LIQUID SELECTION METHOD, LIQUID EJECTION DEVICE, AND COMPUTER PROGRAM

Abstract

To specify ink that realizes discharge characteristics desired for a printer head used by a user.SOLUTION: A liquid selection method includes: an acquisition step of executing a first acquisition process for a plurality of first liquid candidates respectively, wherein the first acquisition process is a process for acquiring first information expressing a first discharge characteristic for liquid to be discharged from a liquid discharge head when a drive waveform is applied to a drive element of the liquid discharge head; and a liquid selection step of selecting one or more liquids to be discharged from the liquid discharge head, on the basis of the first information and at least a part of the plurality of first liquid candidates.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present disclosure relates to a liquid selection method, a liquid ejection device, and a computer program. [Background technology]

[0002] Conventionally, there is a method for determining parameters that define the waveform of a drive signal based on the results obtained by ejecting ink droplets and measuring the ejection characteristics in an inkjet printer. In the technology of Patent Document 1, a plurality of drive signals having different values ​​of parameters that define the drive waveform are prepared. Then, ink droplets are ejected simultaneously from a plurality of nozzles using one of the plurality of drive signals. The simultaneous ejection of ink droplets using one drive signal is performed for a plurality of nozzles of different numbers. Such processing is performed for each drive signal. Then, the parameter of the drive signal that causes the smallest deviation in the ejection speed of ink droplets when ink droplets are ejected simultaneously from different numbers of nozzles is adopted as the parameter of the drive signal that is actually used for printing. As a result, in printing, ink droplets are stably ejected from each nozzle regardless of the number of nozzles that eject ink droplets simultaneously. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2010-131910 A Summary of the Invention [Problem to be solved by the invention]

[0004] A user may select ink for reproducing a certain color from inks of multiple manufacturers and apply it to a printer. Also, a single manufacturer may provide inks of similar colors that are mutually replaceable. The inks may have different properties such as viscosity and surface tension. When the properties such as viscosity and surface tension are different, even if a drive signal that has been confirmed to achieve desirable ejection characteristics for another ink is applied, desirable ejection characteristics, such as the ejection volume, ejection speed, and amount of sub-droplets, may not necessarily be achieved. For this reason, a technology is desired that can identify an ink that achieves desirable ejection characteristics for the head of a printer used by a user. [Means for solving the problem]

[0005] According to one aspect of the present disclosure, there is provided a liquid selection method for selecting a liquid to be ejected from a liquid ejection head, the liquid selection method including: an acquisition step of executing a first acquisition process for acquiring, for each of a plurality of first liquid candidates, first information relating to a first ejection characteristic of the liquid when a drive waveform is applied to a drive element of the liquid ejection head; and a liquid selection step of selecting one or more of the liquids to be ejected from the liquid ejection head based on the first information and at least a portion of the plurality of first liquid candidates. [Brief description of the drawings]

[0006] [Figure 1] FIG. 1 is a block diagram showing the configurations of a printer 1 and a computer 60 included in a printing system according to a first embodiment. [Diagram 2] FIG. 2 is a perspective view showing part of the configuration of the printer 1. [Diagram 3] 2 is a cross-sectional view of the ink ejection head 41 taken along a cross section perpendicular to the sub-scanning direction Ds. [Figure 4] 13 is a diagram showing a drive waveform W of a drive signal COM. FIG. [Diagram 5] 10 is a flowchart showing a method for determining the ink to be applied to the printer 1. [Figure 6]10 is a flowchart showing a method for determining the ink to be applied to the printer 1 in the second embodiment. [Figure 7] 13 is a flowchart showing a method for determining the ink to be applied to the printer 1 in the third embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0007] A. First embodiment: A1. Printing system configuration: 1 is a block diagram showing the configurations of a printer 1 and a computer 60 included in the printing system of the first embodiment. The printing system includes the printer 1 and a computer 60.

[0008] The printer 1 drives drive 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.

[0009] 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.

[0010] The interface unit 11 transmits and receives data between the printer 1 and the computer 60. The CPU 12 is an arithmetic processing unit for controlling the entire printer 1. The memory 13 includes an auxiliary memory that stores computer programs executed by the CPU 12, and a main memory that functions as a work area. As a processor, the CPU 12 realizes various functions by loading programs stored in the auxiliary memory into the main memory and executing them. The main memory is preferably a non-volatile memory, but may be a volatile memory. Either non-volatile or volatile memory can be suitably used as the auxiliary memory.

[0011] The unit control circuit 14 controls each unit of the printer 1 in response to instructions from the CPU 12. The unit control circuit 14 includes multiple drive signal generation circuits 15. The drive signal generation circuits 15 generate drive signals COM that include multiple drive waveforms W that are generated at regular intervals. To facilitate understanding of the technology, FIG. 1 shows the drive signal generation circuit 15 as a single component.

[0012] The transport unit 20 transports the printing medium PM to a position where printing is possible, and transports the printing medium PM by a transport amount of a predetermined pattern during printing. The carriage unit 30 moves the ink ejection head 41 and ink cartridges attached to the carriage 31 in a direction intersecting the transport direction of the printing medium PM. In this specification, the movement direction of the ink ejection head 41 is referred to as the "main scanning direction Dm," and the transport direction of the printing medium PM is referred to as the "sub-scanning direction Ds."

[0013] The head unit 40 ejects ink supplied from an ink cartridge onto a print medium PM. The head unit 40 includes an ink ejection head 41 and a head controller HC. A plurality of nozzles Nz are provided on the bottom 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 application of a driving signal COM. The ink ejection head 41 ejects ink droplets from the nozzle Nz by driving the driving element PZT. Note that in this embodiment, a piezoelectric element made of lead zirconate titanate is used as the driving element PZT, but it may be a piezoelectric element made of a material other than lead zirconate titanate, or it may be a heating element.

[0014] The head controller 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 based on the print data. When the drive waveform W is applied to the drive element PZT corresponding to a certain nozzle Nz, an amount of ink corresponding to the drive waveform W is ejected from that nozzle Nz, forming a dot on the printing medium PM. On the other hand, if the drive waveform W is not applied to the drive element PZT corresponding to a certain nozzle Nz, no ink droplets are ejected from that nozzle Nz.

[0015] 2 is a perspective view showing part of the configuration of the printer 1. The printer 1 can perform a dot formation process in which ink droplets are intermittently ejected from an ink ejection head 41 that moves along a main scanning direction Dm to form dots on the printing medium PM. The printer 1 can perform a transport process in which the printing medium PM is transported in a sub-scanning direction Ds. The printer 1 alternately repeats the dot formation process and the transport process to form dots at each position on the printing medium PM and form an image.

[0016] The detector group 50 monitors the situation inside the printer 1 (see the lower part of FIG. 1). In response to output signals from the detector group 50, the controller 10 controls each part that constitutes the printer 1. The detector group 50 includes a CCD camera 55.

[0017] The CCD camera 55 acquires an image of ink droplets ejected from the ink ejection head 41, and outputs the image data to the CPU 12. The CCD camera 55 can capture still images and moving images. In this specification, the term "image" includes still images and moving images.

[0018] The CCD camera 55 is used for photographing to obtain information representing the discharge characteristics as described below, but any part capable of obtaining information representing the 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 representing the discharge characteristics such as the discharge amount.

[0019] The computer 60 transmits print data to the printer 1. The computer 60 transmits parameters that represent a drive waveform W of a drive signal for a 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.

[0020] The display 64 outputs images under the control of the CPU 62. The keyboard 65 and mouse 66 are operated by the user to input user instructions to the CPU 62.

[0021] The interface unit 61 transmits and receives data between the computer 60 and the printer 1. The memory 63 includes an auxiliary memory that stores computer programs executed by the CPU 62, and a main memory that functions as a work area. The CPU 62 as a processor realizes various functions by loading programs stored in the auxiliary memory into the main memory and executing them.

[0022] For example, the CPU 62 realizes a function of acquiring information that indicates the ejection characteristics, which are the characteristics of the ink ejection from the ink ejection head 41. More specifically, the CPU 62 can acquire the ejection amount of ink ejected from one nozzle Nz by the ejection operation of the drive element PZT, the ejection speed of the ink ejected from the nozzle Nz, and the total amount of sub-droplets of ink ejected from one nozzle Nz by the ejection operation of the drive element PZT, based on an image of an ink droplet acquired by the CCD camera 55 of the printer 1. The CPU 62 also realizes a function of selecting the ink to be ejected from the ink ejection head 41.

[0023] 3 is a cross-sectional view of the ink ejection head 41 taken along a cross section perpendicular to the sub-scanning direction Ds. The ink ejection head 41 has a case 411, a flow passage unit 412, and a plurality of driving elements PZT. The case 411 houses the plurality of driving elements PZT. The flow passage unit 412 is joined to the lower surface of the case 411.

[0024] The flow passage unit 412 includes a flow passage forming plate 412a, an elastic plate 412b, and a nozzle plate 412c.

[0025] The flow path forming plate 412a has a groove portion 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 portion that functions as an ink supply path 412g. One common ink chamber 412f is provided for a plurality of nozzles Nz included in one nozzle row. One nozzle Nz is provided with a combination of a set of ink supply path 412g, a pressure chamber 412d, and a nozzle communication port 412e. In the ink ejection head 41, ink is supplied to the pressure chamber 412d via the common ink chamber 412f and the ink supply path 412g. The ink in the pressure chamber 412d is ejected from the nozzle Nz via the nozzle communication port 412e.

[0026] The elastic plate 412b has an island portion 412h to which the tip of the driving element PZT is joined. An elastic region is formed around the island portion 412h by an elastic film 412i.

[0027] The nozzle plate 412c is a plate in which a plurality of nozzles Nz are formed. A yellow nozzle row for ejecting yellow ink, a magenta nozzle row for ejecting magenta ink, a cyan nozzle row for ejecting cyan ink, and a black nozzle row for ejecting black ink are formed on one surface of the nozzle plate 412c, that is, the nozzle Nz surface. Each nozzle row is composed of 180 nozzles Nz arranged at a predetermined interval in the sub-scanning direction Ds. Each nozzle row is arranged in the main scanning direction Dm. FIG. 3 is a cross-sectional view of a section perpendicular to the sub-scanning direction Ds. In the unit control circuit 14, one drive signal generating circuit 15 is provided for each nozzle row.

[0028] The driving elements PZT are configured as comb-shaped elements. A driving signal COM is applied to the driving elements PZT by a wiring board on which the head controller HC is mounted. The driving elements PZT expand and contract in response to the potential of the driving signal COM. When the driving element PZT contracts, the island portion 412h deforms toward the driving element PZT. When the driving element PZT expands, the island portion 412h deforms toward the pressure chamber 412d. As a result, the pressure in the pressure chamber 412d changes, and ink droplets are ejected from the nozzle Nz. One driving signal generating circuit 15 is provided for one nozzle row. Therefore, the driving signal COM generated by a certain driving signal generating circuit 15 is commonly applied to the driving elements PZT of all the nozzles Nz belonging to the nozzle row corresponding to that driving signal generating circuit 15. However, whether or not the driving waveform W of the driving signal COM is applied to each driving element PZT is determined by the head controller HC.

[0029] Fig. 4 is a diagram showing a drive waveform W of the drive signal COM. In the drive signal COM, the drive waveform W shown in Fig. 4 is repeatedly generated at a constant cycle. The drive waveform W has a first expansion element S1 whose potential rises from an intermediate potential Vc to a maximum potential Vh, a first hold element S2 that holds the maximum potential Vh, a contraction element S3 whose potential falls from the maximum potential Vh to a minimum potential Vl, a second hold element S4 that holds the minimum potential Vl, and a second expansion element S5 whose potential rises from the minimum potential Vl to the intermediate potential Vc.

[0030] In a state where 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 the "reference volume."

[0031] When the first expansion element S1 of the drive signal COM is applied to the drive element PZT from a state in which the intermediate potential Vc is applied to the drive element PZT, the drive element PZT contracts in the longitudinal direction. As a result, the volume of the pressure chamber 412d increases (see FIG. 3). When the first hold 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 expands from the contracted state. As a result, the volume of the pressure chamber 412d decreases. The ink pressure in the pressure chamber 412d increases, and an ink droplet is ejected from the nozzle Nz. After that, the second hold element S4 of the drive signal COM is applied to the drive element PZT, and the expanded state of the drive element PZT and the contracted state of the pressure chamber 412d are maintained. When the second expansion component S5 is applied to the driving element PZT, the volume of the pressure chamber 412d returns to the reference volume.

[0032] The time when the first expansion element S1 occurs is called the "first expansion time Pwc1." The time when the first hold element S2 occurs is called the "first hold time Pwh1." The time when the contraction element S3 occurs is called the "contraction time Pwd1." The time when the second hold element S4 occurs is called the "second hold time Pwh2." The time when the second expansion element S5 occurs is called the "second expansion time Pwc2." The first expansion time Pwc1, the first hold time Pwh1, the contraction time Pwd1, the second hold time Pwh2, and the second expansion time Pwc2 are parameters that define the shape of the drive waveform W of the drive signal COM.

[0033] A2.Determining the liquid: Fig. 5 is a flowchart showing a method for determining the ink to be applied to the printer 1. The processing of the ink determination method in Fig. 5 is executed mainly by the CPU 62 of the computer 60 controlling each part of the computer 60 and the printer 1 in response to instructions input by the user. The liquid to be supplied to the printer 1 and ejected from the ink ejection head 41 is determined by the processing shown in Fig. 5.

[0034] In step S11, the user selects one ink candidate from a plurality of ink candidates Lci prepared in advance. The ink candidates Lci are inks that can be supplied to the ink ejection head 41 and ejected from the nozzles Nz, and are mutually substitutable inks. In this embodiment, the ink candidates Lci prepared in advance are inks for evaluation. For example, the ink candidates Lci are inks provided as "cyan ink" by a plurality of different manufacturers.

[0035] In step S12, the user attaches the selected ink cartridge to the carriage 31 and fills the nozzles Nz of the ink ejection head 41. Specifically, the user operates the keyboard 65 and mouse 66 to cause the printer 1 to perform an ink filling process via the computer 60. Note that if the printer 1 is equipped with input devices such as buttons or a touch panel, the user may operate the input devices to cause the printer 1 to perform an ink filling process.

[0036] In step S15, the CPU 62 of the computer 60 instructs the CPU 12 of the printer 1 to execute the following process. The CPU 12 controls the unit control circuit 14 to cause the drive signal generation circuit 15 to generate a drive signal COM. The CPU 12 then applies the drive signal COM to the drive element PZT of the ink ejection head 41. As a result, ink droplets of the ink candidate Lci are ejected from the nozzle Nz.

[0037] In step S16, the CPU 12 causes the CCD camera 55 to capture an image of the ink droplets ejected from the nozzles Nz in response to the drive signal COM. The CPU 12 sends the image data to the computer 60. In step S15, the CPU 62 of the computer 60 instructs the CPU 12 of the printer 1 to execute the above processes of steps S15 and S16.

[0038] The CPU 62 calculates the ejection amount Pwm of the ink candidate Lci ejected from one nozzle Nz of the ink ejection head 41 by the ejection operation of the drive element PZT based on the image data. The ejection amount of ink is determined by mass. Since the mass is based on the volume and ink density, the ejection amount of ink may be determined by the volume. The CPU 62 stores information representing the ejection amount of the ink candidate Lci in the memory 63 in association with information identifying the ink candidate Lci. This information representing the ejection amount is referred to as "first information Ii1" (see the upper right part of FIG. 1). Note that the ejection amount Pwm of the ink candidate Lci may be the ejection amount ejected from one nozzle Nz by one ejection operation of the drive element PZT.

[0039] The CPU 62 calculates the ejection speed Pvm of the ink ejected from the ink ejection head 41 based on the image data. The ink ejection speed is one aspect of the "ejection characteristics." The CPU 62 stores information representing the ejection speed for the ink candidate Lci in the memory 63 in association with information specifying the ink candidate Lci. This information representing the ejection speed is called "second information Ii2" (see the upper right part of FIG. 1).

[0040] Based on the image data, the CPU 62 calculates the total amount Psm of sub-droplets of the ink candidate Lci ejected from one nozzle Nz of the ink ejection head 41 by the ejection operation of the drive element PZT. The total amount of sub-droplets is determined by the number of sub-droplets. In this specification, the total amount of sub-droplets is referred to as the "sub-droplet amount." The sub-droplet amount is one aspect of the "ejection characteristics." The CPU 62 stores information representing the sub-droplet amount for the ink candidate Lci in the memory 63 in association with information identifying the ink candidate Lci. This information representing the ejection amount is referred to as the "third information Ii3" (see the upper right part of FIG. 1).

[0041] The first information Ii1 to the third information Ii3 represent the ejection characteristics of the ink candidate Lci ejected from the head unit 40 when a certain drive waveform W is applied to the drive element PZT. The process of acquiring the first information Ii1, which is executed in steps S15 and S16, is referred to herein as the "first acquisition process." The process of acquiring the second information Ii2, which is executed in steps S15 and S16, is referred to herein as the "second acquisition process." The process of acquiring the third information Ii3, which is executed in steps S15 and S16, is referred to herein as the "third acquisition process."

[0042] The functional section of the CPU 62 that executes the processes of steps S15 and S16 is shown in FIG. 1 as a characteristic acquisition section 622 (see the upper center section of FIG. 1).

[0043] 5, the CPU 62 determines whether or not the processing of steps S15 and S16 has been performed for all ink candidates Lci for which the ejection characteristics are to be measured, in other words, for a plurality of ink candidates Lci prepared in advance. If the processing of steps S15 and S16 has been performed for all ink candidates Lci for which the ejection characteristics are to be measured, the process proceeds to step S30. If the processing of steps S15 and S16 has not been performed for all ink candidates Lci for which the ejection characteristics are to be measured, the process returns to step S11. In step S11, one ink candidate Lci for which the processing of step S16 has not yet been performed is selected from the plurality of ink candidates Lci prepared in advance, and then the processing of steps S12 and onward is performed.

[0044] In step S30, the CPU 62 selects ink to be ejected from the ink ejection head 41 based on the first information Ii1 to third information Ii3 and the multiple ink candidates Lci. Step S30 includes steps S31 to S35.

[0045] In step S31, the CPU 62 selects one ink candidate from among a plurality of ink candidates Lci that have been prepared in advance and subjected to the processes in steps S15 and S16.

[0046] In steps S32b to S34b, the CPU 62 determines whether or not the ejection characteristics indicated by the first information Ii1 of the selected candidate ink Lci satisfy the predetermined selection conditions. Specifically, the CPU 62 performs the following process.

[0047] In step S32b, the CPU 62 determines whether the discharge amount indicated by the first information Ii1 satisfies the first discharge amount condition. First, the CPU 62 calculates a value Dw using the following formula. The value Dw represents the difference between the discharge amount as the discharge characteristic indicated by the first information Ii1 and the target discharge amount as the ideal discharge characteristic.

[0048] Dw = |Pwt - Pwm| (1) Pwt is the target discharge rate. Pwm is the ejection amount of the candidate ink Lci indicated by the first information Ii1.

[0049] The CPU 62 determines whether the selected ink candidate Lci satisfies the first ejection amount condition [Dw≦Thwa], where Thwa is a predetermined threshold value and is a positive number smaller than Pwt.

[0050] The first discharge rate condition [Dw≦Thwa] can also be expressed as follows. [Pwt-Thwa] ≦ Pwm ≦ [Pwt+Thwa] ··· (2) That is, the first discharge amount condition is that the discharge amount is included in a predetermined range [Pwt-Thwa] to [Pwt+Thwa]. By appropriately determining Thwa and performing the process of step S32b, it is possible to select ink that realizes a desired discharge amount.

[0051] In step S32b, if the discharge speed satisfies the first discharge amount condition, the process proceeds to step S33b. If the discharge speed does not satisfy the first discharge amount condition, the process returns to step S31.

[0052] In step S33b, the CPU 62 determines whether the discharge speed indicated by the second information Ii2 satisfies the first discharge speed condition. First, the CPU 62 calculates a value Dv using the following formula. The value Dv represents the difference between the discharge speed as the discharge characteristic indicated by the second information Ii2 and the target discharge speed as the ideal discharge characteristic.

[0053] Dv = |Pvt - Pvm| (3) Pvt is the target delivery velocity. Pvm is the ejection speed of the candidate ink Lci indicated by the second information Ii2.

[0054] The CPU 62 determines whether the selected ink candidate Lci satisfies the first ejection speed condition [Dv≦Thva], where Thva is a predetermined threshold value and is a positive number smaller than Pvt.

[0055] The first discharge speed condition [Dv≦Thva] can also be expressed as follows. [Pvt-Thva] ≦ Pvm ≦ [Pvt+Thva] ··· (4) That is, the first ejection speed condition is that the ejection speed of the selected ink candidate Lci is within a predetermined range [Pvt-Thva] to [Pvt+Thva]. By appropriately determining Thva and performing the process of step S33b, it is possible to select an ink that achieves a desired ejection speed.

[0056] In step S33b, if the ejection speed satisfies the first ejection speed condition, the process proceeds to step S34b. If the ejection speed does not satisfy the first ejection speed condition, the process returns to step S31.

[0057] In step S34b, the CPU 62 determines whether the sub-droplet volume Psm indicated by the third information Ii3 satisfies the sub-droplet volume condition [Psm≦Thsa]. Thsa is a predetermined threshold value. By appropriately determining Thsa and performing the processing of step S34b, it is possible to select ink with a sub-droplet volume smaller than the standard desired by the user.

[0058] In step S34b, if the ejection speed satisfies the sub-droplet volume condition, the process proceeds to step S35. If the ejection speed does not satisfy the sub-droplet volume condition, the process returns to step S31.

[0059] In step S35, the CPU 62 adds the ink candidate Lci selected in the last executed step S31 to the selected ink Iks stored in the memory 63 (see the upper right part of FIG. 1). When the process of step S35 is executed for the first time in the process of FIG. 5, the CPU 62 stores the ink candidate Lci selected in the last executed step S31 as the selected ink Iks in the memory 63 (see the upper right part of FIG. 1).

[0060] In step S35b, the CPU 62 determines whether or not the process of step S32b has been executed for all of the ink candidates Lci that were prepared in advance and that have been subjected to the processes of steps S15 and S16. If the process of step S32b has been executed for all of those ink candidates Lci, the process proceeds to step S36. If the process of step S32b has not been executed for all of those ink candidates Lci, the process returns to step S31. In step S31, one ink candidate Lci that has not yet been subjected to the process of step S32b is selected from among the multiple ink candidates Lci that were prepared in advance and that have been subjected to the processes of steps S15 and S16, and then the processes of steps S32b and onward are executed.

[0061] By repeating the processing of steps S31 to S35, one or more ink candidates Lci, among all the ink candidates Lci that have been prepared in advance and have been processed in steps S15 and S16, whose ejection characteristics indicated by the first information Ii1 to the third information Ii3 satisfy the predetermined conditions, are stored in memory 63 as selected inks Iks (see the upper right part of Figure 1).

[0062] As a result of the processing of steps S31 to S34b, in step S35, the ink to be ejected from the ink ejection head 41 is selected based on the first information Ii1, the second information Ii2, the third information Ii3, and the selected ink Iks which is at least a part of the multiple ink candidates Lci prepared in advance. The functional part of the CPU 62 which executes the processing of step S30 is shown in FIG. 1 as a liquid selection part 628 (see the upper center part of FIG. 1). The processing of steps S11 to S36 realizes a liquid selection method which selects one or more liquids to be ejected from the liquid ejection head. Through the processing after step S36, the ink to be applied to the printer 1 is determined.

[0063] It should be noted that it is sufficient to perform at least one of the processes in steps S32b, S33b, and S34b, and the other steps may be omitted.

[0064] In step S36, the CPU 62 presents to the user information representing one or more candidate ink Lci to be ejected from the ink ejection head 41 selected in step S30. The presented candidate ink Lci are inks that are recommended for use in the printer 1. Specifically, the CPU 62 displays on the display 64 an indication representing the candidate ink Lci included in the selected inks Iks, and an indication representing the ejection characteristics indicated by the first information Ii1 to the third information Ii3. At the same time, the CPU 62 displays a display prompting the user to input a selection of the candidate ink Lci from among the candidate ink Lci included in the selected inks Iks.

[0065] By carrying out such processing, one or more inks can be presented to the user as candidates for the ink to be ejected from the ink ejection head 41.

[0066] In step S38, the CPU 62 accepts an input of selection of ink candidate Lci from the user who has viewed the display of step S36 via the keyboard 65 and mouse 66. As a result, an input of selection from one or more ink candidate Lci whose ejection characteristics satisfy the conditions of steps S32b to S34b, out of a plurality of predetermined ink candidate Lci, is accepted. The functional section of the CPU 62 that executes the process of step S38 is shown in Figure 1 as acceptance section 626 (see the upper center section of Figure 1).

[0067] In step S39, the CPU 62 determines the candidate ink Lci selected in step S36 as the ink to be ejected from the ink ejection head 41.

[0068] According to the ink selection method of this embodiment, from among a plurality of ink candidates Lci which are mutually substitutable when ejected from the ink ejection head 41, an ink candidate Lci which has superior ejection volume, ejection speed, and sub-drop volume when ejected from the ink ejection head 41 can be selected as the liquid to be ejected from the ink ejection head 41 (see steps S16, S32b to S34b in Figure 5).

[0069] A3. Modification of the first embodiment: In the first embodiment, in step S30 of Fig. 5, ink candidates are selected based on the first information Ii1 to the third information Ii3 which represent the ejection characteristics of the inks. However, the selection of ink candidates in step S30 may also be performed based on other information. For example, in the process of step S30, one or more inks to be ejected from the ink ejection head 41 may also be selected based on individual information Ie1, Ie2 which are prepared in advance and which are associated with the multiple ink candidates Lci, respectively.

[0070] The individual information Ie1 and Ie2 can be stored, for example, in a server 70 on a network that can be accessed by the computer 60 (see the upper right part of FIG. 1). The computer 60 can obtain the individual information Ie1 and Ie2 by accessing the server 70 via the network.

[0071] The CPU 62 may set conditions for the parameters represented by the individual information, similar to the first ejection volume condition, the first ejection speed condition, etc., and select the driving waveform candidate Wci as the ink to be ejected from the ink ejection head 41 when the conditions are met (see equations (2) and (4) above).

[0072] By adopting such an embodiment, it is possible to select the ink to be ejected from the ink ejection head 41 while taking into consideration information other than the ejection characteristics such as the ejection amount and the ejection speed.

[0073] The individual information Ie1 includes information indicating the cost of the associated ink candidate Lci. More specifically, the cost of the ink candidate Lci is the price per unit amount of the ink candidate Lci. The unit amount of the ink candidate Lci may be a unit volume, a unit weight, or the amount of ink consumed to fill a predetermined area. The cost of the ink candidate Lci may also be the amount of ink itself consumed to fill a predetermined area. By referring to the individual information Ie1, it is possible to select the ink to be ejected from the ink ejection head 41, taking into consideration the cost of the ink candidate Lci.

[0074] The individual information Ie2 includes information that indicates an evaluation of the associated ink candidate Lci with respect to aspects other than the ejection characteristics, such as the ejection volume. More specifically, the evaluation with respect to aspects other than the ejection characteristics includes the number or ratio of ink candidate Lci used in printers of the same model used by other people, the purchaser's evaluation of the ink candidate Lci as a whole, and the purchaser's evaluation of individual evaluation items of the ink candidate Lci. Individual evaluation items can be, for example, drying speed, resistance to bleed-through, resistance to clogging, etc. By referring to the individual information Ie2, it is possible to select the liquid to be ejected from the ink ejection head 41, taking into consideration the evaluation with respect to aspects other than the ejection characteristics of the ink candidate Lci.

[0075] It should be noted that the associated individual information may be used for only some of the multiple ink candidates Lci prepared in advance.

[0076] The ink ejection head 41 in this embodiment is also referred to as the "liquid ejection head." Ink is also referred to as the "liquid." The unit control circuit 14 is also referred to as the "drive control unit." The ink candidate Lci that is the processing target of step S15 is also referred to as the "first liquid candidate." The process of step S30 is also referred to as the "liquid selection process." The process of step S36 is also referred to as the "presentation process." The ejection volume Pwm is also referred to as the "first ejection characteristic." The ejection speed Pvm is also referred to as the "second ejection characteristic."

[0077] B. Second embodiment: FIG. 6 is a flowchart showing a method for determining the ink to be applied to the printer 1 in the second embodiment. The method in FIG. 6 corresponds to the method in the first embodiment shown in FIG. 5. In the second embodiment, the processes of steps S16b to S26 are executed between steps S16 and S26b in the method in FIG. 5. Also, in the second embodiment, in step S15 in FIG. 6, a further process is executed in addition to the process executed in step S15 in FIG. 5. In step S16 in FIG. 6, a further process is executed in addition to the process executed in step S16 in FIG. 5. Other points of the second embodiment are the same as those of the first embodiment.

[0078] In step S15 in Fig. 6, the CPU 62 selects one of a plurality of predetermined drive waveform candidates Wci, and transmits a set of parameters representing the selected drive waveform candidate Wci to the printer 1. The plurality of predetermined drive waveform candidates Wci are candidates for the drive waveform W of the drive signal COM applied to the printer 1. The plurality of sets of parameters representing these drive waveform candidates Wci are stored in advance in the memory 63 of the computer 60. The plurality of sets of parameters representing the plurality of drive waveform candidates Wci are shown in Fig. 1 as "waveform parameters 631" (see the upper right part of Fig. 1).

[0079] In step S15, the CPU 12 of the printer 1 controls the unit control circuit 14 to generate a drive signal COM based on a set of parameters that represents one of the received drive waveform candidates Wci. The CPU 12 then applies the drive signal COM to the drive element PZT of the ink ejection head 41. Other aspects of the process of step S15 in FIG. 6 are the same as step S15 in FIG. 5.

[0080] In step S16, similarly to the processing of step S16 in Fig. 5, the first acquisition processing to the third acquisition processing are executed, and the first information Ii1, the second information Ii2, and the third information Ii3 are acquired. The CPU 62 stores the first information Ii1, the second information Ii2, and the third information Ii3 in the memory 63 in association with a combination of the ink candidate Lci selected in the last executed step S11 and the drive waveform candidate Wci selected in the last executed step S21. Other aspects of the processing of step S16 in Fig. 6 are the same as step S16 in Fig. 5.

[0081] In step S16b, it is determined whether or not the processes of steps S15 and S16 have been performed for all the drive waveform candidates Wci for which the ejection characteristics are to be measured. If the processes of steps S15 and S16 have been performed for all the drive waveform candidates Wci for which the ejection characteristics are to be measured, the process proceeds to step S21. If the processes of steps S15 and S16 have not been performed for all the drive waveform candidates Wci for which the ejection characteristics are to be measured, the process returns to step S15. Then, from among the multiple drive waveform candidates Wci, one drive waveform candidate Wci for which the processes of steps S15 and S16 have not yet been performed is selected, and the processes of steps S15 and S16 are performed.

[0082] By repeating the processes of steps S15 and S16, the first acquisition process to the third acquisition process are executed for each of the predetermined plurality of driving waveform candidates Wci. As a result, the first information Ii1 to the third information Ii3 for the predetermined plurality of driving waveform candidates Wci associated with the same ink candidate Lci are stored in the memory 63 (see the upper right part of FIG. 1). By performing the processes of steps S11 and S26b described in the first embodiment, the processes of steps S15 to S16b are executed for each of the predetermined plurality of ink candidates Lci. The functional part of the CPU 62 that executes the processes of steps S15 to S16b is the characteristic acquisition part 622.

[0083] In step S21 of FIG. 6, the CPU 62 selects one ink candidate from the multiple driving waveform candidates Wci stored in the memory 63.

[0084] In step S22b, the CPU 62 determines whether the ejection amount indicated by the first information Ii1 and corresponding to the combination of the ink candidate Lci selected in the last executed step S11 and the driving waveform candidate Wci selected in the last executed step S21 satisfies a second ejection amount condition. The second ejection amount condition is [Dw≦Thwb]. Thwb is a predetermined threshold value, and is a positive number greater than Thwa and less than Pwt.

[0085] The second discharge rate condition [Dw≦Thwb] can also be expressed as follows. [Pwt-Thwb] ≦ Pwm ≦ [Pwt+Thwb] ··· (5) That is, the second discharge amount condition is that the discharge amount Pwm of the selected ink candidate Lci is included in a predetermined range [Pwt-Thwb] to [Pwt+Thwb]. By appropriately determining Thwb and performing the process of step S22b, a drive waveform that realizes a desired discharge amount is selected.

[0086] In step S22b, if the discharge amount satisfies the second discharge amount condition, the process proceeds to step S23b. If the discharge amount does not satisfy the second discharge amount condition, the process returns to step S21.

[0087] In step S23b, the CPU 62 determines whether the ejection speed indicated by the second information Ii2 and corresponding to the combination of the ink candidate Lci selected in the last executed step S11 and the driving waveform candidate Wci selected in the last executed step S21 satisfies a second ejection speed condition. The second ejection speed condition is [Dv≦Thvb]. Thvb is a predetermined threshold value, and is a positive number greater than Thva and less than Pvt.

[0088] The second discharge speed condition [Dv≦Thvb] can also be expressed as follows. [Pvt-Thvb] ≦ Pvm ≦ [Pvt+Thvb] ··· (6) That is, the second discharge speed condition is that the discharge speed Pvm is included in a predetermined range [Pvt-Thvb] to [Pvt+Thvb]. By appropriately determining Thvb and performing the process of step S22b, a drive waveform that realizes a desired discharge speed is selected.

[0089] In step S22b, if the discharge speed satisfies the second discharge speed condition, the process proceeds to step S23b. If the discharge speed does not satisfy the second discharge speed condition, the process returns to step S21.

[0090] In step S24b, the CPU 62 determines whether the minimum value of the sub-droplet amount of the drive waveform candidate Wci selected in step S21 executed after the last executed step S11 has been updated. Specifically, it determines whether the sub-droplet amount indicated by the third information Ii3, which corresponds to the combination of the ink candidate Lci selected in the last executed step S11 and the drive waveform candidate Wci selected in the last executed step S21, is smaller than the previous minimum value of the sub-droplet amount. The previous minimum value of the sub-droplet amount is the minimum value of the sub-droplet amount of the drive waveform candidate Wci selected in step S21 executed after the last executed step S11. If the minimum value of the sub-droplet amount has been updated, the CPU 62 associates the sub-droplet amount with the drive waveform candidate Wci and stores it in the memory 63 as the minimum value of the sub-droplet amount. If the minimum value of the sub-droplet amount has not been updated, the records of the previous minimum value of the sub-droplet amount and the drive waveform candidate Wci corresponding to that sub-droplet amount are maintained. Incidentally, in step S24n, instead of determining whether the minimum value of the sub-droplet volume of the drive waveform candidate Wci has been updated, it may be determined whether the sub-droplet volume of the drive waveform candidate Wci has fallen below a predetermined threshold volume.

[0091] In step S25b, the CPU 62 determines whether or not the process of step S22b has been performed for all the drive waveform candidates Wci. If the process of step S22b has been performed for all the drive waveform candidates Wci, the process proceeds to step S26. If the process of step S22b has not been performed for all the drive waveform candidates Wci, the process returns to step S21. In step S21, one drive waveform candidate Wci for which the process of step S22b has not yet been performed is selected from among the multiple drive waveform candidates Wci, and then the processes from step S22b onwards are performed.

[0092] By repeating the processing of steps S21 to S25b, the driving waveform candidate Wci among a plurality of predetermined driving waveform candidates Wci, in which the ejection amount indicated by the first information Ii1 satisfies the second ejection amount condition, the ejection speed indicated by the second information Ii2 satisfies the second ejection speed condition, and the sub-drop amount indicated by the third information Ii3 is the smallest, is stored in memory 63.

[0093] It should be noted that it is sufficient to perform at least one of the processes in steps S22b, S23b, and S24b, and the other steps may be omitted.

[0094] In step S26, the CPU 62 determines the driving waveform candidate Wci stored in the memory 63 as the corresponding driving waveform Wcs corresponding to the ink candidate Lci selected in the last executed step S11 as the driving waveform that realizes the minimum value of the sub-droplet volume.

[0095] The process from step S26b onward in FIG. 6 is the same as the process from step S26b onward in FIG.

[0096] By performing the processing of steps S11 and S26b described in the first embodiment, one driving waveform candidate Wci is determined from among the multiple driving waveform candidates Wci for each of the multiple ink candidates Lci prepared in advance, based on the first information Ii1 to the third information Ii3.

[0097] As a result, in step S30, the ink to be ejected from the ink ejection head 41 is selected based on the first information Ii1 to the third information Ii3 corresponding to the combination of the corresponding drive waveform Wcs determined for each of the multiple ink candidates Lci prepared in advance and each of the multiple ink candidates Lci (see S31 to S35b in Figure 5).

[0098] According to the second embodiment, from among combinations of multiple ink candidates Lci and multiple driving waveform candidates Wci that are mutually replaceable when ejected from the ink ejection head 41, a combination of the ink candidate Lci and the driving waveform candidate Wci that has excellent ejection characteristics when ejected from the ink ejection head 41 can be selected as a combination of the ink to be ejected from the ink ejection head 41 and the driving waveform to be applied to the ink ejection head 41.

[0099] The process of step S26 in this embodiment is also called a "waveform determination step."

[0100] In this embodiment, the corresponding drive waveform Wcs is determined under the condition that the discharge amount indicated by the first information Ii1 satisfies the second discharge amount condition in step S22b. However, the corresponding drive waveform Wcs may be determined by optimizing the discharge amount indicated by the first information Ii1 as a parameter. For example, the corresponding drive waveform Wcs may be determined by giving priority to the drive waveform candidate Wci with a small discharge amount indicated by the first information Ii1. The discharge speed indicated by the second information Ii2 in step 23b may also be optimized in the same manner. When multiple discharge characteristics (e.g., discharge amount and discharge speed) are optimized simultaneously, multi-objective optimization may be performed. The search process in the optimization may be performed automatically. In addition, optimization may be performed for one of the first information Ii1 and the second information Ii2, and a determination may be made as to whether the other satisfies the conditions described in steps 22b and 23b.

[0101] C. Third embodiment: Fig. 7 is a flowchart showing a method for determining the ink to be applied to the printer 1 in the third embodiment. The method in Fig. 7 corresponds to the method in the first embodiment shown in Fig. 5 and the method in the second embodiment shown in Fig. 6. In the third embodiment, the processing of steps S13 to S14b is executed between steps S12 and S15 in the method in Fig. 6. Other points of the third embodiment are the same as those of the second embodiment.

[0102] In step S13 in Fig. 7, the CPU 62 transmits a set of parameters representing a predetermined evaluation drive waveform to the printer 1. In this embodiment, the evaluation drive waveform is a drive waveform that vibrates the meniscus of the ink in the nozzle Nz to such an extent that ink droplets are not ejected from the nozzle Nz. The parameters representing the evaluation drive waveform are stored in advance in the memory 63 of the computer 60. The parameters representing the evaluation drive waveform are included in the "waveform parameters 631" (see the upper right part of Fig. 1).

[0103] In step S13, the CPU 12 of the printer 1 controls the unit control circuit 14 to generate a drive signal COM based on the received set of parameters representing the evaluation drive waveform. The CPU 12 then applies the drive signal COM to the drive element PZT of the ink ejection head 41. Other aspects of the processing in step S13 are the same as those in step S15 in FIG. 6.

[0104] In step S14, the CPU 12 measures the residual vibration generated in the ink in the pressure chamber 412d by the drive of the drive element PZT by the drive signal COM. Specifically, the CPU 12 measures the change in voltage generated in the drive element PZT by the pressure change of the ink in the pressure chamber 412d after the second expansion component S5 of the drive waveform W (see the lower center part of FIG. 3 and the lower right part of FIG. 4). The CPU 12 transmits the voltage data to the computer 60.

[0105] The CPU 62 extracts a residual vibration signal NVT from the voltage data. The residual vibration signal NVT indicates the residual vibration after a drive signal is applied to the drive element PZT. The residual vibration is a vibration with a natural frequency determined by the flow path resistance of the ink flow path in the head unit 40, the inertance of the ink in the flow path, and the elastic compliance of the elastic membrane 412i, etc. The CPU 62 stores parameter information representing the characteristics of the residual vibration signal NVT for the ink candidate Lci in the memory 63 in association with information specifying the ink candidate Lci. This parameter information of the residual vibration signal NVT is called "vibration information Irv."

[0106] The vibration information Irv represents the characteristics of residual vibration of the liquid in the ink ejection head 41 when a certain drive waveform W is applied to the drive element PZT of the ink ejection head 41. The process of acquiring the vibration information Irv, which is executed in steps S13 and S14, is referred to in this specification as a "vibration acquisition process."

[0107] The functional part of the CPU 62 that executes the processes of steps S13 and S14 is the characteristic acquisition part 622 (see the upper center part of FIG. 1).

[0108] In step S14b, the CPU 62 determines whether or not the characteristics of the ink candidate Lci satisfy predetermined conditions based on the parameters of the vibration information Irv. The predetermined conditions determine whether or not it is worth continuing the evaluation in steps S15 and onward. Specifically, the predetermined conditions are conditions related to the viscosity and surface tension of the ink candidate Lci. These conditions are determined as conditions under which no ink ejection defects occur and conditions under which the ejection characteristics acquired in step S16 are close to the target values ​​to a certain extent.

[0109] In step S14b, if the characteristics of the ink candidate Lci indicated by the vibration information Irv satisfy the conditions, the process proceeds to step S15. If the characteristics of the ink candidate Lci indicated by the vibration information Irv do not satisfy the conditions, the process returns to step S11. If the characteristics of the ink candidate Lci indicated by the vibration information Irv do not satisfy the conditions, the processes from step S15 onwards are not performed for the ink candidate Lci selected in the previous step S11.

[0110] The process from step S15 onward in FIG. 7 is the same as the process from step S15 onward in FIG.

[0111] By carrying out the processes of steps S11 and S26b described in the first embodiment, the processes of steps S13 and S14 are carried out for each of the multiple ink candidates Lci prepared in advance. As a result, the ink candidates Lci to be subjected to the processes of step S15 and thereafter are selected from the multiple ink candidates Lci prepared in advance based on the vibration information Irv and the multiple ink candidates Lci prepared in advance.

[0112] In the third embodiment, prior to the processing of step S30, a selection is made based on a predetermined condition from a plurality of prepared ink candidates Lci (see S14b in FIG. 7). As a result, in step S30, the ink to be ejected from the ink ejection head 41 is selected based on a portion of the prepared ink candidates Lci.

[0113] According to the third embodiment, it is possible to exclude from the processing of steps S15 and S16b ink candidates that are unlikely to become the liquid to be ejected from the ink ejection head 41, based on the vibration information Irv. This makes it possible to reduce the time required to determine the ink to be applied to the printer 1, and the amount of ink consumed for this purpose.

[0114] In this embodiment, the multiple ink candidates Lci prepared in advance and subject to the processes in steps S13 and S14 are also referred to as "second liquid candidates." The ink candidates Lci that are subject to the processes in steps S15 and S16 are also referred to as "first liquid candidates." The process in step S14 is also referred to as the "vibration acquisition process." The process in step S14b is also referred to as the "preliminary selection process."

[0115] D. Other embodiments: D1. Alternative embodiment 1: (1) In the first embodiment, the multiple ink candidates Lci are multiple inks provided by multiple different manufacturers as "cyan ink." However, the ink candidates can be inks of other colors, such as yellow, black, red, green, and transparent. However, it is preferable that the multiple ink candidates Lci are inks used to reproduce the same color and are mutually replaceable.

[0116] (2) In the first embodiment described above, in step S12 of Fig. 5, the user attaches a cartridge of the selected ink to the carriage 31 and fills the nozzles Nz of the ink ejection head 41. Then, each time steps S11 and S12 are performed, the same nozzles are used in step S15 to eject a different ink. However, if cartridges of multiple candidate inks Lci that have been prepared in advance can be attached to the carriage 31 at the same time, the following processing can also be performed.

[0117] After the ink candidate Lci is selected in step S11, the CPU 12 of the printer 1 ejects ink droplets from nozzles that can be supplied with the selected ink candidate Lci in step S15. Then, in step S16, the CPU 62 acquires the ejection characteristics of the ejected ink droplets. If the printer 1 is equipped with multiple ink ejection heads 41, the nozzles that eject ink droplets may be nozzles of different ink ejection heads 41. In this embodiment, the process of step S12 that is executed after step S11 in the method of FIG. 5 is omitted.

[0118] In addition, when multiple printers 1 of the same model are connected via a network, cartridges of multiple ink candidates Lci that have been prepared in advance may be installed in the different printers 1, and ink droplets may be ejected from the nozzles of the different printers 1 to obtain the ejection characteristics.

[0119] (3) In the first embodiment, the discharge amount Pwm is estimated based on the image captured by the CCD camera 55. However, the discharge amount Pwm may be measured using a scale.

[0120] (4) In the first embodiment described above, the ink to be ejected from the ink ejection head 41 is selected based on the first information Ii1 regarding the ejection volume Pwm, the second information Ii2 regarding the ejection speed Pvm, and the third information Ii3 regarding the sub-droplet volume Psm (see S32b to S34b in FIG. 5). However, it is also possible to adopt a mode in which one or more of these evaluation parameters are not taken into consideration when selecting the ink to be ejected from the ink ejection head 41. When selecting one or more liquids to be ejected from the liquid ejection head, it is sufficient that the liquids are selected based on information that represents some ejection characteristic of the liquid ejected from the liquid ejection head when a drive waveform is applied to a drive element of the liquid ejection head.

[0121] (5) In the third embodiment described above, in the process of step S14 in Fig. 7, the drive element is driven and the residual vibration is measured. In the process of step S16, ink droplets are ejected and the ejection characteristics are measured. However, for example, if at least a portion of the first information Ii1 to third information Ii3 and the vibration information Irv are stored in a storage unit such as the memory 63 of the computer 60 or the memory 13 of the printer 1, the drive waveform and ink may be determined based on the information stored in advance.

[0122] (6) In the first embodiment described above, in step S35 which is repeatedly executed, the selected ink Iks is determined from among a plurality of ink candidate Lci prepared in advance. The selected ink Iks is presented to the user (see S36 in FIG. 5). The ink candidate Lci constituting this selected ink Iks may be one ink or a plurality of inks. The number of ink candidate Lci constituting the selected ink Iks is determined by the contents of the plurality of ink candidate Lci prepared in advance, as well as the first ejection volume condition, the first ejection speed condition, the sub-droplet volume condition, etc.

[0123] 6, it is determined whether the second ejection amount condition is satisfied, and in step S23b it is determined whether the second ejection speed condition is satisfied. Then, in step S24b, among the drive waveform candidates Wci that satisfy these conditions, the drive waveform candidate Wci with the smallest sub-droplet volume is determined as the corresponding drive waveform Wcs that corresponds to the ink candidate Lci selected in step S11.

[0124] However, the sub-droplet volume Psm may also be used as a parameter for determining a constraint condition. The ejection volume Pwm and the ejection speed Pvm may also be used as parameters that serve as indices for selecting the optimal corresponding drive waveform Wcs.

[0125] In addition, in a solution space defined by a plurality of evaluation parameters, a plurality of drive waveform candidates Wci that are Pareto optimal solutions may be presented to a user, and a selection of the drive waveform candidate Wci from the user may be accepted. Furthermore, the drive waveform candidate Wci that minimizes or maximizes a predetermined objective function including a plurality of evaluation parameters may be determined as the corresponding drive waveform Wcs.

[0126] (8) In the third embodiment described above, the evaluation drive waveform is a drive waveform that vibrates the meniscus of the ink in the nozzle Nz to such an extent that ink droplets are not ejected from the nozzle Nz (see S13 in FIG. 7 and FIG. 3). However, the evaluation drive waveform may also be a drive waveform that ejects ink droplets from the nozzle Nz. However, it is preferable that the evaluation drive waveform ejects a smaller amount of ink than the drive waveform candidate Wci applied in step S15 in FIG. 7. By adopting such an embodiment, the amount of ink consumed in determining the ink to be applied to the printer 1 can be further reduced.

[0127] (9) In the third embodiment described above, as a result of performing the processes in steps S13 to S14b in Fig. 7, ink candidates Lci to be subjected to the processes in step S15 and thereafter are selected from the plurality of ink candidates Lci prepared in advance based on the vibration information Irv and the plurality of ink candidates Lci prepared in advance. However, prior to the process in step S13, further selection based on predetermined conditions may be performed on the plurality of ink candidates Lci prepared in advance. In such an embodiment, in step S14b, ink candidates Lci to be subjected to the processes in step S15 and thereafter are selected from the plurality of ink candidates Lci based on a portion of the plurality of ink candidates Lci prepared in advance.

[0128] (10) In the above embodiment, the liquid ejection apparatus is a printer that ejects ink. However, the liquid ejection apparatus may be other apparatus, such as an apparatus for manufacturing electronic devices.

[0129] (11) In the above embodiment, the first information Ii1 and the second information Ii2 are information that represents the ejection characteristics. However, the first information and the second information do not have to be information that represents the ejection characteristics themselves. In other words, the first information and the second information only need to be information about the ejection characteristics themselves.

[0130] (12) In the above embodiment, the vibration information Irv is information on the parameters of the residual vibration signal NVT. However, the vibration information does not have to be information that represents the residual vibration itself. In other words, the vibration information may be information related to the residual vibration.

[0131] D2. Alternative embodiment 2: In the process of step S30 in the modification of the first embodiment, the inks to be ejected from the ink ejection head 41 are selected based on the individual information Ie1, Ie2 associated with the multiple ink candidates Lci (see the upper right part of FIG. 1). However, one or more inks to be ejected from the ink ejection head 41 may be selected based on information that represents the ejection characteristics, rather than on the individual information.

[0132] D3. Alternative embodiment 3: In the modified example of the first embodiment, the individual information Ie1 includes information indicating the cost of the associated ink candidate Lci (see the upper right part of FIG. 1). However, the individual information may be information that does not include information indicating the cost. Furthermore, the individual information may be, for example, information on the purchaser's evaluation of the ink candidate Lci, as shown as individual information Ie2.

[0133] D4. Alternative embodiment 4: In the modified example of the first embodiment, the individual information Ie2 includes information that represents an evaluation of the associated ink candidate Lci, but not related to the ejection characteristics (see the upper right part of FIG. 1). However, the individual information may be information that does not include information that represents an evaluation other than related to the ejection characteristics. Furthermore, the individual information may be, for example, information that represents the cost of the ink candidate Lci, as shown as the individual information Ie1.

[0134] D5. Alternative embodiment 5: 5, the ink to be ejected from the ink ejection head 41 is selected based on the second information Ii2 and the third information Ii3 in addition to the first information Ii1. However, the ink to be ejected from the ink ejection head 41 may be selected based on one, two, or four or more types of ejection characteristics.

[0135] D6. Alternative embodiment 6: In the third embodiment described above, in step S30, the ink to be ejected from the ink ejection head 41 is selected based on the first information Ii1 to the third information Ii3 corresponding to the combination of the corresponding drive waveform Wcs determined for each of the multiple ink candidates Lci prepared in advance and each of the multiple ink candidates Lci (see S30 in FIG. 7 and S31 to S35b in FIG. 5).

[0136] However, the ink to be ejected from the ink ejection head 41 may be determined based on the ejection characteristics of a single drive waveform candidate Wci, rather than based on a corresponding drive waveform Wcs selected from a plurality of drive waveform candidates Wci, as shown in the first embodiment.

[0137] D7. Alternative Embodiment 7: In the third embodiment described above, if the characteristics of the ink candidate Lci do not satisfy predetermined conditions based on the parameters of the vibration information Irv, the processes from step S15 onwards are not performed for the ink candidate Lci selected in the immediately preceding step S11 (see S14b in FIG. 7). However, as shown in the first and second embodiments, the acquisition step may be performed for all of a plurality of ink candidates Lci prepared in advance, and the ink to be ejected from the ink ejection head 41 may be selected.

[0138] D8. Alternative Embodiment 8: In step S36 of the first embodiment described above, the CPU 62 outputs information representing one or more candidate ink Lci to be ejected by the ink ejection head 41 selected in step S30 (see S36 in FIG. 5). However, the processor may determine the ink most highly rated according to a predetermined criterion as the ink to be ejected by the ink ejection head 41 without outputting information representing the candidate ink Lci and without receiving a selection by the user.

[0139] D9. Other Embodiment 9: The parameters used to represent the ejection characteristics are the ejection volume Pwm, the ejection speed Pvm, and the sub-droplet volume Psm (see Ii1, Ii2, and Ii3 in the upper right part of Fig. 1). However, other parameters, such as the impact position deviation of ink droplets in the main scanning direction and / or the sub-scanning direction, can also be used as parameters to represent the ejection characteristics.

[0140] E. Further forms: The present disclosure is not limited to the above-mentioned embodiment, and can be realized in various forms without departing from the spirit of the present disclosure. For example, the present disclosure can be realized in the following forms. The technical features in the above-mentioned embodiments corresponding to the technical features in each form described below can be appropriately replaced or combined in order to solve some or all of the problems of the present disclosure, or to achieve some or all of the effects of the present disclosure. Furthermore, if the technical feature is not described as essential in this specification, it can be appropriately deleted.

[0141] (1) According to one aspect of the present disclosure, there is provided a liquid selection method for selecting a liquid to be ejected from a liquid ejection head, the liquid selection method including: an acquisition step of executing a first acquisition process for acquiring, for each of a plurality of first liquid candidates, first information relating to a first ejection characteristic of the liquid when a drive waveform is applied to a drive element of the liquid ejection head; and a liquid selection step of selecting one or more of the liquids to be ejected from the liquid ejection head based on the first information and at least a portion of the plurality of first liquid candidates. In this manner, from among a plurality of first liquid candidates which are mutually replaceable when ejected from a liquid ejection head, a first liquid candidate which has superior first ejection characteristics when ejected from a liquid ejection head can be selected as the liquid to be ejected from the liquid ejection head.

[0142] (2) In the liquid selection method of the above aspect, the liquid selection process may further be a process of selecting one or more of the liquids to be ejected from the liquid ejection head based on individual information each corresponding to at least a portion of the plurality of first liquid candidates. In this manner, the liquid to be ejected from the liquid ejection head can be selected in consideration of information other than the first ejection characteristic.

[0143] (3) In the liquid selection method according to the above aspect, the individual information may include information indicating a cost of the associated first liquid candidate. In this manner, the liquid to be ejected from the liquid ejection head can be selected taking into consideration the cost of the first liquid candidate.

[0144] (4) In the liquid selection method according to the above aspect, the individual information may include information indicating an evaluation of the associated first liquid candidate. In this embodiment, it is possible to select the liquid to be ejected from the liquid ejection head by taking into consideration the evaluation of the first liquid candidate with respect to factors other than the first ejection characteristic.

[0145] (5) In the liquid selection method of the above aspect, the acquisition process may include a process of executing a second acquisition process for each of the plurality of first liquid candidates to acquire second information regarding second ejection characteristics of the liquid when a drive waveform is applied to a drive element of the liquid ejection head, the second ejection characteristics being different from the first ejection characteristics, and the liquid selection process may further be a process of selecting one or more of the liquids to be ejected by the liquid ejection head based on the second information. In this manner, from among a plurality of first liquid candidates which are mutually interchangeable when ejected from a liquid ejection head, it is possible to select a first liquid candidate which also has excellent second ejection characteristics when ejected from a liquid ejection head, as the liquid to be ejected from the liquid ejection head.

[0146] (6) In the liquid selection method of the above embodiment, the acquisition process may include a process of executing the first acquisition process for each of a plurality of driving waveform candidates as the drive waveform, for each of the plurality of first liquid candidates, and the liquid selection method may further include a waveform determination process of determining one driving waveform candidate from among a plurality of driving waveform candidates based on the first information, for each of the plurality of first liquid candidates, and the liquid selection process may be a process of selecting one or more of the liquids to be ejected from the liquid ejection head based on the first information corresponding to a combination of the driving waveform candidate determined for each of at least a portion of the plurality of first liquid candidates and each of at least a portion of the plurality of first liquid candidates. In this manner, from among combinations of a plurality of first liquid candidates and a plurality of driving waveform candidates which are mutually interchangeable when ejected from a liquid ejection head, a combination of a first liquid candidate and a driving waveform candidate which has superior first ejection characteristics when ejected from a liquid ejection head can be selected as the liquid to be ejected from the liquid ejection head and the driving waveform to be applied to the liquid ejection head.

[0147] (7) In the liquid selection method of the above aspect, the liquid selection method can further include a vibration acquisition process that executes a vibration acquisition process for each of a plurality of second liquid candidates, the vibration acquisition process being a process of acquiring vibration information relating to residual vibration of the liquid in the liquid ejection head when a drive waveform is applied to a drive element of the liquid ejection head, and a preliminary selection process that selects the plurality of first liquid candidates from the plurality of second liquid candidates based on the vibration information and at least a portion of the plurality of second liquid candidates. With this aspect, it is possible to determine a plurality of first liquid candidates to be subjected to the acquisition process from among a plurality of second liquid candidates based on the vibration information, and therefore it is possible to exclude liquid candidates that are unlikely to become the liquid to be ejected from the liquid ejection head from the acquisition process based on the vibration information.

[0148] (8) The liquid selection method of the above aspect may further include a presentation step of presenting to a user information representing one or more of the liquids to be ejected from the liquid ejection head selected in the liquid selection step. According to this embodiment, one or more liquids can be presented to the user as candidates for the liquid to be ejected from the liquid ejection head.

[0149] (9) In the liquid selection method according to the above aspect, the first ejection characteristic may be an ejection amount of liquid ejected by the ejection operation of the drive element. According to this aspect, a liquid candidate that has a preferable ejection amount of liquid ejected from the nozzle can be selected as the liquid to be ejected from the liquid ejection head.

[0150] (10) In the liquid selection method according to the above aspect, the second ejection characteristic may be an ejection speed of the liquid ejected from the liquid ejection head. According to this aspect, a liquid candidate that has a preferable ejection speed when ejected from the nozzle can be selected as the liquid to be ejected from the liquid ejection head.

[0151] (11) 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 according to any one of the above aspects.

[0152] (12) According to another aspect of the present disclosure, there is provided a liquid ejection device comprising: a liquid ejection head including a drive element that is driven by application of a drive signal and ejects liquid by driving the drive element, a drive control unit that controls the liquid ejection head, a characteristic acquisition unit that executes a first acquisition process to acquire, for each of a plurality of first liquid candidates, first information relating to a first ejection characteristic of the liquid when a drive waveform is applied to the drive element of the liquid ejection head, and one or more liquid selection units that select a liquid to be ejected from the liquid ejection head based on the first information and at least a portion of the plurality of first liquid candidates.

[0153] The present disclosure can be realized in various forms other than the liquid selection method, the liquid ejection device, and the computer program for executing the liquid selection method. For example, the present disclosure can be realized in the form of a control method for a liquid ejection device, a computer program for implementing the control method, a non-transient recording medium on which the computer program is recorded, etc. Also, although the printer 1 has been described in each embodiment, a printer does not have to be used in the liquid ejection device, and so-called experimental equipment or evaluation equipment may be used instead as long as it has a function of ejecting liquid. [Explanation of symbols]

[0154] 1...printer, 10...controller, 11...interface section, 12...CPU, 13...memory, 14...unit control circuit, 15...driving signal generating circuit, 20...transport unit, 30...carriage unit, 31...carriage, 40...head unit, 41...ink ejection head, 50...detector group, 55...CCD camera, 60...computer, 61...interface section, 62...CPU, 63...memory, 64...display, 65...keyboard, 66...mouse, 411...case, 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 path, 412h...island section, 41 2i...elastic film, 622...characteristics acquisition section, 628...liquid selection section, 631...waveform parameter, Dm...main scanning direction, Ds...sub-scanning direction, HC...head control section, Ie1...individual information, Ie2...individual information, Ii1...first information, Ii2...second information, Ii3...third information, Iks...selected ink, Irv...vibration information, Lci...ink candidate, Nz...nozzle, PM...printing medium, PZT...driving element, Pwc1...first expansion time, Pwc2...second expansion time, Pwd1...contraction time, Pwh1...first hold time, Pwh2...second hold time, S1...first expansion element, S2...first hold element, S3...contraction element, S4...second hold element, S5...second expansion element, Vc...intermediate potential, Vh...maximum potential, Vl...minimum potential, W...driving waveform, Wcs...corresponding driving waveform

Claims

1. A liquid selection method for selecting a liquid to be ejected from a liquid ejection head, comprising the steps of: an acquisition step of executing a first acquisition process for acquiring first information on a first ejection characteristic of the liquid when a drive waveform is applied to a drive element of the liquid ejection head for each of a plurality of first liquid candidates; a liquid selection step of selecting one or more of the liquids to be ejected from the liquid ejection head from among the plurality of first liquid candidates based on the first information, The liquid selection method, wherein the first ejection characteristic is an ejection amount of liquid ejected by an ejection operation of the drive element.

2. A liquid selection method for selecting a liquid to be ejected from a liquid ejection head, comprising the steps of: an acquisition step of executing a first acquisition process for acquiring first information on a first ejection characteristic of the liquid when a drive waveform is applied to a drive element of the liquid ejection head for each of a plurality of first liquid candidates; a liquid selection step of selecting one or more of the liquids to be ejected from the liquid ejection head from among the plurality of first liquid candidates based on the first information, The liquid selection method, wherein the first ejection characteristic is an ejection speed of the liquid ejected from the liquid ejection head.

3. A liquid selection method for selecting a liquid to be ejected from a liquid ejection head, comprising the steps of: an acquisition step of executing a first acquisition process for acquiring first information on a first ejection characteristic of the liquid when a drive waveform is applied to a drive element of the liquid ejection head for each of a plurality of first liquid candidates; a liquid selection step of selecting one or more of the liquids to be ejected from the liquid ejection head from among the first liquid candidates based on the first information and individual information corresponding to each of the first liquid candidates, A liquid selection method, wherein the individual information includes information representing a cost of the associated first liquid candidate.

4. A liquid selection method for selecting a liquid to be ejected from a liquid ejection head, comprising the steps of: an acquisition step of executing a first acquisition process for acquiring first information on a first ejection characteristic of the liquid when a drive waveform is applied to a drive element of the liquid ejection head for each of a plurality of first liquid candidates; a liquid selection step of selecting one or more of the liquids to be ejected from the liquid ejection head from among the first liquid candidates based on the first information and individual information corresponding to each of the first liquid candidates, A liquid selection method, wherein the individual information includes information representing an evaluation of the associated first liquid candidate.

5. A liquid selection method for selecting a liquid to be ejected from a liquid ejection head, comprising the steps of: a first acquisition process for acquiring, for each of a plurality of first liquid candidates, first information relating to a first ejection characteristic of the liquid when a drive waveform is applied to a drive element of the liquid ejection head; an acquisition step of executing a second acquisition process for acquiring second information on a second ejection characteristic of the liquid when a drive waveform is applied to a drive element of the liquid ejection head, the second ejection characteristic being different from the first ejection characteristic, for each of the plurality of first liquid candidates; a liquid selection step of selecting one or more of the liquids to be ejected from the liquid ejection head from among the plurality of first liquid candidates based on both the first information and the second information.

6. A liquid selection method for selecting a liquid to be ejected from a liquid ejection head, comprising the steps of: an acquisition step of executing a first acquisition process for acquiring first information on a first ejection characteristic of the liquid when a drive waveform is applied to a drive element of the liquid ejection head for each of a plurality of first liquid candidates; a liquid selection step of selecting one or more of the liquids to be ejected from the liquid ejection head from among the plurality of first liquid candidates based on the first information; a presentation step of presenting to a user information representing one or more liquids to be ejected from the liquid ejection head selected in the liquid selection step.

7. A computer program for causing a computer to execute the liquid selection method according to any one of claims 1 to 6.

8. A liquid ejection device, a liquid ejection head including a drive element that is driven by an applied drive signal, and ejects liquid by driving the drive element; A drive control unit that controls the liquid ejection head; a characteristic acquisition unit that executes a first acquisition process for acquiring first information on a first ejection characteristic of the liquid when a drive waveform is applied to a drive element of the liquid ejection head for each of a plurality of first liquid candidates; a liquid selection unit that selects one or more liquids to be ejected from the liquid ejection head from among the plurality of first liquid candidates based on the first information, The liquid ejection device, wherein the first ejection characteristic is an ejection amount of liquid ejected by an ejection operation of the drive element.

9. A liquid ejection device, a liquid ejection head including a drive element that is driven by an applied drive signal, and ejects liquid by driving the drive element; A drive control unit that controls the liquid ejection head; a characteristic acquisition unit that executes a first acquisition process for acquiring first information on a first ejection characteristic of the liquid when a drive waveform is applied to a drive element of the liquid ejection head for each of a plurality of first liquid candidates; a liquid selection unit that selects one or more liquids to be ejected from the liquid ejection head from among the plurality of first liquid candidates based on the first information, The liquid ejection device, wherein the first ejection characteristic is an ejection speed of the liquid ejected from the liquid ejection head.

10. A liquid ejection device, a liquid ejection head including a drive element that is driven by an applied drive signal, and ejects liquid by driving the drive element; A drive control unit that controls the liquid ejection head; a first acquisition process for acquiring, for each of a plurality of first liquid candidates, first information relating to a first ejection characteristic of the liquid when a drive waveform is applied to a drive element of the liquid ejection head; a characteristic acquisition unit that executes a second acquisition process to acquire, for each of the plurality of first liquid candidates, second information on a second ejection characteristic of the liquid when a drive waveform is applied to a drive element of the liquid ejection head, the second ejection characteristic being different from the first ejection characteristic; a liquid selection section that selects one or more liquids to be ejected from the liquid ejection head from among the plurality of first liquid candidates based on both the first information and the second information.

11. A liquid ejection device, a liquid ejection head including a drive element that is driven by an applied drive signal, and ejects liquid by driving the drive element; A drive control unit that controls the liquid ejection head; a characteristic acquisition unit that executes a first acquisition process for acquiring first information on a first ejection characteristic of the liquid when a drive waveform is applied to a drive element of the liquid ejection head for each of a plurality of first liquid candidates; a liquid selection unit that selects one or more liquids to be ejected from the liquid ejection head from among the plurality of first liquid candidates based on the first information; a presentation unit that presents to a user information representing the one or more liquids to be ejected from the selected liquid ejection head.

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