Printing apparatus and printing method

Abstract

The invention relates to a printing apparatus and a printing method. And the image printing quality is improved. A mixing section belonging to an overlapping section of a first position in a second direction with respect to the first head and a mixing section belonging to an overlapping section of the first position with respect to the second head are arranged in a first order in such a manner that positions in the second direction are different. A mixing section of the first head belonging to an overlapping section located at a second position in the second direction and a mixing section of the second head belonging to the overlapping section located at the second position are arranged in a second order symmetrical to the first order in such a manner that positions in the second direction are different.

Description

Technical Field

[0001] The present disclosure relates to a printing device and a printing method. Background Art

[0002] Patent Document 1 discloses a printer equipped with an inkjet head. Multiple chips ejecting the same color ink are arranged in a staggered pattern, partially overlapping. Specifically, Patent Document 1 discloses a structure that suppresses banding by staggering the positions of the mixing areas (corresponding to the "mixing area" in this disclosure) of the respective colors within the same overlapping region (corresponding to the "overlapping area" in this disclosure) when viewed in the conveyance direction of the recording medium.

[0003] Patent Document 1: Japanese Patent Application Laid-Open No. 2015-150828

[0004] In the structure disclosed in Patent Document 1, the staggered manner of the positions of the mixed areas of each color is certain. In the case of such a structure, the time difference between the timing of ejecting the first color ink from both sides of the two overlapping chips and the timing of ejecting the second color ink from one of the other two overlapping chips is different according to the position of the overlapping area. It should be noted that the position of the overlapping area mentioned here refers to the position observed from the conveying direction of the recording medium. Therefore, in the above document, the difference in the landing timing of the first color ink and the second color ink is different according to the position of the overlapping area. Therefore, there is a problem that in a part of the overlapping area, stripes with different characteristics from the stripes generated in other overlapping areas are generated, and the stripes are obvious. Therefore, there is a need for a technology to further improve the printing quality of the image. Summary of the Invention

[0005] The printing device disclosed herein comprises: a head unit capable of ejecting multiple liquids; and a control unit for controlling the ejection of the liquids from the head unit, wherein the head unit comprises at least a first head and a second head as a plurality of heads, the first head comprising three or more chips each having a nozzle array consisting of nozzles capable of ejecting a first liquid, the second head comprising three or more chips each having a nozzle array consisting of nozzles capable of ejecting a second liquid, the first head and the second head being arranged at intervals in a first direction, the configuration of the three or more chips of the first head in the first head and the configuration of the three or more chips of the second head in the second head being the same, the three or more chips being arranged in a staggered manner in a second direction intersecting the first direction in such a way that adjacent chips have overlapping sections when viewed from the first direction, the overlapping section in the first head and the overlapping section in the second head being arranged at intervals from the first direction. When viewed in the first direction, they overlap, and the control unit controls the ejection of the liquid in such a manner that the overlapping interval includes a mixing interval for ejecting the liquid from both sides of the two adjacent chips and a non-mixing interval for ejecting the liquid from only one side of the chip. The mixing interval belonging to the overlapping interval located at the first position in the first head and the mixing interval belonging to the overlapping interval located at the first position in the second head are arranged in a first order in such a manner that their positions are different in the second direction. The mixing interval belonging to the overlapping interval located at the second position in the first head and the mixing interval belonging to the overlapping interval located at the second position in the second head are arranged in a second order symmetrical to the first order in such a manner that their positions are different in the second direction. The first position and the second position are the respective positions of the two overlapping intervals connected in the second direction in the second direction.

[0006] The present disclosure relates to a method for printing a pattern, which is a method for printing a pattern using the printing device, wherein a set of chips arranged at a first position in the first direction among the chips arranged in a staggered manner on the head is set as a first chip group, and a set of chips arranged at a second position in the first direction is set as a second chip group. The method for printing a pattern comprises: a first ejection step of ejecting color ink from the nozzles of the first chip group, which belong to an interval other than the overlapping interval, the nozzles belonging to the mixed interval, and the nozzles belonging to the non-mixed interval in the chip on one side; and a second ejection step of ejecting the color ink from the nozzles of the second chip group, which belong to an interval other than the overlapping interval, the nozzles belonging to the mixed interval, and the nozzles belonging to the non-mixed interval in the chip on one side. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 This is a schematic configuration diagram of a printing system according to an embodiment.

[0008] Figure 2 is a schematic diagram showing the structure of the head unit.

[0009] Figure 3 It is a schematic diagram showing the arrangement of a mixing section according to a comparative example.

[0010] Figure 4 It is a schematic diagram showing the arrangement of a mixing section according to a comparative example.

[0011] Figure 5 It is a schematic diagram showing the configuration of the mixing section involved in the embodiment.

[0012] Figure 6 It is a schematic diagram showing the configuration of the mixing section involved in the embodiment.

[0013] Figure 7 This is a schematic block diagram of a control system of a printing system according to an embodiment.

[0014] Figure 8 This is an explanatory diagram of the nozzles driven during printing.

[0015] Figure 9 This is a schematic diagram showing an example of a pattern printed on a recording medium.

[0016] Figure 10 It is a schematic diagram showing the arrangement of a mixing section according to a modification of the embodiment.

[0017] Figure 11 This is a schematic diagram showing an example of a pattern printed on a recording medium.

[0018] Figure 12 It is a schematic diagram showing the arrangement of a mixing section according to a modification of the embodiment.

[0019] Figure 13 It is a schematic diagram showing the arrangement of a mixing section according to a comparative example.

[0020] Description of Reference Numerals

[0021] 1: Printing system; 2: Terminal device; 3: Printing device; 11: Head unit; 12: Media conveying path; 13: Conveyor unit; 14: Imprint unit; 15: Guide roller; 16: Drive roller; 17: Conveyor belt; 18: Conveyor motor; 21-24: Head; 31-34: Nozzle; 211-214: Chip; 221-224: Chip; 231-234: Chip; 241-244: Chip; 400: Processor; 402: Application program; 403: Printer driver; 410: Memory; 420: Communication interface; 500: Processor; 510: Memory; 520: Communication interface; 550: Control unit; 551: Image processing unit; 552: printing control unit; A: printing position; B: conveying direction; C: cross direction; Mb1~Mb3: mixed interval; Mc1~Mc3: mixed interval; Mm1~Mm3: mixed interval; My1~My3: mixed interval; Nb11~Nb12: non-mixed interval; Nc11~Nc12: non-mixed interval; Nm11~Nm12: non-mixed interval; Ny11~Ny12: non-mixed interval; OL1~OL3: overlapping interval; P211~P214: color block; P221~P224: color block; P231~P234: color block; P241~P244: color block; Q: recording medium. DETAILED DESCRIPTION

[0022] Hereinafter, about embodiment, it is described while referring to accompanying drawing. For the purpose of clear explanation, the following description and accompanying drawing are appropriately omitted and simplified. In addition, in each accompanying drawing, the same figure mark is marked for the same element, and repeated description is omitted as needed. It should be noted that, in the present disclosure, the expression "adjacent" is used not only when there is no element of a different type from the two elements between two elements, but also when there is an element of a different type from the two elements between two elements. In addition, in the present disclosure, the expression "connected" is used not only when there is no element of a different type from the multiple elements between multiple elements, but also when there is an element of a different type from the multiple elements between multiple elements.

[0023] Printing system

[0024] Figure 1 1 is a schematic diagram of a printing system 1 according to an embodiment of the present invention. The printing system 1 includes a terminal device 2 and a printing device 3 connected to the terminal device 2 so as to be communicable therewith.

[0025] The printing device 3 includes a head unit 11 capable of ejecting various liquids; a media transport path 12 extending through a printing position A of the head unit 11; and a conveyor unit 13, which is a conveying mechanism that conveys a recording medium Q in a conveying direction B along the media transport path 12. The conveyor unit 13 is mounted on a platen unit 14, which is positioned vertically below the head unit 11 and faces the head unit 11 with a predetermined gap therebetween. The conveyor unit 13 includes an endless conveyor belt 17 mounted on a plurality of guide rollers 15 and a drive roller 16, and a conveyor motor 18 that rotates the conveyor belt 17 by rotating the drive roller 16. The conveyor motor 18 drives the recording medium Q at a constant speed.

[0026] head unit

[0027] Figure 2 Schematic diagram showing the structure of the head unit 11. Figure 2 As shown, the head unit 11 includes four line inkjet heads, namely, head 21, head 22, head 23, and head 24, arranged at predetermined intervals along the conveying direction B of the recording medium Q. That is, the heads 21, head 22, head 23, and head 24 are arranged at intervals in the conveying direction B. For example, these heads are arranged at equal intervals. The heads 21, head 22, head 23, and head 24 are each capable of ejecting liquid. In this embodiment, specifically, the head 21 located at the most upstream end of the conveying direction B ejects black ink, and the head 22 on its downstream side ejects cyan ink. In addition, the head 23 on the downstream side of the head 22 ejects magenta ink, and the head 24 on its downstream side ejects yellow ink.

[0028] Each of the heads 21, 22, 23, and 24 includes N chips arranged in a cross direction C that intersects the conveying direction B. Specifically, in this embodiment, N is 4. That is, each of the heads 21, 22, 23, and 24 includes four chips. It should be noted that in this embodiment, the value of N is 4, but is not limited to 4; any integer greater than 3 may be used. Furthermore, in more detail, the cross direction C is a direction perpendicular to the conveying direction B.

[0029] In this embodiment, specifically, the head 21 has a chip 211, a chip 212, a chip 213, and a chip 214. These four chips 211, 212, 213, and 214 are arranged in a staggered manner along the cross direction C. In other words, the four chips 211, 212, 213, and 214 are arranged in front of and behind each other in the conveying direction B. Therefore, the chips of the head 21 are divided into two chip groups as follows. The first chip group of the head 21 is a collection of chips arranged at a prescribed position in the conveying direction B, specifically, a chip group consisting of the chip 211 and the chip 213. In addition, the second chip group of the head 21 is a collection of chips arranged at a position in the conveying direction B that is different from the above-mentioned prescribed position, specifically, a chip group consisting of the chip 212 and the chip 214.

[0030] In addition, the four chips 211, 212, 213, and 214 partially overlap each other when viewed from the conveying direction B. That is, the chips provided by the head 21 are arranged in such a manner that the adjacent chips have overlapping sections when viewed from the conveying direction B. Here, the overlapping section refers to the section where two chips belonging to the same head overlap when viewed from the conveying direction B. Specifically, Figure 2 As shown, the chips 211 and 212 are arranged with an overlapped section OL1. In addition, the chips 212 and 213 are arranged with an overlapped section OL2. Furthermore, the chips 213 and 214 are arranged with an overlapped section OL3.

[0031] Similarly, the head 22 has chips 221, 222, 223, and 224 arranged in a staggered pattern. Therefore, the head 22 has a first chip group consisting of the chips 221 and 223 arranged at predetermined positions in the conveying direction B, and a second chip group consisting of the chips 222 and 224 arranged at other positions in the conveying direction B. The chips provided by the head 22 also partially overlap with each other when viewed from the conveying direction B. Specifically, as Figure 2 As shown, the chips 221 and 222 are arranged with an overlapped section OL1. In addition, the chips 222 and 223 are arranged with an overlapped section OL2. Furthermore, the chips 223 and 224 are arranged with an overlapped section OL3.

[0032] Similarly, the head 23 has chips 231, 232, 233, and 234 arranged in a staggered pattern. Therefore, the head 23 has a first chip group consisting of the chips 231 and 233 arranged at predetermined positions in the conveying direction B, and a second chip group consisting of the chips 232 and 234 arranged at other positions in the conveying direction B. The chips provided by the head 23 are also arranged so that adjacent chips partially overlap each other when viewed from the conveying direction B. Specifically, as Figure 2 As shown, the chips 231 and 232 are arranged with an overlapped section OL1. In addition, the chips 232 and 233 are arranged with an overlapped section OL2. Furthermore, the chips 233 and 234 are arranged with an overlapped section OL3.

[0033] Similarly, the head 24 has chips 241, 242, 243, and 244 arranged in a staggered pattern. Therefore, the head 24 has a first chip group consisting of the chips 241 and 243 arranged at predetermined positions in the conveying direction B, and a second chip group consisting of the chips 242 and 244 arranged at other positions in the conveying direction B. The chips provided by the head 24 are also arranged so that adjacent chips partially overlap each other when viewed from the conveying direction B. Specifically, as Figure 2 As shown, the chips 241 and 242 are arranged in a manner that has an overlap section OL1. In addition, the chips 242 and 243 are arranged in a manner that has an overlap section OL2. Furthermore, the chips 243 and 244 are arranged in a manner that has an overlap section OL3.

[0034] It should be noted that, in more detail, in the overlapping intervals OL1 and OL3, the left end of the chip on the upstream side of each head overlaps with the right end of the chip on the downstream side when viewed from the upstream side of the conveying direction B. It should be noted that the conveying direction B refers to a direction in which the recording medium Q is conveyed (in the case of the recording medium Q). Figure 2 In the direction from right to left in the conveying direction B), it is obvious that "viewed from the conveying direction B" means "viewed from the upstream side of the conveying direction B". Therefore, hereinafter, "viewed from the upstream side of the conveying direction B" will be referred to as "viewed from the conveying direction B". For example, in the case of the head 21, in the overlapping interval OL1, the left end of the chip 211 on the upstream side of the conveying direction B overlaps with the right end of the chip 212 on the downstream side, and in the overlapping interval OL3, the left end of the chip 213 on the upstream side of the conveying direction B overlaps with the right end of the chip 214 on the downstream side. In contrast, it can be said that in the overlapping interval OL2, when viewed from the conveying direction B, the right end of the chip on the upstream side of each head overlaps with the left end of the chip on the downstream side. It should be noted that Figure 2This is just an example of the structure of the head unit 11. In each head, the positions of the first chip group and the second chip group in the conveying direction B may be different. Figure 2 The opposite position to the one shown.

[0035] From the above description about heads 21 to 24 and Figure 2 It can also be seen that the configuration of the four chips of head 21 in head 21, the configuration of the four chips of head 22 in head 22, the configuration of the four chips of head 23 in head 23, and the configuration of the four chips of head 24 in head 24 are common. That is, these configurations are the same. It should be noted that, as mentioned above, in this embodiment, the number of chips possessed by each head is not limited to four, so when the number of chips possessed by each head is set to N, the following can be described for all integers n that satisfy 1≤n≤N-1. The nth overlapping interval in head 21, the nth overlapping interval in head 22, the nth overlapping interval in head 23, and the nth overlapping interval in head 24 exist in the same position in the cross direction C. In other words, the nth overlapping interval of each head along the cross direction C exists in the same position when viewed from the conveying direction B. In other words, the nth overlapping interval of each head along the cross direction C overlaps when viewed from the conveying direction B. It should be noted that, in the present disclosure, it is assumed that when viewed from the conveying direction B, the Figure 2 The overlapping sections are counted sequentially from the top of the head. Specifically, the rightmost overlapping section when viewed in the conveying direction B is called the first overlapping section. Thus, the nth overlapping section, counted from the right when viewed in the conveying direction B, exists in the same position in all heads when viewed in the conveying direction B. Therefore, overlapping section OL1 can be considered common to all heads. The same applies to overlapping sections OL2 and OL3.

[0036] As described later Figure 4 or Figure 6As shown, each chip of each head has a plurality of nozzles arranged in the cross direction C. The plurality of nozzles of each chip are arranged in a staggered manner along the cross direction C. In other words, the plurality of nozzles of each chip are arranged in front and back in the conveying direction B to form a nozzle column. Specifically, the nozzles 31 of each of the chips 211, 212, 213, and 214 of the head 21 are nozzles that eject black ink onto the recording medium Q. In addition, the nozzles 32 of each of the chips 221, 222, 223, and 224 of the head 22 are nozzles that eject cyan ink onto the recording medium Q. The nozzles 33 of each of the chips 231, 232, 233, and 234 of the head 23 are nozzles that eject magenta ink onto the recording medium Q. Furthermore, the nozzles 34 of each of the chips 241, 242, 243, and 244 of the head 24 are nozzles that eject yellow ink onto the recording medium Q. The arrangement of the nozzles 31 in the head 21, the arrangement of the nozzles 32 in the head 22, the arrangement of the nozzles 33 in the head 23, and the arrangement of the nozzles 34 in the head 24 are common. That is, these arrangements are the same.

[0037] Comparative Example

[0038] Next, a comparative example that was one of the triggers for considering the present embodiment will be described. Outside the overlapping interval, any color ink is ejected from only one chip. In contrast, in the overlapping interval, color ink can be ejected from both sides of the two overlapping chips. Here, in the overlapping interval, the interval in which color ink is ejected from both sides of the two chips is referred to as a mixed interval. In more detail, the mixed interval refers to an interval defined as being within the overlapping interval when viewed from the conveying direction B, that is, an interval in which color ink is ejected from both sides of two adjacent chips arranged in a manner having the overlapping interval. In contrast, in the overlapping interval, the interval in which color ink is ejected from only one chip of the two adjacent chips is referred to as a non-mixed interval. It should be noted that the mixed interval may also be referred to as an interval in which an image is formed on the recording medium Q by ejecting ink from two chips in the overlapping interval. In addition, the non-mixed interval may also be referred to as an interval in which an image is formed on the recording medium Q by ejecting ink from one chip in the overlapping interval.

[0039] Figure 3 Schematic diagram showing the configuration of the mixing section involved in the comparative example. Figure 3 and the following Figure 5 、 Figure 10 、 Figure 12 as well as Figure 13 In the figure, the area where the nozzles belonging to the mixing section of each chip are distributed is filled in and shown, and the area outside this area where ink is ejected is shaded. Therefore, the area that is not filled in or shaded represents the area where the nozzles are distributed that are not used. Figure 4 and Figure 3Likewise, it is a schematic diagram showing the arrangement of the mixing section according to the comparative example, and in particular, it is a schematic diagram showing the arrangement of the mixing section in the overlapping section OL1.

[0040] It should be noted that, as described above, in the non-mixing interval within the overlapping interval, color ink is ejected from only one of the two overlapping chips. Specifically, the chip that ejects color ink in the non-mixing interval is the chip whose non-mixing interval is set to be closer to the center side of the chip than the mixing interval in the two overlapping chips. This is also the same in the embodiment. It should be noted that, in more detail, the center side of the chip refers to the center of the chip in the intersection direction C. Regarding the chip that ejects ink in the non-mixing interval, refer to Figure 4 This will be described in more detail.

[0041] like Figure 4 As shown, the overlapping section OL1 of the head 21 includes, in addition to the mixing section Mb1, a non-mixing section Nb11 and a non-mixing section Nb12. Here, the non-mixing section Nb11 is located closer to the center of the chip 211 than the mixing section Mb1 in the chip 211, and closer to the front end of the chip 212 than the mixing section Mb1 in the chip 212. Furthermore, the non-mixing section Nb12 is located closer to the front end of the chip 211 than the mixing section Mb1 in the chip 211, and closer to the center of the chip 212 than the mixing section Mb1 in the chip 212. Therefore, the chip that ejects black ink in the non-mixing section Nb11 is the chip 211 in the overlapping two chips 211 and 212, where the non-mixing section Nb11 is set closer to the center of the chip than the mixing section Mb1. Furthermore, the chip that ejects black ink in non-mixing section Nb12 is the chip 212 that is located closer to the center of the chip than the mixing section Mb1, among the two overlapping chips 211 and 212. In other words, among the non-mixing sections Nb11 and Nb12 included in the overlapping section OL1 of the head 21, the chip 211 ejects color ink in the non-mixing section Nb11, which is continuous with the non-overlapping section OL1 of the chip 211. The chip 212 ejects color ink in the non-mixing section Nb12, which is continuous with the non-overlapping section OL1 of the chip 212.

[0042] Similarly, the chip that ejects cyan ink in the non-mixing section Nc11 of the head 22 during the overlap section OL1 is the chip 221 of the two overlapping chips 221 and 222, where the non-mixing section Nc11 is set closer to the center of the chip than the mixing section Mc1. Furthermore, the chip that ejects cyan ink in the non-mixing section Nc12 of the head 22 during the overlap section OL1 is the chip 222 of the two overlapping chips 221 and 222, where the non-mixing section Nc12 is set closer to the center of the chip than the mixing section Mc1. Furthermore, the chip that ejects magenta ink in the non-mixing section Nm11 of the head 23 during the overlap section OL1 is the chip 231 of the two overlapping chips 231 and 232, where the non-mixing section Nm11 is set closer to the center of the chip than the mixing section Mm1. Furthermore, the chip that ejects magenta ink in the non-mixing section Nm12 of head 23 during overlap section OL1 is chip 232, of the two overlapping chips 231 and 232, whose non-mixing section Nm12 is set closer to the center of the chip than the mixing section Mm1. Furthermore, the chip that ejects yellow ink in the non-mixing section Ny11 of head 24 during overlap section OL1 is chip 241, of the two overlapping chips 241 and 242, whose non-mixing section Ny11 is set closer to the center of the chip than the mixing section My1. Furthermore, the chip that ejects yellow ink in the non-mixing section Ny12 of head 24 during overlap section OL1 is chip 242, of the two overlapping chips 241 and 242, whose non-mixing section Ny12 is set closer to the center of the chip than the mixing section My1. The above description focuses on the chips that eject ink in the non-mixing section of overlap section OL1, and the same description applies to the other overlapping sections.

[0043] In the comparative example, the mixing sections of each head are staggered in the cross direction C according to the same rule. Figure 3 and Figure 4 As shown, each mixing interval is configured as follows. It should be noted that, in the comparative example and the embodiment, each overlapping interval includes four partial intervals that do not overlap with each other, and the mixing interval is configured in any partial interval. It should be noted that, in the present disclosure, regarding these four partial intervals, when viewed from the upstream side of the conveying direction B, from the right side in order, that is, from Figure 3 as well as Figure 4The upper side of the is sequentially referred to as the first, second, third, and fourth partial intervals. In overlapping interval OL1, mixing interval Mb1 of head 21 is placed in the fourth partial interval of overlapping interval OL1. Furthermore, in overlapping interval OL1, mixing interval Mc1 of head 22 is placed in the third partial interval, mixing interval Mm1 of head 23 is placed in the second partial interval, and mixing interval My1 of head 24 is placed in the first partial interval. Similarly, in overlapping interval OL2, mixing interval Mb2 of head 21 is placed in the fourth partial interval, mixing interval Mc2 of head 22 is placed in the third partial interval, mixing interval Mm2 of head 23 is placed in the second partial interval, and mixing interval My2 of head 24 is placed in the first partial interval. Furthermore, in the overlapping interval OL3, the mixing interval Mb3 of head 21 is arranged in the fourth partial interval, the mixing interval Mc3 of head 22 is arranged in the third partial interval, the mixing interval Mm3 of head 23 is arranged in the second partial interval, and the mixing interval My3 of head 24 is arranged in the first partial interval. In this way, the positions of the mixing areas of each color are staggered in a fixed manner.

[0044] As in the comparative example, staggering the mixed sections for each color in the overlapping sections can suppress the occurrence of banding. However, even in the comparative example, it is difficult to completely eliminate banding. The following issues still exist regarding the occurrence of banding in the mixed section configuration involved in the comparative example.

[0045] exist Figure 3 In FIG. 1 , arrows 91 to 96 represent the actual distance between the nozzles ejecting ink of the first head and the nozzles ejecting ink of the second head in a portion of the mixing interval where either the first head or the second head exists. It should be noted that the first head and the second head are adjacent heads. Figure 3 In the example, head 22 and head 23 are the first and second heads. Here, we focus on head 22 and head 23 for discussion, and the following also applies to other adjacent head pairs. It should be noted that, Figure 3 and the following Figure 5 、 Figure 10 、 Figure 12 and Figure 13 In the figure, when arrows indicating distances are shown, for two chips ejecting the same color ink, the midpoint between these chips is used as the actual nozzle position, and the arrows are shown.

[0046] like Figure 3As shown, arrows 93 and 94 in the overlap section OL2 are shorter than arrows 91, 92, 95, and 96 in the overlap sections OL1 and OL3. This means that in the overlap section OL2, the time interval from when the ink ejected from the head 22 (i.e., cyan ink) lands on the recording medium Q to when the ink ejected from the head 23 (i.e., magenta ink) lands on the recording medium Q is different from that in the other overlap sections. Specifically, in Figure 3 In the example shown, the landing intervals in the overlapping interval OL2 are shorter than those in the other overlapping intervals. Thus, because the staggered positions of the mixed areas of each color are constant in the mixing interval configuration shown in the comparative example, the landing intervals in the overlapping interval OL2 differ from those in the other overlapping intervals. Consequently, the overlapping interval OL2 produces stripes with characteristics different from those produced in the overlapping intervals OL1 and OL3, making the stripes more noticeable. Therefore, in this embodiment, a different mixing interval configuration is employed than in the comparative example.

[0047] Figure 5 Schematic diagram showing the configuration of the mixing section involved in the embodiment. Figure 6 and Figure 5 Likewise, it is a schematic diagram showing the arrangement of the mixing sections according to the embodiment, and in particular, it is a schematic diagram showing the arrangement of the mixing sections in the overlapping section OL2.

[0048] In this embodiment, the mixing sections of each head are also staggered in the cross direction C. However, in this embodiment, the positions of the mixing sections in all overlapping sections are not staggered in the same manner, but two symmetrical staggering methods are alternately used in each overlapping section. Specifically, Figure 5 and Figure 6 As shown, each mixing interval is configured as follows.

[0049] In the present embodiment, in the overlapping section OL1, the mixing sections of the heads are arranged in the same manner as in the comparative example. That is, in the overlapping section OL1, the mixing section Mb1 of the head 21 is arranged in the fourth partial section of the overlapping section OL1. Then, in the overlapping section OL1, the mixing section Mc1 of the head 22 is arranged in the third partial section, the mixing section Mm1 of the head 23 is arranged in the second partial section, and the mixing section My1 of the head 24 is arranged in the first partial section. That is, in the overlapping section OL1, the mixing sections of the heads 21, 22, 23, and 24 arranged in the conveying direction B are arranged in such a manner that as the position of the head is located on the downstream side of the conveying direction B, the position of the mixing section is located on the right side when viewed from the upstream side of the conveying direction B. That is, the mixing sections of the heads arranged in the conveying direction B are arranged in order from the left when viewed from the upstream side of the conveying direction B. In this way, in the overlapping section OL1, the following arrangement is adopted: Figure 4The configuration of the mixing interval is shown.

[0050] In contrast, Figure 5 and Figure 6 As shown, in the overlapping section OL2, the mixing sections of each head are arranged symmetrically with the mixing sections in the overlapping section OL1. Specifically, a symmetrical arrangement refers to an arrangement that is line-symmetrical about an axis parallel to the conveying direction B. Specifically, in the overlapping section OL2, the mixing section Mb2 of head 21 is arranged in the first subsection of the overlapping section OL2. Furthermore, in the overlapping section OL2, the mixing section Mc2 of head 22 is arranged in the second subsection, the mixing section Mm2 of head 23 is arranged in the third subsection, and the mixing section My2 of head 24 is arranged in the fourth subsection. In other words, in the overlapping section OL2, the mixing sections of heads 21, 22, 23, and 24 arranged in the conveying direction B are arranged so that, as the head position is downstream in the conveying direction B, the mixing section is positioned to the left when viewed from the upstream side of the conveying direction B. In other words, the mixing sections of the heads arranged in the conveying direction B are arranged sequentially from the right when viewed from the upstream side of the conveying direction B.

[0051] Then, in the overlapping interval OL3, the mixing intervals of each head are arranged in the same manner as in the overlapping interval OL1. That is, in the overlapping interval OL3, the mixing interval Mb3 of the head 21 is arranged in the fourth partial interval of the overlapping interval OL3. Then, in the overlapping interval OL3, the mixing interval Mc3 of the head 22 is arranged in the third partial interval, the mixing interval Mm3 of the head 23 is arranged in the second partial interval, and the mixing interval My3 of the head 24 is arranged in the first partial interval. In this way, the overlapping interval OL3 is also arranged in the same manner as in the overlapping interval OL1. Figure 4 The configuration of the mixing interval is shown.

[0052] It should be noted that in this embodiment, the mixing zone is set to exclude the ends of the overlapping zone (more specifically, the ends in the intersecting direction C), but it can also be set to include the ends of the overlapping zone. That is, in this embodiment, the mixing zone is set to not use the nozzles at the front ends of each chip in the intersecting direction C, but the mixing zone can also be set to use such nozzles.

[0053] the following, Figure 4 The arrangement of the mixing sections shown here is such that, when viewed from the conveying direction B, the mixing sections of each head shift in the order of the fourth section, the third section, the second section, and the first section. Therefore, for the sake of convenience, they are referred to as descending order. Similarly, for the sake of convenience, Figure 6 The configuration of mixed intervals shown is called ascending order.

[0054] Here, the time interval between the landing of the two colors of ink in this embodiment is studied. Figure 5 In FIG. 8 , arrows 81 to 86 represent the actual distance between the nozzles ejecting ink of the first head and the nozzles ejecting ink of the second head in a portion of the mixing interval where either the first head or the second head exists. It should be noted that the first head and the second head are adjacent heads. Figure 5 In the embodiment, the first and second heads 22 and 23 are also paid attention to. Here, the discussion is also conducted with attention to the first and second heads 22 and 23. The following items are also applicable to other adjacent pairs of heads.

[0055] In this embodiment, as described above, a symmetrical arrangement of mixed intervals is adopted for each overlapping interval. That is, in this embodiment, descending order and ascending order are alternately adopted for each overlapping interval. Figure 5 As shown, the lengths of arrows 81 to 86 are all the same. This means that, in the portion of the interval where the mixed interval exists, the time interval from when ink ejected from head 22 lands on recording medium Q to when ink ejected from head 23 lands on recording medium Q is constant, regardless of the overlapping interval. Therefore, the occurrence of peculiar banding, as in the comparative example, can be suppressed.

[0056] When the number of nozzles of each chip is set to N and generalized, in this embodiment, the configuration of the mixing interval has the following characteristics. With respect to all odd numbers i that satisfy 1≤i≤N-1, it can be described as follows. The mixing interval belonging to the i-th overlapping interval in the head 21, the mixing interval belonging to the i-th overlapping interval in the head 22, the mixing interval belonging to the i-th overlapping interval in the head 23, and the mixing interval belonging to the i-th overlapping interval in the head 24 are arranged in a prescribed order in the cross direction C. In particular, these mixing intervals are arranged in a prescribed order in a manner that their positions in the cross direction C are different. In this embodiment, the prescribed order is referred to as a descending order for the sake of convenience. In addition, with respect to all even numbers j that satisfy 1≤j≤N-1, it can be described as follows. The mixing interval belonging to the j-th overlapping interval in the head 21, the mixing interval belonging to the j-th overlapping interval in the head 22, the mixing interval belonging to the j-th overlapping interval in the head 23, and the mixing interval belonging to the j-th overlapping interval in the head 24 are arranged in a symmetrical order in the cross direction C. In particular, these mixing sections are arranged in a symmetrical order so that their positions in the cross direction C differ. Here, the symmetrical order is an order that is symmetrical to the above-described prescribed order, and in this embodiment, it is referred to as an ascending order for convenience. The arrangement of the mixing sections arranged in the prescribed order and the arrangement of the mixing sections arranged in the symmetrical order are line-symmetrical about an axis parallel to the conveying direction B.

[0057] Furthermore, the arrangement of the mixing sections in the head unit 11 can also be described as follows. It should be noted that the positions of two overlapping sections connected in the cross direction C in the cross direction C are referred to as the first position and the second position, and the four heads included in the head unit 11 are referred to as the first head, the second head, the third head, and the fourth head. In this case, it can be said that the four mixing sections of the first to fourth heads belonging to the overlapping section located in the first position are arranged in a first order (prescribed order) with different positions in the cross direction C. Furthermore, it can be said that the four mixing sections of the first to fourth heads belonging to the overlapping section located in the second position are arranged in a second order (symmetrical order) that is symmetrical to the first order with different positions in the cross direction C.

[0058] Furthermore, when each head of the head unit 11 has five or more chips, the arrangement of the mixing sections in the head unit 11 can be described as follows. In this case, since there are four overlapping sections connected in the cross direction C, the positions of these four overlapping sections are referred to as the first position, the second position, the third position, and the fourth position. In this case, as described above, the four mixing sections for the first through fourth heads belonging to the overlapping section located in the first position are arranged in a first order (prescribed order) with different positions in the cross direction C. Furthermore, the four mixing sections for the first through fourth heads belonging to the overlapping section located in the second position are arranged in a second order (symmetrical order) with different positions in the cross direction C. Furthermore, the four mixing sections for the first through fourth heads belonging to the overlapping section located in the third position are arranged in the first order (prescribed order) with different positions in the cross direction C. Furthermore, the four mixing sections for the first through fourth heads belonging to the overlapping section located in the fourth position are arranged in a second order (symmetrical order) with different positions in the cross direction C. In this way, the first order (prescribed order) and the second order (symmetrical order) are repeated for each overlapping interval. It should be noted that the above-mentioned first position, second position, third position, and fourth position are defined in more detail as follows. The first position is the position of the first overlapping interval along the cross direction C among the four overlapping intervals connected in the cross direction C. The second position is the position of the second overlapping interval along the cross direction C among the four overlapping intervals connected in the cross direction C. The third position is the position of the third overlapping interval along the cross direction C among the four overlapping intervals connected in the cross direction C. The fourth position is the position of the fourth overlapping interval along the cross direction C among the four overlapping intervals connected in the cross direction C.

[0059] It should be noted that in this embodiment, there are four head units 11, but the head unit 11 only needs to have two or more heads. In the case where the head unit 11 has two, three, or five or more heads instead of four, the arrangement of the mixing sections can be described in the same way as above.

[0060] In addition, if Figure 4 or Figure 6 As shown, the above descending or ascending order is arranged in a stepped manner in the overlapping interval. Figure 4 or Figure 6 The descending or ascending order shown is the following order. It should be noted that, hereinafter, k is an arbitrary integer satisfying 1≤k≤N-1. The mixed interval belonging to the kth overlapping interval in the header 21 and the mixed interval belonging to the kth overlapping interval in the header 22 are adjacent in the cross direction C. In addition, the mixed interval belonging to the kth overlapping interval in the header 22 and the mixed interval belonging to the kth overlapping interval in the header 23 are adjacent in the cross direction C. Furthermore, the mixed interval belonging to the kth overlapping interval in the header 23 and the mixed interval belonging to the kth overlapping interval in the header 24 are adjacent in the cross direction C.

[0061] In addition, about Figure 4 or Figure 6 The stepped arrangement of the mixing intervals shown in FIG. 1 can also be described as follows as an arrangement of the mixing intervals in a head unit having at least three heads. It should be noted that, here, the three heads of the head unit 11 are referred to as the first head, the second head, and the third head. In this case, two mixing intervals arranged in the first order (prescribed order) or the second order (symmetrical order) of two heads adjacent in the conveying direction B among the first head, the second head, and the third head are adjacent in the cross direction C. For example, Figure 4 As shown, the mixing section Mb1 and the mixing section Mc1 arranged in the first order (prescribed order) of the head 21 and the head 22 adjacent to each other in the conveying direction B are adjacent to each other in the cross direction C. Similarly, the mixing section Mc1 and the mixing section Mm1 arranged in the first order (prescribed order) of the head 22 and the head 23 adjacent to each other in the conveying direction B are adjacent to each other in the cross direction C. Similarly, the mixing section Mm1 and the mixing section My1 arranged in the first order (prescribed order) of the head 23 and the head 24 adjacent to each other in the conveying direction B are adjacent to each other in the cross direction C. Here, referring to Figure 4 Specifically described, Figure 6The same explanation can be applied to the mixing sections arranged in the second order (symmetrical order) as shown. Thus, the control unit 550, described later, sets each mixing section so that two mixing sections arranged in the first or second order for two adjacent heads in the conveying direction B, among the first, second, and third heads, are adjacent in the cross direction C. Consequently, the mixing sections of the heads 21, 22, 23, and 24 arranged in the conveying direction B are positioned downstream in the conveying direction B, and the positions of the mixing sections are staggered in a certain direction when viewed from the upstream side of the conveying direction B. In other words, the mixing sections are arranged in a stepped manner.

[0062] By arranging the mixing area in a stepwise manner, the time interval between the ink landing on the recording medium Q in the mixing section of two adjacent heads in the conveying direction B can be made constant regardless of the combination of the two adjacent heads. Figure 5 In the example, if the time interval between the landing of heads 22 and 23 in the mixing zone indicated by arrows 81 to 86 is set to T, the time interval between the landing of heads 21 and 22 and the time interval between the landing of heads 23 and 24 in the mixing zone are both T. Therefore, for example, even if the heads responsible for cyan and magenta are changed from heads 22 and 23 to heads 23 and 24, the time interval between the landing of these two colors does not change. This allows for flexible handling even if the specifications of the printing apparatus are changed.

[0063] Control systems for printing systems

[0064] Figure 7 This is a schematic block diagram of the control system of the printing system 1 . Figure 8 This is an explanatory diagram of the nozzles driven during printing.

[0065] The terminal device 2 includes a processor 400 , a memory 410 , and a communication interface 420 , and has a function as a computer.

[0066] The memory 410 is composed of, for example, a combination of a volatile memory and a nonvolatile memory. The memory 410 stores programs executed by the processor 400 and data used for various processes. The communication interface 420 is an interface for communicating with the printing device 3 .

[0067] Processor 400 reads and executes programs from memory 410. Processor 400 thereby implements the functions of OS (operating system) 401, application program 402, and printer driver 403. Processor 400 may be, for example, a microprocessor, an MPU (Microprocessor Unit), or a CPU (Central Processing Unit). Processor 400 may also include multiple processors.

[0068] The OS 401 is software that controls the operation of the terminal device 2 . The application 402 is software that creates image data. The printer driver 403 receives the image data from the application 402 via the OS 401 and supplies the image data to the printing device 3 .

[0069] The printing device 3 includes a processor 500 , a memory 510 , and a communication interface 520 , and functions as a computer.

[0070] The memory 510 is composed of, for example, a combination of a volatile memory and a nonvolatile memory. The memory 510 is used to store programs executed by the processor 500 and data used for various processes. The communication interface 520 is an interface for communicating with the terminal device 2.

[0071] The processor 500 reads and executes a program from the memory 510. Thus, the processor 500 realizes the function of the control unit 550. The processor 500 may be, for example, a microprocessor, an MPU, or a CPU. The processor 500 may also include a plurality of processors.

[0072] The communication interface 520 receives image data supplied from the terminal device 2 (printer driver 403 ) and inputs the image data to the processor 500 . The head unit 11 and the conveyance motor 18 are connected to the processor 500 via a device driver (not shown).

[0073] The control unit 550 controls printing. That is, the control unit 550 controls the ejection of liquid (ink) from the head unit 11 and the conveyance of the recording medium Q. In particular, as described above, the control unit 550 controls the ejection of ink so that the overlapping intervals have a mixed interval and a non-mixed interval arranged as described above. In this embodiment, the control unit 550 includes an image processing unit 551 and a printing control unit 552 to control printing. The image processing unit 551 first renders the image data input to the processor 500 and converts each pixel of the image data into RGB data. Here, R represents red, G represents green, and B represents blue. Next, the image processing unit 551 refers to a lookup table and converts the RGB data of each pixel into CMYK data. Here, C represents cyan, M represents magenta, Y represents yellow, and K represents black. Next, the image processing unit 551 performs halftoning processing based on the CMYK data to generate printing data in a format that can be interpreted by the printing device 3. It should be noted that the image processing unit 551 can also adjust the ink ejection volume to suppress banding when generating print data. Print data is a set of instructions for ejecting ink from each nozzle of the head unit 11, indicating which nozzles to drive (i.e., which nozzles eject ink). Print data is also called dot data. Thus, the image processing unit 551 generates print data for driving the nozzles of each head of the head unit 11 based on the image data.

[0074] Specifically, when generating print data, the image processing unit 551 sets the mixing and non-mixing intervals for each overlapping interval as described above. Therefore, for the mixing interval within the overlapping interval, the image processing unit 551 generates print data that drives the nozzles of both adjacent chips. For the non-mixing interval within the overlapping interval and for intervals outside the overlapping interval, the image processing unit 551 generates print data that drives the nozzles of only one of the two adjacent chips.

[0075] In other words, the image processing unit 551 generates print data for driving the nozzles of both adjacent chips for pixels formed in the portion corresponding to the mixed section of the recording medium Q passing through the print position A. Furthermore, the image processing unit 551 generates print data for driving the nozzles of one of the two adjacent chips for pixels formed in the portion corresponding to the non-mixed section or the section other than the overlap section of the recording medium Q passing through the print position A.

[0076] Note that, in order to suppress banding due to individual differences between nozzles, the print data for the drive mixing section may be data for controlling the ratio of the ejection amounts of ink from two adjacent chips as follows. Figure 8 Schematic diagram illustrating the ratio of the ink ejection amount between two adjacent chips. Figure 8 , as a representative of two adjacent chips, a diagram of chip 211 and chip 212 is shown. More specifically, Figure 8 The upper portion schematically shows the periphery of the overlapping section OL1 of the chip 211 and the chip 212 of the head 21. Figure 8 The lower part of is a graph showing the ratio of the ejection amount of the chip 211 and the chip 212. Figure 8 As shown, the image processing unit 551 can also generate the following printing data. It should be noted that, here, the chip ( Figure 8 The chip 211 of the adjacent two chips is called the first chip, and the chip on the other side of the cross direction C ( Figure 8 The chip 212 is referred to as the second chip. The image processing unit 551 may also generate print data such that, during the mixing period, the ejection volume of each nozzle of the first chip decreases as the nozzle is positioned closer to the other side of the intersecting direction C, and, during the same mixing period, the ejection volume of each nozzle of the second chip decreases as the nozzle is positioned closer to the one side of the intersecting direction C. However, this ejection volume control is merely an example, and it is not necessary to control the ejection volume in this manner.

[0077] It should be noted that, in this embodiment, the control unit 550 configures the mixing interval as follows. Figure 4 and Figure 6 As shown in FIG, two mixing sections arranged in the first order (prescribed order) or the second order (symmetrical order) and adjacent in the cross direction C are adjacent without a gap. That is, when viewed from the conveying direction B, no non-mixing section is inserted between such two mixing sections. For example, Figure 4 As shown, the two mixed sections Mb1 and the mixed section Mc1 arranged in the first order and adjacent to each other in the cross direction C are adjacent to each other without a gap in the cross direction C. Similarly, the two mixed sections Mc1 and the mixed section Mm1 arranged in the first order and adjacent to each other in the cross direction C are adjacent to each other without a gap in the cross direction C. Similarly, the two mixed sections Mm1 and the mixed section My1 arranged in the first order and adjacent to each other in the cross direction C are adjacent to each other without a gap in the cross direction C. Here, referring to Figure 4 Specifically described, Figure 6 The mixed intervals arranged in the second order (symmetrical order) as shown can also be explained in the same way. The above features can also be explained as follows. For all integers n that satisfy 1≤n≤N-1, the mixed intervals that are adjacent in the cross direction C and belong to the nth overlapping interval are arranged in an adjacent manner. In this way, by arranging the mixed intervals without gaps, the mixed intervals can be set longer in the overlapping intervals compared to the case where the mixed intervals are arranged with gaps. Therefore, in the mixed interval, as Figure 8 As shown, when the ink ejection volume is reduced according to the position in the cross direction C, the change in the ink ejection volume corresponding to the position can be made smoother. Therefore, banding caused by differences in nozzle performance between two adjacent chips can be more effectively suppressed. In particular, the greater the number of heads mounted on the head unit 11, the more mixing sections should be arranged within the overlapping sections. Therefore, when the number of heads mounted on the head unit 11 is large, as in this embodiment, it is particularly preferable to arrange the mixing sections without gaps.

[0078] When print data is generated, the print control unit 552 drives the transport motor 18 to transport the recording medium Q at a predetermined speed along the medium transport path 12. Furthermore, the print control unit 552 drives the head unit 11 based on the print data to print on the recording medium Q at the print position A. Specifically, the print control unit 552 controls the ejection of ink from each head based on the print data to print on the recording medium Q.

[0079] The above describes the printing device 3 according to the embodiment. Unlike the comparative example described above, the printing device 3 employs a method for staggering the positions of the mixed areas for each color. This prevents the problem of noticeable banding, which can occur when banding with different characteristics occurs in some overlapping intervals compared to banding in other overlapping intervals. Furthermore, since the banding generated in each overlapping interval is of the same level, it is easier to suppress banding by adjusting the ink ejection volume than when banding of varying levels occurs.

[0080] Furthermore, the printing device 3 can print an arbitrary image on the recording medium Q under the control of the control unit 550 , and can also print a check pattern for checking whether the nozzles of the head unit 11 have defects (eg, nozzle clogging).

[0081] Figure 9 It shows that in each overlapping interval Figure 5 When the mixing section and the non-mixing section are arranged in this manner, this is a schematic diagram of an example of a pattern printed on the recording medium Q in order to confirm whether the nozzles of the head unit 11 are defective. More specifically, Figure 9 : is a schematic top view of a recording medium Q printed with a pattern. Figure 9 In the example, the test pattern printed on recording medium Q includes color patches P211 to P214 printed by head 21, color patches P221 to P224 printed by head 22, color patches P231 to P234 printed by head 23, and color patches P241 to P244 printed by head 24. Specifically, color patch P211 is printed by chip 211, color patch P212 is printed by chip 212, color patch P213 is printed by chip 213, and color patch P214 is printed by chip 214. This correspondence between color patches and chips also applies to the other color patches.

[0082] Each color patch is printed by ejecting ink from nozzles belonging to the intervals other than the overlapping interval, nozzles belonging to the mixing interval, and nozzles belonging to the non-mixing interval, i.e., nozzles of the chip responsible for ejecting ink in the non-mixing interval, under the control of the control unit 550. For example, the color patch P211 is printed by ejecting ink from nozzles belonging to the intervals other than the overlapping interval OL1, nozzles belonging to the mixing interval Mb1, and nozzles belonging to the non-mixing interval Nb11, among all the nozzles of the chip 211 (see Figure 4 ). That is, the nozzles of the chip 211 that do not correspond to these nozzles, that is, the nozzles Nb12 in the overlapping section OL1 are not used for printing the test pattern.

[0083] For printing Figure 9 The control unit 550 performs the following control while conveying the recording medium Q using the test pattern shown.

[0084] The control unit 550 first controls the ejection of yellow ink from the nozzles of the chips 241 and 243 of the head 24, which are used to print the color patches P241 and P243. The control unit 550 then controls the ejection of yellow ink from the nozzles of the chips 242 and 244 of the head 24, which are used to print the color patches P242 and P244.

[0085] Next, the control unit 550 controls the nozzles of the chips 231 and 233 of the head 23 to eject magenta ink, which are used to print the patches P231 and P233. Next, the control unit 550 controls the nozzles of the chips 232 and 234 of the head 23 to eject magenta ink, which are used to print the patches P232 and P234.

[0086] Next, the control unit 550 controls the nozzles of the chips 221 and 223 of the head 22 to eject cyan ink from the nozzles used to print the patches P221 and P223. Next, the control unit 550 controls the nozzles of the chips 222 and 224 of the head 22 to eject cyan ink from the nozzles used to print the patches P222 and P224.

[0087] Next, the control unit 550 controls the nozzles of the chips 211 and 213 of the head 21 to eject black ink from the nozzles used to print the color patches P211 and P213. Finally, the control unit 550 controls the nozzles of the chips 212 and 214 of the head 21 to eject black ink from the nozzles used to print the color patches P212 and P214.

[0088] It should be noted that the example shown here shows the test pattern printing in the order of printing the color patches by head 24 (yellow ink), printing the color patches by head 23 (magenta ink), printing the color patches by head 22 (cyan ink), and finally printing the color patches by head 21 (black ink). However, when printing the test pattern on recording medium Q, the order of the colors of the printed color patches can be arbitrary. For example, the test pattern can also be printed in the reverse order, that is, printing the color patches by head 21 (black ink), printing the color patches by head 22 (cyan ink), printing the color patches by head 23 (magenta ink), and finally printing the color patches by head 24 (yellow ink).

[0089] By printing such a test pattern, a test pattern suitable for confirming a defect of a nozzle actually used in the printing device 3 of this embodiment can be obtained. Figure 9 Although the test pattern shown has color patches printed on all heads, color patches may be printed on only some heads, or color patches may be printed on only some chips of some heads.

[0090] Modification

[0091] exist Figure 5 In the arrangement of the mixed intervals shown in FIG, the mixed intervals are arranged in descending order in the overlapping intervals OL1 and OL3, and the mixed intervals are arranged in ascending order in the overlapping interval OL2. Figure 10 As shown, it is also possible to arrange the mixed intervals in the overlapping intervals OL1 and OL3 in ascending order, and arrange the mixed intervals in the overlapping interval OL2 in descending order. In other words, it is sufficient to repeat the ascending and descending order for each overlapping interval. In this case, the lengths of arrows 71 to 76 (i.e., the time intervals between the ink landings) are also the same. It should be noted that when setting Figure 10 In the case of the arrangement of the mixing section shown above, a pattern is printed on the recording medium Q by the printing device 3 to confirm whether the nozzles of the head unit 11 are defective. Figure 11 The test pattern shown.

[0092] In addition, Figure 5 or Figure 10 In the configuration of the mixing intervals shown in FIG, the mixing intervals of each head are arranged in a stepped manner in the same overlapping interval, but they do not need to be arranged in a stepped manner. Figure 12 As shown, mixed intervals can also be configured. Figure 12 The configuration example of the mixed section shown is a modified comparative example. Figure 13 An example of a configuration of a mixing interval is shown. Figure 13 In the example shown, the arrangement of the mixing sections of the heads is not stepped, and the arrangement is the same in any overlapping section. Figure 12 In the example shown, the arrangement of the mixing sections of the heads in the overlapping section OL2 is symmetrical to the arrangement of the mixing sections of the heads in the overlapping section OL1 and the overlapping section OL3.

[0093] exist Figure 12 In FIG. 1 , arrows 61 to 69 indicate the actual distance between the nozzles ejecting ink of one head and the nozzles ejecting ink of the other head in the mixing zone between two heads adjacent in the conveying direction B. Figure 13 In FIG. 5 , arrows 51 to 59 represent the actual distance between the nozzles ejecting ink of one head and the nozzles ejecting ink of the other head in the mixing zone between two heads adjacent in the conveying direction B. Figure 13 As shown, for any head group, the length of the arrow in the overlapping interval OL2 (i.e., the time interval of ink landing) is different from the length of the arrow in the overlapping intervals OL1 and OL3 (i.e., the time interval of ink landing). Figure 12In the example shown, the length of the arrow between the head 21 and the head 22 (i.e., the time interval between the ink landings) is the same regardless of the overlap interval. Figure 12 In the embodiment, the length of the arrow between heads 22 and 23 (i.e., the time interval between ink landings) is the same regardless of the overlap interval, and the length of the arrow between heads 23 and 24 (i.e., the time interval between ink landings) is also the same regardless of the overlap interval. Therefore, as in the above embodiment, the generation of banding can be suppressed. However, in the above embodiment in which the mixing intervals are arranged in a stepwise manner, the time interval between ink landings for any head group is a constant time T, but in Figure 12 In the arrangement example shown, the time intervals (arrows 67, 68, 69) at which the ink of the head 21 and head 22 lands are as follows: Figure 12 As shown, it is different from the group of other heads.

[0094] In the above embodiment, the image processing unit 551 is mounted on the printing device 3. Alternatively, the image processing unit 551 may be provided on the terminal device 2. In this case, the printing device 3 and the terminal device 2 may be collectively referred to as a printing device. In other words, the printing system 1 may also be referred to as a printing device.

[0095] It should be noted that, in the present disclosure, a program includes a set of commands (or software code) that, when loaded into a computer, causes the computer to perform one or more functions described in the embodiments. The program may also be stored on a non-transitory computer-readable medium or a physical storage medium. As non-limiting examples, computer-readable or physical storage media include random-access memory (RAM), read-only memory (ROM), flash memory, solid-state drives (SSDs) or other storage technologies, CD-ROMs, digital versatile disks (DVDs), Blu-ray discs or other optical disks, magnetic cassettes, magnetic tapes, magnetic disks, or other magnetic storage devices. The program may also be transmitted on a transitory computer-readable medium or a communication medium. As non-limiting examples, computer-readable or communication media include electrical, optical, acoustic, or other forms of transmission signals.

[0096] The present invention is not limited to the above-described embodiment and its modifications, and can be appropriately modified within a scope not departing from the spirit and scope of the invention.

[0097] A part or all of the above-mentioned embodiment and modified examples may be described as the following supplementary notes, but are not limited to the following.

[0098] (Note 1)

[0099] A printing device comprising:

[0100] a head unit capable of ejecting a variety of liquids; and

[0101] a control unit for controlling the ejection of the liquid from the head unit,

[0102] The head unit comprises at least a first head and a second head,

[0103] The first head includes three or more chips each having a nozzle array composed of nozzles capable of ejecting a first liquid.

[0104] The second head includes three or more chips each having a nozzle array composed of nozzles capable of ejecting the second liquid.

[0105] The first head and the second head are arranged at intervals in the first direction,

[0106] The arrangement of the three or more chips of the first head in the first head is the same as the arrangement of the three or more chips of the second head in the second head,

[0107] The three or more chips are arranged in a staggered manner in a second direction such that adjacent chips have overlapping sections when viewed from the first direction, and the second direction is a direction intersecting the first direction.

[0108] The overlapping section in the first head and the overlapping section in the second head overlap when viewed from the first direction,

[0109] The control unit controls the discharge of the liquid so that the overlapping section includes a mixing section in which the liquid is discharged from both of the two adjacent chips and a non-mixing section in which the liquid is discharged from only one of the chips.

[0110] The mixed sections belonging to the overlapping sections located at a first position in the second direction with respect to the first head and the mixed sections belonging to the overlapping sections located at the first position with respect to the second head are arranged in a first order with different positions in the second direction.

[0111] The mixed sections belonging to the overlapping sections located at a second position in the second direction with respect to the first head and the mixed sections belonging to the overlapping sections located at the second position with respect to the second head are arranged in a second order symmetrical to the first order in such a manner that their positions in the second direction are different.

[0112] The first position and the second position are positions in the second direction of two overlapping sections connected in the second direction.

[0113] (Note 2)

[0114] The printing device according to Supplementary Note 1, wherein:

[0115] The first head and the second head each include five or more chips.

[0116] The mixed section belonging to the overlapping section located at a third position in the second direction with respect to the first head and the mixed section belonging to the overlapping section located at the third position with respect to the second head are arranged in the first order in a manner different from each other in the second direction.

[0117] The mixed section belonging to the overlapping section located at a fourth position in the second direction with respect to the first head and the mixed section belonging to the overlapping section located at the fourth position with respect to the second head are arranged in the second order in a manner different from each other in the second direction.

[0118] The first position, the second position, the third position, and the fourth position are positions in the second direction of four overlapping intervals connected in the second direction.

[0119] The first position is the position of the first overlapping interval among the four overlapping intervals along the second direction,

[0120] The second position is the position of the second overlapping interval among the four overlapping intervals along the second direction,

[0121] The third position is the position of the third overlapping interval in the second direction among the four overlapping intervals.

[0122] The fourth position is the position of the fourth overlapping interval among the four overlapping intervals along the second direction.

[0123] (Note 3)

[0124] The printing device according to Supplementary Note 1 or 2, wherein:

[0125] Two mixing sections arranged in the first order or the second order and adjacent to each other in the second direction are adjacent to each other without a gap.

[0126] (Note 4)

[0127] The printing device according to any one of Supplementary Notes 1 to 3, wherein:

[0128] The head unit further includes a third head having three or more chips each having a nozzle array composed of nozzles capable of ejecting a third liquid.

[0129] The first head, the second head, and the third head are arranged at intervals in the first direction.

[0130] The arrangement of the three or more chips of the first head, the arrangement of the three or more chips of the second head, and the arrangement of the three or more chips of the third head are common.

[0131] The overlapping section in the first head, the overlapping section in the second head, and the overlapping section in the third head overlap when viewed from the first direction,

[0132] The mixed section of the first head belonging to the overlapping section located at the first position in the second direction, the mixed section of the second head belonging to the overlapping section located at the first position, and the mixed section of the third head belonging to the overlapping section located at the first position are arranged in the first order in a manner that their positions in the second direction are different.

[0133] The mixed section of the first head belonging to the overlapping section located at the second position in the second direction, the mixed section of the second head belonging to the overlapping section located at the second position, and the mixed section of the third head belonging to the overlapping section located at the second position are arranged in the second order in a manner different from each other in the second direction.

[0134] The two mixing sections arranged in the first order or the second order for two heads adjacent to each other in the first direction among the first head, the second head, and the third head are adjacent to each other in the second direction.

[0135] (Note 5)

[0136] A method for printing a pattern, comprising: using the printing device described in any one of Supplementary Notes 1 to 4;

[0137] The chips arranged in a staggered manner in the head are grouped together at a first position in the first direction as a first chip group, and the chips arranged at a second position in the first direction as a second chip group.

[0138] The printing method of the pattern comprises:

[0139] A first ejection step of ejecting color ink from the nozzles of the first chip group belonging to the section other than the overlapping section, the nozzles belonging to the mixing section, and the nozzles belonging to the non-mixing section of the one chip; and

[0140] The second ejection step ejects the color ink from the nozzles belonging to the section other than the overlapping section, the nozzles belonging to the mixing section, and the nozzles belonging to the non-mixing section in the one chip, among the nozzles of the second chip group.

Claims

1. A printing device, characterized in that have: a head unit capable of ejecting a variety of liquids; and a control unit for controlling the ejection of the liquid from the head unit, The head unit has at least a first head and a second head as a plurality of heads, The first head includes three or more chips each having a nozzle array composed of nozzles capable of ejecting a first liquid. The second head includes three or more chips each having a nozzle array composed of nozzles capable of ejecting the second liquid. The first head and the second head are arranged at intervals in the first direction, The arrangement of the three or more chips of the first head in the first head is the same as the arrangement of the three or more chips of the second head in the second head, The three or more chips are arranged in a staggered manner in a second direction intersecting the first direction so that adjacent chips have overlapping sections when viewed from the first direction. The overlapping section in the first head and the overlapping section in the second head overlap when viewed from the first direction, The control unit controls the discharge of the liquid so that the overlapping section includes a mixing section in which the liquid is discharged from both of the two adjacent chips and a non-mixing section in which the liquid is discharged from only one of the chips. The mixed sections belonging to the overlapping sections located at a first position in the first head and the mixed sections belonging to the overlapping sections located at the first position in the second head are arranged in a first order so as to have different positions in the second direction. The mixed sections belonging to the overlapping sections located at a second position in the first head and the mixed sections belonging to the overlapping sections located at the second position in the second head are arranged in a second order symmetrical to the first order in such a manner that their positions in the second direction are different. The first position and the second position are respective positions in the second direction of two overlapping sections connected in the second direction.

2. The printing device according to claim 1, wherein The first head and the second head each include five or more chips. The mixed sections belonging to the overlapping sections located at a third position in the second direction in the first head and the mixed sections belonging to the overlapping sections located at the third position in the second head are arranged in the first order in a manner different from each other in the second direction. The mixed sections belonging to the overlapping sections located at a fourth position in the second direction in the first head and the mixed sections belonging to the overlapping sections located at the fourth position in the second head are arranged in the second order in a manner different from each other in the second direction. The first position, the second position, the third position, and the fourth position are respective positions of four overlapping intervals connected in the second direction. The first position is the position of the first overlapping interval among the four overlapping intervals along the second direction, The second position is the position of the second overlapping interval among the four overlapping intervals along the second direction, The third position is the position of the third overlapping interval in the second direction among the four overlapping intervals. The fourth position is the position of the fourth overlapping interval among the four overlapping intervals along the second direction.

3. The printing device according to claim 1 or 2, characterized in that Two mixing sections arranged in the first order or the second order and adjacent to each other in the second direction are adjacent to each other without a gap.

4. The printing device according to claim 1, wherein The head unit further includes a third head having three or more chips each having a nozzle array composed of nozzles capable of ejecting a third liquid. The first head, the second head, and the third head are arranged at intervals in the first direction. The configuration of the three or more chips of the first head, the configuration of the three or more chips of the second head, and the configuration of the three or more chips of the third head are common, The overlapping section in the first head, the overlapping section in the second head, and the overlapping section in the third head overlap when viewed from the first direction, The mixed intervals belonging to the overlapping intervals located at the first position in the second direction in the first head, the mixed intervals belonging to the overlapping intervals located at the first position in the second head, and the mixed intervals belonging to the overlapping intervals located at the first position in the third head are arranged in the first order in a manner that their positions in the second direction are different. The mixed intervals belonging to the overlapping interval located at the second position in the second direction in the first head, the mixed intervals belonging to the overlapping interval located at the second position in the second head, and the mixed intervals belonging to the overlapping interval located at the second position in the third head are arranged in the second order in a manner that their positions in the second direction are different. In two heads adjacent to each other in the first direction among the first head, the second head, and the third head, the two mixing sections arranged in the first order or the second order are adjacent to each other in the second direction.

5. A method for printing a pattern, characterized in that: A method for printing a pattern using the printing device according to claim 1, The chips arranged in a staggered manner in the head are grouped together at a first position in the first direction as a first chip group, and the chips arranged at a second position in the first direction as a second chip group. The printing method of the pattern comprises: A first ejection step of ejecting color ink from the nozzles of the first chip group belonging to the section other than the overlapping section, the nozzles belonging to the mixing section, and the nozzles of the one chip belonging to the non-mixing section; as well as The second ejection step ejects the color ink from the nozzles belonging to the section other than the overlapping section, the nozzles belonging to the mixing section, and the nozzles belonging to the non-mixing section in the one chip, among the nozzles of the second chip group.

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