printer

Abstract

Reduces variations in ink placement between multiple nozzle rows. [Solution] The printer stores multiple drive signals and multiple adjustment signals, each with a predetermined characteristic value of the drive signal changed by a predetermined amount. The printer registers multiple adjustment values ​​Tp1 to Tp4 when multiple drive signals are supplied to multiple nozzle rows, comparison values ​​Ta1 to Ta4 which are the adjustment values ​​when multiple adjustment signals are supplied to multiple nozzle rows, and a common target value Tt for the adjustment values ​​Tp1 to Tp4. Based on the difference between the adjustment values ​​Tp1 to Tp4 and the target value Tt, the difference between the adjustment values ​​Tp1 to Tp4 and the comparison values ​​Ta1 to Ta4, and the amount of change, the printer calculates correction values ​​ΔVc1 to ΔVc4 for the characteristic values ​​of the drive signals so that the adjustment values ​​Tp1 to Tp4 match the target value Tt.

Description

Technical Field

[0001] The present invention relates to a printer.

Background Art

[0002] Conventionally, there has been known a printer including a recording head having a plurality of nozzles for ejecting ink, and forming an image by ejecting ink onto a recording medium. Further, there is known such a printer that can correct a shift when a shift occurs in the landing position of the ink due to deterioration of the recording head. For example, Patent Document 1 discloses an inkjet printer including a piezoelectric element as an element for ejecting ink from a nozzle, and capable of correcting the landing position of the ink by changing the maximum voltage of a drive waveform supplied to the piezoelectric element. The inkjet printer described in Patent Document 1 determines the change width of the maximum voltage of the drive waveform using a trial drive waveform with a higher maximum voltage of the drive waveform. The inkjet printer described in Patent Document 1 obtains the relationship between the increase width of the voltage of the trial drive waveform with respect to the drive waveform and the positional difference of the ink landing position, and determines the change width of the maximum voltage of the drive waveform based on the distance between the actual landing position of the ink and the target position and the obtained relationship.

[0003] The inkjet printer described in Patent Document 1 is configured to perform printing while reciprocating the ejection head. The inkjet printer described in Patent Document 1 adjusts the voltage of the drive waveform so that the ink landing position in the forward path and the ink landing position in the return path are at the same position. According to Patent Document 1, in bidirectional printing, the positional difference of the ink landing position due to changing the voltage of the drive waveform is the position where the ink landing positions in the forward path and the return path substantially coincide when the drive waveform is supplied to the piezoelectric element to eject the ink, and the position where the ink landing positions in the forward path and the return path substantially coincide when the trial drive waveform is supplied to the piezoelectric element to eject the ink, and the positional difference between them.

Prior Art Documents

Patent Documents

[0004] [Patent Document 1] Japanese Patent Publication No. 2021-121489 [Overview of the Initiative] [Problems that the invention aims to solve]

[0005] In inkjet printers typically have multiple nozzle rows on the print head. These multiple nozzle rows have varying characteristics, and even with a common drive signal, the ink ejection speeds may not be the same. If the ink ejection speeds differ among the multiple nozzle rows, the ink will land in different positions on each row.

[0006] This invention has been made in view of the above, and aims to provide a printer that can reduce variations in the ink landing position between multiple nozzle rows. [Means for solving the problem]

[0007] The printer disclosed herein comprises a recording head having first to n nozzle rows each composed of a plurality of nozzles arranged in a predetermined direction, and first to n element groups each ejecting ink from the nozzles of the first to n nozzle rows, a moving device for moving the ink head in a scanning direction orthogonal to the direction of arrangement, and a control device for controlling the first to n element groups and the moving device. The control device comprises a first storage unit, a second storage unit, a drive signal supply unit, a first registration unit, a second registration unit, a third registration unit, and a correction value calculation unit. The first storage unit stores first to n drive signals supplied to the first to n element groups, respectively. The second storage unit stores first to n adjustment signals, which are a plurality of drive signals supplied to the first to n element groups, respectively, and which change a predetermined characteristic value of the first to n drive signals by a predetermined first to n change amount. The drive signal supply unit supplies the first to nth drive signals or the first to nth adjustment signals to the first to nth element groups, respectively. The first registration unit registers the first to nth adjustment values, which are adjustment values ​​related to the ink's landing position, and are multiple adjustment values ​​when the first to nth drive signals are supplied to the first to nth element groups, respectively. The second registration unit registers the first to nth comparison values, which are adjustment values ​​related to the ink's landing position, and are multiple adjustment values ​​when the first to nth adjustment signals are supplied to the first to nth element groups, respectively. The third registration unit registers a common target value for the first to nth adjustment values. The correction value calculation unit calculates first to n correction values ​​for the characteristic values ​​of the first to n drive signals such that the first to n adjustment values ​​match the target value, based on the differences between the first to n adjustment values ​​and the target value, the differences between the first to n adjustment values ​​and the first to n comparison values, and the first to n change amounts.

[0008] According to the above printer, the first to nth correction values ​​are correction values ​​for the characteristic values ​​(e.g., voltage) of the first to nth drive signals that make the first to nth adjustment values ​​match a common target value. By adding the first to nth correction values ​​to the characteristic values ​​of the first to nth drive signals, variations in the ink landing positions between the first to nth nozzle rows can be reduced. By examining the differences between the first to nth adjustment values ​​and the first to nth comparison values, and the corresponding first to nth change amounts, the relationship between the change in the characteristic values ​​of the first to nth drive signals and the fluctuation in the first to nth adjustment values ​​can be estimated. Therefore, the first to nth correction values ​​for the characteristic values ​​can be calculated based on the differences between the first to nth adjustment values ​​and the target value, the differences between the first to nth adjustment values ​​and the first to nth comparison values, and the first to nth change amounts. [Brief explanation of the drawing]

[0009] [Figure 1] This is a front view of a printer according to one embodiment. [Figure 2] This is a bottom view of the carriage. [Figure 3] This is a cross-sectional view of the vicinity of one nozzle of the recording head. [Figure 4] This is a cross-sectional view of the recording head, cut along a plane extending in the sub-scanning direction. [Figure 5] This is a block diagram of a printer. [Figure 6] This is a schematic diagram showing an example of a drive signal. [Figure 7] This is a schematic plan view of the bidirectional adjustment pattern. [Figure 8] This is a flowchart illustrating the determination of correction values ​​related to the voltage of the drive signal. [Modes for carrying out the invention]

[0010] Hereinafter, embodiments of the inkjet printer (hereinafter referred to as "printer") according to the present invention will be described with reference to the drawings. Naturally, the embodiments described herein are not intended to particularly limit the present invention. Furthermore, the same reference numerals are used for components and parts that perform the same function, and redundant explanations are omitted or simplified.

[0011] Figure 1 is a front view of a printer 10 according to one embodiment. In the following description, when viewing the printer 10 from the front, the direction away from the printer 10 is referred to as the front, and the direction towards the printer 10 is referred to as the rear. The symbols F, Rr, L, R, U, and D in the drawing represent front, rear, left, right, up, and down, respectively. The symbol X in the drawing (see Figure 2) indicates the sub-scanning direction. The sub-scanning direction X is the extension direction of the multiple nozzle rows 42A to 42D, which will be described later. The sub-scanning direction X is also the transport direction of the recording medium 5. Here, the sub-scanning direction X is the front-back direction. The symbol Y indicates the main scanning direction Y which is perpendicular to the sub-scanning direction X. Here, the main scanning direction Y is the left-right direction. However, these directions are merely for the convenience of explanation and do not limit the installation configuration of the printer 10.

[0012] As shown in Figure 1, the printer 10 prints an image on the recording medium 5 by sequentially moving the rolled recording medium 5 forward and ejecting ink from a recording head 40 mounted on a carriage 30 that moves in the main scanning direction Y.

[0013] The recording medium 5 is the object on which the image is printed. The recording medium 5 is not particularly limited. The recording medium 5 may be, for example, paper such as plain paper or inkjet printing paper. The recording medium 5 may be, for example, a transparent sheet made of resin or glass. The recording medium 5 may be, for example, a sheet made of metal or rubber.

[0014] As shown in Figure 1, the printer 10 comprises a platen 15, a transport device 20, a carriage 30, a carriage moving device 35, a recording head 40, a control device 100, and an operation panel 120.

[0015] The platen 15 is an example of a support base for supporting the recording medium 5. As shown in Figure 1, the platen 15 extends in the main scanning direction Y. The recording medium 5 is placed on the platen 15. The transport device 20 transports the recording medium 5 on the platen 15 in the sub-scanning direction X. The transport device 20 includes a grid roller 21, a pinch roller 22, and a feed motor 23 (see Figure 5). The grid roller 21 is embedded in the platen 15. The grid roller 21 rotates in the front-rear direction by receiving the driving force of the feed motor 23. The pinch roller 22 is provided above the grid roller 21. The pinch roller 22 is positioned opposite the grid roller 21. The pinch roller 22 presses down on the recording medium 5 from above. When the grid roller 21 rotates with the recording medium 5 sandwiched between the grid roller 21 and the pinch roller 22, the recording medium 5 is transported in the sub-scanning direction X.

[0016] The carriage 30 is positioned above the platen 15. The carriage 30 holds the recording head 40. The carriage moving device 35 moves the carriage 30 in the main scanning direction Y, thereby moving the recording head 40 in the main scanning direction Y. The carriage moving device 35 includes a guide rail 36, left and right pulleys 37a and 37b, an endless belt 38, and a carriage motor 39.

[0017] The guide rail 36 extends in the main scanning direction Y. The carriage 30 is slidably engaged with the guide rail 36 in the main scanning direction Y. Pulleys 37a and 37b are provided on the left and right sides of the guide rail 36. The belt 38 is wrapped around the left and right pulleys 37a and 37b. When the carriage motor 39 is driven, one of the pulleys 37b rotates, and the belt 38 moves. As a result, the carriage 30 and the recording head 40 move along the guide rail 36 in the main scanning direction Y. In the following, the left side of the main scanning direction Y may be referred to as the forward path direction Y1, and the right side as the return path direction Y2.

[0018] FIG. 2 is a bottom view of carriage 30. As shown in FIG. 2, recording head 40 is provided on the lower surface of carriage 30. Recording head 40 includes a plurality of ink heads 40A to 40D. Hereinafter, ink heads 40A to 40D will be referred to as first ink head 40A to fourth ink head 40D as appropriate. The plurality of ink heads 40A to 40D are arranged side by side in the main scanning direction Y. Each of the plurality of ink heads 40A to 40D includes a plurality of nozzles 41 arranged side by side in the sub-scanning direction X. The plurality of nozzles 41 each eject ink toward the recording medium 5 on platen 15 (here, downward). In each of ink heads 40A to 40D, the plurality of nozzles 41 are arranged side by side in the sub-scanning direction X, and constitute nozzle rows 42A to 42D respectively. Hereinafter, nozzle rows 42A to 42D will be referred to as first nozzle row 42A to fourth nozzle row 42D as appropriate. In each of nozzle rows 42A to 42D, the plurality of nozzles 41 are arranged side by side in the sub-scanning direction X at a density of, for example, 300 dpi. However, the density of nozzles 41 in nozzle rows 42A to 42D is not particularly limited.

[0019] In this embodiment, inks of different colors are ejected from the plurality of nozzle rows 42A to 42D respectively. However, the inks ejected from the plurality of nozzle rows 42A to 42D may be the same type of ink. A plurality of nozzle rows may be formed in one ink head, and in that case, the number of ink heads may be less than the number of nozzle rows.

[0020] FIG. 3 is a cross-sectional view near one nozzle 41 of the recording head 40. FIG. 4 is a cross-sectional view of the recording head 40 cut along a plane extending in the sub-scanning direction X. As shown in FIG. 3, the recording head 40 includes a hollow case 51 having a plurality of pressure chambers 53 in which ink is stored. As shown in FIG. 4, the plurality of pressure chambers 53 are arranged in the sub-scanning direction X. As shown in FIG. 3, the recording head 40 includes a plurality of diaphragm plates 52 attached to the case 51 so as to partition a part of each of the pressure chambers 53, and a plurality of piezoelectric elements 56 connected to each diaphragm plate 52. The piezoelectric element 56 is an example of an element group that discharges ink from the nozzles 41 of the plurality of nozzle rows 42A to 42D. The diaphragm plate 52 is elastically deformable inside and outside the pressure chamber 53. The diaphragm plate 52 is configured to be deformable so as to increase and decrease the volume of the pressure chamber 53. The diaphragm plate 52 is typically a resin film or a metal foil.

[0021] As shown in FIG. 3, a common flow path 58 through which ink supplied from an ink cartridge (not shown) flows is formed in the case 51. An ink inlet 54 through which ink flows in is formed in the case 51. Note that the ink inlet 54 only needs to communicate with the pressure chamber 53, and the position of the ink inlet 54 is not limited in any way. The ink inlet 54 is formed between the common flow path 58 and the pressure chamber 53. Ink is supplied from the common flow path 58 to the pressure chamber 53 through the ink inlet 54, and a predetermined amount of ink is temporarily stored. The ink that has flowed into the pressure chamber 53 through the ink inlet 54 is guided to the nozzle 41. As shown in FIG. 4, the nozzles 41 are respectively formed on the lower surface 51B of the case 51. The nozzles 41 communicate with the pressure chambers 53 respectively. The nozzles 41 discharge ink toward the recording medium 5.

[0022] As shown in Figure 3, the piezoelectric element 56 is connected to the side of the diaphragm 52 opposite to the pressure chamber 53 side (in this case, the top surface). The piezoelectric element 56 is connected to the control device 100 via a flexible cable (not shown). An electrical signal is supplied to the piezoelectric element 56 via the flexible cable. When the piezoelectric element 56 receives an electrical signal from the control device 100, it expands or contracts, causing the diaphragm 52 to elastically deform outwards or inwards of the pressure chamber 53. The piezoelectric element 56 is, for example, a longitudinal vibration mode piezoelectric element (PZT). A longitudinal vibration mode PZT is expandable and contractible in the stacking direction, for example, it contracts when discharged and expands when charged. However, the type of piezoelectric element 56 is not particularly limited.

[0023] In the recording head 40, for example, by lowering the potential of the piezoelectric element 56 from the reference potential, the piezoelectric element 56 contracts. In response, the diaphragm 52 elastically deforms outward from its initial position, causing the pressure chamber 53 to expand. Note that expansion of the pressure chamber 53 means that the volume of the pressure chamber 53 increases due to the deformation of the diaphragm 52. Next, by raising the potential of the piezoelectric element 56, the piezoelectric element 56 stretches in the stacking direction. As a result, the diaphragm 52 elastically deforms inward, causing the pressure chamber 53 to contract. Note that contraction of the pressure chamber 53 means that the volume of the pressure chamber 53 decreases due to the deformation of the diaphragm 52. Due to this expansion and contraction of the pressure chamber 53, the pressure inside the pressure chamber 53 fluctuates. This pressure fluctuation inside the pressure chamber 53 pressurizes the ink inside the pressure chamber 53, causing it to be ejected as ink droplets from the nozzle 41. Subsequently, by returning the potential of the piezoelectric element 56 to the reference potential, the diaphragm 52 returns to its initial position and the pressure chamber 53 expands. At this time, ink flows into the pressure chamber 53 from the ink inlet 54.

[0024] Hereinafter, the group of piezoelectric elements 56 that eject ink from multiple nozzles 41 of the first nozzle row 42A will also be referred to as the first piezoelectric element group 56A, the group of piezoelectric elements 56 that eject ink from multiple nozzles 41 of the second nozzle row 42B will also be referred to as the second piezoelectric element group 56B, the group of piezoelectric elements 56 that eject ink from multiple nozzles 41 of the third nozzle row 42C will also be referred to as the third piezoelectric element group 56C, and the group of piezoelectric elements 56 that eject ink from multiple nozzles 41 of the fourth nozzle row 42D will also be referred to as the fourth piezoelectric element group 56D.

[0025] As shown in Figure 1, the control panel 120 is located on the front of the printer 10. The control panel 120 includes a display unit for showing the device status and input keys operated by the user. The control device 100 is housed inside the control panel 120.

[0026] Figure 5 is a block diagram of the printer 10. As shown in Figure 5, the control device 100 is connected to the feed motor 23 of the transport device 20, the carriage motor 39 of the carriage moving device 35, and the piezoelectric element 56 of the recording head 40. The control device 100 controls the operation of these devices. The control device 100 is typically a computer. The control device 100 includes, for example, an interface (I / F) for receiving print data from external devices such as a host computer, a central processing unit (CPU) for executing instructions of the control program, a ROM for storing programs executed by the CPU, RAM used as a working area for expanding the program, and a storage device such as memory for storing the program and various data.

[0027] As shown in Figure 5, the control device 100 includes a first drive signal storage unit 101, a second drive signal storage unit 102, a third drive signal storage unit 103, a drive signal generation unit 104, a drive signal supply unit 105, a first adjustment value registration unit 106, a second adjustment value registration unit 107, an adjustment pattern printing unit 108, a first adjustment value input unit 109, a second adjustment value input unit 110, a third adjustment value registration unit 111, a target value calculation unit 112, a correction value calculation unit 113, and a correction unit 114. The functions of each part of the control device 100 are realized by a program. This program may be read from a recording medium such as a CD or DVD. This program may also be downloaded via the Internet. The functions of each part of the control device 100 may also be realized by a processor and / or circuits.

[0028] The first drive signal storage unit 101 stores the first drive signal Wp1 to the fourth drive signal Wp4 supplied to the first piezoelectric element group 56A to the fourth piezoelectric element group 56D, respectively. Figure 6 is a schematic diagram showing an example of the first drive signal Wp1 to the fourth drive signal Wp4. The vertical axis in Figure 6 is voltage. The horizontal axis in Figure 6 is time. In Figure 6, for convenience, the first drive signal Wp1 to the fourth drive signal Wp4 are represented in a single figure, but the first drive signal Wp1 to the fourth drive signal Wp4 may be drive signals of different shapes. As shown in Figure 6, each drive signal Wp1 to Wp4 contains one or more drive pulses. The first drive signal Wp1 to the fourth drive signal Wp4 are drive signals before correction.

[0029] The second drive signal storage unit 102 stores the first adjustment signal Wa1 to the fourth adjustment signal Wa4, which are supplied to the first piezoelectric element group 56A to the fourth piezoelectric element group 56D, respectively. As shown in Figure 6, the first adjustment signal Wa1 to the fourth adjustment signal Wa4 are drive signals obtained by changing a predetermined characteristic value, in this case voltage, of the first drive signal Wp1 to the fourth drive signal Wp4 by a predetermined first change amount ΔV1 to the fourth change amount ΔV4, respectively. The first adjustment signal Wa1 to the fourth adjustment signal Wa4 are correction drive signals used to correct the first drive signal Wp1 to the fourth drive signal Wp4. The predetermined characteristic value of the first drive signal Wp1 to the fourth drive signal Wp4 is, in this case, voltage. The voltage is the characteristic value of the first drive signal Wp1 to the fourth drive signal Wp4 related to the ink ejection speed. In this embodiment, the voltages of the first drive signal Wp1 to the fourth drive signal Wp4 are changed by a first change amount ΔV1 to a fourth change amount ΔV4, respectively, by changing the gain of the first drive signal Wp1 to the fourth drive signal Wp4. However, the voltages of the first drive signal Wp1 to the fourth drive signal Wp4 may also be changed by a first change amount ΔV1 to a fourth change amount ΔV4, respectively, by adding a predetermined offset voltage to each of the first drive signal Wp1 to the fourth drive signal Wp4. Hereinafter, the first change amounts ΔV1 to the fourth change amounts ΔV4 will also be referred to as the first gain values ​​ΔV1 to the fourth gain values ​​ΔV4, respectively. In this embodiment, the first gain values ​​ΔV1 to the fourth gain values ​​ΔV4 are a common gain value ΔV. However, some or all of the first gain values ​​ΔV1 to the fourth gain values ​​ΔV4 may have different gain values. Furthermore, the first gain value ΔV1 to the fourth gain value ΔV4 may be positive or negative.

[0030] The third drive signal storage unit 103 stores the corrected first drive signal Wp1 to the fourth drive signal Wp4 (referred to as the corrected first drive signal Ws1 to the fourth drive signal Ws4, respectively; see Figure 5).

[0031] The drive signal generation unit 104 generates drive signals to drive the first piezoelectric element group 56A to the fourth piezoelectric element group 56D for each drive cycle. Depending on the situation, the drive signals generated by the drive signal generation unit 104 are either the first drive signal Wp1 to the fourth drive signal Wp4, the first adjustment signal Wa1 to the fourth adjustment signal Wa4, or the first drive signal Ws1 to the fourth drive signal Ws4 after correction.

[0032] The drive signal supply unit 105 supplies the first drive signals Wp1 to the fourth drive signals Wp4, the first adjustment signals Wa1 to the fourth adjustment signals Wa4, or the first drive signals Ws1 to the fourth drive signals Ws4, respectively, to the first piezoelectric element group 56A to the fourth piezoelectric element group 56D. When supplying the corrected first drive signals Ws1 to the fourth drive signals Ws4 (typically when printing an image), the drive signal supply unit 105 supplies part or all of the drive signals Ws1 to Ws4 generated by the drive signal generation unit 104 to the first piezoelectric element group 56A to the fourth piezoelectric element group 56D. The drive signal supply unit 105 can change the amount of ink ejected from the nozzle 41 during one drive cycle by appropriately selecting the drive pulses of the drive signals Ws1 to Ws4 supplied to the first piezoelectric element group 56A to the fourth piezoelectric element group 56D.

[0033] The first adjustment value registration unit 106 registers a number of adjustment values ​​related to the ink landing position, namely the first adjustment value Tp1 to the fourth adjustment value Tp4 (see Figure 8), which are the adjustment values ​​when the first drive signal Wp1 to the fourth drive signal Wp4 before correction are supplied to the first piezoelectric element group 56A to the fourth piezoelectric element group 56D, respectively. In this embodiment, the first adjustment value Tp1 to the fourth adjustment value Tp4 are bidirectional adjustment values ​​that represent the deviation of the ink landing position with respect to the main scanning direction Y between forward printing, in which ink is ejected from the recording head 40 while the recording head 40 is moved in the forward direction Y1, and return printing, in which ink is ejected from the recording head 40 while the recording head 40 is moved in the return direction Y2. The first adjustment value registration unit 106 registers one of each of the bidirectional adjustment values ​​from the first bidirectional adjustment pattern 201A to the fourth bidirectional adjustment pattern 201D (see Figure 7, described later) as the first adjustment value Tp1 to the fourth adjustment value Tp4. Hereafter, the first adjustment value Tp1 to the fourth adjustment value Tp4 will also be referred to as the first bidirectional adjustment value Tp1 to the fourth bidirectional adjustment value Tp4. However, as will be described later in the description of other embodiments, the adjustment values ​​related to the ink impact position are not limited to bidirectional adjustment values.

[0034] The bidirectional adjustment value is an adjustment value that corrects the difference in ink landing positions between forward and return printing, and in this case, it is the time by which the ink ejection timing is advanced during return printing. During printing, the recording head 40 moves with the carriage 30 in the main scanning direction Y. Therefore, the ink landing position in the main scanning direction Y differs depending on the direction of movement of the recording head 40 (forward or return printing). In addition, the amount of difference in ink landing positions between forward and return printing may vary between nozzle rows 42A to 42D due to variations in the characteristics of nozzle rows 42A to 42D. In that case, the bidirectional adjustment value will differ between nozzle rows 42A to 42D. By correcting (advancing in this case) the ink ejection timing during return printing, the difference in ink landing positions between forward and return printing can be eliminated or reduced. Alternatively, the difference in ink landing positions between forward and return printing may be eliminated or reduced by correcting the ink ejection timing during forward printing.

[0035] The second adjustment value registration unit 107 registers the first comparison value Ta1 to the fourth comparison value Ta4 (see Figure 8), which are adjustment values ​​related to the ink landing position, and represent multiple adjustment values ​​when the first adjustment signal Wa1 to the fourth adjustment signal Wa4 are supplied to the first piezoelectric element group 56A to the fourth piezoelectric element group 56D, respectively. In this embodiment, the first comparison value Ta1 to the fourth comparison value Ta4 are also bidirectional adjustment values ​​that correct the deviation of the ink landing position with respect to the main scanning direction Y between forward printing and return printing. The second adjustment value registration unit 107 registers one of each of the bidirectional adjustment values ​​from the bidirectional adjustment patterns 211A to 211D for the first adjustment signal (described later, see Figure 7) as the first comparison value Ta1 to the fourth comparison value Ta4.

[0036] The adjustment pattern printing unit 108 controls the recording head 40 and the carriage moving device 35 to print a bidirectional adjustment pattern 200 on the recording medium 5 on the platen 15 for determining the bidirectional adjustment values ​​for the first nozzle row 42A to the fourth nozzle row 42D, respectively.

[0037] Figure 7 is a schematic plan view of the bidirectional adjustment pattern 200 according to this embodiment. As shown in Figure 7, the bidirectional adjustment pattern 200 includes first bidirectional adjustment patterns 201A to 4th bidirectional adjustment patterns 201D, which are printed by supplying first drive signals Wp1 to 4th drive signals Wp4 before correction, and first adjustment signal bidirectional adjustment patterns 211A to 4th adjustment signal bidirectional adjustment patterns 211D, which are printed by supplying first adjustment signals Wa1 to 4th adjustment signals Wa4.

[0038] The first bidirectional adjustment patterns 201A to the fourth bidirectional adjustment patterns 201D are patterns formed by ink ejected from the nozzles 41 of the first nozzle rows 42A to the fourth nozzle row 42D when the first drive signals Wp1 to the fourth drive signals Wp4, before correction, are supplied to the first piezoelectric element group 56A to the fourth piezoelectric element group 56D, respectively. As shown in Figure 7, the first bidirectional adjustment patterns 201A to the fourth bidirectional adjustment patterns 201D are arranged side by side in the sub-scanning direction X. Each of the first bidirectional adjustment patterns 201A to the fourth bidirectional adjustment patterns 201D includes a plurality of adjustment patterns 202 with different bidirectional adjustment values ​​set. In each bidirectional adjustment pattern 201A to 201D, the plurality of adjustment patterns 202 are arranged side by side in the main scanning direction Y.

[0039] As shown in Figure 7, each adjustment pattern 202 includes a forward pattern 203 printed in the forward printing and a return pattern 204 printed in the return printing. In this embodiment, a bidirectional adjustment value is set for each of the multiple return patterns 204.

[0040] The bidirectional adjustment patterns 211A to 211D for adjustment signals are configured similarly to the bidirectional adjustment patterns 201A to 201D. The bidirectional adjustment patterns 211A to 211D and the bidirectional adjustment patterns 201A to 201D are arranged in the sub-scanning direction X. The bidirectional adjustment patterns 211A to 211D for the first to fourth adjustment signals are patterns formed by ink ejected from the nozzles 41 of the first nozzle rows 42A to 42D when the first adjustment signal Wa1 to 4th adjustment signal Wa4 are supplied to the first piezoelectric element group 56A to 4th piezoelectric element group 56D, respectively. The bidirectional adjustment patterns 211A to 211D for the first to fourth adjustment signals are arranged in the sub-scanning direction X. Each of the bidirectional adjustment patterns 211A to 211D for the first to fourth adjustment signals contains multiple adjustment patterns 212 with different bidirectional adjustment values ​​set. In each of the bidirectional adjustment patterns 211A to 211D for adjustment signals, the multiple adjustment patterns 212 are arranged in the main scanning direction Y. Each adjustment pattern 212 includes a forward pattern 213 printed in forward printing and a return pattern 214 printed in return printing.

[0041] As shown in Figure 7, the bidirectional adjustment pattern 200 includes a plurality of drive signal symbols 205 corresponding to the bidirectional adjustment values ​​of the plurality of adjustment patterns 202 of the first bidirectional adjustment pattern 201A to the fourth bidirectional adjustment pattern 201D, and a plurality of adjustment signal symbols 215 corresponding to the bidirectional adjustment values ​​of the plurality of adjustment patterns 212 of the first bidirectional adjustment pattern 211A to the fourth bidirectional adjustment pattern 211D. In this embodiment, the drive signal symbols 205 and the adjustment signal symbols 215 are integers representing the order of magnitude of the bidirectional adjustment values ​​(in Figure 7, integers "14" to "17" are shown). However, the drive signal symbols 205 and the adjustment signal symbols 215 are not limited to integers. The drive signal symbols 205 and the adjustment signal symbols 215 may be, for example, real values ​​of the time to advance the ink ejection timing, or the resulting change in the ink landing position. The drive signal symbol 205 and the adjustment signal symbol 215 may be letters such as A, B, ..., for example.

[0042] The first adjustment value input unit 109 is configured to accept one bidirectional adjustment value from each of the first bidirectional adjustment patterns 201A to 4th bidirectional adjustment patterns 201D as the first bidirectional adjustment value Tp1 to 4th bidirectional adjustment value Tp4. In this case, the first adjustment value input unit 109 is configured to accept the drive signal symbol 205 as the bidirectional adjustment value.

[0043] The second adjustment value input unit 110 is configured to accept one bidirectional adjustment value from each of the bidirectional adjustment values ​​of the first bidirectional adjustment pattern 211A to the fourth bidirectional adjustment pattern 211D as the first comparison value Ta1 to the fourth comparison value Ta4. In this case, the second adjustment value input unit 110 is configured to accept the adjustment signal symbol 215 as the bidirectional adjustment value.

[0044] The third adjustment value registration unit 111 registers a common target value Tt (see Figure 8) for the first bidirectional adjustment value Tp1 to the fourth bidirectional adjustment value Tp4.

[0045] The target value calculation unit 112 calculates the target value Tt from the first bidirectional adjustment value Tp1 to the fourth bidirectional adjustment value Tp4. In this embodiment, the target value Tt is the average value of the first bidirectional adjustment value Tp1 to the fourth bidirectional adjustment value Tp4. However, the target value Tt is not limited to the average value of the first bidirectional adjustment value Tp1 to the fourth bidirectional adjustment value Tp4. For example, the target value Tt may be the median of the first bidirectional adjustment value Tp1 to the fourth bidirectional adjustment value Tp4, or the average value excluding the maximum and minimum values. Furthermore, the target value Tt may be a target value determined independently of the first bidirectional adjustment value Tp1 to the fourth bidirectional adjustment value Tp4.

[0046] The correction value calculation unit 113 calculates the first correction value ΔVc1 to the fourth correction value ΔVc4 (see Figure 8) related to the above-mentioned characteristic value (in this case, voltage) of the first drive signal Wp1 to the fourth drive signal Wp4. The correction value calculation unit 113 calculates the first correction value ΔVc1 to the fourth correction value ΔVc4 such that the first bidirectional adjustment value Tp1 to the fourth bidirectional adjustment value Tp4 each match the target value Tt. By correcting the voltages of the first drive signal Wp1 to the fourth drive signal Wp4 to a voltage such that the first bidirectional adjustment value Tp1 to the fourth bidirectional adjustment value Tp4 have a common adjustment value (target value Tt), the ink ejection speeds by the nozzle rows 42A to 42D are corrected and standardized.

[0047] The correction value calculation unit 113 calculates correction values ​​ΔVc1 to ΔVc4 for the voltages of the first drive signal Wp1 to the fourth drive signal Wp4, such that the bidirectional adjustment values ​​Tp1 to Tp4 match the target value Tt, based on the differences between the bidirectional adjustment values ​​Tp1 to Tp4 and the target value Tt (Tp1-Tt, Tp2-Tt, Tp3-Tt, and Tp4-Tt), the differences between the bidirectional adjustment values ​​Tp1 to Tp4 and the comparison values ​​Ta1 to Ta4 (Tp1-Ta1, Tp2-Ta2, Tp3-Ta3, and Tp4-Ta4), and the gain values ​​ΔV1 to ΔV4 (here, a common gain value ΔV). More specifically, the first correction value ΔVc1 to the fourth correction value ΔVc4 are obtained by multiplying each of the values ​​obtained by dividing the difference between the first bidirectional adjustment value Tp1 to the fourth bidirectional adjustment value Tp4 and the target value Tt by the difference between the first bidirectional adjustment value Tp1 to the fourth bidirectional adjustment value Tp4 and the first comparison value Ta1 to the fourth comparison value Ta4 by the first gain value ΔV1 to the fourth gain value ΔV4 (here, a common gain value ΔV). Details of the calculation formulas used by the correction value calculation unit 113 to calculate the first correction value ΔVc1 to the fourth correction value ΔVc4 will be described later.

[0048] The correction unit 114 shifts the voltages of the first drive signal Wp1 to the fourth drive signal Wp4 by the first correction value ΔVc1 to the fourth correction value ΔVc4, respectively.

[0049] [Procedure for determining correction values] The following describes the procedure for determining the correction values ​​ΔVc1 to ΔVc4 for the voltages of the first drive signal Wp1 to the fourth drive signal Wp4. Figure 8 is a flowchart for determining the correction values ​​ΔVc1 to ΔVc4 for the voltages of the first drive signal Wp1 to the fourth drive signal Wp4. As shown in Figure 8, in step S01 of determining the correction values ​​ΔVc1 to ΔVc4 for the voltages of the first drive signal Wp1 to the fourth drive signal Wp4, the recording medium 5 is set in the printer 10. In step S02, the bidirectional adjustment pattern 200 is printed on the recording medium 5.

[0050] In step S03, the first bidirectional adjustment values ​​Tp1 to the fourth bidirectional adjustment values ​​Tp4 are determined from the first bidirectional adjustment patterns 201A to the fourth bidirectional adjustment patterns 201D of the bidirectional adjustment pattern 200. Specifically, the bidirectional adjustment value set for the adjustment pattern 202 with the smallest positional misalignment between the forward pattern 203 and the return pattern 204 in the first bidirectional adjustment pattern 201A, the bidirectional adjustment value set for the adjustment pattern 202 with the smallest positional misalignment between the forward pattern 203 and the return pattern 204 in the second bidirectional adjustment pattern 201B, the bidirectional adjustment value set for the adjustment pattern 202 with the smallest positional misalignment between the forward pattern 203 and the return pattern 204 in the third bidirectional adjustment pattern 201C, and the bidirectional adjustment value set for the adjustment pattern 202 with the smallest positional misalignment between the forward pattern 203 and the return pattern 204 in the fourth bidirectional adjustment pattern 201D. In this embodiment, a drive signal symbol 205 associated with the bidirectional adjustment value is selected.

[0051] In step S04, the user inputs the four selected drive signal symbols 205 into the control panel 120. This registers the first bidirectional adjustment value Tp1 to the fourth bidirectional adjustment value Tp4 in the printer 10.

[0052] In step S05, the first comparison value Ta1 to the fourth comparison value Ta4 are determined from the bidirectional adjustment patterns 211A to 211D for the first and fourth adjustment signals of the bidirectional adjustment pattern 200. Specifically, the bidirectional adjustment value set for the adjustment pattern 212 with the smallest positional misalignment between the forward pattern 213 and the return pattern 214 is selected in the bidirectional adjustment pattern 211A for the first adjustment signal, the bidirectional adjustment value set for the adjustment pattern 212 with the smallest positional misalignment between the forward pattern 213 and the return pattern 214 is selected in the bidirectional adjustment pattern 211B for the second adjustment signal, the bidirectional adjustment value set for the adjustment pattern 212 with the smallest positional misalignment between the forward pattern 213 and the return pattern 214 is selected in the bidirectional adjustment pattern 211C for the third adjustment signal, and the bidirectional adjustment value set for the adjustment pattern 212 with the smallest positional misalignment between the forward pattern 213 and the return pattern 214 is selected in the bidirectional adjustment pattern 211D for the fourth adjustment signal. In this embodiment, the adjustment signal symbol 215 associated with the bidirectional adjustment value is selected.

[0053] In step S06, the user inputs the four selected adjustment signal symbols 215 into the control panel 120. This registers the first comparison value Ta1 to the fourth comparison value Ta4 in the printer 10.

[0054] In step S07, the target value Tt for the bidirectional adjustment is calculated. Specifically, the target value Tt is calculated as the average of the first bidirectional adjustment value Tp1 to the fourth bidirectional adjustment value Tp4.

[0055] In step S08, the first correction value ΔVc1 to the fourth correction value ΔVc4 are calculated for the voltages of the first drive signal Wp1 to the fourth drive signal Wp4. The first correction value ΔVc1 is obtained by the following formula.

[0056] ΔVc1={(Tp1-Tt) / (Tp1-Ta1)}×ΔV1

[0057] In the above calculation formula, ΔVc1 is obtained by dividing (Tp1-Tt) by {(Tp1-Ta1) / ΔV1}. {(Tp1-Ta1) / ΔV1} represents the amount by which the bidirectional adjustment value changes when the voltage gain value is changed by a unit voltage (for example, 1V). Therefore, by dividing the difference between the target value Tt and the current value Tp1 of the bidirectional adjustment value (Tp1-Tt) by {(Tp1-Ta1) / ΔV1}, we can find the voltage at which the voltage of the first drive signal Wp1 should be shifted, that is, the voltage that can cancel out the positional misalignment between the forward and return prints caused by changing the current value Tp1 of the bidirectional adjustment value to the target value Tt.

[0058] Similarly, the second correction value ΔVc2 to the fourth correction value ΔVc4 can be calculated using the following formulas.

[0059] ΔVc2={(Tp2-Tt) / (Tp2-Ta2)}×ΔV2

[0060] ΔVc3={(Tp3-Tt) / (Tp3-Ta3)}×ΔV3

[0061] ΔVc4={(Tp4-Tt) / (Tp4-Ta4)}×ΔV4

[0062] Because there is variation in the driving characteristics of the first nozzle row 42A to the fourth nozzle row 42D, the first correction value ΔVc1 to the fourth correction value ΔVc4 are calculated accordingly. The voltage gain value ΔV can be a voltage that is predetermined to be appropriate. The voltage gain value ΔV is not particularly limited.

[0063] The voltages of the first drive signal Wp1 to the fourth drive signal Wp4 (before correction) may be, for example, the voltages individually set for each ink head 40A to 40D as recommended voltages. The recommended voltages are voltages set for each ink head to suppress variations in the drive characteristics of the ink heads and to ensure that all ink heads operate similarly. However, the voltages of the first drive signal Wp1 to the fourth drive signal Wp4 do not have to be the recommended voltages. The voltages of the first drive signal Wp1 to the fourth drive signal Wp4 may be partially or entirely the same. However, by setting the voltages of the first drive signal Wp1 to the fourth drive signal Wp4 to the recommended voltages, variations in ink heads 40A to 40D can be suppressed in advance. Therefore, it is easier to perform voltage correction of the first drive signal Wp1 to the fourth drive signal Wp4.

[0064] In step S09, the voltages of the first drive signal Wp1 to the fourth drive signal Wp4 are shifted by the first correction value ΔVc1 to the fourth correction value ΔVc4, respectively. This makes it possible to equalize the ejection speed of the ink ejected from the first nozzle row 42A to the fourth nozzle row 42D.

[0065] [Effects of the Embodiment] The following describes the effects and benefits that can be achieved by the printer 10 according to this embodiment.

[0066] The printer 10 according to this embodiment includes a recording head 40 comprising a first nozzle row 42A to a fourth nozzle row 42D, each composed of a plurality of nozzles 41 arranged in the sub-scanning direction X, and a first piezoelectric element group 56A to a fourth piezoelectric element group 56D, each ejecting ink from the nozzles 41 of the first nozzle row 42A to the fourth nozzle row 42D; a carriage moving device 35 that moves the recording head 40 in the main scanning direction Y perpendicular to the sub-scanning direction X; and a control device 100 that controls the first piezoelectric element group 56A to the fourth piezoelectric element group 56D and the carriage moving device 35. The control device 100 comprises a first drive signal storage unit 101, a second drive signal storage unit 102, a drive signal supply unit 105, a first adjustment value registration unit 106, a second adjustment value registration unit 107, a third adjustment value registration unit 111, and a correction value calculation unit 113. The first drive signal storage unit 101 stores the first drive signals Wp1 to the fourth drive signals Wp4 supplied to the first piezoelectric element group 56A to the fourth piezoelectric element group 56D, respectively. The second drive signal storage unit 102 stores the first adjustment signals Wa1 to the fourth adjustment signals Wa4, which are a plurality of drive signals supplied to the first piezoelectric element group 56A to the fourth piezoelectric element group 56D, respectively, and which are obtained by changing a predetermined characteristic value (in this case, voltage) of the first drive signals Wp1 to the fourth drive signals Wp4 by a predetermined first gain value ΔV1 to the fourth gain value ΔV4, respectively. The drive signal supply unit 105 supplies the first drive signals Wp1 to the fourth drive signals Wp4 or the first adjustment signals Wa1 to the fourth adjustment signals Wa4 to the first piezoelectric element group 56A to the fourth piezoelectric element group 56D, respectively. The first adjustment value registration unit 106 registers the first adjustment value Tp1 to the fourth adjustment value Tp4, which are adjustment values ​​related to the ink's impact position, and represent multiple adjustment values ​​when the first drive signal Wp1 to the fourth drive signal Wp4 are supplied to the first piezoelectric element group 56A to the fourth piezoelectric element group 56D, respectively. The second adjustment value registration unit 107 registers the first comparison value Ta1 to the fourth comparison value Ta4, which are adjustment values ​​related to the ink's impact position, and represent multiple adjustment values ​​when the first adjustment signal Wa1 to the fourth adjustment signal Wa4 are supplied to the first piezoelectric element group 56A to the fourth piezoelectric element group 56D, respectively. The third adjustment value registration unit 111 registers the common target value Tt for the first adjustment value Tp1 to the fourth adjustment value Tp4.The correction value calculation unit 113 calculates first correction values ​​ΔVc1 to fourth correction values ​​ΔVc4 for the characteristic values ​​(in this case, voltage) of the first drive signals Wp1 to fourth drive signals Wp4, based on the differences between the first adjustment values ​​Tp1 to fourth adjustment values ​​Tp4 and the target value Tt (Tp1-Tt, Tp2-Tt, Tp3-Tt, and Tp4-Tt), the differences between the first adjustment values ​​Tp1 to fourth adjustment values ​​Tp4 and the first comparison values ​​Ta1 to fourth comparison values ​​Ta4 (Tp1-Ta1, Tp2-Ta2, Tp3-Ta3, and Tp4-Ta4), and the first gain values ​​ΔV1 to fourth gain values ​​ΔV4, so that the first adjustment values ​​Tp1 to fourth adjustment values ​​Tp4 match the target value Tt.

[0067] With this configuration, the first correction value ΔVc1 to the fourth correction value ΔVc4 are correction values ​​of the characteristic values ​​(in this case, voltage) of the first drive signals Wp1 to the fourth drive signals Wp4 such that the first adjustment value Tp1 to the fourth adjustment value Tp4 match a common target value Tt. By adding these first correction value ΔVc1 to the fourth correction value ΔVc4 to the characteristic values ​​(voltage) of the first drive signals Wp1 to the fourth drive signals Wp4, the ink ejection speeds between the first nozzle row 42A to the fourth nozzle row 42D can be made uniform. As described above, by examining the differences between the first adjustment value Tp1 to the fourth adjustment value Tp4 and the first comparison value Ta1 to the fourth comparison value Ta4, and the corresponding first gain values ​​ΔV1 to the fourth gain value ΔV4, it is possible to estimate the relationship between the change in the characteristic value (voltage) of the first drive signal Wp1 to the fourth drive signal Wp4 and the fluctuation in the first adjustment value Tp1 to the fourth adjustment value Tp4. Therefore, based on the differences between the first adjustment value Tp1 to the fourth adjustment value Tp4 and the target value Tt, the differences between the first adjustment value Tp1 to the fourth adjustment value Tp4 and the first comparison value Ta1 to the fourth comparison value Ta4, and the first gain values ​​ΔV1 to the fourth gain value ΔV4, it is possible to calculate the first correction value ΔVc1 to the fourth correction value ΔVc4 related to the characteristic value (voltage) of the first drive signal Wp1 to the fourth drive signal Wp4.

[0068] In this embodiment, the first correction value ΔVc1 to the fourth correction value ΔVc4 are obtained by multiplying each of the values ​​obtained by dividing the differences between the first adjustment value Tp1 to the fourth adjustment value Tp4 and the target value Tt (Tp1-Tt, Tp2-Tt, Tp3-Tt, and Tp4-Tt) by the differences between the first adjustment value Tp1 to the fourth adjustment value Tp4 and the first comparison value Ta1 to the fourth comparison value Ta4 (Tp1-Ta1, Tp2-Ta2, Tp3-Ta3, and Tp4-Ta4), respectively, by the first gain value ΔV1 to the fourth gain value ΔV4.

[0069] Using this calculation formula, the first correction value ΔVc1 to the fourth correction value ΔVc4 related to the characteristic values ​​(voltages) of the first drive signal Wp1 to the fourth drive signal Wp4 can be appropriately calculated.

[0070] In this embodiment, the control device 100 includes a target value calculation unit that calculates a target value Tt from the first adjustment value Tp1 to the fourth adjustment value Tp4. The target value Tt is the average value of the first adjustment value Tp1 to the fourth adjustment value Tp4.

[0071] In this configuration, the target value Tt is set between the maximum and minimum values ​​among the first adjustment value Tp1 to the fourth adjustment value Tp4. Therefore, the first correction value ΔVc1 to the fourth correction value ΔVc4 can be reduced. In addition, the average value is often appropriate as a representative value among multiple values.

[0072] In this embodiment, the first adjustment value Tp1 to the fourth adjustment value Tp4 and the first comparison value Ta1 to the fourth comparison value Ta4 are bidirectional adjustment values ​​that represent the deviation of the ink landing position with respect to the main scanning direction Y between forward printing, in which ink is ejected from the recording head 40 while the recording head 40 is moved in the forward direction Y1, and return printing, in which ink is ejected from the recording head 40 while the recording head 40 is moved in the return direction Y2.

[0073] With this configuration, the differences between the first adjustment values ​​Tp1 to the fourth adjustment values ​​Tp4 and the target value Tt (Tp1-Tt, Tp2-Tt, Tp3-Tt, and Tp4-Tt), and the differences between the first adjustment values ​​Tp1 to the fourth adjustment values ​​Tp4 and the first comparison values ​​Ta1 to the fourth comparison values ​​Ta4 (Tp1-Ta1, Tp2-Ta2, Tp3-Ta3, and Tp4-Ta4) can be easily determined. In other embodiments, the differences between each adjustment value and the target value, and the differences between each adjustment value and each comparison value can also be determined using the adjustment values ​​described later, but as will be described later, it is easier to determine these by using bidirectional adjustment values.

[0074] In this embodiment, the control device 100 includes an adjustment pattern printing unit 108 that controls the recording head 40 and the carriage moving device 35 to print bidirectional adjustment patterns 200 on the recording medium 5 on the platen 15 for determining bidirectional adjustment values ​​for the first nozzle row 42A to the fourth nozzle row 42D, respectively. The bidirectional adjustment pattern 200 includes a first bidirectional adjustment pattern 201A to a fourth bidirectional adjustment pattern 201D, each containing a plurality of adjustment patterns 202, each with different bidirectional adjustment values, which are formed by ink ejected from the nozzles 41 of the first nozzle rows 42A to the fourth nozzle rows 42D while the first drive signals Wp1 to the fourth drive signals Wp4 are supplied to the first piezoelectric element group 56A to the fourth piezoelectric element group 56D, respectively, and a first bidirectional adjustment pattern 211A to a fourth bidirectional adjustment pattern 211D for the first adjustment signal, each containing a plurality of adjustment patterns 212, each with different bidirectional adjustment values, which are formed by ink ejected from the nozzles 41 of the first nozzle rows 42A to the fourth nozzle rows 42D while the first adjustment signals Wa1 to the fourth adjustment signals Wa4 are supplied to the first piezoelectric element group 56A to the fourth piezoelectric element group 56D, respectively. In the first adjustment value registration unit 106, one of each of the bidirectional adjustment values ​​from the first bidirectional adjustment pattern 201A to the fourth bidirectional adjustment pattern 201D is registered as the first adjustment value Tp1 to the fourth adjustment value Tp4. In the second adjustment value registration unit 107, one of each of the bidirectional adjustment values ​​from the first bidirectional adjustment pattern 211A to the fourth bidirectional adjustment pattern 211D for the first adjustment signal is registered as the first comparison value Ta1 to the fourth comparison value Ta4.

[0075] With this configuration, the bidirectional adjustment values ​​for the first bidirectional adjustment pattern 201A to the fourth bidirectional adjustment pattern 201D, and the bidirectional adjustment values ​​for the first adjustment signal bidirectional adjustment pattern 211A to the fourth adjustment signal bidirectional adjustment pattern 211D can be easily selected from the printed bidirectional adjustment pattern 200.

[0076] In this embodiment, the control device 100 includes a first adjustment value input unit 109 that can input one bidirectional adjustment value from each of the bidirectional adjustment values ​​of the first bidirectional adjustment pattern 201A to the fourth bidirectional adjustment pattern 201D as the first bidirectional adjustment value Tp1 to the fourth bidirectional adjustment value Tp4, and a second adjustment value input unit 110 that can input one bidirectional adjustment value from each of the bidirectional adjustment values ​​of the first bidirectional adjustment pattern 211A to the fourth bidirectional adjustment pattern 211D as the first comparison value Ta1 to the fourth comparison value Ta4. The bidirectional adjustment pattern 200 includes a plurality of drive signal symbols 205 corresponding to the bidirectional adjustment values ​​of the plurality of adjustment patterns 202 of the first bidirectional adjustment pattern 201A to the fourth bidirectional adjustment pattern 201D, and a plurality of adjustment signal symbols 215 corresponding to the bidirectional adjustment values ​​of the plurality of adjustment patterns 212 of the first bidirectional adjustment pattern 211A to the fourth bidirectional adjustment pattern 211D. The first adjustment value input unit 109 is configured to accept the drive signal symbol 205 as a bidirectional adjustment value. The second adjustment value input unit 110 is configured to accept the adjustment signal symbol 215 as a bidirectional adjustment value.

[0077] With this configuration, the user simply selects the drive signal symbol 205 and the adjustment signal symbol 215 printed on the bidirectional adjustment pattern 200 and inputs them into the first adjustment value input unit 109 and the second adjustment value input unit 110, respectively. Therefore, the registration of the first bidirectional adjustment value Tp1 to the fourth bidirectional adjustment value Tp4 and the first comparison value Ta1 to the fourth comparison value Ta4 is easy.

[0078] [Other embodiments] Preferred embodiments of the present invention have been described above. However, the embodiments described above are merely illustrative, and the present invention can be implemented in various other forms.

[0079] For example, in the embodiment described above, the first correction value ΔVc1 to the fourth correction value ΔVc4 were obtained by multiplying each of the values ​​obtained by dividing the differences between the first bidirectional adjustment value Tp1 to the fourth bidirectional adjustment value Tp4 and the target value Tt (Tp1-Tt, Tp2-Tt, Tp3-Tt, and Tp4-Tt) by the differences between the first bidirectional adjustment value Tp1 to the fourth bidirectional adjustment value Tp4 and the first comparison value Ta1 to the fourth comparison value Ta4 (Tp1-Ta1, Tp2-Ta2, Tp3-Ta3, and Tp4-Ta4) by the first gain value ΔV1 to the fourth gain value ΔV4, respectively. However, the calculation formula for calculating the first correction value ΔVc1 to the fourth correction value ΔVc4 is not limited to the formula used to perform the above calculation. For example, the formulas for calculating the first correction value ΔVc1 to the fourth correction value ΔVc4 may be obtained by integrating (e.g., averaging) other first correction values ​​to fourth correction values ​​obtained based on other first gain values ​​to fourth gain values ​​that are different from the first gain value ΔV1 to the fourth gain value ΔV4, and the first correction values ​​to fourth correction values ​​obtained based on the first gain value ΔV1 to the fourth gain value ΔV4.

[0080] In the embodiment described above, the user determined which adjustment pattern 202 had the smallest misalignment between the forward pattern 203 and the return pattern 204, and which adjustment pattern 212 had the smallest misalignment between the forward pattern 213 and the return pattern 214. However, the selection of such adjustment patterns 202 and 212 may be performed by the printer 10. Automatic selection may be performed, for example, based on an image of the bidirectional adjustment pattern 200 captured by a camera provided on the carriage 30 or the like. Various known methods can be used without particular limitation as methods for calculating the amount of misalignment based on the image.

[0081] In the embodiment described above, the first correction value ΔVc1 to the fourth correction value ΔVc4 were calculated using the bidirectional adjustment value set for the adjustment pattern 212 with the smallest positional misalignment between the forward path pattern 213 and the return path pattern 214. However, the first correction value ΔVc1 to the fourth correction value ΔVc4 may also be calculated using the bidirectional adjustment value set for the adjustment pattern 212 where the positional misalignment between the forward path pattern 213 and the return path pattern 214 is a predetermined value. The selection criteria for the bidirectional adjustment value used to calculate the correction values ​​are not particularly limited, as long as the selection criteria are consistent among the first nozzle row 42A to the fourth nozzle row 42D.

[0082] In the embodiment described above, the first correction value ΔVc1 to the fourth correction value ΔVc4 were calculated using a bidirectional adjustment value to correct the positional misalignment between the forward path pattern 213 and the return path pattern 214. However, the adjustment value used to calculate the correction value related to the characteristic value of the drive signal is not limited to a bidirectional adjustment value. The adjustment value used to calculate the correction value may be, for example, the amount of misalignment of the ink landing position between nozzle rows in one-way printing. The adjustment value is not limited to time, such as the ink ejection timing, but may also be a distance, such as the amount of misalignment of the ink landing position. When using the amount of misalignment of the ink landing position between nozzle rows in one-way printing as the adjustment value, for example, ink is ejected from multiple nozzle rows so that the ink lands at the same position in the main scanning direction. Next, the distance of the landing position of the ink ejected from each nozzle row from an arbitrarily set position is measured. These distances correspond to the differences between each adjustment value and the target value. Similarly, for the adjustment signal obtained by adding a gain value to the original drive signal, the distance of the ink impact point from the original drive signal is measured for each nozzle row. These distances correspond to the differences between each adjustment value and each comparison value.

[0083] Furthermore, the above method requires measuring the small deviation between the adjustment value and the target value, as well as the small deviation between the adjustment value and the comparison value. Therefore, it requires precise measuring equipment or the effort of the adjuster (distance measurement is also possible by methods such as reading the distance from a magnified image). Using bidirectional adjustment values ​​makes it easy to obtain these differences. In bidirectional adjustment patterns, the adjustment pattern with the smallest deviation between the forward and return paths can be easily identified by visual inspection. In bidirectional adjustment patterns, the deviation is twice as large as in unidirectional printing, which also makes visual identification easier. Moreover, the adjustment values ​​for the selected adjustment pattern are known in advance. For these reasons, using bidirectional adjustment values ​​makes it easy to determine the differences between each adjustment value and the target value, as well as the differences between each adjustment value and each comparison value.

[0084] Unless otherwise specified, the embodiments do not limit the present invention. [Explanation of Symbols]

[0085] 5. Recording media 10 Printers 15. Platen (support stand) 35. Carriage moving device (moving device) 40 Recording heads 41 nozzles 42A~42D Nozzle rows 1~4 56A~56D First to fourth piezoelectric element groups (first to fourth element groups) 100 Control device 101 First drive signal storage unit (first storage unit) 102 Second drive signal storage unit (second storage unit) 105 Drive signal supply unit 106 First Adjustment Value Registration Unit (First Registration Unit) 107 Second Adjustment Value Registration Section (Second Registration Section) 108 Adjustment Pattern Printing Section (Pattern Printing Section) 109 First Adjustment Value Input Section (First Input Section) 110 Second Adjustment Value Input Section (Second Input Section) 111 Third Adjustment Value Registration Section (Third Registration Section) 112 Target Value Calculation Unit 113 Correction Value Calculation Unit 200 bidirectional adjustment patterns 201A~201D 1st~4th Bidirectional Adjustment Patterns 202 Adjustment Patterns 203 Outbound Pattern 204 Return Trip Pattern 205 Symbol for drive signal 211A~211D Bidirectional adjustment patterns for the 1st to 4th adjustment signals 212 adjustment patterns 213 Outbound Pattern 214 Return Trip Pattern 215 Symbol for adjustment signal Wp1~Wp4 1st~4th drive signals Wa1~Wa4 1st~4th Adjustment Signals Tp1~Tp4 1st~4th Bidirectional Adjustment Values ​​(1st~4th Adjustment Values) Ta1~Ta4 1st~4th comparative values Tt Target Value ΔV1~ΔV4 1st~4th Gain Values ​​(1st~4th Change Amount) ΔVc1~ΔVc4 1st~4th Correction Values X Sub-scanning direction (alignment direction) Y Main scanning direction (scanning direction) Y1 Outbound direction Y2 Return Route

Claims

1. A recording head comprising: a first to nth nozzle row (n is a natural number of 2 or more) each composed of a plurality of nozzles arranged in a predetermined direction; and a first to nth element group each ejecting ink from the nozzles of the first to nth nozzle row; A moving device for moving the recording head in a scanning direction perpendicular to the aforementioned alignment direction, The system comprises the first to nth element groups and a control device for controlling the moving device, The control device is A first storage unit that stores the first to nth drive signals supplied to each of the first to nth element groups, A second storage unit stores a plurality of drive signals supplied to each of the first to nth element groups, wherein the predetermined characteristic values ​​of the first to nth drive signals are changed by predetermined first to nth change amounts to obtain first to nth adjustment signals, A drive signal supply unit that supplies the first to nth drive signals or the first to nth adjustment signals to the first to nth element groups, A first registration unit registers adjustment values ​​relating to the ink impact position, which are a plurality of adjustment values, the first to the nth adjustment values, when the first to the nth drive signals are supplied to the first to the nth element groups, respectively. A second registration unit registers adjustment values ​​relating to the ink impact position, which are a plurality of adjustment values, the first to the nth comparison values, when the first to the nth adjustment signals are supplied to the first to the nth element groups, respectively. A third registration unit where a common target value for the first to nth adjustment values ​​is registered, The system includes a correction value calculation unit that calculates first to n correction values ​​for the characteristic values ​​of the first to n drive signals such that the first to n adjustment values ​​match the target value, based on the differences between the first to n adjustment values ​​and the target value, the differences between the first to n adjustment values ​​and the first to n comparison values, and the first to n change amounts. Printer.

2. The first to nth adjustment values ​​and the first to nth comparison values ​​are bidirectional adjustment values ​​that represent the deviation of the ink landing position in the scanning direction between forward printing, in which ink is ejected from the recording head while the recording head is moved to one side of the scanning direction, and return printing, in which ink is ejected from the recording head while the recording head is moved to the other side of the scanning direction. The printer according to claim 1.

3. The system further comprises a support base provided opposite to the first to nth nozzle rows, which supports the recording medium. The control device includes a pattern printing unit that controls the recording head and the moving device to print bidirectional adjustment patterns on the recording medium on the support base for determining the bidirectional adjustment values ​​for the first to nth nozzle rows, respectively. The aforementioned bidirectional adjustment pattern is The first to nth bidirectional adjustment patterns each include a plurality of adjustment patterns, each having different bidirectional adjustment values, which are formed by the ink ejected from the nozzles of the first to nth nozzle rows while the first to nth drive signals are supplied to the first to nth element groups, respectively, and The first to nth adjustment signal bidirectional adjustment patterns include, each of a plurality of adjustment patterns, each having a different bidirectional adjustment value, which are formed by ink ejected from the nozzles of the first to nth nozzle rows while the first to nth adjustment signals are supplied to the first to nth element groups, respectively, The first registration unit registers one of the bidirectional adjustment values ​​from the first to nth bidirectional adjustment patterns as the first to nth adjustment values, respectively. The second registration unit registers, for each of the first to nth comparison values, one of the bidirectional adjustment values ​​of the first to nth adjustment signal bidirectional adjustment patterns. The printer according to claim 2.

4. The control device is A first input unit that can input one bidirectional adjustment value from each of the first to nth bidirectional adjustment patterns as the first to nth adjustment values, The system includes a second input unit that can input one bidirectional adjustment value from each of the bidirectional adjustment values ​​of the first to nth adjustment signal bidirectional adjustment patterns as the first to nth comparison values, The aforementioned bidirectional adjustment pattern is A plurality of drive signal symbols corresponding to the bidirectional adjustment values ​​of the plurality of adjustment patterns of the first to nth bidirectional adjustment patterns, Includes a plurality of adjustment signal symbols corresponding to the bidirectional adjustment values ​​of the plurality of adjustment patterns of the first to nth adjustment signal bidirectional adjustment patterns, The first input unit is configured to accept the drive signal symbol as a bidirectional adjustment value, The second input unit is configured to accept the adjustment signal symbol as a bidirectional adjustment value. The printer according to claim 3.

5. The first to nth correction values ​​are obtained by multiplying each of the values ​​obtained by dividing the difference between the first to nth adjustment values ​​and the target value by the difference between the first to nth adjustment values ​​and the first to nth comparison values ​​by the first to nth change amounts. The printer according to claim 1.

6. The control device includes a target value calculation unit that calculates the target value from the first to nth adjustment values, The target value is the average of the first to nth adjustment values. The printer according to claim 1.

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