Liquid ejection apparatus, liquid ejection method, article manufacturing method, and recording method

Abstract

The invention provides a liquid ejecting apparatus, a liquid ejecting method, an article manufacturing method, and a recording method. The present invention seeks a technique for suppressing crosstalk occurring between a plurality of nozzles that supply liquid through a common liquid chamber. The liquid ejecting apparatus includes: a plurality of liquid ejecting elements; a common liquid chamber for supplying liquid to the discharge nozzles of the plurality of liquid discharge elements; and a drive unit that applies a drive pulse having a first waveform set for each of the plurality of liquid ejection elements, the drive pulse being configured from a rising period in which the first voltage rises to the second voltage, a holding period in which the second voltage is held, and a falling period in which the second voltage falls to the first voltage, and the drive pulse having a second waveform set for each of the plurality of liquid ejection elements. When any two or more liquid ejection elements among the plurality of liquid ejection elements are simultaneously driven, a drive pulse of a first waveform is applied to one liquid ejection element, and a drive pulse of a second waveform a or a drive pulse of a second waveform b is applied to the other liquid ejection elements.

Description

Technical Field

[0001] The present invention relates to a liquid ejecting device, a liquid ejecting method, etc. Background Art

[0002] Liquid ejection devices, such as so-called inkjet printers, typically use energy-generating elements such as electrothermal converters (heaters) and piezoelectric elements to impart kinetic energy to the liquid, ejecting it from a nozzle. Recently, liquid ejection heads have been developed that include multiple pressure chambers, each equipped with an energy-generating element, and multiple nozzles, enabling independent control of the ejection of liquid from each nozzle. In such a liquid ejection head, each nozzle is connected to one of the pressure chambers equipped with an energy-generating element, and each of the multiple pressure chambers communicates with a common liquid chamber that supplies the liquid.

[0003] In such a liquid ejection head, when the energy generating element is driven to eject liquid from a nozzle, a pressure wave is generated in the pressure chamber where the nozzle is located and propagates through the liquid. When this pressure wave propagates through the common liquid chamber to the interior of other pressure chambers, it may cause pressure fluctuations in the other pressure chambers.

[0004] If the energy generating element is driven to eject liquid from the nozzles of other pressure chambers while the pressure in other pressure chambers is fluctuating, the volume, velocity, and direction of the ejected droplets may become unstable. This can cause a phenomenon known as crosstalk, where the action of ejecting liquid from one nozzle affects the action of ejecting liquid from other nozzles. When crosstalk occurs, for example, in a liquid ejection device used for image formation, it can cause image degradation such as density variations and streaks. In a liquid ejection device used to manufacture functional devices, it can also compromise the performance of the functional devices.

[0005] Patent Document 1 describes that when applying a rectangular drive signal to eject droplets, in order to reduce the influence of crosstalk between multiple nozzles, the pulse width of the drive signal applied to each nozzle is changed by weighting according to the distance between the nozzles.

[0006] Prior art literature

[0007] Patent Literature

[0008] Patent Document 1: Japanese Patent Application Laid-Open No. 4-357036 Summary of the Invention

[0009] Problems to be solved by the invention

[0010] When correcting the drive signal applied to each nozzle, sufficient accuracy may not be achieved by simply changing the pulse width by performing weighting corresponding to the distance between nozzles.

[0011] For example, when the first to third nozzles are arranged at a distance that causes crosstalk between them, the pulse width of the drive signal for the second nozzle is changed so that the second nozzle can properly eject droplets even if crosstalk is received from the first and third nozzles. In this way, the volume (ejection amount) and flight speed (ejection speed) of the droplets ejected from the second nozzle can be corrected, but when the pulse width applied to the second nozzle is changed, the magnitude of the crosstalk applied by the second nozzle to the other nozzles will change. Therefore, in order to reduce the impact of the crosstalk received from the second nozzle, it is necessary to change the pulse width of the drive signal for the first or third nozzle. When the pulse width of the drive signal for the first or third nozzle is changed, the magnitude of the crosstalk received by the second nozzle will change, so it is necessary to correct the pulse width of the drive signal for the second nozzle again. In this way, by simply changing the pulse width by weighting according to the distance between the nozzles, the actual ejection amount or ejection speed of the droplets ejected from all nozzles may not necessarily fall within the appropriate range. Furthermore, it is not practical to repeat the calculation multiple times until the discharge amount and discharge speed of all nozzles fall within an appropriate range in terms of device operation.

[0012] Solutions to Problems

[0013] 14. The liquid dispensing device of claim 13, wherein the drive unit is configured to provide a liquid dispensing system comprising: a plurality of liquid dispensing elements, each comprising a discharge nozzle and an energy generating element that generates energy for dispensing liquid; a common liquid chamber for supplying the liquid to the discharge nozzles of the plurality of liquid dispensing elements; and a driving unit for applying a driving pulse to any of the energy generating elements, the driving pulse being composed of a rising period from a first voltage to a second voltage, a holding period for maintaining the second voltage, and a falling period from the second voltage to the first voltage, a driving pulse having a first waveform being set for each of the plurality of liquid dispensing elements, and the driving unit, when simultaneously driving any two or more of the plurality of liquid dispensing elements, controls the voltage of one of the two or more liquid dispensing elements. The energy generating element applies a driving pulse of the first waveform, and applies a driving pulse of the second waveform a or a driving pulse of the second waveform b to the energy generating element of the liquid ejecting element other than the one liquid ejecting element among the two or more liquid ejecting elements. The driving pulse of the second waveform a is set so that the start timing of the rising period is late, the holding period is short, and the start timing of the falling period is early, relative to the driving pulse of the first waveform of the liquid ejecting element to which the driving pulse of the second waveform a is applied. The driving pulse of the second waveform b is set so that the start timing of the rising period is early, the holding period is long, and the start timing of the falling period is late, relative to the driving pulse of the first waveform of the liquid ejecting element to which the driving pulse of the second waveform b is applied.

[0014] 14. The liquid dispensing device of claim 13, wherein the nozzles of the nozzles are connected to the nozzles of the liquid dispensing device and the nozzles are connected to the nozzles of the liquid dispensing device. The nozzles are connected to the nozzles of the liquid dispensing device and the nozzles are connected to the nozzles of the liquid dispensing device. The nozzles are connected to the nozzles of the liquid dispensing device and the nozzles are connected to the nozzles of the liquid dispensing device. The energy generating element of one liquid ejecting element among the elements applies a driving pulse of the first waveform, and the energy generating element of the liquid ejecting element other than the one liquid ejecting element among the two or more liquid ejecting elements applies a driving pulse of the second waveform a or a driving pulse of the second waveform b, the driving pulse of the second waveform a is set so that the start timing of the rising period is late, the holding period is short, and the start timing of the falling period is early relative to the driving pulse of the first waveform of the liquid ejecting element to which the driving pulse of the second waveform a is applied, and the driving pulse of the second waveform b is set so that the start timing of the rising period is early, the holding period is long, and the start timing of the falling period is late relative to the driving pulse of the first waveform of the liquid ejecting element to which the driving pulse of the second waveform b is applied.

[0015] Effects of the Invention

[0016] According to the present invention, it is possible to effectively suppress crosstalk occurring between a plurality of nozzles connected via a common liquid chamber. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 (a) is a schematic plan view of the liquid ejection device according to the embodiment. Figure 1 (b) is a schematic side view of the liquid ejection device according to the embodiment.

[0018] Figure 2 It is a block diagram schematically showing the structure of a control system.

[0019] Figure 3 This is a schematic perspective view of the liquid flow path portion of the liquid ejection head as viewed from an oblique direction.

[0020] Figure 4 (a) is a schematic perspective view of the liquid ejection head as viewed from the Z direction. Figure 4 (b) is along Figure 4 (a) is a schematic cross-sectional view of the liquid ejection head taken along line AA'.

[0021] Figure 5 Schematic diagram showing the configuration of the drive control unit 207 .

[0022] Figure 6 This is an example of a driving waveform applied to a piezoelectric element.

[0023] Figure 7 (a) is a graph showing changes in the discharge speed (G1) and discharge amount (G2) of the liquid when the length of the holding period HP is changed. Figure 7 (b) is a graph showing changes in the discharge speed (G3) and discharge amount (G4) of the liquid when the magnitude of the voltage V2 as the holding voltage is changed.

[0024] Figure 8 This is a flowchart showing the procedure for adjusting (correcting) the drive waveform applied to each nozzle.

[0025] Figure 9 This is a flowchart for explaining the processing procedure of step S108 in detail.

[0026] Fig. 10(a) is a graph illustrating drive waveforms before and after correction in the embodiment. Fig. 10(b) shows the pressure generated in the pressure chamber when the nozzle is driven with each drive waveform in the embodiment.

[0027] Figure 11 (a) is a graph illustrating the drive waveforms before and after correction in Comparative Example 1. Figure 11 (b) shows the pressure generated in the pressure chamber when the nozzle is driven by each driving waveform of Comparative Method 1.

[0028] Figure 12 (a) is a graph illustrating the drive waveforms before and after correction in Comparative Example 2. Figure 12 (b) is the pressure generated in the pressure chamber when the nozzle is driven by each driving waveform of Comparative Method 2.

[0029] Figure 13 (a) is an evaluation result of the ejection characteristics when the nozzle is used while being driven with the first waveform. Figure 13 (b) shows the evaluation results of the ejection characteristics when the nozzles were driven simultaneously with the second waveform.

[0030] Figure 14 This is a table showing the conditions of the rising start time and the falling start time in Examples 1 to 5 and Comparative Examples 1 and 2.

[0031] Figure 15This is a table showing the evaluation results of the discharge characteristics in Examples 1 to 5 and Comparative Examples 1 and 2. DETAILED DESCRIPTION

[0032] With reference to the accompanying drawings, the liquid ejection device and the liquid ejection method according to the present invention are described. In addition, the embodiments shown below are illustrative only, and those skilled in the art can appropriately modify and implement the detailed structures without departing from the scope of the present invention.

[0033] In the drawings referred to in the following description of the embodiments and examples, elements denoted by the same reference numerals have the same functions unless otherwise specified. In the drawings, when multiple identical elements are arranged, the reference numerals and their descriptions may be omitted.

[0034] In addition, for the convenience of illustration and description, the drawings may sometimes be shown schematically. Therefore, the shapes, sizes, and configurations of the elements described in the drawings may not necessarily strictly correspond to reality. In addition, the description of "XX or more and YY or less" or "XX to YY" indicating a numerical range, unless otherwise specified, refers to the numerical range including XX (lower limit) and YY (upper limit) as endpoints. When the numerical range is described in stages, the upper and lower limits of each numerical range can be arbitrarily combined.

[0035] In this specification, the liquid processed by the liquid ejection head is sometimes described as "ink", but the ink of the embodiment is not limited to the liquid containing the recording material for forming text or images. For example, it can also be a liquid containing functional films such as electrodes, optical filters, etc., or functional materials for forming functional elements such as organic EL elements. It can also be a liquid containing insoluble solid components. In addition, sometimes the imparting of ejected liquid to an object is described as "recording", but the recording mentioned here is not necessarily limited to recording information such as text and images. For example, it also includes imparting liquid to an object in order to manufacture functional films, functional elements, three-dimensional objects and other articles. In addition, the object to which the liquid is imparted is sometimes described as a "recording medium", but it is not limited to a medium for recording information such as text and images, and also includes a component (such as a substrate) that serves as a base material for manufacturing functional films, functional elements, three-dimensional objects and other articles.

[0036] In the following description, a unit that ejects liquid droplets, including a nozzle hole, a pressure chamber, a piezoelectric element, and electrodes, may be referred to as a "liquid ejection element." Furthermore, a liquid ejection element may be simply referred to as a "nozzle."

[0037] [Implementation Method]

[0038] (Liquid ejection device)

[0039] First, the overall structure of the liquid ejection device 1 according to the embodiment will be described. Figure 1 (a) is a schematic top view of the liquid ejection device 1, Figure 1 For the sake of convenience, the elements constituting the liquid ejecting device, such as a power supply and a device cover, which are not directly related to the present invention, are omitted from the illustration.

[0040] The liquid ejection device 1 includes a base 9, on which is provided a stage 10 for placing a recording medium 6 (for example, a substrate for forming an organic EL element). In addition, a sub-scanning guide 7 extending in the X direction when viewed from above is fixed to the base 9 via a supporting member 8. A main scanning guide 5, which is a slide that can move in the X direction on the sub-scanning guide 7, is placed on the sub-scanning guide 7, and a main scanner 4 that can move in the Y direction on the main scanning guide 5 is placed on the main scanning guide 5. A liquid ejection unit 2 that can eject liquid toward the recording medium 6 is mounted on the main scanner 4. By moving the main scanning guide 5 in the X direction and the main scanner 4 in the Y direction, the liquid ejection unit 2 can be freely scanned in the XY direction above the recording medium 6 placed on the stage 10 at a height separated from the recording medium 6 in the Z direction by a predetermined interval.

[0041] In this manner, the liquid ejection device 1 can move the liquid ejection unit 2 to perform scanning. However, the scanning mechanism is not limited to the illustrated structure and may be any structure as long as it can scan the liquid ejection unit 2 relative to the recording medium 6. For example, the recording medium 6 may be moved in one of the X and Y directions while the liquid ejection unit 2 is moved in the other direction. Alternatively, the liquid ejection unit 2 may be fixed and the recording medium 6 may be moved in both the X and Y directions.

[0042] The liquid ejection unit 2 is provided with a liquid ejection head 3 capable of ejecting liquid (e.g., ink for forming an organic EL element) toward a recording medium 6. The liquid ejection head 3 is provided with a liquid ejection element that applies pressure to the ink by, for example, deformation of a piezoelectric element or boiling caused by a heating element, thereby ejecting the ink from a nozzle.

[0043] A liquid tank 23 is provided on the base 9. The liquid tank 23 stores ink for supply to the liquid ejection unit 2, and is connected to a liquid flow path 11 and a liquid flow path 12. The liquid flow path 11 is a flow path for supplying the ink stored in the liquid tank 23 to the liquid ejection unit 2, while the liquid flow path 12 is a flow path for returning ink not ejected from the liquid ejection unit 2 to the liquid tank 23.

[0044] As described later, the liquid ejection device 1 of this embodiment suppresses crosstalk between nozzles when droplets are ejected simultaneously from multiple nozzles, thereby enabling stable production of organic EL elements, for example, or stable high-quality recording using information recording ink.

[0045] (Control Department)

[0046] Figure 2 It is a block diagram schematically showing the configuration of a control system included in the liquid ejecting device 1 . Figure 2 The functional elements shown are conceptual elements and do not necessarily need to be physically configured as shown. For example, the specific method of distributing or integrating the functional blocks is not limited to the examples shown in the figure. All or part of them can be functionally or physically distributed or integrated in arbitrary units depending on usage conditions. Each functional block can be configured using hardware or software.

[0047] The control unit 200 is connected to various sensors and various controlled elements of the liquid ejection device 1. Figure 2 The control unit 200 is a computer for controlling the operation of the liquid ejection device 1 and internally includes a CPU 201, a ROM 202, a RAM 203, an I / O port 210, etc. The CPU 201 is a central processing unit that executes programs to perform various calculations and processes.

[0048] The action program of the liquid ejecting device 1 is stored in the ROM 202 as a non-volatile storage medium. The program for executing the various processes involved in the liquid ejecting method of this embodiment can be stored in the ROM 202 in the same way as other action programs, but can also be loaded into the RAM 203 from the outside via a network. Alternatively, it can be loaded into the RAM 203 via a computer-readable recording medium on which the program is recorded. The program can also be recorded in any recording medium as long as it is a computer-readable recording medium. As a recording medium for supplying the program, in addition to the ROM 202, an external storage device not shown in the figure can also be used. To give a specific example, as a recording medium, a hard disk, a floppy disk, an optical disk, a magneto-optical disk, a magnetic tape, a USB memory, an SSD, etc. can be used.

[0049] The RAM 203 , which is a volatile storage medium, can temporarily store data, programs, and the like necessary for processing executed by the CPU 201 , and functions as a work area for executing the processing.

[0050] The I / O port 210, serving as an input / output unit, is connected to an external device or network and, for example, can input and output data required for manufacturing organic EL elements to and from an external computer. Furthermore, the I / O port is connected to a display device or input device (not shown) to display information related to the operating status of the liquid ejection device 1 to the operator or to receive commands from the operator. Examples of the display device include a liquid crystal display (LCD) or an organic EL display, and examples of the input device include a keyboard, a jog dialer, a mouse, a pointing device, and a voice input device.

[0051] The recording processing unit 206 determines the ejection nozzle to be driven in correspondence with the scanning timing of the main scanner 4 or the main scanning guide 5 according to the pattern to be recorded (for example, the arrangement of the organic EL elements to be produced or the recorded image). The drive control unit 207, which is a drive unit for driving the ejection nozzle, generates a drive signal to be delivered to the liquid ejection head in order to eject the liquid from the ejection nozzle determined by the recording processing unit 206. The recording processing unit 206 and the drive control unit 207 can be constituted by, for example, the CPU 201 reading and executing a control program stored in the ROM 202 or other non-temporary recording medium. Alternatively, part or all of it can be constituted by hardware such as an ASIC possessed by the control unit 200.

[0052] For example, when the liquid ejection device 1 is caused to eject liquid and perform a recording operation, the control unit 200 controls the transport unit 204 (main scanner 4 or main scanning guide 5) to scan the liquid ejection unit 2 relative to the recording medium 6, thereby ejecting liquid from the liquid ejection head 3. Furthermore, when the liquid ejection head 3 needs to be cleaned, the control unit 200 activates the cleaning unit 205 to perform a cleaning process.

[0053] The control unit 200 is connected to the discharge volume detection unit 208 and the discharge speed detection unit 209, and can obtain information about the amount (volume) and flight speed of the droplets discharged from the discharge nozzles. Based on this information, the control unit 200 can correct the drive signal output by the drive control unit 207 and adjust the discharge volume (volume) and discharge speed (flight speed) of the droplets discharged from each discharge port of the liquid discharge head 3.

[0054] (Liquid ejection head)

[0055] Figure 3 1 is a schematic perspective view showing the liquid flow path portion of the liquid ejection head 3 as viewed from an oblique direction. Figure 1 (a)) is supplied to the liquid ejection head 3 through the liquid flow path 11. The liquid not ejected from the ejection head 3 is discharged from the ejection head 3 through the liquid flow path 12 and returned to the liquid tank 23. As a method for supplying liquid, for example, a pressure supply method, a head difference supply method, etc. can be used.

[0056] The liquid ejection head 3 includes a plurality of nozzle holes 20, and ejects liquid in the negative Z direction from each nozzle hole 20. Figure 3 In the example shown, a system having four nozzle holes 20 is shown, but the number of nozzle holes provided in the liquid ejection head 3 is not limited to this. Each nozzle hole 20 is provided in an independent pressure chamber 19. The independent pressure chamber 19 is connected to the supply-side common liquid chamber 15 via an independent supply flow path 17 and to the discharge-side common liquid chamber 16 via an independent discharge flow path 18.

[0057] Liquid is supplied from the liquid tank 23 to the supply-side common liquid chamber 15 through the liquid flow path 11 and the liquid supply port 21. Liquid not used for discharge flows from the discharge-side common liquid chamber 16 through the liquid discharge port 22 and the liquid flow path 12 and returns to the liquid tank 23.

[0058] Figure 4 (a) is a schematic perspective view of the liquid ejection head 3 as viewed from the Z direction (a direction perpendicular to the orifice surface where a plurality of nozzle holes are arranged). Figure 4 (b) is along Figure 4 A schematic cross-sectional view of the liquid ejection head 3 cut along the line AA' in (a). In the liquid ejection head 3, a row of nozzle holes 20 are arranged at predetermined intervals. Figure 4 Although only a portion of the liquid ejecting head 3 is shown in (a), four or more nozzle holes 20 may be arranged along a plurality of rows in each row.

[0059] like Figure 4 As shown in (b), a piezoelectric element 100 is provided at a position facing the nozzle hole 20 across the pressure chamber 19. When the drive control unit 207 ( Figure 2 ) is applied to piezoelectric element 100 via electrodes 101a and 101b, causing piezoelectric element 100 to vibrate due to electrostriction. This causes the internal volume of pressure chamber 19 to change slightly, and the contraction pressure pressurizes the liquid in pressure chamber 19, causing the liquid to be ejected from nozzle hole 20.

[0060] In the following description, the unit consisting of the nozzle hole 20, pressure chamber 19, piezoelectric element 100, electrode 101a, and electrode 101b may be referred to as a liquid ejection element. Furthermore, one or both of the supply-side common liquid chamber 15 and the discharge-side common liquid chamber 16 may be referred to as a common liquid chamber. The ejection head 3 of the embodiment can be said to include a common liquid chamber (common flow path) that supplies liquid to the ejection nozzles of multiple liquid ejection elements.

[0061] (Drive control unit)

[0062] Figure 5The structure of the drive control unit 207 for discharging liquid from the liquid ejection head 3 is schematically shown. While the figure illustrates a circuit for applying drive signals to four liquid ejection elements, the scale of the circuit can be varied depending on the number of liquid ejection elements. The drive control unit 207 includes a waveform setting unit 301, a waveform generating unit 302, and a waveform selecting unit 303.

[0063] The waveform setting unit 301 sets a driving waveform to be applied to the piezoelectric element 100 of the liquid ejecting element based on the pattern of the recorded image and the correction data. Figure 6 An example of a driving waveform is shown. The waveform setting unit 301 sets, for example, voltage V1 as the base voltage, voltage V2 as the holding voltage, the length of the rising period RP from voltage V1 to voltage V2, and the start timing STR of the rising period. Furthermore, the waveform setting unit 301 sets the length of the holding period HP during which the voltage V2 is maintained, the length of the falling period FP from voltage V2 to voltage V1, and the start timing STF of the falling period. While a trapezoidal waveform as shown in the figure is preferred for the driving waveform, a substantially rectangular waveform with a very short rising period RP or falling period FP may also be used.

[0064] The waveform generation unit 302 generates a driving waveform (voltage pulse) to be applied to the piezoelectric element of the liquid ejection element based on the driving waveform information set by the waveform setting unit 301. As will be described later, the driving waveforms applied to each liquid ejection element are not necessarily the same. Therefore, the waveform generation unit 302 can be configured such that, for example, the waveform generation unit 302 generates a first waveform, a second waveform a, and a second waveform b, and the waveform selection unit 303 selects the driving waveform to be applied to each liquid ejection element. The waveform selection unit 303 includes a switch 304 for selecting the driving waveform to be applied to the piezoelectric element 100 of each liquid ejection element from among the first waveform, the second waveform a, and the second waveform b. The switch 304 provided for each liquid ejection element includes a switch 304a, a switch 304b, and a switch 304c.

[0065] The switching switch 304 turns off all three switches when liquid is not ejected from the corresponding liquid ejection element, and turns on one of the three switches according to the applied waveform when liquid is ejected from the liquid ejection element. In this way, the waveform selection unit 303, under the control of the waveform setting unit, can apply any one of the first waveform, the second waveform a, and the second waveform b to the liquid ejection element ejecting liquid. Figure 5In the example shown, the waveform generator 302 generates three types of drive waveforms, and the waveform selector 303 selectively applies the three types of drive waveforms to the liquid ejection elements. However, the structure of the drive control unit 207 is not limited to this example. For example, the types of drive waveforms generated by the waveform generator 302 are not limited to three. Alternatively, instead of providing the waveform selector 303, a waveform generator may be provided for each liquid ejection element.

[0066] (Drive waveform control and crosstalk suppression)

[0067] exist Figure 6 In the driving waveform shown, during the rising period RP, forced displacement is applied to the piezoelectric element 100 in the direction of increasing the volume of the pressure chamber 19, generating negative pressure within the pressure chamber. After the holding period HP, the start timing STF of the falling period is set based on the timing of the pressure reversal and increase due to the reaction force. During the falling period FP, forced displacement is applied in the direction of contracting the pressure chamber, effectively pressurizing and discharging the liquid.

[0068] Therefore, if the time span from the start timing STR of the rising period to the start timing STF of the falling period deviates significantly from the resonance period of the pressure chamber, efficient ejection cannot be performed and instability occurs. Therefore, it is preferable to set the time span from the start timing STR of the rising period to the start timing STF of the falling period to a range of 0.38 to 0.63 times the resonance period of the pressure chamber (0.75 to 1.25 times 1 / 2 of the resonance period of the pressure chamber).

[0069] The control unit 200 can adjust the drive waveform for each individual liquid ejection element each time a droplet is ejected based on the ejection speed and ejection volume detected by the ejection speed detection unit 209 and the ejection volume detection unit 208. The drive control unit 207 can adjust, for example, the magnitude of the voltage V2 serving as the holding voltage and the length of the holding period HP for each individual liquid ejection element. The following example illustrates the relationship between the drive waveform applied to the liquid ejection element included in the liquid ejection head 3 and the ejection speed and ejection volume of the ejected liquid.

[0070] Figure 7 (a) indicates that the liquid ejection element is applied Figure 6 The graph of the change in the liquid discharge speed (G1) and discharge amount (G2) when the length of the holding period HP is changed in the case of the driving waveform shown. Figure 7 (b) means that Figure 6 The graphs shown are graphs showing changes in the liquid discharge speed (G3) and the discharge amount (G4) when the magnitude of the voltage V2 as the holding voltage is changed when the driving waveform is applied to the liquid discharge element.

[0071] The resonance frequency of the pressure chamber 19 of the liquid ejection element used for the measurement, when liquid was introduced, was 185 kHz, and the resonance period was 5.4 μs. The duration of the rising period RP and the falling period FP of the driving waveform was set to 1.2 μs.

[0072] like Figure 7 As shown in (a), in the example liquid ejection element, if the length of the holding period HP is changed, the curves representing the liquid ejection speed (G1) and the ejection amount (G2) both become quadratic curves. Near the apex (extreme value) of each curve, the rate of change of the ejection speed relative to the change of time and the rate of change of the ejection amount relative to the change of time are slow. In addition, as Figure 7 As shown in (b), if the voltage V2, which serves as the holding voltage, is varied, the curves representing the liquid discharge speed (G3) and discharge volume (G4) both become substantially linear. By utilizing these characteristics to change the drive waveform, the discharge speed and discharge volume of the discharged liquid can be adjusted according to target values.

[0073] In this example, it can be seen that if the length of the hold period HP is between 1.0μs and 1.8μs, the discharge volume can be adjusted while suppressing changes in the discharge speed. Specifically, the voltage V2 of the drive waveform is first adjusted so that the hold period HP is between 1.0μs and 1.8μs, achieving the target discharge speed. Then, the hold period HP is adjusted between 1.0μs and 1.8μs to achieve the target discharge volume. Alternatively, the sensitivity to changes in the hold period HP and the sensitivity to changes in the voltage V2 can be numerically stored for each of the discharge speed and discharge volume, and CPU 201 can calculate the optimal hold period HP duration and voltage V2. Furthermore, methods other than those described above can be used to adjust the hold period HP duration and voltage V2.

[0074] Next, the sequence of ejecting droplets of appropriate volume (ejection amount) at appropriate flight speeds (ejection speeds) from the plurality of liquid ejecting elements included in the liquid ejecting head 3 and controlling the droplets so that they land at appropriate locations will be described. In the following description, the liquid ejecting elements may be referred to simply as "nozzles."

[0075] Reference Figure 8 The flowchart shown in FIG. 1 illustrates the sequence for adjusting (correcting) the drive waveform applied to each nozzle. In the following description, the first waveform may be a drive waveform that is common to all nozzles. Alternatively, the first waveform may be a drive waveform that is pre-adjusted for each nozzle based on variations in the ejection angle in the scanning direction caused by variations in the pressure chamber or piezoelectric element characteristics of each nozzle, the roundness or tilt of the nozzle hole, or surface unevenness of the nozzle inner wall.

[0076] When the process of correcting the landing position and the discharge amount starts in step S101 , the waveform setting unit 301 sets a common drive waveform for all nozzles in step S102 .

[0077] Next, in step S103, the ejection angle of each nozzle in the scanning direction in which the liquid ejection head is scanned relative to the recording medium is measured. Figure 1 (a)), a landing position detection substrate is set at a position at a predetermined distance from the ejection hole, so that the landing position can be observed. Next, each nozzle is driven individually to eject liquid, and the ejection speed detection unit 209 is used to measure the ejection speed of the droplets. During the measurement, in order to eliminate the influence of crosstalk caused by the pressure generated when the nozzle is driven and transmitted to other nozzles through the common liquid chamber, the measurement of each nozzle is carried out at sufficient intervals in time. That is, after driving one nozzle, the next nozzle is driven for measurement after a sufficient time has passed until the pressure vibration ends. The landing position of the droplets ejected from each nozzle in the scanning direction is measured using the landing position detection plate, and the landing position deviation caused by the manufacturing deviation of the nozzle is evaluated. Based on the measurement results of the ejection speed of the liquid ejected from each nozzle and the landing position deviation, the offset of the ejection angle in the scanning direction can be calculated.

[0078] Next, in step S104, the first waveform of the drive signal is set for each nozzle based on the ejection angle of each nozzle obtained in step S103. Setting the first waveform can also be considered as correcting the ejection angle of each nozzle. Here, the first waveform refers to the drive waveform adjusted so that droplets ejected from a nozzle reach a predetermined landing position when driving a single nozzle. If the ejection characteristics of all nozzles are highly uniform, the same first waveform may be set for all nozzles.

[0079] The landing position deviation caused by recording in each nozzle can be calculated based on the actual scanning speed of the liquid ejection head 3 during recording, as well as the ejection speed and ejection angle of each nozzle. To correct this landing position deviation, the waveform setting unit 301 adjusts the start timing STR of the rising period of the drive waveform applied to each nozzle. The first waveform is not limited to the waveform set using the illustrative method; it may be set using other methods as long as it can correct for variations in ejection speed and ejection volume caused by variations in the characteristics of the piezoelectric element and the size of the pressure chamber for each nozzle.

[0080] When the liquid ejection device 1 ejects liquid according to recorded pattern information or image information, if the liquid is ejected from only a single nozzle and the first waveform is applied to that nozzle, droplets of an appropriate amount of liquid are deposited at appropriate locations on the recording medium 6. However, in practice, to shorten recording time, droplets are ejected from multiple nozzles simultaneously according to the recorded pattern or image. Therefore, the influence of crosstalk between nozzles becomes a problem.

[0081] Therefore, in this embodiment, in step S105 , nozzles driven according to a pattern or image to be recorded are determined as active nozzles, and in step S108 , a driving waveform for suppressing crosstalk is set for the active nozzles.

[0082] In step S105, the recording processing unit 206 ( Figure 2 ) According to the pattern to be recorded (for example, the arrangement of the organic EL elements to be produced or the recorded image), the nozzle to be used at each scanning position is determined in correspondence with the scanning position of the main scanner 4 or the main scanning guide 5.

[0083] Next, in steps S106 to S111, the drive control unit 207 ( Figure 2 ) Based on the active nozzles of the liquid ejection head 3 determined in step S105, the drive waveform applied to each nozzle is set. Steps S106-S107 and S110-S111 are steps related to process management for setting the drive waveform for all active nozzles and completing the setting with an appropriate amount of calculation. If the liquid ejection head 3 has multiple nozzle arrays, the drive waveform is set for each nozzle array.

[0084] The setting of the drive waveform applied to each nozzle is performed by the waveform setting unit 301 of the drive control unit 207 in step S108 . Figure 9 A flowchart for explaining the processing procedure of step S108 in detail is shown. In addition, the nozzles described as "correction nozzles" in the figure are used nozzles to be processed as targets for correction of the driving waveform.

[0085] In step S108-1, the waveform setting unit 301 sets the first waveform as the default value as the driving waveform of the nozzle in use acquired in step S105. In subsequent steps, the first waveform set as the default value is corrected as needed for each nozzle in use.

[0086] For example, at a certain scanning position (scanning timing), when there is only one nozzle being driven, the first waveform set as the default value is used for the nozzle. In addition, at a certain scanning position (scanning timing), when there are multiple nozzles being driven simultaneously, the first waveform set as the default value can be used for one nozzle, and the first waveform can be corrected to generate the second waveform for the other nozzles. Alternatively, the first waveform set as the default value can be corrected to generate the second waveform for all nozzles being used. In addition, the nozzles to be corrected that are affected by crosstalk that substantially becomes a problem are the nozzles that are located within a specified distance from the nozzle being corrected. Therefore, when correcting the driving waveform for a certain nozzle being used, the processing load can be reduced by performing correction processing in consideration of the positions of the other nozzles being used. In step S108-2, the set value of the number of nozzles to be corrected is initialized.

[0087] In step S108-3, other active nozzles located close to the active nozzle whose drive waveform is to be corrected are selected. The other active nozzles are selected in order of proximity to the active nozzle whose drive waveform is to be corrected. These selected other active nozzles and the active nozzle whose drive waveform is to be corrected are driven simultaneously to eject droplets. During ejection, the pressure generated in pressure chamber 19 propagates to the surrounding area through the common liquid chamber, generating crosstalk. However, this propagated pressure attenuates as the distance increases. Therefore, by selecting other active nozzles in an order close to the active nozzle whose drive waveform is to be corrected and driving them simultaneously, an ejection attempt is made under conditions that simulate the crosstalk generated during actual recording.

[0088] In step S108 - 4 , the discharge volume detection unit 208 and the discharge speed detection unit 209 are used to measure the volume (discharge volume) and the flying speed (discharge speed) of the droplet discharged from the nozzle used for which the drive waveform is to be corrected.

[0089] Next, in step S108-5, based on the discharge volume and discharge speed obtained in step S108-4, the length of the hold period HP and the voltage V2 set for the first waveform of the nozzle whose drive waveform is to be corrected are modified as needed. As described above, the length of the hold period HP and the voltage V2 can be set so that the discharge volume reaches the target discharge volume within a range with low sensitivity to discharge speed, or they can be calculated based on pre-acquired sensitivity characteristics.

[0090] Next, in step S108 - 6 , the start timing STR set in the rising period of the first waveform of the nozzle to be used for the drive waveform to be corrected is corrected as needed.

[0091] In the next step S108-7, the waveform setting unit 301 uses the first waveform as a basis and sets the modified driving waveform as the second waveform as the driving waveform for the nozzle in use. In step S108-8, the process returns to step S108-3 to modify the driving waveform for the next nozzle in use.

[0092] During the repetitive processing loop, the nozzles driven simultaneously in step S108 - 3 may contain a mixture of nozzles that have been corrected to the second waveform and nozzles that are driven by the uncorrected first waveform.

[0093] As described above, in this embodiment, when correcting the first waveform to the second waveform, the start timing of the rise period STR is corrected after the length of the hold period HP is corrected. This suppresses pressure changes that propagate to the surrounding areas due to the correction. In other words, by correcting the drive waveform of a particular active nozzle, crosstalk fluctuations in surrounding active nozzles can be suppressed, preventing cascading crosstalk fluctuations. Consequently, the correction process for keeping the discharge volume and discharge speed from all active nozzles within appropriate ranges can be executed with a low processing load.

[0094] Fig. 10(a) is a graph illustrating a first waveform and a second waveform generated by correction. As the second waveform, a second waveform a is shown as one example, and a second waveform b is shown as another example.

[0095] In this example, the start timing STR of the rising period of the first waveform is 0 μs, the lengths of the rising period RP and the falling period FP are both 1.2 μs, the length of the holding period HP is 1.5 μs, and the voltage V2 during the holding period is 21V.

[0096] Depending on the characteristics of the nozzle being used, the generated (corrected) second waveform may have a shorter hold period HP than the first waveform, or a longer hold period HP. Therefore, the former is represented as second waveform a, and the latter as second waveform b.

[0097] The second waveform a is set such that the length of the holding period HP is 0.9 μs, the start timing STR of the rising period is delayed by 0.2 μs relative to the first waveform, and the start timing STF of the falling period is advanced by 0.4 μs relative to the first waveform.

[0098] The second waveform b is set such that the length of the holding period HP is 2.1 μs, the start timing STR of the rising period is advanced by 0.2 μs relative to the first waveform, and the start timing STF of the falling period is delayed by 0.4 μs relative to the first waveform.

[0099] FIG10(b) shows the results of fluid simulation analysis of the pressure generated in the pressure chamber 19 when the nozzle is driven using the first waveform, the second waveform a, and the second waveform b shown in FIG10(a).

[0100] As a comparison method 1, Figure 11 (a) shows the driving waveform when the start timing STR of the rising period is made the same as that of the first waveform and the length of the holding period HP is corrected. Figure 11 (b) shows the analysis result of the pressure generated in the pressure chamber in this case. In addition, as a comparative method 2, Figure 12 (a) shows a driving waveform when the start timing STF of the falling period is made the same as that of the first waveform and the length of the holding period HP is corrected. Figure 12 (b) shows the analysis result of the pressure generated in the pressure chamber in this case.

[0101] Figure 11 (a) Figure 12 The first waveform shown in (a) is the same as the first waveform shown in FIG10 . The second waveform a and the second waveform b have the same length of the holding period HP, but different starting timings STR and STF of the rising period. In the following description, the difference obtained by subtracting the length of the holding period HP of the first waveform from the length of the holding period HP of the second waveform is referred to as Δt. w .

[0102] When the start timing STR of the rising period is made uniform and only the length of the holding period HP is modified as in the comparison method 1, the crosstalk propagating to the surroundings will vary. Figure 11 As shown in (b), during the period when the piezoelectric element is forced to be displaced by the driving waveform, the time difference between the initial peak of the pressure generated in the pressure chamber and the length of the holding period HP is Δt w As a result, the deviation from the first waveform becomes larger in the first peak and the second trough of the pressure, and when the second waveform a or the second waveform b is corrected, the crosstalk propagating to the surroundings changes.

[0103] Furthermore, after the forced displacement ends, the pressure in the pressure chamber repeatedly oscillates and decays. At this point, the oscillation period gradually stabilizes at the pressure chamber's fluid dynamics resonance period Tr. Therefore, after the end of the forced displacement, the pressure difference between the first and second waveforms in the pressure chamber, while smaller than before, gradually disappears, and the periodic difference stabilizes at a constant phase offset.

[0104] Thus, in Comparative Method 1, if the first waveform is corrected to the second waveform, the pressure generated by the nozzle changes, and thus the phase of the pressure propagating from the nozzle to the surrounding nozzles via the common liquid chamber shifts. Figure 11 If the drive waveform is corrected as in step (a), the pressure propagation state to other nozzles that have already been corrected will change, and the other nozzles that have already been corrected will need to be corrected again. Therefore, it is necessary to repeat the correction cycle of the second waveform in step S108 multiple times, or even if multiple cycles are performed, the target ejection speed and ejection volume may not be within the range.

[0105] When the start timing STF of the falling period is made uniform and only the length of the holding period HP is modified as in the comparative method 2, the crosstalk propagating to the surroundings will vary. Figure 12 As shown in (b), although the shift of the initial peak of the pressure at the end of forced displacement is small, the forced displacement start time shift Δt w , so the timing of the first trough of the pressure generated in the pressure chamber shifts by Δt w Immediately after the forced vibration ends, the effect of the change in the length of the holding period HP remains, and the timing of the pressure peaks and troughs shifts, but the period difference gradually disappears and stabilizes at a certain phase shift.

[0106] In Comparative Method 2, the pressure generated at the nozzle changes due to the correction to the second waveform. This also changes the pressure propagated from the nozzle to the surrounding nozzles via the common liquid chamber, altering the crosstalk characteristics imparted to the surrounding nozzles. Consequently, multiple iterations of the second waveform correction cycle in step S108 are necessary, or even repeated iterations may result in the target ejection speed and volume not being within the specified range.

[0107] In contrast, in this embodiment, as shown in FIG10(b), the difference in pressure distribution between the first waveform and the second waveform is suppressed to be relatively small, and the pressure fluctuation before and after the correction is suppressed both during the time when the forced displacement is applied to the piezoelectric element and after the forced displacement. In other words, in this embodiment, not only the length of the holding period HP is changed, but also the difference Δt between the lengths of the holding period HP before and after the correction is obtained. w , adjust the start timing STR of the rising period and the start timing STF of the falling period.

[0108] If the difference obtained by subtracting the length of the hold period HP of the second waveform after correction from the length of the hold period HP of the first waveform is defined as Δt w , as in the second waveform a, when the length of the holding period HP is corrected to be shorter than that of the first waveform, Δt w> 0. On the contrary, when the length of the holding period HP is corrected to be longer than that of the first waveform as in the second waveform b, Δt w <0.

[0109] In this embodiment, as in the second waveform a, Δt w >0, the start timing STR of the rising period of the second waveform a is corrected to be later than the start timing STR of the rising period of the first waveform, and the start timing STF of the falling period is corrected to be earlier than the start timing STF of the falling period of the first waveform. w <0, the start timing STR of the rising period of the second waveform b is corrected to be earlier than the start timing STR of the rising period of the first waveform, and the start timing STF of the falling period is corrected to be later than the start timing STF of the falling period of the first waveform.

[0110] In order to effectively suppress the change in pressure before and after correction, it is preferable that the change in the length of the holding period HP before and after correction and the change in the start timing STR of the rising period before and after correction satisfy the following relationship.

[0111] That is, at Δt as in the second waveform a w When >0, it is preferable to satisfy the following relational expression (1), and it is more preferable to satisfy the following relational expression (2).

[0112] (Equation 1)

[0113] 0.2×(H1-H2)≤D12≤0.7×(H1-H2)

[0114] (Equation 2)

[0115] 0.3×(H1-H2)≤D12≤0.45×(H1-H2)

[0116] H1 [sec]: a holding period of the first waveform set before correction to the liquid ejection element to which the driving pulse of the second waveform a is applied.

[0117] H2[sec]: holding period of the second waveform a.

[0118] D12 [sec]: Time width for delaying the start timing of the rising period of the second waveform a relative to the start timing of the rising period of the first waveform.

[0119] Among them, H1>H2.

[0120] In addition, when the start timing of the falling period of the second waveform a is advanced by a time width of D13 [sec] relative to the start timing of the falling period of the first waveform, it is preferable to satisfy D12 <D13。

[0121] In addition, as in the second waveform b, Δt w When <0, it is preferable to satisfy the following relational expression (3), and more preferably to satisfy the following relational expression (4).

[0122] (Equation 3)

[0123] 0.2×(H3-H1)≤D31≤0.7×(H3-H1)

[0124] (Equation 4)

[0125] 0.3×(H3-H1)≤D31≤0.45×(H3-H1)

[0126] H1 [sec]: a holding period of the first waveform set before correction to the liquid ejection element to which the driving pulse of the second waveform b is applied.

[0127] H3[sec]: holding period of the second waveform b.

[0128] D31 [sec]: time width for advancing the start timing of the rising period of the second waveform b relative to the start timing of the rising period of the first waveform.

[0129] Among them, H1<H3.

[0130] In addition, when the time width of the delay between the start timing of the falling period of the second waveform b and the start timing of the falling period of the first waveform is set to D32 [sec], it is preferable to satisfy D31 <D32。

[0131] Typically, inkjet printers use liquids with viscosities between 0.5 mPa·s and 100 mPa·s. However, the residual pressure oscillations generated in the pressure chamber during ejection are damped by the fluid's viscosity. Therefore, when the viscosity of the liquid is high, the pressure propagating to the surrounding area decreases over time, minimizing the impact of crosstalk. On the other hand, when the viscosity of the liquid is between 0.5 mPa·s and 20 mPa·s, and the ejection timing of multiple nozzles ejecting droplets simultaneously is set to within four times the resonant period of each individual pressure chamber, the impact of crosstalk is often significant, so it is preferable to adjust the drive waveform.

[0132] [Example 1]

[0133] like Figures 3 and 4As shown in (b), a liquid ejection head 3 having multiple pressure chambers 19 and ejecting liquid from nozzle holes 20 provided in individual pressure chambers was fabricated and installed in the liquid ejection device 1. Four nozzle arrays were arranged at intervals of 1.2 mm, with each array having 128 nozzles arranged at intervals of 150 dpi. The liquid used had a viscosity of 10 mPa·s and a surface tension of 40 mN / m. The fluid dynamics resonant frequency of each pressure chamber 19 was 185 kHz, with a period of 5.4 μs.

[0134] According to the reference Figure 8 、 Figure 9 The process flow described above generates a driving waveform. First, a first waveform set so that the ejection angles of the nozzles in the scanning direction of the ejection head are consistent will be described.

[0135] First, the piezoelectric elements 100 provided in the respective pressure chambers 19 are temporarily set as follows: Figure 6 The trapezoidal driving waveform shown in FIG. 1 is a trapezoidal driving waveform with a rising period RP set to 1.2 μs, a holding period HP set to 1.5 μs, a falling period FP set to 1.2 μs, and a voltage V2 during the holding period set to 21V.

[0136] The substrate for landing position detection was placed on stage 10 at a Z-direction distance of 300 μs from the nozzle orifice 20. Using a provisionally set first waveform, each nozzle was driven sequentially at sufficient intervals. The ejection speed and landing position were evaluated without crosstalk, and the ejection angle in the scanning direction was calculated. Based on the ejection angle, the scanning speed used during actual recording, and the distance to the recording medium, the ejection timing to correct for landing deviation caused by the ejection angle was calculated. The start timing STR of the rising period in the driving waveform was set individually for each nozzle as the first waveform.

[0137] Next, the generation of the second waveform is described. First, the nozzles used for ejection are determined based on the actual recording pattern. Since the correction method is the same for each nozzle row, the description will be made using one nozzle row as an example.

[0138] Before modifying the first waveform to generate the second waveform, the ejection characteristics of 64 active nozzles in a nozzle array were evaluated when the first waveform was driven simultaneously. The predetermined start timing STR of the rising period of the first waveform for each of the 64 active nozzles was compared, and the difference between the maximum and minimum values ​​was 20.1 μs. The piezoelectric elements of each of the 64 active nozzles were driven simultaneously with the first waveform, and the ejection speed and ejection volume were measured. Figure 13(a) shows the measurement results of the ejection velocity and ejection volume. The horizontal axis represents the Y-axis position within the nozzle array. The average ejection velocity is 4.51 m / s, with a variation of 66.5%. The average ejection volume is 2.01 pl, with a variation of 53.6%.

[0139] Next, the generation of the second waveform is described. The drive waveform applied to the nozzles is corrected element by element, following the order in which the nozzles are arranged in the Y direction. During correction, active nozzles located within 3.38 mm of the active nozzle being corrected are simultaneously driven. While crosstalk is occurring, the drive waveform is corrected nozzle by nozzle, in ascending order of nozzle number, to generate the second waveform.

[0140] When the first waveform is corrected for each nozzle to generate the second waveform, the absolute value of the change in the start timing STF of the falling period is corrected to be greater than the absolute value of the change in the start timing STR of the rising period. Specifically, the change Δt relative to the holding period HP is w The absolute value of the change in STR at the start of the rising period is 0.45 times. In addition, the absolute value of the change in HP during the holding period is Δt w The absolute value of the change in the start timing STF of the falling period is 0.55 times. In this way, the first waveform is corrected only once for all 64 nozzles in use, and the second waveform is generated.

[0141] Figure 13 (b) shows the results of measuring the deviation of the ejection speed and ejection amount when driven by the second waveform. The average ejection speed is 4.99m / s, and its deviation range is 5.1%. The average ejection amount is 2.01pl, and its deviation range is 5.0%. Figure 13 Compared with (a), it is clear that the influence of crosstalk can be suppressed by correcting the driving waveform based on the state where crosstalk occurs. Figure 15 The table shows the results of driving the nozzle using the driving waveform generated each time and measuring the discharge amount and discharge speed.

[0142] [Example 2]

[0143] When the first waveform is corrected to generate the second waveform, the change Δt relative to the holding period HP w The absolute value of the change in STR at the start of the rising period is 0.3 times. In addition, the absolute value of the change in HP during the holding period is Δt w The absolute value of the change in STF at the start timing of the falling period is 0.7 times.

[0144] Since the same nozzle array as in Example 1 was used, the first waveform was the same as in Example 1, and the deviation when driving 64 nozzles with the first waveform was also the same. After correcting all 64 nozzles only once and setting the second waveform, the deviation of the ejection speed and ejection amount when driving 64 nozzles with the second waveform was measured. The results of measuring the deviation of the ejection speed and ejection amount when driven with the second waveform showed that the average ejection speed was 5.02m / s, and the deviation range was 4.9%. The average ejection amount was 1.99pl, and the deviation range was 5.1%. Figure 15 The table shows the results of driving the nozzle using the generated driving waveform and measuring the discharge amount and discharge speed.

[0145] [Example 3]

[0146] When the first waveform is corrected to generate the second waveform, the change Δt relative to the holding period HP w The absolute value of the change in STR at the start of the rising period is 0.6 times. In addition, the absolute value of the change in HP during the holding period is Δt w The absolute value of the change in STF at the start timing of the falling period is 0.4 times.

[0147] After all 64 nozzles are corrected once and the second waveform is set, the second waveform is set as the first waveform and the processing step S108 is executed to correct again. This process is repeated cyclically and a total of 5 correction processes are performed. Figure 15 The table shows the results of driving the nozzle using the driving waveform generated each time and measuring the discharge amount and discharge speed.

[0148] [Example 4-Example 5]

[0149] When the first waveform is corrected to generate the second waveform, the change Δt relative to the holding period HP w The absolute value of the change in STR at the start time of the rising period becomes Figure 14 The values ​​in the table are as follows. In addition, the change Δt of HP during the maintenance period is w The absolute value of the change in STF at the start of the falling period becomes Figure 14 The values ​​recorded in the table are as follows. As in Example 3, a total of 5 correction processes were performed. Figure 15 The table shows the results of driving the nozzle using the driving waveform generated each time and measuring the discharge amount and discharge speed.

[0150] [Comparative Example 1]

[0151] When the first waveform is corrected to generate the second waveform, the start timing STR of the rising period is not changed but the length of the holding period HP is changed, and the correction process is cyclically performed a total of five times. Figure 15 The table shows the results of driving the nozzle using the driving waveform generated each time and measuring the discharge amount and discharge speed.

[0152] [Comparative Example 2]

[0153] When the first waveform is corrected to generate the second waveform, the length of the holding period HP is changed without changing the start timing STF of the falling period, and the correction process is cyclically performed a total of five times. Figure 15 The table shows the results of driving the nozzle using the driving waveform generated each time and measuring the discharge amount and discharge speed.

[0154] Summarizing the above results, the relative Δt w The conditions for the rise start time and fall start time are shown in Figure 14 The average value and deviation of the ejection speed and ejection amount of the 64 nozzles for the number of corrections are shown in Figure 15 .exist Figure 15 In the evaluation column, numerical values ​​that are practically extremely superior to conventional methods are recorded as "A", numerical values ​​that are excellent are recorded as "B", and numerical values ​​that are the same as conventional methods are recorded as "C".

[0155] In the comparative example, each correction caused a large variation in the discharge volume and discharge speed of each nozzle due to the pressure change propagating to the surrounding area and the influence of crosstalk. In contrast, Examples 1 to 5 were able to minimize this variation. Furthermore, Examples 1 and 2 achieved a significant effect, minimizing the variation with a small number of corrections.

[0156] [Other embodiments]

[0157] The present invention is not limited to the above-described embodiments or examples, and many modifications are possible within the technical concept of the present invention. For example, all or part of the above-described different embodiments may be combined and implemented.

[0158] As an example of a liquid ejection head or a liquid ejection element, there is shown Figure 3 、 Figure 4 (a) Figure 4 (b), but the liquid ejection head or liquid ejection element is not limited to this structure. For example, it can also be an element that provides an energy generating element (such as a piezoelectric element) on the orifice plate to impart energy to the liquid and eject it from the ejection port.

[0159] In addition, an embodiment of the present invention includes the implementation of a method for manufacturing an article by using the above-mentioned liquid ejecting device to impart a liquid containing a material for manufacturing the article. For example, the method includes the step of using the above-mentioned liquid ejecting device to impart a liquid for manufacturing a functional film such as an electrode or an optical filter to a substrate. Alternatively, the method includes the step of using the above-mentioned liquid ejecting device to impart a liquid for manufacturing a functional element such as an organic EL element to a substrate. Alternatively, the method includes the step of using the above-mentioned liquid ejecting device to eject a liquid for manufacturing a three-dimensional object, etc. According to the method for manufacturing an article of the embodiment, since crosstalk between nozzles is suppressed, it is possible to manufacture an extremely high-quality article with uniform ejection direction and ejection amount of ejected droplets.

[0160] Furthermore, embodiments of the present invention include implementations of recording methods that use the aforementioned liquid ejection device to eject a liquid containing a recording material and apply the ejected liquid to a recording medium. According to the recording method of the embodiment, since crosstalk between nozzles is suppressed, the ejection direction and ejection amount of the ejected liquid droplets are uniform, achieving extremely high-quality recording.

[0161] Description of Reference Numerals

[0162] 1. Liquid ejection device; 2. Liquid ejection unit; 3. Liquid ejection head; 4. Main scanner; 5. Main scanning guide rail; 6. Recording medium; 7. Sub-scanning guide rail; 8. Support member; 9. Base; 10. Carrier; 11. Liquid flow path; 12. Liquid flow path; 15. Common liquid chamber on the supply side; 16. Common liquid chamber on the discharge side; 17. Separate supply flow path; 18. Separate discharge flow path; 19. Pressure chamber; 20. Nozzle hole; 21. Liquid supply port; 22. Liquid discharge port; 23. Liquid tank; 100. Piezoelectric Element; 101a, electrode; 101b, electrode; 200, control unit; 201, CPU; 202, ROM; 203, RAM; 204, conveying unit; 205, cleaning unit; 206, recording processing unit; 207, drive control unit; 208, ejection amount detection unit; 209, ejection speed detection unit; 210, I / O port; 301, waveform setting unit; 302, waveform generating unit; 303, waveform selecting unit; 304, switching switch; 304a, 304b, 304c, switch.

Claims

1. A liquid ejection device, characterized in that: The liquid ejection device comprises: a plurality of liquid ejecting elements, each including an ejection nozzle and an energy generating element that generates energy for ejecting the liquid; a common liquid chamber for supplying the liquid to the ejection nozzles of the plurality of liquid ejection elements; as well as a driving unit for applying a driving pulse to any of the energy generating elements; The driving pulse includes a rising period from a first voltage to a second voltage, a holding period for maintaining the second voltage, and a falling period from the second voltage to the first voltage, and a driving pulse of a first waveform is set for each of the plurality of liquid ejecting elements. When the driving unit simultaneously drives any two or more liquid ejecting elements among the plurality of liquid ejecting elements, the driving unit applies a driving pulse of the first waveform to the energy generating element of one of the two or more liquid ejecting elements, and applies a driving pulse of the second waveform a or a driving pulse of the second waveform b to the energy generating elements of the liquid ejecting elements other than the one liquid ejecting element among the two or more liquid ejecting elements. The driving pulse of the second waveform a is set so that, relative to the driving pulse of the first waveform set for the liquid ejection element to which the driving pulse of the second waveform a is applied, the start timing of the rising period is delayed, the holding period is short, and the start timing of the falling period is early. The driving pulse of the second waveform b is set so that the start timing of the rising period is earlier, the holding period is longer, and the start timing of the falling period is later than the driving pulse of the first waveform set for the liquid ejection element to which the driving pulse of the second waveform b is applied.

2. The liquid ejection device according to claim 1, wherein The driving pulse of the first waveform is set for each of the plurality of liquid ejecting elements so that, when only the liquid ejecting element is driven, the liquid droplets ejected from the ejection nozzle of the liquid ejecting element reach a predetermined landing position.

3. The liquid ejection device according to claim 1 or 2, wherein: When the holding period of the first waveform of the liquid ejecting element to which the driving pulse of the second waveform a is applied is set to H1 [sec], the holding period of the second waveform a is set to H2 [sec], and the time width by which the start timing of the rising period of the second waveform a is delayed relative to the start timing of the rising period of the first waveform is set to D12 [sec], It satisfies 0.2×(H1-H2)≤D12≤0.7×(H1-H2) and H2<H1.

4. The liquid ejection device according to claim 1 or 2, wherein: When the holding period of the first waveform of the liquid ejecting element to which the driving pulse of the second waveform a is applied is set to H1 [sec], the holding period of the second waveform a is set to H2 [sec], and the time width by which the start timing of the rising period of the second waveform a is delayed relative to the start timing of the rising period of the first waveform is set to D12 [sec], 0.3×(H1-H2)≤D12≤0.45×(H1-H2) and H2<H1.

5. The liquid ejection device according to claim 3, wherein: When the time width by which the start timing of the falling period of the second waveform a is advanced relative to the start timing of the falling period of the first waveform is set to D13 [sec], Satisfies D12<D13.

6. The liquid ejection device according to claim 1 or 2, wherein: When the holding period of the first waveform of the liquid ejecting element to which the driving pulse of the second waveform b is applied is set to H1 [sec], the holding period of the second waveform b is set to H3 [sec], and the time width by which the start timing of the rising period of the second waveform b is advanced relative to the start timing of the rising period of the first waveform is set to D31 [sec], Satisfying 0.2×(H3-H1)≤D31≤0.7×(H3-H1) and H1 <H3。 7. The liquid ejection device according to claim 1 or 2, wherein: When the holding period of the first waveform of the liquid ejecting element to which the driving pulse of the second waveform b is applied is set to H1 [sec], the holding period of the second waveform b is set to H3 [sec], and the time width by which the start timing of the rising period of the second waveform b is advanced relative to the start timing of the rising period of the first waveform is set to D31 [sec], Satisfying 0.3×(H3-H1)≤D31≤0.45×(H3-H1) and H1 <H3。 8. The liquid ejection device according to claim 6, wherein: When the time width by which the start timing of the falling period of the second waveform b is delayed relative to the start timing of the falling period of the first waveform is set to D32 [sec], Satisfies D31<D32.

9. The liquid ejection device according to claim 1 or 2, wherein: In the second waveform a and the second waveform b, the time from the start timing of the rising period to the start timing of the falling period is 0.38 times or more and 0.63 times or less of the resonance period of the pressure chamber where the ejection nozzle is arranged.

10. The liquid ejection device according to claim 1 or 2, wherein: The viscosity of the liquid is 0.5 mPa·s or more and 20 mPa·s or less, The driving pulse is set so that the timing of ejecting the liquid from the arbitrary two or more liquid ejecting elements is within four times the resonance period of the pressure chamber in which the ejection nozzle is arranged.

11. The liquid ejection device according to claim 1 or 2, wherein: The rising period, the holding period, and the falling period of the first waveform set in the plurality of liquid ejection elements are the same.

12. The liquid ejection device according to claim 1 or 2, wherein: The first waveform is a waveform for driving the plurality of liquid ejecting elements element by element using a temporarily set waveform to measure a landing position, and correcting the temporarily set waveform so that the landing position approaches a predetermined landing position.

13. The liquid ejection device according to claim 1 or 2, wherein: The second waveform a and the second waveform b are waveforms generated by modifying the first waveform.

14. The liquid ejection device according to claim 1 or 2, wherein: The second waveform a and the second waveform b are waveforms generated by correcting the first waveform based on the result of measuring the landing position of the liquid droplet by simultaneously driving the arbitrary two or more liquid ejection elements using the first waveform.

15. A method for manufacturing an article, characterized in that: The article manufacturing method manufactures an article by using the liquid ejecting device according to any one of claims 1 to 14 to eject the liquid containing the material for manufacturing the article.

16. A recording method, characterized in that: The recording method uses the liquid ejecting device according to any one of claims 1 to 14 to eject the liquid containing the recording material and apply it to a recording medium.

17. A liquid ejection method, which is a liquid ejection method for ejecting liquid from a liquid ejection device, characterized in that: The liquid ejection device comprises: a plurality of liquid ejecting elements, each having an ejection nozzle and an energy generating element that generates energy for ejecting the liquid; a common liquid chamber for supplying the liquid to the ejection nozzles of the plurality of liquid ejection elements; as well as a driving unit for applying a driving pulse to any of the energy generating elements; The driving pulse includes a rising period from a first voltage to a second voltage, a holding period for maintaining the second voltage, and a falling period from the second voltage to the first voltage, and a driving pulse of a first waveform is set for each of the plurality of liquid ejecting elements. When the driving unit simultaneously drives any two or more liquid ejecting elements among the plurality of liquid ejecting elements, the driving unit applies a driving pulse of the first waveform to the energy generating element of one of the two or more liquid ejecting elements, and applies a driving pulse of the second waveform a or a driving pulse of the second waveform b to the energy generating elements of the liquid ejecting elements other than the one liquid ejecting element among the two or more liquid ejecting elements. The driving pulse of the second waveform a is set so that, relative to the driving pulse of the first waveform set for the liquid ejection element to which the driving pulse of the second waveform a is applied, the start timing of the rising period is delayed, the holding period is short, and the start timing of the falling period is early. The driving pulse of the second waveform b is set so that the start timing of the rising period is earlier, the holding period is longer, and the start timing of the falling period is later than the driving pulse of the first waveform set for the liquid ejection element to which the driving pulse of the second waveform b is applied.

18. The liquid ejection method according to claim 17, wherein: The driving pulse of the first waveform is set for each of the plurality of liquid ejecting elements so that, when only the liquid ejecting element is driven, the liquid droplets ejected from the ejection nozzle of the liquid ejecting element reach a predetermined landing position.

19. The liquid ejection method according to claim 17, wherein: The driving pulse of the second waveform a and the driving pulse of the second waveform b are generated by changing the start timing of the rising period after changing the holding period of the driving pulse of the first waveform.

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