Printing device and adjustment method

Abstract

To provide a printing device, which is configured so that a difference in output densities during printing caused by an individual difference between printing chips can be adjusted accurately, while being prevented from increasing in manufacturing cost and from enlarging in size.SOLUTION: A printing device 1 according to one aspect of the present invention comprises a printing head 11 provided with a plurality of printing chips having a plurality of nozzles, a main scanning part, a sub scanning part and a control part 10, which can print test patterns for obtaining a correction value for adjusting discharge characteristics for each of the printing chips. The test patterns include a reference pattern having a single density gradation and an adjustment pattern including a patch group in which patches having the single density gradation are formed for a plurality of different gradations. The control part 10 performs printing control so that the reference pattern and the adjustment pattern are formed at positions adjacent to each other and so that the reference pattern is formed in the same target area of a medium by discharging liquid to the same target area using at least two printing chips of the printing chips provided in the printing head 11.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a printing apparatus and an adjustment method. [Background technology]

[0002] Patent Document 1 discloses a technique for calibrating an input voltage between print chips in a printing device using an image captured by an imaging unit. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2018-144362 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the technology described in Patent Document 1, by calibrating the input voltage between the print chips, the difference in output density during printing caused by individual differences between the print chips can be reduced, but since an imaging unit is required, there are concerns that the manufacturing cost and size of the printing device will increase. In addition, instead of using an imaging unit, the present inventor has considered a method of visually evaluating the difference in output density between the print chips during printing and correcting the input voltage based on the evaluation, but since the evaluation depends on the evaluator, it is difficult to make adjustments that reduce the above-mentioned differences with satisfactory quality.

[0005] Therefore, it is desirable to develop technology for a printing device that can accurately adjust differences in output density during printing caused by individual differences between printing chips while suppressing increases in manufacturing costs and size. [Means for solving the problem]

[0006] A printing device according to one aspect of the present invention comprises a print head equipped with a plurality of printing chips each having a plurality of nozzles capable of ejecting liquid onto a medium, a main scanning unit which moves the print head and the medium relatively in a main scanning direction, a sub-scanning unit which moves the print head and the medium relatively in a sub-scanning direction intersecting the main scanning direction, and a control unit which performs printing on the medium by performing printing control including control of the relative movement by the main scanning unit and the sub-scanning unit and control of the ejection of the liquid from the print head, and a tester for acquiring a correction value for adjusting the ejection characteristics for each of the printing chips equipped in the print head. a control unit that controls printing so that, when printing the test pattern, the reference pattern and the adjustment pattern are formed in positions adjacent to each other, and the reference pattern is formed in the same target area of ​​the medium by ejecting the liquid toward the same target area using at least two of the printing chips provided in the print head.

[0007] An adjustment method according to one aspect of the present invention is an adjustment method for a printing device comprising a print head including a plurality of printing chips each having a plurality of nozzles capable of ejecting liquid onto a medium, a main scanning unit which moves the print head and the medium relatively in a main scanning direction, and a sub-scanning unit which moves the print head and the medium relatively in a sub-scanning direction intersecting the main scanning direction, and which performs printing on the medium by performing print control including control of relative movement by the main scanning unit and the sub-scanning unit and control of ejection of the liquid from the print head, wherein the printing device performs adjustment using a controller for adjusting the ejection characteristics of each of the printing chips included in the print head. The present invention is characterized in that test pattern printing is performed to print a test pattern for obtaining a correction value, the test pattern including a reference pattern of a single density gradation and an adjustment pattern including a patch group in which patches of a single density gradation are formed for each of a plurality of different gradations, and the test pattern printing is performed by performing printing control so that the reference pattern and the adjustment pattern are formed in positions adjacent to each other, and so that the reference pattern is formed in the same target area of ​​the medium by ejecting the liquid toward the same target area using at least two of the printing chips provided in the print head.

[0008] A printing device according to another aspect of the present invention comprises a print head equipped with a plurality of printing chips each having a plurality of nozzles capable of ejecting liquid onto a medium, a main scanning unit which moves the print head and the medium relatively in a main scanning direction, a sub-scanning unit which moves the print head and the medium relatively in a sub-scanning direction intersecting the main scanning direction, and a control unit which performs printing on the medium by performing printing control including control of the relative movement by the main scanning unit and the sub-scanning unit and control of the ejection of the liquid from the print head, and obtains a correction value for adjusting the ejection characteristics for each of the printing chips equipped in the print head. a control unit that controls printing so that the reference pattern and the adjustment pattern are formed adjacent to each other when printing the test pattern, and determines the printing chip to be used when forming the reference pattern according to the information received by the control unit. [Brief description of the drawings]

[0009] [Figure 1] 1 is a block diagram showing an example of a printing device according to a first embodiment; [Diagram 2] 2 is a diagram showing an example of a carriage on which a print head is mounted in the printing device of FIG. 1, together with a medium. FIG. [Diagram 3] 4 is a flowchart showing an example of an inter-chip output density adjustment process in the printing device of FIG. [Figure 4] 2 is a schematic diagram showing an example of a test pattern printed on a medium by the printing device of FIG. 1. [Diagram 5] 2A to 2C are schematic diagrams illustrating an example of printing control of a reference pattern using a plurality of printing chips in the printing device of FIG. [Figure 6]13 is a flowchart showing an example of an inter-chip output density adjustment process in the printing device according to the second embodiment. [Figure 7] 7 is a diagram showing an example of a user interface used when setting the inter-chip output density adjustment process in FIG. 6. FIG. [Figure 8] 7 is a diagram showing an example of a user interface used when executing and resetting the inter-chip output density adjustment process in FIG. 6. FIG. [Figure 9] 7 is a schematic diagram showing another example of the test pattern printed on the medium in the inter-chip output density adjustment process in FIG. 6. [Figure 10] 9 is a schematic diagram showing an example of a test pattern printed based on an instruction from the user interface in FIG. 8 in the inter-chip output density adjustment process in FIG. 6. [Figure 11] 8 is a schematic diagram showing an example of a test pattern printed based on another instruction from the user interface in FIG. 7 in the inter-chip output density adjustment process in FIG. 6. [Figure 12] FIG. 2 illustrates an example of a hardware configuration of the apparatus. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Note that each drawing is merely an example for explaining the embodiment. For example, in the drawings of the printed result, the ratio, shape, and shading may be inaccurate, may not match each other, or some parts may be omitted.

[0011] (Embodiment 1) A printing device according to a first embodiment and an adjustment method in the printing device will be described with reference to Fig. 1 to Fig. 5. Fig. 1 is a block diagram showing an example of a printing device according to a first embodiment. Fig. 2 is a schematic diagram showing an example of a carriage carrying a print head in the printing device of Fig. 1, together with a medium.

[0012] The printing device 1 shown in Fig. 1 includes a control unit 10 and a print head 11. The printing device 1 may also include a carriage 12, a transport unit 13, a memory unit 14, a display unit 15, an operation reception unit 16, and a communication unit 17. Although not shown, the printing device 1 may also include a detector group that monitors the operating status within the printing device 1, in which case the control unit 10 can control each unit based on the detection results from the detector group. Each component will be described below, assuming that the printing device 1 is an inkjet printer that performs printing by an inkjet method.

[0013] The control unit 10, which may also be referred to as a controller, performs overall control of the printing device 1. This control includes print control, which includes control of the relative movement between the medium 30 and the print head 11 by the carriage 12 and the transport unit 13, and control of the ejection of liquid from the print head 11. Through this print control, the control unit 10 ejects liquid onto the medium 30 to execute printing. As this print control, the control unit 10 is configured to be able to perform print control for printing a test pattern. This print control in printing the test pattern is one of the features of this embodiment, and a specific example will be described later.

[0014] The control unit 10 can be configured to include, for example, an arithmetic processing device such as a CPU (Central Processing Unit) or a GPU (Graphics Processing Unit), a working memory, and a storage device that stores control programs, parameters, and the like. The control unit 10 can also be configured as a SoC (System on a Chip). As can be seen from these examples, the control unit 10 can be configured to store the control programs in an executable state. However, the control unit 10 can also be configured to store the control programs as a circuit configuration such as an FPGA (field-programmable gate array), or can be configured as a dedicated circuit. The above programs can include a program that performs print control as described below.

[0015] The print head 11 performs printing by ejecting liquid onto the medium 30 using an inkjet method under the control of the control unit 10. The droplets ejected by the print head 11 are called dots. The liquid is mainly ink, and the following description will be given on the assumption that the liquid is ink, but the print head 11 may be capable of ejecting liquids other than ink. The print head 11 may also be called an ink ejection head. The print head 11 is for recording on the medium 30, and may also be called a recording head. For the same reason, the printing device 1 may also be called a recording device. The medium 30 is, for example, paper, but may be any medium that can be printed on with ink, and may be a material other than paper, such as film or fabric.

[0016] The print head 11 has a plurality of nozzle rows formed on its underside. Each nozzle row is formed by arranging nozzles 20 capable of ejecting ink onto the medium 30 in one or more rows. Each nozzle 20 ejects ink of a predetermined color. The print head 11 is configured to be capable of ejecting ink of a plurality of predetermined colors from the nozzle rows formed therein, but may be configured to be capable of ejecting ink of only one predetermined color. The nozzles 20 of each color communicate with an ink chamber filled with ink of the corresponding color, and ink of the corresponding color is supplied from the ink chamber. The ink ejection method from the nozzles 20 can be a piezo method in which a voltage is applied to a piezo element as a driving element to expand and contract the ink chamber, thereby ejecting ink from the nozzles 20. However, the ink ejection method from the nozzles 20 may be another method, such as a thermal method in which a voltage is applied to a heating element to generate bubbles in the nozzles 20, and the bubbles eject ink from the nozzles 20.

[0017] In this embodiment, the print head 11 forms the above-mentioned multiple nozzle rows by including multiple print chips each having a multiple nozzles 20. Below, an example will be described in which the print head 11 includes print heads 11C, 11M, 11Y, and 11K that eject cyan (C), magenta (M), yellow (Y), and black (K) inks onto the medium 30, respectively, as shown in FIG.

[0018] In the example of FIG. 2, each of the print heads 11C, 11M, 11Y, and 11K includes print chips c1 to c5 having five nozzles 20. The print head 11C is a print head for cyan and includes five print chips c1 to c5 that include a nozzle group in which a plurality of nozzles 20 that eject cyan ink are arranged. Similarly, the print head 11M is a print head for magenta and includes five print chips c1 to c5 that include a nozzle group in which a plurality of nozzles 20 that eject magenta ink are arranged. The print head 11Y is a print head for yellow and includes five print chips c1 to c5 that include a nozzle group in which a plurality of nozzles 20 that eject yellow ink are arranged. The print head 11K is a print head for black and includes five print chips c1 to c5 that include a nozzle group in which a plurality of nozzles 20 that eject black ink are arranged.

[0019] The five printing chips c1 to c5 of each print head 11C, 11M, 11Y, and 11K are all similarly arranged in similar positions on each print head 11C, 11M, 11Y, and 11K. Specifically, the printing chips c1 to c3 are arranged in a row in the sub-scanning direction D2, and the printing chips c4 to c5 are also arranged in a row in the sub-scanning direction D2. The printing chips c1 to c3 and the printing chips c4 to c5 are arranged in a row in the main scanning direction D1 so that there is a partial overlapping area in the sub-scanning direction D2.

[0020] The print heads 11C, 11M, 11Y, and 11K are aligned along the main scanning direction D1, and the positions of the nozzles 20 in the sub-scanning direction D2 are the same. Each of the print chips c1 to c5 has a nozzle row in which five nozzles 20 are aligned at a predetermined interval in the sub-scanning direction D2. This predetermined interval is called the nozzle pitch. In FIG. 2, the nozzle alignment direction in which the nozzles 20 constituting the same nozzle row are aligned is parallel to the sub-scanning direction D2, but the nozzle alignment direction may be obliquely intersecting with the sub-scanning direction D2. Each of the print chips c1 to c5 is a print chip in which an ink discharge mechanism such as a piezoelectric element, an ink chamber, and a nozzle is formed into a chip by applying semiconductor processing technology.

[0021] In the print chips c1 to c5 of the print head 11C, an input signal is supplied from the control unit 10, and ink is ejected from the nozzle group according to the input voltage applied by the input signal. Here, different input signals, that is, different input voltages, may be supplied to the nozzle groups arranged on different print chips as input signals for forming dots of the same size. For example, the input voltage supplied to the nozzle group arranged on the print chip c1 for forming a dot of a certain size may differ from the input voltage supplied to the nozzle group arranged on the print chip c2 for forming a dot of the same size. The ejection of ink in each of the print heads 11M, 11Y, and 11K is similar to that of the print head 11C.

[0022] Such initial values ​​of the input signals used for each printing chip, in other words, initial values ​​of the input voltages, are stored in advance in a memory in the control unit 10. These initial values ​​are set at least before the shipping of the printing device 1 as voltage values ​​common to printing devices of the same model as the printing device 1. However, due to individual differences between the printing chips c1 to c5, that is, differences in the ejection characteristics between the printing chips, even if the initial input voltage is supplied, the amount of ink ejected may differ, and dots of the desired size may not be obtained.

[0023] Therefore, the printer 1 executes an input voltage correction process for correcting the input voltage, i.e., an input voltage calibration process, to reduce the difference in the amount of ink ejected due to such individual differences and obtain the desired ink density. In other words, in the printer 1, even if the same amplitude waveform of the drive waveform, which is the waveform of the input signal, is applied to multiple printing chips, dots of different sizes may be ejected, resulting in different ink densities, and in order to correct this, the input voltage is corrected. This input voltage correction process adjusts the ink output density between the printing chips, and is therefore hereinafter referred to as inter-chip output density adjustment process. This inter-chip output density adjustment process is premised on being executed by the user of the printer 1, but can also be performed before the printer 1 is shipped.

[0024] Here, the printing device 1 prints a test pattern to perform this inter-chip output density adjustment process, and allows the user to visually evaluate the difference in output density between the printing chips during printing, and select a correction value for the input voltage. Such evaluation and selection methods, as well as examples of test patterns that facilitate such evaluation, will be described later. In this way, the printing device 1 has a function of printing a test pattern for acquiring a correction value for adjusting the ejection characteristics of each of the printing chips provided in the print head 11. Note that the test pattern may be referred to as a visual adjustment chart, since it is used to adjust the output density by visual inspection.

[0025] 1 is the print head 11 shown in FIG. 2, but the print head 11 in FIG. 1 may be any print head capable of printing an image of desired image quality on a medium and equipped with a plurality of print chips. In other words, the number of nozzles for each color, the nozzle pitch, the ink color, the number of colors, and the like in the print head 11 are not limited to those illustrated. For example, an example is given in which five nozzles 20 are formed in the print chips c1 to c5 dedicated to each color, but the number of nozzles 20 formed in each of the print chips c1 to c5 does not matter. In addition, the print head 11 may be configured to have a large number of nozzles per color for ink such as black, which is used frequently. In addition, the ink may be a photocurable ink such as a UV (Ultra Violet) curable ink that is cured when irradiated with ultraviolet light, and in that case, an irradiation unit for irradiating ultraviolet light is provided in the printing device 1.

[0026] The carriage 12 is an example of a main scanning unit that moves the print head 11 and the medium 30 relative to each other in the main scanning direction D1. The carriage 12 moves the print head 11 back and forth along a predetermined main scanning direction D1 under the control of the control unit 10. For this back and forth movement, the carriage 12 carries the print head 11. Therefore, the movement of the carriage 12 is synonymous with the movement of the print head 11. For this back and forth movement, the printing device 1 may also include a guide rail, a movement mechanism, and a carriage motor (not shown). The guide rail is a rail that functions as a guide for moving the carriage 12 in the main scanning direction D1, and the movement mechanism is a mechanism that uses the carriage motor as power to move the carriage 12 along the guide rail in the main scanning direction D1.

[0027] The main scanning direction D1 can refer to the width direction of the medium 30, that is, the direction in which the print head 11 is moved in the carriage 12. For convenience, the direction of the main scanning direction D1 shown in Figure 2 is referred to as the forward path, and the opposite direction is referred to as the return path. The printing device 1 can print on both the forward path and the return path, but it is also possible to print on only one of the forward path or the return path, and only move the carriage 12 back to its original position on the other path.

[0028] The transport unit 13 is an example of a sub-scanning unit that moves the print head 11 and the medium 30 relative to each other in the sub-scanning direction D2. The transport unit 13 transports the medium 30 along a predetermined transport path to a position where printing is possible under the control of the control unit 10, and transports the medium 30 a predetermined transport amount in the sub-scanning direction D2, which is the transport direction, during printing. The transport unit 13 can include, for example, rollers that rotate to transport the medium 30, and a motor as a power source for rotation. The transport unit 13 may also be a mechanism that transports the medium 30 by placing the medium 30 on a drum, belt, or pallet that is driven by a motor.

[0029] The relationship between the print head 11 and the medium 30 will now be discussed. Figure 2 shows a simplified view of the relationship between the print head 11 and the medium 30 from above. The main scanning direction D1 and the sub-scanning direction D2 intersect. The intersection here is perpendicular or nearly perpendicular.

[0030] As described above, the carriage 12 is equipped with the print head 11 and is capable of reciprocating together with the print head 11 in the main scanning direction D1. The transport unit 13 transports the medium 30 from upstream to downstream in the sub-scanning direction D2, as indicated by the arrow in the sub-scanning direction D2. In addition, the transport of a predetermined distance downstream in the sub-scanning direction D2 performed by the transport unit 13 between passes can be referred to as "paper feeding." The control unit 10 prints a two-dimensional image on the medium 30 by alternately repeating passes and paper feeding.

[0031] The printer 1 can also be configured so that the carriage 12 carrying the print head 11 can move back and forth not only along the main scanning direction D1 but also along the sub-scanning direction D2. In other words, the print head 11 can print a two-dimensional image on the medium 30 by moving a predetermined distance upstream in the transport direction D2, which serves as a substitute for paper feed, between passes.

[0032] 2, a printing method in which the print head 11 performs passes while moving along the main scanning direction D1, and the medium 30 is fed in the sub-scanning direction D2 between passes is called a serial method. On the other hand, a printing method in which the print head 11 performs passes while moving along the main scanning direction D1, and moves along the sub-scanning direction D2 between passes instead of feeding the paper is called a lateral method. The following explanation will be continued assuming the serial method, but the explanation may of course be interpreted by substituting the lateral method.

[0033] The storage unit 14 is, for example, a hard disk drive, a solid state drive, or another memory-based storage device. A part of the memory included in the control unit 10 may be regarded as the storage unit 14. The storage unit 14 may also be regarded as a part of the control unit 10.

[0034] The display unit 15 is a portion for displaying information, and is configured with a display device such as a liquid crystal display, an organic EL display, etc. The display unit 15 may also be configured to include a display and a drive circuit for driving the display.

[0035] The operation reception unit 16 is a part that receives operations and inputs by the user. The operation reception unit 16 can be realized, for example, by either one or both of physical buttons and a touch panel mounted on the display unit 15. In a configuration in which the operation reception unit 16 includes a touch panel, the display unit 15 and the touch panel can be collectively referred to as the operation panel of the printing device 1.

[0036] The communication unit 17 can be one or more communication interfaces for the printing device 1 to communicate with one or more external devices in a wired or wireless manner in accordance with a predetermined communication protocol including a predetermined communication standard. The external device is, for example, a personal computer (PC), a server, a smartphone, a tablet terminal, or other device equipped with a communication function. The external device can also output print data to the printing device 1 for causing the printing device 1 to print an image, and the printing device 1 that receives the print data can print on a medium. The external device can also perform various settings in the printing device 1. These various settings can include an instruction to print a test pattern and a setting of a correction value for the input voltage thereafter, as described below.

[0037] Next, an example of inter-chip output density adjustment processing including test pattern printing processing in the printing device 1 will be described with reference to Figs. 3 and 4. Fig. 3 is a flow chart showing an example of inter-chip output density adjustment processing in the printing device 1 of Fig. 1. Fig. 4 is a schematic diagram showing an example of a test pattern printed on a medium 30 in the printing device 1 of Fig. 1. Fig. 5 is a schematic diagram showing an example of printing control of a reference pattern by a plurality of printing chips in the printing device 1 of Fig. 1.

[0038] The control unit 10 controls the print head 11, the carriage 12, and the transport unit 13 to print a test pattern. This test pattern includes a reference pattern with a single density gradation and an adjustment pattern including a patch group in which patches with a single density gradation are formed for each of a plurality of different gradations. The patch may be called a pattern or a solid pattern. The reference pattern is a pattern that serves as a reference for comparison to allow a user to confirm which patch of the patch group included in the adjustment pattern is to be corrected, that is, which patch is to be corrected as a target. The reference pattern may also be called a reference pattern, a reference pattern, a target pattern, or the like. The adjustment pattern is a pattern for adjusting the printing chip, and is formed for each printing chip to be adjusted, so it may also be called a printing chip adjustment pattern or an adjustment pattern.

[0039] The printing chips to be adjusted in the inter-chip output density adjustment process can basically be all of the printing chips included in the print head 11. However, all of the printing chips included in the print head 11 may be adjusted in multiple times, for example, by color, and in that case, the adjustment target for each time may be specified based on a user specification or a pre-setting. The printing chips to be adjusted may also be a part of the printing chips included in the print head 11 that is predetermined by a user specification or a pre-setting. In an extreme example, the printing chip to be adjusted may be one printing chip, such as the printing chip c1 of the print head 11C. However, even in that case, multiple printing chips including other printing chips of the same color, such as the printing chips c2 and c1 of the print head 11C or the printing chips c2 and c3 of the print head 11C, are used to form the reference pattern, as described later.

[0040] In the following, for the sake of simplicity, only the test pattern printing and adjustment for the print chips c1 to c5 mounted on the print head 11C will be described. However, the same applies to the print heads 11M, 11Y, and 11K dedicated to other colors, and even when some of the print chips c1 to c5 dedicated to a certain color are to be adjusted, a test pattern including a similar reference pattern may be printed. When adjusting print heads dedicated to two or more colors at the same time, test patterns for the print heads dedicated to each color may be printed at once, and the user may select a correction value at once to adjust the output density between the print chips of the target colors.

[0041] The test pattern printed for print head 11C includes a reference pattern formed by print head 11C and adjustment patterns formed by each of the print chips c1 to c5 mounted on print head 11C.

[0042] Then, the control unit 10 performs printing control so that the reference pattern and the adjustment pattern are formed adjacent to each other when printing the test pattern (step S1). An example of forming patterns in adjacent positions will be described with reference to FIG.

[0043] 4 shows medium 30A obtained by printing a test pattern on medium 30. The test pattern includes adjustment pattern 42c1 consisting of a patch group of patches 42c1-1, 42c1-3, 42c1-5, 42c1-7, 42c1-9, 42c1-11, and 42c1-13 for printing chip c1, and reference pattern 41c1 formed in a position adjacent thereto.

[0044] The patches in the adjustment pattern 42c1 are printed by increasing the input voltage at a predetermined interval from left to right in FIG. 4. The predetermined interval may be a predetermined interval. If the predetermined interval is different, the density difference between adjacent patches included in the adjustment pattern 42c1 will be different. The input voltage when forming the reference pattern 41c1 may be determined in advance. The input voltage when forming the reference pattern 41c1 may be matched to the input voltage when forming one patch in the adjustment pattern 42c1, for example. For example, the input voltage when forming the central patch 42c1-7 in the adjustment pattern 42c1 may be matched to the input voltage when forming the reference pattern 41c1. The target density of the reference pattern 41c1 is matched to the target density of each patch of the adjustment pattern 42c1. The size and print position of the reference pattern 41c1 and each patch of the adjustment pattern 42c1 may be determined in advance.

[0045] 4, a blank area 44 is provided between the adjustment pattern 42c1 and the reference pattern 41c1 to make it easier to distinguish between them, but the blank area 44 may be omitted. Without the blank area 44, it becomes easier to compare the difference in density between the adjustment pattern 42c1 and the reference pattern 41c1, and the two can be compared with high accuracy. Also, a blank area 43 is provided between patches, such as between patch 42c1-1 and patch 42c1-3, to make it easier to distinguish between them, but the blank area 43 may be omitted. However, since a change in the input voltage changes the speed of the ink droplets and causes the landing of the ink droplets to shift in the scanning direction of the carriage 12, it is beneficial to provide the blank area 43 to prevent the landing of the ink droplets from shifting and overlapping between adjacent patches.

[0046] The test pattern also includes reference patterns and adjustment patterns for the other printing chips c2 to c5 to be adjusted. Specifically, the test pattern includes a reference pattern 41c2 and an adjustment pattern 42c2 for the printing chip c2, and a reference pattern 41c3 and an adjustment pattern 42c3 for the printing chip c3. The test pattern further includes a reference pattern 41c4 and an adjustment pattern 42c4 for the printing chip c4, and a reference pattern 41c2 and an adjustment pattern 42c2 for the printing chip c5. Of course, if the patterns cannot be printed on one sheet of medium 30, they may be printed on multiple sheets.

[0047] Although not illustrated in FIG. 4, it is advisable to print characters indicating which test patterns each of the printing chips c1 to c5 refers to. On the medium 30A, it is printed that the reference pattern 41c1 and the adjustment pattern 42c1 are test patterns for the printing chip c1, and at least the adjustment pattern 42c1 is an adjustment pattern for the printing chip c1. This can prevent the user from being confused with the selection points for other printing chips when selecting a patch that matches the reference pattern. The reference pattern 41c2 can also be referred to as the reference pattern for the adjustment pattern 42c1. Of course, as illustrated in FIG. 4, the reference pattern 41c6 may also be formed under the adjustment pattern 42c5. This makes it possible to arrange the reference patterns above and below all the adjustment patterns, making it easier to compare them with the reference patterns.

[0048] Then, in step S1, the reference pattern is formed by the following control. That is, the control unit 10 performs printing control so that at least two printing chips among the printing chips c1 to c5 of the print head 11C eject ink onto the same target area of ​​the medium 30, thereby forming the reference pattern in the same target area. The same target area can also be referred to as within the same band. At least two printing chips among the printing chips c1 to c5 may be predefined as, for example, printing chips c1 and c2. In this case, all of the reference patterns 41c1, 41c2, 41c3, 41c4, and 41c5 are formed by the printing chips c1 and c2. Hereinafter, the present embodiment will be described using an example in which the printing chips used to form the reference pattern are two printing chips c1 and c2, but this is not limiting. The control unit 10 may perform printing control so that, for example, the reference pattern is formed by all of the printing chips c1 to c5 of the print head 11C eject ink.

[0049] It should be noted that "printing control is performed so that at least two printing chips eject ink onto the same target area of ​​medium 30, thereby forming a reference pattern in the same target area" includes forming the reference pattern using at least one nozzle of each of the printing chips used to form the reference pattern, and it is not necessary to form the reference pattern using all nozzles of the printing chips used to form the reference pattern.

[0050] 5, the control unit 10 may control the printing chips c1 and c2 used when forming the reference pattern to equally divide the pixels of the same target area 53 and print the reference pattern. More specifically, the control unit 10 allocates an equal number of pixels of the same target area 53 to the printing chips c1 and c2 used when forming the reference pattern. The control unit 10 may then perform printing control so that the reference pattern is formed by each of the printing chips c1 and c2 ejecting ink at the same target density for the equally allocated pixels.

[0051] Ejecting ink at equal target densities means ejecting ink with equal input voltage and ejection duty. Ejecting ink for evenly allocated pixels means ejecting ink of equal target densities between printing chips c1 and c2 in an evenly allocated manner so that the target areas on medium 30 to which ink is ejected do not overlap. Note that since the reference pattern is a pattern of a single density gradation, the reference pattern is printed so that even when ejecting ink in an evenly allocated manner, there are no visible areas to which ink is not ejected.

[0052] For example, when the target density of the reference pattern is 80% of the maximum density, the control unit 10 controls the ink ejection of the printing chips c1 and c2 so that each of the printing chips c1 and c2 is responsible for a density of 40%. In other words, in this case, the control unit 10 controls the ejection duties of the printing chips c1 and c2 to be 40%, 40%, respectively. Note that, in addition to such ejection control, the control unit 10 also controls the relative movement of the printing chips c1 and c2, and preferably forms the reference pattern in multiple passes.

[0053] In order to equally divide the target density with the printing chips c1 and c2 and form a reference pattern in the same target area 53, the control unit 10 performs control, for example, as shown in Fig. 5. That is, the control unit 10 causes the printing chip c1 to form an image on a portion 51 of the same target area 53 indicated by pixels I, and causes the printing chip c2 to form an image on the other portion 52 of the same target area 53 indicated by pixels II. In other words, the control unit 10 performs printing control so that the printing chips c1 and c2 print alternately for each pixel or each rectangular pixel area in the same target area 53.

[0054] As a result, printing chip c1 is responsible for printing half the pixels in the same target area 53, and printing chip c2 is responsible for printing the remaining half of the pixels, and the reference pattern can be printed with the average density of printing chip c1 and printing chip c2. In particular, by ensuring that the image formation area is not completely divided into the left half and right half, etc., by printing chips c1 and c2, and that the portions in which images are formed by each of printing chips c1 and c2 are printed alternately as shown in Figure 5, a uniformly visible reference pattern can be printed. Furthermore, with this type of control, the reference pattern can be printed with a density appropriate for correction, without the need for special processing such as acquiring and calculating the output density of each of printing chips c1 and c2 as a numerical value.

[0055] However, the control unit 10 may control the printing chips c1 and c2 used when forming the reference pattern to eject ink at different target densities, as long as the target density of the reference pattern matches the target density of each patch of the adjustment pattern.

[0056] Also, although an example has been given in which a reference pattern is formed in the same target area 53 by the printing chips c1 and c2, the same applies when a reference pattern is formed in the same target area 53 by three or more printing chips. For example, when the target density of the reference pattern is set to 80% of the maximum density and printing chips c1 to c4 are used to form the reference pattern, the control unit 10 may control the ejection of ink from the printing chips c1 to c4 so that each of the printing chips c1 to c4 is responsible for a density of 20%.

[0057] In particular, the control unit 10 performs printing control so that the reference pattern is formed by discharging ink from all the printing chips c1 to c5 of the print head 11C, and thus it is possible to print a reference pattern in which the discharge characteristics of all the printing chips c1 to c5 are averaged. Thus, by forming the reference pattern in this manner, it is possible to perform correction with a more appropriate value when taking into account the discharge characteristics of all the printing chips c1 to c5. However, by forming a reference pattern using multiple printing chips without using all the printing chips, it is possible to form a reference pattern that takes into account at least the discharge characteristics of the multiple printing chips, and therefore it is possible to perform correction with a more appropriate value than when using one printing chip. This is because the discharge characteristics of the multiple printing chips are somewhat close to the discharge characteristics of all the printing chips, and even if one printing chip has an extreme value, it is possible to perform correction with a value that can reduce the influence.

[0058] Returning to the description of the flowchart in FIG. 3, after printing the test pattern in step S1, the control unit 10 performs the following process. That is, the control unit 10 judges whether or not an operation to select a patch matching the reference pattern has been received from the operation receiving unit 16 or from an external device such as a PC via the communication unit 17 for each of the printing chips c1 to c5. For this reason, the operation receiving unit 16 is configured to be able to receive a user operation to select a patch of a gradation matching the reference pattern printed on the medium 30 from among a group of patches of each gradation in the adjustment pattern printed on the medium 30. Alternatively, the external device such as a PC is configured to be able to receive such a user operation and transmit the contents of the user operation to the printing device 1 via the communication unit 17. Of course, such a user operation may be received from both the operation receiving unit 16 and the external device.

[0059] The user visually checks the medium 30A and selects, for example, patches 42c1-9, 42c2-11, 42c3-7, 42c4-5, and 42c5-5 as patches that are close to the reference patterns for the printing chips c1, c2, c3, c4, and c5, respectively.

[0060] If the answer is NO in step S2, the control unit 10 waits for the reception of the above selection operation. If the answer is YES in step S2, the control unit 10 adjusts the input voltage for each of the printing chips c1 to c5 with a correction value corresponding to the patch designated by the above selection operation (step S3), and ends the process. This adjustment is performed by rewriting the initial value of the input voltage stored in the internal memory or storage unit 14 of the control unit 10 to a correction value associated with the above selection operation, or by storing the correction value associated with the initial value in the internal memory or storage unit 14. In order to rewrite the initial value to a correction value or to store the correction value associated with the initial value, a table or the like that associates the patches included in the adjustment pattern with the correction values ​​for each of the printing chips c1 to c5 may be stored in the memory or storage unit 14 of the control unit 10.

[0061] That is, the control unit 10 acquires the correction values ​​for each of the printing chips c1 to c5 by reading out the correction values ​​corresponding to the patches selected by the user operation from the correspondence relationships stored in advance.The control unit 10 then adjusts the individual differences in the ejection characteristics among the printing chips c1 to c5 by setting the acquired correction values ​​to be used during printing.In the above-mentioned selection example, the input voltages for the printing chips c1, c2, c3, c4, and c5 are adjusted to correspond to the patches 42c1-9, 42c2-11, 42c3-7, 42c4-5, and 42c5-5, respectively.

[0062] Here, we will provide further details on adjustment using correction values. As described above, accepting an operation to select a patch that matches a reference pattern for a certain printing chip from a patch group means accepting an instruction to specify a correction value for adjusting the ejection characteristics of that printing chip at an interval corresponding to the above-mentioned predetermined interval (hereinafter, adjustment interval). In other words, the printing device 1 can be equipped with a correction acceptance unit that accepts an instruction to specify the above correction value at the above-mentioned adjustment interval. An example of this correction acceptance unit is the operation acceptance unit 16 or the communication unit 17.

[0063] As described above, in this embodiment, a test pattern in which a reference pattern and an adjustment pattern are arranged adjacent to each other is printed, making it easy to visually compare the difference between the reference pattern and the adjustment pattern. Therefore, in this embodiment, it is possible to visually recognize which patch of the adjustment pattern the input voltage between the printing chips should be corrected for, and correction can be performed with reduced individual differences between observers. In this way, according to the printing device 1, the difference in output density between the printing chips during printing is evaluated visually, but the adjustment pattern is printed at a position adjacent to the reference pattern. Therefore, according to the printing device 1, the evaluation is less dependent on the evaluator, and as a result, the difference in output density during printing caused by individual differences between the printing chips can be accurately adjusted.

[0064] In addition, the printing device 1 of this embodiment does not require a sensor such as an imaging unit to reduce differences in output density during printing caused by individual differences between printing chips, thereby preventing increases in manufacturing costs and size.

[0065] As described above, the printer 1 can accurately adjust the difference in output density between the print chips while suppressing increases in manufacturing costs and size. In fact, the difference in output density between the print chips, that is, the difference in print density between the print chips, has a large impact on image quality, but the printer 1 can reduce this difference, improving image quality.

[0066] Furthermore, while there is a possibility that the reference pattern may be printed at an extremely dark or light density when relying on one printing chip, in this embodiment, the reference pattern is formed by multiple printing chips. Therefore, in this embodiment, it is possible to prevent adjustment to match the ejection characteristics of one printing chip, and to form a reference pattern at a density appropriate for correction. In this embodiment, it is possible to at least avoid a situation where correction is made to match a reference pattern of an extremely dark density without a user's specification.

[0067] In addition, according to this embodiment, there is an advantage that the user who purchased the printing device 1 can print a test pattern on paper that he or she normally uses and adjust the ejection characteristics to match the paper that the user wants to use. Therefore, it is not necessary to prepare the paper recommended by the manufacturer of the printing device 1 for adjusting the ejection characteristics.

[0068] (Embodiment 2) The printing device according to the second embodiment differs from the printing device according to the first embodiment only in the print control for test pattern printing. Therefore, the second embodiment will also be described based on the configuration of the printing device 1 in Figs. 1 and 2, focusing on the differences from the first embodiment, but the various examples described in the first embodiment can also be applied. In this embodiment, for the sake of simplicity, only the test pattern printing and adjustment for the printing chips c1 to c5 mounted on the print head 11C will be described.

[0069] In the first embodiment, an example was described in which the multiple printing chips used to form the reference pattern were predetermined. This test pattern printing is called test pattern printing in default mode. In contrast, in the present embodiment, the multiple printing chips used to form the reference pattern can be changed.

[0070] For this reason, the printing device 1 according to the present embodiment includes a receiving unit that receives information indicating priorities when adjusting the ejection characteristics. Hereinafter, this information is referred to as priority information. The priority information can be, for example, information indicating whether adjustment should be made with priority given to color development or to reducing ink consumption. The receiving unit can be exemplified by an operation receiving unit 16 or a communication unit 17. The operation receiving unit 16 passes the priority information received as a user operation to the control unit 10. The communication unit 17 receives the priority information from an external device such as a PC, and passes it to the control unit 10.

[0071] The control unit 10 determines the printing chips to be used when forming the reference pattern according to the priority information received by the operation reception unit 16 or via the communication unit 17. For example, the control unit 10 changes the printing chips to be used when forming the reference pattern from the printing chips c1 and c2 to the printing chips c2 and c3, or to the printing chips c4 and c5, according to the priority information. Rules may be determined in advance as to which printing chips are to be used to form the reference pattern according to the priority information.

[0072] With this configuration, the printer 1 can visually correct the input voltage between the print chips with high accuracy by arranging the reference pattern and the adjustment pattern adjacent to each other, and can print by changing the gradation of the reference pattern based on the priority of the user. Therefore, it can be said that the printer 1 according to this embodiment can execute a designation mode for designating a priority.

[0073] However, this example of determining the printing chip to be used when forming the reference pattern according to the priority information can be applied to cases other than cases where the reference pattern is formed by at least two printing chips ejecting ink onto the same target area 53. In other words, the determination of the printing chip according to the priority information can be applied even to cases where only one printing chip is used to form the reference pattern. However, even in this case, the control unit 10 makes it easier to compare the two by performing printing control such that the reference pattern and the adjustment pattern are formed in positions adjacent to each other when printing the test pattern.

[0074] Next, an example of inter-chip output density adjustment processing including a test pattern printing process in the printing device 1 according to the present embodiment will be described with reference to FIGS. 6 to 11 and 4. FIG. 6 is a flowchart showing an example of inter-chip output density adjustment processing in the printing device 1 according to the present embodiment. FIG. 7 is a diagram showing an example of a user interface used when setting the inter-chip output density adjustment processing in FIG. 6. FIG. 8 is a diagram showing an example of a user interface used when executing and resetting the inter-chip output density adjustment processing in FIG. 6. FIG. 9 is a schematic diagram showing another example of a test pattern printed on the medium 30 in the inter-chip output density adjustment processing in FIG. 6. FIG. 10 is a schematic diagram showing an example of a test pattern printed based on an instruction from the user interface in FIG. 8 in the inter-chip output density adjustment processing in FIG. 6. FIG. 11 is a schematic diagram showing an example of a test pattern printed based on another instruction from the user interface in FIG. 7 in the inter-chip output density adjustment processing in FIG. 6.

[0075] The inter-chip output density adjustment process can be performed, for example, according to a flow as shown in Fig. 6. Specifically, first, the control unit 10 determines whether or not priority item information has been received by the operation receiving unit 16 or via the communication unit 17, that is, whether or not a priority item has been specified (step S11).

[0076] To receive the priority information, for example, a user interface image 70 shown in Fig. 7 is displayed on the display unit 15 or an external device such as a PC. When displaying on an external device, driver software for the printing device 1 capable of displaying image 70 and transmitting information specified therein to the printing device 1 side can be stored in an executable state in the external device.

[0077] Image 70 may include, for example, radio buttons 71 and 72 for specifying priorities, radio buttons 73 to 75 for setting adjustment units, an OK button 76, and a cancel button 77. Radio button 71 is a button for specifying that adjustment should be performed with priority given to color development. Radio button 72 is a button for specifying that adjustment should be performed with priority given to reducing ink usage.

[0078] The adjustment unit refers to the difference in input voltage between adjacent patches included in the adjustment pattern, that is, a predetermined interval for the input voltage between adjacent patches. The radio button 73 is a button for selecting to perform coarse adjustment and is a button for setting a first interval as the predetermined interval. The radio button 74 is a button for selecting to perform fine adjustment and is a button for setting a second interval smaller than the first interval as the predetermined interval. The radio button 75 is a button for selecting to perform fine adjustment as necessary after printing a test pattern for coarse adjustment. When the OK button 76 is selected with the radio button 75 selected, a test pattern for coarse adjustment in which the first interval is set as the predetermined interval is printed, and then the image 80 shown in FIG. 8 is displayed, which allows the user to select whether or not to perform fine adjustment. Of course, the example is not limited to the example in which the adjustment unit can be selected in two stages, coarse adjustment and fine adjustment, and it is also possible to select an adjustment unit in three or more stages. The process according to the adjustment unit will be described later.

[0079] The OK button 76 is a button for executing printing of a test pattern. The Cancel button 77 is a button for canceling and terminating the process. Note that instead of each radio button, a pull-down menu or the like may be used to allow the user to make a selection.

[0080] If either radio button 71 or 72 is selected, the result is YES in step S11. If the result is YES in step S11, the control unit 10 selects a reference pattern corresponding to the designated priority by changing the printing chip used when forming the reference pattern in accordance with the designated priority (step S12). If the radio button 71 is selected, a reference pattern that prioritizes color development is selected, and if the radio button 72 is selected, a reference pattern that uses less ink is selected. The user making adjustments with reference to the selected reference pattern means that the ejection characteristics are adjusted so that printing that matches the designated priority is performed. On the other hand, if the result is NO in step S11, the control unit 10 selects a reference pattern for the default mode (step S13).

[0081] Next, the control unit 10 performs control to form the reference pattern and adjustment pattern selected in step S12 or step S13 at adjacent positions, thereby printing the test pattern on the medium 30 (step S14). The adjustment pattern printed in step S14 is determined according to the adjustment method selected in the adjustment unit setting item in the image 70 in FIG. 7, although it is not shown in FIG.

[0082] In step S14, for example, when a color-prioritized reference pattern is selected and radio button 73 or 75 is selected, a test pattern such as that illustrated in Fig. 4 is printed on medium 30. That is, in this case, a test pattern including reference patterns 41c1-41c6 and adjustment patterns 42c1-42c5 is printed on medium 30. As a result, medium 30A is obtained.

[0083] Here, the formation of a reference pattern with coloring priority will be described. When the received priority item information indicates that coloring is to be prioritized, the control unit 10 performs printing control so that the reference pattern is formed by ejecting ink from the printing chip that prints at the highest density among the printing chips c1 to c5 of the print head 11C. In this way, by adjusting the reference pattern to a high density, the printing device 1 can adjust the ejection characteristics so that printing with a guaranteed color gamut, that is, printing at a high density, can be performed. Note that by printing the reference pattern with one specific printing chip as in this example, the number of control steps can also be reduced.

[0084] Although an example was given in which the printing chip that forms the reference pattern was selected from among the printing chips c1 to c5 equipped in the print head 11C, the printing chip that prints at the highest density may be selected from among the printing chips predetermined as candidates to be used when forming the reference pattern, for example, from among the printing chips c1 and c2. In an example in which the number of printing chips that print the reference pattern is limited to two or more, the printing chip that prints at the highest density may be a predetermined number of printing chips selected in descending order of density, such as the top two printing chips among the high-density printing chips.

[0085] Also, the printing chip that prints with the highest density can be determined by, for example, printing solid patterns in advance with each of the printing chips c1 to c5 and having the user specify which one is the highest density. Similarly, when selecting a predetermined number of printing chips starting from the high density side, the user can specify in advance.

[0086] Return to the description of FIG. 6. In step S14, for example, when a color-development-priority reference pattern is selected and fine adjustment is selected, a test pattern including reference patterns 41c1 to 41c6 and adjustment patterns 46c1 to 46c5 is printed on the medium 30 as illustrated in FIG. 9. As a result, the medium 30B is obtained. Here, the test pattern illustrated in FIG. 9 includes, for the printing chip c1, an adjustment pattern 46c1 consisting of a patch group of patches 46c1-5 to 46c1-11, and a reference pattern 41c1 formed in a position adjacent thereto. Of course, the test pattern illustrated in FIG. 9 also includes similar reference patterns and adjustment patterns for the other printing chips c2 to c5. The adjustment patterns 46c1 to 46c5 have an input voltage interval between patches of about 50% compared to the adjustment patterns 42c1 to 42c5, respectively. For example, if the input voltage interval between each patch of adjustment patterns 42c1-42c5 is 1.0 V, the input voltage interval between each patch of adjustment patterns 46c1-46c5 will be 0.5 V. However, the values ​​and ratios of the intervals between patches in the patch group for coarse adjustment and the intervals between patches in the patch group for fine adjustment are not limited to this. For example, the input voltage interval between patches in the patch group for coarse adjustment may be 0.5 V, and the input voltage interval between patches in the patch group for fine adjustment may be 0.1 V.

[0087] Here, the coarse adjustment and the fine adjustment will be described. The printing device 1 according to the present embodiment is configured to be able to perform both the coarse adjustment and the fine adjustment. The user can select in advance which of the coarse adjustment and the fine adjustment to perform, for example, from among the radio buttons 73 and 74 in the image 70 of FIG. 7 described above. Here, as a further option, an example is given in which a test pattern for the coarse adjustment is printed, and then a test pattern for the fine adjustment and the fine adjustment are printed as necessary by selecting the radio button 75 in the image 70 of FIG. 7. Also, the test pattern for the coarse adjustment and the test pattern for the fine adjustment may be printed at the same time, and the user may check and perform the adjustment as desired.

[0088] That is, the control unit 10 may perform printing control so as to form the first patch group and the second patch group, which will be described below, simultaneously or at different timings as adjustment patterns. Both the first patch group and the second patch group are formed for each printing chip to be adjusted. The first patch group is a patch group in which the driving voltage for driving the printing chip is changed at a first interval. Note that this driving voltage refers to the input voltage applied to the printing chip. The second patch group is a patch group in which the driving voltage for driving the printing chip is changed at a second interval smaller than the first interval. As described above, the first interval and the second interval are examples of the above-mentioned predetermined interval. Here, the values ​​and ratios of the first interval for rough adjustment and the second interval for fine adjustment are not limited to fixed values ​​and may be changeable. This change can be implemented by a user's designation from the operation reception unit 16 or an external device.

[0089] When the first patch group and the second patch group are formed simultaneously, for example, medium 30A in Fig. 4 and medium 30B in Fig. 9 can be obtained by a single print command, or they can be printed on a single medium by a single print command. When the first patch group and the second patch group are formed in different areas of the same medium, both patch groups may be formed adjacent to the reference pattern, for example, by sandwiching a reference pattern between the first patch group and the second patch group. Alternatively, the first patch group and the second patch group may be arranged in a row and a reference pattern formed parallel to the row.

[0090] On the other hand, when the first patch group and the second patch group are formed at different times, for example, the medium 30A in Fig. 4 and the medium 30B in Fig. 9 are obtained at different times. This example will be described later.

[0091] Returning to the description of FIG. 6, for example, in step S14, when a reference pattern that prioritizes reducing the amount of ink used, that is, reducing the amount of ink used, is selected and fine adjustment is selected, the following printing is performed. That is, as illustrated in FIG. 11, a test pattern including reference patterns 47c1 to 47c6 and adjustment patterns 48c1 to 48c5 is printed on the medium 30, and the medium 30D is obtained. Here, the test pattern illustrated in FIG. 11 includes, for the printing chip c1, an adjustment pattern 48c1 consisting of a patch group of patches 48c1-5 to 48c1-11, and a reference pattern 47c1 formed in a position adjacent thereto. Of course, the test pattern illustrated in FIG. 11 also includes similar reference patterns and adjustment patterns for the other printing chips c2 to c5. The reference patterns 47c1 to 47c6 are formed with a lower target density compared to the reference patterns 41c1 to 41c6. Adjustment patterns 48c1 to 48c5 are adjustment patterns in which the target density is lowered in accordance with the decrease in the target density of the reference pattern compared to adjustment patterns 46c1 to 46c5, respectively. Of course, if the decrease in the target density of the reference pattern is slight, the target density of the adjustment pattern does not need to be lowered.

[0092] Note that, although we will not show an example of what happens when a reference pattern that prioritizes reducing ink usage is selected and coarse adjustment is selected, a test pattern will be printed in which the density difference between adjacent patches is greater than that of medium 30D, as in the example of Figure 4.

[0093] Here, the formation of a reference pattern that reduces the amount of ink used will be described. When the received priority item information indicates that a reduction in the amount of ink used is to be prioritized, the control unit 10 performs the following printing control. That is, in this case, the control unit 10 performs printing control so that the reference pattern is formed by ejecting ink from the printing chip that prints at the lowest density among the printing chips provided in the print head 11C. In this way, by matching the reference pattern to the printing chip with the lowest density, that is, the printing chip that prints the lightest, the printing device 1 can save the amount of ink consumed when printing a test pattern and adjust the ejection characteristics specialized for printing that saves the amount of ink consumed.

[0094] Although an example has been given in which the printing chip that forms the reference pattern is selected from among the printing chips c1 to c5 equipped in the print head 11C, the printing chip that prints at the lowest density may be selected from among the printing chips predetermined as candidates to be used when forming the reference pattern, for example, from among the printing chips c1 and c2. In an example in which the number of printing chips that print the reference pattern is limited to two or more, the printing chip that prints at the lowest density may be a predetermined number of printing chips selected in order from the lowest density, such as the two lowest density printing chips among the low density printing chips.

[0095] Also, the printing chip that prints with the lowest density can be determined by, for example, printing solid patterns in advance with each of the printing chips c1 to c5 and having the user specify which one is the lowest density. Similarly, when selecting a predetermined number of printing chips from the low density side, the user can specify in advance.

[0096] Alternatively, the priority information may be, for example, information indicating that a balance between good color development and reduced ink usage is to be prioritized. In this case, if the received priority information indicates that a balance is to be prioritized, printing control is performed so that a reference pattern is formed by ejecting ink from a printing chip that performs plausible printing that is neither too light nor too dark, among the printing chips provided in print head 11C.

[0097] An example was given in which the printing chip that forms the reference pattern was selected from among the printing chips c1 to c5 included in the print head 11C. However, a printing chip that performs plausible printing may be selected from among the printing chips that are predetermined as candidates to be used when forming the reference pattern, for example, from among the printing chips c1 and c2. The printing chip that performs plausible printing may be selected by the user or automatically by the control unit 10 from among the printing chips that print the darkest and lightest solid patterns that are formed by printing solid patterns in advance with each of the printing chips c1 to c5. Alternatively, a printing chip that performs plausible printing may be selected by other methods, such as printing solid patterns in advance with each of the printing chips c1 to c5 and selecting a chip that the user judges to be visually close to the average from among them.

[0098] Returning to the explanation of FIG. 6, a case will be described here where the OK button 76 is selected with the radio button 75 selected. In this case, after a test pattern for coarse adjustment is printed in step S14 as on the medium 30A in FIG. 4, the image 80 in FIG. 8 is displayed on the display unit 15 or an external device such as a PC, and the selection of a patch that matches the reference pattern is accepted (step S15). When displaying on an external device, driver software for the printing device 1 that can display the image 80 and transmit the information specified or selected thereto to the printing device 1 side can be stored in an executable state in the external device.

[0099] The image 80 includes, for example, the chip numbers of the printing chips c1 to c5, and includes a selection field 81 for selecting the number of the patch closest to the reference pattern corresponding to each chip number, and radio buttons 82 and 83 for selecting the process to be executed. The image 80 also includes an OK button 84 and a cancel button 85. The chip numbers and patch numbers are also printed on the test pattern. The selection field 81 may simply be an input field for inputting the number of the patch closest to the reference pattern. The radio button 82 is a button for executing adjustment. The radio button 83 is a button for executing fine adjustment. The user selects either the radio button 82 or 83 for each chip number. Note that the image 80 may allow the user to select neither the radio button 82 or 83. For the printing chip corresponding to the chip number for which neither the radio button 82 or 83 is selected, neither the coarse adjustment nor the fine adjustment may be executed. Also, instead of the radio buttons 82 and 83, the user may select the process to be executed using a pull-down menu or the like. The OK button 84 is a button for executing the process selected from the radio buttons 82 and 83. The cancel button 77 is a button for canceling and terminating the process.

[0100] On the other hand, when the OK button 76 is selected with either the radio button 73 or 74 selected, an image (not shown) that does not include the radio button 83 can be displayed in the image 80 in Fig. 8. When the radio button 74 is selected, a test pattern including a patch group for fine adjustments can be printed, allowing finer adjustments to be made, compared to when the radio button 73 is selected.

[0101] If the answer is YES in step S15, the control unit 10 adjusts the input voltage for each printing chip with a correction value corresponding to the patch having the patch number specified in the selection field 81 (step S16), and ends the process. If the answer is NO in step S15, the control unit 10 determines whether or not a fine adjustment instruction has been received from the image 80 by selecting a radio button 83 (step S17). Note that, although details are not shown in FIG. 6, the reception of the patch selection in step S15 and the determination of the reception of the fine adjustment instruction in step S17 are performed for each printing chip.

[0102] If the result is NO in step S17, the process returns to the determination in step S15, and is repeated until the result is YES in step S15. If the result is YES in step S17, the control unit 10 changes the second interval of the input voltage between the patches according to the fine adjustment instruction, and proceeds to step S14 to perform control to print a test pattern. As a result, as illustrated in the medium 30C of FIG. 10, a medium is obtained on which a test pattern for fine adjustment is printed for the printing chips c1 and c5 for which the radio button 83 for fine adjustment is selected. In addition, in the medium 30C, patches 46c1-6 to 46c1-12 and patches 46c5-3 to 46c5-9 are formed around the numbers selected in the selection column 81 for the printing chip c1 and the printing chip c5, respectively. In addition, in the medium 30C, reference patterns 41c1 and 41c5 are formed for comparison with the adjustment pattern 46c1, and reference patterns 41c5 and 41c6 are formed for comparison with the adjustment pattern 46c5. If fine adjustment is selected for all of the printing chips c1 to c5 in the image 80, a medium on which a test pattern for fine adjustment is printed will be obtained, as exemplified by medium 30B in FIG.

[0103] In this way, in the example of FIG. 6, fine adjustment is performed as necessary after printing the test pattern for coarse adjustment. As a result, even if there is no patch that matches the reference pattern in the test pattern printing for coarse adjustment, a patch that matches the reference pattern can be selected by printing the test pattern for fine adjustment, and the ejection characteristics can be easily adjusted by visual inspection. For example, in FIG. 4, there is no patch that matches the reference pattern 41c5 and the adjustment pattern 42c5, but it can be seen that the reference pattern 41c5 has a density between the patch 42c5-5 and the patch 42c5-7. Therefore, by forming a patch that includes at least one of the patch 42c5-5 and the patch 42c5-7 and has an input voltage interval that is smaller than the input voltage interval between each patch in the coarse adjustment, it is possible to form a patch that more closely matches the reference pattern. Of course, if it is not possible to select a patch that matches the reference pattern in one fine adjustment test pattern printing, the fine adjustment test pattern printing may be repeated with a smaller input voltage interval until a patch that matches the reference pattern can be selected. In this way, by printing a test pattern for fine adjustment as necessary after printing a test pattern for coarse adjustment, the ejection characteristics can be easily adjusted even by visual inspection.

[0104] Printing a test pattern for fine adjustment after printing a test pattern for coarse adjustment is an example of a case where the first patch group and the second patch group are formed at different times. The case where the first patch group and the second patch group are formed at different times will be supplemented. As illustrated in FIG. 4 and FIG. 9, forming at different times may refer to forming images on different media. As described for the radio button 75 in FIG. 7, when the first patch group and the second patch group are formed on different media, an adjustment pattern including the second patch group may be formed adjacent to the reference pattern only when the user cannot confirm a patch that matches the reference pattern in the first patch group. Note that when the first patch group and the second patch group are formed on different media, they can also be considered as being formed as different test patterns.

[0105] A supplementary explanation will be given regarding an example of control for printing a test pattern for fine adjustment after printing a test pattern for coarse adjustment. The control unit 10 performs printing control so as to form a first patch group in which the driving voltage for driving the printing chip is changed at a first interval as an adjustment pattern. Then, the control unit 10 performs printing control so as to change the driving voltage for driving the printing chip at a predetermined second interval smaller than the first interval when forming the adjustment pattern, and to form a second patch group in which the driving voltage for driving the printing chip is changed at a second interval as an adjustment pattern. Alternatively, the printing device 1 may include a receiving unit that receives an instruction to change the driving voltage for driving the printing chip at a second interval smaller than the first interval when forming the adjustment pattern. This receiving unit can also be exemplified by the operation receiving unit 16 or the communication unit 17, similar to the receiving unit that receives priority item information. Then, the control unit 10 may perform printing control so as to form a patch group in which the driving voltage for driving the printing chip is changed at a second interval as an adjustment pattern. In either example, after printing a test pattern including a group of patches changed at a second interval, in steps S15 and S16, the input voltage can be adjusted with a correction value corresponding to the patch of the patch number selected by user operation from the group of patches.

[0106] As described above, an example of performing fine adjustment as necessary after printing a test pattern for coarse adjustment has been given with reference to FIG. 6. However, the printing device 1 may be configured to always accept a selection of a patch that matches the reference pattern from the user after printing a test pattern for coarse adjustment, even if the radio button 75 is selected, and to adjust the ejection characteristics once with coarse adjustment. In that case, the control unit 10 adjusts the input voltage with a correction value corresponding to the patch of the patch number specified for each printing chip according to the selection, and after such coarse adjustment, prints a test pattern for fine adjustment. In this case, the test pattern for fine adjustment is printed so as to include a patch group in which the input voltage is changed at the second interval based on the input voltage corrected by the coarse adjustment for each printing chip. Then, after this printing, similar to the coarse adjustment, the user selects a patch that matches the reference pattern, and the control unit 10 adjusts the input voltage with a correction value corresponding to the patch of the patch number specified for each printing chip according to the selection, and the fine adjustment can be completed.

[0107] Also, here, the case where a test pattern for fine adjustment is printed after a test pattern for coarse adjustment is described, but it is of course possible to print only the test pattern for fine adjustment. For example, if an adjustment has been performed once in the past and the appropriate input voltage is known, or if the voltage that matches the reference pattern is known to a certain extent, it is sufficient to print only the test pattern for fine adjustment. In that case, the test pattern for fine adjustment may be printed at intervals of the input voltage for fine adjustment centered on that voltage.

[0108] Also, in the above, an example has been given in which the user selects one patch from the group of patches included in the printed test pattern in the selection field 81, and the input voltage is adjusted with the correction value corresponding to the selected patch. However, as a modified example, the printing device 1 may be configured so that the input voltage can also be adjusted to the intermediate value between two correction values ​​corresponding to adjacent patches in the group of patches included in the printed test pattern, for example, in the selection field 81. This halves the adjustment unit of the input voltage, i.e., the adjustment unit of the ejection characteristics, allowing finer adjustments to be made.

[0109] The above modified example will be described in detail. The control unit 10 performs printing control so as to form a patch group in which the driving voltage for driving the printing chip is changed at a predetermined interval as an adjustment pattern to be formed at a position adjacent to the reference pattern. However, in the above modified example, the printing device 1 sets the adjustment interval received by the correction receiving unit to an interval corresponding to an interval in units of half the above predetermined interval. In other words, the printing device 1 includes a correction receiving unit that receives an instruction to specify a correction value for adjusting the ejection characteristics of the printing chip at an adjustment interval corresponding to an interval in units of half the above predetermined interval. This correction receiving unit can also be exemplified by the operation receiving unit 16 or the communication unit 17.

[0110] In the above modification, even if a test pattern such as the medium 30A in FIG. 4 is printed, the adjustment can be performed to a correction value corresponding to the middle between the patch 42c5-5 and the patch 42c5-7. For example, in FIG. 4, there is no patch that matches the reference pattern 41c5 and the adjustment pattern 42c5, but it can be seen that the reference pattern 41c5 has a density between the patch 42c5-5 and the patch 42c5-7. In this case, the user can select "6" between "5" and "7" as the "closest number" in the selection field 81 for the fifth chip indicating the printing chip c5. This allows the control unit 10 to adjust the input voltage of the printing chip c5, which is the fifth chip, with a correction value that is intermediate between the correction value corresponding to the patch 42c5-5 and the correction value corresponding to the patch 42c5-7. Therefore, in the above modification, the adjustment unit of the input voltage, that is, the adjustment unit of the ejection characteristics, is halved, and finer adjustment can be performed. In other words, the above modification has the effect of reducing the number of patches to be printed in the test pattern.

[0111] Next, a supplementary explanation will be given regarding a program that causes an external device such as a PC to execute printing on the printing device 1. This program is called driver software or the like.

[0112] This program is a program for causing a computer such as a PC that controls the printing device 1 to execute an acquisition process for causing the printing device 1 to acquire a correction value for adjusting the ejection characteristics for each of the printing chips included in the print head 11C. This acquisition process includes a process for executing a test pattern printing that prints the test pattern as described above. This acquisition process also accepts a user operation for selecting a patch of a gradation that matches the reference pattern printed on the medium 30 from a patch group of each gradation in the adjustment pattern printed on the medium 30, as a correction value for each of the printing chips included in the print head 11C. This acquisition process causes the printing device 1 to acquire a correction value corresponding to the patch selected by this user operation by reading it from a correspondence relationship stored in advance. As for other application examples, various application examples described in the first and second embodiments can be applied. For example, this program can also include a program for causing the computer to execute a process for adjusting the ejection characteristics for each of the printing chips included in the print head 11C based on the correction value acquired in the acquisition process.

[0113] As described above, according to this embodiment, in addition to the same effects as those of the first embodiment, it is possible to change the printing chip used to form the reference pattern. In particular, by determining the printing chip used to form the reference pattern according to the user's designation, it is possible to form the reference pattern according to the user's desired priority, and it is possible to obtain a printing device 1 in which the ejection characteristics are adjusted according to the priority. Note that other effects obtained by this embodiment are as described for each application example.

[0114] (Other variations) The present invention is not limited to the above embodiment, and can be modified as appropriate without departing from the spirit of the present invention. For example, the printing device according to the present embodiment can be configured without some of the components of the printing device 1 shown in Fig. 1. For example, the printing device 1 can accept user operations even if it is equipped with only one of the display unit 15 and operation acceptance unit 16 and the communication unit 17.

[0115] In the above description, the printing device is provided with a print head dedicated to each color, such that one color of ink corresponds to one printing chip, but this is not limited to the above. For example, the printing device may be provided with one or more print heads in which two or more colors of ink correspond to one printing chip. In this case, the adjustment may be performed for each printing chip and for each color, or for each printing chip, using a composite color pattern of the colors of ink that the printing chip can eject. The printing device may also be provided with one or more print heads from which one or more colors of ink are ejected from multiple printing chips. In this case, the adjustment may be performed for each printing chip and for each color, or for each printing chip, using a composite color pattern of the colors of ink that the printing chip can eject. Of course, adjustments for multiple printing chips included in multiple printing heads can be performed simultaneously, and in this case, a test pattern for each printing chip may be printed simultaneously on the same or successively transported medium.

[0116] In addition, although the above explanation is based on the assumption that the nozzle ejects one type of dot, the printing device may be configured to eject two or more types of dots of different sizes by changing the type of input signal, i.e., by changing the input voltage. In this case, the printing of the test pattern and the adjustment of the ejection characteristics can be performed only for dots of a predetermined type or a type specified by the user, but may also be performed for each type of dot.

[0117] Furthermore, in the above description, it has been assumed that the printing device is an inkjet printer, but the printing device can be widely applied to a copying machine, a facsimile machine, a multifunction machine having these functions, and the like.

[0118] Furthermore, each of the above-mentioned printing devices and external devices such as a PC can have, for example, the following hardware configuration: Fig. 12 is a diagram showing an example of the hardware configuration of the device.

[0119] 12 may include a processor 101, a memory 102, and an interface 103. The interface 103 may include, for example, a communication interface, an interface with an input / output device, etc., as required depending on the device.

[0120] The processor 101 may be, for example, a CPU, a GPU, or an MPU (Micro Processor Unit) also called a microprocessor. The processor 101 may include multiple processors. The memory 102 is configured, for example, by a combination of a volatile memory and a non-volatile memory. The functions of each device are realized by the processor 101 reading a program stored in the memory 102 and executing the program while exchanging necessary information via the interface 103.

[0121] Moreover, the above-mentioned program includes a set of instructions (or software code) for making the computer perform one or more functions described in the embodiment when the program is loaded into the computer. The program may be stored in a non-transitory computer-readable medium or a tangible storage medium. By way of example and not limitation, the computer-readable medium or tangible storage medium includes random-access memory (RAM), read-only memory (ROM), flash memory, solid-state drive (SSD) or other memory technology. By way of example and not limitation, the computer-readable medium or tangible storage medium includes CD-ROM, digital versatile disc (DVD), Blu-ray (registered trademark) disk or other optical disk storage, magnetic cassette, magnetic tape, magnetic disk storage or other magnetic storage device. The program may be transmitted on a transitory computer-readable medium or communication medium. By way of example and not limitation, the transitory computer-readable medium or communication medium includes electrical, optical, acoustic, or other forms of propagating signals.

[0122] While the present invention has been described above in accordance with the above-described embodiment, the present invention is not limited to the configuration of the above-described embodiment, and naturally includes various modifications, alterations, and combinations that may be made by a person skilled in the art within the scope of the invention as defined in the claims of the present application. [Explanation of symbols]

[0123] c1, c2, c3, c4, c5...printing chips, D1...main scanning direction, D2...sub-scanning direction (transport direction), 1...printing device, 10...control unit, 11...printing head, 11C...cyan printing head, 11M...magenta printing head, 11Y...yellow printing head, 11K...black printing head, 12...carriage, 13...transport unit, 14...storage unit, 15...display unit, 16...operation reception unit, 17...communication unit, 20...nozzle, 30, 30A, 30B, 30C, 30D...medium, 41c1, 41c2, 41c3, 41c4, 41c5, 41c6, 47c1, 47c2, 47c3, 47c4, 47c5, 47c6... Reference pattern, 42c1, 42c2, 42c3, 42c4, 42c5, 46c1, 46c2, 46c3, 46c4, 46c5, 48c1, 48c2, 48c3, 48c4, 48c5... Adjustment pattern, 42c1-1, 42c1-3, 42c1-5, 42c1-6, 42c1-7, 42c1-8, 42c1-9, 42c1 -10,42c1-11,42c1-12,42c1-13,42c2-11,42c3-7,42c4-5,42c5-5,42c5-7... patches,46c1-5,46c1-6,46c1-7,46c1-8,46c1-9,46c1-10,46c1-11,46c1-12,46c2-11,46c3-7,46c4-5,46c5-3,46c5-4,46c5-5,46c5-6,46c5-7,46c5-8,46c5-9... patches, 48c1-5, 48c1-6, 48c1-7, 48c1-8, 48c1-9, 48c1-10, 48c1-11, 48c2-9, 48c3-7, 48c4-5, 48c5-6...patch, 53...same target area, 70, 80...image, 71, 72, 73, 74, 75, 82, 83...radio button, 76, 84...OK button, 77, 85...cancel button, 81...selection field, 100...device, 101...processor, 102...memory, 103...interface

Claims

1. a print head including a plurality of print tips each having a plurality of nozzles capable of ejecting liquid onto a medium; a main scanning unit that moves the print head and the medium relatively in a main scanning direction; a sub-scanning unit that moves the print head and the medium relatively in a sub-scanning direction that intersects with the main scanning direction; a control unit that performs printing on the medium by performing print control including control of relative movement by the main scanning unit and the sub-scanning unit and control of ejection of the liquid from the print head; A printing device capable of printing a test pattern for acquiring a correction value for adjusting an ejection characteristic of each of the printing chips included in the print head, The test pattern is A reference pattern having a single density gradation; an adjustment pattern including a patch group in which a patch of a single density gradation is formed for each of a plurality of different gradations; When printing the test pattern, the control unit A printing device characterized by performing printing control so that the reference pattern and the adjustment pattern are formed in adjacent positions, and so that the reference pattern is formed in the same target area of ​​the medium by ejecting the liquid using at least two of the printing chips provided in the print head.

2. The printing device according to claim 1, characterized in that the control unit performs printing control so that the reference pattern is formed by ejecting the liquid at equally allocated positions with the same target density for all of the printing chips used when forming the reference pattern.

3. The printing device according to claim 1 or claim 2, characterized in that the control unit performs printing control so that the reference pattern is formed by ejecting the liquid onto the same target area using all of the printing chips of the printing head.

4. a reception unit that receives information indicating a priority when adjusting the ejection characteristics, 2. The printing apparatus according to claim 1, wherein the control unit determines the printing chip to be used when forming the reference pattern in accordance with the information received by the reception unit.

5. a print head including a plurality of print tips each having a plurality of nozzles capable of ejecting liquid onto a medium; a main scanning unit that moves the print head and the medium relatively in a main scanning direction; a sub-scanning unit that moves the print head and the medium relatively in a sub-scanning direction that intersects with the main scanning direction; a control unit that performs printing on the medium by performing print control including control of relative movement by the main scanning unit and the sub-scanning unit and control of ejection of the liquid from the print head; A printing device capable of printing a test pattern for acquiring a correction value for adjusting an ejection characteristic of each of the printing chips included in the print head, A receiving unit that receives information indicating a priority when adjusting the ejection characteristics, The test pattern is A reference pattern having a single density gradation; an adjustment pattern including a patch group in which a patch of a single density gradation is formed for each of a plurality of different gradations; The control unit is performing printing control so that the reference pattern and the adjustment pattern are formed adjacent to each other when printing the test pattern; a printing device that determines the printing chip to be used when forming the reference pattern in accordance with the information received by the reception unit;

6. The control unit is A printing device as described in claim 4 or claim 5, characterized in that when the information indicates that color development is to be prioritized, printing control is performed so that the reference pattern is formed by the printing chip that prints at the highest density among the printing chips provided in the print head or among the printing chips that have been predetermined as candidates for use in forming the reference pattern ejecting the liquid.

7. The control unit is A printing device as described in claim 4 or claim 5, characterized in that when the information indicates that a reduction in the amount of liquid used is to be prioritized, printing control is performed so that the reference pattern is formed by the printing chip that prints at the lowest density ejecting the liquid, among the printing chips provided in the print head or among the printing chips that have been predetermined as candidates for use in forming the reference pattern.

8. The control unit may set the adjustment pattern as a first patch group in which a driving voltage for driving the printing chip is changed at a first interval; 3. The printing device according to claim 1, wherein printing control is performed so as to form a second patch group in which the driving voltage is changed by a second interval smaller than the first interval, at the same time or at a different timing.

9. The control unit is performing printing control so as to form, as the adjustment pattern, a patch group in which a driving voltage for driving the printing chip is changed at a predetermined interval; The printing device is a correction receiving unit that receives an instruction to specify the correction value for adjusting the ejection characteristics of the printing tip at intervals corresponding to half the predetermined intervals; 3. The printing apparatus according to claim 1, wherein the first and second printing units are arranged in a first direction.

10. a print head including a plurality of print tips each having a plurality of nozzles capable of ejecting liquid onto a medium; a main scanning unit that moves the print head and the medium relatively in a main scanning direction; a sub-scanning unit that moves the print head and the medium relatively in a sub-scanning direction that intersects with the main scanning direction; a control unit for controlling the relative movement of the main scanning unit and the sub-scanning unit and the ejection of the liquid from the print head, thereby performing printing on the medium, the printing device executes test pattern printing for printing a test pattern for acquiring a correction value for adjusting ejection characteristics for each of the printing chips included in the print head; The test pattern is A reference pattern having a single density gradation; an adjustment pattern including a patch group in which a patch of a single density gradation is formed for each of a plurality of different gradations; The test pattern printing is An adjustment method characterized by being carried out by performing printing control so that the reference pattern and the adjustment pattern are formed in positions adjacent to each other, and so that the reference pattern is formed in the same target area of ​​the medium by ejecting the liquid using at least two of the printing chips provided in the print head.

11. The printing device, The correction value for each of the printing chips included in the print head is accepting a user operation for selecting a patch having a gradation that matches the reference pattern printed on the medium from among a group of patches of each gradation in the adjustment pattern printed on the medium; 11. The adjustment method according to claim 10, wherein the correction value corresponding to the patch selected by the user operation is obtained by reading it from a correspondence relationship stored in advance.

Images