Liquid ejecting apparatus, method of controlling the same, substrate processing apparatus, and article manufacturing method

Abstract

The present application provides a liquid discharge device and a control method thereof, a substrate processing device, and an article manufacturing method, which are advantageous in reducing the time required for recovery processing of a discharge abnormality of liquid in the liquid discharge device and the amount of liquid used. The liquid discharge device includes a plurality of discharge elements that discharge liquid in accordance with a drive signal, and a control section that controls supply of the drive signal to each of the plurality of discharge elements. In a case where a first discharge element and a second discharge element having a lower degree of discharge abnormality than the first discharge element are determined as discharge elements having a discharge abnormality from among the plurality of discharge elements, in recovery processing in which the discharge abnormality of the plurality of discharge elements is reduced, a first drive signal of a first frequency is not supplied to the second discharge element but is supplied to the first discharge element, and a second drive signal of a second frequency that is lower than the first frequency is supplied to the second discharge element.

Description

Technical Field

[0001] This invention relates to a liquid ejection device, a control method for the liquid ejection device, a substrate processing apparatus, and a method for manufacturing articles. Background Technology

[0002] In recent years, inkjet printers have been used to apply materials to substrates to form patterns (patterning) when manufacturing various functional components. Patterning using inkjet printers has the following advantages: high material utilization efficiency due to the ability to perform patterning on demand; smaller manufacturing equipment due to the non-vacuum process; and the ability to coat large areas at high speed.

[0003] In the aforementioned inkjet apparatuses, during dot pattern formation or standby, problems such as poor ejection and quality irregularities (ejection abnormalities) can sometimes occur due to foreign matter adhering to the flow path or near the nozzle opening, ink thickening, ink component sedimentation, electrophoresis, etc. Patent Document 1 discloses a technique for performing medium-volume and large-volume pre-ejections, starting with a small amount of pre-ejection and continuing until recovery is confirmed. Patent Document 2 discloses a technique for removing ink by increasing or decreasing the drive frequency of the recording head while removing air bubbles. Patent Document 3 discloses the following: determining the cause of the droplet ejection abnormality, and selecting one of rinsing, wiping, or pump suction as the recovery process for the droplet ejection head based on the determined cause of the ejection abnormality.

[0004] Prior art literature

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2012-201076

[0007] Patent Document 2: Japanese Patent No. 2659954

[0008] Patent Document 3: Japanese Patent No. 4269731 Summary of the Invention

[0009] The problem that the invention aims to solve

[0010] However, in the recovery method described in Patent Document 1, recovery is performed solely by changing the pre-ejection volume, sometimes resulting in nozzles that cannot be recovered. Furthermore, in the structure described in Patent Document 2, since the drive frequency is continuously changed while pre-ejecting all nozzles, the recovery process takes a long time and increases ink (liquid) consumption. Additionally, in the structure described in Patent Document 3, only one of rinsing, wiping, or pump suction is selected as the recovery process, depending on the cause of the droplet ejection abnormality. Therefore, depending on the severity of the ejection abnormality, the amount of ink (liquid) consumed in the selected recovery process may increase.

[0011] Therefore, the object of the present invention is to provide a technique that helps reduce the time required for recovery processing of abnormal liquid ejection in a liquid ejection device and the amount of liquid used.

[0012] Solution for solving the problem

[0013] To achieve the above objective, a liquid ejection device according to one aspect of the present invention is characterized in that the liquid ejection device comprises: a plurality of ejection elements that eject liquid according to a drive signal; and a control unit that controls the supply of the drive signal to each of the plurality of ejection elements, wherein, when the control unit determines a first ejection element and a second ejection element having an ejection abnormality less than the first ejection element as ejection elements having an ejection abnormality, in a recovery process that reduces the ejection abnormality of the plurality of ejection elements, the control unit supplies a first drive signal of a first frequency to the first ejection element but not to the second ejection element, and supplies a second drive signal of a second frequency lower than the first frequency to the second ejection element.

[0014] To achieve the above objective, a control method according to one aspect of the present invention is a control method for a liquid ejection device having a plurality of ejection elements that eject liquid according to a drive signal. The control method is characterized by comprising: a determination step, determining an ejection element with ejection abnormality from among the plurality of ejection elements; and a recovery processing step, reducing the ejection abnormality of the plurality of ejection elements. In the determination step, if a first ejection element and a second ejection element with a lower degree of ejection abnormality than the first ejection element are determined to be ejection elements with ejection abnormality, in the recovery processing step, a first step and a second step are performed. In the first step, a first drive signal of a first frequency is supplied to the first ejection element but not to the second ejection element. In the second step, a second drive signal of a second frequency lower than the first frequency is supplied to at least the second ejection element.

[0015] The effects of the invention

[0016] According to the present invention, techniques can be provided that, for example, reduce the time required for recovery processing of abnormal liquid ejection in a liquid ejection device and the amount of liquid used.

[0017] Further objects or other aspects of the invention will become apparent from the preferred embodiments described below with reference to the accompanying drawings. Attached Figure Description

[0018] Figure 1 This is a diagram showing the structure of an inkjet device.

[0019] Figure 2 This is a diagram illustrating an example of the control structure for a nozzle.

[0020] Figure 3 This is a diagram showing an example of the circuit structure of each nozzle.

[0021] Figure 4 It is a graph illustrating the relationship between the residual signal waveform and the abnormal ejection state.

[0022] Figure 5 This diagram illustrates a method for determining abnormal nozzle ejection status using residual signal waveforms.

[0023] Figure 6 This diagram illustrates the recovery process based on the pre-ejection stage.

[0024] Figure 7 This is a flowchart illustrating the recovery process of Example 1.

[0025] Figure 8A This is a flowchart illustrating the recovery process in Example 2.

[0026] Figure 8B This is a flowchart illustrating the recovery process in Example 2.

[0027] Figure 9 This is a diagram showing the residual signal waveform when an ejection anomaly occurs due to the mixing of air bubbles.

[0028] Figure 10 It is a flowchart showing the sequence of operations of the inkjet device.

[0029] Figure 11 This is a schematic diagram illustrating an example of material coating for a functional component. Detailed Implementation

[0030] Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. Furthermore, the following embodiments do not limit the technical solutions covered by the claims. Although multiple features are described in the embodiments, these multiple features are not all limited to the features necessary for the technical solution; in addition, multiple features can be combined arbitrarily. Furthermore, in the drawings, the same or identical structures are labeled with the same reference numerals, and repeated descriptions are omitted.

[0031] Reference Figure 1 The structure and operating principle of the inkjet apparatus 1 (substrate processing apparatus) will be explained. The inkjet apparatus 1, which functions as a substrate processing apparatus for processing substrates such as display panels or semiconductor substrates, applies material for functional elements onto the substrate to form patterns or films. As shown in the specification and accompanying drawings... Figure 1 As shown, the direction is represented in the XYZ coordinate system, where the plane parallel to the surface on which the substrate 2 is disposed is the XY plane. The inkjet apparatus 1 includes, for example, a substrate stage 3 that holds and moves the substrate 2, which is the display panel. The substrate 2 can be appropriately selected from glass substrates or plastic substrates, depending on the product to be manufactured. The substrate 2 is typically a plate-shaped component, but its shape is not limited as long as it can function as a substrate. For example, the substrate 2 can be a deformable film or a circular substrate. The substrate 2 on the substrate stage 3 has a pixel region 201 for applying ink and arranging multiple display pixels, and an evaluation region 202 for experimentally ejecting ink to evaluate its state. The evaluation region 202 can also be provided in a specific area of ​​the substrate stage 3. Furthermore, in this specification, "ink" refers to a liquid used to form patterns or films on the substrate 2. In this specification, the composition of the ink is not particularly limited; for example, a liquid containing a solute and solvent for forming an organic film can be used.

[0032] The inkjet apparatus 1 includes: a printhead 5 (liquid ejection device) capable of ejecting ink droplets 4 toward a predetermined position on a substrate 2; and an ink supply system 6 supplying ink from an ink cartridge 7 containing ink to the printhead 5. The printhead 5 has a plurality of nozzles 19 (ejection elements) that eject ink (liquid) according to a drive signal. The ink cartridge 7 may be disposed inside or outside the inkjet apparatus 1. Furthermore, the inkjet apparatus 1 may also include a recovery unit 8, which restores the ejection characteristics by cleaning the ejection nozzles of the printhead 5, etc.

[0033] When the substrate 2 is mounted on the substrate stage 3, placement errors may occur. Furthermore, due to various manufacturing processes, the substrate 2 may undergo shape deformation in the XY direction. Therefore, the inkjet apparatus 1 may include an alignment observer 9 that measures the position and deformation of the substrate 2. To perform alignment measurement on the entire surface of the substrate 2, the alignment observer 9 and the substrate stage 3 are driven relative to each other in the XY direction. That is, the alignment observer 9 and / or the substrate stage 3 are driven in the XY direction. Additionally, the substrate 2 mounted on the substrate stage 3 has thickness variations. Therefore, if ink is ejected from the printhead 5 while scanning the substrate stage 3 in the Y direction, the impact position (adhesion position) of the ink droplets on the substrate 2 may deviate due to the thickness variations of the substrate 2. Therefore, the inkjet apparatus 1 may also include a height sensor 10 that measures the position (height) of the substrate 2 in the Z direction. To measure the height of the entire surface of the substrate 2, the height sensor 10 and the substrate stage 3 are driven relative to each other in the XY direction. That is, the height sensor 10 and / or the substrate stage 3 are driven in the XY direction.

[0034] The main control unit 11 controls all parts of the inkjet device 1, encompassing the patterning on the substrate 2. The main control unit 11 can be configured as a computer having a processor such as a CPU (Central Processing Unit) and a storage unit such as a memory. The main control unit 11 can be configured, for example, as a PLD (Programmable Logic Device) such as a FPGA (Field Programmable Gate Array), or an ASIC (Application Specific Integrated Circuit), or a programmed general-purpose computer, or a combination of all or some of them.

[0035] In one example, multiple ejector heads 5 are arranged in the X and Y directions respectively. By controlling the ejection of ink droplets from each ejector head 5, the desired distribution of ink can be applied to the pixel area 201 on the substrate 2. Figure 2 This illustrates an example of the control structure for a nozzle 5. The nozzle 5 may have multiple nozzles 19. Each of the multiple nozzles 19 constitutes a discharge element including a piezoelectric element P (discharge energy generating element, piezoelectric actuator). Each of the multiple nozzles 19 is connected to a driver D that drives the piezoelectric element P via a flexible cable F. The driver D is connected to a discharge control unit C (control unit).

[0036] The ejection control unit C individually controls the ejection of ink droplets from each of the plurality of nozzles 19 (piezoelectric elements P) by controlling the supply of drive signals to each of the nozzles 19 (piezoelectric elements P) via the driver D. The ejection control unit C may be configured as a computer including a processor such as a CPU (Central Processing Unit) and a storage unit such as memory. Furthermore, in the recovery process of restoring nozzles with ejection abnormalities among the plurality of nozzles 19, the ejection control unit C supplies drive signals for restoring the abnormal nozzles to each nozzle 19 (piezoelectric element P) via the driver D. Specifically, the ejection control unit C sends a recovery process command for restoring the abnormal nozzles to the driver D. Upon receiving the recovery process command, the driver D generates a drive signal (e.g., voltage) corresponding to the recovery process command and supplies it to the piezoelectric element P of the abnormal nozzle, thereby driving the piezoelectric element P of the abnormal nozzle to perform the recovery process. Furthermore, the recovery process can also be understood as a process that reduces ejection abnormalities among the plurality of nozzles 19. Additionally, the functions of the ejection control unit C may also be implemented by the main control unit 11.

[0037] For each of the multiple nozzles 19, during the formation of the dot pattern onto the substrate or during standby, problems such as poor ejection or quality disorder (ejection anomalies) may occur due to foreign matter adhering to the flow path or near the nozzle opening, ink thickening or ink component sedimentation, electrophoresis, etc. These problems (ejection anomalies) are caused by the combined effects of various factors such as ejection time, flow path shape, distance from the electrode, and standby time before ejection. The degree of ejection anomaly may vary in each nozzle.

[0038] The recovery unit 8 is used for recovering from severe nozzle blockages, such as those that have produced foam or cannot be recovered through pre-ejection. However, recovery using the recovery unit 8 takes a long time and requires a large amount of ink. Therefore, recovery using the recovery unit 8 is only performed at scheduled maintenance times. In normal operation, pre-ejection from multiple nozzles 19 is appropriately performed in the pre-ejection area 20 to restore abnormal nozzles to normal operation.

[0039] The degree of ejection abnormality (ejection abnormality state) of each nozzle 19 can be confirmed using a related signal (residual signal waveform) measured after a specific pressure wave is generated in the piezoelectric element P. Specifically, the ejection control unit C sends a specific drive signal (e.g., a pulse signal) to the piezoelectric element P via the driver D, causing the piezoelectric element P to operate. Accompanying the operation of the piezoelectric element P, a specific pressure wave is generated in the piezoelectric element P. If the piezoelectric element is functioning normally, ink drips from the nozzle through this pressure wave. At this time, due to the pressure wave generated in the piezoelectric element P, deformation occurs in the piezoelectric element P, leaving a residual electrical signal corresponding to this deformation. This electrical signal is called the "residual signal". The ejection control unit C can detect this residual signal and measure (determine) the degree of ejection abnormality based on the waveform of the detected residual signal.

[0040] Figure 3 This illustrates an example of the circuit structure for each nozzle 19 in this embodiment. Figure 3 The example shown illustrates the circuit structure for one nozzle 19, but the same circuit structure can be applied to each of multiple nozzles 19. Figure 3 As shown, each nozzle 19 may include a piezoelectric element P, a signal generation unit 21, a switching unit 22, and a measuring unit 23.

[0041] The signal generation unit 21, for example, is a driver D, which generates a drive signal for the piezoelectric element P based on a command supplied from the ejection control unit C. During the recovery process, since the ejection control unit C supplies a recovery processing command to the signal generation unit 21, the signal generation unit 21 generates a drive signal corresponding to the recovery processing command. The drive signal generated by the signal generation unit 21 is supplied to the piezoelectric element P via the switching unit 22. Thus, the piezoelectric element P can eject ink corresponding to the drive signal supplied from the signal generation unit 21. Furthermore, the residual signal generated in the piezoelectric element P by the supply of the drive signal is supplied to the measuring unit 23 via the switching unit 22.

[0042] The switching unit 22 is a mechanism that switches between the supply of a drive signal from the signal generation unit 21 to the piezoelectric element P and the supply of a residual signal from the piezoelectric element P to the measuring unit 23. Figure 3 In the structural example, the switching unit 22 is configured as a switching element, but it can also be configured as a circulator that guides the drive signal from the signal generation unit 21 to the piezoelectric element P and guides the residual signal from the piezoelectric element P to the measuring unit 23.

[0043] The measuring unit 23 is a mechanism that detects the residual signal supplied from the piezoelectric element P via the switching unit 22, and measures an index (hereinafter sometimes referred to as the ejection anomaly index) indicating the degree of ejection anomaly based on the detected residual signal. Figure 3In this structural example, the measuring unit 23 may include an amplifier 23a and a processing unit 23b (processor). The amplifier 23a amplifies the residual signal supplied from the piezoelectric element P via the switching unit 22 and supplies it to the processing unit 23b. The processing unit 23b measures the ejection anomaly index of the nozzle 19 (piezoelectric element P) based on the period of the waveform of the residual signal supplied from the amplifier 23a, or the initial peak position in the waveform of the residual signal. For example, the processing unit 23b can measure the ejection anomaly index as the difference between the period of the waveform of the residual signal supplied from the amplifier 23a (piezoelectric element P) and a reference waveform, or the difference between the initial peak position. The reference waveform is the waveform of the residual signal that should be obtained from the piezoelectric element P in normal operation, obtained in advance through experiments or simulations. Here, the measuring unit 23... Figure 3 In the structural example, it is configured to measure the ejection anomaly index for one nozzle 19, but it can also be understood as a unit that measures the ejection anomaly index for each of multiple nozzles 19. In addition, the processing unit 23b of the measuring unit 23 can also be configured as part of the ejection control unit C.

[0044] Figure 4 (a) shows an example of a residual signal waveform. The horizontal axis represents time, and the vertical axis represents potential. Figure 4 The residual signal waveform shown in (a) is a reference residual signal waveform (reference waveform) representing the state of a nozzle capable of stable ejection. If a residual signal waveform of the same value is obtained, the nozzle is determined to be in a normal state. If the ejection abnormality of nozzle 19 develops and the degree of ejection abnormality increases, the waveform changes as described below.

[0045] If the nozzle's ejection abnormality develops (i.e., the degree of ejection abnormality increases), then as Figure 4 As shown in (b), the residual signal waveform changes from the state shown by the solid line to the state shown by the dashed line. Specifically, the initial peak position moves from T0 to T1 and T2, and the period of the residual signal waveform also lengthens. As the ejection anomaly develops, the residual signal waveform moves from dashed line 1 to dashed line 2. The aforementioned measurement unit 23 can measure the difference in period between the residual signal waveform (e.g., dashed lines 1 and 2) detected by the piezoelectric element P and the reference waveform (e.g., solid line 1), or the difference in the initial peak position, as an ejection anomaly indicator. Furthermore, the nozzle in this ejection anomaly state (ejection anomaly nozzle) returns to the normal state by performing a pre-ejection at a frequency corresponding to the degree of ejection anomaly. That is, the residual signal waveform returns to Figure 4 (a) The original reference waveform (solid line waveform).

[0046] Reference Figure 5 (a) to (d) illustrate the recovery process based on the pre-ejection. Figure 5(a) shows the residual signal waveform detected by the measuring unit 23 for each of the five nozzles A to E. Since the ejection abnormality state (i.e., the degree of ejection abnormality) varies for each nozzle, as shown... Figure 5 As shown in (a), the residual signal waveforms also differ among nozzles A through E. Recovery processing is used to... Figure 5 (a) shows an abnormal ejection state that varies for each nozzle, which is restored to normal by pre-ejection. Figure 4 The processing follows the normal state (reference waveform) shown in (a). Furthermore, the recovery process is implemented by determining a pre-ejection frequency suitable for the nozzle's ejection abnormality and applying a drive signal (e.g., a pulse signal) of that pre-ejection frequency to the nozzle. By implementing such a recovery process, the nozzle with ejection abnormality can be restored. In this embodiment, an example is described where the pre-ejection frequency applied sequentially to the same nozzle group decreases starting from the pre-ejection frequency suitable for the nozzle with the greatest degree of ejection abnormality, but this is not a limitation. For example, the pre-ejection frequency applied sequentially to the same nozzle group may also increase starting from the pre-ejection frequency suitable for the nozzle with the least degree of ejection abnormality.

[0047] In this embodiment, the ejection control unit C, based on the measurement results of the measurement unit 23, classifies the degree of ejection abnormality (ejection abnormality state) into multiple groups and determines the nozzles belonging to each group from among the multiple nozzles. Specifically, the ejection control unit C determines one or more first nozzles (first ejection elements) whose ejection abnormality index is within a first range and one or more second nozzles (second ejection elements) whose ejection abnormality index is within a second range from among the multiple nozzles 19. Hereinafter, one or more first nozzles are referred to as the first nozzle group (first ejection element group), and one or more second nozzles are referred to as the second nozzle group (second ejection element group). Here, the first nozzle group is the nozzle group whose ejection abnormality degree is higher than that of the second nozzle group. That is, the first range is the range where the ejection abnormality index is higher than the second range, and the lower limit of the ejection abnormality index in the first range can be set to be higher than the upper limit of the ejection abnormality index in the second range. Furthermore, the following describes examples of three types of nozzle groups with varying degrees of ejection abnormality: a severely abnormal nozzle group, a moderately abnormal nozzle group, and a slightly abnormal nozzle group. In this case, if the severely abnormal nozzle group is considered the first nozzle group, the moderately abnormal nozzle group can be classified as the second nozzle group. Conversely, if the moderately abnormal nozzle group is considered the first nozzle group, the slightly abnormal nozzle group can be classified as the second nozzle group.

[0048] In one example, such as Figure 5 As shown in (a), when there are multiple nozzles with varying degrees of ejection anomalies, the ejection control unit C... Figure 5 As shown in (b) to (d), the degree of ejection anomalies is classified into three groups (severe, moderate, and mild). Furthermore, the ejection controller C determines the severely abnormal nozzle group, the moderately abnormal nozzle group, and the mildly abnormal nozzle group from among the multiple nozzles 19 based on the ejection anomaly index measured by the measurement unit 23 for each nozzle. Additionally, the following explanation uses an example of using the initial peak position in the residual signal waveform as the ejection anomaly index.

[0049] For example, such as Figure 5 As shown in (d), since the initial peak position in the residual signal waveform of nozzle E is located within region I containing T2, the ejection control unit C identifies nozzle E as a severely abnormal nozzle group. Figure 5 As shown in (c), since the initial peak position in the residual signal waveform of nozzle D is located within region II containing T1, the ejection controller C identifies nozzle D as a moderately abnormal nozzle group. Furthermore, as... Figure 5 As shown in (b), since the initial peak position in the residual signal waveforms of nozzles B to C is located within region III, which includes T0, the ejection controller C identifies nozzles B to C as a slightly abnormal nozzle group. Furthermore, since nozzle A is in a normal state, therefore... Figure 5 (b) shows the residual signal waveform of nozzle A and Figure 4 (a) has the same reference waveform.

[0050] Next, the ejection control unit C, via the driver D, performs pre-ejection by using a drive signal at a frequency appropriate to the degree of ejection anomaly. That is, the ejection control unit C controls the driver D to supply the nozzles with a drive signal (e.g., a pulse signal) at a frequency suitable to the degree of ejection anomaly for pre-ejection. In this embodiment, firstly, pre-ejection is performed on the first nozzle group by supplying a first drive signal based on a first frequency. At this time, pre-ejection is not performed on the second nozzle group by supplying the first drive signal. To reduce the degree of ejection anomaly in the first nozzle group, the first frequency of the first drive signal is preset through experimentation or simulation. In the first nozzle group where pre-ejection based on the first drive signal has been performed, the degree of ejection anomaly can be reduced, causing the ejection anomaly index to move into a second range. That is, in the first nozzle group where pre-ejection based on the first drive signal has been performed, the degree of ejection anomaly can become the same as that of the second nozzle group. Then, pre-ejection is performed on both the first and second nozzle groups by supplying a second drive signal based on a second frequency lower than the first frequency. In order to reduce the degree of ejection abnormality of the second nozzle group, the second frequency of the second drive signal is preset through experiments or simulations.

[0051] exist Figure 5In the example, for the nozzle group with a severe anomaly where the initial peak of the residual signal waveform is located in region I, a high-frequency drive signal is suitable for pre-ejection. For the nozzle group with a moderate anomaly where the initial peak of the residual signal waveform is located in region II, a medium-frequency drive signal is suitable for pre-ejection. For the nozzle group with a slight anomaly where the initial peak of the residual signal waveform is located in region III, a low-frequency drive signal is suitable for pre-ejection. In one example, "high frequency" refers to a frequency in the range of 10kHz to 50kHz. "Medium frequency" refers to a frequency in the range of 1kHz to 10kHz. "Low frequency" refers to a frequency in the range of 100Hz to 1kHz.

[0052] Here, if the severely abnormal nozzle group is designated as the first nozzle group, the high-frequency drive signal supplied to the severely abnormal nozzle group is equivalent to the first drive signal at the first frequency. In this case, the moderately abnormal nozzle group is equivalent to the second nozzle group, and the medium-frequency drive signal supplied to the moderately abnormal nozzle group is equivalent to the second drive signal at the second frequency. On the other hand, if the moderately abnormal nozzle group is designated as the first nozzle group, the medium-frequency drive signal supplied to the moderately abnormal nozzle group is equivalent to the first drive signal at the first frequency. In this case, the slightly abnormal nozzle group is equivalent to the second nozzle group, and the low-frequency drive signal supplied to the slightly abnormal nozzle group is equivalent to the second drive signal at the second frequency.

[0053] Figure 6 (a) to (d) are diagrams illustrating the steps (processes) for restoring nozzle E, which belongs to the severely abnormal nozzle group. Figure 6 (a) indicates and Figure 5 (d) The same residual signal waveform. For example... Figure 6 As shown in (a), since the initial peak position in the residual signal waveform of nozzle E is located in region I, a pre-ejection using a high-frequency drive signal is first implemented (hereinafter, sometimes referred to as high-frequency pre-ejection). By implementing this high-frequency pre-ejection, as... Figure 6 As shown in (b), the period of the residual signal waveform of nozzle E shortens, and consequently, the initial peak position advances, moving into region II. Furthermore, corresponding to the initial peak position moving into region II, a pre-ejection of the drive signal at the medium frequency is implemented (hereinafter, sometimes referred to as medium-frequency pre-ejection). By performing this medium-frequency pre-ejection, as... Figure 6 As shown in (c), the period of the residual signal waveform of nozzle E is further shortened, and correspondingly, the initial peak position is further advanced, moving to region III. Furthermore, corresponding to the initial peak position moving to region III, a pre-ejection using a low-frequency drive signal is implemented (hereinafter, sometimes referred to as low-frequency pre-ejection). By performing this low-frequency pre-ejection, as... Figure 6As shown in (d), the residual signal waveform of nozzle E returns to the reference waveform. That is, it can reduce (restore, eliminate) the ejection abnormality of nozzle E.

[0054] Here, to achieve the same recovery effect for nozzles with different degrees of ejection anomaly than nozzle E, the residual signal waveform of each nozzle can be analyzed, and a pre-ejection frequency can be determined for each nozzle. Pre-ejection is then performed based on this determination. For example, for nozzle D, high-frequency pre-ejection is not performed; only medium-frequency and low-frequency pre-ejection are performed. This allows the residual signal waveform of nozzle D to become a reference waveform. That is, the ejection anomaly of nozzle D can be reduced (recovered, eliminated). Furthermore, since high-frequency pre-ejection is not performed for nozzle D, the time required for overall recovery processing of multiple nozzles and the amount of ink used can be reduced. Similarly, for nozzles B to C, high-frequency and medium-frequency pre-ejection are not performed; only low-frequency pre-ejection is performed. This allows the residual signal waveforms of nozzles B to C to become reference waveforms. That is, the ejection anomaly of nozzles B to C can be reduced (recovered, eliminated). Furthermore, since high-frequency and medium-frequency pre-ejection are not performed for nozzles B to C, the time required for overall recovery processing of multiple nozzles and the amount of ink used can be reduced. Here, in the recovery process, the results obtained by analyzing the residual signal waveforms of each nozzle are used to group nozzles with similar degrees of ejection abnormality together, and the ejection abnormality is recovered sequentially starting from the group with severe ejection abnormality, which is preferred in terms of efficiency.

[0055] [Example 1 of recovery processing]

[0056] The following describes Example 1 of the recovery process in this embodiment. Figure 7 This is a flowchart illustrating the recovery process of Embodiment 1 of this implementation. Figure 7 Each step in the flowchart can be executed by the ejection control unit C, but it can also be executed by the main control unit 11.

[0057] In step S101, the ejection control unit C acquires the residual signal waveform for each of the plurality of nozzles 19. For example, for each of the plurality of nozzles 19, the ejection control unit C supplies a specific drive signal (e.g., a pulse signal) to the piezoelectric element P via the driver D, causing the piezoelectric element P to generate a specific pressure wave, and the measuring unit 23 detects the residual signal remaining in the piezoelectric element P. Thus, the ejection control unit C is able to acquire the residual signal waveform for each of the plurality of nozzles 19.

[0058] In step S102, the ejection control unit C determines whether each of the plurality of nozzles 19 is an ejection malfunction nozzle. The determination of whether a nozzle is an malfunction nozzle can be based on the period (e.g., the initial peak position) of the residual signal waveform obtained in step S101. For example, as described above, the ejection control unit C determines nozzles 19 whose period of the residual signal waveform obtained in step S101 differs from the reference waveform as ejection malfunction nozzles. For nozzles 19 determined to be ejection malfunction nozzles, the process proceeds to step S103; for nozzles 19 determined not to be ejection malfunction nozzles (normal nozzles), the process ends.

[0059] In step S103, the ejection control unit C acquires the pre-ejection frequency for performing pre-ejection from the nozzle 19. In this embodiment, the pre-ejection frequency includes a frequency suitable for pre-ejection of a severely abnormal nozzle group (high frequency), a frequency suitable for pre-ejection of a moderately abnormal nozzle group (medium frequency), and a frequency suitable for pre-ejection of a slightly abnormal nozzle group (low frequency). These pre-ejection frequencies can be preset through experiments, simulations, etc.

[0060] In step S104, the ejection control unit C groups the nozzles 19 identified as having ejection abnormalities in step S102 according to the degree of ejection abnormality, determining a group of nozzles with severe abnormalities, a group of nozzles with moderate abnormalities, and a group of nozzles with slight abnormalities. Specifically, as described above, based on the residual signal waveform obtained in step S101, the ejection control unit C determines the nozzles with the initial peak position of the residual signal waveform located in region I as the group of nozzles with severe abnormalities. Similarly, the nozzles with the initial peak position of the residual signal waveform located in region II are determined as the group of nozzles with moderate abnormalities, and the nozzles with the initial peak position of the residual signal waveform located in region III are determined as the group of nozzles with slight abnormalities.

[0061] In step S105, the ejection control unit C performs high-frequency pre-ejection. High-frequency pre-ejection is performed only on severely abnormal nozzle groups, not on moderately abnormal or slightly abnormal nozzle groups. In the high-frequency pre-ejection, the high-frequency drive signal obtained in step S103 is used as the pre-ejection frequency suitable for the severely abnormal nozzle groups. The ejection control unit C supplies a high-frequency drive signal to the piezoelectric element P via the driver D, causing the severely abnormal nozzle groups to eject ink. Here, in the severely abnormal nozzle groups where high-frequency pre-ejection has been performed, the degree of ejection abnormality is reduced to the same level as in the moderately abnormal nozzle groups, and the initial peak position of the residual signal waveform can be moved to region II. Therefore, for the severely abnormal nozzle groups, after the high-frequency pre-ejection in step S105, step S106 proceeds to perform medium-frequency pre-ejection.

[0062] In step S106, the ejection controller C performs intermediate frequency pre-ejection. Intermediate frequency pre-ejection is performed only on the severely abnormal nozzle group (after high-frequency pre-ejection has been completed) and the moderately abnormal nozzle group, not on the slightly abnormal nozzle group. During intermediate frequency pre-ejection, the intermediate frequency drive signal obtained in step S103 is used as the pre-ejection frequency suitable for the moderately abnormal nozzle group. For the severely abnormal nozzle group (after high-frequency pre-ejection has been completed) and the moderately abnormal nozzle group, the ejection control unit C supplies an intermediate frequency drive signal to the piezoelectric element P via the driver D, causing it to eject ink. Here, in the severely abnormal nozzle group (after high-frequency pre-ejection has been completed) and the moderately abnormal nozzle group where intermediate frequency pre-ejection has been performed, the degree of ejection abnormality is reduced to the same level as in the slightly abnormal nozzle group, and the initial peak position of the residual signal waveform can be moved to region III. Therefore, for the severely abnormal nozzle group (after the high-frequency pre-ejection is completed) and the moderately abnormal nozzle group, after the medium-frequency pre-ejection in step S106, the process proceeds to step S107 for low-frequency pre-ejection.

[0063] In step S107, the ejection control unit C performs low-frequency pre-ejection. Low-frequency pre-ejection is performed on the severely abnormal nozzle group (after high-frequency and medium-frequency pre-ejection are completed), the moderately abnormal nozzle group (after medium-frequency pre-ejection is completed), and the slightly abnormal nozzle group. During low-frequency pre-ejection, a low-frequency drive signal obtained in step S103 is used as the pre-ejection frequency suitable for the slightly abnormal nozzle group. The ejection control unit C supplies a low-frequency drive signal to the piezoelectric element P via the driver D, causing ink to eject from the severely abnormal nozzle group (after high-frequency and medium-frequency pre-ejection are completed), the moderately abnormal nozzle group (after medium-frequency pre-ejection is completed), and the slightly abnormal nozzle group. Here, in the severely abnormal nozzle group (after high-frequency and medium-frequency pre-ejection are completed), the moderately abnormal nozzle group (after medium-frequency pre-ejection is completed), and the slightly abnormal nozzle group, after low-frequency pre-ejection, the ejection abnormality is restored, and the residual signal waveform is the same as the reference waveform.

[0064] In step S108, the ejection control unit C acquires the residual signal waveform for each of the plurality of nozzles 19. Next, in step S109, the ejection control unit C determines whether each of the plurality of nozzles 19 is an ejection malfunction nozzle. Steps S108 and S109 are the same procedures as steps S101 and S102, therefore detailed descriptions are omitted here. If there are no nozzles 19 determined to be ejection malfunction nozzles in step S110, the process ends. On the other hand, if there are nozzles 19 determined to be ejection malfunction nozzles in step S109, the process proceeds to step S110. In step S110, the ejection control unit C sets the nozzles 19 determined to be ejection malfunction nozzles in step S109 as "unusable nozzles" that should not be used when ejecting ink onto the substrate 2.

[0065] [Example 2 of recovery processing]

[0066] The following describes Example 2 of the recovery process in this embodiment. Figures 8A-8B This is a flowchart illustrating the recovery process of Embodiment 2 of this implementation. Figures 8A-8B Each step in the flowchart can be executed by the ejection control unit C, or by the main control unit 11. Additionally, besides the content mentioned in Embodiment 2, please refer to Embodiment 1.

[0067] In step S201, the ejection controller C acquires the residual signal waveform for each of the plurality of nozzles 19. Next, in step S202, the ejection control unit C, based on the residual signal waveform acquired in step S201, determines whether each of the plurality of nozzles 19 is an ejection malfunction nozzle. Since steps S201 to S202 are related to... Figure 7 Steps S101 to S102 are the same process, so detailed descriptions are omitted here.

[0068] In step S203, the ejection controller C determines (identifies) a severely abnormal nozzle group from the nozzles 19 identified as ejection abnormal nozzles in step S202. Specifically, as described above, the ejection control unit C, based on the residual signal waveform obtained in step S201, identifies the abnormal nozzles whose initial peak position of the residual signal waveform is located in region I as severely abnormal nozzle groups. For severely abnormal nozzle groups, the process proceeds to step S204; for other nozzle groups (moderately abnormal nozzle groups, slightly abnormal nozzle groups), the process proceeds to step S207.

[0069] In step S204, the ejection control unit C obtains a pre-ejection frequency (high frequency) suitable for the pre-ejection of the severely abnormal nozzle group. Next, in step S205, the ejection controller C performs high-frequency pre-ejection on the severely abnormal nozzle group. This high-frequency pre-ejection is only performed on the severely abnormal nozzle group determined in step S203, and not on other nozzle groups (moderately abnormal nozzle groups, slightly abnormal nozzle groups). Furthermore, since step S204 is related to... Figure 7 The process is the same as step S105, so detailed descriptions are omitted here.

[0070] In step S206, the ejection control unit C acquires residual signal waveforms for each nozzle 19 of the severely abnormal nozzle group that has undergone high-frequency pre-ejection, and determines whether the severe ejection abnormality has decreased (recovered, eliminated) based on the residual signal waveforms. That is, it determines whether the initial peak position of the residual signal waveform has moved from region I due to the high-frequency pre-ejection. If the severe ejection abnormality in the severely abnormal nozzle group has not decreased, the process returns to step S204. That is, the ejection control unit C repeatedly performs high-frequency pre-ejection until the degree of ejection abnormality in the severely abnormal nozzle group decreases and falls below the degree of ejection abnormality in the moderately abnormal nozzle group. For example, the ejection control unit C repeatedly performs high-frequency pre-ejection until the initial peak position of the residual signal waveform of the severely abnormal nozzle group moves to region II or region III. On the other hand, if the severe ejection abnormality in the severely abnormal nozzle group has decreased, the process proceeds to step S207.

[0071] In step S207, the ejection control unit C determines (identifies) a group of nozzles with moderate abnormalities from among the nozzles 19 identified as ejection abnormalities in step S202. More specifically, as described above, the ejection control unit C identifies nozzles whose initial peak position of the residual signal waveform is located in region II as a group of nozzles with moderate abnormalities based on the residual signal waveform obtained in step S201. In addition, in step S207, the ejection control unit C also identifies a group of nozzles whose initial peak position has moved to region II from the group of nozzles with severe abnormalities that have undergone high-frequency pre-ejection (steps S204 to S206) as a group of nozzles with moderate abnormalities. Hereinafter, the definition of "group of nozzles with moderate abnormalities" will include a group of nozzles with moderate abnormalities identified based on the residual signal waveform and a group of nozzles with severe abnormalities that have undergone high-frequency pre-ejection and whose peak position has moved to region II. If the nozzle group is determined to be a moderately abnormal nozzle group, proceed to step S208; if the nozzle group is determined to be any other nozzle group (a slightly abnormal nozzle group), proceed to step S211.

[0072] In step S208, the ejection control unit C obtains a pre-ejection frequency (medium frequency) suitable for the pre-ejection of the moderately abnormal nozzle group. Next, in step S209, the ejection controller C performs medium-frequency pre-ejection on the moderately abnormal nozzle group. This medium-frequency pre-ejection is only performed on the moderately abnormal nozzle group determined in step S207, and not on other nozzle groups (slightly abnormal nozzle groups). Furthermore, step S209 is related to... Figure 7 The process is the same as step S106, so detailed descriptions are omitted here.

[0073] In step S210, the ejection controller C acquires residual signal waveforms for each nozzle 19 of the moderately abnormal nozzle group that has undergone intermediate frequency pre-ejection, and determines whether the moderate ejection abnormality has decreased (recovered, eliminated) based on the residual signal waveforms. That is, it determines whether the initial peak position of the residual signal waveform has moved from region II through intermediate frequency pre-ejection. If the moderate ejection abnormality in the moderately abnormal nozzle group has not decreased, the process returns to step S208. That is, the ejection control unit C repeatedly performs intermediate frequency pre-ejection until the degree of ejection abnormality in the moderately abnormal nozzle group decreases and falls within the range of the degree of ejection abnormality in the mildly abnormal nozzle group. For example, the ejection controller C repeatedly performs intermediate frequency pre-ejection until the initial peak position of the residual signal waveform of the moderately abnormal nozzle group moves to region III. On the other hand, if the moderate ejection abnormality in the moderately abnormal nozzle group has decreased, the process proceeds to step S211.

[0074] In step S211, the ejection control unit C determines (identifies) a group of nozzles with slight abnormalities from among the nozzles 19 identified as ejection abnormalities in step S202. Specifically, as described above, the ejection controller C determines that the nozzles whose initial peak position of the residual signal waveform is located in region III are considered to be a group of nozzles with slight abnormalities based on the residual signal waveform obtained in step S201. In addition, in step S211, the ejection control unit C also identifies groups of nozzles with severe abnormalities (where the moderate ejection abnormality has decreased due to mid-frequency pre-ejection (steps S208 to S210)) and groups of nozzles with moderate abnormalities as groups of nozzles with slight abnormalities. Hereinafter, the definition of "group of nozzles with slight abnormalities" will include groups of nozzles with slight abnormalities identified based on the residual signal waveform, and groups of nozzles with severe abnormalities (where the moderate ejection abnormality has decreased due to mid-frequency pre-ejection) and groups of nozzles with moderate abnormalities. If a group of nozzles with slight abnormalities is identified, the process proceeds to step S212; if a group of nozzles other than this is identified, the process ends.

[0075] In step S212, the ejection control unit C obtains a pre-ejection frequency (low frequency) suitable for the pre-ejection of the nozzle group with minor abnormalities. Next, in step S213, the ejection control unit C performs low-frequency pre-ejection on the nozzle group with minor abnormalities. This low-frequency pre-ejection is performed only on the nozzle group with minor abnormalities determined in step S2211, and not on other nozzle groups. Furthermore, step S213 is related to... Figure 7 The process is the same as step S107, so detailed descriptions are omitted here.

[0076] In step S214, the ejection control unit C acquires residual signal waveforms for each nozzle 19 of the mildly abnormal nozzle group that has undergone low-frequency pre-ejection, and determines whether the mild ejection abnormality has decreased (recovered, eliminated) based on the residual signal waveforms. That is, it determines whether the period of the residual signal waveform after low-frequency pre-ejection is the same as the reference waveform. If the mild ejection abnormality in the mildly abnormal nozzle group has not decreased, the process returns to step S212. That is, the ejection control unit C repeatedly performs low-frequency pre-ejection until the ejection abnormality in the mildly abnormal nozzle group is recovered (for example, until the waveform of the residual signal waveform is the same as the reference waveform). On the other hand, if the mild ejection abnormality in the mildly abnormal nozzle group has decreased, the process ends.

[0077] As described above, in this embodiment (Examples 1-2), the following steps are performed in the recovery process that reduces (restores, eliminates) the abnormal ejection of the plurality of nozzles 19.

[0078] (1) High-frequency pre-ejection is only performed on nozzle groups with severe abnormalities.

[0079] (2) After high-frequency pre-ejection, medium-frequency pre-ejection is performed only on the severely abnormal nozzle group (after the high-frequency pre-ejection is completed) and the moderately abnormal nozzle group, or only on the moderately abnormal nozzle group.

[0080] (3) After the medium frequency pre-ejection, perform low frequency pre-ejection on the severely abnormal nozzle group (after the high frequency pre-ejection and medium frequency pre-ejection are completed), the medium abnormal nozzle group (after the medium frequency pre-ejection is completed), and the slightly abnormal nozzle group, or only on the slightly abnormal nozzle group.

[0081] This recovery process eliminates the need for high-frequency pre-ejection for moderately and slightly abnormal nozzle groups, as well as medium-frequency pre-ejection for slightly abnormal nozzle groups. Therefore, it reduces the time and ink consumption required for the recovery process.

[0082] In this embodiment, an example of classifying the degree of ejection abnormality into three groups (severe, moderate, and mild) is described, but it is not limited to this; the degree of ejection abnormality may also be classified into two or more groups. Furthermore, the recovery process in this embodiment is for reducing (restoring, eliminating) ejection abnormalities caused by ink thickening and / or ink component sedimentation, not for reducing ejection abnormalities caused by the incorporation of air bubbles into the nozzle (air bubble intake). Regarding nozzles that produce ejection abnormalities due to air bubble incorporation, such as... Figure 9As shown, the residual signal waveform becomes an irregular waveform. Therefore, the ejection control unit C can identify (determine) whether the ejection abnormality is caused by ink thickening and / or ink component sedimentation, or by the incorporation of air bubbles, based on this residual signal waveform. By performing cleaning treatment, such as using the recovery unit 8, the ejection abnormality caused by the incorporation of air bubbles can be reduced (recovered, eliminated).

[0083] [Sequence of Inkjet Printer Operation]

[0084] Next, refer to Figure 10 The following describes the operating sequence of the inkjet unit 1. In step S301, the main control unit 11 controls a substrate transport device (not shown) to transport the substrate 2 into the inkjet unit 1. In step S302, the ejection control unit C performs a recovery determination on the plurality of nozzles 19 of the printhead 5. The recovery determination is performed by determining whether the period (e.g., the initial peak position) of the residual signal waveform is the same as that of the reference waveform. Specifically, the ejection control unit C provides a specific pulse signal to the nozzle via the driver D to activate the nozzle, and detects the electrical signal corresponding to the deformation of the nozzle caused by the pressure wave generated by the operation of the nozzle as a residual signal. Then, the ejection control unit C determines the ejection defect state of the nozzle based on a comparison between the initial peak position of the residual signal waveform and the peak position of the reference waveform. In addition, the recovery determination of the plurality of nozzles 19 can also be performed before ink ejection. If there is a nozzle that is determined to be ejection defective in the recovery determination, in step S303, the ejection control unit C performs nozzle recovery processing on that nozzle. The recovery process described in Example 1 or Example 2 can be applied to nozzle recovery process.

[0085] In step S304, the main control unit 11 controls the substrate stage 3 and the alignment observer 9 to perform alignment measurements on the substrate 2. In step S305, the main control unit 11 controls the substrate stage 3 and the height sensor 10 to measure the height of the substrate 2. Alternatively, the order of the alignment measurement in step S304 and the height measurement in step S305 can be reversed. Information related to the position, deformation, and height of the substrate 2 obtained through the alignment and height measurements is stored, for example, in a memory within the main control unit 11. The main control unit 11 determines ejection control information based on pixel data containing information such as pixel configuration or pixel size formed on the substrate 2. The ejection control information includes information indicating the target coating distribution of ink in the pixel region 201 and the evaluation region 202 on the substrate 2.

[0086] In step S306, the ejection control unit C performs a recovery determination on the plurality of nozzles 19 of the ejection head 5. As described above, the recovery determination is performed by determining whether the waveform of the residual signal waveform (e.g., the initial peak position) is the same as that of the reference waveform. If there is a nozzle that is determined to have poor ejection in this recovery determination, in step S307, the ejection control unit C performs nozzle recovery processing on that nozzle. Steps S306 to S307 are the same procedures as those described in steps S302 to S303.

[0087] In step S308, the main control unit 11 synchronously drives the printhead 5 and the substrate stage 3, and the printhead control unit C controls the ink droplet ejection using the printhead 5 according to the target coating distribution. In order to form multiple functional elements on the substrate using the inkjet device 1, the coating area of ​​the ink and the printhead 5 are scanned relative to each other to coat the material of the functional elements. Figure 11 A schematic diagram illustrating the coating of a material for such a functional element is shown. Figure 11 In the diagram, substrate surface 101 is the surface of substrate 2 on which the functional element 102 is formed. Arrows 103, 104, 105, and 106 indicate the scanning direction. Because... Figure 11 This is a schematic diagram, so only 7×5 functional elements 102 are shown, but in reality, a great many functional elements can be formed.

[0088] In step S309, the main control unit 11 determines whether the spraying towards the target coating distribution is complete based on the spraying control information. If the spraying is not complete, the process returns to step S306; if the spraying is complete, the process proceeds to step S310. In step S310, the main control unit 11 controls a substrate transport device (not shown) to move the substrate 2 from the inkjet unit 1.

[0089] [Implementation Method of Item Manufacturing]

[0090] The article manufacturing method of this invention is suitable for manufacturing articles such as display panels for organic EL devices, microdevices such as semiconductor devices, and components with fine structures. The article manufacturing method of this embodiment includes: a step of forming an ejected liquid film by spraying liquid onto a substrate using the aforementioned inkjet apparatus; a step of drying the substrate with the ejected liquid film and processing it to form a dried film; and a step of manufacturing an article from the processed substrate. Furthermore, this article manufacturing method includes other well-known steps (firing, cooling, cleaning, oxidation, film formation, vapor deposition, doping, planarization, etching, resist stripping, cutting, bonding, encapsulation, etc.). Compared to conventional methods, the article manufacturing method of this embodiment is advantageous in at least one aspect of article performance, quality, productivity, and production cost.

[0091] This invention is not limited to the embodiments described above, and various changes and modifications can be made without departing from the spirit and scope of the invention. Therefore, claims are appended to disclose the scope of this invention.

[0092] Explanation of reference numerals in the attached figures

[0093] 1: Inkjet device (substrate processing device), 2: Substrate, 3: Substrate stage, 5: Printhead (liquid ejection device), 9: Alignment observer, 10: Height sensor, 11: Main control unit, 19: Nozzle (ejection element), C: Ejection control unit (control unit), D: Driver.

Claims

1. A liquid ejection device, characterized in that, The liquid ejection device includes: Multiple ejection elements eject liquid according to a drive signal; and The control unit controls the supply of the drive signal to each of the plurality of ejection elements. When the control unit determines, from among the plurality of ejection elements, a first ejection element whose index indicating the degree of ejection abnormality is within a first range and a second ejection element whose index is within a second range lower than the first range as ejection elements having ejection abnormalities, in the recovery process of reducing the ejection abnormalities of the plurality of ejection elements, The first drive signal of the first frequency is supplied to the first ejection element instead of the second ejection element. When the index of the first ejection element is outside the second range, the first drive signal is repeatedly supplied to the first ejection element. When the index of the first ejection element moves to the second range, a second drive signal with a second frequency lower than the first frequency is supplied to the second ejection element.

2. The liquid ejection device according to claim 1, characterized in that, During the recovery process, the control unit also supplies the second drive signal to the first ejection element.

3. The liquid ejection device according to claim 1, characterized in that, The lower limit of the indicator in the first range is higher than the upper limit of the indicator in the second range.

4. The liquid ejection device according to claim 1, characterized in that, The first frequency of the first drive signal is preset to reduce the degree of ejection abnormality of the first ejection element. The second frequency of the second drive signal is preset to reduce the degree of ejection abnormality of the second ejection element.

5. The liquid ejection device according to claim 1, characterized in that, The liquid ejection device also includes a measuring unit, which measures an index representing the degree of ejection abnormality for each of the plurality of ejection elements. Based on the measurement results from the measuring unit, the control unit determines the first ejection element and the second ejection element from among the plurality of ejection elements.

6. The liquid ejection device according to claim 5, characterized in that, The plurality of ejection elements each include a piezoelectric element. The measuring unit detects the residual signal remaining in the piezoelectric element when a specific pressure wave is generated in the piezoelectric element, and measures the index based on the waveform of the residual signal.

7. The liquid ejection device according to claim 6, characterized in that, The measurement unit measures the index based on the period of the waveform of the residual signal.

8. The liquid ejection device according to claim 6, characterized in that, The measurement unit measures the index based on the initial peak position in the waveform of the residual signal.

9. A substrate processing apparatus for processing a substrate, characterized in that, The substrate processing apparatus includes: A stage for holding and moving the substrate; and The liquid ejection device according to any one of claims 1 to 8 ejects liquid onto the substrate held by the stage.

10. A method for manufacturing an article, characterized in that, The method for manufacturing the article includes: The process of spraying liquid onto a substrate using the substrate processing apparatus according to claim 9; The process of processing the substrate from which the liquid has been sprayed; and The process of manufacturing articles from the processed substrate.

11. A control method for a liquid ejection device comprising a plurality of ejection elements that eject liquid according to a drive signal. Its features are, The control method includes: The process involves identifying, from among the plurality of ejection elements, the ejection element exhibiting the ejection abnormality; and The recovery process reduces the ejection abnormalities of the multiple ejection elements. In the determination process, if a first ejection element whose index indicating the degree of ejection abnormality is within a first range and a second ejection element whose index is within a second range lower than the first range are determined to be ejection elements with ejection abnormality, the following process is performed in the recovery process: In the first step, the first driving signal of the first frequency is not supplied to the second ejection element but is supplied to the first ejection element; The second step, after the first step, is to determine whether the index of the first ejection element has moved into the second range; In the third step, if the index of the first ejector element has not moved to the second range, the first drive signal is repeatedly supplied to the first ejector element until the index of the first ejector element moves to the second range; and In the fourth step, when the index of the first ejection element moves to the second range, a second drive signal with a second frequency lower than the first frequency is supplied to the second ejection element at least.

Images