Liquid droplet ejection device

Abstract

To simply correct the variation of droplet discharge characteristic between a plurality of nozzles.SOLUTION: A droplet discharge device causes relative movement means to make different a position in a conveyance direction of recording paper P and perform a unit recording operation multiple times to record, on a recording target medium, a plurality of pattern block groups 93a-93e arranged side by side in the conveyance direction and having first pattern blocks and second pattern blocks arranged side by side in a scanning direction. In the unit recording operation, the droplet discharge device causes the relative movement means to discharge ink drops from a first nozzle 10a including a nozzle of an upstream end of a nozzle array 9 in the conveyance direction and record the first pattern blocks, then convey the recording paper P by a distance according to the interval between the first nozzle 10a and a second nozzle 10b including a nozzle of a downstream end of the nozzle array 9 in the conveyance direction, and then discharge ink drops from the second nozzle 10b and record the second pattern blocks. The densities of the first pattern blocks are made the same between the plurality of pattern block groups 93a to 93b, and the densities of the second pattern blocks are made to be different from each other.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to a droplet ejection device that ejects droplets from a nozzle. [Background technology]

[0002] As an example of a droplet ejection device that ejects droplets from nozzles, Patent Document 1 describes an image recording device that performs recording by ejecting ink from nozzles. In the image recording device described in Patent Document 1, an inkjet head mounted on a carriage has multiple nozzles aligned in the transport direction. Then, while moving the carriage in a scanning direction perpendicular to the transport direction, a recording pass in which ink is ejected from multiple nozzles of the inkjet head to form dots on paper, and a transport operation in which the paper is transported in the transport direction are repeatedly performed to record on the paper. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-177556 A Summary of the Invention [Problem to be solved by the invention]

[0004] In an image recording device such as that described in Patent Document 1, the inkjet head may have variations in the amount of ink ejected between multiple nozzles due to manufacturing variations, etc. In this case, if recording is performed by repeating the recording pass and the transport operation as described above, there is a risk that density unevenness will occur in the recorded image along the transport direction.

[0005] An object of the present invention is to provide a droplet ejection device that can easily correct variations in droplet ejection characteristics among a plurality of nozzles. [Means for solving the problem]

[0006] A droplet discharge device according to the present invention includes a droplet discharge head having a nozzle row formed by arranging a plurality of nozzles in a first direction, a carriage on which the droplet discharge head is mounted and which moves in a second direction intersecting the first direction, relative movement means for relatively moving the droplet discharge head and a discharge receiving medium in the first direction, and a control unit, the nozzle row including a first nozzle and a second nozzle that is farther from one end of the nozzle row in the first direction than the first nozzle, and the relative movement means moves the discharge receiving medium in the first direction relative to the droplet discharge head. the control unit relatively moves the droplet ejection head and the ejection receiving medium so as to move in a direction from the one end of the nozzle row toward the other end, and the control unit performs a unit recording operation including a first recording operation, a relative movement operation, and a second recording operation, the first recording operation being an operation for causing the droplet ejection head to eject droplets from the first nozzles toward the ejection receiving medium while moving the carriage in the second direction, thereby recording a first pattern block extending in the first direction and the second direction on the ejection receiving medium, and the relative movement operation is performed after the first recording operation. the second recording operation is an operation of causing the droplet ejection head and the ejection receiving medium to relatively move an amount corresponding to a distance between the first nozzle and the second nozzle in the first direction by using a relative movement means, and causing the carriage to move in the second direction while causing the droplet ejection head to eject droplets from the second nozzle toward the ejection receiving medium after the relative movement operation, thereby recording, on the ejection receiving medium, a second pattern block that extends in the first direction and the second direction and is disposed adjacent to the first pattern block in the second direction, by causing the carriage to move in the second direction while causing the droplet ejection head to eject droplets from the second nozzle toward the ejection receiving medium, thereby recording, on the recording medium, a pattern block set that is a set of the first pattern block and the second pattern block that are arranged in the second direction, and recording, on the recording medium, a plurality of sets of the pattern block sets that are arranged in the first direction, by changing the positional relationship in the first direction between the droplet ejection head and the ejection receiving medium by the relative movement means and performing the unit recording operation a plurality of times, and further recording a plurality of sets of the pattern block sets that are arranged in the first direction,A plurality of patterns block sets are recorded such that the density of the different density pattern block, which is the other of the first pattern block and the second pattern block, differs among the plurality of patterns block sets. Effect of the Invention

[0007] According to the present invention, the difference in the amount of droplets discharged between the first nozzle and the second nozzle can be grasped based on which of a plurality of pattern block sets has the smallest density difference between the first pattern block and the second pattern block. Then, by correcting the amount of droplets discharged from the nozzle based on the difference in the amount of droplets discharged, the variation in the amount of droplets discharged between the nozzles can be reduced. [Brief description of the drawings]

[0008] [Figure 1] 1 is a schematic configuration diagram of a printer according to an embodiment of the present invention; [Diagram 2] FIG. 2 is a block diagram showing the electrical configuration of the printer. [Diagram 3] 10 is a flowchart showing a process for adjusting the amount of ink droplets ejected from each nozzle. [Figure 4] (a) is a diagram for explaining the recording of the first first pattern block, (b) is a diagram for explaining the recording of the second first pattern block, (c) is a diagram for explaining the recording of the third first pattern block, (d) is a diagram for explaining the recording of the fourth first pattern block, and (e) is a diagram for explaining the recording of the fifth first pattern block. [Diagram 5] (a) is a diagram for explaining the recording of the first second pattern block, (b) is a diagram for explaining the recording of the second second pattern block, (c) is a diagram for explaining the recording of the third second pattern block, (d) is a diagram for explaining the recording of the fourth second pattern block, and (e) is a diagram for explaining the recording of the fifth second pattern block. [Figure 6](a) is a diagram for explaining the recording of the first second pattern block when the density is lighter the more downstream the second pattern block is in the transport direction, (b) is a diagram for explaining the recording of the second second pattern block when the density is lighter the more downstream the second pattern block is in the transport direction, (c) is a diagram for explaining the recording of the third second pattern block when the density is lighter the more downstream the second pattern block is in the transport direction, (d) is a diagram for explaining the recording of the fourth second pattern block when the density is lighter the more downstream the second pattern block is in the transport direction, and (e) is a diagram for explaining the recording of the fifth second pattern block when the density is lighter the more downstream the second pattern block is in the transport direction. [Figure 7] (a) is a diagram for explaining recording of the downstream portion of the first first pattern block when the number of first nozzles is large, (b) is a diagram for explaining recording of the upstream portion of the first first pattern block when the number of first nozzles is large, (c) is a diagram for explaining recording of the downstream portion of the second first pattern block when the number of first nozzles is large, (d) is a diagram for explaining recording of the upstream portion of the second first pattern block when the number of first nozzles is large, and (e) is a diagram for explaining recording of the downstream portion of the third first pattern block when the number of first nozzles is large. [Figure 8] (a) is a diagram for explaining recording of the upstream portion of the third first pattern block when the number of first nozzles is large, (b) is a diagram for explaining recording of the downstream portion of the fourth first pattern block when the number of first nozzles is large, (c) is a diagram for explaining recording of the upstream portion of the fourth first pattern block when the number of first nozzles is large, (d) is a diagram for explaining recording of the downstream portion of the fifth first pattern block when the number of first nozzles is large, and (e) is a diagram for explaining recording of the upstream portion of the fifth first pattern block when the number of first nozzles is large. [Figure 9](a) is a diagram explaining the recording of the first second pattern block when the number of first nozzles is large, (b) is a diagram explaining the recording of the second second pattern block when the number of first nozzles is large, (c) is a diagram explaining the recording of the third second pattern block when the number of first nozzles is large, (d) is a diagram explaining the recording of the fourth second pattern block when the number of first nozzles is large, and (e) is a diagram explaining the recording of the fifth second pattern block when the number of first nozzles is large. [Figure 10] (a) is a diagram for explaining the recording of the sixth second pattern block when the number of first nozzles is large, (b) is a diagram for explaining the recording of the seventh second pattern block when the number of first nozzles is large, (c) is a diagram for explaining the recording of the eighth second pattern block when the number of first nozzles is large, (d) is a diagram for explaining the recording of the ninth second pattern block when the number of first nozzles is large, and (e) is a diagram for explaining the recording of the tenth second pattern block when the number of first nozzles is large. [Figure 11] FIG. 10(a) is a diagram for explaining the third nozzle, and FIG. 10(b) is a diagram for explaining a test pattern printed using the first to third nozzles. [Figure 12] (a) is a diagram for explaining the recording of the first first pattern block, (b) is a diagram for explaining the recording of the second first pattern block and the first third pattern block, (c) is a diagram for explaining the recording of the third first pattern block and the second third pattern block, (d) is a diagram for explaining the recording of the fourth first pattern block and the third third pattern block, (e) is a diagram for explaining the recording of the fifth first pattern block and the fourth third pattern block, and (f) is a diagram for explaining the recording of the fifth third pattern block. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Preferred embodiments of the present invention will now be described.

[0010] <Overall printer configuration> As shown in FIG. 1, a printer 1 according to this embodiment (the “droplet ejection device” of the present invention) includes a carriage 2, an inkjet head 3 (the “droplet ejection head” of the present invention), a platen 4, and transport rollers 5 and 6 (the “relative movement means” of the present invention).

[0011] The carriage 2 is supported by two guide rails 11, 12 extending in a horizontal scanning direction (the "second direction" of the present invention). The carriage 2 is connected to a carriage motor 86 (see FIG. 2) via a belt or the like (not shown). When the carriage motor 86 is driven, the carriage 2 moves in the scanning direction along the guide rails 11, 12. In the following description, the right and left sides of the scanning direction are defined as shown in FIG. 1.

[0012] The inkjet head 3 is mounted on the carriage 2. The inkjet head 3 ejects ink ("droplets" of the present invention) from a plurality of nozzles 10 formed on a nozzle surface 3a, which is the lower surface of the inkjet head 3. The plurality of nozzles 10 are arranged in a horizontal transport direction ("first direction" of the present invention) perpendicular to the scanning direction to form a nozzle row 9. The inkjet head 3 also has four nozzle rows 9 aligned in the scanning direction. The nozzles 10 eject black, yellow, cyan, and magenta ink droplets from the nozzles 10, starting from the nozzle row 9 on the right side in the scanning direction. The plurality of nozzles 10 forming each nozzle row 9 also have a plurality of first nozzles 10a aligned consecutively in the transport direction, including a first end nozzle 10a1 located at the end of the nozzle row 9 on the upstream side in the transport direction ("one side of the first direction" of the present invention), and a plurality of second nozzles 10b aligned consecutively in the transport direction, including a second end nozzle 10b1 located at the end of the nozzle row 9 on the downstream side in the transport direction ("the other side of the first direction" of the present invention). As a result, the second nozzles 10b are farther from the upstream end of the nozzle row 9 in the transport direction than the first nozzles 10a. In this embodiment, the number of the first nozzles 10a is the same as the number of the second nozzles 10b. Note that, although the number of the first nozzles 10a and the second nozzles 10b is two in FIG. 1, the number of the first nozzles 10a and the second nozzles 10b may be three or more.

[0013] The inkjet head 3 is also connected to four ink cartridges (not shown) via tubes (not shown) etc. The four colors of ink are supplied to the inkjet head 3 from the four ink cartridges.

[0014] The platen 4 is disposed below the inkjet head 3 and faces the multiple nozzles 10. The platen 4 extends over the entire length of the recording paper P (the "ejection receiving medium" of the present invention) in the scanning direction and supports the recording paper P from below. The transport rollers 5 and 6 transport the recording paper P in the transport direction. The transport roller 5 is disposed upstream of the inkjet head 3 and the platen 4 in the transport direction. The transport roller 6 is disposed downstream of the inkjet head 3 and the platen 4 in the transport direction. The transport rollers 5 and 6 are connected to a transport motor 87 (see FIG. 2) via gears (not shown). When the transport motor 87 is driven, the transport rollers 5 and 6 rotate and transport the recording paper P in the transport direction. As a result, the inkjet head 3 and the recording paper P move relative to each other so that the recording paper P moves in a direction from the upstream end of the nozzle row 9 in the transport direction to the downstream end of the nozzle row 9.

[0015] <Printer electrical configuration> Next, we will explain the electrical configuration of the printer 1. As shown in Fig. 2, the printer 1 is equipped with a control unit 80. The control unit 80 is made up of a CPU (Central Processing Unit) 81, a ROM (Read Only Memory) 82, a RAM (Random Access Memory) 83, a flash memory 84, an ASIC (Application Specific Integrated Circuit) 85, etc. The control unit 80 controls the operations of a carriage motor 86, an inkjet head 3, a transport motor 87, etc.

[0016] In addition to the configuration described above, the printer 1 also has a display unit 71 and an operation unit 72. The display unit 71 is a liquid crystal display or the like provided on the housing of the printer 1. The control unit 80 controls the display unit 71 to cause the display unit 71 to display information necessary for the operation of the printer 1. The operation unit 72 is a button provided on the housing of the printer 1, a touch panel provided on the display unit 71, or the like. When the user operates the operation unit 72, a signal corresponding to the operation is transmitted to the control unit 80.

[0017] The control unit 80 may be one in which only the CPU 81 performs various processes, one in which only the ASIC 85 performs various processes, or one in which the CPU 81 and the ASIC 85 work together to perform various processes. The control unit 80 may be one in which one CPU 81 performs processes independently, or one in which multiple CPUs 81 share the processes. The control unit 80 may be one in which one ASIC 85 performs processes independently, or one in which multiple ASICs 85 share the processes.

[0018] <Processing during recording> Next, a process for recording on the recording paper P in the printer 1 will be described. When recording on the recording paper P in the printer 1, the control unit 80 controls a paper feed mechanism and a transport motor 87 (not shown) to cause the paper feed mechanism and transport rollers 5 and 6 to supply the recording paper P. The control unit 80 then controls the carriage motor 86 to move the carriage 2 in the scanning direction, while repeating a recording pass in which ink droplets are ejected from the multiple nozzles 10 toward the recording paper P, and a transport operation in which the transport motor 87 is controlled to cause the transport rollers 5 and 6 to transport the recording paper P the length of the nozzle row 9 in the transport direction, thereby causing recording on the recording paper P to be performed.

[0019] <Processing for correcting the discharge amount> Next, a description will be given of a process for correcting the amount of ink droplets ejected from the nozzles 10 in the printer 1. In order to correct the amount of ink droplets ejected from the nozzles 10 in the printer 1, the control unit 80 performs a process in accordance with the flow of FIG.

[0020] More specifically, the control unit 80 first executes a pattern recording process (S101). In the pattern recording process, the control unit 80 causes the recording of a test pattern 90 (see FIG. 5(e)). More specifically, the control unit 80 causes the paper feed mechanism and the transport rollers 5 and 6 to supply the recording paper P, as in the case of recording on the recording paper P. Then, the control unit 80 controls the carriage motor 86 to move the carriage 2 in the scanning direction, while controlling the inkjet head 3 to perform a first recording pass (the "first ejection operation" of the present invention) in which ink droplets are ejected from the first nozzles 10a toward the recording paper P, thereby recording a plurality of first pattern blocks 91a formed by ink droplets ejected from the first nozzles 10a and arranged at intervals in the scanning direction, as shown in FIG. 4(a). The shape of the first pattern blocks 91a is a rectangle extending in the scanning direction and the transport direction. Furthermore, in the first recording pass, the control unit 80 records an identification symbol 94a ("A" in FIG. 4A) to the left of the first pattern block 91a located at the leftmost position. The identification symbol 94a is intended to allow a user to identify a pattern block set 93a, which will be described later. In the following description, the first pattern block 91a and first pattern blocks 91b to 91e, which will be described later, may be referred to as the first pattern block 91 when they are not differentiated from each other. The same applies to each pattern block and pattern block set, which will be described later.

[0021] Next, the control unit 80 controls the conveying motor 87 to convey the recording paper P by the length of the first pattern block 91 in the conveying direction to the conveying rollers 5 and 6, and then performs a first recording pass, thereby recording on the recording paper P a plurality of first pattern blocks 91b adjacent to the upstream side of the plurality of first pattern blocks 91a in the conveying direction, as shown in Fig. 4(b). Furthermore, the control unit 80 records an identification symbol 94b ("B" in Fig. 4(b)) to the left of the leftmost first pattern block 91b in the first recording pass. The identification symbol 94b is intended to allow the user to identify a pattern block set 93b, which will be described later.

[0022] Furthermore, the control unit 80 repeats the operation of causing the transport rollers 5 and 6 to transport the recording paper P by the length of the first pattern block 91 in the transport direction and then performing a first recording pass, so as to sequentially record the multiple first pattern blocks 91c to 91e on the recording paper P, as shown in Figures 4(c) to 4(e). The multiple first pattern blocks 91c to 91e are adjacent to the multiple first pattern blocks 91b to 91d on the upstream side in the transport direction, respectively.

[0023] In addition, in these first recording passes, identification symbols 94c-94e ("C", "D", and "E" in Figs. 4(c)-(e)) are recorded to the left of the first pattern blocks 91c-91e located at the leftmost positions, respectively. The identification symbols 94c-94e are intended to allow the user to identify pattern block sets 93c-93e, which will be described later.

[0024] In this embodiment, the amount of ink droplets ejected per unit area from the nozzles 10 is set to be the same in the first printing pass for printing the first pattern blocks 91a-91e. As a result, the first pattern blocks 91a-91e are all printed with approximately the same density. In this embodiment, the first pattern blocks 91a-91e correspond to the "constant density pattern blocks" of the present invention.

[0025] Next, the control unit 80 controls the conveying motor 87 to make the conveying rollers 5 and 6 convey the recording paper P in the conveying direction until the second nozzle 10b and the first pattern block 91a are positioned in the same direction, and then controls the carriage motor 86 to move the carriage 2 in the scanning direction while controlling the inkjet head 3 to perform a second recording pass (the "second ejection operation" of the present invention) in which ink droplets are ejected from the second nozzle 10b toward the recording paper P, thereby recording a plurality of second pattern blocks 92a that are formed by ink droplets ejected from the second nozzle 10b and are arranged alternately in the scanning direction with the plurality of first pattern blocks 91a, as shown in FIG. 5(a). The shape of the second pattern blocks 92a is also a rectangle extending in the scanning direction and the conveying direction.

[0026] Next, the control unit 80 controls the conveying motor 87 to cause the conveying rollers 5, 6 to convey the recording paper P the length of the second pattern block 92 in the conveying direction, and then performs a second recording pass, thereby recording on the recording paper P a plurality of second pattern blocks 92b that are adjacent to the upstream side of the plurality of second pattern blocks 92a in the conveying direction and that are arranged alternately with the plurality of first pattern blocks 91b in the scanning direction, as shown in Figure 5 (b).

[0027] Furthermore, the control unit 80 repeats the operation of causing the transport rollers 5 and 6 to transport the recording paper P by the length of the second pattern block 92 in the transport direction and then performing a second recording pass, so that the second pattern blocks 92c to 92e are sequentially recorded on the recording paper P, as shown in Figures 5(c) to 5(e). The second pattern blocks 92c to 92e are adjacent to the second pattern blocks 92b to 92d on the upstream side in the transport direction. The second pattern blocks 92c to 92e are alternately arranged in the scanning direction with the first pattern blocks 91c to 91e.

[0028] In this embodiment, in the second recording pass for recording the second pattern block 92c, the inkjet head 3 is driven with the same drive signal as when recording the first pattern blocks 91a to 91e. In this embodiment, in the second recording pass for recording the second pattern blocks 92a to 92e, in recording the second pattern block on the upstream side in the transport direction, the inkjet head 3 is driven so that the amount of ink droplets ejected from the nozzles 10 per unit area decreases as the distance from the second pattern block 92a, which is the most downstream in the transport direction, increases.

[0029] As a result, among the second pattern blocks 92a to 92e, the second pattern block 92e located at the upstream end in the transport direction has the lightest density, and the second pattern blocks 92 farther from the second pattern block 92e have the darker density. Also, if the first nozzle 10a and the second nozzle 10b eject the same amount of ink droplets when the inkjet head 3 is driven with the same drive signal to eject ink droplets, the density of the second pattern block 92c will be approximately the same as the density of the first pattern blocks 91a to 91e. In this embodiment, the second pattern blocks 92a to 92e correspond to the "different density pattern blocks" of the present invention.

[0030] Then, by recording the first pattern blocks 91a-91e and the second pattern blocks 92a-92e in this manner, a unit recording operation consisting of a first recording pass for recording the first pattern block 91a, transporting the recording paper P from the position shown in FIG. 4(a) to the position shown in FIG. 5(a) (the "relative movement operation" of the present invention), and a second recording pass for recording the second pattern block 92a records a pattern block set 93a in which a plurality of first pattern blocks 91a and a plurality of second pattern blocks 92a are arranged alternately in the scanning direction.

[0031] Similarly, by a unit recording operation consisting of a first recording pass for recording the first pattern blocks 91b to 91e, transporting the recording paper P from the position shown in Figures 4(b) to (e) to the position shown in Figures 5(b) to (e) (the "relative movement operation" of the present invention), and a second recording pass for recording the second pattern blocks 92b, a pattern block set 93b in which a plurality of first pattern blocks 91b and a plurality of second pattern blocks 92b are alternately arranged in the scanning direction, a pattern block set 93c in which a plurality of first pattern blocks 91c and a plurality of second pattern blocks 92c are alternately arranged in the scanning direction, a pattern block set 93d in which a plurality of first pattern blocks 91d and a plurality of second pattern blocks 92d are alternately arranged in the scanning direction, and a pattern block set 93e in which a plurality of first pattern blocks 91e and a plurality of second pattern blocks 92e are alternately arranged in the scanning direction are recorded.

[0032] In this embodiment, the unit recording operation is performed while varying the position of the recording paper P in the transport direction, thereby recording the test pattern 90 having the pattern block groups 93a to 93e aligned in the transport direction.

[0033] In this embodiment, as shown in Fig. 4(e) and Fig. 5(a), when the second pattern block 92a is recorded, the recording paper P is located downstream in the transport direction compared to when the first pattern block 91e is recorded, so that the second pattern blocks 92a to 92e are recorded after the first pattern blocks 91a to 91e are recorded, but this is not limited to this. When the distance between the first nozzle 10a and the second nozzle 10b in the transport direction is smaller than in this embodiment, the first pattern block 91 of a certain pattern block set 93 and the second pattern block 92 of a pattern block set 93 other than the said pattern block set 93 may be recorded by ejecting ink droplets from the first nozzle 10a and the second nozzle 10b in a recording pass. Alternatively, any of the second pattern blocks 92 may be recorded by performing a second recording pass after a certain first recording pass and before the next first recording pass.

[0034] 3, after the pattern recording process in S101, the control unit 80 executes a selection screen display process (S102). In the selection screen display process, the control unit 80 controls the display unit 71 to display a selection screen on the display unit 71 for selecting a pattern block set 93 having the smallest density difference between the first pattern block 91 and the second pattern block 92 from among the pattern block sets 93a to 93e. The control unit 80 then waits until it receives a selection signal for selecting a pattern block set 93 (identification symbols 94a to 94e) based on the user's operation of the operation unit 72 (S103: NO).

[0035] Then, when the selection signal is received (S103: YES), the control unit 80 executes the ejection amount correction process (S104). In the ejection amount correction process, the control unit 80 corrects the amount of ink droplets ejected from the nozzles 10.

[0036] For example, when the selection signal indicates the pattern block set 93c, the amount of ink droplets ejected from the nozzles 10 is not corrected.

[0037] Furthermore, when the selection signal indicates the pattern block set 93a or the pattern block set 93b, at least one of a correction to increase the amount of ink droplets ejected from the second nozzle 10b and a correction to decrease the amount of ink droplets ejected from the first nozzle 10a is performed. When a correction to increase the amount of ink droplets ejected from the second nozzle 10b is performed, the amount of ink droplets ejected from the second nozzle 10b is increased as the selection signal indicates a pattern block set 93 that is further downstream in the transport direction. When a correction to decrease the amount of ink droplets ejected from the first nozzle 10a is performed, the amount of ink droplets ejected from the first nozzle 10a is decreased as the selection signal indicates a pattern block set 93 that is further downstream in the transport direction.

[0038] Furthermore, when the selection signal indicates the pattern block set 93d or the pattern block set 93e, at least one of a correction to reduce the amount of ink droplets ejected from the second nozzle 10b and a correction to increase the amount of ink droplets ejected from the first nozzle 10a is performed. When a correction to reduce the amount of ink droplets ejected from the second nozzle 10b is performed, the amount of ink droplets ejected from the second nozzle 10b is reduced as the selection signal indicates a pattern block set 93 that is further upstream in the transport direction. When the amount of ink droplets ejected from the first nozzle 10a is increased, the amount of ink droplets ejected from the first nozzle 10a is increased as the selection signal indicates a pattern block set 93 that is further upstream in the transport direction.

[0039] Note that, although the recording of the test pattern 90 for one nozzle row 9 and the correction of the amount of ink droplets ejected from the nozzles 10 have been described here, by recording the test pattern 90 for each nozzle row 9 in the same manner as described above, for example, four test patterns 90 for four nozzle rows 9 are recorded on the recording paper P lined up in the scanning direction. Then, for each nozzle row 9, the amount of ink droplets ejected from the nozzles 10 is corrected based on the recording results of the test pattern 90.

[0040] <Effects> In this embodiment, a first pattern block 91 is recorded by ink droplets ejected from the first nozzle 10a, and a second pattern block 92 is recorded by ink droplets ejected from the second nozzle 10b and is aligned in the scanning direction with the first pattern block 91. A plurality of pattern block sets 93a-93e are recorded and aligned in the transport direction. The first pattern blocks 91a-91e are all made to have the same density, and the second pattern blocks 92a-92e are made to have different densities.

[0041] This makes it possible to grasp the difference in the amount of ink droplets ejected between the first nozzle 10a and the second nozzle 10b based on which pattern block set 93 out of the multiple pattern block sets 93a-93e has the smallest density difference between the first pattern block 91 and the second pattern block 92. Then, by correcting the amount of ink droplets ejected from the nozzle 10 based on the difference in the amount of ink droplets ejected, it is possible to reduce variation in the amount of ink droplets ejected between the nozzles 10.

[0042] In this embodiment, the first pattern blocks 91a-91e can all be made to have the same density by discharging the same amount of ink droplets per unit area onto the recording paper P when recording the first pattern blocks 91a-91e. The second pattern blocks 92a-92e can all be made to have different densities by discharging different amounts of ink droplets per unit area onto the recording paper P when recording the second pattern blocks 92a-92e.

[0043] In this embodiment, the second pattern blocks 92a-92e located at the upstream end in the transport direction have the lowest density, and the second pattern blocks 92 farther from the second pattern block 92e have higher density. As a result, in the test pattern 90 in which a plurality of pattern block sets 93a-93e are arranged in the transport direction, the density difference between the first pattern block 91 and the second pattern block 92 gradually changes from the upstream to the downstream in the transport direction. Therefore, the user can easily check which pattern block set 93 among the plurality of pattern block sets 93a-93e has the smallest density difference between the first pattern block 91 and the second pattern block 92.

[0044] Also, unlike this embodiment, when there is only one first nozzle 10a in the nozzle row 9, it is necessary to repeatedly perform a first recording pass and transport the recording paper P in order to record the first pattern block 91 extending in the transport direction. Similarly, when there is only one second nozzle 10b in the nozzle row 9, it is necessary to repeatedly perform a second recording pass and transport the recording paper P in order to record the second pattern block 92 extending in the transport direction.

[0045] In contrast, in this embodiment, the nozzle row 9 has a plurality of first nozzles 10a that are continuously aligned in the transport direction. This allows each of the first pattern blocks 91a to 91e extending in the transport direction to be printed in a single first printing pass. That is, the number of first printing passes required to print the first pattern blocks 91a to 91e can be reduced. Similarly, in this embodiment, the nozzle row 9 has a plurality of second nozzles 10b that are continuously aligned in the transport direction. This allows each of the second pattern blocks 92a to 92e extending in the transport direction to be printed in a single second printing pass. That is, the number of second printing passes required to print the second pattern blocks 92a to 92e can be reduced.

[0046] In this embodiment, while moving the carriage 2 in the scanning direction, a recording pass in which ink droplets are ejected from the multiple nozzles 10 of the inkjet head 3 toward the recording paper P and a transport operation in which the recording paper P is transported in the transport direction by the length of the nozzle row 9 using transport rollers 5 and 6 are repeated to form an image on the recording paper P. In this case, an area of ​​the recording paper P where ink droplets are ejected from the first end nozzle 10a1 in one recording pass and an area where ink droplets are ejected from the second end nozzle 10b1 in the next recording pass are adjacent to each other in the transport direction.

[0047] In this embodiment, among the multiple nozzles 10 forming the nozzle row 9, some of the nozzles 10 that are continuously aligned in the transport direction, including the first end nozzles 10a1, are the first nozzles 10a, and some of the nozzles 10 that are continuously aligned in the transport direction, including the second end nozzles 10b1, are the second nozzles 10b. Therefore, by correcting the amount of ink droplets ejected from the nozzles 10 based on the recording results of the multiple pattern block groups 93a to 93e, it is possible to make the density difference at the boundary between the above two regions of the image recorded on the recording paper P less noticeable.

[0048] In this embodiment, the pattern block set 93 has a plurality of first pattern blocks 91 arranged at intervals in the scanning direction, and a plurality of second pattern blocks 92 arranged in the scanning direction alternating with the plurality of first pattern blocks 91. This makes it easy for the user to check in the test pattern 90, in which the pattern block sets 93a to 93e are arranged in the transport direction, which pattern block set 93 has the smallest density difference between the first pattern block 91 and the second pattern block 92.

[0049] <Modification> Although the preferred embodiment of the present invention has been described above, the present invention is not limited to the above-mentioned embodiment, and various modifications are possible within the scope of the claims.

[0050] In the above-described embodiment, among the second pattern blocks 92a to 92e, the second pattern block 92e located at the upstream end in the transport direction has the lightest density, and the second pattern blocks farther from the second pattern block 92e have higher density, but this is not limited to the above.

[0051] In the first modification, the control unit 80 records a plurality of first pattern blocks 91a-91e and identification symbols 94a-94e as shown in Fig. 4(a)-(e) in the pattern recording process in the same manner as in the above embodiment, and then records a plurality of second pattern blocks 102a-102e as shown in Fig. 6(a)-(e) in the same manner as in the above embodiment. As a result, a test pattern 100 having a plurality of pattern block sets 103a-103e aligned in the transport direction is recorded on the recording paper P.

[0052] However, in the first modified example, in the second recording pass for recording the second pattern block 102c, the inkjet head 3 is driven with the same drive signal as in the first recording pass for recording the first pattern blocks 91a to 91e. Also, when the second pattern blocks 102a to 102e are recorded in the second recording pass, the inkjet head 3 is driven so that the amount of ink droplets discharged from the nozzles 10 per unit area increases in the second pattern block 102 on the upstream side in the transport direction as the distance from the second pattern block 102e on the most downstream side in the transport direction increases.

[0053] As a result, among the second pattern blocks 102a to 102e, the second pattern block 102e located at the upstream end in the transport direction has the highest density, and the density of the second pattern block 102 that is farther from the second pattern block 102 decreases. Furthermore, if the first nozzle 10a and the second nozzle 10b eject the same amount of ink droplets when the inkjet head 3 is driven with the same drive signal to eject ink droplets, the density of the second pattern block 102c will be approximately the same as the density of the first pattern blocks 91a to 91e.

[0054] In this case, in the ejection amount correction process, for example, if the selection signal indicates the pattern block set 103c, the ejection amount of ink droplets from the second nozzles 10b is not corrected.

[0055] When the selection signal indicates the pattern block set 103a or the pattern block set 103b, at least one of a correction to reduce the amount of ink droplets ejected from the second nozzle 10b and a correction to increase the amount of ink droplets ejected from the first nozzle 10a is performed. When a correction to reduce the amount of ink droplets ejected from the second nozzle 10b is performed, the amount of ink droplets ejected from the second nozzle 10b is reduced as the selection signal indicates a pattern block set 103 that is further downstream in the transport direction. When a correction to increase the amount of ink droplets ejected from the first nozzle 10a is performed, the amount of ink droplets ejected from the first nozzle 10a is increased as the selection signal indicates a pattern block set 103 that is further downstream in the transport direction.

[0056] Also, when the selection signal indicates the pattern block set 103d or the pattern block set 103e, at least one of a correction to increase the amount of ink droplets ejected from the second nozzle 10b and a correction to decrease the amount of ink droplets ejected from the first nozzle 10a is performed. When a correction to increase the amount of ink droplets ejected from the second nozzle 10b is performed, the amount of ink droplets ejected from the second nozzle 10b is increased as the selection signal indicates a pattern block set 103 that is further upstream in the transport direction. When a correction to decrease the amount of ink droplets ejected from the first nozzle 10a is performed, the amount of ink droplets ejected from the first nozzle 10a is decreased as the selection signal indicates a pattern block set 103 that is further upstream in the transport direction.

[0057] In the first modification, among the second pattern blocks 102a-102e, the second pattern block 102e located at the upstream end in the transport direction has the highest density, and the second pattern blocks 102 farther from the second pattern block 92e have lower density. As a result, in the test pattern 100 in which a plurality of pattern block sets 103a-103e are arranged in the transport direction, the density difference between the first pattern block 91 and the second pattern block 102 gradually changes from the upstream to the downstream in the transport direction. Therefore, the user can easily confirm which pattern block set 103 among the plurality of pattern block sets 103a-103e has the smallest density difference between the first pattern block 91 and the second pattern block 102.

[0058] Furthermore, the densities of the second pattern portions aligned in the transport direction may be different from each other in a manner different from that described in the above embodiment and modification example 1.

[0059] Furthermore, in the above embodiment, the number of the first nozzles 10a and the number of the second nozzles 10b are the same, but this is not limited to the above.

[0060] In Modification 2, as shown in Figures 7(a)-(e), 8(a)-(e), 9(a)-(e), and 10(a)-(e), the number of first nozzles 10a is twice the number of second nozzles 10b. Note that in Modification 2, the first nozzles 10a correspond to the "majority nozzles" of the present invention, and the second nozzles 10b correspond to the "minority nozzles" of the present invention.

[0061] In the second modification, in the pattern recording process of S101, the control unit 80 causes the recording of the test pattern 110 (see FIG. 10(e)). In more detail, the control unit 80 causes the recording paper P to be supplied as in the above-described embodiment, and then controls the carriage motor 86 to move the carriage 2 in the scanning direction, while controlling the inkjet head 3 to perform a first recording pass in which ink droplets are ejected from the downstream half of the first nozzles 10a in the transport direction (the first nozzles 10a having the same number as the second nozzles 10b) among the first nozzles 10a, thereby recording downstream portions 111a1, which are the downstream half in the transport direction, of the multiple first pattern blocks 111a arranged at intervals in the scanning direction, as shown in FIG. 7(a).

[0062] Next, while maintaining the position of the recording paper P, the control unit 80 controls the carriage motor 86 to move the carriage 2 in the scanning direction, and controls the inkjet head 3 to perform a first recording pass in which ink droplets are ejected from the upstream half of the first nozzles 10a in the transport direction (the same number of first nozzles 10a as the second nozzles 10b) of the first nozzles 10a toward the recording paper P, thereby recording the upstream portions 111a2, which are the upstream half of the first pattern blocks 111a in the transport direction, as shown in Fig. 7(b). As a result, the first pattern blocks 111a are recorded.

[0063] Furthermore, in the first recording pass for recording the upstream portions 111a2, the control unit 80 also causes the downstream half of the first nozzles 10a to eject ink droplets, thereby recording the identification symbol 114a. Note that the identification symbol 114a may also be recorded by causing the upstream half of the first nozzles 10a to eject ink droplets during recording of the downstream portion 111a1. The same applies to the identification symbols 114b to 114e described below.

[0064] Next, the control unit 80 controls the transport motor 87 to cause the transport rollers 5, 6 to transport the recording paper P the length of the first pattern block 111 in the transport direction, and then performs a first recording pass in which ink droplets are ejected from the downstream half of the first nozzles 10a in the transport direction, thereby recording the downstream portions 111b1 of the multiple first pattern blocks 111b adjacent to the upstream side of the multiple first pattern blocks 111a in the transport direction on the recording paper P, as shown in Figure 7(c).

[0065] Next, the control unit 80 performs a first recording pass in which ink droplets are ejected from the upstream half of the first nozzles 10a in the transport direction while maintaining the position of the recording paper P, thereby recording the upstream portions 111b2 of the first pattern blocks 111b as shown in Fig. 7(d). This causes the first pattern blocks 111b adjacent to the first pattern blocks 111a on the upstream side in the transport direction to be recorded.

[0066] In addition, in a first recording pass in which the upstream portions 111b2 of the multiple first pattern blocks 111b are recorded, the control unit 80 also causes ink droplets to be ejected from the downstream half of the first nozzles 10a, thereby recording the identification symbol 114b.

[0067] Furthermore, the control unit 80 causes the conveying rollers 5 and 6 to convey the recording paper P the length of the first pattern block 111 in the conveying direction, and then repeats the operation of performing a first recording pass in which ink droplets are ejected from the downstream half of the first nozzles 10a in the conveying direction, and a first recording pass in which ink droplets are ejected from the upstream half of the first nozzles 10a in the conveying direction, to sequentially record the downstream portions 111c1 and upstream portions 111c2 of the multiple first pattern blocks 111c, the downstream portions 111d1 and upstream portions 111d2 of the multiple first pattern blocks 111d, and the downstream portions 111e1 and upstream portions 111e2 of the multiple first pattern blocks 111e, as shown in Figure 7(e) and Figures 8(a) to (e).

[0068] As a result, the first pattern blocks 111c to 111e are recorded on the recording paper P. The first pattern blocks 111c to 111e are adjacent to the first pattern blocks 111b to 111d on the upstream side in the transport direction, respectively. Also, in the first recording pass for recording the upstream portions 111c2 to 111e2, ink is also ejected from the downstream half of the first nozzles 10a in the transport direction, thereby recording the identification symbols 114c to 114e, respectively.

[0069] In addition, in the second modification, when the downstream portions 111a1-111e1 and the upstream portions 111a2-111e2 of the first pattern blocks 111a-111e are printed by the first printing pass, the amount of ink droplets ejected from the first nozzles 10a per unit area is set to be the same. As a result, the first pattern blocks 111a-111e are all printed with approximately the same density. In this embodiment, the first pattern blocks 111a-111e correspond to the "constant density pattern blocks" and "long pattern blocks" of the present invention.

[0070] Next, the control unit 80 controls the conveying motor 87 to cause the conveying rollers 5 and 6 to convey the recording paper P in the conveying direction until the second nozzle 10b and the downstream portion 111a1 of the first pattern block 111a are positioned in the same direction, and then performs a second recording pass, thereby recording a plurality of second pattern blocks 112a1 arranged alternately in the scanning direction with the downstream portions 111a1 of the plurality of first pattern blocks 111a, as shown in Figure 9(a).

[0071] Next, the control unit 80 controls the conveying motor 87 to cause the conveying rollers 5 and 6 to convey the recording paper P the length of the second pattern block 112a in the conveying direction, and then performs a second recording pass, thereby recording on the recording paper P a plurality of second pattern blocks 112a2 that are adjacent to the upstream side of the plurality of second pattern blocks 112a in the conveying direction and are arranged alternately in the scanning direction with the upstream portions 111a2 of the plurality of first pattern blocks 111a, as shown in FIG. 9(b).

[0072] Furthermore, the control unit 80 repeats the operation of causing the conveying rollers 5 and 6 to convey the recording paper P the length of the second pattern block 112 in the conveying direction and then performing a second recording pass, thereby recording multiple second pattern blocks 112b1, 112b2, 112c1, 112c2, 112d1, 112d2, 112e1, and 112e2 in sequence, as shown in Figures 9(c) to (e) and Figures 10(a) to (e).

[0073] The second pattern blocks 112b1-112e1 are adjacent to the second pattern blocks 112a2-112d2 on the upstream side in the transport direction, and are alternately arranged in the scanning direction with the downstream portions 111b1-111e1 of the first pattern blocks 111b-111e. The second pattern blocks 112b2-112e2 are adjacent to the second pattern blocks 112b1-112e1 on the upstream side in the transport direction, and are alternately arranged in the scanning direction with the upstream portions 111b2-111e2 of the first pattern blocks 111b-111e.

[0074] As a result, a test pattern 110 having a plurality of pattern block sets 113a to 113e arranged in the transport direction is recorded on the recording paper P. The pattern block set 113a is formed by a plurality of first pattern blocks 111a and a plurality of second pattern blocks 112a1 and 112a2. The pattern block set 113b is formed by a plurality of first pattern blocks 111b and a plurality of second pattern blocks 112b1 and 112b2. The pattern block set 113c is formed by a plurality of first pattern blocks 111c and a plurality of second pattern blocks 112c1 and 112c2. The pattern block set 113d is formed by a plurality of first pattern blocks 111d and a plurality of second pattern blocks 112d1 and 112d2. The pattern block set 113e is formed by a plurality of first pattern blocks 111e and a plurality of second pattern blocks 112e1 and 112e2.

[0075] Furthermore, in variant example 2, the inkjet head 3 is driven with the same drive signal in the second recording pass for recording the second pattern blocks 112a1, 112a2, the second recording pass for recording the second pattern blocks 112b1, 112b2, the second recording pass for recording the second pattern blocks 112c1, 112c2, the second recording pass for recording the second pattern blocks 112d1, 112d2, and the second recording pass for recording the second pattern blocks 112e1, 112e2.

[0076] In addition, in the second recording pass for recording the second pattern blocks 112c1 and 112c2, the inkjet head 3 is driven with the same drive signal as that of the first recording pass for recording the first pattern blocks 111a to 111e (downstream portions 111a1 to 111e1, upstream portions 111a2 to 111e2).

[0077] In addition, in Modification 2, the inkjet head 3 is driven so that the amount of ink droplets ejected from the nozzles 10 per unit area decreases as the second pattern block 112 corresponding to the first pattern block 111 located upstream in the transport direction is recorded. In this embodiment, the second pattern blocks 112a1-112e1 and 112a2-112e2 correspond to the "different density pattern blocks" and "short pattern blocks" of the present invention.

[0078] In the second modification, when the number of first nozzles 10a is twice the number of second nozzles 10b, pattern block sets 113a-113e in which a first pattern block 111 and two second pattern blocks 112 aligned in the transport direction are aligned in the scanning direction are recorded. This makes it possible to make the length of the first pattern block 111 in the transport direction and the sum of the lengths of the two second pattern blocks 112 in the transport direction in the pattern block sets 113a-113e the same. In other words, it is possible to reduce the difference between the length of the first pattern block 111 in the transport direction and the sum of the lengths of the two second pattern blocks 112 in the transport direction.

[0079] This prevents any blank spaces from appearing between first pattern blocks 111 adjacent to each other in the transport direction or between second pattern blocks 112 adjacent to each other in the transport direction in the test pattern 110. As a result, the user can easily check which pattern block set, among the multiple pattern block sets 113a to 113e, has the smallest density difference between the first pattern block 111 and the second pattern block 112.

[0080] Also, unlike Modification 2, it is possible to print the first pattern block 111 in a single first printing pass in which ink droplets are ejected from all of the first nozzles 10a. However, in this case, the number of nozzles 10 used simultaneously in the first printing pass for printing the first pattern block 111 differs from the number of nozzles 10 used simultaneously in the second printing pass for printing each of the second pattern blocks 112. Then, due to the difference in the number of nozzles 10 used simultaneously between the first printing pass and the second printing pass, a density difference may occur between the first pattern block 111 and the two second pattern blocks 112.

[0081] Therefore, in the second modification, the downstream and upstream parts of the first pattern block 111 are printed by separate first printing passes. That is, the first pattern block 111 is printed by repeatedly printing a part of the first pattern block 111 by using different first nozzles 10a. This makes the number of nozzles 10 used simultaneously in the first printing pass for printing the downstream and upstream parts of the first pattern block 111 the same as that in the second printing pass for printing each of the second pattern blocks 112. As a result, it is possible to prevent a density difference between the first pattern block 111 and the two second pattern blocks 112 due to the difference in the nozzles 10 used simultaneously between the first printing pass and the second printing pass.

[0082] In addition, in the second modification, the first pattern block is recorded in two first recording passes, one for recording the downstream portion and the other for recording the upstream portion, so that the two second pattern blocks 112 adjacent to each other in the transport direction are aligned with the same first pattern block 111 in the scanning direction, but this is not limited to the above. The first pattern block 111 may be recorded in one first recording pass in which ink droplets are ejected from all of the first nozzles 10a.

[0083] In addition, in the second modification, the number of the first nozzles 10a is twice the number of the second nozzles 10b, that is, the integer N of the present invention is 2, but the present invention is not limited to this. N may be an integer of 3 or more, the number of the first nozzles 10a may be N times the number of the second nozzles 10b, and in the pattern block set, N or more second pattern blocks adjacent to each other in the transport direction may be aligned with one identical first pattern block in the scanning direction.

[0084] Furthermore, when the number of the first nozzles 10a is greater than the number of the second nozzles 10b, the number of the first nozzles 10a does not have to be an integer multiple of the number of the second nozzles 10b.

[0085] Furthermore, even when the number of first nozzles 10a is greater than the number of second nozzles 10b, a pattern block set in which one first pattern block and one second pattern block are alternately arranged in the scanning direction may be recorded.

[0086] In addition, in the second modification, the number of the first nozzles 10a is greater than the number of the second nozzles 10b, but this is not limited to the above. The number of the second nozzles 10b may be greater than the number of the first nozzles 10a, and in a pattern block set, a plurality of first pattern blocks adjacent to each other in the transport direction may be aligned with one identical second pattern block in the scanning direction. In this case, the first nozzles 10a correspond to the "minority nozzles" of the present invention, and the second nozzles 10b correspond to the "majority nozzles" of the present invention. In this case, the first pattern blocks correspond to the "short pattern blocks" of the present invention, and the second pattern blocks correspond to the "long pattern blocks" of the present invention.

[0087] In addition, in the above example, only a test pattern having a first pattern block recorded by ink droplets ejected from the first nozzle 10a and a second pattern block recorded by ink droplets ejected from the second nozzle 10b was recorded, but this is not limited to this.

[0088] In the third modification, as shown in Fig. 11(a), the nozzle row 9 of the inkjet head 3 has third nozzles 10c to 10f in addition to the first nozzles 10a and the second nozzles 10b. The third nozzles 10c to 10f are located between the first nozzles 10a and the second nozzles 10b in the transport direction. The third nozzles 10c to 10f are consecutively arranged in the transport direction, and the number of the third nozzles 10c to 10f is the same as the number of the first nozzles 10a and the number of the second nozzles 10b. The third nozzles 10c to 10f are arranged in the order of the third nozzles 10c, 10d, 10e, and 10f from the upstream to downstream in the transport direction.

[0089] In the third modification, the control unit 80 also performs processing according to the flow of FIG. 3 in order to correct the amount of ink droplets ejected from each nozzle 10 in the printer 1. However, in the third modification, in the pattern recording processing of S101 (see FIG. 3), as shown in FIG. 11(b), in addition to recording the test pattern 90 in the same procedure as described in the above embodiment, the control unit 80 also records the test patterns 120c to 120f aligned in the transport direction. The test patterns 120c to 120f are aligned in the transport direction with the test pattern 90. The test patterns 120c to 120f are obtained by replacing the second pattern blocks 92a to 92e in the test pattern 90 with the third pattern blocks 122a to 122e, respectively. The third pattern blocks 122a to 122e of the test patterns 120c to 120f are recorded by ink droplets ejected from the third nozzles 10c to 10f, respectively. In FIG. 11B, the test patterns 120c, 120d, 120e, 120f, and 90 are arranged in this order from downstream to upstream in the transport direction, but the test patterns 90, 120c to 120f may be arranged in a different order in the transport direction.

[0090] The procedure for recording the test patterns 120c to 120f will be described below. When recording the test pattern 120c, the control unit 80 causes the inkjet head 3 to perform a first recording pass, as shown in Fig. 12(a), to record a plurality of first pattern blocks 91a and an identification symbol 94a.

[0091] Next, the control unit 80 controls the conveying motor 87 to convey the recording paper P by the length of the first pattern block 91 in the conveying direction to the conveying rollers 5 and 6, and then performs a recording pass in which ink is ejected from the first nozzle 10a and the third nozzle 10c, thereby recording a plurality of first pattern blocks 91b, a plurality of third pattern blocks 122a, and an identification symbol 94b on the recording paper P, as shown in FIG. 12(b). As a result, a pattern block set 123a in which a plurality of first pattern blocks 91a and a plurality of third pattern blocks 122a are alternately arranged in the scanning direction is recorded on the recording paper P. The recording pass in which ink is ejected from the first nozzle 10a and the third nozzle 10c serves as both the "first ejection operation" and the "third ejection operation" of the present invention.

[0092] Next, the control unit 80 repeats the operation of causing the conveying rollers 5, 6 to convey the recording paper P the length of the first pattern block 91 in the conveying direction, and then performing a recording pass in which ink is ejected from the first nozzle 10a and the third nozzle 10c, thereby sequentially recording a plurality of first pattern blocks 91c, a plurality of third pattern blocks 122b, and an identification symbol 94c, a plurality of first pattern blocks 91d, a plurality of third pattern blocks 122c, and an identification symbol 94d, and a plurality of first pattern blocks 91e, a plurality of third pattern blocks 122d, and an identification symbol 94e, as shown in Figures 12(c) to (e). As a result, a pattern block set 123b in which a plurality of first pattern blocks 91b and a plurality of third pattern blocks 122b are alternately arranged in the scanning direction, a pattern block set 123c in which a plurality of first pattern blocks 91c and a plurality of third pattern blocks 122c are alternately arranged in the scanning direction, and a pattern block set 123d in which a plurality of first pattern blocks 91d and a plurality of third pattern blocks 122d are alternately arranged in the scanning direction are recorded on the recording paper P.

[0093] Next, the control unit 80 controls the transport motor 87 to transport the recording paper P by the length of the first pattern block 91 in the transport direction to the transport rollers 5 and 6, and then performs a third recording pass (the "third ejection operation" of the present invention) in which ink droplets are ejected from the third nozzles 10c, thereby recording a plurality of third pattern blocks 122e on the recording paper P, as shown in Fig. 12(f). As a result, a pattern block set 123e in which a plurality of first pattern blocks 91e and a plurality of third pattern blocks 122e are alternately arranged in the scanning direction is recorded on the recording paper P.

[0094] In the third modification, when the third pattern block 122c is recorded, the inkjet head 3 is driven with the same drive signal as when the first pattern blocks 91a to 91e are recorded. In the third modification, when the third pattern blocks 122a to 122e are recorded, the inkjet head 3 is driven so that the amount of ink droplets discharged from the nozzles 10 per unit area decreases as the distance from the third pattern block 122a at the most downstream side in the transport direction increases. As a result, among the third pattern blocks 122a to 122e, the third pattern block 122e located at the upstream end in the transport direction has the lowest density, and the third pattern blocks 122 farther from the third pattern block 122e have higher density. In addition, if the amount of ink droplets discharged is the same when the inkjet head 3 is driven with the same drive signal in the multiple nozzles 10 forming the nozzle row 9 to discharge ink droplets, the density of the third pattern block 122c becomes approximately the same as the density of the first pattern blocks 91a to 91e.

[0095] When test pattern 120c is recorded in this manner, pattern block set 123a is recorded by a unit recording operation ("another unit recording operation" of the present invention) consisting of a recording pass that records first pattern block 91a ("first ejection operation" of the present invention), transporting recording paper P from the position shown in Figure 12(a) to the position shown in Figure 12(b) ("another relative movement operation" of the present invention), and a recording pass that records third pattern block 122a ("third ejection operation" of the present invention).

[0096] Similarly, pattern block sets 123b to 123e are recorded by a unit recording operation ("another unit recording operation" of the present invention) consisting of a recording pass ("first ejection operation" of the present invention) that records the first pattern blocks 91b to 91e, transporting the recording paper P from the position shown in Figures 12(b) to (e) to the position shown in Figures 12(c) to (f) ("another relative movement operation" of the present invention), and a recording pass ("third ejection operation" of the present invention) that records the third pattern blocks 122b to 122e.

[0097] In this embodiment, as described above, the different unit recording operations are performed while varying the position of the recording paper P in the transport direction, thereby recording the test pattern 120c having the pattern block groups 123a to 123e aligned in the transport direction.

[0098] Test patterns 120d-120f are also printed in the same procedure as test pattern 120c. However, due to differences in the positional relationship between the first nozzles 10a and the third nozzles 10c-10f, when test patterns 120d-120f are printed, the relationship between the printing pass for printing first pattern blocks 91a-91e and the printing pass for printing third pattern blocks 122a-122c is different from when test pattern 120c is printed.

[0099] More specifically, when the test pattern 120c is recorded, as described above, the first pattern blocks 91a are recorded in a recording pass different from that used to record the third pattern blocks 122a-122e. Also, the third pattern blocks 122a-122d are recorded in the same recording pass as the first pattern blocks 91b-91e. Also, the third pattern blocks 122e are recorded in a recording pass different from that used to record the first pattern blocks 91a-91e.

[0100] In contrast, when the test pattern 120d is recorded, the first pattern blocks 91a and 91b are recorded in a recording pass different from that used to record the third pattern blocks 122a to 122e. Also, the third pattern blocks 122a to 122c are recorded in the same recording pass as the first pattern blocks 91c to 91e. Also, the third pattern blocks 122d and 122e are recorded in a recording pass different from that used to record the first pattern blocks 91a to 91e.

[0101] When the test pattern 120e is recorded, the first pattern blocks 91a-91c are recorded in a different recording pass from the third pattern blocks 122a-122e. The third pattern blocks 122a and 122b are recorded in the same recording pass as the first pattern blocks 91d and 91e. The third pattern blocks 122c-122e are recorded in a different recording pass from the first pattern blocks 91a-91e.

[0102] Furthermore, when the test pattern 120f is recorded, the first pattern blocks 91a-91d are recorded in a recording pass different from that used to record the third pattern blocks 122a-122e. The third pattern blocks 122a are recorded in the same recording pass as the first pattern blocks 91e. The third pattern blocks 122b-122e are recorded in a recording pass different from that used to record the first pattern blocks 91a-91e.

[0103] In recording the test patterns 120d-120f, the pattern block sets 123b-123e are also recorded by a unit recording operation (another unit recording operation of the present invention) consisting of a recording pass for recording the first pattern blocks 91a-91e (the ``first ejection operation'' of the present invention), transporting the recording paper P from the position when the first recording pass was performed to the position when the third pattern blocks 122a-122e are recorded (the ``other relative movement operation'' of the present invention), and a recording pass for recording the third pattern blocks 122b-122e (the ``third ejection operation'' of the present invention).

[0104] Furthermore, in the third variant, in the selection screen display process of S102, the display unit 71 is controlled to display a selection screen for allowing the display unit 71 to select the pattern block set 93 having the smallest density difference between the first pattern block 91 and the second pattern block 92 among the pattern block sets 93a-93e in the test pattern 90, and the pattern block set 123 having the smallest density difference between the first pattern block 91 and the third pattern block 122 among the pattern block sets 123a-123e in each of the test patterns 120c-120f.

[0105] Then, the control unit 80 executes the ejection amount correction process of S104 when it receives a selection signal for selecting the pattern block set 93, 123 for all of the test patterns 90, 120c-120f based on the user's operation of the operation unit 72. In the ejection amount correction process of S104, in the third modification, ejection amount distribution information on the distribution of the ejection amount of ink droplets from the multiple nozzles 10 forming the nozzle row 9 is acquired based on the above selection signal for the test patterns 90, 120c-120f. Then, the control unit 80 corrects the ejection amount of ink droplets from the nozzles 10 based on the acquired ejection amount distribution information.

[0106] For example, when the selection signal indicates the pattern block set 93c, the amount of ink droplets ejected from the nozzles 10 is not corrected.

[0107] When the selection signal indicates the pattern block set 93a or the pattern block set 93b, a correction is made to increase the amount of ink droplets ejected from the second nozzles 10b. At this time, the more the selection signal indicates the pattern block set 93 that is further downstream in the transport direction, the more the amount of ink droplets ejected from the second nozzles 10b is increased.

[0108] When the selection signal indicates the pattern block set 93d or the pattern block set 93e, a correction is made to reduce the amount of ink droplets ejected from the second nozzles 10b. At this time, the more the selection signal indicates the pattern block set 93 that is further upstream in the transport direction, the more the amount of ink droplets ejected from the second nozzles 10b is reduced.

[0109] Moreover, when the selection signal for the test patterns 120c to 120f indicates the pattern block set 123c, the amount of ink droplets ejected from the nozzles 10 is not corrected.

[0110] When the selection signal for the test patterns 120c-120f indicates the pattern block sets 123a and 123b, a correction is made to increase the amount of ink droplets ejected from the third nozzles 10c-10f. Also, at this time, the amount of ink droplets ejected from the third nozzles 10c-10f is increased as the selection signal indicates the pattern block set 123 that is further downstream in the transport direction.

[0111] When the selection signal for the test patterns 120c-120f indicates the pattern block set 123d or the pattern block set 123e, the amount of ink droplets ejected from the third nozzles 10c-10f is corrected to be smaller. Also, at this time, the amount of ink droplets ejected from the third nozzles 10c-10f is reduced as the selection signal indicates the pattern block set 123 that is further upstream in the transport direction.

[0112] In the third modification, in addition to printing the test pattern 90 having a plurality of pattern block sets 93a-93e, test patterns 120c-120f each having a plurality of pattern block sets 123a-123e are printed. This makes it possible to more accurately obtain information on the distribution of the amount of ink droplets ejected from the nozzles 10 in the nozzle row 9 based on the printing results of the test patterns 90 and 120c-120f.

[0113] Then, by correcting the amount of ink droplets ejected from the nozzles 10 based on the acquired information on the distribution of the amount of ink droplets ejected from the nozzles 10 in the nozzle row 9, it is possible to reduce the variation in the amount of ink droplets ejected among the multiple nozzles 10 that form the nozzle row 9.

[0114] In this embodiment, the test patterns 90, 120c to 120f are recorded in a line in the transport direction. As a result, for example, after a recording pass for recording the first pattern blocks 91a to 91e of the test pattern 90, a recording pass for recording the first pattern blocks 91a to 91e of the test patterns 120c to 120f is performed in order, and a recording pass for recording the second pattern blocks 92a to 92e of the test pattern 90 and a recording pass for recording the third pattern blocks 122a to 122e of the test patterns 120c to 120f are performed in accordance with the transport of the recording paper P at this time, thereby simplifying the control for recording the test patterns 90, 120c to 120f. In addition, since the test patterns 90, 120c to 120f are recorded on one recording paper P, the number of recording papers P used to record the test patterns 90, 120c to 120f can be reduced.

[0115] In addition, in the third modification, the test patterns 90, 120c to 120f are recorded on one sheet of recording paper P so as to be aligned in the transport direction, but this is not limiting. For example, the test patterns 90, 120c to 120f may be recorded on separate sheets of recording paper P.

[0116] In the above example, among the multiple nozzles 10 forming the nozzle row 9, some of the nozzles 10 arranged in the transport direction, including the first end nozzle 10a1, were the first nozzles 10a. Also, among the multiple nozzles 10 forming the nozzle row 9, some of the nozzles 10 arranged in the transport direction, including the second end nozzle 10b1, were the second nozzles 10b. However, this is not limited to the above.

[0117] For example, only the first end nozzle 10a1 may be the first nozzle. Also, only the second end nozzle 10b1 may be the second nozzle. Alternatively, among the multiple nozzles 10 forming the nozzle row 9, one nozzle 10 other than the first end nozzle 10a1 may be the first nozzle. Also, among the multiple nozzles 10 forming the nozzle row 9, one nozzle 10 other than the second end nozzle 10b1, which is located downstream of the first nozzle 10a in the transport direction, may be the second nozzle.

[0118] Alternatively, among the multiple nozzles 10 forming the nozzle row 9, some of the nozzles 10 arranged in the transport direction, excluding the first end nozzle 10a1, may be the first nozzles. Also, among the multiple nozzles 10 forming the nozzle row 9, some of the nozzles 10 arranged in the transport direction, located downstream of the first nozzle 10a in the transport direction, excluding the second end nozzle 10b1, may be the first nozzles.

[0119] In the above example, the inkjet head 3 and the recording paper P are moved relatively in the transport direction by transporting the recording paper P in the transport direction by the transport rollers 5 and 6, but this is not limited to the above. For example, a frame supporting the guide rails 11 and 12 that support the carriage 2 may be movable in the transport direction, and the inkjet head 3 and the recording paper P may be moved relatively in the transport direction by moving this frame in the transport direction.

[0120] In the above example, the first pattern blocks have the same density, and the second pattern blocks have different density, but this is not limited to the above. The second pattern blocks may have the same density, and the first pattern blocks may have different density. In this case, the second pattern blocks correspond to the "constant density pattern blocks" of the present invention, and the first pattern blocks correspond to the "different density pattern blocks" of the present invention.

[0121] In addition, in the above example, a test pattern was recorded in which multiple pattern block sets, each formed by first pattern blocks arranged at intervals in the scanning direction and multiple second patterns arranged alternately with the first pattern blocks in the scanning direction, were arranged in the transport direction, but this is not limited to this.

[0122] For example, in the above-described embodiment and modified example 1, a test pattern may be recorded in which a plurality of pattern block sets each formed by one first pattern block and one second pattern block are arranged in the transport direction. Also, for example, in modified example 2, a test pattern may be recorded in which a plurality of pattern block sets each formed by one first pattern block and two second pattern blocks adjacent to each other in the transport direction are arranged in the transport direction.

[0123] In the above example, the user inputs a signal corresponding to the recording result of the test pattern by operating the operation unit 72. Then, when this signal is received, the control unit 80 obtains information regarding the difference in the amount of ink droplets ejected between the multiple nozzles 10 in the nozzle row 9 based on the signal, and corrects the amount of ink droplets ejected from the nozzles 10 based on this information. However, this is not limited to this.

[0124] For example, a user may operate a PC connected to the printer to input a signal corresponding to the results of printing the test pattern to the PC. Then, when the PC receives this signal, it may obtain information regarding the difference in the amount of ink droplets ejected between the multiple nozzles 10 in the nozzle row 9 based on the signal, and generate data for correcting the amount of ink droplets ejected from the nozzles 10 based on this information. Then, the PC may send this data to the printer, and the printer's control unit may correct the amount of ink droplets ejected from the nozzles 10 based on the received data.

[0125] In the above, an example of applying the present invention to a printer that ejects ink from nozzles to perform recording on recording paper P has been described, but the present invention is not limited to this. The present invention can also be applied to printers that record images on recording media other than recording paper, such as T-shirts, sheets for outdoor advertising, cases for mobile terminals such as smartphones, cardboard, and resin members. The present invention can also be applied to liquid ejection devices that eject liquids other than ink, such as liquid resins and metals. [Explanation of symbols]

[0126] 1. Printer 2 Carriage 3 Inkjet head 5,6 Transport roller 9 nozzle rows 10 Nozzles 80 Control section 91a~91e 1st pattern block 92a~92e 2nd pattern block 93a~93e Pattern block set 102a~102e Second pattern block 103a~103e Pattern block group 111a~111e 1st pattern block 112a1~112e1,112a2~112e2 Second pattern block 113a~113e Pattern block set 122a~122e 3rd pattern block 123a~123e Pattern block set

Claims

1. a droplet ejection head having a nozzle row formed by arranging a plurality of nozzles in a first direction; a carriage on which the droplet ejection head is mounted and which moves in a second direction intersecting the first direction; a relative movement unit that moves the droplet discharge head and the discharge receiving medium relatively in the first direction; A control unit, the nozzle row includes a first nozzle and a second nozzle that is farther from one end of the nozzle row in the first direction than the first nozzle, the relative movement means moves the droplet ejection head and the ejection receiving medium relative to each other such that the ejection receiving medium moves in a direction from the one end of the nozzle row to the other end of the nozzle row in the first direction with respect to the droplet ejection head; The control unit is A unit recording operation including a first recording operation, a relative movement operation, and a second recording operation, the first recording operation is an operation of causing the droplet ejection head to eject droplets from the first nozzles toward an ejection receiving medium while moving the carriage in the second direction, thereby recording a first pattern block extending in the first direction and the second direction on the ejection receiving medium; the relative movement operation is an operation of causing the relative movement means to relatively move the droplet ejection head and the ejection receiving medium by an amount corresponding to a distance between the first nozzles and the second nozzles in the first direction after the first recording operation, the second recording operation, after the relative movement operation, causes the carriage to move in the second direction while causing the droplet ejection head to eject droplets from the second nozzles toward the ejection receiving medium, thereby performing the unit recording operation, which is an operation for recording, on the ejection receiving medium, a second pattern block that extends in the first direction and the second direction and is disposed adjacent to the first pattern block in the second direction, thereby recording, on the ejection receiving medium, a pattern block set that is a set of the first pattern block and the second pattern block that are arranged in the second direction, on the recording medium; the relative movement means changes a positional relationship between the liquid ejection head and the ejection receiving medium in the first direction, and the unit recording operation is performed a plurality of times, thereby recording a plurality of sets of the pattern blocks that are aligned in the first direction, and further the density of a constant density pattern block, which is one of the first pattern block and the second pattern block, is the same among a plurality of the pattern block sets, A droplet ejection device characterized in that a plurality of patterns block sets are recorded so that the density of the different density pattern block, which is the other of the first pattern block and the second pattern block, differs among the plurality of patterns block sets.

2. The control unit is by making the amount of droplets discharged per unit area onto the discharge receiving medium when recording the constant density pattern blocks the same among the plurality of pattern block sets, the density of the constant density pattern blocks becomes the same among the plurality of pattern block sets; The droplet ejection device according to claim 1, characterized in that the density of the different density pattern blocks is made different between the multiple pattern block groups by making the amount of droplets ejected per unit area onto the ejection medium when recording the different density pattern blocks different between the multiple pattern block groups.

3. The control unit is Among the different density pattern blocks forming the plurality of pattern block sets, the different density pattern block located at one end in the first direction has the lightest density, and A droplet ejection device as described in claim 1 or 2, characterized in that, of the multiple different density pattern blocks that form the multiple pattern block groups, the multiple pattern block groups are recorded so that the different density pattern blocks that are farther away from the different density pattern block located at one end in the first direction have a higher density.

4. The control unit is Among the different density pattern blocks forming the plurality of pattern block sets, the different density pattern block located at one end in the first direction has the highest density, and The droplet ejection device according to claim 1 or 2, characterized in that, among the multiple different density pattern blocks that form the multiple pattern block groups, the different density pattern blocks that are farther from the different density pattern block group located at one end in the first direction have a lighter density.

5. The nozzle row is A plurality of the first nozzles arranged continuously in the first direction; 5. The droplet ejection device according to claim 1, further comprising: a plurality of the second nozzles arranged consecutively in the first direction.

6. the number of the first nozzles is different from the number of the second nozzles, The control unit is In one of the first recording operation and the second recording operation, while moving the carriage in the second direction, ejecting droplets from a majority nozzle, which is a larger number of the first nozzles and the second nozzles, toward an ejection receiving medium, thereby recording a long pattern block corresponding to the majority nozzles out of the first pattern block and the second pattern block; In the other of the first recording operation and the second recording operation, The droplet ejection device described in claim 5, characterized in that while moving the carriage in the second direction, droplets are ejected toward a receiving medium from a minority of nozzles, which are the fewer number of nozzles among the first nozzles and the second nozzles, thereby recording a short pattern block corresponding to the minority of nozzles among the first pattern block and the second pattern block, and further, by repeatedly recording the short pattern block and relative movement between the droplet ejection head and the receiving medium by the relative movement means, a plurality of short pattern blocks arranged adjacent to each other in the first direction, which are adjacent to the long pattern block and the second direction, are recorded.

7. the number of the majority nozzles is N times the number of the minority nozzles, where N is an integer equal to or greater than 2; The control unit is In the other recording operation, The droplet ejection device described in claim 6, characterized in that N short pattern blocks arranged adjacent to each other in the first direction and adjacent to the long pattern block in the second direction are recorded by repeating the recording of the short pattern block N times.

8. The control unit is In the one recording operation, while moving the carriage in the second direction, ejecting droplets from a portion of the majority nozzles, the portion being equal in number to the minority nozzles, to record a portion of the long pattern block on the ejection receiving medium; 8. The droplet ejection device according to claim 7, wherein the long pattern block is recorded by repeatedly recording a part of the long pattern block using different nozzles.

9. the first nozzle is a first end nozzle located at one end in the first direction among the plurality of nozzles forming the nozzle row, or a part of nozzles that are continuously arranged in the first direction and include the first end nozzle, A droplet ejection device as described in any one of claims 1 to 8, characterized in that the second nozzle is a second end nozzle located at the other end of the first direction among the multiple nozzles forming the nozzle row, or a part of nozzles arranged continuously in the first direction including the second end nozzle.

10. the nozzle row includes a third nozzle different from the first nozzle and the second nozzle, The control unit is the relative movement means changes the positional relationship between the droplet discharge head and the discharge receiving medium in the first direction, and the unit recording operation is performed a plurality of times, thereby recording a plurality of sets of the pattern block groups; Another unit recording operation includes the first recording operation, a relative movement operation different from the relative movement operation, and a third recording operation, the different relative movement operation is an operation of causing the relative movement means to relatively move the droplet ejection head and the ejection receiving medium by an amount corresponding to a distance between the first nozzle and the third nozzle in the first direction after the first recording operation, the third recording operation is an operation of causing the droplet ejection head to eject droplets from the third nozzles toward the ejection receiving medium while moving the carriage in the second direction after the another relative movement operation, thereby recording, on the ejection receiving medium, a third pattern block that extends in the first direction and the second direction and is disposed adjacent to the first pattern block in the second direction, on the ejection receiving medium, by performing the another unit recording operation, thereby recording, on the ejection receiving medium, another pattern block set that is a set of the first pattern block and the third pattern block that are arranged in the second direction, on the recording medium, the relative movement means changes a positional relationship between the droplet discharge head and the discharge receiving medium in the first direction, and the different unit recording operation is performed a plurality of times, thereby recording a plurality of different pattern block sets that are aligned in the first direction, and further The density of one of the first pattern block and the third pattern block is the same among the plurality of sets of the other pattern block, A droplet ejection device as described in any one of claims 1 to 9, characterized in that a plurality of sets of the other pattern block groups are recorded so that the density of the other pattern block of the first pattern block and the third pattern block differs between the plurality of sets of the other pattern block groups.

11. The control unit is The droplet ejection device according to claim 10 , wherein a plurality of the pattern block sets and a plurality of the other pattern block sets are printed while being aligned in the first direction.

12. The control unit is When receiving a signal corresponding to the recording results of the plurality of pattern block sets and the recording results of the plurality of other pattern block sets, acquiring, based on the signal, discharge amount distribution information relating to a distribution of the discharge amounts of droplets from the plurality of nozzles in the nozzle row; 12. The droplet ejection device according to claim 11, wherein an amount of droplets ejected from each nozzle when the droplet ejection head ejects droplets from the plurality of nozzles toward a droplet receiving medium is corrected based on the ejection amount distribution information.

13. The control unit is when performing the first recording operation, the carriage is moved in the second direction while the droplet ejection head is caused to eject droplets from the first nozzles, thereby recording a plurality of the first pattern blocks arranged at intervals in the second direction on the ejection receiving medium; A droplet ejection device as described in any one of claims 1 to 12, characterized in that when performing the second recording operation, the carriage is moved in the second direction while the droplet ejection head is caused to eject droplets from the second nozzles, thereby recording a plurality of second pattern blocks that are arranged alternately with a plurality of the first pattern blocks in the second direction.

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