Driving method of liquid discharge device, and liquid discharge device

Abstract

To improve printing quality while reducing the size in a device.SOLUTION: A driving method of a liquid discharge device which includes a liquid discharge head having a plurality of nozzle arrays for discharging a liquid and a plurality of driving elements provided on each nozzle of the plurality of nozzle arrays, and a plurality of temperature sensors corresponding to the plurality of nozzle arrays: totalizes liquid discharge amounts discharged from the plurality of nozzle arrays within a prescribed period, for each of the nozzle arrays; acquires temperatures of each of the plurality of nozzle arrays by the plurality of temperature sensors; determines a temperature for correction, on the basis of the liquid discharge amounts for each of the nozzle arrays of the plurality of nozzle arrays and the temperatures of each of the plurality of nozzle arrays; corrects a driving waveform corresponding to the temperature for correction; and supplies the corrected driving waveform to the driving elements of the plurality of nozzle arrays.SELECTED DRAWING: Figure 9

Description

[Technical field]

[0001] The present disclosure relates to a method for driving a liquid ejection device and a liquid ejection device. [Background technology]

[0002] A liquid ejection device, such as an inkjet printer, generally includes a liquid ejection head having a plurality of nozzle rows for ejecting liquid such as ink. Here, the liquid ejection head is provided with a plurality of driving elements, such as piezoelectric elements, corresponding to the plurality of nozzles constituting each nozzle row, and each driving element receives a driving signal to generate a driving force for ejecting liquid from the corresponding nozzle.

[0003] The viscosity of ink changes with temperature. Therefore, if the same drive signal is supplied to the drive element regardless of the ink temperature, the amount of ink ejected from the nozzle will vary due to changes in the ink viscosity, which may result in changes in the quality of the printed image. Therefore, as disclosed in Patent Document 1, for example, parameters such as the voltage value of the drive waveform, which is the waveform of the drive signal, are adjusted according to the ink temperature. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2011-218680 A Summary of the Invention [Problem to be solved by the invention]

[0005] In a liquid ejection head having multiple nozzle rows, the temperature of the ink may differ for each nozzle row due to differences in conditions such as the amount of liquid ejected or the arrangement between the nozzle rows. If an attempt is made to adjust the drive signal for each nozzle row according to the ink temperature using the technology described in Patent Document 1, then a circuit for generating the drive signal would be required in the same number as the number of nozzle rows, which would result in an increase in the size of the device. [Means for solving the problem]

[0006] In order to solve the above problems, a driving method of a liquid ejection device according to a preferred aspect of the present disclosure is a driving method of a liquid ejection device including a liquid ejection head having a plurality of nozzle rows that eject liquid and a plurality of driving elements provided for each nozzle of the plurality of nozzle rows, and a plurality of temperature sensors corresponding to the plurality of nozzle rows, wherein the method comprises: collating, for each nozzle row, the amount of liquid ejected from the plurality of nozzle rows within a predetermined period of time; acquiring the temperature of each of the plurality of nozzle rows using the plurality of temperature sensors; determining a correction temperature based on the amount of liquid ejected from each of the plurality of nozzle rows and the temperature of each of the plurality of nozzle rows; correcting a driving waveform in accordance with the correction temperature; and supplying the corrected driving waveform to the driving elements of the plurality of nozzle rows.

[0007] A liquid ejection device according to a preferred embodiment of the present invention is a liquid ejection head including a plurality of nozzle rows for ejecting liquid, and a plurality of driving elements provided for each nozzle of the plurality of nozzle rows, and a plurality of temperature sensors corresponding to the plurality of nozzle rows, and the liquid ejection amount ejected from the plurality of nozzle rows within a predetermined period is compiled for each nozzle row, the plurality of temperature sensors obtain the temperature of each of the plurality of nozzle rows, a correction temperature is determined based on the liquid ejection amount for each of the plurality of nozzle rows and the temperature of each of the plurality of nozzle rows, a drive waveform is corrected in accordance with the correction temperature, and the corrected drive waveform is supplied to the drive elements of the plurality of nozzle rows. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic diagram illustrating an example of the configuration of a liquid ejection device according to a first embodiment. [Diagram 2] 2 is a block diagram showing the electrical configuration of the liquid ejection device according to the first embodiment. FIG. [Diagram 3] FIG. 2 is an exploded perspective view of the head chip according to the first embodiment. [Figure 4] 1 is a cross-sectional view of a head chip according to a first embodiment. [Diagram 5] FIG. 2 is a plan view of the head chip according to the first embodiment. [Figure 6] 6 is a cross-sectional view taken along line BB in FIG. 5. [Figure 7] 6 is a cross-sectional view taken along line DD in FIG. 5. [Figure 8] FIG. 4 is a diagram showing an example of a driving waveform. [Figure 9] 5 is a flowchart showing a method for driving the liquid ejection device of the first embodiment. [Figure 10] FIG. 4 is a diagram for explaining a method for setting a correction temperature in the first embodiment. [Figure 11] FIG. 11 is a diagram for explaining a method for setting a correction temperature in the second embodiment. [Figure 12] FIG. 13 is a diagram for explaining a method for setting a correction temperature in the third embodiment. [Figure 13] FIG. 13 is a block diagram showing the electrical configuration of a liquid ejection device according to a fourth embodiment. [Figure 14] 13 is a flowchart showing a method for driving a liquid ejection device according to a fourth embodiment. [Figure 15] FIG. 11 is a diagram for explaining selection of a correction temperature setting method. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, preferred embodiments of the present disclosure will be described with reference to the accompanying drawings. Note that the dimensions and scale of each part in the drawings may differ from the actual dimensions, and some parts are shown diagrammatically to facilitate understanding. In addition, the scope of the present disclosure is not limited to these forms unless otherwise specified in the following description to the effect that the present disclosure is limited.

[0010] In the following description, for the convenience of specifying positions or directions, the mutually intersecting X-axis, Y-axis, and Z-axis are appropriately used. In addition, in the following, one direction along the X-axis is the X1 direction, and the direction opposite to the X1 direction is the X2 direction. Similarly, the opposite directions along the Y-axis are the Y1 direction and the Y2 direction. In addition, the opposite directions along the Z-axis are the Z1 direction and the Z2 direction.

[0011] Typically, the Z axis is a vertical axis, and the Z2 direction corresponds to the downward direction in the vertical direction. However, the Z axis does not have to be a vertical axis. Also, the X axis, the Y axis, and the Z axis are typically perpendicular to each other, but are not limited to this, and may intersect at an angle within a range of 80° to 100°, for example.

[0012] A: First embodiment A1: Overall configuration of the liquid ejection device 1 is a schematic diagram showing an example of the configuration of a liquid ejection device 100 according to a first embodiment. The liquid ejection device 100 is an inkjet printing device that ejects ink, which is an example of a "liquid," as droplets toward a medium M. The medium M is, for example, printing paper. Note that the medium M is not limited to printing paper, and may be a printing target made of any material, such as a resin film or fabric.

[0013] As shown in FIG. 1, the liquid ejection device 100 includes a liquid container 10, a control module 20, a transport mechanism 30, a moving mechanism 40, a liquid ejection head 50, a support section 60, a heating section 70, and a plurality of temperature sensors 80.

[0014] The liquid container 10 stores ink. Specific examples of the liquid container 10 include a cartridge that is detachable from the liquid ejection device 100, a bag-shaped ink pack made of a flexible film, and an ink tank that can be refilled with ink. The type of ink stored in the liquid container 10 is arbitrary.

[0015] The control module 20 controls the operation of each element of the liquid ejection device 100. Here, the control module 20 outputs a drive signal Com for driving the liquid ejection head 50 and a control signal SI for controlling the driving of the liquid ejection head 50. In addition, the control module 20 receives a detection signal Dt indicating the temperature of each nozzle row Ln of the liquid ejection head 50 from a plurality of temperature sensors 80. The control module 20 corrects a drive waveform, which is the waveform of the drive signal Com, based on the detection signal Dt. Details of the control module 20 will be described later based on FIG. 2.

[0016] The transport mechanism 30 transports the medium M under the control of the control module 20. In the example shown in Fig. 1, the transport direction of the medium M by the transport mechanism 30 is the Y1 direction.

[0017] The moving mechanism 40 reciprocates the liquid ejection head 50 along the X-axis under the control of the control module 20. The moving mechanism 40 has a substantially box-shaped transport body 41 called a carriage that houses the liquid ejection head 50, and an endless transport belt 42 to which the transport body 41 is fixed. The number of liquid ejection heads 50 mounted on the transport body 41 is not limited to one, and may be multiple. In addition to the liquid ejection head 50, the above-mentioned liquid container 10 may be mounted on the transport body 41.

[0018] Under the control of the control module 20, the liquid ejection head 50 ejects ink supplied from the liquid container 10 from each of a plurality of nozzles onto the medium M. This ejection is performed in parallel with the transportation of the medium M by the transport mechanism 30 and the reciprocating movement of the liquid ejection head 50 by the movement mechanism 40, so that an image is formed on the surface of the medium M using ink.

[0019] In the example shown in FIG. 1, the liquid ejection head 50 includes a plurality of head chips 51. Each head chip 51 has a nozzle row Ln. Thus, the liquid ejection head 50 has a plurality of nozzle rows Ln. Each nozzle row Ln is composed of a plurality of nozzles N that eject ink. A temperature sensor 80 is provided in each head chip 51. Thus, the plurality of temperature sensors 80 correspond to the plurality of nozzle rows Ln. Configuration examples of the head chips 51 and the temperature sensor 80 will be described later with reference to FIG. 3 to FIG. 7. Note that the number of head chips 51 included in the liquid ejection head 50 is not limited to the example shown in FIG. 1, and may be 1 to 5 or less, or 7 or more.

[0020] The support unit 60 is a stand, also called a platen, that supports the medium M in a state in which it receives the ink ejected from the liquid ejection head 50. Such a support unit 60 supports the medium M that faces the multiple nozzles N of the liquid ejection head 50 during printing.

[0021] The heating unit 70 heats the support unit 60 to a set temperature under the control of the control module 20. In this way, the heating unit 70 heats the medium M on which the ink ejected from the multiple nozzle rows Ln has landed. This heating can promote drying of the ink on the medium M. As a result, the ink on the medium M is kept at a desired position, improving image quality. Note that the heating unit 70 is provided as necessary and may be omitted.

[0022] A2: Electrical configuration of the liquid ejection device 2 is a block diagram showing the electrical configuration of the liquid ejection device 100 according to the first embodiment. As shown in FIG. 2, the liquid ejection head 50 has a plurality of head chips 51, a plurality of drive circuits 52, and a detection circuit 53.

[0023] Each of the multiple head chips 51 has multiple driving elements 560 and a temperature sensor 80 .

[0024] Each of the multiple drive elements 560 of the head chip 51 is provided for each nozzle N, and is driven by the inverse piezoelectric effect upon receiving the supply drive signal Vin. The temperature sensor 80 is a resistor having a characteristic that the resistance value changes according to the temperature change. The details of the head chip 51 will be described later with reference to Figs. 3 to 7.

[0025] Drive circuits 52 are provided for each of the multiple head chips 51, and drive drive elements 560 of the corresponding head chips 51 under the control of control module 20. Specifically, drive circuits 52, under the control of control module 20, switch whether or not to supply drive signal Com output from control module 20 as supply drive signal Vin for each of the multiple drive elements 560 of head chip 51.

[0026] Detection circuit 53 is a circuit for detecting the temperature of each of the multiple head chips 51. Specifically, detection circuit 53 has a circuit for supplying current Id to temperature sensor 80 of each head chip 51, and a circuit for detecting potential Vd corresponding to the voltage applied to temperature sensor 80 of each head chip 51, and outputs a detection signal Dt corresponding to potential Vd.

[0027] The current Id is a predetermined constant current flowing between two predetermined positions, such as both ends of the temperature sensor 80. The potential Vd is the potential of the temperature sensor 80 with a constant potential, such as the offset potential VBS, as a reference potential. The potential Vd changes according to the resistance value of the temperature sensor 80. As described above, the resistance value of the temperature sensor 80 changes according to temperature changes, so the potential Vd changes according to temperature changes. Therefore, the detection signal Dt according to the potential Vd is a signal indicating the temperature of the head chip 51, more specifically, the temperature of ink in a pressure chamber C, which will be described later, of the head chip 51. The temperature indicated by the detection signal Dt is the temperature of ink in the pressure chamber C of each head chip 51. In other words, the temperature indicated by the detection signal Dt is the temperature of each nozzle row Ln.

[0028] As shown in FIG. 2, the control module 20 includes a processing circuit 21, a memory circuit 22, a power supply circuit 23, and a drive signal generating circuit 24.

[0029] The processing circuit 21 has a function of controlling the operation of each part of the liquid ejection device 100, and a function of processing various data.

[0030] The processing circuit 21 includes, for example, one or more processors such as a CPU (Central Processing Unit). The processing circuit 21 may include a programmable logic device such as an FPGA (field-programmable gate array) instead of or in addition to a CPU. When the processing circuit 21 is configured with a plurality of processors, for example, the operation control of the drive circuit 52 and the operation control of the detection circuit 53 may be performed by separate processors. When the processing circuit 21 is configured with a plurality of processors, the plurality of processors may be mounted on different boards or the like.

[0031] The memory circuitry 22 stores various programs executed by the processing circuitry 21 and various data such as print data processed by the processing circuitry 21. The memory circuitry 22 includes one or both of semiconductor memories, for example, a volatile memory such as a random access memory (RAM) and a non-volatile memory such as a read only memory (ROM), an electrically erasable programmable read-only memory (EEPROM) or a programmable ROM (PROM). The print data is supplied from an external device such as a personal computer or a digital camera. Note that a part or the whole of the memory circuitry 22 may be configured as a part of the processing circuitry 21.

[0032] The memory circuit 22 stores the discharge amount information Dv. The discharge amount information Dv is information indicating the result of tallying up the liquid discharge amount discharged from the multiple nozzle rows Ln of the liquid discharge head 50 within a predetermined period for each nozzle row Ln, and is generated by a correction unit 21a described later. Here, the predetermined period is, for example, a period for each printing pass or each printing page when printing on the medium M.

[0033] The power supply circuit 23 receives power from a commercial power supply (not shown) and generates various predetermined potentials. The generated various potentials are appropriately supplied to each section of the liquid ejection device 100. For example, the power supply circuit 23 generates a power supply potential VHV and an offset potential VBS. The offset potential VBS is supplied to the liquid ejection head 50. In addition, the power supply potential VHV is supplied to the drive signal generation circuit 24.

[0034] The drive signal generating circuit 24 is a circuit that generates a drive signal Com for driving each drive element 560. Specifically, the drive signal generating circuit 24 has, for example, a DA conversion circuit and an amplifier circuit. In the drive signal generating circuit 24, the DA conversion circuit converts the waveform designation signal dCom from the processing circuit 21 from a digital signal to an analog signal, and the amplifier circuit amplifies the analog signal using the power supply potential VHV from the power supply circuit 23 to generate the drive signal Com. Here, among the waveforms included in the drive signal Com, the signal of the waveform that is actually supplied to the drive element 560 is the aforementioned supply drive signal Vin. The waveform designation signal dCom is a digital signal for defining the drive waveform, which is the waveform of the drive signal Com.

[0035] In the above-described control module 20, the processing circuit 21 executes a program stored in the memory circuit 22 to control the operation of each part of the liquid ejection device 100. Here, the processing circuit 21 executes the program to generate a control signal Sk1, a control signal Sk2, a control signal Sk3, a control signal SI, and a waveform designation signal dCom as signals for controlling the operation of each part of the liquid ejection device 100.

[0036] The control signal Sk1 is a signal for controlling the driving of the transport mechanism 30. The control signal Sk2 is a signal for controlling the driving of the movement mechanism 40. The control signal Sk3 is a signal for controlling the driving of the heating unit 70. The control signal SI is a digital signal for specifying the operating state of the drive element 560. The control signal SI may include a timing signal for defining the drive timing of the drive element 560. The timing signal is generated, for example, based on the output of an encoder (not shown) that detects the position of the transport body 41 described above.

[0037] In addition, the processing circuitry 21 executes a program stored in the memory circuitry 22 to function as a correction unit 21a.

[0038] The correction unit 21a adjusts the waveform designation signal dCom based on the discharge amount information Dv and the detection signal Dt. This adjustment corrects the drive waveform, which is the waveform of the drive signal Com. Details of this correction will be described later with reference to Figures 9 and 10.

[0039] A3: Head chip Fig. 3 is an exploded perspective view of head chip 51 according to the first embodiment. Fig. 4 is a cross-sectional view of head chip 51 according to the first embodiment. Fig. 4 is a cross-sectional view taken along line AA in Fig. 3.

[0040] As shown in FIGS. 3 and 4, head chip 51 has a plurality of nozzles N arranged in the direction along the Y axis.

[0041] The multiple nozzles N of the head chip 51 constitute a nozzle row Ln. In the example shown in Fig. 3 and Fig. 4, the nozzle row Ln is divided into a first nozzle row Ln1 and a second nozzle row Ln2. The first nozzle row Ln1 and the second nozzle row Ln2 are arranged at intervals from each other in the direction along the X-axis. Each of the first nozzle row Ln1 and the second nozzle row Ln2 is a collection of multiple nozzles N linearly arranged in the direction along the Y-axis.

[0042] The head chips 51 are configured to be substantially symmetrical to each other in the direction along the X-axis. However, the positions of the nozzles N of the first nozzle row Ln1 and the nozzles N of the second nozzle row Ln2 in the direction along the Y-axis may be the same or different. Figures 3 and 4 show an example in which the positions of the nozzles N of the first nozzle row Ln1 and the nozzles N of the second nozzle row Ln2 in the direction along the Y-axis are the same.

[0043] As shown in Figures 3 and 4, the head chip 51 has a flow path substrate 510, a pressure chamber substrate 520, a nozzle substrate 530, a vibration absorber 540, a vibration plate 550, a plurality of driving elements 560, a protection substrate 570, a case 580, and a wiring substrate 590.

[0044] The flow path substrate 510 and the pressure chamber substrate 520 are laminated in this order in the Z1 direction to form a flow path for supplying ink to the multiple nozzles N. In an area located in the Z1 direction from the laminated body consisting of the flow path substrate 510 and the pressure chamber substrate 520, a vibration plate 550, multiple driving elements 560, a protective substrate 570, a case 580, a wiring substrate 590, and a driving circuit 52 are installed. On the other hand, in an area located in the Z2 direction from the laminated body, a nozzle substrate 530 and a vibration absorber 540 are installed. Each element of the head chip 51 is roughly a plate-like member elongated in the Y direction, and is joined to each other by, for example, an adhesive. Each element of the head chip 51 will be described in order below.

[0045] The nozzle substrate 530 is a plate-like member provided with a plurality of nozzles N of the first nozzle row Ln1 and the second nozzle row Ln2. Each of the plurality of nozzles N is a through hole that allows ink to pass through. Here, the surface of the nozzle substrate 530 facing the Z2 direction is the nozzle surface FN. The nozzle substrate 530 is manufactured by processing a silicon single crystal substrate by a semiconductor manufacturing technique using a processing technique such as dry etching or wet etching. However, other known methods and materials may be appropriately used for manufacturing the nozzle substrate 530. In addition, the cross-sectional shape of the nozzle is typically circular, but is not limited thereto, and may be a non-circular shape such as a polygonal or elliptical shape.

[0046] The flow path substrate 510 is provided with a space R1, a plurality of supply flow paths Ra, and a plurality of communication flow paths Na for each of the first nozzle row Ln1 and the second nozzle row Ln2. The space R1 is an elongated opening extending in the direction along the Y axis in a plan view seen in the direction along the Z axis. Each of the supply flow paths Ra and the communication flow paths Na is a through hole formed for each nozzle N. Each supply flow path Ra communicates with the space R1.

[0047] The pressure chamber substrate 520 is a plate-like member in which a plurality of pressure chambers C called cavities are provided for each of the first nozzle row Ln1 and the second nozzle row Ln2. The pressure chambers C are arranged in a direction along the Y axis. Each pressure chamber C is formed for each nozzle N and is an elongated space extending in a direction along the X axis in a plan view.

[0048] The flow path substrate 510 and the pressure chamber substrate 520 are each manufactured by processing a silicon single crystal substrate using, for example, semiconductor manufacturing technology, in the same manner as the above-mentioned nozzle substrate 530. However, other known methods and materials may be appropriately used to manufacture the flow path substrate 510 and the pressure chamber substrate 520, respectively.

[0049] The pressure chambers C are located between the flow path substrate 510 and the vibration plate 550. A plurality of pressure chambers C are arranged in the direction along the Y axis for each of the first nozzle row Ln1 and the second nozzle row Ln2. The pressure chambers C are also connected to each of the communication flow path Na and the supply flow path Ra. Therefore, the pressure chambers C are connected to the nozzles N via the communication flow path Na, and are connected to the space R1 via the supply flow path Ra.

[0050] A vibration plate 550 is disposed on the surface facing the Z1 direction of the pressure chamber substrate 520. The vibration plate 550 is a plate-shaped member that can elastically vibrate. Details of the vibration plate 550 will be described later with reference to Figs. 5 to 7.

[0051] On the surface of the vibration plate 550 facing the Z1 direction, a plurality of driving elements 560 corresponding to the nozzles N are arranged for each of the first nozzle row Ln1 and the second nozzle row Ln2. Each driving element 560 is a piezoelectric element, and generates a pressure fluctuation in the ink in the pressure chamber C by deforming when a supply driving signal Vin corresponding to the driving signal Com is supplied. Each driving element 560 has an elongated shape extending in a direction along the X axis in a plan view. The plurality of driving elements 560 are arranged in a direction along the Y axis so as to correspond to the plurality of pressure chambers C. The driving elements 560 overlap the pressure chambers C in a plan view. Details of the driving elements 560 will be described later with reference to FIGS. 5 to 7. Note that the driving elements 560 are not limited to piezoelectric elements, and may be, for example, heating elements that generate bubbles in the pressure chambers by heat generation.

[0052] Protective substrate 570 is a plate-like member installed on a surface of diaphragm 550 facing the Z1 direction, and protects multiple driving elements 560 and reinforces the mechanical strength of diaphragm 550. Here, multiple driving elements 560 are housed in space S between protective substrate 570 and diaphragm 550. Protective substrate 570 is made of, for example, a resin material.

[0053] The case 580 is a case for storing ink to be supplied to the multiple pressure chambers C. The case 580 is made of, for example, a resin material. The case 580 is provided with a space R2 for each of the first nozzle row Ln1 and the second nozzle row Ln2. The space R2 is a space that communicates with the above-mentioned space R1, and functions as a reservoir R that stores ink to be supplied to the multiple pressure chambers C together with the space R1. The case 580 is provided with an inlet HL for supplying ink to each reservoir R. The ink in each reservoir R is supplied to the pressure chamber C via each supply flow path Ra.

[0054] The vibration absorber 540 is also called a compliance substrate, and is a flexible resin film that constitutes the wall surface of the reservoir R, and absorbs pressure fluctuations of the ink in the reservoir R. The vibration absorber 540 may be a flexible thin metal plate. The surface of the vibration absorber 540 facing the Z1 direction is bonded to the flow path substrate 510 with an adhesive or the like.

[0055] The wiring board 590 is mounted on the surface of the diaphragm 550 facing the Z1 direction, and is a mounting component for electrically connecting the control module 20 and the head chip 51. The wiring board 590 is a flexible wiring board such as a COF (Chip On Film), an FPC (Flexible Printed Circuit), or an FFC (Flexible Flat Cable). The above-mentioned driving circuit 52 is mounted on the wiring board 590 of this embodiment. The wiring board 590 may be a rigid board. In this case, the driving circuit 52 is mounted on the rigid board or on a flexible board connected to the rigid board.

[0056] Fig. 5 is a plan view of head chip 51 according to the first embodiment. Fig. 6 is a cross-sectional view taken along line BB in Fig. 5. Fig. 7 is a cross-sectional view taken along line DD in Fig. 5. For ease of explanation, these figures representatively show, among the elements constituting head chip 51, elements electrically connected to wiring board 590 on diaphragm 550 and their associated elements.

[0057] As shown in FIGS. 5 to 7, head chip 51 has individual drive wiring 91, common drive wiring 92, detection wiring 93, and temperature sensor 80 in addition to the above-mentioned components.

[0058] Prior to describing these wirings and temperature sensor 80, diaphragm 550 and driving element 560 will be described below.

[0059] As shown in FIGS. 6 and 7, diaphragm 550 has elastic film 551 and insulating film 552, which are laminated in this order in the Z1 direction.

[0060] The elastic film 551 is made of, for example, silicon oxide (SiO2) and is formed by thermally oxidizing one surface of a silicon single crystal substrate. The insulating film 552 is made of, for example, zirconium oxide (ZrO2) and is formed by forming a layer of zirconium by a sputtering method and thermally oxidizing the layer.

[0061] Note that diaphragm 550 is not limited to the laminated structure of elastic film 551 and insulating film 552 described above, and may be, for example, a single layer or three or more layers. Furthermore, the material of each layer constituting diaphragm 550 is not limited to the above-mentioned materials, and may be, for example, silicon or silicon nitride.

[0062] A plurality of driving elements 560 are arranged on the surface facing the Z1 direction of the above-described vibration plate 550. As shown in Fig. 6 and Fig. 7, each driving element 560 has a first electrode 561, a piezoelectric body 562, and a second electrode 563, which are laminated in this order in the Z1 direction.

[0063] The first electrodes 561 are individual electrodes spaced apart from each other for each driving element 560. A supply drive signal Vin corresponding to the drive signal Com is supplied to the first electrodes 561. The second electrode 563 is a band-shaped common electrode extending in a direction along the Y-axis so as to be continuous across the multiple driving elements 560. A constant potential is supplied to the second electrode 563, for example. Examples of metal materials for these electrodes include metal materials such as platinum (Pt), aluminum (Al), nickel (Ni), gold (Au), and copper (Cu), and among these, one type can be used alone or two or more types can be combined in the form of an alloy or a laminate.

[0064] 5, the piezoelectric body 562 is in the form of a strip extending in the direction along the Y-axis so as to be continuous across the plurality of driving elements 560. Here, the piezoelectric body 562 is provided with through-holes 562a that extend through the piezoelectric body 562 in the direction along the X-axis in regions that correspond in plan view to the gaps between the adjacent pressure chambers C. Note that the piezoelectric body 562 may be provided individually for each driving element 560.

[0065] 7, the driving element 560 of this embodiment has a wiring portion 564 in addition to the above-mentioned first electrode 561, piezoelectric body 562, and second electrode 563. The wiring portion 564 is provided for each driving element 560, and is arranged so as to straddle the piezoelectric body 562 and the first electrode 561 at a position closer to the wiring board 590 than the second electrode 563 and spaced apart from the second electrode 563. The wiring portion 564 is preferably formed collectively by the same film formation process as the second electrode 563. In this case, the manufacturing process of the head chip 51 can be simplified, and as a result, the cost of the head chip 51 can be reduced.

[0066] In such a driving element 560, the piezoelectric body 562 is deformed by the inverse piezoelectric effect when a voltage is applied between the first electrode 561 and the second electrode 563. When the vibration plate 550 vibrates in conjunction with this deformation, the pressure in the pressure chamber C fluctuates, and ink is ejected from the nozzle N.

[0067] The above driving elements 560 are electrically connected to a wiring board 590 via individual driving wiring 91 and common driving wiring 92, as shown in FIG.

[0068] The individual drive wiring 91 is provided for each drive element 560, and is electrically connected to the first electrode 561 of the corresponding drive element 560. On the other hand, the common drive wiring 92 is provided in common to the multiple drive elements 560, and is electrically connected to the second electrode 563.

[0069] Individual drive wiring 91 and common drive wiring 92 are arranged at intervals from each other. Here, individual drive wiring 91 and common drive wiring 92 are preferably formed collectively in the same film formation process. In this case, the manufacturing process of head chip 51 can be simplified, and as a result, the cost of head chip 51 can be reduced.

[0070] The constituent materials of the individual driving wiring 91 and the common driving wiring 92 may be any conductive material, and are not particularly limited, and examples thereof include metals such as gold (Au), copper (Cu), titanium (Ti), tungsten (W), nickel (Ni), chromium (Cr), platinum (Pt), and aluminum (Al). Among these, gold (Au) is preferably used as the constituent material of the individual driving wiring 91 and the common driving wiring 92. The individual driving wiring 91 and the common driving wiring 92 may have an adhesion layer for improving adhesion with the first electrode 561, the second electrode 563, and the diaphragm 550.

[0071] In this embodiment, the individual driving wiring 91 is connected to the first electrode 561 via the wiring portion 564, as shown in FIG. 7, and is drawn out for each driving element 560 in a direction from above the wiring portion 564 toward the wiring substrate 590 to above the vibration plate 550.

[0072] On the other hand, as shown in FIG. 5, the common drive wiring 92 is drawn from the second electrode 563 to the wiring board 590 on both ends of the second electrode 563 in the Y1 direction and the Y2 direction to the vibration plate 550. Here, the common drive wiring 92 has a pair of portions 92a, 92b extending in the direction along the Y axis. The portion 92a of the common drive wiring 92 overlaps with the end of the pressure chamber C in the direction along the X axis that is farther from the wiring board 590 as viewed in the direction along the Z axis. On the other hand, the portion 92b of the common drive wiring 92 overlaps with the end of the pressure chamber C in the direction along the X axis that is closer to the wiring board 590 as viewed in the direction along the Z axis. As can be understood from the above, each of the portions 92a, 92b extends in the direction along the Y axis across the multiple pressure chambers C aligned in the direction along the Y axis.

[0073] The temperature sensor 80 is a resistive wiring for detecting the temperature of the ink in the pressure chamber C, and has a characteristic that the resistance value changes according to the temperature change. Therefore, the temperature sensor 80 is made of a material whose electrical resistance value has temperature dependency. However, the temperature sensor 80 is made of the same material as any one of the first electrode 561, the second electrode 563, the individual drive wiring 91, and the common drive wiring 92. Specifically, examples of materials constituting the temperature sensor 80 include metals such as gold (Au), platinum (Pt), iridium (Ir), aluminum (Al), copper (Cu), titanium (Ti), tungsten (W), nickel (Ni), and chromium (Cr). Of these, platinum (Pt) is preferably used as a material constituting the temperature sensor 80 because it has a larger change in resistance value due to temperature change compared to other metals and is capable of detecting temperature with high accuracy.

[0074] As shown in FIG. 5, the temperature sensor 80 is disposed at a distance from the individual drive wiring 91 and the common drive wiring 92 described above. In the example shown in FIG. 5, the temperature sensor 80 is disposed at a position that does not overlap with the pressure chamber C when viewed in the direction along the Z axis. Therefore, the temperature of the pressure chamber C can be detected using the temperature sensor 80 without being affected by the deformation of the diaphragm 550. Note that the temperature sensor 80 may be disposed at a position that overlaps with the pressure chamber C when viewed in the direction along the Z axis. In this case, a correction process that takes into account the deformation of the diaphragm 550 is used for temperature detection using the temperature sensor 80 as necessary.

[0075] In the example shown in FIG. 5, the temperature sensor 80 has a shape extending so as to surround the entirety of the multiple pressure chambers C corresponding to the first nozzle row Ln1 and the multiple pressure chambers C corresponding to the second nozzle row Ln2 when viewed in the direction along the Z axis. Here, as shown in FIG. 5 and FIG. 7, the temperature sensor 80 has multiple parts 81 extending in the direction along the Y axis for each of the nozzle rows of the first nozzle row Ln1 and the second nozzle row Ln2. The multiple parts 81 are arranged at intervals from each other in the direction along the X axis. Then, one ends of two adjacent parts 81 among the multiple parts 81 are alternately connected to each other. As a result, the temperature sensor 80 has a part having a meandering shape. Therefore, the length of the temperature sensor 80 can be made longer than a configuration without the part. As a result, the change in resistance value of the temperature sensor 80 with respect to the temperature change becomes large, so that the accuracy of temperature detection using the temperature sensor 80 can be improved. Note that the planar shape of the temperature sensor 80 is not limited to the example shown in FIG. 5 and is arbitrary.

[0076] In the example shown in FIG. 7, the temperature sensor 80 is disposed between the vibration plate 550 and the piezoelectric body 562, and is in contact with both the vibration plate 550 and the piezoelectric body 562. This configuration has the advantage that it is easier to improve the accuracy of temperature detection using the temperature sensor 80 compared to a configuration in which the temperature sensor 80 is disposed on a surface of the piezoelectric body 562 facing the Z1 direction. The location of the temperature sensor 80 may be a part of the head chip 51, and is not limited to the location shown in FIG. 7. For example, the temperature sensor 80 may be disposed on the surface of the piezoelectric body 562 facing the Z1 direction, or may be disposed on the vibration plate 550 without being disposed between the vibration plate 550 and the piezoelectric body 562.

[0077] Here, temperature sensor 80 of the present embodiment is disposed at a distance from first electrode 561, but is preferably formed collectively in the same film formation process as first electrode 561. In this case, the manufacturing process of head chip 51 can be simplified, and as a result, the cost of head chip 51 can be reduced.

[0078] The above-described temperature sensor 80 is electrically connected to the wiring board 590 via the detection wiring 93. The detection wiring 93 has a detection wiring 93a connected to one end of the temperature sensor 80 and a detection wiring 93b connected to the other end of the temperature sensor 80. The detection wirings 93a and 93b are electrically connected to the detection circuit 53 via the wiring board 590. Therefore, a current Id can be supplied from the detection circuit 53 to the temperature sensor 80 and a potential Vd of the temperature sensor 80 can be detected by the detection circuit 53 via the detection wirings 93a and 93b.

[0079] Detection wiring 93 including detection wiring 93a and detection wiring 93b is disposed at a distance from individual drive wiring 91 and common drive wiring 92, but is preferably formed collectively in the same film formation process as individual drive wiring 91 and common drive wiring 92. In this case, the manufacturing process of head chip 51 can be simplified, and as a result, the cost of head chip 51 can be reduced.

[0080] The material constituting the detection wiring 93 may be any conductive material, and is not particularly limited. For example, metals such as gold (Au), copper (Cu), titanium (Ti), tungsten (W), nickel (Ni), chromium (Cr), platinum (Pt), and aluminum (Al) may be used. Among them, from the viewpoint of making the material of the detection wiring 93 the same as the material of the individual drive wiring 91 and the common drive wiring 92, gold (Au) is preferable as the material of the detection wiring 93. In this case, it is the same material as. Note that the detection wiring 93 may have an adhesion layer for improving adhesion with the temperature sensor 80 or the diaphragm 550, like the individual drive wiring 91 and the common drive wiring 92.

[0081] A4: Drive waveform Fig. 8 is a diagram showing an example of the drive waveform PD. Fig. 8 shows a voltage waveform of the drive waveform PD, which is the waveform of the drive signal Com described above. Note that the drive waveform PD is not limited to the example shown in Fig. 8, and may be any waveform.

[0082] 8, the driving waveform PD is included in the driving signal Com for each unit period Tu. The driving waveform PD includes a first expansion element S1, a first hold element S2, a contraction element S3, a second hold element S4, and a second expansion element S5, in this order.

[0083] The first expansion element S1 is an element that lowers the potential from the intermediate potential Vc to the minimum potential Vl. The first hold element S2 is an element that holds the potential at the minimum potential Vl. The contraction element S3 is an element that raises the potential from the minimum potential Vl to the maximum potential Vh. The second hold element S4 is an element that holds the potential at the maximum potential Vh. The second expansion element S5 is an element that lowers the potential from the maximum potential Vh to the intermediate potential Vc.

[0084] When the first expansion element S1 is applied to the driving element 560 from a state in which the intermediate potential Vc is applied to the driving element 560, the volume of the pressure chamber C of the liquid ejection head 50 increases from the reference state. Then, when the first hold element S2 is applied to the driving element 560, the increased state of the volume of the pressure chamber C is maintained. Next, when the contraction element S3 is applied to the driving element 560, the volume of the pressure chamber C contracts rapidly. As a result, the ink pressure in the pressure chamber C increases, and ink droplets are ejected from the nozzle N communicating with the pressure chamber C. Thereafter, when the second hold element S4 is applied to the driving element 560, the contracted state of the volume of the pressure chamber C is maintained. Next, when the second expansion element S5 is applied to the driving element 560, the volume of the pressure chamber C returns to the reference state.

[0085] Here, the time length of the first expansion element S1 is the first expansion time Pwd1. The time length of the first hold element S2 is the first hold time Pwh1. The time length of the contraction element S3 is the first contraction time Pwc1. The time length of the second hold element S4 is the second hold time Pwh2. The time length of the second expansion element S5 is the second expansion time Pwd2.

[0086] The intermediate potential Vc, the maximum potential Vh, the minimum potential Vl, the first expansion time Pwd1, the first hold time Pwh1, the first contraction time Pwc1, the second hold time Pwh2, and the second expansion time Pwd2 are parameters that define the shape of the driving waveform PD. Therefore, by changing these parameters, the driving waveform PD can be adjusted to obtain the desired ejection characteristics.

[0087] A5: Driving method of liquid ejection device Fig. 9 is a flowchart showing a method for driving the liquid ejection device 100 of the first embodiment. The method for driving the liquid ejection device 100 includes steps ST1, ST2, ST3, ST4, and ST5, as shown in Fig. 9. That is, the liquid ejection device 100 executes steps ST1, ST2, ST3, ST4, and ST5.

[0088] 9, steps ST1, ST2, ST3, ST4, and ST5 are executed in this order. Note that the execution order of steps ST1 and ST2 may be reversed.

[0089] In step ST1, the liquid ejection amount ejected from the nozzle rows Ln within a predetermined period is tallied for each nozzle row Ln. Specifically, in step ST1, the correction unit 21a tallies the liquid ejection amount ejected from the nozzle rows Ln within a predetermined period for each nozzle row Ln, thereby generating the ejection amount information Dv. This tallying may be performed, for example, based on the ink ejection amount for each nozzle row Ln indicated by data obtained by subjecting the print data to color conversion processing, binarization processing, and pass distribution processing, or based on the result of counting the number of ink ejections based on the control signal SI or the like for each nozzle row Ln. The correction unit 21a updates the ejection amount information Dv in a timely manner. For this reason, the aforementioned predetermined period, which is the tallying period for the liquid ejection amount indicated by the ejection amount information Dv, may be a period before or after the timing at which the correction unit 21a, described later, acquires the temperature indicated by the detection signal Dt.

[0090] In step ST2, the temperature of each of the multiple nozzle rows Ln is obtained by the multiple temperature sensors 80. Specifically, in step ST2, the correction unit 21a obtains the detection signal Dt. As a result, the correction unit 21a obtains the temperature of each of the multiple nozzle rows Ln by the multiple temperature sensors 80.

[0091] In step ST3, a correction temperature is determined based on the liquid ejection amount of each of the nozzle rows Ln and the temperature of each of the nozzle rows Ln. Specifically, in step ST3, the correction unit 21a determines a correction temperature based on the liquid ejection amount of each of the nozzle rows Ln and the temperature of each of the nozzle rows Ln. This determination is performed based on the ejection amount indicated by the ejection amount information Dv and the temperature indicated by the detection signal Dt.

[0092] In step ST4, the drive waveform PD is corrected in response to the correction temperature. Specifically, in step ST4, the correction unit 21a corrects the drive waveform PD in response to the correction temperature. This correction is performed by changing the parameters of the drive waveform PD shown in FIG. 8 described above. For example, the correction unit 21a corrects the drive waveform PD so that the difference between the maximum potential Vh and the minimum potential Vl increases as the correction temperature decreases. This reduces the decrease in the ejection amount due to the increase in ink viscosity accompanying a decrease in temperature. Note that the method of correcting the drive waveform PD is not particularly limited.

[0093] In step ST5, the corrected drive waveform PD is supplied to the drive elements 560 of the multiple nozzle rows Ln. Specifically, in step ST5, the correction unit 21a updates data (not shown) indicating the drive waveform PD so that the corrected drive waveform PD is supplied to the drive elements 560 of the multiple nozzle rows Ln.

[0094] FIG. 10 is a diagram for explaining a method for setting the correction temperature in the first embodiment. In FIG. 10, the relationship between the nozzle rows Ln-1 to Ln6, the discharge amount, the discharge amount ratio, the acquired temperature, and the correction temperature is illustrated. Here, each of the nozzle rows Ln-1 to Ln6 is a nozzle row Ln provided on a different head chip 51. The discharge amount is the ink amount indicated by the discharge amount information Dv. The discharge amount ratio is the ratio of the liquid discharge amount of each nozzle row Ln to the total amount of the liquid discharge amount of the nozzle rows Ln-1 to Ln-6. The acquired temperature is the temperature indicated by the detection signal Dt. The correction temperature is the temperature determined in the above-mentioned step ST3. Note that, although FIG. 10 illustrates a case where the number of nozzle rows Ln is six, the number of nozzle rows Ln is not limited to the example illustrated in FIG. 10, and may be five or less or seven or more.

[0095] As shown in FIG. 10, in a liquid ejection head 50 having nozzle rows Ln-1 to Ln6, the temperature of the ink may differ for each nozzle row Ln due to differences in conditions such as the ink ejection amount or arrangement between the nozzle rows Ln.

[0096] In this embodiment, as described above, the liquid ejection device 100 includes a heating unit 70. In an aspect in which such a heating unit 70 is used, the nozzle rows Ln having a small liquid ejection amount continue to be heated by the heating unit 70, whereas the nozzle rows Ln having a large liquid ejection amount are cooled by the supply of new ink, so that a temperature difference is likely to occur between the nozzle rows Ln.

[0097] Here, it is conceivable to adjust the drive waveform PD for each nozzle row Ln according to the temperature of the ink. However, if a different drive waveform PD is used for each nozzle row Ln, the above-mentioned drive signal generating circuits 24 for generating the drive signals Com are required in the same number as the number of nozzle rows Ln, which causes a problem of an increase in the size of the device.

[0098] Therefore, in the above-mentioned step ST3, a correction temperature for correcting the drive waveform PD common to the nozzle rows Ln-1 to Ln6 is determined. This determination is performed so that when printing is performed by supplying a common drive waveform PD to the nozzle rows Ln-1 to Ln6, the drive waveform PD is corrected to one that ejects droplets close to the design value from the nozzle rows Ln that eject a large amount of liquid, which has a large impact on the quality of the printed image, while taking into consideration temperature correction for the nozzle rows Ln with a small ejection amount, thereby reducing the ejection amount difference between the nozzle rows Ln as much as possible.

[0099] In this embodiment, the correction temperature is set to a weighted average value of the temperatures of the nozzle arrays Ln, with the ratio of the liquid ejection amount of each nozzle array Ln to the total amount of the liquid ejection amount of the nozzle arrays Ln being used as a weight, so that the correction temperature taking into account the liquid ejection amount of each nozzle array Ln can be determined according to the degree of the liquid ejection amount of each nozzle array Ln.

[0100] In the example shown in Fig. 10, among the discharge amount ratios of the nozzle rows Ln-1 to Ln6, the discharge amount ratio of the nozzle row Ln-3 is the largest, while the discharge amount ratio of the nozzle row Ln-4 is the smallest. Therefore, the weight of the acquired temperature of the nozzle row Ln-3 is the largest, while the weight of the acquired temperature of the nozzle row Ln-4 is the smallest. Here, when the discharge amount ratio is A and the acquired temperature is B, the correction temperature is the sum of A x B of the nozzle rows Ln-1 to Ln6. Note that the numerical values ​​shown in Fig. 10 are merely examples and are not limited to these.

[0101] As described above, in the liquid ejection device 100 or the driving method thereof, the driving waveform PD is corrected in response to the correction temperature determined based on the liquid ejection amount for each nozzle array Ln of the multiple nozzle arrays Ln and the temperature of each of the multiple nozzle arrays Ln. Therefore, the driving waveform PD can be appropriately corrected so that the amount of droplets ejected from the nozzle array Ln with a large liquid ejection amount is closer to the design value while taking into account the temperature correction for the nozzle array Ln with a small ejection amount, thereby reducing the difference in the liquid ejection amount between the nozzle arrays Ln. As a result, the dots of the liquid that is used in a large proportion of the printed image are closer to the design value in size, thereby suppressing deterioration of image quality. In addition, since the corrected driving waveform PD is supplied to the driving elements 560 of the multiple nozzle arrays Ln, there is no need to prepare a circuit for generating the driving waveform PD for each nozzle array Ln, and therefore the device can be prevented from becoming large.

[0102] In this embodiment, as described above, step ST2 is executed after step ST1. Therefore, the aforementioned predetermined period, which is the period for tallying the liquid discharge amount indicated by the discharge amount information Dv, is a period before the timing when the temperature of each of the nozzle rows Ln is acquired by the plurality of temperature sensors 80. When correcting the temperature between passes, there is often not much difference in the discharge status in successive passes, so that deterioration of image quality can be suppressed even if weighting is performed by the discharge status in the pass before the temperature acquisition. Here, existing discharge count data can be diverted to tally up the liquid discharge amount. This aspect is suitable when the predetermined period is the period for printing one image and the same image is printed on multiple sheets.

[0103] Note that step ST2 may be performed before step ST1. In this case, the aforementioned predetermined period, which is the period for tallying the liquid ejection amount indicated by the ejection amount information Dv, is a period after the timing at which the temperatures of the nozzle rows Ln are acquired by the temperature sensors 80. In this case, the correction temperature can be determined by weighting the temperature of the nozzle row Ln having a large liquid ejection amount before printing after the temperature is acquired by the temperature sensor 80.

[0104] B: Second embodiment A second embodiment of the present disclosure will be described below. In the following example, for elements whose actions and functions are similar to those of the first embodiment, the reference numerals used in the description of the first embodiment will be used and detailed descriptions of each will be omitted as appropriate.

[0105] 11 is a diagram for explaining a method for setting the correction temperature in the second embodiment. This embodiment is similar to the above-described first embodiment, except that the method for setting the correction temperature is different.

[0106] The correction temperature in this embodiment is set to the average value of the temperature of the nozzle row Ln where the liquid ejection amount is the maximum value and the temperature of the nozzle row Ln where the liquid ejection amount is the minimum value among the temperatures of the multiple nozzle rows Ln. That is, the correction temperature in this embodiment is set to the average value of the temperature of the nozzle row Ln where the ejection ratio is the maximum value and the temperature of the nozzle row Ln where the ejection amount ratio is the minimum value among the temperatures of the multiple nozzle rows Ln. This makes it possible to simply determine the correction temperature taking into account the liquid ejection amount of each nozzle row Ln.

[0107] In the example shown in Fig. 11, among the ejection amounts of the nozzle rows Ln-1 to Ln6, the ejection amount of the nozzle row Ln-3 is the largest, while the ejection amount of the nozzle row Ln-4 is the smallest. Therefore, the correction temperature is the average of the temperatures of the nozzle rows Ln-3 and Ln-4. Note that the numerical values ​​shown in Fig. 11 are merely examples and are not limited to these.

[0108] According to the second embodiment described above, it is also possible to improve the print quality while miniaturizing the device.

[0109] C: Third embodiment The third embodiment of the present disclosure will be described below. In the following exemplary embodiment, the elements having the same actions and functions as those in the first embodiment will be referred to by the same reference numerals used in the description of the first embodiment, and detailed descriptions thereof will be omitted as appropriate.

[0110] 12 is a diagram for explaining a method for setting the correction temperature in the third embodiment. This embodiment is similar to the above-described first embodiment, except that the method for setting the correction temperature is different.

[0111] The correction temperature in this embodiment is set to the average value of the temperatures of the nozzle rows Ln from the nozzle row Ln with the largest liquid ejection volume to the Nth nozzle row Ln among the temperatures of the multiple nozzle rows Ln. That is, the correction temperature in this embodiment is set to the average value of the temperatures of the nozzle rows Ln from the nozzle row Ln with the largest ejection volume ratio to the Nth nozzle row Ln among the temperatures of the multiple nozzle rows Ln. This makes it possible to determine the correction temperature by giving priority to the nozzle rows Ln with the largest liquid ejection volume. Here, k is the number of the multiple nozzle rows Ln, and N is a natural number between 1 and k. More preferably, N is a natural number between 1 and k.

[0112] In the example shown in Fig. 12, N is 1, and among the ejection amounts of the nozzle rows Ln-1 to Ln6, the ejection amount of the nozzle row Ln-3 is the largest. Therefore, the correction temperature is equal to the temperature of the nozzle row Ln-3. Note that the numerical values ​​shown in Fig. 12 are merely examples and are not limited to these.

[0113] Here, N may be determined based on whether the discharge amount ratio is greater than a predetermined threshold value. In this case, the correction temperature is set to the average value of the temperatures of the nozzle arrays Ln in which the ratio of the liquid discharge amount of each nozzle array Ln to the total amount of liquid discharged from the nozzle arrays Ln is greater than a threshold value. This allows the correction temperature to be determined by giving priority to the nozzle arrays Ln with a large liquid discharge amount. Here, by allowing the deterioration of image quality due to the nozzle arrays Ln with a small discharge amount, the deterioration of image quality can be effectively suppressed.

[0114] According to the above third embodiment, it is also possible to improve the print quality while miniaturizing the device.

[0115] D: Fourth embodiment The fourth embodiment of the present disclosure will be described below. In the following exemplary embodiments, the elements having the same actions and functions as those in the first embodiment will be referred to by the same reference numerals used in the description of the first embodiment, and detailed descriptions thereof will be omitted as appropriate.

[0116] 13 is a block diagram showing the electrical configuration of a liquid ejection device 100A according to the fourth embodiment. The liquid ejection device 100A has a control module 20A instead of the control module 20 of the first embodiment, and is configured similarly to the liquid ejection device 100 of the first embodiment, except that a display device 110 and an input device 120 are added.

[0117] The display device 110 displays various images under the control of the control module 20. Here, the display device 110 has various display panels, such as a liquid crystal display panel or an organic EL (electro-luminescence) display panel. The display device 110 may be provided outside the liquid ejection device 100.

[0118] The input device 120 is a device that accepts operations from a user. For example, the input device 120 has a pointing device such as a touch pad, a touch panel, or a mouse. Here, when the input device 120 has a touch panel, it may also serve as the display device 110. Note that the input device 120 may be provided outside the liquid ejection device 100.

[0119] The control module 20A is configured similarly to the control module 20 of the first embodiment, except that the processing circuit 21 functions as a correction unit 21b. The correction unit 21b is similar to the correction unit 21a of the first embodiment, except that the method of setting the correction temperature is different.

[0120] The correction unit 21b can automatically or manually select one of a plurality of setting methods as a method for setting the correction temperature, and uses the selected method to determine the correction temperature. The plurality of setting methods include, for example, one or more of the setting methods described in the first to third embodiments. The correction unit 21b also makes the display device 110 display an image GU, which is a GUI (Graphical User Interface) image for selecting the setting method, and then makes the selection based on the input result to the input device 120. Details of this selection will be described later with reference to FIG. 14 and FIG. 15.

[0121] 14 is a flowchart showing a method for driving the liquid ejection device 100A of the fourth embodiment. The method for driving the liquid ejection device 100A is similar to the method for driving the liquid ejection device 100 of the first embodiment, except that step ST3A is included instead of step ST3 of the first embodiment, and steps ST6 and ST7 are added before step ST1.

[0122] In step ST6, it is determined whether or not there is an input regarding a method for setting the correction temperature. Specifically, in step ST6, the correction unit 21b determines whether to automatically or manually select one method from among a plurality of setting methods for the correction temperature based on an input to an image GU shown in Fig. 15 described later, and if the selection is to be performed manually, whether or not the selection content has been input by the user.

[0123] The above step ST6 is repeated until an input regarding the setting method of the correction temperature is received (step ST6: NO).

[0124] If there is an input regarding the setting method of the correction temperature (step ST6: YES), step ST7 selects one method from among a plurality of setting methods as the setting method of the correction temperature based on the input result in step ST6. Specifically, in step ST7, the correction unit 21b automatically selects one method from among a plurality of setting methods for the correction temperature based on the input result for the image GU shown in FIG. 15 described later, or selects one method selected by the user. Then, in step ST3A, the correction unit 21b determines the correction temperature using the selected method.

[0125] When the setting method for the correction temperature is automatically selected, for example, a table showing the correspondence between the type of image to be printed and the setting method is used. In the table, for example, the case where the type of image to be printed is a monochrome mode using only black ink is associated with the setting method of the third embodiment, and the case where the type of image to be printed is a mode using multiple colors of ink is associated with the setting method of the first embodiment.

[0126] In this way, when the setting method for the correction temperature is automatically selected, the correction temperature is set by a method selected from a plurality of setting methods according to the image to be printed, which makes it possible to determine an appropriate correction temperature according to the usage environment of the liquid ejection device 100, etc.

[0127] Fig. 15 is a diagram for explaining selection of a method for setting the correction temperature. Fig. 15 shows an image GU, which is an example of the GUI image displayed on the display device 110 in the above-mentioned step ST6.

[0128] Image GU includes buttons B1, B2, a drop-down list B3, and buttons B4, B5.

[0129] Buttons B1 and B2 are elements for inputting whether to automatically or manually select one method from among a plurality of setting methods for the correction temperature. Buttons B1 and B2 allow for selective input of one of these. When input is made to button B1, an input is made to automatically select one method from among a plurality of setting methods for the correction temperature. When input is made to button B2, an input is made to manually select one method from among a plurality of setting methods for the correction temperature.

[0130] Drop-down list B3 is an element for manually inputting one of a plurality of setting methods for the correction temperature. For example, when an operation is performed on drop-down list B3, a plurality of selectable setting methods are displayed.

[0131] Button B4 is an element for determining the input results for buttons B1, B2 and drop-down list B3. When an input is made to button B4, if an input is made to button B1, the automatic selection of a setting method is input to correction unit 21b as the input result, whereas if an input is made to button B2, the selection result in drop-down list B3 is input to correction unit 21b as the input result.

[0132] According to the fourth embodiment described above, it is also possible to improve the print quality while miniaturizing the device.

[0133] E: Variation Each of the above-mentioned exemplary embodiments may be modified in various ways. Specific modified embodiments that may be applied to each of the above-mentioned embodiments are illustrated below. Any embodiment selected from the following examples may be appropriately combined to the extent that they are not inconsistent with each other.

[0134] E1: Variation 1 In the above embodiment, the nozzle row Ln is composed of the first nozzle row Ln1 and the second nozzle row Ln2, but is not limited to this embodiment. For example, the nozzle row Ln may be composed of only one of the first nozzle row Ln1 and the second nozzle row Ln2.

[0135] E2: Variation 2 In the above embodiment, the liquid ejection device is a serial type printer, but the present invention is not limited to this embodiment, and the liquid ejection device may be a line type printer. In the liquid ejection head used in the line type printer, multiple nozzles N are arranged over the entire area in the width direction of the medium M.

[0136] E3: Variation 3 The liquid ejection device 100 exemplified in the above embodiment may be adopted in various devices such as facsimile machines and copy machines in addition to devices dedicated to printing, and the use of the present disclosure is not particularly limited. However, the use of the liquid ejection device 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 that forms a color filter of a display device such as a liquid crystal display panel. In addition, a liquid ejection device that ejects a solution of a conductive material is used as a manufacturing device that forms wiring and electrodes of a wiring board. In addition, a liquid ejection device that ejects a solution of an organic substance related to a living body is used as a manufacturing device that manufactures, for example, a biochip.

[0137] F: Notes

[0138] (Appendix 1) A driving method for a liquid ejection device according to a first aspect, which is a preferred example of the present disclosure, is a driving method for a liquid ejection device including a liquid ejection head having a plurality of nozzle rows that eject liquid and a plurality of driving elements provided for each nozzle of the plurality of nozzle rows, and a plurality of temperature sensors corresponding to the plurality of nozzle rows, and comprises the steps of: tallying up the amount of liquid ejected from the plurality of nozzle rows within a predetermined period for each nozzle row; obtaining the temperatures of each of the plurality of nozzle rows using the plurality of temperature sensors; determining a correction temperature based on the liquid ejection amount for each of the plurality of nozzle rows and the temperature of each of the plurality of nozzle rows; correcting a driving waveform in accordance with the correction temperature; and supplying the corrected driving waveform to the driving elements of the plurality of nozzle rows.

[0139] In the above aspect, the drive waveform is corrected in response to the correction temperature determined based on the liquid ejection amount for each of the multiple nozzle arrays and the temperature of each of the multiple nozzle arrays, so that the drive waveform can be appropriately corrected so as to reduce the difference in liquid ejection amount between the nozzle arrays. Furthermore, since the corrected drive waveform is supplied to the drive elements of the multiple nozzle arrays, there is no need to prepare a circuit for generating the drive waveform for each nozzle array, so that the device can be prevented from becoming large in size.

[0140] (Note 2) In a second aspect, which is a preferred example of the first aspect, the correction temperature is set to a weighted average value of the temperatures of the plurality of nozzle rows, with the ratio of the liquid ejection amount of each nozzle row to the total amount of liquid ejection amount of the plurality of nozzle rows being used as a weight. In the above aspect, the correction temperature taking into account the liquid ejection amount of each nozzle row can be determined according to the level of the liquid ejection amount of each nozzle row.

[0141] (Note 3) In the third aspect, which is a preferred example of the first aspect, the correction temperature is set to the average value of the temperature of the nozzle row having the maximum liquid ejection amount and the temperature of the nozzle row having the minimum liquid ejection amount among the temperatures of the plurality of nozzle rows. In the above aspect, the correction temperature can be determined in a simple manner, taking into account the liquid ejection amount of each nozzle row.

[0142] (Note 4) In the fourth aspect, which is a preferred example of the first aspect, when the number of the plurality of nozzle rows is k and N is a natural number between 1 and k, the correction temperature is set to the average value of the temperatures of the nozzle rows from the nozzle row having the greatest liquid ejection volume to the Nth nozzle row among the temperatures of the plurality of nozzle rows. In the above aspect, the correction temperature can be determined by giving priority to the nozzle row having the greatest liquid ejection volume.

[0143] (Note 5) In a fifth aspect, which is a preferred example of the first aspect, the correction temperature is set to an average value of the temperatures of the nozzle rows in which the ratio of the liquid ejection amount of each nozzle row to the total amount of liquid ejection amount of the nozzle rows is greater than a threshold value. In the above aspect, the correction temperature can be determined by giving priority to the nozzle rows in which the liquid ejection amount is greater.

[0144] (Note 6) In a sixth aspect, which is a preferred example of any of the first to fifth aspects, the predetermined period is a period following the timing at which the temperatures of the nozzle rows are acquired by the temperature sensors. In the above aspect, the correction temperature can be determined by weighting the temperature of the nozzle row that ejects a large amount of liquid before printing.

[0145] (Note 7) In the seventh aspect, which is a preferred example of any of the first to fifth aspects, the predetermined period is a period before the timing at which the temperatures of the nozzle rows are acquired by the temperature sensors. In the above aspects, when temperature correction is performed between passes, there is often not much difference in the ejection conditions in successive passes, so that deterioration in image quality can be suppressed even if weighting is performed using the ejection conditions in the pass before the temperature acquisition. Here, existing ejection count data can be diverted to tally up the liquid ejection amount. This aspect is suitable when printing multiple copies of the same image.

[0146] (Note 8) In an eighth aspect, which is a preferred example of any one of the first to seventh aspects, the liquid ejection device further includes a heating unit that heats a medium on which liquid ejected from the plurality of nozzle rows lands. In the above aspect, the nozzle rows ejecting a small amount of liquid continue to be heated by the heating unit, whereas the nozzle rows ejecting a large amount of liquid are cooled by the supply of new liquid, so that a temperature difference is likely to occur between the nozzle rows. For this reason, in this aspect, the effect of the present disclosure becomes prominent.

[0147] (Note 9) In a ninth aspect, which is a preferred example of any one of the first to eighth aspects, the correction temperature is set by a method selected from a plurality of setting methods according to the image to be printed. In the above aspect, an appropriate correction temperature can be determined according to the usage environment of the liquid ejection device, etc.

[0148] (Appendix 10) A liquid ejection device of a tenth aspect, which is a preferred example of the present disclosure, is a liquid ejection device comprising a liquid ejection head having a plurality of nozzle rows for ejecting liquid and a plurality of driving elements provided for each nozzle of the plurality of nozzle rows, and a plurality of temperature sensors corresponding to the plurality of nozzle rows, and which compiles for each nozzle row the amount of liquid ejected from the plurality of nozzle rows within a predetermined period, obtains the temperature of each of the plurality of nozzle rows using the plurality of temperature sensors, determines a correction temperature based on the liquid ejection amount for each of the plurality of nozzle rows and the temperature of each of the plurality of nozzle rows, corrects a drive waveform in response to the correction temperature, and supplies the corrected drive waveform to the drive elements of the plurality of nozzle rows.

[0149] In the above aspect, the drive waveform is corrected in response to the correction temperature determined based on the liquid ejection amount for each of the multiple nozzle arrays and the temperature of each of the multiple nozzle arrays, so that the drive waveform can be appropriately corrected so as to reduce the difference in liquid ejection amount between the nozzle arrays. Furthermore, since the corrected drive waveform is supplied to the drive elements of the multiple nozzle arrays, there is no need to prepare a circuit for generating the drive waveform for each nozzle array, so that the device can be prevented from becoming large in size. [Explanation of symbols]

[0150] 10...liquid container, 20...control module, 20A...control module, 21...processing circuit, 21a...correction section, 21b...correction section, 22...memory circuit, 23...power supply circuit, 24...driving signal generation circuit, 30...transport mechanism, 40...movement mechanism, 41...transport body, 42...transport belt, 50...liquid ejection head, 51...head chip, 52...driving circuit, 53...detection circuit, 60...support section, 70...heating section, 80...temperature sensor, 81...portion, 91...individual driving wiring, 92...common driving wiring, 92a...portion, 92b...portion, 93...detection wiring, 93a...detection wiring, 93b ...detection wiring, 100...liquid ejection device, 100A...liquid ejection device, 110...display device, 120...input device, 510...flow path substrate, 520...pressure chamber substrate, 530...nozzle substrate, 540...vibration absorber, 550...diaphragm, 551...elastic membrane, 552...insulating film, 560...driving element, 561...first electrode, 562...piezoelectric body, 562a...through hole, 563...second electrode, 564...wiring section, 570...protective substrate, 580...case, 590...wiring substrate, B1...button, B2...button, B3...drop-down list, B4...button, B5...button, C...pressure chamber, Com ...driving signal, Dt...detection signal, Dv...discharge amount information, FN...nozzle surface, GU...image, HL...inlet, Id...current, Ln...nozzle row, Ln-1...nozzle row, Ln-3...nozzle row, Ln-4...nozzle row, Ln1...first nozzle row, Ln2...second nozzle row, M...medium, N...nozzle, Na...connecting flow path, PD...driving waveform, Pwc1...first expansion time, Pwc2...second expansion time, Pwd1...first contraction time, Pwh1...first hold time, Pwh2...second hold time, R...reservoir, R1...space, R2...space, Ra...supply flow path, S...space, S1...second 1 expansion element, S2...first hold element, S3...contraction element, S4...second hold element, S5...second expansion element, SI...control signal, ST1...step, ST2...step, ST3...step, ST3A...step, ST4...step, ST5...step, ST6...step, ST7...step, Sk1...control signal, Sk2...control signal, Sk3...control signal, Tu...unit period, VBS...offset potential, VHV...power supply potential, Vc...intermediate potential, Vd...potential, Vh...highest potential, Vin...supplied drive signal, Vl...lowest potential, dCom...waveform designation signal.

Claims

1. a liquid ejection head having a plurality of nozzle rows for ejecting liquid, and a plurality of drive elements provided for each nozzle of the plurality of nozzle rows; A plurality of temperature sensors corresponding to the plurality of nozzle rows; A method for driving a liquid ejection device comprising: Amounts of liquid ejected from the plurality of nozzle rows within a predetermined period are tallied for each nozzle row; acquiring temperatures of the plurality of nozzle rows by the plurality of temperature sensors; determining a correction temperature based on a liquid ejection amount for each of the plurality of nozzle rows and a temperature for each of the plurality of nozzle rows; correcting a driving waveform in response to the correction temperature; supplying the corrected drive waveforms to drive elements of the plurality of nozzle arrays; A method for driving a liquid ejection device comprising the steps of:

2. the correction temperature is set to a weighted average value of the temperatures of the plurality of nozzle arrays, with a ratio of the liquid ejection amount of each nozzle array to a total amount of the liquid ejection amount of the plurality of nozzle arrays being used as a weight. The method for driving the liquid ejection device according to claim 1 .

3. the correction temperature is set to an average value of a temperature of a nozzle row having a maximum liquid ejection amount and a temperature of a nozzle row having a minimum liquid ejection amount, among the temperatures of the plurality of nozzle rows; The method for driving the liquid ejection device according to claim 1 .

4. The number of the plurality of nozzle rows is k, When N is a natural number between 1 and k, the correction temperature is set to an average value of temperatures of the Nth nozzle row having the largest liquid ejection volume among the temperatures of the plurality of nozzle rows; The method for driving the liquid ejection device according to claim 1 .

5. the correction temperature is set to an average value of temperatures of the nozzle arrays in which a ratio of a liquid ejection amount of each nozzle array to a total amount of liquid ejection amount of the nozzle arrays is greater than a threshold value, among the temperatures of the nozzle arrays. The method for driving the liquid ejection device according to claim 1 .

6. the predetermined period is a period following a timing at which the temperatures of the plurality of nozzle rows are acquired by the plurality of temperature sensors; The method for driving the liquid ejection device according to claim 1 .

7. the predetermined period is a period prior to a timing at which the temperatures of the plurality of nozzle arrays are acquired by the plurality of temperature sensors; The method for driving the liquid ejection device according to claim 1 .

8. the liquid ejection device further includes a heating unit that heats a medium on which the liquid ejected from the plurality of nozzle rows lands, The method for driving the liquid ejection device according to claim 1 .

9. the correction temperature is set by a method selected from a plurality of setting methods according to an image to be printed; The method for driving the liquid ejection device according to claim 1 .

10. a liquid ejection head having a plurality of nozzle rows for ejecting liquid, and a plurality of drive elements provided for each nozzle of the plurality of nozzle rows; A plurality of temperature sensors corresponding to the plurality of nozzle rows; A liquid ejection device comprising: Amounts of liquid ejected from the plurality of nozzle rows within a predetermined period are tallied for each nozzle row; acquiring temperatures of the plurality of nozzle rows by the plurality of temperature sensors; determining a correction temperature based on a liquid ejection amount for each of the plurality of nozzle rows and a temperature for each of the plurality of nozzle rows; correcting a driving waveform in response to the correction temperature; supplying the corrected drive waveforms to drive elements of the plurality of nozzle arrays; A liquid ejection device comprising:

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