correcting unit 15d adjusts the printing control by the back surface printing control unit 15b according to the amount of misalignment between the front position mark 62 and the back position mark 72, thereby shifting the image printed on both surfaces of the medium 80. Correct. Therefore, regarding the mirrored target image 71 newly printed on the back surface 80b by the back surface printing control unit 15b, the deviation from the target image 61 printed on the front surface 80a of the medium 80 is corrected.

  The deviation correcting unit 15d determines in S115 that the allowable amount is not exceeded, or ends the operation shown in FIG.

  As described above, the inkjet printing system 10 controls printing according to the amount of deviation between the front position mark 62 printed on the front surface 80 a of the medium 80 and the back position mark 72 printed on the back surface 80 b of the medium 80. Is adjusted to correct the deviation of the image printed on both sides of the medium 80 (S116), so that the deviation of the image printed on both sides of the medium 80 can be reduced.

  Therefore, the inkjet printing system 10 can print a high-definition image on both sides of the medium 80. For this reason, the inkjet printing system 10 can print a high-quality product of a thin fabric with beautiful both sides, such as a scarf and a handkerchief. Also, it is possible to print high-quality fabrics and fabrics of thick fabrics that can be observed from both sides, such as curtains. In particular, if the thin fabric is printed only on the surface, when the fiber is repeatedly washed by washing, the back portion of the fiber that is not printed will appear on the surface, As a result, the image printed on the surface tends to be thinned every time washing is performed. However, since the inkjet printing system 10 can perform printing on both sides of a thin fabric, the image printed on both sides is unlikely to become thin even if the fibers are repeated by washing. As a result, it is possible to generate a printed material that is resistant to washing.

  The inkjet printing system 10 corrects the back position mark 72 to be printed on the back surface 80b of the medium 80 so that it does not shift with respect to the front position mark 62 printed on the front surface 80a of the medium 80 (S104). After printing is performed, the deviation of the image printed on both sides of the medium 80 is further corrected according to the amount of deviation between the front position mark 62 and the back position mark 72 (S116), so that printing is performed on both sides of the medium 80. Image shift can be further reduced.

  Since the inkjet printing system 10 automatically calculates the amount of deviation between the front position mark 62 and the back position mark 72, the user determines the amount of deviation between the front position mark 62 and the back position mark 72 from the medium 80. Compared with, convenience can be improved.

  The inkjet printing system 10 may be configured such that the user determines from the medium 80 without automatically calculating the amount of deviation between the front position mark 62 and the back position mark 72. For example, if the graduation is printed as the front position mark 62 and the back position mark 72 in the inkjet printing system 10, the user can easily determine the amount of deviation from the medium 80.

  FIG. 11A is a diagram illustrating an example of the front position mark 62 and the back position mark 72 when there is no deviation. FIG. 11B is a view showing the front position mark 62 and the back position mark 72 shown in FIG.

  The scale of the back position mark 72 shown in FIG. 11A is drawn 5% shorter than the scale of the front position mark 62. In FIG. 11A, the table position mark 62 includes a triangle 62c indicating the position of the reference scale line. Similarly, the back position mark 72 includes a triangle 72c indicating a reference graduation line. Accordingly, when the scale of the front position mark 62 and the scale of the back position mark 72 are shifted as shown in FIG. 11B, the scale lines at the positions indicated by the arrows 100, that is, the reference scale line. Since the graduation lines separated by 4 graduations are aligned with each other, the printing on the back surface 80b (see FIG. 1) is one graduation in the direction indicated by the arrow 101 with respect to the printing on the front surface 80a (see FIG. 1). It can be seen that the distance is shifted by a distance of 20% (= 5% × 4). Note that the deviation amount shown in FIG. 11B may be determined visually by the user from the medium 80, or may be automatically calculated by the inkjet printing system 10. Further, the scale may be drawn so as to extend in a direction indicated by an arrow 10b (see FIG. 1), or may be drawn so as to extend in a direction indicated by an arrow 10c (see FIG. 1). good. Further, in the above, 5% is an example, so other ratios may be used.

  The inkjet printing system 10 automatically corrects the deviation of images printed on both sides of the medium 80 in accordance with the amount of deviation between the front position mark 62 and the back position mark 72 calculated automatically. Compared with a configuration in which an appropriate instruction for correcting a deviation of images printed on both sides of the image is manually input by the user based on the amount of deviation of the front position mark 62 and the back position mark 72 Can be improved.

  Note that the inkjet printing system 10 does not automatically correct the misalignment of images printed on both sides of the medium 80, and does not automatically correct the misalignment of the medium 80 according to instructions input by the user via the operation unit 11 or the communication unit 13. It may be configured to correct a deviation of images printed on both sides. For example, the user calculates the amount of deviation between the front position mark 62 and the back position mark 72 automatically calculated by the inkjet printing system 10 and displayed on the display unit 12, or the user determines from the medium 80. Based on the amount of misalignment between the front position mark 62 and the back position mark 72, an instruction for correcting the misalignment of images printed on both sides of the medium 80 can be input via the operation unit 11 or the communication unit 13. .

  The inkjet printing system 10 can simultaneously detect the front position mark 62 printed on the front surface 80a of the medium 80 and the back position mark 72 printed on the back surface 80b of the medium 80 from one side of the medium 80. The front position mark 62 printed on the front surface 80a and the back position mark 72 printed on the back surface 80b of the medium 80 are compared with the configuration in which the front position mark 62 is detected from the front surface 80a side of the medium 80 and the back surface mark 80b of the medium 80, respectively. The amount of deviation between the mark 62 and the back position mark 72 can be detected with high accuracy. Therefore, the inkjet printing system 10 can correct the deviation of images printed on both sides of the medium 80 with high accuracy, and as a result, the deviation of images printed on both sides of the medium 80 can be further reduced. it can.

  In addition, when the medium 80 is a thick cloth, the inkjet printing system 10 prints the front position mark 62 on the surface 80a of the medium 80 with a large amount of ink soaking into the medium 80. The front position mark 62 can be transmitted through the back surface 80 b of the medium 80. In addition, the inkjet printing system 10 can be configured such that the medium 80 is formed in a transparent or light color without printing the surface position mark 62 on the surface 80a of the medium 80 with a large amount of ink soaking into the medium 80. When the thickness of the medium 80 is thin and the medium 80 itself has a certain degree of transparency, the front position mark 62 is printed on the surface 80a of the medium 80 in a dark color. Can be transmitted through the back surface 80 b of the medium 80. Further, when the medium 80 itself has high transparency, the inkjet printing system 10 normally prints the front position mark 62 on the front surface 80 a of the medium 80, so that the front position mark 62 is applied to the back surface 80 b of the medium 80. Can be transmitted.

  The shift amount calculation means 15c of the inkjet printing system 10 is configured to shift the front position mark 62 and the back position mark 72 based on an average of a plurality of detection results of the front position mark 62 and the back position mark 72 by the front and back image position detection device 52. May be calculated. With this configuration, the inkjet printing system 10 allows the amount of deviation of the front position mark 62 and the back position mark 72 to vary every time the front position mark 62 and the back position mark 72 are detected by the front and back image position detection device 52. It is possible to improve the accuracy of correcting the deviation of images printed on both sides of the medium 80. Therefore, the inkjet printing system 10 can further reduce the deviation of images printed on both sides of the medium 80.

  In this embodiment, the deviation correction unit 15d of the inkjet printing system 10 adjusts the printing control by the back surface printing control unit 15b in order to correct the deviation of images printed on both sides of the medium 80. However, the deviation correcting unit 15d performs at least one of printing control by the front surface printing control unit 15a and printing control by the back surface printing control unit 15b in order to correct a deviation of images printed on both sides of the medium 80. Adjust it.

  In the present embodiment, the inkjet printing system 10 uses the target image and the front position mark as separate images. However, the inkjet printing system 10 may use the target image itself as the front position mark and may use the mirrored target image itself as the back position mark.

  In the present embodiment, in the ink jet printing system 10, the front image position detection device 51 detects the front position mark 62 printed on the front surface 80a of the medium 80 from the back surface 80b side of the medium 80. However, the front image position detecting device 51 may detect the front position mark 62 printed on the surface 80a of the medium 80 from the front surface 80a side of the medium 80.

  In the present embodiment, the ink jet printing system 10 uses the front and back image position detection device 52 to display the front position mark 62 printed on the front surface 80a of the medium 80 and the back position mark 72 printed on the back surface 80b of the medium 80. 80 is detected from the back surface 80b side. However, the front / back image position detection device 52 detects the front position mark 62 printed on the front surface 80a of the medium 80 and the back position mark 72 printed on the back surface 80b of the medium 80 from the front surface 80a side of the medium 80. It may be. Further, the front / back image position detection device 52 detects the front position mark 62 printed on the front surface 80a of the medium 80 from the front surface 80a side of the medium 80, and also uses the back position mark 72 printed on the back surface 80b of the medium 80 as the medium. 80 may be detected from the back surface 80b side.

  In the present embodiment, the inkjet printing system 10 includes two inkjet printers, a front surface printer 20 and a back surface printer 30. However, the inkjet printing system 10 includes two ink jet heads that perform printing on the front surface 80a of the medium 80 and two ink jet heads that perform printing on the back surface 80b of the medium 80 on which printing is performed on the front surface 80a. You may be comprised by one inkjet printer provided with the inkjet head.

10 Inkjet printing system 15a Surface printing control means (first printing control means)
15b Back side printing control means (second printing control means)
15c Deviation amount calculation means 15d Deviation correction means 21 Front head (first inkjet head)
31 Back head (second inkjet head)
51 Front image position detection device (single-sided image detection unit)
52 Front / Back Image Position Detection Device (Double-sided Image Detection Unit)
60 images (images including the first image)
62 Front position mark (first image)
70 images (images including the second image)
72 Back position mark (second image)
80 Medium 80a Surface (one side)
80b Back side (the other side)

Claims (5)

A first inkjet head that performs printing on one side of the medium;
A second inkjet head for performing printing on the other surface of the medium on which printing has been performed by the first inkjet head;
A transport direction changing mechanism that is disposed between the first inkjet head and the second inkjet head in the transport path of the medium, reverses the front and back of the medium, and changes the transport direction of the medium;
First printing control means for printing an image including a first image for adjustment of printing control by the first inkjet head;
Second print control means for printing an image including a second image for adjustment of print control by the second inkjet head;
A single-sided image detection unit that detects the first image from the medium after the transport direction is changed by the transport direction change mechanism and before printing is performed by the second inkjet head;
A double-sided image detection unit for detecting the first image and the second image from the medium;
A deviation amount calculating means for calculating a deviation amount between the first image and the second image based on a detection result by the double-sided image detection unit;
A displacement correction means for correcting a displacement of images printed on both sides of the medium,
The transport direction changing mechanism is
A transport direction of a portion of the medium in which printing is performed by the first inkjet head;
Changing the transport direction of the medium so that the transport direction of the portion of the medium on which printing is performed by the second inkjet head intersects
The deviation correction unit performs at least one of printing control by the first printing control unit and printing control by the second printing control unit with respect to deviation of the first image and the second image. Correct the deviation of the image printed on both sides of the medium by adjusting according to the amount ,
The misalignment correcting unit corrects misalignment of images printed on both sides of the medium by adjusting printing control by the second print control unit according to a detection result by the single-sided image detection unit. Inkjet printing system.   2. The inkjet printing system according to claim 1, wherein the double-sided image detection unit detects the first image and the second image from one side of the medium.   The deviation correction unit corrects a deviation of images printed on both surfaces of the medium according to a deviation amount of the first image and the second image calculated by the deviation amount calculation unit. The inkjet printing system according to claim 1 or 2.   The first print control unit and the second print control unit are configured so that the double-sided image detection unit can detect the first image and the second image from one side of the medium. The inkjet printing system according to any one of claims 1 to 3, wherein an image and the second image are printed.   The deviation amount calculation means is an amount of deviation between the first image and the second image based on an average of a plurality of detection results of the first image and the second image by the double-sided image detection unit. The inkjet printing system according to claim 1, wherein the inkjet printing system is calculated.

Images