Liquid discharge apparatus and control method for liquid discharge apparatus

Abstract

To enable appropriate and easy evaluation of crosstalk.SOLUTION: A liquid discharge apparatus 100 comprises: a liquid discharge head 1 including a detection circuit 19 that detects residual vibration of a diaphragm 14 caused by driving at least one of a first piezoelectric element PZ and a second piezoelectric element PZ corresponding to nozzles N1c and N1d; and an evaluation control unit 40. The evaluation control unit 40 causes the detection circuit 19 to detect, from the first piezoelectric element PZ, a first residual vibration caused by driving the first piezoelectric element PZ and the second piezoelectric element PZ with a driving signal COMa for discharging ink, causes the detection circuit 19 to detect, from the first piezoelectric element PZ, a second residual vibration caused by driving the first piezoelectric element PZ with the driving signal COMa and driving the second piezoelectric element PZ with a driving signal COMb for not discharging ink, and evaluates crosstalk between the nozzles N1c and N1d on the basis of the first residual vibration and the second residual vibration detected by the detection circuit 19.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a liquid ejection apparatus and a method for controlling the liquid ejection apparatus. [Background technology]

[0002] Liquid ejection devices are known that print images by ejecting liquid such as ink from nozzles using piezoelectric elements. For example, a liquid ejection device has a liquid ejection head that ejects liquid filled in a pressure chamber from the nozzle by vibrating a diaphragm that constitutes part of the pressure chamber using a piezoelectric element. This type of liquid ejection device is known to have a problem called structural crosstalk, in which the ejection characteristics of one nozzle among multiple nozzles vary depending on the ejection status of other nozzles, such as nozzles adjacent to the one nozzle. Various technologies have been proposed to suppress the occurrence of this structural crosstalk. For example, Patent Document 1 discloses a waveform that reduces structural crosstalk as an ejection drive pulse waveform for ejecting liquid from a nozzle. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-88279 Summary of the Invention [Problem to be solved by the invention]

[0004] Incidentally, the manner in which crosstalk occurs varies not only depending on the structure of the liquid ejection head but also on the conditions under which the liquid ejection head is used. For example, the manner in which crosstalk occurs varies depending on ink conditions, such as the type of ink. Consider a business model in which a head manufacturer that produces liquid ejection heads sells the liquid ejection heads to a printing device manufacturer, which then assembles the liquid ejection device. In this business model, in many cases, the conditions under which the liquid ejection head is used, such as the ink conditions, are determined by the printing device manufacturer, not the head manufacturer. If the head manufacturer also assembles the liquid ejection device, the head manufacturer also determines the conditions of use, allowing for appropriate evaluation of crosstalk. In contrast, in the above-described business model, there is a risk that the head manufacturer may not be able to properly evaluate crosstalk after manufacturing and selling the liquid ejection head. In such a case, it is difficult for the head manufacturer to determine an appropriate drive signal waveform to suppress crosstalk. Therefore, in the above-described business model, the printing device manufacturer is required to properly evaluate crosstalk and determine an appropriate drive signal waveform to suppress crosstalk, which may place an excessive burden on the printing device manufacturer. For this reason, in the above-mentioned business model, it is desirable to be able to appropriately and easily evaluate crosstalk and determine the waveform of the drive signal that drives the piezoelectric element. In particular, it is desirable to be able to appropriately and easily evaluate crosstalk. The above-mentioned problem is also desirable, although to a relatively small extent, even if the manufacturer of the liquid ejection device and the manufacturer of the liquid ejection head share the same business model. For example, it is conceivable that a user may independently set usage conditions that differ from those previously assumed by the manufacturer of the liquid ejection head or liquid ejection device, and in such a case, a similar problem would arise. [Means for solving the problem]

[0005] In order to solve the above problems, the liquid ejection device of the present invention comprises a liquid ejection head including a first nozzle that ejects liquid, a second nozzle that ejects liquid and is located at a position different from the first nozzle, a first piezoelectric element corresponding to the first nozzle, a second piezoelectric element corresponding to the second nozzle, a vibration plate that vibrates by driving at least one of the first piezoelectric element and the second piezoelectric element, and a detection unit that detects residual vibration of the vibration plate caused by driving at least one of the first piezoelectric element and the second piezoelectric element; and a control unit, wherein the control unit causes the detection unit to detect, from the first piezoelectric element, the residual vibration caused by driving the first piezoelectric element and the second piezoelectric element with an ejection signal that causes liquid to be ejected, as a first residual vibration, and causes the detection unit to detect, from the first piezoelectric element, the residual vibration caused by driving the first piezoelectric element with the ejection signal and driving the second piezoelectric element with a hold signal that does not cause liquid to be ejected, as a second residual vibration, and evaluates crosstalk between the first nozzle and the second nozzle based on the first residual vibration and the second residual vibration detected by the detection unit.

[0006] Another liquid ejection device according to the present invention comprises a liquid ejection head having a first nozzle that ejects liquid, a second nozzle that ejects liquid and is located at a position different from the first nozzle, a first piezoelectric element corresponding to the first nozzle, a second piezoelectric element corresponding to the second nozzle, a vibration plate that vibrates by driving at least one of the first piezoelectric element and the second piezoelectric element, and a detection unit that detects residual vibration of the vibration plate caused by driving at least one of the first piezoelectric element and the second piezoelectric element; and a control unit, wherein the control unit causes the detection unit to detect, from the first piezoelectric element, the residual vibration caused by driving the first piezoelectric element and the second piezoelectric element with an ejection signal that ejects liquid as a first residual vibration, and causes the detection unit to detect, from the first piezoelectric element, the residual vibration caused by driving the first piezoelectric element with the ejection signal and driving the second piezoelectric element with a hold signal that does not eject liquid as a second residual vibration, and determines the waveform of the ejection signal and the waveform of the hold signal based on the first residual vibration and the second residual vibration detected by the detection unit.

[0007] Furthermore, a control method for a liquid ejection device according to the present invention is a control method for a liquid ejection device having a liquid ejection head including a first nozzle that ejects liquid, a second nozzle that ejects liquid and is located at a position different from the first nozzle, a first piezoelectric element corresponding to the first nozzle, a second piezoelectric element corresponding to the second nozzle, a vibration plate that vibrates by driving at least one of the first piezoelectric element and the second piezoelectric element, and a detection unit that detects residual vibration of the vibration plate caused by driving at least one of the first piezoelectric element and the second piezoelectric element, wherein the detection unit detects, from the first piezoelectric element, the residual vibration caused by driving the first piezoelectric element and the second piezoelectric element with an ejection signal that causes liquid to be ejected, as a first residual vibration, and the detection unit detects, from the first piezoelectric element, the residual vibration caused by driving the first piezoelectric element with the ejection signal and driving the second piezoelectric element with a hold signal that does not cause liquid to be ejected, as a second residual vibration, and evaluates crosstalk between the first nozzle and the second nozzle based on the first residual vibration and the second residual vibration detected by the detection unit. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a block diagram showing an example of a configuration of a liquid ejection apparatus according to an embodiment of the present invention. [Figure 2] FIG. 1 is a configuration diagram schematically illustrating a liquid ejection device. [Figure 3] FIG. 2 is an exploded perspective view of the liquid ejection head. [Figure 4] FIG. 4 is a cross-sectional view taken along the line III-III shown in FIG. [Figure 5] FIG. 2 is a block diagram showing an example of the configuration of a liquid ejection head. [Figure 6] FIG. 10 is an explanatory diagram for explaining crosstalk. [Figure 7] 10 is a timing chart showing an example of an operation of the liquid ejection device in a unit period. [Figure 8] FIG. 10 is a diagram showing an example of a waveform of a residual vibration signal. [Figure 9]10 is a flowchart showing an example of the operation of the liquid ejection device when evaluating crosstalk. [Figure 10] 10 is a flowchart showing an example of a comparison process of residual vibration shown in FIG. 9. [Figure 11] FIG. 10 is a block diagram showing an example of the configuration of a liquid ejection head according to a first modified example. [Figure 12] 10 is a timing chart showing an example of the operation of the liquid ejection device according to the first modified example. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, in each drawing, the dimensions and scale of each part are appropriately different from those of the actual parts. Furthermore, since the embodiments described below are preferred examples of the present invention, various technically preferable limitations are applied, but the scope of the present invention is not limited to these embodiments unless otherwise specified in the following description to the effect that the present invention is limited.

[0010] [1. Embodiment] First, an overview of a liquid ejection device 100 according to this embodiment will be described with reference to Fig. 1. In this embodiment, it is assumed as an example that the liquid ejection device 100 is an inkjet printer that forms an image by ejecting ink onto a medium PP. In this embodiment, it is assumed that the medium PP is recording paper shown in Fig. 2, which will be described later. Ink is an example of a "liquid."

[0011] FIG. 1 is a block diagram showing an example of the configuration of a liquid ejection device 100 according to an embodiment of the present invention.

[0012] Print data IMG indicating an image to be formed by the liquid ejection device 100 is supplied from a host computer such as a personal computer or a digital camera to the liquid ejection device 100. The liquid ejection device 100 executes a printing process to form, on a medium PP, an image indicated by the print data IMG supplied from the host computer.

[0013] The liquid ejection device 100 includes a liquid ejection head 1 provided with an ejection section D including nozzles N that eject ink, a drive signal generation unit 2 that generates a plurality of drive signals COM for driving the ejection section D, and an analysis unit 3 that analyzes residual vibrations (described later). The nozzles N will be described later with reference to FIGS. 3 and 4. The liquid ejection device 100 also includes a control unit 4 that controls each section of the liquid ejection device 100, and a storage unit 5 that stores various information such as print data IMG and a control program PG for the liquid ejection device 100. The liquid ejection device 100 also includes a maintenance unit 7 that performs maintenance processing for the liquid ejection head 1, a medium transport mechanism 8 that transports a medium PP, a carriage transport mechanism 9 that reciprocates a carriage 91, and an ink container 60 that stores ink. The carriage 91 will be described later with reference to FIG. 2.

[0014] In this embodiment, it is assumed that the liquid ejection head 1 and the drive signal generation unit 2 correspond to each other, and that the liquid ejection head 1 and the analysis unit 3 correspond to each other. For example, the liquid ejection device 100 may have a plurality of liquid ejection heads 1, a plurality of drive signal generation units 2, and a plurality of analysis units 3. In this case, for example, the plurality of drive signal generation units 2 correspond to the plurality of liquid ejection heads 1 one-to-one, and the plurality of analysis units 3 correspond to the plurality of liquid ejection heads 1 one-to-one. Alternatively, the liquid ejection device 100 may have one liquid ejection head 1, one drive signal generation unit 2 corresponding to the liquid ejection head 1, and one analysis unit 3 corresponding to the liquid ejection head 1.

[0015] In this embodiment, it is assumed that the liquid ejection device 100 has four liquid ejection heads 1 corresponding to four types of ink: cyan, magenta, yellow, and black. That is, in this embodiment, it is assumed that the liquid ejection device 100 has four liquid ejection heads 1, four drive signal generation units 2, and four analysis units 3. However, for convenience of explanation, the following description may focus on one of the four liquid ejection heads 1 and one drive signal generation unit 2 corresponding to that one liquid ejection head 1, as exemplified in FIG.

[0016] First, before describing the liquid ejection head 1, the control unit 4, the drive signal generating unit 2, and the storage unit 5 will be described.

[0017] The control unit 4 is configured to include one or more CPUs (Central Processing Units). Note that the control unit 4 may be configured to include a programmable logic device such as an FPGA (field-programmable gate array) instead of or in addition to a CPU. Also, for example, the control unit 4 operates in accordance with a control program PG stored in the storage unit 5 to generate signals for controlling the operation of each part of the liquid ejection device 100, such as a print signal SI and a waveform designation signal dCOM.

[0018] Here, the waveform designation signal dCOM is a digital signal that defines the waveform of each of the multiple drive signals COM. Furthermore, each drive signal COM is an analog signal for driving a discharge section D. In this embodiment, as shown in FIG. 5 (to be described later), it is assumed that the multiple drive signals COM include drive signals COMa and COMb. Furthermore, the print signal SI is a digital signal for designating the type of operation of the discharge section D. Specifically, the print signal SI is a signal that designates whether or not to supply each drive signal COM to the discharge section D, thereby designating the type of operation of the discharge section D.

[0019] In this embodiment, the control unit 4 functions as the evaluation control unit 40 by operating in accordance with the control program PG stored in the storage unit 5. The control program PG may be provided, for example, by the head manufacturer that produces the liquid ejection head 1. Details of the operation of the evaluation control unit 40 are described in FIGS. 9 and 10 . For example, the evaluation control unit 40 evaluates crosstalk between multiple nozzles N based on the residual vibration analyzed by the analysis unit 3. The crosstalk evaluated by the evaluation control unit 40 is, for example, crosstalk in which the ejection characteristics of one nozzle N among the multiple nozzles N vary depending on the ejection states of the nozzles N surrounding the one nozzle N. The nozzles N surrounding a nozzle N are, for example, the nozzles N adjacent to the one nozzle N. The ejection characteristics of the nozzle N are, for example, the ejection characteristics of ink emitted by the ejection unit D.

[0020] In this manner, in this embodiment, so-called structural crosstalk that occurs due to the structure of the liquid ejection head 1, such as the arrangement of the ejection units D, is evaluated by the evaluation control unit 40. The evaluation control unit 40 is an example of a "control unit."

[0021] The drive signal generation unit 2 includes, for example, a DAC (Digital Analog Converter), and generates a plurality of drive signals COM based on a waveform designation signal dCOM supplied from the control unit 4. For example, each of the plurality of drive signals COM generated by the drive signal generation unit 2 includes a waveform defined by the waveform designation signal dCOM. The drive signal generation unit 2 outputs the plurality of drive signals COM generated based on the waveform designation signal dCOM to a switching circuit 18 included in the liquid ejection head 1.

[0022] The storage unit 5 includes one or both of a volatile memory such as a RAM (Random Access Memory) and a non-volatile memory such as a ROM (Read Only Memory), an EEPROM (Electrically Erasable Programmable Read-Only Memory), or a PROM (Programmable ROM). The storage unit 5 may be included in the control unit 4.

[0023] The liquid ejection head 1 includes a switching circuit 18, a recording head 10, and a detection circuit 19. The detection circuit 19 is an example of a "detection section."

[0024] The print head 10 has M ejection sections D. In this embodiment, it is assumed that the value M is an even number equal to or greater than 2. Hereinafter, the m-th ejection section D of the M ejection sections D provided in the print head 10 may be referred to as ejection section D[m]. Here, the variable m is a natural number that satisfies "1≦m≦M." Furthermore, hereinafter, when a component or signal of the liquid ejection device 100 corresponds to a ejection section D[m] of the M ejection sections D, the subscript [m] may be added to the symbol representing the component or signal.

[0025] The switching circuit 18 switches whether to supply each drive signal COM to the discharge section D[m] based on the print signal SI. Note that, hereinafter, as shown in FIG. 5 and other figures, the drive signal COM supplied to the discharge section D[m] among the multiple drive signals COM may be referred to as an individual drive signal Vin[m]. The switching circuit 18 also switches whether to electrically connect the discharge section D[m] to the detection circuit 19 based on the print signal SI. When the discharge section D[m] is electrically connected to the detection circuit 19, for example, a detection signal Vout[m] detected from the discharge section D[m] is supplied to the detection circuit 19 via the switching circuit 18. The detection signal Vout[m] is, for example, an analog signal indicating the waveform of residual vibration, which is vibration remaining in the discharge section D[m] after the discharge section D[m] is driven by the individual drive signal Vin[m]. Specifically, for example, the detection signal Vout[m] indicates the waveform of the residual vibration of the diaphragm 14 after the piezoelectric element PZ[m] is driven. The piezoelectric element PZ and the diaphragm 14 will be described later with reference to FIGS.

[0026] The detection circuit 19 generates the residual vibration signal VR[m] based on the detection signal Vout[m]. For example, the detection circuit 19 amplifies the amplitude of the detection signal Vout[m] or removes noise components contained in the detection signal Vout[m], thereby shaping the detection signal Vout[m] into a waveform suitable for processing in the analysis unit 3. In this way, the residual vibration signal VR[m] is generated. For example, the detection circuit 19 may be configured to include a negative feedback amplifier for amplifying the detection signal Vout[m], a low-pass filter for attenuating high frequency components of the detection signal Vout[m], and a voltage follower for converting impedance and outputting a low-impedance residual vibration signal VR[m].

[0027] For example, the residual vibration signal VR[m] generated based on the detection signal Vout[m] is an analog signal that indicates the waveform of the residual vibration of the diaphragm 14 after the piezoelectric element PZ[m] is driven by the individual drive signal Vin[m]. The detection circuit 19 outputs the residual vibration signal VR[m] generated based on the detection signal Vout[m] to the analysis unit 3. In this way, the detection circuit 19 detects the residual vibration of the diaphragm 14 caused by driving the piezoelectric element PZ[m] based on the detection signal Vout[m].

[0028] The analysis unit 3 includes, for example, an ADC (Analog to Digital Converter) and converts the analog residual vibration signal VR[m] into a digital signal. The analysis unit 3 then analyzes the residual vibration detected by, for example, the detection circuit 19 using the digitally converted residual vibration signal VR[m]. The analysis unit 3 also generates residual vibration information Vinf indicating the analysis results of the residual vibration and outputs the generated residual vibration information Vinf to the control unit 4. The residual vibration information Vinf indicates, for example, the period, amplitude, and phase of the residual vibration. However, the residual vibration information Vinf may indicate only part of the period, amplitude, and phase of the residual vibration. Alternatively, the residual vibration information Vinf may include information other than the period, amplitude, and phase of the residual vibration. The evaluation control unit 40 evaluates crosstalk between the multiple nozzles N, for example, based on the residual vibration information Vinf. The analysis unit 3 may be included in the control unit 4. For example, the control unit 4 may function as the analysis unit 3 by operating in accordance with a control program PG stored in the storage unit 5. Furthermore, a part of the analysis unit 3 may be included in the control unit 4. Specifically, an ADC may be provided outside the control unit 4, and the control unit 4 may include a function of analyzing the residual vibration using the residual vibration signal VR converted into a digital signal.

[0029] Furthermore, in this embodiment, as described above, the maintenance process is performed by the maintenance unit 7. For example, the maintenance unit 7 performs the maintenance process under the control of the control unit 4. The maintenance process includes, for example, a flushing process that discharges ink from the ejection section D, a wiping process that wipes off foreign matter such as ink adhering to the vicinity of the nozzle N of the ejection section D with a wiper, and a pumping process that sucks ink from inside the ejection section D with a tube pump or the like.

[0030] The maintenance unit 7 has a discharged ink receiving section for receiving the discharged ink when the ink in the discharge section D is discharged during the flushing process, a wiper for wiping off foreign matter such as ink adhering to the vicinity of the nozzle N of the discharge section D, and a tube pump for sucking ink, air bubbles, etc. from the discharge section D. The discharged ink receiving section, wiper, and tube pump are not shown in the drawings.

[0031] Next, the overall configuration of the liquid ejection device 100 will be described with reference to FIG.

[0032] Fig. 2 is a schematic diagram showing the configuration of the liquid ejection device 100. In Fig. 2, the ink container 60, the medium transport mechanism 8, and the carriage transport mechanism 9 will be mainly described.

[0033] The ink container 60 stores ink. Examples of the ink container 60 include a cartridge that is detachable from the liquid ejection device 100, a bag-shaped ink pack made of flexible film, and an ink tank that can be refilled with ink. The type of ink stored in the ink container 60 is not particularly limited and can be any type. As described above, this embodiment assumes that the liquid ejection device 100 has four liquid ejection heads 1, each corresponding to one of four inks: cyan, magenta, yellow, and black. Therefore, in this embodiment, the ink container 60 stores the four inks: cyan, magenta, yellow, and black. The ink container 60 supplies the stored ink to the liquid ejection head 1.

[0034] The medium conveying mechanism 8 conveys the medium PP in the Y1 direction along the Y axis under the control of the control unit 4. Hereinafter, the Y1 direction and the Y2 direction opposite to the Y1 direction will be collectively referred to as the Y-axis direction. Hereinafter, the X1 direction along the X axis intersecting the Y axis and the X2 direction opposite to the X1 direction will be collectively referred to as the X-axis direction. Hereinafter, the Z1 direction along the Z axis intersecting the X and Y axes and the Z2 direction opposite to the Z1 direction will be collectively referred to as the Z-axis direction. In this embodiment, as an example, a case will be described in which the X axis, Y axis, and Z axis are orthogonal to one another. However, the present invention is not limited to this example. It is sufficient that the X axis, Y axis, and Z axis intersect with one another.

[0035] The carriage transport mechanism 9 reciprocates the plurality of liquid ejection heads 1 in the X1 and X2 directions under the control of the control unit 4. As shown in Fig. 2, the carriage transport mechanism 9 has a substantially box-shaped carriage 91 that houses the plurality of liquid ejection heads 1, and an endless belt 92 to which the carriage 91 is fixed. Note that the ink containers 60 may be housed in the carriage 91 together with the liquid ejection heads 1.

[0036] The liquid ejection head 1 is driven by a drive signal COM under the control of a print signal SI, and ejects ink in the Z1 direction from some or all of the multiple nozzles N provided in the liquid ejection head 1. That is, the liquid ejection head 1 ejects ink from some or all of the multiple nozzles N in conjunction with the transport of the medium PP by the medium transport mechanism 8 and the reciprocating movement of the liquid ejection head 1 by the carriage transport mechanism 9, and forms a desired image on the surface of the medium PP by causing the ejected ink to land on the surface of the medium PP. In this embodiment, as described above, the Z1 direction is the direction in which ink is ejected from the nozzles N.

[0037] Next, the general structure of the liquid ejection head 1 will be described with reference to FIGS.

[0038] FIG. 3 is an exploded perspective view of the liquid ejection head 1. FIG. 4 is a cross-sectional view taken along line III-III in FIG. 3. The cross section taken along line III-III is parallel to the XZ plane and passes through inlets HL1 and HL2, which will be described later. In FIGS. 3 and 4, the numerals "1" and "2" are added to the end of the reference numerals of the nozzle rows Ln to distinguish between the two nozzle rows Ln, which will be described later. In addition, in FIGS. 3 and 4, for ease of explanation, the numeral "1" is added to the end of the reference numeral of the nozzle N included in the nozzle row Ln1, and the numeral "2" is added to the end of the reference numeral of the nozzle N included in the nozzle row Ln2.

[0039] 3 and 4, the liquid ejection head 1 has a nozzle substrate 11, compliance sheets CS1 and CS2, a communication plate 12, a pressure chamber substrate 13, a vibration plate 14, a sealing substrate 15, a flow path forming substrate 16, and a wiring board 17 on which electronic components EC are mounted. The electronic components EC include, for example, electrical circuits such as a switching circuit 18 and a detection circuit 19. For example, the recording head 10 is electrically connected to the switching circuit 18, the detection circuit 19, etc. via the wiring board 17.

[0040] As shown in FIG. 3, the recording head 10 includes, for example, a nozzle substrate 11, compliance sheets CS1 and CS2, a communication plate 12, a pressure chamber substrate 13, a vibration plate 14, a sealing substrate 15, and a flow path forming substrate 16.

[0041] The nozzle substrate 11 is a plate-like member that is elongated in the Y-axis direction and extends approximately parallel to the XY plane. Here, "approximately parallel" is a concept that includes not only completely parallel but also a case where it can be considered to be parallel when an error is taken into consideration. In this embodiment, "approximately parallel" is a concept that includes a case where it can be considered to be parallel when an error of about 10% is taken into consideration. Like "approximately parallel," the term "approximately perpendicular," which will be described later, is a concept that includes not only completely perpendicular but also perpendicular when an error is taken into consideration. The nozzle substrate 11 is manufactured by processing a silicon single crystal substrate using semiconductor manufacturing techniques such as etching, for example, but known materials and manufacturing methods may be arbitrarily adopted for manufacturing the nozzle substrate 11.

[0042] M nozzles N are formed on the nozzle substrate 11. Here, the nozzles N are through-holes formed in the nozzle substrate 11. In this embodiment, it is assumed that the multiple nozzles N formed on the nozzle substrate 11 include multiple nozzles N1 arranged to extend in the Y-axis direction and multiple nozzles N2 arranged to extend in the Y-axis direction at positions in the X2 direction as viewed from the multiple nozzles N1. Hereinafter, the multiple nozzles N1 arranged to extend in the Y-axis direction will be referred to as a nozzle row Ln1, and the multiple nozzles N2 arranged to extend in the Y-axis direction will be referred to as a nozzle row Ln2. For example, the number of nozzles N included in each of the nozzle rows LN1 and Ln2 is half the value M. Hereinafter, the nozzle row Ln1 and the nozzle row Ln2 may be collectively referred to as the nozzle row Ln. Also, in Figures 3 and 4, to make the explanation easier to understand, the numeral "1" is added to the end of the reference numeral of the component of the liquid ejection head 1 that corresponds to nozzle row Ln1, and the numeral "2" is added to the end of the reference numeral of the component that corresponds to nozzle row Ln2.

[0043] 3 and 4, a communicating plate 12 is provided at a position in the Z2 direction as viewed from the nozzle substrate 11. The communicating plate 12 is a plate-shaped member that is long in the Y-axis direction and extends approximately parallel to the XY plane. The communicating plate 12 is manufactured, for example, by processing a silicon single crystal substrate using semiconductor manufacturing technology, but the communicating plate 12 may be manufactured using any known material and method.

[0044] Ink flow paths are formed in the communicating plate 12. Specifically, the communicating plate 12 is formed with one supply flow path BA1 extending in the Y-axis direction and one supply flow path BA2 extending in the Y-axis direction at a position in the X2 direction as viewed from the supply flow path BA1. The communicating plate 12 also is formed with a plurality of connection flow paths BK1 corresponding to the plurality of nozzles N1, a plurality of connection flow paths BK2 corresponding to the plurality of nozzles N2, a plurality of communication flow paths BR1 corresponding to the plurality of nozzles N1, and a plurality of communication flow paths BR2 corresponding to the plurality of nozzles N2.

[0045] As shown in FIG. 4, the connection flow path BK1 communicates with the supply flow path BA1 and is provided so as to extend in the Z-axis direction at a position in the X2 direction as viewed from the supply flow path BA1. The communication flow path BR1 is provided so as to extend in the Z-axis direction at a position in the X2 direction as viewed from the connection flow path BK1. The communication flow path BR1 communicates with the nozzle N1 corresponding to the communication flow path BR1. The connection flow path BK2 communicates with the supply flow path BA2 and is provided so as to extend in the Z-axis direction at a position in the X1 direction as viewed from the supply flow path BA2. The communication flow path BR2 is provided so as to extend in the Z-axis direction at a position in the X1 direction as viewed from the connection flow path BK2 and at a position in the X2 direction as viewed from the communication flow path BR1. The communication flow path BR2 communicates with the nozzle N2 corresponding to the communication flow path BR2.

[0046] The supply flow paths BA1 and BA2 are also referred to as supply flow paths BA without any particular distinction, the connection flow paths BK1 and BK2 are also referred to as connection flow paths BK without any particular distinction, and the communicating flow paths BR1 and BR2 are also referred to as communicating flow paths BR without any particular distinction.

[0047] 3 and 4, a pressure chamber substrate 13 is provided at a position in the Z2 direction as viewed from the communication plate 12. The pressure chamber substrate 13 is a plate-shaped member that is long in the Y-axis direction and extends approximately parallel to the XY plane. The pressure chamber substrate 13 is manufactured, for example, by processing a silicon single crystal substrate using semiconductor manufacturing technology, but the pressure chamber substrate 13 may be manufactured using any known material and manufacturing method.

[0048] Ink flow paths are formed in the pressure chamber substrate 13. Specifically, the pressure chamber substrate 13 is formed with a plurality of pressure chambers CV1 corresponding to the plurality of nozzles N1 and a plurality of pressure chambers CV2 corresponding to the plurality of nozzles N2. For example, as shown in FIG. 3, the plurality of pressure chambers CV1 are partitioned by partition walls WL1 of the pressure chamber substrate 13 and are arranged in the Y-axis direction. The plurality of pressure chambers CV2 are partitioned by partition walls WL2 of the pressure chamber substrate 13 and are arranged in the Y-axis direction at positions in the X2 direction as viewed from the plurality of pressure chambers CV1. As shown in FIG. 4, the pressure chamber CV1 is provided so as to connect the X2-direction end of the connection flow path BK1 and the X1-direction end of the communication flow path BR1 when viewed in the Z-axis direction, and extend in the X-axis direction. The pressure chamber CV2 is provided so as to connect the X1-direction end of the connection flow path BK2 and the X2-direction end of the communication flow path BR2 when viewed in the Z-axis direction, and extend in the X-axis direction. The pressure chambers CV1 and CV2 are also referred to as pressure chambers CV without any particular distinction, and the partition walls WL1 and WL2 are also referred to as partition walls WL without any particular distinction.

[0049] As shown in FIGS. 3 and 4 , a diaphragm 14 is provided at a position in the Z2 direction as viewed from the pressure chamber substrate 13. The diaphragm 14 is a plate-shaped member that is elongated in the Y-axis direction and extends substantially parallel to the XY plane, and is capable of elastically vibrating. In this embodiment, the diaphragm 14 has, for example, an elastic layer made of silicon oxide and an insulating layer made of zirconium oxide provided at a position in the Z2 direction as viewed from the elastic layer. That is, in this embodiment, the Z2-direction surface of the diaphragm 14 is formed of a non-conductive material. Here, the first-direction surface of element A is a surface of element A that is substantially perpendicular to the first direction and is the surface that is visible when element A is viewed from the first direction to the second direction. The second direction is the direction opposite to the first direction. Note that the elastic layer of the diaphragm 14 is not limited to an elastic layer made of silicon oxide. Similarly, the insulating layer of the diaphragm 14 is not limited to an insulating layer made of zirconium oxide.

[0050] 3 and 4, a plurality of piezoelectric elements PZ1 corresponding to the plurality of pressure chambers CV1 and a plurality of piezoelectric elements PZ2 corresponding to the plurality of pressure chambers CV2 are provided in positions in the Z2 direction as viewed from the vibration plate 14. Note that the piezoelectric elements PZ1 and PZ2 are also referred to as piezoelectric elements PZ without any particular distinction. The piezoelectric elements PZ are driven by the supply of a drive signal COM.

[0051] Although not shown in FIGS. 3 and 4 , the piezoelectric element PZ includes a common electrode Zc to which a predetermined bias potential VBS is supplied, an individual electrode Za to which an individual drive signal Vin is supplied, and a piezoelectric body Zb disposed between the individual electrode Za and the common electrode Zc, as shown in FIG. 5 . For example, the individual electrode Za, the piezoelectric body Zb, and the common electrode Zc are disposed in this order on the Z2-direction surface of the diaphragm 14 along the Z2 direction. Here, the expression “element B is formed on the surface of element A” in this specification does not intend to limit the configuration to one in which element A and element B are in direct contact with each other. In other words, even if element C is formed on the surface of element A and element B is formed on the surface of element C, the concept of “element B is formed on the surface of element A” is encompassed as long as at least a portion of element A and element B overlap in a planar view. Note that in this embodiment, the common electrode Zc is a so-called upper electrode and the individual electrode Za is a so-called lower electrode. However, the common electrode Zc may be a lower electrode and the individual electrode Za may be an upper electrode.

[0052] The piezoelectric element PZ is a passive element that deforms in response to changes in the potential of the drive signal COM supplied to the individual electrode Za as the individual drive signal Vin. In other words, the piezoelectric element PZ is an example of an energy conversion element that converts the electrical energy of the drive signal COM into kinetic energy. Specifically, the piezoelectric element PZ is driven and deforms in response to changes in the potential of the drive signal COM.

[0053] As shown in FIGS. 3 and 4, a piezoelectric element PZ is provided on the Z2-direction surface of the vibration plate 14, and therefore the vibration plate 14 vibrates in conjunction with the deformation of the piezoelectric element PZ. That is, the vibration plate 14 vibrates when the piezoelectric element PZ is driven. When the vibration plate 14 vibrates, the pressure in the pressure chamber CV fluctuates. Then, as the pressure in the pressure chamber CV fluctuates, ink filled in the pressure chamber CV is ejected from the nozzle N via the communication flow path BR. In this way, the pressure chamber CV is filled with ink, and pressure for ejecting the ink from the nozzle N is applied by the vibration of the vibration plate 14. Furthermore, the vibration remaining in the ejection portion D[m] described in FIG. 1 can also be considered, for example, as vibration remaining in the ink in the pressure chamber CV of the ejection portion D.

[0054] 3 and 4, a sealing substrate 15 for protecting the plurality of piezoelectric elements PZ1 and the plurality of piezoelectric elements PZ2 is provided at a position in the Z2 direction as viewed from the pressure chamber substrate 13. The sealing substrate 15 is a plate-like member that is elongated in the Y-axis direction and extends approximately parallel to the XY plane. The sealing substrate 15 is manufactured, for example, by processing a silicon single crystal substrate using semiconductor manufacturing technology, but the sealing substrate 15 may be manufactured using any known material and manufacturing method.

[0055] 4, the surface of the sealing substrate 15 in the Z1 direction is provided with recesses for covering the plurality of piezoelectric elements PZ1 and recesses for covering the plurality of piezoelectric elements PZ2. Hereinafter, the sealed space covering the plurality of piezoelectric elements PZ1 and formed between the vibration plate 14 and the sealing substrate 15 will be referred to as the sealed space SP1, and the sealed space covering the plurality of piezoelectric elements PZ2 and formed between the vibration plate 14 and the sealing substrate 15 will be referred to as the sealed space SP2. The sealed spaces SP1 and SP2 will also be referred to as the sealed space SP without any particular distinction. The sealed space SP is a space for sealing the piezoelectric elements PZ and preventing the piezoelectric elements PZ from being altered by the influence of moisture, etc.

[0056] A through hole 15h is provided in the sealing substrate 15. When the sealing substrate 15 is viewed in the Z1 direction, the through hole 15h is located between the sealed space SP1 and the sealed space SP2, and is a hole that penetrates from the surface of the sealing substrate 15 in the Z1 direction to the surface of the sealing substrate 15 in the Z2 direction. The wiring substrate 17 is inserted into the through hole 15h.

[0057] 3 and 4, a flow path forming substrate 16 is provided at a position in the Z2 direction as viewed from the communication plate 12. The flow path forming substrate 16 is a plate-like member that is elongated in the Y-axis direction and extends substantially parallel to the XY plane. The flow path forming substrate 16 is formed, for example, by injection molding of a resin material, but the flow path forming substrate 16 may be manufactured using any known material and method.

[0058] As shown in FIG. 4, ink flow paths are formed in the flow path forming substrate 16. Specifically, one supply flow path BB1 and one supply flow path BB2 are formed in the flow path forming substrate 16. Of these, supply flow path BB1 communicates with supply flow path BA1 and is provided so as to extend in the Y-axis direction at a position in the Z2 direction as viewed from supply flow path BA1. Supply flow path BB2 communicates with supply flow path BA2 and is provided so as to extend in the Y-axis direction at a position in the Z2 direction as viewed from supply flow path BA2 and at a position in the X2 direction as viewed from supply flow path BB1. Note that supply flow paths BB1 and BB2 are also referred to as supply flow paths BB without any particular distinction being made.

[0059] The flow channel forming substrate 16 is provided with an inlet HL1 that communicates with the supply channel BB1 and an inlet HL2 that communicates with the supply channel BB2. Ink is supplied to the supply channel BB1 from the ink container 60 via the inlet HL1. The ink supplied to the supply channel BB1 from the ink container 60 via the inlet HL1 flows into the supply channel BA1. Some of the ink that flows into the supply channel BA1 passes through the connecting channel BK1 and fills the pressure chamber CV1. When the piezoelectric element PZ1 is driven by the drive signal COM, some of the ink that has filled the pressure chamber CV1 is ejected from the nozzle N1 via the communicating channel BR1.

[0060] Furthermore, ink is supplied to supply flow path BB2 from the ink container 60 via inlet HL2. The ink supplied from the ink container 60 to supply flow path BB2 via inlet HL2 flows into supply flow path BA2. Some of the ink that flows into supply flow path BA2 passes through connecting flow path BK2 and fills pressure chamber CV2. When piezoelectric element PZ2 is driven by drive signal COM, some of the ink that has filled pressure chamber CV2 is ejected from nozzle N2 via communicating flow path BR2.

[0061] A through hole 16h is provided in the flow path forming substrate 16. When the flow path forming substrate 16 is viewed in the Z1 direction, the through hole 16h is located between the supply flow path BB1 and the supply flow path BB2, and is a hole that penetrates from the surface of the flow path forming substrate 16 in the Z1 direction to the surface of the flow path forming substrate 16 in the Z2 direction. The wiring substrate 17 is inserted into the through hole 16h.

[0062] 3 and 4, a wiring board 17 is mounted on the Z2 direction surface of the diaphragm 14. The wiring board 17 is a component for electrically connecting the liquid ejection head 1 to the control unit 4. For example, a flexible wiring board such as an FPC (Flexible Printed Circuit) or an FFC (Flexible Flat Cable) is preferably used as the wiring board 17. As described above, electronic components EC including the switching circuit 18 and the detection circuit 19 are mounted on the wiring board 17.

[0063] 3 and 4, a compliance sheet CS1 is provided in a position in the Z1 direction as viewed from the communicating plate 12 so as to block the supply flow path BA1 and the connecting flow path BK1, and a compliance sheet CS2 is provided so as to block the supply flow path BA2 and the connecting flow path BK2. The compliance sheets CS1 and CS2 are also referred to as the compliance sheet CS without any particular distinction. The compliance sheet CS is a plate-like member that is elongated in the Y-axis direction and extends substantially parallel to the XY plane. The compliance sheet CS is made of an elastic material and absorbs pressure fluctuations of the ink in the supply flow path BA and the connecting flow path BK.

[0064] 4, the ejection section D1 has a piezoelectric element PZ1, a pressure chamber CV1, a nozzle N1 communicating with the pressure chamber CV1, and a portion of the vibration plate 14 that contacts the piezoelectric element PZ1. Similarly, the ejection section D2 has a piezoelectric element PZ2, a pressure chamber CV2, a nozzle N2 communicating with the pressure chamber CV2, and a portion of the vibration plate 14 that contacts the piezoelectric element PZ2. The ejection sections D1 and D2 are also referred to as ejection section D without any particular distinction. In the following, the second element of the first element and second element included in one ejection section D will also be referred to as the second element corresponding to the first element. Specifically, for example, the piezoelectric element PZ included in the ejection section D that has one nozzle N will also be referred to as the piezoelectric element PZ corresponding to the one nozzle N.

[0065] Although not shown, the liquid ejection head 1 also has a cap for sealing the nozzle surface, which is the surface in the Z1 direction of the nozzle substrate 11. The cap seals the nozzle surface of the nozzle substrate 11 on which the nozzles N are formed, during periods when ink is not ejected from the nozzles N.

[0066] Next, an overview of the liquid ejection head 1 will be described with reference to FIG.

[0067] FIG. 5 is a block diagram showing an example of the configuration of the liquid ejection head 1. As shown in FIG.

[0068] 1, the liquid ejection head 1 has a recording head 10, a switching circuit 18, and a detection circuit 19. The liquid ejection head 1 also has a wiring La to which a drive signal COMa is supplied from the drive signal generation unit 2, and a wiring Lb to which a drive signal COMb is supplied from the drive signal generation unit 2. The liquid ejection head 1 also has a wiring Ls that supplies a detection signal Vout to the detection circuit 19, a wiring Li[m] that supplies an individual drive signal Vin[m] to the ejection section D[m], and a wiring Ld to which a bias potential VBS is supplied.

[0069] The switching circuit 18 has M switches SWa[1] to SWa[M] that correspond one-to-one to the M discharge units D[1] to D[M], M switches SWb[1] to SWb[M] that correspond one-to-one to the M discharge units D[1] to D[M], and M switches SWs[1] to SWs[M] that correspond one-to-one to the M discharge units D[1] to D[M].

[0070] The switching circuit 18 also has a connection state designation circuit CSC. The connection state designation circuit CSC designates the connection states of the M switches SWa, M switches SWb, and M switches SWs. For example, the connection state designation circuit CSC generates connection state designation signals Qa[m], Qb[m], and Qs[m] based on at least a portion of the print signal SI and the latch signal LAT supplied from the control unit 4.

[0071] For example, the connection state designation signal Qa[m] is a signal that designates the on / off state of the switch SWa[m], the connection state designation signal Qb[m] is a signal that designates the on / off state of the switch SWb[m], and the connection state designation signal Qs[m] is a signal that designates the on / off state of the switch SWs[m].

[0072] The switch SWa[m] switches between conduction and non-conduction between the wiring La and the individual electrode Za[m] of the piezoelectric element PZ[m] provided in the discharge section D[m] based on the connection state designation signal Qa[m]. That is, the switch SWa[m] switches between conduction and non-conduction between the wiring La and the wiring Li[m] connected to the individual electrode Za[m] based on the connection state designation signal Qa[m]. In this embodiment, the switch SWa[m] is turned on when the connection state designation signal Qa[m] is high level and turned off when it is low level. When the switch SWa[m] is on, the drive signal COMa supplied to the wiring La is supplied as the individual drive signal Vin[m] to the individual electrode Za[m] of the discharge section D[m] via the wiring Li[m].

[0073] The switch SWb[m] switches between conduction and non-conduction between the wiring Lb and the individual electrode Za[m] of the piezoelectric element PZ[m] provided in the discharge section D[m] based on the connection state designation signal Qb[m]. That is, the switch SWb[m] switches between conduction and non-conduction between the wiring Lb and the wiring Li[m] connected to the individual electrode Za[m] based on the connection state designation signal Qb[m]. In this embodiment, the switch SWb[m] is turned on when the connection state designation signal Qb[m] is high level and turned off when the connection state designation signal Qb[m] is low level. When the switch SWb[m] is on, the drive signal COMb supplied to the wiring Lb is supplied as the individual drive signal Vin[m] to the individual electrode Za[m] of the discharge section D[m] via the wiring Li[m].

[0074] The switch SWs[m] switches between electrical continuity and non-conduction between the wiring Ls and the individual electrode Za[m] of the piezoelectric element PZ[m] provided in the discharge portion D[m] based on the connection state designation signal Qs[m]. That is, the switch SWs[m] switches between electrical continuity and non-conduction between the wiring Ls and the wiring Li[m] connected to the individual electrode Za[m] based on the connection state designation signal Qs[m]. In this embodiment, the switch SWs[m] is turned on when the connection state designation signal Qs[m] is high level and turned off when the connection state designation signal Qs[m] is low level.

[0075] For example, the connection state designation signal Qs[m] becomes high level when residual vibration of a discharge section D[m] is detected. Hereinafter, the discharge section D from which residual vibration is detected may be referred to as the discharge section D of the detection target. Also, below, the nozzle N of the discharge section D of the detection target may be referred to as the nozzle N of the detection target. When the switch SWs[m] is turned on, a detection signal Vout[m] indicating the potential of the individual electrode Za[m] of the piezoelectric element PZ[m] of the discharge section D[m] of the detection target is supplied to the detection circuit 19 via the wiring Li[m] and the wiring Ls. The detection circuit 19 generates a residual vibration signal VR[m] based on the detection signal Vout[m].

[0076] As described above, the individual drive signal Vin[m] is the signal of the drive signals COMa and COMb that is supplied to the piezoelectric element PZ[m] of the ejection section D[m] via the switch SWa[m] or SWb[m]. In this embodiment, it is assumed that the drive signal COMa is the drive signal COM that causes ink to be ejected from the nozzle N, and the drive signal COMb is the drive signal COM that does not cause ink to be ejected from the nozzle N. Therefore, in this embodiment, the drive signal COMa is an example of an "ejection signal," and the drive signal COMb is an example of a "hold signal."

[0077] Here, in a liquid ejection head 1 having a plurality of nozzles N, it is preferable to suppress fluctuations in the ejection characteristics of the nozzles N due to structural crosstalk. In this embodiment, the occurrence of crosstalk is suppressed by adjusting the potential difference between the individual electrode Za and the common electrode Zc of the piezoelectric element PZ corresponding to the nozzle N that does not eject ink. Hereinafter, the nozzle N that does not eject ink is also referred to as a non-ejecting nozzle N. In this embodiment, the occurrence of crosstalk is suppressed, for example, by adjusting the potential of the drive signal COMb supplied to the piezoelectric element PZ corresponding to the non-ejecting nozzle N. Note that this embodiment assumes that the reference potential of the drive signal COMa is set to the same potential as the potential of the drive signal COMb, but the reference potential of the drive signal COMa may be a potential different from the potential of the drive signal COMb.

[0078] Next, crosstalk will be briefly described with reference to Fig. 6. In this embodiment, crosstalk refers to so-called structural crosstalk, in which the ejection characteristics from a nozzle N communicating with a target pressure chamber vary depending on the drive state of a pressure chamber close to (particularly adjacent to) the target pressure chamber.

[0079] FIG. 6 is an explanatory diagram for explaining crosstalk. In FIG. 6, crosstalk will be explained using the multiple nozzles N1 included in the nozzle row Ln1 as an example. Note that in FIG. 6, for ease of understanding, the reference numerals of the multiple nozzles N1 are suffixed with the letters "a," "b," "c," "d," "e," or "f." Furthermore, the reference numeral of the pressure chamber CV1 corresponding to nozzle N1c is suffixed with the letter "c," and the reference numeral of the pressure chamber CV1 corresponding to nozzle N1d is suffixed with the letter "d."

[0080] In Figure 6, as shown in the "nozzle row" of Figure 6, it is assumed that nozzle N1c is the nozzle N to be detected. That is, Figure 6 briefly explains one reason why the ejection characteristics of nozzle N1c vary depending on the ejection state of nozzles N1d and other nozzles adjacent to nozzle N1c. Nozzle N1c is an example of a "first nozzle," nozzle N1d is an example of a "second nozzle," and nozzle N1b is an example of a "third nozzle." Furthermore, the piezoelectric element PZ corresponding to nozzle N1c is an example of a "first piezoelectric element," the piezoelectric element PZ corresponding to nozzle N1d is an example of a "second piezoelectric element," and the piezoelectric element PZ corresponding to nozzle N1b is an example of a "third piezoelectric element."

[0081] "Full ejection" in Figure 6 schematically shows the diaphragm 14 and other components when all of the multiple nozzles N1 included in nozzle row Ln1 are driven to eject ink. Hereinafter, driving to eject ink from all of the multiple nozzles N is also referred to as "full ejection." Note that forces FY1 and FY2 in Figure 6 represent forces in the Y1 and Y2 directions, respectively, applied to the portion of the diaphragm 14 connected to the partition wall WL1 between pressure chamber CV1c and pressure chamber CV1d.

[0082] 6 shows a schematic diagram of the diaphragm 14 when only the even-numbered nozzles N1 or only the odd-numbered nozzles N1 of the multiple nozzles N1 included in the nozzle row Ln1 are driven to eject ink. That is, the "adjacent non-ejection" diagram in FIG. 6 shows a schematic diagram of the diaphragm 14 when the nozzles N1a, N1c, and N1e are driven to eject ink, and the nozzles N1b, N1d, and N1f are driven not to eject ink. Hereinafter, driving to eject ink using only the even-numbered nozzles N or only the odd-numbered nozzles N of the multiple nozzles N arranged along the Y-axis direction is also referred to as "alternate ejection."

[0083] During full discharge, the piezoelectric elements PZ are driven in the same way in the nozzle N1c that is the detection target and in the nozzle N1d that is adjacent to the nozzle N1c, and therefore the force FY1 is considered to be similar to the force FY2.

[0084] In contrast, during alternating ejection, the piezoelectric element PZ corresponding to nozzle N1d is driven so that ink is not ejected from nozzle N1d, and so it is believed that the force FY1 during alternating ejection varies from the force FY1 during full ejection. For this reason, it is believed that the difference between force FY1 and force FY2 differs between full ejection and alternating ejection. It is believed that the variation in the difference between force FY1 and force FY2 varies the way in which vibration of diaphragm 14 occurs, and thus the ejection characteristics of nozzle N1c vary.

[0085] Thus, the difference between the forces FY1 and FY2 fluctuates between full ejection and alternating ejection, which is thought to be one cause of crosstalk. The force FY1 during alternating ejection is controlled, for example, by adjusting the potential difference between the individual electrode Za and the common electrode Zc of the piezoelectric element PZ corresponding to the non-ejecting nozzle N. Therefore, in this embodiment, by adjusting the potential difference between the individual electrode Za and the common electrode Zc of the piezoelectric element PZ corresponding to the non-ejecting nozzle N, the difference between the forces FY1 and FY2 during alternating ejection is prevented from fluctuating from the difference between the forces FY1 and FY2 during full ejection. As a result, in this embodiment, the occurrence of crosstalk is suppressed.

[0086] Here, we have explained that the variations in the forces FY1 and FY2 applied to the diaphragm 14 are a cause of structural crosstalk, but there are other influences as well. For example, in full ejection, when pressure chamber CV1c contracts during ejection, its internal pressure exerts a force that pushes the partition wall WL outward. However, a similar force also acts on pressure chamber CV1d, so the force from the internal pressure acting on partition wall WL is actually canceled out. On the other hand, in alternating ejection, pressure chamber CV1d does not contract and its internal pressure does not increase, so when pressure chamber CV1c contracts, its internal pressure can cause the partition wall WL to tilt slightly toward pressure chamber CV1d. This impairs the internal pressure that contributes to liquid ejection, resulting in variations in ejection characteristics, such as a slight decrease in the ejection volume.

[0087] As described above, structural crosstalk occurs due to a combination of several causes, but in any case, structural crosstalk is "variation in the ejection characteristics of a target pressure chamber depending on the drive state of adjacent pressure chambers," and in this embodiment, the potential of the drive signal COMb is adjusted to eliminate this. Note that elements other than the potential of the drive signal COMb may also be adjusted to suppress the occurrence of crosstalk.

[0088] Next, the operation of the liquid ejection device 100 in the unit period TU will be described with reference to FIG.

[0089] 7 is a timing chart showing an example of the operation of the liquid ejection device 100 in a unit period TU. In this embodiment, when the liquid ejection device 100 executes a printing process, a printing process period including one or more unit periods TU is set as the operating period of the liquid ejection device 100. The liquid ejection device 100 according to this embodiment can drive each ejection section D for the printing process in each unit period TU. Furthermore, the liquid ejection device 100 according to this embodiment can drive the ejection section D to be detected and detect the detection signal Vout[m] from the ejection section D to be detected in each unit period TU.

[0090] 7 shows three examples of sets of drive signals COMa and COMb used in evaluating crosstalk, indicated by solid lines, dashed lines, and dotted lines. However, the drive signals COMa and COMb supplied to the liquid ejection head 1 in each unit period TU are one of the three sets of drive signals COMa and COMb. For example, the set of drive signals COMa and COMb supplied to the liquid ejection head 1 in each unit period TU is selected based on the results of the crosstalk evaluation shown in FIGS. 9 and 10, which will be described later.

[0091] The control unit 4 outputs a latch signal LAT having a pulse PlsL, thereby defining a unit period TU as the period from the rising edge of one pulse PlsL to the rising edge of the next pulse PlsL.

[0092] The print signal SI includes, for example, M individual designation signals Sd[1] to Sd[M] that correspond one-to-one to the M discharge sections D[1] to D[M]. The individual designation signal Sd[m] designates the driving mode of the discharge section D[m] in each unit period TU when the liquid discharger 100 executes a printing process.

[0093] Prior to each unit period TU during which printing is performed, the control unit 4 supplies a print signal SI, including individual designation signals Sd[1] to Sd[M], to the connection state designation circuit CSC in synchronization with the clock signal CL. Then, during the unit period TU, the connection state designation circuit CSC generates connection state designation signals Qa[m], Qb[m], and Qs[m] based on the individual designation signal Sd[m].

[0094] For example, in a unit period TP during which the printing process is executed, an ejection section D[m] is designated by an individual designation signal Sd[m] as either an ejection section D that forms dots, an ejection section D that does not form dots, or an ejection section D that is the detection target. An ejection section D that forms dots is an ejection section D whose piezoelectric element PZ is driven so that ink is ejected from the nozzle N of the ejection section D. Also, an ejection section D that does not form dots is an ejection section D whose piezoelectric element PZ is driven so that ink is not ejected from the nozzle N of the ejection section D.

[0095] First, we will explain the operation of the connection state designation circuit CSC and other components when the drive mode of the discharge unit D that forms dots is designated by the individual designation signal Sd[m]. When the drive mode of the discharge unit D that forms dots is designated by the individual designation signal Sd[m], for example, the connection state designation circuit CSC sets the connection state designation signal Qa[m] to a high level and the connection state designation signals Qb[m] and Qs[m] to a low level during the unit period TU. This causes the drive signal COMa to be supplied from the drive signal generation unit 2 to the discharge unit D that forms dots.

[0096] For example, the drive signal generation unit 2 outputs one ejection signal DS as the drive signal COMa that ejects ink from the nozzle N. In the example shown in FIG. 7, the drive signal generation unit 2 outputs one of an ejection signal DS1 having a pulse PA1, an ejection signal DS2 having a pulse PA2, and an ejection signal DS3 having a pulse PA3 as the drive signal COMa. The ejection signals DS1, DS2, and DS3 are also referred to as ejection signals DS without any particular distinction, and the pulses PA1, PA2, and PA3 are also referred to as pulses PA without any particular distinction. One of the ejection signals DS1, DS2, and DS3 is an example of a "first ejection signal," and the other ejection signals DS are each an example of a "second ejection signal."

[0097] The pulse PA is, for example, a pulse that causes ink to be ejected from the nozzle N. For example, the pulse PA1 is a waveform in which the potential of the ejection signal DS1 changes from a potential VC1 to a potential VLa and a potential VHa before returning to the potential VC1. Similarly, the pulse PA2 is a waveform in which the potential of the ejection signal DS2 changes from a potential VC2 to a potential VLa and a potential VHa before returning to the potential VC2, and the pulse PA3 is a waveform in which the potential of the ejection signal DS3 changes from a potential VC3 to a potential VLa and a potential VHa before returning to the potential VC3.

[0098] The potential VC1 is the potential at the start and end of the pulse PA1 and is the reference potential of the ejection signal DS1. Similarly, the potential VC2 is the potential at the start and end of the pulse PA2 and is the reference potential of the ejection signal DS2. The potential VC3 is the potential at the start and end of the pulse PA3 and is the reference potential of the ejection signal DS3. The potential VLa is a potential lower than the potentials VC1, VC2, and VC3 and is an example of an "expansion potential" and a "minimum potential." The potential VHa is a potential higher than the potentials VC1, VC2, and VC3 and is an example of a "contraction potential" and a "maximum potential." The potentials VC1, VC2, and VC3 are potentials between the potentials VLa and VHa. Hereinafter, the potentials VC1, VC2, and VC3 will also be referred to as potentials VC without any particular distinction. The potential VC is an example of a "reference potential." One of the potentials VC1, VC2, and VC3, the potential VC, is an example of a "first potential," and each of the other potentials VC is an example of a "second potential."

[0099] For example, the pulse PA has a waveform element Pa1 whose potential changes from potential VC to potential VLa, a waveform element Pa2 whose potential is maintained at the potential VLa at the end of the waveform element Pa1, and a waveform element Pa3 whose potential changes from potential VLa to potential VHa. The pulse PA further includes a waveform element Pa4 whose potential is maintained at the potential VHa at the end of the waveform element Pa3, and a waveform element Pa5 whose potential changes from potential VHa to potential VC. Waveform element Pa1 is an example of a "first element," and waveform element Pa3 is an example of a "second element."

[0100] The waveform elements Pa1 and Pa5 are expansion elements for displacing the piezoelectric body Zb in the Z2 direction. In the expansion elements, the potential of the drive signal COMa changes to drive the piezoelectric element PZ so as to expand the volume of the pressure chamber CV. Therefore, in the waveform elements Pa1 and Pa5, the potential of the drive signal COMa changes so as to expand the volume of the pressure chamber CV. When the volume of the pressure chamber CV expands, the surface of the ink in the nozzle N is pulled in the Z2 direction, which is the opposite direction to the ejection direction. Hereinafter, pulling the surface of the ink in the nozzle N in the direction opposite to the ejection direction may be referred to as "pull."

[0101] Furthermore, the waveform element Pa3 is a contraction element for displacing the piezoelectric body Zb in the Z1 direction. In the contraction element, the potential of the drive signal COMa changes to drive the piezoelectric element PZ so as to contract the volume of the pressure chamber CV. Therefore, in the waveform element Pa3, the potential of the drive signal COMa changes so as to contract the volume of the pressure chamber CV. When the volume of the pressure chamber CV contracts, the surface of the ink in the nozzle N is pushed in the Z1 direction, which is the ejection direction. Hereinafter, pushing the surface of the ink in the nozzle N in the ejection direction may be referred to as a push.

[0102] Furthermore, waveform elements Pa2 and Pa4 are maintaining elements for maintaining the position of piezoelectric body Zb in the Z-axis direction. For example, waveform element Pa2 maintains the potential of drive signal COMa in order to drive piezoelectric element PZ so as to maintain the volume of pressure chamber CV expanded by waveform element Pa1. For example, waveform element Pa4 maintains the potential of drive signal COMa in order to drive piezoelectric element PZ so as to maintain the volume of pressure chamber CV contracted by waveform element Pa3.

[0103] In this way, the pulse PA has a so-called pull-push-pull waveform. However, the waveform of the drive signal COMa that causes ink to be ejected from the nozzle N, that is, the waveform of the ejection signal DS, is not limited to the pull-push-pull waveform.

[0104] The pulse PA is determined so that a predetermined amount of ink is ejected from the ejection section D[m] when an individual drive signal Vin[m] having the pulse PA is supplied to the ejection section D[m]. Note that in this embodiment, it is assumed that when the potential of the individual drive signal Vin[m] is high, the volume of the pressure chamber CV of the ejection section D[m] is smaller than when the potential is low. Therefore, when the ejection section D[m] is driven by the individual drive signal Vin[m] having the pulse PA, the ink in the ejection section D[m] is ejected from the nozzle N by the waveform element Pa3, in which the potential of the individual drive signal Vin[m] changes from low to high.

[0105] For example, the waveform elements Pa1, Pa2, Pa3, Pa4, and Pa5 included in the pulse PA are determined based on the ink ejection characteristics of the ejection unit D. The ink ejection characteristics include, for example, the amount of ink ejected as ink droplets and the ejection speed of the ejected ink droplets. In addition, in this embodiment, the reference potential, which is the potential VC at the start and end of the pulse PA, is determined so as to suppress the occurrence of crosstalk.

[0106] That is, in this embodiment, the occurrence of crosstalk is suppressed by adjusting the reference potential VC, which is the potential at the start and end of the pulse PA. The occurrence of crosstalk is controlled, for example, by adjusting the potential of the drive signal COMb supplied to the piezoelectric element PZ corresponding to the non-ejecting nozzle N, as described with reference to FIG. 6 . In this embodiment, it is assumed that the same potential as the potential of the drive signal COMb is used as the reference potential of the pulse PA. Therefore, for example, the evaluation control unit 40 evaluates crosstalk using multiple ejection signals DS with different reference potentials of the pulse PA. Then, for example, among the multiple ejection signals DS, an ejection signal DS that does not cause crosstalk is set as the drive signal COMa. This suppresses fluctuations in the ejection characteristics of ink ejected from one nozzle N among multiple nozzles N due to the ejection status of other nozzles N, such as nozzles N adjacent to the one nozzle N.

[0107] Next, we will explain the operation of the connection state designation circuit CSC and other components when the individual designation signal Sd[m] designates a drive mode for a discharge unit D that does not form dots. When the individual designation signal Sd[m] designates a drive mode for a discharge unit D that does not form dots, for example, the connection state designation circuit CSC sets the connection state designation signal Qb[m] to a high level and the connection state designation signals Qa[m] and Qs[m] to a low level during the unit period TU. This causes the drive signal COMb to be supplied from the drive signal generation unit 2 to the discharge unit D that does not form dots.

[0108] For example, the drive signal generation unit 2 outputs one hold signal HS as the drive signal COMb that does not cause ink to be ejected from the nozzle N. In the example shown in FIG. 7, the drive signal generation unit 2 outputs, as the drive signal COMb, one of a hold signal HS1 maintained at a potential VC1, a hold signal HS2 maintained at a potential VC2, and a hold signal HS3 maintained at a potential VC3. Note that the hold signals HS1, HS2, and HS3 are also referred to as hold signals HS without any particular distinction. One of the hold signals HS1, HS2, and HS3 is an example of a "first hold signal," and each of the other hold signals HS is an example of a "second hold signal."

[0109] In this embodiment, the same potential as the potential of the drive signal COMb is set as the reference potential of the drive signal COMa, so that, for example, when the ejection signal DS1 is selected as the drive signal COMa, the hold signal HS1 is selected as the drive signal COMb, when the ejection signal DS2 is selected as the drive signal COMa, the hold signal HS2 is selected as the drive signal COMb, and when the ejection signal DS3 is selected as the drive signal COMa, the hold signal HS3 is selected as the drive signal COMb.

[0110] Next, the operation of the connection state specification circuit CSC and the like when the drive mode of the discharge unit D to be detected is specified by the individual specification signal Sd[m] will be described. Below, the operation of the connection state specification circuit CSC and the like when the drive mode of the discharge unit D to be detected is specified by the individual specification signal Sd[m] will be described using the case of evaluating crosstalk as an example. For example, when evaluating crosstalk, the discharge unit D to be detected is specified by the individual specification signal Sd[m] in the detection unit period TU, which is the unit period TU next to the unit period TU in which the multiple piezoelectric elements PZ are driven by full discharge or alternating discharge.

[0111] For example, when the drive mode of the discharge section D to be detected is specified by the individual specification signal Sd[m], the connection state specification circuit CSC sets the connection state specification signal Qs[m] to a high level during the detection unit period TU, and also sets the connection state specification signals Qa[m] and Qb[m] to a low level during the detection unit period TU.

[0112] In this case, the piezoelectric element PZ[m] of the discharge section D[m] to be detected is driven by the drive signal COMa during the unit period TU before the detection unit period TU. As a result, the piezoelectric element PZ[m] is displaced by the pulse PA of the drive signal COMa during the unit period TU before the detection unit period TU. As a result, vibrations occur in the discharge section D[m] to be detected. The vibrations that occurred during the unit period TU before the detection unit period TU remain during the detection unit period TU. During the detection unit period TU, the potential of the individual electrode Za[m] of the piezoelectric element PZ[m] of the discharge section D[m] to be detected changes depending on the residual vibrations occurring in the discharge section D[m]. That is, during the detection unit period TU, the potential of the individual electrode Za of the piezoelectric element PZ of the discharge section D to be detected becomes a potential corresponding to the electromotive force of the piezoelectric element PZ caused by the residual vibrations occurring in the discharge section D to be detected. The potential of the individual electrode Za is detected as a detection signal Vout during the detection unit period TU.

[0113] Note that the connection state designation signals Qa and Qs corresponding to the discharge units D other than the discharge unit D[m] to be detected are set to a low level, for example, during the unit period TU for detection. Also, the connection state designation signal Qb corresponding to the discharge units D other than the discharge unit D[m] to be detected may be set to a high level or a low level during the unit period TU for detection. Also, the connection state designation circuit CSC may set the connection state designation signal Qs[m] to a high level during the first half of the unit period TU for detection, and set the connection state designation signal Qs[m] to a low level during the second half of the unit period TU for detection.

[0114] The operation of the liquid ejection device 100 is not limited to the example shown in FIG. 7 . For example, while FIG. 7 illustrates a case where one drive signal COM is used to eject ink from a nozzle N, the present invention is not limited to this embodiment. For example, multiple drive signals COM corresponding to different dot sizes may be used as the drive signal COM to eject ink from a nozzle N. Even in this case, the reference potential of each of the multiple drive signals COM corresponding to different dot sizes is set to, for example, the same potential as the potential of drive signal COMb. Furthermore, the multiple drive signals COM may include one or both of a drive signal COM having a micro-vibration waveform for preventing ink thickening and a drive signal COM having a micro-vibration waveform for generating residual vibrations for detecting ejection abnormalities. Even in this case, the reference potential of the drive signal COM having a micro-vibration waveform is set to, for example, the same potential as the potential of drive signal COMb.

[0115] Furthermore, the drive signal COMb may not be used. In this case, the wiring Lb shown in FIG. 5 may be omitted. In a mode in which the drive signal COMb is not used, for example, before the start of the first unit period TU, the drive signal generation unit 2 applies a potential VC, which is the reference potential of the drive signal COMa, to all piezoelectric elements PZ. Then, when the individual designation signal Sd[m] designates a drive mode as a discharge section D that does not form dots, for example, the connection state designation circuit CSC sets the connection state designation signals Qa[m] and Qs[m] to a low level during the unit period TU. As a result, if no leakage current occurs, the potential of the individual electrode Za of the piezoelectric element PZ of the discharge section D that does not form dots is maintained at the potential VC before the connection state designation signal Qa[m] was set to a low level. Therefore, even in this mode, the piezoelectric element PZ corresponding to the non-discharge nozzle N can be considered to be driven by the potential VC.

[0116] Furthermore, Figure 7 illustrates a case where multiple ejection signals DS with different reference potentials, which are the potentials VC at the start and end of the pulse PA, are used to evaluate crosstalk, but multiple ejection signals DS with different reference potentials and other factors may also be used to evaluate crosstalk.

[0117] Next, the operation of the analysis unit 3 will be described with reference to FIG.

[0118] FIG. 8 is a diagram showing an example of the waveform of the residual vibration signal VR. FIG. 8 schematically shows an example of the waveform of the residual vibration signal VR when full ejection and alternating ejection are performed using two sets of drive signals COMa and COMb. The vertical axis of the diagram represents the potential of the residual vibration signal VR, and the horizontal axis represents time. Hereinafter, a set in which the ejection signal DS1 is used as the drive signal COMa and the hold signal HS1 is used as the drive signal COMb will also be referred to as the set of the ejection signal DS1 and the hold signal HS1. Similarly, a set in which the ejection signal DS2 is used as the drive signal COMa and the hold signal HS2 is used as the drive signal COMb will also be referred to as the set of the ejection signal DS2 and the hold signal HS2.

[0119] For example, the residual vibration signal VRf1 is the residual vibration signal VR that indicates the residual vibration when multiple piezoelectric elements PZ are driven for full ejection using a set of ejection signals DS1 and hold signals HS1. The residual vibration signal VRf2 is the residual vibration signal VR that indicates the residual vibration when multiple piezoelectric elements PZ are driven for full ejection using a set of ejection signals DS2 and hold signals HS2. In FIG. 8, to make the diagram easier to understand, it is assumed that the waveform of the residual vibration signal VRf2 is the same as the waveform of the residual vibration signal VRf1. Also, for example, the residual vibration signal VRa1 is the residual vibration signal VR that indicates the residual vibration when multiple piezoelectric elements PZ are driven for alternating ejection using a set of ejection signals DS1 and hold signals HS1. And the residual vibration signal VRa2 is the residual vibration signal VR that indicates the residual vibration when multiple piezoelectric elements PZ are driven for alternating ejection using a set of ejection signals DS2 and hold signals HS2. In other words, the difference between the residual vibration signal VRf1 and the residual vibration signal VRa1 indicates the variation in residual vibration between full ejection and alternating ejection when the set of ejection signal DS1 and hold signal HS1 is used, i.e., the degree of structural crosstalk. Similarly, the difference between the residual vibration signal VRf2 and the residual vibration signal VRa2 indicates the variation in residual vibration between full ejection and alternating ejection when the set of ejection signal DS2 and hold signal HS2 is used, i.e., the degree of structural crosstalk. Note that the waveforms shown in Figure 8 are waveforms used to explain the operation of the analysis unit 3, and do not accurately represent the relationship between the ejection signal DS and hold signal HS shown in Figure 7 and the residual vibration during full ejection or alternating ejection.

[0120] As described above, the residual vibration signal VR indicates a waveform corresponding to the residual vibration occurring in the ejection portion D to be detected, i.e., the residual vibration of the diaphragm 14. Specifically, the residual vibration signal VR indicates an amplitude corresponding to the amplitude of the residual vibration of the diaphragm 14, a period corresponding to the period of the residual vibration of the diaphragm 14, and a phase corresponding to the phase of the residual vibration of the diaphragm 14.

[0121] 8, for example, the analysis unit 3 identifies the amplitude λ of the first peak among the peaks at which the potential of the residual vibration signal VR reaches a maximum value, i.e., the peaks at which the waveform of the residual vibration signal VR reaches a crest, as the amplitude of the residual vibration of the vibration plate 14. Specifically, the analysis unit 3 identifies the amplitude λf1 of the first peak at which the waveform of the residual vibration signal VRf1 reaches a crest as the amplitude of the residual vibration of the vibration plate 14 when the plurality of piezoelectric elements PZ are driven for full ejection using the set of the ejection signal DS1 and the hold signal HS1. Similarly, the analysis unit 3 identifies the amplitude λf2 of the first peak at which the waveform of the residual vibration signal VRf2 reaches a crest as the amplitude of the residual vibration of the vibration plate 14 when the plurality of piezoelectric elements PZ are driven for full ejection using the set of the ejection signal DS2 and the hold signal HS2. The analysis unit 3 also determines the amplitude λa1 of the first peak where the waveform of the residual vibration signal VRa1 becomes a crest as the amplitude of the residual vibration of the vibration plate 14 when the plurality of piezoelectric elements PZ are driven by alternating ejection using the set of ejection signal DS1 and hold signal HS1. The analysis unit 3 also determines the amplitude λa2 of the first peak where the waveform of the residual vibration signal VRa2 becomes a crest as the amplitude of the residual vibration of the vibration plate 14 when the plurality of piezoelectric elements PZ are driven by alternating ejection using the set of ejection signal DS2 and hold signal HS2.

[0122] The method for determining the amplitude of the residual vibration signal VR is not limited to the above example, and any known method can be used. For example, the amplitude of the residual vibration signal VR may be the amplitude of the first peak where the waveform of the residual vibration signal VR becomes a valley, or may be the average of the amplitudes of multiple peaks.

[0123] Furthermore, for example, the analysis unit 3 identifies the phase of the residual vibration signal VR as the phase of the residual vibration of the diaphragm 14. In this embodiment, for example, it is assumed that the time T from the start of the unit period TU to the first peak where the waveform of the residual vibration signal VR becomes a mountain is identified as the phase of the residual vibration signal VR.

[0124] Therefore, for example, the analysis unit 3 determines the time Tf1 from the start of the unit period TU to the first peak at which the waveform of the residual vibration signal VRf1 becomes a crest as the phase of the residual vibration of the diaphragm 14 when the plurality of piezoelectric elements PZ are driven for full ejection using the set of the ejection signal DS1 and the hold signal HS1. Similarly, the analysis unit 3 determines the time Tf2 from the start of the unit period TU to the first peak at which the waveform of the residual vibration signal VRf2 becomes a crest as the phase of the residual vibration of the diaphragm 14 when the plurality of piezoelectric elements PZ are driven for full ejection using the set of the ejection signal DS2 and the hold signal HS2. Furthermore, the analysis unit 3 determines the time Ta1 from the start of the unit period TU to the first peak at which the waveform of the residual vibration signal VRa1 becomes a crest as the phase of the residual vibration of the diaphragm 14 when the plurality of piezoelectric elements PZ are driven for alternating ejection using the set of the ejection signal DS1 and the hold signal HS1. In addition, the analysis unit 3 identifies the time Ta2 from the start of the unit period TU to the first peak at which the waveform of the residual vibration signal VRa2 becomes a mountain as the phase of the residual vibration of the vibration plate 14 when multiple piezoelectric elements PZ are driven by alternating ejection using a set of ejection signal DS2 and holding signal HS2.

[0125] The method for identifying the phase of the residual vibration signal VR is not limited to the above example, and any known method can be used. For example, if the potential of the residual vibration signal VR when the residual vibration of diaphragm 14 has attenuated and subsided is taken as the center potential, the time it takes for the potential of the residual vibration signal VR to change from the center potential to the potential of the first peak of the waveform of the residual vibration signal VRf1 may be identified as the phase of the residual vibration signal VR.

[0126] Furthermore, for example, the analysis unit 3 identifies the period of the residual vibration signal VR as the period of the residual vibration of the diaphragm 14. In this embodiment, for example, it is assumed that the time C from the first peak to the next peak among the peaks at which the waveform of the residual vibration signal VR becomes a mountain is identified as the period of the residual vibration of the diaphragm 14. Hereinafter, the time C from the first peak to the next peak among the peaks at which the waveform of the residual vibration signal VR becomes a mountain is also simply referred to as the time C from the first peak to the next peak of the residual vibration signal VR.

[0127] Therefore, for example, the analysis unit 3 determines the time Cf1 from the first peak to the next peak of the residual vibration signal VRf1 as the period of residual vibration of the vibration plate 14 when the plurality of piezoelectric elements PZ are driven for full ejection using the set of ejection signal DS1 and hold signal HS1. Similarly, the analysis unit 3 determines the time Cf2 from the first peak to the next peak of the residual vibration signal VRf2 as the period of residual vibration of the vibration plate 14 when the plurality of piezoelectric elements PZ are driven for full ejection using the set of ejection signal DS2 and hold signal HS2. Furthermore, the analysis unit 3 determines the time Ca1 from the first peak to the next peak of the residual vibration signal VRa1 as the period of residual vibration of the vibration plate 14 when the plurality of piezoelectric elements PZ are driven for alternating ejection using the set of ejection signal DS1 and hold signal HS1. In addition, the analysis unit 3 identifies the time Ca2 from the first peak to the next peak of the residual vibration signal VRa2 as the period of the residual vibration of the vibration plate 14 when multiple piezoelectric elements PZ are driven by alternating ejection using a set of ejection signal DS2 and holding signal HS2.

[0128] The method for determining the period of the residual vibration signal VR is not limited to the above example, and any known method can be used. For example, if the potential of the residual vibration signal VR when the residual vibration of the diaphragm 14 has attenuated and subsided is taken as the center potential, the period of the residual vibration signal VR may be determined based on the interval at which the potential of the residual vibration signal VR becomes the center potential.

[0129] The analysis unit 3 outputs residual vibration information Vinf to the control unit 4, which indicates, for example, the amplitude λ identified as the amplitude of the residual vibration signal VR, the time T identified as the phase of the residual vibration signal VR, and the time C identified as the period of the residual vibration signal VR.

[0130] Next, with reference to FIG. 9, the operation of the liquid ejection device 100 when evaluating crosstalk will be described.

[0131] Fig. 9 is a flowchart showing an example of the operation of the liquid ejection device 100 when evaluating crosstalk. Note that the timing at which the operation shown in Fig. 9 is performed is not particularly limited, but it is preferable that it be performed when the liquid ejection device 100 is used for the first time, or when the usage conditions of the liquid ejection device 100 are changed due to a change in the type of ink used, etc. Note that the usage conditions of the liquid ejection device 100 also include the usage conditions of the liquid ejection head 1. The operation shown in Fig. 9 is performed, for example, for each of the multiple liquid ejection heads 1. Furthermore, the nozzle N to be detected when evaluating crosstalk is a nozzle N that represents the multiple nozzles N.

[0132] The control unit 4 functions as the evaluation control unit 40 in each of steps S100 to S152 shown in FIG. 9 and in step S200. The process of step S100 is executed, for example, in a state where the pressure chambers CV are filled with ink to be used by a user of the liquid ejection device 100. That is, the process of step S100 is executed after the pressure chambers CV are filled with ink to be used by the user. The process of filling the pressure chambers CV with ink may be executed by the evaluation control unit 40, or may be executed by a processing unit other than the evaluation control unit 40. The user is, for example, a user of the liquid ejection device 100. Furthermore, if the manufacturer and the user of the liquid ejection device 100 are the same, the manufacturer of the liquid ejection device 100 may be regarded as the user.

[0133] First, in step S100, the evaluation control unit 40 sets the variable i to 1. After executing the process of step S100, the evaluation control unit 40 moves the process to step S110.

[0134] In step S110, the evaluation control unit 40 controls the liquid ejection head 1 so that the multiple piezoelectric elements PZ are driven for full ejection using the i-th drive signal candidate. The i-th drive signal candidate is, for example, a set of the i-th ejection signal DS and the i-th hold signal HS. For example, the evaluation control unit 40 selects the i-th ejection signal DS as the drive signal COMa, and controls the liquid ejection head 1 so that all of the multiple piezoelectric elements PZ are driven using the selected drive signal COMa. As a result, the multiple piezoelectric elements PZ are driven so that ink is ejected from all of the nozzles N.

[0135] Next, in step S120, the evaluation control unit 40 detects residual vibrations in the nozzle N to be detected. For example, the evaluation control unit 40 causes the detection circuit 19 to detect residual vibrations from the piezoelectric element PZ corresponding to the nozzle N to be detected. As a result, the detection circuit 19 detects residual vibrations of the diaphragm 14 resulting from driving the plurality of piezoelectric elements PZ so that ink is ejected from all of the nozzles N. The residual vibrations detected by the detection circuit 19 are then analyzed by the analysis unit 3. In the example shown in FIG. 6, the analysis unit 3 analyzes the residual vibrations detected from the piezoelectric element PZ corresponding to the nozzle N1c during full ejection. The evaluation control unit 40 acquires residual vibration information Vinf from the analysis unit 3, which indicates the analysis results of the residual vibrations detected by the detection circuit 19. The residual vibrations detected in step S120 are an example of a "first residual vibration."

[0136] Next, in step S130, the evaluation control unit 40 controls the liquid ejection head 1 so that the multiple piezoelectric elements PZ are driven by alternating ejection using the i-th drive signal candidate. For example, the evaluation control unit 40 selects the i-th ejection signal DS as the drive signal COMa and the i-th hold signal HS as the drive signal COMb. For example, the evaluation control unit 40 then controls the liquid ejection head 1 so that the piezoelectric element PZ adjacent to the piezoelectric element PZ driven by the drive signal COMa is driven by the drive signal COMb. This drives the multiple piezoelectric elements PZ so that ink is ejected from the nozzle N to be detected and ink is not ejected from the nozzle N adjacent to the nozzle N to be detected.

[0137] Next, in step S140, the evaluation control unit 40 detects residual vibrations in the nozzle N to be detected. The processing in step S140 is similar to the processing in step S120. In step S140, for example, the detection circuit 19 detects residual vibrations of the diaphragm 14 resulting from driving the piezoelectric element PZ corresponding to the nozzle N to be detected with the drive signal COMa and driving the piezoelectric element PZ corresponding to the nozzle N adjacent to the nozzle N to be detected with the drive signal COMb. In the example shown in FIG. 6, residual vibrations during alternating ejection are detected from the piezoelectric element PZ corresponding to the nozzle N1c. The evaluation control unit 40 acquires residual vibration information Vinf from the analysis unit 3, which indicates the analysis results of the residual vibrations detected by the detection circuit 19. The residual vibrations detected in step S140 are an example of a "second residual vibration."

[0138] Next, in step S150, the evaluation control unit 40 determines whether the variable i is the final value. The final value of the variable i is, for example, the number of sets of drive signals COMa and COMb prepared in advance as drive signal candidates. That is, the evaluation control unit 40 determines whether residual signals during full ejection and alternating ejection have been detected for all sets of drive signals COMa and COMb prepared in advance as drive signal candidates.

[0139] If the result of the determination in step S150 is negative, the evaluation control unit 40 adds "1" to the variable i in step S152, and then returns the process to step S110. On the other hand, if the result of the determination in step S150 is positive, the evaluation control unit 40 moves the process to step S200.

[0140] In step S200, the evaluation control unit 40 performs a comparison process of the residual vibrations. For example, the evaluation control unit 40 compares, for each drive signal candidate, the residual signal at the time of full ejection detected in step S120 with the residual signal at the time of alternating ejection detected in step S140. By executing the process of step S120, it is determined for each drive signal candidate whether crosstalk will occur, and the operation shown in FIG. 9 ends.

[0141] Next, the residual vibration comparison process executed in step S200 will be described with reference to FIG.

[0142] Fig. 10 is a flowchart showing an example of the comparison process of residual vibration shown in Fig. 9. A series of processes from step S210 to step S262 shown in Fig. 10 corresponds to the process of step S200 shown in Fig. 9. The control unit 4 functions as the evaluation control unit 40 in each of steps S210 to S262 shown in Fig. 10. The process of step S210 is executed when the result of the determination in step S150 shown in Fig. 9 is positive.

[0143] The operation shown in Fig. 10 uses times Tfi and Tai, times Cfi and Cai, and amplitudes λfi and λai determined by a series of processes from step S100 to step S152 shown in Fig. 9. The times Tfi, Cfi, and amplitude λfi respectively indicate the phase, period, and amplitude of residual vibration resulting from full ejection using the i-th drive signal candidate, and are determined by the process of step S120 shown in Fig. 9. Furthermore, the times Tai, Cai, and amplitude λai in Fig. 10 respectively indicate the phase, period, and amplitude of residual vibration resulting from alternating ejection using the i-th drive signal candidate, and are determined by the process of step S140 shown in Fig. 9.

[0144] First, in step S210, the evaluation control unit 40 sets the variable i to 1. After executing the process of step S210, the evaluation control unit 40 moves the process to step S220.

[0145] In step S220, the evaluation control unit 40 determines whether the time Tai is 0.7 to 1.3 times the time Tfi. The range of 0.7 to 1.3 times the time Tfi is an example of a "first range." That is, the evaluation control unit 40 determines whether the phase of the residual vibration caused by the alternating ejection using the i-th drive signal candidate is included in the first range specified based on the phase of the residual vibration caused by the full ejection using the i-th drive signal candidate. Note that the first range is not limited to the above example and may be appropriately set based on data obtained by experiments, etc. Also, for example, the first range may be a range obtained by adding or subtracting a predetermined value from the time Tfi. However, it is preferable that the determination in step S220 be a determination of "whether the time Tai and the time Tfi are relatively close in value."

[0146] If the result of the determination in step S220 is negative, the evaluation control unit 40 determines in step S252 that crosstalk has occurred, and then proceeds to step S260. That is, if the phase of the residual vibration caused by the alternating ejection using the i-th drive signal candidate is not included in the first range, the evaluation control unit 40 determines that crosstalk has occurred in the i-th drive signal candidate. In this way, the evaluation control unit 40 evaluates crosstalk based on the phase of the residual vibration caused by the alternating ejection using the i-th drive signal candidate and the phase of the residual vibration caused by the full ejection using the i-th drive signal candidate.

[0147] On the other hand, if the result of the determination in step S220 is positive, the evaluation control unit 40 moves the process to step S230.

[0148] In step S230, the evaluation control unit 40 determines whether the time Cai is 0.8 to 1.2 times the time Cfi. The range of 0.8 to 1.2 times the time Cfi is an example of a "second range." That is, the evaluation control unit 40 determines whether the period of the residual vibration resulting from the alternating ejection using the i-th drive signal candidate is within a second range determined based on the period of the residual vibration resulting from the full ejection using the i-th drive signal candidate. Note that the second range is not limited to the above example and may be appropriately set based on data obtained through experiments, etc. Furthermore, for example, the second range may be a range obtained by subtracting or adding a predetermined value from or to the time Cfi. However, it is preferable that the determination in step S230 be a determination of "whether the time Cai and the time Cfi are relatively close in value."

[0149] If the result of the determination in step S230 is negative, the evaluation control unit 40 determines in step S252 that crosstalk has occurred, and then proceeds to step S260. That is, if the period of residual vibration caused by alternating ejection using the i-th drive signal candidate is not included in the second range, the evaluation control unit 40 determines that crosstalk has occurred in the i-th drive signal candidate. In this way, the evaluation control unit 40 evaluates crosstalk based on the period of residual vibration caused by alternating ejection using the i-th drive signal candidate and the period of residual vibration caused by full ejection using the i-th drive signal candidate.

[0150] On the other hand, if the result of the determination in step S230 is positive, the evaluation control unit 40 moves the process to step S240.

[0151] In step S240, the evaluation control unit 40 determines whether the amplitude λai is 0.7 to 1.3 times the amplitude λfi. The range of 0.7 to 1.3 times the amplitude λfi is an example of a "third range." That is, the evaluation control unit 40 determines whether the amplitude of residual vibration resulting from alternating ejection using the i-th drive signal candidate is within a third range specified based on the amplitude of residual vibration resulting from full ejection using the i-th drive signal candidate. Note that the third range is not limited to the above example and may be appropriately set based on data obtained through experiments, etc. Furthermore, for example, the third range may be a range obtained by subtracting or adding a predetermined value from or to the amplitude λfi. However, it is preferable that the determination in step S240 be a determination of "whether the amplitude λai and the amplitude λfi are relatively close in value."

[0152] If the result of the determination in step S240 is negative, the evaluation control unit 40 determines in step S252 that crosstalk has occurred, and then proceeds to step S260. That is, if the amplitude of the residual vibration caused by the alternating ejection using the i-th drive signal candidate is not within the third range, the evaluation control unit 40 determines that crosstalk has occurred in the i-th drive signal candidate. In this way, the evaluation control unit 40 evaluates crosstalk based on the amplitude of the residual vibration caused by the alternating ejection using the i-th drive signal candidate and the amplitude of the residual vibration caused by the full ejection using the i-th drive signal candidate.

[0153] On the other hand, if the result of the determination in step S230 is positive, the evaluation control unit 40 determines in step S250 that there is no crosstalk, and then proceeds to step S260. That is, the evaluation control unit 40 determines that no crosstalk will occur in the i-th drive signal candidate if the waveform of the residual vibration caused by alternate ejection using the i-th drive signal candidate matches or is similar to the waveform of the residual vibration caused by full ejection using the i-th drive signal candidate.

[0154] In step S260, the evaluation control unit 40 determines whether the variable i is the final value. That is, the evaluation control unit 40 determines whether the comparison of the residual vibrations detected by the series of processes from step S100 to step S152 shown in FIG. 9 has ended.

[0155] If the result of the determination in step S260 is negative, the evaluation control unit 40 adds "1" to the variable i in step S262, and then returns the process to step S220. On the other hand, if the result of the determination in step S260 is positive, the evaluation control unit 40 ends the operations shown in FIGS.

[0156] 9 and 10. For example, a predetermined number of three or more piezoelectric elements PZ may be selected from the plurality of piezoelectric elements PZ included in the liquid ejection head 1 as targets for full ejection and alternating ejection.

[0157] 9, for example, the i-th drive signal candidate may be used to drive only the piezoelectric element PZ corresponding to the nozzle N to be detected so as to eject ink. That is, in step S130 shown in Fig. 9, the piezoelectric element PZ corresponding to the nozzle N to be detected may be driven by the drive signal COMa, and all of the piezoelectric elements PZ other than the piezoelectric element PZ corresponding to the nozzle N to be detected may be driven by the drive signal COMb. Hereinafter, driving the piezoelectric element PZ corresponding to the nozzle N to be detected by the drive signal COMa, and driving all of the piezoelectric elements PZ other than the piezoelectric element PZ corresponding to the nozzle N to be detected by the drive signal COMb may be referred to as ejecting ink only from the nozzle N to be detected.

[0158] Furthermore, for example, in addition to the residual vibration caused by the full discharge and the residual vibration caused by the alternating discharge, the residual vibration caused by the discharge of only the nozzle N to be detected may be used to evaluate crosstalk. Specifically, for example, the piezoelectric element PZ corresponding to the nozzle N1c shown in FIG. 6 may be driven by the drive signal COMa, and the piezoelectric elements PZ corresponding to the nozzles N1a, N1b, N1d, N1e, and N1f may be driven by the drive signal COMb. In this case, the nozzle N1e is an example of a "fourth nozzle," and the piezoelectric element PZ corresponding to the nozzle N1e is an example of a "fourth piezoelectric element." Furthermore, the residual vibration caused by the discharge of only the nozzle N to be detected is an example of a "third residual vibration." In this embodiment, the evaluation control unit 40 may compare the residual vibration caused by the discharge of only the nozzle N to be detected with the residual vibration caused by the full discharge, in the same way as the residual vibration caused by the alternating discharge.

[0159] Furthermore, instead of or in addition to the residual vibrations resulting from the total discharge and the alternating discharge, residual vibrations resulting from discharge of another specific pattern may be used to evaluate crosstalk. For example, for the specific pattern of discharge, multiple piezoelectric elements PZ arranged in a predetermined direction may be driven by a drive signal COMa, with every third piezoelectric element. Specifically, for example, the piezoelectric elements PZ corresponding to the nozzles N1c and N1f shown in FIG. 6 may be driven by a drive signal COMa, and the piezoelectric elements PZ corresponding to the nozzles N1a, N1b, N1d, and N1e may be driven by a drive signal COMb. In this embodiment, the evaluation control unit 40 may compare the residual vibrations resulting from the specific pattern of discharge with the residual vibrations resulting from the total discharge, as well as the residual vibrations resulting from the alternating discharge. Alternatively, in this embodiment, the evaluation control unit 40 may compare the residual vibrations resulting from the alternating discharge with the residual vibrations resulting from the specific pattern of discharge.

[0160] Also, for example, one or two of the processing in step S220, the processing in step S230, and the processing in step S240 may be omitted.

[0161] Furthermore, for example, the evaluation control unit 40 may determine the waveform of the drive signal COMa and the potential of the drive signal COMb based on the results of the crosstalk evaluation. Note that determining the potential of the drive signal COMb can also be interpreted as determining the waveform of the drive signal COMb. For example, the evaluation control unit 40 may adopt the drive signal candidate determined to be free of crosstalk in the process shown in FIG. 10 as the drive signals COMa and COMb to be used in the actual printing process. That is, the evaluation control unit 40 may determine the waveform of the drive signal COMa and the waveform of the drive signal COMb based on the residual vibration caused by full ejection and the residual vibration caused by alternating ejection. Furthermore, for example, if there are multiple drive signal candidates determined to be free of crosstalk, the evaluation control unit 40 may adopt, as the drive signals COMa and COMb, the drive signal candidate whose waveform of the residual vibration caused by alternating ejection matches or is most similar to the waveform of the residual vibration caused by full ejection. In this way, in this embodiment, the occurrence of crosstalk can be easily suppressed by determining the waveforms of the drive signals COMa and COMb based on the results of the crosstalk evaluation.

[0162] As described above, in this embodiment, the liquid ejection device 100 comprises a liquid ejection head 1 including a nozzle N1c that ejects ink, a nozzle N1d that is arranged at a position different from the nozzle N1c and that ejects ink, a first piezoelectric element PZ corresponding to the nozzle N1c, a second piezoelectric element PZ corresponding to the nozzle N1d, a vibration plate 14 that vibrates when at least one of the first piezoelectric element PZ and the second piezoelectric element PZ is driven, and a detection circuit 19 that detects residual vibration of the vibration plate 14 caused by the driving of at least one of the first piezoelectric element PZ and the second piezoelectric element PZ, and an evaluation control unit 40. The evaluation control unit 40 causes the detection circuit 19 to detect, from the first piezoelectric element PZ, the residual vibration resulting from driving the first piezoelectric element PZ and the second piezoelectric element PZ with the drive signal COMa that causes ink to be ejected, as the first residual vibration, and causes the detection circuit 19 to detect, from the first piezoelectric element PZ, the residual vibration resulting from driving the first piezoelectric element PZ with the drive signal COMa and driving the second piezoelectric element PZ with the drive signal COMb that does not cause ink to be ejected, as the second residual vibration, and evaluates crosstalk between the nozzles N1c and N1d based on the first residual vibration and the second residual vibration detected by the detection circuit 19. The evaluation control unit 40 may also determine the waveform of the drive signal COMa and the waveform of the drive signal COMb based on the first residual vibration and the second residual vibration detected by the detection circuit 19.

[0163] As described above, in this embodiment, the evaluation control unit 40 evaluates crosstalk between nozzles N1c and N1d based on the first residual vibration when both nozzles N1c and N1d eject ink and the second residual vibration when nozzle N1d does not eject ink. Therefore, in this embodiment, crosstalk evaluation can be performed appropriately and easily. In particular, this embodiment can appropriately and easily evaluate so-called structural crosstalk that occurs due to the structure of the liquid ejection head 1, such as the arrangement of the nozzles N. Furthermore, in this embodiment, the evaluation control unit 40 determines the waveforms of the drive signals COMa and COMb based on the first residual vibration and the second residual vibration, thereby appropriately and easily determining the waveform of the drive signal COMa that drives the piezoelectric element PZ. For example, in this embodiment, the evaluation control unit 40 determines the waveforms of the drive signals COMa and COMb based on the crosstalk evaluation results, thereby appropriately and easily determining the waveform of the drive signal COMa that drives the piezoelectric element PZ.

[0164] In this embodiment, the evaluation control unit 40 may detect the second residual vibration in each of the cases where the hold signal HS1 maintained at the potential VC1 is used as the drive signal COMb and where the hold signal HS2 maintained at the potential VC2 higher than the potential VC1 is used as the drive signal COMb. In this embodiment, it is possible to easily determine whether the potential of the drive signal COMb should be set to the potential VC1 or the potential VC2.

[0165] In this embodiment, the evaluation control unit 40 may detect the first residual vibration when the ejection signal DS1 is used as the drive signal COMa and when the ejection signal DS2 is used as the drive signal COMa. The waveforms of the ejection signals DS1 and DS2 each include a waveform element Pa1, in which the potential changes from a reference potential between potentials VLa and VHa, and a waveform element Pa3, which follows the waveform element Pa1 and in which the potential changes from potential VLa to potential VHa. The reference potential of the ejection signal DS1 is potential VC1, and the reference potential of the ejection signal DS2 is potential VC2. In this embodiment, it is easy to determine whether the reference potential of the drive signal COMa should be set to potential VC1 or potential VC2.

[0166] In addition, in this embodiment, the evaluation control unit 40 may evaluate crosstalk based on the first and second residual vibrations detected by the detection circuit 19 when the ejection signal DS1 is used as the drive signal COMa and the hold signal HS1 is used as the drive signal COMb, and the first and second residual vibrations detected by the detection circuit 19 when the ejection signal DS2 is used as the drive signal COMa and the hold signal HS2 is used as the drive signal COMb. In this aspect, it can be easily determined whether it is better to adopt the set of ejection signal DS1 and hold signal HS1 or the set of ejection signal DS2 and hold signal HS2 as the set of drive signals COMa and COMb.

[0167] In this embodiment, the nozzle N1c and the nozzle N1d may be disposed adjacent to each other, in which case the structural crosstalk can be evaluated with high accuracy.

[0168] In this embodiment, the liquid ejection head 1 further includes a nozzle N1b adjacent to the nozzle N1c that ejects ink, and a third piezoelectric element PZ corresponding to the nozzle N1b. The diaphragm 14 vibrates when at least one of the first piezoelectric element PZ, the second piezoelectric element PZ, and the third piezoelectric element PZ is driven. The nozzle N1b, the nozzle N1c, and the nozzle N1d are arranged in this order in the Y-axis direction. The evaluation control unit 40 may cause the detection circuit 19 to detect, from the first piezoelectric element PZ, a residual vibration resulting from driving the first piezoelectric element PZ, the second piezoelectric element PZ, and the third piezoelectric element PZ with the drive signal COMa as a first residual vibration, and may cause the detection circuit 19 to detect, from the first piezoelectric element PZ, a residual vibration resulting from driving the first piezoelectric element PZ with the drive signal COMa and driving the second piezoelectric element PZ and the third piezoelectric element PZ with the drive signal COMb as a second residual vibration. In this embodiment as well, structural crosstalk can be evaluated with high accuracy.

[0169] In this embodiment, the liquid ejection head 1 further includes a nozzle N1e that is disposed adjacent to the nozzle N1d and ejects ink, and a fourth piezoelectric element PZ that corresponds to the nozzle N1e. The vibration plate 14 vibrates when at least one of the first piezoelectric element PZ, the second piezoelectric element PZ, and the fourth piezoelectric element PZ is driven. The nozzle N1c, the nozzle N1d, and the nozzle N1e are arranged in this order in the Y-axis direction. The evaluation control unit 40 may cause the detection circuit 19 to detect, from the first piezoelectric element PZ, the residual vibration resulting from driving the first piezoelectric element PZ, the second piezoelectric element PZ, and the fourth piezoelectric element PZ with the drive signal COMa as the first residual vibration, cause the detection circuit 19 to detect, from the first piezoelectric element PZ, the residual vibration resulting from driving the first piezoelectric element PZ and the fourth piezoelectric element PZ with the drive signal COMa and driving the second piezoelectric element PZ with the drive signal COMb as the second residual vibration, and cause the detection circuit 19 to detect, from the first piezoelectric element PZ, the residual vibration resulting from driving the first piezoelectric element PZ with the drive signal COMa and driving the second piezoelectric element PZ and the fourth piezoelectric element PZ with the drive signal COMb as the third residual vibration, and evaluate crosstalk based on the first residual vibration, second residual vibration, and third residual vibration detected by the detection circuit 19. In this embodiment, structural crosstalk can also be evaluated with high accuracy.

[0170] In this embodiment, the evaluation control unit 40 may evaluate the crosstalk based on the phase of the first residual vibration and the phase of the second residual vibration. In this embodiment, the crosstalk can be easily evaluated with high accuracy.

[0171] In this embodiment, the evaluation control unit 40 may evaluate that crosstalk is occurring when the phase of the second residual vibration is not included in a first range determined based on the phase of the first residual vibration. In this embodiment, crosstalk can also be evaluated easily and accurately.

[0172] In this embodiment, the evaluation control unit 40 may evaluate the crosstalk based on the period of the first residual vibration and the period of the second residual vibration. In this embodiment, the crosstalk can be easily evaluated with high accuracy.

[0173] In this embodiment, the evaluation control unit 40 may evaluate that crosstalk is occurring when the period of the second residual vibration is not included in a second range determined based on the period of the first residual vibration. In this embodiment, crosstalk can also be evaluated easily and accurately.

[0174] In this embodiment, the evaluation control unit 40 may evaluate the crosstalk based on the amplitude of the first residual vibration and the amplitude of the second residual vibration. In this embodiment, the crosstalk can be easily evaluated with high accuracy.

[0175] In this embodiment, the evaluation control unit 40 may evaluate that crosstalk is occurring when the amplitude of the second residual vibration is not included in a third range determined based on the amplitude of the first residual vibration. In this embodiment, crosstalk can also be evaluated easily and accurately.

[0176] [2. Modifications] Each of the above embodiments can be modified in various ways. Specific modified embodiments are exemplified below. Two or more embodiments arbitrarily selected from the following examples can be combined as appropriate within a range that does not contradict each other. In the modified examples exemplified below, elements whose actions and functions are equivalent to those of the embodiments will be designated by the same reference numerals as in the above description, and detailed descriptions of each will be omitted as appropriate.

[0177] [First Modification] In the above-described embodiment, the drive signal COM for detecting an ejection abnormality in the nozzle N may be supplied from the drive signal generation unit 2 to the liquid ejection head 1.

[0178] Fig. 11 is a block diagram showing an example of the configuration of a liquid ejection head 1 according to a first modified example. The liquid ejection head 1 shown in Fig. 11 is similar to the liquid ejection head 1 shown in Fig. 5, except that a drive signal COMc for detecting ejection abnormalities in a nozzle N is supplied from a drive signal generation unit 2. Specifically, the liquid ejection head 1 shown in Fig. 11 is similar to the liquid ejection head 1 shown in Fig. 5, except that it has a switching circuit 18A instead of the switching circuit 18 shown in Fig. 5.

[0179] 5, except that a wiring Lc to which a drive signal COMc is supplied from the drive signal generating unit 2 and M switches SWc[1] to SWb[M] corresponding one-to-one to the M discharge sections D[1] to D[M] are added to the switching circuit 18. However, the connection state specifying circuit CSC generates connection state specifying signals Qa[m], Qb[m], Qc[m], and Qs[m] based on at least some of the print signal SI, latch signal LAT, and period specifying signal Tsig supplied from the control unit 4.

[0180] The switch SWc[m] switches between conduction and non-conduction between the wiring Lc and the individual electrode Za[m] of the piezoelectric element PZ[m] provided in the discharge section D[m] based on the connection state designation signal Qc[m]. That is, the switch SWc[m] switches between conduction and non-conduction between the wiring Lc and the wiring Li[m] connected to the individual electrode Za[m] based on the connection state designation signal Qc[m]. In this modified example, the switch SWc[m] is turned on when the connection state designation signal Qc[m] is at a high level and turned off when it is at a low level. When the switch SWc[m] is turned on, the drive signal COMc supplied to the wiring Lc is supplied as an individual drive signal Vin[m] to the individual electrode Za[m] of the discharge section D[m] via the wiring Li[m].

[0181] Next, the operation of the liquid ejection device 100 according to the first modified example will be described with reference to FIG.

[0182] FIG. 12 is a timing chart showing an example of the operation of the liquid ejection device 100 according to the first modified example. The operation of the connection state specification circuit CSC and other components when the drive modes of the ejection units D that form dots, the ejection units D that do not form dots, and the ejection units D that are the detection targets for crosstalk evaluation are specified by the individual specification signal Sd[m] is the same as the operation described in FIG. 7. Therefore, FIG. 12 describes the operation of the connection state specification circuit CSC and other components when the drive mode of the ejection unit D that is the detection target for ejection abnormalities of nozzle N is specified by the individual specification signal Sd[m]. Note that FIG. 12 assumes that the reference potential of the drive signal COMa and the potential of the drive signal COMb are set to potential VC1 based on the crosstalk evaluation results. In this case, it is preferable that the reference potential of the drive signal COMc is also set to potential VC1.

[0183] For example, the drive signal generation unit 2 outputs a drive signal COMc having a pulse PS. The pulse PS has a waveform in which the potential of the drive signal COMc changes from a potential VC1 to a potential VLs lower than the potential VC1, passes through a potential VHs higher than the potential VC1, and returns to the potential VC1. In this modification, the pulse PS is determined so that the potential difference between the potential VHs, which is the highest potential of the pulse PS, and the potential VLs, which is the lowest potential, is smaller than the potential difference between the potential VHa, which is the highest potential of the pulse PA, and the potential VLa, which is the lowest potential. Specifically, when the drive signal COMc having the pulse PS is supplied to the ejection section D[m], the waveform of the pulse PS is determined so that the ejection section D[m] is driven to such an extent that ink is not ejected from the ejection section D[m]. As described above, the start and end potentials of the pulse PS are set to the potential VC1.

[0184] The control unit 4 also outputs a period defining signal Tsig having a pulse PLSt1 and a pulse PLSt2, thereby dividing the unit period TU into a control period TSS1 from the start of the pulse PlsL to the start of the pulse PLSt1, a control period TSS2 from the start of the pulse PLSt1 to the start of the pulse PLSt2, and a control period TSS3 from the start of the pulse PLSt2 to the start of the next pulse PlsL.

[0185] For example, when the individual designation signal Sd[m] designates the discharge section D[m] as the discharge section D for which discharge abnormalities are to be detected, the connection state designation circuit CSC sets the connection state designation signals Qa[m] and Qb[m] to a low level during the unit period TU. The connection state designation circuit CSC also sets the connection state designation signal Qc[m] to a high level during the control periods TSS1 and TSS3, and to a low level during the control period TSS2. The connection state designation circuit CSC also sets the connection state designation signal Qs[m] to a low level during the control periods TSS1 and TSS3, and to a high level during the control period TSS2.

[0186] In this case, the piezoelectric element PZ[m] of the discharge section D[m] to be detected for discharge abnormalities is driven by the pulse PS of the drive signal COMc during the control period TSS1. Specifically, the piezoelectric element PZ[m] is displaced by the pulse PS of the drive signal COMc during the control period TSS1. As a result, vibration occurs in the discharge section D[m] to be detected. The vibration generated during the control period TSS1 remains during the control period TSS2. Then, during the control period TSS2, the potential of the individual electrode Za[m] of the piezoelectric element PZ[m] of the discharge section D[m] to be detected changes depending on the residual vibration generated in the discharge section D[m]. That is, during the control period TSS2, the potential of the individual electrode Za of the piezoelectric element PZ of the discharge section D to be detected becomes a potential corresponding to the electromotive force of the piezoelectric element PZ caused by the residual vibration generated in the discharge section D to be detected. Then, the potential of the individual electrode Za is detected as the detection signal Vout during the control period TSS2.

[0187] 12 illustrates an example in which the detection signal Vout indicating the residual vibration of the ejection section D targeted for ejection abnormality detection is generated during the printing process period, but the detection signal Vout may be generated during a period other than the printing process period. That is, a process for detecting the residual vibration of the ejection section D targeted for ejection abnormality detection may be executed during a period other than the printing process period. Also, in this modified example, the drive signal COMb may not be used. In this case, the wiring Lb shown in FIG. 11 may be omitted.

[0188] As described above, this modification can also achieve the same effects as the above-described embodiment. Furthermore, this modification can detect ejection abnormalities in the nozzle N based on the residual vibration detected using the drive signal COMc.

[0189] [Second Modification] In the above-described embodiment and first modified example, the waveform information indicating the drive signal candidates may be stored in advance in a storage unit (not shown) of the liquid ejection head 1 at the time the head manufacturer manufactures the liquid ejection head 1. Alternatively, the waveform information indicating the drive signal candidates may be stored in a storage unit 5 or the like from the head manufacturer via a network (not shown) after the liquid ejection head 1 is shipped. For example, the waveform information indicating the drive signal candidates prepared by the head manufacturer is read from the storage unit 5 or the like in which the waveform information indicating the drive signal candidates is stored when the operation shown in FIG. 9 is performed.

[0190] As described above, in this modified example, the same effects as those of the above-described embodiment can be obtained.

[0191] [Third Modification] In the above-described embodiment and modified example, the analysis of the residual vibration detected by the detection circuit 19 is performed by the control unit 4. However, the present invention is not limited to this configuration. For example, the analysis of the residual vibration detected by the detection circuit 19 may be performed by a control unit such as a CPU of an external server managed by the head manufacturer. In this modified example, the liquid ejection device 100 has a communication unit capable of communicating with the external server managed by the head manufacturer. Then, for example, the control unit 4 transmits residual vibration data indicating the residual vibration detected by the detection circuit 19 to the external server managed by the head manufacturer via the communication unit. The control unit of the external server analyzes the residual vibration data transmitted from the liquid ejection device 100. Specifically, for example, the control unit of the external server identifies the amplitude, phase, and period of the residual vibration during full ejection and the amplitude, phase, and period of the residual signal during alternating ejection, and compares the residual vibration during full ejection with the residual signal during alternating ejection based on the identification results. The control unit of the external server may then determine the presence or absence of crosstalk based on the results of a comparison between the residual vibration during full ejection and the residual signal during alternating ejection, and transmit an analysis result indicating the presence or absence of crosstalk to the liquid ejection device 100. Alternatively, the control unit of the external server may identify which drive signal COM should be used to suppress the occurrence of crosstalk based on the results of a comparison between the residual vibration during full ejection and the residual signal during alternating ejection, and transmit information indicating the identification result to the liquid ejection device 100.

[0192] As described above, in this modified example, the same effects as those of the above-described embodiment can be obtained.

[0193] [Fourth Modification] In the above-described embodiment and modified example, the piezoelectric element Zb is displaced in the Z1 direction as the potential of the individual drive signal Vin[m] changes from a low potential to a high potential, but the present invention is not limited to such an embodiment. For example, a piezoelectric element Zb may be used that is displaced in the Z1 direction as the potential of the individual drive signal Vin[m] changes from a high potential to a low potential. In this case, for example, the potential of the drive signal COM changes from a low potential to a high potential in a portion corresponding to an expansion element, and changes from a high potential to a low potential in a portion corresponding to a contraction element. That is, in this modified example, the potential corresponding to the "expansion potential" is higher than the potential VC, and the potential corresponding to the "contraction potential" is lower than the potential VC. This modified example also achieves the same effects as the above-described embodiment and modified example.

[0194] [Fifth Modification] In the above-described embodiment and modified example, one piezoelectric element PZ, one pressure chamber CV, and one nozzle N are provided for one discharge portion D, but the present invention is not limited to this. For example, one discharge portion D may have two piezoelectric elements PZ, two pressure chambers CV, and one nozzle N. As described above, in this modified example, the same effects as those of the above-described embodiment and modified example can be obtained.

[0195] [Sixth Modification] In the above-described embodiment and modified example, a serial-type liquid ejection device 100 in which a carriage 91 carrying a liquid ejection head 1 is reciprocated in the X-axis direction is illustrated, but the present invention is not limited to such an embodiment. For example, the liquid ejection device 100 may be a line-type liquid ejection device in which multiple nozzles N are distributed across the entire width of the medium PP. As described above, this modified example can also achieve the same effects as the above-described embodiment and modified example.

[0196] [Seventh Modification] The liquid ejection device 100 exemplified in the above-described embodiment and modified example can be employed in various devices such as facsimile machines and copiers, as well as devices dedicated to printing. However, the use of the liquid ejection device of the present invention is not limited to printing. For example, a liquid ejection device that ejects a solution of a color material is used as a manufacturing device for forming color filters for liquid crystal display devices. Furthermore, a liquid ejection device that ejects a solution of a conductive material is used as a manufacturing device for forming wiring and electrodes for wiring boards. As described above, this modified example can also achieve the same effects as the above-described embodiment and modified example.

[0197] [3. Notes] From the above-described exemplary embodiments, the following configurations can be understood, for example.

[0198] A liquid ejection device according to a preferred aspect 1 comprises a liquid ejection head including a first nozzle that ejects liquid, a second nozzle that ejects liquid and is positioned differently from the first nozzle, a first piezoelectric element corresponding to the first nozzle, a second piezoelectric element corresponding to the second nozzle, a vibration plate that vibrates by driving at least one of the first piezoelectric element and the second piezoelectric element, and a detection unit that detects residual vibration of the vibration plate caused by driving at least one of the first piezoelectric element and the second piezoelectric element; and a control unit, wherein the control unit causes the detection unit to detect, from the first piezoelectric element, the residual vibration caused by driving the first piezoelectric element and the second piezoelectric element with an ejection signal that ejects liquid as a first residual vibration, and causes the detection unit to detect, from the first piezoelectric element, the residual vibration caused by driving the first piezoelectric element with the ejection signal and driving the second piezoelectric element with a hold signal that does not eject liquid as a second residual vibration, and evaluates crosstalk between the first nozzle and the second nozzle based on the first residual vibration and the second residual vibration detected by the detection unit. According to the first aspect, crosstalk can be evaluated appropriately and easily.

[0199] In a liquid ejection device according to aspect 2, which is a specific example of aspect 1, the control unit detects the second residual vibration when a first hold signal maintained at a first potential is used as the hold signal, and when a second hold signal maintained at a second potential higher than the first potential is used as the hold signal. According to the second aspect, it is possible to easily determine whether the potential of the hold signal should be set to the first potential or the second potential.

[0200] In a liquid ejection device according to aspect 3, which is a specific example of aspect 2, the control unit detects the first residual vibration when a first ejection signal is used as the ejection signal and when a second ejection signal is used as the ejection signal, and the waveforms of the first ejection signal and the second ejection signal each include a first element whose potential changes from a reference potential between an expansion potential and a contraction potential, and a second element that is an element subsequent to the first element and whose potential changes from the expansion potential to the contraction potential, and the reference potential of the first ejection signal is the first potential, and the reference potential of the second ejection signal is the second potential. According to the third aspect, it is possible to easily determine whether the reference potential of the ejection signal should be set to the first potential or the second potential.

[0201] In a liquid ejection device according to aspect 4, which is a specific example of aspect 3, the control unit evaluates the crosstalk based on the first residual vibration and the second residual vibration detected by the detection unit when the first ejection signal is used as the ejection signal and the first hold signal is used as the hold signal, and based on the first residual vibration and the second residual vibration detected by the detection unit when the second ejection signal is used as the ejection signal and the second hold signal is used as the hold signal. According to aspect 4, it is possible to easily determine whether it is better to adopt a set of a first ejection signal and a first hold signal, or a set of a second ejection signal and a second hold signal, as a set of an ejection signal and a hold signal.

[0202] In the liquid ejection device according to Aspect 5, which is a specific example of any one of Aspects 1 to 4, the first nozzle and the second nozzle are disposed adjacent to each other. According to the fifth aspect, structural crosstalk can be evaluated with high accuracy.

[0203] In a liquid ejection device according to aspect 6, which is a specific example of aspect 5, the liquid ejection head is arranged adjacent to the first nozzle and further has a third nozzle that ejects liquid, and a third piezoelectric element corresponding to the third nozzle, the vibration plate vibrates by driving at least one of the first piezoelectric element, the second piezoelectric element, and the third piezoelectric element, the third nozzle, the first nozzle, and the second nozzle are arranged in this order in a predetermined direction, and the control unit causes the detection unit to detect the residual vibration caused by driving the first piezoelectric element, the second piezoelectric element, and the third piezoelectric element with the ejection signal as the first residual vibration from the first piezoelectric element, and causes the detection unit to detect the residual vibration caused by driving the first piezoelectric element with the ejection signal and driving the second piezoelectric element and the third piezoelectric element with the hold signal as the second residual vibration from the first piezoelectric element. In the sixth aspect as well, the structural crosstalk can be evaluated with high accuracy.

[0204] In a liquid ejection device according to a seventh aspect, which is a specific example of the fifth aspect, the liquid ejection head further includes a fourth nozzle disposed adjacent to the second nozzle for ejecting liquid, and a fourth piezoelectric element corresponding to the fourth nozzle; the vibration plate vibrates by driving at least one of the first piezoelectric element, the second piezoelectric element, and the fourth piezoelectric element; the first nozzle, the second nozzle, and the fourth nozzle are arranged in this order in a predetermined direction; the control unit determines the residual vibration resulting from driving the first piezoelectric element, the second piezoelectric element, and the fourth piezoelectric element with the ejection signal as the first residual vibration, and detects the residual vibration in the detection unit. The residual vibration resulting from driving the first piezoelectric element and the fourth piezoelectric element with the ejection signal and driving the second piezoelectric element with the hold signal is detected by the detection unit as the second residual vibration, and the residual vibration resulting from driving the first piezoelectric element with the ejection signal and driving the second piezoelectric element and the fourth piezoelectric element with the hold signal is detected by the detection unit as the third residual vibration from the first piezoelectric element, and the crosstalk is evaluated based on the first residual vibration, the second residual vibration, and the third residual vibration detected by the detection unit. In the seventh aspect as well, structural crosstalk can be evaluated with high accuracy.

[0205] In a liquid ejection device according to aspect 8, which is a specific example of any one of aspects 1 to 6, the control unit evaluates the crosstalk based on the phase of the first residual vibration and the phase of the second residual vibration. In the eighth aspect, crosstalk can be easily evaluated with high accuracy.

[0206] In a liquid ejection device according to aspect 9, which is a specific example of aspect 8, the control unit evaluates that the crosstalk is occurring when the phase of the second residual vibration is not included in a first range determined based on the phase of the first residual vibration. In the ninth aspect as well, crosstalk can be easily evaluated with high accuracy.

[0207] In a liquid ejection device according to aspect 10, which is a specific example of any one of aspects 1 to 6, aspect 8, and aspect 9, the control unit evaluates the crosstalk based on the period of the first residual vibration and the period of the second residual vibration. In the tenth aspect as well, crosstalk can be easily evaluated with high accuracy.

[0208] In a liquid ejection device according to aspect 11, which is a specific example of aspect 10, the control unit evaluates that crosstalk is occurring when the period of the second residual vibration is not included in a second range determined based on the period of the first residual vibration. In the eleventh aspect as well, crosstalk can be easily evaluated with high accuracy.

[0209] In a liquid ejection device according to aspect 12, which is a specific example of any one of aspects 1 to 6 and aspects 8 to 10, the control unit evaluates the crosstalk based on the amplitude of the first residual vibration and the amplitude of the second residual vibration. In the twelfth aspect as well, crosstalk can be easily evaluated with high accuracy.

[0210] In a liquid ejection device according to aspect 13, which is a specific example of aspect 12, the control unit evaluates that crosstalk is occurring when the amplitude of the second residual vibration is not within a third range determined based on the amplitude of the first residual vibration. In the thirteenth aspect as well, crosstalk can be easily evaluated with high accuracy.

[0211] Furthermore, a liquid ejection device according to aspect 14, which is another preferred aspect, comprises a liquid ejection head having a first nozzle that ejects liquid, a second nozzle that ejects liquid and is positioned at a different position from the first nozzle, a first piezoelectric element corresponding to the first nozzle, a second piezoelectric element corresponding to the second nozzle, a vibration plate that vibrates by driving at least one of the first piezoelectric element and the second piezoelectric element, and a detection unit that detects residual vibration of the vibration plate caused by driving at least one of the first piezoelectric element and the second piezoelectric element; and a control unit, wherein the control unit causes the detection unit to detect from the first piezoelectric element the residual vibration caused by driving the first piezoelectric element and the second piezoelectric element with an ejection signal that ejects liquid as a first residual vibration, and causes the detection unit to detect from the first piezoelectric element the residual vibration caused by driving the first piezoelectric element with the ejection signal and driving the second piezoelectric element with a hold signal that does not eject liquid as a second residual vibration, and determines the waveform of the ejection signal and the waveform of the hold signal based on the first residual vibration and the second residual vibration detected by the detection unit. According to the fourteenth aspect, the waveform of the drive signal for driving the piezoelectric element can be determined appropriately and easily.

[0212] Furthermore, a control method for a liquid ejection device according to aspect 15, which is a preferred aspect, is a control method for a liquid ejection device having a liquid ejection head including a first nozzle that ejects liquid, a second nozzle that ejects liquid and is positioned at a different position from the first nozzle, a first piezoelectric element corresponding to the first nozzle, a second piezoelectric element corresponding to the second nozzle, a vibration plate that vibrates by driving at least one of the first piezoelectric element and the second piezoelectric element, and a detection unit that detects residual vibration of the vibration plate caused by driving at least one of the first piezoelectric element and the second piezoelectric element, wherein the detection unit detects the residual vibration caused by driving the first piezoelectric element and the second piezoelectric element with an ejection signal that ejects liquid as a first residual vibration from the first piezoelectric element, and the detection unit detects the residual vibration caused by driving the first piezoelectric element with the ejection signal and driving the second piezoelectric element with a hold signal that does not eject liquid as a second residual vibration from the first piezoelectric element, and evaluates crosstalk between the first nozzle and the second nozzle based on the first residual vibration and the second residual vibration detected by the detection unit. According to the fifteenth aspect, crosstalk can be evaluated appropriately and easily. [Explanation of symbols]

[0213] 1...liquid ejection head, 2...drive signal generation unit, 3...analysis unit, 4...control unit, 5...storage unit, 7...maintenance unit, 8...medium transport mechanism, 9...carriage transport mechanism, 10...recording head, 18...switching circuit, 19...detection circuit, 40...evaluation control unit, 60...ink container, 100...liquid ejection device, CV...pressure chamber, D...ejection unit, N...nozzle, PP...medium, PZ...piezoelectric element.

Claims

1. a liquid ejection head including a first nozzle that ejects liquid, a second nozzle that is disposed at a position different from the first nozzle and ejects liquid, a first piezoelectric element corresponding to the first nozzle, a second piezoelectric element corresponding to the second nozzle, a vibration plate that vibrates when at least one of the first piezoelectric element and the second piezoelectric element is driven, and a detection unit that detects residual vibration of the vibration plate caused by the driving of at least one of the first piezoelectric element and the second piezoelectric element; A control unit; Equipped with The control unit the residual vibration resulting from driving the first piezoelectric element and the second piezoelectric element with an ejection signal for ejecting a liquid is detected as a first residual vibration by the detection unit from the first piezoelectric element; the residual vibration resulting from driving the first piezoelectric element with the ejection signal and driving the second piezoelectric element with a holding signal that does not eject liquid is detected by the detection unit as a second residual vibration from the first piezoelectric element; evaluating crosstalk between the first nozzle and the second nozzle based on the first residual vibration and the second residual vibration detected by the detection unit; A liquid ejection device characterized by:

2. The control unit the second residual vibration is detected in each of a case where a first hold signal maintained at a first potential is used as the hold signal and a case where a second hold signal maintained at a second potential higher than the first potential is used as the hold signal. The liquid ejection device according to claim 1 .

3. The control unit detecting the first residual vibration in each of a case where the first ejection signal is used as the ejection signal and a case where the second ejection signal is used as the ejection signal; The waveforms of the first ejection signal and the second ejection signal are a first element whose potential changes from a reference potential between an expansion potential and a contraction potential to the expansion potential; a second element subsequent to the first element, the second element having a potential change from the expansion potential to the contraction potential; Including, the reference potential of the first ejection signal is the first potential, the reference potential of the second ejection signal is the second potential; 3. The liquid ejection device according to claim 2.

4. The control unit the first residual vibration and the second residual vibration detected by the detection unit when the first ejection signal is used as the ejection signal and the first hold signal is used as the hold signal; and the first residual vibration and the second residual vibration detected by the detection unit when the second ejection signal is used as the ejection signal and the second hold signal is used as the hold signal; and evaluating the crosstalk based on 4. The liquid ejection device according to claim 3.

5. The first nozzle and the second nozzle are disposed adjacent to each other.

5. The liquid ejection device according to claim 1, wherein the ejection head is a nozzle.

6. the liquid ejection head further includes a third nozzle that is disposed adjacent to the first nozzle and ejects liquid, and a third piezoelectric element that corresponds to the third nozzle; the vibration plate vibrates when at least one of the first piezoelectric element, the second piezoelectric element, and the third piezoelectric element is driven; the third nozzle, the first nozzle, and the second nozzle are arranged in this order in a predetermined direction; The control unit the residual vibration resulting from driving the first piezoelectric element, the second piezoelectric element, and the third piezoelectric element by the ejection signal is detected as the first residual vibration by the detection unit from the first piezoelectric element; driving the first piezoelectric element with the ejection signal and driving the second piezoelectric element and the third piezoelectric element with the holding signal, the residual vibration resulting from this is detected as the second residual vibration by the detection unit from the first piezoelectric element.

6. The liquid ejection device according to claim 5.

7. the liquid ejection head further includes a fourth nozzle that is disposed adjacent to the second nozzle and ejects liquid, and a fourth piezoelectric element that corresponds to the fourth nozzle; the vibration plate vibrates when at least one of the first piezoelectric element, the second piezoelectric element, and the fourth piezoelectric element is driven; the first nozzle, the second nozzle, and the fourth nozzle are arranged in this order in a predetermined direction; The control unit the residual vibration resulting from driving the first piezoelectric element, the second piezoelectric element, and the fourth piezoelectric element by the ejection signal is detected as the first residual vibration by the detection unit from the first piezoelectric element; driving the first piezoelectric element and the fourth piezoelectric element with the ejection signal and driving the second piezoelectric element with the holding signal, the residual vibration resulting from which is detected as the second residual vibration by the detection unit from the first piezoelectric element; driving the first piezoelectric element with the ejection signal and driving the second piezoelectric element and the fourth piezoelectric element with the holding signal, the residual vibration resulting from this is detected as a third residual vibration by the detection unit from the first piezoelectric element; evaluating the crosstalk based on the first residual vibration, the second residual vibration, and the third residual vibration detected by the detection unit; 6. The liquid ejection device according to claim 5.

8. the control unit evaluates the crosstalk based on a phase of the first residual vibration and a phase of the second residual vibration. The liquid ejection device according to claim 1 .

9. The control unit When the phase of the second residual vibration is not included in a first range that is specified based on the phase of the first residual vibration, it is determined that the crosstalk is occurring.

9. The liquid ejection device according to claim 8.

10. the control unit evaluates the crosstalk based on the period of the first residual vibration and the period of the second residual vibration. The liquid ejection device according to claim 1 .

11. The control unit When the period of the second residual vibration is not included in a second range specified based on the period of the first residual vibration, it is determined that the crosstalk is occurring. The liquid ejection device according to claim 10 .

12. the control unit evaluates the crosstalk based on the amplitude of the first residual vibration and the amplitude of the second residual vibration. The liquid ejection device according to claim 1 .

13. The control unit When the amplitude of the second residual vibration is not included in a third range that is specified based on the amplitude of the first residual vibration, it is determined that the crosstalk is occurring. The liquid ejection device according to claim 12 .

14. a liquid ejection head having a first nozzle for ejecting liquid, a second nozzle for ejecting liquid and disposed at a position different from the first nozzle, a first piezoelectric element corresponding to the first nozzle, a second piezoelectric element corresponding to the second nozzle, a vibration plate that vibrates when at least one of the first piezoelectric element and the second piezoelectric element is driven, and a detection unit that detects residual vibration of the vibration plate caused by the driving of at least one of the first piezoelectric element and the second piezoelectric element; A control unit; Equipped with The control unit the residual vibration resulting from driving the first piezoelectric element and the second piezoelectric element with an ejection signal for ejecting a liquid is detected as a first residual vibration by the detection unit from the first piezoelectric element; the residual vibration resulting from driving the first piezoelectric element with the ejection signal and driving the second piezoelectric element with a holding signal that does not eject liquid is detected by the detection unit as a second residual vibration from the first piezoelectric element; determining a waveform of the ejection signal and a waveform of the holding signal based on the first residual vibration and the second residual vibration detected by the detection unit; A liquid ejection device characterized by:

15. A control method for a liquid ejection device having a liquid ejection head including: a first nozzle that ejects liquid; a second nozzle that is disposed at a position different from the first nozzle and ejects liquid; a first piezoelectric element corresponding to the first nozzle; a second piezoelectric element corresponding to the second nozzle; a vibration plate that vibrates by driving at least one of the first piezoelectric element and the second piezoelectric element; and a detection unit that detects residual vibration of the vibration plate resulting from driving at least one of the first piezoelectric element and the second piezoelectric element, the residual vibration resulting from driving the first piezoelectric element and the second piezoelectric element with an ejection signal for ejecting a liquid is detected as a first residual vibration by the detection unit from the first piezoelectric element; the residual vibration resulting from driving the first piezoelectric element with the ejection signal and driving the second piezoelectric element with a holding signal that does not eject liquid is detected by the detection unit as a second residual vibration from the first piezoelectric element; evaluating crosstalk between the first nozzle and the second nozzle based on the first residual vibration and the second residual vibration detected by the detection unit; A method for controlling a liquid ejection device.

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