Setting device, computer program, and setting method

Abstract

To suppress deterioration in image quality of a printing image.SOLUTION: A printing execution part includes a printing head including a first head unit including a first nozzle and a second head unit including a second nozzle. The first head unit and the second head unit have different positions in a crossing direction crossing a specification direction, a first range in the specification direction at which the first nozzle is positioned includes a range overlapping a second range in the specification direction at which the second nozzle is positioned, and a range not overlapping the second range, and each of the first nozzle and the second nozzle is a nozzle for discharging ink of the same color, and includes two or more nozzle groups having the different positions in the crossing direction. A setting device of the printing execution part makes the printing execution part print a specific image, acquires relative position information determined by using a printed specific image, and sets a use nozzle and a non-use nozzle out of the first nozzle and the second nozzle using the information. The relative position information includes information indicating a positional deviation amount in the specification direction of the first nozzle and the second nozzle.SELECTED DRAWING: Figure 9

Description

[Technical Field]

[0001] The present specification relates to a setting for a print execution unit having a print head with multiple head units. [Background technology]

[0002] In printing devices that perform printing using a print head equipped with multiple nozzles that eject ink, the print head may be equipped with multiple head units. Patent Document 1 discloses a technique for printing one raster line using the nozzles of two head units. This technique takes into account the possibility of installation error between the two head units and uses a printed test pattern to determine the nozzles that correspond to one raster line. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-223988 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the above-mentioned patent document only discloses a head unit in which multiple nozzles that eject ink of the same color are aligned in a row, which means that depending on the configuration of the head unit, it may not be possible to sufficiently suppress degradation in image quality.

[0005] This specification discloses a new technology that can prevent degradation in the quality of images printed by a print execution unit that uses a print head equipped with multiple head units. [Means for solving the problem]

[0006] The techniques disclosed in this specification can be implemented in the following application examples.

[0007] [Application Example 1] A setting device for a print execution unit equipped with a print head equipped with a plurality of head units including a first head unit having N1 (N1 is an integer of 4 or greater) first nozzles whose positions in a specific direction are different from one another, and a second head unit having N2 (N2 is an integer of 4 or greater) second nozzles whose positions in the specific direction are different from one another, wherein the first head unit and the second head unit have different positions in an intersecting direction that intersects with the specific direction, and a first range in which the N1 first nozzles are located, the first range being a range in the specific direction, includes a second range in which the N2 second nozzles are located, the second range being a range that overlaps with the second range in the specific direction, and a range that does not overlap with the second range, and each of the N1 first nozzles and the N2 second nozzles are nozzles that eject ink of the same color, and the N1 first nozzles are two or more nozzles whose positions in the intersecting direction are different from one another. and the N2 second nozzles include two or more nozzle groups whose positions in the intersecting direction are different from each other, and the setting device executes: a printing process that causes the print execution unit to print a specific image, the specific image including a first image printed using at least some of the N1 first nozzles and a second image printed using at least some of the N2 second nozzles; an information acquisition process that acquires relative position information determined using the printed specific image, the relative position information including information indicating an amount of positional deviation between the N1 first nozzles and the N2 second nozzles in the specific direction; and a setting process that uses the relative position information to set, within a range where the first range and the second range overlap, which of the N1 first nozzles and the N2 second nozzles to be used for printing and which nozzles not to be used for printing.

[0008] According to the above configuration, the relative position information determined using the printed specific image is used to determine which of the N1 first nozzles and N2 second nozzles will be used for printing and which will not be used for printing. As a result, even if, for example, misalignment between the first head unit and the second head unit occurs in a specific direction due to variations in assembly, it is possible to appropriately determine which nozzles will be used and which will not be used from the N1 first nozzles and N2 second nozzles, each of which includes two or more nozzle groups that eject ink of the same color and are positioned differently in the intersecting direction. Therefore, even if, for example, misalignment between the first head unit and the second head unit occurs in a specific direction, it is possible to prevent a decrease in the quality of the image printed by the print execution unit. [Application example 2] The setting device according to Application Example 1, the active nozzles and the non-active nozzles are set by first boundary nozzles and second boundary nozzles that are determined based on at least one of the distance between the first nozzles and the second nozzles in the intersecting direction and the range in the specific direction in which printing is possible using only the second nozzles of the active nozzles, the first boundary nozzle is one of the N1 first nozzles, and is a nozzle located at the boundary between a range in the first range in which the active nozzle is located and a range in the second range in which the active nozzle is located, A setting device, wherein the second boundary nozzle is one nozzle among the N2 second nozzles and is a nozzle located at the boundary. [Application example 3] The setting device according to Application Example 2 further comprises: a storage unit that stores a table that records, for each positional deviation amount, the first boundary nozzles and the second boundary nozzles that are predetermined based on at least one of the distance between the first nozzles and the second nozzles in the intersecting direction and a specific range that is a range in the specific direction that is printable using only the second nozzles, The setting process is a process of setting the used nozzles and the unused nozzles by referring to the table. [Application example 4] The setting device according to Application Example 2 or 3, A setting device in which the first boundary nozzle and the second boundary nozzle are determined so that the distance between the first boundary nozzle and the second boundary nozzle in the intersecting direction is shortest. [Application example 5] The setting device according to Application Example 4, A setting device in which, when there are two or more pairs of candidates for the first boundary nozzle and the second boundary nozzle that have the shortest distance in the intersecting direction, the candidate with the widest specific range among the two or more pairs of candidates is determined to be the first boundary nozzle and the second boundary nozzle. [Application Example 6] The setting device according to Application Example 4 or 5, the print head further comprises a third head unit having N3 (N3 is an integer of 4 or greater) third nozzles that are positioned differently from one another in the specific direction, the third head unit and the second head unit are positioned differently in the intersecting direction, a third range in which the N3 third nozzles are located, the third range being a range in the specific direction, includes a range that overlaps with the second range and a range that does not overlap with the second range; the N3 third nozzles and the N2 second nozzles are nozzles that eject ink of the same color, the N3 third nozzles include two or more nozzle groups whose positions in the intersecting direction are different from each other, the second range is located between a range of the first range that does not overlap with the second range and a range of the third range that does not overlap with the second range, the specific image further includes a third image printed using at least a portion of the N3 third nozzles; the relative position information includes information indicating a positional deviation amount between the N3 third nozzles and the N2 second nozzles in the specific direction, the setting process further includes using the relative position information to set the used nozzles and the unused nozzles among the N3 third nozzles and the N2 second nozzles; the in-use nozzle and the non-use nozzle are set so that the distance between the third boundary nozzle and the fourth boundary nozzle in the intersecting direction is shortest, the third boundary nozzle is one nozzle among the N3 third nozzles, and is a nozzle located at the boundary between a range in the third range in which the active nozzle is located and a range in the second range in which the active nozzle is located, A setting device, wherein the fourth boundary nozzle is one nozzle among the N2 second nozzles and is a nozzle located at the boundary. [Application Example 7] The setting device according to Application Example 6, A setting device, wherein a distance between the first boundary nozzle and the second boundary nozzle in the specific direction is different from a distance between the third boundary nozzle and the fourth boundary nozzle in the intersecting direction. [Application Example 8] The setting device according to Application Example 6 or 7, When there are two or more pairs of candidates for the first boundary nozzle and the second boundary nozzle that have the shortest distance in the intersecting direction, among the two or more pairs of candidates, the candidates that have the widest specific range that is a range in the specific direction and that can be printed using only the second nozzle of the operating nozzles are determined as the first boundary nozzle and the second boundary nozzle, A setting device in which, when there are two or more pairs of candidates for the third boundary nozzle and the fourth boundary nozzle that have the shortest distance in the intersecting direction, the candidate with the widest specific range among the two or more pairs of candidates is determined to be the third boundary nozzle and the fourth boundary nozzle. [Application Example 9] The setting device according to any one of Application Examples 1 to 8, further comprising: the print execution unit includes a transport unit that transports the print medium in the cross direction; A setting device in which the transport unit transports the printing medium, whose length in the specific direction is shorter than the second range in which the N2 second nozzles are located, to a position in the specific direction where printing can be done using only the N2 second nozzles. [Application Example 10] A computer program for a print execution unit equipped with a print head equipped with a plurality of head units including a first head unit equipped with N1 (N1 is an integer of 4 or more) first nozzles whose positions in a specific direction are different from each other, and a second head unit equipped with N2 (N2 is an integer of 4 or more) second nozzles whose positions in the specific direction are different from each other, the first head unit and the second head unit are positioned differently in an intersecting direction intersecting with the specific direction, a first range in which the N1 first nozzles are located, the first range being a range in the specific direction, includes a second range in which the N2 second nozzles are located, the second range being a range in the specific direction, and a range that does not overlap with the second range; the N1 first nozzles and the N2 second nozzles are nozzles that eject ink of the same color, the N1 first nozzles include two or more nozzle groups whose positions in the intersecting direction are different from each other, the N2 second nozzles include two or more nozzle groups whose positions in the intersecting direction are different from each other, The computer program comprises: a print control function that causes the print execution unit to print a specific image, the specific image including a first image printed using at least a portion of the N1 first nozzles and a second image printed using at least a portion of the N2 second nozzles; an information acquisition function that acquires relative position information determined using the printed specific image, the relative position information including information indicating a positional deviation amount in the specific direction between the N1 first nozzles and the N2 second nozzles; a nozzle setting function that uses the relative position information to set, within an overlapping range of the first range and the second range, nozzles to be used for printing and nozzles not to be used for printing, among the N1 first nozzles and the N2 second nozzles; A computer program that enables a computer to realize the above. [Application Example 11] A setting method for a print execution unit equipped with a print head equipped with a plurality of head units including a first head unit equipped with N1 (N1 is an integer of 4 or more) first nozzles whose positions in a specific direction are different from each other, and a second head unit equipped with N2 (N2 is an integer of 4 or more) second nozzles whose positions in the specific direction are different from each other, the first head unit and the second head unit are positioned differently in an intersecting direction intersecting with the specific direction, a first range in which the N1 first nozzles are located, the first range being a range in the specific direction, includes a second range in which the N2 second nozzles are located, the second range being a range in the specific direction, and a range that does not overlap with the second range; the N1 first nozzles and the N2 second nozzles are nozzles that eject ink of the same color, the N1 first nozzles include two or more nozzle groups whose positions in the intersecting direction are different from each other, the N2 second nozzles include two or more nozzle groups whose positions in the intersecting direction are different from each other, The setting method includes: a printing step of causing the print execution unit to print a specific image, the specific image including a first image printed using at least a portion of the N1 first nozzles and a second image printed using at least a portion of the N2 second nozzles; an information acquiring step of acquiring relative position information determined using the printed specific image, the relative position information including information indicating a positional deviation amount in the specific direction between the N1 first nozzles and the N2 second nozzles; a nozzle setting step of setting, using the relative position information, nozzles to be used for printing and nozzles not to be used for printing among the N1 first nozzles and the N2 second nozzles in a range where the first range and the second range overlap; Including how to set it up.

[0009] The technology disclosed in this specification can be realized in various forms, such as a printing device, a method for determining nozzle characteristic values, a computer program for realizing the functions of these devices and methods, a recording medium on which the computer program is recorded, etc. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 6 is a block diagram showing the configuration of a printer 600 according to an embodiment. [Figure 2] FIG. 2 is a diagram showing a schematic configuration of a print head 240. [Figure 3] 10 is a schematic diagram of the vicinity of the upstream end of a head unit 241 in the X direction and the downstream end of a head unit 242 in the X direction. [Figure 4] A list of boundary nozzle pair candidates for head units 241 and 242. [Figure 5] 10 is a schematic diagram of the vicinity of the upstream end of the head unit 242 in the X direction and the downstream end of the head unit 243 in the X direction. [Figure 6] A list of candidate boundary nozzle pairs for head units 242 and 243. [Figure 7] 10 is a flowchart of the process of creating a reference table RT. [Figure 8] 10 is a flowchart of the process of creating a reference table RT. [Figure 9] FIG. 2 is a diagram showing an example of a reference table RT. [Figure 10] FIG. 1 is a first diagram showing an example of a test image TI. [Figure 11] FIG. 2 is a second diagram showing an example of a test image TI. DETAILED DESCRIPTION OF THE INVENTION

[0011] A. First Example: A-1. Printing device configuration: Next, an embodiment of the present invention will be described based on an example. Fig. 1 is a block diagram showing the configuration of a printer 600 in this example. Fig. 2 is a diagram showing the schematic configuration of a print head 240. The printer 600 comprises a control device 100 that controls the entire printer 600, and a print mechanism 200 that performs printing.

[0012] The control device 100 includes a CPU 110, a volatile memory device 120 such as a DRAM, a non-volatile memory device 130 such as a flash memory or a hard disk drive, a display unit 140 such as an LCD display, an operation unit 150 including a touch panel and buttons superimposed on the LCD display panel, and a communication unit 160 including a communication interface for communication with an external device such as a personal computer (not shown).

[0013] The volatile storage device 120 is provided with a buffer area 125 that temporarily stores various intermediate data generated when the CPU 110 performs processing. The non-volatile storage device 130 stores a computer program PG for controlling the printer 600, a reference table RT (described later), and test image data TD.

[0014] The computer program PG, the reference table RT, and the test image data TD are stored in the non-volatile storage device 130 before the printer 600 is shipped. The computer program PG, the reference table RT, and the test image data TD may be provided in a format stored on a DVD-ROM or downloaded from a server. The CPU 110 executes the computer program PG to realize various processes such as controlling the printer 600. The processes realized by executing the computer program PG include a nozzle setting process, which will be described later. The reference table RT is created by a reference table creation process, which will be described later. The reference table RT will be described later.

[0015] The printing mechanism 200, under the control of the CPU 110 of the control device 100, ejects one type of ink (black (K) ink in this embodiment) to form dots, thereby printing on the printing medium.

[0016] The printing mechanism 200 includes a transport unit 210, a head drive unit 230, and a print head 240. The transport unit 210 includes a transport motor (not shown), and transports paper M, serving as a print medium, in the transport direction using the power of the transport motor. In this embodiment, roll paper made of long label stickers rolled into a cylindrical shape is used as the paper M. This is not a limitation, and other paper such as roll paper made of plain paper or cut paper may also be used. FIG. 2A illustrates a center line CL that passes through the center of the print head 240 in the X direction and is parallel to the Y direction. The transport unit 210 transports the paper M so that the center of the paper M in the X direction coincides with the center (center line CL) of the print head 240 in the X direction.

[0017] The head drive unit 230 supplies a drive signal DS to the print head 240 to drive the print head 240. In accordance with the drive signal DS, the print head 240 ejects ink to form dots on the paper being transported by the transport unit 210. Unlike so-called serial printers, the printing mechanism 200 is a line printer that performs printing without performing main scanning, which moves the print head 240 in a direction intersecting the transport direction.

[0018] As shown in Figure 2(A), the transport direction of the paper M transported by the transport unit 210 is the Y direction, and the direction along the transported paper M and intersecting the transport direction (orthogonal in this embodiment) is the X direction. Since the printing mechanism 200 is a so-called line printer, the print head 240 has a plurality of nozzles NZ aligned along the X direction. This will be explained in detail below.

[0019] The print head 240 includes a base member 245 and three head units 241 to 243 (FIG. 2A). The head units 241 to 243 are attached to the base member 245 at predetermined positions using predetermined fixing means such as screws. FIG. 2B shows the configuration of one head unit 241 as viewed from the -Z side. As shown in FIG. 2B, m nozzle groups NGn (n is an integer between 1 and m) that eject the K ink described above are formed on the nozzle formation surface 241s of the head unit 241. Each nozzle group NGn includes p nozzles NZ (p is an integer between 1 and m) that are aligned in a row at a predetermined nozzle pitch NT along the X direction. The positions of the m nozzle groups NGn in the X direction are offset by (NT / m). For this reason, the total number of nozzles NZ in the m nozzle groups NGn (p × m) is such that their positions in the X direction are different from each other. That is, the (p×m) nozzles NZ are formed at a nozzle pitch of (NT / m). The m nozzle groups NGn are each positioned differently in the Y direction and are lined up at a predetermined interval in the Y direction. (NT / m) is, for example, an interval equivalent to 300 dpi or 600 dpi. While the head unit 241 has been described, the other head units 242 and 243 have the same configuration as the head unit 241. The number m of nozzle groups NGn is, for example, 24, and the number p of nozzles NZ included in one nozzle group NGn is, for example, 70.

[0020] The three head units 241 to 243 are positioned differently in the X direction, and are arranged in order of their final numbers (1 to 3) from the downstream side in the X direction. Two of the head units 241 and 243 are positioned in the same Y direction. One head unit 242 and the other two head units 241 and 243 are positioned differently in the Y direction. The center of the head unit 242 in the X direction coincides with the center of the print head 240 in the X direction and the center (center line CL) of the paper M being transported in the X direction. A portion of the head unit 242, including its downstream end in the X direction, overlaps in position in the X direction with a portion of the head unit 241, including its upstream end in the X direction. A portion of the head unit 242, including its upstream end in the X direction, overlaps in position in the X direction with a portion of the head unit 243, including its downstream end in the X direction (FIG. 2).

[0021] FIG. 3 is a schematic diagram of the vicinity of the upstream end of the head unit 241 in the X direction and the downstream end of the head unit 242 in the X direction. The dots within the head units 241 and 242 indicate the positions of the nozzles NZ formed on the nozzle formation surfaces (surfaces on the -Z side) of the head units 241 and 242. In FIG. 3 and FIG. 5, which will be described later, the number m of nozzle groups NGn is shown as a smaller number (m=10) than the actual number in order to avoid complexity of the diagram. The symbols (e.g., A1 to A10, B1 to B10) near the dots indicating the nozzles NZ are identifiers of the nozzles NZ. Hereinafter, for example, a nozzle NZ with an identifier A1 will also be referred to as "nozzle A1."

[0022] Due to variations in the mounting positions of the head units 241 to 243 relative to the base member 245, there are variations in the relative positional relationships in the X direction between the head units 241 to 243. Due to these variations, the relative positions in the X direction between the multiple nozzles NZ of the head unit 241 and the multiple nozzles NZ of the head unit 242 (hereinafter also referred to as relative nozzle positions) may deviate from the designed positions. Hereinafter, the amount of misalignment between the head units 241 and 242 will be referred to as the misalignment amount ΔXa, and the amount of misalignment between the head units 242 and 243 will be referred to as the misalignment amount ΔXb. It can be said that the misalignment amount ΔXa is information indicating the relative positions in the X direction between the nozzles NZ of the head unit 241 and the nozzles NZ of the head unit 242. It can be said that the positional deviation amount ΔXb is information indicating the relative positions of the nozzles NZ of the head unit 242 and the nozzles NZ of the head unit 243 in the X direction.

[0023] 3(A) illustrates a case where the positional deviation amount ΔXa is 0, i.e., a case where the relative nozzle positions of head unit 241 and head unit 242 are at their designed positions. A portion of the upstream side in the X direction of X direction range RG1 in which the multiple nozzles NZ of head unit 241 are located overlaps with a portion of the downstream side in the X direction of X direction range RG2 in which the multiple nozzles NZ of head unit 242 are located. In the example of FIG. 3(A), the range of range RG1 in which nozzles A6 to A10 are located and the range of range RG2 in which nozzles B0 to B4 exist overlap with each other, forming overlapping ranges. The range of range RG1 excluding the overlapping range does not overlap with range RG2.

[0024] FIG. 3(B) illustrates a case where the positional deviation amount ΔXa is -5. A negative value for the positional deviation amount ΔXa means that the relative nozzle positions of head unit 241 and head unit 242 are deviated from the designed positions in the direction in which the overlap range decreases. In other words, a negative value for the positional deviation amount ΔXa means that head unit 242 is deviated from the designed position to the upstream side in the X direction (to the right in FIG. 3) relative to head unit 241. The unit of the positional deviation amount ΔXa is the number of nozzles. Therefore, when the positional deviation amount ΔXa is -5, this means that head unit 242 is deviated from the designed position to the upstream side in the X direction relative to head unit 241 by 5 nozzles (5 × (NT / m)).

[0025] 3(C) illustrates a case where the positional deviation amount ΔXa is +5. A positive value for the positional deviation amount ΔXa means that the relative nozzle positions of head unit 241 and head unit 242 are deviated from the designed positions in the direction in which the overlap range increases. In other words, a positive value for the positional deviation amount ΔXa means that head unit 242 is deviated downstream in the X direction (left side in FIG. 3) from the designed position relative to head unit 241. Therefore, when the positional deviation amount ΔXa is +5, this means that head unit 242 is deviated by five nozzles downstream in the X direction relative to head unit 241 from the designed position.

[0026] If the positional deviation ΔXa becomes smaller than -5, for example, if the positional deviation ΔXa becomes -6, the distance in the X direction between nozzle A10 at the upstream end in the X direction of head unit 241 and nozzle B0 at the downstream end in the X direction of head unit 242 becomes excessively large. In this case, a gap occurs between the image printed by head unit 241 and the image printed by head unit 242. For this reason, a tolerance for the mounting position of head units 241 and 242 is set so that the positional deviation ΔXa does not become smaller than -5. In this embodiment, the tolerance for the mounting position is determined so that the positional deviation ΔXa is in the range of -5<ΔXa<+5.

[0027] Within the overlapping range, one of a pair of nozzles that are approximately equal in position in the X direction (for example, nozzle A10 and nozzle B4 in FIG. 3A) is used during printing, and the other is not used.

[0028] The nozzles to be used during printing are switched from nozzles NZ of head unit 241 to nozzles of head unit 242, with a predetermined X-direction position of the overlapping range as the boundary. For example, in the example of FIG. 3A, nozzle A7 of head unit 241 and nozzle B2 of head unit 242 may be set as a pair of nozzles located at the boundary of switching between the nozzles to be used (hereinafter also referred to as a boundary nozzle pair). In this case, of the multiple nozzles NZ of head unit 241, nozzle A7 and the nozzles downstream of nozzle A7 in the X direction (left side of FIG. 3) are determined as the nozzles to be used, and nozzles A8 to A10 upstream of nozzle A7 in the X direction (right side of FIG. 3) are determined as the nozzles not to be used. Then, of the multiple nozzles NZ of head unit 242, nozzle B2 and the nozzle NZ upstream of nozzle B2 in the X direction (right side of FIG. 3) are determined as the nozzles to be used, and nozzles B0 and B1 downstream of nozzle B2 in the X direction (right side of FIG. 3) are determined as the nozzles not to be used.

[0029] 3(A) to 3(C), pairs of nozzles NZ that are actually connected indicate pairs that can become boundary nozzle pairs (candidates for boundary nozzle pairs). The nozzle NZ of the head unit 242 that constitutes the boundary nozzle pair is located one nozzle's width, i.e., (NT / m) upstream in the X direction, from the nozzle NZ of the head unit 241 that constitutes the boundary nozzle pair.

[0030] The number of boundary nozzle pair candidates varies depending on the positional deviation amount ΔXa. For example, when the positional deviation amount ΔXa is 0, there are six boundary nozzle pair candidates (FIG. 3(A)). When the positional deviation amount ΔXa is -5, there is only one boundary nozzle pair candidate (FIG. 3(B)). When the positional deviation amount ΔXa is +5, there are 11 boundary nozzle pair candidates (FIG. 3(C)).

[0031] Fig. 4 is a list of boundary nozzle pair candidates for head units 241 and 242. Fig. 4(A) shows a table of six boundary nozzle pair candidates when the positional deviation amount ΔXa is 0. The six boundary nozzle pair candidates are the pair of nozzles A5 and B0, the pair of nozzles A6 and B1, the pair of nozzles A7 and B2, the pair of nozzles A8 and B3, the pair of nozzles A9 and B4, and the pair of nozzles A10 and B5.

[0032] 4B shows a table of one boundary nozzle pair candidate when the positional deviation amount ΔXa is −5. The one boundary nozzle pair candidate is the pair of nozzles A10 and B0.

[0033] 4(C) shows a table of 11 candidate boundary nozzle pairs when the misalignment amount ΔXa is +5. The 11 candidate boundary nozzle pairs are: pair of nozzles A0, B0, pair of nozzles A1, B1, pair of nozzles A2, B2, pair of nozzles A3, B3, pair of nozzles A4, B4, pair of nozzles A5, B5, pair of nozzles A6, B6, pair of nozzles A7, B7, pair of nozzles A8, B8, pair of nozzles A9, B9, and pair of nozzles A10, B10.

[0034] 5 is a schematic diagram of the vicinity of the upstream end in the X direction of head unit 242 and the downstream end in the X direction of head unit 243. As in FIG. 3, the dots within head units 242 and 243 indicate the positions of nozzles NZ formed on the nozzle formation surfaces (-Z side surfaces) of head units 242 and 243. The symbols (for example, C1 to C10, D1 to D10) near the dots indicating the nozzles NZ are identifiers of the nozzles NZ.

[0035] 5(A) illustrates a case where the positional deviation amount ΔXb is 0, that is, a case where the relative nozzle positions of head unit 242 and head unit 243 are at their designed positions. A portion of the upstream side in the X direction of X direction range RG2 in which the multiple nozzles NZ of head unit 242 are located overlaps with a portion of the downstream side in the X direction of X direction range RG3 in which the multiple nozzles NZ of head unit 243 are located. In the example of FIG. 5(A), the range of range RG2 in which nozzles C6 to C10 are located and the range of range RG3 in which nozzles D0 to D4 exist are overlapping ranges.

[0036] As can be seen from Figures 3 and 5, the range RG2 in which the nozzles NZ of the head unit 242 are located is located between the range of range RG1 that does not overlap with range RG2 and the range of range RG3 that does not overlap with range RG2.

[0037] FIG. 5(B) illustrates a case where the positional deviation amount ΔXb is -5, and FIG. 5(C) illustrates a case where the positional deviation amount ΔXb is +5. As with the positional deviation amount ΔXa, a negative value for the positional deviation amount ΔXb means that the relative nozzle positions of head unit 242 and head unit 243 are deviated from the designed positions in the direction in which the overlap range decreases. A positive value for the positional deviation amount ΔXb means that the relative nozzle positions of head unit 242 and head unit 243 are deviated from the designed positions in the direction in which the overlap range increases. As with the positional deviation amount ΔXa, the unit of the positional deviation amount ΔXb is the number of nozzles.

[0038] If the amount of misalignment ΔXb becomes smaller than -5, a gap will appear between the image printed by head unit 242 and the image printed by head unit 243. For this reason, the tolerance of the mounting positions of head units 242 and 243 is determined to be in the range of -5<ΔXb<+5 so that the amount of misalignment ΔXb does not become smaller than -5.

[0039] The nozzles to be used in the overlapping range of head units 242 and 243 are determined based on boundary nozzle pairs, similar to the overlapping range of head units 241 and 242 described above. For example, in the example of FIG. 5A, nozzle C8 of head unit 242 and nozzle D3 of head unit 243 may be set as a boundary nozzle pair. In this case, of the multiple nozzles NZ of head unit 242, nozzle C8 and the nozzle NZ downstream of nozzle C8 in the X direction are determined as the nozzles to be used, and nozzles C9 and C10 upstream of nozzle C8 in the X direction are determined as nozzles not to be used. Then, of the multiple nozzles NZ of head unit 243, nozzle D3 and the nozzle NZ upstream of nozzle D3 in the X direction are determined as nozzles to be used, and nozzles D0 to D2 downstream of nozzle D3 in the X direction are determined as nozzles not to be used.

[0040] 5(A) to 5(C), pairs of nozzles NZ that are actually connected indicate candidates for boundary nozzle pairs. The nozzle NZ of the head unit 243 that constitutes the boundary nozzle pair is located one nozzle upstream in the X direction from the nozzle NZ of the head unit 242 that constitutes the boundary nozzle pair.

[0041] Fig. 6 is a list of boundary nozzle pair candidates for head units 242 and 243. Fig. 6(A) shows a table of six boundary nozzle pair candidates when the positional deviation amount ΔXb is 0. The six boundary nozzle pair candidates are the pair of nozzles C5 and D0, the pair of nozzles C6 and D1, the pair of nozzles C7 and D2, the pair of nozzles C8 and D3, the pair of nozzles C9 and D4, and the pair of nozzles C10 and D5.

[0042] 6B shows a table of one boundary nozzle pair candidate when the positional deviation amount ΔXb is −5. The one boundary nozzle pair candidate is the pair of nozzles C10 and D0.

[0043] 6(C) shows a table of 11 boundary nozzle pair candidates when the misalignment amount ΔXb is +5. The 11 boundary nozzle pair candidates are: pair of nozzles C0 and D0, pair of nozzles C1 and D1, pair of nozzles C2 and D2, pair of nozzles C3 and D3, pair of nozzles C4 and D4, pair of nozzles C5 and D5, pair of nozzles C6 and D6, pair of nozzles C7 and D7, pair of nozzles C8 and D8, pair of nozzles C9 and D9, and pair of nozzles C10 and D10.

[0044] A-2. Creating a reference table RT The reference table RT is a table in which boundary nozzle pairs are recorded for each of the positional deviation amounts ΔXa and ΔXb. The process for creating the reference table RT will now be described.

[0045] FIG. 7 is a flowchart of the process of creating the reference table RT. FIG. 8 is a diagram showing an example of the reference table RT. As shown in FIG. 8, the reference table RT includes a first table RTa and a second table RTb. The first table RTa is a table that records the boundary nozzle pairs between the head units 241 and 242, and the second table RTb is a table that records the boundary nozzle pairs between the head units 242 and 243. The process of FIG. 7 is performed for each of the first table RTa and the second table RTb. The process of FIG. 7 will be described below using the case where the first table RTa is created as an example.

[0046] 7 is executed, for example, by the manufacturer of the printer 600. In S100, the operator selects one attention deviation amount from the estimated positional deviation amounts ΔXa. Specifically, one attention deviation amount is selected one by one from the 11 positional deviation amounts ΔXa (-5, -4, -3, -2, -1, 0, +1, +2, +3, +4, +5).

[0047] In S115, the operator identifies candidates for boundary nozzle pairs when an attention shift amount occurs. For example, when the attention shift amount is 0, six nozzle pairs shown in the table of FIG. 4A are identified as candidates for boundary nozzle pairs. When the attention shift amount is −5 or +5, one nozzle pair shown in the table of FIG. 4B and eleven nozzle pairs shown in the table of FIG. 4C are identified as candidates for boundary nozzle pairs, respectively.

[0048] In S120, the operator calculates the distance in the transport direction between each identified nozzle pair. The distance in the transport direction between a nozzle pair is the distance in the transport direction (Y direction) between one nozzle NZ and the other nozzle NZ that make up the nozzle pair. In this embodiment, coordinates on the design drawing are used to calculate the distance in the transport direction between nozzle pairs. The tables in FIGS. 4 and 6 show the distance in the transport direction between each nozzle pair that is a candidate for a boundary nozzle pair. For example, when the attention deviation amount is 0, the distances in the transport direction (20 mm, 20 mm, 18 mm, 38 mm, 18 mm, 36 mm) are calculated for each of the six nozzle pairs shown in the table in FIG. 4(A) (the pair of nozzles A5 and B0, the pair of nozzles A6 and B1, the pair of nozzles A7 and B2, the pair of nozzles A8 and B3, the pair of nozzles A9 and B4, and the pair of nozzles A10 and B5). When the attention deviation amount is +5, the distance (28 mm) in the transport direction for each of the 11 nozzle pairs shown in the table of FIG. 4(C) is calculated.

[0049] In S125, the operator identifies the nozzle pair with the shortest distance in the transport direction from among the candidate boundary nozzle pairs. For example, when the attention shift amount is 0, the minimum distance in the transport direction is 18 mm, so two nozzle pairs (the pair of nozzles A7 and B2 and the pair of nozzles A9 and B4) with a distance in the transport direction of 18 mm are identified. When the attention shift amount is +5, the minimum distance in the transport direction is 28 mm, so 11 nozzle pairs (all of the nozzle pairs in FIG. 4C) with a distance in the transport direction of 28 mm are identified. In this way, the number of nozzle pairs identified in this step may be one or more.

[0050] In S130, the worker determines whether there are multiple nozzle pairs with the shortest distance in the transport direction. If there is only one nozzle pair with the shortest distance in the transport direction (S130: NO), in S135 the worker determines that one nozzle pair as the boundary nozzle pair.

[0051] If there are multiple nozzle pairs with the shortest distance in the transport direction (S130: YES), in S140, the operator determines the outermost nozzle pair among the multiple nozzle pairs with the shortest distance in the transport direction as the boundary nozzle pair. For example, if the positional deviation amount ΔXa between the head units 241 and 242 is the attention deviation amount, the nozzle pair located most downstream in the X direction (left side in FIG. 3) is determined as the boundary nozzle pair. For example, if the attention deviation amount is +5, the pair of nozzles A0 and B0 located most downstream in the X direction among the 11 nozzle pairs with a distance of 28 mm in the transport direction is identified as the boundary nozzle pair (FIG. 3(C)). For example, if the attention deviation amount is 0, the pair of nozzles A7 and B2 located downstream in the X direction among the two nozzle pairs with a distance of 18 mm in the transport direction is identified as the boundary nozzle pair (FIG. 3(A)). When the positional deviation amount ΔXb between the head units 242 and 243 is the deviation amount of interest, the nozzle pair located most upstream in the X direction (to the right in FIG. 5) is determined to be the boundary nozzle pair. The reason for determining the outermost nozzle pair as the boundary nozzle pair is to widen the range in the X direction that can be printed using only the nozzles NZ of the head unit 242 located in the center in the X direction. The reason for this will be explained later.

[0052] When the attention deviation amount is −5, there is only one nozzle pair that is a candidate for the boundary nozzle pair, so that nozzle pair (the pair of nozzles A10 and B0) is identified as the boundary nozzle pair (FIG. 3B).

[0053] In S145, the operator records the boundary nozzle pair determined in S135 or S140 in association with the attention deviation amount in the first table RTa (FIG. 8).

[0054] In S150, the operator determines whether or not boundary nozzle pairs have been determined for all of the above-mentioned misalignment amounts. If boundary nozzle pairs have not been determined for some of the misalignment amounts (S150: NO), the operator returns to S110 and selects a new target misalignment amount. If boundary nozzle pairs have been determined for all of the misalignment amounts (S150: YES), creation of the reference table ends.

[0055] While the creation of the first table RTa between head units 241 and 242 (FIGS. 3 and 4) has been described above as an example, the creation of the second table RTb between head units 242 and 243 (FIGS. 5 and 6) is also performed in a similar manner. For example, between head units 242 and 243, when the misalignment amount ΔXb is 0, the boundary nozzle pair is determined to be the pair of nozzles C8 and D3. Furthermore, between head units 242 and 243, when the misalignment amount ΔXb is -5, the boundary nozzle pair is determined to be the pair of nozzles C10 and D0, and when the misalignment amount ΔXb is +5, the boundary nozzle pair is determined to be the pair of nozzles C10 and C10. The reference table RT created in this manner is stored in the nonvolatile memory device 130, for example, when the printer 600 is manufactured.

[0056] A-3. Nozzle setting process The following describes the nozzle setting process implemented by the CPU 110 of the printer 600. The nozzle setting process is executed based on a user instruction, for example, when the printer 600 is started for the first time after manufacture, or when a defect such as a streak appears in a printed image. The nozzle setting process may also be executed during the manufacturing process of the printer 600.

[0057] In S210, the CPU 110 supplies the test image data TD to the printing mechanism 200, causing the printing mechanism 200 to print a test image TI on paper M. Figures 10 and 11 are diagrams showing an example of the test image TI.

[0058] The test image TI includes 11 strip images PI(q) that correspond one-to-one to the 11 misalignment amounts ΔXa and ΔXb described above (−5, −4, −3, −2, −1, 0, +1, +2, +3, +4, +5). Here, the number q in parentheses of the symbol of the strip image indicates the corresponding misalignment amount and takes an integer value between −5 and +5.

[0059] The strip-shaped image PI(q) includes a left-side image LI(q), a center image CI(q), and a right-side image RI(q). The left-side image LI(q) is printed using the nozzle NZ of the head unit 241. The center image CI(q) is printed using the nozzle NZ of the head unit 242. The right-side image RI(q) is printed using the nozzle NZ of the head unit 243.

[0060] The left image LI(q) is printed using the nozzles NZ corresponding to the corresponding positional deviation amount (i.e., the value of q). For example, the left image LI(-5) is printed using the nozzles NZ of the head unit 241, from a specific nozzle near the downstream end in the X direction to nozzle A10 (see FIG. 3(A) and the like). The left images LI(-4), LI(-3), LI(-2), LI(-1), and LI(0) are printed using the nozzles from a specific nozzle to nozzle A9, the nozzles from a specific nozzle to nozzle A8, the nozzles from a specific nozzle to nozzle A7, the nozzles from a specific nozzle to nozzle A6, and the nozzles from a specific nozzle to nozzle A5, respectively. The left images LI(+1), LI(+2), LI(+3), LI(+4), and LI(+5) are printed using the nozzles from a specific nozzle to nozzle A4, the nozzles from a specific nozzle to nozzle A3, the nozzles from a specific nozzle to nozzle A2, the nozzles from a specific nozzle to nozzle A1, and the nozzles from a specific nozzle to nozzle A0, respectively. In this way, the nozzles that print the left image LI(q) are reduced by one from the upstream side in the X direction (the right side in FIG. 10) every time the corresponding positional deviation amount (the value of q) increases by 1. As a result, the position of the upstream end of the left image LI(q) in the X direction (the right end in FIG. 10) shifts by one nozzle toward the downstream side in the X direction (the left side in FIG. 10) every time the corresponding positional deviation amount (the value of q) increases by 1.

[0061] The central image CI(q) is printed using all nozzles NZ of the head unit 242, regardless of the corresponding positional offset amount (i.e., the value of q). For this reason, the central image CI(q) is the same image, regardless of the corresponding positional offset amount (i.e., the value of q).

[0062] The right-side image RI(q) is printed using the nozzles NZ corresponding to the corresponding positional deviation amount (i.e., the value of q). For example, the right-side image RI(-5) is printed using the nozzles NZ of the head unit 243, from nozzle D0 (e.g., FIG. 5(A)) to a predetermined nozzle near the upstream end in the X direction. The right-side images RI(-4), RI(-3), RI(-2), RI(-1), and RI(0) are printed using the nozzles from nozzle D1 to a predetermined nozzle, the nozzles from nozzle D2 to a predetermined nozzle, the nozzles from nozzle D3 to a predetermined nozzle, the nozzles from nozzle D4 to a predetermined nozzle, and the nozzles from nozzle D5 to a predetermined nozzle, respectively. The right-side images RI(+1), RI(+2), RI(+3), RI(+4), and RI(+5) are printed using the nozzles from nozzle D6 to a predetermined nozzle, the nozzles from nozzle D7 to a predetermined nozzle, the nozzles from nozzle D8 to a predetermined nozzle, the nozzles from nozzle D9 to a predetermined nozzle, and the nozzles from nozzle D10 to a predetermined nozzle, respectively. In this way, the nozzles that print the right-side image RI(q) are reduced by one from the downstream side in the X direction (left side in FIG. 10) every time the corresponding positional deviation amount (value of q) increases by 1. As a result, the position of the downstream end in the X direction (right end in FIG. 10) of the right-side image RI(q) shifts by one nozzle toward the upstream side in the X direction (right side in FIG. 10) every time the corresponding positional deviation amount (value of q) increases by 1.

[0063] As a result of constructing the test image TI in this manner, when the misalignment amount ΔXa is 0 (FIG. 10), neither a white streak wl nor a black streak bl occurs between the left image LI(0) and the center image CI(0) of the strip-shaped image PI(0) corresponding to a misalignment amount of 0. A black streak bl occurs between the left image LI(q) and the center image CI(q) of the strip-shaped image PI(q) corresponding to a misalignment amount smaller than 0 (q=-5 to -1). The black streak bl occurs when the upstream edge of the left image LI(q) in the X direction overlaps with the downstream edge of the center image CI(q). A white streak wl occurs between the left image LI(q) and the center image CI(q) of the strip-shaped image PI(q) corresponding to a misalignment amount larger than 0 (q=+1 to +5). The white streak wl is a streak that occurs due to the presence of a gap between the upstream edge of the left image LI(q) in the X direction and the downstream edge of the center image CI(q) in the X direction. Note that in Figures 10 and 11, the black streak bl and the white streak wl are shown thick to make the figures easier to see, but in reality they are thin streaks that are at most the width of five nozzles (5 × (NT / m)).

[0064] Similarly, when the misalignment amount ΔXb is 0 (FIG. 10), neither white streaks wl nor black streaks bl occur between the right-side image RI(0) and the center image CI(0) of the strip-shaped image PI(0) corresponding to the misalignment amount "0." Black streaks bl occur between the right-side image RI(q) and the center image CI(q) of the strip-shaped image PI(q) corresponding to the misalignment amount smaller than 0 (q=-5 to -1). White streaks wl occur between the right-side image RI(q) and the center image CI(q) of the strip-shaped image PI(q) corresponding to the misalignment amount larger than 0 (q=+1 to +5).

[0065] When the misalignment amount ΔXa is +2 (FIG. 11), neither white streaks wl nor black streaks bl occur between the left image LI(+2) and the center image CI(+2) of the strip-shaped image PI(+2) corresponding to the misalignment amount "+2." Black streaks bl occur between the left image LI(q) and the center image CI(q) of the strip-shaped image PI(q) corresponding to the misalignment amount smaller than +2 (q=-5 to +1). White streaks wl occur between the left image LI(q) and the center image CI(q) of the strip-shaped image PI(q) corresponding to the misalignment amount larger than +2 (q=+3 to +5).

[0066] When the misalignment amount ΔXb is -3 (FIG. 11), neither white streaks wl nor black streaks bl occur between the right-side image RI(-3) and the center image CI(-3) of the strip-shaped image PI(-3) corresponding to the misalignment amount "-3." Black streaks bl occur between the right-side image RI(q) and the center image CI(q) of the strip-shaped image PI(q) corresponding to the misalignment amount smaller than -3 (q = -5 to -4). White streaks wl occur between the right-side image RI(q) and the center image CI(q) of the strip-shaped image PI(q) corresponding to the misalignment amount larger than -3 (q = -2 to +5).

[0067] As described above, the user can identify the amounts of misregistration ΔXa and ΔXb occurring in the print head 240 by observing the printed test image TI.

[0068] In S220 of FIG. 9, the CPU 110 acquires the misalignment amounts ΔXa and ΔXb determined based on the test image TI. For example, the user observes the test image TI and checks the occurrence of white streaks wl and black streaks in each band-like image PI(q), thereby determining the misalignment amounts ΔXa and ΔXb. The CPU 110 displays a user interface screen on the display unit 140 for inputting the misalignment amounts ΔXa and ΔXb. The user inputs the determined misalignment amounts ΔXa and ΔXb to the user interface screen using the operation unit 150. The CPU 110 acquires the input misalignment amounts ΔXa and ΔXb via the user interface screen.

[0069] In a modified example, the CPU 110 may acquire scan data generated by reading the printed test image TI with a scanner and analyze the scan data to check the occurrence of white streaks wl and black streaks in each belt-like image PI(q). In this case, the CPU 110 acquires the positional deviation amounts ΔXa and ΔXb based on the check results.

[0070] In S230, the CPU 110 determines a boundary nozzle pair by referring to the reference table RT. Specifically, the CPU 110 determines the boundary nozzle pair associated with the positional deviation amount ΔXa as the boundary nozzle pair (also referred to as the left boundary nozzle pair) between the head units 241 and 242 by referring to the first table RTa. The CPU 110 determines the boundary nozzle pair associated with the positional deviation amount ΔXb as the boundary nozzle pair (also referred to as the right boundary nozzle pair) between the head units 242 and 243 by referring to the second table RTb. For example, when the positional deviation amounts ΔXa and ΔXb are −3 and +2, the pair of nozzles A9 and B1 is determined as the left boundary nozzle pair, and the pair of nozzles C8 and D5 is determined as the right boundary nozzle pair.

[0071] In S240, the CPU 110 sets the nozzles to be used and the nozzles not to be used of the head units 241 to 243 based on the boundary nozzle pairs.

[0072] Specifically, the CPU 110 determines, as the nozzles to be used, the nozzles NZ from the nozzle NZ at the downstream end in the X direction to the nozzle NZ of the head unit 241 that constitutes the left boundary nozzle pair, among the nozzles NZ of the head unit 241. The CPU 110 determines, as the nozzles not to be used, the nozzles NZ of the head unit 241 that are upstream in the X direction from the nozzle NZ of the head unit 241 that constitutes the left boundary nozzle pair, among the nozzles NZ of the head unit 241.

[0073] The CPU 110 determines, as nozzles to be used, the nozzles NZ of the head unit 242 that form the left boundary nozzle pair through the nozzles NZ of the head unit 242 that form the right boundary nozzle pair. The CPU 110 determines, as nozzles not to be used, the nozzles NZ of the head unit 242 that are downstream in the X direction from the nozzles NZ of the head unit 242 that form the left boundary nozzle pair and the nozzles NZ of the head unit 242 that are upstream in the X direction from the nozzles NZ of the head unit 242 that form the right boundary nozzle pair.

[0074] The CPU 110 determines, as nozzles to be used, the nozzles NZ of the head unit 243 that form the right boundary nozzle pair, starting from the nozzle NZ of the head unit 243 that forms the right boundary nozzle pair, to the nozzle NZ at the upstream end in the X direction. The CPU 110 determines, as nozzles not to be used, the nozzles NZ of the head unit 243 that are downstream in the X direction from the nozzle NZ of the head unit 243 that form the right boundary nozzle pair.

[0075] For example, when the positional deviation amount ΔXa is -3, the nozzles NZ from the nozzle NZ at the downstream end in the X direction to nozzle A9 are determined as the nozzles to be used in the head unit 241, and nozzle A10 is determined as the nozzle not to be used. When the positional deviation amounts ΔXa and ΔXb are -3 and +2, the nozzles NZ from nozzle B1 to nozzle C8 are determined as the nozzles to be used in the head unit 242, and nozzle B0, nozzles C9, and C10 are determined as the nozzles not to be used. When the positional deviation amount ΔXb is +2, the nozzles NZ from nozzle D5 to the nozzle NZ at the upstream end in the X direction are determined as the nozzles to be used in the head unit 243, and nozzles D0 to D4 are determined as the nozzles not to be used.

[0076] CPU 110 sets the nozzles to be used and the nozzles to be unused by recording at least one of the determined nozzles to be used and the nozzles to be unused in a settings file (not shown). As a result, subsequent printing is performed using the nozzles to be used and not the nozzles to be unused.

[0077] According to the present embodiment described above, the CPU 110 executes a printing process (S210 in FIG. 9) that causes the printing mechanism 200 to print the test image TI, an acquisition process (S220 in FIG. 9) that acquires the positional deviation amount ΔXa, and a setting process (S230, S240 in FIG. 9) that uses the positional deviation amount ΔXa to set the nozzles to be used and the nozzles not to be used among the multiple nozzles NZ of the head unit 241 and the multiple nozzles of the head unit 242.

[0078] As a result, even if there is misalignment in the X direction between the head unit 241 and the head unit 242 due to variations in assembly, it is possible to appropriately determine the nozzles to be used and the nozzles to be unused from the multiple nozzles NZ that each include two or more nozzle groups NGn that eject ink of the same color (K ink in this embodiment) and that are positioned differently in the intersecting direction. Therefore, even if there is misalignment in the X direction between the head unit 241 and the head unit 242, it is possible to prevent a decrease in the quality of the image printed by the printing mechanism 200.

[0079] In this embodiment, the used nozzles and unused nozzles in the overlapping range of head unit 241 and head unit 242 are determined by determining the left boundary nozzle pair based on the distance in the transport direction (Y direction) between nozzle NZ of head unit 241 and nozzle NZ of head unit 242, and the range in the X direction that can be printed using only nozzle NZ of head unit 242 (S125 to S140 in Figure 7).

[0080] Here, the nozzles NZ of the head unit 241 that constitute the left boundary nozzle pair are also referred to as first boundary nozzles, and the nozzles NZ of the head unit 242 that constitute the left boundary nozzle pair are also referred to as second boundary nozzles. The longer the distance in the transport direction between the first boundary nozzles and the second boundary nozzles, the more likely it is that the formation positions on the paper M of the first boundary dots formed using the first boundary nozzles and the second boundary dots formed using the second boundary nozzles will be relatively misaligned in the transport direction. For example, consider a case where the first boundary dots and the second boundary dots are formed at the same position in the transport direction on the paper M. In this case, if the positions of the first boundary nozzles and the second boundary nozzles are different in the transport direction, the timings at which ink is ejected from the two boundary nozzles are controlled to different timings, taking into account the distance in the transport direction between the two boundary nozzles and the transport speed of the paper M. The longer the distance in the transport direction between the two first boundary nozzles and the second boundary nozzles, the greater the difference in timing at which ink is ejected from the two boundary nozzles. The greater the difference in timing, the more likely it is that the formation positions of the first boundary dots and the second boundary dots will be misaligned relative to each other if there is variation in the transport speed of the paper M or if the paper M is transported at an angle relative to the ideal transport direction. When the formation positions of the first boundary dots and the second boundary dots are misaligned relative to each other, a line called banding is likely to appear between the image formed using the nozzles NZ of the head unit 241 and the image formed using the nozzles NZ of the head unit 242. Thus, the longer the distance in the transport direction between the first boundary nozzles and the second boundary nozzles, the more likely it is that banding will occur, degrading the image quality of the printed image. In this embodiment, the left boundary nozzle pair is determined so that the distance in the transport direction between the first boundary nozzles and the second boundary nozzles is shortest (S125 in FIG. 7). As a result, the occurrence of banding in the printed image can be suppressed, thereby suppressing degradation in the image quality of the printed image.

[0081] Furthermore, if an image can be printed using only the nozzles NZ of the head unit 242, the banding described above, which is caused by the relative misalignment between the formation positions of the first boundary dots and the second boundary dots, does not occur in the first place. For this reason, if it is possible to print using only the nozzles NZ of the head unit 242, such as when the width of the image to be printed in the X direction is relatively small, it is preferable to print using only the nozzles NZ of the head unit 242 as much as possible. The wider the range that can be printed using only the nozzles NZ of the head unit 242, the higher the possibility of printing using only the nozzles NZ of the head unit 242. For this reason, in this embodiment, if there are two or more candidates for the left boundary nozzle pair with the shortest distance in the transport direction, the candidate that has the widest range that can be printed using only the nozzles NZ of the head unit 242 is determined as the left boundary nozzle pair. For example, in this embodiment, the outermost nozzle pair of the two or more candidates is determined as the left boundary nozzle pair (140 in FIG. 7). As a result, the occurrence of banding in the printed image can be further suppressed, and the deterioration of the image quality of the printed image can be further suppressed.

[0082] Furthermore, in this embodiment, boundary nozzle pairs are determined in advance based on the distance in the transport direction between the boundary nozzles and the range in which printing is possible using only the nozzles NZ of the head unit 242, and a reference table RT is created that records the boundary nozzle pairs for each amount of misalignment (FIGS. 7 and 8). The printer 600 is equipped with a nonvolatile storage device 130 that stores the reference table RT (FIG. 1), and the CPU 110 references the reference table RT to determine the nozzles to be used and the nozzles not to be used (S230 and S340 in FIG. 9). As a result, the CPU 110 does not need to calculate the distance in the transport direction between the boundary nozzles or identify the range in which printing is possible using only the nozzles NZ of the head unit 242 during the nozzle setting process. As a result, appropriate nozzles to be used and nozzles not to be used can be determined quickly.

[0083] Furthermore, in this embodiment, the CPU 110 executes an acquisition process (S220 in FIG. 9) that acquires the positional deviation amount ΔXb, and a setting process (S230 and S240 in FIG. 9) that uses the positional deviation amount ΔXb to set the nozzles NZ of the head unit 242 and the nozzles NZ of the head unit 243 that are to be used and the nozzles NZ of the head unit 243 that are to be used. Here, the nozzles NZ of the head unit 242 that constitute the right-side boundary nozzle pair are also referred to as third boundary nozzles, and the nozzles NZ of the head unit 243 that constitute the right-side boundary nozzle pair are also referred to as fourth boundary nozzles. The nozzles NZ of the head unit 242 that constitute the right-side boundary nozzle pair are also referred to as fourth boundary nozzles. The nozzles NZ of the head unit 243 that constitute the right-side boundary nozzle pair are determined so that the distance in the transport direction between the third boundary nozzle and the fourth boundary nozzle is shortest (S125 in FIG. 7). As a result, it is possible to prevent banding from occurring between the image printed using the head unit 242 and the image printed using the head unit 243, thereby further preventing degradation in the image quality of the printed image.

[0084] Furthermore, in this embodiment, the left boundary nozzle pair is determined independently based on the positional deviation amount ΔXa, and the right boundary nozzle pair is determined independently based on the positional deviation amount ΔXb. As can be seen from this, the distance in the transport direction between the first and second boundary nozzles that make up the left boundary nozzle pair may differ from the distance in the transport direction between the third and fourth boundary nozzles that make up the right boundary nozzle. In this way, in this embodiment, the left boundary nozzle pair (first and second boundary nozzles) and the right boundary nozzle pair (third and fourth boundary nozzles) can each be appropriately determined, which further reduces the visibility of banding in the printed image.

[0085] Furthermore, in this embodiment, when there are two or more candidates for the left boundary nozzle pair of head units 242 and 243 that have the shortest distance in the transport direction, the candidate that has the widest range that can be printed using only the nozzles of head unit 242 is selected as the right boundary nozzle pair from among those two or more candidates. As a result, it is possible to further prevent banding from occurring in the printed image, and therefore further prevent degradation in the image quality of the printed image.

[0086] Furthermore, in this embodiment, as described above, the transport unit 210 of the printing mechanism 200 transports the paper M so that the center of the paper M in the X direction coincides with the center (center line CL) of the head unit 242 of the print head 240. In other words, a print medium whose length in the X direction is shorter than the range RG2 in which the nozzles NZ of the head unit 242 are located is transported to a position in the X direction where printing can be performed using only the nozzles NZ of the head unit 242. As a result, it is possible to increase the likelihood that the image to be printed can be printed using only the nozzles NZ of the head unit 242. Therefore, it is possible to further suppress degradation in the image quality of the printed image.

[0087] As can be seen from the above explanation, head unit 241 in this embodiment is an example of a first head unit, head unit 242 is an example of a second head unit, and head unit 243 is an example of a third head unit. Test image TI in this embodiment is an example of a specific image, left image LI(q) is an example of a first image, center image CI(q) is an example of a second image, and right image RI(q) is an example of a third image. The X direction in this embodiment is an example of a specific direction, and the Y direction is an example of an intersecting direction.

[0088] B. Variations (1) The configuration of the print head 240 in the above embodiment is merely an example, and various modifications are possible. For example, in the above embodiment, the head units 241 to 243 each have the same configuration, but they may have different configurations. For example, the head units 241 to 243 may have different numbers of nozzles NZ, and the head units 241 to 243 may also have different numbers of nozzle groups NGn. Generally speaking, the head unit 241 may have N1 nozzles NZ (N1 is an integer greater than or equal to 4) and include two or more nozzle groups whose positions in the Y direction are different from each other. The head unit 242 may have N2 nozzles NZ (N2 is an integer greater than or equal to 4) and include two or more nozzle groups whose positions in the Y direction are different from each other. The head unit 243 may have N3 nozzles NZ (N3 is an integer greater than or equal to 4) and include two or more nozzle groups whose positions in the Y direction are different from each other.

[0089] (2) In the above embodiment, the print head has three head units, but it may have two, four, or more. For example, if there are two head units, the nozzles to be used and the nozzles to be unused of the two head units are determined based on the boundary nozzle pair between the right-side head unit and the left-side head unit. Then, for example, the paper is transported so that the left edge of the paper is aligned with the vicinity of the left edge of the left-side head unit. In this case, if there are multiple candidates for the boundary nozzle pair with the shortest distance in the transport direction, the boundary nozzle pair is determined so that the number of nozzles to be used of the left-side head unit is greater; in other words, so that the range that can be printed using only the left-side head unit is wider.

[0090] (3) In the above embodiment, the boundary nozzle pair is determined so that the distance in the transport direction is shortest. If there are multiple candidates for the boundary nozzle pair with the shortest distance in the transport direction, the candidate that will widen the range that can be printed using only the head unit 242 is determined to be the boundary nozzle pair. The method for determining the boundary nozzle pair is not limited to this. For example, in principle, the boundary nozzle pair may be determined so that all of the nozzles NZ of the head unit 242 are used so that the range that can be printed using only the head unit 242 is wide. Then, only if the distance in the transport direction between the boundary nozzles is equal to or greater than a predetermined threshold (e.g., 30 mm), the outermost nozzle pair whose distance in the transport direction is equal to or less than the predetermined threshold may be determined to be the boundary nozzle pair. Alternatively, if there are multiple candidates for the boundary nozzle pair with the shortest distance in the transport direction in the design values, the actual measured values ​​of the distance in the transport direction of the multiple boundary nozzle pair candidates may be obtained, and the nozzle pair among these candidates whose actual measured value of the distance in the transport direction is shortest may be determined to be the boundary nozzle pair. In other words, the boundary nozzle pair may be determined based only on the distance in the transport direction between the nozzle pairs. Generally speaking, it is preferable that the boundary nozzle pairs be determined based on at least one of the distance between the nozzle pairs in the transport direction and the range that can be printed using only the head unit 242.

[0091] (4) In the above embodiment, the CPU 110 determines the boundary nozzle pairs by referencing the reference table RT (FIG. 9). Alternatively, when the positional deviation amounts ΔXa and ΔXb are acquired, the CPU 110 may determine the boundary nozzle pairs by executing S115 to S140 in FIG. 7 using the positional deviation amounts ΔXa and ΔXb as the target deviation amounts.

[0092] (5) In the above embodiment, the steps of creating the lookup table in FIG. 7 are performed by an operator, but some or all of these steps may be realized by the CPU 110 executing a program for creating the lookup table.

[0093] (6) In the above embodiment, the nozzle setting process of FIG. 9 is executed by the CPU 110 of the printer 600. Alternatively, the nozzle setting process may be executed by a computer (for example, a terminal device such as a personal computer or smartphone, or a server such as a cloud server) connected to the printer 600 so that it can communicate with the printer 600. In this case, for example, the computer sets the active and inactive nozzles in the printer 600 by sending a setting file to the printer 600 in which the active and inactive nozzles are recorded. As such, in the above embodiment, the control device 100 of the printer 600 is an example of a setting device, and the printing mechanism 200 is an example of a print execution unit. In this modified example, the computer that executes the nozzle setting process is an example of a setting device, and the printer 600 is an example of a print execution unit.

[0094] (8) In each of the above embodiments, part of the configuration realized by hardware may be replaced by software, and conversely, part or all of the configuration realized by software may be replaced by hardware.

[0095] The present invention has been described above based on examples and modifications, but the above-described embodiments of the invention are intended to facilitate understanding of the present invention and are not intended to limit the present invention. The present invention may be modified or improved without departing from the spirit and scope of the claims, and equivalents thereof are also included in the present invention. [Explanation of symbols]

[0096] 100...control device, 110...CPU, 120...volatile storage device, 125...buffer area, 130...nonvolatile storage device, 140...display unit, 150...operation unit, 160...communication unit, 200...printing mechanism, 210...transport unit, 230...head drive unit, 240...print head, 241, 242, 243...head unit, 245...base member, 600...printer, M...paper, NGn...nozzle group, NZ...nozzle, PG...computer program, RT...reference table, RTa...first table, RTb...second table, TD...test image data, TI...test image

Claims

1. A setting device for a print execution unit equipped with a print head equipped with a plurality of head units including a first head unit equipped with N1 (N1 is an integer of 4 or more) first nozzles that are positioned differently from one another in a specific direction, and a second head unit equipped with N2 (N2 is an integer of 4 or more) second nozzles that are positioned differently from one another in the specific direction, the first head unit and the second head unit are positioned differently in a cross direction that crosses the specific direction, a first range in which the N1 first nozzles are located, the first range being a range in the specific direction, includes a second range in which the N2 second nozzles are located, the first range overlapping with the second range being a range in the specific direction, and a range not overlapping with the second range; the N1 first nozzles and the N2 second nozzles are nozzles that eject ink of the same color, the N1 first nozzles include two or more nozzle groups whose positions in the intersecting direction are different from each other, the N2 second nozzles include two or more nozzle groups whose positions in the intersecting direction are different from each other, The setting device includes: a printing process that causes the print execution unit to print a specific image, the specific image including a first image printed using at least a portion of the N1 first nozzles and a second image printed using at least a portion of the N2 second nozzles; an information acquisition process for acquiring relative position information determined using the printed specific image, the relative position information including information indicating a positional deviation amount in the specific direction between the N1 first nozzles and the N2 second nozzles; a setting process for setting, using the relative position information, nozzles to be used for printing and nozzles not to be used for printing among the N1 first nozzles and the N2 second nozzles in a range where the first range and the second range overlap; Run a storage unit that stores a table that records, for each positional deviation amount, first boundary nozzles and second boundary nozzles that are predetermined based on at least one of the distance between the first nozzles and the second nozzles in the intersecting direction and a specific range that is a range in the specific direction that is printable using only the second nozzles, the setting process is a process of setting the used nozzles and the unused nozzles by referring to the table, the first boundary nozzle is the first nozzle located at the boundary between a range in the first range in which the active nozzle is located and a range in the second range in which the active nozzle is located, The second boundary nozzle is the second nozzle located at the boundary.

2. A setting device for a print execution unit equipped with a print head equipped with a plurality of head units including a first head unit equipped with N1 (N1 is an integer of 4 or more) first nozzles that are positioned differently from one another in a specific direction, and a second head unit equipped with N2 (N2 is an integer of 4 or more) second nozzles that are positioned differently from one another in the specific direction, the first head unit and the second head unit are positioned differently in a cross direction that crosses the specific direction, a first range in which the N1 first nozzles are located, the first range being a range in the specific direction, includes a second range in which the N2 second nozzles are located, the first range overlapping with the second range being a range in the specific direction, and a range not overlapping with the second range; the N1 first nozzles and the N2 second nozzles are nozzles that eject ink of the same color, the N1 first nozzles include two or more nozzle groups whose positions in the intersecting direction are different from each other, the N2 second nozzles include two or more nozzle groups whose positions in the intersecting direction are different from each other, The setting device includes: a printing process that causes the print execution unit to print a specific image, the specific image including a first image printed using at least a portion of the N1 first nozzles and a second image printed using at least a portion of the N2 second nozzles; an information acquisition process for acquiring relative position information determined using the printed specific image, the relative position information including information indicating a positional deviation amount in the specific direction between the N1 first nozzles and the N2 second nozzles; a setting process for setting, using the relative position information, nozzles to be used for printing and nozzles not to be used for printing among the N1 first nozzles and the N2 second nozzles in a range where the first range and the second range overlap; Run the active nozzles and the non-active nozzles are set by first boundary nozzles and second boundary nozzles that are determined based on at least one of a distance between the first nozzles and the second nozzles in the intersecting direction and a specific range that is a range in the specific direction in which printing is possible using only the second nozzles of the active nozzles, the first boundary nozzle is one of the N1 first nozzles, and is a nozzle located at the boundary between a range in the first range in which the active nozzle is located and a range in the second range in which the active nozzle is located, A setting device, wherein the second boundary nozzle is one nozzle among the N2 second nozzles and is a nozzle located at the boundary.

3. 3. The setting device according to claim 2, further comprising: a storage unit that stores a table in which the first boundary nozzles and the second boundary nozzles that are predetermined based on at least one of the distance between the first nozzles and the second nozzles in the intersecting direction and the specific range are recorded for each positional deviation amount, The setting process is a process of setting the used nozzles and the unused nozzles by referring to the table.

4. The setting device according to any one of claims 1 to 3, A setting device wherein the first boundary nozzle and the second boundary nozzle are determined so that a distance between the first boundary nozzle and the second boundary nozzle in the intersecting direction is shortest.

5. 5. The setting device according to claim 4, A setting device in which, when there are two or more pairs of candidates for the first boundary nozzle and the second boundary nozzle that have the shortest distance in the intersecting direction, the candidate with the widest specific range among the two or more pairs of candidates is determined to be the first boundary nozzle and the second boundary nozzle.

6. 6. The setting device according to claim 4 or 5, the print head further includes a third head unit having N3 (N3 is an integer of 4 or greater) third nozzles that are positioned differently from one another in the specific direction, the third head unit and the second head unit are positioned differently in the intersecting direction, a third range in which the N3 third nozzles are located, the third range being a range in the specific direction, includes a range that overlaps with the second range and a range that does not overlap with the second range, the N3 third nozzles and the N2 second nozzles are nozzles that eject ink of the same color, the N3 third nozzles include two or more nozzle groups whose positions in the intersecting direction are different from each other, the second range is located between a range of the first range that does not overlap with the second range and a range of the third range that does not overlap with the second range, the specific image further includes a third image printed using at least a portion of the N3 third nozzles, the relative position information includes information indicating a positional deviation amount in the specific direction between the N3 third nozzles and the N2 second nozzles, the setting process further includes using the relative position information to set the used nozzles and the unused nozzles among the N3 third nozzles and the N2 second nozzles; the active nozzle and the inactive nozzle are set so that the distance between the third boundary nozzle and the fourth boundary nozzle in the intersecting direction is shortest, the third boundary nozzle is one nozzle among the N3 third nozzles, and is a nozzle located at the boundary between a range in the third range in which the active nozzle is located and a range in the second range in which the active nozzle is located, A setting device, wherein the fourth boundary nozzle is one nozzle among the N2 second nozzles and is a nozzle located at the boundary.

7. 7. The setting device according to claim 6, a distance between the first boundary nozzle and the second boundary nozzle in the specific direction and a distance between the third boundary nozzle and the fourth boundary nozzle in the intersecting direction are different.

8. 8. The setting device according to claim 6 or 7, When there are two or more pairs of candidates for the first boundary nozzle and the second boundary nozzle that have the shortest distance in the intersecting direction, among the two or more pairs of candidates, the candidates that have the widest specific range that is a range in the specific direction and that is printable using only the second nozzles of the operating nozzles are determined as the first boundary nozzle and the second boundary nozzle, A setting device in which, when there are two or more pairs of candidates for the third boundary nozzle and the fourth boundary nozzle that have the shortest distance in the intersecting direction, the candidate with the widest specific range among the two or more pairs of candidates is determined to be the third boundary nozzle and the fourth boundary nozzle.

9. The setting device according to any one of claims 1 to 8, further comprising: the print execution unit includes a transport unit that transports the print medium in the cross direction; A setting device in which the transport unit transports the printing medium, whose length in the specific direction is shorter than the second range in which the N2 second nozzles are located, to a position in the specific direction where printing can be done using only the N2 second nozzles.

10. A computer program for a print execution unit having a print head with a plurality of head units including a first head unit having N1 (N1 is an integer of 4 or more) first nozzles that are positioned differently from one another in a specific direction, and a second head unit having N2 (N2 is an integer of 4 or more) second nozzles that are positioned differently from one another in the specific direction, the first head unit and the second head unit are positioned differently in a cross direction that crosses the specific direction, a first range in which the N1 first nozzles are located, the first range being a range in the specific direction, includes a second range in which the N2 second nozzles are located, the first range overlapping with a second range in which the N2 second nozzles are located, the second range being a range in the specific direction, and a range not overlapping with the second range; the N1 first nozzles and the N2 second nozzles are nozzles that eject ink of the same color, the N1 first nozzles include two or more nozzle groups whose positions in the intersecting direction are different from each other, the N2 second nozzles include two or more nozzle groups whose positions in the intersecting direction are different from each other, The computer program comprises: a print control function that causes the print execution unit to print a specific image, the specific image including a first image printed using at least a portion of the N1 first nozzles and a second image printed using at least a portion of the N2 second nozzles; an information acquisition function that acquires relative position information determined using the printed specific image, the relative position information including information indicating a positional deviation amount in the specific direction between the N1 first nozzles and the N2 second nozzles; a nozzle setting function that uses the relative position information to set, within an overlapping range of the first range and the second range, nozzles to be used for printing and nozzles not to be used for printing, among the N1 first nozzles and the N2 second nozzles; This is realized on a computer, the active nozzles and the non-active nozzles are set by first boundary nozzles and second boundary nozzles that are determined based on at least one of the distance between the first nozzles and the second nozzles in the intersecting direction and the range in the specific direction in which printing is possible using only the second nozzles of the active nozzles, the first boundary nozzle is one of the N1 first nozzles, and is a nozzle located at the boundary between a range in the first range in which the active nozzle is located and a range in the second range in which the active nozzle is located, The second boundary nozzle is one nozzle among the N2 second nozzles and is a nozzle located at the boundary.

11. A setting method for a print execution unit equipped with a print head equipped with a plurality of head units including a first head unit equipped with N1 (N1 is an integer of 4 or more) first nozzles whose positions in a specific direction are different from each other, and a second head unit equipped with N2 (N2 is an integer of 4 or more) second nozzles whose positions in the specific direction are different from each other, the first head unit and the second head unit are positioned differently in a cross direction that crosses the specific direction, a first range in which the N1 first nozzles are located, the first range being a range in the specific direction, includes a second range in which the N2 second nozzles are located, the first range overlapping with the second range being a range in the specific direction, and a range not overlapping with the second range; the N1 first nozzles and the N2 second nozzles are nozzles that eject ink of the same color, the N1 first nozzles include two or more nozzle groups whose positions in the intersecting direction are different from each other, the N2 second nozzles include two or more nozzle groups whose positions in the intersecting direction are different from each other, The setting method includes: a printing step of causing the print execution unit to print a specific image, the specific image including a first image printed using at least a portion of the N1 first nozzles and a second image printed using at least a portion of the N2 second nozzles; an information acquiring step of acquiring relative position information determined using the printed specific image, the relative position information including information indicating a positional deviation amount in the specific direction between the N1 first nozzles and the N2 second nozzles; a nozzle setting step of setting, using the relative position information, nozzles to be used for printing and nozzles not to be used for printing among the N1 first nozzles and the N2 second nozzles in a range where the first range and the second range overlap; Including, the active nozzles and the non-active nozzles are set by first boundary nozzles and second boundary nozzles that are determined based on at least one of the distance between the first nozzles and the second nozzles in the intersecting direction and the range in the specific direction in which printing is possible using only the second nozzles of the active nozzles, the first boundary nozzle is one of the N1 first nozzles, and is a nozzle located at the boundary between a range in the first range in which the active nozzle is located and a range in the second range in which the active nozzle is located, A setting method in which the second boundary nozzle is one nozzle among the N2 second nozzles and is a nozzle located at the boundary.

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