Liquid discharge apparatus, article manufacturing method, control method, and storage medium

Abstract

The invention relates to a liquid discharge apparatus, an article manufacturing method, a control method, and a storage medium. The liquid discharge apparatus includes: a plurality of discharge sections each including a liquid chamber including a discharge hole, and a piezoelectric element that applies pressure to the liquid chamber to discharge liquid droplets from the discharge hole; a detection unit that detects, with respect to each of the plurality of discharge units, a signal indicating vibration in the liquid chamber caused by operation of the piezoelectric element; and a control unit that controls each of the plurality of discharge units, in which the signals detected by the detection unit differ from each other and the discharge states of the droplets differ from each other in accordance with the difference in the signals, and that controls the discharge units in accordance with the difference between the plurality of discharge units relating to a group of the signals and the discharge states. In the present invention, information relating to a signal and a discharge state is generated in advance, the information relating to the discharge state is commonly used in a plurality of discharge units, and the discharge state that changes due to deterioration over time is estimated for each discharge unit on the basis of the detection results of a detection unit.

Description

Technical Field

[0001] The present invention relates to a liquid dispensing device, an article manufacturing method, a control method, an information processing device, a generation method, and a storage medium. Background Art

[0002] In recent years, when manufacturing various functional elements, attempts have been made to use a liquid ejection device that ejects (supplies) a liquid that will become a material of the functional element as droplets onto a substrate by an inkjet method to form a pattern (composition) on the substrate. Composition using such a liquid ejection device has the advantages of high material utilization efficiency due to the ability to pattern on demand, a relatively small manufacturing device without a vacuum process, and the ability to coat a large area at high speed.

[0003] However, various display methods have been proposed in display devices, and in recent years, the development of display devices using organic EL elements has been particularly advanced. Organic EL materials used to make organic EL elements are expensive, so sometimes a liquid discharge device that has excellent material use efficiency and can coat a large area at high speed is used. In addition, recently, a color conversion unit including a quantum dot material and a display device having quantum dots as light-emitting elements have attracted attention. For example, in the production of a color conversion unit including a quantum dot material, a liquid discharge device having a liquid discharge head that discharges liquids such as ink is sometimes used. In the liquid discharge head, a plurality of discharge parts are provided, and the plurality of discharge parts respectively have: a pressure chamber (liquid chamber) having a discharge hole; and a pressure generating element (piezoelectric element) that generates pressure in the liquid chamber for causing droplets to be discharged from the discharge hole. In such a liquid discharge head, the piezoelectric element deteriorates due to the applied voltage that repeatedly drives the piezoelectric element and maintains the piezoelectric element for a long time in a displaced state to form a state in which stress is continuously applied. Deterioration of the piezoelectric element leads to a decrease in the displacement of the piezoelectric element, so even if the same applied voltage is applied, the ejection speed and ejection volume of the droplets decrease, resulting in a problem of deterioration in printing quality.

[0004] As a means to solve such a problem, Patent Document 1 describes detecting residual vibration in a pressure chamber generated when a test signal is supplied to a pressure generating element, and correcting a discharge signal supplied to the pressure generating element for discharging liquid based on the detection result.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Publication No. 2020-32622 Summary of the invention

[0008] Conventionally, information indicating the correlation between residual vibration and the ejection velocity or ejection volume of droplets is generated independently for each of the plurality of ejection sections. However, in order to generate this information for one of the plurality of ejection sections, it is necessary to obtain the combination of residual vibration and the ejection velocity or ejection volume of droplets at least twice at a time interval when the pressure generating element of the one ejection section degrades to a certain extent over time. In this case, the ejection signal cannot be corrected until the pressure generating element of the one ejection section degrades to a certain extent over time and the information can be generated, making it difficult to control the plurality of ejection sections with high precision.

[0009] Therefore, an object of the present invention is to provide a technology suitable for controlling a plurality of discharge units in a liquid discharge device with high accuracy.

[0010] In order to achieve the above-mentioned object, as one aspect of the present invention, a liquid discharge device is characterized in that it comprises: a plurality of discharge parts, each of which has a liquid chamber including a discharge hole, and a piezoelectric element that applies pressure to the liquid chamber to discharge liquid droplets from the discharge hole; a detection part that detects, for each of the plurality of discharge parts, a signal indicating vibration in the liquid chamber caused by operating the piezoelectric element; and a control part that controls each of the plurality of discharge parts, wherein the signals detected by the detection part are different from each other in the plurality of discharge parts, and discharge states of liquid droplets discharged from the discharge hole are different from each other according to the difference in the signals, the control part generates in advance related information indicating the correlation between the signal and the discharge state according to the difference between the plurality of discharge parts related to the combination of the signal and the discharge state, uses the related information in common in the plurality of discharge parts, estimates the discharge state that changes due to time-dependent degradation for each discharge part according to the detection result of the detection part, and controls each of the plurality of discharge parts according to the estimated result of the discharge state.

[0011] In order to achieve the above-mentioned object, as one aspect of the present invention, there is provided a control method for a liquid discharge device, the liquid discharge device comprising a plurality of discharge parts, the plurality of discharge parts respectively having a liquid chamber including a discharge hole, and a piezoelectric element for applying pressure to the liquid chamber to discharge liquid droplets from the discharge hole, characterized in that, in the plurality of discharge parts, signals indicating vibrations in the liquid chamber caused by operating the piezoelectric element are different from each other, and discharge states of liquid droplets discharged from the discharge hole are different from each other according to the difference in the signal, the control method comprising: an acquisition step of acquiring a set of the signal and the discharge state for each discharge part; a generation step of generating related information indicating a correlation between the signal and the discharge state according to a difference between the plurality of discharge parts related to the group, using the group acquired for each discharge part in the acquisition step; an estimation step of estimating the discharge state that changes due to time degradation for each discharge part according to a detection result of the signal, using the related information in common in the plurality of discharge parts; and a control step of controlling the plurality of discharge parts according to the estimation result in the estimation step.

[0012] In order to achieve the above-mentioned purpose, as one aspect of the present invention, an information processing device generates information used in a liquid discharge device, the liquid discharge device comprising a plurality of discharge parts, each of the plurality of discharge parts having a liquid chamber including a discharge hole, and a piezoelectric element for applying pressure to the liquid chamber to discharge liquid droplets from the discharge hole, characterized in that, in the plurality of discharge parts, signals indicating vibrations in the liquid chamber caused by operating the piezoelectric element are different from each other, and discharge states of liquid droplets discharged from the discharge hole are different from each other according to the difference in the signal, the information processing device obtains a group of the signal and the discharge state for each discharge part, uses the group obtained for each discharge part, and generates related information indicating the correlation between the signal and the discharge state according to the difference between the plurality of discharge parts related to the group, the related information being information commonly used in the plurality of discharge parts in order to infer the discharge state that changes due to time-dependent degradation for each discharge part based on the detection result of the signal.

[0013] In order to achieve the above-mentioned object, as one aspect of the present invention, there is provided a generation method for generating information used in a liquid discharge device using an information processing device, the liquid discharge device comprising a plurality of discharge parts, the plurality of discharge parts respectively having a liquid chamber including a discharge hole, and a piezoelectric element for applying pressure to the liquid chamber to discharge liquid droplets from the discharge hole, characterized in that, in the plurality of discharge parts, signals indicating vibrations in the liquid chamber caused by operating the piezoelectric element are different from each other, and discharge states of liquid droplets discharged from the discharge hole are different from each other according to the difference in the signals, the generation method comprising: an acquisition step of acquiring a set of the signal and the discharge state for each discharge part; and a generation step of generating related information indicating a correlation between the signal and the discharge state based on a difference between the plurality of discharge parts related to the group using the group acquired for each discharge part in the acquisition step, the related information being information commonly used in the plurality of discharge parts in order to estimate the discharge state that changes due to time degradation for each discharge part based on a detection result of the signal.

[0014] Further objects and other aspects of the present invention will become more apparent from the following preferred embodiments described with reference to the accompanying drawings.

[0015] According to the present invention, for example, it is possible to provide a technique useful for controlling a plurality of discharge units in a liquid discharge device with high accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a schematic diagram showing a configuration example of a liquid discharge device according to an embodiment of the present invention.

[0017] Figure 2 This is a flowchart showing the operation sequence of the liquid discharge device.

[0018] Figure 3 Schematic diagram showing an example of application of a material of a functional element.

[0019] Figure 4 It is a schematic diagram showing a structural example of the ejection head.

[0020] Figure 5 It is a diagram showing the waveform of the vibration signal (voltage) detected by the detection unit.

[0021] Figure 6 This is a diagram for explaining the correlation between the amplitude of a vibration signal and the discharge state in one discharge unit.

[0022] Figure 7 This is a diagram showing related information generated based on the difference between a plurality of discharge units related to group data.

[0023] Figure 8 This is a flowchart showing a control example of a plurality of ejection units in the ejection head.

[0024] (Explanation of symbols)

[0025] 1: liquid supply device; 2: substrate; 3: substrate mounting table; 4: ink droplets; 5: ejection head; 11: control unit; 14: detection unit; 15: droplet measurement unit; 20: ejection unit; 21: ejection hole; 22: liquid chamber; 23: piezoelectric element. DETAILED DESCRIPTION

[0026] The following detailed description of the embodiments is given with reference to the accompanying drawings. In addition, the following embodiments do not limit the invention involved in the claims. A plurality of features are described in the embodiments, but these plurality of features are not necessarily all required in the invention, and a plurality of features can be combined arbitrarily. Furthermore, in the accompanying drawings, the same reference number is added to the same or similar structure, and repeated descriptions are omitted.

[0027] In this specification and the accompanying drawings, directions are represented by an XYZ coordinate system in which a surface parallel to a surface on which a substrate is disposed is set as an XY plane. The directions parallel to the X-axis, Y-axis, and Z-axis in the XYZ coordinate system are set as the X-direction, the Y-direction, and the Z-direction, and the rotation around the X-axis, the rotation around the Y-axis, and the rotation around the Z-axis are set as θX, θY, and θZ, respectively. Control and drive (movement) related to the X-axis, the Y-axis, and the Z-axis respectively mean control or drive (movement) related to the direction parallel to the X-axis, the direction parallel to the Y-axis, and the direction parallel to the Z-axis. In addition, control or drive related to the θX axis, the θY axis, and the θZ axis respectively mean control or drive related to rotation around an axis parallel to the X-axis, rotation around an axis parallel to the Y-axis, and rotation around an axis parallel to the Z-axis.

[0028] <Liquid dispensing device>

[0029] Reference Figure 1 , the basic structure and operation principle of the liquid discharge device 1 are explained. The liquid discharge device 1 is a device that discharges (supplies, imparts) a liquid, which is a material of a functional element, onto a substrate to form a pattern, and functions as a substrate processing device that processes substrates such as display panels and semiconductors. For example, the liquid discharge device 1 can be used to manufacture display devices such as flat panel displays and OLED (Organic Light Emitting Diode) devices. In addition, in this specification, "ink" refers to a liquid that is discharged onto a substrate by the liquid discharge device 1 in order to form a pattern or film on the substrate. In this specification, there is no particular limitation on the composition of the ink. For example, a liquid containing a solute and a solvent for forming an organic film can be used as ink.

[0030] The liquid discharge device 1 includes, for example, a substrate stage 3 that moves while holding a substrate 2 of a display panel. The substrate 2 can be a substrate appropriately selected from a glass substrate or a plastic substrate, etc., depending on the target product to be manufactured. The substrate 2 is typically a plate-shaped component, but is not limited to a specific shape as long as it can function as a substrate. For example, the substrate 2 can be a deformable film or a disc-shaped substrate. In addition, the substrate 2 on the substrate stage 3 is provided with a pixel section 201 for applying ink and arranging a large number of display pixels, and an evaluation section 202 for experimentally discharging ink in order to evaluate the state of the ink.

[0031] The liquid ejection device 1 includes: an ejection head 5 capable of ejecting ink droplets 4 toward a substrate 2; an ink tank 7 for storing ink; and an ink supply system 6 for supplying ink from the ink tank 7 to the ejection head 5. The ejection head 5 includes a plurality of ejection parts 20 for ejecting ink droplets 4 in accordance with a drive signal, and the ejection of the ink droplets 4 in each ejection part 20 is independently controlled by a control part 11. Thus, ink can be supplied (applied) to a pixel segment 201 on the substrate 2 in a desired distribution. The detailed structure of the ejection head 5 will be described later. Here, the ink tank 7 can be arranged either inside the liquid ejection device 1 or outside the liquid ejection device 1. In addition, the liquid ejection device 1 may further include a recovery part 8 for performing a cleaning process on the ejection head 5 to restore the ejection characteristics.

[0032] When the substrate 2 is mounted on the substrate stage 3, a placement error may occur. In addition, the substrate 2 undergoes various manufacturing processes, so that the shape of the substrate 2 may be distorted in the XY direction. Therefore, the liquid discharge device 1 has an alignment mark 9 for measuring the position of the substrate 2 and the amount of distortion of the substrate 2. In order to perform alignment measurement on the entire surface of the substrate 2, the alignment mark 9 and the substrate stage 3 are relatively driven in the XY direction. In addition, there is a thickness deviation in the substrate 2 mounted on the substrate stage 3. Therefore, when the ink is ejected from the ejection head 5 while scanning the substrate stage 3 in the Y direction, the attachment position (dropping position) of the ink droplet 4 attached to the substrate 2 may deviate due to the thickness deviation of the substrate 2. Therefore, the liquid discharge device 1 may also have a height sensor 10 for measuring the position (height) of the substrate 2 in the Z direction. In order to perform height measurement on the entire surface of the substrate 2, the height sensor 10 and the substrate stage 3 are relatively driven in the XY direction.

[0033] The liquid ejection device 1 of the present embodiment may further include a detection unit 14 and a droplet measuring unit 15. The detection unit 14 detects a signal indicating the vibration in the liquid chamber caused by the operation of the piezoelectric element with respect to each ejection unit 20 of the ejection head 5. The detailed structure of the detection unit 14 will be described later. In addition, the droplet measuring unit 15 measures the ejection state of the ink droplets 4 in each ejection unit 20 of the ejection head 5. The ejection state of the ink droplets 4 may include at least one of the ejection speed and the ejection volume of the ink droplets 4 ejected from the ejection hole of each ejection unit 20. The ejection state of the droplets may also include the twist angle of the ink droplets 4 when ejected.

[0034] Here, an example of measuring the ejection speed of the ink droplets 4 ejected from each ejection unit 20 as the ejection state using the droplet measurement unit 15 is described. In this case, the droplet measurement unit 15 can take multiple shots of the ink droplets 4 ejected from each ejection unit 20 at staggered timings during the flight of the ink droplets 4 ejected from each ejection unit 20, and measure the ejection speed based on the difference in the position (height) of the ink droplets 4 in the multiple images obtained thereby. Alternatively, the droplet measurement unit 15 can take pictures of the ink droplets 4 attached to the substrate 2 by scanning the substrate 2 while causing each ejection unit 20 to eject the ink droplets 4, and measure the ejection speed based on the offset between the attachment position of the ink droplets 4 on the substrate 2 and the target position. In addition, the example of measuring the ejection volume of the ink droplets 4 ejected from each ejection unit 20 as the ejection state using the droplet measurement unit 15 is also the same as the example of measuring the ejection speed of the ink droplets 4. That is, the droplet measurement unit 15 may measure the discharge volume by photographing the ink droplets 4 discharged from each discharge unit 20 while they are flying, or may measure the discharge volume by photographing the ink droplets 4 attached to the substrate 2 .

[0035] The control unit 11 is composed of a computer (information processing device) having a processor such as a CPU (Central Processing Unit) and a storage unit such as a memory, and controls each part of the liquid discharge device 1 to generally control the patterning on the control substrate 2. The control unit 11 may also be composed of, for example, a PLD (Programmable Logic Device) such as an FPGA (Field Programmable Gate Array), or an ASIC (Application Specific Integrated Circuit), or a general-purpose computer with an embedded program, or a combination of all or part of these.

[0036] <Operation sequence of liquid discharge device>

[0037] Next, refer to Figure 2, explaining the action sequence of the liquid discharge device 1. In step S101, the control unit 11 carries the substrate 2 into the liquid discharge device 1 by controlling the substrate conveying device (not shown). Specifically, the control unit 11 carries the substrate 2 onto the substrate mounting table 3 by controlling the substrate conveying device (not shown), and holds the substrate 2 on the substrate mounting table 3. Next, in step S102, the control unit 11 performs a recovery determination of each discharge unit 20 of the discharge head 5. In the recovery determination, it is determined whether a discharge abnormality occurs in each discharge unit 20 of the discharge head 5, that is, whether a recovery process is required for each discharge unit 20. In the case where there is a discharge unit 20 that is determined to have a discharge abnormality in the recovery determination, the process proceeds to step S103, and the control unit 11 performs a recovery process on each discharge unit 20 of the discharge head 5. The recovery process may include, for example, a process of restoring the discharge characteristics of the discharge head 5 by performing a cleaning process on the discharge head 5 using the recovery unit 8.

[0038] In step S104, the control unit 11 performs alignment measurement of the substrate 2 by controlling the substrate stage 3 and the alignment mark 9. In step S105, the control unit 11 performs height measurement of the substrate 2 by controlling the substrate stage 3 and the height sensor 10. In addition, the order of the alignment measurement in step S104 and the height measurement in step S105 may be reversed. Information related to the position, skewness, and height of the substrate 2 obtained by the alignment measurement and the height measurement is stored in a memory in the control unit 11, for example. The control unit 11 obtains the ejection control information based on the pixel data including information such as the pixel configuration formed on the substrate and the size of the pixel. The ejection control information includes information representing the target coating distribution of the ink in the pixel segment 201 and the evaluation segment 202 on the substrate 2.

[0039] In step S106, the control unit 11 performs a recovery determination of each of the ejection units 20 of the ejection head 5. If there is an ejection unit 20 determined to be abnormal in the recovery determination, the process proceeds to step S107, and the control unit 11 performs a recovery process on each of the ejection units 20 of the ejection head 5. Steps S106 to S107 are the same steps as the above-mentioned steps S102 to S103.

[0040] In step S108, the control unit 11 synchronously scans (drives) the ejection head 5 and the substrate mounting table 3, and uses the ejection head 5 to control the ejection of ink droplets 4 (ejection processing) according to the target coating distribution. In order to form a large number of functional elements on the substrate 2 using the liquid ejection device 1, the control unit 11 relatively scans the coating area where the ink is applied and the ejection head 5 during the ejection processing, and causes each ejection unit 20 of the ejection head 5 to eject the material of the functional element (ink droplets 4). Figure 3 , a schematic diagram illustrating the application of materials for such a functional element is shown. Figure 3In the figure, the substrate surface 101 is a surface of the substrate 2 on which the functional element 102 is formed. Figure 3 This is a schematic diagram, so only 7×5 functional elements 102 are shown, but in fact a very large number of functional elements can be formed.

[0041] In step S109, the control unit 11 determines whether the discharge process for the substrate 2 is completed. If the discharge process for the substrate 2 is not completed, the process returns to step S106. If the discharge process for the substrate 2 is completed, the process proceeds to step S110. In step S110, the control unit 11 controls the substrate transport device (not shown) to carry out the substrate 2 from the liquid discharge device 1 (on the substrate mounting table 3).

[0042] <spit out head>

[0043] Next, a configuration example of the discharge head 5 will be described. Figure 4 : is a schematic cross-sectional view showing a part of the ejection head 5 in an enlarged manner. The ejection head 5 of the present embodiment includes a common liquid chamber 51 and a module substrate 52. The common liquid chamber 51 is a liquid chamber for storing ink 53 supplied to a plurality of ejection parts 20 provided on the module substrate 52. The ink 53 is supplied to the common liquid chamber 51 from the ink tank 7 via the ink supply system 6. The module substrate 52 is provided with a plurality of ejection parts 20 arranged in a direction (e.g., X direction) intersecting (orthogonal) to the scanning direction (Y direction) of the substrate 2.

[0044] Each of the plurality of ejection parts 20 includes: a liquid chamber 22 having an ejection hole 21; and a piezoelectric element 23 that applies pressure to the liquid chamber 22 to eject ink droplets 4 from the ejection hole 21. In the liquid chamber 22 of each ejection part 20, a connecting hole 24 that communicates with the common liquid chamber 51 is provided, and the ink 53 stored in the common liquid chamber 51 is supplied through the connecting hole 24. The opening area of ​​the ejection hole 21 in each ejection part 20 is smaller than the opening area of ​​the connecting hole 24, and the opening area (cross-sectional area) is the smallest in the flow path of the ink 53 in the ejection head 5. In each ejection part 20 configured in this way, the control unit 11 provides a predetermined drive signal (e.g., a pulse signal) to the piezoelectric element 23 to activate the piezoelectric element 23, and the ink 53 in the liquid chamber 22 is ejected from the ejection hole 21 as ink droplets 4.

[0045] Here, the plurality of discharge parts 20 can also be understood as being constituted as one structure (module substrate 52). In addition, the discharge head 5 including the common liquid chamber 51 and the module substrate 52 constituted by the plurality of discharge parts 20 can be replaced. Furthermore, the number of the plurality of discharge parts 20 can be appropriately set.

[0046] <Detection Department>

[0047] Next, a configuration example of the detection unit 14 is described. The detection unit 14 detects, for each discharge unit 20, a signal (hereinafter sometimes referred to as a vibration signal) indicating vibration in the liquid chamber 22 caused by providing a predetermined inspection signal (e.g., a pulse signal) to the piezoelectric element 23 to actuate the piezoelectric element 23. Specifically, when pressure is generated in the liquid chamber 22 by providing a inspection signal to the piezoelectric element 23 to actuate the piezoelectric element 23, vibration is generated in the liquid chamber 22 due to this, and the vibration remains in the liquid chamber 22 for a short period of time. Such vibration remaining in the liquid chamber 22 is called "residual vibration", and the detection unit 14 detects, for each discharge unit 20, the back electromotive force (voltage, current) generated in the piezoelectric element 23 due to the residual vibration in the liquid chamber 22 as a vibration signal. That is, the detection unit 14 may include a voltage sensor or a current sensor, etc., provided for each discharge unit 20. The vibration signal detected by the detection unit 14 is related to the ejection state of the ink droplets 4 ejected from the ejection hole 21, and is used to estimate the ejection state of the ink droplets 4 that changes due to the time-dependent degradation of the piezoelectric element 23 for each ejection unit 20. Figure 4 Although omitted in the figure, the detection unit 14 is configured to detect the vibration signal for each of the plurality of discharge units 20 independently.

[0048] <Method of estimating the discharge status>

[0049] Next, a method for estimating the ejection state of the ink droplets 4 that has changed due to the aging degradation of the piezoelectric element 23 based on the detection result of the detection unit 14 is described. For example, the control unit 11 provides a predetermined inspection signal (e.g., a pulse signal) to the piezoelectric element 23 for each ejection unit 20 to activate the piezoelectric element 23, thereby causing the detection unit 14 to detect the vibration signal obtained from the piezoelectric element 23. Moreover, the control unit 11 can estimate the ejection state of the ink droplets 4 that has changed due to the aging degradation of the piezoelectric element 23 based on the evaluation value of the vibration signal detected by the detection unit 14. Here, as the predetermined inspection signal, either a signal for actuating the piezoelectric element 23 in a manner of ejecting the ink droplets 4 from the ejection hole 21 or a signal for actuating the piezoelectric element 23 in a manner of not ejecting the ink droplets 4 from the ejection hole 21 can be used. In addition, the evaluation value of the vibration signal detected by the detection unit 14 is an index for evaluating the waveform of the vibration signal, for example, it can be the maximum amplitude or period in the waveform of the vibration signal. In this embodiment, an example is described in which the maximum amplitude in the waveform of the vibration signal detected by the detection unit 14 is used as the evaluation value. In addition, hereinafter, the maximum amplitude in the waveform of the vibration signal detected by the detection unit 14 may be simply expressed as "amplitude of the vibration signal".

[0050] Figure 5 The waveform of the vibration signal (voltage) detected by the detection unit 14 is shown. Figure 5The solid line in represents the waveform of the vibration signal detected by the detection unit 14 at the first timing, which is expressed as "initial signal" in the figure. The first timing refers to, for example, the timing of the first use of the ejection head 5 after maintenance of the ejection head 5 (as an example, after replacement). In addition, Figure 5 The dotted line in φ represents the waveform of the vibration signal detected by the detection unit 14 at the second timing when time has passed from the first timing and the piezoelectric element 23 has deteriorated with time, and is expressed as a “detection signal” in the figure.

[0051] At the second timing when the aging degradation of the piezoelectric element 23 progresses, even if the same predetermined inspection signal (e.g., voltage) as that at the first timing is supplied to the piezoelectric element 23, the displacement generated in the piezoelectric element 23 decreases, and the pressure applied to the liquid chamber 22 also decreases. As a result, the residual vibration in the liquid chamber 22 also decreases, so that Figure 5 As shown, the amplitude of the vibration signal detected by the detection unit 14 at the second timing (detection amplitude) is smaller than the amplitude of the vibration signal detected by the detection unit 14 at the first timing (initial amplitude). That is, the more the time-dependent degradation of the piezoelectric element 23 progresses, the smaller the amplitude of the vibration signal detected by the detection unit 14 becomes.

[0052] In addition, when the pressure applied by the piezoelectric element 23 to the liquid chamber 22 decreases due to the aging degradation of the piezoelectric element 23, the ejection state of the ink droplets 4 ejected from the ejection hole 21 may also change accordingly. Specifically, when the aging degradation of the piezoelectric element 23 progresses, the ejection speed and ejection volume of the ink droplets 4 ejected from the ejection hole 21 may decrease accordingly. That is, the amplitude (evaluation value) of the vibration signal detected by the detection unit 14 is related to the ejection state of the ink droplets 4. Therefore, the ejection state of the ink droplets 4 ejected from the ejection hole 21 can be inferred based on the amplitude of the vibration signal detected by the detection unit 14. Below, the ejection speed of the ink droplets 4 is used as an example to explain the ejection state of the ink droplets 4.

[0053] Figure 6 (a) shows the ejection speed of the ink droplets 4 measured by the droplet measurement unit 15 at a predetermined interval in a predetermined period in one of the plurality of ejection units 20, that is, the temporal change in the ejection speed of the ink droplets 4 measured by the droplet measurement unit 15. In addition, Figure 6 (b) shows the amplitude of the vibration signal detected by the detection unit 14 at a predetermined interval in a certain predetermined period in the one discharge unit 20, that is, the temporal change in the amplitude of the vibration signal detected by the detection unit 14. In addition, Figure 6 (c) is a graph showing the ejection speed of the ink droplet 4 measured by the droplet measurement unit 15 in the one ejection unit 20 as the vertical axis and the amplitude of the vibration signal detected by the detection unit 14 as the horizontal axis. Figure 6As shown in (c), it can be seen that the amplitude of the vibration signal is correlated with the ejection speed of the ink droplet 4.

[0054] It takes a considerable amount of time to measure the discharge state (e.g., discharge speed) using the droplet measurement unit 15. Therefore, when the droplet measurement unit 15 successively measures the discharge state that changes due to the time-dependent degradation of the piezoelectric element 23, it may be disadvantageous in terms of the throughput of the liquid discharge device 1. Figure 6 The information showing the correlation between the amplitude of the vibration signal and the ejection speed of the ink droplet 4 shown in (c) can be used to estimate the ejection state of the ink droplet 4 based on the detection result of the detection unit 14. By estimating the ejection state of the ink droplet 4 in this way, the drive signal provided to the piezoelectric element 23 can be corrected in a manner such that the ejection state of the ink droplet 4 becomes a desired state based on the estimation result.

[0055] However, conventionally, information indicating the correlation between the amplitude of the vibration signal and the ejection speed of the ink droplets 4 is independently generated for each of the plurality of ejection units 20. However, in order to independently generate this information for one ejection unit 20, it is necessary to obtain a set of the amplitude of the vibration signal and the ejection state of the ink droplets 4 at least twice at a time interval when the piezoelectric element 23 of the one ejection unit 20 degrades to a certain extent over time. In this case, the drive signal cannot be corrected before the piezoelectric element 23 of the one ejection unit 20 degrades to a certain extent over time and the information can be generated, making it difficult to control the plurality of ejection units 20 with high precision.

[0056] As a result of intensive research, the inventor of the present application found that, in a plurality of ejection sections 20, the vibration signals (amplitudes) detected by the detection section 14 are different from each other, and the ejection states of the ink droplets 4 are different from each other according to the difference in the vibration signals. In addition, the inventor also found that the "information indicating the correlation between the vibration signal and the ejection state" generated based on the difference between the plurality of ejection sections related to the group of the vibration signal and the ejection state indicates the tendency of the change of the ejection state due to time degradation relative to the change of the vibration signal for each ejection section 20. This means that if the group of the vibration signal and the ejection state is initially obtained in each of the plurality of ejection sections 20, the "information indicating the correlation between the vibration signal and the ejection state" can be generated even without waiting for the time degradation of the piezoelectric element 23 of each ejection section 20. Moreover, by using the "information indicating the correlation between the vibration signal and the ejection state" generated in this way in common in the plurality of ejection sections 20, the ejection state of the ink droplets 4 can be inferred for each ejection section 20 based on the detection result of the detection section 14. In addition, hereinafter, “information indicating the correlation between the vibration signal and the discharge state” generated based on the difference between the plurality of discharge units related to the combination of the vibration signal and the discharge state may be expressed as “correlated information”.

[0057] Figure 7 (a) shows a "combination of the amplitude of the vibration signal and the ejection speed of the ink droplet 4" obtained in each of the ejection sections A to E selected from the plurality of ejection sections 20. Figure 7 In (a), the amplitude of the vibration signal is set as the horizontal axis, and the ejection speed of the ink droplet 4 is set as the vertical axis. Here, the "group of the amplitude of the vibration signal and the ejection speed of the ink droplet 4" is data representing the group of the amplitude of the vibration signal detected by the detection unit 14 and the ejection speed of the ink droplet 4 measured by the droplet measurement unit 15, and is sometimes expressed as "group data" below. In addition, regarding Figure 7 The group data in (a) is obtained for each of the discharge parts A to E. For example, the group data may be data obtained from the first detection / measurement performed on each discharge part 20 after the discharge head 5 is maintained (after replacement as an example). Alternatively, the group data may be a representative value (e.g., an average value, a median value) of a numerical value obtained in multiple detections / measurements in order to reduce the deviation of the detection / measurement.

[0058] like Figure 7 As shown in (a), in a plurality of ejection parts 20 (ejection parts A to E), the amplitudes of the vibration signals detected by the detection unit 14 are different from each other, and the ejection speeds of the ink droplets 4 are different from each other according to the difference in the amplitude. Therefore, it is possible to generate related information based on the differences between the plurality of ejection parts related to the group data. The related information can be generated as a calculation formula (function) for calculating the ejection speed of the ink droplets 4 based on the amplitude of the vibration signal, or as a table representing the relationship between the amplitude of the vibration signal and the ejection speed of the ink droplets 4. As an example, the related information is shown in Figure 7 As shown by the dotted line in (a), a function can be generated as an approximate line 30 (e.g., an approximate straight line) obtained for a plurality of sets of data obtained in the ejection units A to E. In order to estimate the ejection speed of the ink droplet 4 for each ejection unit 20 based on the detection result of the detection unit 14, the related information generated in this way is commonly used in the plurality of ejection units 20.

[0059] Figure 7 (b) shows the result of drawing the amplitude of the vibration signal detected by the detection unit 14 at a predetermined interval during a certain predetermined period and the ejection speed of the ink droplet 4 measured by the droplet measurement unit 15 for each ejection unit A to E. Figure 7 In (b), the approximate line 30 generated as the related information as described above is shown. Figure 7As shown in (b), it can be seen that in each of the ejection parts A to E, the "changing tendency of the amplitude of the ejection speed relative to the vibration signal" due to time degradation follows the "changing tendency of the amplitude of the ejection speed relative to the vibration signal" in the related information (approximate line 30). This means that it can be assumed that the "changing tendency of the amplitude of the ejection speed relative to the vibration signal" due to time degradation in each ejection part 20 follows the "changing tendency of the amplitude of the ejection speed relative to the vibration signal" in the related information. Therefore, in the present embodiment, under such an assumption, the related information is used in common in a plurality of ejection parts 20, and based on the detection result of the detection unit 14, the ejection speed of the ink droplet 4 that changes due to time degradation is estimated for each ejection part 20. Here, in the above, the ejection speed is explained as an example of the ejection state of the ink droplet 4, but the ejection volume is the same as the ejection speed.

[0060] Figure 8 It is a flowchart showing a control example of the plurality of discharge units 20 in the discharge head 5 . Figure 8 Each step of the flowchart can be executed by the control unit 11. In addition, Figure 8 The flowchart can also be understood as a flowchart representing the control method of the liquid discharge device 1.

[0061] In step S201, the control unit 11 determines whether the related information commonly used in the plurality of discharging units 20 has been generated for the currently used discharging head 5. If the related information has been generated, the process proceeds to step S203, and if the related information has not been generated, the process proceeds to step S202.

[0062] In step S202, the control unit 11 generates relevant information about the ejection head 5 currently in use. Specifically, as described above, the control unit 11 obtains group data of a group representing the amplitude of the vibration signal and the ejection state (ejection speed, ejection volume) of the ink droplet 4 for each ejection unit 20. Then, the control unit 11 uses the multiple group data obtained for the multiple ejection units 20 respectively to generate relevant information based on the differences between the multiple ejection units related to the group data. For example, relevant information can be generated in advance when the work of the liquid ejection device 1 starts or when the work is restarted after maintenance is completed. Here, the amplitude of the vibration signal is obtained based on the detection result of the detection unit 14 when a predetermined inspection signal is provided to the piezoelectric element 23. In addition, the ejection state of the ink droplet 4 can be obtained based on the measurement result of the droplet measurement unit 15, but it can also be obtained by an external device that measures the ejection state of the ink droplet 4.

[0063] In step S203, the control unit 11 determines whether it is the timing (detection timing) to detect the vibration signal using the detection unit 14. This determination can be determined, for example, by the cumulative time of driving the piezoelectric element 23 of each discharge unit 20. Regarding the piezoelectric element 23, as described above, the longer the cumulative time of being driven by providing a predetermined drive signal (for example, applying a voltage), the less the displacement caused by time degradation. Therefore, it is best to repeatedly perform the process of detecting the vibration signal using the detection unit 14 at a predetermined time interval, and then at the timing after the liquid discharge device 1 performs the same action, such as the timing of each scanning action of the substrate mounting table 3. In the case of the present embodiment, the control unit 11 determines that it is the detection timing when the elapsed time from the last detection of the vibration signal using the detection unit 14 is greater than the threshold.

[0064] In step S204, the control unit 11 detects the vibration signal using the detection unit 14. Specifically, the control unit 11 provides a predetermined inspection signal to the piezoelectric element 23 for each discharge unit 20 to activate the piezoelectric element 23, and causes the detection unit 14 to detect a vibration signal representing the vibration in the liquid chamber 22 caused by the inspection signal. Moreover, the control unit 11 stores the vibration signal detected by the detection unit 14 for each discharge unit 20 in the memory. In addition, at this time, the control unit 11 may also obtain the amplitude (e.g., the maximum amplitude) of the waveform of the vibration signal detected by the detection unit 14 for each discharge unit 20, and store the obtained amplitude in the memory.

[0065] In step S205, the control unit 11 determines whether to correct the drive signal provided to the piezoelectric element 23 for ejecting the ink droplets 4 from the ejection hole 21 for each ejection unit 20 based on the amplitude of the vibration signal detected in step S204. For example, the control unit 11 determines whether the difference between the amplitude of the vibration signal detected in step S204 and the amplitude of the vibration signal detected last time is greater than a specified value. In the case where the difference is greater than the specified value, it is determined that the drive signal is corrected and the process proceeds to step S206. On the other hand, in the case where the difference is less than the specified value, it is determined that the drive signal is not corrected and the process returns to step S203. Here, in this step S205, the control unit 11 may also determine whether to correct the drive signal based on a prior setting such as once a day.

[0066] In step S206, the control unit 11 estimates the ejection state (ejection speed, ejection volume) of the ink droplet 4 for each ejection unit 20 based on the amplitude of the vibration signal detected in step S24. Specifically, the control unit 11 estimates the ejection state (ejection speed, ejection volume) calculated based on the amplitude of the vibration signal detected in step S204 based on relevant information as the ejection state of the ink droplet 4 that changes due to the time-dependent degradation of the piezoelectric element 23. Figure 7In the description of (a), the control unit 11 can estimate the discharge speed Vt from the amplitude At of the vibration signal detected by the detection unit 14 based on the relevant information (the function of the approximate line 30). The relevant information (the function of the approximate line 30) is used in common in the plurality of discharge units 20, and such a discharge speed estimation is performed for each discharge unit 20. In addition, the control unit 11 stores the result obtained by estimating the discharge state for each discharge unit 20 in the memory.

[0067] In step S207, the control unit 11 corrects the drive signal provided to the piezoelectric element 23 for each ejection unit 20. Specifically, the control unit 11 corrects the drive signal for each ejection unit 20 in accordance with the estimated result of the ejection state of the ink droplet 4 obtained in step S206, so that the ejection state of the ink droplet 4 ejected from the ejection hole 21 becomes the desired ejection state (target ejection speed, target ejection volume). When correcting the ejection speed of the ink droplet 4, the control unit 11 may correct the ejection timing of the ink droplet 4 in accordance with the difference between the ejection speed of the ink droplet 4 estimated in step S206 and the target ejection speed, so that the ink droplet 4 adheres to the target position on the substrate 2. Correction of the ejection timing of the ink droplet 4 can also be understood as correction of the timing of providing the drive signal (e.g., a pulse signal) to the piezoelectric element 23. In addition, when correcting the ejection volume of the ink droplets 4, the control unit 11 may correct the waveform of the drive signal (for example, the amplitude of the pulse signal) supplied to the piezoelectric element 23 so as to reduce the difference between the ejection volume of the ink droplets 4 estimated in step S206 and the target ejection volume. Alternatively, the control unit 11 may correct (change) the combination of the ejection units 20 used to eject the ink droplets 4 onto the substrate 2 so as to make the total amount of ink ejected onto the substrate 2 the target amount based on the ejection volume of the ink droplets 4 estimated for each ejection unit 20.

[0068] In step S208, the control unit 11 determines whether the liquid discharge device 1 has stopped due to maintenance or the like. The maintenance of the liquid discharge device 1 may also include the replacement of the discharge head 5. If the liquid discharge device 1 has not stopped, the process returns to step S203 and steps S203 to S208 are repeatedly executed. On the other hand, if the liquid discharge device 1 has stopped, the process ends. In this case, when the liquid discharge device 1 is working again, Figure 8 The flowchart may start again from step S201.

[0069] As described above, the liquid discharge device 1 of the present embodiment generates in advance the related information indicating the correlation between the vibration signal and the discharge state of the ink droplet 4 based on the difference between the plurality of discharge units related to the group of the vibration signal (amplitude) and the discharge state of the ink droplet 4. Then, the related information is used in common in the plurality of discharge units 20, and based on the detection result of the detection unit 14, the discharge state of the ink droplet 4 that changes due to the time-dependent degradation of the piezoelectric element 23 is estimated for each discharge unit 20. Thus, compared with the prior art that generates the related information for each discharge unit 20, the time required for generating the related information can be shortened, so the plurality of discharge units 20 can be controlled with high precision using the related information.

[0070] Here, in this embodiment, an example is described in which the control unit 11 of the liquid discharge device 1 generates the related information commonly used in the plurality of discharge units 20, but the related information may be generated by an information processing device provided outside the liquid discharge device 1. That is, the information processing device outside the liquid discharge device 1 may also generate the related information. Figure 8 In this case, the external information processing device generates relevant information by obtaining the "group of vibration signal and ejection state of ink droplet 4" of each ejection unit 20, and the liquid ejection device 1 can obtain the relevant information generated by the information processing device from the external information processing device.

[0071] <Implementation Method of Article Manufacturing Method>

[0072] The article manufacturing method in the embodiment of the present invention is suitable for manufacturing articles such as panels for displays such as organic EL, micro devices such as semiconductor devices, and components with fine structures. The article manufacturing method of this embodiment includes: a discharge step, using the above-mentioned liquid supply device (liquid supply method) to discharge (supply) liquid onto a substrate; a processing step, processing the substrate after the liquid is supplied in the discharge step; and a step of manufacturing an article based on the substrate processed in the processing step. Furthermore, the above-mentioned article manufacturing method includes other well-known steps (firing, cooling, cleaning, oxidation, film formation, evaporation, doping, flattening, etching, resist stripping, cutting, bonding, packaging, etc.). Compared with previous methods, the article manufacturing method of this embodiment is more advantageous in at least one of the performance, quality, productivity, and production cost of the article.

[0073] <Other Implementation Methods>

[0074] The present invention can also be implemented by providing a program that implements one or more functions of the above-mentioned embodiments to a system or device via a network or storage medium, and one or more processors in a computer of the system or device read out and execute the program. In addition, it can also be implemented by a circuit (such as an ASIC) that implements one or more functions.

[0075] Other embodiments

[0076] The embodiments of the present invention may also be implemented by providing software (program) for executing the functions of the above embodiments to a system or device through a network or various storage media, and a computer or a central processing unit (CPU) or a microprocessing unit (MPU) of the system or device reads and executes the program.

[0077] The invention is not limited to the above-described embodiments, and various changes and modifications can be made without departing from the spirit and scope of the invention. Therefore, claims are attached to disclose the scope of the invention.

Claims

1. A liquid dispensing device, characterized in that: have: A plurality of discharge parts each having a liquid chamber including a discharge hole, and a piezoelectric element for applying pressure to the liquid chamber to discharge liquid droplets from the discharge hole; a detection unit that detects, for each of the plurality of discharge units, a signal indicating vibration in the liquid chamber caused by operating the piezoelectric element; as well as a control unit that controls each of the plurality of discharge units, In the plurality of discharge units, the signals detected by the detection unit are different from each other, and discharge states of droplets discharged from the discharge holes are different from each other according to the difference in the signals. The control unit generating in advance related information indicating a correlation between the signal and the discharge state based on a difference between the plurality of discharge units related to a set of the signal and the discharge state, The related information is commonly used in the plurality of discharge units, and the discharge state that changes due to time-dependent degradation is estimated for each discharge unit based on the detection result of the detection unit. Each of the plurality of discharge units is controlled based on the estimation result of the discharge state.

2. The liquid discharge device according to claim 1, characterized in that: The control unit estimates, for each discharge unit, the discharge state converted from the signal detected by the detection unit according to the related information as the discharge state that changes due to time-dependent degradation.

3. The liquid discharge device according to claim 2, characterized in that: The control unit estimates the discharge state that changes due to time-dependent degradation for each discharge unit by assuming that the discharge state of each discharge unit changes due to time-dependent degradation according to the change tendency of the discharge state with respect to the signal in the related information.

4. The liquid discharge device according to claim 1, characterized in that: The control unit generates the related information based on at least one of the groups acquired for each discharge unit.

5. The liquid discharge device according to claim 1, characterized in that: The detection unit detects the signal when the piezoelectric element is operated so as to discharge droplets from the discharge hole for each of the plurality of discharge units.

6. The liquid discharge device according to claim 1, characterized in that: The detection unit detects the signal when the piezoelectric element is operated so as not to discharge droplets from the discharge hole for each of the plurality of discharge units.

7. The liquid discharge device according to claim 1, characterized in that: further comprising a measuring unit for measuring the discharge state of each of the plurality of discharge units, The control unit generates the related information by acquiring, for each discharge unit, a combination of the signal detected by the detection unit and the discharge state measured by the measurement unit.

8. The liquid discharge device according to claim 1, characterized in that: The control unit generates the related information by acquiring, for each discharge unit, a combination of the signal detected by the detection unit and the discharge state measured by an external device.

9. The liquid discharge device according to claim 1, characterized in that: The discharge state includes at least one of a speed and a volume of a droplet discharged from the discharge hole.

10. The liquid discharge device according to claim 1, characterized in that: The plurality of discharge portions are configured as one structure.

11. A method for manufacturing an article, characterized in that: include: a discharging step of discharging the liquid onto the substrate using the liquid discharging device according to any one of claims 1 to 10; a processing step of processing the substrate after the liquid is ejected in the ejecting step; as well as A manufacturing step is to manufacture an article based on the substrate processed in the processing step.

12. A control method for a liquid discharge device, the liquid discharge device comprising a plurality of discharge parts, each of the plurality of discharge parts having a liquid chamber including a discharge hole, and a piezoelectric element for applying pressure to the liquid chamber to discharge liquid droplets from the discharge hole, characterized in that: In the plurality of discharge units, signals indicating vibrations in the liquid chamber caused by operating the piezoelectric element are different from each other, and discharge states of liquid droplets discharged from the discharge holes are different from each other according to the difference in the signals. The control method comprises: an acquisition step of acquiring a combination of the signal and the discharge state for each discharge unit; a generating step of generating, using the group acquired for each discharge unit in the acquiring step, related information indicating a correlation between the signal and the discharge state based on a difference between the plurality of discharge units associated with the group; an estimating step of using the relevant information in common among the plurality of ejection units to estimate the ejection state that changes due to time-dependent degradation for each ejection unit based on a detection result of the signal; and The control step controls the plurality of discharge units based on the estimation result in the estimation step.

13. An information processing device for generating information used in a liquid discharge device, the liquid discharge device comprising a plurality of discharge parts, each of the plurality of discharge parts having a liquid chamber including a discharge hole, and a piezoelectric element for applying pressure to the liquid chamber to discharge liquid droplets from the discharge hole, characterized in that: In the plurality of discharge units, signals indicating vibrations in the liquid chamber caused by operating the piezoelectric element are different from each other, and discharge states of liquid droplets discharged from the discharge holes are different from each other according to the difference in the signals. The information processing device acquiring a combination of the signal and the discharge state for each discharge unit, generating, using the group obtained for each discharge unit, related information indicating a correlation between the signal and the discharge state based on a difference between the plurality of discharge units related to the group, The related information is information commonly used in the plurality of discharge units in order to estimate the discharge state that has changed due to time-dependent degradation for each discharge unit based on a detection result of the signal.

14. A method for generating information used in a liquid discharge device using an information processing device, wherein the liquid discharge device comprises a plurality of discharge parts, each of which comprises a liquid chamber including a discharge hole, and a piezoelectric element for applying pressure to the liquid chamber to discharge liquid droplets from the discharge hole, characterized in that: In the plurality of discharge units, signals indicating vibrations in the liquid chamber caused by operating the piezoelectric element are different from each other, and discharge states of liquid droplets discharged from the discharge holes are different from each other according to the difference in the signals. The generation method comprises: an acquisition step of acquiring a combination of the signal and the discharge state for each discharge unit; and a generating step of generating, using the group acquired for each ejection unit in the acquiring step, related information indicating a correlation between the signal and the ejection state based on a difference between the plurality of ejection units associated with the group, The related information is information commonly used in the plurality of discharge units in order to estimate the discharge state that has changed due to time-dependent degradation for each discharge unit based on a detection result of the signal.

15. A storage medium storing a program for causing a computer to execute the generation method according to claim 14.

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