JP5317109B2 - Ink ejection device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ink ejection apparatus combining the high speed and high precise operation of a movable stage loading an inkjet head part thereon with the maintenance of the ink jet head part directly before the ejection. <P>SOLUTION: The ink ejection apparatus is an ink jet application apparatus ejecting ink to a glass substrate 200 placed on a placing table 100 and is provided with the inkjet head part 1 for ejecting the ink to the glass substrate 200, a maintenance unit 2 carrying out the maintenance of the inkjet head part 1 and a preparatory maintenance unit 3. The maintenance unit 2 is movable while keeping the relative position with respect to the inkjet head part 1. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to, for example, a color filter-formed display element component manufacturing apparatus and a display element component correcting apparatus used in a color display panel such as a liquid crystal panel, a plasma panel, a micromirror panel, a cathode ray tube display, and a projection television, and a liquid crystal panel. The present invention relates to an ink ejection device included in a driving circuit unit manufacturing apparatus and a driving circuit unit correcting apparatus such as a plasma panel, a micromirror panel, and a projection television, and a display element component manufacturing apparatus for a light emitting layer of a display using EL material.

  For example, a color filter as a display element component used in a color display panel such as a liquid crystal panel or a plasma panel is formed by R (red), G (green), B (blue), and BM (black) patterns, and is printed. R (red), G (green), B (blue), and BM (black) patterns can be formed by a method, an electrodeposition method, a pigment dispersion method by photolithography, or an ink jet method.

  The printing method is inferior to other methods in terms of pattern accuracy, and is rarely used in the current display element formation process.

  In the electrodeposition method, conductivity is indispensable for the colored ink, and since the color purity of the conductive ink is low, vivid color display is difficult to achieve, so the commercial value is low.

  The pigment dispersion method by photolithography is currently most widely used. However, since at least three photolithography steps are required to form the R (red), G (green), B (blue), and BM (black) patterns, there is a problem that the manufacturing cost increases.

  Therefore, in recent years, an inkjet method has attracted attention as a method capable of improving pattern accuracy, improving color purity, and reducing manufacturing costs. However, in this ink jet method, there is a problem that when ink is ejected with high accuracy, it mixes with adjacent pixels, degrading the display quality, and the direction in which the ink is ejected from the ink jet head section is shifted or not ejected. is there.

  In addition, it is difficult to manufacture a good product with a probability of 100% using any of the above-described methods, such as defects due to foreign matter, R (red) G (green) B (blue), and BM (black) patterns. Defects may occur.

  In addition, in a circuit driving unit such as a liquid crystal panel, it is necessary to form an electric circuit composed of a multilayer film by photolithography, and in a driving circuit unit of a TFT liquid crystal, four to six photolithography steps are required. Therefore, there exists a subject that manufacturing cost will become high.

  Therefore, in recent years, an inkjet method has attracted attention as a method capable of reducing manufacturing costs. However, even when the inkjet method is used in the manufacturing process of the circuit driving unit, there is a problem that the direction in which the ink is ejected from the inkjet head unit is shifted or is not ejected. When the circuit drive unit is formed by ink jet, the allowable amount of ink landing deviation is often smaller than that of the color filter.

  As described above, in the inkjet head unit, it is necessary to prevent non-ejection and landing disturbance.

  Japanese Patent Laying-Open No. 2006-113127 (Patent Document 1) discloses an ink jet apparatus in which a maintenance mechanism portion is arranged in the immediate vicinity of an ink jet head portion mounted on a movable stage.

  Japanese Patent Application Laid-Open No. 8-118674 (Patent Document 2) describes an ink jet apparatus in which preliminary ejection portions are provided on both sides of a scanning region of an ink jet head portion.

  In Japanese Patent Application Laid-Open No. 2001-199061 (Patent Document 3) and Japanese Patent Application Laid-Open No. 2005-88307 (Patent Document 4), the ink discharge state of the nozzles of the ink jet head unit is inspected to detect undischarge nozzles. Ink jet recording is performed by changing the ink ejection timing of the ejectable nozzles, the scanning pitch of the ink jet head, and the number of scans so that the recording pattern can be formed with the ejectable nozzles without using the non-ejection nozzles. An ink jet device is described.

  In Japanese Patent Application Laid-Open No. 2001-315318 (Patent Document 5), a non-ejection nozzle is detected, and another nozzle in the vicinity of the location where the non-ejection nozzle on the surface of the recording material such as paper should be recorded. There has been described an apparatus for performing ink jet recording in which an ink increased in amount at a location than a predetermined amount is complemented by ejecting ink from a nozzle adjacent to the defective nozzle so that the location where the defective nozzle should eject ink is inconspicuous.

JP 2006-113127 A JP-A-8-118674 JP 2001-199061 A JP 2005-88307 A JP 2001-315318 A

  In recent years, liquid crystal panels and plasma panels have become larger, and a mother glass used for production sometimes has a size exceeding 3 m. In addition, high-quality display is progressing at a high speed, and the practical application of broadcasting technology for transmitting video with a density four times that of current high-definition is beginning to be considered. In addition, high performance is also required for moving image performance and ease of viewing. Thus, in the field of displays, the increase in size, definition, and image quality of substrates is rapidly progressing.

  With the increase in display definition and image quality, the raw materials used in displays are also changing. Therefore, in recent years, opportunities for changes in physical properties of materials and significant changes in types have increased. Changes in raw materials are also frequently occurring in ink jet ink, and the ink viscosity increases due to drying of the ink solvent component in the ink discharge holes (nozzles) of the ink jet head, and the ink meniscus (gas-liquid interface) in the nozzle portion. Dissolved air was degassed depending on the ink that was difficult to be stably ejected by the inkjet head and the ink components due to changes in the dispersion state of the ink components due to changes in the orientation of the solvent and solute, and changes in the ink physical properties due to chemical reactions. Even when the ink jet drive is performed or when the ink passes through the filter in the ink flow path, the minute air bubbles remaining in the ink jet head easily expand and float by cavitation, and once the air bubbles are generated. Then you have to use ink that takes time to dissolve bubbles in deaerated ink. Become not opportunity also tends to increase.

  As a result of using ink that is difficult to stably discharge, the cause of ink non-ejection increases. Therefore, a maintenance unit having a nozzle surface wiping mechanism and a nozzle surface capping mechanism is usually sufficient for an inkjet head. In addition to the places where maintenance can be performed, with an ink that is difficult to clean the nozzle surface simply by wiping the nozzle surface with the wiping mechanism, an ultrasonic cleaning mechanism that has a function to circulate the cleaning liquid for cleaning the nozzle surface, or a wiping mechanism A wiping blade wiping mechanism for preventing the ink adhering to the wiping blade from being solidified, a wiping blade cleaning mechanism is required, or a wiping blade for effective cleaning of the nozzle surface to which the solidified ink adheres Wash the ink solvent etc. It is necessary to provide a cleaning liquid supply and waste liquid mechanism for use in a wet state, or a large suction pump for discharging bubbles or the like firmly attached inside the inkjet head from the nozzle hole, Ink that requires a capping mechanism, the ink jet head maintenance unit is complicated and large in size, and has a very fast drying solvent component, or the solute component dispersion state changes easily at the gas-liquid interface at the nozzle meniscus, etc. However, even if the decap state of the nozzle surface of the inkjet head is a relatively short time of a few tens of seconds to a few tens of seconds, the ink physical property change at the nozzle meniscus may be significant, and stable ejection may be difficult. It is necessary to perform maintenance such as discarding as soon as possible before application, The maintenance period of the jet head is shortened, the maintenance unit is used for a long time, and even if the solute does not change in quality (chemical change or aggregation) in the solvent dispersion state, the solvent evaporates at the nozzle meniscus. Due to the change in the dispersion state of the solute, the solute may be difficult to re-dissolve in the ink or the ink solvent, and the nozzle may be blocked by the solute alteration and the inkjet head may be damaged. Therefore, it is impossible to decap for a long period of time, or in order to make all the nozzles of the inkjet head discharge normally, a great amount of maintenance time and ink consumed for maintenance increase. Ink jet nozzles that use normal nozzles with some nozzles not discharging There is a tendency to increase the number of cases in which a process is performed. In addition, the load on the maintenance unit increases, and maintenance by the operator of the maintenance unit itself is required. However, when maintenance is performed by an operator, if the inkjet head unit is left in a decap state for a long time, a phenomenon that ink cannot be ejected occurs.

  Incidentally, one cause of the complexity and increase in size of the maintenance unit is that it is necessary to mount a waste liquid tank on the maintenance unit. Maintenance by workers is required for replacement of the waste liquid tank.

  On the other hand, a large and highly accurate stage is necessary to cope with an increase in size and definition of a substrate such as a display, and in order to reduce tact time, it is necessary to increase the speed of the stage. Therefore, the weight load to be mounted on the movable stage on which the ink jet head unit is mounted must be reduced. In order to reduce the stage as much as possible, the mounted object needs to be as small as possible. Most ideally, it is preferable that only the inkjet head unit is mounted on the movable stage.

  In addition, even if the size of the inkjet device increases with the increase in size of the substrate, basic requirements such as stable operation and tact reduction are not relaxed, and ink that is not suitable for long-term stable use is used. Even so, the ink jet apparatus is required to operate with high precision and stably discharge.

  Even in the case of pattern correction in which the drawing area is relatively small, an increase in the moving distance of the movable stage is inevitable as the substrate becomes larger. Furthermore, as the number of places that need to be corrected increases, drawing tends to take a long time. As a result, the time from the maintenance of the ink jet head unit to the drawing becomes long, and a non-ejection state may occur or the landing may be disturbed.

  Further, even when correcting the pattern of a substrate such as a display, it is still necessary to increase the size, increase the definition, and improve the image quality. Further, when maintenance of the maintenance unit by the operator is performed, if the ink jet head portion is left in a decap state for a long time, there is no change in the phenomenon that ink cannot be ejected.

  Increasing the size of the substrate increases the possibility of trouble causing defects. Therefore, the importance of preventing defects at the time of manufacturing and remedy by correction after the occurrence of defects is increasing.

  When a structure in which a maintenance unit is arranged in the immediate vicinity of the inkjet head unit as in Patent Document 1, maintenance of the inkjet head unit can be performed immediately before ink discharge, but the inkjet head maintenance unit is maintained by an operator. In doing so, it is inevitable that the inkjet head part is left in a decap state for a long time. In addition, when the maintenance unit becomes larger and more complicated, it is piped with an inkjet head and ink supply unit, which are normally required, and a large-capacity waste liquid tank and a suction unit for discharging ink and bubbles from the nozzles. In addition, a large maintenance unit having a suction pump, a drive source for the suction section, a solenoid valve, a power source and a control circuit, a drive section such as a wiping blade, and a mechanism section for cleaning the wiping blade is installed. A unit having a weight (600 kg or more depending on the number of inkjet heads mounted) is mounted on the movable stage, and there is a problem that the apparatus cannot be operated with high accuracy.

  On the other hand, if the structure which arrange | positions the maintenance unit of an inkjet head part in 2 places like patent document 2 is adopted, when an inkjet head maintenance unit is maintained by an operator, an inkjet head part will be taken for a long time. You can avoid being left in the state of crossing decaps. Also, even when the maintenance unit becomes larger and more complicated, the maintenance unit is not mounted on the movable stage, so only the inkjet head unit and ink supply unit need be mounted on the movable stage, reducing the load on the operating stage. This makes it easy to operate the device with high accuracy. However, it is impossible to maintain the ink jet head immediately before ejection, and in an ink jet apparatus for a large substrate, the moving distance of the head after maintenance may be as long as 5 m. In the case of a moving speed of 250 mm / s, the ink is ejected after a decap state of 50 to 20 seconds or more, and the ink is thickened with a fast drying ink or the like, and a defect such as non-ejection with a normal inkjet head ejection voltage. There was a problem that was likely to occur.

  In addition, special inks that are very difficult to stably discharge in industrial applications may be used. However, as in Patent Document 3 and Patent Document 4, ink discharge from some nozzles of the inkjet head unit is abandoned. Inspect the ink ejection status, detect non-ejection nozzles, and change the ink ejection timing of normal nozzles, the scanning pitch of the inkjet head, and the number of scans without using non-ejection nozzles, and form an appropriate recording pattern Ink jet heads can be manufactured without excessively shortening the life of the ink jet heads and reducing ink consumption due to maintenance, even if the ink is very difficult to stably discharge. The running cost for the ink can be reduced. However, the nozzles that appear to be normal adjacent to the non-ejection nozzles of the inkjet head have not been properly ejected properly, and the ejection is dependent on the structure of the inkjet head and the cause of non-ejection of the non-ejection nozzles. In the case where a change in ink jet performance of about 1 to 5% per ink drop and about 3 to 8% of the ejection speed of ejected ink occurs, or when non-ejection nozzles are inspected by continuously ejecting ink from nozzles Adjacent nozzles that are completely non-ejecting can perform relatively stable continuous ejection, but this is because the temperature of the inkjet head rises due to the driving of the inkjet head and the ink agitation of the ink meniscus due to the oscillation of the nozzle meniscus Easily eject ink as viscosity decreases (recovers to normal ink viscosity) after drying and thickening the ink. It is considered that stable ejection is achieved through a non-ejection state until it reaches a state (while driving from the first droplet to several tens of droplets), and industrial applications (especially the ability to apply ink from the first droplet to the first droplet by inkjet) In the process of correcting the functional film), it may be determined that the nozzle is a defective nozzle, and there is no problem if it is a recording pattern for documents for consumer use. In industrial applications aimed at the process of correcting functional films that require stable ejection, fluctuations in the ink landing position (formation of an ink coating film) due to variations in the film thickness of the recording pattern, ink wetting spread size and ejection speed There has been a problem that the film function deteriorates and fluctuates due to the change in position) and the production yield decreases.

  Further, in Patent Document 5, non-ejection nozzles are detected, and ink that is increased by a predetermined amount to an ink ejection portion adjacent to a portion where the non-ejection nozzles are to be recorded is ejected from nozzles adjacent to the defective nozzles. Ink jet recording methods have been proposed in which defective nozzles are not conspicuous where ink should be ejected. However, as in Patent Document 3 and Patent Document 4, an effective recording method for recording documents and the like for consumer use. However, the variation in the ink ejection position and the variation in the ink ejection amount also caused the performance deterioration of the functional inkjet coating film, and there was a problem that the production yield of a substrate such as a display manufactured or corrected by inkjet recording was lowered. .

  The present invention has been made in view of the above problems, and an object of the present invention is to perform a high-speed and high-precision operation of a movable stage on which an inkjet head unit is mounted, and maintenance of the inkjet head unit immediately before ejection. An ink discharge apparatus capable of preventing an increase in ink consumption due to excessive maintenance, an increase in tact time, and a decrease in the life of an inkjet head even when ink that is extremely difficult to stably discharge is used. There is.

  An ink ejection apparatus according to the present invention is an ink ejection apparatus that ejects ink onto an object to be ejected placed on a mounting table, and is provided so as to be movable relative to the object to be ejected. An inkjet head unit that ejects ink to the ejected matter, and a first maintenance unit and a second maintenance unit that can perform maintenance of the inkjet head unit, and at least one of the first maintenance unit and the second maintenance unit includes: It can move while maintaining the relative positional relationship with the inkjet head unit.

In one aspect , the ink discharge device is attached to a first movable portion that is movable in a first direction with respect to an object to be discharged, the first movable portion, and the first direction with respect to the first movable portion. And a second movable portion movable in a second direction intersecting with the inkjet head portion, the inkjet head portion being attached to the second movable portion, and the first maintenance portion maintaining a relative positional relationship with the inkjet head portion The second maintenance part is provided within a movable range of the second movable part. Here, the second maintenance unit preferably has a function different from that of the first maintenance unit. Further preferably, the first maintenance unit has at least one of a discharge inspection function, a liquid sag detection function, a discarded discharge function, a liquid level swing function, and a cap function, and the second maintenance part has a discharge failure. And at least one of a function of removing dirt on the nozzle surface.

  In the ink ejection apparatus, preferably, the first maintenance unit is movable while maintaining a relative positional relationship with the inkjet head unit, and the second maintenance unit is provided outside the mounting table. Further, preferably, the second maintenance part is provided movably outside the mounting table.

In another aspect , the ink discharge device is movable in a second direction that intersects the first direction with respect to the discharge target and a first movable portion that can move the discharge target in the first direction. A second movable part, the inkjet head part is attached to the second movable part, the first maintenance part is movable while maintaining a relative positional relationship with the inkjet head part, and the second maintenance part is The second movable part is provided within the movable range. Here, the second maintenance unit preferably has a function different from that of the first maintenance unit. Further preferably, the first maintenance unit has at least one of a discharge inspection function, a liquid sag detection function, a discarded discharge function, a liquid level swing function, and a cap function, and the second maintenance part has a discharge failure. And at least one of a function of removing dirt on the nozzle surface.

  Preferably, the ink ejection device further includes a control unit capable of controlling operations of the first maintenance unit and the second maintenance unit, the first maintenance unit detecting a defect of the inkjet head unit, and a defect. A recovery unit that recovers and a determination unit that determines whether the failure can be recovered by the recovery unit, and the control unit determines that the occurrence of the failure is detected by the detection unit and that the failure cannot be recovered by the recovery unit The first maintenance unit and the second maintenance unit are controlled so that the maintenance by the second maintenance unit is performed based on the determination made by the above.

  Preferably, the ink ejection device further includes a control unit capable of controlling operations of the first maintenance unit and the second maintenance unit, the first maintenance unit detecting a defect of the inkjet head unit, and a defect. And a recovery unit that recovers, based on the fact that after the occurrence of a failure is detected by the detection unit, the recovery operation is repeated a predetermined number of times by the first maintenance unit and then the detection unit detects the failure. The first maintenance unit and the second maintenance unit are controlled to perform maintenance by the second maintenance unit.

  Preferably, the ink ejection device further includes a control unit capable of controlling operations of the first maintenance unit and the second maintenance unit, and the control unit measures a time after the maintenance by the second maintenance unit is completed. The control unit includes a timer unit, and when the timer unit detects that a predetermined time has elapsed since the maintenance by the second maintenance unit has been completed, the control unit performs the maintenance by the second maintenance unit again. The first maintenance unit and the second maintenance unit are controlled.

  Preferably, the ink ejection device further includes a control unit capable of controlling operations of the first maintenance unit and the second maintenance unit, the first maintenance unit including a first cap unit that caps the inkjet head unit, The second maintenance unit includes a second cap unit that caps the inkjet head unit, and the control unit measures a time from when the cap of the inkjet head unit by the first cap unit or the second cap unit is released. And a second timer unit that measures a time during which the cap of the inkjet head unit by the first cap unit is continued, and the control unit is configured to cap the first cap unit and the second cap unit by the first timer unit. The first cap is detected based on the detection that a predetermined time has elapsed since the release of The first maintenance unit and the second maintenance unit are configured to perform the capping by the second cap unit based on the fact that the second timer unit detects that the cap by the first cap unit has continued for a predetermined time or longer. Control the maintenance unit.

In another aspect , the ink ejection apparatus further includes a control unit capable of controlling operations of the first maintenance unit and the second maintenance unit, and the control unit selects a usable nozzle of the inkjet head unit. The first maintenance unit includes a determination unit, a detection unit that detects a defect of the inkjet head unit, a recovery unit that recovers the defect, and a determination unit that determines whether the defect can be recovered by the recovery unit, The first maintenance unit and the second maintenance unit perform maintenance by the second maintenance unit based on the fact that the detection unit detects the occurrence of the failure and the determination unit determines that the failure cannot be recovered by the recovery unit. The maintenance unit is controlled, and after the maintenance by the second maintenance unit, the detection unit of the first maintenance unit And the determination nozzle determines that the defect cannot be recovered by the maintenance by the first maintenance unit and the second maintenance unit. The first maintenance unit and the second maintenance unit are controlled so as to select a usable nozzle other than that and perform ink ejection.

  In the ink ejection apparatus, preferably, the selection of usable nozzles by the used nozzle determining unit is determined to be unrecoverable by the maintenance by the first maintenance unit and the second maintenance unit by the detection unit and the determination unit of the first maintenance unit. And selecting a nozzle to be used from normal nozzles in a discharge state, excluding at least two nozzles on both sides up to at least the first nozzle in one side of the defective nozzle in the nozzle row parallel to the defective nozzle and the defective nozzle Including.

In yet another aspect , the ink ejection device further includes a drive unit that moves the inkjet head unit in a direction orthogonal to the main surface direction of the ejection target, and performs maintenance of the inkjet head unit by the first maintenance unit. The height of the inkjet head unit with respect to the discharged object is different between when the maintenance is performed on the inkjet head unit with the second maintenance unit.

  According to the present invention, in the ink ejection apparatus, it is possible to achieve both high-speed and high-precision operation of the movable stage on which the inkjet head unit is mounted and maintenance of the inkjet head unit immediately before ejection, and very stable ejection. Even when difficult ink is used, it is possible to prevent an increase in consumed ink, an increase in tact time, and a decrease in the life of the inkjet head due to excessive maintenance.

It is the figure which showed the inkjet coating apparatus which concerns on Embodiment 1 of this invention, (a) is a top view, (b) is a side view. It is the figure which showed the inkjet coating apparatus which concerns on Embodiment 2 of this invention, (a) is a top view, (b) is a side view. It is the figure which showed the inkjet coating apparatus which concerns on Embodiment 3 of this invention, (a) is a top view, (b) is a side view. It is the figure which showed the inkjet coating apparatus which concerns on Embodiment 4 of this invention, (a) is a top view, (b) is a side view. It is the figure which showed the inkjet coating apparatus which concerns on Embodiment 5 of this invention, (a) is a top view, (b) is a side view. It is the figure which showed the inkjet coating apparatus which concerns on Embodiment 6 of this invention, (a) is a top view, (b) is a side view. It is the figure which showed the inkjet coating apparatus which concerns on Embodiment 7 of this invention, (a) is a top view, (b) is a side view. It is the figure which showed the inkjet coating apparatus which concerns on Embodiment 8 of this invention, (a) is a top view, (b) is a side view. It is the figure which showed the inkjet coating apparatus which concerns on Embodiment 9 of this invention, (a) is a top view, (b) is a side view. It is the figure which showed the inkjet coating apparatus which concerns on Embodiment 10 of this invention, (a) is a top view, (b) is a side view. It is the figure which showed the inkjet coating apparatus which concerns on Embodiment 11 of this invention, (a) is a top view, (b) is a side view. It is the figure which showed the inkjet coating apparatus which concerns on Embodiment 12 of this invention, (a) is a top view, (b) is a side view. It is a figure for demonstrating a "discharge inspection function." It is a figure for demonstrating "liquid dripping". It is a figure for demonstrating a "liquid level rocking | fluctuation function." It is the figure which showed an example of the nozzle cleaning method in a preliminary maintenance unit. It is the block diagram which showed an example of the structure of the inkjet coating apparatus which concerns on Embodiment 1-12 of this invention. It is a flowchart (the 1) which shows an example of the control method by the main control part in FIG. It is a flowchart (the 2) which shows an example of the control method by the main control part in FIG. It is a flowchart which shows the modification of the control method by the main control part in FIG. It is the block diagram which showed the modification of the structure of the inkjet coating apparatus which concerns on Embodiment 1-12 of this invention. It is a flowchart (the 1) which shows an example of the control method by the main control part in FIG. FIG. 22 is a flowchart (No. 2) illustrating an example of a control method by the main control unit in FIG. 21. It is a flowchart which shows an example of the control method by the main control part in FIG.

  Embodiments of the present invention will be described below. Note that the same or corresponding portions are denoted by the same reference numerals, and the description thereof may not be repeated.

  Note that in the embodiments described below, when referring to the number, amount, and the like, the scope of the present invention is not necessarily limited to the number, amount, and the like unless otherwise specified. In the following embodiments, each component is not necessarily essential for the present invention unless otherwise specified. In addition, when there are a plurality of embodiments below, it is planned from the beginning to appropriately combine the configurations of the embodiments unless otherwise specified.

(Embodiment 1)
FIG. 1 is a view showing an inkjet coating apparatus as an “ink ejection apparatus” according to Embodiment 1 of the present invention. In FIG. 1 and FIGS. 2 to 12 described later, (a) is a top view and (b) is a side view.

  Referring to FIG. 1, the inkjet coating apparatus according to the present embodiment is an apparatus that applies ink to a glass substrate 200 mounted on a mounting table 100, and includes an inkjet head unit 1, a maintenance unit 2, It includes a preliminary maintenance unit 3, a gantry 10, a maintenance unit driving unit 20, and a preliminary maintenance unit driving unit 30. In this embodiment, an inkjet coating apparatus as an example of an “ink ejection apparatus” will be described. However, the scope of the present invention is not limited to the inkjet coating apparatus, and is applicable to all apparatuses having a mechanism for ejecting ink. Is possible. In the present specification, “maintenance” means all mechanisms for maintaining and managing the ink ejection mechanism part normally, and is not limited to the act of directly cleaning the ink ejection mechanism part manually.

  The inkjet head unit 1 ejects ink toward the glass substrate 200. The inkjet head unit 1 is mounted on a gantry 10 and moves in the Y direction by the gantry 10. The maintenance unit 2 is mounted on the maintenance unit driving unit 20 and is moved in the Y direction by the maintenance unit driving unit 20. The maintenance unit 2 is movable while maintaining the relative positional relationship with the inkjet head unit 1. Therefore, the maintenance unit 2 can continuously perform maintenance such as capping the nozzle surface of the inkjet head of the inkjet head unit 1 that is moving and intermittent or continuous ink discharge, and as necessary. It is also possible to perform an ink discharge inspection immediately before the ink jet process. The spare maintenance unit 3 is mounted on the spare maintenance unit drive unit 30 and is moved in the Y direction by the spare maintenance unit drive unit 30.

  The glass substrate 200 may be a transparent glass on which a pattern is formed in advance or a transparent glass on which a pattern is not formed. Here, as an example of the application of the ink jet coating apparatus according to the present embodiment, red, green, and blue are formed on a 3 m square glass substrate in order to form a color filter for a 40-inch super full high-definition (3940 × 2160) television. A case of discharging blue ink will be described.

  First, conventional problems to be solved by the ink jet coating apparatus according to the present embodiment will be described.

  When manufacturing color filters by the inkjet method, after forming a black matrix pattern in advance, a method of obtaining a color filter by discharging red, green and blue inks in a lump along the black matrix pattern and drying them Can be considered. In the case of a 40-inch screen, it is necessary to arrange 3940 × 2160 = 8,510,400 pixels of 76 μm × 230 μm for each color. Since the black matrix pattern usually has a width of about 30 μm, the red, green, and blue patterns each have a rectangular area of 46 μm × 200 μm. It is necessary to eject ink accurately in this rectangular area.

  The ink ejected from the inkjet head unit 1 is often required to have high color reproducibility when the panel is used in a television, and needs a darker color than a PC monitor or the like. For this reason, an ink for ink jet is required to have a high pigment concentration relative to the resin component in the solvent, and the ink viscosity becomes high. Therefore, it is necessary to take measures for stable ink ejection. By increasing the concentration of the ink, the equilibrium of the dispersion state of the pigments is easily lost, and drying of the ink solvent facilitates the aggregation of the pigment and the reaction of the resin component contained separately from the pigment, resulting in a remarkable ink viscosity. Since the ink changes easily, it becomes difficult to discharge by decapping the nozzle. Further, since the pigment is easily fixed in the nozzle of the ink jet head unit 1, there is a high possibility that the ink discharge angle is disturbed (deterioration of ink landing accuracy) or non-discharge occurs.

  Pigment ink containing highly concentrated resin has high ink viscosity, but the extreme increase in ink viscosity accompanying ink solvent drying is ejected to a rectangular area of 46 μm x 200 μm surrounded by a black matrix. Reduce the wet spread of ink. Therefore, it is required to land the ink accurately at a position of about 5 μm on the side of the black matrix and to prevent the extreme increase in the viscosity of the ink as described above. On the other hand, there is a case where the droplet diameter of the ejected ink is required to be 10 μm or less so as not to be mixed with other colors of adjacent pixels, and accordingly, the nozzle diameter of the inkjet head unit 1 is reduced. There is a need to. Due to the above influences, at present, the concentration of the resin component in the solvent is 10%, whereas ink having a pigment content of about 5% is often used, and the ink is discharged accordingly. There is a problem that the amount increases and the tact time becomes long. In addition, there is a method of increasing the color reproducibility by darkening the color without changing the pigment content by changing the resin component concentration to about 5%, but unevenness in the shape after drying the ink tends to occur. In some cases, the display quality of the panel was lowered. In addition, there is a method of changing the solvent of the ink to one having a low viscosity, but the solvent having a low viscosity tends to have a low saturated vapor pressure, and accordingly, the evaporation is accelerated and the fixing of the pigment is also accelerated. , It will not be a fundamental solution. Therefore, in the production of color filters by the ink jet method, the degree of freedom of ink physical properties is low, and in order to improve the color reproducibility of television, it becomes a method with extremely low productivity, such as performing discharge drying several times. There was a trend. The same problem occurs even when the panel drive circuit is formed by inkjet.

  Also, if the diameter of the nozzle of the inkjet head section is less than 30 μm, the allowable amount for the fixation of the pigment in the ink becomes extremely small, and even in the case of the fixation of the pigment that cannot be observed with an optical microscope, the ink discharge direction is disturbed. It's easy to do.

  In the ink jet coating apparatus according to the present embodiment, the following operation is performed because an ink having a nozzle diameter of 20 μm and a high pigment concentration is used.

  The glass substrate 200 is placed on the mounting table 100 inside the apparatus by a substrate transfer robot or the like (not shown). The glass substrate 200 placed on the mounting table 100 is finely adjusted in position so that the short side thereof is orthogonal to the moving direction (Y direction) of the gantry 10, and has an angle with respect to the gantry 10. Then, an alignment operation is performed to measure whether it has been placed. Thereafter, the ink jet head unit 1 installed in the gantry 10 is moved to a discharge location inside the glass substrate 200 while being protected in a state suitable for discharge by the maintenance unit 2 mounted on the maintenance unit driving unit 20. At this time, the gantry 10 and the maintenance unit drive unit 20 move so that the relative positions of the inkjet head unit 1 and the maintenance unit 2 do not change. The maintenance unit 2 includes a plurality of maintenance mechanisms. When each maintenance mechanism has an optimum positional relationship with the inkjet head unit 1, the inkjet head unit 1 and the maintenance unit are within the installation range of the maintenance mechanism. Although the positional relationship of 2 may change, the movement is performed with the relative distance maintained.

  The maintenance unit drive unit 20 moves away from the gantry 10 immediately before the inkjet head unit 1 reaches the ink ejection position inside the glass substrate 200. The distance to be separated is desirably as close as possible within a range that does not hinder the ink ejection of the ink jet head unit 1, and varies depending on the air current in the apparatus, but the distance is about 100 mm or less. Thereafter, ink is ejected from the inkjet head unit 1 in a predetermined pattern, but the maintenance unit drive unit 20 moves while maintaining a relative distance from the gantry 10 during ink ejection. This is because it is easy to take the operation of protecting the inkjet head unit 1 by the maintenance unit 2 quickly when the gantry 10 stops due to an unexpected trouble during ink ejection. When the operation reliability of the gantry 10 is high and the occurrence of trouble is extremely small, the maintenance unit drive unit 20 may be retracted outside the scanning range of the gantry 10. When ink is ejected to the glass substrate 200 by reciprocating scanning, the maintenance of the inkjet head unit 1 can be performed once by the maintenance unit 2 at the turn-back position.

  When the ink ejection to the glass substrate 200 is completed, the distance between the maintenance unit driving unit 20 and the gantry 10 changes. That is, the inkjet head unit 1 returns to the position of the maintenance unit 2. Thereby, the inkjet head part 1 is protected from drying, or the maintenance in preparation for the next ink discharge is implemented.

  In addition, the ejection position can be finely adjusted by moving the glass substrate 200 within a range where there is no adverse effect such as ink ejection or landing deviation immediately before ink ejection. The range of fine adjustment is about ½ of the pixel size for normal ejection. For example, in the case of a pixel size of 46 μm × 200 μm, it is about 100 μm.

  After completion of ink ejection, the glass substrate 200 is carried out of the inkjet coating apparatus by a substrate transfer robot or the like (not shown). The panel is produced by repeating the above series of operations. However, if the continuous operation is continued for a long time, the dirt gradually accumulates in the maintenance unit 2, and even if the inkjet head unit 1 is maintained, the discharge is performed. It becomes a state that can not be kept in the optimum state. Normally, the maintenance unit 2 periodically cleans, but when using ink in which a high-concentration pigment is dispersed, the inkjet head unit 1 is left in a decapped state even for a short time required for the cleaning operation. As a result, the performance cannot be recovered even in the maintenance by the maintenance unit 2, and in the worst case, it may be necessary to replace the inkjet head unit 1. In order to avoid this, it is necessary to protect the inkjet head unit 1 with the preliminary maintenance unit 3 attached to the preliminary maintenance unit drive unit 30 while cleaning the maintenance unit 2 attached to the maintenance unit drive unit 20. . Further, as described above, when the ink is ejected onto the glass substrate 200, the maintenance unit drive unit 20 moves to a position away from the gantry 10, so that the maintenance unit 2 can be cleaned at this time. That is, it is possible to carry out the cleaning operation of the maintenance unit 2 while performing a normal production operation for discharging ink onto the glass substrate 200. The maintenance function by the preliminary maintenance unit 3 may be the same as the maintenance function by the maintenance unit 2 or may be different.

  In the following, an example of the division of roles between the functions of the maintenance unit 2 and the spare maintenance unit 3 will be described.

  In a typical example, the maintenance unit 2 has at least one of a discharge inspection function, a liquid dripping detection function, a discard discharge function, a liquid level swing function, and a cap function. Further, a function of detecting the ink ejection speed may be provided.

  Here, the “ejection inspection function” of the maintenance unit 2 is a function for inspecting whether or not ink can be normally ejected from the inkjet head unit 1 immediately before ink ejection to the glass substrate 200. The outline of the “ejection inspection function” will be described with reference to FIG. As shown in FIG. 13, laser light is emitted from the light emitting element 2A1 toward the light receiving element 2A2. Ink is ejected from the inkjet head unit 1 toward this light path. When a predetermined amount of ink is normally ejected from the inkjet head unit 1, the laser beam directed to the light receiving element 2A2 is blocked, and the amount of received light detected by the light receiving element 2A2 decreases. In this case, the result of the discharge inspection is “pass”. On the other hand, when a predetermined amount of ink is not normally ejected from the inkjet head unit 1 (that is, there is “ejection failure”), the laser beam toward the light receiving element 2A2 is not blocked and is received by the light receiving element 2A2. The amount does not decrease. In this case, the result of the discharge inspection is “failed”.

  The “liquid dripping detection function” of the maintenance unit 2 is a function of inspecting whether or not unnecessary ink is attached to the bottom surface of the inkjet head unit 1. As shown in FIG. 14, a state where ink is attached to a portion other than the nozzle hole 1 </ b> A on the bottom surface (nozzle surface) of the inkjet head unit 1 is referred to as “liquid dripping”. The presence / absence of “liquid dripping” can be determined using the light emitting element 2A1 and the light receiving element 2A2 shown in FIG. That is, if the inkjet head unit 1 is moved downward from the state of FIG. 13 (ink ejection direction) and set so that the laser beam passes through the vicinity of the bottom surface of the inkjet head unit 1, the “ejection inspection function” The presence / absence of ink attached to the bottom surface of the inkjet head unit 1 can be determined based on the same principle as in the case of “. In this case, if the amount of received light detected by the light receiving element 2A2 does not decrease, it is determined that there is no “liquid dripping” (that is, “pass”), and if the amount of received light detected by the light receiving element 2A2 decreases, “liquid” It is determined that there is “sag” (that is, “fail”).

  The weights of the light emitting element 2A1 and the light receiving element 2A2 for performing the above-described “ejection inspection” and “liquid dripping detection” are as light as, for example, about 10 g. Therefore, even if such a light emitting element 2A1 and light receiving element 2A2 are arranged in the immediate vicinity of the inkjet head unit 1, it is unlikely that the speed and accuracy of operation of the inkjet head unit 1 will decrease.

  In addition, the “disposal discharge function” of the maintenance unit 2 refers to intermittently or continuously immediately before ink discharge (ink application process) to the glass substrate 200 or during movement of the gantry 10 on which the inkjet unit 1 is mounted. This is a function of preventing non-ejection of ink due to drying in the nozzle holes by ejecting ink (discarding ejection) within the cap. Since such a function can be realized without separately providing a large unit, it is unlikely that the operation speed and accuracy of the inkjet head unit 1 will be reduced by this function.

  Further, the “liquid level swinging function” of the maintenance unit 2 refers to the nozzle hole of the ink jet head unit 1 immediately before the ink is discharged onto the glass substrate 200 or during the movement of the gantry 10 as shown in FIG. This is a function of swinging the 1A liquid surface (the ink meniscus in the nozzle hole), and promotes ink viscosity reduction (recovery to normal ink viscosity) by drying and thickening the ink due to the stirring effect of the ink in the ink meniscus portion. It makes it easy to discharge. This liquid level fluctuation is realized by applying light vibration to the ink jet head unit 1 and can be realized without separately providing a large unit. This function reduces the speed and accuracy of operation of the ink jet head unit 1. It's hard to think.

  On the other hand, the preliminary maintenance unit 3 has at least one function among a discharge failure recovery function and a nozzle surface dirt removal function. The preliminary maintenance unit 3 is mounted with a larger and heavier element than the maintenance unit 2. An example of this is a nozzle cleaning unit as shown in FIG. In the example of FIG. 16, a cleaning liquid tank 3A1 in which a cleaning liquid is stored and an ultrasonic transducer 3A2 attached to the cleaning liquid tank 3A1 are provided. The cleaning tank 3A1 includes a cleaning liquid storage tank and a cleaning waste liquid storage tank (not shown), and when the inkjet head unit 1 needs to be cleaned, the cleaning liquid is supplied to the cleaning tank 3A1, and the inkjet head unit 1 is cleaned with the cleaning liquid tank 3A1. The inkjet head unit 1 is cleaned by immersing it in the cleaning liquid stored in.

  Although the ultrasonic cleaning apparatus 3A shown in FIG. 16 is relatively large and heavy, cleaning using this apparatus is performed as frequently as “discharge failure” and “liquid sag” detection and “liquid level fluctuation”. Since it is not necessary to carry out the maintenance, it can be provided in the preliminary maintenance unit 3 separated from the maintenance unit 2 so that the maintenance can be carried out when the necessity arises.

  As described above, the maintenance unit 2 is provided with a function that is miniaturized / lightened to such an extent that the high-speed and high-accuracy movement of the inkjet head unit 1 is not hindered. Although it depends on the number of installed units, the spare maintenance unit 3 is provided with a function that is relatively large and heavy, but less frequently used than the function provided in the maintenance unit 2, and its total weight is Depending on the number of inkjet heads installed, it may be 300 kg or more, but it may be 600 kg or more. In general, the function provided in the preliminary maintenance unit 3 often gives a relatively large physical force to the ink jet head unit 1. Examples of such functions include, for example, a wiper function that wipes off dirt from the inkjet head unit 1, a suction function that sucks the dirt, a jet function that removes the dirt by a jet, and a high pressure that removes the dirt by a high-pressure gas. A spray function etc. are mentioned. In addition to the above functions, a wiping blade cleaning mechanism mounted on the wiper function, a wiping blade moving mechanism, and a wiping blade for an effective cleaning of the nozzle surface to which the solidified ink adheres, such as an ink solvent Cleaning liquid supply and waste liquid mechanism for use in a wet state with the cleaning liquid, large suction pump for strongly discharging air bubbles that adhere firmly inside the inkjet head from the nozzle hole, and large capping mechanism that emphasizes airtightness Therefore, the preliminary maintenance unit 3 is complicated, large, and heavy.

  Next, a method for controlling the maintenance unit 2 and the preliminary maintenance unit 3 in the inkjet coating apparatus according to the present embodiment will be described.

  FIG. 17 is a block diagram showing an example of the configuration of the ink jet coating apparatus according to the present embodiment. Referring to FIG. 17, the ink jet coating apparatus according to the present embodiment includes a maintenance unit 2 as a “first maintenance unit”, a spare maintenance unit 3 as a “second maintenance unit”, a maintenance unit 2 and a spare unit. And a main control unit 4 as a “control unit” for controlling the maintenance unit 3.

  The maintenance unit 2 includes a control unit 201, a detection unit 202 that detects defects such as ejection defects and liquid sag of the inkjet head unit 1, a recovery unit 203 that recovers the defects, and the inkjet head unit 1 until just before ink ejection. And a simple cap portion 204 that can be discharged immediately before the discharge of the cap or ink (ink application process). The control unit 201 controls the detection unit 202, the recovery unit 203, and the simple cap unit 204. The control unit 201 also has a function as a “determination unit” that determines whether the failure can be recovered by the recovery unit 203 of the maintenance unit 2.

  The detection unit 202 can perform liquid dripping detection and ejection inspection of the inkjet head unit 1. The recovery unit 203 recovers the state of the ink jet head unit 1 by causing the ink jet head unit 1 to perform waste discharge to the waste discharge region.

  The preliminary maintenance unit 3 maintains the inkjet head unit 1 with a more effective and physically effective maintenance method than the maintenance unit 2 for defects that cannot be recovered by the control unit 301 and the recovery unit of the maintenance unit 2. Recovery parts 302A and 302B to be used, and a cap part 303 for performing a cap when the ink jet head part 1 is not used for a long time. The control unit 301 controls the recovery units 302A and 302B and the cap unit 303. The recovery units 302A and 302B recover the state of the inkjet head unit 1 by a wiping operation and a nozzle suction operation, respectively.

  The main control unit 4 includes a CPU 401 that controls the maintenance unit 2 and the preliminary maintenance unit 3, a timer circuit 402 as a “timer unit”, communication modules 403A and 403B, a memory 404, an external storage element 405, Used nozzle determining unit 406. The external storage element 405 incorporates an application program for controlling the control units 201 and 301 of the maintenance unit 2 and the preliminary maintenance unit 3 via the communication modules 403A and 403B. The application program may be an automatic processing program that performs a certain process, or may be a program that is controlled by a conversational method using a keyboard, a mouse, or the like.

  Referring to the flowchart shown in FIG. 18, in the failure detection operation (S110), the detection unit 202 of the maintenance unit 2 detects the occurrence of the failure (S120), and the failure is recovered by the recovery unit 203 of the maintenance unit 2. If the control unit 201 determines that recovery is not possible (S130), the main control unit 4 controls the maintenance unit 2 and the preliminary maintenance unit 3 to perform maintenance by the preliminary maintenance unit 3 (S140).

  In this way, defects that can be recovered by the maintenance unit 2 are recovered by the maintenance unit 2, and defects that cannot be recovered by the maintenance unit 2 are physically and chemically strong and more effective maintenance is performed. It can be recovered by a preliminary maintenance unit 3 that can be performed.

  Referring to the flowchart shown in FIG. 19, when the maintenance (S210) by the preliminary maintenance unit 3 is completed, the timer circuit 402 is activated (S220). That is, the timer circuit 402 measures the time after the maintenance by the preliminary maintenance unit 3 is completed. In S230, when the maintenance by the preliminary maintenance unit 3 is performed again, the timer circuit 402 is reset (S231). In S230, when the maintenance by the preliminary maintenance unit 3 is not performed again, the operation of the timer circuit 402 is continued (S232). When a predetermined time elapses after the maintenance by the preliminary maintenance unit 3 is completed, the maintenance by the preliminary maintenance 3 is automatically performed again. That is, the main control unit 4 performs maintenance so that the maintenance by the preliminary maintenance unit 3 is performed again based on the fact that the timer circuit 402 detects that a predetermined time has passed since the maintenance by the preliminary maintenance unit 3 is completed. The unit 2 and the preliminary maintenance unit 3 are controlled.

  By doing in this way, the maintenance of the inkjet head unit 1 by the preliminary maintenance unit 3 can be performed periodically.

  FIG. 20 is a flowchart showing a modification of the control method of the maintenance unit 2 and the preliminary maintenance unit 3 by the main control unit 4. In the example of FIG. 20, after the occurrence of a failure is detected by the detection unit 202 of the maintenance unit 2 (S310, S320), the recovery operation by the recovery unit 203 of the maintenance unit 2 is repeated a predetermined number of times (S330). When a defect is detected by the detection unit 202 (S340), control is performed such that maintenance by the preliminary maintenance unit 3 is performed (S350).

In this case, the maintenance unit 2 performs the following processing based on the maintenance command from the main control unit 4.
1) In the recovery unit 203, the inkjet head unit 1 is made to discard and discharge.
2) Liquid sag detection is performed by the detection unit 202, and if normal, a discharge inspection is further performed. When an abnormality is detected in the discharge inspection, the recovery unit 203 again performs discard discharge (recovery operation). When the discarding discharge (recovery operation) in the recovery unit 203 does not return even after repeating a preset number of times (for example, twice), the control unit 201 notifies the main control unit 4 of the discharge abnormality via the communication module 403A. .
3) When an abnormality is detected in the liquid dripping detection, the control unit 201 notifies the main control unit 4 of the liquid dripping abnormality via the communication module 403A.

When the liquid dripping abnormality is notified to the main control unit 4, the following processing is performed.
1) The main control unit 4 instructs the control unit 301 of the preliminary maintenance unit 3 to execute a wiping operation (recovery operation) by the recovery unit 302.
2) The control unit 301 controls the recovery unit 302 to perform a wiping operation.
3) Thereafter, the maintenance operation in the maintenance unit 2 is performed.

Further, when a discharge abnormality is notified to the main control unit 4, the following processing is performed.
1) The main control unit 4 instructs the control unit 301 of the preliminary maintenance unit 3 to execute the nozzle suction and wiping operation (recovery operation) by the recovery unit 302.
2) The control unit 301 controls the recovery unit 302 to perform nozzle suction.
3) The control unit 301 controls the recovery unit 302 to perform a wiping operation.
4) Thereafter, the maintenance operation in the maintenance unit 2 is performed.

  As described above, even if two maintenance units are provided, if the cooperation is sparse, a sufficient effect of providing maintenance units at two locations cannot be expected. On the other hand, by operating the maintenance unit 2 and the preliminary maintenance unit 3 in cooperation with each other, it is possible to prevent an operation error and shorten the work time.

  FIG. 21 is a block diagram showing a modification of the configuration of the ink jet coating apparatus according to the present embodiment. Referring to FIG. 21, in the present modification, two timer circuits 402A and 402B are provided in main controller 4. In the maintenance unit 2 and the preliminary maintenance unit 3, cap confirmation sensors 205 and 304 are provided, respectively.

  The timer circuit 402 </ b> A as the “first timer unit” measures the time from when the cap of the inkjet head unit 1 by the simple cap unit 204 or the cap unit 303 is released. On the other hand, the timer circuit 402B as the “second timer unit” measures the time during which the cap of the inkjet head unit 1 by the simple cap unit 204 is continued.

  With reference to the flowcharts shown in FIGS. 22 and 23, it can be confirmed by the cap confirmation sensors 205 and 304 that the caps by the simple cap unit 204 and the cap unit 303 are released (S410). When the release of the cap by the simple cap unit 204 and the cap unit 303 is confirmed, the timer circuit 402A is activated (S420). In S430, when the capping by the simple cap unit 204 or the cap unit 303 is started, the timer circuit 402A is reset (S431). In S430, when the cap by the simple cap unit 204 or the cap unit 303 is not started, the operation of the timer circuit 402A is continued (S432). Then, when the predetermined time has elapsed, capping by the simple cap unit 204 is automatically started (S440). That is, the main control unit 4 performs the cap by the simple cap unit 204 based on the fact that the timer circuit 402A detects that a predetermined time has elapsed since the caps by the simple cap unit 204 and the cap unit 303 are released. Thus, the maintenance unit 2 and the preliminary maintenance unit 3 are controlled.

  By doing in this way, since the cap by the simple cap part 204 can be performed regularly, the non-ejection by drying of the inkjet head part 1 can be reduced.

  When the capping by the simple cap unit 204 is started, the timer circuit 402B is activated (S450). If the cap by the simple cap unit 204 is released in S460, the timer circuit 402B is reset (S461). In S460, when the cap by the simple cap unit 204 is not released, the operation of the timer circuit 402B is continued (S462). When the cap by the simple cap unit 204 continues for a predetermined time, the cap by the simple cap unit 204 is automatically released (S470), and the cap by the cap unit 303 is started (S480). That is, the main control unit 4 detects that the cap by the simple cap unit 204 has continued for a predetermined time or longer by the timer circuit 402B, so that the maintenance unit 2 and the preliminary maintenance unit perform the cap by the cap unit 303. 3 is controlled.

  By doing in this way, the cap by the cap part 303 can be performed regularly. The cap by the simple cap unit 204 only keeps the inkjet head unit 1 in a solvent environment and cannot be stored for a long time. With only the cap formed by the simple cap unit 204, the ink may accumulate and adhere to the nozzle surface of the inkjet head unit 1. When the ink is fixed, the recovery operation by the preliminary maintenance unit 3 may not be performed unless the recovery operation is continuously performed a plurality of times, which causes problems such as an increase in waste of ink and an increase in maintenance time. On the other hand, non-ejection due to drying of the inkjet head unit 1 can be reduced by periodically performing the capping by the cap unit 303.

  In the present embodiment, the main control unit 4 causes the CPU 401 that controls the maintenance unit 2 and the preliminary maintenance unit 3 to function, and the use nozzle determination unit 406 that selects a usable nozzle of the inkjet head unit 1. Thus, even if the two maintenance units described above are used, it is possible to apply the inkjet coating process to industrial applications with high accuracy even if it is difficult to stably eject ink.

  Referring to the flowchart shown in FIG. 24, in the defect detection operation (S510), the detection unit 202 of the maintenance unit 2 detects the occurrence of the defect (S520), and the defect is recovered by the recovery unit 203 of the maintenance unit 2. If the control unit 201 determines that recovery is not possible (S530), the main control unit 4 controls the maintenance unit 2 and the preliminary maintenance unit 3 to perform maintenance by the preliminary maintenance unit 3 (S540). Further, when using ink that is very difficult to stably discharge, the preliminary maintenance unit 3 may cause a failure that cannot be recovered. In a correction process where the functional ink is applied locally, it is possible to improve productivity by avoiding excessive maintenance, and the nozzle used in the current process and at least the nozzle adjacent to the used nozzle After the maintenance in the preliminary maintenance unit 3 for the nozzles (preferably up to the second adjacent nozzle), the detection unit 202 of the maintenance unit 2 detects again whether there is a defect (S550), and the determination unit 201 determines that the defect has not yet recovered. (S560), the used nozzle determining unit 406 uses it in the next process. (Preferably up to two adjacent nozzle eyes (5 nozzles nozzles stable central position in continuous)) at least adjacent nozzles of the nozzle is selected from the available nozzles is stable ejection (S570).

  The above flow will be described in more detail. When the main control unit 4 detects the ink ejection failure of the inkjet head unit 1 by the “ejection inspection function” (detection unit) in the maintenance unit 2 by the use nozzle determining unit that selects the usable nozzles of the inkjet head unit 1. Then, control is performed so as to attempt to recover the defect by a light maintenance function (recovery unit) such as a “disposal discharge function” or a “liquid level swing function”. Thereafter, the detection unit checks again whether or not the failure has been recovered by the recovery unit 203, and the main control unit 4 receives the result of the discharge inspection after the recovery operation of the maintenance unit 2. If it is recovered by simple maintenance, the maintenance of the inkjet head unit 1 will be terminated at this point, but if the determination unit determines that the recovery unit 203 of the maintenance unit 2 cannot recover, The maintenance unit 2 is retracted from the position of the inkjet head unit 1 so that the maintenance by the preliminary maintenance unit 3 that can perform maintenance of the chemically powerful and effective inkjet head unit 1 is performed, and the inkjet head unit 1 is reserved. Move to the position of the maintenance unit 3 It controls to allow maintenance operation Bei maintenance unit 3. further. Implemented “ultrasonic cleaning function”, “wiper function”, “strong ink suction function from nozzle”, etc. by the preliminary maintenance unit 3 and installed the maintenance unit 2 in the maintenance unit 2 after the maintenance of the preliminary maintenance unit 3 This is performed by the detection unit and the determination unit. At this time, the preliminary maintenance unit 3 is also equipped with functions equivalent to those of the detection unit and the determination unit mounted on the maintenance unit 2, and the preliminary maintenance unit 3 performs the head discharge state after maintenance. Pass / fail judgment may be performed.

  At this point, there is no problem as long as the ink discharge from all the nozzles in the ink jet head unit 1 is in a good state, but the ink is notable due to drying of the ink solvent component at the ink meniscus of the nozzle of the ink jet head unit 1. Dissolves depending on the ink and ink components that are difficult to be stably ejected due to changes in the dispersion state of the ink components due to thickening and changes in the orientation of the solvent and solute at the ink meniscus in the nozzle and chemical properties. Even when the air is deaerated, the minute bubbles remaining in the ink jet head when the ink jet is driven or when the ink passes through the filter in the ink flow path are easily expanded and floated by cavitation. Once bubbles are generated, it takes time to dissolve the bubbles in the degassed ink. When using such hunt ink, to perform maintenance to allow good ink discharge from all the nozzles of the inkjet head 1 can be very difficult. In some cases, it may be a good idea to perform the inkjet coating process by operating the inkjet head unit 1 with some non-ejection nozzles, and excessive physical and chemical damage to the inkjet head unit 1 due to excessive maintenance In addition to causing scratches on the nozzle surface, peeling of the nozzles, changes in ink ejection characteristics due to chemical changes in the constituent members of the inkjet head unit 1, the frequency of replacement of the inkjet head unit 1 increases, and the productivity is remarkably increased. The maintenance time increases due to the decrease or excessive maintenance, the operating rate of the equipment decreases, and the productivity is significantly reduced, or the excessive amount of indirect members such as cleaning liquid used for maintenance is consumed due to excessive maintenance. This increases the running cost of the equipment and significantly reduces productivity. If an inkjet coating process is possible even when some nozzles are not usable, it is preferable not to pursue stable discharge from all nozzles and avoid excessively strong maintenance. .

  Next, after it is determined that the maintenance unit 2 cannot recover, if it is determined that the maintenance cannot be recovered by the maintenance of the spare maintenance unit 3, the maintenance by the spare maintenance unit 3 may be performed again. The control unit 4 compares the discharge state of the nozzles of the ink jet head unit 1 (the number and position of nozzles that can be used with good ink discharge state) with the minimum number of nozzles necessary for the ink jet coating process. If it is determined that the inkjet coating process is possible even if the nozzles are in a non-ejection state, the nozzles other than the defective nozzles of the inkjet head unit 1 in which the defects are generated by the used nozzle determination function included in the main control unit 4 The maintenance unit 2 and the spare mem And it controls the Maintenance Manual unit 3, without undue maintenance, controls the inkjet head unit 1 to perform the ink jet coating process. At this time, in the present embodiment, the process and apparatus for applying the color ink to the entire surface (all pixels) of the color filter substrate have been described for the manufacturing process of the color filter, but to the specific pixel in the correction process of the color filter. In the color ink application process and the TFT substrate wiring correction process, the metal fine particle-containing ink application process to a specific disconnection location, etc., can be performed sufficiently if one to several tens of nozzles are used. The function of selecting the used nozzle is particularly effective, and an ink jet coating process with high productivity can be realized.

  Next, the used nozzle determining function for selecting the used nozzle will be described. As described above, when maintenance is performed so that all the nozzles of the inkjet head unit 1 can be ejected, in the case of industrial use ink, the ink solidified film at the ink meniscus is re-applied to the cleaning liquid such as ink or ink solvent. Driven from ink or nozzles that have low solubility, strong ink solidified film, and low destructiveness due to ultrasonic vibration, and that are less likely to generate ink bubbles due to cavitation due to ink jet head drive etc. In some cases, if the ink is easy to bite in and the bubble elimination is low, stable ink ejection is very difficult. On the other hand, in the correction process or the like in which a functional film is formed on a part of the ink ejection substrate as described above, the inkjet coating process is often performed without using all the nozzles of the inkjet head unit 1. If the inkjet coating process can be performed with nozzles other than non-ejection nozzles or nozzles with unstable ejection, maintenance of the excessively strong inkjet head unit 1 is performed, and the apparatus is operated without reducing productivity. be able to. However, any nozzle that seems to be in a stable discharge state at first glance, excluding nozzles that are unstable and non-discharge nozzles, may not be selected as the use nozzle. As shown in Table 1, the ink ejection volume and ejection speed from the nozzles adjacent to the non-ejection nozzles are reduced by 1.5 to 1.9% and 2.5 to 3.0% from the normal state, respectively. The discharge characteristics have changed. Further, as shown in Table 2, when the ink ejection volume and ejection speed from the adjacent nozzles of the non-ejection nozzle are maintained in a normal state and there is no change in the ink ejection characteristics, or as shown in Table 3, the second adjacent nozzle May be affected. In addition, as shown in Table 4, the defective nozzle is not non-ejection, and the result of the inspection that measures the light shielding rate of the laser beam by the ejected droplets is that the light shielding rate is different from the normal time. The change in ink ejection characteristics is slightly observed even in nozzles adjacent to nozzles that are determined to have large variations in the light-blocking rate reproducibility and the instantaneous value of the light-blocking rate in FIG. In non-ejecting ink is fatal in consumer applications such as printers and fax machines, but if defective nozzles are not used, the quality of printed matter is significantly reduced even when ink jet recording is performed with nozzles including nozzles adjacent to defective nozzles. However, in industrial applications where it is necessary to perform the inkjet coating process precisely at the specified film thickness and position, the functional coating is a fatal characteristic change, and the nozzle adjacent to the unstable nozzle is used. Should not be selected.

  The cause of the change in the ink ejection characteristics of the nozzles adjacent to the defective nozzle described above is the result of experimentally performing the cause of failure described in the remarks column of Tables 1 to 4, and the cause of the failure that occurs during actual operation of the apparatus. It is extremely difficult to specify the nozzle, and at least the nozzle adjacent to the defective nozzle (one nozzle on both sides) is highly likely to have changed ink ejection characteristics. Up to the second nozzles on both sides of the nozzle may not be selected as a nozzle to be used because some ink ejection characteristics may be changed.

  The ink jet head of the ink jet head unit 1 has a partition wall between the ink chambers of adjacent nozzles by applying voltage (ink jet driving) to the piezoelectric material that is a part of the constituent members of the ink chamber to the ink in the ink chamber storing the ink. This is a share mode type piezo-type inkjet head (not shown) that is driven so as to be deformed into a "<" shape. The shock wave is generated in the ink chamber, and the ink is ejected from the nozzle hole communicating with the ink chamber by control. . In addition, a direct mode type piezo-type inkjet head (not shown) in which a piezoelectric material is driven so as to push the partition wall of the ink chamber is generally used in industrial applications, and any type of inkjet head is used in the ink chamber. Ink is discharged from the nozzle by controlling the ink pressure. If there is a bubble in the adjacent ink chamber, there is a bubble with a low compression rate due to fluctuations in the ink pressure inside the driven ink chamber. The partition walls of the adjacent ink chambers are easily deformed, and the ink pressure applied for ejection causes the partition walls to be deformed, or when the ink shock waves are controlled to eject the ink. The ink compression ratio) changes, making it impossible to control shock waves properly, and changes in ejection speed and volume It is considered to appear. However, the direct mode inkjet head has a smaller effect on the ink ejection characteristics to adjacent nozzles and further distant nozzles, but it forms a functional film that requires a film thickness control of 0.5 to 1% or less. In industrial applications, it is characteristic variation to be noted regardless of the type of inkjet head.

  The above contents are summarized as follows. In other words, the ink jet coating apparatus according to the present embodiment is an ink jet coating apparatus that ejects ink onto a glass substrate 200 as an “object to be ejected” placed on a mounting table 100, The inkjet head unit 1 that ejects ink to the glass substrate 200, the maintenance unit 2 as a “first maintenance unit” that can perform maintenance of the inkjet head unit 1, and the “first maintenance unit”. And a preliminary maintenance unit 3 as a “2 maintenance section”. The maintenance unit 2 is movable while maintaining the relative positional relationship with the inkjet head unit 1.

(Embodiment 2)
FIG. 2 is a diagram showing an ink jet coating apparatus according to the second embodiment. The ink jet coating apparatus according to the present embodiment is a modification of the ink jet coating apparatus according to the first embodiment. As shown in FIG. 2, the maintenance unit drive provided in the same unit as the ink jet head unit 1 is used. The maintenance unit 2 is driven by the unit 20A. By doing in this way, the structure of the apparatus of an inkjet coating device becomes simple, and the precision of application | coating may improve or it may lead to a cost reduction. Further, the maintenance unit drive unit 20A can be easily disposed in the immediate vicinity of the inkjet head unit 1, and can reduce the time for which the inkjet head unit 1 is left (decap time) slightly compared to the structure of FIG.

  Whether the structure shown in FIG. 1 or the structure shown in FIG. 2 is adopted depends on the properties of the inkjet head unit 1 used, the accuracy of ink ejection onto the glass substrate 200, and the characteristics of the ink used. It is determined appropriately.

  Since other matters are the same as those in the above-described embodiment, detailed description will not be repeated.

(Embodiment 3)
FIG. 3 is a diagram showing an ink jet coating apparatus according to the third embodiment. The ink jet coating apparatus according to the present embodiment is a modification of the ink jet coating apparatus according to the first and second embodiments, and as illustrated in FIG. The gantry 10 as a “first movable part” that can move in the direction) and attached to the gantry 10 and movable in the second direction (X direction) that intersects the first direction (Y direction) with respect to the gantry 10 One feature is that the inkjet head unit 1 is moved by the driving unit 10 </ b> A as the “second movable unit”. Another feature of the ink jet coating apparatus according to the present embodiment is that the preliminary maintenance unit 3 is a fixed unit.

  Also in the present embodiment, the maintenance unit 2 is movable while maintaining the relative positional relationship with the inkjet head unit 1. The preliminary maintenance unit 3 is provided within the movable range of the drive unit 10A, and can perform maintenance of the inkjet head unit 1 as necessary.

  Since other matters are the same as those in the above-described embodiment, detailed description will not be repeated.

(Embodiment 4)
FIG. 4 is a diagram showing an ink jet coating apparatus according to the fourth embodiment. The ink jet coating apparatus according to the present embodiment is a more specific example of the ink jet coating apparatus according to the third embodiment. As shown in FIG. 4, the maintenance unit 2 includes the above-described “ejection inspection function” and A feature is that a laser 2 </ b> A and a cap 2 </ b> B for the “liquid dripping detection function” are provided.

  Since other matters are the same as those in the above-described embodiment, detailed description will not be repeated.

(Embodiment 5)
FIG. 5 is a diagram showing an ink jet coating apparatus according to the fifth embodiment. The ink jet coating apparatus according to the present embodiment is a modification of the ink jet coating apparatus according to the first embodiment, and the preliminary maintenance unit 3 is provided in a fixed state outside the mounting table 100 as shown in FIG. It is characterized by that.

  Since other matters are the same as those in the above-described embodiment, detailed description will not be repeated.

(Embodiment 6)
FIG. 6 is a diagram showing an ink jet coating apparatus according to the sixth embodiment. The ink jet coating apparatus according to the present embodiment is a modification of the ink jet coating apparatus according to the first embodiment, and the preliminary maintenance unit 3 is provided outside the mounting table 100 in a movable state as shown in FIG. It is characterized by that.

  As the preliminary maintenance unit driving unit 30A for driving the preliminary maintenance unit 3, one having a relatively low accuracy can be used, for example, a ball screw moving mechanism can be used. In the ink jet coating apparatus according to the present embodiment, the maintenance position of the ink jet head unit 1 can be freely set by making the preliminary maintenance unit 3 movable. In the example of FIG. 6, the preliminary maintenance unit 3 is movable in the Y direction, but the preliminary maintenance unit 3 may be movable in the X direction, or may be movable in the X direction and the Y direction.

  Since other matters are the same as those in the above-described embodiment, detailed description will not be repeated.

(Embodiment 7)
FIG. 7 is a view showing an ink jet coating apparatus according to the seventh embodiment. The ink jet coating apparatus according to the present embodiment is a modification of the ink jet coating apparatus according to the first to sixth embodiments. As shown in FIG. 7, the gantry 10 is used as a fixed gantry and the glass substrate 200 is placed thereon. The inkjet head unit 1 is positioned at a predetermined position on the glass substrate 200 by moving the mounting table 100 in the Y direction by the mounting table driving unit 100A.

  In the inkjet coating apparatus according to the present embodiment, the size of the apparatus is increased as a whole, but by fixing the gantry 10, it is possible to perform highly accurate inkjet coating.

  Since other matters are the same as those in the above-described embodiment, detailed description will not be repeated.

(Embodiment 8)
FIG. 8 is a view showing an ink jet coating apparatus according to the eighth embodiment. The ink jet coating apparatus according to the present embodiment is a more specific example of the ink jet coating apparatus according to the seventh embodiment. As shown in FIG. 8, the maintenance unit 2 includes the above-described “ejection inspection function” and A feature is that a laser 2 </ b> A and a cap 2 </ b> B for the “liquid dripping detection function” are provided.

  Since other matters are the same as those in the above-described embodiment, detailed description will not be repeated.

(Embodiment 9)
FIG. 9 is a view showing an ink jet coating apparatus according to the ninth embodiment. The ink jet coating apparatus according to the present embodiment is a further modification of the ink jet coating apparatus according to the third embodiment, and is a direction orthogonal to the main surface (XY plane) direction of the glass substrate 200 (Z direction). ) Is provided with a drive unit 10B for moving the inkjet head unit 1.

  In some cases, the distance between the glass substrate 200 and the tip of the inkjet head unit 1 during ink ejection is about 1 mm or less. It is practically difficult to produce the maintenance unit 2 with a thickness of about 1 mm or less. In contrast, in the inkjet coating apparatus according to the present embodiment, when the maintenance unit 2 performs maintenance of the inkjet head unit 1 by providing the drive unit 10B that moves the inkjet head unit 1 up and down in the Z direction, the inkjet unit 1 Can be raised and lowered otherwise. That is, in this embodiment, when the maintenance of the inkjet head unit 1 is performed by the maintenance unit 2 and when the maintenance of the inkjet head unit 1 is performed by the preliminary maintenance unit 3, the height of the inkjet head unit 1 relative to the glass substrate 200 is increased. Is different. By doing so, the maintenance unit 2 having a predetermined function can be provided even when the distance between the glass substrate 200 and the tip of the inkjet head unit 1 during ink ejection is small.

(Embodiment 10)
FIG. 10 is a diagram showing an ink jet coating apparatus according to the tenth embodiment. The ink jet coating apparatus according to the present embodiment is a combination of the characteristic part of the ink jet coating apparatus according to the seventh embodiment and the characteristic part of the ink jet coating apparatus according to the ninth embodiment. Do not repeat.

(Embodiment 11)
FIG. 11 shows an inkjet coating apparatus according to the eleventh embodiment. The ink jet coating apparatus according to the present embodiment is a combination of the characteristic part of the ink jet coating apparatus according to the first embodiment and the characteristic part of the ink jet coating apparatus according to the ninth embodiment. Do not repeat.

(Embodiment 12)
FIG. 12 is a diagram showing an ink jet coating apparatus according to the twelfth embodiment. The ink jet coating apparatus according to the present embodiment is a combination of the characteristic part of the ink jet coating apparatus according to the second embodiment and the characteristic part of the ink jet coating apparatus according to the ninth embodiment. Do not repeat.

  Although the embodiments of the present invention have been described above, the embodiments disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  DESCRIPTION OF SYMBOLS 1 Inkjet head part, 1A nozzle hole, 2 maintenance unit, 2A laser, 2A1 light emitting element, 2A2 light receiving element, 2B cap, 3 preliminary maintenance unit, 3A ultrasonic cleaning device, 3A1 cleaning liquid tank, 3A2 ultrasonic transducer, 4 main Control unit, 10 gantry, 10A, 10B drive unit, 20, 20A Maintenance unit drive unit, 30, 30A Preliminary maintenance unit drive unit, 100 mounting table, 100A mounting table drive unit, 200 glass substrate, 201 control unit, 202 detection unit , 203 recovery unit, 204 simple cap unit, 205 cap confirmation sensor, 301 control unit, 302A, 302B recovery unit, 303 cap unit, 304 cap confirmation sensor, 401 CPU, 402, 402A, 402B timer circuit, 40 A, 403B communication module, 404 a memory, 405 an external storage device, 406 used nozzle determination unit.

Claims (15)

An ink discharge device that discharges ink to an object to be discharged mounted on a mounting table,
An inkjet head unit that is provided so as to be relatively movable with respect to the discharge target, and discharges ink to the discharge target;
A first maintenance unit and a second maintenance unit capable of performing maintenance of the inkjet head unit;
At least one of the first maintenance unit and the second maintenance unit is movable while maintaining a relative positional relationship with the inkjet head unit ,
A first movable part movable in a first direction with respect to the discharged object;
A second movable part attached to the first movable part and movable in a second direction intersecting the first direction with respect to the first movable part;
The inkjet head part is attached to the second movable part,
The first maintenance unit is movable while maintaining a relative positional relationship with the inkjet head unit,
The second maintenance unit is an ink ejection device provided within a movable range of the second movable unit . The ink discharge apparatus according to claim 1 , wherein the second maintenance unit has a function different from that of the first maintenance unit. The first maintenance unit has at least one of a discharge inspection function, a liquid dripping detection function, a discard discharge function, a liquid level swing function, and a cap function,
3. The ink ejection device according to claim 1 , wherein the second maintenance unit has at least one of a recovery function of ejection failure and a function of removing dirt on the nozzle surface. The first maintenance unit is movable while maintaining a relative positional relationship with the inkjet head unit,
4. The ink ejection device according to claim 1, wherein the second maintenance unit is provided outside the mounting table. 5. The ink ejection apparatus according to claim 4 , wherein the second maintenance unit is movably provided outside the mounting table. An ink discharge device that discharges ink to an object to be discharged mounted on a mounting table,
An inkjet head unit that is provided so as to be relatively movable with respect to the discharge target, and discharges ink to the discharge target;
A first maintenance unit and a second maintenance unit capable of performing maintenance of the inkjet head unit;
At least one of the first maintenance unit and the second maintenance unit is movable while maintaining a relative positional relationship with the inkjet head unit,
A first movable part capable of moving the discharged object in a first direction;
A second movable part that is movable in a second direction intersecting the first direction with respect to the discharged object;
The inkjet head part is attached to the second movable part,
The first maintenance unit is movable while maintaining a relative positional relationship with the inkjet head unit,
The second maintenance unit is provided within the movable range of the second movable portion, Lee ink ejection device. The ink ejection apparatus according to claim 6 , wherein the second maintenance unit has a function different from that of the first maintenance unit. The first maintenance unit has at least one of a discharge inspection function, a liquid dripping detection function, a discard discharge function, a liquid level swing function, and a cap function,
The ink discharge apparatus according to claim 6 or 7 , wherein the second maintenance unit has at least one of a discharge failure recovery function and a nozzle surface dirt removal function. A control unit capable of controlling operations of the first maintenance unit and the second maintenance unit;
The first maintenance unit includes a detection unit that detects a defect of the inkjet head unit, a recovery unit that recovers the defect, and a determination unit that determines whether the defect can be recovered by the recovery unit,
The control unit performs maintenance by the second maintenance unit based on the detection of the occurrence of the defect by the detection unit and the determination unit determining that the defect cannot be recovered by the recovery unit. The ink discharge apparatus according to claim 1, wherein the first maintenance unit and the second maintenance unit are controlled as described above. A control unit capable of controlling operations of the first maintenance unit and the second maintenance unit;
The first maintenance unit includes a detection unit that detects a defect of the inkjet head unit, and a recovery unit that recovers the defect.
The control unit is based on the detection of the defect again by the detection unit after the recovery operation is repeated a predetermined number of times by the first maintenance unit after the occurrence of the defect is detected by the detection unit. 9. The ink ejection apparatus according to claim 1, wherein the first maintenance unit and the second maintenance unit are controlled to perform maintenance by the second maintenance unit. 10. A control unit capable of controlling operations of the first maintenance unit and the second maintenance unit;
The control unit includes a timer unit that measures a time after completion of maintenance by the second maintenance unit,
The control unit is configured to perform the maintenance by the second maintenance unit again based on the fact that the timer unit detects that a predetermined time has elapsed since the maintenance by the second maintenance unit has been completed. The ink discharge apparatus according to any one of claims 1 to 8 , wherein the first maintenance unit and the second maintenance unit are controlled. A control unit capable of controlling operations of the first maintenance unit and the second maintenance unit;
The first maintenance unit includes a first cap unit that caps the inkjet head unit,
The second maintenance unit includes a second cap unit that caps the inkjet head unit,
The control unit includes: a first timer unit that measures a time after the cap of the inkjet head unit by the first cap unit or the second cap unit is released; and the inkjet head unit by the first cap unit. Including a second timer unit that measures the time during which the cap continues,
The control unit uses the first cap unit based on the detection that a predetermined time has elapsed after the first timer unit releases the caps of the first cap unit and the second cap unit. The first maintenance unit is configured to perform capping and to perform capping by the second cap unit when the second timer unit detects that the cap by the first cap unit has continued for a predetermined time or more. The ink ejection device according to claim 1 , wherein the ink ejection device controls the second maintenance unit. An ink discharge device that discharges ink to an object to be discharged mounted on a mounting table,
An inkjet head unit that is provided so as to be relatively movable with respect to the discharge target, and discharges ink to the discharge target;
A first maintenance unit and a second maintenance unit capable of performing maintenance of the inkjet head unit;
At least one of the first maintenance unit and the second maintenance unit is movable while maintaining a relative positional relationship with the inkjet head unit,
A control unit capable of controlling operations of the first maintenance unit and the second maintenance unit;
The control unit includes a use nozzle determining unit that selects a usable nozzle of the inkjet head unit,
The first maintenance unit includes a detection unit that detects a defect of the inkjet head unit, a recovery unit that recovers the defect, and a determination unit that determines whether the defect can be recovered by the recovery unit,
The control unit performs maintenance by the second maintenance unit based on the detection of the occurrence of the defect by the detection unit and the determination unit determining that the defect cannot be recovered by the recovery unit. The first maintenance unit and the second maintenance unit are controlled as described above, and after the maintenance by the second maintenance unit, the defect is detected by the detection unit and the determination unit of the first maintenance unit. Based on the determination that the maintenance cannot be performed by the maintenance by the second maintenance unit, the usable nozzle determining unit of the control unit selects a usable nozzle other than the defective nozzle of the inkjet head unit that has caused the defect. The first maintenance unit so as to eject ink Controlling the preliminary second maintenance unit, Lee ink ejection device. The nozzles that can be used by the used nozzle determining unit are determined to be unrecoverable by maintenance by the first maintenance unit and the second maintenance unit by the detection unit and the determination unit of the first maintenance unit. And at least one nozzle on both sides up to at least the first nozzle on one side of the defective nozzle in a nozzle row parallel to the defective nozzle, and selecting a used nozzle from normal nozzles in a discharge state, The ink ejection device according to claim 13 . An ink discharge device that discharges ink to an object to be discharged mounted on a mounting table,
An inkjet head unit that is provided so as to be relatively movable with respect to the discharge target, and discharges ink to the discharge target;
A first maintenance unit and a second maintenance unit capable of performing maintenance of the inkjet head unit;
At least one of the first maintenance unit and the second maintenance unit is movable while maintaining a relative positional relationship with the inkjet head unit,
A drive unit that moves the inkjet head unit in a direction orthogonal to the main surface direction of the discharge target;
The height of the inkjet head unit with respect to the discharged object is different when the maintenance of the inkjet head unit is performed by the first maintenance unit and when the maintenance of the inkjet head unit is performed by the second maintenance unit . Lee ink ejection device.

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