Driving waveform determination method, liquid ejection device, and recording medium

Abstract

The present disclosure relates to a driving waveform determination method, a liquid ejection device, and a recording medium for determining a driving waveform in which the characteristics of the liquid ejected are unlikely to change even when the conditions of the environment used change. The driving waveform determination method comprises: a first acquisition step, performing a first acquisition process to acquire first information related to the liquid ejection characteristics when each of a plurality of driving waveform candidates is applied to the driving element under the conditions of the environment in which the liquid ejection head is placed, i.e., the first environmental conditions; a second acquisition step, performing a second acquisition process to acquire second information related to the liquid ejection characteristics when each of a plurality of driving waveform candidates is applied to the driving element under the conditions of the environment in which the liquid ejection head is placed and the second environmental conditions are different from the first environmental conditions; and a waveform determination step, determining the driving waveform based on the first information and the second information.

Description

Technical Field

[0001] The present disclosure relates to a driving waveform determination method, a liquid ejection device, and a recording medium. Background Art

[0002] Inkjet printers have long used a method for determining parameters for the waveform of a drive signal based on the results obtained by ejecting ink droplets and measuring the ejection characteristics. In the technology of Patent Document 1, multiple drive signals are prepared, each with a different value for the parameter that specifies the drive waveform. Then, ink droplets are ejected simultaneously from multiple nozzles using one of the multiple drive signals. The simultaneous ejection of ink droplets using one drive signal is performed for multiple nozzles of different numbers. This process is performed for each drive signal. Moreover, the parameters of the drive signal that minimize the deviation in the ejection velocity of the ink droplets when ink droplets are ejected simultaneously from different numbers of nozzles are used as the parameters of the drive signal actually used for printing. As a result, during printing, ink droplets are stably ejected from each nozzle regardless of the number of nozzles that eject ink droplets simultaneously.

[0003] If the printer's environmental conditions, such as temperature or humidity, change, the characteristics of the ink ejected from the nozzle, such as the ejection volume, ejection velocity, and the number of secondary droplets, can change. Therefore, even if the technique described in Patent Document 1 is used to determine parameters, the desired ejection characteristics may not necessarily be achieved when the printer's environmental conditions change. For example, when using an inkjet device installed in a clean room for electronic manufacturing, changes in ejection volume caused by temperature fluctuations can significantly affect product quality.

[0004] Patent Document 1: Japanese Patent Application Laid-Open No. 2010-131910 Summary of the Invention

[0005] According to one embodiment of the present disclosure, a driving waveform determination method is provided for determining a driving waveform of a driving signal applied to a driving element of a liquid ejection head in order to eject liquid from the liquid ejection head. The method comprises: a first acquisition step for performing a first acquisition process for acquiring first information, wherein the first information is information related to the ejection characteristics of the liquid when the driving element is applied to each of a plurality of driving waveform candidates under a first environmental condition, which is a condition of the environment in which the liquid ejection head is placed; a second acquisition step for performing a second acquisition process for acquiring second information, wherein the second information is information related to the ejection characteristics when each of a plurality of driving waveform candidates is applied to the driving element under a second environmental condition, which is different from the first environmental condition, which is a condition of the environment in which the liquid ejection head is placed; and a waveform determination step for determining the driving waveform based on the first information and the second information. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] Figure 1 This is a block diagram showing the configuration of the printer 1 and the computer 60 included in the printing system according to the first embodiment.

[0007] Figure 2 It is a perspective view showing a portion of the structure of the printer 1 .

[0008] Figure 3 It is a cross-sectional view of the ink ejection head 41 taken along a cross section perpendicular to the sub-scanning direction Ds.

[0009] Figure 4 2 is a diagram showing a driving waveform W of the driving signal COM.

[0010] Figure 5 1 is a flowchart showing a method for determining a driving waveform of a driving signal applied to the printer 1 .

[0011] Figure 6 This is a block diagram showing printers 1 a and 1 b and computers 60 a and 60 b constituting the printing system according to the second embodiment.

[0012] Figure 7 This is a flowchart showing a method for determining a driving waveform of a driving signal applied to the printer 1 b in the second embodiment.

[0013] Figure 8 This is a block diagram showing printers 1 a and 1 b , computers 60 a and 60 b , and a server 70 that constitute the printing system according to the third embodiment.

[0014] Figure 9 This is a flowchart showing a method for determining the driving waveform of the driving signal applied to the printers 1 a and 1 b in the third embodiment.

[0015] Figure 10 This is a block diagram showing printers 1 a and 1 b and a computer 60 constituting a printing system according to a fourth embodiment.

[0016] Figure 11 This is a flowchart showing a method for determining the driving waveform of the driving signal applied to the printers 1 a and 1 b in the fourth embodiment.

[0017] Figure 12 This is a flowchart showing a method for determining the driving waveform of the driving signal applied to the printers 1 a and 1 b in the fifth embodiment.

[0018] Figure 13 Flowchart showing a method of determining a driving waveform of a driving signal in the sixth embodiment. DETAILED DESCRIPTION

[0019] A. First embodiment:

[0020] A1.Structure of printing system:

[0021] Figure 1 This is a block diagram showing the configuration of a printer 1 and a computer 60 included in the printing system according to the first embodiment. The printing system includes the printer 1 and the computer 60 .

[0022] The printer 1 drives driving elements based on print data to eject ink droplets from nozzles and form an image on the print medium PM. The printer 1 includes a controller 10 , a transport unit 20 , a carriage unit 30 , a head unit 40 , and a detector group 50 .

[0023] The controller 10 is a control unit that controls the printer 1. The controller 10 includes an interface unit 11, a CPU 12, a memory 13, and a unit control circuit 14.

[0024] The interface unit 11 transmits and receives data between the printer 1 and the computer 60. The memory 13 includes auxiliary memory, which stores computer programs executed by the CPU 12, and main memory, which functions as a workspace. The CPU 12 is a processing unit for controlling the entire printer 1. The CPU 12, acting as a processor, loads programs stored in the auxiliary memory into the main memory and executes them, thereby achieving various functions. While the main memory is preferably nonvolatile memory, it can also be volatile memory. Both nonvolatile and volatile memories can be used as auxiliary memory as appropriate.

[0025] The unit control circuit 14 controls each unit of the printer 1 according to instructions from the CPU 12. The unit control circuit 14 includes a plurality of drive signal generation circuits 15. The drive signal generation circuit 15 generates a drive signal COM including a drive waveform W at regular intervals.

[0026] The transport unit 20 transports the print medium PM to a position where printing is possible. During printing, the print medium PM is transported at a predetermined feed rate. The carriage unit 30 moves the inkjet head 41, mounted on the carriage 31, in a direction intersecting the direction in which the print medium PM is transported. In this specification, the direction in which the inkjet head 41 moves is referred to as the "main scanning direction Dm." The direction in which the print medium PM is transported is referred to as the "sub-scanning direction Ds."

[0027] The head unit 40 ejects ink droplets onto the printing medium PM. The head unit 40 includes an ink ejection head 41 and a head control unit HC. A plurality of nozzles Nz are provided on the lower surface of the ink ejection head 41. The ink ejection head 41 includes a plurality of driving elements PZT. Specifically, the driving element PZT is a piezoelectric element. One driving element PZT is provided for each nozzle Nz. The driving element PZT is driven by applying a driving signal COM. The ink ejection head 41 ejects ink from the nozzle Nz by being driven by the driving element PZT. In addition, although a piezoelectric element made of lead zirconate titanate is used as the driving element PZT in this embodiment, a piezoelectric element made of a material other than lead zirconate titanate or a heating element may also be used.

[0028] Based on print data, the head control unit HC controls whether or not to apply the drive waveform W of the drive signal COM to the drive element PZT corresponding to each nozzle Nz. When the drive waveform W is applied to the drive element PZT corresponding to a particular nozzle Nz, an amount of ink corresponding to the drive waveform W is ejected from that nozzle Nz, thereby forming a dot on the print medium PM. On the other hand, if the drive waveform W is not applied to the drive element PZT corresponding to a particular nozzle Nz, no ink droplets are ejected from that nozzle Nz.

[0029] Figure 2 This is a perspective view showing a portion of the structure of the printer 1. The printer 1 can perform a dot formation process in which ink droplets are intermittently ejected from the ink ejection head 41 moving along the main scanning direction Dm to form dots on the print medium PM. The printer 1 can also perform a transport process in which the print medium PM is transported along the sub-scanning direction Ds. By alternately and repeatedly performing the dot formation process and the transport process, the printer 1 forms dots at various locations on the print medium PM, thereby forming an image.

[0030] The detector group 50 monitors the status inside the printer 1 (see Figure 1 The controller 10 controls the various components of the printer 1 based on output signals from the detector group 50. The detector group 50 includes a temperature sensor 51, a humidity sensor 52, an air pressure sensor 53, and a CCD camera 55.

[0031] The temperature sensor 51 measures the air temperature and outputs a signal indicating the air temperature to the CPU 12. The air temperature measured by the temperature sensor 51 is the temperature of the environment in which the ink ejection head 41 is located. The humidity sensor 52 measures the humidity and outputs a signal indicating the humidity to the CPU 12. The humidity measured by the humidity sensor 52 is the humidity of the environment in which the ink ejection head 41 is located. The air pressure sensor 53 measures the air pressure and outputs a signal indicating the air pressure to the CPU 12. The air pressure measured by the air pressure sensor 53 is the air pressure of the environment in which the ink ejection head 41 is located.

[0032] The CCD camera 55 captures images of ink droplets ejected from the ink ejection head 41 and outputs image data to the CPU 12. The CCD camera 55 can capture both still and moving images. In this specification, the term "image" includes both still and moving images.

[0033] Although the CCD camera 55 is used for imaging to obtain information indicating discharge characteristics as described later, any component capable of obtaining information indicating discharge characteristics may be used in place of the CCD camera 55. For example, an electronic balance may be used in place of the CCD camera 55 to obtain information indicating discharge characteristics such as the discharge volume.

[0034] The computer 60 sends print data to the printer 1. The computer 60 sends parameters representing the drive waveform of the drive signal of the drive element to the printer 1. The computer 60 includes an interface unit 61, a CPU 62, a memory 63, a display 64, a keyboard 65, and a mouse 66.

[0035] The display 64 is controlled by the CPU 62 to output images. The keyboard 65 and the mouse 66 are operated by the user to input user instructions to the CPU 62.

[0036] The interface unit 61 transmits and receives data between the computer 60 and the printer 1. The memory 63 includes auxiliary memory, which stores programs executed by the CPU 62, and main memory, which functions as a work area. The CPU 62, acting as a processor, loads programs stored in the auxiliary memory into the main memory and executes them, thereby achieving various functions.

[0037] For example, the CPU 62 functions to obtain information indicating the characteristics of ink ejected from the ink ejection head 41, namely, the ejection characteristics. More specifically, the CPU 62 can obtain the ejection velocity of ink ejected from the nozzle Nz and the amount of ink ejected from the nozzle Nz as a result of the ejection operation of the drive element PZT based on the ink droplet image captured by the CCD camera 55. Furthermore, the CPU 62 functions to determine the drive waveform of the drive signal COM applied to the drive element PZT.

[0038] Figure 3 This is a cross-sectional view of the ink ejection head 41 taken along a section perpendicular to the sub-scanning direction Ds. The ink ejection head 41 includes a housing 411, a flow channel unit 412, and a plurality of drive elements PZT. The housing 411 houses the plurality of drive elements PZT. The flow channel unit 412 is bonded to the bottom surface of the housing 411.

[0039] The flow path unit 412 includes a flow path forming plate 412 a , an elastic plate 412 b , and a nozzle plate 412 c .

[0040] The flow channel forming plate 412a is formed with a groove that functions as a pressure chamber 412d, a through-hole that functions as a nozzle communication port 412e, a through-hole that functions as a common ink chamber 412f, and a groove that functions as an ink supply channel 412g. In the ink ejection head 41, ink is supplied to the pressure chamber 412d via the common ink chamber 412f and the ink supply channel 412g. The ink in the pressure chamber 412d is ejected from the nozzle Nz via the nozzle communication port 412e. A combination of the ink supply channel 412g, the pressure chamber 412d, and the nozzle communication port 412e is provided for each nozzle Nz.

[0041] The elastic plate 412b has an island portion 412h to which the tip of the driving element PZT is bonded, and an elastic region formed of an elastic film 412i is formed around the island portion 412h.

[0042] The nozzle plate 412c is a plate formed with a plurality of nozzles Nz. On the nozzle Nz surface, which is one surface of the nozzle plate 412c, there are formed a yellow nozzle array that ejects yellow ink, a magenta nozzle array that ejects magenta ink, a cyan nozzle array that ejects cyan ink, and a black nozzle array that ejects black ink. Each nozzle array consists of 180 nozzles Nz arranged at predetermined intervals in the sub-scanning direction Ds. Figure 3 It is a cross-sectional view taken along a cross section perpendicular to the sub-scanning direction Ds. In the unit control circuit 14 , one drive signal generating circuit 15 is provided for one nozzle row.

[0043] The plurality of driving elements PZT are constructed as a plurality of comb-shaped elements. A driving signal COM is applied to the driving element PZT via a wiring substrate on which a head control unit HC and the like are mounted. The driving element PZT expands and contracts according to the potential of the driving signal COM. When the driving element PZT expands, the island portion 412h deforms toward the pressure chamber 412d. When the driving element PZT contracts, the island portion 412h deforms toward one side of the driving element PZT. As a result, the pressure in the pressure chamber 412d changes, causing ink droplets to be ejected from the nozzle Nz. A driving signal generating circuit 15 is provided for one nozzle column. Therefore, the driving signal COM generated by a certain driving signal generating circuit 15 is applied in a common manner to the driving elements PZT of all nozzles Nz belonging to the nozzle column corresponding to the driving signal generating circuit 15.

[0044] Figure 4 The driving waveform W of the driving signal COM is shown in FIG. In the driving signal COM, a constant cycle is repeatedly generated. Figure 4 The driving waveform W is shown.

[0045] The driving waveform W includes a first expansion element S1 in which the potential rises from the intermediate potential Vc to the maximum potential Vh, a first holding element S2 in which the maximum potential Vh is maintained, a contraction element S3 in which the potential drops from the maximum potential Vh to the minimum potential Vl, a second holding element S4 in which the minimum potential Vl is maintained, and a second expansion element S5 in which the potential rises from the minimum potential Vl to the intermediate potential Vc.

[0046] When the intermediate potential Vc is applied to the driving element PZT, the driving element PZT does not expand or contract. The volume of the pressure chamber 412d when the intermediate potential Vc is applied to the driving element PZT is referred to as a "reference volume."

[0047] When the first expansion element S1 of the driving signal COM is applied to the driving element PZT from the state where the intermediate potential Vc is applied to the driving element PZT, the driving element PZT contracts in the longitudinal direction. As a result, the volume of the pressure chamber 412d increases (see Figure 3). When the first holding element S2 of the drive signal COM is applied to the drive element PZT, the contracted state of the drive element PZT is maintained. At this time, the expanded state of the pressure chamber 412d is also maintained. When the contraction element S3 of the drive signal COM is applied to the drive element PZT, the drive element PZT begins to stretch from the contracted state. As a result, the volume of the pressure chamber 412d will become smaller. As a result, the ink pressure in the pressure chamber 412d increases, so that ink droplets are ejected from the nozzle Nz. Thereafter, the second holding element S4 of the drive signal COM is applied to the drive element PZT, so that the extended state of the drive element PZT and the contracted state of the pressure chamber 412d are maintained. When the second expansion element S5 is applied to the drive element PZT, the volume of the pressure chamber 412d returns to the reference volume.

[0048] The time period of the first expansion element S1 is referred to as "first expansion time Pwc1." The time period of the first retention element S2 is referred to as "first retention time Pwh1." The time period of the contraction element S3 is referred to as "contraction time Pwd1." The time period of the second retention element S4 is referred to as "second retention time Pwh2." The time period of the second expansion element S5 is referred to as "second expansion time Pwc2." The first expansion time Pwc1, the first retention time Pwh1, the contraction time Pwd1, the second retention time Pwh2, and the second expansion time Pwc2 are parameters that define the shape of the drive waveform W of the drive signal COM.

[0049] A2. Determination of driving waveform:

[0050] Figure 5 1 is a flowchart showing a method for determining a driving waveform of a driving signal applied to the printer 1 . Figure 5 The processing is performed mainly by the CPU 62 of the computer 60 controlling each part according to the instruction input by the user. Figure 5 The processing shown here determines the driving waveform of the driving signal COM applied to the driving element PZT to eject ink from the ink ejection head 41 .

[0051] In step S111, the CPU 62 uses the temperature sensor 51 of the printer 1 to obtain the temperature Ta of the environment in which the printer 1 is placed. The environmental conditions defined by the temperature Ta measured in step S111 are also referred to as "first environmental conditions." The temperature Ta is transmitted to the computer 60 via the CPU 12 and interface 11 of the printer 1.

[0052] In step S121, the CPU 62 selects one of a plurality of predetermined drive waveform candidates Wci and sends a set of parameters representing the selected drive waveform candidate Wci to the printer 1 (see FIG. 1 ). Figure 4 ). The plurality of predetermined driving waveform candidates Wci are candidates for the driving waveform W of the driving signal COM applied to the printer 1. The plurality of sets of parameters representing the driving waveform candidates Wci are stored in advance in the memory 63. Figure 1 , a plurality of sets of parameters representing a plurality of driving waveform candidates Wci are shown as “waveform parameters 631 ”.

[0053] The CPU 62 instructs the CPU 12 of the printer 1 to execute the following processing. The CPU 12 controls the unit control circuit 14 to generate a drive signal based on a set of parameters representing one of the received drive waveform candidates Wci. The CPU 12 then applies this drive signal COM to the drive element PZT of the ink ejection head 41. As a result, ink droplets are ejected from the nozzles Nz.

[0054] In step S131, the CPU 12 causes the CCD camera 55 to capture images of ink droplets ejected from the nozzles Nz in response to the drive signal COM. The CPU 12 transmits this image data to the computer 60. In step S121, the CPU 62 of the computer 60 instructs the CPU 12 of the printer 1 to execute the above processing of steps S121 and S131.

[0055] In step S131, the CPU 62 calculates the ejection volume Pwa of the ink ejected from one nozzle Nz of the ink ejection head 41 by the ejection action of the driving element PZT based on the image data. The ejection volume of the ink is specified by mass. Since the mass is based on the volume and the ink density, the ejection volume of the ink can also be specified by the volume. The ejection volume of the ink is one of the forms of "ejection characteristics". The CPU 62 stores the information of the ejection characteristics under the environment of the temperature Ta in the memory 63 in a manner that establishes a correspondence with the information that specifies the drive waveform candidate Wci applied to the driving element PZT. The information representing the ejection characteristics is referred to as "first information Ic1". In addition, as the ejection volume Pwa of the ink, the ejection volume ejected from one nozzle Nz by one ejection action of the driving element PZT can also be used.

[0056] In this specification, the processing performed in steps S121 and S131, that is, the processing of obtaining the first information Ic1, is referred to as the "first acquisition processing". The first information Ic1 shows the ink ejection characteristics when a certain drive waveform candidate Wci is applied to the drive element PZT at a temperature Ta representing the environmental conditions in which the ink ejection head 41 of the printer 1 is placed.

[0057] In step S131b, the CPU 62 determines whether the processes of steps S121 and S131 have been executed for all drive waveform candidates Wci for which the first acquisition process should be executed. If the processes of steps S121 and S131 have been executed for all drive waveform candidates Wci for which the first acquisition process should be executed, the process proceeds to step S141. If the processes of steps S121 and S131 have not been executed for all drive waveform candidates Wci for which the first acquisition process should be executed, the process returns to step S121. Then, one drive waveform candidate Wci for which the processes of steps S121 and S131 have not been executed is selected from the plurality of drive waveform candidates Wci, and the processes of steps S121 and S131 are executed.

[0058] By repeating the processing of steps S121 and S131, the first acquisition processing is performed for each of the plurality of predetermined drive waveform candidates Wci. As a result, the first information Ic1 on the plurality of predetermined drive waveform candidates Wci is stored in the memory 63 (see Figure 1 ).

[0059] That is, in the first embodiment, the first acquisition process for acquiring the first information Ic1 is performed by applying the drive waveform candidate Wci to the drive element PZT under the environment of the temperature Ta and measuring the ejection characteristics of the ink droplets ejected from the ink ejection head 41 (see Figure 5 S121, S131). Figure 1 In FIG. 6 , the functional portion of the CPU 62 that executes the processing of steps S121 to S131 b is shown as a first characteristic acquisition portion 622 a .

[0060] exist Figure 5 In step S141 , the CPU 62 extracts the driving waveform candidate Wci whose discharge characteristics indicated by the first information Ic1 satisfy a predetermined first condition as the first selected waveform Ws1 .

[0061] First, the CPU 62 obtains first deviation information Id1 indicating the difference between the discharge characteristics indicated by the first information Ic1 and the target discharge characteristics as the ideal discharge characteristics. As a specific example, the value Dwa is calculated as the first deviation information Id1 using the following equation.

[0062] Dwa=|Pwt-Pwa|…(1)

[0063] Here, Pwt is the ideal discharge amount.

[0064] Pwa is the ejection amount indicated by the first information Ic1 and is the ejection amount when a certain driving waveform candidate Wci is applied to the printer 1 .

[0065] When Thwa is a positive number, the CPU 12 extracts a drive waveform candidate satisfying Dwa≦Thwa from among the plurality of drive waveform candidates Wci as the first selected waveform Ws1 .

[0066] In step S161, the CPU 62 waits until the temperature measured by the temperature sensor 51 reaches a predetermined temperature. Specifically, the user uses a temperature-changing mechanism, such as an air conditioner or thermostat, to change the temperature of the environment in which the printer 1 is placed. When the temperature measured by the temperature sensor 51 changes from Ta to a temperature significantly different from the predetermined temperature difference, the process proceeds to step S211. Alternatively, the temperature-changing mechanism can be automatically activated by the computer in step S161 to change the ambient temperature without the user's intervention. Furthermore, in step S161, the ambient temperature can be either increased or decreased.

[0067] In step S211, the CPU 62 uses the temperature sensor 51 of the printer 1 to obtain the temperature Tb of the environment in which the printer 1 is placed. The environmental condition defined by the temperature Tb measured in step S211 is also referred to as the "second environmental condition." The process in step S211 is the same as that in step S111.

[0068] The processing of steps S221, S231, and S231b is the same as that of steps S121, S131, and S131b. However, the processing of steps S121, S131, and S131b is performed under the environment of temperature Ta, whereas the processing of steps S221, S231, and S231b is performed under the environment of temperature Tb. Figure 1 In FIG. 6 , the functional portion of the CPU 62 that executes the processing of steps S221 to S231 b is shown as a second characteristic acquisition portion 622 b .

[0069] The processing performed in steps S221 and S231, that is, the processing of obtaining the second information Ic2 is called "second acquisition processing", and the second information Ic2 is information showing the ink ejection characteristics when a certain drive waveform candidate Wci is applied to the drive element PZT at a temperature Tb representing the environmental conditions in which the ink ejection head 41 of the printer 1 is placed.

[0070] By repeating the processing of steps S221 and S231, the second acquisition processing is performed for each of the plurality of predetermined drive waveform candidates Wci. As a result, the second information Ic2 on the plurality of predetermined drive waveform candidates Wci is stored in the memory 63 (see Figure 1The second information Ic2 is information on ejection characteristics under the environment of the air temperature Tb, which is associated with information specifying the drive waveform candidate Wci applied to the drive element PZT.

[0071] That is, in the first embodiment, the second acquisition process for acquiring the second information Ic2 is performed by applying the drive waveform candidate Wci to the drive element PZT under the temperature Tb environment and measuring the ejection characteristics of the ink droplets ejected from the ink ejection head 41 (see Figure 5 S221, S231).

[0072] In step S241 , the CPU 62 extracts, as the second selected waveform Ws2 , a driving waveform candidate Wci whose discharge characteristics, indicated by the second information Ic2 stored in the memory 63 , satisfy a predetermined second condition.

[0073] First, the CPU 62 obtains second deviation information Id2 indicating the difference between the discharge characteristics indicated by the second information Ic2 and the target discharge characteristics as the ideal discharge characteristics. As a specific example, the value Dwb is calculated as the second deviation information Id2 using the following equation.

[0074] Dwb=|Pwt-Pwb|…(2)

[0075] Here, Pwb is the discharge amount indicated by the second information Ic2 and is the discharge amount when a certain drive waveform candidate Wci is applied to the printer 1 .

[0076] The process of acquiring the first deviation information Id1 and the second deviation information Id2 is also referred to as a “fourth acquisition process”.

[0077] When Thwb is a positive number, the CPU 12 extracts a drive waveform candidate satisfying Dwb≦Thwb from among the plurality of drive waveform candidates Wci as the second selected waveform Ws2 .

[0078] By executing the processing of steps S141 and S241, the driving waveform W is determined based on the first deviation information Id1 and the second deviation information Id2. As a result, the driving waveform candidate is determined as the driving waveform W, in which the discharge characteristic Pwa indicated by the first information Ic1 satisfies the predetermined condition [|Pwt - Pwa| ≤ Thwa] and the discharge characteristic indicated by the second information Ic2 satisfies the predetermined condition [|Pwt - Pwb| ≤ Thwb].

[0079] In step S311, the CPU 62 extracts the drive waveform candidate Wci included in both the first selected waveform Ws1 and the second selected waveform Ws2 as the third selected waveform Ws3. Furthermore, in the first embodiment, it is assumed that among the plurality of predetermined drive waveform candidates Wci, there is one or more drive waveform candidate Wci included in both the first selected waveform Ws1 and the second selected waveform Ws2.

[0080] In step S321, the CPU 62 obtains third information Ic3, which is information related to the difference between the ejection characteristics shown in the first information Ic1 and the ejection characteristics shown in the second information Ic2, obtained using the same drive waveform candidate. This process is referred to as the "third acquisition process." The CPU 62 executes the third acquisition process for the drive waveform candidate Wci included in the third selected waveform Ws3.

[0081] As a specific example, the CPU 62 calculates the following evaluation value DP1 as the third information Ic3 for the drive waveform candidate Wci included in the third selected waveform Ws3 .

[0082] DP1=|Pwb-Pwa|…(3)

[0083] In step S331 , the CPU 62 determines the driving waveform W based on the evaluation value DP1. Specifically, the CPU 62 determines the driving waveform candidate Wci with the smallest DP1 among the driving waveform candidates Wci included in the third selected waveform Ws3 as the driving waveform W of the driving signal COM applied to the driving element PZT of the ink ejection head 41 .

[0084] As a result, in step S331, the driving waveform W is determined based on the first information Ic1, the second information Ic2, and at least a portion of a plurality of predetermined driving waveform candidates Wci (see FIG. Figure 5 Then, the driving waveform candidate with the smaller difference between the ejection characteristics indicated by the first information Ic1 and the ejection characteristics indicated by the second information Ic2 is preferentially determined as the driving waveform W (refer to Figure 5 Steps S321 and S331). Figure 1 In FIG. 6 , the functional portion of the CPU 62 that executes the processing of steps S311 to S331 is shown as a waveform determination portion 624 .

[0085] This method can determine a driving waveform W that is unlikely to change the discharge amount of liquid, which is one form of discharge characteristics, even if the temperature that defines the environmental conditions in which the printer is placed changes.

[0086] Furthermore, since the processes of steps S141 and S241 are performed before step S321, the drive waveform W is determined based on the first deviation information Id1 and the second deviation information Id2 through the processes of steps S141, S241, S321, and S331. Then, the drive waveform candidate having the smallest difference between the discharge characteristics indicated by the first information Ic1 and the target discharge characteristics, and the smallest difference between the discharge characteristics indicated by the second information Ic2 and the target discharge characteristics, is preferentially determined as the drive waveform W.

[0087] As a result, the drive waveform W is determined by taking into account the difference Dwa between the discharge characteristics under the temperature Ta environment indicated by the first deviation information Id1 and the ideal discharge characteristics, and the difference Dwb between the discharge characteristics under the temperature Tb environment indicated by the second deviation information Id2 and the ideal discharge characteristics. Therefore, for example, it is possible to prevent a situation where, even though the difference DP1 between the discharge characteristics under the temperature Ta environment and the discharge characteristics under the temperature Tb environment is small, a drive waveform candidate Wci in which both the discharge characteristics under the temperature Ta environment and the discharge characteristics under the temperature Tb environment deviate significantly from the ideal discharge characteristics is determined as the drive waveform W.

[0088] In the first embodiment, the driving element PZT to which the driving signal COM having the determined driving waveform W is applied is used to measure the ejection characteristics under the environment of the temperature Ta as the first environmental condition and the ejection characteristics under the environment of the temperature Tb as the second environmental condition (see Figure 5 Thus, a drive waveform W suitable for the drive element PZT to which the drive signal COM having the determined drive waveform W is applied is determined.

[0089] In addition, any method that achieves the same effect as the first embodiment may be implemented. Figure 5 For example, the extraction of the first selection waveform Ws1 in step S141 and the extraction of the second selection waveform Ws2 in step S241 may be omitted, and the extraction of the first selection waveform Ws1 and the second selection waveform Ws2 may be performed in step S311, followed by the extraction of the driving waveform candidate Ws3.

[0090] The printing system in this embodiment is also referred to as a "liquid ejection device" (see Figure 1 ). The ink ejection head 41 is also referred to as a "liquid ejection head". The unit control circuit 14 is also referred to as a "drive control unit". Figure 5Step S131 is also called the "first acquisition step." Step S231, which is repeatedly executed, is also called the "second acquisition step." Step S321 is also called the "third acquisition step." Steps S141 and S241 are also called the "fourth acquisition step." Step S331 is also called the "waveform determination step."

[0091] B. Second embodiment:

[0092] Figure 6 This is a block diagram showing printers 1a and 1b and computers 60a and 60b constituting a printing system according to Embodiment 2. In Embodiment 2, the printing system includes a combination of a computer 60a and printer 1a, and a combination of a computer 60b and printer 1b.

[0093] Computer 60a and computer 60b are connected together in a manner that enables mutual communication. Figure 1 The computer 60 is the same as that of the first embodiment described above.

[0094] Structure and Use of Printers 1a and 1b Figure 1 as well as Figure 2 The printers 1 of the first embodiment described above are identical. The printers 1a and 1b are preferably of the same model, but may be of different models. The printers 1a and 1b are placed in environments with different temperatures, humidity, and air pressures.

[0095] Figure 7 This is a flowchart showing a method for determining a driving waveform of a driving signal applied to the printer 1 b in the second embodiment. Figure 7 Methods and Figure 5 The method of the first embodiment shown corresponds to the method of the first embodiment shown. Figure 7 In each step of the first embodiment, Figure 5 The first and second digits in the symbol representing the step are the same as Figure 5 The first and second digits in the corresponding steps are the same.

[0096] The computer 60a and the printer 1a execute the processes of steps S112 to S152.

[0097] The processing of steps S112 to S142 is similar to that of steps S112 to S142, except that the target printer is the printer 1a. Figure 5 The processing of steps S111 to S141 is the same.

[0098] In step S152, the CPU 62 of the computer 60a sends the parameters defining the waveform shape and the ink ejection volume Pwa for the driving waveform candidate Wci included in the first selected waveform Ws1 to the computer 60b, each associated with information specifying the driving waveform candidate Wci. This completes the processing in the computer 60a and printer 1a.

[0099] The computer 60b and the printer 1b execute the processing of steps S212 to S332.

[0100] The processing of steps S212 to S242 is similar to that of steps S212 to S242, except that the target printer is the printer 1b. Figure 5 The processing of steps S111 to S141 is the same. In addition, the memory 63 of the printers 1a and 1b of the same model stores the same waveform parameters 631 (see Figure 7 S122, S222).

[0101] In step S252 , the CPU 62 of the computer 60 b receives from the computer 60 b the parameters defining the shape of the waveform and the ink discharge amount Pwa, which are associated with the information specifying the driving waveform candidate Wci.

[0102] In step S312, the CPU 62 of the computer 60b extracts the drive waveform candidate Wci included in both the first selected waveform Ws1 and the second selected waveform Ws2 as the third selected waveform Ws3. Furthermore, in the second embodiment, it is assumed that among the plurality of predetermined drive waveform candidates Wci, there is one or more drive waveform candidate Wci included in both the first selected waveform Ws1 and the second selected waveform Ws2.

[0103] The processing of steps S322 and S332 is respectively Figure 5 The processing of steps S321 and 331 is the same.

[0104] In this manner, similar to the first embodiment, it is possible to determine a driving waveform W that is unlikely to change the discharge characteristics even if the temperature that defines the environmental condition in which the printer is placed changes.

[0105] In the second embodiment, the discharge characteristics under the temperature Ta and the discharge characteristics under the temperature Tb can be measured in parallel (see Figure 7 Therefore, the first information Ic1 and the second information Ic2 can be obtained in a short time (refer to S122 to S132b, S222 to S232b). Figure 3 ). Therefore, the driving waveform W used in the printer 1b can be determined in a short time.

[0106] C. Third embodiment:

[0107] Figure 8 This is a block diagram showing printers 1a and 1b, computers 60a and 60b, and a server 70 that constitute a printing system according to a third embodiment. In the third embodiment, the printing system includes a combination of computer 60a and printer 1a, a combination of computer 60b and printer 1b, and server 70. Another combination of computer and printer is connected to server 70. However, in the third embodiment, the technical details are described focusing on the combination of computer 60a and printer 1a, the combination of computer 60b and printer 1b, and server 70.

[0108] Structure and Use of Computers 60a and 60b Figure 1 The computer 60 of the first embodiment described above is the same. The structure and use of the printers 1a and 1b Figure 1 as well as Figure 2 The printers 1 of the first embodiment described above are identical. While printers 1a and 1b are preferably of the same model, they may be of different models. The combination of computer 60a and printer 1a and the combination of computer 60b and printer 1b may be owned by different users. The temperature, humidity, and air pressure in the environments where printers 1a and 1b are installed may differ.

[0109] The server 70 includes an interface unit 71, a CPU 72, and a memory 73. The interface unit 71 transmits and receives data between the server 70 and the computers 60a and 60b. The memory 73 includes auxiliary memory, which stores programs executed by the CPU 72, and main memory, which functions as a workspace. The CPU 72, acting as a processor, loads programs stored in the auxiliary memory into the main memory and executes them, thereby achieving various functions.

[0110] Figure 9 This is a flowchart showing a method for determining the driving waveform of the driving signal applied to the printers 1 a and 1 b in the third embodiment. Figure 9 Methods and Figure 5 The method of the first embodiment shown and Figure 7 The method of the second embodiment shown in FIG. Figure 9 In each step of the first embodiment, Figure 5 The first and second digits in the symbol representing the step are the same as Figure 5 The first and second digits in the corresponding steps are the same. Figure 9 In each step of the second embodiment Figure 7The first and second digits in the symbol representing the step are the same as Figure 7 The first and second digits in the corresponding steps are the same.

[0111] The computer 60a and the printer 1a execute the processes of steps S113 to S163.

[0112] The processing of steps S113 to S133b is respectively Figure 7 The processing of step S112 to S132b is the same as that of step S143 except that the target printer is printer 1a. Figure 5 The processing of step S141 is the same as that of step S141.

[0113] In step S153, the CPU 62 of the computer 60a sends the parameters that specify the shape of the waveform and the ink ejection amount Pwa to the server 70 in a manner that establishes a correspondence with the combination of information that specifies the type of ink ejection head 41, the air temperature Ta, and the information that specifies the driving waveform candidate Wci for the driving waveform candidate Wci included in the first selection waveform Ws1. In addition, the information that specifies the type of ink ejection head 41 is information for distinguishing the design of the ink ejection head 41. Liquid ejection heads of the same design are consistent with the information that specifies the type of liquid ejection head. The information that specifies the type of ink ejection head 41 is pre-stored in the memory 13 of the printer 1. Figure 1 In FIG, information specifying the type of the ink ejection head 41 is shown as “head ID 132 .” The CPU 62 of the computer 60 a receives information specifying the type of the ink ejection head 41 from the printer 1 a .

[0114] The CPU 72 of the server 70 receives from the computer 60a the parameters defining the waveform shape and the ink ejection amount Pwa, which are associated with the combination of information specifying the type of the ink ejection head 41, the temperature Ta, and information specifying the drive waveform candidate Wci included in the first selection waveform Ws1. The CPU 72 of the server 70 then stores this information in the memory 73. Figure 8 In the figure, parameters defining the waveform shape and the ink ejection volume Pwa for the first selection waveform Ws1 are shown as "first information Ic1s." Furthermore, the server 70 similarly transmits the first information Ic1s from multiple printers connected to the server 70 and stores this information in a manner associated with combinations of information specifying the type of ink ejection head 41, the temperature Ta, and information specifying the candidate drive waveform Wci included in the first selection waveform Ws1.

[0115] In step S163, the CPU 62 of the computer 60a determines the driving waveform W based on the first deviation information Id1. Specifically, the CPU 62 determines the driving waveform candidate Wci with the smallest Dwa among the driving waveform candidates Wci included in the first selected waveform Ws1 as the driving waveform W of the driving signal COM applied to the driving element PZT of the ink ejection head 41 of the printer 1a (see equation (1) above). This concludes the processing in the computer 60a and printer 1a.

[0116] The computer 60b and the printer 1b execute the processing of steps S213 to S333.

[0117] The processing of steps S213 to S233b is respectively Figure 7 The processing of step S212 to S232b is the same as that of step S243 except that the target printer is printer 1b. Figure 5 The processing of step S241 is the same.

[0118] That is, in the third embodiment, the second acquisition process for acquiring the second information is performed by applying the drive waveform candidate Wci to the drive element PZT of the other ink ejection head 41 of the same type as the ink ejection head 41 associated with the first information Ic1 under the environment of the temperature Tb, and measuring the ejection characteristics of the ejected ink droplets (refer to FIG. Figure 9 S223, S233).

[0119] In step S253, the CPU 62 of the computer 60b transmits a signal requesting the first information Ic1s, along with information specifying the type of the ink ejection head 41 of the printer 1b, to the server 70. The CPU 62 then receives the first information Ic1s from the computer 60b, indicating the type of the ink ejection head 41. The first information Ic1s includes parameters defining the waveform shape and the ink ejection volume Pwa, which are associated with a combination of the information specifying the type of the ink ejection head 41, the temperature Ta, and information specifying the drive waveform candidate Wci included in the first selected waveform Ws1.

[0120] That is, in the third embodiment, the first acquisition process of acquiring the first information is executed by reading the first information Ic1s stored in the server 70 in association with the type of the ink ejection head 41 and the temperature Ta.

[0121] The processing of steps S313 to S333 is similar to that of steps S313 to S333, except that the target printer is printer 1b. Figure 5 The processing of steps S311 to S331 is the same.

[0122] In this manner, similar to the first embodiment, it is possible to determine a driving waveform W that is unlikely to change the discharge characteristics even if the temperature that defines the environmental condition in which the printer is placed changes.

[0123] According to this embodiment, the user of the printer 1a and the computer 60b can use the ink ejection head 41 to eject liquid in an environment with a temperature Ta, and can obtain first information Ic1s (see Figure 9 Therefore, the driving waveform W can be easily determined from a plurality of driving waveform candidates Wci.

[0124] D. Fourth embodiment:

[0125] Figure 10 1 is a block diagram showing printers 1a and 1b and a computer 60 constituting a printing system according to a fourth embodiment. In the printing system according to the fourth embodiment, two printers 1a and 1b are connected to a computer 60.

[0126] The structure and use of computer 60 Figure 1 The computer 60 described in the first embodiment is the same. The computer 60 can send different print data to printers 1a and 1b. Alternatively, the computer 60 can send the same print data to printers 1a and 1b. The computer 60 sends parameters representing the drive waveform of the drive signal to printers 1a and 1b. In this embodiment, the computer 60 sends the same parameters representing the drive waveform of the drive signal to printers 1a and 1b. That is, printers 1a and 1b are driven by a drive signal COM containing the same drive waveform W.

[0127] Structure and Use of Printers 1a and 1b Figure 1 as well as Figure 2 The printer 1 of the first embodiment described above is the same. The printers 1a and 1b are preferably of the same model. The printers 1a and 1b are placed in environments with different temperatures, humidity, and air pressure.

[0128] Figure 11 This is a flowchart showing a method for determining the driving waveform of the driving signal applied to the printers 1 a and 1 b in the fourth embodiment. Figure 11 Methods and Figure 5 The method of the first embodiment shown, Figure 7 The method of the second embodiment shown, and Figure 10 The method of the third embodiment shown in FIG. Figure 11 In each step of the first embodiment, Figure 5The first and second digits in the symbol representing the step are the same as Figure 5 The first and second digits in the corresponding steps are the same. Figure 11 In each step of the second embodiment Figure 7 The first and second digits in the symbol representing the step are the same as Figure 7 The first and second digits in the corresponding steps are the same. Figure 11 In each step of the third embodiment Figure 9 The first and second digits in the symbol representing the step are the same as Figure 9 The first and second digits in the corresponding steps are the same.

[0129] The processing of steps S114 to S134b is similar to that of steps S114 to S134b, except that the target printer is the printer 1a. Figure 5 The processing of steps S111 to S131b is the same.

[0130] The processing of steps S214 to S234b is similar to that of steps S214 to S234b, except that the target printer is printer 1b. Figure 5 The processing of steps S211 to S231b is the same.

[0131] In step S324, the CPU 62 of the computer 60 executes a third acquisition process for each of the plurality of predetermined drive waveform candidates Wci. Specifically, the CPU 62 acquires, for each drive waveform candidate Wci, an evaluation value DP4 associated with the difference between the ejection characteristics indicated by the first information Ic1 and the ejection characteristics indicated by the second information Ic2, obtained using the same drive waveform candidate.

[0132] At this time, the CPU 62 obtains the evaluation value DP4 including the value Dwa of the first deviation information Id1 and the value Dwa of the second deviation information Id2 , and as a result, determines the drive waveform W based on the first deviation information Id1 and the second deviation information Id2 .

[0133] As a specific example, the CPU 62 calculates the following evaluation value DP4 for each drive waveform candidate Wci.

[0134] DP4=Dwa 2 +Dwb 2 +DP1 2

[0135] =(Pwt-Pwa) 2 +(Pwt-Pwb) 2 +(Pwb-Pwa)2 …(4)

[0136] By performing such processing, the drive waveform W can be determined by taking into account the following considerations in addition to the difference between the discharge characteristic Pwa in the environment of temperature Ta and the discharge characteristic Pwb in the environment of temperature Tb, as indicated by the third information Ic3. Specifically, the drive waveform W can be determined by taking into account the difference Dwa between the discharge characteristic Pwa in the environment of temperature Ta and the ideal discharge characteristic Pwt, as indicated by the first deviation information Id1, and the difference Dwa between the discharge characteristic Pwb in the environment of temperature Tb and the ideal discharge characteristic Pwt, as indicated by the second deviation information Id2. More specifically, the drive waveform candidate Wci having a smaller difference Dwa between the discharge characteristic Pwa in the environment of temperature Ta and the ideal discharge characteristic Pwt, and a smaller difference Dwa between the discharge characteristic Pwb in the environment of temperature Tb and the ideal discharge characteristic Pwt, as indicated by the second deviation information Id2, is preferentially determined as the drive waveform W.

[0137] Therefore, for example, the possibility of determining the following driving waveform candidate as the driving waveform W can be reduced, wherein the driving waveform candidate is a driving waveform candidate in which the difference between the ejection characteristic Pwa under the temperature Ta environment and the ejection characteristic Pwb under the temperature Tb environment is small, but the ejection characteristic Pwa under the temperature Ta environment and the ejection characteristic Pwb under the temperature Tb environment both deviate significantly from the ideal ejection characteristic Pwt.

[0138] In step S334 , the CPU 62 determines the driving waveform W based on the evaluation value DP4. Specifically, the CPU 62 determines the driving waveform candidate Wci with the smallest DP4 as the driving waveform W of the driving signal COM applied to the driving elements PZT of the ink ejection heads 41 of the printers 1a and 1b.

[0139] As a result, in step S331, the driving waveform W is determined based on the first information Ic1, the second information Ic2, and a plurality of predetermined driving waveform candidates Wci. Furthermore, the driving waveform candidate with the smallest difference between the ejection characteristics indicated by the first information Ic1 and the ejection characteristics indicated by the second information Ic2 is preferentially determined as the driving waveform W (see the third term of equation (4)).

[0140] In this manner, similar to the first embodiment, it is possible to determine a driving waveform W that is unlikely to change the discharge characteristics even if the temperature that defines the environmental condition in which the printer is placed changes.

[0141] E. Fifth embodiment:

[0142] The configuration of the printing system of the fifth embodiment is the same as that of the printing system of the first embodiment (see Figure 1 However, in the printing system of the fifth embodiment, a portion of the method for determining the driving waveform of the driving signal differs from the method for determining the driving waveform of the driving signal of the first embodiment in that it includes the processing of steps S325, S415, and S425. The other aspects of the fifth embodiment are the same as those of the first embodiment.

[0143] Figure 12 This is a flowchart showing a method for determining the driving waveform of the driving signal applied to the printers 1 a and 1 b in the fifth embodiment. Figure 12 Methods and Figure 5 The method of the first embodiment shown in FIG. Figure 12 In each step of the first embodiment, Figure 5 The first and second digits in the symbol representing the step are the same as Figure 5 The first and second digits in the corresponding steps are the same.

[0144] The processing of steps S115 to S325 is respectively Figure 5 The processing of steps S111 to S321 is the same.

[0145] In step S325b, the CPU 62 of the computer 60 determines whether the driving waveform candidate Wci included in the third selected waveform Ws3 satisfies predetermined conditions. Predetermined conditions are conditions that a driving waveform used in the printer 1 must meet. If the driving waveform candidate Wci does not meet these conditions, it cannot be adopted as the driving waveform used in the printer 1. Here, the predetermined condition is that the evaluation value DP1 is below a predetermined threshold value Thd. However, other conditions may also be adopted as the predetermined condition.

[0146] If a drive waveform candidate Wci exists whose evaluation value DP1 is less than or equal to the predetermined threshold value Thd, the process proceeds to step S335. If no drive waveform candidate Wci exists whose evaluation value DP1 is less than or equal to the predetermined threshold value Thd, the process proceeds to step S415. In other words, the execution of step S415 and the subsequent step S425 indicates that the drive waveform W has not been selected from the plurality of predetermined drive waveform candidates Wci.

[0147] In step S335, the CPU 62 determines the drive waveform W based on the evaluation value DP1 (see equation (3) above). Specifically, the CPU 62 determines the drive waveform candidate Wci with the smallest DP1 among the drive waveform candidate Wci included in the third selected waveform Ws3 and that meet the conditions of step S325b as the drive waveform W of the drive signal COM applied to the drive element PZT of the ink ejection head 41 of the printers 1a and 1b. The waveform determination unit 624, a functional unit of the CPU 62, performs the processing of steps S325b and S335.

[0148] In step S415, the CPU 62 determines the termination condition. Specifically, the CPU 62 determines whether the number of times the process reaches step S415 after passing step S325b exceeds a predetermined threshold. If the number of times the process reaches step S415 after passing step S325b exceeds the predetermined threshold, the process ends. If the number of times the process reaches step S415 after passing step S325b does not exceed the predetermined threshold, the process proceeds to step S425.

[0149] In step S425, the CPU 62 generates new drive waveform candidates based on the first information Ic1, the second information Ic2, and at least a portion of the predetermined plurality of drive waveform candidates Wci. Specifically, the CPU 62 uses an optimization technique to determine a parameter set defining one or more new drive waveform candidates Wci based on the parameters defining the drive waveform candidates Wci included in the third selected waveform Ws3 and the evaluation values ​​DP1 of these drive waveform candidates Wci. The evaluation value DP1 is information determined based on the first information Ic1 and the second information Ic2 (see equation (3)). The drive waveform candidates Wci included in the third selected waveform Ws3 are at least a portion of the predetermined plurality of drive waveform candidates Wci. Various optimization techniques, such as Bayesian optimization, can be employed.

[0150] Thereafter, the processing of steps S115 to S325 is executed using the parameter group defining these drive waveform candidates Wci. As a result, the first acquisition processing and the second acquisition processing are executed for the new drive waveform candidate Wci (see Figure 12 Then, the driving waveform W is determined based on the first information Ic1 and the second information Ic2 of the new driving waveform candidate Wci and the new driving waveform candidate Wci (see Figure 12 S315~S335).

[0151] By adopting this method, it is possible to determine a more optimal drive waveform W without being limited to the plurality of predetermined drive waveform candidates Wci. Furthermore, in the fifth embodiment, since a new drive waveform candidate Wci is generated based on at least a portion of the plurality of predetermined drive waveform candidates Wci in step S425, the drive waveform W is determined based on the plurality of predetermined drive waveform candidates Wci.

[0152] F. Sixth embodiment:

[0153] Figure 13 This is a flowchart showing a method for determining a driving waveform of a driving signal in the sixth embodiment. The method for determining a driving waveform of a driving signal in the sixth embodiment includes, in part, the methods for determining a driving waveform of a driving signal in the first to fifth embodiments. The hardware structure of the printing system in the sixth embodiment can adopt the hardware structure of the first to fifth embodiments (see Figure 1 、 Figure 6 、 Figure 8 as well as Figure 10 Here, as a hardware configuration of the printing system of the sixth embodiment, the hardware configuration of the first embodiment will be described as an example.

[0154] In step S510, the CPU 62 of the computer 60 displays on the display 64 a prompt to select a method for determining the driving waveform of the driving signal. Specifically, the prompt determines whether it is desired to determine a driving waveform that is unlikely to change the printing quality even if the environmental conditions in which the printer is installed change, or to determine a driving waveform that is optimal for the current environmental conditions in which the printer is installed. The process of determining a driving waveform that is unlikely to change the printing quality even if the environmental conditions in which the printer is installed change is referred to as the "first determination process." The process of determining the driving waveform that is optimal for the current environmental conditions in which the printer is installed is referred to as the "second determination process."

[0155] Then, the CPU 62 receives a selection of either the first decision process or the second decision process via the keyboard 65 and the mouse 66. Figure 1 In FIG. 6 , the functional portion of the CPU 62 that performs the function of step S510 is shown as a “receiving portion 626 ”.

[0156] In step S520, the CPU 62 of the computer 60 determines whether the first determination process is selected. If the first determination process is selected, the process proceeds to step S530. If the second determination process is selected, the process proceeds to step S540.

[0157] In step S530, the CPU 62 of the computer 60 executes Figure 5 The process of the first embodiment shown in FIG. 5 is performed to determine the drive waveform W. The waveform determination unit 624 (see FIG. 5 ) as a functional unit of the CPU 62 realizes the process of step S530. Figure 1 ).

[0158] In step S540, the CPU 62 of the computer 60 executes the Figure 7 The drive waveform W is determined by the processing of steps S112 to S152 of the second embodiment shown in FIG. As a result, the drive waveform W is determined not based on the first information Ic1 related to the environment of the temperature Ta, but based on the second information Ic2 related to the environment of the temperature Tb and a plurality of predetermined drive waveform candidates Wci. The processing of step S540 is implemented by the waveform determination unit 624 (see FIG. 1 ) as a functional unit of the CPU 62. Figure 1 ).

[0159] That is, the CPU 62 executes the decision process selected in step S520 between the first decision process and the second decision process in step S530 or step S540 .

[0160] According to this embodiment, when environmental conditions are unlikely to change, and when determining a waveform that optimizes the assumed environment should be prioritized over responding to changes in environmental conditions, the user can select the second determination process to determine the driving waveform. As a result, a waveform that optimizes the assumed environment is determined.

[0161] In addition to the present embodiment, a method may be adopted in which a relatively large number of Pareto solutions under optimization are presented to the user so that the user can select a balance between the first decision process and the second decision process.

[0162] G. Other implementation methods:

[0163] (1) In the first embodiment described above, the following evaluation value DP1 is calculated as the third information Ic3, which is related to the difference between the ejection characteristics indicated by the first information Ic1 and the ejection characteristics indicated by the second information Ic2 obtained using the same drive waveform candidate (see Figure 5 S321).

[0164] DP1=|Pwb-Pwa|…(3)

[0165] In the fourth embodiment, the third information Ic3 is calculated as the following evaluation value DP4 (see Figure 11 S324).

[0166] DP4=Dwa 2 +Dwb2 +DP 2

[0167] =(Pwt-Pwa) 2 +(Pwt-Pwb) 2 +(Pwb-Pwa) 2 …(4)

[0168] However, the third information Ic3 may also employ an evaluation value determined by another method. For example, the following evaluation value DP7 may be employed as the third information Ic3. Furthermore, let Ta be the value indicated by the first environmental condition, such as temperature; Tb be the value indicated by the second environmental condition, such as temperature; Pa be the value of the discharge characteristic indicated by the first information Ic1; and Pb be the value of the discharge characteristic indicated by the second information Ic2.

[0169] DP7=|Pb-Pa| / |Tb-Ta|…(5)

[0170] By determining the evaluation value DP7 in this manner, it is possible to determine a drive waveform W that minimizes the rate of change in the discharge characteristics when environmental conditions change. Furthermore, because the rate of change is used as the evaluation value DP7 rather than the difference, the drive waveform W determined based on the evaluation value DP7 can cause liquid to be discharged from the head with a certain degree of quality even when the value representing the environmental conditions is not between Ta and Tb.

[0171] In addition, as the third information Ic3, for example, the following evaluation values ​​DP8 and DP9 can also be used.

[0172] DP8=|Pvb-Pva| / |Tb-Ta|…(6)

[0173] DP9={(Pwb-Pwa)^2+(Pvb-Pva)^2}^(1 / 2) / |Tb-Ta|…(7)

[0174] (2) In the above embodiment, the ejection characteristics considered when determining the driving waveform are the ejection amount of liquid ejected from one nozzle of the ink ejection head 41 by the ejection operation of the driving element PZT (see Figure 5 As a result, a driving waveform W is determined in which the amount of liquid ejected from a nozzle by the ejection operation of the driving element PZT is unlikely to change even if environmental conditions change. However, the ejection characteristics considered when determining the driving waveform may be other characteristics.

[0175] For example, the discharge characteristic can be the discharge speed of the liquid discharged from the nozzles of the liquid discharge head. In this way, a driving waveform can be determined that is unlikely to change the discharge speed of the liquid discharged from the nozzles even if the environmental conditions change.

[0176] In such a method, Dva as the first deviation information Id1 is calculated as follows.

[0177] Dva=|Pvt-Pva|…(8)

[0178] Here,

[0179] Pvt is the ideal ejection velocity.

[0180] Pva is the ejection speed when a certain drive waveform candidate Wci is applied to the printer 1 as indicated by the first information Ic1.

[0181] Dvb, which is the second deviation information Id2, is calculated as follows.

[0182] Dvb=|Pvt-Pvb|…(9)

[0183] Here,

[0184] Pvb is the ejection speed when a certain drive waveform candidate Wci is applied to the printer 1 , as indicated by the second information Ic2 .

[0185] The evaluation value DPv serving as the third information Ic3 is calculated as follows.

[0186] DPv=|Pvb-Pva|…(10)

[0187] Furthermore, the ejection characteristics can be defined as the amount of subsidiary drops, or so-called auxiliary dots, ejected from a single nozzle of the ink ejection head 41 by the ejection operation of the driving element PZT. This approach allows the determination of a drive waveform that minimizes the change in the amount of subsidiary drops ejected from the nozzle even when environmental conditions change.

[0188] (3) In the above embodiment, the environmental conditions for measuring the discharge characteristics are defined based on the ambient temperature. Furthermore, the second environmental condition includes the ambient temperature Tb, which is a value different from the temperature Ta of the first environmental condition. As a result, a drive waveform W is determined that is unlikely to change the discharge characteristics even if the ambient temperature changes. However, the environmental conditions for measuring the discharge characteristics can also be defined based on other parameters.

[0189] The environmental conditions for measuring discharge characteristics can be defined based on one or more parameters, including ambient humidity. Furthermore, the second environmental condition can include ambient humidity, which is a different value from the humidity of the first environmental condition. This results in a drive waveform W that is determined such that discharge characteristics are unlikely to change even when the ambient humidity changes. The ambient humidity can be acquired by the humidity sensor 52.

[0190] The environmental conditions for measuring discharge characteristics can be defined based on one or more parameters, including ambient air pressure. Furthermore, the second environmental condition can include an ambient air pressure that is different from the air pressure of the first environmental condition. This results in a drive waveform W that is determined such that even if the ambient air pressure changes, the discharge characteristics are unlikely to change. The ambient air pressure can be obtained by the air pressure sensor 53.

[0191] That is, the environmental condition can be a condition defined by at least one of the environmental temperature, the environmental humidity, and the environmental air pressure.

[0192] (4) In the first embodiment described above, Figure 5 In step S161, the user uses the temperature changing mechanism to change the temperature of the environment in which printer 1 is placed. However, steps S121 to S131b and steps S221 to S231b can also be performed in different environments by performing them at different time periods, such as in the morning and at noon, or before and during factory operations.

[0193] (5) In the fifth embodiment described above, Figure 12 In step S325b, a determination is made as to whether the evaluation value DP1 is below a predetermined threshold value Thd. However, in step S325b, the determination may be based on other conditions. For example, the CPU 62 may display an image of the ink droplet discharge state captured by the CCD camera 55 to the user via the display 64, prompting the user to determine whether the ink droplet discharge state satisfies the requirements. Furthermore, the CPU 62 may receive the determination result via the keyboard 65 and mouse 66.

[0194] (6) In the first embodiment described above, the CPU 62 of the computer 60 controls the printer 1 and determines the drive waveform. However, the printer may also function as the computer in the above embodiments. Furthermore, the printer may be connected to a server without intermediary to the computer 60. Furthermore, a server connected to the printer may also function as the computer in the above embodiments.

[0195] (7) In the fourth embodiment described above, the ejection characteristics were measured using the ink ejection heads 41 of the different printers 1a and 1b (see Figure 10 ,as well as Figure 11 However, the measurement of ejection characteristics may also be performed using different ink ejection heads of one printer.

[0196] (8) In the first embodiment described above, the drive waveform candidate Wci with the smallest DP1 among the drive waveform candidates Wci included in the pre-selected third selected waveform Ws3 is determined as the drive waveform W of the drive signal COM applied to the drive element PZT of the ink ejection head 41. However, for example, the drive waveform W may be determined by setting constraints for the value Dwa of the first deviation information Id1 and the value Dwb of the second deviation information Id2, respectively, and performing a single optimization process with constraints using the evaluation value DP1 as the objective function.

[0197] (9) In the above embodiment, the discharge characteristics are measured under two environmental conditions to determine the drive waveform W of the drive signal COM (see Figure 5 、 Figure 7 、 Figure 9 、 Figure 11 as well as Figure 12 ). However, the discharge characteristics may be measured under three or more environmental conditions to determine the driving waveform of the driving signal.

[0198] (10) In the above embodiment, the liquid ejecting device is a printer that ejects ink. However, the liquid ejecting device may be another device such as a device for manufacturing electronic equipment.

[0199] (11) In the above embodiment, the first deviation information Id1 indicates the difference between the discharge characteristics indicated by the first information Ic1 and the target discharge characteristics, which are ideal discharge characteristics. However, the first deviation information need not be information indicating the difference between the discharge characteristics indicated by the first information and the target discharge characteristics, which are ideal discharge characteristics. In other words, the first deviation information only needs to be information related to the difference between the discharge characteristics indicated by the first information and the target discharge characteristics, which are ideal discharge characteristics.

[0200] (12) In the above embodiment, Figure 9 In step S153, the parameters defining the waveform shape and the ink ejection volume Pwa, which are associated with a combination of information specifying the type of ink ejection head 41, the temperature Ta, and information specifying the drive waveform candidate Wci included in the first selected waveform Ws1, are stored in the memory 73. However, the first information may also be associated with the manufacturing number, individual number, or lot number of the liquid ejection head. In other words, it is sufficient to associate the first information with the liquid ejection head.

[0201] (13) In the above embodiment, in step S331, the driving waveform W is determined based on the first information Ic1, the second information Ic2, and at least a portion of a plurality of predetermined driving waveform candidates Wci (see Figure 5 However, the driving waveform may be determined based on the first information and the second information instead of the plurality of driving waveform candidates.

[0202] (14) In the above embodiment, in step S540 , the driving waveform W is determined not based on the first information Ic1 but based on the second information Ic2 related to the environment of the temperature Tb and a plurality of predetermined driving waveform candidates Wci.

[0203] However, the driving waveform may be determined based on the second information instead of the first information and the plurality of driving waveform candidates.

[0204] H. Another way:

[0205] The present disclosure is not limited to the above-mentioned embodiments, and can be implemented in various ways without departing from its main purpose. For example, the present disclosure can also be implemented in the following ways. In order to solve part or all of the problems of the present disclosure, or to achieve part or all of the effects of the present disclosure, the technical features in the above-mentioned embodiments corresponding to the technical features in the various methods described below can be appropriately replaced or combined. In addition, as long as the technical feature is not described as a necessary technical feature in this specification, it can be appropriately deleted.

[0206] (1) According to one embodiment of the present disclosure, a driving waveform determination method is provided for determining a driving waveform of a driving signal applied to a driving element of a liquid ejection head in order to eject liquid from the liquid ejection head. The method comprises: a first acquisition step of performing a first acquisition process of acquiring first information, wherein the first information is information related to the ejection characteristics of the liquid when the driving element is applied to each of a plurality of driving waveform candidates under a first environmental condition, which is a condition of the environment in which the liquid ejection head is placed; a second acquisition step of performing a second acquisition process of acquiring second information, wherein the second information is information related to the ejection characteristics when each of a plurality of driving waveform candidates is applied to the driving element under a second environmental condition, which is different from the first environmental condition, which is a condition of the environment in which the liquid ejection head is placed; and a waveform determination step of determining the driving waveform based on the first information and the second information.

[0207] According to this method, it is possible to determine a driving waveform in which the discharge characteristics are unlikely to change even when the environmental conditions change.

[0208] (2) The driving waveform determination method of the above-described embodiment may further include a third acquisition step of performing a third acquisition process for acquiring third information for at least a portion of the plurality of driving waveform candidates, wherein the third information is information related to a difference between the ejection characteristics indicated by the first information and the ejection characteristics indicated by the second information, obtained using the same driving waveform candidate, and the waveform determination step is a step of determining the driving waveform based on the third information.

[0209] According to this method, it is possible to determine a driving waveform that minimizes the difference in discharge characteristics when environmental conditions change.

[0210] (3) In the above-described driving waveform determination method, it is also possible to adopt a method such that, when the value of the discharge characteristic indicated by the first information is Pa, the value of the discharge characteristic indicated by the second information is Pb, and the value indicated by the third information is DP,

[0211] DP=|Pb-Pa|.

[0212] According to this embodiment, the driving waveform can be determined in consideration of the difference in discharge characteristics when the environmental conditions change.

[0213] (4) In the above-described driving waveform determination method, it is also possible to adopt a method such that, when the value indicated by the first environmental condition is Ta, the value indicated by the second environmental condition is Tb, the value of the ejection characteristic indicated by the first information is Pa, the value of the ejection characteristic indicated by the second information is Pb, and the value indicated by the third information is DP,

[0214] DP=|Pb-Pa| / |Tb-Ta|.

[0215] According to this configuration, the drive waveform W can be determined in consideration of the rate of change in discharge characteristics when environmental conditions change.

[0216] (5) In the driving waveform determination method of the above-mentioned embodiment, it can also be set as follows, that is, the waveform determination process is a process of preferentially determining as the driving waveform a driving waveform candidate having a smaller difference between the ejection characteristics indicated by the first information and the ejection characteristics indicated by the second information based on the third information.

[0217] According to this method, it is possible to determine a driving waveform in which the discharge characteristics are unlikely to change even when the environmental conditions change.

[0218] (6) In the driving waveform determination method of the above-mentioned embodiment, it is also possible to configure the method as follows, namely, including a fourth acquisition step of executing a fourth acquisition process for each of the plurality of driving waveform candidates, wherein the fourth acquisition process acquires first deviation information related to a difference between the ejection characteristic indicated by the first information and a target ejection characteristic serving as an ideal ejection characteristic, and acquires second deviation information related to a difference between the ejection characteristic indicated by the second information and the target ejection characteristic, wherein the waveform determination step is a step of determining the driving waveform based on the first deviation information and the second deviation information.

[0219] By adopting this approach, the drive waveform can be determined by taking into account the following aspects in addition to the difference between the discharge characteristics under the first environmental condition and the discharge characteristics under the second environmental condition, as indicated by the third information. Specifically, the drive waveform can be determined by taking into account the difference between the discharge characteristics under the first environmental condition, as indicated by the first deviation information, and the difference between the discharge characteristics under the second environmental condition, as indicated by the second deviation information. This reduces the likelihood of determining a drive waveform candidate for which, while the difference between the discharge characteristics under the first environmental condition and the discharge characteristics under the second environmental condition is small, both the discharge characteristics under the first environmental condition and the discharge characteristics under the second environmental condition deviate significantly from the ideal discharge characteristics.

[0220] (7) In the above-described driving waveform determination method, it is also possible to adopt a method such that, when the value of the discharge characteristic indicated by the first information is Pa, the value of the discharge characteristic indicated by the second information is Pb, the value of the target discharge characteristic is Pt, the value indicated by the first deviation information is Da, and the value indicated by the second deviation information is Db,

[0221] Da=|Pt-Pa|

[0222] Db=|Pt-Pb|.

[0223] (8) In the driving waveform determination method of the above-mentioned manner, the following manner can also be adopted, that is, the waveform determination process is a process of preferentially determining as the driving waveform a driving waveform candidate in which the difference between the ejection characteristic indicated by the first information and the target ejection characteristic is smaller, and the difference between the ejection characteristic indicated by the second information and the target ejection characteristic is smaller, based on the first deviation information and the second deviation information.

[0224] (9) In the driving waveform determination method of the above-mentioned embodiment, the following embodiment can also be adopted, that is, the waveform determination process is a process of preferentially determining as the driving waveform a driving waveform candidate in which the ejection characteristics indicated by the first information satisfy a first condition and the ejection characteristics indicated by the second information satisfy a second condition.

[0225] According to this embodiment, there is a higher possibility that conditions can be added to the discharge characteristics under the first environmental condition and the discharge characteristics under the second environmental condition, and a drive waveform candidate satisfying these conditions can be determined as the drive waveform.

[0226] (10) In the above-described driving waveform determination method, the discharge characteristic may be a discharge amount of liquid discharged from one nozzle of the liquid discharge head by the discharge operation of the driving element.

[0227] According to this embodiment, it is possible to determine a driving waveform that is unlikely to change the discharge amount of liquid discharged from one nozzle by the discharge operation of the driving element even if environmental conditions change.

[0228] (11) In the above-described driving waveform determination method, it is also possible to adopt an embodiment in which the discharge characteristic is a discharge speed of the liquid discharged from a nozzle of the liquid discharge head.

[0229] According to this method, it is possible to determine a driving waveform that is unlikely to change the discharge speed of the liquid discharged from the nozzle even if the environmental conditions change.

[0230] (12) In the driving waveform determination method of the above-mentioned method, the following method can also be adopted, that is, the first acquisition processing includes a process of acquiring the first information by reading the first information stored in the server in a manner that establishes a correspondence between the liquid ejection head and the first environmental condition, and the second acquisition processing includes a process of acquiring the second information by applying a driving waveform candidate to a driving element possessed by another liquid ejection head different from the liquid ejection head under the second environmental condition and measuring the ejection characteristics of the ejected liquid.

[0231] According to this method, the first information indicating the discharge characteristics of the liquid can be obtained without using the liquid discharge head to discharge the liquid. Therefore, the driving waveform can be easily determined from a plurality of driving waveform candidates.

[0232] (13) In the driving waveform determination method of the above-mentioned method, the following method can also be adopted, that is, the first acquisition processing includes a process of obtaining the first information by applying a driving waveform candidate to the driving element under the first environmental condition and measuring the ejection characteristics of the liquid ejected from the liquid ejection head, and the second acquisition processing includes a process of obtaining the second information by applying a driving waveform candidate to the driving element under the second environmental condition and measuring the ejection characteristics of the liquid ejected from the liquid ejection head.

[0233] In this manner, the ejection characteristics under the first environmental condition and the ejection characteristics under the second environmental condition are measured using a driving element to which a driving signal having a determined driving waveform is applied. Thus, a driving waveform suitable for the driving element to which a driving signal having the determined driving waveform is applied is determined.

[0234] (14) In the driving waveform determination method of the above-mentioned method, the following method can also be adopted, that is, the first acquisition processing includes a process of obtaining the first information by applying a driving waveform candidate to the driving element under the first environmental condition and measuring the ejection characteristics of the liquid ejected from the liquid ejection head, and the second acquisition processing includes a process of obtaining the second information by applying a driving waveform candidate to the driving element of other liquid ejection heads different from the liquid ejection head under the second environmental condition and measuring the ejection characteristics of the liquid ejected from the other liquid ejection heads.

[0235] In this manner, the discharge characteristics under the first environmental condition and the discharge characteristics under the second environmental condition can be measured in parallel, thereby enabling the first information and the second information to be acquired in a short time.

[0236] (15) In the driving waveform determination method of the above-described embodiment, a method may be further adopted, including a step executed when the driving waveform is not selected from the plurality of driving waveform candidates, in which a new driving waveform candidate is generated based on the first information, the second information, and at least a portion of the plurality of driving waveform candidates, the first acquisition process and the second acquisition process are executed for the new driving waveform candidate, and the driving waveform is determined based on the first information and the second information of the new driving waveform candidate and the new driving waveform candidate.

[0237] According to this method, the driving waveform can be determined without being limited to a plurality of driving waveform candidates.

[0238] (16) In the driving waveform determination method of the above aspect, the first environmental condition may include a temperature of the environment, and the second environmental condition may include a temperature of the environment that is a value different from the temperature of the first environmental condition.

[0239] According to this method, it is possible to determine a driving waveform in which the discharge characteristics are unlikely to change even if the ambient temperature changes.

[0240] (17) In the driving waveform determination method of the above aspect, the first environmental condition may include humidity of the environment, and the second environmental condition may include humidity of the environment that is a value different from the humidity of the first environmental condition.

[0241] According to this method, it is possible to determine a driving waveform in which the discharge characteristics are unlikely to change even if the humidity of the environment changes.

[0242] (18) In the above-described driving waveform determination method, the first environmental condition may include the atmospheric pressure of the environment, and the second environmental condition may include the atmospheric pressure of the environment having a value different from the atmospheric pressure of the first environmental condition.

[0243] According to this method, it is possible to determine a driving waveform that is unlikely to change the discharge characteristics even if the ambient air pressure changes.

[0244] (19) According to another aspect of the present disclosure, there is provided a computer program for causing a computer to execute the drive waveform determination method of any one of Application Examples 1 to 18.

[0245] (20) According to another embodiment of the present disclosure, a liquid ejection device is provided. The liquid ejection device comprises: a liquid ejection head having a driving element driven by a driving signal, and ejecting liquid by the driving of the driving element; a drive control unit that controls the liquid ejection head; a first characteristic acquisition unit that can perform a first acquisition process for acquiring first information, wherein the first information is information indicating the ejection characteristics of the liquid when each of a plurality of driving waveform candidates is applied to the driving element under a first environmental condition, which is a condition of the environment in which the liquid ejection head is placed; a second characteristic acquisition unit that can perform a second acquisition process for acquiring second information, wherein the second information is information indicating the ejection characteristics of each of the plurality of driving waveform candidates when the driving element is applied under a second environmental condition, which is different from the first environmental condition, which is a condition of the environment in which the liquid ejection head is placed; and a waveform determination unit that can perform a first determination process for determining a driving waveform of a driving signal applied to the driving element based on the first information and the second information.

[0246] (21) In the liquid ejection device of the above-mentioned method, the following method can also be adopted, that is, the waveform determination unit can execute a second determination process that determines the driving waveform based on the second information rather than the first information, and the liquid ejection device includes a receiving unit that receives a selection of either the first determination process or the second determination process, and the waveform determination unit executes the selected determination process between the first determination process and the second determination process.

[0247] With this approach, when environmental conditions are unlikely to change, or when determining a waveform that optimizes the assumed environment is prioritized over responding to changes in environmental conditions, the user can select the second determination process and cause the drive waveform determination device to execute it. As a result, a waveform that optimizes the assumed environment is determined.

[0248] The present disclosure can also be implemented in various forms other than a drive waveform determination method, a liquid ejection device, and a computer program. For example, it can be implemented in forms such as a drive waveform determination device, a drive waveform determination auxiliary device, a control method for these devices, a computer program that implements the control method, and a non-transitory recording medium that records the computer program. Furthermore, although the various embodiments describe a printer 1, a printer need not be used as the liquid ejection device. Instead, a so-called experimental device or evaluation device can be used as long as it has the function of ejecting liquid.

[0249] Explanation of symbols

[0250] 1…Printer; 1a…Printer; 1b…Printer; 10…Controller; 11…Interface; 12…CPU; 13…Memory; 14…Unit control circuit; 15…Drive signal generation circuit; 20…Conveyor unit; 30…Carriage unit; 31…Carriage; 40…Head unit; 41…Ink ejection head; 50…Detector group; 51…Temperature sensor; 52…Humidity sensor; 53…Air pressure sensor; 55…CCD camera; 60…Computer; 60a…Computer; 60b… Computer; 61…Interface; 62…CPU; 63…Memory; 64…Display; 65…Keyboard; 66…Mouse; 70…Server; 71…Interface; 72…CPU; 73…Memory; 132…Head ID; 411…Casing; 412…Flow path unit; 412a…Flow path forming plate; 412b…Elastic plate; 412c…Nozzle plate; 412d…Pressure chamber; 412e…Nozzle communication port; 412f…Common ink chamber; 412g…Ink supply channel; 412h ...island portion; 412i...elastic membrane; 622a...first characteristic acquisition portion; 622b...second characteristic acquisition portion; 624...waveform determination portion; 626...receiving portion; 631...waveform parameter; Dm...main scanning direction; Ds...sub-scanning direction; HC...head control portion; Ic1...first information; Ic1s...first information; Ic2...second information; Ic3...third information; Id1...first deviation information; Id2...second deviation information; Nz...nozzle; PM...printing medium; PZT...driving element Component; Pwc1…first expansion time; Pwc2…second expansion time; Pwd1…contraction time; Pwh1…first holding time; Pwh2…second holding time; S1…first expansion element; S2…first holding element; S3…contraction element; S4…second holding element; S5…second expansion element; Vc…intermediate potential; Vh…highest potential; Vl…lowest potential; W…driving waveform; Ws1…first selection waveform; Ws2…second selection waveform; Ws3…third selection waveform.

Claims

1. A driving waveform determination method for determining a driving waveform of a driving signal applied to a driving element of a liquid ejection head in order to eject liquid from the liquid ejection head, the driving waveform determination method comprising: a first acquisition step of performing a first acquisition process for acquiring first information related to liquid ejection characteristics when a driving element is applied to each of a plurality of driving waveform candidates under a first environmental condition, which is an environmental condition in which the liquid ejection head is placed; a second acquisition step of performing a second acquisition process for acquiring second information related to the ejection characteristics when each of a plurality of drive waveform candidates is applied to a drive element under a second environmental condition different from the first environmental condition, which is the environmental condition in which the liquid ejection head is placed; The waveform determination step determines the driving waveform based on the first information and the second information.

2. The driving waveform determination method according to claim 1, wherein: The method further includes a third acquisition step of performing a third acquisition process for acquiring third information on at least a portion of the plurality of drive waveform candidates, the third information being information related to a difference between the ejection characteristics indicated by the first information and the ejection characteristics indicated by the second information, obtained using the same drive waveform candidate. The waveform determination step is a step of determining the driving waveform based on the third information.

3. The driving waveform determination method according to claim 2, wherein: When the value of the discharge characteristic indicated by the first information is Pa, the value of the discharge characteristic indicated by the second information is Pb, and the value indicated by the third information is DP, DP=|Pb-Pa|.

4. The driving waveform determination method according to claim 2, wherein: When the value indicated by the first environmental condition is Ta, the value indicated by the second environmental condition is Tb, the value of the ejection characteristic indicated by the first information is Pa, the value of the ejection characteristic indicated by the second information is Pb, and the value indicated by the third information is DP, DP=|Pb-Pa| / |Tb-Ta|.

5. The driving waveform determination method according to any one of claims 2 to 4, wherein: The waveform determination step is a step of preferentially determining, as the drive waveform, a drive waveform candidate having a smaller difference between the discharge characteristics indicated by the first information and the discharge characteristics indicated by the second information based on the third information.

6. The driving waveform determination method according to claim 1, wherein: a fourth acquisition step of executing a fourth acquisition process for each of the plurality of drive waveform candidates, the fourth acquisition process acquiring first deviation information related to a difference between the discharge characteristic indicated by the first information and a target discharge characteristic serving as the ideal discharge characteristic, and acquiring second deviation information related to a difference between the discharge characteristic indicated by the second information and the target discharge characteristic, The waveform determination step is a step of determining the driving waveform based on the first deviation information and the second deviation information.

7. The driving waveform determination method according to claim 6, wherein: When the value of the discharge characteristic indicated by the first information is Pa, the value of the discharge characteristic indicated by the second information is Pb, the value of the target discharge characteristic is Pt, the value indicated by the first deviation information is Da, and the value indicated by the second deviation information is Db, Da=|Pt-Pa| Db=|Pt-Pb|.

8. The driving waveform determination method according to claim 6 or 7, wherein: The waveform determination step is a step of preferentially determining, as the driving waveform, a driving waveform candidate having a smaller difference between the discharge characteristic indicated by the first information and the target discharge characteristic and a smaller difference between the discharge characteristic indicated by the second information and the target discharge characteristic based on the first deviation information and the second deviation information.

9. The driving waveform determination method according to any one of claims 1, wherein: The waveform determination step is a step of preferentially determining, as the drive waveform, a driving waveform candidate in which the discharge characteristics indicated by the first information satisfy a first condition and the discharge characteristics indicated by the second information satisfy a second condition.

10. The driving waveform determination method according to claim 1, wherein: The discharge characteristic is a discharge amount of liquid discharged from one nozzle of the liquid discharge head by the discharge operation of the driving element.

11. The driving waveform determination method according to claim 1, wherein: The discharge characteristic is a discharge speed of liquid discharged from a nozzle included in the liquid discharge head.

12. The driving waveform determination method according to claim 1, wherein: The first acquisition process includes a process of acquiring the first information by reading the first information stored in the server in a manner corresponding to the liquid ejection head and the first environmental condition. The second acquisition process includes acquiring the second information by applying a drive waveform candidate to a drive element of a liquid ejection head different from the liquid ejection head under the second environmental condition and measuring ejection characteristics of the ejected liquid.

13. The driving waveform determination method according to claim 1, wherein: The first acquisition process includes acquiring the first information by applying a drive waveform candidate to the drive element under the first environmental condition and measuring the discharge characteristics of the liquid discharged from the liquid discharge head. The second acquisition process includes a process of acquiring the second information by applying a drive waveform candidate to the drive element under the second environmental condition and measuring the discharge characteristics of the liquid discharged from the liquid discharge head.

14. The driving waveform determination method according to claim 1, wherein: The first acquisition process includes acquiring the first information by applying a drive waveform candidate to the drive element under the first environmental condition and measuring the discharge characteristics of the liquid discharged from the liquid discharge head. The second acquisition process includes acquiring the second information by applying a drive waveform candidate to a drive element of another liquid ejection head different from the liquid ejection head under the second environmental condition and measuring ejection characteristics of liquid ejected from the other liquid ejection head.

15. The driving waveform determination method according to claim 1, wherein: The method includes a step performed when the driving waveform is not selected from the plurality of driving waveform candidates, wherein: generating a new driving waveform candidate based on the first information, the second information, and at least a portion of the plurality of driving waveform candidates; executing the first acquisition process and the second acquisition process for the new drive waveform candidate, The driving waveform is determined based on the first information and the second information of the new driving waveform candidate and the new driving waveform candidate.

16. The driving waveform determination method according to claim 1, wherein: The first environmental condition includes the temperature of the environment, The second environmental condition includes the temperature of the environment as a value different from the temperature of the first environmental condition.

17. The driving waveform determination method according to claim 1, wherein: The first environmental condition includes the humidity of the environment, The second environmental condition includes humidity of the environment as a value different from the humidity of the first environmental condition. 18 . A recording medium storing a computer program for causing a computer to execute the drive waveform determination method according to claim 1 .

19. A liquid ejection device comprising: a liquid ejection head including a driving element driven by application of a driving signal, and ejecting liquid by the driving of the driving element; a drive control unit for controlling the liquid ejection head; a first characteristic acquisition unit capable of executing a first acquisition process for acquiring first information indicating a liquid ejection characteristic when each of a plurality of drive waveform candidates is applied to the drive element under a first environmental condition, which is an environmental condition in which the liquid ejection head is placed; a second characteristic acquisition unit capable of executing a second acquisition process for acquiring second information indicating the discharge characteristic when each of the plurality of drive waveform candidates is applied to a drive element under a second environmental condition different from the first environmental condition, which is the condition of the environment in which the liquid discharge head is placed; The waveform determination unit is configured to execute a first determination process for determining a drive waveform of a drive signal applied to the drive element based on the first information and the second information.

20. The liquid ejecting device according to claim 19, wherein The waveform determination unit is capable of executing a second determination process for determining the drive waveform based on the second information instead of the first information. The liquid ejecting device includes a receiving unit configured to receive a selection of either the first determination process or the second determination process. The waveform determination unit executes a selected determination process between the first determination process and the second determination process.

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