Printing apparatus, printing method, and printing program

Abstract

The present invention provides a printing apparatus, a printing method, and a printing program that can reduce the visibility of graininess in printed materials. [Solution] The printing apparatus comprises a discharge head having a nozzle provided on the nozzle surface for discharging droplets, and a control device. The control device performs the following processes: acquiring instruction information indicating whether to print on a permeable medium, which is the printing target, or an impermeable medium, which is the transfer medium to the printing target; discharging a first-size droplet from the nozzle when printing on a permeable medium based on the instruction information; and discharging a second-size droplet, smaller than the first size, from the nozzle when printing on an impermeable medium based on the instruction information.

Description

Technical Field

[0001] The present disclosure relates to a printing apparatus, a printing method, and a printing program.

Background Art

[0002] Conventionally, an image forming apparatus including a discharge head that directly discharges ink droplets onto a fabric has been known (Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When printing is performed on a permeable medium such as a fabric, for example, it is conceivable to increase the distance between the nozzle surface and the permeable medium in consideration of the inclusion of fluff or the like in the permeable medium. When the amount of ink droplets discharged from the discharge head is small in such a state where the above distance is large, there is a risk that a large amount of mist will occur. Therefore, it is conceivable to discharge a large amount of ink droplets that are less likely to generate mist.

[0005] <所 By the way, it is conceivable to print the same image not only on a permeable medium but also on a non-permeable medium such as a film. However, when ink droplets are discharged onto a non-permeable medium, the ink droplets are difficult to penetrate. Therefore, there is a problem that the ink droplets discharged onto the non-permeable medium are difficult to spread on the non-permeable medium, and the granular feeling becomes prominent on the non-permeable medium.

[0006] An object of the present disclosure is to provide a printing apparatus, a printing method, and a printing program capable of making the granular feeling less prominent in a printed matter.

Means for Solving the Problems

[0007] The printing apparatus of the present disclosure comprises a discharge head having a nozzle provided on the nozzle surface for discharging droplets, and a control device, wherein the control device performs the following processes: acquiring instruction information indicating whether to print on a permeable medium that is the printing target or a non-permeable medium that is a transfer medium to the printing target; discharging a first-size droplet from the nozzle when printing on the permeable medium based on the instruction information; and discharging a second-size droplet smaller than the first size from the nozzle when printing on the non-permeable medium based on the instruction information.

[0008] According to this disclosure, when printing is performed on a non-impermeable medium, droplets of a second size, which are smaller than the first size, are ejected, and because the droplets themselves are small, their visibility is reduced, and therefore the graininess becomes less noticeable. [Effects of the Invention]

[0009] This disclosure provides a printing apparatus, a printing method, and a printing program that can reduce the visibility of graininess in printed materials. [Brief explanation of the drawing]

[0010] [Figure 1] Figure 1 is a plan view showing the configuration of a printing system including a printing apparatus and an external image processing apparatus according to one embodiment. [Figure 2] Figure 2 shows each nozzle in the discharge head unit shown in Figure 1. [Figure 3] Figure 3 is a block diagram showing the configuration of the control system of the printing system shown in Figure 1. [Figure 4] Figure 4 shows the support position and printing position, which are the positions where the platen moves. [Figure 5] Figure 5 shows an example of the screen for specifying the print mode. [Figure 6]Figure 6A shows multiple large ink droplets ejected onto a permeable medium, and Figure 6B shows multiple large ink droplets ejected onto a non-permeable medium. [Figure 7] Figure 7 shows examples of large, medium, and small ink droplets dispensed onto an impermeable medium. [Figure 8] Figure 8 is a flowchart showing the processing flow in a printing device. [Modes for carrying out the invention]

[0011] Embodiments of this disclosure will be described below with reference to the drawings. The embodiments described below are only one embodiment of this disclosure. Therefore, this disclosure is not limited to the embodiments described below, and additions, deletions, and modifications are permitted without departing from the spirit of this disclosure. In the following, the same reference numerals will be used for the same or corresponding elements throughout all drawings, and redundant descriptions will be omitted unless otherwise noted.

[0012] Figure 1 is a plan view showing the configuration of a printing system 100 including a printing apparatus 101 and an external image processing apparatus 102 according to one embodiment. Figure 2 is a diagram showing each nozzle in the ejection head unit HU of Figure 1. Figure 3 is a block diagram showing the configuration of the control system of the printing system 100 of Figure 1. Figure 4 is a diagram showing the support position Ps and printing position Pp, which are the positions to which the platen 11 moves.

[0013] In Figures 1 and 2, etc., mutually orthogonal directions are denoted as the first direction Dy, the second direction Dx, and the third direction Dz. In this embodiment, for example, the first direction Dy is the transport direction of the printing medium W, the second direction Dx is the movement direction of the carriage 41 described later, and the third direction Dz is the vertical direction. In the following description, Dx will be referred to as the movement direction, Dy as the transport direction, and Dz as the vertical direction. One direction of the transport direction Dy will be called Dy1, and the direction opposite to direction Dy1 will be called Dy2. The printing medium W is transported in direction Dy1, for example, during printing. Also, one direction of the movement direction Dx will be called Dx1, and the direction opposite to direction Dx1 will be called Dx2. Furthermore, the upward direction of the vertical direction Dz will be called Dz1, and the downward direction will be called Dz2. However, the above directions are examples and are not limiting.

[0014] As shown in Figure 1, the printing system 100 comprises a printing device 101 and an image processing device 102. The image processing device 102 corresponds to an external device. The printing device 101 and the image processing device 102 are connected to each other so as to be able to communicate via wireless or wired connections, such as a network. The image processing device 102 is, for example, a personal computer. The image processing device 102 generates print data from image data of a print image, which is an image to be printed on a printing medium W by the printing device 101, and transmits the generated print data to the printing device 101 via wireless or wired connections. The printing device 101 prints the print image on the printing medium W based on the print data received from the image processing device 102. Examples of the printing medium W include cloth, sheet-fed film, and roll film.

[0015] The printing device 101 is, for example, a serial head type inkjet printer. Based on the print data, the printing device 101 alternately repeats a pass process in which the inkjet head 20 is moved in the movement direction Dx while ejecting ink droplets, and a transport process in which the printing medium W is transported in the transport direction Dy. As a result, a predetermined image is printed on the printing medium W. Hereinafter, the inkjet head 20 will be abbreviated as head 20. Note that head 20 corresponds to the ejection head.

[0016] As shown in FIG. 1, FIG. 3 or FIG. 4, the printing apparatus 101 includes a discharge head unit HU having a plurality of heads 20, a platen 11, a plurality of tanks 12, a moving device 30, a conveying device 40, an interval changing device 47, and a support plate 110. Hereinafter, each component included in the printing apparatus 101 will be described respectively.

[0017] The head 20 prints an image on the printing medium W with predetermined ink droplets based on print data. A plurality of heads 20 are provided. The plurality of heads 20 are provided as a discharge head unit HU. Examples of the plurality of heads 20 include a first inkjet head 21, a second inkjet head 22, and a third inkjet head 23. Hereinafter, the first inkjet head 21 will be abbreviated as the first head 21, the second inkjet head 22 will be abbreviated as the second head 22, and the third inkjet head 23 will be abbreviated as the third head 23.

[0018] The first head 21 performs printing on the printing medium W with white ink. Thereby, a base is formed on the printing medium W. The second head 22 performs printing on the printing medium W with special ink. The third head 23 performs printing on the printing medium W with color ink. Hereinafter, when referred to as the head 20, the head 20 includes the first head 21, the second head 22, and the third head 23.

[0019] The conveying device 40 has, for example, a drive unit including a ball screw or a rack and pinion (not shown) and a conveying motor 46. The drive unit is connected to the conveying motor 46. By driving the conveying motor 46, the platen 11 reciprocates in the conveying direction Dy to convey the printing medium W in the conveying direction Dy. The conveying device 40 corresponds to a conveying mechanism.

[0020] The spacing change device 47 includes a drive unit, such as a ball screw or rack and pinion (not shown), and a moving motor 48. The drive unit is connected to the moving motor 48. The platen 11 moves in the vertical direction Dz when driven by the moving motor 48. As a result, the spacing change device 47 changes the spacing between the nozzle surfaces NM1, NM2, NM3 (described later) and the platen 11. The spacing change device 47 corresponds to the spacing change mechanism. The movement of the platen 11 in the transport direction Dy by the transport device 40 and the movement of the platen 11 in the vertical direction Dz by the spacing change device 47 will be explained later.

[0021] The platen 11 has a flat upper surface and defines the distance between the printing medium W placed on its upper surface and the nozzle surface of the head 20 provided opposite it. The platen 11 moves back and forth in the transport direction Dy. As a result, the printing medium W supported by the platen 11 moves back and forth in the transport direction Dy. Ink is stored in each tank 12. The tanks 12 are connected to the head 20 via the flow paths described below to supply ink to the head 20. The number of tanks 12 is equal to or greater than the number of ink types. For example, the tanks 12 include four first tanks 12a each storing four types of color ink, one or more second tanks 12b each storing white ink, and one or more third tanks 12c each storing spot color ink. Examples of color inks include cyan ink, magenta ink, yellow ink, and black ink. Examples of spot color inks include red ink, green ink, and blue ink.

[0022] The first tank 12a is connected to the third head 23 via the first channel 13a. Color ink is supplied from the first tank 12a to the third head 23 via the first channel 13a. The second tank 12b is connected to the first head 21 via the second channel 13b. White ink is supplied from the second tank 12b to the first head 21 via the second channel 13b. The third tank 12c is connected to the second head 22 via the third channel 13c. Special color ink is supplied from the third tank 12c to the second head 22 via the third channel 13c.

[0023] The moving device 30 includes a carriage 41, two guide rails 42, a moving motor 34, and an endless belt 44. The two guide rails 42 extend above the platen 11 in the direction of movement Dx, sandwiching the carriage 41 between them in the transport direction Dy. The carriage 41 holds the head 20. The carriage 41 is supported by the two guide rails 42 so as to be movable in directions Dx1 and Dx2 of the direction of movement Dx. The endless belt 44 extends in the direction of movement Dx and is attached to the carriage 41, and is connected to the moving motor 34 via a pulley 45. When the moving motor 34 is driven, the endless belt 44 acts, and the carriage 41 reciprocates along the guide rails 42 in the direction of movement Dx. As a result, the head 20 is reciprocated by the carriage 41 in the direction of movement Dx.

[0024] Next, as shown in Figure 2, the first head 21, the second head 22, and the third head 23 are arranged side by side in the transport direction Dy. The first head 21 has a nozzle surface NM1 and a plurality of nozzles 24 provided on the nozzle surface NM1 for ejecting white ink onto the printing medium W. The second head 22 has a nozzle surface NM2 and a plurality of nozzles 25 provided on the nozzle surface NM2 for ejecting spot color ink onto the printing medium W. The third head 23 has a nozzle surface NM3 and a plurality of nozzles 26 provided on the nozzle surface NM3 for ejecting color ink onto the printing medium W. The nozzles 26 include a nozzle 26c for ejecting cyan ink, a nozzle 26m for ejecting magenta ink, a nozzle 26y for ejecting yellow ink, and a nozzle 26k for ejecting black ink. In the transport direction Dy, the nozzles 25 are arranged between the nozzles 24 and 26. In the first head 21, the plurality of nozzles 24 form a nozzle row along the transport direction Dy. The same applies to the multiple nozzles 25 in the second head 22 and the multiple nozzles 26 in the third head 23. Note that the arrangement of the first head 21, the second head 22, and the third head 23, as well as the arrangement of the nozzles, are examples and can be changed as appropriate.

[0025] As shown in Figure 3, the first head 21 is provided with a drive element 27 and a pressure chamber 31 for each nozzle 24. The second head 22 is provided with a drive element 28 and a pressure chamber 32 for each nozzle 25. The third head 23 is provided with a drive element 29 and a pressure chamber 33 for each nozzle 26. The drive elements 27, 28, and 29 are piezoelectric elements or heating elements, etc. When the drive element 27 is driven, discharge pressure is applied to the ink in the pressure chamber 31 to eject ink droplets from the corresponding nozzle 24. The operation of the drive element 28 of the second head 22 and the drive element 29 of the third head 23 is the same as the operation of the drive element 27 of the first head 21.

[0026] In Figure 3, the printing device 101 includes a second control device 50. The printing device 101 also includes a second storage device 51, a second communication interface 52, a first head drive circuit 53, a second head drive circuit 54, a third head drive circuit 57, a movement drive circuit 55, a transport drive circuit 56, a spacing change drive circuit 58, and a sensor Ca, all connected to the second control device 50. The second control device 50 corresponds to the control device, and the second communication interface 52 corresponds to the communication device.

[0027] The second storage device 51 is a memory accessible from the second control device 50, and includes, for example, RAM and ROM. The RAM temporarily stores print data and various data from calculations performed by the second control device 50. The ROM stores print programs and various data for performing various data processing.

[0028] The second control device 50 is composed of a computer and includes, for example, a processor such as a CPU or an integrated circuit such as an ASIC. The second control device 50 controls the operation of each part of the printing device 101 by executing a printing program while referring to the data stored in the second storage device 51. The second control device 50 also receives various data, such as printing data, from the image processing device 102 via the second communication interface 52. For example, the communication standard between the second control device 50 and the second communication interface 52 is Wi-Fi or Ethernet. The second control device 50 may be composed of a single device, or it may be configured so that multiple independently arranged devices cooperate to control the operation of the printing device 101. Specifically, the second control device 50 may cooperate with the first control device 61 of the image processing device 102 to form a control device 70, and this control device 70 may control the operation of the printing device 101.

[0029] The first head drive circuit 53 controls the operation of the drive element 27 based on instructions from the second control device 50. In this case, the second control device 50 outputs a control signal to the first head drive circuit 53 to drive the drive element 27, and the first head drive circuit 53 generates a drive signal based on the control signal and outputs this drive signal to the drive element 27. Based on the drive signal, the drive element 27 applies a predetermined discharge pressure to the white ink in the pressure chamber 31 at a predetermined timing. As a result, white ink is discharged from the nozzle 24. The second head drive circuit 54 controls the operation of the drive element 28 based on instructions from the second control device 50, similar to the first head drive circuit 53. As a result, spot color ink is discharged from the nozzle 25. The third head drive circuit 57 controls the operation of the drive element 29 based on instructions from the second control device 50, similar to the first head drive circuit 53 and the second head drive circuit 54. As a result, color ink is discharged from the nozzle 26. The following explains how ink droplets are ejected when the second control device 50 applies a drive voltage to each of the drive elements 27, 28, and 29.

[0030] The moving drive circuit 55 controls the operation of the moving motor 34 of the moving device 30 based on instructions from the second control device 50. As a result, the carriage 41 moves back and forth in the direction of movement Dx. Consequently, the first head 21, the second head 22, and the third head 23 move back and forth in the direction of movement Dx.

[0031] The transport drive circuit 56 controls the operation of the transport motor 42 of the transport device 40 based on instructions from the second control device 50. As a result, the platen 11 transports the printing medium W intermittently or continuously along the transport direction Dy, and also stops the printing medium W at a predetermined position.

[0032] The spacing change drive circuit 58 controls the operation of the moving motor 48 of the spacing change device 47 based on instructions from the second control device 50. As a result, the platen 11 moves in the vertical direction Dz.

[0033] Next, the image processing device 102 is a device that processes print images for printing by the printing device 101, and is, for example, a personal computer. The image processing device 102 includes a first control device 61, and a first storage device 62, a first communication interface 63, a reader 64, and a display device 65 connected to the first control device 61. The image processing device 102 may be a smartphone or a tablet, etc.

[0034] The first storage device 62 is a memory accessible from the first control device 61, and includes, for example, RAM and ROM. The RAM temporarily stores image data and various data used during calculations by the first control device 61. The ROM stores printing programs and various data for performing various data processing. Examples of the image data include raster data showing an image to be printed on the printing medium W.

[0035] The first control device 61 is composed of a computer and includes, for example, a processor such as a CPU or an integrated circuit such as an ASIC. The first control device 61 controls the operation of the printing device 101 and the display device 65 by executing a printing program while referring to the data stored in the first storage device 62. The first control device 61 transmits various data, such as printing data, to the printing device 101 via the first communication interface 63. The first control device 61 may be composed of a single device, or it may be configured so that multiple independently arranged devices cooperate to control the operation of the image processing device 102.

[0036] The reader 64 reads a print program stored on a storage medium KB, such as a CD-ROM or USB flash memory. The read print program is stored in the first storage device 62. Alternatively, the print program may be downloaded via a predetermined communication network and stored in the first storage device 62. The display device 65 is a display that shows print images and the like printed by the printer 101 based on image data.

[0037] In this embodiment, as shown in Figure 6 and other figures described later, a permeable medium W1 or an impermeable medium W2 is placed on the platen 11 as the printing medium W. This supports the permeable medium W1 or the impermeable medium W2 on the platen 11. Examples of permeable medium W1 include cloth and paper, which are the printing targets. Examples of impermeable medium W2 include film, which is a transfer medium to the printing target. The image printed on the impermeable medium W2 is transferred to the printing target medium using a thermal transfer apparatus (not shown).

[0038] As shown in Figure 4, the platen 11 is connected to the aforementioned spacing change device 47. The spacing change device 47 is supported by the aforementioned transport device 40 located below the spacing change device 47. The transport device 40 is supported by a support plate 110 so as to be able to reciprocate in the transport direction Dy. In this configuration, the transport device 40 transports the platen 11 from a support position Ps where the printable medium W, which is either a permeable medium W1 or an impermeable medium W2, is supported on the platen 11, to a printing position Pp where the permeable medium W1 or impermeable medium W2 supported on the platen 11 faces the head 20. As a result, the permeable medium W1 or impermeable medium W2 on the platen 11 moves between the support position Ps and the printing position Pp. The support position Ps is the position where the printable medium W is placed on the platen 11. As will be described later, when the second control device 50 performs print control, the transport of the permeable medium W1 or the non-permeable medium W2 from the support position Ps toward the print position Pp begins.

[0039] The second control device 50 acquires position information indicating the height position of the permeable medium W1 or impermeable medium W2 supported by the platen 11 during transport of the platen 11 from the support position Ps to the printing position Pp. In this case, the sensor Ca detects the height position of the permeable medium W1 or impermeable medium W2 and transmits the detection result to the second control device 50. The sensor Ca can be any device capable of detecting the height position of the object to be detected, such as a laser displacement sensor. The second control device 50 acquires position information indicating the height position of the permeable medium W1 or impermeable medium W2 during transport of the platen 11 from the support position Ps to the printing position Pp, but is not limited to this. The platen 11 or the impermeable medium W2 may be transported to a position below the sensor Ca, and position information indicating the height position of the permeable medium W1 or impermeable medium W2 may be acquired during the upward movement Dz1 of the permeable medium W1 or impermeable medium W2 that has been transported to that position.

[0040] Here, when printing on the permeable medium W1, if the height position acquired by the sensor Ca during transport is above a predetermined reference position, the second control device 50 lowers the platen 11 using the spacing change device 47 so that the height position is below the reference position, and continues transport. In this regard, when printing is performed on the permeable medium W1, if the gap between the permeable medium W1 and the nozzle surfaces NM1, NM2, NM3 widens, the accuracy of ink droplet placement may decrease, potentially resulting in a decrease in image quality. However, because the ink droplets have good permeability, even if the ink droplets are ejected with a widened gap, the placement accuracy is not significantly affected. This allows the above transport to continue. In contrast, when printing on the non-permeable medium W2, if the height position acquired by the sensor Ca during transport is above a reference position, the second control device 50 moves the platen 11, which is moving from the support position Ps toward the printing position Pp, back to the support position Ps using the transport device 40. This allows the user to reset the non-permeable medium W2 on the platen 11. In this regard, when printing is performed on a non-permeable medium W2, the ink droplets do not penetrate well, so if the ink droplets are ejected with a widened gap, it will have a significant impact on the accuracy of the droplet placement. For this reason, the platen 11 is moved to the support position Ps without continuing the above transport.

[0041] Figure 5 shows an example of the print mode selection screen Sc. The selection screen Sc is displayed on the display device 65 of the image processing device 102. As shown in Figure 5, the selection screen Sc includes a selection section Pd1 and a selection section Pd2. The user can select either "DTG (Direct to garment) printing" or "DTF (Direct to film) printing" in the selection section Pd1. If the user wishes to print on a permeable medium W1, they can select "DTG printing" in the selection section Pd1, and if they wish to print on a non-permeable medium W2, they can select "DTF printing" in the selection section Pd1. If "DTG printing" is selected, the user can select, for example, one of the predetermined values ​​of the platen height from "A" to "H". On the other hand, if "DTF printing" is selected, the user cannot select, for example, the platen height, and the platen height is determined to be the "DTF height" for "DTF printing". In this embodiment, the "DTF height", which is the platen height, is set higher than all other platen heights except for the "DTF height". Therefore, when DTF printing is performed, the distance between the nozzle surfaces NM1, NM2, NM3 and the platen 11 is smaller than when DTG printing is performed.

[0042] The first control device 61 of the image processing device 102 transmits information to the printing device 101 via the first communication interface 63 as instruction information, indicating whether to perform "DTG printing" or "DTF printing," that is, information indicating whether to print on the permeable medium W1 or the non-permeable medium W2. In addition, the first control device 61 transmits information on the determined platen height to the printing device 101 via the first communication interface 63 along with the instruction information.

[0043] The second control device 50 of the printing apparatus 101 acquires the instruction information and platen height information transmitted from the image processing apparatus 102 via the second communication interface 52. Based on the acquired platen height information, the second control device 50 moves the platen 11 in the vertical direction Dz using the spacing change device 47, and also executes the processing described below based on the acquired instruction information.

[0044] Here, we will explain the granular texture based on the ejected ink droplets. Figure 6A shows multiple large ink droplets DLG ejected onto a permeable medium W1, and Figure 6B shows multiple large ink droplets DLF ejected onto a non-permeable medium W2. In Figures 6A and 6B, the print density in lines L2, L3, and L4 along the movement direction Dx is lower than the print density in line L1. In this embodiment, print density is the ratio of the area of ​​ink droplets per unit area. Therefore, when the print density is low, the ratio of the area of ​​ink droplets per unit area is relatively small, and when the print density is high, the ratio of the area of ​​ink droplets per unit area is relatively large.

[0045] As shown in Figure 6A, for example, when a large ink droplet DLG is dispensed onto a permeable medium W1, the ink droplet DLG easily penetrates the permeable medium W1. Therefore, after penetrating the permeable medium W1, the dot diameter of the ink droplet DLG increases due to this penetration. In contrast, as shown in Figure 6B, for example, when a large ink droplet DLF is dispensed onto a non-permeable medium W2, the ink droplet DLF does not easily penetrate the non-permeable medium W2. Therefore, the dot diameter of the ink droplet DLF does not easily increase.

[0046] In this way, ink droplets DLG dispensed onto the permeable medium W1 penetrate the medium W1 and become larger in diameter, so the granular texture is relatively less noticeable, especially in lines L2, L3, and L4. On the other hand, ink droplets DLF dispensed onto the non-permeable medium W2 do not penetrate the non-permeable medium W2 easily, so the granular texture is relatively more noticeable, especially in lines L2, L3, and L4.

[0047] Figure 7 shows examples of large ink droplets (DLF), medium ink droplets (DMF), and small ink droplets (DSF) dispensed onto an impermeable medium W2.

[0048] First, the second control device 50, based on the acquired instruction information, changes the spacing between the nozzle surfaces NM1, NM2, NM3 and the platen 11 using the spacing change device 47 before executing the ink droplet ejection process. In this case, when performing DTF printing, i.e., printing on a non-permeable medium W2, the second control device 50 changes the spacing using the spacing change device 47 so that the spacing between the nozzle surfaces NM1, NM2, NM3 and the platen 11 is smaller compared to when performing DTG printing, i.e., printing on a permeable medium W1. Specifically, if DTF printing is selected by the user, the second control device 50 moves the platen 11 in the vertical direction Dz using the spacing change device 47 so that the height of the platen 11 becomes the "DTF height". On the other hand, if DTG printing is selected by the user, the second control device 50 moves the platen 11 in the vertical direction Dz using the spacing change device 47 so that the height of the platen 11 becomes the platen height selected by the user. After moving the platen 11 in this way, the second control device 50 executes the following processes based on the instruction information.

[0049] When the second control device 50 prints on the permeable medium W1 based on the instruction information, it performs a process to eject, for example, extra-large ink droplets DLG from nozzles 24, 25, and 26. In contrast, when the second control device 50 prints on the non-permeable medium W2 based on the instruction information, the following first to fourth ejection modes are given as examples of the ejection process.

[0050] (First discharge mode) In the first ejection mode, when printing on a permeable medium W1, the second control device 50 ejects, for example, a large ink droplet DLG. When the second control device 50 ejects, for example, an ink droplet DLF, it applies a higher voltage to the drive elements 27, 28, and 29 than when ejecting an ink droplet DLG. In the first ejection mode, the ink droplet DLG corresponds to a droplet of a first size.

[0051] In contrast, when printing on an impermeable medium W2, as shown in Figure 7, the second control device 50 ejects large ink droplets DLF, medium ink droplets DMF, and small ink droplets DSF. In the first ejection embodiment, ink droplets DMF and DSF correspond to second-size droplets smaller than the first size, and ink droplet DLF corresponds to a third-size droplet larger than the first size. Therefore, the size of ink droplet DLF is larger than the size of ink droplet DLG. In this case, for example, ink droplet DLF may be an extra-large droplet.

[0052] Here, because the printing target is an impermeable medium W2 into which ink droplets do not easily penetrate, the parts formed by ink droplets DMF and DSF become thinner compared to the parts formed by ink droplets DLF. As a result, banding, which is the streaking of print, becomes more noticeable. Therefore, as shown in Figure 7, the second control device 50 ejects ink droplet DLF, which is larger than ink droplet DLG. In addition, the second control device 50 ejects at least one of ink droplet DMF and ink droplet DSF. Consequently, thinning is suppressed in each line, and therefore banding can be suppressed.

[0053] In Figure 7, line L1 in the impermeable medium W2 is shown as an example in which ink droplets DLF are ejected at approximately equal intervals in the direction of extension of line L1, for comparison with lines L2, L3, and L4.

[0054] In contrast, line L2 shows a configuration in which ink droplets DMF and DSF are ejected in addition to ink droplet DLF. Specifically, the ink droplet DLF in line L2 is ejected at the same position as the ink droplet DLF in the direction of movement Dx in line L1, and at different positions. Furthermore, ink droplets DMF and DSF are ejected in line L2 at the same position as the ink droplet DLF ejected in line L1 in the direction of movement Dx. Also, ink droplets DMF and DSF are ejected in line L2 at a position between one ink droplet DLF and the other ink droplet DLF adjacent to each other in the direction of movement Dx in line L1. Note that "same position" means that the position of at least some of the ink droplets DMF and DSF in line L2 in the direction of movement Dx is the same as the position of the ink droplet DLF in line L1 in the direction of movement Dx. Note that the same "same position" will also be used in the following explanation.

[0055] Line L3 shows a configuration in which ink droplets DMF and DSF are ejected instead of ink droplet DLF. Specifically, similar to line L2, ink droplets DMF and DSF are ejected on line L3 at the same position in the direction of movement Dx as the ink droplet DLF ejected on line L1. Also, similar to line L2, ink droplets DMF and DSF are ejected on line L3 at a position between one ink droplet DLF and the other ink droplet DLF adjacent to each other in the direction of movement Dx on line L1.

[0056] Line L4, like line L3, shows an embodiment in which ink droplets DMF and DSF are ejected instead of ink droplet DLF. Specifically, similar to line L3, ink droplets DMF and DSF are ejected in line L4 at the same position in the direction of movement Dx as the ink droplet DLF ejected in line L1. Also, similar to line L3, ink droplets DMF and DSF are ejected in line L4 at a position between one ink droplet DLF and the other ink droplet DLF adjacent to each other in the direction of movement Dx in line L1.

[0057] Note that the arrangement of ink droplets DMF and DSF in lines L2, L3, and L4 is not limited to the example in Figure 7. In other words, as long as the requirement that the ink droplets DMF and DSF are ejected at the same position in the direction of movement Dx as the ink droplet DLF ejected in line L1, or at a position between one ink droplet DLF and the other ink droplet DLF adjacent to each other in the direction of movement Dx in line L1 is satisfied, the arrangement is not limited to the example in Figure 7.

[0058] Thus, according to the first ejection mode, when printing is performed on an impermeable medium W2, the size of the ink droplet DMF and the ink droplet DSF are smaller than the size of the ink droplet DLG. As a result, visibility is reduced on the impermeable medium W2, and therefore the graininess becomes less noticeable.

[0059] Furthermore, according to the first ejection mode, since the size of the ink droplet DLF is larger than the size of the ink droplet DMF and ink droplet DSF, banding, which is the streaking of print, is suppressed and the granularity is less noticeable compared to when only ink droplet DMF and ink droplet DSF are ejected.

[0060] Furthermore, according to the first ejection mode, both DMF and DSF ink droplets are ejected as ink droplets of different sizes, making the graininess less noticeable. In addition, it becomes easier to obtain high print density, which can reduce the number of print passes and thereby improve productivity.

[0061] Furthermore, according to the first ejection mode, since the size of the ink droplet DLF is larger than the size of the ink droplet DLG, banding can be further suppressed.

[0062] Furthermore, according to the first ejection mode, when ink droplet DLF is ejected, a higher voltage is applied to the drive elements 27, 28, and 29 than when ink droplet DLG is ejected. This makes it easier to eject the third size ink droplet DLF compared to the case where the ink droplet DLF is ejected by a method that does not change the applied voltage, such as a method by which the supplier or consumer of the printing device changes the ejection waveform to eject ink droplet DLG for ejection of ink droplet DLF.

[0063] In the first ejection embodiment, it is sufficient for at least one of the ink droplets DMF and DSF to be ejected.

[0064] (Second discharge mode) In the first dispensing mode described above, the ink droplet DLF was dispensed in the impermeable medium W2, but the ink droplet DLF does not need to be dispensed. In the second dispensing mode, the ink droplet DLG corresponds to a first-size droplet, and the ink droplet DMF and ink droplet DSF correspond to a second-size droplet that is smaller than the first size.

[0065] In the second ejection embodiment, it is sufficient for at least one of the ink droplets DMF and DSF to be ejected.

[0066] (Third discharge mode) In the first dispensing mode described above, ink droplets DMF and DSF are dispensed, along with ink droplet DLF which is larger than the size of ink droplet DLG, but the dispensing mode is not limited to this. In the third dispensing mode, ink droplets DMF and DSF are dispensed, along with ink droplet DLF which is smaller than the size of ink droplet DLG. In the third dispensing mode, ink droplet DLG corresponds to a first-size droplet, ink droplets DMF and DSF correspond to second-size droplets, and ink droplet DLF corresponds to a third-size droplet. In this case, for example, ink droplet DLG may be an extra-large droplet, and ink droplet DLF may be a large droplet.

[0067] Thus, according to the third dispensing mode, ink droplets DLF, which are smaller than the size of ink droplet DLG, can be dispensed, thereby suppressing ink droplet bleeding in the non-permeable medium W2.

[0068] (Fourth discharge pattern) In the first ejection mode described above, when an ink droplet DLF is ejected, a higher voltage is applied to the drive elements 27, 28, and 29 than when an ink droplet DLG is ejected, but this is not limited to this. In the fourth ejection mode, an ink droplet DLF may be formed based on an ejection waveform different from the ejection waveform that forms the ink droplet DLG.

[0069] Figure 8 is a flowchart showing the processing flow in the printing device 101. As shown in Figure 8, the second control device 50 acquires the instruction information described above (step S1). The second control device 50 changes the platen 11 to the platen height specified on the designation screen. Next, the second control device 50 transports the platen 11 from the support position Ps to the printing position Pp (step S2).

[0070] Next, the second control device 50 obtains position information from sensor Ca indicating the height position of the permeable medium W1 or the non-permeable medium W2 (step S3). The second control device 50 then determines whether the printing target indicated in the instruction information is the permeable medium W1, for example, from the information of "DTG (Direct to garment) printing" and "DTF (Direct to film) printing" selected in the designation unit Pd1 (step S4). If the printing target is the permeable medium W1 (Yes in step S4), the second control device 50 determines whether the height position of the permeable medium W1 is above a reference value (step S5).

[0071] If the height of the permeable medium W1 is above a reference value (Yes in step S5), the second control device 50 lowers the platen 11 using the spacing change device 47 so that the height is below the reference position (step S6), and continues transporting the platen 11 (step S7). On the other hand, if the height of the permeable medium W1 is not above a reference value (No in step S5), the second control device 50 continues transporting the platen 11 (step S7). Then, the second control device 50 performs an ejection process to eject ink droplets DLG as first-size ink droplets onto the permeable medium W1 (step S8).

[0072] On the other hand, if the printing target is not a permeable medium W1, that is, if the printing target is a non-permeable medium W2 (No in step S4), the second control device 50 determines whether the height position of the non-permeable medium W2 is above a reference value (step S9).

[0073] If the height of the impermeable medium W2 is above a reference value (Yes in step S9), the second control device 50 moves the platen 11 to the support position Ps (step S10). After the user sets the impermeable medium W2 back onto the platen 11, the second control device 50 returns to the process in step S2 described above and repeats the subsequent processes.

[0074] On the other hand, if the height of the impermeable medium W2 is not above a reference value (No in step S9), the second control device 50 continues transporting the platen 11 (step S11). The second control device 50 then performs an ejection process to eject ink droplets of second size, such as ink droplet DMF and ink droplet DSF, to the impermeable medium W2, and ink droplet DLF as a third size (step S12). If the sensor Ca is an infrared sensor or the like, S3 is omitted, and it is determined in S5 and S9 whether a signal from the infrared sensor has been received. If the second control device 50 determines that a signal has been received, S6 and S10 are executed, respectively.

[0075] In this embodiment, when printing is performed on a non-permeable medium W2, the spacing between the nozzle surfaces NM1, NM2, NM3 and the platen 11 is reduced by the spacing adjustment device 47 compared to when printing is performed on a permeable medium W1. This improves the accuracy of ink droplet placement and thus improves print quality.

[0076] Furthermore, in this embodiment, when printing is performed on a non-permeable medium W2, for example, if the non-permeable medium W2 is supported by the platen 11 in a tilted state, and only a portion of the height of the non-permeable medium W2 is above the reference position, the platen 11 is not lowered by the spacing change device 47. This is to avoid the gap between the remaining portion of the non-permeable medium W2 and the nozzle surfaces NM1, NM2, and NM3 becoming larger if the platen 11 supporting the non-permeable medium W2 in the tilted state is lowered. If the gap between the remaining portion and the nozzle surfaces NM1, NM2, and NM3 becomes larger in this way, the ejected ink droplets will not spread easily on the non-permeable medium W2, which may cause the misalignment of the landing position to be more noticeable than with permeable medium W1. Therefore, in this embodiment, when printing is performed on a non-permeable medium W2 and the height is above the reference position, the platen 11 is moved to the support position Ps without being lowered. This allows the user to readjust the non-permeable medium W2 on the platen 11 so that it is in the correct position. On the other hand, when printing is performed on the permeable medium W1 and the height position is above a predetermined reference position, the platen 11 is lowered by the spacing change device 47. This reduces the possibility that the permeable medium W1 may come into contact with the nozzle surfaces NM1, NM2, and NM3.

[0077] Furthermore, in this embodiment, the user can transmit the above-mentioned instruction information from an application on an external device, such as an image processing device 102. Therefore, the instruction information can be easily transmitted.

[0078] This disclosure is not limited to the embodiments described above, and the following modifications may be adopted without departing from the gist of this disclosure.

[0079] In the above embodiment, when printing is performed on the permeable medium W1, medium and small ink droplets may be ejected along with the large ink droplet DLG.

[0080] In the above embodiment, if a base layer is formed by discharging white ink onto the permeable medium W1 and the non-permeable medium W2, this disclosure may not apply. Similarly, if color ink is discharging onto the permeable medium W1 and the non-permeable medium W2, this disclosure may not apply.

[0081] Furthermore, in the above embodiment, when the distance between the nozzle surfaces NM1, NM2, NM3 and the platen 11 was changed, the platen 11 was moved in the vertical direction Dz by the distance changing device 47, but this is not limited to this. The head 20 may be moved in the vertical direction Dz by one distance changing device. Alternatively, the head 20 may be moved in the vertical direction Dz by one distance changing device, and the platen 11 may be moved in the vertical direction Dz by the other distance changing device.

[0082] Furthermore, in the above embodiment, the second control device 50 may acquire instruction information by having the user input instruction information in advance in the printing system 100 regarding whether the printing medium W is a permeable medium W1 or a non-permeable medium W2. Alternatively, an imaging device provided in the printing system 100 may image the printing medium W before printing, and the second control device 50 may acquire the imaging result from the imaging device as the instruction information.

[0083] Furthermore, although the above embodiment describes a configuration in which the medium to be printed W is transported in the transport direction Dy by the platen 11 supporting the medium to be printed W reciprocating in the transport direction Dy, the embodiment is not limited to this. A roll-shaped transfer film as the medium to be printed W may be transported on the platen by transport rollers. In this embodiment, the image printed on the medium to be printed W is transferred to the transfer medium by the thermal transfer device. In this embodiment, when a process is performed to change the distance between the nozzle surface of the discharge head and the platen, the discharge head may be moved up and down, the platen may be moved up and down, or both the discharge head and the platen may be moved up and down.

[0084] Furthermore, in the above embodiment, a configuration was adopted in which a first head 21, a second head 22, and a third head 23 were provided as multiple heads 20, but the invention is not limited to this. In the printing apparatus 101 of the above embodiment, it is sufficient that at least the third head 23 is provided. [Explanation of symbols]

[0085] 11 Platen 20 inkjet heads 24, 25, 26 nozzles 27, 28, 29 Driving elements 31, 32, 33 Pressure chambers 40 Conveying device 47 Interval change device 50 Second control device 52 Second communication interface 61 First control device 70 Control device 100 Printing Systems 101 Printing device 102 Image Processing Device DLF, DMF, DSF ink droplets NM1, NM2, NM3 nozzle surfaces Pp Print position Ps support position W Printing medium W1 Permeable media W2 Non-permeable media

Claims

1. A discharge head having a nozzle provided on the nozzle surface for discharging droplets, A control device is provided, The control device is A process to obtain instruction information indicating whether to print on a permeable medium to be printed on, or a non-permeable medium to be transferred to the printing target, When printing on the permeable medium based on the instruction information, the process involves ejecting a first-size droplet from the nozzle, A printing apparatus that, when printing on the non-permeable medium based on the instruction information, performs the process of ejecting droplets of a second size smaller than the first size from the nozzle.

2. The printing apparatus according to claim 1, wherein the control device, when printing on the non-permeable medium, discharges droplets of the second size and droplets of a third size larger than the second size from the nozzle.

3. The aforementioned second size includes multiple different sizes, The printing apparatus according to claim 1, wherein the control device, when printing on the non-permeable medium, discharges droplets of the plurality of sizes as the second size from the nozzle.

4. The printing apparatus according to claim 1, wherein the control device, when printing on the non-permeable medium, discharges droplets of a third size, which are larger than the first size, from the nozzle.

5. The discharge head has a pressure chamber provided for each nozzle and a drive element that applies discharge pressure to the pressure chamber. The printing apparatus according to claim 4, wherein the control device applies a higher voltage to the drive element when ejecting droplets of the third size from the nozzle than when ejecting droplets of the first size.

6. The printing apparatus according to claim 1, wherein the control device, when printing on the non-permeable medium, discharges droplets of the second size and droplets of the third size which are larger than the second size and smaller than the first size from the nozzle.

7. A platen on which the permeable medium or the non-permeable medium is placed, The system further includes a spacing adjustment mechanism for changing the distance between the nozzle surface and the platen, The printing apparatus according to claim 1, wherein the control device changes the interval by the interval changing mechanism so that the interval is smaller when printing on the non-permeable medium compared to when printing on the permeable medium.

8. A platen on which the permeable medium or the non-permeable medium is placed, A spacing changing mechanism for changing the distance between the nozzle surface and the platen, The system further comprises a conveying mechanism for conveying the platen from a support position on which the permeable medium or the non-permeable medium is supported on the platen to a printing position on which the permeable medium or the non-permeable medium supported on the platen faces the discharge head, The control device is During transport from the support position to the printing position, position information indicating the height position of the permeable medium or the non-permeable medium supported by the platen is acquired. When printing on the permeable medium, if the height position obtained during transport is above a predetermined reference position, the platen is lowered by the spacing changing mechanism so that the height position is below the reference position, and transport continues. The printing apparatus according to claim 1, wherein when printing on the non-permeable medium, if the height position obtained during transport is greater than or equal to the reference position, the transport mechanism moves the platen to the support position.

9. It is further equipped with a communication device that communicates with external devices, The printing apparatus according to claim 1, wherein the control device acquires the instruction information transmitted from the external device via the communication device.

10. The system obtains instruction information indicating whether to print on a permeable medium that is the target of printing, or on a non-permeable medium that is the transfer medium to the target of printing. When printing on the permeable medium based on the instruction information, a first-size droplet is ejected from a nozzle provided on the nozzle surface of the ejection head. A printing method in which, when printing on the non-permeable medium based on the instruction information, droplets of a second size smaller than the first size are ejected from the nozzle.

11. A printing program to be executed by a computer in a printing apparatus comprising a discharge head having a nozzle provided on the nozzle surface for ejecting droplets, and a computer, To the aforementioned computer, A step of obtaining instruction information indicating whether to print on a permeable medium that is the target of printing, or a non-permeable medium that is the transfer medium to the target of printing, When printing on the permeable medium based on the instruction information, the steps include: discharging a first-size droplet from a nozzle provided on the nozzle surface of the discharge head; When printing on the non-permeable medium based on the instruction information, the steps include: discharging a second-size droplet smaller than the first size from the nozzle; A printing program that executes the print command.

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